prof. dr hab. Adam Patkowski

@article{molecules27031010,

title = {Nanomolar Nitric Oxide Concentrations in Living Cells Measured by Means of Fluorescence Correlation Spectroscopy},

author = {Roksana Markiewicz and Jagoda Litowczenko and Jacek Gapiński and Anna Woźniak and Stefan Jurga and Adam Patkowski},

url = {https://www.mdpi.com/1420-3049/27/3/1010},

doi = {10.3390/molecules27031010},

issn = {1420-3049},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Molecules},

volume = {27},

number = {3},

abstract = {Measurement of the nitric oxide (NO) concentration in living cells in the physiological nanomolar range is crucial in understanding NO biochemical functions, as well as in characterizing the efficiency and kinetics of NO delivery by NO-releasing drugs. Here, we show that fluorescence correlation spectroscopy (FCS) is perfectly suited for these purposes, due to its sensitivity, selectivity, and spatial resolution. Using the fluorescent indicators, diaminofluoresceins (DAFs), and FCS, we measured the NO concentrations in NO-producing living human primary endothelial cells, as well as NO delivery kinetics, by an external NO donor to the immortal human epithelial living cells. Due to the high spatial resolution of FCS, the NO concentration in different parts of the cells were also measured. The detection of nitric oxide by means of diaminofluoresceins is much more efficient and faster in living cells than in PBS solutions, even though the conversion to the fluorescent form is a multi-step reaction.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{LITOWCZENKO2021111507,

title = {Synthesis, characterization and in vitro cytotoxicity studies of poly-N-isopropyl acrylamide gel nanoparticles and films},

author = {Jagoda Litowczenko and Jacek Gapiński and Roksana Markiewicz and Anna Woźniak and Jacek K Wychowaniec and Barbara Peplińska and Stefan Jurga and Adam Patkowski},

url = {http://www.sciencedirect.com/science/article/pii/S0928493120334251},

doi = {https://doi.org/10.1016/j.msec.2020.111507},

issn = {0928-4931},

year  = {2021},

date = {2021-01-01},

journal = {Materials Science and Engineering: C},

volume = {118},

pages = {111507},

abstract = {In this work, we show synthesis that leads to thermoreponsive poly-N-isopropyl acrylamide (pNIPAM) nanogels with sizes below 100 nm, irrespectively of the surfactant to crosslinker ratio. We also show that in many environments the temperature induced pNIPAM collapse at Lower Critical Solution Temperature (LCST) of 32.5 °C is accompanied by gel nanoparticles' aggregation. Thus, the proper information on the nanoparticle (NP) structure and deswelling can be obtained only if the routinely measured hydrodynamic radius is supplemented by information on the molecular weight, which can be obtained from the intensity of scattered light. We measured the dynamics and reversibility of the deswelling and subsequent aggregation processes. Furthermore, we show that the highly concentrated pNIPAM gel NPs reversibly form bulk hydrogel networks of varied interconnected porous structure. We show, that in case of drying pNIPAM gel NPs above the LCST, it is possible to obtain films with 20-fold increase in storage modulus (G′) compared to hydrogel networks measured at room temperature. They exhibit temperature hysteresis behavior around LCST of 32.5 °C similar to pNIPAM films. Finally, we show that these hydrogel films, lead to extended proliferation of cells across three different types: fibroblast, endothelial and cancer cells. Additionally, none of the films exhibited any cytotoxic effects. Our study brings new insights into physicochemical characterization of pNIPAM gel NPs and networks behavior in realistic conditions of in vitro measurements, especially by means of dynamic light scattering as well as final unique properties of both gel NPs and formed porous films for possible tissue engineering applications.},

keywords = {Cell cytotoxicity, Dynamic light scattering, Films, Hydrogels, Poly-N-isopropyl acrylamide (pNIPAM), Swelling and deswelling properties},

pubstate = {published},

tppubtype = {article}

}

@article{Wojnarowska_2020,

title = {Revealing Fast Proton Transport in Condensed Matter by Means of Density Scaling Concept},

author = {Żaneta Wojnarowska and Małgorzata Musiał and Shinian Cheng and Jacek Gapiński and Adam Patkowski and Jürgen Pionteck and Marian Paluch},

url = {https://doi.org/10.1021%2Facs.jpcc.0c03548},

doi = {10.1021/acs.jpcc.0c03548},

year  = {2020},

date = {2020-06-01},

journal = {The Journal of Physical Chemistry C},

volume = {124},

number = {29},

pages = {15749--15756},

publisher = {American Chemical Society (ACS)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Comez2019,

title = {Inelastic x-ray scattering reveals the ergodic to nonergodic transition of salol, a liquid with local order},

author = {L. Comez and D. Fioretto and Jacek Gapiński and G. Monaco and Adam Patkowski and W. Steffen},

doi = {10.5488/CMP.22.43603},

year  = {2019},

date = {2019-11-01},

journal = {Condensed Matter Physics},

volume = {22},

number = {4},

pages = {43603},

abstract = {We have studied the high-frequency dynamics of salol by inelastic x-ray scattering over a wide temperature range between 50 and 450 K, across the glass transition. We find that salol efficiently realizes the mechanism of dynamical arrest described by the mode-coupling theory, as manifested by a cusp singularity in the behaviour of the non-ergodicity parameter and a Q dependence of the critical non-ergodicity parameter that is in phase with the static structure factor. These results confront positively the mode-coupling theory with liquids with local order.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{POCHYLSKI201951,

title = {Nature of intramolecular dynamics in protic ionic glass-former: insight from ambient and high pressure Brillouin spectroscopy},

author = {Mikołaj Pochylski and Jacek Gapiński and Z Wojnarowska and M Paluch and Adam Patkowski},

url = {http://www.sciencedirect.com/science/article/pii/S0167732219302417},

doi = {https://doi.org/10.1016/j.molliq.2019.02.131},

issn = {0167-7322},

year  = {2019},

date = {2019-01-01},

journal = {Journal of Molecular Liquids},

volume = {282},

pages = {51 - 56},

abstract = {Proton conducting materials play an important role in a variety of electrochemical devices. Especially, the class of protic ionic glass-formers with fast water-independent proton transport within the Grotthuss mechanism has been envisioned as promising fuel cell electrolytes. Nevertheless, despite a number of reports on protic ionic glasses the description of proton transport phenomenon in these systems is still incomplete. Herein, we employed the Brillouin scattering technique to investigate the intramolecular dynamics of acebutolol hydrochloride, protic ionic glass-former with isomerization ability. The studies performed at ambient and elevated pressure revealed the fast relaxation dynamics that may control the proton conductivity, especially at temperatures T < Tg where the vehicle mechanism contribution is negligible.},

keywords = {Brillouin scattering, High pressure, Intramolecular dynamics, Ionic liquids},

pubstate = {published},

tppubtype = {article}

}

@article{Meier2018,

title = {Nano-viscosity of supercooled liquid measured by fluorescence correlation spectroscopy: Pressure and temperature dependence and the density scaling},

author = {G Meier and Jacek Gapiński and M Ratajczyk and M P Lettinga and K Hirtz and Ewa Banachowicz and Adam Patkowski},

url = {https://doi.org/10.1063/1.5011196},

doi = {10.1063/1.5011196},

year  = {2018},

date = {2018-01-01},

journal = {The Journal of Chemical Physics},

volume = {148},

number = {9},

pages = {094201},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Wojnarowska2017,

title = {Experimental evidence of high pressure decoupling between charge transport and structural dynamics in a protic ionic glass-former},

author = {Z Wojnarowska and M Rams-Baron and J Knapik-Kowalczuk and Agnieszka Połatyńska and Mikołaj Pochylski and Jacek Gapiński and Adam Patkowski and P Wlodarczyk and M Paluch},

url = {http://www.nature.com/articles/s41598-017-07136-5},

doi = {10.1038/s41598-017-07136-5},

issn = {2045-2322},

year  = {2017},

date = {2017-12-01},

journal = {Scientific Reports},

volume = {7},

number = {1},

pages = {7084},

publisher = {Nature Publishing Group},

abstract = {textcopyright 2017 The Author(s). In this paper the relaxation dynamics of ionic glass-former acebutolol hydrochloride (ACB-HCl) is studied as a function of temperature and pressure by using dynamic light scattering and broadband dielectric spectroscopy. These unique experimental data provide the first direct evidence that the decoupling between the charge transport and structural relaxation exists in proton conductors over a wide T-P thermodynamic space, with the time scale of structural relaxation being constant at the liquid-glass transition ($tau$ $alpha$ = 1000 s). We demonstrate that the enhanced proton transport, being a combination of intermolecular H + hopping between cation and anion as well as tautomerization process within amide moiety of ACB molecule, results in a breakdown of the Stokes-Einstein relation at ambient and elevated pressure with the fractional exponent k being pressure dependent. The dT g /dP coefficient, stretching exponent $beta$ KWW and dynamic modulus E a /$Delta$V # were found to be the same regardless of the relaxation processes studied. This is in contrast to the apparent activation volume parameter that is different when charge transport and structural dynamics are considered. These experimental results together with theoretical considerations create new ideas to design efficient proton conductors for potential electrochemical applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Poznar2017,

title = {Structural properties of the intrinsically disordered, multiple calcium ion-binding otolith matrix macromolecule-64 (OMM-64)},

author = {Monika Poznar and Rafał Hołubowicz and Magdalena Wojtas and Jacek Gapiński and Ewa Banachowicz and Adam Patkowski and Andrzej Ożyhar and Piotr Dobryszycki},

url = {https://www.sciencedirect.com/science/article/pii/S1570963917302054?via%3Dihub http://linkinghub.elsevier.com/retrieve/pii/S1570963917302054},

doi = {10.1016/j.bbapap.2017.08.019},

issn = {15709639},

year  = {2017},

date = {2017-11-01},

journal = {Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics},

volume = {1865},

number = {11},

pages = {1358--1371},

publisher = {Elsevier},

abstract = {Fish otoliths are calcium carbonate biominerals that are involved in hearing and balance sensing. An organic matrix plays a crucial role in their formation. Otolith matrix macromolecule-64 (OMM-64) is a highly acidic, calcium-binding protein (CBP) found in rainbow trout otoliths. It is a component of high-molecular-weight aggregates, which influence the size, shape and polymorph of calcium carbonate in vitro. In this study, a protocol for the efficient expression and purification of OMM-64 was developed. For the first time, the complete structural characteristics of OMM-64 were described. Various biophysical methods were combined to show that OMM-64 occurs as an intrinsically disordered monomer. Under denaturing conditions (pH, temperature) OMM-64 exhibits folding propensity. It was determined that OMM-64 binds approximately 61 calcium ions with millimolar affinity. The folding-unfolding experiments showed that calcium ions induced the collapse of OMM-64. The effect of other counter ions present in trout endolymph on OMM-64 conformational changes was studied. The significance of disordered properties of OMM-64 and the possible function of this protein is discussed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Poatynska2017,

title = {Temperature dependent FCS studies using a long working distance objective: Viscosities of supercooled liquids and particle size},

author = {Agnieszka Połatyńska and Karolina Tomczyk and Mikołaj Pochylski and Gerd Meier and Jacek Gapiński and Ewa Banachowicz and Tomasz Śliwa and Adam Patkowski},

url = {http://aip.scitation.org/doi/10.1063/1.4977047},

doi = {10.1063/1.4977047},

issn = {00219606},

year  = {2017},

date = {2017-02-01},

journal = {Journal of Chemical Physics},

volume = {146},

number = {8},

pages = {084506},

publisher = {AIP Publishing LLC},

abstract = {In this work, we describe new experimental setups for Fluorescence Correlation Spectroscopy (FCS) where a long working distance objective is used. Using these setups, FCS measurements in a broad temperature range for a small sample volume of about 50 $mu$l can be performed. The use of specially designed cells and a dry long working distance objective was essential for avoiding temperature gradients in the sample. The performance of the new setups and a traditional FCS setup with immersion objectives is compared. The FCS data in combination with the Stokes-Einstein (SE) relation were used to obtain the values of the nanoviscosity of a fluid. We show for selected molecular van der Waals supercooled liquids that despite the fact that in these systems, a characteristic length scale can be defined, the nanoviscosity obtained from FCS is in a very good agreement with the macroscopic (rheometric) viscosity of the sample in a broad temperature range. This result corroborates the applicability of the SE relation to s...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Mazuryk2016,

title = {Rapamycin-loaded solid lipid nanoparticles: Morphology and impact of the drug loading on the phase transition between lipid polymorphs},

author = {Jarosław Mazuryk and Tobiasz Deptuła and Alice Polchi and Jacek Gapiński and Stefano Giovagnoli and Alessandro Magini and Carla Emiliani and Joachim Kohlbrecher and Adam Patkowski},

url = {https://www.sciencedirect.com/science/article/pii/S0927775716303259 http://linkinghub.elsevier.com/retrieve/pii/S0927775716303259},

doi = {10.1016/j.colsurfa.2016.05.017},

issn = {09277757},

year  = {2016},

date = {2016-08-01},

journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects},

volume = {502},

pages = {54--65},

publisher = {Elsevier},

abstract = {In recent decades solid lipid nanoparticles (SLN) have become a well-performing tool for the site-targeted delivery of water-insoluble drugs. In this study, Compritoltextregistered 888 ATO-based SLN, coated with polysorbate 80, were loaded with rapamycin (Rap), a lipophilic immunomodulator, broadly-used in therapies of cancer and neurodegenerative diseases. Rap-SLN were formulated using cold high-pressure homogenization and ultrasound-assisted emulsion. The exploitation of these methods yielded the nanoparticles of various values of zeta-potential (from −1mV to −20mV) and efficacies of the Rap entrapment (from 37.5±2.3% to 77.0±5.4%). The SEM and AFM imaging and shape-modeling by the combined DLS-SANS analysis revealed that the Rap-SLN of the hydrodynamic radius of ∼46nm preserve the platelet-like or flat ellipsoidal structure with a thickness as large as 8–9nm. These dimensions correspond to a single lipid bilayer, organized in a triclinic L$beta$ polymorph, and covered with a 1–2-nm shell of the surfactant. Consistently, FT-IR spectra acquired in the range 52–75°C, showed that the Rap incorporation within the lipid matrix decreases the point of the gel-liquid crystalline (L$beta$-L$alpha$) phase transition. These outcomes imply a thermodynamically-driven mechanism of the Rap release from SLN.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Polchi2016,

title = {Rapamycin Loaded Solid Lipid Nanoparticles as a New Tool to Deliver mTOR Inhibitors: Formulation and in Vitro Characterization},

author = {Alice Polchi and Alessandro Magini and Jarosław Mazuryk and Brunella Tancini and Jacek Gapiński and Adam Patkowski and Stefano Giovagnoli and Carla Emiliani},

url = {http://www.mdpi.com/2079-4991/6/5/87},

doi = {10.3390/nano6050087},

issn = {2079-4991},

year  = {2016},

date = {2016-05-01},

journal = {Nanomaterials},

volume = {6},

number = {5},

pages = {87},

publisher = {Multidisciplinary Digital Publishing Institute},

abstract = {Recently, the use of mammalian target of rapamycin (mTOR) inhibitors, in particular rapamycin (Rp), has been suggested to improve the treatment of neurodegenerative diseases. However, as Rp is a strong immunosuppressant, specific delivery to the brain has been postulated to avoid systemic exposure. In this work, we fabricated new Rp loaded solid lipid nanoparticles (Rp-SLN) stabilized with polysorbate 80 (PS80), comparing two different methods and lipids. The formulations were characterized by differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), wide angle X-ray scattering (WAXS), cryo-transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS) and particle tracking. In vitro release and short-term stability were assessed. Biological behavior of Rp-SLN was tested in SH-SY5Y neuroblastoma cells. The inhibition of mTOR complex 1 (mTORC1) was evaluated over time by a pulse-chase study compared to free Rp and Rp nanocrystals. Compritol Rp-SLN resulted more stable and possessing proper size and surface properties with respect to cetyl palmitate Rp-SLN. Rapamycin was entrapped in an amorphous form in the solid lipid matrix that showed partial crystallinity with stable L$beta$, sub-L$alpha$ and L$beta$′ arrangements. PS80 was stably anchored on particle surface. No drug release was observed over 24 h and Rp-SLN had a higher cell uptake and a more sustained effect over a week. The mTORC1 inhibition was higher with Rp-SLN. Overall, compritol Rp-SLN show suitable characteristics and stability to be considered for further investigation as Rp brain delivery system.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Jarzebski2016,

title = {Core–shell fluorinated methacrylate nanoparticles with Rhodamine-B for confocal microscopy and fluorescence correlation spectroscopy applications},

author = {Maciej Jarzębski and Yingze Zhang and Tomasz Śliwa and Jarosław Mazuryk and Tobiasz Deptuła and Malgorzata Kucinska and Marek Murias and Johan Buitenhuis and Jacek Gapiński and Adam Patkowski},

url = {https://www.sciencedirect.com/science/article/pii/S0022113916300148 http://linkinghub.elsevier.com/retrieve/pii/S0022113916300148},

doi = {10.1016/j.jfluchem.2016.01.014},

issn = {00221139},

year  = {2016},

date = {2016-03-01},

journal = {Journal of Fluorine Chemistry},

volume = {183},

pages = {92--99},

publisher = {Elsevier},

abstract = {There is a need to develop nanosized and submicron sized stable and efficient fluorescent particles for confocal microscopy and fluorescence correlation spectroscopy, which are useful methods to study dynamics and interactions in complex colloidal systems and living cells. Fluorescent core–transparent shell fluorinated polymer nanoparticles exhibit low refractive index, close to that of water, high fluorescence efficiency, high stability and no cytotoxicity which makes them excellent probes for water based and living systems. Fluorescent core–transparent shell submicron particles were synthesized using 1H,1H-heptafluoro-n-butyl methacrylate (HFBMA) as a monomer and Rhodamine-B-isothiocyanate as a dye. The fluorescent polymeric core was surrounded by a non-fluorescent shell obtained by the seeded growth synthesis. The spherical shape of the particles was confirmed by scanning electron microscopy and the particle size in suspension was characterized by dynamic light scattering (DLS) and fluorescence correlation spectroscopy (FCS). The effect of different reaction parameters, such as initiator concentration and polymerization time on the particle size and charge density as well as their toxicity were studied. The smallest nanoparticles, of diameter d=240nm for the core measured by DLS, were obtained with higher initiator concentration. Repeated confocal imaging, DLS and FCS measurements after a few months up to two years confirmed high fluorescence efficiency, stability and usefulness of prepared particles as versatile systems for confocal microscopy and fluorescence correlation spectroscopy studies in water-based colloidal suspensions. The cytotoxicity tests confirmed a possible use of these nanoparticles also in living cells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2016,

title = {Structure and Dimensions of Core–Shell Nanoparticles Comparable to the Confocal Volume Studied by Means of Fluorescence Correlation Spectroscopy},

author = {Jacek Gapiński and Maciej Jarzębski and Johan Buitenhuis and Tobiasz Deptuła and Jarosław Mazuryk and Adam Patkowski},

url = {http://pubs.acs.org/doi/10.1021/acs.langmuir.5b04605},

doi = {10.1021/acs.langmuir.5b04605},

issn = {0743-7463},

year  = {2016},

date = {2016-03-01},

journal = {Langmuir},

volume = {32},

number = {10},

pages = {2482--2491},

publisher = {American Chemical Society},

abstract = {In some applications the dye distribution within fluorescently labeled nanoparticles and its stability over long periods of time are important issues. In this article we study numerically and experimentally the applicability of fluorescence correlation spectroscopy (FCS) to resolve such questions. When the size of fluorescently labeled particles is comparable to or larger than the confocal volume, the effective confocal volume seen in FCS experiments is increasing. Such an effect has already been studied for uniformly labeled spherical particles. In this work we analyze the form of the FCS correlation functions (CFs) for core-labeled and shell-labeled core–shell particles. For shell-labeled particles an additional fast decay was found both in simulations and in experiments on custom-made surface-labeled particles. Universal scaling of FCS correlation times based on the squared ratio of the labeled part radius of gyration to the Gaussian radius of the beam profile was found. Recipes based on the analysis o...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kryjewski2015,

title = {Porphyrazine with bulky 2-(1-adamantyl)-5-phenylpyrrol-1-yl periphery tuning its spectral and electrochemical properties},

author = {Michal Kryjewski and Ewa Tykarska and Tomasz Rebis and Jolanta Dlugaszewska and Magdalena Ratajczak and Anna Teubert and Jacek Gapiński and Adam Patkowski and Jaroslaw Piskorz and Grzegorz Milczarek and Maria Gdaniec and Tomasz Goslinski and Jadwiga Mielcarek},

url = {https://www.sciencedirect.com/science/article/pii/S0277538715002934 http://linkinghub.elsevier.com/retrieve/pii/S0277538715002934},

doi = {10.1016/j.poly.2015.05.033},

issn = {02775387},

year  = {2015},

date = {2015-09-01},

journal = {Polyhedron},

volume = {98},

pages = {217--223},

publisher = {Pergamon},

abstract = {The synthesis and physicochemical properties of a novel porphyrazine possessing an alternate system of two peripheral substituents, 2-(1-adamantyl)-5-phenylpyrrol-1-yl and dimethylamino, are presented. Precursor maleonitriles were characterized using X-ray crystallography. Novel porphyrazine was subjected to spectroscopic studies, including the determination of fluorescence quantum yield and singlet oxygen quantum yield. Moreover, its electrochemical and spectroelectrochemical properties were investigated. The antimicrobial photodynamic activities of the novel porphyrazine encapsulated in various liposomal formulations were tested against Staphylococcus aureus and Pseudomonas aeruginosa.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Deptua2015,

title = {Size of Submicrometer Particles Measured by FCS: Correction of the Confocal Volume},

author = {Tobiasz Deptuła and Johan Buitenhuis and Maciej Jarzębski and Adam Patkowski and Jacek Gapiński},

url = {http://pubs.acs.org/doi/10.1021/acs.langmuir.5b01225},

doi = {10.1021/acs.langmuir.5b01225},

issn = {0743-7463},

year  = {2015},

date = {2015-06-01},

journal = {Langmuir},

volume = {31},

number = {24},

pages = {6681--6687},

publisher = {American Chemical Society},

abstract = {When fluorescence correlation spectroscopy (FCS) in combination with a confocal microscope is used to determine the hydrodynamic radius a of particles comparable to or larger than the linear size $sigma$ of the confocal volume of the microscope, a correction must be used that depends on the a2/$sigma$2 ratio and the distribution of the dye within the particle. Here we present the experimental validation of the theoretically predicted approximate correction necessary for appropriate measurements of the size of uniformly fluorescently labeled spheres of radius comparable to the size of the confocal volume. We also test the approximate correction formula for different ranges of the a/$sigma$ ratio and propose a simple procedure to obtain the correct nanoparticle size from such a measurement.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Deptua2015a,

title = {Cytotoxicity of thermo-responsive polymeric nanoparticles based on N-isopropylacrylamide for potential application as a bioscaffold},

author = {Tobiasz Deptuła and Alicja Warowicka and Anna Woźniak and Mikołaj Grzeszkowiak and Maciej Jarzębski and Magdalena Bednarowicz and Adam Patkowski and Ryszard Słomski},

url = {http://www.ncbi.nlm.nih.gov/pubmed/25980357 http://www.actabp.pl/#File?./html/2_2015/2015_1007.html},

doi = {10.18388/abp.2015_1007},

issn = {0001-527X},

year  = {2015},

date = {2015-06-01},

journal = {Acta Biochimica Polonica},

volume = {62},

number = {2},

pages = {311--316},

abstract = {Polymeric nanoparticles based on poly-N-isopropylacrylamide (pNiPAM NPs) and their bio-medical applications have been widely investigated in recent years. These tunable nanoparticles are considered to be great candidates for drug delivery systems, biosensors and bioanalytical devices. Thus, the biocompatibility and toxicity of these nanoparticles is clearly a crucial issue. In this work, the cytotoxicity of thermo-responsive pNiPAM nanoparticles was studied, followed by a detailed analysis of the NPs morphology in growing cell cultures and their 3D structure. Cytotoxic examination was conducted for two cell cultures - HeLa (cervical cancer cell line) and HeK293 (human embryonic kidney cell line), employing MTT (3-4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide) assay and viability tests. We used Cryo-SEM (scanning electron microscopy) and fluorescence microscopy (IN Cell Analyzer) in order to investigate the morphological structure of the polymer network. We show that pNiPAM nanoparticles do not exhibit any cytotoxicity effects on the investigated cell lines. Additionally, we report that the pNiPAM nanoparticle based scaffold promotes cell growth.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2014,

title = {Freezing lines of colloidal Yukawa spheres. II. Local structure and characteristic lengths},

author = {Jacek Gapiński and Gerhard Naegele and Adam Patkowski},

url = {http://aip.scitation.org/doi/10.1063/1.4895965},

doi = {10.1063/1.4895965},

issn = {0021-9606},

year  = {2014},

date = {2014-09-01},

journal = {The Journal of Chemical Physics},

volume = {141},

number = {12},

pages = {124505},

publisher = {American Institute of Physics},

abstract = {Using the Rogers-Young (RY) integral equation scheme for the static pair correlation functions combined with the liquid-phase Hansen-Verlet freezing rule, we study the generic behavior of the radial distribution function and static structure factor of monodisperse charge-stabilized suspensions with Yukawa-type repulsive particle interactions at freezing. In a related article, labeled Paper I [J. Gapinski, G. Naegele, and A. Patkowski, J. Chem. Phys. 136, 024507 (2012)], this hybrid method was used to determine two-parameter freezing lines for experimentally controllable parameters, characteristic of suspensions of charged silica spheres in dimethylformamide. A universal scaling of the RY radial distribution function maximum is shown to apply to the liquid-bcc and liquid-fcc segments of the universal freezing line. A thorough analysis is made of the behavior of characteristic distances and wavenumbers, next-neighbor particle coordination numbers, osmotic compressibility factor, and the Ravache-Mountain-Stre...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Banachowicz2014,

title = {Successful FCS Experiment in Nonstandard Conditions},

author = {Ewa Banachowicz and Adam Patkowski and Gerd Meier and Kamila Klamecka and Jacek Gapiński},

url = {http://pubs.acs.org/doi/10.1021/la5015708},

doi = {10.1021/la5015708},

issn = {0743-7463},

year  = {2014},

date = {2014-07-01},

journal = {Langmuir},

volume = {30},

number = {29},

pages = {8945--8955},

publisher = {American Chemical Society},

abstract = {Fluorescence correlation spectroscopy (FCS) is frequently used to measure the self-diffusion coefficient of fluorescently labeled probes in solutions, complex media, and living cells. In a standard experiment water immersion objectives and window thickness in the range of 0.13–0.19 mm are used. We show that successful FCS measurements can be performed using samples of different refractive index placed in cells having windows of different thickness, even much thicker than nominally allowed. Different water, oil, and silicon oil immersion as well as long working distance dry objectives, equipped with the correction collar, were tested and compared. We demonstrate that the requirements for FCS experiments are less stringent than those for high resolution confocal imaging and reliable relative FCS measurements can be performed even beyond the compensation range of the objectives. All these features open new possibilities for construction of custom-made high temperature and high pressure cells for FCS.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2012,

title = {Freezing lines of colloidal Yukawa spheres. I. A Rogers-Young integral equation study},

author = {Jacek Gapiński and Gerhard Naegele and Adam Patkowski},

url = {http://www.ncbi.nlm.nih.gov/pubmed/22260603 http://aip.scitation.org/doi/10.1063/1.3675607},

doi = {10.1063/1.3675607},

issn = {0021-9606},

year  = {2012},

date = {2012-01-01},

journal = {The Journal of Chemical Physics},

volume = {136},

number = {2},

pages = {024507},

abstract = {Using the Rogers-Young (RY) integral equation scheme for the static structure factor combined with the one-phase Hansen-Verlet (HV) freezing rule, we study the equilibrium structure and two-parameter freezing lines of colloidal particles with Yukawa-type pair interactions representing charge-stabilized silica spheres suspended in dimethylformamide (DMF). Results are presented for a vast range of concentrations, salinities and effective charges covering particles with masked excluded-volume interactions. The freezing lines were obtained for the low-charge and high-charge solutions of the static structure factor, for various two-parameter sets of experimentally accessible system parameters. All RY-HV based freezing lines can be mapped on a universal fluid-solid coexistence line in good agreement with computer simulation predictions. The RY-HV calculations extend the freezing lines obtained in earlier simulations to a broader parameter range. The experimentally observed fluid-bcc-fluid reentrant transition of charged silica spheres in DMF can be explained using the freezing lines obtained in this work.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kalwarczyk2011,

title = {Comparative Analysis of Viscosity of Complex Liquids and Cytoplasm of Mammalian Cells at the Nanoscale},

author = {Tomasz Kalwarczyk and Natalia Ziȩbacz and Anna Bielejewska and Ewa Zaboklicka and Kaloian Koynov and Jȩdrzej Szymański and Agnieszka Wilk and Adam Patkowski and Jacek Gapiński and Hans-Jürgen Butt and Robert Hołyst},

url = {http://www.ncbi.nlm.nih.gov/pubmed/21513331 http://pubs.acs.org/doi/abs/10.1021/nl2008218},

doi = {10.1021/nl2008218},

issn = {1530-6984},

year  = {2011},

date = {2011-05-01},

journal = {Nano Letters},

volume = {11},

number = {5},

pages = {2157--2163},

abstract = {We present a scaling formula for size-dependent viscosity coefficients for proteins, polymers, and fluorescent dyes diffusing in complex liquids. The formula was used to analyze the mobilities of probes of different sizes in HeLa and Swiss 3T3 mammalian cells. This analysis unveils in the cytoplasm two length scales: (i) the correlation length $xi$ (approximately 5 nm in HeLa and 7 nm in Swiss 3T3 cells) and (ii) the limiting length scale that marks the crossover between nano- and macroscale viscosity (approximately 86 nm in HeLa and 30 nm in Swiss 3T3 cells). During motion, probes smaller than $xi$ experienced matrix viscosity: $eta$(matrix) ≈ 2.0 mPatextperiodcentereds for HeLa and 0.88 mPatextperiodcentereds for Swiss 3T3 cells. Probes much larger than the limiting length scale experienced macroscopic viscosity, $eta$(macro) ≈ 4.4 × 10(-2) and 2.4 × 10(-2) Patextperiodcentereds for HeLa and Swiss 3T3 cells, respectively. Our results are persistent for the lengths scales from 0.14 nm to a few hundred nanometers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2010,

title = {Size and Shape of Micelles Studied by Means of SANS, PCS, and FCS},

author = {Jacek Gapiński and Jȩdrzej Szymański and Agnieszka Wilk and Joachim Kohlbrecher and Adam Patkowski and Robert Hołyst},

url = {http://pubs.acs.org/doi/abs/10.1021/la100181d},

doi = {10.1021/la100181d},

issn = {0743-7463},

year  = {2010},

date = {2010-06-01},

journal = {Langmuir},

volume = {26},

number = {12},

pages = {9304--9314},

publisher = {American Chemical Society},

abstract = {The hexaethylene glycol monododecyl ether (C12E6) micelles at concentrations up to 10% have been studied in their isotropic phase (10−48 °C) by means of small angle neutron scattering (SANS) and photon correlation spectroscopy (PCS). The SANS data obtained at low temperatures could be unequivocally interpreted as a result of scattering from a suspension of compact globular micelles with the shape of a triaxial ellipsoid or a short end-capped elliptical rod. Different models have been applied to analyze the SANS data obtained at higher temperatures: (i) elongated rod-like micelles with purely sterical interactions, (ii) compact globular micelles with a weak attractive potential, and (iii) globular micelles influenced by the critical phenomena in the whole temperature range studied. The good quality of the experimental data indicated model (i) as the best fit for our data. The diffusion coefficients obtained from the PCS measurements have been compared to the diffusion coefficients calculated for the rod-li...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2010a,

title = {Generic behavior of the hydrodynamic function of charged colloidal suspensions},

author = {Jacek Gapiński and Adam Patkowski and Gerhard Naegele},

url = {http://www.ncbi.nlm.nih.gov/pubmed/20136325 http://aip.scitation.org/doi/10.1063/1.3306397},

doi = {10.1063/1.3306397},

issn = {0021-9606},

year  = {2010},

date = {2010-02-01},

journal = {The Journal of Chemical Physics},

volume = {132},

number = {5},

pages = {054510},

abstract = {We discuss the generic behavior of the hydrodynamic function H(q) and diffusion function D(q) characterizing the short-time diffusion in suspensions of charge-stabilized colloidal spheres, by covering the whole fluid regime. Special focus is given to the behavior of these functions at the freezing transition specified by the Hansen-Verlet freezing rule. Results are presented in dependence on scattering wavenumber q, effective particle charge, volume fraction, salt concentration, and particle size, by considering both the low-charge and high-charge branch solutions of static structure factors. The existence of two charge branches leads to the prediction of a re-entrant melting-freezing-melting transition for increasing particle concentration at very low salinity. A universal limiting contour line is derived for the principal peak height value of H(q), independent of particle charge and diameter, and concentration and salinity, which separates the fluid from the fluid-solid coexistence region. This line is only weakly dependent on the value of the structure factor peak height entering the Hansen-Verlet rule. A dynamic freezing criterion is derived in terms of the short-time cage diffusion coefficient, a quantity easily measurable in a scattering experiment. The higher-dimensional parameter scans underlying this study make use of the fast and highly efficient deltagamma-scheme in conjunction with the analytic rescaled mean spherical approximation input for the static structure factor. Our results constitute a comprehensive database useful to researchers performing dynamic scattering experiments on charge-stabilized dispersions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Holyst2009,

title = {Scaling form of viscosity at all length-scales in poly(ethylene glycol) solutions studied by fluorescence correlation spectroscopy and capillary electrophoresis},

author = {Robert Holyst and Anna Bielejewska and Jędrzej Szymański and Agnieszka Wilk and Adam Patkowski and Jacek Gapiński and Andrzej żywociński and Tomasz Kalwarczyk and Ewelina Kalwarczyk and Marcin Tabaka and Natalia Ziębacz and Stefan A Wieczorek},

url = {http://xlink.rsc.org/?DOI=b908386c},

doi = {10.1039/b908386c},

issn = {1463-9076},

year  = {2009},

date = {2009-10-01},

journal = {Physical Chemistry Chemical Physics},

volume = {11},

number = {40},

pages = {9025},

publisher = {The Royal Society of Chemistry},

abstract = {We measured the viscosity of poly(ethylene glycol) (PEG 6000, 12 000, 20 000) in water using capillary electrophoresis and fluorescence correlation spectroscopy with nanoscopic probes of different diameters (from 1.7 to 114 nm). For a probe of diameter smaller than the radius of gyration of PEG (e.g.rhodamine B or lyzozyme) the measured nanoviscosity was orders of magnitude smaller than the macroviscosity. For sizes equal to (or larger than) the polymer radius of gyration, macroscopic value of viscosity was measured. A mathematical relation for macro and nanoviscosity was found as a function of PEG radius of gyration, Rg, correlation length in semi-dilute solution, $xi$, and probe size, R. For R textless Rg, the nanoviscosity (normalized by water viscosity) is given by exp(b(R/$xi$)a), and for R textgreater Rg, both nano and macroviscosity follow the same curve, exp(b(R/$xi$)a), where a and b are two constants close to unity. This mathematical relation was shown to equally well describe rhodamine (of size 1.7 nm) in PEG 20 000 and the macroviscosity of PEG 8 000 000, whose radius of gyration exceeds 200 nm. Additionally, for the smallest probes (rhodamine B and lysozyme) we have verified, using capillary electrophoresis and fluorescence correlation spectroscopy, that the Stokes–Einstein (SE) relation holds, providing that we use a size-dependent viscosity in the formula. The SE relation is correct even in PEG solutions of very high viscosity (three orders of magnitude larger than that of water).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Banachowicz2009,

title = {High-pressure small-angle neutron scattering studies of glucose isomerase conformation in solution},

author = {Ewa Banachowicz and Maciej Kozak and Adam Patkowski and Gerhard Meier and Joachim Kohlbrecher},

url = {http://scripts.iucr.org/cgi-bin/paper?S0021889809007456},

doi = {10.1107/S0021889809007456},

issn = {0021-8898},

year  = {2009},

date = {2009-06-01},

journal = {Journal of Applied Crystallography},

volume = {42},

number = {3},

pages = {461--468},

publisher = {International Union of Crystallography},

abstract = {Small-angle neutron scattering (SANS) of solutions of glucose/xylose isomerase from Streptomyces rubiginosus was measured as a function of pressure. It is shown that the structure of the enzyme in solution as seen by SANS is practically the same as that in the crystal and does not change with pressure up to 150 MPa. This reflects the unusually high structural stability of this material, which makes it extremely interesting to use as a secondary standard for pressure-dependent SANS experiments. This lack of pressure dependence of the SANS data also indicates that any possible change in hydration of the protein induced by pressure is not visible in the SANS curves. An appropriate correction procedure must be used for the SANS data in order to account for the distortion of the intensity curve due to hard-sphere and electrostatic interactions. After this correction, the isomerase can be readily used as a secondary standard for SANS measurements.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2009,

title = {Structure and short-time dynamics in suspensions of charged silica spheres in the entire fluid regime},

author = {Jacek Gapiński and Adam Patkowski and A J Banchio and J Buitenhuis and P Holmqvist and M P Lettinga and G Meier and G Naegele},

url = {http://aip.scitation.org/doi/10.1063/1.3078408},

doi = {10.1063/1.3078408},

issn = {0021-9606},

year  = {2009},

date = {2009-02-01},

journal = {The Journal of Chemical Physics},

volume = {130},

number = {8},

pages = {084503},

publisher = {American Institute of Physics},

abstract = {We present an experimental study of short-time diffusion properties in fluidlike suspensions of monodisperse charge-stabilized silica spheres suspended in dimethylformamide. The static structure factor S(q), the short-time diffusion function D(q), and the hydrodynamic function H(q) have been probed by combining x-ray photon correlation spectroscopy experiments with static small-angle x-ray scattering. Our experiments cover the full liquid-state part of the phase diagram, including de-ionized systems right at the liquid-solid phase boundary. We show that the dynamic data can be consistently described by the renormalized density fluctuation expansion theory of Beenakker and Mazur over a wide range of concentrations and ionic strengths. In accordance with this theory and Stokesian dynamics computer simulations, the measured short-time properties cross over monotonically, with increasing salt content, from the bounding values of salt-free suspensions to those of neutral hard spheres. Moreover, we discuss an u...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2008,

title = {Structure and Dynamics of Colloidal Suspensions Studied by Means of XPCS},

author = {Adam Patkowski and Jacek Gapiński and A Fluerasu and P Holmqvist and G Meier and M P Lettinga and G Naegele},

url = {http://przyrbwn.icm.edu.pl/APP/PDF/114/a114z204.pdf},

doi = {10.12693/APhysPolA.114.339},

issn = {0587-4246},

year  = {2008},

date = {2008-08-01},

journal = {Acta Physica Polonica A},

volume = {114},

number = {2},

pages = {339--350},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kriegs2008,

title = {The effect of intramolecular relaxations on the damping of longitudinal and transverse phonons in polysiloxanes studied by Brillouin spectroscopy},

author = {H Kriegs and G Meier and Jacek Gapiński and Adam Patkowski},

url = {http://www.ncbi.nlm.nih.gov/pubmed/18190204 http://aip.scitation.org/doi/10.1063/1.2816136},

doi = {10.1063/1.2816136},

issn = {0021-9606},

year  = {2008},

date = {2008-01-01},

journal = {The Journal of Chemical Physics},

volume = {128},

number = {1},

pages = {014507},

abstract = {The effect of intramolecular relaxations on the damping of longitudinal and transverse phonons was studied in poly(methylphenylsiloxane) (PMPS) and poly(ethylmethylsiloxane) (PEMS) polymers by means of Brillouin spectroscopy. It is shown that studies of the polarized and depolarized Brillouin spectra as functions of temperature and pressure allow for the separation of the contributions of the internal and structural relaxations to the damping of longitudinal and transverse phonons, respectively. In polymers with intramolecular relaxations these processes contribute not only to the damping of longitudinal phonons, according to theoretical predictions, but also transverse phonons, in contradiction to the theory.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kang2007,

title = {Diffusion of spheres in isotropic and nematic networks of rods: Electrostatic interactions and hydrodynamic screening},

author = {Kyongok Kang and Agnieszka Wilk and Adam Patkowski and Jan K G Dhont},

url = {http://www.ncbi.nlm.nih.gov/pubmed/17567202 http://aip.scitation.org/doi/10.1063/1.2737446},

doi = {10.1063/1.2737446},

issn = {0021-9606},

year  = {2007},

date = {2007-06-01},

journal = {The Journal of Chemical Physics},

volume = {126},

number = {21},

pages = {214501},

abstract = {Translational diffusion of a small charged tracer sphere in isotropic and nematic suspensions of long and thin charged rods is investigated as a function of ionic strength and rod concentration. A theory for the diffusive properties of a small sphere is developed, where both (screened) hydrodynamic interactions and charge interactions between the tracer sphere and the rod network are analyzed. Hydrodynamic interactions are formulated in terms of the hydrodynamic screening length. As yet, there are no independent theoretical predictions for the hydrodynamic screening length for rod networks. Experimental tracer-diffusion data are presented for various ionic strengths as a function of the rod concentration, both in the isotropic and nematic states. Orientational order parameters are measured for the same ionic strengths as a function of the rod concentration. The hydrodynamic screening length is determined from these experimental data and scaling relations obtained from the above mentioned theory. For the isotropic networks, a master curve is found for the hydrodynamic screening length as a function of the rod concentration. For the nematic networks the screening length turns out to be a very sensitive function of the orientational order parameter.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2007,

title = {Collective diffusion in charge-stabilized suspensions: Concentration and salt effects},

author = {Jacek Gapiński and Adam Patkowski and A J Banchio and P Holmqvist and G Meier and M P Lettinga and G Naegele},

url = {http://www.ncbi.nlm.nih.gov/pubmed/17362085 http://aip.scitation.org/doi/10.1063/1.2538891},

doi = {10.1063/1.2538891},

issn = {0021-9606},

year  = {2007},

date = {2007-03-01},

journal = {The Journal of Chemical Physics},

volume = {126},

number = {10},

pages = {104905},

abstract = {The authors present a joint experimental-theoretical study of collective diffusion properties in aqueous suspensions of charge-stabilized fluorinated latex spheres. Small-angle x-ray scattering and x-ray photon correlation spectroscopy have been used to explore the concentration and ionic-strength dependence of the static and short-time dynamic properties including the hydrodynamic function H(q), the wave-number-dependent collective diffusion coefficient D(q), and the intermediate scattering function over the entire accessible range. They show that all experimental data can be quantitatively described and explained by means of a recently developed accelerated Stokesian dynamics simulation method, in combination with a modified hydrodynamic many-body theory. In particular, the behavior of H(q) for de-ionized and dense suspensions can be attributed to the influence of many-body hydrodynamics, without any need for postulating hydrodynamic screening to be present, as it was done in earlier work. Upper and lower boundaries are provided for the peak height of the hydrodynamic function and for the short-time self-diffusion coefficient over the entire range of added salt concentrations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2007,

title = {Isotropic Brillouin spectra of liquids having an internal degree of freedom},

author = {Adam Patkowski and Jacek Gapiński and G Meier and H Kriegs},

url = {http://aip.scitation.org/doi/10.1063/1.2426347},

doi = {10.1063/1.2426347},

issn = {0021-9606},

year  = {2007},

date = {2007-01-01},

journal = {The Journal of Chemical Physics},

volume = {126},

number = {1},

pages = {014508},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Szymanski2006a,

title = {Diffusion and Viscosity in a Crowded Environment: from Nano- to Macroscale},

author = {Jedrzej Szymański and Adam Patkowski and Agnieszka Wilk and Piotr Garstecki and Robert Holyst},

url = {http://pubs.acs.org/doi/abs/10.1021/jp0666784},

doi = {10.1021/jp0666784},

issn = {1520-6106},

year  = {2006},

date = {2006-12-01},

journal = {The Journal of Physical Chemistry B},

volume = {110},

number = {51},

pages = {25593--25597},

publisher = {American Chemical Society},

abstract = {Although water is the chief component of living cells, food, and personal care products, the supramolecular components make their viscosity larger than that of water by several orders of magnitude. Using fluorescence correlation spectroscopy (FCS), photon correlation spectroscopy (PCS), NMR, and rheology data, we show how the viscosity changes from the value for water at the molecular scale to the large macroviscosity. We determined the viscosity experienced by nanoprobes (of sizes from 0.28 to 190 nm) in aqueous micellar solution of hexaethylene-glycol-monododecyl-ether (in a range of concentration from 0.1% w/w to 35% w/w) and identified a clear crossover at the length scale of 17 ± 2 nm (slightly larger than persistence length of micelles) at which viscosity acquires its macroscopic value. The sharp dependence of the viscosity coefficients on the size of the probe in the nanoregime has important consequences for diffusion-limited reactions in crowded environments (e.g., living cells).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2006a,

title = {Physical nature of complex structural relaxation in polysiloxane – PMpTS: $alpha$ and $alpha$′ relaxations},

author = {Adam Patkowski and Jacek Gapiński and T Pakula and G Meier},

url = {https://www.sciencedirect.com/science/article/pii/S0032386106006860 http://linkinghub.elsevier.com/retrieve/pii/S0032386106006860},

doi = {10.1016/j.polymer.2006.05.065},

issn = {00323861},

year  = {2006},

date = {2006-09-01},

journal = {Polymer},

volume = {47},

number = {20},

pages = {7231--7240},

publisher = {Elsevier},

abstract = {Structural relaxation processes in poly(methyl-para-tolyl-siloxane) (PMpTS) polymers of three molecular weights were studied using dynamic light scattering. Two relaxation processes: the usual $alpha$ and an additional slow one $alpha$′ were observed and studied as function of temperature and molecular weight. Contrary to the structural relaxation, we find that in a plot T–Tg the relaxation times for the $alpha$′ process for all molecular weights do not collapse to a single curve. For one of the samples the light scattering correlation functions were compared with the corresponding functions obtained by means of mechanical relaxation, dielectric spectroscopy and computer simulations. The simulations show that the bimodal distribution, i.e. the $alpha$ relaxation and the slow ($alpha$′) process are contained in the correlation functions of most of the probes (optical anisotropy, dipole moment, chain bond, density) in agreement with experimental observations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Szymanski2006b,

title = {Movement of Proteins in an Environment Crowded by Surfactant Micelles: Anomalous versus Normal Diffusion},

author = {Jȩdrzej Szymański and Adam Patkowski and Jacek Gapiński and Agnieszka Wilk and Robert Hołyst},

url = {http://www.ncbi.nlm.nih.gov/pubmed/16599511 http://pubs.acs.org/doi/abs/10.1021/jp055626w},

doi = {10.1021/jp055626w},

issn = {1520-6106},

year  = {2006},

date = {2006-04-01},

journal = {The Journal of Physical Chemistry B},

volume = {110},

number = {14},

pages = {7367--7373},

abstract = {Small proteins move in crowded cell compartments by anomalous diffusion. In many of them, e.g., the endoplasmic reticulum, the proteins move between lipid membranes in the aqueous lumen. Molecular crowding in vitro offers a systematic way to study anomalous and normal diffusion in a well controlled environment not accessible in vivo. We prepared a crowded environment in vitro consisting of hexaethylene glycol monododecyl ether (C(12)E(6)) nonionic surfactant and water and observed lysozyme diffusion between elongated micelles. We have fitted the data obtained in fluorescence correlation spectroscopy using an anomalous diffusion model and a two-component normal diffusion model. For a small concentration of surfactant (below 4 wt %) the data can be fitted by single-component normal diffusion. For larger concentrations the normal diffusion fit gave two components: one very slow and one fast. The amplitude of the slow component grows with C(12)E(6) concentration. The ratio of diffusion coefficients (slow to fast) is on the order of 0.1 for all concentrations of surfactant in the solution. The fast diffusion is due to free proteins while the slow one is due to the protein-micelle complexes. The protein-micelle interaction is weak since even in a highly concentrated solution (35% of C(12)E(6)) the amplitude of the slow mode is only 10%, despite the fact that the average distance between the micelles is the same as the size of the protein. The anomalous diffusion model gave the anomaly index (r(2)(t) approximately t(alpha)), alpha monotonically decreasing from alpha = 1 (at 4% surfactant) to alpha = 0.88 (at 37% surfactant). The fits for two-component normal diffusion and anomalous diffusion were of equally good quality, but the physical interpretation was only straightforward for the former.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Banchio2006,

title = {Many-Body Hydrodynamic Interactions in Charge-Stabilized Suspensions},

author = {Adolfo J Banchio and Jacek Gapiński and Adam Patkowski and Wolfgang Haeußler and Andrei Fluerasu and Stefano Sacanna and Peter Holmqvist and Gerhard Meier and Paul M Lettinga and Gerhard Naegele},

url = {http://www.ncbi.nlm.nih.gov/pubmed/16712043 https://link.aps.org/doi/10.1103/PhysRevLett.96.138303},

doi = {10.1103/PhysRevLett.96.138303},

issn = {0031-9007},

year  = {2006},

date = {2006-04-01},

journal = {Physical Review Letters},

volume = {96},

number = {13},

pages = {138303},

abstract = {In this joint experimental-theoretical work we study hydrodynamic interaction effects in dense suspensions of charged colloidal spheres. Using x-ray photon correlation spectroscopy we have determined the hydrodynamic function H(q), for a varying range of electrosteric repulsion. We show that H(q) can be quantitatively described by means of a novel Stokesian dynamics simulation method for charged Brownian spheres, and by a modification of a many-body theory developed originally by Beenakker and Mazur. Very importantly, we can explain the behavior of H(q) for strongly correlated particles without resorting to the controversial concept of hydrodynamic screening, as was attempted in earlier work by Riese [Phys. Rev. Lett. 85, 5460 (2000)].},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kriegs2006,

title = {Pressure effects on the $alpha$ and $alpha$′ relaxations in polymethylphenylsiloxane},

author = {H Kriegs and Jacek Gapiński and G Meier and M Paluch and S Pawlus and Adam Patkowski},

url = {http://aip.scitation.org/doi/10.1063/1.2177242},

doi = {10.1063/1.2177242},

issn = {0021-9606},

year  = {2006},

date = {2006-03-01},

journal = {The Journal of Chemical Physics},

volume = {124},

number = {10},

pages = {104901},

publisher = {American Institute of Physics},

abstract = {In some polymers, in addition to the usual structural $alpha$ relaxation, a slower $alpha$′ relaxation is observed with a non-Arrhenius temperature dependence. In order to understand better the molecular origin of this $alpha$′ relaxation in poly(methylphenylsiloxane) (PMPS) we have studied, for the first time, the pressure dependence of its relaxation time, together with the usual temperature dependence, by means of dynamic light scattering (DLS). For the same material the $alpha$ relaxation was also studied by means of DLS and dielectric spectroscopy (DS) in broad temperature and pressure ranges. We find that the temperature dependence of both $alpha$ and $alpha$′ relaxation times, at all pressures studied, can be described by a double Vogel-Fulcher-Tammann (VFT) law. The pressure dependence of the characteristic temperatures Tg (glass transition temperature) and T0 (Vogel temperature) as well as the activation volumes for both $alpha$ and $alpha$′ processes are very similar, indicating, that both relaxation processes originate from similar local mol...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2006b,

title = {Unexpected effect of internal degrees of freedom on transverse phonons in supercooled liquids},

author = {Adam Patkowski and Jacek Gapiński and G Meier and H Kriegs and Le A Grand and C Dreyfus},

url = {http://stacks.iop.org/0295-5075/73/i=4/a=607?key=crossref.8b86e9eb8242607bf9be17b90e358bd2},

doi = {10.1209/epl/i2005-10429-y},

issn = {0295-5075},

year  = {2006},

date = {2006-02-01},

journal = {Europhysics Letters (EPL)},

volume = {73},

number = {4},

pages = {607--613},

publisher = {IOP Publishing},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kang2006,

title = {Diffusion of spheres in isotropic and nematic suspensions of rods},

author = {Kyongok Kang and Agnieszka Wilk and J Buitenhuis and Adam Patkowski and Jan K G Dhont},

url = {http://aip.scitation.org/doi/10.1063/1.2161204},

doi = {10.1063/1.2161204},

issn = {0021-9606},

year  = {2006},

date = {2006-01-01},

journal = {The Journal of Chemical Physics},

volume = {124},

number = {4},

pages = {044907},

publisher = {American Institute of Physics},

abstract = {Diffusion of a small tracer sphere (apoferritin) in isotropic and nematic networks [of fd virus] is discussed. For a tracer sphere that is smaller than the mesh size of the network, screened hydrodynamic interactions between the sphere and the network determine its diffusion coefficient. A theory is developed for such interactions as well as their relation to the long-time self-diffusion coefficient. Fluorescence correlation spectroscopy measurements on mixtures of apoferritin and fd virus are presented. The long-time self-diffusion coefficient of apoferritin is measured as a function of the fd-virus concentration, both in the isotropic and nematic state, in directions parallel and perpendicular to the nematic director. The hydrodynamic screening length of the fd-virus network as a function of fd concentration is obtained by combining these experimental data with the theory. Surprisingly, the screening length increases with increasing concentration in nematic networks. This is due to the increase in the d...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2005,

title = {Diffusion and microstructural properties of solutions of charged nanosized proteins: Experiment versus theory},

author = {Jacek Gapiński and Agnieszka Wilk and Adam Patkowski and W Haeußler and A J Banchio and R Pecora and G Naegele},

url = {http://www.ncbi.nlm.nih.gov/pubmed/16108686 http://aip.scitation.org/doi/10.1063/1.1996569},

doi = {10.1063/1.1996569},

issn = {0021-9606},

year  = {2005},

date = {2005-08-01},

journal = {The Journal of Chemical Physics},

volume = {123},

number = {5},

pages = {054708},

abstract = {We have reanalyzed our former static small-angle x-ray scattering and photon correlation spectroscopy results on dense solutions of charged spherical apoferritin proteins using theories recently developed for studies of colloids. The static structure factors S(q), and the small-wave-number collective diffusion coefficient D(c) determined from those experiments are interpreted now in terms of a theoretical scheme based on a Derjaguin-Landau-Verwey-Overbeek-type continuum model of charged colloidal spheres. This scheme accounts, in an approximate way, for many-body hydrodynamic interactions. Stokesian dynamics computer simulations of the hydrodynamic function have been performed for the first time for dense charge-stabilized dispersions to assess the accuracy of the theoretical scheme. We show that the continuum model allows for a consistent description of all experimental results, and that the effective particle charge is dependent upon the protein concentration relative to the added salt concentration. In addition, we discuss the consequences of small ions dynamics for the collective protein diffusion within the framework of the coupled-mode theory.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hoyst2005,

title = {Hidden Minima of the Gibbs Free Energy Revealed in a Phase Separation in Polymer/Surfactant/Water Mixture},

author = {R Hołyst and K Staniszewski and Adam Patkowski and Jacek Gapiński},

url = {http://www.ncbi.nlm.nih.gov/pubmed/16852004 http://pubs.acs.org/doi/abs/10.1021/jp050634y},

doi = {10.1021/jp050634y},

issn = {1520-6106},

year  = {2005},

date = {2005-05-01},

journal = {The Journal of Physical Chemistry B},

volume = {109},

number = {18},

pages = {8533--8537},

abstract = {We observed a very unusual kinetic pathway in a separating C(12)E(6)/PEG/H(2)O ternary mixture. We let the mixture separate above the spinodal temperature (cloud point temperature) for some time and next cool it into a metastable region of a phase diagram, characterized by two minima of the Gibbs potential, one corresponding to the homogeneous mixture and one to the fully separated PEG-rich and C(12)E(6)-rich phases. Despite the fact that in the metastable region the thermodynamic equilibrium corresponds to the separated phases (global minimum of the Gibbs free energy), we observe perfect mixing of the initially separated phase. The homogeneous state, obtained in this way, does not separate, if left undisturbed. However, many cooling-heating cycles or full separation with visible meniscus above the cloud point temperature induce the phase separation in the metastable region. The metastable region can exist tens of degrees below the cloud point temperature. This effect is not observed in the binary mixture of C(12)E(6)/H(2)O.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Wodarczyk2005,

title = {Effect of Ions on the Polymorphism, Effective Charge, and Stability of Human Telomeric DNA. Photon Correlation Spectroscopy and Circular Dichroism Studies},

author = {Agnieszka Włodarczyk and Przemysław Grzybowski and Adam Patkowski and Andrzej Dobek},

url = {http://www.ncbi.nlm.nih.gov/pubmed/16851398 http://pubs.acs.org/doi/abs/10.1021/jp045274d},

doi = {10.1021/jp045274d},

issn = {1520-6106},

year  = {2005},

date = {2005-03-01},

journal = {The Journal of Physical Chemistry B},

volume = {109},

number = {8},

pages = {3594--3605},

abstract = {The effect of different ions on the formation and behavior of quadruplex structures of the human telomere sequence d(TTAGGG)(4) has been studied by photon correlation spectroscopy (PCS) and circular dichroism (CD). The saturation and melting curves obtained in the presence of K(+), Na(+), Rb(+), Li(+), Cs(+), and Sr(2+) ions were recorded by CD spectroscopy and indicated the formation of monomeric quadruplexes. Analysis of the saturation curves obtained at 2 degrees C has shown that the presence of a single Sr(2+) ion per oligomer is sufficient for the formation of a monomeric quadruplex of the DNA sequence studied. In the presence of SrCl(2) at a concentration of 50 mM, the formation of tetrameric quadruplexes has been detected. The effect of Sr(2+) ions on the formation of quadruplex structures by the human telomere sequence d(TTAGGG)(4) is stronger and different from that of the other ions tested. The paper also presents results of a study of electrostatic interactions in solution. The translation diffusion coefficients D(T) of the structures present in solution have been determined by photon correlation spectroscopy and the effective charges on the structures have been calculated by combining the experimental data with the results based on the coupled mode theory. Analysis of the melting points monitored by the CD method has permitted a determination of Deltan, the number of ions released in the process of thermal denaturation. All the results are in good agreement with the predictions based on the theory of polyelectrolytes. The effect of ions on the formation and behavior of quadruplex structures of the human telomere sequence d(TTAGGG)(4) has been studied by photon correlation spectroscopy and circular dichroism.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kahle2005,

title = {A comparison of relaxation processes in structurally related van der Waals glass formers: The role of internal degrees of freedom},

author = {S Kahle and Jacek Gapiński and G Hinze and Adam Patkowski and G Meier},

url = {http://www.ncbi.nlm.nih.gov/pubmed/15743253 http://aip.scitation.org/doi/10.1063/1.1846653},

doi = {10.1063/1.1846653},

issn = {0021-9606},

year  = {2005},

date = {2005-02-01},

journal = {The Journal of Chemical Physics},

volume = {122},

number = {7},

pages = {074506},

abstract = {Depolarized dynamic light scattering (DLS), dielectric relaxation (DS), and deuterium NMR studies of fragile van der Waals glass forming liquids phenylphthalein-dimethylether (PDE) and cresolphthalein-dimethylether (KDE) are presented. In PDE a new dielectric loss process was found, which can be attributed to the 180 degrees flip of the phenyl rings. The previous finding that the distribution of the structural relaxation times measured for PDE and KDE by DS is substantially narrower than that measured by DLS is explained by partial decoupling of the dynamics of the dipole moment from the structural relaxation of the sample. The dynamics of PDE and KDE is compared with the previous studies of two other structurally similar liquids: 1,1'-di(4-methoxy-5-methylphenyl)cyclohexane (BMMPC) and 1,1'-bis(p-methoxyphenyl)cyclohexane (BMPC) in order to relate dynamical features with the chemical structure of the material. The evidence for the intramolecular character of the secondary relaxations observed in BMPC and PDE is presented.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kang2005,

title = {Diffusion of spheres in crowded suspensions of rods},

author = {Kyongok Kang and Jacek Gapiński and M P Lettinga and J Buitenhuis and G Meier and M Ratajczyk and Jan K G Dhont and Adam Patkowski},

url = {http://www.ncbi.nlm.nih.gov/pubmed/15740296 http://aip.scitation.org/doi/10.1063/1.1834895},

doi = {10.1063/1.1834895},

issn = {0021-9606},

year  = {2005},

date = {2005-01-01},

journal = {The Journal of Chemical Physics},

volume = {122},

number = {4},

pages = {044905},

abstract = {Translational tracer diffusion of spherical macromolecules in crowded suspensions of rodlike colloids is investigated. Experiments are done using several kinds of spherical tracers in fd-virus suspensions. A wide range of size ratios L/2a of the length L of the rods and the diameter 2a of the tracer sphere is covered by combining several experimental methods: fluorescence correlation spectroscopy for small tracer spheres, dynamic light scattering for intermediate sized spheres, and video microscopy for large spheres. Fluorescence correlation spectroscopy is shown to measure long-time diffusion only for relatively small tracer spheres. Scaling of diffusion coefficients with a/xi, predicted for static networks, is not found for our dynamical network of rods (with xi the mesh size of the network). Self-diffusion of tracer spheres in the dynamical network of freely suspended rods is thus fundamentally different as compared to cross-linked networks. A theory is developed for the rod-concentration dependence of the translational diffusion coefficient at low rod concentrations for freely suspended rods. The proposed theory is based on a variational solution of the appropriate Smoluchowski equation without hydrodynamic interactions. The theory can, in principle, be further developed to describe diffusion through dynamical networks at higher rod concentrations with the inclusion of hydrodynamic interactions. Quantitative agreement with the experiments is found for large tracer spheres, and qualitative agreement for smaller spheres. This is probably due to the increasing importance of hydrodynamic interactions as compared to direct interactions as the size of the tracer sphere decreases.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Dreyfus2004,

title = {Scaling the $backslashalpha $ -relaxation time of supercooled fragile organic liquids},

author = {C Dreyfus and A Le Grand and Jacek Gapiński and W Steffen and Adam Patkowski},

url = {http://link.springer.com/10.1140/epjb/e2004-00386-3},

doi = {10.1140/epjb/e2004-00386-3},

issn = {1434-6028},

year  = {2004},

date = {2004-12-01},

journal = {The European Physical Journal B - Condensed Matter and Complex Systems},

volume = {42},

number = {3},

pages = {309--319},

publisher = {EDP Sciences},

abstract = {It was shown recently [1] that the structural $alpha$-relaxation time $backslashtau $ of supercooled o-terphenyl depends on a single control parameter $backslashGamma $, which is the product of a function of density $E(backslashrho )$, by the inverse temperature T -1. We extend this finding to other fragile glassforming liquids using light scattering data. Available experimental results do not allow to discriminate between several analytical forms of the function $E(backslashrho )$, the scaling arising from the separation of density and temperature in $backslashGamma $. We also propose a simple form for $backslashtau (backslashGamma )$, which depends only on three material-dependent parameters, reproducing relaxation times over 12 orders of magnitude.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Wilk2004,

title = {Self-diffusion in solutions of a 20 base pair oligonucleotide: Effects of concentration and ionic strength},

author = {Agnieszka Wilk and Jacek Gapiński and Adam Patkowski and R Pecora},

url = {http://www.ncbi.nlm.nih.gov/pubmed/15549965 http://aip.scitation.org/doi/10.1063/1.1811599},

doi = {10.1063/1.1811599},

issn = {0021-9606},

year  = {2004},

date = {2004-12-01},

journal = {The Journal of Chemical Physics},

volume = {121},

number = {21},

pages = {10794--10802},

abstract = {The long-time self-diffusion coefficients of a 20 base pair duplex oligonucleotide are measured as functions of 20-mer and added NaCl salt concentrations. The self-diffusion coefficients decrease monotonically with increasing 20-mer concentrations for the high-added salt sample and display non-monotonically decreasing 20-mer concentration dependences at lower added salt concentrations. The non-monotonic behavior is attributed to the opposing effects of the tendency to increase the interactions between 20-mers as the concentration is increased and to a decrease in the extent of the Coulomb forces as counterions from the 20-mer increasingly screen them. Attempts to account for the effect of the Coulomb forces on the self-diffusion coefficients by using effective dimensions in the hard rod theory give good agreement with experiment at the highest salt concentration studied. For the lower salt concentrations there appear to be two scaling regimes--one at low polyion concentration in which the high salt scaling of the rod dimensions by adding the Debye screening to the length and diameter of the rod is appropriate and one at high polyion concentrations where the scaling of the dimensions is the addition of 1/2 the Debye screening length. Estimates of the "overlap" concentration C*=1/L(eff) indicate that the non-monotonic decrease occurs at concentrations lower than C*. Finally, the fluorescence correlation spectroscopy self-diffusion coefficients measured here are compared with the mutual diffusion coefficients measured by dynamic light scattering.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2004,

title = {Dynamics of supercooled van der Waals liquid under pressure. A dynamic light scattering study},

author = {Adam Patkowski and Jacek Gapiński and Gerhard Meier},

url = {http://link.springer.com/10.1007/s00396-004-1102-7},

doi = {10.1007/s00396-004-1102-7},

issn = {0303-402X},

year  = {2004},

date = {2004-06-01},

journal = {Colloid & Polymer Science},

volume = {282},

number = {8},

pages = {874--881},

publisher = {Springer-Verlag},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Angelini2004,

title = {Study of the Rytov dip for liquid o -terphenyl},

author = {R Angelini and D Fioretto and Jacek Gapiński and G Monaco and Adam Patkowski},

url = {http://www.tandfonline.com/doi/abs/10.1080/14786430310001644224},

doi = {10.1080/14786430310001644224},

issn = {1478-6435},

year  = {2004},

date = {2004-05-01},

journal = {Philosophical Magazine},

volume = {84},

number = {13-16},

pages = {1463--1469},

publisher = {Taylor & Francis Group},

abstract = {Light scattering spectra in the depolarized configuration are presented for the fragile glass former o-terphenyl in the temperature range between 350 and 421 K. These spectra are characterized by the presence of the Rytov dip and have been analysed in terms of the two-variable model of Andersen and Pecora. This model works well in the whole temperature range explored, that is over a range where the shear viscosity varies by almost one decade. The coupling parameter R is extracted and turns out to be almost temperature independent and very similar to that derived for other studied systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Skibinska2004,

title = {Structural similarity ofE. coli 5S rRNA in solution and within the ribosome},

author = {Lidia Skibinska and Ewa Banachowicz and Jacek Gapiński and Adam Patkowski and Jan Barciszewski},

url = {http://doi.wiley.com/10.1002/bip.10598},

doi = {10.1002/bip.10598},

issn = {0006-3525},

year  = {2004},

date = {2004-02-01},

journal = {Biopolymers},

volume = {73},

number = {3},

pages = {316--325},

publisher = {Wiley Subscription Services, Inc., A Wiley Company},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Wodarczyk2004,

title = {The effect of mono- and divalent cations on Tetrahymena thermophila telomeric repeat fragment. A photon correlation spectroscopy study.},

author = {Agnieszka Włodarczyk and Adam Patkowski and Przemysław Grzybowski and Andrzej Dobek},

url = {http://www.actabp.pl/pdf/4_2004/971.pdf http://www.ncbi.nlm.nih.gov/pubmed/15625569},

doi = {045104971},

issn = {0001-527X},

year  = {2004},

date = {2004-01-01},

journal = {Acta Biochimica Polonica},

volume = {51},

number = {4},

pages = {971-981},

abstract = {The structure of the Tetrahymena thermophila telomeric sequence d(TGGGGT)(4) was studied by photon correlation spectroscopy (PCS) in aqueous solution in the presence of NaCl, KCl and SrCl(2). The sample studied was polydisperse in all conditions studied. Translational diffusion coefficients D(T) describing the diffusion modes observed were determined. On the basis of a comparison between the experimental D(T) values with those calculated assuming the bead model, two forms were identified as telomeric quadruplex structures: monomer and tetramer. In the presence of SrCl(2) formation of aggregates was observed, with a size that reached several micrometres. The relative weighted concentrations of the structures observed for different concentrations of a salt and DNA were determined. The results obtained in the presence of monovalent ions were qualitatively similar and could be presented in a coherent plot in which the concentration of salt was expressed by the number of ions per DNA molecule. A large number of ions per DNA molecule favoured tetramer formation while a small number favoured the monomer form. A structural phase transition from the monomer to the tetramer induced by a change in the number of ions per DNA molecule was observed. The main difference between the results for Na(+) and K(+) was a greater effectiveness of the K(+) ions in formation of tetramers. The effect of Sr(2+) ions on the structures formed was different than that of the monovalent ions. The results obtained in the presence of Sr(2+) could not be described as a function of the number of ions per DNA molecule.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Jurga-Nowak2004,

title = {Supramolecular Guanosine 5 ′-Monophosphate Structures in Solution. Light Scattering Study},

author = {Hanna Jurga-Nowak and Ewa Banachowicz and Andrzej Dobek and Adam Patkowski},

url = {http://pubs.acs.org/doi/abs/10.1021/jp030905%2B},

doi = {10.1021/jp030905},

issn = {1520-6106},

year  = {2004},

date = {2004-01-01},

journal = {Journal of Physical Chemistry B},

volume = {108},

pages = {2744--2750},

publisher = {American Chemical Society},

abstract = {During the past decade, from the vast evidence it became clear that DNA oligomers rich in guanine stretches can form in solution highly ordered forms called G-quadruplexes and G-wires. G-quadruplexes are present in many sites of the human genome, can inhibit telomerase, and can be used as drug delivery supramolecules. G-wires and related structures seem to be an excellent material of biological origin for nanostructures. Therefore, in this paper we have studied the structures formed by specific association of guanosine 5‘-monophosphate (GMP) nucleotide molecules in water solutions by photon correlation spectroscopy and depolarized Rayleigh light scattering. One relaxation process with distinct amplitude was observed, as a function of temperature and sample concentration. It was attributed to the translational diffusion coefficient of the stacks of G-quartets in a range of high concentration and to the stacks of GMP monomer associates for low concentration (less than 40 mg/mL). From the measurements the hy...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2003,

title = {Relationship between T0, Tg and their pressure dependence for supercooled liquids},

author = {Adam Patkowski and M Paluch and Jacek Gapiński},

url = {https://www.sciencedirect.com/science/article/pii/S0022309303006781 http://linkinghub.elsevier.com/retrieve/pii/S0022309303006781},

doi = {10.1016/j.jnoncrysol.2003.09.002},

issn = {00223093},

year  = {2003},

date = {2003-11-01},

journal = {Journal of Non-Crystalline Solids},

volume = {330},

number = {1-3},

pages = {259--263},

publisher = {North-Holland},

abstract = {We show that simple expressions can be derived from the Vogel–Fulcher–Tammann (VFT) law relating the glass transition temperature Tg, the VFT temperature T0, their pressure derivatives, the steepness index of the ‘Angell plot' and the strength parameter D of the VFT equation, in good agreement with experimental data. In the same way one can describe the dependence of the dTg/dP on the relaxation time $tau$g chosen to define the temperature Tg. Thus, this procedure allows a consistent rescaling and comparison of pressure dependent parameters obtained from different experiments and simulations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Thurn-Albrecht2003,

title = {Photon correlation spectroscopy with high-energy coherent x rays},

author = {T Thurn-Albrecht and F Zontone and G Grubel and W Steffen and P Muller-Buschbaum and Adam Patkowski},

url = {https://link.aps.org/doi/10.1103/PhysRevE.68.031407},

doi = {10.1103/PhysRevE.68.031407},

issn = {1063-651X},

year  = {2003},

date = {2003-09-01},

journal = {Physical Review E},

volume = {68},

number = {3},

pages = {031407},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Paluch2003a,

title = {Effect of volume changes on segmental relaxation in siloxane polymers},

author = {M Paluch and R Casalini and Adam Patkowski and T Pakula and C M Roland},

url = {http://www.ncbi.nlm.nih.gov/pubmed/14524793 https://link.aps.org/doi/10.1103/PhysRevE.68.031802},

doi = {10.1103/PhysRevE.68.031802},

issn = {1063-651X},

year  = {2003},

date = {2003-09-01},

journal = {Physical Review E},

volume = {68},

number = {3},

pages = {031802},

abstract = {From dielectric relaxation and equation-of-state measurements on polymethylphenylsiloxane and polymethyltolylsiloxane, the relative contributions of volume and thermal energy to the temperature dependence of the segmental relaxation times are quantified. In both polymers, volume exerts a substantial effect, being almost as significant as thermal energy. A possible consequence of this prominent role of volume in governing the segmental dynamics is the finding that the relaxation times, measured for a series of temperature at various (fixed) pressures, can be expressed as a single function of the volume normalized by the volume at the glass transition temperature. A similar result is found for the (isothermal) relaxation times measured at various pressures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2003a,

title = {Pressure dependence of the high-frequency light scattering susceptibility of ortho-terphenyl: A mode coupling analysis},

author = {Adam Patkowski and M Matos Lopes and E W Fischer},

url = {http://aip.scitation.org/doi/10.1063/1.1581847},

doi = {10.1063/1.1581847},

issn = {0021-9606},

year  = {2003},

date = {2003-07-01},

journal = {The Journal of Chemical Physics},

volume = {119},

number = {3},

pages = {1579--1585},

publisher = {American Institute of Physics},

abstract = {The high frequency part of the depolarized light scattering susceptibility has been measured for ortho-terphenyl (OTP) in a broad temperature and pressure range and analyzed using the mode-coupling theory (MCT). We found that the time–temperature–pressure superposition does not work for OTP in the frequency range of the susceptibility minimum and both a and b exponents of the MCT are temperature and pressure dependent. The pressure induced shift of the position of the minimum is much weaker than that of the $alpha$-peak resulting in dTc/dP=8.5 K/kbar while dTg/dP=26 K/kbar. Thus any universal scaling of the entire susceptibility including both the $alpha$-peak and the MCT minimum is not possible. These results are in contradiction to the previously reported conclusions obtained from the analysis of incoherent neutron scattering data [A. Toelle et al., Phys. Rev. Lett. 80, 2374 (1998)].},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Dreyfus2003,

title = {Temperature and pressure study of Brillouin transverse modes in the organic glass-forming liquid orthoterphenyl},

author = {C Dreyfus and A Aouadi and Jacek Gapiński and M Matos-Lopes and W Steffen and Adam Patkowski and R M Pick},

url = {https://link.aps.org/doi/10.1103/PhysRevE.68.011204},

doi = {10.1103/PhysRevE.68.011204},

issn = {1063-651X},

year  = {2003},

date = {2003-07-01},

journal = {Physical Review E},

volume = {68},

number = {1},

pages = {011204},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Paluch2003b,

title = {The relative contributions of temperature and volume to structural relaxation of van der Waals molecular liquids},

author = {M Paluch and C M Roland and R Casalini and G Meier and Adam Patkowski},

url = {http://aip.scitation.org/doi/10.1063/1.1545449},

doi = {10.1063/1.1545449},

issn = {0021-9606},

year  = {2003},

date = {2003-03-01},

journal = {The Journal of Chemical Physics},

volume = {118},

number = {10},

pages = {4578--4582},

publisher = {American Institute of Physics},

abstract = {Pressure-volume-temperature measurements were carried out on two van der Waals liquids, 1,1′-bis(p-methoxyphenyl)cyclohexane (BMPC) and 1,1′-di(4-methoxy-5methylphenyl)cyclohexane (BMMPC). In combination with dielectric spectroscopy results, the relative contribution of temperature and density to the structural relaxation times were quantified. We find that the ratio of the isobaric expansion coefficient [−$rho$−1 (∂$rho$/∂T)P, where $rho$ is mass density and T is temperature, evaluated at P=0.1 MPa] to the coefficient of isochronal expansivity [−$rho$−1 (∂$rho$/∂T)$tau$, evaluated at $tau$=1 s] equals 0.58 and 0.72 for BMPC and BMMPC, respectively. This indicates that density exerts more influence on the structural relaxation times than does thermal energy. Corroborating this finding, the ratio of the isochoric activation energy to the activation energy at constant pressure is determined to be ca. 0.4 at ambient pressure for both glass formers. The prevalence of density over thermal energy is contrary to prevailing ideas concerning...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Paluch2003c,

title = {Pressure and temperature dependence of structural relaxation in diglycidylether of bisphenol A},

author = {M Paluch and C M Roland and Jacek Gapiński and Adam Patkowski},

url = {http://aip.scitation.org/doi/10.1063/1.1538597},

doi = {10.1063/1.1538597},

issn = {0021-9606},

year  = {2003},

date = {2003-02-01},

journal = {The Journal of Chemical Physics},

volume = {118},

number = {7},

pages = {3177--3186},

publisher = {American Institute of Physics},

abstract = {The structural ($alpha$-) relaxation in diglycidylether of bisphenol A (DGEBA) has been examined using three spectroscopic methods: dielectric spectroscopy (DS), dynamic light scattering–photon correlation spectroscopy (LS), and mechanical spectroscopy. The DS and LS measurements were carried out as a function of both temperature and pressure. Moreover, pressure-volumetemperature measurements were obtained for the DGEBA. These data allow an assessment of the relative contributions of thermal energy and free volume to structural relaxation in DGEBA. The results clearly show a substantial role for both thermal and free volume fluctuations in the dramatic slowing down of the dynamics. The combined temperature- and pressure-dependences of the dielectric and light scattering relaxation times were analyzed using the Avramov equation, implying that the fragility (normalized temperature dependence) is pressure independent over the studied range of pressures. The pressure dependence was the same as measured by the diffe...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2003b,

title = {Dynamics of supercooled liquids confined to the pores of sol-gel glass: A dynamic light scattering study},

author = {Adam Patkowski and T Ruths and E W Fischer},

url = {http://www.ncbi.nlm.nih.gov/pubmed/12636678 https://link.aps.org/doi/10.1103/PhysRevE.67.021501},

doi = {10.1103/PhysRevE.67.021501},

issn = {1063-651X},

year  = {2003},

date = {2003-02-01},

journal = {Physical Review E},

volume = {67},

number = {2},

pages = {021501},

abstract = {Dynamics of low molecular weight and polymeric glass forming liquids in confined geometries has been studied by means of depolarized dynamic light scattering: photon correlation spectroscopy and Fabry-Perot interferometry. The pore size of the glassy matrix amounted to 2.5, 5.0, and 7.5 nm. The glass transition temperature T(g) of these liquids in confined geometries has been measured using differential scanning calorimetry. A systematic decrease of T(g) (up to 25 K) with decreasing pore size has been observed. The relaxation times of the alpha process at constant temperature were decreasing with decreasing pore size (up to 6 orders of magnitude at T(g)), while the width of their distribution was increasing. The change of the relaxation times can be assigned to the change of T(g) in confined geometries. After correcting the activation plots for the shift of T(g) a master curve was obtained for all pore sizes and the bulk material. The effect of chemical modification of the surface of the porous matrix on the dynamics of ortho-terphenyl has also been studied. These dramatic changes of the T(g) and the relaxation time of confined liquids can be explained by simple thermodynamic arguments. There is no indication that they are related to the change of the correlation length of cooperative dynamics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Paluch2002,

title = {Volume effects on the molecular mobility close to glass transition in supercooled phenylphthalein-dimethylether. II},

author = {Marian Paluch and Riccardo Casalini and Andreas Best and Adam Patkowski},

url = {http://aip.scitation.org/doi/10.1063/1.1510115},

doi = {10.1063/1.1510115},

issn = {0021-9606},

year  = {2002},

date = {2002-10-01},

journal = {The Journal of Chemical Physics},

volume = {117},

number = {16},

pages = {7624--7630},

publisher = {American Institute of Physics},

abstract = {Pressure–volume–temperature measurements in phenylphthalein-dimethylether (PDE) are reported, in combination with recently published dynamic light scattering data obtained under high pressure. We discuss the role that volume and thermal effects play in controlling the dynamics in the vicinity of the glass transition. Although volume is not the unique thermodynamical parameter characterizing the relaxation dynamics in PDE, its contribution to the super-Arrhenius behavior of the relaxation times in the vicinity of the glass transition is remarkable. The contribution of volume to the temperature dependence of the relaxation times has been characterized by means of the ratio of the activation energy at constant volume to the enthalpy of activation at constant pressure, EV/HP. We point out that this quantity is correlated with the temperature behavior of the nonexponentiallity parameter, $beta$KWW. Moreover, the $tau$(T,P) values were analyzed in terms of an extension of the Adam–Gibbs model. It was shown that this mod...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fischer2002,

title = {Heterophase fluctuations in supercooled liquids and polymers},

author = {E W Fischer and A Bakai and Adam Patkowski and W Steffen and L Reinhardt},

url = {https://www.sciencedirect.com/science/article/pii/S0022309302015107 http://linkinghub.elsevier.com/retrieve/pii/S0022309302015107},

doi = {10.1016/S0022-3093(02)01510-7},

issn = {00223093},

year  = {2002},

date = {2002-09-01},

journal = {Journal of Non-Crystalline Solids},

volume = {307-310},

pages = {584--601},

publisher = {North-Holland},

abstract = {Glass-forming liquids and polymers consist of `solid-like' and `fluid-like' clusters of a finite lifetime in a dynamic equilibrium. The experimental observations leading to the heterophase fluctuation model are reviewed. They are: (i) long range density fluctuations as measured by static light scattering and ultra small angle X-ray scattering, (ii) ultra-slow hydrodynamic modes of density fluctuations as observed by photon correlation spectroscopy, (iii) temperature depending structural changes as studied by wide angle X-ray scattering. In order to explain these observations a new order parameter ns(x,t) is proposed, which describes the local mass fraction of energetically preferred structures (`aperiodic solid states'). The thermodynamic potentials can be analyzed in terms of the temperature dependence of 〈ns(T)〉. The $alpha$-relaxation process of supercooled liquids is directly related to the local fluctuations of ns (x,t).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2002a,

title = {Dynamic light scattering studies of supercooled phenylphthalein–dimethylether dynamics under high pressure},

author = {Adam Patkowski and Marian Paluch and Hartmut Kriegs},

url = {http://aip.scitation.org/doi/10.1063/1.1489902},

doi = {10.1063/1.1489902},

issn = {0021-9606},

year  = {2002},

date = {2002-08-01},

journal = {The Journal of Chemical Physics},

volume = {117},

number = {5},

pages = {2192--2198},

publisher = {American Institute of Physics},

abstract = {The behavior of the $alpha$-relaxation process in phenylphthalein–dimethylether (PDE) under high pressure was studied by means of dynamic light scattering–photon correlation spectroscopy (DLS-PCS). The temperature dependence of the relaxation time of the $alpha$-process at ambient pressure was found to resemble that obtained from dielectric relaxation (DR) measurements. On the basis of the DLS measurements one can conclude that PDE satisfies the correlation between nonexponentiality and fragility established for low-molecular weight glass forming liquids and polymers. On the other hand, dielectric relaxation studies indicate that PDE is an exception from this correlation. These differences between the DLS and DR studies do not result from the overlap of the $alpha$- and $beta$-processes in the DLS experiments but might be due to the different coupling of the probes seen in these experiments (optical anisotropy and dipole moment) to the dynamics of the entire PDE molecule. We also studied the effect of pressure on fragility and ...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski2002,

title = {Correlation between nonexponential relaxation and non-Arrhenius behavior under conditions of high compression},

author = {Jacek Gapiński and Marian Paluch and Adam Patkowski},

url = {http://www.ncbi.nlm.nih.gov/pubmed/12241364 https://link.aps.org/doi/10.1103/PhysRevE.66.011501},

doi = {10.1103/PhysRevE.66.011501},

issn = {1063-651X},

year  = {2002},

date = {2002-07-01},

journal = {Physical Review E},

volume = {66},

number = {1},

pages = {011501},

abstract = {Photon correlation spectroscopy was used to investigate the behavior of the dynamical properties of 1,1'-di(4-methoxy-5-methyl-phenyl)cyclohexane (BMMPC) at elevated pressures. The fragility of BMMPC measured by the steepness index m(T) is decreasing and the nonexponentiality parameter beta(KWW) is increasing with increasing pressure. This result strongly suggests that the phenomenological correlation between the steepness index and nonexponentionality is also preserved under high compression. The pressure dependence of the structural relaxation times is well characterized by a simple activation volume form. The activation volume continuously increases with decreasing temperature, which is probably due to the increase of cooperativity of the structural relaxation process. Moreover, we found that the glass-transition temperature exhibits a significant dependence on pressure.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Haußler2002,

title = {Interparticle correlations due to electrostatic interactions: A small angle x-ray and dynamic light scattering study. I. Apoferritin},

author = {W Haeußler and Agnieszka Wilk and Jacek Gapiński and Adam Patkowski},

url = {http://aip.scitation.org/doi/10.1063/1.1481383},

doi = {10.1063/1.1481383},

issn = {0021-9606},

year  = {2002},

date = {2002-07-01},

journal = {The Journal of Chemical Physics},

volume = {117},

number = {1},

pages = {413--426},

publisher = {American Institute of Physics},

abstract = {The structure and dynamics of the spherical protein Apoferritin in aqueous solution are studied over a wide range of protein concentrations and ionic strengths. At high ionic strength and low protein concentration, the intermolecular forces are screened and, therefore, the proteins behave like uncharged molecules. Under these conditions, the form factor of Apoferritin was measured by means of small angle x-ray scattering (SAXS) and the hydrodynamic radius was determined by means of dynamic light scattering (DLS). The sample was found to be highly monodisperse. By decreasing the content of salt added, interactions between the Apoferritin particles were initiated. These intermolecular forces lead to a pronounced maximum in the SAXS intensity. At the same time, a slow mode appears in the relaxation time distribution, additionally to the diffusive mode. The relative amplitudes and correlation times of the diffusive and the slow mode were investigated and compared with predictions of the coupled mode theory. B...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2002b,

title = {Struktura i dynamika materiałow szkłopodobnych},

author = {Adam Patkowski},

year  = {2002},

date = {2002-01-01},

journal = {Postępy Fizyki},

volume = {53D},

pages = {146--151},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Benmouna2001,

title = {Dynamic light scattering from liquid crystal polymer brushes swollen in a nematic solvent},

author = {Farida Benmouna and Bin Peng and Jacek Gapiński and Adam Patkowski and Jurgen Ruhe and Diethelm Johannsmann},

url = {http://www.tandfonline.com/doi/abs/10.1080/02678290110061395},

doi = {10.1080/02678290110061395},

issn = {0267-8292},

year  = {2001},

date = {2001-09-01},

journal = {Liquid Crystals},

volume = {28},

number = {9},

pages = {1353--1360},

publisher = {Taylor & Francis Group},

abstract = {Surface-attached side group liquid crystal polymer monolayers ('brushes') swollen in a nematic solvent were studied by means of dynamic light scattering. In the temperature range 47.5-66°C, the swollen brush is nematic while the bulk liquid crystal is isotropic. Under these conditions the light scattering is dominated by the brush. The fluctuations in the brush are 1-2 orders of magnitude slower than the fluctuations in the bulk nematic. The autocorrelation functions are well fitted by Kohlrausch-Williams-Watts stretched exponentials of the form exp[(-t/$tau$)$beta$] with a dynamic exponent $beta$ in the range 0.6-0.8.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2001,

title = {Apparent nonergodic behavior of supercooled liquids above the glass transition temperature},

author = {Adam Patkowski and H Glaeser and T Kanaya and E W Fischer},

url = {http://www.ncbi.nlm.nih.gov/pubmed/11580338 https://link.aps.org/doi/10.1103/PhysRevE.64.031503},

doi = {10.1103/PhysRevE.64.031503},

issn = {1063-651X},

year  = {2001},

date = {2001-08-01},

journal = {Physical Review E},

volume = {64},

number = {3},

pages = {031503},

abstract = {A speckle pattern can be observed in the polarized component of light scattered from glass forming liquids far above their glass transition temperature. This speckle pattern fluctuates with characteristic time that corresponds to the relaxation time of the additional ultraslow component in the correlation function and is about seven orders of magnitude longer than the relaxation time of the alpha-process. This slow process is out of the experimental time window when the alpha-process is measured by means of the photon correlation spectroscopy and results in an apparent nonergodicity which can be seen as a baseline offset in the ensemble-averaged correlation function. In contrast, the time-averaged field correlation functions which have been measured in practically all light scattering studies always decay to zero. The slow process contributes a q-dependent excess intensity to the polarized component of scattered light. The values of the nonergodicity parameters obtained from the static and dynamic light scattering experiments are equal. Both the slow component and the excess intensity result from denser regions of fractal character which develop in glass-forming liquids on approaching the glass transition.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2001a,

title = {Unusual features of long-range density fluctuations in glass-forming organic liquids: A Rayleigh and Rayleigh-Brillouin light scattering study},

author = {Adam Patkowski and E W Fischer and W Steffen and H Glaeser and M Baumann and T Ruths and G Meier},

url = {http://www.ncbi.nlm.nih.gov/pubmed/11415106 https://link.aps.org/doi/10.1103/PhysRevE.63.061503},

doi = {10.1103/PhysRevE.63.061503},

issn = {1063-651X},

year  = {2001},

date = {2001-05-01},

journal = {Physical Review E},

volume = {63},

number = {6},

pages = {061503},

abstract = {A new feature of glass-forming liquids, i.e., long-range density fluctuations of the order of 100 nm, has been extensively characterized by means of static light scattering, photon correlation spectroscopy and Rayleigh-Brillouin spectroscopy in orthoterphenyl (OTP) and 1,1-di(4(')-methoxy-5(')methyl-phenyl)-cyclohexane (BMMPC). These long-range density fluctuations result in the following unusual features observed in a light scattering experiment, which are not described by the existing theories: (i) strong q-dependent isotropic excess Rayleigh intensity, (ii) additional slow component in the polarized photon correlation function, and (iii) high Landau-Placzek ratio. These unusual features are equilibrium properties of the glass-forming liquids and depend only on temperature, provided that the sample has been equilibrated long enough. The temperature-dependent equilibration times were measured for BMMPC and are about 11 orders of magnitude longer than the alpha process. It was found that the glass-forming liquid OTP may occur in two states: with and without long-range density fluctuations ("clusters"). We have characterized the two states by static and dynamic light scattering in the temperature range from T(g) to T(g)+200 K. The relaxation times of the alpha process as well as the parameters of the Brillouin line are identical in both OTP with and without clusters. The alpha process (density fluctuations) in OTP was characterized by measuring either the polarized (VV) or depolarized (VH) correlation function, which are practically identical and q-independent. This feature, which is commonly observed in glass-forming liquids, is not fully explained by the existing theories.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Paluch2001,

title = {Does fragility depend on pressure? A dynamic light scattering study of a fragile glass-former},

author = {Marian Paluch and Jacek Gapiński and Adam Patkowski and Erhard W Fischer},

url = {http://aip.scitation.org/doi/10.1063/1.1362293},

doi = {10.1063/1.1362293},

issn = {0021-9606},

year  = {2001},

date = {2001-05-01},

journal = {The Journal of Chemical Physics},

volume = {114},

number = {18},

pages = {8048--8055},

publisher = {American Institute of Physics},

abstract = {Relaxation times of the $alpha$-process in the fragile glass-forming liquid diglycidyl ether of bisphenol-A (EPON 828) were measured in a broad pressure (1–1500 bar) and temperature (264–293 K) ranges by means of the depolarized dynamic light scattering—photon correlation spectroscopy. Based on this experimental data the fragility of the supercooled liquid was calculated in two ways: as a steepness index m of the “Angell plot” and as the DT-parameter from the Vogel–Fulcher–Tammann Law, and was studied as a function of pressure. It was found, that while the steepness index depends on pressure, the DT parameter is pressure independent. The pressure dependence of the glass transition temperature Tg in EPON 828 was found to be nonlinear. Additionally, we established a relationship between the steepness index mT, the activation volume $Delta$V#, and the coefficient ∂Tg/∂Pg. In this pressure dependent study we found that also for EPON 828 the nonexponentiality of the correlation function of the $alpha$-process correlates well wi...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Liu2000,

title = {Effect of electrostatic interactions on the dynamics of semiflexible monodisperse DNA fragments},

author = {Hui Liu and Jacek Gapiński and Lidia Skibinska and Adam Patkowski and R Pecora},

url = {http://aip.scitation.org/doi/abs/10.1063/1.1290477 http://aip.scitation.org/doi/10.1063/1.1290477},

doi = {10.1063/1.1290477},

issn = {0021-9606},

year  = {2000},

date = {2000-10-01},

journal = {The Journal of Chemical Physics},

volume = {113},

number = {14},

pages = {6001--6010},

publisher = {American Institute of Physics},

abstract = {The dynamics of three monodisperse linear duplex DNA fragments—a 2311 base pair restriction fragment and 1500 and 1100 base pair polymerase chain reaction fragments—in dilute solution are studied as functions of added salt (NaCl) concentration by dynamic light scattering-photon correlation spectroscopy. Translational diffusion coefficients and intramolecular relaxation times are extracted from the measured light scattering intensity time autocorrelation functions as the added salt concentration is reduced from 100 mM to approximately 0.1 mM. The relaxation times of the first intramolecular mode increase as the added salt concentration is lowered. The dependence of the translational diffusion coefficient D on the added salt concentration is not very large, although it exhibits a maximum for all three fragments. The maximum is interpreted as the consequence of two opposing effects—the stiffening of the molecule that produces an increase of the size (decrease of D) as the added salt concentration is lowered,...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Paluch2000,

title = {Temperature and Pressure Scaling of the alpha Relaxation Process in Fragile Glass Formers: A Dynamic Light Scattering Study},

author = {Marian Paluch and Adam Patkowski and Erhard W Fischer},

url = {http://www.ncbi.nlm.nih.gov/pubmed/10970482 https://link.aps.org/doi/10.1103/PhysRevLett.85.2140},

doi = {10.1103/PhysRevLett.85.2140},

issn = {0031-9007},

year  = {2000},

date = {2000-09-01},

journal = {Physical Review Letters},

volume = {85},

number = {10},

pages = {2140--2143},

abstract = {The dynamics of two fragile glass forming liquids was studied as a function of temperature and pressure using dynamic light scattering. On the basis of measured data we evaluated the pressure and temperature scaling of the alpha relaxation. All the isotherms can be superimposed and form a master curve when the reduced relaxation times are plotted versus reduced pressure. The Kohlrausch-Williams-Watts stretching parameter beta(KWW) is increasing with increasing temperature and decreasing pressure and plotted versus logtextlesstau(KWW)textgreater follows a master curve at all temperatures and pressures studied.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Aouadi2000,

title = {Light scattering study of the liquid–glass transition of meta-toluidine},

author = {A Aouadi and C Dreyfus and M Massot and R M Pick and T Berger and W Steffen and Adam Patkowski and C Alba-Simionesco},

url = {http://aip.scitation.org/doi/abs/10.1063/1.481642 http://aip.scitation.org/doi/10.1063/1.481642},

doi = {10.1063/1.481642},

issn = {0021-9606},

year  = {2000},

date = {2000-06-01},

journal = {The Journal of Chemical Physics},

volume = {112},

number = {22},

pages = {9860--9873},

publisher = {American Institute of Physics},

abstract = {An experimental study of the glass transition of meta-toluidine combining several light scattering techniques was performed. The structural relaxation time is measured in depolarized geometry from the glass transition temperature up to well above the melting point and found to vary over 13 time decades. An analysis by means of the idealized Mode Coupling Theory shows that, as found in other aromatic liquids, experimental results obtained in depolarized light scattering can be described by this theory above Tc in a two-decade frequency range. The polarized Brillouin doublet, measured in the backscattering geometry between 176 K and 300 K, is also analyzed. None of the sets of parameters we obtained in fitting those spectra could fulfil all the requirements of this Mode Coupling Theory.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski2000,

title = {Long-range density fluctuations in orthoterphenyl as studied by means of ultrasmall-angle x-ray scattering.},

author = {Adam Patkowski and T Thurn-Albrecht and Ewa Banachowicz and W Steffen and P Boesecke and T Narayanan and E W Fischer},

url = {http://www.ncbi.nlm.nih.gov/pubmed/11088383},

issn = {1063-651X},

year  = {2000},

date = {2000-06-01},

journal = {Physical review E},

volume = {61},

number = {6 Pt B},

pages = {6909--13},

abstract = {The structure factor of a fragile glass-forming liquid orthoterphenyl was measured in the previously inaccessible intermediate q range between the conventional light scattering (LS) and small-angle x-ray scattering (SAXS) q ranges using the low-angle scattering beam line at the European Synchrotron Radiation Facility. At low q the structure factor exhibits an excess scattering and matches well the LS data. This excess scattering is due to long-range density fluctuations also observed in the isotropic component of scattered light. At high q the structure factor decays to a plateau corresponding to the isothermal compressibility in agreement with the conventional SAXS data. In the intermediate q range, the structure factor exhibits a power law q dependence which indicates that the excess scattering is due to fractal aggregates of denser domains.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Banachowicz2000,

title = {Solution Structure of Biopolymers: A New Method of Constructing a Bead Model},

author = {Ewa Banachowicz and Jacek Gapiński and Adam Patkowski},

url = {http://www.ncbi.nlm.nih.gov/pubmed/10620274 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC1300618 http://linkinghub.elsevier.com/retrieve/pii/S0006349500765738},

doi = {10.1016/S0006-3495(00)76573-8},

issn = {00063495},

year  = {2000},

date = {2000-01-01},

journal = {Biophysical Journal},

volume = {78},

number = {1},

pages = {70--78},

publisher = {The Biophysical Society},

abstract = {We propose a new, automated method of converting crystallographic data into a bead model used for the calculations of hydrodynamic properties of rigid macromolecules. Two types of molecules are considered: nucleic acids and small proteins. A bead model of short DNA fragments has been constructed in which each nucleotide is represented by two identical, partially overlapping spheres: one for the base and one for the sugar and phosphate group. The optimum radius sigma = 5.0 A was chosen on the basis of a comparison of the calculated translational diffusion coefficients (D(T)) and the rotational relaxation times (tau(R)) with the corresponding experimental data for B-DNA fragments of 8, 12, and 20 basepairs. This value was assumed for the calculation D(T) and tau(R) of tRNA(Phe). Better agreement with the experimental data was achieved for slightly larger sigma = 5.7 A. A similar procedure was applied to small proteins. Bead models were constructed such that each amino acid was represented by a single sphere or a pair of identical, partially overlapping spheres, depending on the amino acid's size. Experimental data of D(T) of small proteins were used to establish the optimum value of sigma = 4.5 A for amino acids. The lack of experimental data on tau(R) for proteins restricted the tests to the translational diffusion properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Comez1999a,

title = {Light-scattering study of a supercooled epoxy resin},

author = {L Comez and D Fioretto and L Palmieri and L Verdini and P A Rolla and Jacek Gapiński and T Pakula and Adam Patkowski and W Steffen and E W Fischer},

url = {http://www.ncbi.nlm.nih.gov/pubmed/11970116},

issn = {1063-651X},

year  = {1999},

date = {1999-09-01},

journal = {Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics},

volume = {60},

number = {3},

pages = {3086--96},

abstract = {The dynamics of the fragile glass-forming liquid diglycidyl ether of bisphenol-A was studied by depolarized Rayleigh-Brillouin light-scattering and photon correlation spectroscopy above the glass transition, in the temperature range from 261 to 473 K and in the frequency range from 1 Hz to 300 GHz. The structural (alpha-) relaxation process was revealed and no signature of the secondary relaxation previously evidenced by dielectric spectroscopy at about 0.1 GHz was observed. The characteristic time of the alpha process differs from that determined by dielectric spectroscopy of an amount, which increases with increasing temperature. The relaxation times were compared with viscosity data to test the predictions of the classic Stokes-Einstein-Debye model. The tau proportional, variant eta behavior was verified for dielectric data, while a fractional power law of viscosity tau proportional, variant eta(0.89) was obtained for light-scattering relaxation times, extending over more than seven decades in viscosity and time. This deviation of light scattering from viscosity data could be interpreted in terms of cooperative motion in the supercooled liquid with a characteristic length xi(a) proportional, variant(T-T0)(-v) where T(0)=229 K is the Vogel temperature and v is close to 2 / 3 which is consistent with the prediction of the fluctuation theory of glass transition.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Vass1999,

title = {Positron annihilation study of a low-molecular-weight organic glass-forming liquid (BMMPC)},

author = {Sz Vass and Adam Patkowski and E W Fischer and K Suvegh and A Vertes},

url = {http://stacks.iop.org/0295-5075/46/i=6/a=815?key=crossref.98a693291d44d9ebe7550d7a50a4db8e},

doi = {10.1209/epl/i1999-00337-8},

issn = {0295-5075},

year  = {1999},

date = {1999-06-01},

journal = {Europhysics Letters (EPL)},

volume = {46},

number = {6},

pages = {815--820},

publisher = {IOP Publishing},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Dreyfus1999,

title = {Light scattering by transverse waves in supercooled liquids and application to metatoluidine},

author = {C Dreyfus and A Aouadi and R M Pick and T Berger and Adam Patkowski and W Steffen},

url = {http://link.springer.com/10.1007/s100510050783},

doi = {10.1007/s100510050783},

issn = {1434-6028},

year  = {1999},

date = {1999-06-01},

journal = {The European Physical Journal B},

volume = {9},

number = {3},

pages = {401--419},

publisher = {EDP Sciences},

abstract = {We discuss the hydrodynamic equations which describe the shear dynamics of a liquid composed of anisotropic molecules, both in its normal and its supercooled phases. We use these equations to analyze 90° depolarized light scattering experiments performed in the supercooled phase of a glass forming liquid, metatoluidine, and show that the information extracted from this analysis is consistent with independent shear viscosity measurements performed on that liquid in the same temperature range.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gapinski1999,

title = {Spectrum of fast dynamics in glass forming liquids: Does the “knee” exist?},

author = {Jacek Gapiński and W Steffen and Adam Patkowski and A P Sokolov and A Kisliuk and U Buchenau and M Russina and F Mezei and H Schober},

url = {http://aip.scitation.org/doi/abs/10.1063/1.477966 http://aip.scitation.org/doi/10.1063/1.477966},

doi = {10.1063/1.477966},

issn = {0021-9606},

year  = {1999},

date = {1999-02-01},

journal = {The Journal of Chemical Physics},

volume = {110},

number = {5},

pages = {2312--2315},

publisher = {American Institute of Physics},

abstract = {A knee-shaped feature observed earlier in light scattering spectra of Ca0.4K0.3(NO3)1.4 (CKN) below Tc is used as a strong argument in favor of mode-coupling theory of the glass transition (MCT). Our careful measurements reveal no “knee” in the spectra of two glass forming liquids, CKN and ortho-terphenyl. Instead of the knee the spectra show nontrivial broadening and an increase of the intensity with a temperature increase. Both variations are confirmed by neutron scattering measurements on CKN and are neither expected in the asymptotic MCT predictions nor in any other model.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Wodarczyk1999,

title = {Structural polymorphism of telomeres studied by photon correlation spectroscopy.},

author = {Agnieszka Włodarczyk and Jacek Gapiński and Adam Patkowski and Andrzej Dobek},

url = {http://www.ncbi.nlm.nih.gov/pubmed/10698269},

issn = {0001-527X},

year  = {1999},

date = {1999-01-01},

journal = {Acta Biochimica Polonica},

volume = {46},

number = {3},

pages = {609-613},

abstract = {Photon Correlation Spectroscopy (PCS) was used to study the dynamics and structure of Tetrahymena telomeric sequence d(5'-TGGGGT-3')4. Two different modes were observed, corresponding to the following structures: intermolecular (tetramolecular) G-quadruplex and intramolecular (monomeric) G-quartet. Experimental values of translational diffusion coefficients DT were obtained for each structural form. The value of DT for the monomer equals to 1.4 x 10(6) (cm2/s), while for the tetramolecular structure, to 0.8 x 10(6) (cm2/s). The relative weight concentrations of these two forms were analyzed versus the concentration of NaCl varied from 10 mM to 500 mM. The values of experimentally determined diffusion coefficients were compared with those calculated assuming the "bead model" and with the atomic coordinates from the NMR and X-ray crystallographic data. For both structures the experimental and calculated values of DT were in reasonable agreement. In the entire NaCl concentration range studied, the contribution of the relative weight concentration of the monomeric telomere form changed from 85% for 10 mM NaCl to 60% for 500 mM NaCl.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Skibinska1999,

title = {Effect of electrostatic interactions on the structure and dynamics of a model polyelectrolyte. II. Intermolecular correlations},

author = {Lidia Skibinska and Jacek Gapiński and Hui Liu and Adam Patkowski and Erhard W Fischer and R Pecora},

url = {http://aip.scitation.org/doi/abs/10.1063/1.477887 http://aip.scitation.org/doi/10.1063/1.477887},

doi = {10.1063/1.477887},

issn = {0021-9606},

year  = {1999},

date = {1999-01-01},

journal = {The Journal of Chemical Physics},

volume = {110},

number = {3},

pages = {1794--1800},

publisher = {American Institute of Physics},

abstract = {The peak in the small angle x-ray scattering and the dynamic light-scattering slow mode for a 20 base-pair duplex oligonucleotide (“B-DNA”) are studied as functions of oligonucleotide and added-salt (NaCl) concentrations. Both the x-ray peak intensity and the relative intensity of the slow mode decrease as the added-salt concentration is increased. The hydrodynamic radius of the slow mode increases as the added-salt concentration is decreased. The x-ray peak gradually disappears with increasing salt while the slow mode decreases in intensity, but still has some residual intensity at the highest added-salt concentration studied. There is no abrupt change in either the peak or the slow mode with increasing salt. The existence and behavior of both the x-ray peak and the slow mode indicate local ordering in the solution due to electrostatic forces. The x-ray peak position for the oligonucleotide is correlated with the static light-scattering peak seen by other workers for dilute solutions of larger polyions. ...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Liu1998,

title = {Effect of electrostatic interactions on the structure and dynamics of a model polyelectrolyte. I. Diffusion},

author = {Hui Liu and Lidia Skibinska and Jacek Gapiński and Adam Patkowski and Erhard W Fischer and R Pecora},

url = {http://aip.scitation.org/doi/10.1063/1.477377},

doi = {10.1063/1.477377},

issn = {0021-9606},

year  = {1998},

date = {1998-11-01},

journal = {The Journal of Chemical Physics},

volume = {109},

number = {17},

pages = {7556--7566},

publisher = {American Institute of Physics},

abstract = {The dynamics of a 20 base pair oligonucleotide is studied by dynamic light scattering-photon correlation spectroscopy and depolarized Fabry–Perot interferometry. The 20 base pair oligonucleotide is a well-defined, albeit short, rigid rod molecule that serves as a model for polyelectrolyte solution dynamics. The effects of added salt on the solution rotational and translational dynamics are examined in detail as functions of the 20-mer concentration. Coupled mode theory together with counterion condensation theory gives good predictions for the effects of salt on the translational diffusion of the 20-mer at the relatively low oligonucleotide concentrations studied. Comparison of the experimental results with these theories shows that the effective charge density of the polyion in solution is approximately equal to the reciprocal of the product of the Bjerrum length and the counterion charge, $nu$eff≅1/N$łambda$B. Calculation shows that the numerical solution of the coupled mode theory matrix gives a better fit of ou...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1998a,

title = {Comments on `Relaxation dynamics in orthoterphenyl: comparing $beta$K from extended mode coupling theory and phenomenological analyses'},

author = {Adam Patkowski and W Steffen and E W. Fischer},

url = {https://www.sciencedirect.com/science/article/pii/S0022309398006474 http://linkinghub.elsevier.com/retrieve/pii/S0022309398006474},

doi = {10.1016/S0022-3093(98)00647-4},

issn = {00223093},

year  = {1998},

date = {1998-08-01},

journal = {Journal of Non-Crystalline Solids},

volume = {235-237},

pages = {268--270},

publisher = {North-Holland},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Dreyfus1998,

title = {Light scattering measurement of shear viscosity in a fragile glass-forming liquid, metatoluidine},

author = {C Dreyfus and A Aouadi and R M Pick and T Berger and Adam Patkowski and W Steffen},

url = {http://stacks.iop.org/0295-5075/42/i=1/a=055?key=crossref.6fe7960e1ae53646913cca0cd4f82873},

doi = {10.1209/epl/i1998-00551-4},

issn = {0295-5075},

year  = {1998},

date = {1998-04-01},

journal = {Europhysics Letters (EPL)},

volume = {42},

number = {1},

pages = {55--60},

publisher = {IOP Publishing},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1997,

title = {Depolarized dynamic light scattering from three low molecular weight glass forming liquids: A test of the scattering mechanism},

author = {Adam Patkowski and W Steffen and H Nilgens and E W Fischer and R Pecora},

url = {http://aip.scitation.org/doi/abs/10.1063/1.474117 http://aip.scitation.org/doi/10.1063/1.474117},

doi = {10.1063/1.474117},

issn = {0021-9606},

year  = {1997},

date = {1997-05-01},

journal = {The Journal of Chemical Physics},

volume = {106},

number = {20},

pages = {8401--8408},

publisher = {American Institute of Physics},

abstract = {Depolarized dynamic light scattering (DDLS) experiments are performed on the glass forming materials ortho terphenyl (OTP), bis-methyl-methoxy-phenyl-cyclohexane (BMMPC), and bis-methyl-phenyl-cyclohexane (BMPC). Depolarized spectra are obtained for the bulk liquids and for solutions of varying concentration in CCl4 . Effective optical anisotropies of the molecules are obtained from the solution spectra. A detailed analysis of the DDLS spectra, as well as a comparison with the results of quasielastic neutron scattering (QENS) experiments, indicates that the DDLS spectra in the bulk liquids result from at least two physical mechanisms: (i) The low frequency part of the spectrum, in the frequency range of the $alpha$ peak, arises mainly from the molecular reorientation mechanism. The integrated intensity of this contribution is proportional to the square of the effective molecular anisotropy. (ii) At higher frequencies (but still below the Boson peak), the predominant contribution to the DDLS spectrum arises from...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Aouadi1997,

title = {A light-scattering study of 1-4 cis - trans polybutadiene},

author = {A Aouadi and M J Lebon and C Dreyfus and B Strube and W Steffen and Adam Patkowski and R M Pick},

url = {http://stacks.iop.org/0953-8984/9/i=18/a=018?key=crossref.dff5bf1a2ee8339982daa7110313ce39},

doi = {10.1088/0953-8984/9/18/018},

issn = {0953-8984},

year  = {1997},

date = {1997-05-01},

journal = {Journal of Physics: Condensed Matter},

volume = {9},

number = {18},

pages = {3803--3820},

publisher = {IOP Publishing},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Thurn-Albrecht1996,

title = {Photon Correlation Spectroscopy of Colloidal Palladium Using a Coherent X-Ray Beam},

author = {T Thurn-Albrecht and W Steffen and Adam Patkowski and G Meier and E W Fischer and G Grubel and D L Abernathy},

url = {http://www.ncbi.nlm.nih.gov/pubmed/10062803 https://link.aps.org/doi/10.1103/PhysRevLett.77.5437},

doi = {10.1103/PhysRevLett.77.5437},

issn = {0031-9007},

year  = {1996},

date = {1996-12-01},

journal = {Physical Review Letters},

volume = {77},

number = {27},

pages = {5437--5440},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kanaya1995,

title = {Light-Scattering Studies of Short- and Long-Range Density and Anisotropy Fluctuations in a Bulk Polysiloxane},

author = {T Kanaya and Adam Patkowski and E W Fischer and J Seils and H Glaeser and K Kaji},

url = {http://pubs.acs.org/doi/abs/10.1021/ma00127a033 http://doi.wiley.com/10.1002/actp.1994.010450302},

doi = {10.1021/ma00127a033},

issn = {0024-9297},

year  = {1995},

date = {1995-11-01},

journal = {Macromolecules},

volume = {28},

number = {23},

pages = {7831--7836},

publisher = {American Chemical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Chu1995,

title = {An X-ray Photon Correlation Experiment},

author = {B Chu and Q -C Ying and F -J Yeh and Adam Patkowski and W Steffen and E W Fischer},

url = {http://pubs.acs.org/doi/abs/10.1021/la00005a001},

doi = {10.1021/la00005a001},

issn = {0743-7463},

year  = {1995},

date = {1995-05-01},

journal = {Langmuir},

volume = {11},

number = {5},

pages = {1419--1421},

publisher = {American Chemical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1994,

title = {Mode-coupling and phenomonological analysis of the depolarized light scattering spectra of ortho-terphenyl},

author = {Adam Patkowski and W Steffen and G Meier and E W Fischer},

url = {https://www.sciencedirect.com/science/article/pii/0022309394904162?via%3Dihub http://linkinghub.elsevier.com/retrieve/pii/0022309394904162},

doi = {10.1016/0022-3093(94)90416-2},

issn = {00223093},

year  = {1994},

date = {1994-09-01},

journal = {Journal of Non-Crystalline Solids},

volume = {172-174},

pages = {52--60},

publisher = {North-Holland},

abstract = {The depolarized dynamic light scattering spectra of ortho-terphenyl covering a broad frequency range from 10−2 to 6 × 1012 Hz have been analyzed using both the mode coupling theory (MCT) and the phenomenological approach. Similarities and differences of these two approaches as well as the frequency range and the quality of the fits to the experimental data are discussed. The main differences between these two models occur only in the intermediate frequency range (0.1–100 GHz) where either the MCT $beta$-relaxation with a scaling time diverging on both sides of Tc or a ‘fast' process of a constant relaxation time can be used to fit the data.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Steffen1994a,

title = {Depolarized light scattering studies of the boson peak and the transversal phonons in a glass-forming liquid: OTP},

author = {W Steffen and B Zimmer and Adam Patkowski and G Meier and E W Fischer},

url = {https://www.sciencedirect.com/science/article/pii/0022309394904146 http://linkinghub.elsevier.com/retrieve/pii/0022309394904146},

doi = {10.1016/0022-3093(94)90414-6},

issn = {00223093},

year  = {1994},

date = {1994-09-01},

journal = {Journal of Non-Crystalline Solids},

volume = {172-174},

pages = {37--42},

publisher = {North-Holland},

abstract = {A lineshape analysis of the Rayleigh wing of ortho-terphenyl obtained by low frequency Raman spectroscopy has been performed. The so-called boson peak was studied from 100 to 300 K, from far below to above the glass transition at Tg = 244 K. A model of disorder-induced scattering was used to interpret the features of the boson peak. A complementary measurement of the transversal phonons of OTP was done in the temperature range from 250 to 360 K. It was found that the shear waves are only present up to 320 K.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Seils1994,

title = {Static and Dynamic Light Scattering from Polystyrene/Poly(methyl methacrylate)/Bromobenzene: Temperature Effects},

author = {J Seils and M Benmouna and Adam Patkowski and E W Fischer},

url = {http://pubs.acs.org/doi/abs/10.1021/ma00096a029},

doi = {10.1021/ma00096a029},

issn = {0024-9297},

year  = {1994},

date = {1994-08-01},

journal = {Macromolecules},

volume = {27},

number = {18},

pages = {5043--5051},

publisher = {American Chemical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kanaya1994,

title = {Light scattering studies on long-range density fluctuations in a glass-forming polymer},

author = {T Kanaya and Adam Patkowski and E W Fischer and J Seils and H Glaeser and K Kaji},

url = {http://doi.wiley.com/10.1002/actp.1994.010450302},

doi = {10.1002/actp.1994.010450302},

issn = {03237648},

year  = {1994},

date = {1994-05-01},

journal = {Acta Polymerica},

volume = {45},

number = {3},

pages = {137--142},

publisher = {Akademie Verlag GmbH},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Steffen1994b,

title = {Depolarized-light-scattering study of orthoterphenyl and comparison with the mode-coupling model},

author = {W Steffen and Adam Patkowski and H Glaeser and G Meier and E W Fischer},

url = {https://link.aps.org/doi/10.1103/PhysRevE.49.2992},

doi = {10.1103/PhysRevE.49.2992},

issn = {1063-651X},

year  = {1994},

date = {1994-04-01},

journal = {Physical Review E},

volume = {49},

number = {4},

pages = {2992--3002},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Benmouna1993,

title = {Critical fluctuations in ternary polymer solutions},

author = {M Benmouna and J Seils and G Meier and Adam Patkowski and E W Fischer},

url = {http://pubs.acs.org/doi/abs/10.1021/ma00056a018},

doi = {10.1021/ma00056a018},

issn = {0024-9297},

year  = {1993},

date = {1993-07-01},

journal = {Macromolecules},

volume = {26},

number = {4},

pages = {668--678},

publisher = {American Chemical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Steffen1992,

title = {Depolarized dynamic light scattering studies of ortho‐terphenyl dynamics above T g},

author = {W Steffen and Adam Patkowski and G Meier and E W Fischer},

url = {http://aip.scitation.org/doi/10.1063/1.461873},

doi = {10.1063/1.461873},

issn = {0021-9606},

year  = {1992},

date = {1992-03-01},

journal = {The Journal of Chemical Physics},

volume = {96},

number = {6},

pages = {4171--4179},

publisher = {American Institute of Physics},

abstract = {Depolarized Rayleigh spectra of ortho‐terphenyl (OTP) were measured in the temperature range from Tg to Tg+190 K. Two samples prepared with and without ‘‘clusters'' were used for the measurement. Four different Fabry–Perot interferometers covering the time range from about 0.5 ps to 100 ns were employed. Two relaxation modes were observed: a slow mode with all its characteristics of the $alpha$ process, and a fast mode with a constant, temperature independent relaxation time of about 3 ps. The fast mode has not been reported heretofore. The intensity of the fast mode vanishes at about the Vogel–Fulcher–Tamman temperature T0. The relaxation times of these two processes are found to be identical for both OTP with and without clusters. The temperature dependence of the relaxation time of the $alpha$ process is Arrhenius at high temperatures, but shows a Williams–Landel–Ferry (WLF) behavior in the range from Tg to Tg+80 K for both samples with and without the long‐range density fluctuations (i.e., cluster).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kivelson1991,

title = {A possible molecular structural indicator of the liquid–glass transition},

author = {Daniel Kivelson and Werner Steffen and Gerhard Meier and Adam Patkowski},

url = {http://aip.scitation.org/doi/10.1063/1.460990},

doi = {10.1063/1.460990},

issn = {0021-9606},

year  = {1991},

date = {1991-08-01},

journal = {The Journal of Chemical Physics},

volume = {95},

number = {3},

pages = {1943--1949},

publisher = {American Institute of Physics},

abstract = {In studying the VH depolarized Rayleigh light‐scattering spectrum of orthoterphenyl we have separated an ‘‘intermediate'' line with almost temperature‐independent halfwidth of 50 GHz from both the narrower rotational line with strongly temperature‐dependent halfwidth and the broader base line associated with short‐range overlap interactions. The integrated intensity IVH of the intermediate line decreases by a factor of 25 as the temperature decreases over a range for which the viscosity increases by 11 orders of magnitude. It appears that the extrapolated value of (IVH/$rho$2)1/2 for this line vanishes as T→T0, where $rho$ is the density and T0 is the ideal liquid–glass transition temperature established by fitting a Vogel–Fulcher relation to the viscosity. We associate this intermediate line with dipole–induced‐dipole interactions; its intensity is then given by an equal‐time correlation function involving two‐, three‐, and four‐body interactions. Because dipole interactions are quite long range, this correlatio...},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fischer1991,

title = {Density fluctuations around the glass-transition of low molecular weight glass-forming liquids},

author = {E W Fischer and G Meier and T Rabenau and Adam Patkowski and W Steffen and W Thoennes},

url = {https://www.sciencedirect.com/science/article/pii/002230939190288H http://linkinghub.elsevier.com/retrieve/pii/002230939190288H},

doi = {10.1016/0022-3093(91)90288-H},

issn = {00223093},

year  = {1991},

date = {1991-06-01},

journal = {Journal of Non-Crystalline Solids},

volume = {131-133},

pages = {134--138},

publisher = {North-Holland},

abstract = {The Rayleigh-Brillouin spectra of ortho-terphenyl (OTP) samples with and without ‘clusters' were measured in the temperature range from Tg to Tg + 200 K. The values of the Landau-Placzek ratio for cluster-free OTP were low, in agreement with the theoretical predictions, while for OTP with clusters much higher values were obtained. The isotropic part of the Rayleigh intensity for OTP with clusters contained an additional angular-dependent component that could be reversibly reduced after annealing the samples at temperatures textgreater Tm. Rotational relaxation times of OTP samples with and without clusters were measured by means of depolarized Rayleigh spectroscopy. In addition to the usual rotational relaxation time, an additional fast component was found. The relaxation time of the fast process was practically constant in the entire temperature range amounting to 3 ps and the intensity decreased to zero around TO. The temperature dependence of the rotational relaxation time cannot be described by the Wohlrausch-Landel-Ferry formula over the entire relaxation time range from 4 × 10−11 to 10 s, but only down to 10−10 s.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1991,

title = {Conformation of muscle proteins: a laser light-scattering study},

author = {Adam Patkowski and Joachim Seils and Wolfgang Eimer and Thomas Dorfmuller},

url = {http://www.ncbi.nlm.nih.gov/pubmed/1653739 http://biochemsoctrans.org/lookup/doi/10.1042/bst0190507},

doi = {10.1042/bst0190507},

issn = {0300-5127},

year  = {1991},

date = {1991-04-01},

journal = {Biochemical Society Transactions},

volume = {19},

number = {2},

pages = {507--508},

publisher = {Portland Press Limited},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Floudas1990,

title = {Optical anisotropies of nematogens from the depolarized Rayleigh spectra},

author = {G Floudas and Adam Patkowski and George. Fytas and M Ballauff},

url = {http://pubs.acs.org/doi/abs/10.1021/j100370a085},

doi = {10.1021/j100370a085},

issn = {0022-3654},

year  = {1990},

date = {1990-04-01},

journal = {The Journal of Physical Chemistry},

volume = {94},

number = {7},

pages = {3215--3219},

publisher = {American Chemical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1990,

title = {The molecular dimensions of G-actin in solution as studied by dynamic light scattering},

author = {Adam Patkowski and W Eimer and J Seils and G Schneider and B M Jockusch and Th. Dorfmuller},

url = {http://doi.wiley.com/10.1002/bip.360301312},

doi = {10.1002/bip.360301312},

issn = {00063525},

year  = {1990},

date = {1990-01-01},

journal = {Biopolymers},

volume = {30},

number = {13-14},

pages = {1281--1287},

publisher = {Wiley Subscription Services, Inc., A Wiley Company},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1990a,

title = {Size and shape parameter of the actin-binding protein profilin in solution: A depolarized and polarized dynamic light scattering study},

author = {Adam Patkowski and J Seils and F Buß and B M Jockusch and Th. Dorfmuller},

url = {http://doi.wiley.com/10.1002/bip.360300123},

doi = {10.1002/bip.360300123},

issn = {00063525},

year  = {1990},

date = {1990-01-01},

journal = {Biopolymers},

volume = {30},

number = {1-2},

pages = {219--222},

publisher = {Wiley Subscription Services, Inc., A Wiley Company},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1990b,

title = {Size, shape parameters, and Ca 2+ -induced conformational change of the gelsolin molecule: A dynamic light scattering study},

author = {Adam Patkowski and J Seils and Th. Dorfmuller and H Hinssen},

url = {http://doi.wiley.com/10.1002/bip.360300320},

doi = {10.1002/bip.360300320},

issn = {00063525},

year  = {1990},

date = {1990-01-01},

journal = {Biopolymers},

volume = {30},

number = {3-4},

pages = {427--435},

publisher = {Wiley Subscription Services, Inc., A Wiley Company},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1990c,

title = {Internal dynamics of tRNA Phe studied by depolarized dynamic light scattering},

author = {Adam Patkowski and W Eimer and Th. Dorfmuller},

url = {http://www.ncbi.nlm.nih.gov/pubmed/2092826 http://doi.wiley.com/10.1002/bip.360300912},

doi = {10.1002/bip.360300912},

issn = {00063525},

year  = {1990},

date = {1990-01-01},

journal = {Biopolymers},

volume = {30},

number = {9-10},

pages = {975--983},

abstract = {The collective internal dynamics of transfer RNA(Phe) from brewer's yeast in solution was studied by depolarized dynamic light scattering (DDLS). Within the melting region of tRNA the depolarized spectra consist of two Lorentzian, where the narrow (slow) component describes the overall rotation of the macromolecule. The broad component is attributed to the collective reorientation of the bases within the biopolymer. At high temperature only this relaxation process is observed in the spectrum. The viscosity dependence of the collective internal relaxation process is described by the Stokes-Einstein-Debye equation for rotational diffusion. Estimates of the internal orientational pair correlation factor from the integral depolarized intensities of tRNA(Phe) solutions indicates that the observed dynamics correspond to the collective reorientation of approximately 5 bases. A comparison of the results presented with DDLS studies on the aggregation of the mononucleotide guanosine-5'-monophosphate confirms this result. For a further characterization of the relaxation process we studied the effect of hydrostatic pressure (1-1000 bar) on the depolarized spectra of tRNA. While other spectroscopic methods like nmr, fluorescence polarization anisotropy decay, or ESR give information about the very local motion of a single base within the DNA or RNA, this study shows that by DDLS one can characterize collective internal motions of macromolecules.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Patkowski1990d,

title = {A polarized and depolarized dynamic light scattering study of the tRNA phe conformation in solution},

author = {Adam Patkowski and W Eimer and Th. Dorfmuller},

url = {http://doi.wiley.com/10.1002/bip.360300111},

doi = {10.1002/bip.360300111},

issn = {00063525},

year  = {1990},

date = {1990-01-01},

journal = {Biopolymers},

volume = {30},

number = {1-2},

pages = {93--105},

publisher = {Wiley Subscription Services, Inc., A Wiley Company},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Fytas1988,

title = {Optical anisotropy of polysiloxanes in bulk and solution by depolarized Rayleigh scattering},

author = {G Fytas and Adam Patkowski and G Meier and E W Fischer},

url = {http://pubs.acs.org/doi/abs/10.1021/ma00189a020},

doi = {10.1021/ma00189a020},

issn = {0024-9297},

year  = {1988},

date = {1988-11-01},

journal = {Macromolecules},

volume = {21},

number = {11},

pages = {3250--3254},

publisher = {American Chemical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}