Author
Sylwester J. Rzoska
Other affiliations: University of Silesia in Katowice, Silesian University
Bio: Sylwester J. Rzoska is an academic researcher from Polish Academy of Sciences. The author has contributed to research in topics: Dielectric & Liquid crystal. The author has an hindex of 33, co-authored 216 publications receiving 3570 citations. Previous affiliations of Sylwester J. Rzoska include University of Silesia in Katowice & Silesian University.
Papers published on a yearly basis
Papers
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TL;DR: The results showed that HPP leads to preservation of adipokines, growth factor, and lactoferrin, IgG much better or comparable with HoP and resulted not statistically significant change of adiponectin level compare to raw milk.
Abstract: High-pressure processing (HPP) is a non-thermal technology that is being increasingly applied in food industries worldwide. It was proposed that this method could be used as an alternative to holder pasteurization (HoP; 62.5°C, 30 min) in milk banks but its impact on the immunologic, enzymatic and hormonal components of human milk has not yet been evaluated in detail. The aim of our study was to compare the effects of HPP in variants: (1) 600 MPa, 10 min (2) 100 MPa, 10 min, interval 10 min, 600 MPa, 10 min (3) 200 MPa, 10 min, interval 10 min, 400 MPa, 10 min (4) 200 MPa, 10 min, interval 10 min, 600 MPa, 10 min in temperature range 19-21°C and HoP on the leptin, adiponectin, insulin, hepatocyte growth factor (HGF), lactoferrin and IgG contents in human milk. HoP was done at the Regional Human Milk Bank in Warsaw at the Holy Family Hospital on S90 Eco pasteurizer (Sterifeed, Medicare Colgate Ltd). Apparatus U4000/65 (Unipress Equipment, Poland) was used for pascalization. Milk samples were obtained from women during 2-6 weeks of lactation. Post-treatment culture showed no endogenous bacterial contamination in any tested option. Concentrations of selected components were determined using ELISA tests. The level of all analyzed components were significantly decreased by HoP: leptin 77.86%, adiponectin 32.79%, insulin 32.40%, HGF 88.72%, lactoferrin 60.31@.%, IgG 49.04%. All HPP variants caused an increase in leptin concentration, respectively (1) 81.79% (2) 90.01% (3) 86.12% (4) 47.96%. Retention of insulin after HPP was (1) 88.20% (2) 81.98% (3) 94.76% (4) 90.31% HGF (1) 36.15% (2) 38.81% 97.15% (3) 97.15% (4) 43.02%, lactoferrin (1) 55.78% (2) 57.63% (3) 78.77% (4) 64.75%. Moreover, HPP variant as 200 + 400 MPa preserved IgG (82.24%) better than HoP and resulted not statistically significant change of adiponectin level (38.55%) compare to raw milk. Our results showed that HPP leads to preservation of adipokines, growth factor, and lactoferrin, IgG much better or comparable with HoP.
50 citations
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TL;DR: The densification of these glasses is found to occur at temperatures much below the glass transition temperature, indicating that a non-viscous mechanism is at play, and density relaxes in a stretched exponential manner upon subsequent annealing at ambient pressure with an exponent of ∼0.62.
Abstract: The mixed modifier effect (MME) in oxide glasses manifests itself as a non-additive variation in certain properties when one modifier oxide species is substituted by another one at constant total modifier content. However, the structural and topological origins of the MME are still under debate. This study provides new insights into the MME by investigating the effect of isostatic compression on density and hardness of mixed MgO/CaO sodium aluminosilicate glasses. This is done using a specially designed setup allowing isostatic compression of bulk glass samples up to 1 GPa at elevated temperature. A mixed alkaline earth effect is found in the compressibility and relative change of hardness, viz., a local maximum of density as a function of Mg/Ca ratio appears following compression, whereas a local minimum of hardness in the uncompressed glasses nearly disappears after compression. Moreover, the densification of these glasses is found to occur at temperatures much below the glass transition temperature, indicating that a non-viscous mechanism is at play. This is further supported by the fact that density relaxes in a stretched exponential manner upon subsequent annealing at ambient pressure with an exponent of ∼0.62. This is close to the Phillips value of 3/5 for relaxation in three dimensions when both short- and long-range interactions are activated.
50 citations
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TL;DR: The application of a modified Simon-Glatzel-type relation for the pressure evolution of the glass temperature is presented and the hypothetical maximum of the Tg(P) curve is suggested, which can be estimated due to the application of the supporting derivative-based analysis.
Abstract: The application of a modified Simon-Glatzel-type relation [Z. Anorg. Allg. Chem. 178, 309 (1929)] for the pressure evolution of the glass temperature is presented, namely, Tg(P)=Tg0[1+ΔP∕(π+Pg0)]1∕bexp[−(ΔP∕c)], where (Tg0,Pg0) are the reference temperature and pressure, ΔP=P−Pg0, −π is the negative pressure asymptote, b is the power exponent, and c is the damping pressure coefficient. The discussion is based on the experimental Tg(P) data for magmatic silicate melt albite, polymeric liquid crystal P8, and glycerol. The latter data are taken from Cook et al. [J. Chem. Phys. 100, 5178 (1994)] and from the authors’ dielectric relaxation time (τ(P)) measurements, which employs the novel pressure counterpart of the Vogel-Fulcher-Tammann equation: τ(P)=τ0Pexp[DPΔP∕(P0−P)], where ΔP=P−PSL (PSL is the stability limit hidden under negative pressure), P0 is the estimation of the ideal glass pressure, and DP is the isothermal fragility strength coefficient. Results obtained suggest the hypothetical maximum of the T...
50 citations
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TL;DR: In this article, the authors measured the high-pressure behavior of complex electric permittivity in supercooled glycerol and showed that the observed peaks of relaxation in absorption curves show increasing relaxation time with increasing pressure.
Abstract: Measurements of isothermal (), high-pressure behaviour (up to 270 MPa) of complex electric permittivity in supercooled glycerol are presented. The observed peaks of relaxation in absorption curves show increasing relaxation time with increasing pressure. The behaviour of can be reproduced by the pressure version of an Arrhenius relation or by a modified Vogel - Fulcher - Tammann equation. The data obtained can be superimposed by applying the scaling form used by Dixon et al 1990 Phys. Rev. Lett. 65 1108.
47 citations
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TL;DR: The derivative-based analysis for detecting regions of the validity of the Vogel-Fulcher-Tammann (VFT) dependence for superpressed and supercooled liquids is discussed and the relation between the derivative based behavior mentioned above and the apparent activation enthalpy (temperature path) or the apparentactivation volume (pressure path) is indicated.
Abstract: The derivative-based analysis for detecting regions of the validity of the Vogel-Fulcher-Tammann VFT dependence for superpressed and supercooled liquids is discussed. For the temperature T path the analysis introduced by Stickel et al. J. Chem. Phys. 104, 2043 1996; 107, 1086 1997 is recalled. For the pressure P path the derivation based on the counterpart of the VFT dependence proposed in Paluch et al. J. Phys.: Condens. Mater 10, 4131 1998 is presented. The appearance of two ideal glass temperatures T0 or pressures P0, fragility strength coefficients DT,DP, and prefactors 0 , 0 for VFT equations in following dynamical domains, i.e., high-temperature Thigh and low-temperature Tlow or low-pressure Plow and high-pressure Phigh, is stressed. It is noteworthy that the values of T0ThighT0Tlow,DTThigh DTTlow, and 0 Thigh0 Tlow. Analogous behavior was noted for isothermal PL and PH dynamic domains. A similar derivative-based approach is also applied to test the validity of the mode coupling
47 citations
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TL;DR: In this paper, the critical behavior of spin systems at equilibrium is studied in three and two dimensions, and the results in three-dimensional space are presented in particular for the six-loop perturbative series for the β -functions.
1,363 citations
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TL;DR: This work identifies the class of secondary relaxations that bears a strong connection or correlation to the primary relaxation in all the dynamic properties and proposes that only these should be called the Johari-Goldstein beta-relaxation.
Abstract: Dynamic properties, derived from dielectric relaxation spectra of glass-formers at variable temperature and pressure, are used to characterize and classify any resolved or unresolved secondary relaxation based on their different behaviors. The dynamic properties of the secondary relaxation used include: (1) the pressure and temperature dependences; (2) the separation between its relaxation time τβ and the primary relaxation time τα at any chosen τα; (3) whether τβ is approximately equal to the independent (primitive) relaxation time τ0 of the coupling model; (4) whether both τβ and τ0 have the same pressure and temperature dependences; (5) whether it is responsible for the “excess wing” of the primary relaxation observed in some glass-formers; (6) how the excess wing changes on aging, blending with another miscible glass-former, or increasing the molecular weight of the glass-former; (7) the change of temperature dependence of its dielectric strength Δeβ and τβ across the glass transition temperature Tg; ...
715 citations
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TL;DR: In this paper, a review of the mechanisms underlying the relaxation properties of glass-forming liquids and polymers is provided, with an emphasis in the insight provided into the mechanism underlying the glass relaxation properties.
Abstract: An intriguing problem in condensed matter physics is understanding the glass transition, in particular the dynamics in the equilibrium liquid close to vitrification Recent advances have been made by using hydrostatic pressure as an experimental variable These results are reviewed, with an emphasis in the insight provided into the mechanisms underlying the relaxation properties of glass-forming liquids and polymers
638 citations
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TL;DR: Although differential scanning calorimetry is the most widely used thermal analytical technique applied to the characterization of amorphous solid dispersions, there are many established and emerging techniques which have been shown to provide useful information.
399 citations