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291.
Prnová Anna Valúchová Jana Mutlu Nurshen Parchovianský Milan Klement Róbert Plško Alfonz Galusek Dušan 《Journal of Thermal Analysis and Calorimetry》2020,142(1):129-138
Journal of Thermal Analysis and Calorimetry - Yttrium aluminate glasses (76.8 mol% of Al2O3, 23.2 mol% of Y2O3) doped with Er3+ and Nd3+ ions at different concentration levels... 相似文献
292.
Emily P. Bentley Benjamin B. Frey Ashok A. Deniz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(22):5600-5610
Compartmentalization of biochemical processes is essential for cell function. Although membrane-bound organelles are well studied in this context, recent work has shown that phase separation is a key contributor to cellular compartmentalization through the formation of liquid-like membraneless organelles (MLOs). In this Minireview, the key mechanistic concepts that underlie MLO dynamics and function are first briefly discussed, including the relevant noncovalent interaction chemistry and polymer physical chemistry. Next, a few examples of MLOs and relevant proteins are given, along with their functions, which highlight the relevance of the above concepts. The developing area of active matter and non-equilibrium systems, which can give rise to unexpected effects in fluctuating cellular conditions, are also discussed. Finally, our thoughts for emerging and future directions in the field are discussed, including in vitro and in vivo studies of MLO physical chemistry and function. 相似文献
293.
Ayşe Aytaç Veli Deniz Murat Şen El-Sayed Hegazy Olgun Güven 《Radiation Physics and Chemistry》2010,79(3):297-300
The effects of gamma and e-beam irradiation on mechanical and structural properties of nylon 66 (Ny 66), nylon 6 (Ny 6) and poly(ethylene terephthalate) (PET) fabrics used in tyres were investigated. The untreated (greige), treated cords and calendered fabrics were irradiated at different doses. It is found that the effects of high energy irradiation on greige, treated cords and calendered fabrics are similar. No protective effect of compounds used in calendering was observed against radiation-induced oxidative degradation. The deterioration effect of gamma irradiation on mechanical properties is much higher than that of e-beam irradiation for all types of samples. Limiting viscosity numbers of both gamma and e-beam irradiated nylon 6 and nylon 66 cords were found to decrease with increasing dose. It is concluded that PET calendered fabric has higher resistance to ionizing radiation. Ny 6 and Ny 66 calendered fabrics are more sensitive even at low doses. Therefore, the effects of high energy irradiation on tyre cords have to be taken into consideration during tyre design reinforced with particularly Ny fabrics if pre-vulcanization with high energy radiation is to be applied. 相似文献
294.
An alternative electrochemical method for the determination of proteolytic activity based on cyclic voltammetry of the electroactive probe ferricyanide (Fe(CN)63?) on the gelatin film coated ITO electrodes was proposed. The gelatin film behaves as a kinetic barrier for Fe(CN)63? and the proteolytic digestion of the gelatin film results an increase in the penetration of the Fe(CN)63?. Thus, by the change of peak potential in cyclic voltammogram of Fe(CN)63?, activity of the enzyme was determined. 相似文献
295.
Inci Durucasu Kiymet Mutlu Levent Sik Ihsan Yasa Nazli Arda Suheyla Kirmizigul 《Chemistry of Natural Compounds》2009,45(6):782-785
The apolar constituents of four Dianthus (Caryophyllaceae) species were determined by GC-MS. Palmitic, linoleic, and oleic acids were detected as dominant components
in all species. D. elegans d’Urv. var. elegans had the highest antioxidant activity. All four species also showed considerable antimicrobial activity against S. epidermidis and C. albicans. 相似文献
296.
Mutlu Sönmez Çelebi 《Talanta》2009,78(2):405-409
A new surface based on poly(vinylferrocenium) (PVF+)-modified platinum electrode was developed for determination of Hg2+ ions in aqueous solutions. The polymer was electrodeposited on platinum electrode by constant potential electrolysis as PVF+ClO4−. Cl− ions were then attached to the polymer matrix by anion exchange and the modified electrode was dipped into Hg2+ solution. Hg2+ was preconcentrated at the polymer matrix by adsorption and also complexation reaction with Cl−. Detection of Hg2+ was carried out by differential pulse anodic stripping voltammetry (DPASV) after reduction of Hg2+. Mercury ions as low as 5 × 10−10 M could be detected with the prepared electrode and the relative standard deviation was calculated as 6.35% at 1 × 10−6 M concentration (n = 6). Interferences of Ag+, Pb2+ and Fe3+ ions were also studied at two different concentration ratios with respect to Hg2+. The developed electrode was applied to the determination of Hg2+ in water samples. 相似文献
297.
Deniz Akta Uygun Murat Uygun Alev Karagzler Nevra
ztürk Sinan Akgl Adil Denizli 《Colloids and surfaces. B, Biointerfaces》2009,70(2):266-270
Linoleic acid attached chitosan beads [poly(LA-Ch)] (1.25 μm in diameter) are obtained by the formation of amide linkages between linoleic acid and chitosan. Poly(LA-Ch) beads are characterized by FTIR, TEM, and swelling studies. Poly(LA-Ch) beads are used for the purification of immunoglobulin-G (IgG) from human plasma in a batch system. The maximum IgG adsorption is observed at pH 7.0 for HEPES buffer. IgG adsorption onto the plain chitosan beads is found to be negligible. Adsorption values up to 136.7 mg/g from aqueous solutions are obtained by poly(LA-Ch) beads. IgG adsorption saw an increase as a result of increasing temperature. Higher amounts of IgG are adsorbed from human plasma (up to 390 mg/g) with a purity of 92%. The adsorption phenomena appeared to follow a typical Langmuir isotherm. It is observed that IgG could be repeatedly adsorbed and desorbed without significant loss when we take into account the adsorption amount. It is concluded that the poly(LA-Ch) beads allowed one-step purification of IgG from human plasma. 相似文献
298.
In the effective mass approximation, we calculated the binding energy and wave function for the 1s-, 1p-, 1d- and 1f-states of a spherical quantum dot (QD) with parabolic potential by using a combination of quantum genetic algorithm (QGA) and Hartree-Fock-Roothaan (HFR) method. In addition, we also investigated the linear and the third-order nonlinear optical absorption coefficients as a function of the incident photon energy for the 1s-1p, 1p-1d and 1d-1f transitions. Our results are shown that the existence of impurity has great influence on optical absorption coefficients. Moreover, the optical absorption coefficients are strongly affected by the incident optical intensity, relaxation time, parabolic potential and dot radius. 相似文献
299.
Structural bifurcation of divergence-free vector fields near non-simple degenerate points with symmetry 下载免费PDF全文
In this study, topological features of an incompressible two-dimensional flow far from any boundaries is considered. A rigorous theory has been developed for degenerate streamline patterns and their bifurcation. The homotopy invariance of the index is used to simplify the differential equations of fluid flows which are parameter families of divergence-free vector fields. When the degenerate flow pattern is perturbed slightly, a structural bifurcation for flows with symmetry is obtained. We give possible flow structures near a bifurcation point. A flow pattern is found where a degenerate cusp point appears on the x-axis. Moreover, we also show that bifurcation of the flow structure near a non-simple degenerate critical point with double symmetry is generic away from boundaries. Finally, we give an application of the degenerate flow patterns emerging when index 0 and -2 in a double lid driven cavity and in two dimensional peristaltic flow. 相似文献
300.