排序方式: 共有90条查询结果,搜索用时 15 毫秒
81.
Christoph J. Behrens Kateryna Zelena Ralf G. Berger 《Applied biochemistry and biotechnology》2016,179(8):1404-1417
Dye-decolorizing peroxidases (DyPs) from Auricularia auricula-judae, Bjerkandera adusta, Pleurotus ostreatus and Marasmius scorodonius (Basidiomycota) were expressed in Escherichia coli using the cold shock-inducible expression system pCOLD I DNA. Functional expression was achieved without the addition of hemin or the co-expression of any chaperones. The presence or absence of the native signal sequence had a strong impact on the success of the expression, but the effect was not consistent for the different DyPs. While BaDyP and AajDyP were stable at 50 °C, the more thermolabile MsP2 and PoDyp, upon catalytic intervention, lend themselves to more rapid thermal inactivation. The bleaching of norbixin (E 160b) using MsP2 was most efficient at pH 4.0, while BaDyP and AajDypP worked best in the weakly acidic to neutral range, indicating a choice of DyPs for a broad field of applications in different food matrices. 相似文献
82.
Kateryna Bazaka 《Polymer Degradation and Stability》2010,95(6):1123-2961
Owing to the structural flexibility, uncomplicated processing and manufacturing capabilities, plasma polymers are the subject of active academic as well as industrial research. Polymer thin films prepared from non-synthetic monomers combine desirable optical and physical properties with biocompatibility and environmental sustainability. However, the ultimate expediency and implementation of such materials will dependent on the stability of these properties under varied environmental conditions. Polyterpenol thin films were manufactured at different deposition powers. Under ambient conditions, the bulk of ageing occurred within first 150 h after deposition and was attributed to oxidation and volumetric relaxation. Films observed for further 12 months showed no significant changes in thickness or refractive index. Thermal degradation behaviour indicated thermal stability increased for the films manufactured at higher RF powers. Annealing the films to 405 °C resulted in full degradation, with retention between 0.29 and 0.99%, indicating films' potential as sacrificial material. 相似文献
83.
Potential Analysis - We consider parabolic equations of the form $$ u_{t}-\text{div} \left( |\nabla u|^{p-2}\nabla u+ a(x,t)|\nabla u|^{q-2}\nabla u\right)= 0, a(x,t)\geq 0. $$ In the range $\frac... 相似文献
84.
Viktor Yu. Kramarenko Tetyana A. Shantalil Iryna L. Karpova Kateryna S. Dragan Eleonora G. Privalko Valery P. Privalko Daniel Fragiadakis Polycarpos Pissis 《先进技术聚合物》2004,15(3):144-148
Polyimide (PI) nanocomposites prepared by the in situ generation of crosslinked organosilicon nanophase (ON) through the sol‐gel process were characterized by densities, thermally stimulated depolarization currents and dielectric relaxation spectroscopy. Both a looser molecular packing of PI chain fragments adjacent to the ON and a loose inner structure of the spatial aggregates of ON were assumed to be responsible for a non‐additive decrease of the experimental values of dielectric permittivity for the nanocomposites. The pattern of composition dependence of the apparent dielectric permittivity of the ON suggested a probability of a morphological change around the composition PAAS/MTS = 100/16 (presumably, a sort of percolation transition from small‐size, individual clusters into large‐size, infinite clusters). Thus, PI reinforced with the sol‐gel derived nanophase may have a reasonably good potential as low dielectric permittivity materials. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
85.
Andriy Kostruba Alexander Zaichenko Natalya Mitina Kateryna Rayevska Kateryna Hertsyk 《Central European Journal of Physics》2008,6(3):454-461
Functional oligoperoxide surfactants and coordinating oligoperoxide metal complexes were studied as modifiers of glass flat
plates to provide the localization of radical forming sites and other functional fragments in adsorbed polymeric layers of
a nanoscale thickness. Both the kinetics of the coating formation and properties of the nanolayers witness the dependence
of the packing density of oligoperoxide molecules in the coatings on the oligoperoxide natures, concentrations and conditions
of the sorption modification. The availability of definite amount of peroxide groups in formed nanolayer provides the possibility
of controlled radical graft polymerization initiated from modified surface leading to reliable surface protection, functionality
and targeted surface hydrophilic-hydrophobic properties.
相似文献
86.
Studies of Benzothiazole and Benzoselenazole Squaraines as Fluorescent Probes for Albumins Detection
Volkova KD Kovalska VB Losytskyy MY Bento A Reis LV Santos PF Almeida P Yarmoluk SM 《Journal of fluorescence》2008,18(5):877-882
Series of squaraine benzothiazole and benzoselenazole dyes were studied as possible fluorescent probes for the detection of
proteins, particularly albumins. It was shown that majority of the studied squaraines give significant fluorescent response
on the human serum albumin (HSA) and bovine serum albumin presence. For squaraine dyes with N-hexyl pendent groups (P-1, P-2, P-3, P-5) about 100−540-fold fluorescence intensity increase upon albumins addition was observed.
At the same time in presence of other proteins, namely insulin, avidin from hen egg white, immunoglobulin G (IgG), carbonic
anhydrase fluorescence enhancement values were considerably lower —up to 43 times in IgG presence. It was noted that generally,
squaraines with long N-hexyl pendent groups demonstrate higher emission increase values upon proteins addition comparing with their analogues with
short N-ethyl tails. It was shown that fluorescence intensity enhancement for benzothiazole squaraine dye P-3, relates linearly to
the HSA concentration over the wide range—from 0.2 to 500 μg/ml. Together with noticeable selectivity of this dye to albumins,
existence of wide dynamic range gives possibility to propose P-3 dye as probe for HSA quantification. 相似文献
87.
Kumar Avishek Al-Jumaili Ahmed Prasad Karthika Bazaka Kateryna Mulvey Peter Warner Jeffrey Jacob Mohan V. 《Plasma Chemistry and Plasma Processing》2020,40(1):339-355
Plasma Chemistry and Plasma Processing - Antifouling/antibacterial coating derived from a sustainable natural resource for biomedical devices have shown promising outcomes, especially in the... 相似文献
88.
Kateryna Vus Valeriya Trusova Galyna Gorbenko Rohit Sood Elena Kirilova Georgiy Kirilov Inta Kalnina Paavo Kinnunen 《Journal of fluorescence》2014,24(2):493-504
A series of novel fluorescent benzanthrone dyes have been tested for their ability to identify and characterize fibrillar aggregates of lysozyme prepared by protein denaturation in concentrated ethanol solution (Feth) or acidic buffer (Fac). Quantitative parameters of the dye association with native and fibrillar protein have been derived from the results of fluorimetric titration. The binding characteristics proved to be different for Feth- and Fac-bound benzanthrones, highlighting the dye sensitivity to the distinctions in fibril morphology. By comparing the dye preference to fibrillar protein aggregates, AM2, A8 and A6 were selected as the most prospective amyloid tracers. Based on the analysis of red edge excitation shifts and fluorescence lifetimes of the amyloid-bound dyes it was assumed that surface grooves or dry “steric zipper” interface are potential fibril binding sites for the novel fluorophores. 相似文献
89.
Volkova KD Kovalska VB Losytskyy MY Fal KO Derevyanko NO Slominskii YL Tolmachov OI Yarmoluk SM 《Journal of fluorescence》2011,21(2):775-784
In present paper series of trimethine cyanines modified in 5,5′- or 6,6′- position with hydroxy- or methoxy- substituents
is studied for their ability to interact selectively with fibrillar formations. Processes of dye aggregation that accompany
this interaction were also investigated. Meso-methyl trimethynecyanines with 5,5′- methoxy (7519) and hydroxy (7515) substituents
strongly (up to 40 times) increase fluorescence intensity in the presence of fibrillar insulin, and also give noticeable fluorescent
response on the presence of various aggregated proteins (lysozyme, β-lactoglobulin, α-synuclein A53T). 7519 and 7515 dyes
can be used for fluorometric detection of fibrillar insulin at concentrations of approximately 1.5–120 microg/ml. For meso-ethyl
substituted dye 7514 the ability to form H- and J-aggregates upon interaction with insulin fibrils was suggested. The model
of the H- and J-aggregate packing in the protein fibrillar structure has been proposed. 相似文献
90.
Johannes Steinreiber Kateryna Fesko Christoph Reisinger Herfried Griengl 《Tetrahedron》2007,63(34):8088-8093
The l- and d-threonine aldolase catalyzed formation of γ-halogenated and long-chain l- and d-3-alkylserine-derivatives 1-12, respectively, was shown starting from glycine and halogenated C2- or C4-C12 aldehydes. lTA from Pseudomonas putida accepted all tested aldehydes with strongly varying diastereoselectivity (de up to 93%). Only aldehydes smaller than decanal were converted by dTA from Alcaligenes xylosoxidans with good selectivities (de up to 73%). Utilizing isobutanal enantio- and diastereopure d-syn-2-amino-3-hydroxy-4-methylpentanoic acid was obtained (ee>99%, de>95%), which was converted to the corresponding 2-amino-1,3-diol. 相似文献