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91.
Synthesis of iminosugar-based affinity-based proteomics probes for use in probing exo-α-glycosidase activity. 相似文献
92.
The kinetics of CO(2) uptake by the cis-[Cr(C(2)O(4))(BaraNH(2))(OH(2))(2)]+ complex cation and the acid hydrolysis of the cis-[Cr(C(2)O(4))(BaraNH(2))OCO(2)]- complex anion (where BaraNH(2) denotes methyl 3-amino-2,3-dideoxy-b-D-arabino-hexopyranoside) were studied using the stopped-flow technique. The reactions under study were investigated in aqueous solution in the 288-308 K temperature range. In the case of the reaction between CO(2) and cis-[Cr(C(2)O(4))(BaraNH(2))(OH(2))(2)]+ cation variable pH values (6.82-8.91) and the constant ionic strength of solution (H+, Na+, ClO(4)- = 1.0) were used. Carbon dioxide was generated by the reaction between sodium pyruvate and hydrogen peroxide. The acid hydrolysis of cis-[Cr(C(2)O(4))(BaraNH(2))OCO(2)]- was investigated for varying concentrations of H+ ions (0.01-2.7 M). The obtained results enabled the determination of the number of steps of the studied reactions. Based on the kinetic equations, rate constants were determined for each step. Finally, mechanisms for both reactions were proposed and discussed. Based on the obtained results it was concluded that the carboxylation (CO(2) uptake) reactions of cis-[Cr(C(2)O(4))(BaraNH(2))(OH(2))(2)]+ and the decarboxylation (acid hydrolysis) of the cis-[Cr(C(2)O(4))(BaraNH(2))OCO(2)]- are the opposite of each other. 相似文献
93.
Tutueva Aleksandra V. Karimov Timur I. Moysis Lazaros Nepomuceno Erivelton G. Volos Christos Butusov Denis N. 《Nonlinear dynamics》2021,104(1):727-737
Nonlinear Dynamics - One of the widely-used ways in chaos-based cryptography to generate pseudo-random sequences is to use the least significant bits or digits of finite-precision numbers defined... 相似文献
94.
Agnieszka Jankowska Aleksandra Grześkiewicz Krystyna Wiśniewska Arnold Reps 《高压研究》2013,33(3):339-346
Natural yoghurt was subject to pressures of 200 and 250 MPa/4 and 18°C/15 min, after which milk-activated inocula of Lactobacillus acidophilus and Bifidobacterium sp. were added. The yoghurts were stored for 4 weeks at refrigeration temperature. After preparation and each week of storage, the count of bacteria, acidity, antibacterial property and an organoleptic assessment was determined. The highest survival rate was demonstrated by the bacteria of Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus and Bifidobacterium sp. in the yoghurt pressurised 200 MPa/15min at 4°C. Acidity increases in the control yoghurts were higher than in the pressurised ones. Pressurised yoghurts demonstrated weaker antibacterial effect in comparison to control yoghurts. Slight changes in the smell and taste were observed after pressurisation. Yoghurts pressurised at 18°C were characterised by more favourable organoleptic properties. Better conciseness of the curd and lower whey seep out were observed in pressurised yoghurt. 相似文献
95.
Nowadays many leading companies understand that creating outstanding customer value is necessary to achieving sustainable market success. The main problem discussed in this article is the examination of factors affecting perceived value, emphasizing the relationship between perceived price and perceived value. Based on literature and their own findings, the authors designed a model of relationships between researched factors. This model was tested using structural equation modeling. The results reflected that statistically significant relationships exists and that perceived price has direct as well as indirect efects on perceived product value. 相似文献
96.
Dagmara Jacewicz Aleksandra Dąbrowska Agnieszka Łapińska Lech Chmurzyński 《Transition Metal Chemistry》2006,31(5):575-579
The cis-[Cr(phen)2(O2CO)]+ ion was prepared through the displacement of two molecules of water from the cis-[Cr(phen)2(OH2)2]3+ by the bidentate carbonate anion. It underwent two-phase hydrolysis reactions under acidic conditions (0.1 < [H+] < 2.7 m) at 5, 10, 15, 20 and 25 °C. Via slow carbonato chelate ring opening (first step k1slow) and a second fast decarboxylation(k2fast value). The first step was preceded by protonation of the coordinate bidentate carbonate ligand. The second step exhibited
no pH dependence, while k1slow values increased with acid concentration that suggested the presence of both protonated and deprotonated reactant species.
Based on these observations we have proposed a hydrolysis mechanism featuring H2O-induced ring-opening of the coordinate CO32− group in the first step k1slow followed by loss of CO32− from two intermediates, [Cr(phen)2(O2COH)]2+ (k1slow) and [Cr(phen)2(OH2)(O2COH)]2+ (k2fast). 相似文献
97.
Discrete modulational instability within the first band of uniform one-dimensional waveguide arrays possessing a saturable self-defocusing nonlinearity is investigated in detail within the coupled mode approach. Explicit analytical results for both the threshold and the maximal gain of instability are compared with the corresponding data from waveguide arrays exhibiting Kerr nonlinearity. We find that saturation bounds the interval of existence of discrete modulational instability, stabilizes the frequency region of perturbations around ±π/2 and decreases both gain and critical spatial frequency of perturbations. 相似文献
98.
The kinetics of individual stages of thermal dissociation of basic aluminium potassium sulfate (BAPS) were studied thermogravimetrically under isobaric and isothermal conditions at a reduced pressure of the order of 10?3 hPa and in the atmosphere of gaseous products of the reaction (H2O, SO2).The kinetic parameters of all the reaction stages have been identified and the nature of the stages and the effect of changes of the reaction of conditions on the course of the processes have been determined. 相似文献
99.
100.
Frański R Klonowska-Wieszczyck K Borowiak-Resterna A Olszanowski A 《European journal of mass spectrometry (Chichester, England)》2006,12(5):311-316
The interactions of copper(II) with N-alkyl-pyridine-2-carboxamides (M) were studied by electrospray ionization mass spectrometry. The influence of solvent and counter ion (Cl-, ClO4-) on the type of ions (complexes) observed was discussed. By cone voltage increase, the fragmentation "in source" of the ions discussed was achieved. In methanol solution containing N-alkyl-pyridine-2-carboxamide (M) and CuCl2 the singly- and doubly charged-ions [M+CuCl]+ and [M2+Cu]+2 were detected. In acetonitrile solution containing N-alkyl-pyridine-2-carboxamide and CuCl2, the copper(I)-containing ions [M+CH3CN+Cu]+ were formed. The use of Cu(ClO4)2 instead of CuCl2 resulted in more abundant doubly-charged ions in both methanol and acetonitrlile solutions and, for the former solution, the ions containing methoxyl anion, namely [M+CuOCH3]+, were observed. When water was used as a solvent, the abundant ions corresponding to the protonated ligands were formed, while the ions corresponding to copper complexes were characterised by low abundances. 相似文献