A new study of the enzymatic hydrolysis of carboxymethyl cellulose with a bulk acoustic wave sensor

A new bulk acoustic wave (BAW) cellulase sensing technique, which is based on the enzymatic hydrolysis process of sodium carboxymethylcellulose (CMC) by cellulase, was established. The frequency shift curves of BAW sensor indicated that the viscosity of the tested solutions decreased during the hydrolysis process. The hydrolysis rate of CMC by cellulase was calculated from the frequency shift curves. The hydrolysis rate of CMC under different pH conditions at 30°C showed that cellulase had high hydrolysis ability approximately at pH 5.0. Kinetic parameters (the Michaelis constant K_m and the maximum rate V_max) of the process were estimated by using a linear method of Lineweaver–Burk plot. K_m is 1.95±0.25 mg ml⁻¹ and V_max is −(4.25±0.58)×10⁻³ g^1/2 cm^−3/2 cP^1/2 min⁻¹. Also the activation energy (E_a) of the enzymatic hydrolysis, with a value of 51.99±1.26 kJ mol⁻¹, was estimated in this work.     

The structure characteristics of photoproducts of indolinospirooxazines

Photochromic reactions of four indolinospirooxazine derivatives have been studied using nanosecond laser flash photolysis techniques. Photolysis of the four compounds in acetonitrile and in cyclohexane all leads to the formation of the short-lived CT intermediates as the predominant photoproducts. In certain circumstances few photomerocyanines (PMC) can be observed. From the absorption bands and the lifetimes of CT intermediates, it has been speculated that the substituents at the nitrogen atom of the indole ring influence the structural characteristics of CT intermediates mainly through steric hindrance effects, whereas the substituents at the 5 position of the indoline ring influence mainly through electron effects. A potential energy surface model is established to explain the results.     

On bandwidth sums of graphs

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Electropolymerized m-phenylenediamine as a means to immobilize active protein on thickness-shear-mode quartz crystal

Electropolymerized m-phenylenediamine was used as an active coating for immobilizing urease and lectin on a gold-plated thickness-shear-mode (TSM) crystal. To enhance effectiveness of immobilization. a bilayer polymer film composed of polyaniline and poly-m-phenylenediamine was proposed. Compared with single poly-m-phenylenediamine film, the bilayer polymer film gave better results in terms of immobilizing capacity, stability and reproductivity. On this bilayer-film-coated TSM quartz crystal, the amount of immobilized lectin was estimated about 1.8 mug/cm(2). Detection of purified human erythrocytes is demonstrated as an example of potential application of this lectin-modified TSM biosensor in clinic.     

含吲哚核端基多甲川菁染料的合成及性能

我们曾合成了具有桥环的硫三碳菁及多甲川苯乙烯菁,并测定了光学性能。本文报道吲哚环为端基的桥链三碳菁和四甲川苯乙烯菁的合成及在有机溶剂中电子吸收光谱及溶解性能的测定。所用仪器同前,7种多甲川菁染料的合成反应如下:     

Self-assembly of highly oriented one-dimensional h-WO3 nanostructures

A new self-assembled and highly oriented one-dimensional single-crystal nanostructure of WO3 with hexagonal form was successfully prepared by a mild, solution-based colloidal approach.     

ULTRASONICALLY DISPERSED POTASSIUM AS DEPROTONATING AND COUPLING AGENT──SYNTHESIS OF 1，6－DINITRILES IN SITU

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Mitochondria-targeted ratiometric fluorescent probes for micropolarity and microviscosity and their applications

Two fluorescent "off-on" probes YYH1 and YYH2 were used for bioimaging mitochondrial polarity and viscosity.