Ring-opening polymerization of epsilon-caprolactone and L-lactide using organic amino calcium catalyst

Poly (6-caprolactone) (PCL) and poly (L-lactide) (PLA) were prepared by ring-opening Polymerization catalyzed by organic amino calcium catalysts (Ca/PO and Ca/EO) which were prepared by reacting calcium ammoniate Ca(NH3)(6) with propylene oxide and ethylene oxide, respectively. The catalysts exhibited high activity and the ring-opening polymerization behaved a quasi-living characteristic. Based on the Fr-IR spectra and the calcium contents of the catalysts, and based on the H-1 NMR end-group analysis of the low molecular weight PCL prepared using catalysts Ca/PO and Ca/EO, it was proposed that the catalysts have the structure of NH2-Ca-O-CH(CH3)(2) and NH2-CaO-CH2CH3 for Ca/PO and Ca/EO, respectively. The ring-opening polymerization of CL and LA follows a coordination-insertion mechanism and the active site is the Ca-O bond.

Fluorescence analysis of phospholipase A(2) isolated from Chinese agkistrodon blomhoffii Ussurensis venom

The general and synchronous spectra of phospholipase A(2) (PLA(2)) isolated from Chinese agkistrodon blomhoffii Ussurensis snake venom were studied. The chromophores of PLA(2) were mainly contributed by tyrosine and tryptophane residues when the intervals between the excitation wavelength and the emssion waveleagth (Delta lambda) were 20nm and 75nm, respectively. The pH of buffers could change the fluorescence intensities of PLA(2) by changing the charge distribution of its amino acid chain. Ca2+ can not only increase the emission fluorescence intensity of PLA(2) but also improve the reaction rate of PLA(2) with its corresponding substrate DPPC.

不同结构聚酯的体外生物降解

目的 :观察自行合成的聚己内脂 (PCL)、聚丙交酯 (PLA)及其不同比例的共聚物己内酯 /丙交酯共聚物a(PCLA2 /1)、己内酯 /丙交酯共聚物b(PCLA1/2 )在体外模拟的不同生物环境中的降解性质 ,探讨环境及材料结构与生物降解性质的关系 ,为在不同生物环境下选用适宜的生物降解材料提供实验依据。方法 :4种聚合物在血浆、胆汁、胰腺悬液中降解 1～ 7d ,观察材料的物理性状改变、测量质量损失和分子量变化。结果 :在不同生物降解液中 :PCL降解不明显、PLA降解最明显 ,PCLA2 /1和PCLA1/2在不同环境中降解规律不同。结论 :用不同比例单体共聚的方法获得了不同结构的生物材料 ,它们在不同环境中降解性质不同。

The application of matrix-assisted laser desorption jonization mass spectrometry in enzymes of Agkistrodon blomhoffii Ussurensis venom analysis

The matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS) spectra of four enzymes (PLA, AEase, Fibrolase, L-a.a. oxidase) in Agkistrodon blomhoffii Ussurensis venom, were given and interpreted. The experiment data showed that MALDI-TOF-MS can be used directly in enzyme analysis with high sensitivity and rapidity. In addition, the results were better than those from sodium dodecyl sulfate-polyacrylamide.

人工合成生物降解可吸收材料细胞免疫学及致突变实验研究

目的：探讨骨科生物降解材料，聚己内酯（PCL）及其与聚乳酸（PLA）的共聚物的生物相容性。方法：采用细胞免疫学方法，观察材料对小鼠淋巴细胞转化功能及NK细胞活性的影响；采用小鼠体内微核试验观察四种不同生物降解材料对染色体的影响。结果：四种不同生物材料在不同时间对小鼠淋巴细胞转化功能及NK细胞活性的影响，与对照组无明显差异，微核实验致突变阴性。结论：本材料有良好的组织相容性，与国外同类产品对比，无明显差异。

Partial characterization of the hemolytic activity of the nematocyst venom from the jellyfish Cyanea nozakii Kishinouye

Using a recently developed technique to extract jellyfish venom from nematocysts, the present study investigated the hemolytic activity of Cyanea nozakii Kishinouye nematocyst venom on chicken erythrocytes. Venom extract caused a significant concentration-dependent hemolytic effect. The extract could retain its activity at -80 degrees C but was unstable when kept at 4 degrees C and -20 degrees C for 2 days. The hemolytic activity was inhibited by heating within the range of 37-100 degrees C. The extract was active over a pH range of 5.0-8.63 and the pH optima for the extract was 7.8. Incubation of the venom with sphingomyelin specially inhibited hemolytic activity by up to 70%. Cu2+ and Mn2+ greatly reduced the hemolytic activity while Mg2+, Sr2+ and Ba2+ produced a relatively low inhibiting effect on the hemolytic activity. Treatment with Ca2+ induced a concentration-dependent increase in the hemolytic activity. In the presence of 5 mM EDTA, all the hemolytic activity was lost, however, the venom containing 1.5 mM EDTA was stable in the long-term storage. PLA(2) activity was also found in the nematocyst venom of C. nozakii. These characteristics provide us a fundamental knowledge in the C. nozakii nematocyst venom which would benefit future research. (C) 2010 Published by Elsevier Ltd.

机器人多传感器实验平台中的图像传感器在线标定研究

本文结合智能机器人多传感器实验平台的研制工作,系统地介绍了图像传感器在线标定的原理和方法,并对标定系统的构成做了概述,同时结合实验对相关问题进行进一步的探讨。