Solvents effects on crystallinity and dissolution of β-artemether*

β-artemether (ARM) is a widely used anti-malarial drug isolated from the Chinese antimalarial plant, Artemisia annua. The solvent effects on crystal habits and dissolution of ARM were thoroughly investigated and discussed herein. The ARM was recrystallized in nine different solvents of varied polarity, namely, methanol, ethanol, isopropanol, tetrahydrofuran, dichloromethane, trichloromethane, ethyl acetate, acetone and hexane by solvent evaporation method. The obtained crystals were morphologically characterized using scanning electron microscope (SEM). The average sizes of crystals were 1.80–2.64?μm calculated from microscopic images using Image-Pro software. No significant change in chemical structure was noticed after recrystallization and the specific band at 875?cm^?1 wavenumber (C–O–O–C) confirmed the presence of most sensitive functional group in the ARM chemical structure. The existence and production of two polymorphic forms, polymorph A and polymorph B, was confirmed by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). The data suggested that the fabrication of polymorph B can be simply obtained from the recrystallization of ARM in a specific solvent. Significant effects of solvent polarity, crystals shapes and sizes on drug dissolution were noticed during in vitro dissolution test. The release kinetics were calculated and well fitted by the Higuchi and Hixon–Crowell models. The ARM-methanol and ARM-hexane showed highest and slowest dissolution, respectively, due to the effects of solvent polarity and crystal morphologies. Overall, proper selection of the solvents for the final crystallization of ARM helps to optimize dissolution and bioavailability for a better delivery of anti-malarial drug.     

Vibrio sp.LX菌的分离及性质研究

ＬＸ菌是从土壤中分离出的一株革兰氏阴性菌,该菌兼性厌氧生长,单极生鞭毛,氧化酶阴性,经鉴定该菌属Ｖｉｂｒｉｏ属中的一个种。ＬＸ菌既能降解纤维素,又能降解琼脂,所产ＣＭＣ糖化酶为诱导酶。该菌的最适生长温度为３０℃,最适生长ｐＨ为７．０￣８．５。     

矢量场图计算机辅助绘制

提出并详细阐明了一种新的计算机辅助绘制场图的方法．该方法能用彩色图形在同一图上描绘出场矢量的大小、方向和轨迹．并通过实例验证了该方法的正确性及其软件的实用性．     

Moodle在高职辅助教学中的应用探究

基于Moodle完整的实际应用流程,探讨了Moodle平台的建立与使用,对一些设置细节工作做了说明;着重探究了Moodle平台下网络课程(以高职的计算机网络技术基础课程为例)的设计及应用,并结合两年的高职辅助教学实践,对Moodle的使用体会做了较为详细的介绍。     

变色栓菌来源漆酶的酶学性质及对染料脱色性能的研究

漆酶是一种含铜的多酚氧化酶,能催化多种酚类化合物和芳香族胺氧化,在食品、造纸、能源、高分子化合物合成等领域有着广阔的应用前景。近年对于漆酶的开发利用逐渐受到重视,作者在变色栓菌摇瓶发酵过程中,通过加入法尼醇诱导调控菌丝形态以提高漆酶产量,结果表明,变色栓菌发酵获得的漆酶酶活力和蛋白质质量浓度分别达到（161.37±1.58） U/L和（29.19±1.30） mg/L,均比对照组提高了10倍以上,其最适反应温度为40℃,最适pH为4.0,且在25～55℃有较好的热稳定性。进一步在酶促反应动力学研究基础上,发现漆酶对伊文思蓝、铬黑T、刚果红3种染料均有一定的脱色效果,其中对伊文思蓝的脱色能力最强,具有较好的应用潜力。     

让现代教育技术为课堂增辉

随着计算机信息技术普及程度的提高,应用现代教育技术教学己成为教师改革教学方法、改进教学手段、改善教材形式和重新整合教学内容及结构的重要途径。掌握现代教育技术,组织形式多样的教学方式,是21世纪教师办公自动化的具体体现,也是现代教育教学发展的方向。文中重点阐述了制作多媒体课件遵循的一般原则,制作多媒体课件时应考虑和注意的问题及课件制作中的需掌握的一些准则,期望现代教育技术在高职教育教学改革中发挥其作用,在教学中实现新的飞跃。     

基于Fluent的UV杀菌器结构设计和仿真

随着紫外线(Ultraviolet,简称UV)杀菌技术在船舶压载水处理方面的应用日趋成熟,对UV杀菌器的结构设计要求越来越高,其设计核心就是确定UV照射剂量。根据杀灭不同微生物所需UV剂量大小确定杀菌器辐照剂量,应用经验公式进行UV杀菌器结构设计,对流场进行了仿真。根据仿真结果的不足,提出在进出口加一旋向相反的导流叶片,对改进后的杀菌器的流场进行再仿真。最后,对两次的结果进行比对,并统计了二者的过流时间,得出在优化后,流速分布变得均匀,从而保证了杀菌效果,说明该优化结构是可行的。     

Rheological properties and permeability of soy protein-stabilised emulsion gels made by acidification with glucono-δ-lactone

BACKGROUND: Soy protein, an important efficient emulsifier, is widely used by the food industry for incorporation into milk, yogurts, ice cream, salad dressings, dessert products, etc. The objective of this study was to investigate the rheological and physical properties of soy protein‐stabilised emulsion gels as affected by protein concentration and gelation temperature. RESULTS: The rheological properties and permeability were determined using oscillatory rheometry, permeability and whey separation. The modulus (G′ and G″), fracture stress and fracture strain of acid‐induced emulsion gels after 20 h of glucono‐δ‐lactone addition depended strongly on soy protein concentration and gelation temperature. At increasing soy protein concentrations, acid‐induced emulsion gels had shorter gelation times but higher storage moduli (G′), fracture stresses and strains. Increasing gelation temperature decreased the gelation time, G′, fracture stresses and strains. Permeability and whey separation were significantly affected by the protein concentration and the gelation temperature. A significant positive correlation was observed between whey separation and permeability coefficient in emulsion gels formed at different temperatures. CONCLUSION: The rheological properties and permeability of soy protein‐stabilised emulsion gels were significantly influenced by protein concentration and gelation temperature. Copyright © 2011 Society of Chemical Industry     

洪海沟铀矿床Ⅶ旋回水化学条件与铀源分析

本文主要以洪海沟铀矿床Ⅶ旋回为研究对象,通过对其水化学条件、铀源对铀矿床成因影响的深入分析,总结了此类铀矿的区域成矿规律.本文认为洪海沟铀矿床Ⅶ旋回砂体中的铀元素大部分是在含矿建造形成完整的补-径-排体系之后,由含氧水从矿床南部山区淋滤并携带进入Ⅶ旋回砂体中.研究区目的 含水层砂体厚度适中,隔水层连续、稳定,与上下含矿...     

Synthesis,structure, and properties of dinuclear copper (II) complex with a (H2O)12 cluster

A novel pyrazole complex, namely [Cu₂(4,4′-bpy)₂(2,2′-bpy)(L)₂]·6H₂O has been synthesized under mild condition (4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine). We report the structural evidence in the solid state of discrete water hexamers chair-like conformation. These units were found to act as supramolecular glue in the aggregation of dinuclear copper (II) complex to give a three dimensional network through hydrogen-bonding. The preliminary investigation on the electrochemical property and fluorescence property of the complex are presented.