A rapid and accurate 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assay for quantification of bacteriocins with nisin as an example

The objective of this study is to propose a more accurate and faster MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] colorimetric assay (MCA) for quantitative measurement of polypeptide bacteriocins in solutions with nisin as an example. After an initial incubation of nisin and indicator bacterium Micrococcus luteus NCIB 8166 in tubes, MTT was added for another incubation period. After that, nisin was quantified by estimating the number of viable bacteria based on measuring the amount of purple formazan produced by cleavage of yellow tetrazolium salt MTT. Then MCA was compared to a standard agar diffusion assay (ADA). The results suggested a high correlation coefficient (r ²=0.975±0.004) between optical density (OD) and the inhibitory effect of nisin on a bacterial strain Micrococcus luteus NCIB 8166 at a range of 0.125~32 IU/ml. The MCA described in this study was very quick. Quantification of nisin took only 7~8 h and the detection limit was at the level of 0.125 IU/ml when compared to 12 IU/ml and 24~28 h for ADA. The MCA provides an accurate and rapid method for quantification of nisin in solutions and is expected to be used for quantification of other antimicrobial substances.     

对马克思主义三分法的再认识

长期以来,马克思主义被分解为哲学、政治经济学和科学社会主义三个组成部分。这种做法,既不符合马克思、恩格斯的本意,也不符合列宁的初衷,反而引发出了很多问题：三分法淡化了马克思主义的理论性质;容易使人对三个部分产生孤立片面的理解;妨碍了我国学科事业的发展。     

10-对硝基苯氧基癸酸合成工艺的改进

对10-对硝基苯氧基癸酸合成工艺进行了改进.以10-溴代癸酸为原料,与甲醇反应生成10-溴代癸酸甲酯,再与对硝基酚钠反应生成10-对硝基苯氧基癸酸甲酯,最后以固定化脂肪酶水解得到10-对硝基苯氧基癸酸.对中间体的折光率和紫外-可见光谱进行分析,并通过紫外-可见光谱1、H-NMR和13C-NMR以及酶分析应用对最终产物进行确证.结果表明,成功合成出目标化合物,总收率达到71.6%.     

陈骥《文则》的现代修辞观

陈骏的《文则》是中国历史上第一部谈及文法修辞的专著，其价值是多方面的，本文从陈骏创作实践中运用多种积极辞格阐述相关的修辞理论，以评价他的积极修辞观；《文则》“虽以事出创造，不无瑕疵”，但论及了语法、句法、辞格、文章、风格、文体等多方面内容，初步建立了大修辞学体系，体现了现代修辞学界所倡导的广义修辞观；陈骏虽是对《诗》《书》《礼》《易》《春秋》等静态书面语言的考察，但用动态的辩证的眼光提出了不少真知灼见，体现了动态的辩证的修辞观。     

移动通信系统安全机制发展的研究

从移动通信系统演进的角度介绍了安全机制的发展历程,分析研究了2G的安全性措施,阐述了3G认证签权方案及其优缺点,并对移动通信安全机制提出了一些见解。     

Amniotic membrane transplantation for porous sphere orbital implant exposure

Objective: This study is aimed at describing the clinical outcome of amniotic membrane transplantation for exposure of porous sphere implants. Methods: A retrospective review of consecutive cases of porous sphere orbital implant exposure was carried out. Eight cases were presented between May 2004 and Oct. 2006 (5 males, 3 females; mean age 44.5 years). Six had enucleation and two had evisceration. Exposure occurred in two primary and six secondary. Orbital implant diameter was 22 mm in seven cases and 20 mm in one case. Six patients are with hydroxyapatite and two with high-density porous polyethylene (Medpor) orbital implants. The mean time from implantation to exposure was 1.1 months (range 0.8~2 months). All patients required surgical intervention. Results: The time of follow-up ranged from 3.0 to 28.0 months (mean 16.5 months). Amniotic membrane grafting successfully closed the defect without re-exposure in all of these patients. The grafts were left bare with a mean time to conjunctiva of about 1 month (range 0.8~1.5 months). Conclusion: Exposed porous sphere implants were treated successfully with amniotic membrane graft in all of patients. The graft is easy to harvest. This technique is useful, dose not lead to prolonged socket inflammation and infection, and it is valuable application extensively.     

浅谈利用任务驱动法进行单片机教学与职业核心能力的培养

本文就任务驱动法在单片机教学中的应用与职业核心能力培养进行了阐述，并且以实例的形式得到了很好的验证。     

数字监控系统中有辨认价值的人面像

结合案例,从分辨率的角度对监控系统中人面像的可分辨程度进行了论述,并说明了数字监控系统中提取的人面像在公安工作中的利用价值。     

WEB站点结构优化仿真

WEB站点结构优化技术是解决WWW浏览中搜寻与获取有益信息的困难问题及信息搜寻行为的效率低下问题的有效方法。基于WEB站点的超链体系结构特征与网页节点的访问频度值特征,建立了一种站点结构优化的数学模型,其目标是使整个站点具有较小的平均访问代价。分析了站点超链体系结构特征与节点访问频度特征,采用仿真算法分别模拟了WEB站点的超链体系结构与页面节点的访问频度值,并通过量化新增超链接的影响因素设计了相应的站点结构优化方法。实验结果表明:优化后的站点结构具有较小的平均访问代价。     

陕西球迷从众行为分析与对策研究

运用文献资料、问卷调查、逻辑分析和数理统计等方法对陕西球迷的从众行为进行了调查,从群体因素、情景因素、个人因素等方面进行了分析,并提出建议与对策.