An overview of the legislation and light microscopy for detection of processed animal proteins in feeds

From the first cases of bovine spongiform encephalopathy (BSE) among cattle in the United Kingdom in 1986, the route of infection of BSE is generally believed by means of feeds containing low level of processed animal proteins (PAPs). Therefore, many feed bans and alternative and complementary techniques were resulted for the BSE safeguards in the world. Now the feed bans are expected to develop into a "species to species" ban, which requires the corresponding species-specific identification methods. Currently, banned PAPs can be detected by various methods as light microscopy, polymerase chain reaction, enzyme-linked immunosorbent assay, near infrared spectroscopy, and near infrared microscopy. Light microscopy as described in the recent Commission Regulation EC/152/2009 is the only official method for the detection and characterization of PAPs in feed in the European Union. It is able to detect the presence of constituents of animal origin in feed at the level of 1 g/kg with hardly any false negative. Nevertheless, light microscopy has the limitation of lack of species specificity. This article presents a review of legislations on the use of PAPs in feedstuff, the detection details of animal proteins by light microscopy, and also presents and discusses the analysis procedure and expected development of the technique.     

对氨基苯酚生产工艺分析

介绍了合成对氨基苯酚的主要工艺路线,并对工艺的优缺点作了分析说明。     

产品设计中PAP评价体系的构建

阐明了产品设计中对消费者心理进行合理分析的必要性,提出产品心理属性(PAP)评价体系的概念,并对其进行了横向和纵向两个角度的研究,通过需求分析、评价体系框架图、数值分析计算和权重的比较,建立起横纵相关的三维评价体系框架,完善了产品心理属性(PAP)评价体系.     

磁性纳米粒子的制备及环糊精葡萄糖基转移酶的固定化

为实现木瓜蛋白酶（Papain,PAP）的高效固定化,本文构建了易于磁分离的亲水性三维立体结构的固定化载体,采用单因素和响应面法优化了固定条件。在磁性Fe₃O₄表面包覆聚甲基丙烯酸甲酯（PMMA）制备核-壳结构的纳米磁球Fe₃O₄@PMMA,接枝不同分子量聚乙烯亚胺（Polyethyleneimide,PEI）,将PAP物理吸附在PEI上,以戊二醛（Glutaraldehyde,GA）为交联剂,构筑易于磁分离的亲水性三维立体结构的固定化载体Fe₃O₄@PMMA-PEI,对PAP交联封装并对其微观结构和理化性质进行表征。以纳米磁球的固定化能力为评价指标,探究其固定PAP的最佳交联时间、戊二醛浓度、交联温度、交联转速等。结果表明,磁球表面PMMA酯解后形成的羧基含量为0.95 mmol/g,接枝不同分子量PEI后,磁球表面氨基含量为0.16~0.48 mmol/g;纳米磁球对PAP的固载量可通过接枝PEI的分子量进行调控,当PEI分子量为1800时,固载量达到120.71 mg/g,选择PEI 1800为接枝空间臂。纳米磁球微观形貌较规整,单体分散性良好,粒径约150~200 nm。通过响应面试验优化得到最佳条件：当交联时间为32 min、戊二醛浓度为0.02%、交联温度为25 ℃、交联转速为90 r/min时,Fe₃O₄@PMMA-PEI 1800对PAP的固载量达139.80 mg/g。Fe₃O₄@PMMA-PEI 1800-PAP在重复使用5次之后,相对酶活力能保持80.35%。本研究设计合成纳米结构的磁性微球,实现PAP在纳米磁球表面的高效固定,为固定化PAP的研究和应用提供实验依据。

     

硝基苯加氢制对氨基苯酚的工业化研究

本文详细介绍了硝基苯催化加氢生产对氨基苯酚的工业化路线,同时对此工艺生产PAP的前景作了分析,确定此工艺进行工业化生产是可以实现的。     

DYNAMIC BANDWIDTH ALLOCATION IN AN ATM MULTIPLEXER WITH MULTICLASS TRAFFIC AND ITS PERFORMANCE ANALYSIS

This paper introduces two source models: MAP(Markovian arrival process) model for the traffic with correlation and burst, e.g., voice, video, etc. and PAP(Poisson arrival process) model for the traffic with non-correlation, such as data, etc. Then a movable boundary bandwidth access policy is chosen.Basing on above model, the performance measures, e.g., mean waiting time and loss probability,especially the queue length time distribution are obtained. Finally, a number of numerical results are provided and shown through simulation.     

美洲商陆细胞株系的选择和蛋白质产生情况比较

美洲商陆抗病毒蛋白（ＰＡＰ）是由多基因转译的，在不同细胞株系中这些基因的表达情况有所区别，在商陆愈伤组织培养中分离获得数株色泽有区别的株系，分析其过氧化物同工酶酶谱表明，这些株系在遗传上有区别。同时，这些株系在生长速度，总蛋白质含量、蛋白质组成及部分区域的蛋白质比例上存在较大的差别，其中白色株系具有较明显的优点，对其培养条件进行优化又使总蛋白质含量提高７０％，从而用于进一步的研究。     

产品设计中的PAP评价体系的构建

通过对现代社会和消费者心理的分析,阐明了产品设计中心理属性评价的必要性。提出产品心理属性(PAP)评价体系的概念,并初步建立了评价体系框架。     

硫酸+水+PAP体系密度的测定及关联

对氨基苯酚(PAP)是一种重要的有机精细化工中间体,其用途广泛,主要应用于医药。染料和显影剂等的生产。测定不同浓度的硫酸+水+PAP体系在293.15~343.15 K温度下的密度和粘度数据,并将密度数据分别与温度和浓度进行关联,可为工程设计和相关研究提供参考依据。