Inhibiting effect of polymerization and degradation of myosin heavy chain during preheating at 30°C and 50°C on the gel-forming ability of walleye pollack surimi

ABSTRACT: To confirm the contribution of polymerization and degradation of myosin heavy chain (MHC) during preheating to the gel-forming ability of fish meat paste, walleye pollack surimi paste was preheated at 30°C and 50°C prior to heating at 80°C in the presence of various inhibitors. At 30°C, ethyleneglycol bis(2-aminoethyl ether) -N,N,N ', N '-tetraacetic acid (EGTA) and ethylenediaminetetraacitic acid (EDTA) inhibited gel formation as well as the polymerization of MHC, whereas dithiothreitol (DTT) and leupeptin promoted gel formation, which was accompanied by the enhancement of MHC polymerization and decreased MHC degradation, respectively. At 50°C, leupeptin inhibited MHC degradation and improved gel strength, whereas EGTA, EDTA and DTT had no effect on MHC polymerization and degradation and did not affect gel formation. The results demonstrate that the gel strength of cooked gel (80°C) is not affected by preheating at 30°C and 50°C and does not inhibit polymerization and degradation. Results suggest that the gel strength of cooked gel is dependent on the polymerization and degradation of MHC during preheating.     

机械制造中降低零件废品率的处理方法探讨

对机械制造中由于工件的测量误差及工艺尺寸的换算而引起的误收和误废进行了分析，做出正确的判断并采取相应的措施进行处理。从而达到零件制造中不致误收废品及误废合格品的目的，以提高零件制造的质量。     

基于CSMA/CD/RR协议的有限缓存排队系统性能分析

提出了一种具有动态分配重传策略的CSMA/CD协议，并利用二维马尔可夫链分析了有限缓冲CSMA/CD/RR协议的性能特性，仿真实验表明，与CSMA/CD协议相比，CSMA/CD/RR协议很好地解决了高负载时的拥塞问题。     

传染性法氏囊病病毒浙江分离株(ZJ2000)基因组A节段全长cDNA的克隆和序列分析

以传染性法氏囊病病毒（IBDV）浙江分离株（ZJ2000）基因组RNA为模板，采用Long-accurate RT-PCR(LA-PCR)一步法扩增并克隆了IBDV ZJ2000株基因组A节段全长cDNA。序列测定结果表明，克隆的A节段全长共3259个核苷酸，包括5'、3'端的非编码区（NCRs）和2个部分重叠的开放阅读框（ORF1和ORF2），与参比的血清1型毒株核苷酸序列的同源性高达95．2％－99．2％。二级结构预测表明，在5'-NCRs存在1个大型的茎环发夹结构。ORF2编码145个氨基酸的VP5，与参比毒株的同源性高达98．6％－100％。ORF1编码1012个氨基酸的VP2／VP4／VP3，在氨基酸水平上VP2、VP3、VP4与参比毒株的同源性分别达到94．9％－98．8、96．1％－98．5％、97．1％－99．2％。ZJ2000共有14－38氨基酸的替代，其中特有氨基酸6个，变异大多数集中在VP2高变区，突变率达2．9％－11％。第2个小亲水区内280位氨基酸由S替代了N、290位M替代了L。这2个突变可能与IBDV的抗原性有关。VP2－VP4剪切位点附近511和540位氨基酸的变异可能使ZJ2000株的毒力增强。分子系统进化树分析表明，ZJ2000与欧洲Cu-1株、P2株、CEF94株和中国Harbin株的有关最近，而与欧洲、香港、日本的超强毒株和美国的变异株相对较远。     

时序误差权马尔可夫链在粮食丰欠状况预测中的应用

针对粮食产量时间序列既有摆动又有一定趋势的特点，首先对粮食产量进行时间趋势项拟合，然后对粮食产量的误差序列进行分析，以其规范化的各阶自相关系数为权，用加权的马尔可夫链来预测粮食未来的丰欠状况。并以广西粮食产量为例进行了实证分析。     

哺乳动物胚胎性别鉴定技术的研究进展

性别控制是通过人为方法使雌性成年动物按照人们的意愿生产特定性别后代的动物繁殖新技术。早期胚胎鉴定是性别控制的一条重要途径，近年来取得了长足进展，尤其是聚合酶链式反应技术。本文综述了胚胎性别鉴定的基本原理、鉴定方法以及研究概况，并阐述了该技术存在的问题及发展前景。     

对收获机械中杆条输送链的初步分析

对收获机械中杆条输送链的运动不均匀特性提出了新的认识，并从如何利用这种特性及设计中如何选择有关参数提出了意见．     

具有函数放养率或捕获率n步食物链生态系统的稳定性

运用Ｌｉａｐｕｎｏｖ第二方法研究具有函数放养率或捕获率ｎ步食物链生态系统的稳定性，由此得到其全局稳定，大范围稳定，不稳定的判定条件，是很有理论和实践意义的。     

Restricted expansion of T cell receptor (TCR)Vβ genes in leukemic patients subjected to allogeneic hematopoeitic stem cell transplantation

AIM: To investigate restricted expansion of TCR Vβ gene repertoire in patients with leukemia following allogeneic hematopoietic stem cell transplantation. METHODS: TCR Vβ subfamily genes in peripheral blood mononuclear cells from 7 cases of leukemia was amplified using RT-PCR. RESULTS: Only two-eight fragments of Vβ genes were detected in samples from these patients, and the detected fragments are different in different patients. CONCLUSION: TCR complexes were abnormal in all patients, part of the genes were seletively expansed and part of them were suppressed after transplantation.     

猪圆环病毒2型内蒙古株全基因组的克隆及序列分析

取内蒙古某猪场疑似断奶仔猪多系统衰竭综合征 (PMWS)病猪的肝、淋巴结、肺、脾等器官组织病料 ,处理后负染 ,透射电镜观察到约 17nm的病毒粒子。用 PCR法从病料中扩增获得 2型猪圆环病毒的全基因组序列 ,其全长为176 7bp,与 Gen Bank中公布的 11株 PCV- 2型序列比较 ,同源性为 95 .2 %～ 99.8%