茶多酚提取优化工艺研究

本文研究了可食用茶多酚的提取优化工艺。萃取剂为乙醇,料液比1：15,浸提过程伴随300W超声波震荡,就乙醇的浓度、提取温度、提取时间和提取次数等因素利用正交设计筛选了茶多酚的最佳提取工艺条件,并对浸提液最佳离子沉淀方法作了比较。结果表明,茶多酚提取的最佳工艺条件为：65％的乙醇溶液作浸提剂,当浸提温度为50℃,浸提时间30min,两次超声波辐射浸提后茶多酚从粗茶叶中的提取率为20．1％。沉淀剂AlCl3和ZnSO4质量比为1：2对茶多酚的沉淀效果最佳,pH=6．0。     

药用植物三七和金银花多糖提取工艺优化与比较

以野生植物三七、金银花为材料,采用热水浸提、乙醇沉淀、Sevag法除蛋白制备多糖,探讨最佳提取工艺。结果表明,浸提温度和醇沉浓度对金银花多糖提取结果影响较大,其最佳工艺为100℃浸提3 h,氯仿萃取2次,70%乙醇沉淀;影响三七多糖提取的因素顺序为醇沉浓度提取时间提取次数料水比,最佳提取工艺组合为1∶20的料水比提3 h,提取3次,醇沉浓度为80%。根据正交试验结果,金银花粗多糖最高提取率为3.05%,三七粗多糖最高提取率为15.96%,云南文山三七与河南巩义产金银花相比含有较多的多糖。     

衣康酸发酵生产后提取研究

由铅盐沉淀、硫酸酸解和碳酸氢铵再生这几个步骤组成的新工艺流程,能有效地从发酵液或结晶母液中提取衣康酸。与原来的铅盐沉淀工艺相比,新工艺有流程简单、投资小、操作费用低、辅料便宜易得、副产品价值高等优点。该工艺配合衣康酸的浓缩结晶法使用,可大幅度提高总衣康酸提取得率有利于降低生产成本。     

紫云英叶蛋白提取工艺研究

本文采用正交试验对紫云英叶蛋白提取工艺进行了研究,结果表明:蛋白质萃取工艺较优条件为:萃取剂与紫云英鲜叶料液比为5:1,萃取温度为20℃,萃取pH值7.0,萃取剂中盐浓度为0.5％;绿色蛋白质在50℃时沉淀,白色蛋白质在pH=5.0时沉淀。采用此工艺提取得率为25.4％,每吨紫云英鲜叶可得粗蛋白0.04吨,所得粗蛋白含真蛋白50％左右。     

地生枝顶孢（AT01）多糖提取工艺的研究

用正交试验确定地生枝顶孢(AT01) 胞内多糖的最佳提取工艺为:提取3 次,每次提取时间为1-5h ,每次加水20 倍,多糖沉淀时乙醇浓度为75 % 。     

芪术胃安颗粒剂制备工艺优化选择

通过不同制备工艺的研究,确定对芪术胃安颗粒剂的最佳提取工艺。方法采用水提取－醇沉淀、乙醇回流提取,以氏甲甙甲和延胡索乙素为指标成分,采用双波长扫描、紫外分光光度法测定黄芪甲甙及延胡索乙素含量。结果：水提取－醇沉淀法与乙醇回流法的优化结果比较,两种提取工艺的黄芪甲甙,延胡萦乙素含量均无显著性差异。结论：从生产实际出发,芪术胃安颗粒剂提取工艺应选用乙醇回流法即乙醇浓度为５０％,回流温度为９０℃,回流时     

从人发中连续提取亮氨酸和胱氨酸工艺初探

介绍了一种从人发中连续提取亮氨酸和胱氨酸的新工艺。人发用盐酸水解后 ,将水解液减压赶酸 ,再直接加入邻二甲苯 - 4-磺酸沉淀亮氨酸 ,所得沉淀经氨解及后续的精制过程可得亮氨酸精品 ,沉淀亮氨酸后所得的母液按传统的工艺用液氨和得胱氨酸粗品 ,再经一次精制中和可得胱氨酸精品。亮氨酸和胱氨酸的收率分别可达 4 .9%和 7.8% ,产品质量符合日本味之素标准     

食品淀粉酶的特异性吸附分离提取技术研究(925228)

本课题研究的食品级α-淀粉酶提取工艺,采用高分子分离介质来提取淀粉酶,分离率平均为98.7%,酒精耗量小于0.3吨/吨成品酶。与超滤法相比,具有设备投资少,工艺简单、操作简便的特点;与酒精沉淀相比:具有酒精用量少、能耗低,从而降低成本,提高经     

极端嗜酸热古菌Acidianus manzaensis膜蛋白提取方法的建立及应用

以万座嗜酸两面菌(Acidianus manzaensis)为研究对象,探索并优化其膜蛋白提取方法,以优化后的方法提取该菌分别以单质硫(S0)和亚铁(Fe2+)为能源底物进行生长时的膜蛋白质,并进行聚丙烯酰胺凝胶电泳(SDS-PAGE)研究膜蛋白在两种能源底物培养下的表达差异。首先通过80℃水浴60-70 min对A.manzaensis胞外黏附蛋白进行初步分离。其次比较了不同提取剂(Triton X-110,SDS和Triton X-114)对膜蛋白的提取效果,结果表明Triton X-114的提取效果较好,其最佳浓度为10%(w/v);比较了不同沉淀剂(三氯乙酸(TCA),丙酮,三氯乙酸/丙酮,甲醇和乙醇)对膜蛋白质沉淀的效果,结果表明TCA/丙酮的沉淀效果最不理想,会导致沉淀后低分子量蛋白发生缺失,而其他几种没有明显差别,综合比较选择较常用的丙酮作为膜蛋白提取的沉淀剂。最后基于优化后膜蛋白提取方法,分别对S0和Fe2+培养的A.manzaensis膜蛋白质进行提取及SDS-PAGE,结果发现分子量为35.6 k D和16.9 k D的蛋白只在A.manzaensis以S0生长时出现,表明这些蛋白质很可能在A.manzaensis硫氧化中发挥了重要作用;分子量为72 k D和26 k D的蛋白质在A.manzaensis以Fe2+生长时比其以S0生长时显著表达上调,表明此蛋白可能与A.manzaensis铁氧化相关。     

海南红树林淡紫拟青霉胞外多糖提取条件的优化

为了探讨影响红树林淡紫拟青霉胞外多糖提取的因素,确定最佳提取方案,设置不同的发酵液浓缩倍数、三氯乙酸用量等因素,设计单因素实验测定多糖提取最佳条件。然后设计正交试验,检测多糖在不同条件下的提取率,以获得最佳提取工艺。结果发现,发酵液浓缩3~5倍时多糖提取率最高,10%的三氯乙酸对蛋白质脱除效果最好;正交试验表明影响多糖提取的因素依次为乙醇用量、沉淀时间和温度,最优方案为3倍95%乙醇、4 ℃沉淀24 h。该条件下,多糖提取率可达57.835%±1.206%。研究结果为红树林淡紫拟青霉胞外多糖的提取研究提供了参考。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.