红景天根中总黄酮和多糖的微波提取及含量分析

目的;从红景天中提取有效成分总黄酮,多糖,并测定其含量。方法：分光光度法,结果：测得红景天总黄酮含量4．62％,平均回收率为98．59％,RSD1．23（n=3),多糖含量9．12％,平均回收率为99．25％,RSD1．12％（n=3)。结论：运用微波技术辅助测定红景天中总黄酮和多糖的含量,反应速度加快,收率提高。     

白花蛇舌草多糖的分离提取及含量测定

采用热水浸提法提取白花蛇舌草水溶性多糖,薄层层析法鉴定其多糖的单糖组成。通过正交试验优选浸提显色条件,以苯酚-硫酸法制得有色糖醛衍生物,用分光光度法在490nm波长处测定吸光度,其曲线方程为Y=0．01361x-0．08161,相关系数r=0．9997。结果表明,白花蛇舌草多糖由鼠李糖、葡萄糖、半乳糖及甘露糖等组成,含量为15．10％,回收率达95．68％。     

响应面法优化微波辅助提取发酵虫草菌丝体多糖工艺

为优化发酵虫草菌粉多糖的微波辅助提取工艺,在单因素实验基础上,以液固比、微波功率以及提取时间为自变量,多糖提取率为响应值,采用中心组合设计的方法,研究各自变量及其交互作用对多糖提取率的影响。利用SAS软件和响应面分析相结合的方法对发酵虫草菌粉多糖的微波辅助提取工艺进行优化,确定了微波辅助提取多糖的最佳条件：液固比值12．2,微波功率650．5W,提取时间11．8min,在此条件下,多糖提取率达到6．41％。采用此法提取的虫草菌丝体多糖,当质量浓度为1mg／mL时,对二苯代苦味肼基自由基（DPPH）清除率达到76％。     

野油菜黄单胞菌(Xanthomonas campestris)L4胞外多糖的理化分析

本文报道野油菜黄单胞菌(Xanthomonas campcstris)L4以蔗糖为底物在2吨发酵罐中生产的胞外多糖的理化分析结果,并与美国的商品黄单胞菌多糖(Xanthan)相比较。两种多糖纯化后单糖组分的气相色谱分析表明,它们均含有D-葡萄糖和D-甘露糖,克分子比为1：1。糖醛酸含量相同,为19％。 L4多糖和Xanthan的丙酮酸含量也相当,分别为4．23％和4.66％,元素分析和红外光谱分析表明,它们有相似的元素组成和基团吸收。L4多糖的沉降系数S02。W为11．5-11．9 S,比美国商品高(10．10S)。L4多糖的持性粘度[η]=11．8dl／g,偏比容-v=0．55ml／g,分子量为2 2 25 600—378 3000。     

草果多糖的含量测定

目的：为了充分利用草果资源,减少资源浪费,研究草果多糖含量的测定.方法：利用热水浸泡充分提取草果多糖,并用Sevag法脱蛋白法将其提纯,然后进行草果多糖含量的测定.结果：样品多糖的含量测得为0.312％,回收率为97.14％,RSD =0.827％ （n =5）.结论：广西贵港草果中含有一定的多糖,且该方法操作简便,准确,可靠,可作为检验草果多糖含量的较好方法.     

蜜环菌多糖的生物合成与发酵条件的相关性

培养基的碳、氮源,ＰＨ值直接影响蜜环菌多糖的生物合成,泥炭水解液的添加量占培养基的１０％～３９％（Ｖ／Ｖ）时,对蜜环菌多糖的生物合成有促进作用。液体振范培养时,蜜环菌生长形成球形菌丝体,菌丝生物量３．４５ｇ／Ｌ,菌丝多糖（精糖）得率为０．２８４％,而静置液体培养有利于菌索形成,菌素生物量１４．０５ｇ／Ｌ,菌索多糖（精糖）得率为０．５１５％,胞外多糖的得率分别为２９．４％和８．３％     

深层培养云芝菌丝体蛋白多糖的提取及性质

采用水、３％草酸和０．２ｍｏｌ／Ｌ氢氧化钠为溶剂分别提取深层培养的云芝〔Ｐｏｌｙｓｔｉｃｔｕｓｖｅｒｓｉｃｏｌｏｒ（Ｌ．）Ｆｒ．〕菌丝体蛋白多糖,其得率分别为菌丝体干重的２０％、４９％和１９％。提取的粗多糖经ＳｅｐｈａｄｅｘＧ１００柱层析进一步分离、纯化,纯化的多糖经聚丙烯酰胺凝胶电泳分离后呈现一个斑点,在ＳｅｐｈａｄｅｘＧ１００柱层析中有一个对称峰,紫外及红外光谱分析和蛋白质含量测定表明该多糖为蛋白多糖,其蛋白质和多糖含量在水提多糖中分别为１３％和６２％、在酸提多糖中分别为５％和９１％。在碱提多糖中分别为３％和８１％。组成该多糖的主要单糖是葡萄糖和木糖。     

蛹虫草菌产生的胞外多糖及其理化性能和抗氧化活性的初步研究

蛹虫草菌Cordycepsmilitaris在液体发酵条件下可产生胞外多糖,其粗多糖的蛋白含量在14．31％左右,氨基酸含量为13．8％,共有17种氨基酸,水分5％左右,多糖含量大约占80％。蛹虫草菌胞外多糖具有良好的增稠性、触变性、抗盐耐热和对广泛pH的稳定性能。蠕虫草菌丝体及其胞外多糖具有一定的抗氧化活性,在60℃的促进氧化条件下放置7天,0．05％含量的菌丝体及其胞外多糖降低油脂氧化率分别达到18．8％和19．8％。     

香菇多糖提取分离的研究

采用DEAE—cellulose柱层析和Sephadex G-200柱层析从香菇子实体热水浸提的粗多糖中分离出两个多糖组分Lenl—A、Len2-A,经旋光度法、Sepharose 4B柱层析、红外光谱等方法检测确定为均一多糖组分,且均为α-构型的吡喃糖,苯酚硫酸法测得其糖质量分数分别为91．5％和92．3％,旋光度为＋5．6°、＋11．2°,相对分子质量为375×10^3、718×10^3。     

阿魏蘑多糖理化性质及免疫活性研究

以阿魏蘑Pleurotus ferulae Lanzi子实体和菌丝体为试验材料,采用水浸法提取阿魏蘑多糖,分别得到子实体粗多糖A和菌丝体粗多糖B。将A经Sevag法去蛋白、透析、CTAB络合、乙醇沉淀、NaCl溶液溶解、透析,得到多糖A1。紫外光谱分析鉴定多糖A1为均一组分。苯酚一流酸法测得多糖A1糖含量为82．9％。凝胶渗透色谱法测得多糖A1数均分子量Mn=141088,重均分子量MW＝142897。气相色谱分析多糖A1单糖组成及其摩尔比为Xyl:Gal:Gal=1:1.02:2.899。巨噬细胞吞噬作用试验、迟发型变态反应试验、白细胞介素－2（IL－2）的诱生与检测试验测得粗多糖A、粗多糖B具有免疫活性。     

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.