陕北红枣中多糖的酶加水法提取工艺研究

以多糖含量和得率为指标,采用正交试验法对陕北红枣中多糖的提取与分离工艺进行优选。酶加水提取的最佳工艺为：①温度70℃、酶添加量3．0％、时间2h;②温度70℃、酶添加量2．0％、时间4h。分离的最佳工艺为：分级沉淀多糖时采用浓缩液：无水乙醇（v／v）1：3效果最好;当采用活性炭脱色时,活性炭用量为7g／L时,既达到了脱色的目的,多糖的损失率又较小。     

菜籽降压肽双酶水解液脱色工艺的研究

用活性炭对菜籽降压肽双酶水解液进行脱色处理,采用单因素试验以及单因素试验基础上的正交试验法。考察活性炭用量、pH、温度、时间对水解液脱色率、肽损失率、活性及ACE抑制率的影响。正交试验优化结果表明,菜籽降压肽双酶水解液脱色最佳工艺为活性炭的用量为1%、脱色pH值为3.0、脱色温度为80℃、脱色时间为50 min,在此条件下脱色率为85.52%、ACE抑制率为57.83%、活性损失率为5.69%。     

百尾参多糖脱色脱蛋白工艺及其免疫活性研究

以百尾参多糖脱色率、多糖损失率为指标,通过单因素和正交试验研究活性炭含量、时间、温度和pH对多糖脱色效果的影响,优化百尾参多糖最佳脱色条件;对Sevage法、三氯乙酸（TCA）法、蛋白质等电点法以及酶法4种脱蛋白方法进行比较,选择较好的脱蛋白方法。建立环磷酰胺免疫低下小鼠模型,研究百尾参多糖的免疫调节活性。结果表明活性炭脱色的最佳条件是活性炭加入量1%、温度60 ℃,时间45 min、pH 4.5;酶法为4种方法中较好的脱蛋白方法。百尾参多糖能加速恢复环磷酰胺致小鼠免疫器官萎缩,也能剂量依赖性地提高小鼠血清中的白介素-2（IL-2）、肿瘤坏死因子α（TNF-α）等细胞因子含量,表明百尾参多糖对环磷酰胺的免疫抑制具有保护作用。     

棘白菌素B提取液脱色工艺

研究碱性阴离子交换树脂WD-6对发酵棘白菌素B(ECB)提取液的脱色效果。通过对ECB提取液和ECB标准溶液的全波长扫描,确定ECB提取液中色素的最佳吸收波长为315nm;考察了树脂添加量、脱色温度、摇床转速和脱色时间对脱色率和ECB损失率的影响,获得最佳脱色工艺:树脂添加量4%(质量分数),脱色温度30℃,摇床转速150r/min,脱色时间100min。在此条件下,ECB提取液的脱色率可达88.3%,ECB损失率仅为4.8%。     

塔拉多糖的脱色工艺化研究

塔拉多糖是一种半乳甘露聚糖胶,对于我们具有非常重要的应用价值。本实验主要对塔拉提取物中的塔拉多糖进行脱色工艺化研究;在单因素实验的基础上,对活性炭颗粒质量、脱色时间、脱色温度以及脱色次数这四种因素进行正交优化实验,其最佳脱色实验参数为：活性炭颗粒0.6 g,脱色45 min,脱色温度45℃脱色次数3次,脱色率可以达到50.21%,同时多糖类保留率为90.39%。     

板蓝根多糖活性炭脱色工艺及抗氧化活性研究

采用活性炭对板蓝根多糖进行了脱色研究。在单因素实验的基础上进行了正交实验,得到活性炭脱色的最佳工艺条件为:70℃下调节p H为7.0,添加体积分数为1.0%的活性炭,搅拌80 min,脱色率为92.97%、多糖保留率为92.45%。采用DPPH孤电子配对法测定DPPH自由基的清除作用;采用邻苯三酚自氧化法检测超氧阴离子自由基的清除作用。实验结果表明,板蓝根多糖具有一定的清除自由基的能力,但脱色后的多糖清除自由基的能力降低。     

板蓝根多糖活性炭脱色工艺及抗氧化活性研究北大核心CSCD

采用活性炭对板蓝根多糖进行了脱色研究。在单因素实验的基础上进行了正交实验,得到活性炭脱色的最佳工艺条件为:70℃下调节p H为7.0,添加体积分数为1.0%的活性炭,搅拌80 min,脱色率为92.97%、多糖保留率为92.45%。采用DPPH孤电子配对法测定DPPH自由基的清除作用;采用邻苯三酚自氧化法检测超氧阴离子自由基的清除作用。实验结果表明,板蓝根多糖具有一定的清除自由基的能力,但脱色后的多糖清除自由基的能力降低。     

氨基酸的冷电弧-光催化-吸附脱色工艺优化

将TiO2光催化剂负载于活性炭,然后将活性炭装填于冷电弧-光催化-吸附集成反应器中,用该反应器对豆粕氨基酸进行脱色。以豆粕氨基酸的脱色率和氨基酸保留率为指标,探讨处理电压、处理时间、溶液pH和活性炭填充量4个因素对脱色效果的影响。在单因素试验的基础上,利用二次回归正交旋转组合设计建立回归模型方程确定最佳工艺条件,并对方程进行回归分析和系数检验。结果表明:回归方程在#=0.01水平上高度显著。各因素对脱色效果的影响程度大小依次为:溶液pH>活性炭填充量>处理时间>处理电压。最佳脱色条件为处理电压20kV、处理时间11min、溶液pH 3.6和活性炭填充量63g,此条件下氨基酸溶液脱色率为94.8%,保留率为83.1%。     

L-鸟氨酸发酵液的脱色研究

为了提高L-鸟氨酸发酵液的脱色效率,对其脱色工艺开展研究。首先通过树脂的选择性吸附确定L-鸟氨酸发酵液中色素的化学性质,随后结合颗粒活性炭的物理结构和零电荷点分析,优选出在接近中性条件下具有优良脱色性能的颗粒活性炭。在静态条件下考察pH、温度、时间和活性炭用量等因素对其脱色性能的影响。在此基础上,考察活性炭层析柱对L-鸟氨酸发酵液的动态脱色工艺和基于两步解吸法的活性炭再生工艺,单柱可动态脱色处理45倍床层体积(BV)的发酵液,脱色率达97%以上,脱色液呈无色透明状,L-鸟氨酸损失率低于1%,活性炭再生效果保持稳定。     

山茱萸多糖大孔树脂脱色技术的优化

以脱色率、多糖保留率和细胞抑制率3个指标,从D301、D303、D315、D900树脂筛选出脱色效果较好的树脂;采用MTT法检测,脱色后的山茱萸粗多糖抗HL-60细胞活性提高;对D303树脂,通过单因素和正交试验对其进行优化,确定最优工艺条件是时间7 h、温度50℃、样品浓度15 mg/m L,脱色率和多糖保留率分别为79.71%、81.12%。大孔树脂脱色工艺的研究,为山茱萸药物的研发提供了一定实验基础。     

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.