红松树皮中原花青素提取工艺研究

采用溶剂回流提取的方法,以红松树皮中原花青素的提取率为考察指标,考察了提取溶剂种类、溶剂浓度、提取温度、料液比、提取时间、提取次数等因素对原花青素提取效果的影响.通过正交实验,确定红松树皮中原花青素的最佳提取工艺条件为:提取溶剂60%乙醇,提取温度50℃,料液比1:7,提取时间60 min.     

苹果渣中原花青素的提取分离条件的优化

采用单因素和正交试验优化了溶剂直接提取及微波辅助提取苹果渣中原花青素的提取条件。结果表明:溶剂直接提取苹果渣中原花青素的最佳提取条件为乙醇体积分数30%,料液比(g/mL)1∶12,浸提温度90℃,提取时间0.5h;微波辅助提取法提取苹果渣中原花青素的最佳提取条件为乙醇体积分数50%,料液比(g/mL)1∶9,微波功率为700W,提取时间3min。与溶剂直接提取法相比,微波辅助提取法能更省时、高效地提取苹果渣中的原花青素。     

落叶松树皮原花青素提取工艺的研究

本文考察了落叶松树皮原花青素的料液比、乙醇浓度、提取温度、超声时间对原花青素提取效果的影响。采用正交实验,对提取工艺进行了优化。结果表明各因素对原花青素的提取效果的影响程度为提取温度>提取时间>乙醇浓度>料液比。从而确定落叶松树皮中原花青素的最佳工艺条件为:提取温度为35℃,提取时间为0.5 h,乙醇浓度为50%,料液比为1∶15(g/mL)。     

山葡萄籽中原花青素的提取

研究了提取溶剂、温度、时间、料液比4个因素对山葡萄籽中原花青素得率的影响.确定最佳提取工艺以70%丙酮为提取剂,在60℃条件下,提取120 min,料液比为17,原花青素的得率为2.31%     

山葡萄籽中原花青素的提取

研究了提取溶剂、温度、时间、料液比4个因素对山葡萄籽中原花青素得率的影响。确定最佳提取工艺：以70％丙酮为提取荆,在60℃条件下,提取120min,料液比为1：7,原花青素的得率为2．31％     

真空低温工艺技术在黑胡萝卜花青素提取中的应用

通过单因素和正交试验优化了真空低温工艺技术提取黑胡萝卜花青素的工艺参数,比较了真空低温提取法和常压提取法对花青素提取的影响,利用色差检测技术建立了黑胡萝卜花青素提取过程颜色控制标准。结果表明:最优提取条件为提取温度35℃、液料比(L/kg)8∶1、提取时间100 min、真空度-0.05 MPa,在此条件下,黑胡萝卜花青素提取率为96.3%;提取温度对花青素提取影响最为显著,真空度影响最小。     

胭脂萝卜花青素提取及对NCI-N87细胞增殖侵袭的影响

为研究胭脂萝卜花青素的提取工艺,考察了液料比、浸提温度、浸提时间、超声功率、超声时间对花青素提取率的影响。采用MTT实验、细胞侵袭实验研究了花青素对人胃癌细胞NCIN87增殖、侵袭的作用,进一步用免疫印迹分析其对HER2信号通过的影响。结果表明,结合响应面分析得出胭脂萝卜花青素最佳提取工艺为:以1%盐酸乙醇为提取剂,液料比10∶1,40℃浸提2h,400W超声波破碎15min,在此条件下,花青素的最高提取量为3.92mg/g。30μg/ml的胭脂萝卜花青素能显著抑制NCI-N87细胞的增殖和侵袭能力,同时抑制HER2蛋白及Akt的磷酸化水平。     

混合溶剂提取虎杖多极性成分的研究

为了研究混合溶剂对虎杖多成分提取的可行性与先进性,本文采用多种混合溶剂对虎杖进行提取,并与石油醚、乙酸乙酯、70%乙醇提取进行比较研究,在确定最佳提取溶剂的条件下,考察溶剂配比、料液比、温度以及时间因素对虎杖苷和大黄素提取率的影响。结果表明70%乙醇-乙酸乙酯混合溶剂提取效率最高,最佳条件为70%乙醇∶乙酸乙酯=3∶1,料液比1∶12.5,温度85℃,提取时间2 h。多元混合溶剂可以增加虎杖广泛极性成分的提取效率,为中药多成分提取给出了一种新方法。     

基于绿色低共熔溶剂法高效提取鸡骨草中的黄酮和皂苷

为了研究鸡骨草中总黄酮和总皂苷的最佳提取工艺,通过单因素试验和星点设计-响应面法,对低共熔溶剂的性质(如种类、组分摩尔比、含水量)、提取温度、提取时间、液料比等多个因素进行考察。结果显示,总黄酮的最佳提取条件为:摩尔比1∶2、含水量30%的氯化胆碱/乙二醇作溶剂,提取温度80℃,提取时间40min,液料比15∶1(mL/g);总皂苷的最佳提取条件为∶摩尔比1∶4、含水量25%的氯化胆碱/乳酸作溶剂,提取温度80℃,提取时间64min,液料比56∶1(mL/g)。在最佳条件下,总黄酮和总皂苷的提取率较传统提取溶剂分别提高了33.3%和96.4%。本研究为鸡骨草中黄酮和皂苷的高效、安全提取提供了一条新思路。     

响应面法优化回流提取紫薯花青素工艺

旨在获得紫薯花青素的最佳提取工艺,采用中心组合(Box-Behnken)试验设计及响应面分析相结合的方法,对紫薯花青素的回流提取工艺进行优化。单因素试验结果显示,最佳乙醇体积浓度为75%、提取温度为60℃、提取时间为60 min、液料比为7∶1,在此基础上,利用中心组合(Box-Behnken)试验设计及响应面分析法进行回归分析,获得最优工艺参数为:乙醇体积浓度74%、提取温度66℃、提取时间56 min、液料比8∶1。在优化后的条件下进行验证试验,得到紫薯花青素的提取率为4.64mg/g,与理论值(4.68 mg/g)相比,相对误差较小,为0.85%。研究表明,采用响应面法分析优化紫薯花青素的水浴回流提取工艺参数准确可靠,可应用于紫薯花青素的提取生产。     

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.