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％     

超声集成双水相体系提取葡萄籽中的原花青素

采用响应面优化超声集成双水相体系提取葡萄籽中的原花青素最佳工艺条件.首先利用Plackett-Burmart(PB)实验设计对6个相关因素进行了筛选,结果表明,乙醇质量分数、硫酸铵质量分数和超声时间对葡萄籽中原花青素提取率影响较大.用最陡爬坡试验及Box-Benhnken设计进一步优化,利用Design-Expert软件进行二次回归分析,得出主要因素最佳条件为:按乙醇质量分数21.45％,硫酸铵质量分数23.46％配制双水相,在料液比1∶7,50℃温度下超声提取45.46 min,原花青素的提取率可达30.23％,分配系数可达11.5,提取率比优化前提高了6倍.     

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)。     

树莓种子原花青素的提取分离工艺研究

本文对树莓种子原花青素的提取及分离的工艺条件进行了研究和探讨。结果表明:水对原花青素的提取效果较好。用10倍于树莓种子重量的水(pH 8)于80℃提取三次,每次90 min,原花青素的提取效果最佳。提取液浓缩后,用NKA树脂吸附,当上样液pH值为7时,以50%乙醇溶液洗脱,分离出的原花青素含量最高,达23.66%,且产品得率也最大,达11.0%。     

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。     

山楂果中原花青素提取工艺研究

优选回流提取方法,以山楂果中原花青素含量为考察指标,研究提取溶剂种类、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,确定山楂果中原花青素的最佳提取工艺条件为:提取溶剂70%乙醇,提取温度80℃,料液比1∶15,提取时间2 h,提取3次。     

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%     

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.     

离子液体超声辅助提取桑葚中原花青素

采用离子液体超声辅助提取桑葚中原花青素,在单因素实验基础上,采用响应面优化[Bmim]Cl(1-丁基-3-甲基咪唑氯)浓度、料液比、超声功率、超声时间对桑葚中原花青素得率的影响,利用扫描电镜分析了该技术提取效果较好的原因。结果表明,桑葚中原花青素的最佳提取工艺为:[Bmim]Cl浓度为0.73 mol/L、料液比1∶21(g/mL)、超声功率188 W、超声时间11 min,此条件下原花青素得率可达3.51%,与模型预测值接近。扫描电镜观察发现,离子液体超声对桑葚粉末微观结构破坏影响较大。     

超临界CO2萃取刺葡萄籽原花青素的工艺研究

刺葡萄(Vitis davidii Foex．)是属于葡萄属东亚种群的一个种,在湖南西部和南部的山区分布广泛,资源丰富,其果实酸甜、风味浓,但其果粒小,种子多,从种子中提取天然活性物质——原花青素的前景可能更为广阔。目前关于刺葡萄的研究报道少,为此本文以“紫秋”刺葡萄种子为原料,采用单因素试验和正交试验,探讨了超临界CO2萃取刺葡萄籽原花青素的工艺。研究结果表明,超临界CO2萃取刺葡萄籽原花青素的适宜工艺条件为:萃取压力30MPa,萃取温度55℃,料液比1:0．8,60％的乙醇为夹带剂,在此条件下,原花青素的产率为17．58 mg/100g,纯度可达89．7％。     

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.