不同剂量的He—Ne激光对Raji细胞膜表面SH的影响

本文以离体培养的Ｒａｊｉ细胞为材料,采用ＥＬＬＭＡＮ方法检测了不同剂量的Ｈｅ－Ｎｅ激光对Ｒａｊｉ细胞膜表面ＳＨ含量的影响。发现０．５Ｊ／ｃｍ＾２Ｈｅ－Ｎｅ激光能量可明显增加膜表面ＳＨ含量（Ｐ〈０．０５）。大于或小于此剂量的Ｈｅ－Ｎｅ激光对膜表面ＳＨ含量的影响均不明显（Ｐ〉０．０５）。提示０．５Ｊ／ｃｍ＾２的激光能量对膜有刺激作用。     

小麦黄花叶病毒的分离提纯及其血清学等特性

应用梯度离心和超速离心浓缩获得部分提纯的病毒制剂,产量约为7.45g/kg病叶提纯的病毒制剂的紫外吸收曲线呈典型的核蛋白吸收曲线,OD260/OD242和OD260/OD280的比值分别为1.24和1.38。病毒粒子呈线状,宽13—14nm,长度主要分布于250—300nm和550—700nm之间,1000nm以上的粒子也有检到。病毒外壳蛋白仅由一个分子量约为30Kd的亚基组成。在免疫电镜试验中、病毒粒子与日本WYMV抗血清发生强烈的血清学反应。新鲜病叶的超薄切片中可看到大量风轮体和膜状体。     

从酵母中提取谷胱甘肽的初步研究

考察了不同提取方法对从酵母中提取谷胱甘肽（ＧＳＨ）的影响,热水抽提由于其提取收率高（９０％）,耗时短（１０ｍｉｎ）经济性强而明显优于其它提取方法,对７３２阳离子交换树脂纯化ＧＳＨ进行了初步研究,主要研究了树脂颗粒大小对提纯ＧＳＨ的影响,采用６０～８０目的树脂,ＧＳＨ收率为５７．６％,虽然比８０目以上的树脂低１０％但前者操作作所需时间只有后者的１／３。     

The airborne metagenome in an indoor urban environment

The indoor atmosphere is an ecological unit that impacts on public health. To investigate the composition of organisms in this space, we applied culture-independent approaches to microbes harvested from the air of two densely populated urban buildings, from which we analyzed 80 megabases genomic DNA sequence and 6000 16S rDNA clones. The air microbiota is primarily bacteria, including potential opportunistic pathogens commonly isolated from human-inhabited environments such as hospitals, but none of the data contain matches to virulent pathogens or bioterror agents. Comparison of air samples with each other and nearby environments suggested that the indoor air microbes are not random transients from surrounding outdoor environments, but rather originate from indoor niches. Sequence annotation by gene function revealed specific adaptive capabilities enriched in the air environment, including genes potentially involved in resistance to desiccation and oxidative damage. This baseline index of air microbiota will be valuable for improving designs of surveillance for natural or man-made release of virulent pathogens.     

附子多糖FI的分离纯化及部分理化性质研究

白附片经热水抽提、Sevag法脱蛋白、乙醇沉淀、DEAE- C32柱层析分离 ,再通过 Sephadex G- 2 0 0柱层析进一步纯化 ,得到一种纯白色粉末状多糖 ,糖含量为 97% ,平均分子量为 2 .6× 10 5,熔点为 2 70℃。经完全酸水解、薄层层析、红外光谱分析 ,证明为葡聚糖。     

Genome editing in livestock: Are we ready for a revolution in animal breeding industry?

Genome editing is a powerful technology that can efficiently alter the genome of organisms to achieve targeted modification of endogenous genes and targeted integration of exogenous genes. Current genome-editing tools mainly include ZFN, TALEN and CRISPR/Cas9, which have been successfully applied to all species tested including zebrafish, humans, mice, rats, monkeys, pigs, cattle, sheep, goats and others. The application of genome editing has quickly swept through the entire biomedical field, including livestock breeding. Traditional livestock breeding is associated with rate limiting issues such as long breeding cycle and limitations of genetic resources. Genome editing tools offer solutions to these problems at affordable costs. Generation of gene-edited livestock with improved traits has proven feasible and valuable. For example, the CD163 gene-edited pig is resistant to porcine reproductive and respiratory syndrome (PRRS, also referred to as “blue ear disease”), and a SP110 gene knock-in cow less susceptible to tuberculosis. Given the high efficiency and low cost of genome editing tools, particularly CRISPR/Cas9, it is foreseeable that a significant number of genome edited livestock animals will be produced in the near future; hence it is imperative to comprehensively evaluate the pros and cons they will bring to the livestock breeding industry. Only with these considerations in mind, we will be able to fully take the advantage of the genome editing era in livestock breeding.     

重楼属植物甾体皂甙的高效液相色谱分析

应用高效液相层析技术,对重楼属十八个种植物的甾体皂甙进行了定性、定量分析。植物用甲醇提取,抽出物经DIAION柱,以90％甲醇洗出总甙。在HPLC上,用ODS柱先将总甙以用醇:水(9:1)洗脱分为三馏段,每馏再在ODS柱或Rp-8柱上以甲醇:水(8:2;7:3.5)洗脱,使各个皂甙成分完全分离。被分离的每个色谱峰与已知重楼皂甙的保留时间进行比较并配合HPLC的加入法,TLC分析及用HPLC制备少量样品做MS测定来加以定性鉴定。定量采用内标及校正曲线法。     

地衣芽孢杆菌耐高温α-淀粉酶基因的克隆、烟草瞬时表达及转化拟南芥的研究

从地衣芽孢杆菌(Bacillus licheniformis)中克隆到耐高温α-淀粉酶基因全长, 构建了原核表达载体, 转入大肠杆菌(Escherichia coli)中, 使用IPTG于28°C诱导6小时后, 通过SDS-PAGE检测到目的蛋白, 分子量约为55 kDa, 并通过酶活力检测实验证明该蛋白具有耐高温α-淀粉酶活性。同时构建了该基因融合GFP的植物表达载体, 通过农杆菌(Agro- bacterium tumefaciens)介导瞬时转化烟草(Nicotiana tabacum)下表皮细胞并在荧光显微镜下观察, 发现在烟草下表皮细胞的细胞质和液泡中均有绿色荧光。使用I₂-KI溶液对乙醇脱色后的烟草叶片进行染色, 显色反应表明在烟草中表达的耐高温α-淀粉酶具有酶活性。最后, 采用农杆菌介导的花蕾浸泡法将重组载体转化到拟南芥(Arabidopsis thaliana)中, 筛选到稳定遗传的耐高温α-淀粉酶基因的拟南芥纯合子。研究结果为后期开展表达耐高温α-淀粉酶的转基因植物的相关研究奠定了实验基础。     

Rapid and sensitive assay for the phytotoxin rhizobitoxine.

Rhizobitoxine is a phytotoxin synthesized by some strains of the legume symbiont genus Bradyrhizobium and the plant pathogen Pseudomonas andropogonis. We demonstrate here a new enzymatic assay which is 100-fold more sensitive than previous assays and can detect as little as 1.0 pmol of rhizobitoxine. The assay is based on the inhibition of Salmonella typhimurium beta-cystathionase by rhizobitoxine. Interestingly, beta-cystathionase from Bradyrhizobium japonicum is insensitive to rhizobitoxine at concentrations lower than 75 microM.     

Kosteletzkya virginica, a halophytic species with potential for agroecotechnology in Jiangsu Province, China

Kosteletzkya virginica (L.) Presl. is a perennial dicot halophytic species, that grows in brackish portions of coastal tidal marshes of the mid-Atlantic and southeastern United States. New saline mudflats have been increasing every year in Northern Jiangsu, China. In 1993, we introduced K. virginica (L.) into China from the Halophyte Biotechnology Center (University of Delaware, USA) as a potential species to improve the soil and develop ecologically sound saline agriculture. Our nearly 10 years of experimental research, both in a test garden and in the field, indicated that K. virginica adapts excellently to the heavy saline soils of Jiangsu Province, China. The average seed yield of K. virginica in 2001 at Yancheng was 638 kg/ha from 1-year old seedlings. There were significant variations among individuals from the unselected population of K. virginica on growth, quality, and seed yield traits. There is great potential to increase the seed yield if superior clones are selected. The seed yield of 35 selected individuals was six times greater than that of the average. Four growth traits of K. virginica were found to have a significant correlation with seed yield. However, there was no strong positive or negative correlation among seed quality traits. The mean seed weight and the germination ratio of the 35 selected individuals of K. virginica were 16.36±0.32 g and 76.11±1.82%, respectively. The percentage content of oil and crude protein in the seeds was 11.28±0.67 and 8.17±0.19%, respectively. The percentage of seed vigor of the selected individuals was 99%, as determined by soft X-ray radiography.