中国种子植物区系定量化研究——Ⅰ区域性种子植物区系研究实用程序工作原理(QX—系列程序)

本文根据吴征镒教授对中国种子植物属分市区类型研究结果,研制出定量化研究区域性种子植物区系的电子计算机程序,应用本程序可完成某区系的分布区类型统计分析,科属组成分析和与其它地区以共有属关系构建的相似性系数的谁知盘中计算,同时可大量节省研究人员的劳动强度和时间,对提高研究水平有一定的效果。     

1,25-双羟胆钙化醇及其受体含量检测的实验研究

 建立了一种改良的血清1,25-双羟胆钙化醇(1,25-Dihydroxycholecalciferol,DHCC)超微量放射受体检测(RRA)技术。完成了灵敏度、精密度、准确度、稳定性及特异性等技术指标。报告了我国健康青年血清DHCC正常值;检测了先天性佝偻病、青春期佝偻病病人及患肾性骨病奶牛等血清DHCC水平。 根据配体与受体相互结合的定量关系,建立了DHCCR(DHCC受体)检测技术。在游离与结合配基分离方面,除建立与比较了DCC(葡聚糖包埋的活性炭)及HAP(羟基磷灰石)方法外,还首次将IEF(等电聚焦电泳)应用于DHCCR分离技术。对佝偻病鸡小肠粘膜上皮细胞受体含量进行了检测并比较了鸡小肠、输卵管壳腺及肝组织DHCCR含量。     

Determination of 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-5-(1-methylethyl)imidazo[1,5-a]quinoxalin-4(5H)-one in serum by high-performance liquid chromatography

A high-performance liquid chromatographic assay with solid-phase extraction (SPE) for the rapid and sensitive quantitation of 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-5-(1-methylethyl)imidazo[1,5-a]quinoxalin-4(5H)-one (I, U-78875) in serum is described. The validation results indicated that the present method had excellent intra- and inter-assay precision (≤ 9.5%, mean ± S.D. = 3.9±3.0%, n = 25) and accuracy (≤ 10.0%, mean ± S.D. = 3.0 ± 2.9%, n = 25), as well as improved sensitivity (2 ng/ml, using a 100-μl injection). Each chromatographic run is only 10 min and the organic solvent for the extraction of I and internal standard (U-82217) from serum was only 300 μl. The application results obtained from the SPE method were in good agreement with the advanced automated sample preparation method.     

Idiotypic and antiidiotypic T and B lymphocytes in myasthenia gravis.

The prevalence of Id and anti-Id T and B cells as measured by their reactivities with two human mAb, one antiacetylcholine receptor mAb and one anti-Id mAb, was studied in 38 patients with myasthenia gravis and in 27 healthy individuals. Id and anti-Id T cells were estimated by enumerating the numbers of cells secreting IFN-gamma in response to 10 pg/ml of the human mAb. T cell stimulation, measured as numbers of IFN-gamma-secreting cells that exceeded the mean + 2 SD of controls, was induced by the Id mAb in 78.9% of the patients and in 7.4% of the controls, whereas the anti-Id mAb-stimulated T cells in 55.3% of the patients and in 3.7% of the controls. The mean value of the Id and anti-Id-reactive T cells in the patients was 18.3/10(5) and 10.1/10(5) PBMC, respectively. B cells secreting IgM antibodies binding to the human mAb were increased in patients with myasthenia gravis compared to healthy controls. Seventy-five percent of the patients and 12% of the controls had B cells secreting IgM antibodies binding to the Id mAb, although 89% of the patients and 16% of the controls had B cells secreting IgM antibodies binding to the anti-Id mAb. The mean value of B cells secreting IgM antibodies binding to Id or anti-Id mAb in the patients were 7.4 cells/10(6) and 5.5 cells/10(6) PBMC, respectively. We conclude that Id and anti-Id T and B cells are present in myasthenia gravis. These methods allow a quantitative estimation of T and B cells with defined specificities and thus a way of mapping the repertoire of lymphocytes.     

Formation ofα,ω-dodecanedioic acid andα,ω-tridecanedioic acid from different substrates by immobilized cells of a mutant ofCandida tropicalis

Summary The metabolic formation of either,-dodecanedioic acid or,-tridecanedioic acid from the individual n-alkane, n-alcohol, n-monoacid and,-diol with corresponding carbon chain length using K-carrageenan entrapped mutants S76 ofCandida tropicalis was studied. The immobilized cells of S76 could also directly produce-hydroxy acid and,-dioic acid from,-diol. With n-alcohol and n-monoacid as substrate, the amount of-hydroxy acid and,-dioic acid produced was also a function of the incubation time.The results demonstrated that in the immobilized cells of S76 the formation of,-dioic acid from n-alcohol can also run both via n-monoacid and via,-diol as well as in the normal cells of S76.     

A new metabolic pathway from n-dodecane to α, ω-dodecanedioic acid in a mutant of Candida tropicalis

Summary The metabolic formation of ,-dodecanedioic acid via ,-dodecanediol from n-dodecane using a mutant S76 of Candida tropicalis was studied.It was found that resting cells of S76 produce ,-dodecanediol from n-dodecane. This intermediate was identified by different analytical methods. With n-dodecanol as substrate the quantitative changes in the concentrations of ,-dodecanediol as well as other intermediates, e.g. monoacid, -hydroxy acid and ,-dioic acid produced by resting cells of S76 for different periods of time were determined. With ,-dodecanediol as the sole carbon source, quantitative changes of -hydroxy acid and ,-dioic acid produced by S76 were also recorded.The results confirm the existence of a new metabolic pathway via ,-diol in the course of ,-dioic acid formation from n-alkane in the mutant S76 of C. tropicalis.     

A radioimmunoassay method for the rapid detection of Candida antibodies in experimental systemic candidiasis

Rabbits were employed as experimental models to evaluate a solid-phase radioimmunoassay (RIA) method for the diagnosis of systemic candidiasis. Ten rabbits were inoculated subcutaneously to mimic superficial candidiasis and were found to produce no antibodies to Candida as determined by both immunodiffusion and RIA procedures. However, 94 per cent of 18 rabbits systemically infected by intravenous injection of Candida cells were observed to produce antibody as assessed by the RIA technique. These data encourage further tests with human sera and the continued development of this RIA procedure as a useful tool in the early serodiagnosis of systemic candidiasis.     

滇南喀斯特地区灌木群落和人工林土壤元素化学计量特征

在云南喀斯特地区,为提升退化灌木群落的生态系统服务功能,营造了不同树种的人工林分。这些人工林分如何影响土壤化学性质还未得到充分认识。以云南泸西县灌木群落及三种常见人工林(云南松(Pinus yunnanensis)、赤杨(Alnus japonica)和侧柏(Platycladus orientalis))土壤为研究对象探讨喀斯特地区在人工林建造后土壤的13种元素全量、可利用性含量和化学计量学特征变异格局,为喀斯特石漠化治理提供理论依据。结果表明,1)基于判别分析,四种群落土壤化学计量特征可以显著区分。土壤Fe、P、K、Mn全量及交换性Ca、交换性Mg和NH_4~+-N对区分四种群落土壤贡献最大。2)四种群落之间相比,侧柏林土壤C、N、S、Na全量和NO_3~--N含量均低于其他三种群落,土壤肥力较低;赤杨林铵态氮含量最高;云南松林有效Fe、有效Cu含量/N、C素具有显著相关性,占所有元素对数的38.5%,说明该地土壤元素积累的相互依赖性。与灌木群落相比,人工林土壤元素全量和可利用性含量相关性比例均更高。这些研究结果对今后基于适地适树人工林营造、生态系统服务功能提升和经营利用,均具有重要指导意义。     

哈尔滨城市和乡村青年居民肠道菌群多样性研究

【目的】分析居住于哈尔滨城市和乡村的青年居民肠道菌群多样性的异同。【方法】采用PCR和DGGE技术相结合的方法对生活于哈尔滨城市和乡村的青年志愿者肠道菌群多样性进行研究。基于DGGE指纹图谱,分别使用聚类和PCA分析对志愿者肠道微生物相似性进行分析,使用Shannon-Weine多样性指数(H′)、丰度(S)和均匀度(EH)对志愿者肠道微生物多样性进行分析,对图谱中具有代表性的共性和特异性条带进行胶回收和克隆测序以分析志愿者肠道微生物组成。基于PCR技术在种水平上对城乡志愿者肠道内乳杆菌属和双歧杆菌属多样性进行定性分析。【结果】相似性分析显示,城乡青年居民间肠道微生物群落结构存在分开趋势,相似性小于城市或乡村青年居民内部;多样性分析显示,城乡青年居民肠道微生物多样性差异不显著;测序结果表明,城乡居民肠道微生物组成在门水平上相同,但是在种属水平上存在差异。PCR定性分析显示Lactobacillus plantarum、L.casei和L.salivarius在哈尔滨城乡青年居民肠道内检出率接近100%,Bifidobacterium longum和B.breve的检测率约90%,在哈尔滨城乡青年居民肠道内普遍存在;乳杆菌属和双歧杆菌属各细菌种在城乡居民肠道中的检出频率差异不显著。【结论】哈尔滨城市和乡村青年居民肠道微生物多样性差异不显著。     

径流雨水中溶解性有机质特征演化及其对典型污染物迁移和生物有效性的影响

地表径流污染已经逐渐成为城市面源污染的重要组成部分。其中溶解性有机质DOM (Dissolved organic matter)是有机污染物的主要组成部分。DOM中因为含有大量不饱和结构、官能团,其中包括羟基、羧基、羰基、胺基等,这些结构容易与径流中重金属结合发生络合反应,改变重金属的赋存形态,从而对其迁移转化及其生物有效性产生很大的影响。本文以北京市地表径流为研究对象,研究城市地表径流在冬、夏季不同功能区不同下垫面中溶解性有机质特征及其与典型重金属的作用机制,通过荧光淬灭滴定实验,研究夏季径流雨水中DOM的不同组分与重金属Cu~(2+)、Pb~(2+)、Zn~(2+)之间的结合机制。研究结果显示PARAFAC将获得的样品都分解成2类6个不同的组分,1种腐殖酸,1种类蛋白;类蛋白物质的荧光强度与Cu~(2+)、Pb~(2+)的淬灭率要强于腐殖酸,而Zn~(2+)则呈现相反趋势;通过使用二维相关同步光谱发现DOM对重金属Cu~(2+)、Pb~(2+)、Zn~(2+)的敏感性呈现递减趋势,二维相关异步光谱发现Cu~(2+)、Pb~(2+)会先与位于270—300nm附近类蛋白光谱带反应,Zn~(2+)则会先与330nm附近的腐殖酸光谱带反应。