离体培养植物细胞的表面与细胞粘连

对离体培养的胡萝卜（Ｄａｕｃｕｓｃａｒｏｔａ）细胞和普通烟草（Ｎｉｃｏｔｉａｎａｔａｂａｃｕｍ）细胞的表面进行了扫描电镜观察．观察表明，细胞的自由表面上有很多疣突和纤丝．疣突的大小不同、形状各异，主要含果胶质；有些细胞表面出现小坑，坑中集中有许多微小颗粒．疣突相互可融合成更大的疣突或连成桥；纤丝常与疣突结合．纤丝－纤丝的交织，纤丝－疣突的交联，及疣突－疣突的融合，在细胞壁外表面构成交织的网络．同种细胞之间及异种细胞之间均可通过纤丝、疣突的交织融合而粘连．疣突分布不均一，且与细胞的分散性有关．与疏松烟草愈伤组织比较，致密烟草愈伤组织细胞的自由表面上疣突显著较多．在分化再生时，烟草愈伤组织首先致密变绿，然后才见到芽的分化及植株再生．对疣突出现、壁物质沉积与细胞粘连、细胞分化、形态建成几者之间的关系进行了讨论．     

磷偏析对钢耐蚀性影响的机理

采用闭塞腐蚀电池和磷钼蓝比色法初步研究了磷的偏析对钢耐蚀性影响的机理。研究结果表明:钢中含磷高,其闭塞腐蚀电池的电流小;有磷偏析的钢在闭塞腐蚀电池中会形成沿磷偏析方向的腐蚀沟槽,凸起部位含磷量高,凹下部位含磷量低;钢中的磷溶解下来之后,形成磷酸盐缓蚀剂沉积在钢的表面,减缓了阳极溶解速度。     

Demonstration of spontaneously dividing male fetal cells in maternal blood by negative magnetic cell sorting and fish

We investigated a case of massive feto-maternal bleeding by using negative magnetic cell sorting (MACS) and fluorescent in situ hybridization (FISH). A 37-year-old pregnant woman had an uncomplicated amniocentesis for advanced maternal age at 16 weeks' gestation. The fetal karyotype was 46, XY. At 19 weeks' gestation, she had a minor car accident and slight vaginal bleeding. A subsequent Kleihauer-Betke test showed a 140 ml feto-maternal haemorrhage. Serial sonographic examinations indicated a normal fetus and placenta. We performed FISH analysis on maternal peripheral blood at 25 weeks. Anti-CD45 and MACS were used to deplete maternal leucocytes, enriching the proportion of fetal nucleated erythrocytes present. The isolated cells were analysed by using dual-colour FISH with X and Y specific probes. Approximately 65 800 nucleated cells were obtained after MACS depletion. A total of 234 cells were analysed by FISH. The results revealed that 70 of the nucleated cells (30 per cent) were male with one X and one Y signal. Among these cells, six male metaphases were observed in spontaneously dividing cells.     

新世纪的清洁能源--燃料电池

介绍了一种高效，环境良好的发电方式-燃料电池发电技术，阐述了燃料电池的发电原理及其开发现状，对其发展前景作了展望。     

高镍杂铜低温生产电解铜粉试验

用杂铜电解生产铜粉时，电解液的温度一般可控制在２０￣６０℃。本文介绍了在３０℃较低温度和６００￣１２００Ａ／ｍ＾２的较低电流密度下，用杂铜电解生产铜粉的试验过程。试验结果表明：低温和低铜离子浓度对生产细粒铜粉有利，而料低电流密度在保证铜粉粒度的情况下，对节约电能有利。     

Cultivated cells from mid-trimester amniotic fluids. IV. Cell type identification via one and two-dimensional electrophoresis of clonal whole cell homogenates

Clones of cultivated amniotic fluid cells that have distinct morphologic and growth characteristics (F, AF and E-type) were examined by one-dimensional SDS polyacrylamide gel electrophoresis (SDS-PAGE) and by two-dimensional electrophoresis employing isoelectric focusing and SDS-PAGE (IEF-PAGE). No qualitative differences in band pattern were observed in SDS-PAGE between the various amniotic fluid cell types, but consistent quantitative differences in the ratios of four bands of presumed filamentous proteins provided good distinction between amniotic fluid cells and postnatal skin fibroblast-like cells. By adding separation on the basis of electrical charge to that of molecular size (IEF-PAGE), we observed reproducible qualitative differences in the protein spot patterns between F and both AF and E-type amniotic fluid cells. At least eight discrete proteins appear not to be synthesized by prenatal F-type cells in comparison with their isogenic AF and E counterparts under identical culture conditions. The two-dimensional electrophoretic patterns thus confirm that F and AF amniotic cells, in spite of their morphologic and growth kinetic similarities, are developmentally distinct cell types that retain their differentiated states in culture.     

模拟酸雨对菜豆叶片的伤害和Mefluidide保护效应的研究

酸雨的污染和危害已成为一个世界性的问题,我国的酸雨危害也日渐引起关注.由于酸雨所涉及到的地区不少是农作区,必然会危及农作物的产量.近年来对酸雨危害作物的机理已有报道,但关于寻求保护作物免于酸雨危害的研究则不多见.已有报道,Mefluidide(N-[2,4-dimethyl-5-[(trifluoromethyl)sulfonyl]amino]phenylacetamide)(N-[2,4-二甲基-5-[(三氟甲基)磺酰]氨基]苯乙酰胺),一种合成的植物生长调节物质,对植物生长和发育以及物质代谢都有影响,尤其是能有效地保护低温敏感作物免于冷害,而且发现Mefluidide处理的植物,在冷害期间不表现细胞膜透性的增加.另外,有人发现pH2.0—4.0的模拟酸雨喷洒植株(青菜、菠菜和萝卜等)也会导致膜透性增加.我们以模拟酸雨引起菜豆叶片的伤害症状和一些生理指标为依据,     

花生蛋白废水生产的单细胞蛋白安全性的实验研究

花生蛋白废水是在花生蛋白加工过程中排放的一种高浓度有机废水。每生产1t花生蛋白,约有14—15t废水排出,其中BOD,COD高达10000ppm以上。此外还有多种无机离子,如不经处理排放到自然水体,将造成严重的环境污染,使大批水生生物死亡,甚至影响人类的健康。 为此,我们研究出以花生蛋白废水为原料,双菌混合,液、固两步发酵生产单细胞蛋白(SCP)的新工艺。在生产过程中,无培养废液排放,不产生二次污染。生产的SCP含粗     

两株产电菌电子介体介导的胞外电子传递机理研究

构建了Klebsiella oxytoca d7和Shewanella sp.F1 2种纯菌燃料电池，探究了产电菌在产电过程中电子介体传递电子机制.结果表明：K.oxytoca d7只有作产电呼吸时，才会产生电子介体，而Shewanella. sp.F1在好氧呼吸、厌氧呼吸、产电呼吸下均能产生介电体，说明电子介体的产生与产电菌种类有关.两种菌介电体氧化还原电位相当（-250，210mV），且介于呼吸链NADH和辅酶Q之间.其介电体在胞内呼吸链上截获的电子均源于NADH，说明电子“逸出”位点只取决于介电体本身.K.oxytoca d7在碳源充足和不足时，电子介体产电量分别占总电量的60%和41%；Shewanella. sp.F1分别是57%和50%，说明在碳源充足时，2种菌的产电呼吸都以电子介体机制为主.介电体传递电子过程直接影响了阳极底物的转化和燃料电池的产电性能.     

不同阴极电子受体从生物燃料电池中发电的比较研究

以活性炭阳极双室生物燃料电池为基础,使用葡萄糖(COD为2000mg·L-1)作为底物,比较了铁氰化钾、过氧化氢、重铬酸钾和高锰酸钾分别作为生物燃料电池阴极电子受体时电池的开路电压和功率输出.结果表明,铁氰化钾、过氧化氢和重铬酸钾对应的开路电位分别为0.72V、0.33V和1.13V,均低于高锰酸钾的1.4lV.铁氰化钾和重铬酸钾对应的最大功率密度分别为4788mW·m-3和10951m W·m-3,相比之下高锰酸钾对应的最大功率达到了21912 mW·m-3.除过氧化氢外,3种氧化剂对应的电池内阻没有区别,均在2200Ω左右.当高锰酸钾浓度为200mg·L-1、pH为2.0时,开路电位高达1.44V,阴极电位达到1.38V,pH对电池电压输出的影响比高锰酸钾浓度更为显著.将高锰酸钾用于生物燃料电池从有机废水中发电不但可以极大提高系统的功率输出,还具有十分显著的经济和环境效益.