A new species of Galearis (Orchidinae: Orchidaceae) from Sichuan,China

A new species, Galearis huanglongensis Q.W.Meng & Y.B.Luo, is described and illustrated. It is similar to Galearis cyclochila (Franch. & Sav.) Soó and Galearis diantha (Schltr.) P.F.Hunt, but differs in having a short spur, two elliptical lateral stigma lobes and distinctly separated bursicles. This new species is known only from the type locality, the Huanglong Valley, Songpan County, western Sichuan, China, growing amongst mosses under alpine shrubs at an elevation of about 3000 m. Based on two years of observations of its population size, the species was categorized as critically endangered CR (B1a, B2a) according to the World Conservation Union (IUCN) Red List Categories and Criteria, Version 3.1. The micromorphology of pollinia and seeds was observed by scanning electron microscopy and compared with that of G. cyclochila and G. diantha. The results supported G. huanglongensis Q.W.Meng & Y.B.Luo as a new species. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 689–695.     

日本血吸虫尾蚴的组织化学及扫描电镜观察

日本血吸虫尾蚴具有一个头腺、2对前钻腺及3对后钻腺,其解剖学位置、构造、化学成分及功能均有区别。钻腺分泌物含有多糖酶及蛋白酶。尾蚴的前端系特化的头器结构,它具有半月形嵴、钻腺开口及乳突。     

轴浆转运在神经再生中的作用

夹伤坐骨神经阻断标记蛋白在轴浆中的快、慢转运。3天后转运再现。第14天的转运距离与对照相似,说明再生神经的转运动能基本恢复。用快、慢转运测出的14天平均再生速度分别为1.77±0.14与1.96±0.07mm/d,比对照神经的正常生长速度快6.3—7倍,提示再生需要更多的转运物质。进一步发现再生神经中某些标记蛋白(慢转运波W1)的转运速度为10.25±0.66mm/d,约比对照快1倍,因此这些标记蛋白可能包含适应再生需要而加速转运的结构和功能物质。     

从睡眠剥夺树鼩（TBC）尿液提取内源性“睡眠因子”（sleep factor）的研究

本研究报道从睡眠剥夺（ＳＤ）４８—７２ｈ的灵长类原宗（ｐｒｉｍｉｔｉｖｅｓｔｏｃｋ）Ｔｕｐａｉａｂｅｌａｎｇｅｒｉｃｈｉｎｅｎｓｉｓ（ＴＢＣ）提取内源性“睡眠因子”（ｓｌｅｅｐｆａｃｔｏｒ）Ｓ２Ｃ和Ｓ４Ｂ。收集的尿液经超滤,清液冻干经ＳｅｐｈａｄｅｘＧ１５分离得到ＦｒａｃｔｉｏｎⅠ－Ⅴ。活性测定发现Ｆｒａｃｔｉｏｎ－Ⅲ（Ｓ２Ｃ）呈现显著δ－增强促眠效应。经ＳｅｐｈａｄｅｘＧ２５和ＳｅｐｈａｄｅｘＬＨ２０进一步净化的Ｓ４Ｂ也呈现显著δ－增强促眠效应。     

埃及血吸虫毛蚴表皮板的观察

埃及血吸虫毛蚴表皮板共有4排,各排数目为6:9:4:3。除第1排之外,其他各排的表皮板均由无纤毛的嵴所分隔,在第1与第2排之间的环嵴中,除第1排各板底边中央小凹处各有1感受器外,尚可见4对感受器。第2与第3排的环嵴内可见16—20个感受器。此外,于体之两侧第3排表皮板间各见1个排泄孔。顶突似六边形,于其两侧各有1个侧腺开口,其内侧可见14个感受器。本文在讨论中与前人对本虫毛蚴表皮板的描述做了简单比较。     

中国喀斯特地区微生物群落结构和功能的研究进展

频繁的人类生产活动使植被遭到破坏,造成基岩裸露的石漠化现象,严重制约了喀斯特地区自然和社会经济的发展,随着生态修复工程的大力开展,微生物群落的结构和功能在生态修复中逐渐受到重视,因为微生物作为喀斯特生态系统的重要组成部分,不仅在物质循环过程中起着重要作用,也在喀斯特生态系统修复中占有十分重要的地位。所以微生物群落结构和功能的研究可以作为衡量生态系统稳定性的重要指标。就中国喀斯特地区的典型植被恢复的不同阶段、成土过程、不同的土地利用方式、矿山修复过程以及不同水域中的微生物群落结构及功能等方面的研究状况进行系统梳理,结合实例综合论述喀斯特地区生态修复过程中微生物作用的研究进展,以期为喀斯特地区生态修复提供参考。     

渗透胁迫对高粱根K~＋吸收的影响

以ＣａＳＯ４０．５ｍｍｏｌＬ－１溶液培养高粱得到低钾植株,在渗透胁迫下当ＰＥＧ－１０００使外界渗透势下降时,刺激了高粱根高Ｋ＋亲和系统的净Ｋ＋积累,其表观Ｋｍ值和Ｔｍａｘ值分别为１８μｍｏｌＬ－１和４９．６μｍｏｌｇ－１ＤＷｈ－１。此高亲和系统不受可渗物质乙二醇和外界ｐＨ变化的影响,为蛋白质合成抑制剂环己酰亚胺抑制。     

Regions of homology in small colicinogenic plasmids

Restriction maps have been constructed for the colicinogenic plasmids (ColA, ColD, and ColK. Their regions of homology with the ColE1 plasmid and its deletion derivative pAO3 carrying the region responsible for autonomous replication of ColE1 plasmid were determined by means of blotting hybridization and heteroduplex analysis. The plasmids ColA, ColD, and ColK were shown to contain DNA fragments homologous to the region of ColE1 involved in the regulation of replication.     

Hydrazides of N-blocked amino acids as sole substrates with unique difunctional behavior under papain catalysis

Hydrazides of five N-acylamino acids have been used alone as substrates for papain catalysis to yield N¹,N²-diacylhydrazines. With the exception of N-(benzyloxycarbonyl)(Z)- -alanine hydrazide, they were very effective as both acylating agents of the enzyme and nucleophiles in attacking the enzyme-substrate intermediate. Although Z- -alanine hydrazide was a minimal acylating agent, it was a satisfactory nucleophile. The most favorable reaction involved Z- -alanine hydrazide in producing N¹,N²-bis(Z- -alanyl)hydrazine. When Z- -alanine hydrazide was the substrate, this same chiral diacylhydrazine was formed along with meso N¹-(Z- -alanyl)-N²-(Z- -alanyl)hydrazine. For the acylation step, the enzyme displayed powerful, essentially stereospecific, bias toward the enantiomer. Once the thioester intermediate was formed, little preference was detected for attack by the enantiomers as nucleophiles. The most direct procedure for synthesis of substrates was conversion of Z-amino acids to their esters by means of dry HCl in an absolute alcohol. Treatment with hydrazine produced the hydrazides in excellent yield.     

Stereochemical aspects of forcing special substrate hydrazides to behave either as electrophiles or as nucleophiles during catalysis by crude papain

Restriction of hydrazides of N-blocked amino acids mainly to electrophilic action, in acylating crude papain, has been achieved by means of a large amount of aniline, with formation of insoluble anilides of N-acylamino acids. Similarly, nucleophilic behavior, on the part of a hydrazide, has been promoted by introducing a large proportion of an N-acylamino acid to produce an insoluble N¹,N²-diacylhydrazine. Achiral, chiral and racemic hydrazides and their corresponding N-acylamino acids were utilized in the study. Among the more informative combinations of reactants were Z-dl-alanine hydrazide with aniline and then with Z-glycine. A stereospecific response in the former situation produced Z-l-alanine anilide. In the latter case, a stereoselective interaction produced Z-Gly-NHNH-lAla-Z more rapidly than Z-Gly-NHNH-d-Ala-Z. The final incubation period yielded an optically pure D product. Differences in stereochemical control have been delineated in terms of different spatial aspects for interactions at the S and S′ subsites of sulfhydryl proteolytic enzymes. A racemic reactant encountered firm stereospecificity as an electrophile at the S subsite but only modest stereoselectivity as a nucleophile at the S′ subsite. The ready availability of crude papain allows an effective procedure for the synthesis of substantial quantities of diacylhydrazines.