鲻和鲮鳃丝的扫描电镜比较观察

对鲻（Mugil cephalus）和鲮（Cirrhina molitorella）的鳃丝表面结构进行了扫描电镜比较观察,结果表明,鲻鳃丝杆状部比鲮粗．鲻鳃小片高度比鲮低;两者鳃丝表面分泌孔洞口径和密度不同;鲻和鲮细胞外被不同,鲻细胞外被稀疏,鲮的则致密复杂;鳃小片细胞和鳃丝表皮细胞的表面形态存在差异,文章还描述了鳃丝表皮形态特异的细胞。     

小地老虎气管内膜的构造

小地老虎Agrotis ypsilon的幼虫或蛹的气管内膜绝大部分均有螺旋丝结构,在侧气管干和背气管连锁处则呈“手笼状膨大”,形成一个灰白部,其内膜无螺旋丝,而有许多刺状突起。蜕皮时旧气管内膜首先在灰白部缢缩并断裂,然后才从各环节的气门中脱出。因此灰白部的结构与蜕皮以至生长发育都有很大关系。研究昆虫气管的螺旋丝与灰白部的形态结构,不但可以深入了解气管内膜的性质与功能,并且有利于探明灭幼脲一类药剂对表皮内膜产生的生理效应。过去在国内外对螺旋丝的结构与表面扫描观察已有报道,但对灰白部只对家蚕作过非常简单的介绍,对其细微结构与表面特点都了解很少特别对灰白部刺的功能未见有过报道(浙江农大等,1981;赤井 弘,1976),本文重点亦在报道该部位的扫描观察结果。     

长鳍篮子鱼消化道黏膜上皮的扫描电镜观察

采用扫描电镜观察了长鳍篮子鱼(Siganus canaliculatus)消化道黏膜上皮表面细微的结构特征。结果显示,长鳍篮子鱼食道黏膜为纵行黏膜褶皱,在褶皱上形成"V"字型次级褶皱,黏膜上皮表面具有许多分泌孔及较多腺体导管的开口,上皮细胞扁平,似鳞片状,连接紧密。胃黏膜褶皱呈绳状纵向排列,黏膜上皮表面有许多沟回,细胞之间有较多的胃小凹,在上皮表面可见有乳头状突起,未见有微绒毛;上皮细胞为五边形或六边形,无细胞间隙。肠黏膜分布着密集排列的肠绒毛,绒毛呈拇指状或扁平状,黏膜上皮表面呈脑回状,分布有许多分泌颗粒,细胞游离面分布着丰富的微绒毛,细胞为多边形、圆形、不规则形,有细胞间隙。幽门盲囊黏膜上皮的结构与肠道相似。本文探讨了黏膜上皮结构与功能的关系。     

山溪鲵消化道粘膜上皮的扫描电镜研究

用扫描电镜观察了山溪鲵的咽、食管、胃、怕和大肠粘膜上皮表面细微结构及断面的结构特征。发现咽和食道上皮表面有比较宾微脊;胃粘膜上皮表面有微绒毛,周转的长 密集,顶部的短而稀少;胃粘膜上皮表面的微绒毛似苔葡状覆盖在细胞的表面;杯状细胞分布在上皮细胞之间。同时,还讨论了这些结构与机能的关系。     

黄斑篮子鱼和金钱鱼鳃的扫描电镜观察

对两种鲈形目鱼类黄斑篮子鱼(Siganus oramin)和金钱鱼(Scatophagus argus)的鳃结构进行扫描电镜观察。结果表明,黄斑篮子鱼和金钱鱼鳃的表面结构及微细结构与其他硬骨鱼类基本相似,鳃丝表面都具有规则或不规则分布的环形微嵴、沟、坑、孔等结构。黄斑篮子鱼的鳃片中部鳃丝表皮有大量凸起,而端部鳃丝表皮的凹凸程度明显较低,黄斑篮子鱼的鳃小片高度较金钱鱼鳃小片高。黄斑篮子鱼和金钱鱼鳃上皮的扁平上皮细胞、氯细胞和黏液细胞的形态结构及数量分布存在细微的差异。黄斑篮子鱼鳃片鳃丝的端部和中部表面有黏液细胞,金钱鱼鳃丝表面的黏液细胞很难观察到,与大多数淡水鱼类相似。黄斑篮子鱼鳃丝表面分布的氯细胞数量多于金钱鱼,这可能与两种鱼生活环境、生活习性的长期演变相关。     

细胞表面DNA

一些实验表明细胞表面存在DNA,并且具有一定的功能。本文介绍了细胞表面DNA的研究情况,并对其可能存在的结构与功能作了推测。     

珠江口池养梭鱼鳃的光镜、扫描和透射电镜观察

应用光学显微镜、扫描电镜和透射电镜对珠江口池塘养殖梭鱼Liza haematocheila鳃的组织结构、表面形态特征及鳃小片超微结构进行了观察。结果表明梭鱼具有4对鳃,每个鳃由鳃弓、鳃丝、鳃小片和鳃耙组成。梭鱼鳃丝和鳃小片的表面结构和超微结构与其他硬骨鱼类的基本相似,鳃丝表面分布有众多规则或不规则的环形微嵴、沟、坑、孔等结构。鳃丝分为呼吸区和非呼吸区,呼吸区较为平滑,上皮细胞表面无微嵴,呈皱褶状;非呼吸区分布有沟、坑、孔等结构,上皮细胞有较规则的指纹状微嵴。鳃小片是最主要的呼吸场所,由基膜、上皮细胞、内皮细胞、柱细胞和毛细血管网组成。泌氯细胞主要分布在鳃小片基部,并有开口通往外界。本文还探讨了梭鱼鳃的结构与其功能的密切关系。     

甲型H1N1流感病毒HA蛋白结构和功能研究进展

自2009年3月,甲型H1N1流感疫情相继在包括我国在内的许多国家暴发,对人体健康和社会经济发展造成了严重危害。血凝素（HA）蛋白是重要的病毒表面糖蛋白,主要有3种功能：①与宿主细胞表面受体结合;②引起病毒包膜与靶细胞间的膜融合;③刺激机体产生中和性抗体。本文综合了近年来的研究成果,对甲型H1N1流感病毒HA蛋白结构、主要功能、进化、抗原性的研究进展进行了综述。     

生物双重显微结构三维重建图象显示及畸变补偿方法

本文介绍计算机三维重建技术的两个进展:双重显微结构三维重建图象的显示技术及三维重建图象显示畸变的补偿方法。 1.生物双重显微结构的三维显示方法 有些生物的神经核团具有双重结构,例如蛤蚧的中脑峡核,它由大细胞部(Imc)和小细胞部(Ipc)两部分组成,仅Imc与视觉有关,Ipc似乎既无视觉功能也无听觉功能。但Imc与Ipc紧挨着,且有部分结构交迭在     

单纯疱疹病毒包膜糖蛋白的结构及功能研究

包膜糖蛋白是病毒毒粒表面的抗原决定簇,是有包膜病毒表面脂质双层膜的重要成分。目前,已发现并正式命名的单纯疱疹病毒包膜糖蛋白共有12个,大部分具有重要功能。本文就单纯疱疹病毒I型包膜糖蛋白的结构和功能进行综述。     

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.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

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.