云南三种同域分布的棘蛙（蛙科Ranidae：无尾目Anura）的核型和银带研究

本文比较分析了云南景东地区三种同域分布棘蛙的核型和Ａｇ－ＮＯＲｓ。花棘蛙２ｎ＝２６（１６Ｍ＋ １０ＳＭ）,ＮＦ＝５２,次缢痕和Ａｇ－ＮＯＲｓ位于１ｐｉｎｔｅｒ,Ｎｏｓ．２－４,８,９等为ＳＭ。棘肛蛙２ｎ＝４０（１６Ｍ＋ ２０ＳＭ＋２ＳＴ＋２Ｔ）,ＮＦ＝７８,Ｎｏｓ．５－９,１１－１３,１５,１７等１０对为ＳＭ,Ｎｏ．３为ＳＴ,Ｎｏ．１８为Ｔ,其余 均为Ｍ,Ａｇ－ＮＯＲｓ位于１１Ｐ。二种的Ａｇ－ＮＯＲｓ都有异形现象。双团棘胸蛙２ｎ＝６４Ｔ,次缢痕和Ａｇ－ ＮＯＲＳ在４ｑｐｅｒ。都未发现异形性染色体。最后,对棘蛙属的核型演化机制和物种形成方式作了讨论。     

云南景东地区四川湍蛙的核型,C—带和Ag—NORs的研究

本文报道了云南景东四川湍蛙的核型：２ｎ＝２６（２０Ｍ＋６ｓＭ），ＮＦ＝５２，５＋８模式，次缢痕以及Ａｇ－ＮＯＲｓ均位于６ｐｉｎｔｅｒ，Ｃ－带阳性分布于全部染色体的着丝点区域和８ｑｉｎｔｅｒ，但６ｐｉｎｔｅｒ１２ｐｔｅｒ和１３ｑｔｅｒ等处间或也显示Ｃ－带正染。没有发现与性别相关的异形染色体。与采自四川宝兴地区的居群作了比较，并讨论了细胞地理学问题。     

中国四种龟的细胞遗传研究

本文研究了我国四种龟类动物的核型、Ｃ带和Ａｇ－ＮＯＲ＿ｓ。结果表明金头闭壳龟的核型２ｎ＝５２（１４Ｍ＋２ＳＭ＋４ＳＴ＋６Ｔ＋２６ｍ）,ＮＦ＝７２,核型模式为８＋５＋１３,一对次缢痕位于Ｉ组的Ｎｏ．１ｐｉｎｔｅｒ;三线闭壳龟核型２ｎ＝５２（１２Ｍ＋４ＳＭ＋４ＳＴ＋６Ｔ＋２６ｍ）,ＮＦ＝７２,８＋５＋３,黄缘盒龟的核型　２ｎ＝５２（１６Ｍ＋４ＳＴ＋６Ｔ＋２６ｍ）,ＮＦ＝７２,８＋５＋１３,一对次缢痕位于Ｉ组Ｎｏ．１ｐｉｎｔｅｒ;黄额盒龟２ｎ＝５２（１６Ｍ＋２ＳＭ＋４ＳＴ＋６Ｔ＋２４ｍ）,ＮＰ＝７４,９＋５＋１２,有４对次缢痕,分别位于Ｉ组的Ｎｏ．１ｐｉｎｔｅｒ,Ｎｏ．３ｐｐｅｒ,Ｎｏ．７ｐｐｅｒ和Ｎｏ．６（Ｘ染色体）ｑｐｅｒ。黄额盒龟有１对异型（ＸＹ型）性染色体,其余３个种没有。这四种龟的全部染色体都出现着丝粒区Ｃ带正染。它们都仅出现１对ＡｇＮＯＲｓ,其中黄额盒龟的Ａｇ－ＮＯＲｓ。位于ＩＩ组的Ｎｏ．５ｑｐｅｒ,其余３个种的Ａｇ－ＮＯＲ＿ｓ位于Ｉ组的Ｎｏ．７ｑｔｅｒ。本文还阐述了近缘种间核型的演化机制和黄额盒龟性染色体分化的途径。     

四种无尾两栖动物的核型和银染

本文报道了二种角蟾和二种树蛙的核型和银染ＮＯＲ：无量出角蟾：２ｎ＝２６（２４＋２ＳＭ），５＋８，ＳＣ和Ａｇ－ＮＯＲｓ位于６ｑ＾ｐｅｒ沙坪角蟾：２ｎ＝２６（１６Ｍ＋８ＳＭ＋２ＳＴ），５＋８，ＳＣ位于１ｑ＾ｐｅｒ，但Ａｇ－ＮＯＲｓ有二对，分别是ｌｑ＾ｐｅｒ和２ｑ＾ｐｅｒ；黑蹼树蛙：２ｎ＝２６（２４Ｍ＋２ＳＭ），５＋８，ＳＣ和Ａｇ－ＮＯＲｓ在ｌｐ＾ｉｎｔｅｒ；背条跳树蛙；２ｎ＝１６（１２Ｍ＋４ＳＭ），Ｓ     

中国几种棘蛙的核型C—带和Ag—NORs研究

本文对４种棘蛙的核型、Ｃ－带和Ａｇ－ＮＯＲｓ作了观察分析,结果表明无声囊棘蛙２ｎ＝６４Ｔ,Ａｇ－ＮＯＲｓ在２０ｑ＾ｉｎｔｅｒ,全部着丝点区域Ｃ－带正染。云南的棘腹蛙、察隅棘蛙和河南太行山隆肛蛙３者,其２ｎ＝２６,５＋８模式,但相互间ＳＭ的对数和顺序有所不同;前二者的Ａｇ－ＮＯＲｓ均在６ｐ＾ｐｅｒ,但Ｃ－带有很大的不同：察隅棘蛙的着丝点Ｃ－带浅染,但有较多的端部和居间型Ｃ－带。隆肛蛙的Ａｇ－ＮＯＲｓ     

西双版纳地区两种水蛙的核型、C带和Ag－NOR研究

本文报道了西双版纳地区黑带水蛙（ＨｙｌａｒａｎａｎｉｇｒｉｖｉｔａｔａＢｌｙｔｈ）的核型,２ｎ＝２６（１８Ｍ＋８ＳＭ）,ＮＦ＝５２,５＋８,Ｎｏｓ．２、３、８、９为ＳＭ,Ｃ带位于全部染色体的着丝点区域,Ａｇ－ＮＯＲ一对,位于１２ｑｉｎｔｅｒ,有异形现象。黑耳水蛙（Ｈ．ｖａｒｉａｎｕｓＢｏｕｌｅｎｇｅｒ）的核型２ｎ＝２６（２４Ｍ＋２ＳＭ）,ＮＦ＝５２,５＋８,Ｎｏ．８为ＳＭ,Ｎｏｓ．２、３、１０为Ｍ或ＳＭ,Ｃ带亦主要出现在各染色体的着丝类区域,但Ｎｏ．１０者较弱,一对Ａｇ－ＮＯＲ位于１０ｑｉｎｔｅｒ,有异形现象。黑耳水蛙有染色体数目变异。除大多数分裂相为２６外,尚有２７或２８者,后者多一个或一对小Ｍ,Ｃ带或深或浅正染。     

中国五种锄足蟾科无尾两栖动物的细胞遗传学研究

本文对中国５种锄足蟾科无尾两栖动物的骨髓细胞有丝分裂中期作了细胞遗传学研究,内容包括核型、Ａｇ－ＮＯＲｓ和Ｃ－带。研究结果表明景东角蟾：２ｎ＝２６（２０Ｍ＋４ＳＭ＋２ＳＴ）,５＋８,ＳＣ和Ａｇ－ＮＯＲｓ位于６ｐ＾ｐｅｒ,同时呈Ｃ－带正染。Ｃ－带以着丝点区域正染为主;粗皮角蟾：２ｎ＝２６（２０Ｍ＋６ＳＭ）,５＋８,Ａｇ－ＮＯＲｓ在６ｑ＾ｉｎｔｅｒ,以着丝点Ｃ－带为主,但Ｎｏｓ．１２,１３有明显的端位     

云南景东地区四川湍蛙的核型,C—带和Ag—NORs的研究

本文报道了云南景东四川湍蛙的核型：２ｎ＝２６（２０Ｍ＝６ＳＭ）,ＮＦ＝５２,５＋８模式,次缢痕以及Ａｇ－ＮＯＲｓ均位于６ｐ ｉｎｔｅｒ,Ｃ－带阳性分布于全部染色体的着丝点区域和８ｑ ｉｎｔｅｒ,但６这的１２这和ｑｅ１ ｔｅｒ等处间或也显示Ｃ－带正染。没有发现与性别相关的异形染色体。与采自四川宝兴地区的居群作了比较,并讨论了细胞地理学问题。     

宝兴泛树蛙不同地理居群的染色体多样性

本文分析了比较了宝兴泛树蛙四个地理居群的核型,Ｃ－带和Ａｇ－ＮＯＲｓ,结果表明它们有相同的２ｎ＝２６,ＮＦ＝５２,和相同的核型模式：５＋８。但是,它们彼此之间在ＳＭ数目和顺序,次缢痕或随体的位置以及银染的位置,Ｃ－带类型都有所不同。     

云南四种树蛙的细胞遗传学研究（无尾目：树蛙科）

本文报道了分布在云南的４种树蛙（峨眉泛树蛙,黑点泛树蛙,无声囊泛树蛙和棕褶树蛙）垢核型,Ｃ－带及Ａｇ－ＮＯＲｓ它们具有相同的二倍体数（２ｎ＝２６）,除无声囊泛树蛙是６＋７,其余均为５＋８核型模式,种间ＳＭ的数目和顺序,次缢痕和Ａｇ－ＮＯＲｓ相互间有所差异。黑点泛树蛙Ｎｏｓ．３,１２为ＳＭ,Ａｇ－ＮＯＲｓ位于１０ｐ＾ｆｉｎｔｅｒ,峨眉泛树蛙Ｎｆｏｓ２,３,４,６．９为ＳＭ,随体和Ａｇ－ＮＯＲｓ在１２     

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.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细