晚二叠世Ting类Gallowayinella的旋壁超微构造及其时代

电子显微镜研究显示,Gallowayinella旋壁的透明层与Fusulinella型（四层式旋壁）的透明层在晶粒形状,大小和排列方式方面有较大的差异,而与Palaeofusulina旋壁的超微构造特征一致。Gallowayinella属的分类位置应归于古纺锤Ting亚科（Palaeofusulininae M.-Maclay,1963),时限为晚二叠世吴家坪期早期至长兴期早期。G.meitienensis一种不能作为我国长兴阶下部的一个带化石。     

二叠纪古纺锤(Palaeo fusulina)旋壁超微构造及其分类位置

电子显微镜下研究表明 ,Palaeofusulina的旋壁由致密层及“透明层”组成 ,“透明层”的晶粒形状、大小和排列方式与旋壁四层式 (Fusulinella型 )中的透明层超微特征有较大的差异。文中应用Palaeofusulina旋壁的透明层一词 ,加以引号 ,以示两者之间的区别。晚二叠世长兴阶的Palaeofusulina属及其旋壁构造相同的若干属均可归于PalaeofusulininaeM . Maclay ,196 3亚科     

二叠纪古纺锤Ting（Palaeofusulina）旋壁超微构造及其分类位置

电子显微镜下研究表明,Palaeofusulina的旋壁由致密层及“透明层”组成,“透明层”的晶粒形状,大小和排列方式与旋壁四层式（Fusulinella型）中的透明层超微特征有较大的差异,文中应用Palaeofusulina旋壁的透明层一词,加以引号,以示两者之间的区别,晚二叠世长兴阶的Palaeofusulina属及其旋壁造相同的若干属均可归于Palaeofusulininae M.-Maclay,1963亚科。     

长兴阶抑或吴家坪阶?——对赵兵等文章结论的质疑

赵兵等(2006)将羌塘盆地北部产有Codonofusiella-Gallowayinella组合带化石的拉卜查日组归入到上二叠统长兴阶的上部,将那益雄组归入长兴阶下部,可能是错误的。王成源等(1997)早已指出,Gallowayinella的时代是吴家坪期而不是盛金章所确认的长兴期的早期。拉卜查日组应归到吴家坪阶。二叠纪的主导化石门类是牙形刺而不是。     

Quasifusulina的旋壁构造及其在(竹蜓)类分类、演化中的意义

本文介绍作者利用扫描电子显微镜对(竹蜓)类Quasifusulina旋壁超微构造的初步研究结果。电镜观察表明,Quasifusulina旋壁的主要部分系由许多近等轴的方解石微粒构成,这些微粒有规律地叠置在一起,形成了一系列垂直于壳表、彼此相邻的方解石复合体。尽管其光学特征与蜂巢层和透明层颇为相似,但从构成旋壁的方解石微粒的形状、大小及排列和定向方式来看,Quasifusulina旋壁的超微构造既明显地有别于典型的蜂巢层,也不同于典型的透明层。为便于描述,作者建议将Quasifusulina旋壁的这种特殊构造称为“原蜂巢层”(prokeriotheca)。 根据电镜观察,Quasifusulina旋壁由原蜂巢层及不连续的内疏松层构成,它可能代表了?类有孔虫中一种独特的旋壁类型。这种旋壁构造在?类动物的分类及演化研究中可能具有重要意义。     

ting类旋壁超微构造的研究

电子显微镜下观察表明,除史塔夫ting类外,ting类旋壁有8种类型,各分层的超微构造是由开头不同、粒径不一及排列方式各异的方解石晶粒组成。旋壁基本结构包括致密层、透明层、内疏松层、原蜂巢层（?原始层）、蜂巢层及后透明层。ting类标本受后期次生作用,可改变组成旋壁的方解石晶粒原有的形状,晶粒被重结晶,但其旋壁的分层结构仍保留原生的特征。     

(竹蜓)类Protriticites旋壁构造的扫描电镜研究

利用扫描电子显微镜观察Ｔｉｎｇ类Ｐｒｏｔｒｉｔｉｃｉｔｅｓ的旋壁构造,重点研究了透明层,蜂巢层的超微构造特征,并分别与Ｆｕｓｕｌｉｎｅｌｌａ和Ｔｒｉｔｉｃｉｔｅｓ旋壁中的类似构造进行了对比,结果表明,Ｐｒｏｔｒｉｔｉｃｉｔｅｓ内部壳圈的透明层与Ｆｕｓｕｌｉｎｅｌｌａ相似,但整体发育状况较差,并以Ｔｒｉｔｉｃｉｔｅｓ为代表的典型的蜂巢层相比,组成Ｐｒｏｔｒｉｔｉｃｉｔｅｓ外部壳圈旋壁峰巢构造的方解石     

类Protriticites旋壁构造的扫描电镜研究

利用扫描电子显微镜观察类Ｐｒｏｔｒｉｔｉｃｉｔｅｓ的旋壁构造,重点研究了透明层、蜂巢层的超微构造特征,并分别与Ｆｕｓｕｌｉｎｅｌａ和Ｔｒｉｔｉｃｉｔｅｓ旋壁中的类似构造进行了对比。结果表明,Ｐｒｏｔｒｉｔｉｃｉｔｅｓ内部壳圈的透明层与Ｆｕｓｕｌｉｎｅｌａ相似,但整体发育状况较差;与以Ｔｒｉｔｉｃｉｔｅｓ为代表的典型的蜂巢层相比,组成Ｐｒｏｔｒｉｔｉｃｉｔｅｓ外部壳圈旋壁蜂巢构造的方解石晶体在形状、定向及排列方式上具有较原始的特征,代表了类Ｆｕｓｕｌｉｎｅｌａ→Ｐｒｏｔｒｉｔｉｃｉｔｅｓ→Ｍｏｎｔｉｐａｒｕｓ→Ｔｒｉｔｉｃｉｔｅｓ演化系列中旋壁蜂巢层的原始状态。Ｐｒｏｔｒｉｔｉｃｉｔｅｓ的原始蜂巢层构成了随后类希瓦格科旋壁蜂巢层进一步发育、演化的基础     

福建宁化早二叠世早期的史塔夫Ting（Staffella）动物群

福建宁化早二叠世早期的ｔａｆｆｅｌｌａ动物群有３属１９种,主要特征是壳体较小,全一般为近球形及凸镜形,轴率小于１,旋壁四层式,透明层清楚。含Ｓｔａｆｆｅｌｌａ动物群的层位可与福建龙岩、四川巴塘、广西宜山、河南禹县等地相同层位的Ｓｔａｆｆｅｌｌａ带对比。     

江西乐平鸣山矿区上二叠统长兴阶的类

一、前言 鸣山矿区位于江西省乐平县城之西约7.5公里处,为萍乐拗陷带东段的一个小型向斜盆地,是乐平组官山段、老山段、狮子山段和王潘里段的标准剖面所在地。区内乐平组出露完好,但其上的长兴期地层往往被第四纪浮土所覆盖,仅在盆地的东侧有零星出露。1977年江西省煤炭局223地质队在这个地区发现了一个完整的晚二叠世长兴期的地层钻井剖面,系统采集了(竹筳)类标本。这批材料经笔者鉴定,计有7属34种,其中6个新种和5个未定种。Gallowayinella,Palaeofusulina和Parananlingella三属是当前这个(竹筳)类动物群中     

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.     

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.     

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     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.