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1.
标本采自广西宜山、天等和贵州独山、紫云等地的早二叠世地层中。Zellia富集于层面,大多和Pseudoschwagerina,Sphaeroschwagerina,Robustoschwagerina共生,在确定石炭-二叠系界线时具有一定的地层意义。现对Zellia的属征加以阐述、讨论和归并,并对其地理地层分布作一简介。  相似文献   

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周铁明 《古生物学报》2000,39(4):521-532
简要介绍云南墨江下密地早二叠世常么期含Ting地层,对其中Ting类动物群特征作了归纳,记述7属29种,其中包括4新种。依据Ting类化石在该剖面中的垂直分布在常么组建立Eoparafusulina gracilis-Eo.mejiangensis带和Chalaroschwagerina vulgaris-Chalaroschwagerina pseudovulgaris带。并与国内外相关地层进行  相似文献   

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Pseudoschwagerina属的系统渊源、地质历程、分布范围均不同于Sphaeroschwagerina属,二者在地理分布上亦具差异。以它们命名的生物地层延限带顶、底界均不等同。  相似文献   

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广西天等地区晚石炭世-早二叠世含䗴地层及化石带   总被引:6,自引:3,他引:3  
周建平 《古生物学报》1993,32(5):596-610
简要地介绍了广西天等地区晚石炭世-早二叠世含Ting地层,对Ting类动物群进行了较详细的研究,自下而上建立了7个化石带,分别为:1.Montiparus montiparus带;2.Triticites variabilis带;3.Pseudoschwagerina beedei带;4.Sphaeroschwagerina sphaerica带;5.Mccloudia ovata带;6.Schw  相似文献   

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Pseudoschwagerina属的系统渊源,地质历程,分布范围均不同于Sphaeroschwagerina 属,二者在地理分布上亦具差异。以它们命名的生物地层限带顶,底界均不等同。  相似文献   

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桂西北早,中二叠世常么期和栖霞期Ting类动物群   总被引:3,自引:1,他引:2  
周建平 《古生物学报》1998,37(4):467-476
桂西北早、中二叠世常么期和栖霞期Ting类十分丰富,自下而上可建立5带4亚带:1)Pamirina-Schwagerina带(Pamirina pulichrag亚带;Schwagerina cushmani亚带);2)Schwagerina guembeli带;3)Chalaroschwagerina-Robustoschwagerina带(Chalaroschwagerina vulgaris  相似文献   

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桂西北早、中二叠世常么期和栖霞期类十分丰富,自下而上可建立5带4亚带:1)PamirinaSchwagerina带(Pamirinapulchrag亚带;Schwagerinacushmani亚带);2)Schwagerinaguembeli带;3)ChalaroschwagerinaRobustoschwagerina带(Chalaroschwagerinavulgaris亚带;Robustoschwagerinalonglinensis亚带);4)Brevaxinadyhrenfurthi带;5)Miselinaclaudiae带。并对研究区类动物群的特征,岩相和沉积环境进行了探讨。  相似文献   

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福建漳平早二叠世Schwagerinacushmani动物群的层位介于梁山组与含假希瓦格亚科分子的马平组之间。动物群分子以Schwagerinacushmani,Darvasitessinensis,Pseudofusulinagalowayi为主,与湘东南的Schwagerinacushmani类群、江苏宁镇山区的Darvasitesordinatus类群相一致。  相似文献   

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福建涧产早二叠世Shwagerinacushmani动物群的层位介于梁山组与含假瓦格Tinog亚科分子的马平组之间。动物群分子以Shwagerincushmani,Darvasitessinensis,Pseudofusulinagallowayi为主,与湘东南的SchwagerinacushmaniTing类群,江苏宁镇山区的DarvasitesordinatusTing类群相一致。  相似文献   

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本文概括地介绍了两淮地区太原组的岩性特征。根据所含 类动物群的垂直分布情况,该区太原组可建立Sphaerochwagerina带(可细分为下部的Quasifusulinagracilis-Boultoniawillsi亚带和上部的Sphaeroschwagerinasubrotunda亚带),其时代应属晚石炭世晚期。通过对太原组灰岩的沉积特征、 类分异度及其共生生物群保存情况等方面综合研究,较详细地讨论了海水盐度、温度、深度、浑浊度、水动力条件等生态因素对 类的限制作用。  相似文献   

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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.  相似文献   

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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  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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