广东南雄盆地上湖组介形类动物群及白垩-第三系界线

南雄盆地上湖组介形类可划分为2个性质不同的动物群及4个化石带:下部为 Porpocypris 动物群,是以中生代属种为主,中、新生代属种混生的过渡性动物群,时代为晚白垩世最晚期;上部为 Cypris 动物群,以 Cypris 属占优势, Sinocypris 属开始出现, Cypridea 等古老属种绝灭为主要特征,时代为早—中古新世.根据介形类演化发展阶段和白垩纪末生物绝灭事件,南雄盆地白垩系与第三系的界线应划在 Porpocypris 与 Cypris 动物群之间,即上湖组坪岭段与下惠段之间.     

广东三水盆地晚白垩世的介形类动物群

依据24口钻井及4条地表剖面372个样品的采集和分析,三水盆地晚白垩世的介形类动物群含介形类化石28属81种,本文描述其中24属62种,包括1新种.此介形类动物群在数量上以女星介科和玻璃介科最繁盛,次为背足介科、湖花介科和类女星介科,依其横向分布及纵向变化规律,划分为Talicypridea和Porpocypris两个动物群及Talicypridea amoena带、Porpocypris globra带和Porpocypris sphaeroidalis带等3个化石带.依据介形类化石三水组可与南雄群对比,时代属晚白垩世早--中期.大塱山组与上湖组坪岭段对比,时代应属晚白垩世晚期.     

江汉盆地古新世的介形类

该文首次报道了江汉盆地可能属于古新世的非海相地层及其中的介形类化石,计有17属30种(其中新种3个),隶属于3个超科。该介形类动物群自下而上可分为:1.Porpocypris(?)-Paraily-ocypris-Cypridea组合;2.Sinocypris-Eucypris-Limnocythere组合。第2组合完全可与广东南雄盆地罗佛寨组的介形类化石群对比,时代可能为古新世晚期;第1组合的介形类是否可与广东南雄盆地上湖组的化石对比的问题,还有待今后发现更为可靠的Porpocypris属的代表分子来解决,这里暂置于古新世早、中期。     

广东南雄盆地罗佛寨群的介形类动物群

作者依据坪岭、武台岗、罗佛寨、城南、枫门坳、修仁、黄茅坪、暖水塘等8条剖面725个样品的研究,系统描述了罗佛寨群的介形类化石21属78种,包括2个新种;建立了罗佛寨群介形类序列,自下而上划分出.Porpocypris globra,Porpocypris sphaeroidalis,Cypris concina,Sinocypris excelsa和Cyprois reniformis 5个介形类化石带.前两个带合称.Porpocypris动物群,时代属晚白垩最晚期.后三带称为Cypris-Sinocypris动物群,时代分别为早、中、晚古新世.     

湖南衡阳盆地岭茶地区古近纪介形类动物群

描述衡阳盆地东北部岭茶地区介形类化石9属23种。岭茶地区古近纪介形类动物群以Cypris和Li mnocythere两属最繁盛,可划分为两个化石组合:栗木坪组为Cypris henanensis-Cyprois reniformis-Li mno-cythere honggangensis组合,岭茶组为Li mnocythereirregularis-Cypris favosa-Ilyocypris gaoyouensis组合。岭茶地区栗木坪组与珠江三角洲地区宝月组的介形类动物群相同,岭茶组与华涌组的介形类面貌也基本相同,因此栗木坪组和岭茶组的时代应属晚古新世和早始新世,这与栗木坪组和岭茶组中哺乳动物、古地磁和碳氧同位素的研究结果相一致。     

湖南衡阳盆地岭茶地区古近纪介形类动物群北大核心

描述衡阳盆地东北部岭茶地区介形类化石9属23种。岭茶地区古近纪介形类动物群以Cypris和Li mnocythere两属最繁盛,可划分为两个化石组合:栗木坪组为Cypris henanensis-Cyprois reniformis-Li mno-cythere honggangensis组合,岭茶组为Li mnocythereirregularis-Cypris favosa-Ilyocypris gaoyouensis组合。岭茶地区栗木坪组与珠江三角洲地区宝月组的介形类动物群相同,岭茶组与华涌组的介形类面貌也基本相同,因此栗木坪组和岭茶组的时代应属晚古新世和早始新世,这与栗木坪组和岭茶组中哺乳动物、古地磁和碳氧同位素的研究结果相一致。     

广州龙归盆地古新世介形类动物群

广州龙归盆地古新世介形类化石全部来自全取芯钻井剖面,据42口钻井1000个样品统计,发现介形类16属40种,本文描述其中15属39种。龙归盆地古新世介形类动物群以Cypris,Sinocypris,Cyprois,Li mnocythere四属分布最广、最常见,归属Sinocypris动物群,据其纵向分布规律,划分3个化石带,自下而上为:Ⅰ.Cypris con-cina带;Ⅱ.Sinocypris curtovata带;Ⅲ.Cyprois reniformis带。作者认为Ⅰ带的莘庄村组的时代属古新世早期,Ⅱ带的(土布)心组为古新世中期,Ⅲ带的宝月组为古新世晚期。     

广东南雄盆地南雄群的介形类动物群

南雄群及其介形类化石在我国晚白垩世非海相地层划分对比中占重要地位,主田和杨梅坑剖面主田组和浈水组中有270个样品含介形类化石,计有23属(2亚属)99种(12新种)。南雄群介形类动物群是以Talicypridea,Cypridea,Nanxiongium,Candoniella等4属为主,称Talicypridea Cypridea Nanxiongium动物群(简称Tali cypridea动物群)。该动物群在我国和蒙古的非海相地层中广泛分布,时代属晚白垩世中—晚期。     

广东三水盆地古近纪的介形类动物群

三水盆地古近系介形类化石主要来自全取芯钻井剖面.据170口钻井3 855个样品统计,发现介形类17属49种,本文描述其中16属47种,包括2个新种.三水盆地古近纪的介形类动物群以Sinocypris,Cyprois,Limno-cythere三属分布最广、最常见,故称Sinocypris-Cyprois-Limnocythere动物群,简称Sinocypris动物群.根据介形类化石纵向分布和富集规律,选择最常见主要属种的鼎盛时期建立5个化石带(顶峰带),自下而上为:Ⅰ.Cyprisconcina带;Ⅱ.Sinocypris pulchra带;Ⅲ.Cyprois reniformis带;Ⅳ.Sinocypris reticulata带;Ⅴ.Limnocythere ir-recularis带.本文把古新统(E1)/始新统(E2)界线放在Ⅲ/Ⅳ带之间,认为Ⅰ-Ⅲ带的莘庄村组、饰心组、宝月组的时代为古新世,分别为早、中、晚期,Ⅳ、Ⅴ两带的华涌组的时代为早始新世.     

山东平邑盆地晚白垩世介形类

山东平邑盆地固城组、卞桥组共发现介形类化石21属21种4比较种13未定种,本文记述了其中的17属16种4比较种9未定种。卞桥组一段下部的介形类可称为Talicypridea reticulata-Mongolocypris longa-Frambocythere fangjiaheensis介形类动物群,含化石地层的时代被确认为晚白垩世最晚期,即马斯特里赫特期的晚期。该动物群的发现,为平邑盆地白垩系/古近系界线的确定提供了十分重要的依据。     

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.