和县动物群与深海沉积物的对比

根据对和县动物群中哺乳动物成分、性质等的分析,它应代表一个寒冷期。当时和县一带的气候,似与今日华北南部的气候类似,但又较之湿润。它的层位大体上相当于周口店第一地点的3—4层;其地质时代相当于海洋的O~(18)的第8阶段,距今约28—24万年。     

华北四个古人类遗址的哺乳动物群及其与深海沉积物的对比

根据华北地区四个主要的更新世哺乳动物群的性质及其地层学的资料,认为大荔动物群的时代相当于深海O~(18)的第6—7阶段;周口店动物群出现在第8—12阶段;陈家窝动物群与第16—17阶段相当;而公王岭动物群则出现在贾拉米洛事件之前。     

周口店北京猿人洞骨化石铀系年龄数据——混合模式

铀系混合模式得出北京猿人在第一地点生活的年代是距今50万年到23万年。通过周口店猿人洞堆积物骨化石中 Th~(230)/U~(234)和 U~(234)/U~(232)的测定,建立铀系混合模式,给出下列年龄值:第1—3层距今23万年,6—7层距今35万年,8—9层大于40万年,12层距今50万年前或更早。一些中间层位的Th~(230)/U~(234)比值测定年龄偏低,可能是近20万年以来铀发生迁移造成的。     

北京猿人第一个头盖骨及其遗址堆积层年代的电子自旋共振测年研究

裴文中教授在60年前发现的北京猿人第一个头盖骨埋藏的确切年代至今没有获得。本文通过对北京猿人共生的古脊椎动物牙化石进行电子自旋共振(ESR)测年,分别获得了第11层北京猿人第一个头盖骨埋藏的年代为578千年,第8—9层和第3—4层北京猿人埋藏的年代分别为418千年和282千年。依据ESR、U系,TL,FT和古地磁等测年结果,本文推荐了北京猿人洞的洞穴堆积层(周口店组Q_2)年代表供读者参考。     

周口店第一地点粪化石的初步观察

从1964年起,我们整理了周口店北京猿人化石产地(周口店第一地点)的粪化石,以及我国其他化石地点,如广西柳城巨猿洞里的一些同类材料。在整理工作中,清理出周口店遗址现有的粪化石,除破碎的外,约有1500枚左右。在遗址目前发掘到达的40米厚的堆积物剖面中,它们和其他化石一起,占据了从底部到上部的好几个层位,如第10层,第8—9层,第6层等。这些标本,有时密集成层,也有的是较零星的分布的。     

南京汤山早期人类及南方几个猿人遗址的生活环境

南京汤山的早期人类的地质时代相当于中更新世晚期,距今12.7—50万年。该动物群是一个单调的北方型动物群,生活在寒冷期,相当于深海氧同位素的等10阶段,距今33—37万年。郧县的古人类与蓝田的公王岭动物群同时,为早更新世,距今100—140万年。它们生活在温暖期,相当于欧洲的Waalian暖期。与元谋人共生的元谋动物群(相当于元谋组的第四段)包括许多典型的北方型动物,如复齿鼠兔,泥河湾剑齿虎、麅、羚羊等,故它们生活在寒冷期,也属早更新世,距今140—190万年。     

北京猿人生活时期自然环境及其变迁的探讨

本文回顾了北京猿人生活环境研究的概况,利用哺乳动物化石材料,从动物地理、生态、层位变化三方面进行分析和讨论。主要结论为:1)北京猿人生活时期的气候为温带气候,和今日北京一带相似,但较为温和湿润;2)当时周口店附近不是单一的自然景观,草木较今日繁盛;3)北京猿人生活时期气候有过多次波动。从第11层起大致可分为三大段落:第11—10层可能为温带气候、第9—5层为温暖潮湿的气候、第4—1层为温带半干旱的气候。上述结论大致和孢粉分析的结果吻合。     

北京猿人洞穴堆积反映的古气候变化及气候地层上的对比

周口店第一地点洞穴堆积厚达40余米,可划分为17层。它们分别由角砾层与非角砾层(灰烬层、泥砂层以及钟乳石层)等组成。其中角砾层代表冰期、寒冷期或氧同位素的偶数阶段;非角砾层则代表间冰期、温暖期或氧同位素的奇数阶段。它们表明:在中更新世时,周口店地区气候的冷暖变化是明显的,而且气候的大陆性程度有逐渐加强的趋势。第一地点、新洞以及山顶洞等地的沉积物与洞外堆积、陕西洛川的黄土以及深海沉积物等均可进行气候地层学上的对比。     

甘肃灵台雷家河新第三纪晚期的大哺乳动物组合及其时代

讨论的大哺乳动物化石出自甘肃灵台雷家河村东南小石沟[72074(1)、72074(4)]和文王沟(93002)等地的新第三纪晚期地层。它们包括15种,分属8属、9科、4目,可能代表两个不同时代的组合。第一组合所在的地层层位是72074(4)剖面的L5~L3层和72074(1)剖面的第3层,主要由 Hipparion pater、Acerorhinus sp．、Nyctereutes．、 Hyaeninae gen．et sp．indet．和Gazella niheensis等类型组成,其性质与山西榆社高庄组南庄沟段和醋柳沟段产出的大哺乳动物的接近,时代可能为中上新世。第二组合所在的地层层位是72074(1)剖面的第2层,以Anancus sinensis 和Cervidae gen．et sp．indet．为代表,其性质与榆社麻则沟组动物群的相近,时代为晚上新世。     

中国陆相新第三系的初步划分与对比

本文着重介绍了欧洲地中海区新第三纪研究的进展、分期和对比,并提出我国新第三纪哺乳动物群的分期及与世界对比的初步设想。文中着重阐明将蓬蒂期(Pontian(s. s. )相当于我国保德三趾马红土)置于中新世的根据,并建议把新第三纪/第四纪的界限放在1.8百万年(相当奥杜威事件)。对中新世,作者建议划分为五个不同的期:早中新世,谢家期;中中新世早期,山旺期;中中新世晚期,通古尔期;晚中新世,坝河期和最晚中新世,保德期。对上新世的划分目前尚有困难,建议暂时保留静乐期,代表上新世早期,大体相当欧洲的路西南期(Ruscinian, MN14—MN15)。借用游河期代表上新世晚期,约相当于欧洲的维兰尼期(Villanyian,MN16—MN17)。     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various