中国西部准噶尔盆地侏罗纪石树沟组的巨型兽脚类恐龙(英文)

中国西部准噶尔盆地东北缘中侏罗世晚期到晚侏罗世早期沉积的石树沟组(Eberth et al.,2001)产出过巨型的蜥脚类恐龙化石(Russell and Zheng,1993),但产出的兽脚类恐龙个体则相对较小(Currie and Zhao,1993)。我们近年来在石树沟组中采集到大量脊椎动物化石(Clark et al.,2006),其中包括许多零散的骨骼和牙齿标本。本文报道一个产自石树沟组上部的兽脚类牙齿化石(IVPP V 15310),对于全面了解石树沟脊椎动物群具有一定意义。V 15310保存了一个近乎完整的上颌齿或下颌齿的齿冠。它具有典型兽脚类恐龙牙齿的特征:强烈侧扁,向后弯曲,前后缘有锯齿。齿冠有几种不同的磨蚀面:齿尖磨蚀成近圆形,靠近齿尖的齿冠前缘有一较大的平的磨蚀面,锯齿也受到不同程度的磨蚀。V 15310很大,相关的测量数据和一些白垩纪的巨型兽脚类恐龙牙齿的测量数据相近。依据我们定义的一个定量评估锯齿大小的指标(锯齿大小指数),得出V 15310的锯齿大小指数非常小,与霸王龙相似,这与锯齿和齿冠大小具有反比关系的结论是一致的(Farlow et al,1991)。V 15310的另外一些形态特征对于推断它在兽脚类中的系统位置也提供了帮助。这些特征包括后缘锯齿明显高于前缘锯齿以及齿冠的唇侧和舌侧都有微弱的釉质褶皱。根据牙齿大小、釉质褶皱的发育程度以及锯齿的形态(Sereno et al.,1996;Chure et al.,1999;Holtz,2004),V 15310被归入中国盗龙类。其中,后缘锯齿和前缘锯齿的基部长度近似,但前者明显高于后者这一特征组合可能是中国盗龙类的一个鉴定特征。这一特征组合也见于四川的中国盗龙类。相比而言,V 15310在已报道的侏罗纪兽脚类恐龙牙齿中尺寸最大(Smith,2005;Smith et al.,2005),大小接近白垩纪的一些巨型兽脚类恐龙牙齿。新材料的发现表明兽脚类至少在晚侏罗世早期就已演化出了这种巨型体型。     

湖南株洲晚白垩世恐龙化石的初步研究

我国南方上白垩统产丰富的恐龙蛋化石,但发现的恐龙骨骼化石的种类和数量相对较少。本文对湖南株洲天元区新发现的恐龙化石进行详细研究。初步分析结果表明该化石点恐龙种类丰富,可能包括至少两种蜥脚类、三种兽脚类和一种鸭嘴龙类。其中部分蜥脚类材料可能归属于梁龙超科,填补了该类群在东亚上白垩统的空白记录;一个蜥脚类坐骨则显示泰坦巨龙类的典型特征。兽脚类材料可能来自于小型的虚骨龙类、暴龙科和鲨齿龙科。前两者为晚白垩世的常见类群,而鲨齿龙科的化石记录在上白垩统非常少见。本文为鲨齿龙科可能在东亚一直延伸至晚白垩世提供了新的证据。该地区多门类恐龙化石的发现表明我国南方恐龙的种类可能比我们想象的要丰富得多,而且可能是梁龙类和鲨齿龙类的最后栖息地。株洲恐龙动物群的发现对于了解亚洲特别是中国恐龙的生物地理区系的分布具有重要意义。     

中国河南晚白垩世地层一枚可能属于重爪龙亚科(兽脚亚目:棘龙科)的牙齿化石(英文)

中国河南晚白垩世中段地层马家村组发现了一枚大型兽脚龙类牙齿。该牙牙体长,呈圆锥状,横断面卵圆形,沿长轴微向后缘弯曲,前后缘均有大量锯齿状突起,这些特征显示其很可能是重爪龙类牙齿。这可能代表了重爪龙类在亚洲地区的首次发现,也是该类恐龙在晚白垩世地层中的首现,由此表明重爪龙类在时间和地域分布上较之前研究观点更为广泛。综合棘龙科的化石形态学以及推知的生态学证据看,较之其他兽脚类,棘龙类化石记录很少,很可能意味该类动物数量确实稀少,造成这种现象的原因可能是其过分特化的身体形态。     

我国学者在兽脚类恐龙研究方面取得重要进展

１９９９年９月１６日的英国《自然》杂志刊登了我国青年学者徐星、汪波林和吴肖春在兽脚类恐龙研究方面取得的最新成果。中国科学院古脊椎动物与古人类研究所辽西课题组在１９９８年度的野外工作中,从辽西义县组下部页岩中采集到一批珍贵的脊椎动物化石,其中包括一块保存有皮肤衍生物的兽脚类恐龙化石标本。这件标本代表兽脚亚目驰龙科的一个新属种,被命名为中国鸟龙（Ｓｉｎｏｒｎｉｔｈｏｓａｕｒｕｓ）。中国鸟龙和另外四种保存有皮肤衍生物的兽脚类恐龙,即中华龙鸟、原始祖鸟、尾羽鸟和北票龙一样,都产自我国著名的中生代化石产地…     

似鸟龙：恐龙中的素食主义者

提起恐龙,在大多数人印象里都是些体型庞大、暴躁凶残的食肉动物。旗下云集了始盗龙、暴龙、异特龙、窃蛋龙等一大批白垩纪著名"杀手"的兽脚类恐龙就更应该是这样了,兽字当头,岂能食素?但古生物学家最近发现,兽脚类中的似鸟龙类(Ornithomimosauria)却并不像以前人们认为的那样以肉食为主,而是一群偏爱植物的素食主义者。似鸟龙类恐龙与现生的一些犬型鸟类,如鸵鸟、鹈鹕,在形态上相当接近,只不过它们     

禄丰发现新的恐龙化石

我国著名的恐龙之乡———禄丰 ,最近在川街乡发现了一个新的恐龙化石墓地。恐龙化石产于中—上侏罗统的上禄丰组的底部的一套紫红色的砂质泥岩中。在已发掘的４００平方米范围内初步统计出露恐龙化石有巨型的蜥脚类恐龙骨架８具 ,其中有一具近于完整 ,长约１９米 ,肉食性兽脚类恐龙骨架一具 ,还有众多的蛇颈龟化石。埋藏学分析这些动物在死亡后遭到过搬运 ,但搬动的距离不远 ,化石保存较完好也较集中。经鉴定 ,蜥脚类恐龙应归于马门溪龙科 ,兽脚类恐龙相似四川上沙溪庙组产出的永川龙 ,它们生存的时代也应相近 ,距今一亿五千万年前中侏罗世…     

陕西鄂尔多斯盆地中三叠统一离片椎类牙齿化石

陕西省鄂尔多斯盆地渭北油田中三叠统铜川组发现一枚牙齿化石。该枚牙齿具有如下特征:牙齿细长,外形呈圆锥形,齿冠基部横截面为圆形,齿冠整体较直,沿长轴稍微向后缘弯曲,齿冠表面无齿脊和锯齿分布,发育纵向延伸的沟槽状纹饰。通过与鳄型类、蛇颈龙类和离片椎类的牙齿比较,该标本可以归入离片椎类。这枚牙齿化石为这一类群在中三叠统铜川组的首次发现,代表了离片椎类在华北板块最晚的化石记录。     

小盗龙亚科(兽脚亚目:驰龙科)——新标本及简评复合骨在兽脚亚目中的演化（英文）

小盗龙亚科是驰龙科兽脚类恐龙中新近发现的一个亚群,多数属种产自中国辽宁西部下白垩统热河群。本文描记一件产自辽宁省朝阳县大平房地区九佛堂组(热河群上段)的小盗龙亚科的新标本,该标本具有一些未曾报道过的有趣形态特征。尤其值得关注的是,一些特征呈现出介于中国鸟龙和小盗龙之间的过渡状态,其中部分来自牙齿和坐骨。这些特征突出显示了在更接近典型驰龙类的中国鸟龙和具有许多伤齿龙科特征的小盗龙之间存在着一系列的形态变异。然而,这些变异特征在分类上的意义尚未得到充分评估。特别值得一提的是该标本中相互愈合的耻骨和肠骨,这一特征有助于阐明复合骨在兽脚类恐龙中的演化模式。初步分析显示许多鸟类的复合骨都是通过在过型形成过程中各组分的顺序愈合形成的。     

安徽省黄山地区恐龙(足迹)脚印化石的初步研究

简要报道了安徽省黄山地区所发现的恐龙足迹化石。从脚印的形态和足迹上看,至少有三种不同的恐龙（蜥脚类、兽脚类、鸟脚类）共同生存过,其中多数恐龙为两足行走性的。记述了两个典型的小型兽脚类和小型鸟脚类恐龙所留下的脚印化石。黄山地区恐龙足迹、骨骼化石及其蛋化石的发现,对于研究晚白垩世恐龙生活习性以及古气候环境均有着一定的意义。     

内蒙古查布地区下白垩统巨齿龙足印化石

内蒙古鄂尔多斯市鄂托克旗查布地区下白垩统中产有大量的蜥脚类和兽脚类恐龙足迹及鸟类足迹化石,作者对这个地区的足迹化石进行全面普查,发现许多新暴露出来的恐龙足迹化石,包括兽脚类恐龙足迹一新属新种Chapuslockleyiichnogen.etichnosp.nov.属于巨齿龙类(megalosaurid)所留。与兽脚类足迹保存在一起的蜥脚类足迹Brontopodusbirdi分布凌乱,反映了造迹恐龙搏斗的场面。通过测量连续的兽脚类足迹计算,Chapuslockleyi的造迹恐龙的行走速度为4.33km/h。通过足迹化石还识别出造迹恐龙的病态特征。     

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.     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.