走进内蒙

2015年8月1日,我们每一个人收拾好行囊,整装待发,在邓涛老师带领下踏上了去往内蒙古的征程,拉开了探索灰色生命之旅的序幕. 队伍由两辆车、8人组成,我们早晨7点从中国科学院古脊椎动物与古人类研究所出发,披着清晨的阳光,摆脱城市的拥挤,缓缓地“逃离”了北京城.直到抵达张北之后我们的车子才能像矫健的马儿一样驰骋在广袤的公路上,沿途没有了城市的喧闹,没有了交通的堵塞,伴随我们的只有那一眼望去蓝蓝的天空、随风摆动的小草,以及那迷人的风景,偶尔打开车窗,一股凉爽的清风扑面而来,沁人心脾.经过一路的颠簸,我们在傍晚时刻到达锡林浩特,当地文物保护站的同志为我们安顿好了一切.     

小鼠基因组中的微卫星重复序列的数量、分布和密度

作者分析了老鼠基因组中各染色体及其内含子、外显子和基因间区上各种类型的微卫星(1-6个碱基的重复序列)的数量及其密度。SSR约占老鼠基因组的2.85%,其中46.2%存在于基因间区,4.75%存在于外显子,49.05%在内含子区域,即非编码区富含微卫星。微卫星的数量与染色体或基因区域的大小有关,但密度与染色体或基因区域的大小的关系并不十分密切。第4染色体的外显子区域中6种类型的SSR含量都比其它区域少。A,T,AC,AG,AT,AAC,AAG,AGG,AAAC,AAAG,AAAT,AACC,AAAAC,AAAAG,AAAAT,AAACC,AAAGG,AAGAG,AAAAAC,AAAAAG,AAAAAT,AAAGAG,ACACAT,ACAGAG,ACAGGC,ACATAT是老鼠基因组中主要的SSR类型,而一些5碱基重复单元的SSR在老鼠基因组的某一条甚至某几条染色体都不存在     

考察心语

正在亚东原始森林考察前,咨询当地林业局朋友,得知,上月的一场大雨,道路被严重损毁,车辆只能到达半山处……途中,我们多次下车推车,艰难行进!当我们的车行驶到可能是半山处时,路真的被水给冲毁了,车不能再前行了,我们只好步行完成余下的路程,虽然累些,观察拍摄的机会却多了许多。背着重重的器材等,步行进入了下亚东原始深林,耳畔是隆隆的河水声,映入眼帘的是郁郁葱葱青山。在这里,我听见印度洋暖湿气流撞击岩壁发出的声音撼人心魄。空中的云随气流快速移动,沟里的雾在时断时续的阳光照射下蒸腾,当云雾散开时,可见层层叠叠的山外青山,高不可攀,目不可及。同一地点,一会阵雨,一会晴。林中高大的古树多被雷电击断,然后又顽强地发出新枝,吐露新芽。     

周细胞的研究进展

长久以来,周细胞的存在和作用一直很少受重视.但是作为微血管的构成成分之一,周细胞在微血管的发生、发展、稳定、成熟,以及再塑形的过程中都起着重要作用,近来越来越受到关注.本文就周细胞的定位,结构,表达,功能,相关的信号通路,以及和内皮细胞的相互作用进行了综述,为在周细胞的研究提供参考.     

酸雨与微生物

近些年来,酸雨的危害日益引起国际上的关注,我国把酸雨的成因、危害及其防治等方面的问题列入国家重点科研项目,据文献报道,酸雨不仅对农牧业、森林业带来灾难,而且对人类的安全造成威胁,这是当今世界“天然祸害”之一,有人认为这是生物圈的一大病症。随着工业化的大发展,酸雨形成及其危害日益严重,它不但损害自然环境、农作物、森林、水生物以及耐旱的地衣等等,也给人们尤其是老人和儿童的健康带来严重危害,据统计,欧洲一些国家每年因酸雨致死的老人和儿童好几千人,如联邦德国每年达2000—4000人,英国最多的一年可达5000人。这是人们非常关切的一个问题,应引起各有关部门的密切注视。     

姜黄素的提取及其甲基化研究

以姜黄为原料,用70%的乙醇进行粗提,正丙醇进行两次重结晶得醇的姜黄素.再以此纯的姜黄素为原料,用乙醚和甲醇溶解,以过量的CH3I为甲基化试剂,在pH=12～14的条件下进行反应10 h,用氨水沉淀,过滤,水洗至中性,烘干,在经层析柱分离得到一种黄色针状物,经鉴定为一新化合物,即纯的二甲基姜黄素,分子式为C23H24O6,收率为35%以上.     

我家有个机灵鬼

小宠故事多一天,我放学回家,瞧见路边有个阿姨面前摆着一个箱子,里面装着二十几只小鸡,叽叽喳喳活蹦乱跳,可爱极了!我仔细瞧着它们,有红的、黄的、紫的、绿的……其中,一只被染成浅紫色的小鸡最为机灵,它浑身毛茸茸的,黑葡萄似的眼睛警惕地望着四周,好像随时会蹿出一只老鹰叼走它似的。我对这只特别的小鸡产生了好奇,便在征得了爸爸妈妈的同意后,把它带回了家,给它取了个外号——机灵鬼。     

脱落酸（ABA）在蒜苔衰老中的作用

蒜苔在切除珠蒜后可减少贮存中干物质的损失,延缓衰老,在切口处施加外源ABA可加速苔干叶绿素的破坏和组织的老化,气相色谱与色质联用法检测完整蒜苔和无珠蒜蒜苔各部分组织中ABA含量在衰老过程中的变化,发现无珠蒜苔干上,中,下各段ABA含量在衰老进程中是逐步减少的,变化幅度小,而带有珠蒜的苔干各相应段和珠蒜的ABA含量均有一迅速增加而后减少的过程,珠蒜的ABA含量最大,ABA含量高峰出现时间最早,苔干各段ABA含量按上,中,下顺序依次减少,高峰出现的时间也是由上至下依次推迟,没有发现蒜苔在衰老过程中有乙烯放出,外加乙烯对其衰老进程影响不大,本文认为珠蒜是蒜苔衰老的关键部位,能加速苔干衰老的ABA主要是在珠蒜中合成的,并自上向下极性运往苔干组织,进而动员物质的再分配,起着信息传递作用,蒜苔的衰老过程可分为“准备期”和“活跃期”两个阶段。     

植物保护伞

在高温炎热的夏季,植物为了降低自身温度,叶片会自动提高其蒸腾速率,但叶片旺盛的蒸腾作用常常会导致植物体内水分收支失衡,入不敷出,从而出现严重缺水萎蔫,导致植株部分或全部死亡等现象。与此同时,干旱的气候还使植物可吸收的水分有限,特别是对于新移栽的树木,其根系已受到不同程度的伤害,吸水能力尚未全部恢复,此时如不采取适当保护措施,则会影响植物的正常生长或造成移栽树木的死亡。针对上述的情况,人们通常只能对树木进行少量的修剪,以减缓植株地上部分的伤害。为了解决上述过度蒸腾给植物造成的危害,一种新型的夏季型植物抗蒸腾剂现…     

途中偶拾:别样的精彩

正来到西藏,卸去一身的俗务,放下身份和角色,没有网络,没有手机信号,我们在这些简单的元素里走进自然,贴近自然,得到的是超乎想象的精神和视觉的双重盛宴。透过镜头,我们重新拾回心的世界。在登山临水、惊叹河流悠长、玄想星辰回转时,开始重新打量自己。则里拉上空的鹰鹰,空中的霸主,著名的掠食者,动物界里至今还没其他物种能撼动其空中霸主的地位。它孤傲、凶猛,在空中所向无敌。一直以来鹰的形象都是     

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.