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.     

高山栎组化石——喜马拉雅山隆升的证据

巍峨的青藏高原,雄踞于地球之巅,这片既古老而又年轻的大地,以其独特的地理景观,丰富的自然资源和悠久的地域文化,曾召唤着来自不同国度和年龄段的科学工作者致力于以“青藏高原的隆起及其对自然环境和人类活动的影响”为主题的科学研究。他(她)们在这片惊险而又充满神秘色彩的雪域高原的崎岖山路上,留下了其足迹,取得的研究成果,为青藏高原综合研究的主题增添了耐人寻味的古生物学证据。翻开亚洲新生代地质历史,喜马拉雅山的上升被认为是最重要的地质事件。由于这条东西长2400余km,南北宽200~350km的山峦重迭、群峰林立的山系隆起,不仅制约…     

昆虫孤雌生殖中中心体的组装和意义

中心体是动物细胞主要的微管组织中心(microtubule organizing center, MTOC), 负责组织纺锤体.近年来, 关于昆虫卵母细胞减数分裂后中心体形成的深入研究对阐明昆虫孤雌生殖的过程和机制以及了解孤雌生殖的进化和形成具有重要意义.综述了第一次有丝分裂纺锤体的形成、中心体的装配以及中心体对于昆虫孤雌生殖的意义, 表明昆虫孤雌生殖的普遍模式就是在没有精子提供中心粒的情况下, 卵子通过新形成的中心体进行有丝分裂, 中心体自我组装限制的解除可能是进行孤雌生殖的转折点.     

沉水植物光合作用测定的电化学方法

光合作用速率测定是植物光合作用研究的重要基础,沉水植物由于所处生境的特殊性,难以应用在陆生植物光合作用研究中发展起来的速率测定方法.在对水体中二氧化碳的基本特征进行详细描述的基础上,介绍了在沉水植物光合作用研究中广泛应用的电化学方法--pH-stat法和pH-drift法的原理,并给出了应用实例.这两种测定水生植物光合作用的电化学方法所依据的溶液无机碳浓度的变化可以利用Gran滴定法方便地计算出来.     

进化论系列讲座(一)自古以来的问题——我们从哪里来?

今天,当我们谈起进化论的时候,没有人不知道达尔文的鼎鼎大名.没错,正是达尔文根据自己20多年的考察、研究和思考,在1859年出版了影响世界的《物种起源》一书,创立了以自然选择为机制的生物进化理论体系.这个理论就像一盏明灯,照亮了当时那个被《圣经》的教义笼罩得黑沉沉的人类精神世界,使越来越多的人看清了有着更为客观之来龙去脉的世间万物更为真实的面目,同时也给整个科学界和人类的认识领域开启了一个全新的视野.对于生物学这支科学的舰队而言,进化论就象指南针一样,引导着代表各个分支学科的航船向着更远的方向协调前进.当这支舰队已经驶入诸如“人类基因组计划”和“克隆”技术这些现代领域的时候,回顾航迹我们发现,如果没有进化论,这个乘风破浪的远征是无法想象的.     

微生物在水环境污染物降解中的应用

每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中,因此,地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂,除草剂、烃等)的严重挑战,特别是近年来随着集约化养殖的发展,废水污染问题日益突出,并且随着分析手段的进步,能够检测到被排入水环境中的化学污染物质也越来越多,这些化学污染物对水环境中的生物产生有害影响.但是,微生物在污染控制上具有许多重要的作用.因此,本文对微生物在水环境污染物降解中的应用进行了评论.结果表明微生物主要是应用在水产养殖水中,而在其它的水体系(如河、湖、海)的应用较少.     

和狗狗一起去冒险

一群雪橇犬在被冰雪覆盖的南极大陆上孤独地生活着,除了必要的觅食,还坚守着早已人去楼空的勘测站,难以想像的175天——这就是电影《南极大冒险》,一个感人至深的故事。南极大陆是令人神往的地方,圣洁的冰雪世界总给人无尽的遐想,一群科学家为了寻找火     

有機體舆生活條件的統一

在唯物主義的米丘林生物學的基本規律中,關於有機體與他的生活條件的統一這個命題,占據着中心地位。為了支配的目的而了解及掌握有機體的個別的發展及生物的質的改造——物種及變種的界限等,必須對這個命題作多方面的學習,才能達到。因此可見,在講授生物學原理時,使學生對於有機體與他的生活條件的統一的命題,獲得正確的了解,必須予以特別的注意。雖然初看時,這個命題,似乎是很簡單而明白的,然而這種看法往往是不正確的。     

能源危机与生物量

当前,世界上存在着严重的能源危机。据有关专家估计,世界原油如以目前的速度消耗,到二十一世纪中即全部告罄。在这种形势下,各国政府都采取了相应的对策,开发能源作为一个新课题,已十分紧迫地提到科研的日程上。 据调查我国煤和石油的储量不能完全满足未来经济发展的需求,我国也在注意寻找能够代替传统的煤和石油的新能源,如太阳能,风力、地热、生物动力资源……等等。 随着生物工程的飞速发展,对生物量的利用也取得很大进展。从节能与防止环境污染的角度看,利用生物量开发新能源是很有前途的。     

达尔文与米丘林生物学

70年前,1882年4月19日,关于生物界演化的唯物学说的创造者,在生物科学中完成了大革命、把生物学奠立在科学基础上的天才的学者查理士·达尔文逝去了。在将近一世纪的期间,先进的生物科学依靠于奠立在达尔史著作基础上的进步的思想,顺利地发展着,获得了日新月异的成就。反动的科学千方百计的企图颠覆达尔文主义,仍然遭受到了失败。     

人类活动影响下新疆生态环境的一些变化

人类活动引起的新疆生态环境变化主要有以下几方面:1.河流流程缩短,河水矿化度和泥沙含量增加;2.湖泊水位下降,湖面缩小或变干,湖水矿化度升高;3.森林破坏,面积缩小;4.草场的产草量降低,牧草质量下降; 5.土壤次生盐渍化、沼泽化和肥力下降;6.土地沙漠化不断扩大。     

基因药物的前沿技术

基因药物的直接体内基因治疗发展迅速,新型基因药物不断产生。本文讨论了效果比较肯定的基因疫苗、反义ＲＮＡ药物、三链ＤＮＡ药物这三种新型基因药物技术的基本方法。分析了它们各自存在的优点和问题,并介绍了它们的应用范围及应用研究进展。     

Diagnosis of Helicobacter pylori

The different invasive and noninvasive diagnostic tests for Helicobacter pylori have been applied mainly in emerging countries. Molecular methods have been developed, especially a test for detection of H. pylori and its clarithromycin resistance directly from stools. The long-term effects of eradication on histologic lesions have been studied in a meta-analysis and the prognostic value of post-treatment in gastric mucosa-associated lymphoid tissue lymphoma has been assessed. An operating link for gastritis assessment (the OLGA staging) has also been published. Attempts to simplify the urea breath test protocol have been made, and new stool antigen tests have been proposed and compared to those previously available.     

Starch phosphorylase enzymes in developing and germinating pea seeds

Phosphorylase has been fractionated during development and germination of seeds of smooth and wrinkled-seeded peas. The total phosphorylase levels have been compared. In addition, a number of other pea tissues and other legumes have been examined. Some kinetic properties of the two enzymes present have been measured. Both enzymes have been further purified by affinity chromatography on Sepharose 4B-starch columns and by sequential gel filtration in the absence and presence of amylopectin. The MW and sub-unit structures of the two enzymes have been examined and their possible roles discussed.     

Synthesis, resolution and charge-donor properties of six tryptophan analogues.

In order to investigate the special function of tryptophan in peptide hormones, six tryptophan analogues have been synthesized, in which structural resemblance has been grossly retained and potentially essential properties have only partially been varied. The L-enantiomers have been isolated after enzymatic digestion of racemic dipeptide derivatives, and charge-transfer properties of the compounds have been studied.     

Colorectal carcinoma antigens detected by hybridoma antibodies.

Hybridoma cells which secrete colorectal carcinoma-specific antibodies have been produced and used to study the antigenic structure of these tumor cells. Nineteen antibodies have been studied in detail, and 15 of these are colorectal carcinoma specific. Only two antibodies reactive with carcinoembryonic antigen (CEA) have been discovered and five other antibodies that react with distinct epitopes on the cell surface have been defined. Several antigens with distinct molecular characteristics have been shown to exist by use of hybridoma antibodies. Six hybridoma antibodies have been shown to mediate antibody-dependent cell-mediated cytotoxicity (ADCC).     

Phage display in pharmaceutical biotechnology

Over the past year, methods for the construction of M13 phage-display libraries have been significantly improved and new display formats have been developed. Phage-displayed peptide libraries have been used to isolate specific ligands for numerous protein targets. New phage antibody libraries have further expanded the practical applications of the technology and phage cDNA libraries have proven useful in defining natural binding interactions. In addition, phage-display methods have been developed for the rapid determination of binding energetics at protein-protein interfaces.     

Analysis of the aliphatic 1H-NMR spectrum of plasminogen kringle 4. A comparative study of human, porcine, bovine and chicken homologs

The aliphatic 1H-NMR spectrum of the kringle 4 domain of human plasminogen has been studied via two-dimensional chemical shift correlated (COSY) and nuclear Overhauser correlated (NOESY) experiments at 300 MHz and 620 MHz. A number of aliphatic proton spin systems have been identified and several definite assignments have been made. This was mainly achieved by comparison of the human kringle 4 spectrum with spectra of the porcine, bovine and chicken homologs and also with that of the kringle 1 from human plasminogen on which we have reported previously. The three valyl and two leucyl residues of human kringle 4 have been assigned. The eleven threonyl spin systems have been identified via a RELAYED-COSY experiment and Thr17 has been assigned. The three alanyl spin systems have been identified and assigned. Six seryl spin systems have been identified and the signals from the seven glycyl residues of human kringle 4 have been located with Gly45 assigned. Furthermore, 24 AMX spin systems have been mapped in the COSY spectrum of human kringle 4 and H alpha-H beta,beta' spin systems of Tyr2, Tyr41, Tyr50, Tyr74, Trp25 and Trp62 have been assigned. From the spectrum of a deglycosylated chicken homolog, the epsilon-methyl singlets of Met28 and Met48 have been assigned. Finally, ligand effects on selected aliphatic resonances were observed which could be analyzed in terms of residues likely to neighbor the kringle lysine-binding site.     

Measurement and study of the nose and face and their correlations in the young adult of Han nationality

The measurement of 13 items in the face and nose of 220 young adults (110 males and 110 females) of the Han nationality between the ages of 18 and 21 years has been done in the Henan Province of China. The means and standard deviations have been obtained, and the significant differences in many items between males and females have been proved. Some items influencing outer nasal shape have been analyzed. The correlations between nose height, nose length, and morphologic facial height and physiognomic facial height have been discussed. The ratio and amount of nasal breadth to facial breadth and nasal breadth to interocular breadth have been compared and analyzed, and the differences among the different races and between the sexes have been explained.     

Examination of substrate and product inhibition kinetics on the production of ethanol by suspended and immobilized cell reactors

Kinetic expressions for the fermentative production of relatively high concentrations [12% (w/v)] of ethanol have been examined. Several expressions which account for both substrate and product inhibition have been formulated, and have been applied to suspended cell and immobilized cell reactors. Experimental data have been used to validate the kinetic expressions used, and the impact of combined inhibition on optimal reactor configuration has been assessed. The process implications of combined substrate and product inhibition for suspended and immobilized cell systems have been discussed.