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1.
以CH4、N2加热含氨、硫化氢水相混合物, 在3500V高压、电火花连续放电24h, 考察H2S在化学进化中的作用. 气相用质谱分析 , 水相经浓缩纯化并制成衍生物, 气相色谱测定有14种氨基酸. 体系中若无硫化氢时, 只生成六种氨基酸. 这表明硫是合成生命基础分子的必需元素, 可能在原始地球空间的化学进化过程中起重要作用.  相似文献   

2.
杨晓达  张天蓝  王夔 《化学进展》2004,16(5):836-841
在探索生命奥秘的过程中,生物无机化学研究由分子层次上升到细胞层次是一个必然的趋势,也是解决实际问题的需要.细胞无机化学研究在细胞生命体系中的无机化学反应和探索无机物对生命过程调节或干预的作用和机理,是探索生命体系复杂性研究的重要部分.细胞是保留完整生命活动特征的最小单位,存在周期、分化和受激等状态的不同.从化学的观点,细胞是一个严密设计的分子有序组装体,为一个多靶分子系统,细胞应答表现为由相关反应组合成的复杂过程.细胞无机化学研究包括无机物种在细胞膜上的结合和随后发生的膜结构和功能改变、跨细胞膜和跨生物组织屏障的转运和细胞代谢、细胞中无机化学反应同细胞信号系统的偶联、无机离子与自由基的相互代谢关系以及细胞-无机物固相的相互作用等方面.本文对当前细胞无机化学研究的重点问题进行了讨论.  相似文献   

3.
1808年英国化学家Davy通过电解反应,得到了一种在空气中剧烈燃烧,发出黄红色火焰的金属,他把它命名为钙(calcium),Calcium是由拉丁文Cai(l石灰)而来的。有人说"钙乃生命之本",实不为过,从生命进化过程就可看出,若无钙组成的骨骼依附着血肉,就无生命的运动。  相似文献   

4.
自然界中,糖类不仅作为生命体系的能量物质和结构物质,而且还作为信息分子在生命过程的细胞识别和调控中扮演着重要的角色,因此对糖识别的研究将极大地有助于糖类参与生理和病理过程的研究。生命体系中糖识别过程一方面基于受体的极性基团与糖羟基的氢键作用,另一方面依靠受体结构中的含芳环非极性基团与糖CH基相互作用,所以在极性溶液水中通过非共价键相互作用实现糖识别过程是当今化学界一个十分吸引人且又极具挑战性的研究课题。人工合成糖识别受体为研究自然界中糖识别过程的基本机制提供了一种有参考价值的模型系统,同时为仿生应用提供了有力的技术支持。本文从超分子化学、多分枝型、合成凝集素类和聚合物界面4种体系论述了近年来非硼酸类人工糖识别受体在水相中识别糖的研究进展及其潜在应用,并且对合成凝集素和界面糖识别体系做了特殊点评,最后对仿生人工合成受体在水相中对糖识别的未来的发展方向做了展望。  相似文献   

5.
二十世纪以来,自然科学日益成为对自然演化发展史的抽象和概括.化学是研究自然史中由原子至原始生命这一极其重要过程的学科.在自然科学体系中,研究这一过程之前的自然史如核物理、天体物理学、量  相似文献   

6.
从生物的进化过程就可以知道钙与生命有着密不可分的关系。从最原始的腔肠动物——珊瑚虫开始,它的生长过程是从海洋中不断吸收钙并逐次累积,最后组成无数白色枝状钙树即珊瑚礁;腔肠动物经过进化成为软体动物如贝类,此时钙组成贝壳以保护里面的生命体,软体动物已能四处游动;再进一步进化的是脊椎动物,从鱼类圩始,钙组成骨骼和鱼鳞,使它们自由漂游于海水中;  相似文献   

7.
化学进化是生物进化的基础,新课程必修教材关注“化学进化”观念的建构,“化学进化”观念可以从化学与生命的共同进化、化学与认识的协同进步、化学与社会的可持续发展等3个方面来建构,体现化学中人文精神的韵味。  相似文献   

8.
研究了氨基酸与磷酸二氢钠在微波作用下的成肽反应, 结果显示在较短时间里可获得二肽到八肽以及环肽. 同时伴有磷酸氢盐分子间缩合形成多聚磷酸盐的反应. 在微波作用下, 温度200℃反应2 h后磷酸盐的聚合度可达到99%(其中焦磷酸盐64%, 三偏磷酸盐35%). 在反应产物的ESI-MS中还检测到了磷酸盐与甘氨酸分子间脱水生成的混酐中间体. 三偏磷酸盐与氨基酸在水体系中也有成肽反应, 在室温下缬氨酸成肽的转化率达到46%. 发现并证实了在微波作用下“氨基酸-磷酸盐”的体系中可以实现氨基酸生成肽及磷酸盐聚合、再生、利用的循环过程, 在这个过程中只需要输入能量就可以源源不断的生成肽, 这也许是生命起源以前的化学进化中氨基酸成肽的最可能途径.  相似文献   

9.
研究了氨基酸与磷酸二氢钠在微波作用下的成肽反应, 结果显示在较短时间里可获得二肽到八肽以及环肽.同时伴有磷酸氢盐分子间缩合形成多聚磷酸盐的反应.在微波作用下, 温度200℃反应2 h后磷酸盐的聚合度可达到99%(其中焦磷酸盐64%, 三偏磷酸盐35%).在反应产物的ESI-MS中还检测到了磷酸盐与甘氨酸分子间脱水生成的混酐中间体.三偏磷酸盐与氨基酸在水体系中也有成肽反应, 在室温下缬氨酸成肽的转化率达到46%.发现并证实了在微波作用下"氨基酸-磷酸盐"的体系中可以实现氨基酸生成肽及磷酸盐聚合、再生、利用的循环过程, 在这个过程中只需要输入能量就可以源源不断的生成肽, 这也许是生命起源以前的化学进化中氨基酸成肽的最可能途径.  相似文献   

10.
随着化学研究的对象向生命、纳米和表面等复杂反应体系的深入, 提出了非平衡、非线性和复杂性等深层次的科学问题. 结合我们对复杂化学体系中非线性问题的理论研究, 简要介绍了与之相关的若干前沿课题: 非线性态-态动力学, 复杂网络体系非线性化学动力学和介观化学体系非线性动力学. 这些问题的研究, 对于探索化学过程新的动力学规律, 开拓控制化学过程新的原理, 揭示生命体系中化学过程作用的新机制, 推动化学学科与生命、物理等其他学科的交叉渗透, 都将作出重要贡献.  相似文献   

11.
《印度化学会志》2021,98(10):100164
COVID-19 is considered as a major public health problem caused by the SARS CoV-2. This Viral infection is known to induce worldwide pandemic in short period of time. Emerging evidence suggested that the transmission control and drug therapy may influence the preventive measures extensively as the host surrounding environment and pathogenic mechanism may contribute to the pandemic condition earlier in COVID-19 disease. Although, several animals identified as reservoir to date, however human-to-human transmission is well documented. Human beings are sustaining the virus in the communities and act as an amplifier of the virus. Human activities i.e., living with the patient, touching patient waste etc. in the surrounding of active patients or asymptomatic persons cause significant risk factors for transmission. On the other hand, drug target and mechanism to destroy the virus or virus inhibition depends on diversified approaches of drugs and different target for virus life cycle. This article describes the sustainable chemical preventive models understanding, requirements, technology adaptation and the implementation strategies in these pandemic-like situations. As the outbreak progresses, healthcare models focused on transmission control through disinfections and sanitization based on risk calculations. Identification of the most suitable target of drugs and regional control model of transmission are of high priority. In the early stages of an outbreak, availability of epidemiological information is important to encourage preventive measures efforts by public health authorities and provide robust evidence to guide interventions. Here, we have discussed the level of adaptations in technology that research professionals display toward their public health preventive models. We should compile a representative data set of adaptations that humans can consider for transmission control and adopt for viruses and their hosts. Overall, there are many aspects of the chemical science and technology in virus preventive measures. Herein, the most recent advances in this context are discussed, and the possible reasons behind the sustainable preventive model are presented. This kind of sustainable preventive model having adaptation and implementation with green chemistry system will reduce the shedding of the virus into the community by eco-friendly methods, and thus the risk of transmission and infection progression can be mitigated.  相似文献   

12.
Aptamers are a series of high-affinity and high-specificity oligoneucleotides (single-stranded DNA or RNA) to the target, usually selected by the combinatorial chemistry SELEX technique (systematic evolution of ligands by exponential enrichment). Aptamers have proved to be one kind of novel functional molecules in life science and chemistry. After being labeled by signaling groups, the aptamer probe can conveniently transfer the characteristics of aptamer-target recognition to a form of high-sensitive signal, and the high-affinity, high-specificity measurements of metal ion, organic molecules, nucleic acid, proteins, or cells become possible. This article summarizes the recent advances of aptamer probes in different sensing fields, with special emphasis on aptamer probes as fluorescent sensors.  相似文献   

13.
赵玉芬 《大学化学》2019,34(12):86-90
Phosphorus is one of the important elements for life, which participates in various biochemical processes. L-Amino acids are the basic structural units of proteins. N-phosphorylation of amino acids makes them be activated and become one kind of "micro activating enzyme", which possesses a variety of biochemical reaction activities, such as peptide formation. Based on the peptide formation reaction of N-phosphoryl amino acids, L-seryl-L-histidine dipeptide (Seryl-histidine dipeptide) is produced and found that it is the smallest functional peptide with a variety of biological enzyme activities. Seryl-histidine dipeptide could be regarded as the original evolution prototype of modern hydrolytic enzyme. This paper reviews the research process from N-phosphoryl amino acids to the discovery of seryl-histidine dipeptide in detail. There are pain, confusion and joy, which fully embodies the charm of scientific exploration.  相似文献   

14.
Explaining the emergence of life is perhaps central and the most challenging question in modern science. Within this area of research, the emergence and evolution of the genetic code is supposed to be a critical transition in the evolution of modern organisms. The canonical genetic code is one of the most dominant aspects of life on this planet, and thus studying its origin is critical to understanding the evolution of life, including life’s emergence. In this sense it is possible to view the ribosome as a digital-to-analogue information converter. Why the translation apparatus evolved, is one of the enduring mysteries of molecular biology. Assuming the hypothesis that during the emergence of life evolution had to first involve autocatalytic systems, which only subsequently acquired the capacity of genetic heredity, in the present article we discuss some aspects and causes of the possible emergence of digital, discrete information arising from analogue information realized in the intra- and inter-molecular interactions throughout molecular evolution. How such reverse translation was achieved at a molecular level is still unclear. The results of such debates and investigations might shift current biological paradigms and might also have a momentous significance for modern philosophy in understanding our place in the universe.  相似文献   

15.
Ni-Sn电极析氢性能研究   总被引:6,自引:0,他引:6  
常天义  张宝宏  丛文博  骆耀 《电化学》2002,8(3):343-347
在Fe基底材料上电镀Ni_Sn合金制备低析氢过电位的阴极活性材料 .该材料适用于氯碱工业隔膜型电解槽 ,可达到降低槽压、节能降耗的目的 .在电解槽阴极溶液NaOH 12 0 g/L ,NaCl190 g/L ;温度 90℃ ,阴极极化电流密度i=15 0mA/cm2 的条件下 ,测得其析氢过电位为 88mV .X射线衍射分析表明 ,该种材料与传统装饰用Ni_Sn合金的结构状态有所不同 .采用循环伏安法对Fe电极和Ni_Sn合金电极进行分析 ,可初步判断Ni_Sn合金对氢的吸附较弱 ,有利于析氢反应的进行  相似文献   

16.
以具有新型多级孔中空薄壳结构的ZSM-5分子筛(Gel-ZSM-5)作为催化剂,正十六烷作为探针分子,研究了催化剂的孔道结构及酸性对大分子催化裂化反应的影响.实验结果表明,该催化剂中的介孔、大孔多级结构非常有利于大分子反应物、中间产物以及结焦物在其表面及内部的快速传输,从而大幅提高催化转化率并延长了催化剂寿命;另外,催化剂多级孔表面的大量酸性位点可以显著提高针对大分子的催化反应性能,并且明显改善了产物的选择性.在较短的反应时间下,这种构效关系体现得更加显著.因此,合理的酸性分布和多级中空薄壳孔道结构将赋予催化剂在大分子催化裂化中具有更好的催化活性、选择性及更长的催化寿命,为设计新型高效催化剂提供了依据.  相似文献   

17.
化学改性是离子与物质相互作用的一种重要效应,即外来离子的介入引起材料中元素或基团间化学反应,更突出的是离子直接参与化合形成新的物质,从而改变材料的性质*’1.近年来离子注入生物体产生独特的诱变效应引起了广泛关注问.注入离子在生物材料中引起的化学合成较好地解  相似文献   

18.
《中国化学快报》2019,30(12):2089-2109
Green reactions not only provide us chemical products without any pollution,but also offer us the viable technology to realize difficult tasks in normal conditions.Photo-,photoelectro-,and electrocatalytic reactions are indeed powerful tools to help us to embrace bright future.Especially,some gas-involved reactions are extremely useful to change our life environments from energy systems to liquid fuels and cost-effective products,such as H2 evolution(H2 production),02 evolution/reduction,CO_2 reduction,N2 reduction(or N_2 fixation) reactions.We can provide fuel cells clean H_2 for electric vehicles from H_2 evolution reaction(HER),at the same time,we also need highly efficient 02 reduction reaction(ORR) in fuel cells for improving the reaction kinetics.Moreover,we can get the clean oxidant O_2 from water through O_2 evolution reaction(OER),and carry out some reactions without posing any pollution to reaction systems.Furthermore,we can translate the greenhouse gas CO_2 into useful liquid fuels through CO_2 reduction reaction(CRR).Last but not the least,we can get ammonia from N_2 reduction reaction(NRR),which can decrease energy input compared to the traditional Hubble process.These reactions,such as HER,ORR,OER,CRR and NRR could be realized through solar-,photoelectro-and electro-assisted ways.For them,the catalysts used play crucial roles in determining the efficiency and kinds of products,so we should consider the efficiency of catalysts.However,the cost,synthetic methods of catalysts should also be considered.Nowadays,significant progress has been achieved,however,many challenges still exist,reaction systems,catalysts underlying mechanisms,and so on.As extremely active fields,we should pay attention to them.Under the background,it has motivated us to contribute with a roadmap on 'GasInvolved Photo-and Electro-Catalysis'.  相似文献   

19.
Viruses are normally defined as pathogens and have a bad reputation because of pandemics such as Influenza, HIV/AIDS, Ebola, and SARS. Most viruses are, however, not enemies or killers but play important roles in the origin, development and maintenance of life of all species on our planet. This is new information we learnt by new technologies such as sequencing. Viruses are the most successful species on Earth, they are ubiquitous, in the oceans, in our environment, in animals, plants, bacteria, up in the air, perhaps even in the universe, within our body and even as part of our genomes. They influence our health, our well‐being, mental properties, our gut microbiota including obesity, and may help to cope with multi‐drug‐resistant bacteria. There the phages, viruses of bacteria, raise hopes. Viruses built our immunity: viruses protect against viruses. We do not have to lay eggs – thanks to viruses! They are the drivers of evolution and adaptation to environmental changes, also e. g. in plankton. The success story of viruses started about 3.5 billion years ago when life began. Newly discovered giant viruses are almost bacteria in their composition, suggesting that the borderline between dead matter and life is continuous. There are many open questions – how did life begin, is there life on exoplanets, how to find it? Are virus‐like elements, viroids, important for the origin of life? Will viruses eliminate mankind [1]?  相似文献   

20.
In this roadmap, we address the development and perspectives of hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction, carbon dioxide reduction reaction and nitrogen reduction.  相似文献   

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