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《Cell》2022,185(15):2644-2648
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The solution of kuru led us to the solution of Creutzfeldt-Jakob disease and to the elucidation, in humans and other species, of previously unknown mechanisms of infection. These require very close three-dimensional matching, which determines infectious nucleant or prion activity. Evidence for nucleation processes is found widely in the organic and inorganic worlds and in the interactions between them: in the formation of amyloid fibrils; in the biochemistry of silicon; in cave formations deep in the Earth; and in outer space. Kuru in its location in Papua New Guinea has also led to an understanding of the cultural achievements of the Palaeo-Melanesians, with deep roots in human history.  相似文献   

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Evolutionary biology shares many concepts with statistical physics: both deal with populations, whether of molecules or organisms, and both seek to simplify evolution in very many dimensions. Often, methodologies have undergone parallel and independent development, as with stochastic methods in population genetics. Here, we discuss aspects of population genetics that have embraced methods from physics: non-equilibrium statistical mechanics, travelling waves and Monte-Carlo methods, among others, have been used to study polygenic evolution, rates of adaptation and range expansions. These applications indicate that evolutionary biology can further benefit from interactions with other areas of statistical physics; for example, by following the distribution of paths taken by a population through time.  相似文献   

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The replacement of damaged tissues and organs with tissue and organ transplants or bionic implants has serious drawbacks. There is now emerging a new approach to tissue and organ replacement, regenerative biology and medicine. Regenerative biology seeks to understand the cellular and molecular differences between regenerating and non-regenerating tissues. Regenerative medicine seeks to apply this understanding to restore tissue structure and function in damaged, non-regenerating tissues. Regeneration is accomplished by three mechanisms, each of which uses or produces a different kind of regeneration-competent cell. Compensatory hyperplasia is regeneration by the proliferation of cells which maintain all or most of their differentiated functions (e.g., liver). The urodele amphibians regenerate a variety of tissues by the dedifferentiation of mature cells to produce progenitor cells capable of division. Many tissues contain reserve stem or progenitor cells that are activated by injury to restore the tissue while simultaneously renewing themselves. All regeneration-competent cells have two features in common. First, they are not terminally differentiated and can re-enter the cell cycle in response to signals in the injury environment. Second, their activation is invariably accompanied by the dissolution of the extracellular matrix (ECM) surrounding the cells, suggesting that the ECM is an important regulator of their state of differentiation. Regenerative medicine uses three approaches. First is the transplantation of cells into the damaged area. Second is the construction of bioartificial tissues by seeding cells into a biodegradable scaffold where they produce a normal matrix. Third is the use of a biomaterial scaffold or drug delivery system to stimulate regeneration in vivo from regeneration-competent cells. There is substantial evidence that non-regenerating mammalian tissues harbor regeneration-competent cells that are forced into a pathway of scar tissue formation. Regeneration can be induced if the factors leading to scar formation are inhibited and the appropriate signaling environment is supplied. An overview of regenerative mechanisms, approaches of regenerative medicine, research directions, and research issues will be given.  相似文献   

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The Nobel Prize winners works are considered and analyzed. Main attention is paid to the works devoted to biochemistry or problems related to biochemistry. The most prominent biochemical investigations are considered in detail. In some cases it is given the history and chronology of important biochemical discoveries. The survey is devoted due to the 170th anniversary of birth of Alfred Bernhard Nobel--a famous scientist and businessman, the founder of the Nobel Prizes.  相似文献   

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In the past two decades, our ability to study cellular and molecular systems has been transformed through the development of omics sciences. While unlimited potential lies within massive omics datasets, the success of omics sciences to further our understanding of human disease and/or translating these findings to clinical utility remains elusive due to a number of factors. A significant limiting factor is the integration of different omics datasets (i.e., integromics) for extraction of biological and clinical insights. To this end, the National Cancer Institute (NCI) and the National Heart, Lung and Blood Institute (NHLBI) organized a joint workshop in June 2012 with the focus on integration issues related to multi-omics technologies that needed to be resolved in order to realize the full utility of integrating omics datasets by providing a glimpse into the disease as an integrated “system”. The overarching goals were to (1) identify challenges and roadblocks in omics integration, and (2) facilitate the full maturation of ‘integromics’ in biology and medicine. Participants reached a consensus on the most significant barriers for integrating omics sciences and provided recommendations on viable approaches to overcome each of these barriers within the areas of technology, bioinformatics and clinical medicine.  相似文献   

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Although twenty-eigth radionuclides of technetium have been prepared, only technetium-99m, technetium-99 and technetium-95m have so far become important.Technetium-99, available in large amounts, is used in the study of the physical and chemical properties of the element, and offers the possibility of many industrial applications where its radioactivity does not create serious problems. With the increase in the use of nuclear power, however, more and more technetium-99 is being produced which is entering into the environment. This has resulted in increased interest in the biogeochemical behaviour of this radionuclide during recent years.The ideal physical properties, half-life of 6 hours and monochromatic gamma emission of 140 kev, and the versatile chemistry of technetium-99m have recently made it the radiotracer of choice for the external noninvasive imaging of almost all internal organs of the body. In the preparation of technetium- 99m radiopharmaceuticals and in the interpretation of their biological behaviour, the chemistry of technetium-99 has so far served as a guide. Similarly assumptions have been made that technetium-95m and technetium-99 have identical biogeochemical behaviour. We have shown that even the radioisomers, technetium-99m and technetium-99, have different chemical properties. These results suggest that in the study of the biological and environmental behaviour of technetium, a rigorous knowledge of the chemistry of each radionuclide is needed.  相似文献   

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Ever since the first diagnosis of a mitochondrial disease in 1959 (Ernster et al., 1959), the interest for mitochondrial cytopathies has continued to increase. Originally it was believed that the condition was very rare and primarily effected high-energy requiring tissues resulting in a select few pathologies (Luft, 1994). Since 1959, the understanding of mitochondrial cytopathies has evolved immensely and mitochondrial cytopathies are now known to be the largest group of metabolic diseases and to be resulting in a wide variety of pathologies. "Mitochondria in Biology and Medicine" was the title of the first annual conference of Society of Mitochondrial Research and Medicine - India. The conference was organized by A. S. Sreedhar, Keshav Singh and Kumarasamy Thangaraj, and was held at The Centre for Cellular and Molecular Biology (CCMB) Hyderabad, India, during 9-10 December 2011. The conference featured talks from internationally renowned scientists within the field of mitochondrial research and offered both students and fellow researchers a comprehensive update to the newest research within the field. This paper summarizes key outcomes of the presentations.  相似文献   

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Microarrays in biology and medicine   总被引:1,自引:0,他引:1  
The remarkable speed with which biotechnology has become critical to the practice of life sciences owes much to a series of technological revolutions. Microarray is the latest invention in this ongoing technological revolution. This technology holds the promise to revolutionize the future of biology and medicine unlike any other technology that preceded it. Development of microarray technology has significantly changed the way questions about diseases and/or biological phenomena are addressed. This is because microarrays facilitate monitoring the expression of thousands of genes or proteins in a single experiment. This enormous power of microarrays has enabled scientists to monitor thousands of genes and their products in a given living organism in one experiment, and to understand how these genes function in an orchestrated manner. Obtaining such a global view of life at the molecular level was impossible using conventional molecular biological techniques. However, despite all the progress made in developing this technology, microarray is yet to reach a point where all data are obtained, analyzed, and shared in a standardized fashion. The present article is a brief overview of microarray technologies and their applications with an emphasis on DNA microarray.  相似文献   

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Chrysosplenium americanum (Saxifragaceae) accumulates a variety of partially O-methylated flavonol glucosides. Because of the semi-aquatic nature of this plant and its extensive contamination with endogenous organisms, the initiation of shoot and callus cultures could only be achieved after (a) using a special surface sterilization procedure, (b) production of new shoots from initial explants, and (c) selective elimination of organogenic structures during several subcultures. HPLC analysis of the cultured tissues established the presence of a number of flavonoids characteristic of the intact plant, though in lower and variable concentrations. However, shoot and callus cultures exhibited flavonoid profiles similar to those of the intact leaves and roots, respectively.Abbreviations BAP benzylamino purine - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA 3-indoleacetic acid - NAA 1-naphtaleneacetic acid - HPLC high pressure liquid chromatography  相似文献   

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For the computational analysis of biological problems-analyzing data, inferring networks and complex models, and estimating model parameters-it is common to use a range of methods based on probabilistic logic constructions, sometimes collectively called machine learning methods. Probabilistic modeling methods such as Bayesian Networks (BN) fall into this class, as do Hierarchical Bayesian Networks (HBN), Probabilistic Boolean Networks (PBN), Hidden Markov Models (HMM), and Markov Logic Networks (MLN). In this review, we describe the most general of these (MLN), and show how the above-mentioned methods are related to MLN and one another by the imposition of constraints and restrictions. This approach allows us to illustrate a broad landscape of constructions and methods, and describe some of the attendant strengths, weaknesses, and constraints of many of these methods. We then provide some examples of their applications to problems in biology and medicine, with an emphasis on genetics. The key concepts needed to picture this landscape of methods are the ideas of probabilistic graphical models, the structures of the graphs, and the scope of the logical language repertoire used (from First-Order Logic [FOL] to Boolean logic.) These concepts are interlinked and together define the nature of each of the probabilistic logic methods. Finally, we discuss the initial applications of MLN to genetics, show the relationship to less general methods like BN, and then mention several examples where such methods could be effective in new applications to specific biological and medical problems.  相似文献   

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