首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
3.
4.
The symbiosis of the pea aphid Acyrthosphion pisum with the bacterium Buchnera aphidicola APS represents the best-studied insect obligate symbiosis. Here we present a refined picture of this symbiosis by linking pre-genomic observations to new genomic data that includes the complete genomes of the eukaryotic and prokaryotic symbiotic partners. In doing so, we address four issues central to understanding the patterns and processes operating at the A. pisum/Buchnera APS interface. These four issues include: (1) lateral gene transfer, (2) host immunity, (3) symbiotic metabolism, and (4) regulation.  相似文献   

5.
Breast and ovarian cancer are among the most common malignancies diagnosed in women worldwide. Together, they account for the majority of cancer-related deaths in women. These cancer types share a number of features, including their association with hereditary cancer syndromes caused by heterozygous germline mutations in BRCA1 or BRCA2. BRCA-associated breast and ovarian cancers are hallmarked by genomic instability and high sensitivity to DNA double-strand break (DSB) inducing agents due to loss of error-free DSB repair via homologous recombination (HR). Recently, poly(ADP-ribose) polymerase inhibitors, a new class of drugs that selectively target HR-deficient tumor cells, have been shown to be highly active in BRCA-associated breast and ovarian cancers. This finding has renewed interest in hallmarks of HR deficiency and the use of other DSB-inducing agents, such as platinum salts or bifunctional alkylators, in breast and ovarian cancer patients. In this review we discuss the similarities between breast and ovarian cancer, the hallmarks of genomic instability in BRCA-mutated and BRCA-like breast and ovarian cancers, and the efforts to search for predictive markers of HR deficiency in order to individualize therapy in breast and ovarian cancer.  相似文献   

6.
7.
8.
This article discusses the intersection of science and culture in the marketplace and explores the ways in which radium quack and medicinal products were packaged and labelled in the early twentieth century US. Although there is an interesting growing body of literature by art historians on package design, historians of science and medicine have paid little to no attention to the ways scientific and medical objects that were turned into commodities were packaged and commercialized. Thinking about packages not as mere containers but as multifunctional tools adds to historical accounts of science as a sociocultural enterprise and reminds us that science has always been part of consumer culture. This paper suggests that far from being receptacles that preserve their content and facilitate their transportation, bottles and boxes that contained radium products functioned as commercial and epistemic devices. It was the 1906 Pure Food and Drug Act that enforced such functions. Packages worked as commercial devices in the sense that they were used to boost sales. In addition, ‘epistemic’ points to the fact that the package is an artefact that ascribes meaning to and shapes its content while at the same time working as a device for distinguishing between patent and orthodox medicines.  相似文献   

9.
Regulatory variation results from genetic changes with both cis and trans acting effects on gene expression. Here I describe the types of genetic variants that alter cis and trans regulation and discuss differences in the potential for cis and trans changes among different classes of genes. I argue that the molecular function of the protein encoded by each gene and how the gene is wired into the genomic regulatory network may influence its propensity for cis and trans regulatory changes.Received 15 February 2005; received after revision 12 April 2005; accepted 26 April 2005  相似文献   

10.
Analysing the contents of magazines published with the stated intention of conveying information about science and technology to the public provides a mechanism for evaluation what counted as ‘popular science’. This article presents numerical surveys of the contents of three magazines published in inter-war Britain (Discovery, Conquest and Armchair Science) and offers an evaluation of the results. The problem of defining relevant topic-categories is addressed, both direct and indirect strategies being employed to ensure that the topics correspond to what the editors and publishers took to be the principal areas of science and technology of interest to their readers. Analysis of the results of the surveys reveals different editorial policies depending on the backgrounds of the publishers and their anticipated readerships. The strong focus of the two most populist magazines on applied science and ‘hobbyist’ topics such as natural history, radio and motoring is noted and contrasted with the very limited coverage of theoretical science. In conclusion, a survey of changes in the contents over the periods of publication is used to identify trends in the coverage of science during this period.  相似文献   

11.
12.
13.
14.
15.
16.
17.
中国是历史悠久的文明古国,丝绸织造、陶瓷和建筑三大技术与农、医、天(文)、算四大学科共同构成了古代中国独特的科学技术体系。纺织自古以来就是我国经济的支柱,并曾在4000余年的漫长历史中领先于世界,当今我国纺织品生产和出口又跃居世界之首。然而,纺织大国并非纺织强国,其中的原因是多方面的。本文试图通过对中国古代、近现代和当代中国纺织业发展脉络的梳理分析,找出影响其发展的内外因素,提出新世纪中国由纺织大国到纺织强国的发展构想。  相似文献   

18.
19.
The large grain measures used until at least the end of the nineteenth century for controlling the sale of dry goods have precise legal definitions in terms of smaller units of weight or capacity. They are related by experimental procedures which in the modern period have involved water determinations, but it has been appreciated that for medieval measures the medium was grain. A study of the way grain packs in such vessels has enabled the sizes of early Scottish standards to be recovered for the first time and deductions made about their evolution and use, against a background of early English practice.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号