全文获取类型
收费全文 | 255篇 |
免费 | 5篇 |
出版年
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 13篇 |
2012年 | 15篇 |
2011年 | 12篇 |
2010年 | 6篇 |
2009年 | 16篇 |
2008年 | 10篇 |
2007年 | 15篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 10篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 9篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1977年 | 2篇 |
1973年 | 3篇 |
1970年 | 2篇 |
1969年 | 5篇 |
1968年 | 6篇 |
1966年 | 2篇 |
1961年 | 3篇 |
1958年 | 3篇 |
1955年 | 1篇 |
1950年 | 1篇 |
1909年 | 1篇 |
1903年 | 1篇 |
1900年 | 2篇 |
1899年 | 1篇 |
排序方式: 共有260条查询结果,搜索用时 15 毫秒
141.
Edward Jepson 《BMJ (Clinical research ed.)》1909,2(2548):1314-1315
142.
Ricardo A. Correia Ana C. M. Malhado Lays Lins Norah Costa Gamarra Waltyane A. G. Bonfim Anyelet Valencia-Aguilar Chiara Bragagnolo Paul Jepson Richard J. Ladle 《Biodiversity and Conservation》2016,25(8):1503-1513
Protected areas (PAs) are under increasing pressure to demonstrate their broader value and contribution to society. Scientific research and associated knowledge production comprise one such value, which has received relatively little attention in the academic literature. Here, we use the Amazon region as a case study to quantify scientific knowledge production (as measured by scientific publications in peer-reviewed journals) in PAs and identify the main biophysical, geographical and social characteristics that influence such production. We adopt a multi-model inference approach with an innovative hurdle regression model to independently assess the factors influencing the presence of research and the number of studies in PAs. Our results indicate a highly skewed pattern of scientific production, with many PAs with few or no associated scientific articles. Larger, older and more highly protected PAs in Ecuador and Peru were most likely to have scientific production, while time since first publication was most strongly associated with the number of publications from a PA. These findings provide important insights that could be used to support and strengthen policy aimed at increasing the value of Amazonian protected areas for scientific research. 相似文献
143.
Familial clustering of colorectal cancer (CRC) and early disease onset are indicators of an inherited tumour syndrome. Monogenic dispositions account for 3–5% of all CRC cases and are subdivided into hereditary non-polyposis colorectal cancer (HNPCC/Lynch syndrome) and various gastrointestinal polyposis syndromes. Many of these syndromes are characterised by a broad spectrum of extracolonic tumours. Early detection and accurate classification are essential in providing effective surveillance and treatment. Initial diagnosis is based on endoscopic and histological findings as well as on the presence of extracolonic manifestations and family history. Molecular genetic examination is important for the differential diagnosis, evaluation of recurrence risk, and predictive testing of asymptomatic at risk individuals; it is performed according to largely standardised algorithms. Diagnostic difficulties are common among the hamartomatous polyposes due to their broad phenotypic overlap and frequent uncertainties in histological evaluation, as well as among patients with few adenomas. Risk-adapted surveillance guidelines have been established for HNPCC and for the more frequently observed polyposis syndromes. Beyond established tumour syndromes, familial clustering of CRC (which is often of late onset) or the occurrence of few adenomas is likely to be based upon a multifactorial (complex) etiology. Although identification of the underlying genetic risk factors and biological pathways is still in the early stages, rapid progress is being made due to methodical developments such as genome-wide association studies and CNV analysis. 相似文献
144.
Witt AE Hines LM Collins NL Hu Y Gunawardane RN Moreira D Raphael J Jepson D Koundinya M Rolfs A Taron B Isakoff SJ Brugge JS LaBaer J 《Journal of proteome research》2006,5(3):599-610
Functional proteomics approaches that comprehensively evaluate the biological activities of human cDNAs may provide novel insights into disease pathogenesis. To systematically investigate the functional activity of cDNAs that have been implicated in breast carcinogenesis, we generated a collection of cDNAs relevant to breast cancer, the Breast Cancer 1000 (BC1000), and conducted screens to identify proteins that induce phenotypic changes that resemble events which occur during tumor initiation and progression. Genes were selected for this set using bioinformatics and data mining tools that identify genes associated with breast cancer. Greater than 1000 cDNAs were assembled and sequence verified with high-throughput recombination-based cloning. To our knowledge, the BC1000 represents the first publicly available sequence-validated human disease gene collection. The functional activity of a subset of the BC1000 collection was evaluated in cell-based assays that monitor changes in cell proliferation, migration, and morphogenesis in MCF-10A mammary epithelial cells expressing a variant of ErbB2 that can be inducibly activated through dimerization. Using this approach, we identified many cDNAs, encoding diverse classes of cellular proteins, that displayed activity in one or more of the assays, thus providing insights into a large set of cellular proteins capable of inducing functional alterations associated with breast cancer development. 相似文献
145.
Romeis J Bartsch D Bigler F Candolfi MP Gielkens MM Hartley SE Hellmich RL Huesing JE Jepson PC Layton R Quemada H Raybould A Rose RI Schiemann J Sears MK Shelton AM Sweet J Vaituzis Z Wolt JD 《Nature biotechnology》2008,26(2):203-208
An international initiative is developing a scientifically rigorous approach to evaluate the potential risks to nontarget arthropods (NTAs) posed by insect-resistant, genetically modified (IRGM) crops. It adapts the tiered approach to risk assessment that is used internationally within regulatory toxicology and environmental sciences. The approach focuses on the formulation and testing of clearly stated risk hypotheses, making maximum use of available data and using formal decision guidelines to progress between testing stages (or tiers). It is intended to provide guidance to regulatory agencies that are currently developing their own NTA risk assessment guidelines for IRGM crops and to help harmonize regulatory requirements between different countries and different regions of the world. 相似文献
146.
147.
148.
PD Dr. Stefan Schneckenburger 《当今生物学》2010,40(6):411-419
Plant Transfer and Botanical Gardens in Colonial Times A constant of economic history is the need of natural resources – in the past often of vegetable origin and available only from the countries of natural distribution. These countries often tried to protect their interests against the traders or users by declaring monopoles. Between these both poles botanic gardens acted very successfully and by far not according to modern ethic standards. Results of their activities were the transcontinental movements of plants and the initiation of new agricultural based industries. These should be exemplified by the British botanical gardens and species as tea shrub, rubber tree, and cinchona tree. 相似文献
149.
150.