全文获取类型
收费全文 | 1524篇 |
免费 | 102篇 |
国内免费 | 1篇 |
专业分类
1627篇 |
出版年
2024年 | 2篇 |
2023年 | 12篇 |
2022年 | 20篇 |
2021年 | 54篇 |
2020年 | 27篇 |
2019年 | 29篇 |
2018年 | 43篇 |
2017年 | 34篇 |
2016年 | 55篇 |
2015年 | 97篇 |
2014年 | 100篇 |
2013年 | 137篇 |
2012年 | 128篇 |
2011年 | 124篇 |
2010年 | 74篇 |
2009年 | 53篇 |
2008年 | 88篇 |
2007年 | 111篇 |
2006年 | 103篇 |
2005年 | 68篇 |
2004年 | 63篇 |
2003年 | 60篇 |
2002年 | 49篇 |
2001年 | 13篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1940年 | 1篇 |
1935年 | 1篇 |
1931年 | 1篇 |
排序方式: 共有1627条查询结果,搜索用时 15 毫秒
11.
12.
13.
Contradictory statements about the non-steroidal anti-inflammatory drugs from the European Medicines Agency and the United States Food and Drug Administration have raised questions about whether regulatory decisions are evidence-based. For the selective COX-2 inhibitors, there are clear contraindications and warnings in Europe, but only a vaguely worded Black Box warning in the United States. All the non-selective agents are given an almost "clean bill of health" in Europe, while all of them are judged to have a similar risk-benefit ratio as celecoxib in the United States. The regulatory agencies have failed to recognize the clinical trial evidence that the risk of cardiovascular events varies substantially among the non-selective agents, with diclofenac carrying the highest risk of harm. 相似文献
14.
15.
Brousseau Pierre-Marc Chauvat Matthieu De Almeida Tania Forey Estelle 《Biological invasions》2021,23(6):1987-2002
Biological Invasions - Invasive plants often modify the structure of the community of native plants and animals, but their potential impact on the plant–soil interface is poorly studied. In... 相似文献
16.
17.
Alexander Steinkasserer Tania Jones Denise Sheer Karl Koettnitz Joachim Hauber Dorian Bevec 《Genomics》1995,25(3)
The eukaryotic initiation factor 5A (eIF-5A) has been identified as an essential cofactor for the HIV-1 trans-activator protein Rev. Rev plays a key role in the complex regulation of HIV-1 gene expression and thereby in the generation of infectious virus particles. Expression of eIF-5A is vital for Rev function, and inhibition of this interaction leads to a block of the viral replication cycle. In humans, four different eIF-5A genes have been identified. One codes for the eIF-5A protein and the other three are pseudogenes. Using a panel of somatic rodent—human cell hybrids in combination with fluorescence in situ hybridization analysis, we show that the four genes map to threedifferent chromosomes. The coding eIF-5A gene (EIF5A) maps to 17p12–p13, and the three pseudogenes EIF5AP1, EIF5AP2, and EIF5AP3 map to 10q23.3, 17q25, and 19q13.2, respectively. This is the first localization report for a eukaryotic cofactor for a regulatory HIV-1 protein. 相似文献
18.
Tania Pineda-Enríquez Francisco A. Solís-Marín Yuri Hooker Alfredo?Laguarda-Figueras 《ZooKeys》2013,(357):53-65
Ophioderma peruana
sp. n. is a new species of Ophiodermatidae, extending the distribution of the genus Ophioderma to Lobos de Afuera Island, Peru, easily distinguishable from its congeners by its peculiarly fragmented dorsal arm plates. Dense granules, rounded or polygonal cover the disc, the radial shields may be naked or completely covered by granules. A good character for recognizing this species in the field is the dorsal side of the disc which is brown with disc granules lighter cream and brown, the arms are mottled with whitish spots and the ventral part of the disc on the interradial part is brown and the radial part bright yellow. 相似文献
19.
Bea Vuylsteke Gis��le Semd�� Lazare Sika Tania Crucitti Virginie Etti��gne Traor�� Anne Buv�� Marie Laga 《PloS one》2012,7(3)
Objective
To assess condom use and prevalence of STIs and HIV among female sex workers (FSWs), as part of a comprehensive monitoring and evaluation plan of a nationwide sex worker prevention project in Côte d''Ivoire.Design and Methods
Cross sectional surveys were conducted among FSWs attending five project clinics in Abidjan and San Pedro (2007), and in Yamoussoukro and Gagnoa (2009). A standardized questionnaire was administered in a face-to-face interview, which included questions on socio-demographic characteristics, sexual behaviour and condom use. After the interview, the participants were asked to provide samples for STI and HIV testing.Results
A total of 1110 FSWs participated in the surveys. There were large differences in socio-demographic and behavioural characteristics between FSW coming for the first time as compared to FSW coming on a routine visit. The prevalence of N. gonorrhoeae or C.trachomatis was 9.1%, 11.8% among first vs. 6.9% routine attendees (p = 0.004). The overall HIV prevalence was 26.6%, it was lower among first time attendees (17.5% as compared to 33.9% for routine attendees, p<0.001). The HIV prevalence among first attendees was also lower than the proportion of HIV positive tests from routine testing and counselling services in the same clinics.Conclusions
The results show a relatively high STI and HIV prevalence among FSWs in different cities in Côte d''Ivoire. In the light of these results, prevention efforts should continue to focus on FSWs in the country. 相似文献20.
Cristiana Leite N. Tatiana Silva Sandrine Mendes Andreia Ribeiro Joana Paes de Faria Tania Louren?o Francisco dos Santos Pedro Z. Andrade Carla M. P. Cardoso Margarida Vieira Artur Paiva Cláudia L. da Silva Joaquim M. S. Cabral Jo?o B. Relvas Mário Gr?os 《PloS one》2014,9(10)
Mesenchymal stem cells (MSCs) are viewed as safe, readily available and promising adult stem cells, which are currently used in several clinical trials. Additionally, their soluble-factor secretion and multi-lineage differentiation capacities place MSCs in the forefront of stem cell types with expected near-future clinical applications. In the present work MSCs were isolated from the umbilical cord matrix (Wharton''s jelly) of human umbilical cord samples. The cells were thoroughly characterized and confirmed as bona-fide MSCs, presenting in vitro low generation time, high proliferative and colony-forming unit-fibroblast (CFU-F) capacity, typical MSC immunophenotype and osteogenic, chondrogenic and adipogenic differentiation capacity. The cells were additionally subjected to an oligodendroglial-oriented step-wise differentiation protocol in order to test their neural- and oligodendroglial-like differentiation capacity. The results confirmed the neural-like plasticity of MSCs, and suggested that the cells presented an oligodendroglial-like phenotype throughout the differentiation protocol, in several aspects sharing characteristics common to those of bona-fide oligodendrocyte precursor cells and differentiated oligodendrocytes. 相似文献