全文获取类型
收费全文 | 840篇 |
免费 | 43篇 |
国内免费 | 21篇 |
专业分类
904篇 |
出版年
2024年 | 4篇 |
2023年 | 6篇 |
2022年 | 30篇 |
2021年 | 28篇 |
2020年 | 24篇 |
2019年 | 36篇 |
2018年 | 41篇 |
2017年 | 23篇 |
2016年 | 29篇 |
2015年 | 37篇 |
2014年 | 55篇 |
2013年 | 68篇 |
2012年 | 74篇 |
2011年 | 72篇 |
2010年 | 34篇 |
2009年 | 26篇 |
2008年 | 33篇 |
2007年 | 28篇 |
2006年 | 23篇 |
2005年 | 15篇 |
2004年 | 17篇 |
2003年 | 21篇 |
2002年 | 9篇 |
2001年 | 15篇 |
2000年 | 12篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1995年 | 5篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 6篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有904条查询结果,搜索用时 15 毫秒
101.
Hussein Khalil Roberta Santana Daiana de Oliveira Fabiana Palma Ricardo Lustosa Max T. Eyre Ticiana Carvalho-Pereira Mitermayer G. Reis Albert I. Ko Peter J. Diggle Yeimi Alzate Lopez Mike Begon Federico Costa 《PLoS neglected tropical diseases》2021,15(3)
Residents of urban slums suffer from a high burden of zoonotic diseases due to individual, socioeconomic, and environmental factors. We conducted a cross-sectional sero-survey in four urban slums in Salvador, Brazil, to characterize how poverty and sanitation contribute to the transmission of rat-borne leptospirosis. Sero-prevalence in the 1,318 participants ranged between 10.0 and 13.3%. We found that contact with environmental sources of contamination, rather than presence of rat reservoirs, is what leads to higher risk for residents living in areas with inadequate sanitation. Further, poorer residents may be exposed away from the household, and ongoing governmental interventions were not associated with lower transmission risk. Residents at higher risk were aware of their vulnerability, and their efforts improved the physical environment near their household, but did not reduce their infection chances. This study highlights the importance of understanding the socioeconomic and environmental determinants of risk, which ought to guide intervention efforts. 相似文献
102.
103.
104.
Alghzzawy Zakaria Mohamed Elmaghraby Tarek Khaled El-Hamid Hagag Sanaa Abd Awwad Mohammed Hussein 《Molecular biology reports》2020,47(3):1883-1893
Molecular Biology Reports - Hepatocellular carcinoma (HCC) is a tough opponent. HCC contributes to 14.8% of all cancer mortality in Egypt. There are many choices for management of HCC; however... 相似文献
105.
106.
Three acylated flavonol diglucosides, kaempferol 3-O-β-(6″-O-E-p-coumaroylglucoside)-7-O-β-glucoside; quercetin 3-O-β-(6″-O-E-p-coumaroylglucoside)-7-O-β-glucoside; isorhamnetin 3-O-β-(6″-O-E-p-coumaroylglucoside)-7-O-β-glucoside were isolated from the whole plant aqueous alcohol extract of Lotus polyphyllos. The known 3,7-di-O-glucosides of the aglycones kaempferol, quercetin and isorhamnetin were also characterized. All structures were established on the basis of chemical and spectral evidence. 相似文献
107.
Walker JR Alshafie G Nieves N Ahrens J Clagett-Dame M Abou-Issa H Curley RW 《Bioorganic & medicinal chemistry》2006,14(9):3038-3048
All-trans retinoic acid analogues such as N-(4-hydroxyphenyl)retinamide (4-HPR) are effective chemopreventive and chemotherapeutic agents but their utility has been hampered by dose-limiting side effects. The glucuronide derivatives of 4-HPR, the oxygen-linked 4-HPROG and the carbon-linked 4-HPRCG, have been found to be more effective agents. The synthetic route to the fully C-linked analogue of 4-HPROG (4-HBRCG), which employs Suzuki coupling and Umpolung chemistries as key methodologies, is shown. The results of this study show 4-HBRCG to be an effective chemotherapeutic agent in a rat mammary tumor model while being devoid of classical retinoid toxicities. 相似文献
108.
Animal artificial insemination (AI) suffers from bacterial contamination of semen media which results in decreased success of the process of artificial insemination. It is difficult to treat the semen extender medium to reduce the bacterial growth in the presence of semen using the conventional techniques of bacterial inhibition. In the present work, a new optical method developed for bacterial growth inhibition in semen containing extender medium using diode laser (DL) and commercial cheap light emitting diode (LED) is presented. Certain wavelengths and exposure times suitable for the process of artificial insemination are found to be optimum at reducing bacterial growth with a minimum significant effect on the semen motility and viability. 相似文献
109.
Vella P Hussein WM Leung EW Clayton D Ollis DL Mitić N Schenk G McGeary RP 《Bioorganic & medicinal chemistry letters》2011,21(11):3282-3285
The emergence of metallo-β-lactamases (MBLs) capable of hydrolysing a broad spectrum of β-lactam antibiotics is particularly concerning for the future treatment of bacterial infections. This work describes the discovery of lead compounds for the development of new inhibitors using a competitive colorimetric assay based on the chromogenic cephalosporin CENTA, and a 500 compound Maybridge™ library suitable for fragment-based screening. The interactions between identified inhibitory fragments and the active site of the MBL from Klebsiella pneumoniae and Pseudomonas aeruginosa were probed by in silico docking studies. 相似文献
110.