全文获取类型
收费全文 | 9765篇 |
免费 | 732篇 |
国内免费 | 4篇 |
出版年
2023年 | 53篇 |
2022年 | 113篇 |
2021年 | 205篇 |
2020年 | 175篇 |
2019年 | 219篇 |
2018年 | 274篇 |
2017年 | 226篇 |
2016年 | 330篇 |
2015年 | 558篇 |
2014年 | 554篇 |
2013年 | 679篇 |
2012年 | 837篇 |
2011年 | 769篇 |
2010年 | 516篇 |
2009年 | 471篇 |
2008年 | 566篇 |
2007年 | 537篇 |
2006年 | 521篇 |
2005年 | 476篇 |
2004年 | 440篇 |
2003年 | 366篇 |
2002年 | 345篇 |
2001年 | 85篇 |
2000年 | 75篇 |
1999年 | 87篇 |
1998年 | 122篇 |
1997年 | 92篇 |
1996年 | 72篇 |
1995年 | 64篇 |
1994年 | 65篇 |
1993年 | 64篇 |
1992年 | 41篇 |
1991年 | 42篇 |
1990年 | 43篇 |
1989年 | 39篇 |
1988年 | 32篇 |
1987年 | 26篇 |
1986年 | 23篇 |
1985年 | 29篇 |
1984年 | 39篇 |
1983年 | 22篇 |
1982年 | 27篇 |
1981年 | 25篇 |
1980年 | 15篇 |
1979年 | 13篇 |
1978年 | 14篇 |
1976年 | 14篇 |
1975年 | 17篇 |
1974年 | 10篇 |
1973年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
Roberto Arredondo-Valdés Francisco D. Hernández-Castillo Mario Rocandio-Rodríguez Julia C. Anguiano-Cabello Madai Rosas-Mejía Venancio Vanoye-Eligio Salvador Ordaz-Silva Imelda V. López-Sánchez Laura D. Carrazco-Peña Julio C. Chacón-Hernández 《Phyton》2021,90(3):895-906
The tomato (Solanum lycopersicum L.) is one of the world’s most important vegetable crops. Still, phytopathogenic bacteria affect the yield and quality of tomato cultivation, like Agrobacterium tumefeciens (At), Clavibacter
michiganensis subsp. michiganensis (Cmm), Pseudomonas syringae pv. tomato (Pst), Ralstonia solanacearum (Rs),
and Xanthomonas axonopodis (Xa). Synthetic chemical products are used mostly on disease plant control, but
overuse generates resistance to bacterial control. This study aimed to evaluate the in vitro antibacterial activity
of the ethanolic extract of Moringa oleifera Lam. leaves against At, Cmm, Pst, Rs, and Xa, as well as information
about this plant species’ chemical composition. Antibacterial activity against pathogens observed by microplate
technique, phytochemical screening, and FTIR analysis revealed different bio-active compounds on ethanolic
extracts with antibacterial activity. The growth inhibition rate ranged between 0.08% and 99.94%. The inhibitory
concentration, IC50, required to inhibit 50% of At, Cmm, Pst, Rs, and Xa bacterial growth, was 276.67, 350.48,
277.85, 351.49, and 283.22 mg/L, respectively. Inhibition of phytopathogen bacteria’s growth increased as the concentrations of the extract also increased. Moringa oleifera extract can be recommended as a potent bio-bactericide. 相似文献
152.
Ana C.A. Casarotti Daniela Teixeira Ieda M. Longo-Maugeri Mayari E. Ishimura Maria E.R. Coste Henrique T. Bianco Flavio T. Moreira Amanda F. Bacchin Maria C. Izar Iran Gonalves Jr Adriano Caixeta Gilberto Szarf Ibraim M. Pinto Francisco A. Fonseca 《Bioscience reports》2021,41(2)
Despite early reperfusion, patients with ST segment elevation myocardial infarction (STEMI) may present large myocardial necrosis and significant impairment of ventricular function. The present study aimed to evaluate the role of subtypes of B lymphocytes and related cytokines in the infarcted mass and left ventricular ejection fraction obtained by cardiac magnetic resonance imaging performed after 30 days of STEMI. This prospective study included 120 subjects with STEMI submitted to pharmacoinvasive strategy. Blood samples were collected in subjects in the first (D1) and 30th (D30) days post STEMI. The amount of CD11b+ B1 lymphocytes (cells/ml) at D1 were related to the infarcted mass (rho = 0.43; P=0.033), measured by cardiac MRI at D30. These B1 cells were associated with CD4+ T lymphocytes at D1 and D30, while B2 classic lymphocytes at day 30 were related to left ventricular ejection fraction (LVEF). Higher titers of circulating IL-4 and IL-10 were observed at D30 versus D1 (P=0.013 and P<0.001, respectively). Titers of IL-6 at D1 were associated with infarcted mass (rho = 0.41, P<0.001) and inversely related to LVEF (rho = −0.38, P<0.001). After multiple linear regression analysis, high-sensitivity troponin T and IL-6 collected at day 1 were independent predictors of infarcted mass and, at day 30, only HDL-C. Regarding LVEF, high-sensitivity troponin T and high-sensitivity C-reactive protein were independent predictors at day 1, and B2 classic lymphocytes, at day 30. In subjects with STEMI, despite early reperfusion, the amount of infarcted mass and ventricular performance were related to inflammatory responses triggered by circulating B lymphocytes. 相似文献
153.
Mucury Filho Ricardo Camargo Murilo R. Mendes Francisco D. C. 《International journal of primatology》2021,42(2):187-200
International Journal of Primatology - Some nonhuman primates use tools to modify the behavior of other animals in social contexts. For example, during their proceptive periods, female bearded... 相似文献
154.
155.
156.
157.
158.
159.
Josep Lloret Alba Serrat Gudmundur Thordarson Kristin Helle Angelique Jadaud Isabel Bruno Francesc Ordines Paolo Sartor Pierluigi Carbonara Hans-Joachim Rätz 《Journal of fish biology》2021,98(6):1572-1584
Many deep-water fish populations, being K-selected species, have little resilience to overexploitation and may be at serious risk of depletion as a consequence. Sea warming represents an additional threat. In this study, the condition, or health, of several populations of common ling (Molva molva), blue ling (Molva dypterygia) and Mediterranean or Spanish ling (Molva macrophthalma) inhabiting different areas in the North Atlantic and the Mediterranean was evaluated, to shed light on the challenges these deep-water species are facing in the context of fishing activity and a warming climate. The data on the condition of Molva populations which are analysed here have been complemented with data on abundance and, for the southernmost species (Mediterranean ling), with two other health indicators (parasitism and hepato-somatic index). Despite some exceptions (e.g., common ling in Icelandic waters), this study shows that the condition of many populations of Molva species in the northeastern Atlantic and the Mediterranean Sea has worsened, a trend which, in recent decades, has usually been found to be accompanied by a decline in their abundance. In addition, the poor health status of most populations of common ling, blue ling and Mediterranean ling considered in this analysis points to a lower sustainability of these populations in the future. Overall, the health status and abundance of Molva populations in the northeastern Atlantic and the Mediterranean suggest that only some populations located in the North Atlantic may be able to rebuild, whereas the populations in southern North Atlantic and the Mediterranean, which are probably most at risk from sea warming, are facing serious difficulties in doing so. In the context of fisheries and global warming, this study's results strongly indicate that management bodies need to consider the health status of many of the populations of Molva species, particularly in southern European waters, before implementing their decisions. 相似文献