全文获取类型
收费全文 | 1533篇 |
免费 | 145篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 42篇 |
2021年 | 81篇 |
2020年 | 50篇 |
2019年 | 66篇 |
2018年 | 69篇 |
2017年 | 50篇 |
2016年 | 74篇 |
2015年 | 116篇 |
2014年 | 114篇 |
2013年 | 123篇 |
2012年 | 138篇 |
2011年 | 135篇 |
2010年 | 73篇 |
2009年 | 55篇 |
2008年 | 91篇 |
2007年 | 75篇 |
2006年 | 50篇 |
2005年 | 52篇 |
2004年 | 50篇 |
2003年 | 38篇 |
2002年 | 36篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 11篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有1678条查询结果,搜索用时 31 毫秒
141.
142.
143.
Boschi D Guglielmo S Aiello S Morace G Borghi E Fruttero R 《Bioorganic & medicinal chemistry letters》2011,21(11):3431-3434
The antibacterial and antifungal activity of a series of products, in which the 1,5-dimethyl-4-(cyano-NNO-azoxy)pyrazol-3-yl and 1,3-dimethyl-4-(cyano-NNO-azoxy)pyrazol-5-yl moieties were linked to pyridine, pyrazole, isoxazole, thiophene and the furan ring, were examined. No molecule displayed activity against the Gram-negative bacteria tested. Conversely, some compounds displayed activity against two Staphylococcus aureus strains, including the methicillin resistant strain. All compounds displayed interesting antifungal activity, the most active compound of the series being the thiophene derivative 7a. This compound’s activity against Candidakrusei and Candidaglabrata (MIC = 0.25 and 0.5 μg/mL, respectively), two fungal species resistant to azoles, is noteworthy. The presence of the cyano function appeared essential for activity. 相似文献
144.
Rondinini C Di Marco M Chiozza F Santulli G Baisero D Visconti P Hoffmann M Schipper J Stuart SN Tognelli MF Amori G Falcucci A Maiorano L Boitani L 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2011,366(1578):2633-2641
Detailed large-scale information on mammal distribution has often been lacking, hindering conservation efforts. We used the information from the 2009 IUCN Red List of Threatened Species as a baseline for developing habitat suitability models for 5027 out of 5330 known terrestrial mammal species, based on their habitat relationships. We focused on the following environmental variables: land cover, elevation and hydrological features. Models were developed at 300 m resolution and limited to within species' known geographical ranges. A subset of the models was validated using points of known species occurrence. We conducted a global, fine-scale analysis of patterns of species richness. The richness of mammal species estimated by the overlap of their suitable habitat is on average one-third less than that estimated by the overlap of their geographical ranges. The highest absolute difference is found in tropical and subtropical regions in South America, Africa and Southeast Asia that are not covered by dense forest. The proportion of suitable habitat within mammal geographical ranges correlates with the IUCN Red List category to which they have been assigned, decreasing monotonically from Least Concern to Endangered. These results demonstrate the importance of fine-resolution distribution data for the development of global conservation strategies for mammals. 相似文献
145.
146.
Bello C Dal Bello G Cea M Nahimana A Aubry D Garuti A Motta G Moran E Fruscione F Pronzato P Grossi F Patrone F Ballestrero A Dupuis M Sordat B Zimmermann K Loretan J Wartmann M Duchosal MA Nencioni A Vogel P 《Bioorganic & medicinal chemistry》2011,19(24):7720-7727
New derivatives of 1,4-dideoxy-1,4-imino-d-ribitol have been prepared and evaluated for their cytotoxicity on solid and haematological malignancies. 1,4-Dideoxy-5-O-[(9Z)-octadec-9-en-1-yl]-1,4-imino-d-ribitol (13, IC50 ∼2 μM) and its C18-analogues (IC50 <10 μM) are cytotoxic toward SKBR3 (breast cancer) cells. 13 also inhibits (IC50 ∼8 μM) growth of JURKAT cells. 相似文献
147.
148.
Nazaret Hidalgo Giulia Mangiameli Teresa Manzano Galina G. Zhadan John F. Kennedy Valery L. Shnyrov Manuel G. Roig 《Biotechnology and Bioprocess Engineering》2011,16(4):821-829
The degradation and removal of a series of dyes used in the textile industry for polyester/wool (PES/WO) blends and present
in effluents, such as Green, Ash-Grey, Black, Navy Blue, Red and Yellow Domalan, and Orange and Red Bemacid, by catalytic
action, in the presence of H2O2, of extracts of a novel peroxidase from postharvest lentil stubble was investigated. The extracts of this peroxidase (LSP)
were effective in degrading these lastgeneration textile dyes, especially Green Domalan, Orange Bemacid, Grey and Black Domalan.
A sensitivity study was carried out for Green Domalan biodegradation to determine the effects of process parameters such as
pH, H2O2, enzyme and dye concentrations, contact and centrifugation times, and temperature. Standard ecotoxicity studies performed
with Vibrio fischeri revealed that the dye solutions treated with peroxidase and H2O2 were less ecotoxic than the untreated ones. 相似文献
149.
150.
Gai M Camera P Dema A Bianchi F Berto G Scarpa E Germena G Di Cunto F 《Molecular biology of the cell》2011,22(20):3768-3778
The small GTPase RhoA plays a crucial role in the different stages of cytokinesis, including contractile ring formation, cleavage furrow ingression, and midbody abscission. Citron kinase (CIT-K), a protein required for cytokinesis and conserved from insects to mammals, is currently considered a cytokinesis-specific effector of active RhoA. In agreement with previous observations, we show here that, as in Drosophila cells, CIT-K is specifically required for abscission in mammalian cells. However, in contrast with the current view, we provide evidence that CIT-K is an upstream regulator rather than a downstream effector of RhoA during late cytokinesis. In addition, we show that CIT-K is capable of physically and functionally interacting with the actin-binding protein anillin. Active RhoA and anillin are displaced from the midbody in CIT-K-depleted cells, while only anillin, but not CIT-K, is affected if RhoA is inactivated in late cytokinesis. The overexpression of CIT-K and of anillin leads to abscission delay. However, the delay produced by CIT-K overexpression can be reversed by RhoA inactivation, while the delay produced by anillin overexpression is RhoA-independent. Altogether, these results indicate that CIT-K is a crucial abscission regulator that may promote midbody stability through active RhoA and anillin. 相似文献