全文获取类型
收费全文 | 4047篇 |
免费 | 317篇 |
国内免费 | 2篇 |
出版年
2023年 | 12篇 |
2022年 | 9篇 |
2021年 | 49篇 |
2020年 | 47篇 |
2019年 | 51篇 |
2018年 | 53篇 |
2017年 | 73篇 |
2016年 | 92篇 |
2015年 | 187篇 |
2014年 | 184篇 |
2013年 | 258篇 |
2012年 | 331篇 |
2011年 | 352篇 |
2010年 | 225篇 |
2009年 | 203篇 |
2008年 | 297篇 |
2007年 | 242篇 |
2006年 | 251篇 |
2005年 | 232篇 |
2004年 | 226篇 |
2003年 | 237篇 |
2002年 | 203篇 |
2001年 | 48篇 |
2000年 | 34篇 |
1999年 | 52篇 |
1998年 | 49篇 |
1997年 | 34篇 |
1996年 | 40篇 |
1995年 | 41篇 |
1994年 | 31篇 |
1993年 | 20篇 |
1992年 | 36篇 |
1991年 | 13篇 |
1990年 | 20篇 |
1989年 | 16篇 |
1988年 | 15篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 14篇 |
1984年 | 13篇 |
1983年 | 13篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1971年 | 3篇 |
1915年 | 1篇 |
排序方式: 共有4366条查询结果,搜索用时 15 毫秒
61.
62.
63.
Blood and cloacal swab sampling for avian influenza monitoring has no effect on survival rates of free‐ranging ducks 下载免费PDF全文
Matthieu Guillemain Jocelyn Champagnon Marie‐Lucile Gourlay‐Larour Francois Cavallo Anne‐Laure Brochet Jean Hars Gregoire Massez Thierry George Pierre‐Yves Perroi Veronique Jestin Alain Caizergues 《Ibis》2015,157(4):743-753
Concerns about the spread of avian influenza viruses (AIVs) have led to cloacal swab sampling of hundreds of thousands of birds worldwide as part of AIV surveillance schemes, but the effects of cloacal swabbing have not been adequately evaluated. We tested for differences between swabbed, swabbed and bled, and non‐sampled wild ducks in terms of live re‐encounter and dead recoveries for Common Pochard Aythya ferina and Tufted Duck Aythya fuligula, and also determined re‐encounter and recovery rates for Mallard Anas platyrhynchos and Common Teal Anas crecca. No effects of sampling methods were detected, except in Teal. Re‐encounter rates were lower in sampled Teal than in controls, with annual re‐encounter probabilities being 25% and 35% lower in males and females, respectively. Teal possibly left or avoided sampling sites, or sought sites where they were less detectable after sampling. In general, no deleterious effects were found, suggesting that cloacal swabbing and blood sampling are suitable methods for conducting AIV surveillance in ducks. 相似文献
64.
65.
66.
67.
Alain Hendlisz Amelie Deleporte Thierry Delaunoit Rapha?l Maréchal Marc Peeters Stéphane Holbrechts Marc Van den Eynde Ghislain Houbiers Bertrand Filleul Jean-Luc Van Laethem Sarah Ceyssens Anna-Maria Barbuto Renaud Lhommel Gauthier Demolin Camilo Garcia Hazem El Mansy Lieveke Ameye Michel Moreau Thomas Guiot Marianne Paesmans Martine Piccart Patrick Flamen 《PloS one》2015,10(9)
Background
Tumoral heterogeneity is a major determinant of resistance in solid tumors. FDG-PET/CT can identify early during chemotherapy non-responsive lesions within the whole body tumor load. This prospective multicentric proof-of-concept study explores intra-individual metabolic response (mR) heterogeneity as a treatment efficacy biomarker in chemorefractory metastatic colorectal cancer (mCRC).Methods
Standardized FDG-PET/CT was performed at baseline and after the first cycle of combined sorafenib (600mg/day for 21 days, then 800mg/day) and capecitabine (1700 mg/m²/day administered D1-14 every 21 days). MR assessment was categorized according to the proportion of metabolically non-responding (non-mR) lesions (stable FDG uptake with SUVmax decrease <15%) among all measurable lesions.Results
Ninety-two patients were included. The median overall survival (OS) and progression-free survival (PFS) were 8.2 months (95% CI: 6.8–10.5) and 4.2 months (95% CI: 3.4–4.8) respectively. In the 79 assessable patients, early PET-CT showed no metabolically refractory lesion in 47%, a heterogeneous mR with at least one non-mR lesion in 32%, and a consistent non-mR or early disease progression in 21%. On exploratory analysis, patients without any non-mR lesion showed a significantly longer PFS (HR 0.34; 95% CI: 0.21–0.56, P-value <0.001) and OS (HR 0.58; 95% CI: 0.36–0.92, P-value 0.02) compared to the other patients. The proportion of non-mR lesions within the tumor load did not impact PFS/OS.Conclusion
The presence of at least one metabolically refractory lesion is associated with a poorer outcome in advanced mCRC patients treated with combined sorafenib-capecitabine. Early detection of treatment-induced mR heterogeneity may represent an important predictive efficacy biomarker in mCRC.Trial Registration
ClinicalTrials.gov NCT01290926 相似文献68.
69.
Mathieu Daynac Lise Morizur Thierry Kortulewski Laurent R. Gauthier Martial Ruat Marc-André Mouthon Fran?ois D. Boussin 《Journal of visualized experiments : JoVE》2015,(103)
Neural stem cells (NSCs) in the subventricular zone of the lateral ventricles (SVZ) sustain olfactory neurogenesis throughout life in the mammalian brain. They successively generate transit amplifying cells (TACs) and neuroblasts that differentiate into neurons once they integrate the olfactory bulbs. Emerging fluorescent activated cell sorting (FACS) techniques have allowed the isolation of NSCs as well as their progeny and have started to shed light on gene regulatory networks in adult neurogenic niches. We report here a cell sorting technique that allows to follow and distinguish the cell cycle dynamics of the above-mentioned cell populations from the adult SVZ with a LeX/EGFR/CD24 triple staining. Isolated cells are then plated as adherent cells to explore in details their cell cycle progression by time-lapse video microscopy. To this end, we use transgenic Fluorescence Ubiquitination Cell Cycle Indicator (FUCCI) mice in which cells are red-fluorescent during G1 phase due to a G1 specific red-Cdt1 reporter. This method has recently revealed that proliferating NSCs progressively lengthen their G1 phase during aging, leading to neurogenesis impairment. This method is easily transposable to other systems and could be of great interest for the study of the cell cycle dynamics of brain cells in the context of brain pathologies. 相似文献
70.
Ante Žuljević Thierry Thibaut Marija Despalatović Jean-Michel Cottalorda Vedran Nikolić Ivan Cvitković Boris Antolić 《Biological invasions》2011,13(10):2303-2308
Here we present the first observation of the impact of the invasive Caulerpa racemosa var. cylindracea on native photophilic sponge species in the Adriatic Sea, with special focus on Sarcotragus spinosulus. Caulerpa racemosa var. cylindracea is able to completely overgrow the sponge, developing an exceptionally thick canopy with a maximum measured density of 1,887 m
of stolons m−2 and 40,561 fronds m−2. Necrosis of the sponge surface was significantly correlated with the algal dry biomass, frond number and stolon length.
Dense algal canopy, penetration of the algal stolon and rhizoids into the sponge oscula and covering of the ostiae probably
diminishes the seawater circulation through the sponge and consequently results in its smothering and even death. We suggest
that chemotropism is the reason why C. racemosa penetrates the sponge oscula and establishes such dense canopy on the sponge. 相似文献