全文获取类型
收费全文 | 2777篇 |
免费 | 281篇 |
国内免费 | 1篇 |
出版年
2023年 | 18篇 |
2022年 | 36篇 |
2021年 | 78篇 |
2020年 | 63篇 |
2019年 | 62篇 |
2018年 | 68篇 |
2017年 | 67篇 |
2016年 | 95篇 |
2015年 | 144篇 |
2014年 | 162篇 |
2013年 | 193篇 |
2012年 | 227篇 |
2011年 | 206篇 |
2010年 | 116篇 |
2009年 | 120篇 |
2008年 | 151篇 |
2007年 | 137篇 |
2006年 | 137篇 |
2005年 | 125篇 |
2004年 | 102篇 |
2003年 | 120篇 |
2002年 | 96篇 |
2001年 | 46篇 |
2000年 | 36篇 |
1999年 | 30篇 |
1998年 | 28篇 |
1997年 | 18篇 |
1996年 | 14篇 |
1995年 | 21篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 25篇 |
1991年 | 17篇 |
1990年 | 16篇 |
1989年 | 15篇 |
1988年 | 10篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 20篇 |
1984年 | 20篇 |
1983年 | 6篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1979年 | 7篇 |
1978年 | 12篇 |
1974年 | 10篇 |
1879年 | 6篇 |
1878年 | 14篇 |
1877年 | 14篇 |
1876年 | 13篇 |
排序方式: 共有3059条查询结果,搜索用时 15 毫秒
51.
Hannouf Marwa B. Assefa Getachew Hannouf Malek B. Gates Ian 《The International Journal of Life Cycle Assessment》2021,26(5):936-949
The International Journal of Life Cycle Assessment - This study has two aims: first, propose the use of the driver-pressure-state-impact-response (DPSIR) framework to expand the normal focus of... 相似文献
52.
53.
Leduc Antoine O. H. C. Costa Jessica S. Oliveira do Nascimento Silva Renata R. Winandy Gabrielle S. M. de Araújo Carlos B. 《Journal of Ethology》2021,39(2):225-234
Journal of Ethology - Noise pollution may impair the cognitive performances of several animal species, producing suboptimal behavioral responses. Involuntary shifts in attention from noise... 相似文献
54.
55.
Anne-Laure Huber Justine Lebeau Patricia Guillaumot Virginie Pétrilli Mouhannad Malek Julien Chilloux Frédérique Fauvet Léa Payen Alain Kfoury Toufic Renno Eric Chevet Serge N. Manié 《Molecular cell》2013,49(6):1049-1059
- Download : Download high-res image (133KB)
- Download : Download full-size image
56.
Mathieu Nacher Celia Basurko Antoine Adenis Emilie Gaubert-Marechal Emilie Mosnier Sophie Edouard Vincent Vantilcke Sindou Sivapregassam Benoit Tressières André Cabié Pierre Couppié 《PloS one》2013,8(11)
A retrospective cohort study was conducted on 1541 HIV-infected patients to determine variables associated with the incidence of herpes zoster. A single failure Cox model showed that herpes zoster incidence increased following the first 6 months of antiretroviral treatment adjusted hazard ratio (AHR)=5 (95%CI=2.6-9.2), P<0.001; in the >60 years age group AHR=2 (95%CI=1-4), P=0.04; in patients in the top CD8 quartile AHR=2.1 (95%CI=1.3-3.6), P<0.001; and in patients previously reported to use crack cocaine AHR=5.9, (95%CI=1.4-25), P=0.02. Herpes zoster incidence increased in patients with CD4 counts<500 per mm3 and gradually declined since 1992-1996, with AHR=0.3 (95%CI=0.2-0.5), P<0.001 for the 1997-2002 period and AHR=0.24 (95%CI=0.14-0.4), P<0.001 for the 2002-2008 period. Contrary to what has been described elsewhere, there was no specific effect of protease inhibitors on herpes zoster incidence. The present study is the first to suggest that crack cocaine is associated with an increased incidence of herpes zoster. The neurological or immunological effects of crack are discussed. 相似文献
57.
58.
Impairments in flexible goal-directed decisions, often examined by reversal learning, are associated with behavioral abnormalities characterized by impulsiveness and disinhibition. Although the lateral orbital frontal cortex (OFC) has been consistently implicated in reversal learning, it is still unclear whether this region is involved in negative feedback processing, behavioral control, or both, and whether reward and punishment might have different effects on lateral OFC involvement. Using a relatively large sample (N = 47), and a categorical learning task with either monetary reward or moderate electric shock as feedback, we found overlapping activations in the right lateral OFC (and adjacent insula) for reward and punishment reversal learning when comparing correct reversal trials with correct acquisition trials, whereas we found overlapping activations in the right dorsolateral prefrontal cortex (DLPFC) when negative feedback signaled contingency change. The right lateral OFC and DLPFC also showed greater sensitivity to punishment than did their left homologues, indicating an asymmetry in how punishment is processed. We propose that the right lateral OFC and anterior insula are important for transforming affective feedback to behavioral adjustment, whereas the right DLPFC is involved in higher level attention control. These results provide insight into the neural mechanisms of reversal learning and behavioral flexibility, which can be leveraged to understand risky behaviors among vulnerable populations. 相似文献
59.
Mona El Khatib Przemyslaw Bozko Vindhya Palagani Nisar P. Malek Ludwig Wilkens Ruben R. Plentz 《PloS one》2013,8(10)
Cholangiocacinoma (CC) is a cancer disease with rising incidence. Notch signaling has been shown to be deregulated in many cancers. However, the role of this signaling pathway in the carcinogenesis of CC is still not fully explored. In this study, we investigated the effects of Notch inhibition by γ-secretase inhibitor IX (GSI IX) in cultured human CC cell lines and we established a transgenic mouse model with liver specific expression of the intracellular domain of Notch (Notch-ICD) and inactivation of tumor suppressor p53. GSI IX treatment effectively impaired cell proliferation, migration, invasion, epithelial to mesenchymal transition and growth of softagar colonies. In vivo overexpression of Notch-ICD together with an inactivation of p53 significantly increased tumor burden and showed CC characteristics. Conclusion: Our study highlights the importance of Notch signaling in the tumorigenesis of CC and demonstrates that additional inactivation of p53 in vivo. 相似文献
60.
Antoine Huyghe Patrice Fran?ois Andrea Mombelli Manuela Tangomo Myriam Girard Denise Baratti-Mayer Ignacio Bolivar Didier Pittet Jacques Schrenzel the Geneva Study Group on Noma 《PLoS neglected tropical diseases》2013,7(9)
Noma (cancrum oris) is a gangrenous disease of unknown etiology affecting the maxillo-facial region of young children in extremely limited resource countries. In an attempt to better understand the microbiological events occurring during this disease, we used phylogenetic and low-density microarrays targeting the 16S rRNA gene to characterize the gingival flora of acute noma and acute necrotizing gingivitis (ANG) lesions, and compared them to healthy control subjects of the same geographical and social background. Our observations raise doubts about Fusobacterium necrophorum, a previously suspected causative agent of noma, as this species was not associated with noma lesions. Various oral pathogens were more abundant in noma lesions, notably Atopobium spp., Prevotella intermedia, Peptostreptococcus spp., Streptococcus pyogenes and Streptococcus anginosus. On the other hand, pathogens associated with periodontal diseases such as Aggregatibacter actinomycetemcomitans, Capnocytophaga spp., Porphyromonas spp. and Fusobacteriales were more abundant in healthy controls. Importantly, the overall loss of bacterial diversity observed in noma samples as well as its homology to that of ANG microbiota supports the hypothesis that ANG might be the immediate step preceding noma. 相似文献