全文获取类型
收费全文 | 5084篇 |
免费 | 415篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 162篇 |
妇产科学 | 75篇 |
基础医学 | 852篇 |
口腔科学 | 181篇 |
临床医学 | 528篇 |
内科学 | 988篇 |
皮肤病学 | 89篇 |
神经病学 | 580篇 |
特种医学 | 101篇 |
外科学 | 597篇 |
综合类 | 37篇 |
一般理论 | 6篇 |
预防医学 | 507篇 |
眼科学 | 80篇 |
药学 | 342篇 |
中国医学 | 13篇 |
肿瘤学 | 335篇 |
出版年
2023年 | 46篇 |
2022年 | 60篇 |
2021年 | 117篇 |
2020年 | 65篇 |
2019年 | 111篇 |
2018年 | 124篇 |
2017年 | 82篇 |
2016年 | 102篇 |
2015年 | 131篇 |
2014年 | 170篇 |
2013年 | 226篇 |
2012年 | 354篇 |
2011年 | 376篇 |
2010年 | 196篇 |
2009年 | 190篇 |
2008年 | 325篇 |
2007年 | 316篇 |
2006年 | 315篇 |
2005年 | 320篇 |
2004年 | 298篇 |
2003年 | 308篇 |
2002年 | 256篇 |
2001年 | 65篇 |
2000年 | 58篇 |
1999年 | 71篇 |
1998年 | 50篇 |
1997年 | 63篇 |
1996年 | 36篇 |
1995年 | 27篇 |
1994年 | 39篇 |
1993年 | 42篇 |
1992年 | 37篇 |
1991年 | 45篇 |
1990年 | 38篇 |
1989年 | 45篇 |
1988年 | 38篇 |
1987年 | 33篇 |
1986年 | 46篇 |
1985年 | 21篇 |
1984年 | 28篇 |
1983年 | 20篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 22篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1974年 | 12篇 |
1969年 | 15篇 |
1966年 | 12篇 |
1965年 | 12篇 |
排序方式: 共有5525条查询结果,搜索用时 15 毫秒
101.
Crystal structure of a eukaryotic zinc-dependent histone deacetylase, human HDAC8, complexed with a hydroxamic acid inhibitor 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Vannini A Volpari C Filocamo G Casavola EC Brunetti M Renzoni D Chakravarty P Paolini C De Francesco R Gallinari P Steinkühler C Di Marco S 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(42):15064-15069
Histone deacetylases (HDACs) are a family of enzymes involved in the regulation of gene expression, DNA repair, and stress response. These processes often are altered in tumors, and HDAC inhibitors have had pronounced antitumor activity with promising results in clinical trials. Here, we report the crystal structure of human HDAC8 in complex with a hydroxamic acid inhibitor. Such a structure of a eukaryotic zinc-dependent HDAC has not be described previously. Similar to bacterial HDAC-like protein, HDAC8 folds in a single alpha/beta domain. The inhibitor and the zinc-binding sites are similar in both proteins. However, significant differences are observed in the length and structure of the loops surrounding the active site, including the presence of two potassium ions in HDAC8 structure, one of which interacts with key catalytic residues. CD data suggest a direct role of potassium in the fold stabilization of HDAC8. Knockdown of HDAC8 by RNA interference inhibits growth of human lung, colon, and cervical cancer cell lines, highlighting the importance of this HDAC subtype for tumor cell proliferation. Our findings open the way for the design and development of selective inhibitors of HDAC8 as possible antitumor agents. 相似文献
102.
Rheumatoid flat foot and deformity of the first ray 总被引:4,自引:0,他引:4
Bouysset M Tebib J Noel E Tavernier T Miossec P Vianey JC Duivon JP Bonnin M Nemoz C Jalby J 《The Journal of rheumatology》2002,29(5):903-905
OBJECTIVE: To study the relationship between flat foot and forefoot deformities in rheumatoid arthritis (RA) in order to improve understanding of the progression of deformity and thus provide more appropriate treatment. METHODS: Anteroposterior and lateral weight-bearing radiographs were obtained of 308 feet of patients with RA and 202 feet of patients with neck pain (control feet). RESULTS: In women with RA, we observed with disease duration an increased frequency of flat foot that was correlated with first ray deformity (chiefly metatarsus primus adductus) and severe stages of disability. Flat foot increased very markedly after 3-4 years of disease duration. In control women, flat feet were more frequent after the age of 50 years. CONCLUSION: In RA the inflammatory and mechanical factors leading to foot deformity must receive early medical treatment to avoid progressive hindfoot deformities that lead to disability. 相似文献
103.
Jean-Bernard Ruidavets Vincent Bataille Jean Dallongeville Chantal Simon Annie Bingham Philippe Amouyel Dominique Arveiler Pierre Ducimetière Jean Ferrières 《European heart journal》2004,25(13):1153-1162
AIM: Moderate alcohol intake is related to a decrease of coronary heart disease. This protective effect may be attributed to ethanol but may also depend on the type of alcoholic beverages. However, these differences may be confounded by lifestyle and diet. We investigated the relationships between alcohol consumption, beverage type preference and socio-economic status, diet and lifestyle. METHODS AND RESULTS: A cross-sectional survey on cardiovascular risk factors and nutrition was carried out from 1995 to 1997 by the French MONICA Centres. A sample of 1110 middle-aged men (45-64 years) was randomly recruited; 12.8% of men were abstainers and 16.3% reported a consumption of #10878;60 g/d alcohol. Smoking, waist-to-hip ratio and hypertension increased along with the amount of alcohol intake. Physical activity (from 40.9% in abstainers to 23.8% in heavy drinkers, p=0.0025), educational level (from 11.9+/-4.4 to 11.1+/-3.8 years, p=0.01), socio-economic status and diet quality index (from 7.1+/-2.3 to 6.3+/-2.0, p<0.0001 after multivariate adjustment) decreased along with the increase of alcohol consumption and were higher among wine drinkers than among beer or mixed drinkers. Diet quality index was 7.1+/-1.9, 6.4+/-1.8 and 6.6+/-1.9 among wine, beer and mixed drinkers, respectively (p=0.007 after multivariate adjustment). CONCLUSION: Moderate alcohol drinkers or wine drinkers have healthy diet and behaviours compared to other drinkers or abstainers. The living area plays a significant role in the dieting behaviours. 相似文献
104.
105.
Solal-Céligny P Roy P Colombat P White J Armitage JO Arranz-Saez R Au WY Bellei M Brice P Caballero D Coiffier B Conde-Garcia E Doyen C Federico M Fisher RI Garcia-Conde JF Guglielmi C Hagenbeek A Haïoun C LeBlanc M Lister AT Lopez-Guillermo A McLaughlin P Milpied N Morel P Mounier N Proctor SJ Rohatiner A Smith P Soubeyran P Tilly H Vitolo U Zinzani PL Zucca E Montserrat E 《Blood》2004,104(5):1258-1265
The prognosis of follicular lymphomas (FL) is heterogeneous and numerous treatments may be proposed. A validated prognostic index (PI) would help in evaluating and choosing these treatments. Characteristics at diagnosis were collected from 4167 patients with FL diagnosed between 1985 and 1992. Univariate and multivariate analyses were used to propose a PI. This index was then tested on 919 patients. Five adverse prognostic factors were selected: age (> 60 years vs 60 years), Ann Arbor stage (III-IV vs I-II), hemoglobin level (< 120 g/L vs 120 g/L), number of nodal areas (> 4 vs 4), and serum LDH level (above normal vs normal or below). Three risk groups were defined: low risk (0-1 adverse factor, 36% of patients), intermediate risk (2 factors, 37% of patients, hazard ratio [HR] of 2.3), and poor risk ( 3 adverse factors, 27% of patients, HR = 4.3). This Follicular Lymphoma International Prognostic Index (FLIPI) appeared more discriminant than the International Prognostic Index proposed for aggressive non-Hodgkin lymphomas. Results were very similar in the confirmation group. The FLIPI may be used for improving treatment choices, comparing clinical trials, and designing studies to evaluate new treatments. 相似文献
106.
107.
108.
Samantha I. Pitts Andria Apostolou Sarmila DasGupta Nelson Delgado Thomas J. Kirn Barbara Montana Christina Tan Lisa A. McHugh 《Public health reports (Washington, D.C. : 1974)》2015,130(1):54-59
In 2008, the New Jersey Department of Health (NJDOH) identified a 21.1% increase in reported invasive pneumococcal disease (IPD). In 2009, NJDOH piloted nucleic acid-based serotyping to characterize serotypes causing IPD. From April through September, NJDOH received specimens from 149 of 302 (49%) case patients meeting our case definition. An uncommon serotype, 10A, accounted for 25.2% of IPD overall and was identified in 12 counties, but it was associated with one county (rate ratio = 5.4, 95% confidence interval [CI] 2.1, 11.8). NJDOH subsequently conducted a case-control study to assess the presentation of and clinical risk factors for 10A IPD. Case patients with 10A IPD were more likely to have had immunosuppression, asthma, and multiple chronic medical conditions than control subjects had (odds ratio [OR] = 2.6, 95% CI 1.1, 6.3; OR=4.7, 95% CI 1.7, 13.2; and OR=2.3, 95% CI 1.0, 5.2, respectively). State-based pneumococcal serotype testing identified an uncommon serotype in New Jersey. Continued pneumococcal serotype surveillance might help the NJDOH identify and respond to future serotype-specific increases.Streptococcus pneumoniae (S. pneumoniae) is a leading cause of bacterial pneumonia, bacteremia, and meningitis. In 2008, the New Jersey Department of Health (NJDOH) observed a 21.1% increase in reported invasive pneumococcal disease (IPD) compared with IPD cases reported in 2007 (95% confidence interval [CI] 8.6, 35.2, 8.33 cases/100,000 population in 2008 vs. 6.88 cases/100,000 population in 2007), including increases in four counties. In response, in 2009, NJDOH began a pilot project to characterize the serotypes causing IPD and to determine if serotypes not included in current vaccines contributed to these increases. When our investigation identified an unusual serotype, 10A, NJDOH conducted a case-control study to assess the presentation of and clinical risk factors for 10A IPD. 相似文献
109.
110.
Jennes W Sawadogo S Koblavi-Dème S Vuylsteke B Maurice C Roels TH Chorba T Nkengasong JN Kestens L 《AIDS research and human retroviruses》2002,18(3):171-177
The role of beta-chemokines in controlling HIV replication in vivo is still controversial. Therefore, the association between HIV-1 plasma viral load and the capacity of CD4(+) and CD8(+) T cells to produce beta-chemokines was studied in 28 antiretroviral drug-na?ve HIV-1-infected female sex workers in Abidjan, C?te d'Ivoire. Percentages of beta-chemokine-positive T cells were measured in peripheral blood mononuclear cells by flow cytometry after intracellular staining for RANTES (regulated on activation, normal T expressed and secreted), macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta. HIV-1-infected subjects had higher percentages of MIP-1alpha- and MIP-1beta-positive CD4(+) and CD8(+) T cells (p < 0.02) and of RANTES-positive CD8(+) T cells (p = 0.054) than uninfected controls. Percentages of RANTES- and MIP-1beta-positive CD8(+) T cells correlated directly with HIV-1 plasma viral load (p < 0.02). Percentages of beta-chemokine-positive CD4(+) and CD8(+) T cells correlated directly with percentages of HLA-DR-positive T cells (p < 0.02) and inversely (except RANTES in CD4(+) T cells) with absolute numbers of CD4(+) T cells (p < 0.05) in peripheral blood. These data indicate that increased percentages of beta-chemokine-producing T cells in HIV-1-infected subjects correlate with disease progression and are a sign of viremia-driven chronic T cell activation. 相似文献