全文获取类型
收费全文 | 419235篇 |
免费 | 63832篇 |
国内免费 | 9206篇 |
专业分类
耳鼻咽喉 | 4310篇 |
儿科学 | 9793篇 |
妇产科学 | 5238篇 |
基础医学 | 69766篇 |
口腔科学 | 12761篇 |
临床医学 | 34467篇 |
内科学 | 69834篇 |
皮肤病学 | 8482篇 |
神经病学 | 40672篇 |
特种医学 | 15137篇 |
外国民族医学 | 45篇 |
外科学 | 39749篇 |
综合类 | 40185篇 |
现状与发展 | 42篇 |
一般理论 | 16篇 |
预防医学 | 29689篇 |
眼科学 | 5213篇 |
药学 | 51741篇 |
88篇 | |
中国医学 | 18658篇 |
肿瘤学 | 36387篇 |
出版年
2024年 | 821篇 |
2023年 | 5066篇 |
2022年 | 11323篇 |
2021年 | 15442篇 |
2020年 | 16889篇 |
2019年 | 21827篇 |
2018年 | 21277篇 |
2017年 | 22735篇 |
2016年 | 21386篇 |
2015年 | 21838篇 |
2014年 | 24971篇 |
2013年 | 29770篇 |
2012年 | 25681篇 |
2011年 | 29119篇 |
2010年 | 22432篇 |
2009年 | 19190篇 |
2008年 | 20693篇 |
2007年 | 19371篇 |
2006年 | 17851篇 |
2005年 | 16188篇 |
2004年 | 14255篇 |
2003年 | 12675篇 |
2002年 | 10436篇 |
2001年 | 8912篇 |
2000年 | 6959篇 |
1999年 | 5251篇 |
1998年 | 4295篇 |
1997年 | 4288篇 |
1996年 | 3891篇 |
1995年 | 3506篇 |
1994年 | 3308篇 |
1993年 | 2842篇 |
1992年 | 2491篇 |
1991年 | 2242篇 |
1990年 | 1958篇 |
1989年 | 1601篇 |
1988年 | 1519篇 |
1987年 | 1369篇 |
1986年 | 1383篇 |
1985年 | 2217篇 |
1984年 | 2179篇 |
1983年 | 1607篇 |
1982年 | 1647篇 |
1981年 | 1441篇 |
1980年 | 1310篇 |
1979年 | 1063篇 |
1978年 | 719篇 |
1977年 | 615篇 |
1976年 | 671篇 |
1975年 | 471篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Osric A. Forrest Daniel M. Chopyk Yael Gernez Milton R. Brown Carol K. Conrad Richard B. Moss Vin Tangpricha Limin Peng Rabindra Tirouvanziam 《Journal of cystic fibrosis》2019,18(1):64-70
Background
Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.Methods
Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.Results
Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).Conclusions
Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF. 相似文献73.
74.
75.
76.
77.
《Biomedical and environmental sciences : BES》2020,33(5):295-305
Objective Interferon-induced transmembrane protein 3(IFITM3) is an important member of the IFITM family. However, the molecular mechanisms underlying its antiviral action have not been completely elucidated. Recent studies on IFITM3, particularly those focused on innate antiviral defense mechanisms, have shown that IFITM3 affects the body's adaptive immune response. The aim of this study was to determine the contribution of IFITM3 proteins to immune control of influenza infection in vivo.Methods We performed proteomics, flow cytometry, and immunohistochemistry analysis and used bioinformatics tools to systematically compare and analyze the differences in natural killer(NK) cell numbers, their activation, and their immune function in the lungs of Ifitm3-/-and wild-type mice.Results Ifitm3-/-mice developed more severe inflammation and apoptotic responses compared to wild-type mice. Moreover, the NK cell activation was higher in the lungs of Ifitm3-/-mice during acute influenza infection.Conclusions Based on our results, we speculate that the NK cells are more readily activated in the absence of IFITM3, increasing mortality in Ifitm3-/-mice. 相似文献
78.
79.
《Vaccine》2020,38(3):570-577
IntroductionPediatric pneumococcal pneumonia complicated by parapneumonic pleural effusion/empyema (PPE/PE) remains a major concern despite general immunization with pneumococcal conjugate vaccines (PCVs).MethodsIn a nationwide pediatric hospital surveillance study in Germany we identified 584 children <18 years of age with bacteriologically confirmed PPE/PE from October 2010 to June 2018. Streptococcus pneumoniae was identified by culture and/or PCR of blood samples and/or pleural fluid and serotyped.ResultsS. pneumoniae was identified in 256 of 584 (43.8%) children by culture (n = 122) and/or PCR (n = 207). The following pneumococcal serotypes were detected in 114 children: serotype 3 (42.1%), 1 (25.4%), 7F (12.3%), 19A (7.9%), other PCV13 serotypes (4.4%) and non-PCV13 serotypes (7.9%). Between October 2010 and June 2014 serotype 1 (38.1%) and serotype 3 (25.4%) were most prevalent, whereas between July 2014 and June 2018 serotype 3 (62.7%) and non-PCV13 serotypes (15.7%) were dominant. Compared to children with other pneumococcal serotypes, children with serotype 3 associated PPE/PE were younger (median 3.2 years [IQR 2.1–4.3 years] vs. median 5.6 years [IQR 3.8–8.2 years]; p < 0.001) and more frequently admitted to intensive care (43 [89.6%] vs. 48 [73.8%]; p = 0.04). Seventy-six of 114 (66.7%) children with pneumococcal PPE/PE had been vaccinated with pneumococcal vaccines. Thirty-nine of 76 (51.3%) had received a vaccine covering the serotype detected. Thirty of these 39 breakthrough cases were age-appropriately vaccinated with PCV13 and considered vaccine failures, including 26 children with serotype 3, three children with serotype 19A and one child with serotype 1.ConclusionFollowing the introduction of PCV13 in general childhood vaccination we observed a strong emergence of serotype 3 associated PPE/PE in the German pediatric population, including a considerable number of younger children with serotype 3 vaccine breakthrough cases and failures. Future PCVs should not only cover newly emerging serotypes, but also include a more effective component against serotype 3. 相似文献
80.