首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   642篇
  免费   35篇
  国内免费   7篇
耳鼻咽喉   1篇
儿科学   27篇
妇产科学   16篇
基础医学   80篇
口腔科学   3篇
临床医学   68篇
内科学   168篇
皮肤病学   9篇
神经病学   42篇
特种医学   92篇
外科学   70篇
综合类   5篇
预防医学   31篇
眼科学   17篇
药学   17篇
肿瘤学   38篇
  2023年   3篇
  2022年   3篇
  2021年   12篇
  2020年   7篇
  2019年   15篇
  2018年   13篇
  2017年   10篇
  2016年   9篇
  2015年   14篇
  2014年   22篇
  2013年   17篇
  2012年   28篇
  2011年   35篇
  2010年   15篇
  2009年   22篇
  2008年   33篇
  2007年   19篇
  2006年   21篇
  2005年   33篇
  2004年   19篇
  2003年   28篇
  2002年   25篇
  2001年   15篇
  2000年   17篇
  1999年   13篇
  1998年   17篇
  1997年   17篇
  1996年   19篇
  1995年   7篇
  1994年   10篇
  1993年   12篇
  1992年   6篇
  1991年   9篇
  1990年   10篇
  1989年   17篇
  1988年   14篇
  1987年   13篇
  1986年   13篇
  1985年   17篇
  1984年   7篇
  1983年   8篇
  1982年   10篇
  1980年   4篇
  1979年   4篇
  1978年   6篇
  1977年   4篇
  1976年   2篇
  1975年   3篇
  1969年   1篇
  1967年   1篇
排序方式: 共有684条查询结果,搜索用时 6 毫秒
681.
Fifty-nine children with Wilms' tumor (WT) were divided into a normal or poorly nourished group according to anthropometric parameters. The 2 groups were compared for morbidity and survival. There was no difference in the median age or stage of disease in the 38 well nourished and 21 poorly nourished children. There was no difference in the number of children in the normal or poorly nourished group who developed a raised urea or creatinine level, febrile episodes, severe stomatitis, varicella, or upper or lower respiratory infections, or who needed intravenous antibiotics, parenteral nutrition, or red cell and platelet transfusions. Projected survival rate was 56 and 74% for normal and poorly nourished children, respectively (p=.3). Poor nutrition at diagnosis, as determined by anthropometry, had no effect on the morbidity of treatment or survival in children with WT. Based on these results, selective dietary supplementation instead of routine intensive parenteral nutritional support for all children with WT is recommended in countries with limited resources.  相似文献   
682.
Subjects with chronic obstructive pulmonary disease (COPD) have an increased risk of vertebral fractures (VFs); however, VF incidence is largely unknown. Therefore, the aim of our study was to determine the incidence of new and/or worsening VF in subjects with COPD. Smokers and subjects with COPD (GOLD II–IV) from the ECLIPSE study with complete set of chest CT scans (baseline and 1‐ and 3‐year follow‐up) to evaluate vertebrae T1 down to L1 were included. If a VF was diagnosed on the last scan, detailed VF assessment of the previous scans was performed. VFs were scored according to the method of Genant as mild, moderate, or severe. Main outcome measure was the cumulative incidence of new and/or worsening VF at subject level, within 1 and 3 years. Of 1239 subjects (mean age 61 years, 757 males [61%], 999 subjects with COPD), 253 (20.5%) had ≥1 prevalent VF. The cumulative incidence of VFs was 10.1% within 1 year and 24.0% within 3 years. After adjustment for age, sex, body mass index (BMI), pack‐years, and smoking status, prevalence and incidence were similar between smokers and COPD GOLD stages. Within 1 year, 29.2% of the subjects with a prevalent VF had an incident VF, compared with 5.1% in absence of prevalent VF (hazard ratio [HR] = 5.1; 95% confidence interval [CI] 3.6–7.4) and 58.5% versus 15.0% within 3 years (HR = 3.6; 95% CI 2.9–4.6). The incidence of VF was higher with increasing number and severity of prevalent VFs. Among subjects having an incident VF within the first year, 57.3% had a subsequent VF within the next 2 years. In this study, more than half of the smokers and subjects with COPD with a prevalent VF or an incident VF within the first year sustained a subsequent VF within 3 years. The 3‐year risk was even higher in the presence of multiple or severe prevalent VFs. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.  相似文献   
683.
BACKGROUND: In hypertension, sodium sensitivity (SS) of blood pressure is associated with renal hemodynamic abnormalities related to increased activity of the renal renin-angiotensin aldosterone system (RAAS). The renal mechanisms of SS in normotensives are unknown. Therefore, we studied whether SS is related to renal hemodynamics and renal responsiveness to angiotensin II (AngII) in young healthy adults. METHODS: Blood pressure (mean arterial pressure (MAP)) and renal function were measured in 34 healthy men after 1-week low-sodium diet (LS; 50 mmol Na(+)/24 h), 1-week high-sodium diet (HS; 200 mmol Na(+)/24h), and 1-week HS-ACEi (enalapril 20 mg/day). The responses of effective renal plasma flow (ERPF; (131)I-Hippuran clearance) to graded infusion of AngII were assessed during each condition. RESULTS: The sodium-induced change in MAP ranged from -7 to +14 mm Hg. SS (a sodium-induced increase in MAP >3 mm Hg) was present in 13 subjects. ERPF was lower in SS subjects during LS and during HS-ACEi. The AngII-induced decrease in ERPF was blunted in SS on LS (-25 +/- 6 vs. -29 +/- 7% in sodium-resistant (SR) subjects, P < 0.05) and on HS (-30 +/- 5 vs. -35 +/- 6%, P < 0.05). The blunting was corrected by angiotensin-converting enzyme inhibitors (ACEi) (-36 +/- 6 vs. -37 +/- 7%). CONCLUSION: SS normotensive subjects have a blunted renal response to exogenous AngII. This is ameliorated by ACEi, supporting a role for inappropriately high intrarenal RAAS activity. As these findings cannot be attributed to subclinical renal hypertensive damage, high intrarenal RAAS activity and altered renal hemodynamics may be primary phenomena underlying SS.  相似文献   
684.
Plasmacytoid predendritic cells or type 1 interferon (IFN)-producing cells (IPCs) have recently been identified in mice. Although culture systems giving rise to different murine dendritic cell subsets have been established, the developmental regulation of murine plasmacytoid IPCs and the culture conditions leading to their generation remain unknown. Here we show that large numbers of over 40% pure CD11c(+)CD11b(-)B220(+)Gr-1(+) IPCs can be generated from mouse bone marrow cultures with FLT3-ligand. By contrast GM-CSF or TNF-alpha, which promote the generation of CD11c(+)CD11b(+)B220(-) myeloid DCs, block completely the development of IPCs. IPCs generated display similar features to human IPCs, such as the plasmacytoid morphology, the ability to produce large amounts of IFN-alpha in responses to herpes simplex virus, and the capacity to respond to ligands for Toll-like receptor 9 (TLR-9; CpG ODN 1668), but not to ligands for TLR-4 (lipopolysaccharide [LPS]). Unlike human IPCs which produce little IL-12p70, mouse IPCs produce IL-12p70 in response to CpG ODN 1668 and herpes simplex virus. This study demonstrates that the development of murine CD11c(+)CD11b(-)B220(+)Gr-1(+) IPCs and CD11c(+)CD11b(+)B220(-) myeloid DCs is differentially regulated by FLT3-ligand and granulocyte/macrophage colony-stimulating factor. Human IPCs and mouse IPCs display different ability to produce IL-12p70. Large numbers of mouse IPCs can now be obtained from total bone marrow culture.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号