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   2335872篇
  免费   187987篇
  国内免费   7497篇
耳鼻咽喉   31999篇
儿科学   78479篇
妇产科学   64313篇
基础医学   326280篇
口腔科学   63906篇
临床医学   209153篇
内科学   472091篇
皮肤病学   53393篇
神经病学   188628篇
特种医学   94740篇
外国民族医学   883篇
外科学   362535篇
综合类   53155篇
现状与发展   3篇
一般理论   748篇
预防医学   183633篇
眼科学   51065篇
药学   168893篇
  7篇
中国医学   4189篇
肿瘤学   123263篇
  2018年   23703篇
  2017年   18262篇
  2016年   21215篇
  2015年   23839篇
  2014年   33246篇
  2013年   50367篇
  2012年   64973篇
  2011年   69532篇
  2010年   42605篇
  2009年   41104篇
  2008年   65660篇
  2007年   70298篇
  2006年   71391篇
  2005年   69191篇
  2004年   66772篇
  2003年   65007篇
  2002年   62750篇
  2001年   112472篇
  2000年   116380篇
  1999年   97965篇
  1998年   28459篇
  1997年   25604篇
  1996年   26538篇
  1995年   26140篇
  1994年   24531篇
  1993年   22896篇
  1992年   79881篇
  1991年   78079篇
  1990年   75495篇
  1989年   72123篇
  1988年   66588篇
  1987年   65348篇
  1986年   61372篇
  1985年   59043篇
  1984年   44870篇
  1983年   37803篇
  1982年   22926篇
  1981年   20705篇
  1980年   19108篇
  1979年   40403篇
  1978年   28833篇
  1977年   24483篇
  1976年   22554篇
  1975年   23944篇
  1974年   28143篇
  1973年   27016篇
  1972年   24897篇
  1971年   22903篇
  1970年   21235篇
  1969年   19578篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
101.
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain.  相似文献   
102.
103.
104.
BACKGROUND Metabolic disturbances including changes in serum calcium,magnesium or phosphate(P) influence the prevalence of type 2 diabetes mellitus(DM).We assessed the importance of serum P in elderly patients with type 2 DM vs nondiabetes mellitus(non-DM) in relation to renal function.AIM To determine the association between serum P and serum glucose or insulin resistance in diabetic and non-diabetic patients.METHODS One hundred-ten subjects with a mean age of 69.02±14.3 years were enrolled.Twenty-nine of the participants had type 2 DM(26.4%).The incidence of hypertension,smoking and receiving vitamin D(vitD) derivates were recorded.The participants were classified by both estimated glomerular filtration rate(eGFR) and albuminuria categories according to the Kidney Disease Improving Global Outcomes 2012 criteria.RESULTS We divided the patients in two groups according to the P cut-off point related to DM value.A comparison between high and low P showed that body mass index30.2±6.3 vs 28.1±4.6(P=0.04),mean glucose 63.6 vs 50.2(P=0.03),uric acid 6.7±1.6 vs 6.09±1.7(P=0.05),mean intact-parathyroid hormone 68.06 vs 47.4(P=0.001),systolic blood pressure 147.4±16.7 vs 140..2±16.1(P=0.02),mean albuminuria 63.2 vs 50.6(P=0.04) and eGFR 45.6±22.1 vs 55.4±21.5(P=0.02)were significantly different.χ~2 tests showed a significant association between high P and DM,hypertension,receiving vitD,smoking and eGFR stage(χ~2=6.3,P=0.01,χ~2=3.9,P=0.03,χ~2=6.9,P=0.009,χ~2=7.04,P=0.01 and χ~2=7.36,P=0.04,respectively).The adjusted model showed that older age,female gender and increased body mass index were significant predictors of type 2 DM when entering the covariates.CONCLUSION High serum P contributes to vascular and metabolic disturbances in elderly patients with type 2 DM and renal impairment.  相似文献   
105.
106.
107.
108.
109.
Porocarcinoma is an unusual, locally aggressive and potentially fatal neoplasm. Several cutaneous malignancies have been described in association with porocarcinoma, including squamous cell carcinoma, basal cell carcinoma and tricholemmal carcinoma. Previous reports have indicated that the occurrence of malignant tumours in combination with porocarcinoma is extremely rare, in particular with regard to Bowen disease (BD). We report an uncommon case of porocarcinoma occurring synchronously in a single BD lesion in a 63‐year‐old woman with multiple BD lesions. The clinical and histological findings confirmed this diagnosis.  相似文献   
110.
Advancement in microelectromechanical system has facilitated the microfabrication of polymeric substrates and the development of the novel class of controlled drug delivery devices. These vehicles have specifically tailored three dimensional physical and chemical features which together, provide the capacity to target cell, stimulate unidirectional controlled release of therapeutics and augment permeation across the barriers. Apart from drug delivery devices microfabrication technology’s offer exciting prospects to generate biomimetic gastrointestinal tract models. BioMEMS are capable of analysing biochemical liquid sample like solution of metabolites, macromolecules, proteins, nucleic acid, cells and viruses. This review summarized multidisciplinary application of biomedical microelectromechanical systems in drug delivery and its potential in analytical procedures.  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