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   13235篇
  免费   1029篇
  国内免费   62篇
耳鼻咽喉   180篇
儿科学   325篇
妇产科学   283篇
基础医学   1781篇
口腔科学   255篇
临床医学   1265篇
内科学   2967篇
皮肤病学   135篇
神经病学   1117篇
特种医学   405篇
外科学   2278篇
综合类   200篇
一般理论   10篇
预防医学   982篇
眼科学   502篇
药学   780篇
中国医学   47篇
肿瘤学   814篇
  2022年   81篇
  2021年   186篇
  2020年   101篇
  2019年   184篇
  2018年   201篇
  2017年   145篇
  2016年   166篇
  2015年   206篇
  2014年   328篇
  2013年   559篇
  2012年   747篇
  2011年   808篇
  2010年   447篇
  2009年   433篇
  2008年   678篇
  2007年   771篇
  2006年   766篇
  2005年   797篇
  2004年   743篇
  2003年   747篇
  2002年   744篇
  2001年   134篇
  2000年   132篇
  1999年   146篇
  1998年   183篇
  1997年   145篇
  1996年   151篇
  1995年   118篇
  1994年   116篇
  1993年   112篇
  1992年   137篇
  1991年   107篇
  1990年   86篇
  1989年   100篇
  1988年   70篇
  1987年   74篇
  1985年   77篇
  1984年   95篇
  1983年   107篇
  1982年   128篇
  1981年   128篇
  1980年   98篇
  1979年   71篇
  1978年   86篇
  1977年   88篇
  1976年   78篇
  1975年   80篇
  1974年   80篇
  1973年   77篇
  1972年   62篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
BACKGROUND: Growing evidence indicates that the entorhinal cortex (ECx) might be affected in schizophrenia (SZ) and bipolar disorder (BD). To test whether distinct interneuronal subpopulations might be altered, numbers of parvalbumin-immunoreactive (PVB-IR) neurons were measured in the ECx of BD and SZ subjects. These neurons play a pivotal role within ECx intrinsic circuits. METHODS: Numbers, numerical density, and soma size of PVB-IR neurons were measured in the ECx of normal control (n = 16), BD (n = 10), and SZ (n = 10) subjects. The volume of the ECx was measured in Nissl-stained sections. RESULTS: In BD, decreases of total numbers (p = .02) and numerical densities (p = .01) of PVB-IR neurons were detected in the ECx. Within distinct subregions, reductions were detected in the superficial layers of the lateral (p = .02), intermediate (p = .04), and caudal (p = .01) ECx. In SZ, total numbers and numerical densities were not altered. A reduction of soma size was present in the intermediate ECx (p = .01). Volume was unaffected in either disorder. CONCLUSIONS: In BD, a decrease of PVB-IR neurons may alter intrinsic inhibitory networks within the superficial layers of the ECx. The likely consequence is a disruption of integration and transfer of information from the cerebral cortex to the hippocampus.  相似文献   
42.
BACKGROUND: Many studies have shown differences in cardiac care by racial/ethnic groups without accounting for institutional factors at the location of care. OBJECTIVE: Exploratory analysis of the effect of hospital funding status (public vs private) on emergency department (ED) triage decision making for patients with symptoms suggestive of acute coronary syndromes (ACSs) and on the likelihood of ED discharge for patients with confirmed ACS. STUDY DESIGN AND SETTING: Secondary analysis of data from a randomized controlled trial of 10,659 ED patients with possible ACS in five urban academic public and five private hospitals. The main outcome measures were the sensitivity and specificity of hospital admission for the presence of ACS at public and private hospitals and the adjusted odds of a patient with ACS not being hospitalized at public versus private hospitals. RESULTS: Of 10,659 ED patients, 1,856 had confirmed ACS. For patients with suspected ACS, triage decisions at private hospitals were considerably more sensitive (99 vs 96%; p<.001) but less specific (30 vs 48%; p<.001) than at public hospitals. The difference between hospital types persisted after adjustment for multiple patient-level and hospital-level characteristics. CONCLUSION: Significant differences in triage for patients with suspected ACS exist between public and private hospital EDs, even after adjustment for multiple patient demographic, clinical, and institutional factors. Further studies are needed to clarify the causes of the differences.  相似文献   
43.
44.
45.
46.
BackgroundSilastic ring vertical gastric bypass (SRVGB) with jejunal interposition is our standard operation for morbidly obese patients. We present the results of 5 years of follow-up in a cohort of patients who underwent SRVGB in 2001.MethodsThe records of all 160 consecutive patients who underwent SRVGB from January to December 2001 were reviewed. Of the 160 procedures, 143 were primary open cases, 14 were revisions from restrictive procedures, and 3 were laparoscopic cases. At 5 years, the body mass index and percentage of excess weight loss was available for 133 patients (83%) at office visits (n = 91, 68.4%), by telephone (n = 40, 30.1%), or by e-mail (n = 2, 1.5%).ResultsOf the 160 patients, 121 were women and 39 were men, with a mean age of 33.15 ± 10.0 years, percentage of ideal body weight of 195.7% ± 40.8%, and body mass index of 44.6 ± 9.3 kg/m2. The mean hospital stay was 3 ± 1 days. One patient (.6%) died of a pulmonary embolus. Early complications included 3 cases (1.87%) of upper gastrointestinal bleeding and 4 gastric leaks (2.5%): 2 (1.36%) from primary cases and 2 (14.29%) from revisional cases. Late complications included 32 patients (20%) with incisional hernias, 20 (12.5%) with anemia, 14 (8.8%) with dumping, 4 (2.5%) with gastrojejunal stricture, 2 (1.25%) with intestinal obstruction, and 2 (1.25%) requiring silastic ring surgical removal. The 5-year follow-up data were available for 133 patients (83%). The mean body mass index in this group was 27 ± 5 kg/m2, with a percentage of excess weight loss of 83% ± 18.3% at 5 years postoperatively.ConclusionThe results of our study have shown that SRVGB is an effective operation for promoting lasting weight loss, with acceptable mortality and complication rates.  相似文献   
47.
Netlines     
  相似文献   
48.
A cohort of 729 chronically mentally ill patients receiving community support services (CSS) were followed over a nine-month period. Receiving needed community support services was shown to predict change in client functioning as measured by the Global Assessment Scale (GAS) even after the initial values on the GAS, as well as demographic, psychiatric, residential and medication maintenance variables were considered. Adequacy of social support from family, friends and others also contributed to predicting change in global functioning of the CSS patients.Johns Hopkins UniversityPresented at the American Psychological Association Annual Meeting, Washington, D.C., August 16, 1992.  相似文献   
49.
50.
Perhaps the most significant link in achieving the nation's immunization objectives is the extent of parental knowledge. Admittedly, this is a weak link. The 1990 federal objectives calling for an official format using common guidelines for completion of immunizations, though well-conceived, has not been used exclusively by health care givers. The lack of accord has permitted the proliferation of many different immunization records that are not only confusing to parents, but also to health care providers at times. A standard national immunization record could be an essential element in strengthening the weak link of parental knowledge of immunizations and stressing the importance of preserving such a record for a lifetime.  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