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   17984篇
  免费   937篇
  国内免费   125篇
耳鼻咽喉   168篇
儿科学   396篇
妇产科学   387篇
基础医学   2115篇
口腔科学   422篇
临床医学   1323篇
内科学   5423篇
皮肤病学   457篇
神经病学   1542篇
特种医学   349篇
外科学   2476篇
综合类   98篇
一般理论   8篇
预防医学   1172篇
眼科学   329篇
药学   1101篇
中国医学   40篇
肿瘤学   1240篇
  2024年   14篇
  2023年   144篇
  2022年   322篇
  2021年   733篇
  2020年   333篇
  2019年   661篇
  2018年   724篇
  2017年   429篇
  2016年   435篇
  2015年   475篇
  2014年   788篇
  2013年   861篇
  2012年   1585篇
  2011年   1566篇
  2010年   835篇
  2009年   746篇
  2008年   1206篇
  2007年   1215篇
  2006年   1045篇
  2005年   1010篇
  2004年   930篇
  2003年   767篇
  2002年   770篇
  2001年   133篇
  2000年   142篇
  1999年   140篇
  1998年   116篇
  1997年   108篇
  1996年   81篇
  1995年   65篇
  1994年   56篇
  1993年   49篇
  1992年   63篇
  1991年   48篇
  1990年   58篇
  1989年   32篇
  1988年   38篇
  1987年   19篇
  1986年   19篇
  1985年   22篇
  1984年   25篇
  1983年   17篇
  1982年   14篇
  1981年   16篇
  1980年   17篇
  1979年   19篇
  1975年   14篇
  1973年   14篇
  1971年   14篇
  1970年   15篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
Gene expression regulation and cancer   总被引:1,自引:0,他引:1  
  相似文献   
32.
33.
OBJECTIVE: Several studies have shown that repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) is effective in the treatment of depression in patients with Parkinson disease (PD). However, since research into the effect of this type of rTMS regime on motor function is limited, we studied the effect of rTMS over the DLPFC on the motor functions in PD patients. METHODS: Thirteen patients were randomly assigned into 2 groups, one receiving real-rTMS (90% of resting motor threshold, 10 Hz, 450 pulses-day for 10 consecutive days) over the DLPFC contralateral to the more affected side, and the other group receiving sham-rTMS. Assessment included a clinical motor evaluation using part III of the Unified Parkinson's Disease Rating Scale (UPDRS), and several motor tasks. The UPDRS was applied before and after 10 days of rTMS. Finger tapping, reach movement, grip movement and gait were measured in each session before and after the rTMS over the 10 day period. RESULTS: Statistical analysis (ANOVA for repeated measures; group *day *side *rTMS) only showed a significant effect for finger tapping, reach movement and gait for the factor day. No significant change was reported for the UPDRS in any group. CONCLUSIONS: Application of rTMS over the DLPFC as a 10 day course had no significant effect on motor functions and clinical motor status, and the improvement in performance of motor tasks can be attributed to the effects of practice. SIGNIFICANCE: rTMS over the DLPFC did not lead to any motor improvement in PD patients.  相似文献   
34.
The new diagnostic criteria of coeliac disease (CD) give more importance to serological markers. Immunoglobulin A antiendomysial antibodies (IgA-EmA) were determined in 138 sera from 79 coeliac children and the antibody levels compared to IgG and IgA antigliadin antibodies (IgG-AGA, IgA-AGA) in the sera. The assessment was also carried out in 29 children with other gastrointestinal diseases, 29 with non-gastrointestinal diseases and 35 healthy children. The IgA-EmA had a 91.4% specificity and a 88.4% sensitivity for active CD. The corresponding figures were 89.8% and 64.4% for IgA-AGA and 73.7% and 86.2% for IgG-AGA, respectively. The results of IgA-EmA determinations were concordant with the intestinal biopsy findings in 90% of cases, versus 80% for IgA-AGA and 83% for IgG-AGA. In most of the discordant cases the biopsy showed only minor changes, making the classification difficult. All patients with positive IgA2-EmA also had positive IgA1 EmA antibodies. IgA-EmA are an excellent serological marker of CD activity in children and they are useful to decrease the number of intestinal biopsies which are needed to confirm the diagnosis in coeliac patients.  相似文献   
35.
Lung cancer is the most prevalent malignancy in western countries and most of the patients present at advanced stages, but single splenic metastasis is exceptional instead. We report on a case of a seventy-three-year old male presenting with non-hemoptoic productive cough, constitutional syndrome and pain in the left lower quadrant. Physical examination and complementary radiological and hystologycal procedures revealed the presence of an adenocarcinoma of the left lung with probable splenic metastasis. The patient underwent splenectomy, which confirmed the diagnose of splenic metastasis of lung adenocarcinoma and, secondly, lung resection was performed. Topics about lung cancer metastasis are discussed.  相似文献   
36.
37.
38.
39.
40.
Between 1985-1990 we studied by means of two-dimensional echocardiography 286 patients with isolated ventricular septal defect (VSD). A hundred and sixty three being male and 123 female, as a mean age of 5 +/- 3 months. Sixty two cases (22.3%) reveales associated anomalies and in other 63 (22.4%) there was in the evolution an aneurysm of the septum membranous. The projections used were apical 4-chamber, with or without aortic root; parasternal long-short axis of great arterias or at ventricular level; subcostal 4-chamber; right oblique outlet right outflow tract and left oblique outlet left and right outflow tracts. Patients with VSD smaller than 3 mm were excluded. Perimembranous defects, 189 cases (66%), were more frequent than muscular, 91 31.8%), and subarterial defects, 6 (2.1%). Only 19 (9 apical muscular, 6 perimembranous outlet and 4 perimembranous trabecular) were initially misclassified. The diameter of the VSD was large in subarterial (0.85 +/- 0.1 cm) and perimembranous outlet VSD (0.75 +/- 0.5 cm) compared with the rest. Each group of defects was more easily shown by one particular projection except trabecular muscular defect. In conclusion, we are able to state that two-dimensional echocardiography enables us to discover the size and situation of isolated ventricular defects.  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