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   4886篇
  免费   340篇
  国内免费   16篇
耳鼻咽喉   31篇
儿科学   136篇
妇产科学   98篇
基础医学   710篇
口腔科学   82篇
临床医学   484篇
内科学   1102篇
皮肤病学   72篇
神经病学   571篇
特种医学   72篇
外国民族医学   1篇
外科学   476篇
综合类   52篇
一般理论   1篇
预防医学   544篇
眼科学   54篇
药学   330篇
中国医学   7篇
肿瘤学   419篇
  2024年   11篇
  2023年   44篇
  2022年   84篇
  2021年   187篇
  2020年   111篇
  2019年   154篇
  2018年   171篇
  2017年   113篇
  2016年   138篇
  2015年   141篇
  2014年   216篇
  2013年   236篇
  2012年   395篇
  2011年   400篇
  2010年   188篇
  2009年   206篇
  2008年   288篇
  2007年   307篇
  2006年   303篇
  2005年   225篇
  2004年   239篇
  2003年   243篇
  2002年   212篇
  2001年   30篇
  2000年   34篇
  1999年   37篇
  1998年   32篇
  1997年   30篇
  1996年   23篇
  1995年   23篇
  1994年   23篇
  1993年   20篇
  1992年   18篇
  1991年   13篇
  1990年   10篇
  1988年   21篇
  1987年   17篇
  1986年   15篇
  1985年   16篇
  1984年   17篇
  1982年   10篇
  1981年   12篇
  1980年   11篇
  1979年   12篇
  1977年   11篇
  1976年   10篇
  1974年   14篇
  1969年   15篇
  1968年   14篇
  1967年   11篇
排序方式: 共有5242条查询结果,搜索用时 15 毫秒
1.
European Surgery - Treatment of pilonidal sinus disease (PSD) requires a tailored approach. A national guideline was published in 2014. The current status of surgical PSD therapy...  相似文献   
2.
3.
4.
Juvenile Parkinsonism: clinical and metabolic characteristics.   总被引:1,自引:1,他引:0       下载免费PDF全文
Twenty one patients with idiopathic Parkinsonism beginning before the age of 40 years were investigated. The mean duration of the disease was 19 years. There was a good and sustained response to levodopa. Only four patients reached stages IV and V (Hoehn and Yahr). Intolerance to levodopa was observed in the more advanced stages of the disease. In the series the familial incidence of Parkinsonism (2 cases) and essential tremor (3 cases) was very low. Thyroid disorder, diabetes mellitus or macrocytic anaemia was not found in any of the cases.  相似文献   
5.
(18)F-FDG PET has a high accuracy in staging head and neck cancer, but its role in patients with clinically and radiographically negative necks (N0) is less clear. In particular, the value of combined PET/CT has not been determined in this group of patients. METHODS: In a prospective study, 31 patients with oral cancer and no evidence of lymph node metastases by clinical examination or CT/MRI underwent (18)F-FDG PET/CT before elective neck dissection. PET/CT findings were recorded by neck side (left or right) and lymph node level. PET/CT findings were compared with histopathology of dissected nodes, which was the standard of reference. RESULTS: Elective neck dissections (26 unilateral, 5 bilateral; a total of 36 neck sides), involving 142 nodal levels, were performed. Only 13 of 765 dissected lymph nodes harbored metastases. Histopathology revealed nodal metastases in 9 of 36 neck sides and 9 of 142 nodal levels. PET was TP in 6 nodal levels (6 neck sides), false-negative in 3 levels (3 neck sides), true-negative in 127 levels (23 neck sides), and false-positive in 6 levels (4 neck sides). The 3 false-negative findings occurred in metastases smaller than 3 mm or because of inability to distinguish between primary tumor and adjacent metastasis. TP and false-positive nodes exhibited similar standardized uptakes (4.8 +/- 1.1 vs. 4.2 +/- 1.0; P = not significant). Sensitivity and specificity were 67% and 85% on the basis of neck sides and 67% and 95% on the basis of number of nodal levels, respectively. If a decision regarding the need for neck dissection had been based solely on PET/CT, 3 false-negative necks would have been undertreated, and 4 false-positive necks would have been overtreated. CONCLUSION: (18)F-FDG PET/CT can identify lymph node metastases in a segment of patients with oral cancer and N0 neck. A negative test can exclude metastatic deposits with high specificity. Despite reasonably high overall accuracy, however, the clinical application of PET/CT in the N0 neck may be limited by the combination of limited sensitivity for small metastatic deposits and a relatively high number of false-positive findings. The surgical management of the N0 neck should therefore not be based on PET/CT findings alone.  相似文献   
6.
7.
A monoclonal antibody raised by immunization of BALB/c mice with erythrocytic stages of Plasmodium vivax was shown to react with asexual erythrocytic stages of P. chabaudi. The cross-reactivity molecules are antigens of 200 and 148 kDa in P. vivax and of 190 and 70 kDa in P. chabaudi. Immunofluorescence studies of the erythrocytic stages of P. vivax and P. chabaudi indicated that expression of these antigens increased as the parasites' developed from the ring stage to the schizont stage. In the mature trophozoites of P. chabaudi, immunoelectron microscopy revealed clusters of antigen distributed in the cytoplasm of the parasitized erythrocyte. In the schizont, packets of antigen were found associated with the parasitophorous vacuole and the cytoplasm of the infected host cell. Received: 19 March 1996 / Accepted: 28 August 1996  相似文献   
8.
INLANDER, CHARLES B., LEVIN, LOWELL B., AND WEINER, E.D. Medicine on Trial: The Appalling Story of Medical Ineptitude and the Arrogance that Overlooks It.  相似文献   
9.
10.

Background  

Many factors impacting cecal intubation rates have been examined in detail; however, little information exists regarding the effect of the timing of the procedure. We sought to examine any difference in cecal intubation rates between morning and afternoon colonoscopies and identify factors contributing to a discrepancy.  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