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   3672篇
  免费   217篇
  国内免费   21篇
耳鼻咽喉   22篇
儿科学   56篇
妇产科学   21篇
基础医学   483篇
口腔科学   89篇
临床医学   279篇
内科学   1060篇
皮肤病学   93篇
神经病学   239篇
特种医学   153篇
外科学   521篇
综合类   9篇
预防医学   59篇
眼科学   89篇
药学   225篇
中国医学   10篇
肿瘤学   502篇
  2023年   35篇
  2022年   67篇
  2021年   152篇
  2020年   70篇
  2019年   97篇
  2018年   111篇
  2017年   90篇
  2016年   117篇
  2015年   111篇
  2014年   124篇
  2013年   168篇
  2012年   236篇
  2011年   247篇
  2010年   171篇
  2009年   118篇
  2008年   211篇
  2007年   222篇
  2006年   210篇
  2005年   214篇
  2004年   185篇
  2003年   175篇
  2002年   214篇
  2001年   63篇
  2000年   46篇
  1999年   53篇
  1998年   45篇
  1997年   36篇
  1996年   39篇
  1995年   23篇
  1994年   28篇
  1993年   24篇
  1992年   26篇
  1991年   15篇
  1990年   12篇
  1989年   17篇
  1988年   10篇
  1987年   13篇
  1986年   9篇
  1985年   10篇
  1984年   7篇
  1983年   8篇
  1982年   5篇
  1980年   7篇
  1979年   7篇
  1977年   5篇
  1976年   5篇
  1975年   6篇
  1974年   5篇
  1972年   5篇
  1966年   4篇
排序方式: 共有3910条查询结果,搜索用时 234 毫秒
121.
ObjectivesSulfated glycoconjugates (S-GCs) are essential components of dentinogenesis and osteogenesis, and are involved in the regulation of the mineralization process. The scales of Polypterus senegalus, which are homologous to teeth and phylogenetically derived from ancestral dermal skeleton, comprise true enamel, dentine, and bone. As part of the phylogenic evolutional studies on mesenchyme-derived hard tissues, we investigated the ultrastructural distribution patterns and histochemical properties of S-GCs in the dentine and bone of scales.MethodsFor detection of S-GCs, a high iron diamine–thiocarbohydrazide–silver proteinate (HID–TCH–SP) staining technique was used.ResultsS-GCs were observed in unmineralized predentine and osteoid, mineralized dentine, osteocyte pericellular matrix, but not in mineralized bone and isopedine. Most S-GCs in the dentine and osteoid were susceptible to testicular hyaluronidase, indicating that they are chondroitin sulfates.ConclusionDistinct differences in the S-GC distribution pattern between the dentine and bone were observed. The S-GC distribution pattern associated with the dentinogenesis of scales is very similar to that of mammalian mantle dentine.  相似文献   
122.
We report a case of rheumatoid vasculitis (RV) that responded well to abatacept, a cytotoxic T lymphocyte-associated antigen 4 (CTLA4)-immunoglobulin fusion protein. A 38-year-old woman developed RV despite treatment with methotrexate and tumor necrosis factor (TNF) inhibitors. The effects of steroid therapy, immunoabsorption plasmapheresis, and interleukin-6 inhibitor were insufficient, however, administration of abatacept rapidly improved her clinical symptoms with almost normalization of the immunological findings. This is the first published case report of the successful treatment of RV with abatacept.  相似文献   
123.
124.
125.

Background

Preoperative traction for hip fractures is of no benefit in semi-urgent surgery. However, its efficacy has not been assessed in cases in which emergency surgery was not possible. We evaluated the efficacy of preoperative skin traction for hip fractures in a level II trauma center in Japan where many patients undergo delayed surgery.

Methods

We undertook a randomized controlled trial. Eighty-one patients were randomized to be treated with skin traction (41 patients), or bed rest (40 patients). Preoperative pain was assessed by use of a visual analogue scale and the number of analgesics required. Fracture reduction was measured on the basis of leg-length and neck–shaft angle discrepancies on the radiograph on admission, a day before surgery, and after surgery.

Results

The mean time from admission to surgery was 7.5 days. Pain decreased markedly on the day after admission in both the traction and no-traction groups. No significant difference was found during the preoperative waiting period between the groups in either pain score or number of analgesics taken. No significant difference was found in radiographic data either before or after surgery, and satisfactory reduction was achieved after surgery irrespective of the use of skin traction.

Conclusions

In our single-institution prospective randomized controlled trial, preoperative skin traction for patients with hip fracture had no effect on pain relief before surgery or reduction of fracture displacement during surgery, irrespective of preoperative waiting time.  相似文献   
126.
127.
ABSTRACT

Objective: Adult patients with ischemic moyamoya disease (MMD) who receive treatment with antiplatelet drugs reportedly show improvements in neuropsychological test scores after around 2 years. The purpose of the present study subanalyzing the same patient cohort used in a previous study was to determine which antiplatelet drug, clopidogrel or cilostazol, results in better improvement of cognitive function among non-surgical adult patients showing ischemic MMD without severe hemodynamic compromise.

Methods: Sixty-six patients without cerebral misery perfusion on 15O gas positron emission tomography were treated with pharmacotherapy alone. Patients ≥50 years old and <50 years old initially received clopidogrel and cilostazol, respectively. Any patient suffering side effects of the antiplatelet drug switched to the other antiplatelet drug. Neuropsychological tests were performed at study entry and at the end of the 2-year follow-up, and differences in each neuropsychological test score between the two time points (second test score – first test score) were calculated and defined as Δ scores.

Results: Among the five neuropsychological tests, Δ scores for two tests were significantly greater in patients treated with cilostazol (n = 36) than in those treated with clopidogrel (n = 30), and Δ scores of the remaining three tests did not differ between patient groups. Based on Δ scores, 15 patients (23%) were defined as showing interval cognitive improvement. On multivariate analysis, cilostazol administration (95% confidence interval, 1.19–193.98; P = 0.0361) represented an independent predictor of interval cognitive improvement.

Conclusions: Cilostazol may improve cognition better than clopidogrel in non-surgical adult patients with ischemic MMD.  相似文献   
128.
129.
Tubulocystic carcinoma of the kidney is rare and typically indolent. Our case involved an aggressive tubulocystic carcinoma as well as the radiological confirmation of its relation to papillary renal cell carcinoma. A 46-year-old male presented with renal multiloculated cysts with a solid part. On computed tomography and magnetic resonance imaging, the solid part showed the characteristics of papillary renal cell carcinoma. Contrast enhancement of the solid part was fluffy and sparse because of the coexistence of cysts. Perirenal fat invasion resulted in exophytic cysts, and renal-hilar cystic lymph node metastasis existed. The histopathological diagnosis was tubulocystic carcinoma associated with areas of papillary renal cell carcinoma and poorly differentiated carcinoma with metastasis. Our case suggests that the solid part enhancement of tubulocystic carcinoma tends to be fluffy and sparse, and exophytic cysts and cystic lymph nodes may show radiologically aggressive findings.  相似文献   
130.
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