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   3373篇
  免费   138篇
  国内免费   16篇
耳鼻咽喉   126篇
儿科学   39篇
妇产科学   95篇
基础医学   524篇
口腔科学   90篇
临床医学   214篇
内科学   756篇
皮肤病学   23篇
神经病学   259篇
特种医学   111篇
外科学   536篇
综合类   14篇
预防医学   113篇
眼科学   25篇
药学   208篇
中国医学   13篇
肿瘤学   381篇
  2023年   18篇
  2022年   39篇
  2021年   62篇
  2020年   39篇
  2019年   61篇
  2018年   65篇
  2017年   61篇
  2016年   53篇
  2015年   63篇
  2014年   86篇
  2013年   107篇
  2012年   162篇
  2011年   209篇
  2010年   87篇
  2009年   109篇
  2008年   179篇
  2007年   203篇
  2006年   222篇
  2005年   239篇
  2004年   210篇
  2003年   196篇
  2002年   192篇
  2001年   58篇
  2000年   48篇
  1999年   69篇
  1998年   58篇
  1997年   33篇
  1996年   58篇
  1995年   40篇
  1994年   31篇
  1993年   27篇
  1992年   45篇
  1991年   27篇
  1990年   36篇
  1989年   50篇
  1988年   32篇
  1987年   35篇
  1986年   28篇
  1985年   29篇
  1984年   22篇
  1983年   11篇
  1980年   10篇
  1979年   11篇
  1978年   11篇
  1977年   11篇
  1976年   10篇
  1974年   8篇
  1968年   6篇
  1967年   6篇
  1966年   7篇
排序方式: 共有3527条查询结果,搜索用时 15 毫秒
61.
62.
Leptin has been reported to exert an atherosclerotic effect by regulating expression of angiogenic factors that have been implicated in the pathogenesis of coronary artery disease (CAD). The purpose of this study was to investigate whether lipid-lowering therapy (LLT) with statins could affect leptin levels and angiogenic factors in patients with CAD. This study included 76 patients with CAD and 15 subjects without CAD (non-CAD). CAD patients were randomized to 6?months of intensive LLT with atorvastatin or moderate LLT with pravastatin. Plasma leptin, angiopoetin-2 (Ang-2), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) levels were measured prior to statin therapy (baseline) and after 6?months. Baseline levels of leptin, Ang-2, HGF and VEGF were higher in the CAD group than in the non-CAD group (all P?<?0.05). Treatment with intensive LLT decreased leptin, Ang-2, HGF and VEGF levels, whereas moderate LLT did not change these levels. This study suggests that LLT with atorvastatin decreases leptin levels and angiogenic factors in patients with CAD, possibly contributing to the beneficial effects of LLT with atorvastatin in CAD.  相似文献   
63.
Abstract

We have investigated the relationship between angiographic vasospasm and the ability of spastic vessels to relax in response to agents which promote release of endothelium derived relaxing factor. Vasospasm was induced in dogs by the 'single hemorrhage' technique. Animals received a single intracisternal injection of blood, blood activated with thromboplastin or collagen, or inert material, and angiograms were obtained day 0 and day 7. Vasospasm was estimated by measuring the ratio of the diameter of the vessel before and after treatment. Rings of cerebral artery obtained from these animals were suspended in a standard organ- bath arrangement, contracted with prostaglandin F2(X and then treated with increasing doses of adenosine triphosphate or bradykinin, both of which cause relaxation by an endothelium-dependent process. The arteries from animals with moderate to severe vasospasm showed a response to bradykinin and adenosine- triphosphate which was reduced, absent or converted to a contraction, when compared with normal vessels. Vessels in which vasospasm was mild or absent relaxed as expected to these agents. The reduction in vessel diameter showed a highly significant correlation with the reduction in relaxation to bradykinin or adenosine-triphosphate. These results have demonstrated that impairment of endothelium-dependent vasorelaxation correlates with the existence of vasospasm. [Neurol Res 1996; 18: 553-558]  相似文献   
64.
We report a rare case of gamma knife radiation-induced undifferentiated sarcoma in the cavernous sinus. A 24-year-old woman underwent resection of a growth hormone-secreting pituitary adenoma and gamma knife radiosurgery (maximal dose 24 Gray (Gy); marginal dose 16 Gy) for residual adenoma in the right cavernous sinus. Follow-up MRI showed the disappearance of the adenoma. Fifteen years later, she developed right oculomotor nerve palsy. MRI revealed a new tumor in the right cavernous sinus. Partial removal of the tumor was performed via a transsphenoidal approach. Histological diagnosis revealed undifferentiated sarcoma. The patient received three cycles of chemotherapy containing doxorubicin and ifosfamide, then carbon ion radiotherapy (65 GyE in 26 fractions). Subsequent MRI showed tumor regression for five months. To our knowledge, this is the first report of undifferentiated sarcoma following gamma knife radiosurgery for pituitary adenoma. As patients undergoing radiosurgery face the possibility of such neoplasms developing, long-term follow-up is required.  相似文献   
65.
66.

Purpose

Ulcerative colitis (UC) is a chronic, relapsing, and refractory disorder of the intestine. Total proctocolectomy with ileal pouch anal anastomosis (IPAA) is the preferred and standard surgical procedure for patients’ refractory to medical therapy. Pouchitis is one of the most common long-term complications after IPAA. In the present study, the safety and efficacy of Clostridium butyricum MIYAIRI (CBM) as a probiotic were examined.

Methods

A randomized and placebo-controlled study was performed. Seventeen patients were recruited from 2007 to 2013. Nine tablets of MIYA-BM® or placebo were orally administered once daily. The cumulative pouchitis-free survival, pouch condition (using the modified pouch disease activity index), and blood parameters were evaluated. A fecal sample analysis was also performed.

Results

Subjects were randomly allocated to receive MIYA-BM or placebo (9 and 8 subjects, respectively). One subject in the MIYA-BM group and four subjects in the placebo group developed pouchitis. No side effects occurred in either group. Characteristic intestinal flora was observed in each group.

Conclusions

Our results suggest that probiotic therapy with CBM achieved favorable results with minimal side effects and might be a useful complementary therapy for the prevention of pouchitis in patients with UC who have undergone IPAA.
  相似文献   
67.
68.
69.
Annals of Surgical Oncology - Colorectal cancer (CRC) is a major cause of cancer-related deaths. Metastasis is enhanced through epithelial-mesenchymal transition (EMT), a process primarily induced...  相似文献   
70.
OBJECTIVES AND METHODS: Low-density lipoprotein cholesterol (LDL-C) measurements in clinics were evaluated by a multiple-choice questionnaire sent to 146 physicians (78 general practitioners and 68 hospital physicians) in Niigata Prefecture, Japan. RESULTS: Seventy-six percent of the general practitioners and 84% of the hospital staff measured LDL-C, and 60% of all physicians calculated LDL-C using the Friedewald formula. Sixty-two percent of general practitioners and 43% of hospital physicians took blood samples without overnight fasting and 40-50% of whom estimated LDL-C using the Friedewald formula, although the formula is reliable only for samples collected after an overnight fast. Two thirds of the physicians managed patients according to the Japan Atherosclerosis Society Guidelines (1997), whereas 40-50% based diagnoses and treatments on total cholesterol, and only 20-30% used LDL-C-based management. CONCLUSIONS: Direct measurement, education and management of LDL-C not affected by diet are mandatory.  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