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   23538篇
  免费   1106篇
  国内免费   130篇
耳鼻咽喉   196篇
儿科学   416篇
妇产科学   449篇
基础医学   3215篇
口腔科学   455篇
临床医学   1394篇
内科学   5645篇
皮肤病学   655篇
神经病学   2014篇
特种医学   930篇
外科学   3935篇
综合类   89篇
一般理论   5篇
预防医学   715篇
眼科学   422篇
药学   1386篇
中国医学   31篇
肿瘤学   2822篇
  2022年   106篇
  2021年   434篇
  2020年   240篇
  2019年   318篇
  2018年   420篇
  2017年   332篇
  2016年   356篇
  2015年   420篇
  2014年   531篇
  2013年   670篇
  2012年   1117篇
  2011年   1127篇
  2010年   619篇
  2009年   560篇
  2008年   953篇
  2007年   1088篇
  2006年   1058篇
  2005年   1012篇
  2004年   986篇
  2003年   1019篇
  2002年   1083篇
  2001年   694篇
  2000年   772篇
  1999年   715篇
  1998年   313篇
  1997年   251篇
  1996年   242篇
  1995年   224篇
  1994年   229篇
  1993年   204篇
  1992年   655篇
  1991年   581篇
  1990年   552篇
  1989年   569篇
  1988年   520篇
  1987年   492篇
  1986年   447篇
  1985年   454篇
  1984年   256篇
  1983年   215篇
  1982年   101篇
  1979年   237篇
  1978年   133篇
  1977年   103篇
  1975年   101篇
  1974年   106篇
  1973年   98篇
  1970年   104篇
  1969年   115篇
  1968年   97篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Animal and human studies suggest fish oil and green tea may have protective effect on prostate cancer. Fatty acid synthase (FAS) has been hypothesized to be linked to chemoprotective effects of both compounds. This study evaluated the independent and joint effects of fish oil (FO) and green tea supplement (epigallocatechin-3-gallate, EGCG) on FAS and Ki-67 levels in prostate tissue. Through a double-blinded, randomized controlled trial with 2 × 2 factorial design, 89 men scheduled for repeat prostate biopsy following an initial negative prostate biopsy were randomized into either FO alone (1.9 g DHA + EPA/day), EGCG alone (600 mg/day), a combination of FO and EGCG, or placebo. We used linear mixed-effects models to test the differences of prostate tissue FAS and Ki-67 by immunohistochemistry between pre- and post-intervention within each group, as well as between treatment groups. Results did not show significant difference among treatment groups in pre-to-post-intervention changes of FAS (P = 0.69) or Ki-67 (P = 0.26). Comparing placebo group with any of the treatment groups, we did not find significant difference in FAS or Ki-67 changes (all P > 0.05). Results indicate FO or EGCG supplementation for a short duration may not be sufficient to produce biologically meaningful changes in FAS or Ki-67 levels in prostate tissue.  相似文献   
2.
3.
4.
5.
We report a case of a diaphragmatic hernia after a heart transplant operation. A 43-year-old woman, who underwent orthotropic heart transplantation for hypertrophic cadiomyopathy two year earlier, presented with vomiting and epigastric pain. A computed tomography scan showed that the stomach and transverse colon were dislocated in the left thoracic cavity. We diagnosed left diaphragmatic hernia incarceration and performed laparoscopic repair of the diaphragmatic hernia. A 12 × 8 cm diaphragmatic defect was found intraoperatively on the ventrolateral aspect of the left diaphragm, and the stomach with volvulus had herniated into the thorax through the defect. The hernia was considered to be iatrogenic. The diaphragmatic defect was large, and the diaphragm was thinning. We closed the defect by mesh repair. Laparoscopic mesh repair of the diaphragmatic hernia could be performed safely and with minimal invasiveness.  相似文献   
6.
7.
8.
9.
Burning mouth syndrome (BMS) is a chronic oro‐facial pain disorder of unknown cause. It is more common in peri‐ and post‐menopausal women, and sex hormone dysregulation is believed to be an important causative factor. Psychosocial events often trigger or exacerbate symptoms, and persons with BMS appear to be predisposed towards anxiety and depression. Atrophy of small nerve fibres in the tongue epithelium has been reported, and potential neuropathic mechanisms for BMS are now widely investigated. Historically, BMS was thought to comprise endocrinological, psychosocial and neuropathic components. Neuroprotective steroids and glial cell line–derived neurotrophic factor family ligands may have pivotal roles in the peripheral mechanisms associated with atrophy of small nerve fibres. Denervation of chorda tympani nerve fibres that innervate fungiform buds leads to alternative trigeminal innervation, which results in dysgeusia and burning pain when eating hot foods. With regard to the central mechanism of BMS, depletion of neuroprotective steroids alters the brain network–related mood and pain modulation. Peripheral mechanistic studies support the use of topical clonazepam and capsaicin for the management of BMS, and some evidence supports the use of cognitive behavioural therapy. Hormone replacement therapy may address the causes of BMS, although adverse effects prevent its use as a first‐line treatment. Selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs) may have important benefits, and well‐designed controlled studies are expected. Other treatment options to be investigated include brain stimulation and TSPO (translocator protein 18 kDa) ligands.  相似文献   
10.
Abstract: The risk of cardiovascular death is high in hemodialysis (HD) patients, and thickening, stiffening and calcification of the arterial wall have been shown as its predictive factors. Activated vitamin D preparations are used for the treatment of secondary hyperparathyroidism in HD patients, but as they increase serum phosphate and calcium concentrations, there is a concern that they promote vascular calcification and, consequently, exacerbate the outcomes. In this article, the effects of vitamin D therapy on survival, cardiac function, arteriosclerosis, immunity, and inflammation are evaluated by reviewing the literature. In HD patients, the risk of death (particularly cardiovascular death) is significantly lower in those treated than in those not treated with vitamin D. Moreover, activated vitamin D improves cardiac function and alleviates cardiac hypertrophy in HD patients. Experimental data in cultured macrophages, vascular smooth muscle cells, and vascular endothelial cells suggest that it has antiatherosclerotic effects. In vivo, the administration of vitamin D improves immune functions and normalizes inflammatory reactions. In HD patients, vascular calcification is related to the dose of calcium carbonate, but its relationship with the administration of vitamin D is not significant. These observations suggest that, contrary to the general concerns, activated vitamin D exerts favorable effects on the cardiovascular system in HD patients as long as it is used in appropriate clinical doses.  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