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   1290346篇
  免费   98901篇
  国内免费   2019篇
耳鼻咽喉   18578篇
儿科学   44722篇
妇产科学   35284篇
基础医学   183545篇
口腔科学   33768篇
临床医学   112753篇
内科学   260606篇
皮肤病学   28141篇
神经病学   101682篇
特种医学   51670篇
外国民族医学   661篇
外科学   198237篇
综合类   27197篇
现状与发展   1篇
一般理论   388篇
预防医学   96667篇
眼科学   28104篇
药学   95379篇
  2篇
中国医学   2430篇
肿瘤学   71451篇
  2018年   13556篇
  2017年   10264篇
  2016年   11222篇
  2015年   12767篇
  2014年   17710篇
  2013年   26798篇
  2012年   36959篇
  2011年   39051篇
  2010年   23314篇
  2009年   22196篇
  2008年   37374篇
  2007年   39935篇
  2006年   40173篇
  2005年   39039篇
  2004年   38113篇
  2003年   36952篇
  2002年   36245篇
  2001年   64088篇
  2000年   66601篇
  1999年   56504篇
  1998年   15198篇
  1997年   13806篇
  1996年   14244篇
  1995年   13492篇
  1994年   12794篇
  1993年   11842篇
  1992年   44626篇
  1991年   43547篇
  1990年   42299篇
  1989年   40181篇
  1988年   36959篇
  1987年   36297篇
  1986年   33667篇
  1985年   32346篇
  1984年   24189篇
  1983年   20303篇
  1982年   11758篇
  1981年   10721篇
  1980年   9540篇
  1979年   21365篇
  1978年   14855篇
  1977年   12564篇
  1976年   11716篇
  1975年   12649篇
  1974年   14695篇
  1973年   14141篇
  1972年   12969篇
  1971年   11747篇
  1970年   11067篇
  1969年   10042篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
The finer branches of the biliary tree (FBBT) contain a regenerative compartment. We hypothesized that preservation of the FBBT together with its microvasculature will lead to recovery of biliary damage and prolonged preservation of bile ductules during the development of chronic liver allograft rejection. The interlobular bile ducts, portal bile ductules and extraportal biliary cells with and without microvessels were studied in sequential biopsies in five patients who fulfilled the Banff criteria of early chronic rejection (CR) (imminence group). Biopsies of CR patients (n = 12) served as controls. Biopsies were double immunostained with CD34 (microvessels) and cytokeratin 7 (biliary structures). Proliferation and proangiogenic activity were assessed with Ki67 and VEGF-A immunostaining. Severe damage of bile ducts in the imminence group did not progress to significant bile duct loss. This was associated with a high proliferative activity in all biliary structures and preservation of the microvascular compartment. VEGF-A expression was increased in all but the reperfusion biopsies. In conclusion, both regenerative activity of the FBBT and an intact microvascular compartment are associated with less damage of the biliary tree and could therefore be prerequisites for biliary regeneration.  相似文献   
62.
Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases.  相似文献   
63.
We report the case of a patient with a 13-year history of pemphigus vulgaris (PV) treated with immunosuppressive agents, prednisone and mycophenolate mofetil who had developed lesions of Kaposi's sarcoma (KS) on a sole plaque of PV that had been previously treated with intralesional injections of steroids. The lesions were surgically removed and polymerase chain reaction (PCR) demonstrated human herpesvirus-8 (HHV-8) DNA. There were neither recurrences nor later dissemination of KS following gradual decrease of the immunosuppressive therapy. We suggest that the treatment with intralesional steroids may have influenced the local reactivation of a latent infection of the virus, determining the appearance of this localized KS.  相似文献   
64.
OBJECTIVES: To identify and describe current women's thoughts about the menopause, hormone treatment (HT) and perceptions about breast cancer. METHODS: Between December 2004 and January 2005, 4201 postmenopausal women in seven European countries were interviewed via a standardized computer-aided telephone interview protocol. RESULTS: Almost all women reported to have experienced climacteric symptoms, and 63% of the women rated them as being severe. Only 52% of women were aware of the benefits of HT for relief of climacteric symptoms. Although 84% felt that severe symptoms should be treated, only 40% had used HT at some point in time. Thirty-four percent of the women preferring treatment with natural products did so because of the risk of breast cancer associated with HT. HT was recognized by 59% of the women as one of the most important contributors to an increased breast cancer risk. Most women received their information about HT and breast cancer risk from the media. CONCLUSIONS: This European survey reveals that the majority of women experience climacteric symptoms but that their decision whether or not to use HT is highly dependent on their concern about breast cancer risk. An increase in knowledge of the benefits and risks of HT is required for women to make appropriate decisions about hormone use.  相似文献   
65.
66.
Conclusions Limitation of this analysis is participation of limited centers. Though all the regions of the country are represented total number of procedures reported are less. Isolated CABG is commonest procedure performed in 2004. Congenital surgical procedures are more than the valvular heart disease procedure. For appropriate categorization we need standard nomenclature for various congenital surgical procedures.  相似文献   
67.
68.
69.
We report our experience of eight cases of isolated full thickness burns of the penis. Early excision of burns of the penile shaft and repair with a preputial flap or mesh split skin graft produces excellent results, with a reduction in complications and an early re-establishment of sexual function. Conservative treatment of burns of the glans, on the other hand, is appropriate and results in minimal scarring.  相似文献   
70.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia.  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