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   2222篇
  免费   124篇
  国内免费   22篇
耳鼻咽喉   18篇
儿科学   185篇
妇产科学   32篇
基础医学   249篇
口腔科学   90篇
临床医学   232篇
内科学   484篇
皮肤病学   26篇
神经病学   56篇
特种医学   492篇
外科学   203篇
综合类   39篇
预防医学   69篇
眼科学   18篇
药学   92篇
中国医学   3篇
肿瘤学   80篇
  2020年   11篇
  2018年   22篇
  2017年   17篇
  2016年   32篇
  2015年   36篇
  2014年   35篇
  2013年   72篇
  2012年   40篇
  2011年   39篇
  2010年   90篇
  2009年   69篇
  2008年   47篇
  2007年   58篇
  2006年   54篇
  2005年   42篇
  2004年   30篇
  2003年   22篇
  2002年   31篇
  2001年   27篇
  2000年   31篇
  1999年   42篇
  1998年   142篇
  1997年   125篇
  1996年   129篇
  1995年   96篇
  1994年   77篇
  1993年   82篇
  1992年   36篇
  1991年   46篇
  1990年   30篇
  1989年   69篇
  1988年   49篇
  1987年   67篇
  1986年   60篇
  1985年   58篇
  1984年   35篇
  1983年   41篇
  1982年   40篇
  1981年   29篇
  1980年   43篇
  1979年   32篇
  1978年   23篇
  1977年   22篇
  1976年   30篇
  1975年   30篇
  1974年   11篇
  1973年   11篇
  1971年   17篇
  1968年   12篇
  1967年   14篇
排序方式: 共有2368条查询结果,搜索用时 15 毫秒
1.
2.
Between 1978 and 1984 6 cases of ventricular septal defect after myocardial infarction were referred to this hospital. All 6 patients underwent cardiac catheterisation, had severe pulmonary hypertension and large left-to-right shunts (mean 64%). They were treated with high doses of diuretics and vasodilators, and underwent delayed surgery 6 weeks after rupture. Follow-up is from 1 to 7 years. There has been 1 late, non-cardiac death. The remainder are well. In our experience patients with congestive cardiac failure complicating ventricular septal defect after infarction can be stabilized initially on diuretic and vasodilator therapy, and surgery can safely be deferred until septal fibrosis allows adequate closure.  相似文献   
3.
We report an adult female with a rare giant choledochal cyst. The patient presented following a normal pregnancy with the classical triad of an abdominal mass associated with jaundice and right upper quadrant abdominal pain. The cyst was excised using an intramural technique and biliary reconstruction achieved with a Roux-en-Y hepaticojejunostomy. Our patient has remained well with no evidence of malignancy over a 12 year review period. The aetiology and current management of this condition are discussed.  相似文献   
4.
Na+ dependence of in vitro pancreatic amylase release   总被引:1,自引:0,他引:1  
  相似文献   
5.
The recent cloning of the thyroid peroxidase (TPO) has shown that it is identical to the thyroid microsomal antigen (TMA), a potent antigen involved in autoimmune thyroid disease (ATD), which shares significant sequence homology with myeloperoxidase. The present study shows that autoantibodies (aAb) to the TMA/TPO antigen cross-react with human leucocyte myeloperoxidase, bovine lactoperoxidase and horseradish peroxidase. Cross-reactivity to myeloperoxidase was only apparent by ELISA using reduced and alkylated antigen preparations or by immunoblotting following denaturation with SDS. Sequential absorption of sera on SDS-denatured thyroid microsomes immobilized on Sepharose-4B followed by absorption on native microsomes removed all aAb specificities to TMA/TPO and the three peroxidase preparations, giving compelling evidence on the genuine cross-reactive nature of these aAbs. Sera from different patients contain different qualitative and quantitative specificities of aAb to the TMA/TPO antigen, confirming the polyclonal nature of this autoimmune response.  相似文献   
6.
7.
8.
We have previously shown that activated C1s complement and activated T cells cleave beta2-microglobulin (beta2m) in vitro leading to the formation of desLys58 beta2m. This process can specifically be inhibited by C1-esterase inhibitor (C1-inh). Furthermore we showed that exogenously added desLys58 beta2m in nanomolar amounts to a one-way allogenic mixed lymphocyte culture (MLC) increased the endogenous production of IL-2 and the generation of allo-specific cytotoxic T lymphocytes. C1-inh was purified from fresh human plasma and added to human or murine MLC and mitogen-stimulated lymphocyte cultures grown in the presence of complement-inactivated serum. Read-outs were cell proliferation, lymphokine production and development of T cell-mediated cytotoxicity. We found that addition of C1-inh to MLC and mitogen- exposed murine and human lymphocyte cultures inhibited proliferation, the development of allospecific cytotoxic activity, and changed the endogenous production of IL-2, IL-4, IL-10, IL-12 and IFN-gamma. These data clearly demonstrate a regulatory function of C1-inh on T cell- mediated immune functions.   相似文献   
9.
How to use Chlamydia antibody testing in subfertility patients   总被引:1,自引:9,他引:1  
Screening for tubal factor subfertility by means of Chlamydia antibody testing (CAT) was introduced into the initial work-up of subfertile couples several years ago. The results reported, however, are heterogeneous, and no uniformity exists in cut-off levels of titres, or in definitions of tubal factor subfertility. We performed a prospective cohort study to evaluate the implications of varying the definitions of tubal pathology and of modifying the cut-off levels on the clinical impact of CAT in predicting tubal factor subfertility. In 227 consecutive patients who attended our fertility clinic, the Chlamydia IgG antibody titre was determined and related to tuboperitoneal abnormalities at laparoscopy as a reference standard. According to received operating characteristic (ROC) curve analysis, a titre of 16 is the optimum cut-off level. Increasing the cut-off level improves specificity and positive likelihood ratio (LR+), at the expense of sensitivity and negative LR (LR-). Changing the definition of tubal factor subfertility from unspecified tuboperitoneal abnormalities into extensive adhesions and/or bilateral distal tubal occlusion improves LR+, LR- and kappa significantly. We conclude that CAT is more accurate in predicting severe distal tubal pathology than unspecified tuboperitoneal abnormalities. Although from a statistical point of view a titre of 16 is the optimum cut-off level, from a clinical point of view 32 or 64 may be preferable, depending on the aim of screening and the inception cohort.   相似文献   
10.
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