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   683篇
  免费   60篇
  国内免费   9篇
耳鼻咽喉   13篇
儿科学   122篇
妇产科学   6篇
基础医学   99篇
口腔科学   16篇
临床医学   59篇
内科学   162篇
皮肤病学   2篇
神经病学   37篇
特种医学   53篇
外科学   55篇
综合类   15篇
一般理论   3篇
预防医学   58篇
眼科学   1篇
药学   26篇
肿瘤学   25篇
  2021年   11篇
  2019年   5篇
  2018年   4篇
  2016年   5篇
  2015年   10篇
  2014年   15篇
  2013年   15篇
  2012年   18篇
  2011年   13篇
  2010年   10篇
  2009年   14篇
  2008年   16篇
  2007年   23篇
  2006年   22篇
  2005年   18篇
  2004年   24篇
  2003年   22篇
  2002年   28篇
  2001年   20篇
  2000年   18篇
  1999年   28篇
  1998年   24篇
  1997年   21篇
  1996年   23篇
  1995年   25篇
  1994年   24篇
  1993年   15篇
  1992年   15篇
  1991年   25篇
  1990年   20篇
  1989年   30篇
  1988年   20篇
  1987年   18篇
  1986年   16篇
  1985年   11篇
  1984年   13篇
  1983年   12篇
  1982年   7篇
  1981年   10篇
  1980年   9篇
  1979年   10篇
  1978年   11篇
  1977年   10篇
  1976年   6篇
  1975年   7篇
  1974年   4篇
  1971年   5篇
  1970年   3篇
  1969年   3篇
  1968年   4篇
排序方式: 共有752条查询结果,搜索用时 31 毫秒
1.
2.
The clinical and endocrinological findings in 24 children with septo-optic dysplasia and/or agenesis of the corpus callosum are described with particular reference to posterior pituitary function. Nine had diabetes insipidus. The prevalence of diabetes insipidus was similar in children with complete and incomplete forms of septo-optic dysplasia. Maintenance of normal osmotic balance was very difficult in six of these children, even after the introduction of treatment with vasopressin, either as desmopressin, or lysine vasopressin spray in one of the early cases.  相似文献   
3.
Five patients from four families, including two male sibs, are reported with clinical and radiological features of the 3-M syndrome.  相似文献   
4.
Hydrosalpinges adversely affect markers of endometrial receptivity   总被引:22,自引:10,他引:22  
While in-vitro fertilization (IVF) was initially developed in women with tubal factor infertility, recent clinical studies have suggested that the presence of hydrosalpinges lowers implantation and pregnancy rates. We postulated that these hydrosalpinges cause impaired endometrial receptivity. A total of 103 women with hydrosalpinges were prospectively evaluated, and compared with 55 infertile and 44 fertile controls. All women had endometrial biopsies during the window of implantation, analysed by conventional histological criteria, and also stained for three integrin markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha vbeta3). Women with hydrosalpinges (cases) expressed significantly less of the alpha vbeta3 integrin compared with controls. There was no difference in expression of alpha1beta1 or alpha4beta1 among groups. A significantly greater number of cases had out of phase histology and missing alpha vbeta3 (type I defects) and absent integrin expression despite normal histological maturation (type II) defects, compared with controls. Of 20 women with impaired endometrial receptivity who were also biopsied after hydrosalpinx surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven percent of type I and 57% of type II defects were corrected postoperatively. Using markers of endometrial receptivity, this study demonstrates that inflammatory hydrosalpinges have an adverse effect on endometrial receptivity, which in some cases may be overcome by surgical treatment of the hydrosalpinx.   相似文献   
5.
Proliferative expansion and apoptotic cell death play prominent roles in T cell development. The molecular control of cell cycle progression and apoptosis appear to be inter-connected since the Bcl-2 protein can inhibit apoptosis and slow cell cycle progression in cortical thymocytes and mature T cells, particularly during the transition from the quiescent state into the cell cycle. Here the impact of bcl-2 transgene expression on CD3-CD4-CD8- T cell progenitors was assessed. Bcl-2 enhanced the survival of these progenitors at all of the four major differentiation stages, CD25- CD44+ (pro-T1), CD25 + CD44+ (pro- T2), CD25 + CD44- (pro-T3) and CD25-CD44- (pro-T4). However, it reduced cell cycling and slowed turnover only in the pro-T4 subset. From an analysis of bcl-2 transgenic mice expressing a TCR transgene or bearing a mutation in the scid or rag-1 gene we conclude that Bcl-2 inhibits proliferation only of T cell progenitors that are activated via the pre- TCR, not those stimulated via c-Kit and the IL-7 receptor.   相似文献   
6.
Parathyroid hormone secretion is negatively regulated by a 7- transmembrane domain, G-protein coupled Ca(2+)-sensing receptor. We hypothesized that activating mutations in this receptor might cause autosomal dominant hypoparathyroidism (ADHP). Consistent with this hypothesis, we identified, in two families with ADHP, heterozygous missense mutations in the Ca(2+)-sensing receptor gene that cosegregated with the disorder. None of 50 normal controls had either mutation. We also identified a de novo, missense Ca(2+)-sensing receptor mutation in a child with severe sporadic hypoparathyroidism. The amino acid substitution in one ADHP family affected the N-terminal, extracellular domain of the receptor. The other mutations involved the transmembrane region. Unlike patients with acquired hypoparathyroidism, patients with these mutations had hypercalciuria even at low serum calcium concentrations. Their greater hypercalciuria presumably reflected activation of Ca(2+)-sensing receptors in kidney cells, where the receptor negatively regulates calcium reabsorption. This augmented hypercalciuria increases the risk of renal complications and thus has implications for the choice of therapy.   相似文献   
7.
Aspirate from an argyrophil carcinoma ("carcinoid") of the breast showed malignant dispersed epithelial cells. With Diff-Quik, the cytoplasm was seen to be abundant, with prominent eosinophilic granularity. The nuclei were fairly uniform, round or oval, and eccentric and had a finely stippled chromatin pattern. On histology, the tumor appeared typical for argyrophil carcinoma, and staining with Grimelius for argyrophilic granules was positive. Membrane-bound neurosecretory granules were seen on electron microscopy.  相似文献   
8.
BACKGROUND: If a validated questionnaire, when applied to patients reporting with symptoms of intermittent claudication, could adequately discriminate between those with and without peripheral arterial disease, GPs could avoid the diagnostic measurement of the ankle brachial index. AIM: To investigate the Edinburgh Claudication Questionnaire (ECQ) in general practice and to develop a clinical decision rule based on risk factors to enable GPs to easily assess the likelihood of peripheral arterial disease. DESIGN OF STUDY: An observational study. SETTING: General practice in The Netherlands. METHOD: This observational study included patients of > or =55 years visiting their GP for symptoms suggestive of intermittent claudication or with one risk factor. The ECQ and the ankle brachial index were performed. The prevalence of peripheral arterial disease, defined as an ankle brachial index <0.9, was related to risk factors using logistic regression analyses, on which a clinical decision rule was developed and related to the presence of peripheral arterial disease. RESULTS: Of the 4790 included patients visiting their GP with symptoms suggestive of intermittent claudication, 4527 were eligible for analyses. The prevalence of peripheral arterial disease in this group was 48.3%. The sensitivity of the ECQ was only 56.2%. The prevalence of peripheral arterial disease in a clinical decision rule that included age, male sex, smoking, hypertension, hypercholesterolemia, and a positive ECQ, increased from 14% in the lowest to 76% in the highest category. CONCLUSION: This study indicates that the ECQ alone has an inadequate diagnostic value in detecting patients with peripheral arterial disease. The ankle brachial index should be performed to diagnose peripheral arterial disease in patients with complaints suggestive of intermittent claudication, although our clinical decision rule could help to differentiate between extremely high and lower prevalence of peripheral arterial disease.  相似文献   
9.
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