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   1523篇
  免费   62篇
  国内免费   8篇
耳鼻咽喉   23篇
儿科学   42篇
妇产科学   24篇
基础医学   95篇
口腔科学   10篇
临床医学   122篇
内科学   288篇
皮肤病学   8篇
神经病学   112篇
特种医学   27篇
外科学   407篇
综合类   14篇
预防医学   37篇
眼科学   81篇
药学   67篇
中国医学   1篇
肿瘤学   235篇
  2023年   10篇
  2021年   19篇
  2020年   10篇
  2019年   11篇
  2018年   9篇
  2017年   8篇
  2016年   12篇
  2015年   18篇
  2014年   33篇
  2013年   31篇
  2012年   103篇
  2011年   85篇
  2010年   48篇
  2009年   34篇
  2008年   68篇
  2007年   89篇
  2006年   100篇
  2005年   111篇
  2004年   78篇
  2003年   91篇
  2002年   91篇
  2001年   85篇
  2000年   77篇
  1999年   49篇
  1998年   13篇
  1997年   12篇
  1996年   15篇
  1995年   10篇
  1994年   12篇
  1993年   10篇
  1992年   39篇
  1991年   26篇
  1990年   25篇
  1989年   19篇
  1988年   27篇
  1987年   20篇
  1986年   6篇
  1985年   12篇
  1984年   8篇
  1983年   8篇
  1978年   3篇
  1976年   3篇
  1975年   5篇
  1974年   6篇
  1973年   5篇
  1971年   7篇
  1970年   8篇
  1969年   3篇
  1967年   2篇
  1965年   3篇
排序方式: 共有1593条查询结果,搜索用时 15 毫秒
1.
OBJECTIVES: To compare the effect of conjugated equine estrogens (CEE) and raloxifene on lipid profile and hemostasis. MATERIALS AND METHODS: A double-blind, randomized and parallel study was performed with 90 healthy postmenopausal women, aged 54 +/- 5 years, divided into three groups and submitted to daily therapy with either CEE 0.625 mg, raloxifene 60 mg or placebo for 4 months. The lipid profile, coagulation and fibrinolytic factors were analyzed. RESULTS: CEE increased the levels of high density lipoprotein cholesterol (HDL-C) from 49.0 to 56.8 mg/dl (p < 0.001), very low density lipoprotein cholesterol (VLDL-C) from 17.2 to 22.3 mg/dl (p < 0.001), and triglycerides from 86.0 to 111.7 mg/dl (p < 0.001), and decreased the levels of low density lipoprotein cholesterol (LDL-C) from 121.0 to 106.5 mg/dl (p < 0.001). The only significant effect of raloxifene was an increase in the levels of HDL-C from 46.0 to 47.8 mg/dl (p = 0.019). There was no significant reduction in LDL-C, from 115.5 to 110.2 mg/dl (p = 0.06), VLDL-C, from 21.7 to 20.0 mg/dl (p = 0.201), and triglycerides, from 108 to 100 mg/dl (p = 0.201). CEE decreased the levels of fibrinogen, from 370.5 to 326.8 g/l (p = 0.039) and the levels of antithrombin III, from 99.5 to 93.2% (p < 0.001). Raloxifene decreased the levels of fibrinogen, from 354.7 to 302.0 g/l (p = 0.009) and the levels of antithrombin III, from 102.4 to 98.5% (p = 0.039). CEE increased levels of protein C from 103.7 to 115.3 mg/l (p < 0.001) and raloxifene did not change the levels of protein C (107.9 to 105.1 mg/l; p = 0.158). CEE decreased the antigen levels of tissue plasminogen activator (t-PA) from 8.8 to 6.8 U/ml (p < 0.001), and of plasminogen activator inhibitor (PAI-1) from 30.8 to 21.6 U/ml (p < 0.010), whereas raloxifene had no significant effect on either t-PA, from 9.6 to 9.2 U/ml (p = 0.235) or PAI-1 antigen levels, from 32.1 to 30.4 U/ml (p = 0.538). CONCLUSION Both CEE and raloxifene exert significant effects on the lipid and coagulation profile. CEE had a more significant effect on fibrinolysis than raloxifene. These effects may have a significant impact on the cardiovascular risk that needs to be confirmed in larger studies.  相似文献   
2.
Giant aneurysm of the pericallosal artery   总被引:1,自引:0,他引:1  
A rare case of a giant aneurysm of the pericallosal artery, evaluated by computed tomography, magnetic resonance imaging, and angiography, is reported, and the other 7 cases in the literature are reviewed. Giant aneurysms are exceptional in the distal segments of the anterior cerebral arteries, and may simulate a callosal tumor or hematoma on computed tomographic scan. The clinical, radiological, surgical, and pathological findings of giant aneurysms of this location are discussed and the other reported cases are analyzed. The role of magnetic resonance imaging in diagnosing and characterizing giant aneurysms is stressed.  相似文献   
3.
After describing the stages of surgical infection and the efficacy of short-term antibiotic prophylaxis in surgery, the paper reports a trial in which a single dose of Ceftriaxone was administered in 50 cases of cholecystectomy, with excellent results in terms of efficacy and tolerability.  相似文献   
4.
A child had the characteristic clinical and EEG pattern of migrating partial seizures in infancy with left temporal lobe atrophy, hippocampal sclerosis and cortical-subcortical blurring.Seizures were drug-resistant, with recurring episodes of status epilepticus. The child developed microcephaly with arrest of psychomotor development. Focal brain lesions, in the context of migrating partial seizures, have not been previously reported.[Published with video sequences].  相似文献   
5.
Background. Injection of DEAE dextran into Lewis rats can produce proteinuria and has been reported as a model of IgA nephropathy. Methods. Cationic diethyl aminoethyl (DEAE) dextran of molecular weight 500 KDa was injected into male Lewis rats. After a pre-immunization period of 3 weeks, the animals were divided into two groups: group 1 (n=14) received daily i.v. injections of 3.5 mg of antigen, group 2 (n=14) was injected with 1.5 mg three times per week for a total period of 6 weeks. I.v. treatment was initiated with gradually increasing doses of DEAE dextran in both groups for 1 week, after which the maintenance dose was reached. Results. We observed the appearance of proteinuria in a nephrotic range after 5 weeks of i.v. injections in group 1 (urinary excretion: 332±83 mg/24 h, controls: 53±14 mg/24 h). In group 2, the proteinuria was almost equal to protein excretion of healthy rats of the same weight (67±20 mg/24 h). The serum and urine creatinine were normal. By light microscopy of kidney biopsies, the presence of focal and segmental proliferation of mesangial cells after 6 weeks of i.v. injections was identified. Immunohistochemistry revealed no deposition of IgA, IgM, IgG, or C3. Using anti-ED1 antibodies, there was no evidence of interstitial infiltration of monocytes/macrophages after 6 weeks of i.v. injections. Staining for proliferating cell nuclear antigen (PCNA) did not show the presence of proliferating cells either in glomeruli or in the interstitium. Staining with FITC-WGA lectin revealed focal and segmental loss of the negative charge in the capillary wall. By electron microscopy there was deposition of dextran in the basal membrane and segmental and focal damage of the podocyte foot processes. As the chemokine RANTES may be involved in glomerular injury, we examined the kidneys of proteinuric and non-proteinuric rats for the presence of RANTES. By indirect immunofluorescence only the proteinuric rats showed RANTES deposition in mesangium. Conclusions. Injection of rats with DEAE dextran leads to dose-dependent proteinuria without deposition of immune complexes but with podocyte damage. This is associated with local expression of the chemokine RANTES which may play a role in proteinuria of glomerular disease.  相似文献   
6.
The commonest glomerulonephritis in the world: IgA nephropathy   总被引:38,自引:0,他引:38  
  相似文献   
7.
8.
9.
As originally demonstrated for the interleukin 1 (IL-1) type II receptor, some primary proinflammatory cytokines from the IL-1 and tumor necrosis factor families are regulated by decoy receptors that are structurally incapable of signaling. Here we report that concomitant exposure to proinflammatory signals and IL-10 generates functional decoy receptors in the chemokine system. Inflammatory signals, which cause dendritic cell (DC) maturation and migration to lymphoid organs, induce a chemokine receptor switch, with down-regulation of inflammatory receptors (such as CCR1, CCR2, CCR5) and induction of CCR7. Concomitant exposure to lipopolysaccharide (LPS) and IL-10 blocks the chemokine receptor switch associated with DC maturation. LPS + IL-10-treated DCs showed low expression of CCR7 and high expression of CCR1, CCR2 and CCR5. These receptors were unable to elicit migration. We provide evidence that uncoupled receptors, expressed on LPS + IL-10-treated cells, sequester and scavenge inflammatory chemokines. Similar results were obtained for monocytes exposed to activating signals and IL-10. Thus, in an inflammatory environment, IL-10 generates functional decoy receptors on DC and monocytes, which act as molecular sinks and scavengers for inflammatory chemokines.  相似文献   
10.
Because negative mood is a characteristic of both tobacco withdrawal and menstrual discomfort, withdrawal may vary by menstrual cycle phase. Tobacco withdrawal, mood, and menstrual discomfort were assessed in premenopausal women who quit smoking during either the follicular (Days 1-14 postmenstrual onset; n = 41) or luteal (Day 15 or longer postmenstrual onset; n = 37) phase of the menstrual cycle and maintained biochemically verified smoking abstinence during the postquit week. Women quitting during the luteal phase reported significantly greater increases in tobacco withdrawal and self-reported depressive symptoms than women quitting during the follicular phase. These results indicate that selecting a quit-smoking day early in the follicular phase may attenuate withdrawal and negative affect in premenopausal female smokers.  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