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   53646篇
  免费   3613篇
  国内免费   1154篇
耳鼻咽喉   96篇
儿科学   1244篇
妇产科学   669篇
基础医学   2446篇
口腔科学   499篇
临床医学   7355篇
内科学   18419篇
皮肤病学   175篇
神经病学   671篇
特种医学   818篇
外国民族医学   1篇
外科学   6730篇
综合类   8489篇
现状与发展   3篇
一般理论   1篇
预防医学   2445篇
眼科学   82篇
药学   5018篇
  49篇
中国医学   2641篇
肿瘤学   562篇
  2024年   114篇
  2023年   925篇
  2022年   1681篇
  2021年   2300篇
  2020年   2198篇
  2019年   1952篇
  2018年   1886篇
  2017年   1713篇
  2016年   1765篇
  2015年   1825篇
  2014年   3852篇
  2013年   4083篇
  2012年   2993篇
  2011年   3518篇
  2010年   2758篇
  2009年   2764篇
  2008年   2670篇
  2007年   2684篇
  2006年   2390篇
  2005年   2218篇
  2004年   1703篇
  2003年   1433篇
  2002年   1203篇
  2001年   1126篇
  2000年   816篇
  1999年   719篇
  1998年   585篇
  1997年   534篇
  1996年   508篇
  1995年   443篇
  1994年   437篇
  1993年   313篇
  1992年   280篇
  1991年   275篇
  1990年   239篇
  1989年   239篇
  1988年   223篇
  1987年   162篇
  1986年   138篇
  1985年   141篇
  1984年   115篇
  1983年   65篇
  1982年   77篇
  1981年   70篇
  1980年   57篇
  1979年   58篇
  1978年   44篇
  1977年   31篇
  1976年   35篇
  1974年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
In multiple sclerosis (MS) up-regulation of β-adrenoceptors on peripheral blood mononuclear cells (PBMCs) has been attributed to either autonomic dysfunction, inflammation or a combination of the two. We have compared secondary progressive MS patients with normal subjects (NS) and two models of autonomic dysfunction; pure autonomic failure (PAF) and multiple system atrophy (MSA, Shy-Drager syndrome). There was up-regulation of β-adrenoceptors on PBMCs in MS and PAF patients but not in MSA patients. Only in PAF patients β-adrenoceptor up-regulation was correlated with low plasma levels of noradrenaline (NA) and adrenaline (Ad). In addition to studies in the basal state, measurements also were made after the centrally acting sympatholytic agent clonidine. These were combined with haemodynamic and neurohormonal measurements. After clonidine, there was a fall in blood pressure in NS and MSA patients but not in MS and PAF patients; a rise in growth hormone (GH) in NS and PAF patients but not in MS and MSA patients; and an up-regulation in PBMCs β-adrenoceptors in NS but not in MS, MSA and PAF patients. Up-regulation of β-adrenoceptors on PBMCs in MS could be attributed to autonomic dysfunction but the disparity between MS and PAF patients when considering their plasma levels of NA and Ad argue against. Although the neurohormonal responses to clonidine and the physiological assessment of autonomic function in progressive MS patients, demonstrate central autonomic dysfunction resembling that of the MSA patients, the normal basal β-adrenoceptor densities in the latter, suggests that the up-regulation of these receptors is independent of the central autonomic dysfunction in MS.  相似文献   
92.
Nodular hyperplasia surrounding fibrolamellar carcinoma   总被引:2,自引:0,他引:2  
We report a case of acetaminophen-induced liver necrosis in a 14-year-old girl. At autopsy, a 9 cm subcapsular nodule was present in the right lobe of the liver which showed distinct zonation: a central greyish white area of fibrolamellar carcinoma with a peripheral fleshy, tan-coloured rim ranging from 1 to 2 cm in thickness. This peripheral zone consisted of nodular, hyperplastic parenchyma resembling the changes seen in focal nodular hyperplasia, and stood out from the adjacent necrotic parenchyma. The sparing of this zone from the deleterious effects of acetaminophen provides indirect evidence of a predominantly arterial rather than portal blood supply to this region. The arterial supply was most probably derived from the tumour vasculature and may explain the parenchymal hyperplasia sometimes reported adjacent to a fibrolamellar carcinoma. Awareness of this phenomenon is essential when evaluating a needle biopsy, as sampling of this region may lead to a false negative diagnosis.  相似文献   
93.
Acute renal failure and acute heart failure are rare in Kawasaki disease. We experienced two patients with Kawasaki disease who presented acute renal failure and acute heart failure. These two patients gave us an important insight into the understanding of water balance and fluid therapy in Kawasaki disease. One patient showed acute prerenal failure due to fluid exudation from the intravascular to the extravascular space, and subsequent acute heart failure. The other patient showed acute heart failure caused by fluid infusion for the treatment of dehydration. It is suggested that acute renal failure could be caused by a fluid shift from the intravascular to the extravascular space in Kawasaki disease. It is also demonstrated that the reserve of cardiac function could be decreased in patients with Kawasaki disease due to myocarditis even with normal echocardiography and chest X-rays.  相似文献   
94.
We experienced a congenital complete atrioventricular block infant who was born from a Ro/SS-A antibody positive mother. Ro/SS-A antibody was also found in this baby which was presumed to be mediated by the maternal placenta. Temporary cardiac pacing was required at birth and pacemaker implantation was performed at 9 months. At 11 months of age, the baby fell into shock and experienced multiple organ failure because of diabetes mellitus-induced coma. The association between congenital complete heart block and the Ro/SS-A antibody is well known. However, the accompaniment of insulin-dependent diabetes mellitus has not been reported previously. As the Ro/SS-A antigen appears in the cytoplasm of many tissues, the possibility of an association between Ro/SS-A antibody and diabetes mellitus is difficult to deny. We report this rare case to draw attention to the possibility that babies who are born from an Ro/SS-A antibody positive mother may develop diabetes mellitus as well as congenital complete heart block.  相似文献   
95.
18只犬切除右肾,钳夹左肾动脉60分的肾缺血模型,再灌注5小时。将动物随机分成对照组、川芎嗪组及维拉帕米组。观察尿量、菊糖清除率、利钠指数、平均动脉压及心率;再灌注5小时取肾组织作形态学检查。结果显示川芎嗪对肾功能及形态有保护作用,维拉帕米则无此作用,提示在手术中有肾缺血时以川芎嗪作为肾保护药物优于维拉帕米。  相似文献   
96.
97.
The non-sulfhydryl selective angiotensin-converting enzyme inhibitor benazepril (20 mg daily) was compared with hydrochlorothiazide (50 mg daily) in post-infarction (6-24 months) patients with symptomatic (NYHA functional class 2) mild heart failure. No concomitant drug therapy was given. The study had a double-blind cross-over design with 3-month treatment periods. Both drugs were well tolerated, and both caused a similar reduction in systolic blood pressure. Heart rate was higher with the diuretic. Benazepril improved the NYHA functional class in 17 out of 29 (59%) patients, whereas one patient improved with hydrochlorothiazide (P = 0.0004). With regard to global efficacy score, benazepril was also superior. Thus, angiotensin-converting enzyme inhibitors may be superior to diuretics as first-choice therapy in symptomatic mild heart failure.  相似文献   
98.
目的 :观察黄芪注射液对充血性心力衰竭 (CHF)的治疗效果。方法 :将 12 7例心衰病人随机分为 2组。对照组 5 5例 ,给予传统治疗心衰药物洋地黄、利尿剂及休息、低盐饮食、吸氧等治疗 ;治疗组 72例 ,在对照组病人用药的基础上加黄芪注射液 40ml ,静脉滴注 ,每日 1次 ,2组均连续用药 15天。结果 :总有效率治疗组 91 7%,对照组 6 7 3%,治疗组效果明显优于对照组 (P <0 0 1) ,且 2组自身对照 ,治疗后好转程度 ,治疗组优于对照组 ,左室射血分数 (LVEF)明显好于对照组。结论 :在常规治疗CHF的同时加用黄芪注射液可显著提高疗效。  相似文献   
99.
Quality of life was assessed 4–6 months after an acutemyocardial infarction in a randomized double-blind study ofenalapril versus placebo. Quality of life was evaluated usingthe Nottingham Health Profile (NHP), the Physical Symptoms DistressIndex (PSDI), the Work Performance Scale (WPS) and the LifeSatisfaction Index (LSI). The study comprised 36 women (aged46–85 years, mean 68) and 96 males (aged 39–81 years,mean 62). Quality of life did not differ significantly between patientstreated with enalapril versus placebo. The scores were (enalaprilvs placebo, mean± SE): average NHP 15.4 ± 2.3vs 17.1 ± 2.3; PSDI 9.5± 1.0 vs 10.8 ±0.9; WPS 19.8 ± 2.0 vs 19.4 ± 1.4; LSI 24.1 ±1.0 vs 22.5 ±1.4. Men reported a better quality of lifethan women on most assessments, and non-smokers and ex-smokersbetter than smokers. Patients with moderate or severe anginapectoris had a worse quality of life measured by PSDI and NHPthan patients with minimal or no angina pectoris. Patients withcongestive heart failure had a higher PSDI than those without(13.6 ± 1.7 vs 9.4 ± 0.7, P<0.05), while nosignificant differences were observed in the NHP scores. In conclusion, quality of life was similar in enalapril andplacebo- treated patients after an acute myocardial infarction.However, it was reduced in patients with angina pectoris orheart failure and in those who continued smoking.  相似文献   
100.
国产米力农治疗31例严重心力衰竭患者的急性效应,慢难治性及稳定性心力衰竭总有效率为88.8%及57.0%,副作用小.结果提示国产米力农对严重心力衰竭患者有效。  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