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   349232篇
  免费   23458篇
  国内免费   7716篇
耳鼻咽喉   4265篇
儿科学   9939篇
妇产科学   7023篇
基础医学   28673篇
口腔科学   8230篇
临床医学   38725篇
内科学   43208篇
皮肤病学   4728篇
神经病学   19884篇
特种医学   8588篇
外国民族医学   34篇
外科学   39090篇
综合类   52219篇
现状与发展   13篇
一般理论   29篇
预防医学   34549篇
眼科学   5462篇
药学   30671篇
  380篇
中国医学   30769篇
肿瘤学   13927篇
  2023年   5455篇
  2022年   8272篇
  2021年   13624篇
  2020年   12786篇
  2019年   18582篇
  2018年   16199篇
  2017年   13163篇
  2016年   10729篇
  2015年   9991篇
  2014年   20485篇
  2013年   22097篇
  2012年   18799篇
  2011年   20337篇
  2010年   16347篇
  2009年   15019篇
  2008年   14698篇
  2007年   15156篇
  2006年   13269篇
  2005年   11497篇
  2004年   9386篇
  2003年   8228篇
  2002年   6450篇
  2001年   5822篇
  2000年   4796篇
  1999年   4155篇
  1998年   3380篇
  1997年   3214篇
  1996年   2806篇
  1995年   2689篇
  1994年   2564篇
  1993年   2046篇
  1992年   2082篇
  1991年   1820篇
  1990年   1590篇
  1989年   1427篇
  1988年   1333篇
  1987年   1148篇
  1985年   3815篇
  1984年   4833篇
  1983年   3370篇
  1982年   3846篇
  1981年   3572篇
  1980年   3176篇
  1979年   2918篇
  1978年   2548篇
  1977年   1918篇
  1976年   2160篇
  1975年   1636篇
  1974年   1432篇
  1973年   1280篇
排序方式: 共有10000条查询结果,搜索用时 744 毫秒
81.
Alzheimer’s disease is characterized by the extracellular accumulation of the amyloidβin the form of amyloid plaques and the intracellular deposition of the microtubule-associated protein tau in the form of neurofibrillary tangles.Most of the Alzheimer’s drugs targeting amyloidβhave been failed in clinical trials.Particularly,tau pathology connects greatly in the pathogenesis of Alzheimer’s disease.Tau protein enhances the stabilization of microtubules that leads to the appropriate function of the neuron.Changes in the quantity or the conformation of tau protein could affect its function as a microtubules stabilizer and some of the processes wherein it is involved.The molecular mechanisms leading to the accumulation of tau are principally signified by numerous posttranslational modifications that change its conformation and structural state.Therefore,aberrant phosphorylation,as well as truncation of tau protein,has come into focus as significant mechanisms that make tau protein in a pathological entity.Furthermore,the shape-shifting nature of tau advocates to comprehend the progression of Alzheimer’s disease precisely.In this review,we emphasize the recent studies about the toxic and shape-shifting nature of tau in the pathogenesis of Alzheimer’s disease.  相似文献   
82.
83.
84.
85.
86.
87.
88.
The Combined Aerobic and Resistance Exercise (CARE) Trial compared different types and doses of exercise performed during breast cancer chemotherapy. Here, we report the longer-term follow-up of patient-reported outcomes, health-related fitness and exercise behavior at 6, 12 and 24 months postintervention. A multicenter trial in Canada randomized 301 breast cancer patients initiating chemotherapy to thrice weekly, supervised exercise consisting of a standard dose of 25–30 min of aerobic exercise (STAN; n = 96), a higher dose of 50–60 min of aerobic exercise (HIGH; n = 101) or a combined dose of 50–60 min of aerobic and resistance exercise (COMB; n = 104) performed for the duration of chemotherapy (median of 17 weeks). Primary outcomes were patient-reported outcomes including quality of life, cancer-related symptoms and psychosocial outcomes. Secondary outcomes were objective health-related fitness (assessed at 12 months only) and self-reported exercise behavior. A total of 269 (89.4%) participants completed patient-reported outcomes at all three follow-up time points and 263 (87.4%) completed the health-related fitness assessment at 12-month follow-up. COMB was significantly superior to (i) STAN for sleep quality at 6-month follow-up (p = 0.027); (ii) HIGH for upper body muscular endurance at 12-month follow-up (p = 0.020); and (iii) HIGH for meeting the resistance exercise guideline at 6-month follow-up (p = 0.006). Moreover, self-reported meeting of the combined exercise guideline during follow-up was significantly associated with better patient-reported outcomes and health-related fitness. Performing combined exercise during and after breast cancer chemotherapy may result in better longer-term patient-reported outcomes and health-related fitness compared to performing aerobic exercise alone.  相似文献   
89.
目的探讨中西医结合护理改善老年高血压患者心理状态及生活质量的效果。方法在医院2018年1月—2018年6月就诊的老年高血压患者中选出60例,按照随机数字法的原则,分成研究组(n=30)和参考组(n=30)。参考组采用单一西医护理,研究组在此之外联合中医护理,比较两组患者的临床疗效。结果入院时研究组与参考组SAS、SDS、SF-6评分差异不显著(P>0.05),护理后1月、3月与参考组相比,研究组SAS、SDS评分显著降低(P<0.05),SF-6评分显著升高(P<0.05);研究组患者对中西结合护理满意度为96.67%,参考组患者对西医护理满意度为73.33%,研究组满意度较参考组高,差异显著(P<0.05)。结论中西医结合护理能够有效改善老年高血压患者的心理状态,提高生活质量。  相似文献   
90.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  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