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   190119篇
  免费   14191篇
  国内免费   5079篇
耳鼻咽喉   2530篇
儿科学   3109篇
妇产科学   2517篇
基础医学   25919篇
口腔科学   4399篇
临床医学   20559篇
内科学   30442篇
皮肤病学   5024篇
神经病学   12542篇
特种医学   9567篇
外国民族医学   22篇
外科学   22074篇
综合类   14165篇
现状与发展   19篇
一般理论   29篇
预防医学   12812篇
眼科学   4555篇
药学   19018篇
  80篇
中国医学   6120篇
肿瘤学   13887篇
  2024年   251篇
  2023年   1505篇
  2022年   3962篇
  2021年   7417篇
  2020年   4560篇
  2019年   4807篇
  2018年   5536篇
  2017年   5051篇
  2016年   5701篇
  2015年   8429篇
  2014年   10287篇
  2013年   11628篇
  2012年   17221篇
  2011年   16972篇
  2010年   10884篇
  2009年   9267篇
  2008年   12007篇
  2007年   11340篇
  2006年   10501篇
  2005年   9395篇
  2004年   7572篇
  2003年   6633篇
  2002年   5635篇
  2001年   4154篇
  2000年   3667篇
  1999年   2778篇
  1998年   1255篇
  1997年   1058篇
  1996年   772篇
  1995年   702篇
  1994年   613篇
  1993年   466篇
  1992年   884篇
  1991年   824篇
  1990年   730篇
  1989年   620篇
  1988年   520篇
  1987年   504篇
  1986年   363篇
  1985年   386篇
  1984年   283篇
  1983年   201篇
  1982年   142篇
  1981年   180篇
  1980年   139篇
  1979年   230篇
  1978年   167篇
  1976年   135篇
  1975年   124篇
  1974年   147篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
82.
83.
Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case–control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan–Meier analysis with log-rank test (P = 0.008). The AF group''s adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16–1.57; P = 0.009) according to Cox''s proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF.  相似文献   
84.
肠易激综合征(Irritable bowel syndrome,IBS)是临床常见病、多发病,其治疗方法丰富,但部分患者疗效欠佳,发展成难治性IBS。目前国内外关于针灸治疗难治性IBS的临床随机对照试验尚不多见。本文立足试验方案设计的“PICOS”原则,从研究对象及诊断标准、干预措施、对照措施、结局指标四个方面入手,重点探讨针刺辅助治疗难治性肠易激综合征临床试验设计的关键要点。从选择特色优势病种、明确诊断标准、制定符合临床实际的干预方案、运用符合目标的安慰针刺、结合研究设计和目的选定结局指标几个角度,阐述试验相关环节设计的原因和思考。  相似文献   
85.
The cingulum, connecting the orbitofrontal cortex to the medial temporal lobe, involves in diverse cognition functions including attention, memory, and motivation. To investigate the relationship between the cingulum injury and cognitive impairment in patients with chronic mild traumatic brain injury, we evaluated the integrity between the anterior cingulum and the basal forebrain using diffusion tensor tractography in 73 patients with chronic mild traumatic brain injury(39 males, 34 females, age 43.29 ± 11.42 years) and40 healthy controls(22 males, 18 females, age 40.11 ± 16.81 years). The patients were divided into three subgroups based on the integrity between the anterior cingulum and the basal forebrain on diffusion tensor tractography: subgroup A(n = 19 patients)-both sides of the anterior cingulum were intact; subgroup B(n= 36 patients)-either side of the anterior cingulum was intact; and subgroup C(18 patients)-both sides of the anterior cingulum were discontinued. There were significant differences in total Memory Assessment Scale score between subgroups A and B and between subgroups A and C. There were no significant differences in diffusion tensor tractography parameters(fractional anisotropy, apparent diffusion coefficient, and fiber volume) between patients and controls. These findings suggest that the integrity between the anterior cingulum and the basal forebrain, but not diffusion tensor tractography parameter, can be used to predict the cognitive function of patients with chronic mild traumatic brain injury. This study was approved by Yeungnam University Hospital Institutional Review Board(approval No. YUMC-2014-01-425-010) on August 16, 2017.  相似文献   
86.
Sodium butyrate is a histone deacetylase inhibitor that affects various types of brain damages. To investigate the effects of sodium butyrate on hippocampal dysfunction that occurs after whole-brain irradiation in animal models and the effect of sodium butyrate on radiation exposure-induced cognitive impairments,adult C57BL/6 mice were intraperitoneally treated with 0.6 g/kg sodium butyrate before exposure to 10 Gy cranial irradiation. Cognitive impairment in adult C57BL/6 mice was evaluated via an object recognition test 30 days after irradiation. We also detected the expression levels of neurogenic cell markers(doublecortin)and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor. Radiation-exposed mice had decreased cognitive function and hippocampal doublecortin and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression. Sodium butyrate pretreatment reversed these changes. These findings suggest that sodium butyrate can improve radiation-induced cognitive dysfunction through inhibiting the decrease in hippocampal phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression. The study procedures were approved by the Institutional Animal Care and Use Committee of Korea Institute of Radiological Medical Sciences(approval No. KIRAMS16-0002) on December 30, 2016.  相似文献   
87.
88.
89.
90.
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