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   290340篇
  免费   17912篇
  国内免费   8383篇
耳鼻咽喉   3263篇
儿科学   9451篇
妇产科学   3692篇
基础医学   22612篇
口腔科学   5008篇
临床医学   35149篇
内科学   49990篇
皮肤病学   3543篇
神经病学   14972篇
特种医学   15946篇
外国民族医学   29篇
外科学   38915篇
综合类   30506篇
现状与发展   29篇
预防医学   19733篇
眼科学   7852篇
药学   34236篇
  126篇
中国医学   8219篇
肿瘤学   13364篇
  2023年   2900篇
  2022年   5277篇
  2021年   13016篇
  2020年   7833篇
  2019年   13452篇
  2018年   8164篇
  2017年   7461篇
  2016年   9489篇
  2015年   12306篇
  2014年   22073篇
  2013年   20389篇
  2012年   22902篇
  2011年   19816篇
  2010年   17746篇
  2009年   16944篇
  2008年   15764篇
  2007年   15916篇
  2006年   13551篇
  2005年   9517篇
  2004年   5698篇
  2003年   4858篇
  2002年   4074篇
  2001年   3493篇
  2000年   3026篇
  1999年   2169篇
  1998年   2451篇
  1997年   2358篇
  1996年   1952篇
  1995年   2035篇
  1994年   1925篇
  1993年   1545篇
  1992年   1789篇
  1991年   1631篇
  1990年   1612篇
  1989年   1471篇
  1988年   1409篇
  1987年   1252篇
  1986年   1043篇
  1985年   2059篇
  1984年   2188篇
  1983年   1566篇
  1982年   1667篇
  1981年   1590篇
  1980年   1378篇
  1979年   1165篇
  1978年   915篇
  1977年   848篇
  1976年   736篇
  1975年   484篇
  1974年   495篇
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
101.
目的对中国精神分裂症患者采取家庭干预的研究文献进行综合回顾和系统评价, 比较不同条件下家庭干预效果的差异。方法在中国知网、维普、万方、中国生物医学文献数据库四大中文数据库及OVID Medline、Science Direct、Web of Science、EBSCO四大英文数据库中, 检索各数据库建库至2015年1月为止使用社会功能缺陷筛选量表(SDSS)、简明精神病(科)量表(BPRS)、阳性与阴性症状量表(PANSS)研究中国精神分裂症患者家庭干预效果的文献, 以标准化加权均数差( SMD)作为效应量, 采用meta分析比较不同干预时间、不同干预类型、对不同病程和不同严重程度的精神分裂症患者的家庭干预效果差异。 结果共纳入57篇符合标准的文献。SDSS、PANSS分析结果显示:① 干预时间越长干预效果越好( P < 0.0001、 P=0.0025);② 单独家庭干预比多个家庭合并单独家庭干预的效果更明显( P < 0.0001、 P=0.0131);③ 干预对于病情较重患者效果较好( P < 0.0001、 P=0.0280)。SDSS量表还显示家庭干预对于病程短的患者效果更好( P < 0.0001)。 结论家庭干预更适合病程较短的精神分裂症患者, 干预应实施较长时间; 单独家庭干预更有利于患者阴性症状的改善和社会功能的康复, 且对于病情较轻患者的阴性症状改善效果更好。  相似文献   
102.
ObjectivesThis study aimed to determine the effect of lower leg compression during cesarean section (CS) on post-spinal hypotension (PSH) and neonatal hemodynamic parameters.MethodsThis study is a nonrandomized controlled clinical trial conducted in the cesarean delivery unit of the National Medical institute, Damanhour, Egypt. The sample included 120 parturients (60 intervention and 60 control). The researchers developed three tools for data collection: sociodemographic data and reproductive history interview schedule, electronic monitoring of maternal hemodynamic parameters, and neonatal hemodynamic assessment sheet. All parturients received ordinary pre-operative care. For the intervention group, a long elastic stocking (ordinary pressure 20–30 mmHg, 1 mmHg = 0.133 kPa) was applied on both legs during cesarean section. The control group received the same care without the elastic stocking.ResultsSystolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were significantly higher in the intervention group throughout the entire operation period except in the last 5–15 min. Heart rate was significantly lower in the intervention group. Only 13.3% of the intervention group took ephedrine compared with 45% of the control group. Apgar score was higher among neonates of intervention group compared with the control group at 1 min. Neonatal acidosis was significantly higher in the control group than in the contral group.ConclusionLower leg compression technique can effectively reduce PSH and neonatal acidosis.  相似文献   
103.
104.
105.
106.
107.
108.
BackgroundHallux valgus (HV) contributes to deficits in static balance and increased fall risk in older adults. Very limited research has examined dynamic balance deficits in walking in this population. These individuals generally walk slowly, as balance challenge is lesser at slow speeds.Research questionHow does the dynamic balance of older adults with HV differ from healthy controls at controlled slow and fast walking speeds?MethodsNineteen older adults with HV and 13 healthy controls completed 5 continuous walking trials at 1.0 and 1.3 m·s−1 as whole body marker position and ground reaction force data were captured. Dynamic balance was evaluated using whole body center of mass (COM) and center of pressure (COP) inclination angles (IA) and duration of double support.ResultsThere were no differences in measures of dynamic balance between older adults with and without HV at slow and fast speeds. At the faster speed, the peak sagittal plane COM-COP IA increased and the double support duration decreased, while the peak frontal plane COM-COP IA were not affected.SignificanceOlder adults with HV do not exhibit deficits in dynamic balance during continuous walking at comfortable speeds when compared to healthy older adults.  相似文献   
109.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.  相似文献   
110.
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