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   520篇
  免费   52篇
  国内免费   17篇
耳鼻咽喉   3篇
儿科学   19篇
妇产科学   6篇
基础医学   47篇
口腔科学   44篇
临床医学   62篇
内科学   95篇
皮肤病学   16篇
神经病学   9篇
特种医学   95篇
外科学   58篇
综合类   27篇
预防医学   50篇
眼科学   7篇
药学   29篇
中国医学   1篇
肿瘤学   21篇
  2023年   6篇
  2020年   4篇
  2018年   14篇
  2017年   8篇
  2016年   12篇
  2015年   9篇
  2014年   7篇
  2013年   17篇
  2012年   13篇
  2011年   18篇
  2010年   18篇
  2009年   28篇
  2008年   8篇
  2007年   30篇
  2006年   5篇
  2005年   7篇
  2004年   9篇
  2003年   5篇
  2002年   11篇
  2001年   7篇
  2000年   9篇
  1999年   9篇
  1998年   23篇
  1997年   38篇
  1996年   32篇
  1995年   19篇
  1994年   16篇
  1993年   18篇
  1991年   9篇
  1990年   5篇
  1989年   17篇
  1988年   20篇
  1987年   12篇
  1986年   15篇
  1985年   16篇
  1984年   10篇
  1983年   11篇
  1982年   9篇
  1981年   13篇
  1980年   9篇
  1979年   5篇
  1978年   6篇
  1977年   3篇
  1976年   4篇
  1975年   3篇
  1973年   3篇
  1972年   2篇
  1971年   2篇
  1969年   2篇
  1944年   3篇
排序方式: 共有589条查询结果,搜索用时 15 毫秒
81.
82.
Bacterial meningitis in infants: sonographic findings   总被引:1,自引:0,他引:1  
Han  BK; Babcock  DS; McAdams  L 《Radiology》1985,154(3):645-650
A retrospective study was performed on 78 patients (newborn to 2 years old) with clinically proved bacterial meningitis. Sonograms were obtained during the acute illness and medical records were reviewed. The spectrum of sonographic features of meningitis included normal scans (30 patients), ventriculomegaly (11 patients), echogenic sulci (31 patients), extra-axial fluid collections (26 patients), abnormal parenchymal echogenicity (9 patients), evidence of ventriculitis (5 patients), and brain abscess (1 patient). In 46 patients, correlation between the sonographic findings and neurologic outcome on clinical follow-up (6 months to 4 years) was made. Findings of abnormal parenchymal echogenicity and/or moderate-to-marked ventriculomegaly were associated with significant neurologic sequelae; however, echogenic sulci and small extra-axial fluid collections did not appear to have any prognostic significance. Twenty-nine of the 78 patients had sonography without clinical indication of complications of meningitis, and in no patient was a significant abnormality found. Our study suggests that sonography is indicated only when there is clinical suspicion of complications.  相似文献   
83.
84.
85.
本文研制了以四苯硼—唐松草新碱缔合物为电活性物质的变价态唐松草新碱—PVC膜电极。电极膜按电活性物质:PVC:DBP为1:8:8组成。该电极在pH 5.0~6.0,Ⅰ=0.05的NaCl—HCl溶液中Nernst响应范围为1×10-3~1×10-5mol/L。电极斜率为58.2 mV/logc。检测限为2.5×10-6mol/L。用直接电位法考察了TDH+,TDH2CF++共存时溶液pH和电极斜率S的关系。用S—pH关系,测定了25℃,Ⅰ=0.05时的Ka1值为(2.5±0.2)×10-4,用E—pH关系,测定了25℃,Ⅰ=0.05时的Ka2值为(8.1±0.9)×10-8。  相似文献   
86.
Lung involvement in angioimmunoblastic lymphadenopathy (ail)   总被引:2,自引:0,他引:2  
  相似文献   
87.
邵刚  吴芳  王德胜  朱荣  罗旭 《药学学报》1995,30(5):384-389
l-麻黄碱和d-伪麻黄碱是生药麻黄中早为人知而至今仍被广泛用于临床的一对手性异构生物碱。由于二者为生药麻黄中的主要成分但药理活性不同,为便于临床监控及有效用药,高分辨高灵敏度的检测方法的开发迫在眉睫。本文以易于得到的dansylchloride为柱前荧光标识试剂,在确定了最佳衍生化及分离条件的基础上,建立了理想的色谱分析系统(线性检测范围1~800ng·ml-1)。同时运用此方法,完成了对静注l-麻黄碱和d-伪麻黄碱后豚鼠血浆内该对手性异构体水平的考查,并且定量检测了服用中成药小青龙合剂后人血浆中的该对手性异构体。  相似文献   
88.
Two hundred and ninety-seven seventh grade students (143 males and 154 females) participated in a prospective study to predict adolescent cigarette smoking behavior one year later. Predictor variables included 10 survey items assessing the smoking behavior of students' friends and family, students' school behavior and beliefs about smoking and students' intentions to smoke in the future. The one-year follow-up survey was administered under "bogus pipeline" conditions to enhance the validity of self-reported smoking status by including the collection of saliva thiocyanate samples. Univariate analyses indicated that smokers differed from nonsmokers on a number of measures and that there were few sex differences on either the survey variables or on smoking status. Stepwise discriminant function analyses revealed that it was possible to accurately predict the onset of adolescent cigarette smoking by combining the survey variables. The three variables that consistently accounted for the greatest proportion of the variance were number of friends who smoke, intentions to smoke in the future and percent of older siblings who smoke. The implications of this work for programs intended to prevent adolescent smoking are discussed.  相似文献   
89.
Titelbaum  DS; Hayward  JC; Zimmerman  RA 《Radiology》1989,173(3):663-667
Studies of 23 pediatric patients with pachygyriclike changes (PLCs) examined with computed tomography (CT) and magnetic resonance (MR) imaging were reviewed to determine topographic patterns and correlate them with various clinical syndromes and degrees of neurologic impairment. Three types of topographic distributions were identified: unilateral, diffuse, and bilateral nondiffuse (of which eight of 10 showed frontotemporal predominance). PLCs were an isolated finding in seven patients, were associated with various congenital syndromes in nine patients, and were associated with congenital infection in seven patients, six of whom showed marked white matter abnormalities. Although most patients had severe developmental delay, three with nondiffuse PLCs had less severe impairment, permitting less required care.  相似文献   
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