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   1535篇
  免费   80篇
  国内免费   13篇
耳鼻咽喉   9篇
儿科学   96篇
妇产科学   103篇
基础医学   121篇
口腔科学   43篇
临床医学   165篇
内科学   322篇
皮肤病学   45篇
神经病学   25篇
特种医学   145篇
外科学   112篇
综合类   136篇
预防医学   94篇
眼科学   10篇
药学   92篇
  1篇
中国医学   74篇
肿瘤学   35篇
  2021年   15篇
  2020年   11篇
  2018年   14篇
  2017年   19篇
  2016年   16篇
  2015年   33篇
  2014年   42篇
  2013年   42篇
  2012年   49篇
  2011年   46篇
  2010年   54篇
  2009年   45篇
  2008年   43篇
  2007年   33篇
  2006年   36篇
  2005年   18篇
  2004年   17篇
  2003年   13篇
  2002年   11篇
  2001年   20篇
  1999年   19篇
  1998年   43篇
  1997年   54篇
  1996年   47篇
  1995年   42篇
  1994年   55篇
  1993年   35篇
  1992年   15篇
  1991年   14篇
  1990年   15篇
  1989年   28篇
  1988年   27篇
  1987年   30篇
  1986年   25篇
  1985年   16篇
  1984年   16篇
  1983年   17篇
  1982年   13篇
  1981年   23篇
  1980年   16篇
  1977年   9篇
  1959年   35篇
  1958年   58篇
  1957年   87篇
  1956年   45篇
  1955年   75篇
  1954年   67篇
  1953年   17篇
  1952年   14篇
  1949年   10篇
排序方式: 共有1628条查询结果,搜索用时 0 毫秒
101.
新疆卫生人力资源存在着数量不足、素质不高、结构不合理及配置不平衡等问题,尤其新疆南疆三地州卫生人力资源的匮乏急待解决。根据卫生事业发展需与国民经济发展相协调的实际,满足全体人民基本卫生服务需要的目标,按照基本卫生服务均等化原则,建议增加当地卫生人力资源数量、提高基本卫生人力素质与能力、不断调整优化卫生人力资源结构和布局等。  相似文献   
102.
103.
104.
105.
目的研究外源性p53对W nt通路抑制因子D ickkopf-1(DKK-1)的表达作用。方法将携带p53基因的复制缺陷型腺病毒载体(Adp53)导入到p53完全缺失的人肝癌细胞株Hep3B中,并以p53反以寡核苷酸阻断p53阳性细胞p53的表达,以W nt通路的关键因子-βcaten in的改变为功能指标评价W nt通路的变化。以RT-PCR技术检测W nt通路抑制因子DKK-1表达的调节作用,以流式细胞术检测Adp53的转基因情况,肝癌细胞中p53和β-caten in的表达。结果DKK-1mRNA水平在转染Adp53 20 h后即有明显升高,32 h达最高水平,随后逐渐降低。β-caten in表达水平随着转染时间和转染剂量的增加,阳性细胞百分比强度和平均荧光量强度表达水平逐渐下降。以p53反以寡核苷酸阻断p53阳性细胞p53表达后,抑制剂DKK-1的表达逐渐降低,-βcaten in表达水平逐渐增加。结论外源性p53能明显诱导W nt通路抑制剂DKK-1的表达,进而产生抑制W nt通路的作用。  相似文献   
106.
Direct sagittal computed tomographic scanning (DSCT) of the shoulder was performed in 42 symptomatic patients, six healthy volunteers, and two cadaver shoulders. Axial CT scanning and double-contrast arthrography with plain radiographs were performed in 41 patients for comparison. DSCT enabled correct identification of 27 of 29 lesions in 24 patients. Seventeen patients had normal shoulders. Axial CT scanning and DSCT together enabled correct identification of all lesions and were markedly superior to plain-film arthrography. DSCT enabled diagnosis of all cases of complete rotator cuff tear plus three cases of incomplete tear and three of rotator cuff atrophy not identified by the other techniques. Axial CT scanning was better than DSCT for diagnosis of Bankart lesions.  相似文献   
107.
108.
109.
Summary No studies have investigated the effects of the treatments directed at the cervical spine in patients with temporomandibular disorders (TMD). Our aim was to investigate the effects of joint mobilization and exercise directed at the cervical spine on pain intensity and pressure pain sensitivity in the muscles of mastication in patients with TMD. Nineteen patients (14 females), aged 19–57 years, with myofascial TMD were included. All patients received a total of 10 treatment session over a 5‐week period (twice per week). Treatment included manual therapy techniques and exercise directed at the cervical spine. Outcome measures included bilateral pressure pain threshold (PPT) levels over the masseter and temporalis muscles, active pain‐free mouth opening (mm) and pain (Visual Analogue Scale) and were all assessed pre‐intervention, 48 h after the last treatment (post‐intervention) and at 12‐week follow‐up period. Mixed‐model anovas were used to examine the effects of the intervention on each outcome measure. Within‐group effect sizes were calculated in order to assess clinical effect. The 2 × 3 mixed model anova revealed significant effect for time (F = 77·8; P < 0·001) but not for side (F = 0·2; P = 0·7) for changes in PPT over the masseter muscle and over the temporalis muscle (time: F = 66·8; P < 0·001; side: F = 0·07; P = 0·8). Post hoc revealed significant differences between pre‐intervention and both post‐intervention and follow‐up periods (P < 0·001) but not between post‐intervention and follow‐up period (P = 0·9) for both muscles. Within‐group effect sizes were large (d > 1·0) for both follow‐up periods in both muscles. The anova found a significant effect for time (F = 78·6; P < 0·001) for changes in pain intensity and active pain‐free mouth opening (F = 17·1; P < 0·001). Significant differences were found between pre‐intervention and both post‐intervention and follow‐up periods (P < 0·001) but not between the post‐intervention and follow‐up period (P > 0·7). Within‐group effect sizes were large (d > 0·8) for both post‐intervention and follow‐up periods. The application of treatment directed at the cervical spine may be beneficial in decreasing pain intensity, increasing PPTs over the masticatory muscles and an increasing pain‐free mouth opening in patients with myofascial TMD.  相似文献   
110.
Kirkpatrick  JB; Hayman  LA 《Radiology》1987,162(2):509-511
Patchy white-matter lesions occur in the magnetic resonance (MR) imaging brain studies of 20%-30% of neurologically healthy elderly subjects. To determine the frequency of histologically verifiable white-matter lesions at autopsy in such subjects the authors examined serial, microscopic, whole brain sections from 15 clinically healthy subjects aged 52-72 years. Small white-matter lesions were found in 12. In these 12, zones of atrophic perivascular demyelination were present in eight brains. These are not the familiar thrombotic, embolic, or ischemic vascular lesions that produce acute necrosis. This mild vascular insufficiency produces atrophy, which has been recognized in the pathology literature but whose clinical significance remains unknown. Other lesions seen were small vascular malformations in the centrum ovale in four brains, diverticula of the lateral ventricle extending into the white matter in three, and an isolated central white-matter infarction in one. All of these lesions are probably the basis of the patchy white-matter lesions seen on MR imaging studies in the neurologically healthy elderly population.  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