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   3152406篇
  免费   235519篇
  国内免费   4737篇
耳鼻咽喉   44827篇
儿科学   104946篇
妇产科学   85863篇
基础医学   458904篇
口腔科学   86772篇
临床医学   283851篇
内科学   610724篇
皮肤病学   69640篇
神经病学   249416篇
特种医学   119984篇
外国民族医学   1096篇
外科学   477456篇
综合类   67300篇
现状与发展   12篇
一般理论   1119篇
预防医学   246488篇
眼科学   73936篇
药学   235362篇
  11篇
中国医学   6132篇
肿瘤学   168823篇
  2019年   24974篇
  2018年   34768篇
  2017年   26146篇
  2016年   29276篇
  2015年   33020篇
  2014年   46527篇
  2013年   70295篇
  2012年   96782篇
  2011年   103022篇
  2010年   61458篇
  2009年   58150篇
  2008年   97093篇
  2007年   103738篇
  2006年   104670篇
  2005年   101408篇
  2004年   97691篇
  2003年   94259篇
  2002年   91751篇
  2001年   144754篇
  2000年   148996篇
  1999年   126082篇
  1998年   36522篇
  1997年   32176篇
  1996年   32561篇
  1995年   30889篇
  1994年   28719篇
  1993年   26835篇
  1992年   98553篇
  1991年   96559篇
  1990年   93998篇
  1989年   90214篇
  1988年   83040篇
  1987年   81825篇
  1986年   76471篇
  1985年   73601篇
  1984年   55013篇
  1983年   46713篇
  1982年   27729篇
  1981年   24980篇
  1979年   50368篇
  1978年   35731篇
  1977年   30013篇
  1976年   28484篇
  1975年   30773篇
  1974年   36490篇
  1973年   34924篇
  1972年   32576篇
  1971年   30487篇
  1970年   28420篇
  1969年   26749篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
INTRODUCTION: Vasopressin, mainly through the V1a-receptor, is thought to be a major player in the maintenance of hyperfiltration. Its inhibition could therefore lead to a decrease in progression of chronic renal failure. To this end, the effect of the vasopressin V1a-receptor-selective antagonist, YM218, was studied on proteinuria and focal glomerulosclerosis in early and late intervention after 5/6 nephrectomy in rats, and compared with an angiotensin-converting enzyme inhibitor (ACE-I). MATERIALS AND METHODS: After 5/6 nephrectomy, early intervention was performed between week 2 and 10 thereafter with the V1a-receptor-selective antagonist (VRA, 10 mg/kg/day, n=10), enalapril (ACE-I, 10 mg/kg/day, n=9), or vehicle (n=8). Late intervention was performed in another group between week 6 and 12 with VRA (10 mg/kg/day, n=7), lisinopril (ACE-I, 5 mg/kg/day, n=7), or vehicle (n=7). RESULTS: In early intervention, proteinuria and focal glomerulosclerosis were significantly decreased by VRA compared to vehicle (44+7% and 59+8% respectively). ACE-I significantly decreased proteinuria (67+7%) and a trend towards a decrease in focal glomerulosclerosis was observed (30+18%). In late intervention, VRA did not decrease proteinuria and focal glomerulosclerosis compared to vehicle (21+20% and 0%, respectively), ACE-I significantly lowered proteinuria (92+2%) and a focal glomerulosclerosis (69+1%) lowering trend was observed. CONCLUSION: These results indicate that VRA may protect against early progression of renal injury after 5/6 nephrectomy, whereas its effectiveness seems limited in established renal damage.  相似文献   
992.
993.
994.
995.
Surfactant     
Surfactant, a complex substance containing specific proteins and phospholipids, is essential for gas exchange in the lungs. Research shows that surfactant not only lowers surface tension, but also plays a role in host defense. Surfactant replacement therapy is a cornerstone in the treatment of respiratory distress syndrome in premature infants. New information on endogenous surfactant composition including surfactant apoproteins has led to advances in the surfactant replacement products currently available. Because of the success of surfactant deficiency treatment in neonates, surfactant replacement therapy has been studied in both the pediatric and adult population for the treatment of other respiratory disorders. This article describes the composition, metabolism, and function of endogenous surfactant and other uses of surfactant replacement therapies in neonates.  相似文献   
996.
997.
998.
999.
1000.
Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.  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