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   4038篇
  免费   594篇
  国内免费   40篇
耳鼻咽喉   43篇
儿科学   132篇
妇产科学   84篇
基础医学   499篇
口腔科学   61篇
临床医学   360篇
内科学   1057篇
皮肤病学   45篇
神经病学   419篇
特种医学   246篇
外科学   554篇
综合类   176篇
预防医学   465篇
眼科学   97篇
药学   262篇
肿瘤学   172篇
  2021年   46篇
  2017年   34篇
  2016年   34篇
  2015年   47篇
  2014年   53篇
  2013年   84篇
  2012年   130篇
  2011年   133篇
  2010年   80篇
  2009年   82篇
  2008年   119篇
  2007年   128篇
  2006年   136篇
  2005年   165篇
  2004年   133篇
  2003年   103篇
  2002年   116篇
  2001年   106篇
  2000年   99篇
  1999年   105篇
  1998年   69篇
  1997年   56篇
  1996年   58篇
  1995年   52篇
  1994年   60篇
  1993年   55篇
  1992年   104篇
  1991年   101篇
  1990年   123篇
  1989年   140篇
  1988年   131篇
  1987年   134篇
  1986年   138篇
  1985年   124篇
  1984年   122篇
  1983年   141篇
  1982年   85篇
  1981年   88篇
  1980年   82篇
  1979年   109篇
  1978年   86篇
  1977年   76篇
  1976年   47篇
  1975年   57篇
  1974年   49篇
  1973年   41篇
  1972年   46篇
  1971年   47篇
  1970年   48篇
  1969年   35篇
排序方式: 共有4672条查询结果,搜索用时 15 毫秒
1.
Hepatitis C virus (HCV) infection is a major health care issue in liver and kidney transplantation. Besides negatively affecting both patient and graft survival, HCV is associated with a heightened risk for new onset diabetes mellitus (NODM). The mechanisms underlying the diabetogenicity of HCV are complex but are likely to involve insulin resistance caused by inhibitory actions of the virus on insulin regulatory pathways in the liver. The resultant glucose dysregulation is an important determinant of increased morbidity and mortality in liver and kidney recipients. This review highlights the concerns for outcomes in HCV-positive liver and kidney transplant patients with particular focus on the interrelationship between hepatitis C and diabetes. Data about the potential role of calcineurin inhibitors, corticosteroids and mycophenolate mofetil in HCV infection and HCV-associated NODM will also be discussed.  相似文献   
2.
Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery.  相似文献   
3.
4.
SNAP-25 immunoreactivity was translocated into the endings of the processes induced in PC12 cells by dibutyryl-cAMP-treatment. Conversely, the protein was not present in the endings of the processes seen after NGF-treatment unless dibutyryl-cAMP was used simultaneously. This redistribution of SNAP-25 immunoreactivity appeared to be dependent upon new protein synthesis. Finally, dibutyryl-cAMP was capable of inducing SNAP-25 expression.  相似文献   
5.
Regional cerebral [11C]3-O-methyl-D-glucose ([11C]MeG) uptake kinetics have been measured in five insulin-dependent diabetic patients and four normal controls using positron emission tomography (PET). Concomitant measurement of regional cerebral blood volume and CBF enabled corrections for the presence of intravascular [11C]MeG signal in cerebral regions of interest to be carried out, and regional cerebral [11C]MeG unidirectional extraction fractions to be computed. Four of the five diabetic subjects were studied with their fasting plasma glucose level clamped at a normoglycaemic level (4 mM), and four were studied at hyperglycaemic plasma glucose levels (mean 13 mM). The four diabetic subjects whose fasting plasma glucose levels were clamped at a normoglycaemic level of 4 mM had mean fasting whole-brain, cortical, and white matter [11C]MeG extraction fractions of 15, 15, and 16%, respectively, values similar to those found for the four normal controls (whole brain, 14%; cortex, 13%; white matter, 17%). Mean regional cerebral [11C]MeG extraction fractions were significantly reduced in diabetic subjects during hyperglycaemia whether their plasma insulin levels were undetectable or whether they were raised by continuous intravenous insulin infusion. Such a reduction in [11C]MeG extraction under hyperglycaemic conditions can be explained entirely in terms of increased competition between [11C]MeG and D-glucose for the passive facilitated transport carrier system for hexoses across the blood-brain barrier (BBB). It is concluded that the number and affinity of D-glucose carriers present in the BBB are within normal limits in treated insulin-dependent diabetic subjects. In addition, insulin appears to have no effect on the transport of D-glucose across the BBB.  相似文献   
6.
7.
8.
Retroperitoneal Laparoscopic Nephrectomy in Children   总被引:1,自引:0,他引:1  
Retroperitoneal pediatric laparoscopic nephrectomy is described in 3 patients requiring 3 to 5 hours with an estimated blood loss of 10 to 60 cc. The children returned to school within 7 days postoperatively. Advantages of this procedure include the avoidance of intraoperative repositioning of the patient and easy conversion to an open lumbodorsal approach, if necessary; early laparoscopic visualization of the renal artery; applicability in cases of previous abdominal surgery, and avoidance of intraperitoneal adhesion.  相似文献   
9.
10.
This exploratory study examined the family environment of ten families, each with a physically disabled adolescent and at least one non-disabled adolescent. Family members completed the Moos Family Environment Scale (FES) and discussed with the interviewer their experiences as a family. Blind and independent ratings on the FES by social workers involved in the study provided a comparison with the families' self ratings. Family ratings on the FES gave no indication of distress, but showed slightly higher than average emphasis on cohesion and achievement orientation. Social work ratings, in contrast, indicated elevated levels of conflict, achievement orientation, and control. In this report, no attempt is made to generalize these specific findings to all families with disabled adolescents. Rather, results are interpreted, in the light of findings in the recent literature, to underscore the need for better designed research and to alert professionals to the danger of imposing the prevalent dysfunctional view upon families with disabled children and adolescents.  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