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   109705篇
  免费   6783篇
  国内免费   229篇
耳鼻咽喉   1437篇
儿科学   3139篇
妇产科学   2271篇
基础医学   15441篇
口腔科学   3441篇
临床医学   10442篇
内科学   21028篇
皮肤病学   2346篇
神经病学   11207篇
特种医学   5450篇
外国民族医学   8篇
外科学   15796篇
综合类   800篇
一般理论   72篇
预防医学   7932篇
眼科学   2383篇
药学   7013篇
中国医学   156篇
肿瘤学   6355篇
  2023年   518篇
  2022年   514篇
  2021年   1313篇
  2020年   1202篇
  2019年   1458篇
  2018年   2270篇
  2017年   1904篇
  2016年   2396篇
  2015年   2248篇
  2014年   2854篇
  2013年   4582篇
  2012年   6281篇
  2011年   6899篇
  2010年   3771篇
  2009年   2950篇
  2008年   6666篇
  2007年   6901篇
  2006年   6682篇
  2005年   6529篇
  2004年   6190篇
  2003年   6134篇
  2002年   5979篇
  2001年   3310篇
  2000年   4007篇
  1999年   2490篇
  1998年   1197篇
  1997年   979篇
  1996年   801篇
  1995年   723篇
  1994年   650篇
  1993年   601篇
  1992年   691篇
  1991年   603篇
  1990年   567篇
  1989年   646篇
  1988年   546篇
  1987年   543篇
  1986年   537篇
  1985年   613篇
  1984年   652篇
  1983年   568篇
  1982年   579篇
  1981年   519篇
  1980年   479篇
  1979年   478篇
  1978年   420篇
  1977年   403篇
  1976年   369篇
  1975年   363篇
  1974年   350篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
41.
42.
The presented case reports on successful treatment with everolimus in a neonate with left ventricular giant rhabdomyoma. The authors used a different dosage regime compared to literature and documented rapid tumor regression by 3D echocardiography.  相似文献   
43.
44.
Type 1 diabetes is one of the commonest chronic disorders encountered in children and adolescents. When it first becomes apparent in children, approximately 20% of them have clinical and biochemical signs of ketoacidosis (DKA). In the presence of unusual clinical symptoms it is necessary to consider the possibility of associated conditions, such as coeliac disease, immunothyroiditis and Addison’s disease. Children with diabetes must be treated by a multidisciplinary team made up of paediatrician, paediatric diabetes specialist, psychologist, social worker, ophthalmologist, dietitian, nurse and diabetes counsellor, making it essential for them to be treated in regional specialised centres. They are treated in their own psychosocial environment and their families are involved in the therapy. Comprehensive, multidisciplinary treatment strategies have now made it possible for these patients to enjoy normal physical wellbeing and near-normal psychosocial development. Prevention and early treatment of of disturbances associated with diabetes remain an important concern. The fact that type 2 diabetes must now be looked for in overweight children and adolescents is a new aspect of diabetes medicine.  相似文献   
45.
46.
47.
48.
Genomes of some parasites contain dozens of alternative and highly diverged surface antigens, of which only a single one is expressed in any cell. Individual cells occasionally change expression of their surface antigen, allowing them to escape immune surveillance. These switches appear to occur in a partly random way, creating a diverse set of antigenic variants. In spite of this diversity, the parasitemia develops as a series of outbreaks, in which each outbreak is dominated by relatively few antigenic types. Host-specific immunity eventually clears the dominant antigenic types, and a new outbreak follows from antigenic types that have apparently been present all along at low frequency. This pattern of sequential dominance by different antigenic types remains unexplained. We review the five most prominent theories, which have developed mainly from studies of the protozoans Trypanosoma and Plasmodium, and the bacterial spirochete Borrelia. The most promising theories depend on some combination of mechanisms to create favored connectivity pathways through the matrix of transitions between variants. Favored pathways may arise from biased switches at the molecular level of gene expression or from biases imposed by immune selection. We illustrate the concept of connectivity pathways by reanalysis of data on transitions between variants from Borrelia hermsii.  相似文献   
49.
50.
Transforaminal injections are sometimes used for the diagnosis and treatment of painful conditions in the lumbar and to a lesser degree in the cervical spine. The technique is most often used when investigating/treating radiculopathy caused by degenerative disease. But how selective are the nerve root blocks? What possible structures other than the intended nerve root are affected from such injections? This study was undertaken in order to try to answer these questions, as no study focusing on the possible spread from the transforaminal selective nerve root blocks in the cervical spine has been performed earlier. In three groups of patients, each group including three patients, we injected three different volumes (0.6, 1.1 and 1.7 ml) with a transforaminal technique in the cervical spine. In all the injections, a small amount of contrast media was added. The spread of the injections were then investigated using multi-slice computed tomography with reconstructions. The imaging revealed a possible effect on other nerve roots than the intended ones when a larger volume was used for the root blocks. The spread was related to the injected volume as well as to local anatomy (size of foraminal area). In this study, only 0.6-ml injections could be accepted for being selective enough for diagnostic investigations.  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