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   1425237篇
  免费   114568篇
  国内免费   3365篇
耳鼻咽喉   18492篇
儿科学   47021篇
妇产科学   41514篇
基础医学   202590篇
口腔科学   37920篇
临床医学   128068篇
内科学   286808篇
皮肤病学   33640篇
神经病学   118406篇
特种医学   54091篇
外国民族医学   464篇
外科学   211905篇
综合类   32890篇
现状与发展   3篇
一般理论   504篇
预防医学   112108篇
眼科学   31726篇
药学   99524篇
  1篇
中国医学   3371篇
肿瘤学   82124篇
  2021年   11519篇
  2019年   12305篇
  2018年   17218篇
  2017年   13135篇
  2016年   14724篇
  2015年   16550篇
  2014年   23274篇
  2013年   34296篇
  2012年   46736篇
  2011年   49228篇
  2010年   28869篇
  2009年   27603篇
  2008年   45247篇
  2007年   47692篇
  2006年   48167篇
  2005年   46596篇
  2004年   44387篇
  2003年   42202篇
  2002年   40593篇
  2001年   73083篇
  2000年   74584篇
  1999年   61632篇
  1998年   17060篇
  1997年   15482篇
  1996年   15637篇
  1995年   14828篇
  1994年   13433篇
  1993年   12609篇
  1992年   45865篇
  1991年   43514篇
  1990年   41514篇
  1989年   39579篇
  1988年   36198篇
  1987年   35371篇
  1986年   32876篇
  1985年   31290篇
  1984年   23838篇
  1983年   20039篇
  1982年   12212篇
  1981年   10781篇
  1979年   20706篇
  1978年   14579篇
  1977年   12092篇
  1976年   11369篇
  1975年   11623篇
  1974年   13995篇
  1973年   13542篇
  1972年   12638篇
  1971年   11479篇
  1970年   10916篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Die therapieinduzierte Neutropenie kann mit den Kolonie stimulierenden Faktoren (CSF) der Granulopoese (G-CSF und GM-CSF) vermieden,abgemildert oder in ihrer Zeitdauer verkürzt werden. Die CSF erm?glichen die Mobilisation h?matopoetischer Stammzellen in das Blut und deren Sammlung für die Transplantation nach Hochdosistherapie.Diese Faktoren sind daher essenziell in der Supportivtherapie maligner Erkranklungen. Der Arbeitskreis Supportivma?nahmen in der Onkologie (ASO) der Deutschen Krebsgesellschaft hat Richtlinien zur Therapie mit den Kolonie stimulierenden Faktoren entwickelt, die unterschiedlichen klinischen Situationen angepasst sind. Der vollst?ndige Text wurde 12/2001 in “Der Onkologe” publiziert [23], er ist auch auf der Homepage des ASO unter http://www.onkosupport.de zu finden [24]. Prof.Dr. H. Link H?matologie, Internistische Onkologie, Endokrinologie, Medizinische Klinik I, Westpfalz-Klinikum Kaiserslautern, Akademisches Lehrkrankenhaus der Johannes-Gutenberg-Universit?t Mainz, 67653 Kaiserslautern, E-Mail: hlink@westpfalz-klinikum.de  相似文献   
992.
The endotoxin receptor soluble CD14 (sCD14) has been implicated in the 'hygiene hypothesis' suggesting reduced allergic sensitization with bacterial stimulation. However, the relationship between early life sCD14 and allergic diseases is conflicting. We aimed to investigate whether possible risk factors for allergic diseases were associated with sCD14 levels at 2 yr of age. In the nested case-control study of the birth cohort studies 'Environment and Childhood Asthma study in Oslo' 411 children selected with recurrent bronchial obstruction (rBO) (n=241) and no bronchial obstruction (n=170) by 2 yr were investigated with skin prick test and structured parental interview at age 2 yr. Exposure to tobacco smoke, pets and infections was recorded semi-annually by questionnaires (0-2 yr). The sCD14 was analysed from frozen, stored serum by ELISA technique. Regression analyses were performed in all subjects with complete data (n=406, 180 girls), and in girls and in boys separately. Mean sCD14 (ng/ml) was significantly higher among girls 2035 (1973-2096) vs. 1947 (1890-2004) (boys). The sCD14 was significantly reduced among girls exposed to antenatal maternal smoking and with parental asthma, after adjusting for age, parental rhino-conjunctivitis, pet keeping and childhood infections. Recurrent otitis media (OM) increased and common colds significantly decreased sCD14 levels in girls. Boys with atopic dermatitis and rBO had reduced sCD14. Pet exposure was not significantly associated with sCD14. We report novel gender-related effects of sCD14 in early life and suggest that gender, tobacco smoke exposure, age and middle ear disease in particular should be accounted for when assessing the role of sCD14 in childhood allergic diseases.  相似文献   
993.
994.
OBJECTIVE: Tumors arising within augmentation cystoplasties are aggressive, have poor prognosis and the majority are not detected at follow-up cystoscopy. Genetic changes in tumors precede morphological abnormalities. Therefore, the aim of this study was to investigate whether genetic abnormalities detected by comparative genomic hybridization (CGH) could be used to identify those patients with augmentation cystoplasties at increased risk of tumorigenesis. METHODS: Bladder biopsy samples were obtained from 16 augmentation cystoplasty patients both distant from and near to the enterovesical anastomosis. CGH was used to detect genetic abnormalities in DNA extracted from the biopsies, archival specimens of two augmentation cystoplasties and two de novo bladder adenocarcinomas. RESULTS: A greater number of amplifications on 2p, 3q, 8q, 9p, 17p, 18pq and 20pq, were observed in bladder biopsies obtained near to the enterovesical anastomosis compared to those taken distant to the suture line. CGH of archival augmentation cystoplasty tumor DNA indicated abnormalities at several loci with amplifications at 2q, 5q, 10p and 21pq, while deletions occurred at 5p and 16p. CONCLUSIONS: The results of this study suggest that the urothelium adjacent to the bladder and/or bowel anastomosis in augmentation cystoplasties is genetically unstable. Furthermore, longitudinal studies are required to establish whether or not patients exhibiting genetic instability following augmentation cystoplasty are at greater risk of developing tumors than those with genetically stable epithelia.  相似文献   
995.
996.
997.
998.
Conclusions  Noninvasive imaging of neurohumoral upregulation in remodeled myocardium suggests that an imaging strategy can be developed for predicting the rate of remodeling and likelihood of HF development. This should allow a more judicious use of neurohumoral antagonists especially in subjects who do not have manifest HF.74 In others specific targeted imaging may allow timely selection of individualized treatment strategies and ensure optimization of therapeutic intervention. Similar to ACE and AII receptors, multiple other targets in the hormonal cascades can identify the likelihood of adverse and favorable remodeling.74  相似文献   
999.
1000.
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