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   168937篇
  免费   6526篇
  国内免费   365篇
耳鼻咽喉   2231篇
儿科学   4845篇
妇产科学   4043篇
基础医学   24246篇
口腔科学   5506篇
临床医学   9727篇
内科学   37340篇
皮肤病学   4654篇
神经病学   13576篇
特种医学   4105篇
外国民族医学   1篇
外科学   19427篇
综合类   806篇
一般理论   26篇
预防医学   20146篇
眼科学   4395篇
药学   13180篇
中国医学   692篇
肿瘤学   6882篇
  2023年   838篇
  2022年   767篇
  2021年   2778篇
  2020年   1568篇
  2019年   3134篇
  2018年   5029篇
  2017年   3134篇
  2016年   3133篇
  2015年   3489篇
  2014年   4045篇
  2013年   6090篇
  2012年   10266篇
  2011年   10890篇
  2010年   5484篇
  2009年   4106篇
  2008年   8911篇
  2007年   9514篇
  2006年   9114篇
  2005年   8739篇
  2004年   8087篇
  2003年   7586篇
  2002年   7203篇
  2001年   5010篇
  2000年   5551篇
  1999年   4259篇
  1998年   819篇
  1992年   2283篇
  1991年   2039篇
  1990年   2012篇
  1989年   1723篇
  1988年   1622篇
  1987年   1529篇
  1986年   1576篇
  1985年   1461篇
  1984年   1048篇
  1983年   908篇
  1979年   1217篇
  1978年   807篇
  1977年   784篇
  1976年   747篇
  1975年   881篇
  1974年   1132篇
  1973年   1178篇
  1972年   1125篇
  1971年   1087篇
  1970年   1012篇
  1969年   1087篇
  1968年   1112篇
  1967年   984篇
  1966年   884篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Background and objectiveTo analyse frequency, characteristics and patient survival with lung cancer (LC) and Common Obstructive Pulmonary Disease (COPD), comparing them with patients that do not have COPD.Material and methodsA retrospective study, of patients diagnosed by means of cytohistology. Survival was estimated by the Kaplan-Meier method. Statistical analysis was carried out using SPSS 15.0.ResultsA total of 996 patients were diagnosed, 39.8% with COPD. Mean age70±9.19 years. GOLD stages: I 18.2%, II 53.6%, III 24%, IV 4.2%. The histological types: squamous cell carcinoma 48.2%, adenocarcinoma 22%, and small cell carcinoma 22.5%. Survival was longer in the COPD group.ConclusionsLC and COPD are combined in 39.8%. Squamous cell type is more frequent and survival was longer in the COPD group.  相似文献   
52.
53.
54.
55.
The component of a composite prosthesis, which makes contact with the visceral peritoneum, can be reabsorbable or non-reabsorbable, and laminar or reticular. This study was designed to determine whether the composition of this second, barrier component could improve its behavior at this interface. Abdominal wall defects in rabbits were repaired using a polypropylene prosthesis (PP), or the composites Sepramesh (PP+h) or Vicryl (PP+v). Fourteen days after surgery, the implants were evaluated by light and scanning electron microscopy, and immunohistochemistry. Prosthetic areas occupied by adhesions (PP: 71.08±5.09, PP+h: 18.55±4.96, P+v: 69.69±16.81%), neoperitoneal thickness (PP: 256.17±21.68, PP+h: 83.11±19.63, PP+v:213.72±35.90 μm) and macrophage counts (PP: 8.73±1.16, PP+h: 27.33±4.13, PP+v: 31.24±3.08%) showed significant differences (P<0.05). The tested biomaterials induced an optimal recipient tissue infiltration. Least adhesion formation was observed on the PP+h implants. This suggests that the second component, although reabsorbable, should be smooth in structure.  相似文献   
56.
We investigated the effects of anti-psoriatic therapy with dithranol (1/20-1%) in salicylic acid (0.5%) in white petrolatum on lesional skin. FITC-labeled lectins and pemphigus vulgaris antibodies (PV) served as analytical means to study the glycocalyx. Antibodies of bullous pemphigoid (BP) were used as basal membrane markers. Nuclear antigens were recorded according to the binding of speckled, anti-nuclear antibodies (ANA) as well as antibodies to dsDNA. With some lectins, dithranol therapy resulted in pronounced fluorescence of the lower parts of the basal cells. ConA was fixed by the basal cell layer. To a lesser degree, ANA were fixed by nuclei of keratinocytes. PV antibodies were not fixed at all.  相似文献   
57.
58.
Myelofibrosis with myeloid metaplasia (MMM) is currently classified as a classic (ie, BCR-ABL-negative) myeloproliferative disorder characterized by anemia, multiorgan extramedullary hematopoiesis, constitutional symptoms, and premature death from either leukemic transformation or other disease complications. Stem cell transplantation can be curative, but many patients either are not appropriate candidates or do not choose to accept the significant risks associated with transplantation. Current pharmacologic therapy has been beneficial mainly in terms of palliating disease-associated cytopenias, constitutional symptoms, splenomegaly, and other organ damage from excess myeloproliferation. Novel treatment strategies are under investigation, including targeted inhibition of JAK2V617F, the activating tyrosine kinase point mutation present in about half of patients with MMM. In this article, we review both the old and new pharmacologic options for MMM.  相似文献   
59.
To evaluate the long-term effects of entacapone on both mean daily 'on' time and health-related quality of life (QoL) in patients with Parkinson's disease (PD) experiencing 'end-of-dose' motor fluctuations and the benefits of an early therapeutic intervention. A prospective, multicenter, observational, 12-month study was performed with an initial 3-month intervention phase, consisting of a phone call to half of the patients from randomly selected investigators to assess if dose adjustment was necessary. Effectiveness was determined by home diaries ('on' time), subscales II and III of the Unified Parkinson's Disease Rating Scale (UPDRS), and the Parkinson's Disease Questionnaire (PDQ-8). After 3 months of treatment, 4.0% of the intervention group patients discontinued the study, versus 18.4% in the control group ( P  < 0.01). The improvement in 'on' time was significantly increased since the 3-month visit (21%, P  < 0.0001) until the end of the study (23% at 12 months, P  < 0.0001). Entacapone also induced significant reductions in the UPDRS scores for subscales II and III and in the PDQ-8 score. 11.2% of patients experienced at least one adverse reaction. This study confirms the effectiveness of entacapone in reducing motor fluctuations by increasing 'on' time, and in improving QoL of PD patients. An early adjustment of entacapone and levodopa doses reduces the number of treatment discontinuations during the first months of treatment.  相似文献   
60.
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