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   104960篇
  免费   6351篇
  国内免费   633篇
耳鼻咽喉   1030篇
儿科学   3463篇
妇产科学   2445篇
基础医学   15319篇
口腔科学   3898篇
临床医学   9564篇
内科学   23444篇
皮肤病学   2705篇
神经病学   10362篇
特种医学   2456篇
外国民族医学   1篇
外科学   9437篇
综合类   389篇
一般理论   48篇
预防医学   10322篇
眼科学   1699篇
药学   7424篇
中国医学   416篇
肿瘤学   7522篇
  2024年   85篇
  2023年   954篇
  2022年   825篇
  2021年   3630篇
  2020年   2287篇
  2019年   3070篇
  2018年   3486篇
  2017年   2659篇
  2016年   3096篇
  2015年   3421篇
  2014年   4494篇
  2013年   5871篇
  2012年   8921篇
  2011年   9283篇
  2010年   5058篇
  2009年   4259篇
  2008年   7376篇
  2007年   7368篇
  2006年   6777篇
  2005年   6318篇
  2004年   5677篇
  2003年   5048篇
  2002年   4540篇
  2001年   539篇
  2000年   371篇
  1999年   584篇
  1998年   787篇
  1997年   642篇
  1996年   544篇
  1995年   450篇
  1994年   428篇
  1993年   349篇
  1992年   283篇
  1991年   191篇
  1990年   189篇
  1989年   177篇
  1988年   171篇
  1987年   140篇
  1986年   153篇
  1985年   110篇
  1984年   130篇
  1983年   124篇
  1982年   152篇
  1981年   111篇
  1980年   122篇
  1979年   71篇
  1978年   75篇
  1977年   67篇
  1976年   56篇
  1974年   52篇
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
41.
器官移植术是20世纪出现的针对器官功能衰竭的最有效治疗方法,每年拯救全球超过12万例患者。但供器官短缺的现状,与器官移植技术和辅助药物的发展不匹配,制约了器官移植事业的发展。我国自2015年起已成为全球器官捐献和移植大国之一,2017年公民逝世后器官捐献数量超过5 000例,占全球捐献总量的15%以上。黄洁夫教授总结的器官捐献与移植"中国模式"得到了世界卫生组织、国际移植界的高度重视和充分肯定。本文通过整理全球及各国的器官捐献与移植数据,剖析全球现状与发展趋势,进一步探索我国公民器官捐献的影响因素并提出针对性的应对策略,以期实现我国器官捐献和移植的"自给自足"。  相似文献   
42.
43.
44.
45.
46.
Serum thromboxane-B2 (TxB2), together with arachidonic acid (AA)-induced platelet aggregation, are, at the moment, the most used tests to identify patients displaying high on-aspirin treatment platelet reactivity (HAPR). Both tests are specific for aspirin action on cyclooxygenase-1. While the correlation between serum TxB2 assay and clinical outcome is established, data are conflicting with regard to aspirin treatment and a possible association with AA-stimulated platelet markers and clinical outcome. To understand such discrepancy, we performed a retrospective study to compare both assays. We collected data from 132 patients receiving a daily dose of aspirin (100?mg/day) and data from 48 patients receiving aspirin on alternate days. All Patients who received a daily dose of aspirin were studied for AA-induced platelet aggregation together with serum TxB2 levels and AA-induced TxB2 formation was also studied in 71 patients out of entire population. Consistent with recommendations in the literature, we defined HAPR by setting a cut-off point at 3.1?ng/ml for serum levels of thromboxane B2 and 20% for AA-induced platelet aggregation. According to this cut-off point, we divided our overall population into two groups: (1) TxB2?<?3.1?ng/ml and (2) TxB2?>?3.1?ng/ml. We found low agreement between such tests to identify patients displaying HAPR. Our results show that AA-induced platelet aggregation >20% identify a smaller number of HAPR patients in comparison with TxB2. A good correlation between serum TxB2 and arachidonic acid-induced TxB2 production was found (r?=?0.76619).  相似文献   
47.
Capillary malformation–arteriovenous malformation syndrome (CM‐AVM) is an autosomal dominant disorder caused by RASA1 mutations. The prevalence and phenotypic spectrum are unknown. Evaluation of patients with multiple CMs is challenging because associated AVMs can be life threatening. The objective of this study was to describe the clinical characteristics of children presenting with features of CM‐AVM to an academic pediatric dermatology practice. After institutional review board approval was received, a retrospective chart review was performed of patients presenting between 2009 and 2012 with features of CM‐AVM. We report nine cases. Presenting symptoms ranged from extensive vascular stains and cardiac failure to CMs noted incidentally during routine skin examination. All demonstrated multiple CMs, two had Parkes Weber syndrome, and two had multiple infantile hemangiomas. Seven patients had family histories of multiple CMs; three had family histories of large, atypical CMs. Six had personal or family histories of AVMs. Genetic evaluation was recommended for all and was pursued by six families; four RASA1 mutations were identified, including one de novo. Consultations with neurology, cardiology, and orthopedics were recommended. Most patients (89%) have not required treatment to date. CM‐AVM is an underrecognized condition with a wide clinical spectrum that often presents in childhood. Further evaluation may be indicated in patients with multiple CMs. This study is limited by its small and retrospective nature.  相似文献   
48.
49.
Purpose:This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration.Methods:Thirty Wistar rats (Rattus norvegicus albinos) were divided into five groups (according to the grafting material and time to euthanasia): (1) autograft - 14 days (control), (2) autograft - 28 days (control), (3) MSC + PRP - 14 days, (4) MSC + PRP + papaverine - 14 days and (5) MSC + PRP + papaverine - 28 days. After euthanasia, the graft was removed and histological slides were prepared. They were assessed by a blinded pathologist using a previously published histological scale as parameter.Results:There was some degree of neoformed bone trabeculae (NBT) in 93.3% of the samples, as well as osteoblastic activity (OA). The autograft groups (14 and 28 days) had higher levels in the formation of bone trabeculae. Nonparametric data were analyzed using the Wilcoxon-Mann-Whitney test and proved not to be statistically significant at p < 0.05.Conclusions:Experimental parietal bone reconstruction, combining MSC, PRP and papaverine presented regeneration in all groups with no significant difference among them.Key words: Bone Regeneration, Platelet-Rich Plasma, Tissue Engineering, Rats  相似文献   
50.
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