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   191792篇
  免费   11910篇
  国内免费   1315篇
耳鼻咽喉   2056篇
儿科学   6098篇
妇产科学   4586篇
基础医学   26901篇
口腔科学   5921篇
临床医学   16542篇
内科学   42304篇
皮肤病学   4537篇
神经病学   18397篇
特种医学   5891篇
外国民族医学   24篇
外科学   21945篇
综合类   2022篇
一般理论   95篇
预防医学   15410篇
眼科学   3110篇
药学   14621篇
  3篇
中国医学   910篇
肿瘤学   13644篇
  2023年   1244篇
  2022年   1820篇
  2021年   5077篇
  2020年   3209篇
  2019年   4458篇
  2018年   5217篇
  2017年   3988篇
  2016年   4476篇
  2015年   5036篇
  2014年   6647篇
  2013年   9096篇
  2012年   13136篇
  2011年   13687篇
  2010年   7966篇
  2009年   6796篇
  2008年   11292篇
  2007年   11472篇
  2006年   10712篇
  2005年   10090篇
  2004年   9766篇
  2003年   9052篇
  2002年   8616篇
  2001年   4176篇
  2000年   3979篇
  1999年   3468篇
  1998年   1844篇
  1997年   1473篇
  1996年   1311篇
  1995年   1191篇
  1994年   1082篇
  1993年   991篇
  1992年   2030篇
  1991年   1926篇
  1990年   1653篇
  1989年   1593篇
  1988年   1473篇
  1987年   1301篇
  1986年   1306篇
  1985年   1132篇
  1984年   885篇
  1983年   816篇
  1982年   592篇
  1981年   491篇
  1980年   469篇
  1979年   632篇
  1978年   479篇
  1975年   469篇
  1974年   527篇
  1973年   486篇
  1972年   446篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
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   
63.
Although hepatitis E virus (HEV) is the primary cause of enterically transmitted acute hepatitis and jaundice in developing countries, locally acquired HEV infections are increasing in nonendemic countries. As such, HEV is emerging as an underdiagnosed cause of infection. This report describes three clinically variable cases of HEV infection with unusual clinical presentations. These cases highlight the fact that HEV should be considered in the differential diagnosis of patients with unexplained hepatitis (acute or chronic) with or without extrahepatic manifestations. HEV should also be considered in patients with persistently elevated liver enzymes who have not travelled to known HEV-endemic regions. Lack of knowledge among physicians and an absence of standardized diagnostic tests may result in increased morbidity and mortality from HEV infection.  相似文献   
64.
65.
66.
Eosinophilic dermatosis of hematological malignancy is a paraneoplastic skin eruption associated with chronic lymphocytic leukemia and other B‐cell malignancies. It clinically resembles an insect bite reaction and it can precede the symptoms of the hematological malignancy or be related to a more aggressive course. Different treatments have been proposed, but partial response and recurrence are frequent. Herein, we describe a case of eosinophilic dermatosis associated with mantle cell lymphoma with remission after lenalidomide therapy.  相似文献   
67.
68.
Platelet α-granules release growth factors (GFs) that promote healing and tissue regeneration. Platelet-rich plasma (PRP) is shown to be beneficial in treating alopecia, and however, clinical response can be inconsistent. Due to several fold enrichment of platelets secreting large quantities of GFs following PRP injections, heterogeneity in amounts of GFs secreted by platelets may contribute to inconsistent clinical responses. Herein, we evaluated factors that could potentially contribute to heterogeneous secretion of GFs by platelets. We measured platelet secretion of transforming growth factor beta1 (TGFβ1), platelet-derived growth factor (PDGF-BB), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF2) in aliquots of de-identified PRP samples from female patients undergoing therapy in the hair disease clinic. Although secretion of GFs by platelets was comparable in PRP samples of patients with non-cicatricial and cicatricial alopecia, a Shapiro-Wilk test for normal distribution indicated significant variability across all patient samples. The amount of GF secreted by platelets was comparable when PRP prepared from two FDA-cleared devices with distinct techniques were compared. We provide evidence of platelets secreting heterogeneous amounts of GFs within each sample as high and low secretion of random factors could be simultaneously detected. These results suggest inherent heterogeneity in secretion of GFs by platelets in patient samples that are not influenced by the device used to prepare PRP. Since some GFs could have antagonistic effects on hair growth, a balance between amounts of growth promoting and inhibiting factors may be crucial in determining clinical response to PRP therapy.  相似文献   
69.
70.
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