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   36077篇
  免费   3178篇
  国内免费   1706篇
耳鼻咽喉   376篇
儿科学   720篇
妇产科学   616篇
基础医学   3679篇
口腔科学   727篇
临床医学   4340篇
内科学   5899篇
皮肤病学   529篇
神经病学   1884篇
特种医学   1136篇
外国民族医学   10篇
外科学   2892篇
综合类   5639篇
现状与发展   10篇
一般理论   3篇
预防医学   3124篇
眼科学   1044篇
药学   3835篇
  23篇
中国医学   2152篇
肿瘤学   2323篇
  2024年   320篇
  2023年   556篇
  2022年   1065篇
  2021年   1480篇
  2020年   1155篇
  2019年   989篇
  2018年   1187篇
  2017年   1079篇
  2016年   1000篇
  2015年   1460篇
  2014年   1795篇
  2013年   1956篇
  2012年   2821篇
  2011年   2980篇
  2010年   2091篇
  2009年   1672篇
  2008年   2202篇
  2007年   2119篇
  2006年   1958篇
  2005年   1803篇
  2004年   1412篇
  2003年   1305篇
  2002年   1222篇
  2001年   951篇
  2000年   898篇
  1999年   696篇
  1998年   294篇
  1997年   282篇
  1996年   237篇
  1995年   226篇
  1994年   153篇
  1993年   117篇
  1992年   231篇
  1991年   194篇
  1990年   164篇
  1989年   159篇
  1988年   135篇
  1987年   110篇
  1986年   101篇
  1985年   67篇
  1984年   49篇
  1983年   30篇
  1982年   20篇
  1981年   16篇
  1980年   12篇
  1979年   15篇
  1977年   17篇
  1976年   11篇
  1974年   11篇
  1973年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
目的探讨脊髓损伤后短期内小鼠肠道功能的变化。方法将105只昆明种小鼠随机分为正常组(A组,n=30)、假手术组(B组,n=30)和模型组(C组,n=45)。A组不作处理,B组仅暴露脊髓,不夹持。C组采用动脉瘤夹夹持T10处脊髓,复制脊髓损伤模型。分别于术后12 h、24 h、48 h测定小鼠回肠肌电慢波及平滑肌收缩力,并做回肠HE染色。结果脊髓损伤后12 h、24h、48 h,C组小鼠肌电频率和振幅低于A组和B组(P0.05),收缩力振幅低于A组和B组(P0.05),但24 h、48 h后收缩力频率高于A组和B组(P0.05)。C组各时间点肠黏膜评分均较A组和B组高(P0.05)。结论小鼠脊髓损伤后早期,肠道平滑肌肌电活动减弱,收缩力减小,肠黏膜轻度损伤。  相似文献   
104.
105.
目的观察扶他林对心脏电除颤所致电灼伤的治疗效果及安全性。方法 2011年1月至2014年12月在我院就诊的因电除颤引起的皮肤电灼伤患者66例,按照不同的治疗方法随机分为硫酸镁湿敷组、扶他林治疗组,每组33例。硫酸镁组采用50%硫酸镁湿敷,3次/d,连续5~7 d;扶他林组在局部皮肤发红处涂抹薄层扶他林,3次/d,连续5~7 d。比较两组的治疗效果及安全性。结果硫酸镁湿敷组显效13例(39.4%),有效15例(45.6%),无效5例(15.0%);扶他林治疗组显效25例(75.8%),有效8例(24.2%),无效0例。扶他林治疗组疗效优于硫酸镁湿敷组,两组比较差异具有统计学意义(P<0.05)。两组均无药物不良反应发生。结论扶他林治疗心脏电除颤所致电灼伤的效果好于硫酸镁湿敷,且无明显的药物不良反应,是治疗心脏电除颤所致电灼伤的一种非常有效且安全的药物。  相似文献   
106.
107.
It is well known that maternal folate deficiency results in adverse pregnancy outcomes. In addition to aspects in embryonic development, maternal uterine receptivity and the decidualization of stromal cells is also very important for a successful pregnancy. In this study, we focused on endometrium decidualization and investigated whether apoptosis, which is essential for decidualization, was impaired. Flow cytometry and TUNEL detection revealed that apoptosis of mouse endometrium decidual cells was suppressed in the dietary folate-deficient group on Days 7 and 8 of pregnancy (Day 1 = vaginal plug) when decidua regression is initiated. The endometrium decidual tissue of the folate deficiency group expressed less Bax compared to the normal diet group while they had nearly equal expression of Bcl2 protein. Further examination revealed that the mitochondrial transmembrane potential (ΔΨm) decreased, and the fluorescence of diffuse cytoplasmic cytochrome c protein was detected using laser confocal microscopy in normal decidual cells. However, no corresponding changes were observed in the folate-deficient group. Western blotting analyses confirmed that more cytochrome c was released from mitochondria in normal decidual cells. Taken together, these results demonstrated that folate deficiency could inhibit apoptosis of decidual cells via the mitochondrial apoptosis pathway, thereby restraining decidualization of the endometrium and further impairing pregnancy.  相似文献   
108.

Background.

This open-label phase I dose-escalation study investigated the safety, efficacy, pharmacokinetics (PK), and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) effects of the oral angiokinase inhibitor nintedanib in patients with advanced solid tumors.

Methods.

Nintedanib was administered once daily continuously, starting at 100 mg and later amended to allow evaluation of 250 mg b.i.d. The primary endpoint was maximum tolerated dose (MTD). DCE-MRI studies were performed at baseline and on days 2 and 28.

Results.

Fifty-one patients received nintedanib 100–450 mg once daily (n = 40) or 250 mg b.i.d. (n = 11). Asymptomatic reversible liver enzyme elevations (grade 3) were dose limiting in 2 of 5 patients at 450 mg once daily. At 250 mg b.i.d., 2 of 11 patients experienced dose-limiting toxicity (grade 3 liver enzyme elevation and gastrointestinal symptoms). Common toxicities included fatigue, diarrhea, nausea, vomiting, and abdominal pain (mainly grade ≤2). Among 45 patients, 22 (49%) achieved stable disease; 7 remained on treatment for >6 months. DCE-MRI of target lesions revealed effects in some patients at 200 and ≥400 mg once daily.

Conclusion.

Nintedanib is well tolerated by patients with advanced solid malignancies, with MTD defined as 250 mg b.i.d., and can induce changes in DCE-MRI. Disease stabilization >6 months was observed in 7 of 51 patients.  相似文献   
109.
PTEN has been studied in several tumor models as a tumor suppressor. In this study, we explored the role of PTEN in the inhibition state of polarized M2 subtype of macrophage in tumor microenvironment (TME) and the underlying mechanisms. To elucidate the potential effect in TME, RAW 264.7 macrophages and 4T1 mouse breast cancer cells were co-cultured to reconstruct tumor microenvironment. After PTEN was down-regulated with shRNA, the expression of CCL2 and VEGF-A, which are definited to promote the formation of M2 macrophages, have a dramatically increase on the level of both gene and protein in co-cultured RAW 264.7 macrophages. And at the same time, NHERF-1 (Na+/H+ exchanger regulating factor-1), another tumor suppressor has a similar tendency to PTEN. Q-PCR and WB results suggested that PTEN and NHERF-1 were consistent with one another no matter at mRNA or protein level when exposed to the same stimulus. Coimmunoprecipitation and immunofluorescence techniques confirmed that PTEN and NHERF-1 were coprecipitated, and NHERF-1 protein expression was properly reduced with rCCL2 effect. In addition, cell immunofluorescence images revealed a profound transferance, in co-cultured RAW 264.7 macrophages, an up-regulation of NHERF-1 could promote the PTEN marked expression on the cell membrane, and this form for the interaction was not negligible. These observations illustrate PTEN with a certain synergy of NHERF-1, as well as down-regulation of CCL2 suppressing M2 macrophage transformation pathway. The results suggest that the activation of PTEN and NHERF-1 may impede the evolution of macrophages beyond the M1 into M2 phenotype in tumor microenvironment.  相似文献   
110.
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