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   349709篇
  免费   31764篇
  国内免费   13676篇
耳鼻咽喉   3318篇
儿科学   8658篇
妇产科学   4739篇
基础医学   63239篇
口腔科学   8438篇
临床医学   24935篇
内科学   54726篇
皮肤病学   7239篇
神经病学   25104篇
特种医学   7591篇
外国民族医学   168篇
外科学   28360篇
综合类   48108篇
一般理论   6篇
预防医学   13659篇
眼科学   5472篇
药学   37260篇
  46篇
中国医学   11356篇
肿瘤学   42727篇
  2024年   213篇
  2023年   5067篇
  2022年   6399篇
  2021年   11711篇
  2020年   11781篇
  2019年   12170篇
  2018年   11904篇
  2017年   12365篇
  2016年   12100篇
  2015年   13882篇
  2014年   20811篇
  2013年   23352篇
  2012年   20917篇
  2011年   24536篇
  2010年   20747篇
  2009年   19830篇
  2008年   19761篇
  2007年   18816篇
  2006年   17117篇
  2005年   15059篇
  2004年   13316篇
  2003年   11416篇
  2002年   9150篇
  2001年   7847篇
  2000年   6522篇
  1999年   5632篇
  1998年   4499篇
  1997年   4304篇
  1996年   3639篇
  1995年   3736篇
  1994年   3280篇
  1993年   2749篇
  1992年   2300篇
  1991年   2109篇
  1990年   1685篇
  1989年   1503篇
  1988年   1367篇
  1987年   1088篇
  1986年   1045篇
  1985年   1604篇
  1984年   1546篇
  1983年   1077篇
  1982年   1159篇
  1981年   918篇
  1980年   766篇
  1979年   626篇
  1978年   471篇
  1977年   371篇
  1976年   315篇
  1975年   189篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.  相似文献   
2.
3.
4.
5.
Since their inception in the 1960s–70s, mesenchymal stem/stromal cells (MSCs) have gained interest because of their differentiation potential, anti-inflammatory effects, and immune-modulating properties. Both cell-based and cell-free MSC treatments show healing capacity in injured tissues. Cell-based treatment comprises MSCs and all secreted products, whereas cell-free treatments include only the secreted products. MSCs are therapeutically administered to many damaged organs owing to their efficacy. Specifically, the eye is a unique organ system to study the effects of MSCs, as treatment is easily applied and measured owing to its external location. The eye holds an immune-privileged status, wherein inflammation and immune responses are innately down-regulated. As excessive inflammation in the cornea often leads to fibrosis and irreversible corneal hazing, many studies have investigated the anti-inflammatory and immune-modulating capacities of MSCs. Decades of research suggest that MSCs modulate the immune response by secreting cytokines, growth factors, and extracellular matrix proteins that inhibit the infiltration of inflammatory cells following injury and promote a healing phenotype via M2 macrophage polarization. MSCs have also shown trans-differentiation potential into cornea-specific cell types during the wound healing process, such as corneal epithelial, stromal, or endothelial cells. This review discusses recent investigations of MSC treatment in the cornea, focusing on therapeutic efficacy, mechanisms, and future directions.  相似文献   
6.
7.
《Cancer cell》2022,40(11):1392-1406.e7
  1. Download : Download high-res image (241KB)
  2. Download : Download full-size image
  相似文献   
8.
BackgroundSurgical resection is recommended for patients with resectable acinar cell carcinoma (ACC). The aim of this study was to investigate the clinical characteristics and surgical outcomes of resectable ACC in comparison to pancreatic ductal adenocarcinoma (PDAC).MethodA retrospective analysis was performed on all patients who consecutively underwent radical resection with pathologically confirmed ACC and PDAC from December 2011 to December 2018. Clinicopathologic characteristics and follow-up information were analyzed. A 1:3 propensity score matching (PSM) method was used to minimize the bias between ACC and PDAC.ResultsA total of 26 patients with ACC and 1351 with PDAC were included. Compared to PDAC, ACC tended to be larger (4.5 vs. 3.0 cm; p < 0.001) and more frequently located in the pancreatic body/tail (61.5% vs. 36.6%, p = 0.009), with lower total bilirubin levels, lower neutrophil lymphocyte ratio (NLR) levels and lower carbohydrate antigen 19-9 (CA19-9) levels and carcinoembryonic antigen (CEA) levels. There was no difference in postoperative morbidities in patients with ACC and PDAC. The median OS and RFS were longer in ACC when compared to PDAC (OS: 43.5 mo vs. 19.0 mo, p = 0.004; RFS: 24.5 mo vs. 11.6 mo, p = 0.023). After the 1:3 PSM, ACC remained to be a better histological type for OS (p = 0.024), but had comparable RFS with PDAC (p = 0.164).ConclusionPatients with ACC after radical resection had better OS than that with PDAC. However, ACC is also an aggressive tumor with a similar trend of RFS with PDAC after the matching, necessitating the multidisciplinary treatment for resectable ACC disease.  相似文献   
9.
10.
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