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   341555篇
  免费   32100篇
  国内免费   12807篇
耳鼻咽喉   2580篇
儿科学   6470篇
妇产科学   4351篇
基础医学   58918篇
口腔科学   6267篇
临床医学   23812篇
内科学   58256篇
皮肤病学   5354篇
神经病学   26578篇
特种医学   7279篇
外国民族医学   101篇
外科学   24540篇
综合类   46178篇
现状与发展   47篇
一般理论   6篇
预防医学   15777篇
眼科学   3786篇
药学   48944篇
  58篇
中国医学   13214篇
肿瘤学   33946篇
  2024年   287篇
  2023年   5555篇
  2022年   7314篇
  2021年   14523篇
  2020年   12740篇
  2019年   12531篇
  2018年   12005篇
  2017年   12012篇
  2016年   11976篇
  2015年   14177篇
  2014年   20861篇
  2013年   23274篇
  2012年   21075篇
  2011年   24684篇
  2010年   20809篇
  2009年   20509篇
  2008年   19550篇
  2007年   17733篇
  2006年   15990篇
  2005年   13728篇
  2004年   11684篇
  2003年   10104篇
  2002年   7950篇
  2001年   6686篇
  2000年   5563篇
  1999年   4838篇
  1998年   3810篇
  1997年   3638篇
  1996年   3154篇
  1995年   3184篇
  1994年   2847篇
  1993年   2419篇
  1992年   2036篇
  1991年   1858篇
  1990年   1554篇
  1989年   1279篇
  1988年   1174篇
  1987年   942篇
  1986年   911篇
  1985年   1535篇
  1984年   1548篇
  1983年   1073篇
  1982年   1143篇
  1981年   901篇
  1980年   759篇
  1979年   639篇
  1978年   472篇
  1977年   383篇
  1976年   345篇
  1975年   234篇
排序方式: 共有10000条查询结果,搜索用时 46 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.
Objective: Hepatocellular carcinoma (HCC) microenvironment has been recognized as a key contributor for cancer progression, metastasis, and drug resistance. The crosstalk between tumor cells, the vascular endothelial growth factor (VEGF), and the chemokine (C-C motif) ligand 2 (CCL2) signaling networks mediates immunoinhibitory impact and facilitates tumor angiogenesis. The current investigation aimed at exploring the potent anti-cancer activity of the newly designed nano-based anti-cancer therapy comprising anti-VEGF drug, avastin (AV), and CCR2 antagonist (CR) to counteract HCC and tracking its mode of action in vivo. Methods: The prepared AV, CR, and AVCR nanoprototypes were characterized by nanoscale characterization techniques in our previous work. Here, they are applied for unearthing their anti-cancer properties / mechanisms in hepatic cancer-induced rats via analyzing protein levels and genetic expression of the elements incorporated in the angiogenesis, apoptosis, and metastasis signalling pathways. Results: The present results revealed a significant down-regulation in the angiogenesis, survival and metastasis indices along with up-regulation in the pro-apoptotic mediators upon treatment of hepatic cancer-bearing rats with the novel synthesized nanomaterials when compared with the untreated counterparts. We showed across HCC model that anti-VEGF in combination with CCR2 antagonism therapy leads to sensitization and enhanced tumor response over anti-VEGF or CCR2 antagonism monotherapy, particularly in its nanoscale formulation. Conclusion: The present approach provides new mechanistic insights into the powerful anti-hepatic cancer advantage of the novel nanoprototypes which is correlated with modulating critical signal transduction pathways implicated in tumor microenviroment such as angiogenesis, apoptosis and metastasis. This research work presents a substantial foundation for future studies focused on prohibiting cancer progression and recovery by targeting tumor microenviroment.  相似文献   
6.
Whether the underlying mutations are homozygous, heterozygous, or co-inherited with other hemoglobinopathies, sickle cell disease is known to afflict the kidneys, leading to the clinical entity known as sickle cell nephropathy (SCN). Although common, SCN remains diagnostically elusive. Conventional studies performed in the context of renal disorders often fail to detect early stage SCN. This makes the quest for early diagnosis and treatment more challenging, and it increases the burden of chronic kidney disease-related morbidity among patients. Novel diagnostic tools have been employed to overcome this limitation. In this study, we discuss various biomarkers of SCN, including those employed in clinical practice and others recently identified in experimental settings, such as markers of vascular injury, endothelial dysfunction, tubulo-glomerular damage, and oxidative stress. These include kidney injury molecule-1, monocyte chemoattractant protein-1, N-acetyl-B-D-glucosaminidase, ceruloplasmin, orosomucoid, nephrin, and cation channels, among others. Furthermore, we explore the potential of novel biomarkers for refining diagnostic and therapeutic approaches and describe some obstacles that still need to be overcome. We highlight the importance of a collaborative approach to standardize the use of promising new biomarkers. Finally, we outline the limitations of conventional markers of renal damage as extensions of the pathogenic process occurring at the level of the organ and its functional subunits, with a discussion of the expected pattern of clinical and biochemical progression among patients with SCN.  相似文献   
7.
8.
9.
Background & aimsTo determine the trends of self-reported non-adherence rates among adults taking Type 2 medicines (T2D) medicines between 2017 and 2019 and to identify the patterns for the frequently reported reasons for non-adherence in the United States.Methods & resultsData from the National Health and Wellness Survey, a self-administered, internet-based cross-sectional survey of US adults from 2017 to 2019 was used. Non-adherence was measured using the self-reported Medication Adherence Reasons Scale (MAR-Scale). Frequencies were used to identify the reasons for non-adherence for insulin and non-insulin therapies for T2D.Data were obtained from 2983 respondents in 2017, 5416 in 2018, and 5268 in 2019. Based on the MAR-Scale, the self-reported medication non-adherence rate was 25% in 2017, 21% in 2018, and 27% in 2019. The most common reason for non-adherence across all the three years was simple forgetfulness, yet patients reported the lowest mean number of days missing medication for that reason. Though less frequently reported, non-adherence lasted longer when patient did not know how to take their medicines, cost was a reason, or had concerns about the long term effects of the medicines.ConclusionsWith no significant improvement in adherence with T2D medicines over time, regardless of better awareness and extensive diabetes education, focus should be on individualized non-adherence reasons-based interventions.  相似文献   
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