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   2965篇
  免费   115篇
  国内免费   65篇
耳鼻咽喉   19篇
儿科学   62篇
妇产科学   23篇
基础医学   480篇
口腔科学   9篇
临床医学   217篇
内科学   465篇
皮肤病学   12篇
神经病学   408篇
特种医学   76篇
外科学   216篇
综合类   276篇
预防医学   80篇
眼科学   11篇
药学   686篇
  1篇
中国医学   61篇
肿瘤学   43篇
  2023年   16篇
  2022年   32篇
  2021年   43篇
  2020年   36篇
  2019年   40篇
  2018年   35篇
  2017年   49篇
  2016年   48篇
  2015年   65篇
  2014年   125篇
  2013年   121篇
  2012年   107篇
  2011年   149篇
  2010年   112篇
  2009年   116篇
  2008年   157篇
  2007年   147篇
  2006年   111篇
  2005年   122篇
  2004年   111篇
  2003年   104篇
  2002年   87篇
  2001年   82篇
  2000年   75篇
  1999年   66篇
  1998年   64篇
  1997年   73篇
  1996年   62篇
  1995年   80篇
  1994年   94篇
  1993年   51篇
  1992年   49篇
  1991年   41篇
  1990年   62篇
  1989年   52篇
  1988年   37篇
  1987年   47篇
  1986年   29篇
  1985年   39篇
  1984年   42篇
  1983年   17篇
  1982年   17篇
  1981年   13篇
  1980年   28篇
  1979年   18篇
  1978年   14篇
  1977年   14篇
  1975年   11篇
  1974年   9篇
  1971年   7篇
排序方式: 共有3145条查询结果,搜索用时 40 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.
PurposeEpidermal hyperplasia and the involvement of immune cells characterize the clinical picture of psoriasis. Among the several factors involved, attention has been focused on sirtuin 1 (SIRT1) - a deacetylase endowed with a variety of functions including the control of metabolic and inflammatory processes-, and on nicotinamide phosphoribosyltransferase (NAMPT), important for SIRT1 activation and involved in inflammatory events. The aim of the study was to analyze changes of SIRT1 and NAMPT expression in psoriatic skin.Patients and methodsSamples from healthy controls and psoriatic patients were subjected to immunohistochemical analysis.ResultsA strong downregulation of SIRT1 expression was observed in skin samples from psoriatic patients compared to healthy controls. This was accompanied by a parallel reduction of adenosine monophosphate-activated kinase (AMPK) expression and, more strikingly, by the disappearance of cells immunolabeled for its active, phosphorylated form (pAMPK). In both cases, analysis of the distribution of immunopositive cells revealed a shift towards reduced intensity of staining. In contrast, NAMPT expression was upregulated in psoriatic samples in line with its pro-inflammatory role. This was again more visible with an intensity-based distribution analysis that evidenced a shift towards more intensely immunostained cell populations.ConclusionsThe present data correlate in the same samples the expression of SIRT1, pAMPK/AMPK and NAMPT in psoriasis and open the way for novel pharmacological targets in the treatment of the disease.  相似文献   
3.
Background: Gait disorders are common in Parkinson’s disease patients who respond poorly to dopaminergic treatment. Blockade of adenosine A2A receptors is expected to improve gait disorders. Istradefylline is a first-in-class selective adenosine A2A receptor antagonist with benefits for motor complications associated with Parkinson’s disease.

Research design and methods: This multicenter, open-label, single-group, prospective interventional study evaluated changes in total gait-related scores of the Part II/III Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) and Freezing of Gait Questionnaire (FOG-Q) in 31 Parkinson’s disease patients treated with istradefylline. Gait analysis by portable gait rhythmogram was performed.

Results: MDS-UPDRS Part III gait-related total scores significantly decreased at Weeks 4–12 from baseline with significant improvements in gait, freezing of gait, and postural stability. Significant decreases in MDS-UPDRS Part II total scores and individual item scores at Week 12 indicated improved daily living activities. At Week 12, there were significant improvements in FOG-Q, new FOG-Q, and overall movement per 48 h measured by portable gait rhythmogram. Adverse events occurred in 7/31 patients.

Conclusions: Istradefylline improved gait disorders in Parkinson’s disease patients complicated with freezing of gait, improving their quality of life. No unexpected adverse drug reactions were identified.

Trial registration: UMIN-CTR (UMIN000020288).  相似文献   

4.
《Heart rhythm》2022,19(6):1015-1016
  1. Download : Download high-res image (179KB)
  2. Download : Download full-size image
  相似文献   
5.
Introduction: There are considerable interests in the development of novel small-molecule CD73 inhibitors for the treatment of cancers, autoimmune diseases, precancerous syndromes, and other diseases associated with CD73 activity.

Areas covered: The application claims novel substituted benzothiadiazine derivatives as CD73 inhibitors for the treatment of cancer, precancerous syndromes, AIDS, autoimmune diseases, infections, atherosclerosis, and ischemia-reperfusion injury. Many of the exemplified compounds have pIC50 values between 5 to 8.4 against CD73.

Expert Opinion: These benzothiadiazine derivatives provide good leads for the discovery of potent CD73 inhibitors for the treatment of cancer and other diseases mediated by adenosine and its action on adenosine receptors.  相似文献   

6.
摘要:目的 探究海参磷脂型二十碳五烯酸(EPA-PC)对非酒精性脂肪肝(non-alcoholic fatty liver disease, NAFLD)大鼠甘油三酯代谢的影响。方法 采用饮食中添加乳清酸的方法诱导建立NAFLD大鼠模型。雄性Wistar大鼠随机分为5组,分别为正常组、模型组、洛伐他汀对照组、EPA-PC高、低剂量组。饲喂3周后,检测大鼠肝脏及血清中总胆固醇(Total cholesterol,TC)及甘油三酯(Triglycerides,TG)含量;RT-PCR法检测大鼠肝脏中TG合成相关基因GPAT和DGAT,TG分解相关基因ATGL和HSL以及AMPK信号通路相关基因CAMKK和LKB1 mRNA的表达水平。结果 EPA-PC可以显著降低NAFLD大鼠血清和肝脏中TG和TC的含量,显著下调GPAT、DGAT和HSL的表达,显著上调ATGL和AMPK信号通路相关基因表达。结论 EPA-PC可以通过抑制TG合成,促进TG分解,并激活AMPK信号通路,从而改善NAFLD大鼠的TG的代谢。  相似文献   
7.
Heart involvement – often asymptomatic – is largely underestimated in patients with systemic autoimmune diseases (SADs). Cardiovascular events are more frequent in patients with SADs compared to the general population, owing to the consequences of inflammation and autoimmunity and to the high prevalence of traditional risk factors. Coronary microvascular disease (CMD) is a form of cardiac involvement that is increasingly recognised yet still largely neglected. CMD, the incapacity of the coronary microvascular tree to dilate when myocardial oxygen demand increases or when there is a microvascular spasm (or subclinical myocarditis), is increasingly reported because of the widespread use of new cardiac imaging tools, even in a subclinical phase. The assessment of myocardial coronary flow reserve (CFR) emerged as the most effective clinical tool to detect microvascular damage. The potential causes of microvascular damage, molecular and cellular inflammation along with a pathological CD39-CD73 axis, need always to be considered because data show that they play a role in the occurrence of acute coronary syndromes, heart failure and arrhythmias, even in the early asymptomatic stage. Data suggest that controlling disease activity by means of methotrexate, biologic drugs, antimalarial medications, statins and aspirin, according to indication, might reduce the cardiovascular risk related to macrovascular and microvascular damage in most patients with SADs, provided that they are used early and timely to control diseases. The need of new biomarkers and a careful assessment of myocardial CFR emerged as the most effective clinical tool to detect microvascular damage.  相似文献   
8.
9.
10.
Background: Kidney injury commonly occurs following hemorrhagic shock. This study aims to observe the effects of mesenteric lymph duct ligation (MLDL) on the adenosine triphosphate (ATP) levels and the cell membrane adenosine triphosphatase (ATPase) activity in the kidneys of rats subjected to hemorrhagic shock. Methods: Wistar rats were assigned into sham, shock, and ligation groups. The hemorrhagic shock model was established in the shock and ligation groups, and MLDL was performed in the ligation group after resuscitation. Renal homogenates were prepared to determine the ATP and ATPase levels at 90?min after hemorrhage and at 0, 1, 3, 6, 12, and 24?h after resuscitation. Results: The ATP levels, and the Na+–K+–ATPase, Mg2+–ATPase, Ca2+–ATPase, and Ca2+–Mg2+–ATPase activities in the renal tissue of the shock group were lower than those in the sham group at the multiple time points. Furthermore, the corresponding values in the ligation group were significantly higher than those in the shock group at multiple time points. Conclusion: MLDL improves energy metabolism and enhances the ATPase activity in the kidneys of hemorrhagic shock rats, along with other mechanisms that alleviate renal injury after hemorrhagic shock.  相似文献   
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