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   2678篇
  免费   157篇
  国内免费   5篇
耳鼻咽喉   6篇
儿科学   64篇
妇产科学   80篇
基础医学   401篇
口腔科学   83篇
临床医学   193篇
内科学   578篇
皮肤病学   52篇
神经病学   229篇
特种医学   83篇
外科学   482篇
综合类   16篇
预防医学   88篇
眼科学   59篇
药学   166篇
中国医学   9篇
肿瘤学   251篇
  2023年   15篇
  2022年   28篇
  2021年   55篇
  2020年   40篇
  2019年   61篇
  2018年   68篇
  2017年   43篇
  2016年   46篇
  2015年   56篇
  2014年   90篇
  2013年   127篇
  2012年   156篇
  2011年   195篇
  2010年   92篇
  2009年   116篇
  2008年   155篇
  2007年   153篇
  2006年   155篇
  2005年   133篇
  2004年   147篇
  2003年   117篇
  2002年   124篇
  2001年   97篇
  2000年   63篇
  1999年   73篇
  1998年   19篇
  1997年   19篇
  1996年   18篇
  1995年   20篇
  1994年   20篇
  1993年   11篇
  1992年   36篇
  1991年   23篇
  1990年   40篇
  1989年   41篇
  1988年   21篇
  1987年   24篇
  1986年   16篇
  1985年   18篇
  1984年   11篇
  1983年   6篇
  1982年   8篇
  1980年   6篇
  1977年   5篇
  1976年   5篇
  1974年   8篇
  1973年   6篇
  1970年   8篇
  1967年   5篇
  1966年   5篇
排序方式: 共有2840条查询结果,搜索用时 15 毫秒
101.
Type 2 diabetes mellitus(T2DM) is a lifelong condition and a grave threat to human health. Innovative efforts to relieve its detrimental effects are acutely needed. The sine qua non in T2DM management is consistent adherence to a prudent lifestyle and nutrition, combined with aerobic and resistance exercise regimens, together repeatedly shown to lead to complete reversal and even longterm remission. Non-adherence to the above lifestyle adjustments condemns any treatment effort and ultimately the...  相似文献   
102.
Cognitive and cerebrovascular deficits are 2 landmarks of Alzheimer's disease (AD) to target for effective therapy. Here, we evaluated the efficacy of simvastatin in bitransgenic A/T mice overexpressing a mutated form of the human amyloid precursor protein (APPSwe,Ind) and a constitutively active form of transforming growth factor-β1. These mice feature the AD amyloid beta (Aβ) and cerebrovascular pathology. Simvastatin significantly decreased insoluble Aβ peptide levels and Aβ plaque load despite no effect on β-site amyloid precursor protein-cleaving enzyme and Aβ-degrading enzyme neprilysin protein levels. However, simvastatin failed to improve spatial learning and memory deficits and the decreased baseline levels of the memory-related protein early growth response-1 (Egr-1) in the hippocampus CA1 area. The impaired hyperemic response to whisker stimulation in A/T mice was not improved with treatment, but simvastatin fully restored constitutive nitric oxide synthesis in vessel walls and exacerbated agonist-mediated dilatory deficits. These findings point to the efficacy of simvastatin on selective AD features in a complex model of the disease, likely reflecting the challenges faced by recent clinical trials in assessing statin efficacy.  相似文献   
103.
Clinical indications for allergen immunotherapy (AIT) in respiratory and Hymenoptera venom allergy are well established; however, clinical contraindications to AIT are not always well documented. There are some discrepancies when classifying clinical contraindications for different forms of AIT as ‘absolute’ or ‘relative’. EAACI Task Force on ‘Contraindications to AIT’ was created to evaluate and review current literature on clinical contraindications, and to update recommendations for both sublingual and subcutaneous AIT for respiratory and venom immunotherapy. An extensive review of the literature was performed on the use of AIT in asthma, autoimmune disorders, malignant neoplasias, cardiovascular diseases, acquired immunodeficiencies and other chronic diseases (including mental disorders), in patients treated with β‐blockers, ACE inhibitors or monoamine oxidase inhibitors, in children under 5 years of age, during pregnancy and in patients with poor compliance. Each topic was addressed by the following three questions: (1) Are there any negative effects of AIT on this concomitant condition/disease? (2) Are more frequent or more severe AIT‐related side‐effects expected? and (3) Is AIT expected to be less efficacious? The evidence, for the evaluation of these clinical conditions as contraindications, was limited, and most of the conclusions were based on case reports. Based on an extended literature research, recommendations for each medical condition assessed are provided. The final decision on the administration of AIT should be based on individual evaluation of any medical condition and a risk/benefit assessment for each patient.  相似文献   
104.
While Ayurvedic medicine has touted the cognitive enhancing effects of Bacopa monniera for centuries, there is a need for double-blind placebo-controlled investigations. One hundred and seven healthy participants were recruited for this double-blind placebo-controlled independent group design investigation. Sixty-two participants completed the study with 80% treatment compliance. Neuropsychological testing using the Cognitive Drug Research cognitive assessment system was conducted at baseline and after 90 days of treatment with a special extract of Bacopa monniera (2 x 150 mg KeenMind) or placebo. The Bacopa monniera product significantly improved performance on the 'Working Memory' factor, more specifically spatial working memory accuracy. The number of false-positives recorded in the Rapid visual information processing task was also reduced for the Bacopa monniera group following the treatment period. The current study provides support for the two other published studies reporting cognitive enhancing effects in healthy humans after a 90 day administration of the Bacopa monniera extract. Further studies are required to ascertain the effective dosage range, the time required to attain therapeutic levels and the effects over a longer term of administration.  相似文献   
105.
Conventional treatment of an infected aortobifemoral graft includes total graft excision and ex situ bypass grafting, but has been associated with significant perioperative morbidity and mortality. Additionally, the presence of infection in the groin makes limb revascularization problematic. There is increasing evidence that in situ replacement of an infected graft can achieve promising results in selected patients. We present a case of an aortobifemoral graft infection, affecting both the groin as well as the entire pelvis. The patient underwent successful in situ graft replacement with a new aortobipopliteal prosthesis via an alternative extraperitoneal route.  相似文献   
106.
高位腰椎间盘突出症   总被引:2,自引:0,他引:2  
目的:通过147例高位腰椎间盘突出症的回顾性研究,旨在提高对本症的认识,减少漏诊,误诊,方法:回顾性分析报告147例高位腰椎间盘突出,结果:治疗腰1,210例,腰2。3 32例,腰3,4 105例,其中双间隙突出34例,跳跃性突出27例,伴椎管狭窄31例。瘫痪3例,非手术治疗34例,手术113例,优47例,良8例,差92例,重点讨论了高位腰椎及椎间盘和神经根的解剖特点和临床三大特征及诊断治疗,提出对不同程度的病人用不同治疗方式以及手术中需要注意的六个问题。  相似文献   
107.
Background Rhinoviruses (RVs) are responsible for the majority of acute asthma and chronic obstructive pulmonary disease (COPD) exacerbations. RVs infect the lower airways and induce the production of pro-inflammatory and remodelling-associated mediators. Budesonide (BUD) and formoterol (FORM) synergize in controlling asthma and COPD exacerbations; however, their effects on virus-induced inflammation and remodelling are less known.
Objective We investigated whether BUD and FORM synergize in suppressing RV-induced inflammation and remodelling in the airways.
Methods In vitro models of RV infection of BEAS-2B and primary normal human bronchial epithelial (NHBE) cells were used. We assessed the effects of individual and combined drugs administered post-infection, at a clinically relevant concentration range (10−6–10−10  m ), on the production of CCL5, CXCL10, CXCL8, IL-6 and the remodelling-associated VEGF and bFGF, using ELISA and RT-PCR.
Results BUD effectively suppressed RV-mediated induction of all mediators studied, in a concentration-dependent manner. FORM alone suppressed the production of CXCL8 and bFGF. The combination of BUD and FORM had concentration-dependent, additive or synergistic effects in the suppression of RV-induced CCL5, CXCL8 and CXCL10 in both cell types as well as VEGF in NHBE only. Combination treatment also resulted in an enhanced suppression of RV-induced IL-6, and CCL5 at the mRNA level as compared with BUD or FORM alone.
Conclusion BUD and FORM suppress RV-induced chemokines and growth factors in bronchial epithelial cells in a concentration-dependent, synergistic or additive manner. These data further support the combined use of BUD and FORM in asthma and COPD and intensification of this therapy during exacerbations.  相似文献   
108.
This the case of a 63 year-old man with end-stage renal disease (on chronic hemodialysis), unstable angina and significantly impaired myocardial contractility with low left ventricular ejection fraction, who underwent off-pump one vessel coronary bypass surgery. Combined continuous levosimendan and norepinephrine infusion (at 0.07 μg/kg/min and 0.05 μg/kg/min respectively) started immediately after anesthesia induction and continued for 24 hours. The levosimendan/norepinephrine combination helped maintain an appropriate hemodynamic profile, thereby contributing to uneventful completion of surgery and postoperative hemodynamic stability. Although levosimendan is considered contraindicated in ESRD patients, this case report suggests that combined perioperative levosimendan/norepinephrine administration can be useful in carefully selected hemodialysis patients with impaired myocardial contractility and ongoing myocardial ischemia, who undergo off-pump myocardial revascularization surgery.  相似文献   
109.
110.
Percutaneous balloon valvuloplasty was performed in 16 children, 1 1/2 to 14 years old, with congenital pulmonary stenosis with teh use or trefoil balloons. These balloons, which consist of 3 identical angioplasty balloons, do not interrupt completely the blood flow during inflation. The size of the trefoil balloons used was 30 to 50% larger than the valve anulus. A obtain an effective pulmonary valvuloplasty in two patients with large valve anulus. The mean prevalvuloplasty systolic gradient fo 78.2 +/- 28.9 mmHg (range 40 to 140 mmHg) was reduced to 20.3 +/- 5.7 (range 10 to 30 mmHg) after valvuloplasty. No patient developed significant hypotension or bradycardia or other complications as a result of the procedure. The findings demonstrate that percutaneous balloon valvuloplasty with oversized trefoil balloons effectively treated congenital pulmonary stenosis without complications in the cases studied. The use of large trefoil instead of single balloons of a similar diameter is advantageous since they cause no significant compromise of the cardiac output during valvuloplasty.  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