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   48984篇
  免费   4098篇
  国内免费   914篇
耳鼻咽喉   277篇
儿科学   1312篇
妇产科学   479篇
基础医学   1996篇
口腔科学   211篇
临床医学   8750篇
内科学   17974篇
皮肤病学   261篇
神经病学   1989篇
特种医学   1380篇
外国民族医学   2篇
外科学   6899篇
综合类   6157篇
一般理论   1篇
预防医学   1322篇
眼科学   345篇
药学   2999篇
  21篇
中国医学   1233篇
肿瘤学   388篇
  2024年   19篇
  2023年   996篇
  2022年   1201篇
  2021年   2216篇
  2020年   2306篇
  2019年   2267篇
  2018年   2084篇
  2017年   1722篇
  2016年   1517篇
  2015年   1676篇
  2014年   3477篇
  2013年   3239篇
  2012年   2348篇
  2011年   2726篇
  2010年   2230篇
  2009年   2239篇
  2008年   2317篇
  2007年   2317篇
  2006年   2089篇
  2005年   1900篇
  2004年   1496篇
  2003年   1345篇
  2002年   1078篇
  2001年   1078篇
  2000年   845篇
  1999年   835篇
  1998年   651篇
  1997年   685篇
  1996年   549篇
  1995年   493篇
  1994年   487篇
  1993年   402篇
  1992年   396篇
  1991年   368篇
  1990年   312篇
  1989年   234篇
  1988年   237篇
  1987年   213篇
  1986年   216篇
  1985年   191篇
  1984年   214篇
  1983年   158篇
  1982年   152篇
  1981年   112篇
  1980年   107篇
  1979年   74篇
  1978年   61篇
  1977年   32篇
  1976年   30篇
  1973年   18篇
排序方式: 共有10000条查询结果,搜索用时 31 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.
目的 探讨事件相关电位P300在颅脑损伤患者认知功能障碍评定中的应用价值。方法 选取2021年1月-9月在绵阳市第三人民医院神经外科保守治疗、并符合诊断标准的颅脑损伤患者36例作为研究组,同期在医院其他患者家属和护工中招募健康对照组共36名。采用Oddball范式对受试者进行事件相关电位P300检测,采用蒙特利尔认知评估量表(MoCA)和简易精神状态评价量表(MMSE)评定受试者的认知功能。比较两组P300的潜伏期、波幅以及MoCA和MMSE评分,比较P300潜伏期、MoCA和MMSE对颅脑损伤患者认知功能障碍的检出率。结果 研究组MoCA和MMSE评分均低于对照组[(18.08±4.29)分vs.(27.36±1.20)分,(22.53±3.54)分vs.(28.11±1.09)分,t=-12.510、-9.041,P均<0.05];研究组P300潜伏期高于对照组[(406.08±26.95)ms vs.(367.08±22.50)ms,t=6.665,P<0.05],波幅低于对照组[(7.76±0.90)μV vs.(9.87±0.99)μV,t=-9.459,P<0.05]。在研究组中,P300潜伏期阳性检出率和MoCA对认知功能障碍的检出率均高于MMSE对认知功能障碍的检出率(χ2=5.675、7.604,P均<0.05)。结论 事件相关电位P300或许可作为评估颅脑损伤患者认知功能障碍的客观临床指标。  相似文献   
3.
目的:通过对接受腹腔镜直肠癌根治(total mesorectal excision,TME)手术患者的术后随访,探究保留左半结肠血管对术后便秘及相关并发症的影响。方法:我院普外科2015年05月至2017年05月共收治的93例直肠肠癌根治手术患者进行回顾性分析。结果:对于病人的年龄、性别、BMI、术前CEA、术中出血量、吻合口瘘、术后肿瘤复发率,是否保留左半结肠血管方面无差异(P>0.05)。低位结扎组在术后肠道功能恢复、吻合口炎症以及术后便秘发生率中明显优于高位结扎组(P<0.05);高位结扎组在手术时间上优于低位结扎组(P<0.05)。结论:保留左半结肠的TME手术可以完成同样的淋巴结清扫,虽然术中用时较长但一定程度上保护了肠道的血运及神经,降低了术后便秘的发生率,值得临床进一步研究与推广。  相似文献   
4.
5.
肾功能异常指多种原因,包括肾脏疾病或非肾脏疾病引起的血肌酐和尿素氮升高,伴或不伴水肿、电解质紊乱、高血压等多系统、脏器累及症状。儿科临床上很大一部分患者以肾功能异常为首发表现。笔者就儿童肾功能异常的诊断思路进行综述,提出儿童肾功能异常的诊断应该遵循病程和肾功能分期、定位、定因、并发症评估的程序,其中特别建议无论急性或慢性肾功能异常,肾功能分级均采用目前慢性肾脏病的国际分级标准,病因方面儿童肾功能异常仍以遗传性疾病最为常见。先天性肾脏和尿路畸形只是一种形态学诊断,其病因也可能仍以遗传因素为主。  相似文献   
6.
The coronavirus disease 2019 (COVID-19) pandemic continues to be a global problem with over 438 million cases reported so far. Although it mostly affects the respiratory system, the involvement of extrapulmonary organs, including the liver, is not uncommon. Since the beginning of the pandemic, metabolic com-orbidities, such as obesity, diabetes, hypertension, and dyslipidemia, have been identified as poor prognostic indicators. Subsequent metabolic and lipidomic studies have identified several metabolic dysfunctions in patients with COVID-19. The metabolic alterations appear to be linked to the course of the disease and inflammatory reaction in the body. The liver is an important organ with high metabolic activity, and a significant proportion of COVID-19 patients have metabolic comorbidities; thus, this factor could play a key role in orchestrating systemic metabolic changes during infection. Evidence suggests that metabolic dysregulation in COVID-19 has both short- and long-term metabolic implications. Furthermore, COVID-19 has adverse associations with metabolic-associated fatty liver disease. Due to the ensuing effects on the renin-angiotensin-aldosterone system and ammonia metabolism, COVID-19 can have significant implications in patients with advanced chronic liver disease. A thorough understanding of COVID-19-associated metabolic dysfunction could lead to the identification of important plasma biomarkers and novel treatment targets. In this review, we discuss the current understanding of metabolic dysfunction in COVID-19, focusing on the liver and exploring the underlying mechanistic pathogenesis and clinical implications.  相似文献   
7.
AimThis review aims to summarize and discuss some of the most relevant clinical trials in epidemiology, diagnostics, and treatment of hypertension published in 2020 and 2021.Data synthesisThe trials included in this review are related to hypertension onset age and risk for future cardiovascular disease, reliability of different blood pressure monitoring methods, role of exercise-induced hypertension, treatment of hypertension in patients with SARS-CoV-2 infection, management of hypertension high-risk patient groups, e.g., in the elderly (≥80 years) and patients with atrial fibrillation, and the interplay between nutrition and hypertension, as well as recent insights into renal denervation for treatment of hypertension.ConclusionsHypertension onset age, nighttime blood pressure levels and a riser pattern are relevant for the prognosis of future cardiovascular diseases. The risk of coronary heart disease appears to increase linearly with increasing exercise systolic blood pressure. Renin-angiotensin system blockers are not associated with an increased risk for a severe course of COVID-19. In elderly patients, a risk-benefit assessment of intensified blood pressure control should be individually evaluated. A J-shaped association between cardiovascular disease and achieved blood pressure could also be demonstrated in patients with atrial fibrillation on anticoagulation. Salt restriction and lifestyle modification remain effective options in treating hypertensive patients at low cardiovascular risk. Sodium glucose co-transporter 2 inhibitors and Glucagon-like peptide-1 receptor agonists show BP-lowering effects. Renal denervation should be considered as an additional or alternative treatment option in selected patients with uncontrolled hypertension.  相似文献   
8.
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