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   16920篇
  免费   1390篇
  国内免费   391篇
耳鼻咽喉   26篇
儿科学   250篇
妇产科学   387篇
基础医学   1277篇
口腔科学   226篇
临床医学   2437篇
内科学   5289篇
皮肤病学   123篇
神经病学   620篇
特种医学   469篇
外科学   1586篇
综合类   1625篇
现状与发展   4篇
预防医学   2039篇
眼科学   93篇
药学   1670篇
  12篇
中国医学   381篇
肿瘤学   187篇
  2024年   27篇
  2023年   494篇
  2022年   571篇
  2021年   1266篇
  2020年   1121篇
  2019年   1080篇
  2018年   967篇
  2017年   658篇
  2016年   573篇
  2015年   622篇
  2014年   1162篇
  2013年   1620篇
  2012年   843篇
  2011年   948篇
  2010年   718篇
  2009年   632篇
  2008年   674篇
  2007年   651篇
  2006年   570篇
  2005年   469篇
  2004年   413篇
  2003年   336篇
  2002年   289篇
  2001年   263篇
  2000年   198篇
  1999年   180篇
  1998年   130篇
  1997年   145篇
  1996年   110篇
  1995年   84篇
  1994年   94篇
  1993年   78篇
  1992年   93篇
  1991年   80篇
  1990年   52篇
  1989年   51篇
  1988年   54篇
  1987年   38篇
  1986年   45篇
  1985年   66篇
  1984年   50篇
  1983年   36篇
  1982年   31篇
  1981年   12篇
  1980年   29篇
  1979年   16篇
  1978年   17篇
  1977年   15篇
  1976年   9篇
  1974年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
《Australian critical care》2019,32(6):540-559
ObjectivesThe objective of this review was to describe cardiovascular risk (CVR) assessment methods and to identify evidence-based practice recommendations when dealing with population at risk of developing cardiovascular diseases.Review methods and data sourcesA literature review following the Arksey and O'Malley scoping review methodology was conducted. By using appropriate key terms, literature searches were conducted in PubMed, SciELO, Cochrane Library, Dialnet, ENFISPO, Medigraphic, ScienceDirect, Cuiden, and Lilacs databases. A complementary search on websites related to the area of interest was conducted. Articles published in English or Spanish in peer-review journals between 2010 and 2017. Critical appraisal for methodological quality was conducted. Data was extracted using ad-hoc tables and qualitatively synthesized.ResultsAfter eliminating duplicates, 55 325 records remained, and 1432 records were selected for screening. Out of these, 88 full-text articles were selected for eligibility criteria, and finally, 67 studies were selected for this review, and 25 studies were selected for evidence synthesis. In total, 23 CVR assessment tools have been identified, pioneered by the Framingham study. Qualitative findings were grouped into four thematic areas: assessment tools and scores, CVR indicators, comparative models, and evidence-based recommendations.ConclusionsIt is necessary to adapt the instruments to the epidemiological reality of the population. The most appropriate way to estimate CVR is to choose the assessment tool that best suits individual conditions, accompanied by a comprehensive assessment of the patient. More research is required to determine a single, adequate, and reliable tool.  相似文献   
3.
目的探讨妊娠合并右心感染性心内膜炎的临床特征、处理策略和母婴结局,为疾病的诊断和治疗提供理论依据。方法在中国知网、万方数据库、维普网、中国生物医学文献服务系统、PubMed、OVID、EMbase、ScienceDirect数据库检索相关文献,提取临床资料,分析妊娠合并右心感染性心内膜炎的临床表现、危险因素、赘生物位置、血培养结果、治疗策略和母婴结局等。结果纳入15篇文献,共18例患者。患者年龄为(27.7±4.8)岁,发病孕周为(27.8±6.9)周。发热(14例)、咳嗽(12例)、贫血(8例)、气短或呼吸困难(8例)是最常见的症状。心脏听诊时7例可闻及杂音,其中6例为收缩期杂音,1例未明确杂音类型,5例明确心脏听诊无杂音。9例合并肺栓塞和5例合并心力衰竭。危险因素主要为先天性心脏病(10/18)和静脉药瘾史(6/18)。赘生物附着位置以三尖瓣居多(10/18),其次为肺动脉瓣(4/18)。血培养阳性率高(15/16),主要包括葡萄球菌(9/15)及链球菌(3/15)。处理策略上,多以剖宫产适时终止妊娠,针对心内膜炎方面,在应用足量足疗程抗生素的基础上,11例患者行心脏手术,术式主要包括赘生物清除术、瓣膜修复或置换术以及先天性心脏病的手术等,根据患者的孕周、病情和心肺功能等具体情况决定手术在终止妊娠之前、之后或同期进行。18例患者全部存活,新生儿1例死亡(妊娠28周时行剖宫产分娩,因重度窒息死亡)。产妇随访情况基本良好。结论妊娠合并右心感染性心内膜炎临床少见且病情复杂,需及早诊断并实施个体化治疗方案。给予足量足疗程抗生素、选择合适的手术方案以及终止妊娠的时机,对于母婴结局具有重要意义。  相似文献   
4.
5.
Background/objectiveObstructive sleep apnea (OSA) is independently associated with dyslipidemia, a surrogate marker of atherosclerosis. Low-density lipoprotein (LDL)-cholesterol is accepted as a major independent risk factor for cardiovascular disease. However, non-high-density lipoprotein (HDL)-cholesterol is a better marker of atherogenic dyslipidemia and recommended as a target of lipid lowering therapy. We aimed to assess the prevalence of atherogenic dyslipidemia, and relationship between OSA severity and serum LDL-cholesterol and non-HDL cholesterol levels in OSA patients.MethodsWe retrospectively evaluated treatment naïve 2361 subjects admitted to the sleep laboratory of a university hospital for polysomnography. All subjects’ lipid profile including total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and non-HDL-cholesterol were measured.ResultsOut of 2361 patients (mean age 49.6 ± 11.9 years; 68.9% male, apnea-hypopnea index 36.6 ± 28.4/h), 185 (7.8%) had no OSA and 2176 (92.2%) had OSA. Atherogenic dyslipidemia prevalence was high (57–66%) in OSA patients, and especially increased in severe OSA compared to other groups (p < 0.05). Though total and LDL-cholesterol did not differ between those with and without OSA, non-HDL-cholesterol (p = 0.020), and triglycerides (p = 0.001) were higher and HDL-cholesterol levels (p = 0.018) were lower in OSA patients than non-OSA. Non-HDL-cholesterol was significantly correlated with OSA severity (p < 0.001) and hypoxia parameters (p < 0.01), whereas LDL-cholesterol showed no correlation.ConclusionsAtherogenic dyslipidemia is highly prevalent and non-HDL-cholesterol levels are significantly increased, predominantly in severe OSA patients. Non-HDL-cholesterol but not LDL-cholesterol, is significantly correlated with OSA severity and hypoxia parameters. Therefore, it could be better to use non-HDL-cholesterol, which is a guideline recommended target of lipid therapy, as a marker of atherosclerotic cardiovascular risk in OSA patients.  相似文献   
6.

Background

The optimal noninvasive test (NIT) for patients with diabetes and stable symptoms of coronary artery disease (CAD) is unknown.

Objectives

The purpose of this study was to assess whether a diagnostic strategy based on coronary computed tomographic angiography (CTA) is superior to functional stress testing in reducing adverse cardiovascular (CV) outcomes (CV death or myocardial infarction [MI]) among symptomatic patients with diabetes.

Methods

PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) was a randomized trial evaluating an initial strategy of CTA versus functional testing in stable outpatients with symptoms suggestive of CAD. The study compared CV outcomes in patients with diabetes (n = 1,908 [21%]) and without diabetes (n = 7,058 [79%]) based on their randomization to CTA or functional testing.

Results

Patients with diabetes (vs. without) were similar in age (median 61 years vs. 60 years) and sex (female 54% vs. 52%) but had a greater burden of CV comorbidities. Patients with diabetes who underwent CTA had a lower risk of CV death/MI compared with functional stress testing (CTA: 1.1% [10 of 936] vs. stress testing: 2.6% [25 of 972]; adjusted hazard ratio: 0.38; 95% confidence interval: 0.18 to 0.79; p = 0.01). There was no significant difference in nondiabetic patients (CTA: 1.4% [50 of 3,564] vs. stress testing: 1.3% [45 of 3,494]; adjusted hazard ratio: 1.03; 95% confidence interval: 0.69 to 1.54; p = 0.887; interaction term for diabetes p value = 0.02).

Conclusions

In diabetic patients presenting with stable chest pain, a CTA strategy resulted in fewer adverse CV outcomes than a functional testing strategy. CTA may be considered as the initial diagnostic strategy in this subgroup. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550)  相似文献   
7.
8.
9.
2019年12月始,新型冠状病毒肺炎(Corona Virus Disease 2019,COVID-19)以湖北武汉为中心向全国各地蔓延。目前数据显示,COVID-19合并糖尿病、高血压、肿瘤等基础病的患者病情较为严峻,病死率相对较高。该类患者的临床治疗策略有待进一步深入研究。在此次疫情防治过程中,中西医结合治疗手段于COVID-19的防治及患者基础疾病的兼顾治疗方面展现出了一定的特色及优势。本文结合中医“未病先防,既病防变,瘥后防复”思想,拟从COVID-19合并糖尿病、高血压、肿瘤三个方面,探讨COVID-19爆发形势下合并基础病患者的中医药防治策略。  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