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   100706篇
  免费   10158篇
  国内免费   3064篇
耳鼻咽喉   820篇
儿科学   1160篇
妇产科学   971篇
基础医学   12002篇
口腔科学   3653篇
临床医学   10518篇
内科学   10097篇
皮肤病学   1289篇
神经病学   6479篇
特种医学   3152篇
外国民族医学   11篇
外科学   6968篇
综合类   14951篇
现状与发展   8篇
一般理论   3篇
预防医学   16568篇
眼科学   1188篇
药学   13725篇
  112篇
中国医学   5754篇
肿瘤学   4499篇
  2024年   281篇
  2023年   1767篇
  2022年   2935篇
  2021年   4958篇
  2020年   4722篇
  2019年   4102篇
  2018年   3731篇
  2017年   4026篇
  2016年   4075篇
  2015年   4015篇
  2014年   7047篇
  2013年   7582篇
  2012年   6792篇
  2011年   7124篇
  2010年   5335篇
  2009年   4964篇
  2008年   4732篇
  2007年   4718篇
  2006年   4028篇
  2005年   3526篇
  2004年   2918篇
  2003年   2675篇
  2002年   2080篇
  2001年   1975篇
  2000年   1549篇
  1999年   1350篇
  1998年   1292篇
  1997年   1168篇
  1996年   1011篇
  1995年   913篇
  1994年   880篇
  1993年   678篇
  1992年   645篇
  1991年   543篇
  1990年   467篇
  1989年   479篇
  1988年   413篇
  1987年   363篇
  1986年   284篇
  1985年   374篇
  1984年   289篇
  1983年   174篇
  1982年   199篇
  1981年   154篇
  1980年   154篇
  1979年   114篇
  1978年   76篇
  1977年   51篇
  1976年   72篇
  1974年   41篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
101.
Postoperative complications(PC) are a basic health outcome, but no surgery service in the world records and/or audits the PC associated with all the surgical procedures it performs. Most studies that have assessed the cost of PC suffer from poor quality and a lack of transparency and consistency. The payment system in place often rewards the volume of services provided rather than the quality of patients' clinical outcomes. Without a thorough registration of PC, the economic costs involved cannot be determined. An accurate, reliable appraisal would help identify areas for investment in order to reduce the incidence of PC,improve surgical results, and bring down the economic costs. This article describes how to quantify and classify PC using the Clavien-Dindo classification and the comprehensive complication index, discusses the perspectives from which economic evaluations are performed and the minimum postoperative follow-up established, and makes various recommendations. The availability of accurate and impartially audited data on PC will help reduce their incidence and bring down costs. Patients, the health authorities, and society as a whole are sure to benefit.  相似文献   
102.
《Vaccine》2020,38(39):6141-6152
Influenza vaccination is considered the most valuable means to prevent and control seasonal influenza infections, which causes various clinical symptoms, ranging from mild cough and fever to even death. Among various influenza vaccine types, the inactivated subunit type is known to provide improved safety with reduced reactogenicity. However, there are some drawbacks associated with inactivated subunit type vaccines, with the main ones being its low immunogenicity and the induction of Th2-biased immune responses. In this study, we investigated the role of a single-stranded RNA (ssRNA) derived from the intergenic region in the internal ribosome entry site of the Cricket paralysis virus as an adjuvant rather than the universal vaccine for a seasonal inactivated subunit influenza vaccine. The ssRNA adjuvant stimulated not only well-balanced cellular (indicated by IgG2a, IFN-γ, IL-2, and TNF-α) and humoral (indicated by IgG1 and IL-4) immune responses but also a mucosal immune response (indicated by IgA), a key protector against respiratory virus infections. It also increases the HI titer, the surrogate marker of influenza vaccine efficacy. Furthermore, ssRNA adjuvant confers cross-protective immune responses against heterologous influenza virus infection while promoting enhanced viral clearance. Moreover, ssRNA adjuvant increases the number of memory CD4+ and CD8+ T cells, which can be expected to induce long-term immune responses. Therefore, this ssRNA-adjuvanted seasonal inactivated subunit influenza vaccine might be the best influenza vaccine generating robust humoral and cellular immune responses and conferring cross-protective and long-term immunity.  相似文献   
103.
It is well known that a meta-analysis of randomized controlled trials aims to increase the power and precision of the estimated intervention effects. However, when a meta-analysis includes a limited number of patients and a small number of events, overestimation of intervention effect estimates may occur and could cause spurious results. Although many biases can cause the overestimation, random error may be the most common cause. Trial sequential analysis (TSA) can explore the independent effect of random error on intervention effect estimates in meta-analyses and protect meta-analyses against overestimation due to random error.  相似文献   
104.
Tranexamic acid (TXA) is an antifibrinolytic drug that reduces surgical blood loss and death due to bleeding after trauma and post‐partum haemorrhage. One key issue for treatment success is early administration. While usually given intravenously, oral and intramuscular use would be useful in specific circumstances. Therefore, an understanding of TXA pharmacokinetics when given via different routes is valuable. The aim of this study was to perform an individual participant data meta‐analysis of pharmacokinetic studies with TXA given to healthy volunteers via different routes. We searched the following databases: PubMed, Web of Science, Wiley Online Library, Elsevier Science Direct and J‐STAGE. Individual subject data were extracted when available, otherwise arithmetic means were used. A population pharmacokinetic model was developed using nonlinear mixed effect modelling. Seven studies were included in the analysis with data from 10 patients for the IV route, six patients for the IM route and 114 patients for the oral route. The pharmacokinetics was ascribed to a two‐compartment model, and the main covariate was allometrically scaled bodyweight. Oral and IM bioavailabilities were 46 and 105%, respectively. For a 70 kg bodyweight, the population estimates were 7.6 L/h for clearance, 17.9 L for the volume of the central compartment, 2.5 L/h for the diffusional clearance and 16.6 L for the peripheral volume of distribution. Larger well‐designed studies are needed to describe the pharmacokinetics of TXA when given IM or as an oral solution before these can be recommended as alternatives to IV.  相似文献   
105.
目的 探讨脑卒中后偏瘫肩痛患者生活质量的直接和间接影响因素,以期为临床症状管理提供参考信息。 方法 采用一般资料调查表、脑卒中后偏瘫肩痛症状评估表、简易疲乏量表、医院焦虑抑郁量表、Fugl-Meyer上肢功能评分量表和脑卒中生活质量专用量表对205例脑卒中后偏瘫肩痛患者进行调查。结果 偏瘫肩痛患者的生活质量总分为(144.48±27.69),整体处于中等水平。生活质量的主要影响因素是肩痛困扰、肩痛频度、肩外旋、疲乏程度和抑郁,可以解释总变异的63.3%。路径分析结果显示,疲乏程度、肩痛频度和肩痛困扰可直接影响患者的生活质量(β_(疲乏程度-生活质量)=-0.252,P<0.001;β_(肩痛频度-生活质量)=-0.147,P<0.001;β_(肩痛困扰-生活质量)=-0.317,P<0.001);疲乏程度和肩痛频度亦可通过肩痛困扰来间接影响患者的生活质量( β_(疲乏程度-肩痛困扰-生活质量)=-0.066,P<0.001;β_(肩痛频度-肩痛困扰-生活质量)=-0.064,P<0.001)。结论 临床上应同时关注脑卒中患者疲乏和偏瘫肩痛症状,关注抑郁和疲乏对症状体验的协同作用,提高医护人员症状管理的效率,从而提高脑卒中偏瘫肩痛患者的生活质量。  相似文献   
106.
目的探讨家庭逆境致精神病理症状结局的累积性与关键期效应,为预防与干预逆境伤害提供依据。方法2017年12月,采用方便抽样的方法选取安徽省阜阳地区2所农村学校的710名青少年。采用《童年期不良经历问卷》评估家庭逆境,《MacArthur健康与行为问卷》评价内化症状和外化症状。采用多元线性回归分析家庭逆境发生时间与数量和精神病理症状的关联。结果持续家庭逆境组与内化症状、外化症状增加均有相关性[β值(95%CI)分别为0.35(0.15~0.54),0.16(0.01~0.32)]。家庭逆境数量为2和≥3与内化症状[β值(95%CI)分别为0.20(0.04~0.36),0.42(0.24~0.60)]、外化症状[β值(95%CI)分别为0.14(0.01~0.26),0.23(0.09~0.37)]增加有关。在仅童年期家庭逆境中,家庭逆境数量为2和≥3的内化症状[β值(95%CI)分别为0.23(0.06~0.41),0.34(0.11~0.58)]、外化症状[β值(95%CI)分别为0.17(0.02~0.31),0.21(0.02~0.39)]的风险增高。在持续家庭逆境组中,逆境数量≥3与内化症状、外化症状相关[(β值(95%CI)分别为0.56(0.31~0.82),0.24(0.02~0.45)]。仅青春期家庭逆境与精神病理症状无关。结论家庭逆境的多次发生可增加精神病理症状风险,童年期可能是家庭逆境致精神病理症状的关键期。  相似文献   
107.
目的:探讨骨伤科中成药的用药规律,为临床合理用药及新药开发提供参考。方法:以《中国药典》2015年版一部收载的骨伤科类中成药共149个为研究对象,运用频数分析的方法研究其主治病症、所用剂型、各类方剂高频药物、核心药物组成,分析骨伤科中成药用药规律。结果:常用骨伤科中成药中治疗骨关节痹症的最多,其次为跌打损伤和骨关节退行性疾病的中成药;剂型以胶囊剂、片剂、丸剂为主;以活血化瘀药、祛风湿药、补虚药为核心药物组合,各类方剂中三者比例偏重不同。结论:通过对研究结果进行分析,提出了新药研发的方向。  相似文献   
108.
BackgroundThe association of treatment volume and oncological outcome of rectal cancer patients undergoing multidisciplinary treatment is subject of an ongoing debate. Prospective data on long-term local control and overall survival (OS) are not available so far. This study investigated the long-term influence of hospital and surgeon volume on local recurrence (LR) and OS in patients with locally advanced rectal cancers.MethodsIn a post-hoc analysis of the randomized phase III CAO/ARO/AIO-94 trial after a follow-up of more than 10 years, 799 patients with stage II/III rectal cancers were evaluated. LR-rates and OS were stratified by hospital recruitment volume (≤20 vs. 21–90 vs. >90 patients) and by surgeon volume (≤10 vs. 11–50 vs. >50 procedures).ResultsPatients treated in high-volume hospitals had a longer OS than those treated in hospitals with medium or low treatment volume (p = 0.03). The surgeon volume was adversely associated with LR (p = 0.01) but had no influence on overall survival. The positive effect of neoadjuvant chemoradiation (CRT) on local control was the strongest in patients being operated by medium-volume surgeons, less in patients being operated by high-volume surgeons and missing in those being operated by low-volume surgeons.ConclusionsPatients with locally advanced rectal cancers might benefit from treatment in specialized high-volume hospitals. In particular, the surgeon volume had significant influence on long-term local tumour control. The effect of neoadjuvant CRT on local tumour control may likewise depend on the surgeon volume.  相似文献   
109.
目的探析经鼻高流量湿化氧疗用于小儿先心病术后治疗中的效果以及护理措施。方法2014年9月—2017年10月在郑州儿童医院外科监护室接受手术治疗的先心病患儿中随机抽取130例,根据术后氧疗方法不同分组:对照组患儿术后给予常规面罩吸氧,观察组患儿术后给予经鼻高流量湿化氧疗,2组患儿均给予优质术后护理,对比2组的血气指标、住院时间等。结果2组患者氧疗后24h、48h的血氧饱和度差异无统计学意义,在氧疗后24h的PaCO2水平差异无统计学意义,而在氧疗后24h和48h的氧合指数,观察组明显高于对照组,差异有统计学意义(P<0.05);2组ICU入住时间和总住院时间差异无统计学意义(P>0.05)。结论经鼻高流量湿化氧疗的应用提高先心病患儿术后的舒适度,改善呼吸状况,值得推广。  相似文献   
110.
ABSTRACT

Forensic DNA analysis is dependent on comparing the known and the unknown. Expand the number of known profiles, and the likelihood of a successful match increases. Forensic use of DNA is moving towards comparing samples of unknown origin with publicly available genetic data, such as the records held by genetic genealogy providers. Use of forensic genetic genealogy has yielded a number of recent high-profile successes but has raised ethical and privacy concerns. Navigating family trees is complex, even more so when combined with a comparison of genetic relationships. This intelligence-gathering process has led to occasional false leads, and its use also risks a public backlash, similar to concerns over Cambridge Analytica. A cautious approach to use of this technique is therefore warranted.  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