全文获取类型
收费全文 | 12789篇 |
免费 | 850篇 |
国内免费 | 284篇 |
专业分类
耳鼻咽喉 | 104篇 |
儿科学 | 455篇 |
妇产科学 | 176篇 |
基础医学 | 1055篇 |
口腔科学 | 78篇 |
临床医学 | 917篇 |
内科学 | 2775篇 |
皮肤病学 | 110篇 |
神经病学 | 1000篇 |
特种医学 | 207篇 |
外科学 | 925篇 |
综合类 | 1614篇 |
预防医学 | 773篇 |
眼科学 | 127篇 |
药学 | 1078篇 |
3篇 | |
中国医学 | 2306篇 |
肿瘤学 | 220篇 |
出版年
2023年 | 181篇 |
2022年 | 369篇 |
2021年 | 581篇 |
2020年 | 402篇 |
2019年 | 387篇 |
2018年 | 362篇 |
2017年 | 357篇 |
2016年 | 376篇 |
2015年 | 408篇 |
2014年 | 852篇 |
2013年 | 1013篇 |
2012年 | 787篇 |
2011年 | 879篇 |
2010年 | 768篇 |
2009年 | 584篇 |
2008年 | 614篇 |
2007年 | 523篇 |
2006年 | 482篇 |
2005年 | 413篇 |
2004年 | 392篇 |
2003年 | 322篇 |
2002年 | 253篇 |
2001年 | 221篇 |
2000年 | 177篇 |
1999年 | 155篇 |
1998年 | 154篇 |
1997年 | 165篇 |
1996年 | 151篇 |
1995年 | 160篇 |
1994年 | 116篇 |
1993年 | 109篇 |
1992年 | 89篇 |
1991年 | 84篇 |
1990年 | 59篇 |
1989年 | 41篇 |
1988年 | 60篇 |
1987年 | 49篇 |
1986年 | 40篇 |
1985年 | 56篇 |
1984年 | 88篇 |
1983年 | 42篇 |
1982年 | 52篇 |
1981年 | 65篇 |
1980年 | 52篇 |
1979年 | 45篇 |
1978年 | 48篇 |
1976年 | 39篇 |
1974年 | 42篇 |
1973年 | 46篇 |
1972年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
1.
目的 了解我国老年人中医证候分布特征,为中医药辨治老年人提供参考依据。方法 系统检索中国知识基础设施(CNKI)、中文科技期刊数据库(CCD)、万方数据资源系统数据库(CSPD),纳入研究对象为老年人的临床流行病学调查研究文献,对其调查目的、调查疾病及调查结果等进行描述统计。结果 ①最终纳入168篇文献,其中2010至2020年之间发表138篇(82.14%);调查地区涵盖全国28个省市自治区,共纳入43948例老年人,累计覆盖340个研究中心;②主要研究结果显示,老年人中医证候阴虚阳亢证(10.05%)>血瘀证(9.5%)>痰浊(湿)证(8.91%)>阴阳两虚证(4.98%)>痰瘀互结证(4.96%);单元证分布阴虚证(14.70%)>痰证(11.22%)>气虚证(7.15%)>肾虚证(4.72%)>血瘀证(4.18%);涉及病变脏腑肾>肝>脾>肺>心。结论 根据统计结果,可以看出老年人证候分布虚证多于实证,虚证中又以阴虚证、气虚证最为多见,实证常见血瘀证、痰浊(湿)证等,且多见痰瘀互结证;老年人五脏皆损,其中又以肾、肝、脾功能失调最为突出。 相似文献
2.
3.
Although methadone is effective in the management of acute pain, the complexity of its absorption-distribution-metabolism-excretion profile limits its use as an opioid of choice for perioperative analgesia. Because deuteration is known to improve the pharmacokinetic, pharmacodynamic and toxicological properties of some drugs, here we characterized the single dose pharmacokinetic properties and post-operative analgesic efficacy of d9-methadone.The pharmacokinetic profiles of d9-methadone and methadone administered intravenously to CD-1 male mice revealed that deuteration leads to a 5.7- and 4.4-fold increase in the area under the time-concentration curve and maximum concentration in plasma, respectively, as well as reduction in clearance (0.9 ± 0.3 L/h/kg vs 4.7 ± 0.8 L/h/kg). The lower brain-to-plasma ratio of d9-methadone compared to that of methadone (0.35 ± 0.12 vs 2.05 ± 0.62) suggested that deuteration decreases the transfer of the drug across the blood-brain barrier. The estimated LD50 value for a single intravenous dose of d9-methadone was 2.1-fold higher than that for methadone. Moreover, d9-methadone outperformed methadone in the efficacy against postoperative pain by primarily activating peripheral opioid receptors. Collectively, these data suggest that the replacement of three hydrogen atoms in three methyl groups of methadone altered its pharmacokinetic properties, improved safety, and enhanced its analgesic efficacy. 相似文献
4.
目的 通过分析特发性肺纤维化急性加重期(AE-IPF)患者证候与血清生物标志物的关系,为中医辨证治疗提供参考。方法 采用观察性研究设计,收集2019年3月至2019年11月三个中心的AE-IPF患者76例,其中痰热壅肺证26例、痰浊阻肺证50例,并纳入健康志愿者10例作为对照。采用ELISA测定患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平,分析与中医证候的相关性。结果 AE-IPF患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平均显著高于健康对照组。血清CCL18、HMGB1、KL-6、MMP-7和SP-D水平在痰热壅肺证和痰浊阻肺证患者间无显著性差异(P>0.05),而血清SP-A水平存在显著性差异(P<0.05)。结论 血清SP-A与AE-IPF证候存在一定的相关性,血清SP-A的浓度升高,与痰热壅肺证关系越密切,反之,血清SP-A浓度降低,则与痰浊阻肺证关系越密切。AE-IPF痰热壅肺证患者的预后可能较痰浊阻肺证患者更差。 相似文献
5.
6.
7.
8.
《Clinical neurophysiology》2019,130(12):2231-2237
ObjectiveThe clinical and neurophysiological characteristics of myoclonus in Angelman syndrome (AS) have been evaluated in single case or small cohorts, with contrasting results. We evaluated the features of myoclonus in a wide cohort of AS patients.MethodsWe performed polygraphic EEG-EMG recording in 24 patients with genetically confirmed AS and myoclonus. Neurophysiological investigations included jerk-locked back-averaging (JLBA), cortico-muscular coherence (CMC) and generalised partial directed coherence (GPDC). CMC and GPDC analyses were compared to those obtained from 10 healthy controls (HC).ResultsTwenty-four patients (aged 3–35 years, median 20) were evaluated. Sequences of quasi-continuous rhythmic jerks mostly occurred at alpha frequency or just below (mean 8.4 ± 1.4 Hz), without EEG correlate. JLBA did not show any clear transient preceding the jerks. CMC showed bilateral over-threshold CMC in alpha band that was prominent on the contralateral hemisphere in the patient group as compared to HC group. GPDC showed a significantly higher alpha outflow from both hemispheres toward activated muscles in the patient group, and a significantly higher beta outflow from contralateral hemisphere in the HC group.ConclusionsThese neurophysiological findings suggest a subcortical generator of myoclonus in AS.SignificanceMyoclonus in AS has not a cortical origin as previously hypothesised. 相似文献
9.
Elizabeth M. Broad Laura J. Newsome Dustin A. Dew 《The journal of spinal cord medicine》2020,43(3):388-397
Objective: Report measured resting energy expenditure (REE) in wheelchair rugby athletes and evaluate agreement between REE and the prediction models of Chun, Cunningham, Harris-Benedict, Mifflin, Nightingale and Gorgey, and Owen.Design: Cohort-based validation study.Setting. Paralympic team training camp.Participants: Fourteen internationally competitive athletes who play wheelchair rugby, 13 of whom had cervical spinal cord injuries (SCI).Outcome Measures: A portable metabolic analyzer was used to measure REE following an overnight fast and dual-energy X-ray absorptiometry (DXA) was used to assess lean body mass for the prediction equations.Results: REE in the current sample was 1735?±?257?kcal?×?day?1 ranging from 1324 to 2068?kcal?×?day?1. Bland–Altman analyses revealed negative mean bias but similar limits of agreement between measured REE and scores predicted by Chun, Cunningham, Mifflin, Nightingale and Gorgey, and Owen models in elite athletes who play wheelchair rugby.Conclusion: Prediction models regressed on persons with and without SCI under-predicted REE of competitive wheelchair rugby athletes. This outcome may be explained by the higher REE/fat-free mass (FFM) ratio of current athletes compared to less active samples. Findings from the current study will help practitioners to determine nutrient intake needs on training days of varied intensity. 相似文献
10.