全文获取类型
收费全文 | 245792篇 |
免费 | 19630篇 |
国内免费 | 8230篇 |
专业分类
耳鼻咽喉 | 1810篇 |
儿科学 | 4310篇 |
妇产科学 | 2859篇 |
基础医学 | 36399篇 |
口腔科学 | 3951篇 |
临床医学 | 19205篇 |
内科学 | 46388篇 |
皮肤病学 | 3604篇 |
神经病学 | 17101篇 |
特种医学 | 5045篇 |
外国民族医学 | 56篇 |
外科学 | 16944篇 |
综合类 | 33482篇 |
现状与发展 | 20篇 |
一般理论 | 7篇 |
预防医学 | 13679篇 |
眼科学 | 2559篇 |
药学 | 35916篇 |
84篇 | |
中国医学 | 11317篇 |
肿瘤学 | 18916篇 |
出版年
2024年 | 628篇 |
2023年 | 4471篇 |
2022年 | 9698篇 |
2021年 | 12094篇 |
2020年 | 9452篇 |
2019年 | 7964篇 |
2018年 | 7724篇 |
2017年 | 7730篇 |
2016年 | 7962篇 |
2015年 | 9111篇 |
2014年 | 15065篇 |
2013年 | 16218篇 |
2012年 | 14453篇 |
2011年 | 16507篇 |
2010年 | 13373篇 |
2009年 | 13585篇 |
2008年 | 13237篇 |
2007年 | 12151篇 |
2006年 | 10819篇 |
2005年 | 9401篇 |
2004年 | 7820篇 |
2003年 | 6893篇 |
2002年 | 5529篇 |
2001年 | 4605篇 |
2000年 | 3888篇 |
1999年 | 3484篇 |
1998年 | 3165篇 |
1997年 | 2945篇 |
1996年 | 2666篇 |
1995年 | 2346篇 |
1994年 | 2138篇 |
1993年 | 1874篇 |
1992年 | 1641篇 |
1991年 | 1482篇 |
1990年 | 1234篇 |
1989年 | 1074篇 |
1988年 | 1015篇 |
1987年 | 859篇 |
1986年 | 776篇 |
1985年 | 1167篇 |
1984年 | 1049篇 |
1983年 | 722篇 |
1982年 | 762篇 |
1981年 | 600篇 |
1980年 | 509篇 |
1979年 | 414篇 |
1978年 | 298篇 |
1977年 | 244篇 |
1976年 | 227篇 |
1975年 | 147篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
91.
《Clinical neurophysiology》2020,131(1):213-224
ObjectiveSystematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations).MethodsPubmed, ISI Web of Knowledge and BIORXIV were searched for the relevant articles according to PRISMA standards.ResultsERP components are generally delayed across all sensory modalities both in RTT patients and its animal model, while findings on ERPs amplitude strongly depend on stimulus properties and presentation rate. Studies on RTT animal models uncovered the abnormalities in the excitatory and inhibitory transmission as critical mechanisms underlying the ERPs changes, but showed that even similar ERP alterations in auditory and visual domains have a diverse neural basis. A range of novel approaches has been developed in animal studies bringing along the meaningful neurophysiological interpretation of ERP measures in RTT patients.ConclusionsWhile there is a clear evidence for sensory ERPs abnormalities in RTT, to further advance the field there is a need in a large-scale ERP studies with the functionally-relevant experimental paradigms.SignificanceThe review provides insights into domain-specific neural basis of the ERP abnormalities and promotes clinical application of the ERP measures as the non-invasive functional biomarkers of RTT pathophysiology. 相似文献
92.
目的对附加钢板技术治疗股骨干髓内钉术后骨不连的历史、现状和进展进行综述。方法广泛查阅国内外关于附加钢板技术治疗股骨干髓内钉术后骨不连的临床研究文献,并进行综合分析。结果自 1997 年附加钢板技术已成功用于治疗股骨干髓内钉术后骨不连,根据原髓内钉是否失效,可分为保留原髓内钉和更换原髓内钉两类。该技术不仅适用于简单骨不连,还可用于合并严重畸形的复杂性骨不连。相比更换髓内钉、更换外侧钢板和双钢板技术,附加钢板技术手术创伤更小,骨折愈合时间更短,骨折愈合率更高,患者能更早重返社会和工作。然而,该技术也存在一些问题有待解决,包括双皮质螺钉固定困难、缺乏适合股骨干解剖型附加钢板以及缺乏术后功能和生活质量的评估研究。结论相比其他翻修固定方式,附加钢板技术能够获得更高的骨折愈合率和更好的临床预后。然而,术后患者能否在功能和生活质量方面进一步获益还有待证实。此外,还需要更高质量的临床对照研究深入证明其是否确实优于其他翻修固定方式。 相似文献
93.
94.
95.
96.
S. Natoli V. Oliveira P. Calabresi L. F. Maia A. Pisani 《European journal of neurology》2020,27(9):1764-1773
The current coronavirus disease (COVID‐19) outbreak, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has raised the possibility of potential neurotropic properties of this virus. Indeed, neurological sequelae of SARS‐CoV‐2 infection have already been reported and highlight the relevance of considering the neurological impact of coronavirus (CoV) from a translational perspective. Animal models of SARS and Middle East respiratory syndrome, caused by structurally similar CoVs during the 2002 and 2012 epidemics, have provided valuable data on nervous system involvement by CoVs and the potential for central nervous system spread of SARS‐CoV‐2. One key finding that may unify these pathogens is that all require angiotensin‐converting enzyme 2 as a cell entry receptor. The CoV spike glycoprotein, by which SARS‐CoV‐2 binds to cell membranes, binds angiotensin‐converting enzyme 2 with a higher affinity compared with SARS‐CoV. The expression of this receptor in neurons and endothelial cells hints that SARS‐CoV‐2 may have higher neuroinvasive potential compared with previous CoVs. However, it remains to be determined how such invasiveness might contribute to respiratory failure or cause direct neurological damage. Both direct and indirect mechanisms may be of relevance. Clinical heterogeneity potentially driven by differential host immune‐mediated responses will require extensive investigation. Development of disease models to anticipate emerging neurological complications and to explore mechanisms of direct or immune‐mediated pathogenicity in the short and medium term is therefore of great importance. In this brief review, we describe the current knowledge from models of previous CoV infections and discuss their potential relevance to COVID‐19. 相似文献
97.
《Value in health》2020,23(10):1340-1348
ObjectivesWe applied principles for conducting economic evaluations of factorial trials to a trial-based economic evaluation of a cluster-randomized 2 × 2 × 2 factorial trial. We assessed the cost-effectiveness of atorvastatin, omega-3 fish oil, and an action-planning leaflet, alone and in combination, from a UK National Health Service perspective.MethodsThe Atorvastatin in Factorial With Omega EE90 Risk Reduction in Diabetes (AFORRD) Trial randomized 800 patients with type 2 diabetes to atorvastatin, omega-3, or their respective placebos and randomized general practices to receive a leaflet-based action-planning intervention designed to improve compliance or standard care. The trial was conducted at 59 UK general practices. Sixteen-week outcomes for each trial participant were extrapolated for 70 years using the United Kingdom Prospective Diabetes Study Outcomes Model v2.01. We analyzed the trial as a 2 × 2 factorial trial (ignoring interactions between action-planning leaflet and medication), as a 2 × 2 × 2 factorial trial (considering all interactions), and ignoring all interactions.ResultsWe observed several qualitative interactions for costs and quality-adjusted life-years (QALYs) that changed treatment rankings. However, different approaches to analyzing the factorial design did not change the conclusions. There was a ≥99% chance that atorvastatin is cost-effective and omega-3 is not, at a £20 000/QALY threshold.ConclusionsAtorvastatin monotherapy was the most cost-effective combination of the 3 trial interventions at a £20 000/QALY threshold. Omega-3 fish oil was not cost-effective, while there was insufficient evidence to draw firm conclusions about action planning. Recently-developed methods for analyzing factorial trials and combining parameter and sampling uncertainty were extended to estimate cost-effectiveness acceptability curves within a 2x2x2 factorial design with model-based extrapolation. 相似文献
98.
Laysa Toschi Martins Henrique Ravanhol Frigeri Caio Cesar Silva de Castro Marcelo Távora Mira 《Experimental dermatology》2020,29(6):535-538
The aetiology of vitiligo has not been fully elucidated, and several hypotheses have been investigated; among them, the most explored assumes an autoimmune basis for the disease. Supporting this hypothesis is the frequent co-occurrence of autoimmune diseases with vitiligo. In addition, various genetic loci associated with vitiligo harbour key immune response genes. Our general hypothesis is that autoimmunity-associated genes participate in the control of vitiligo susceptibility. To investigate this hypothesis, we tested for association between vitiligo and genes CYP27B1, REL, TNFAIP3 and IL2/IL21, all previously related to autoimmune diseases associated with vitiligo. The study was performed using two independent population samples: a family-based discovery set (211 trios) and a replication set (131 cases/119 controls). Statistically significant association with vitiligo was detected between markers of the REL and IL2 gene in the family-based sample. Both association signals were concentrated among patients displaying autoimmune comorbidity and non-segmental vitiligo. Evidence for validation was detected for IL2 marker. Our findings suggest REL and IL2 as new vitiligo susceptibility genes and reinforce the hypothesis of a shared genetic mechanism controlling vitiligo and other autoimmune diseases. 相似文献
99.