全文获取类型
收费全文 | 332494篇 |
免费 | 25000篇 |
国内免费 | 7048篇 |
专业分类
耳鼻咽喉 | 4433篇 |
儿科学 | 6939篇 |
妇产科学 | 4551篇 |
基础医学 | 23949篇 |
口腔科学 | 8433篇 |
临床医学 | 35872篇 |
内科学 | 41763篇 |
皮肤病学 | 3396篇 |
神经病学 | 15425篇 |
特种医学 | 8203篇 |
外国民族医学 | 13篇 |
外科学 | 30211篇 |
综合类 | 54902篇 |
现状与发展 | 10篇 |
一般理论 | 30篇 |
预防医学 | 47637篇 |
眼科学 | 2587篇 |
药学 | 32026篇 |
429篇 | |
中国医学 | 31638篇 |
肿瘤学 | 12095篇 |
出版年
2024年 | 1108篇 |
2023年 | 5946篇 |
2022年 | 11851篇 |
2021年 | 15543篇 |
2020年 | 14857篇 |
2019年 | 15695篇 |
2018年 | 14385篇 |
2017年 | 12776篇 |
2016年 | 12071篇 |
2015年 | 11581篇 |
2014年 | 24374篇 |
2013年 | 24051篇 |
2012年 | 21860篇 |
2011年 | 23079篇 |
2010年 | 18415篇 |
2009年 | 15964篇 |
2008年 | 14857篇 |
2007年 | 14570篇 |
2006年 | 12330篇 |
2005年 | 10061篇 |
2004年 | 8190篇 |
2003年 | 7087篇 |
2002年 | 5450篇 |
2001年 | 4688篇 |
2000年 | 4078篇 |
1999年 | 3421篇 |
1998年 | 2726篇 |
1997年 | 2400篇 |
1996年 | 1988篇 |
1995年 | 1829篇 |
1994年 | 1691篇 |
1993年 | 1423篇 |
1992年 | 1293篇 |
1991年 | 1160篇 |
1990年 | 1069篇 |
1989年 | 981篇 |
1988年 | 901篇 |
1987年 | 777篇 |
1986年 | 710篇 |
1985年 | 2182篇 |
1984年 | 2554篇 |
1983年 | 1665篇 |
1982年 | 2107篇 |
1981年 | 1559篇 |
1980年 | 1364篇 |
1979年 | 1226篇 |
1978年 | 989篇 |
1977年 | 769篇 |
1976年 | 886篇 |
1975年 | 616篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
73.
《Anais brasileiros de dermatologia》2019,94(1):42-46
BackgroundSkin cancer is a highly prevalent condition with a multifactorial etiology resulting from genetic alterations, environmental and lifestyle factors. In Brazil, among all malignant tumors, skin cancers have the highest incidences.ObjectiveTo retrospectively evaluate the incidence, prevalence and profile of basal cell carcinoma, squamous cell carcinoma and cutaneous melanoma in Campos dos Goytacazes and region.Methods:In total, 2,207 histopathological reports of a local reference hospital were analyzed between January 2013 and December 2015, of which 306 corresponded to the neoplasms studied.Results:Of the 306 reports evaluated, 232 basal cell carcinomas (75.9%), 55 squamous cell carcinomas (18%) and 19 cutaneous melanomas (6.5%) were identified. The face was the most involved anatomical site (58.8%) and women (51%) were the most affected gender. The temporal analysis revealed a decrease in the overall incidence of 3.4% from 2013 to 2014 and 5.4% from 2014 to 2015. There was a 10.1% increase in basal cell carcinomas and 38% in melanomas in this period; however, there was a decrease in the number of squamous cell carcinomas of 14.8% during the studied years.Study limitations:Some samples of cutaneous fragments had no identification of the anatomical site of origin.Conclusion:Research that generates statistical data on cutaneous tumors produces epidemiological tools useful in the identification of risk groups and allows the adoption of more targeted and efficient future prevention measures. 相似文献
74.
75.
John Bickle 《Topics in Cognitive Science》2015,7(2):299-311
David Marr's three-level method for completely understanding a cognitive system and the importance he attaches to the computational level are so familiar as to scarcely need repeating. Fewer seem to recognize that Marr defends his famous method by criticizing the “reductionistic approach.” This sets up a more interesting relationship between Marr and reductionism than is usually acknowledged. I argue that Marr was correct in his criticism of the reductionists of his time—they were only describing (cellular activity), not explaining (cognitive functions). But a careful metascientific account of reductionistic neuroscience over the past two decades reveals that Marr's criticisms no longer have force. Contemporary neuroscience now explains cognition directly, although in a fashion—causal-mechanistically—quite different than Marr recommended. So while Marr was correct to reject the reductionism of his day and offer an alternative method for genuinely explaining cognition, contemporary cognitive scientists now owe us a new defense of Marr's famous method and the advantages of its explanations over the type now pursued successfully in current reductionist neuroscience. There are familiar reasons for thinking that this debt will not be paid easily. 相似文献
76.
77.
《Vaccine》2020,38(45):7118-7128
IntroductionToward the Global Vaccine Action Plan 2020 goal, almost 90% of countries have established a National Immunization Technical Advisory Group (NITAG). However, little is known about NITAG's contributions to governance.MethodsIn 2017–2018, a two-step, qualitative retrospective study was conducted. Jordan (JO), Argentina (AR), and South Africa (SA) were selected owing to government-financed NITAGs from middle-income countries (MICs), geographic diversity, and a vaccine introduction with NITAG support. Country case studies were developed, collecting data through desk review and face-to-face key informant interviews (KIIs) from Ministry of Health (MoH) and NITAG. Case studies were analyzed together, to assess governance applying the European Observatory on Health Systems and Policies framework focusing on transparency, accountability, participation, integrity, and policy capacity (TAPIC).ResultsDocument review and 53 KII (22 AR, 20 SA, 11 JO) showed NITAGs played a pivotal role as advisors promoting a culture of evidence-informed policies. NITAGs strengthened governance, although practices varied among countries. Meetings were conducted behind-closed-doors, participation restricted to members, only in one country agendas, and recommendations were public (AR). To increase participation, policy capacity, and transparency, countries considered adding experts in communications, advocacy, and economics. AR and SA contemplated including community members. NITAGs functioned autonomously from the government, with no established internal or external monitoring or supervision. NITAG meeting minutes allowed the review of integrity, adherence to terms of reference, standard operating procedures, and conflict of interest (CoI). For the most part, NITAGs abided by their mandates. Significant issues were related to the level of MoH support and oversight of CoI declaration and documentation.ConclusionsSystematically implementing governance approaches could improve processes, better tailor policies, and implementation. The long-term survival and resilience of NITAGs in these countries showed they play a significant role in strengthening governance. Lessons learned could be useful to those promoting country-driven evidence-informed decision-making. 相似文献
78.
79.
《Clinical neurophysiology》2020,131(1):259-264
ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS. 相似文献
80.
《Journal of vascular and interventional radiology : JVIR》2020,31(6):869-875
This paper describes country-wide special measures undertaken for interventional radiology staff during the current coronavirus disease 2019 (COVID-19) pandemic. Although each interventional radiology service around the world faces unique challenges, the principles outlined in this article will be useful when designing or strengthening individual practices and integrating them within wider hospital and national measures. Moving beyond the current outbreak, these measures will be useful for any future infectious diseases which are likely to arise. 相似文献