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   8124篇
  免费   889篇
  国内免费   4篇
耳鼻咽喉   135篇
儿科学   242篇
妇产科学   112篇
基础医学   1141篇
口腔科学   316篇
临床医学   801篇
内科学   1569篇
皮肤病学   149篇
神经病学   581篇
特种医学   336篇
外科学   1081篇
综合类   184篇
一般理论   10篇
预防医学   1106篇
眼科学   268篇
药学   557篇
中国医学   10篇
肿瘤学   419篇
  2021年   92篇
  2020年   74篇
  2019年   112篇
  2018年   134篇
  2017年   98篇
  2016年   96篇
  2015年   110篇
  2014年   158篇
  2013年   277篇
  2012年   340篇
  2011年   360篇
  2010年   213篇
  2009年   206篇
  2008年   355篇
  2007年   386篇
  2006年   367篇
  2005年   420篇
  2004年   377篇
  2003年   382篇
  2002年   384篇
  2001年   224篇
  2000年   274篇
  1999年   187篇
  1998年   102篇
  1997年   121篇
  1996年   94篇
  1995年   112篇
  1994年   80篇
  1993年   81篇
  1992年   149篇
  1991年   154篇
  1990年   151篇
  1989年   144篇
  1988年   134篇
  1987年   134篇
  1986年   143篇
  1985年   134篇
  1984年   114篇
  1983年   101篇
  1982年   78篇
  1981年   97篇
  1980年   75篇
  1979年   84篇
  1978年   81篇
  1977年   48篇
  1976年   65篇
  1975年   68篇
  1974年   68篇
  1973年   83篇
  1972年   54篇
排序方式: 共有9017条查询结果,搜索用时 15 毫秒
1.
2.
3.
Single-pulse transcranial magnetic stimulation (sTMS) of the occipital cortex is an effective migraine treatment. However, its mechanism of action and cortical effects of sTMS in migraine are yet to be elucidated. Using calcium imaging and GCaMP-expressing mice, sTMS did not depolarise neurons and had no effect on vascular tone. Pre-treatment with sTMS, however, significantly affected some characteristics of the cortical spreading depression (CSD) wave, the correlate of migraine aura. sTMS inhibited spontaneous neuronal firing in the visual cortex in a dose-dependent manner and attenuated l-glutamate-evoked firing, but not in the presence of GABAA/B antagonists. In the CSD model, sTMS increased the CSD electrical threshold, but not in the presence of GABAA/B antagonists. We first report here that sTMS at intensities similar to those used in the treatment of migraine, unlike traditional sTMS applied in other neurological fields, does not excite cortical neurons but it reduces spontaneous cortical neuronal activity and suppresses the migraine aura biological substrate, potentially by interacting with GABAergic circuits.Electronic supplementary materialThe online version of this article (10.1007/s13311-020-00879-6) contains supplementary material, which is available to authorized users.Key Words: Migraine, transcranial magnetic stimulation, GABA, glutamate, cortex  相似文献   
4.
We sought to collect information about the operations of wholesalers and store owner perceptions of smartphones to plan for and create a smartphone application that will facilitate the distribution of healthy foods to corner stores. In-depth interviews were conducted with wholesalers, corner store owners, distributors, and food environment experts in Baltimore City, Maryland, which included providing feedback for a mockup of the app. Store owners that were comfortable with smartphones liked the idea of the app because it was economically practical, culturally suitable, simple and easy to use, and provided a large variety of items at a fair or low price. We found that barriers to uptake among corner store owners would be high delivery costs, no foreign language capability, and a complicated user interface. This work will inform future projects that will utilize mHealth technology to improve distribution of healthier foods in food deserts.  相似文献   
5.
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.  相似文献   
6.
Background: Soft song is a low-amplitude song produced by many birds. Recent studies have confirmed that soft song is an aggressive signal. For example, the Brownish-flanked Bush Warblers Cettia fortipes use soft song in male-male conflicts, particularly prior to attacks. Although stable signaling systems require that signals be honest on average,models predict that cheating is an acceptable strategy for some individuals or in some contexts.Methods: This study aimed to test the reliability of soft song as an aggressive signal in the brownish-flanked bush warbler. We used mounted specimens accompanied by broadcast songs or soft songs to simulate a male attempting to invade an existing territory.Results: We found the mounted specimen that coupled playback of soft songs suffered more and quicker attacks from the territory owner and that the relationship between soft song and subsequent attack in the territory owner was far from perfect. We observed territory owners that both over-signaled(i.e., produced soft song but did not attack) and under-signaled(i.e., attacked without producing soft song). Under-signaling territory owners were relatively more commonly than were over-signaling territory owners, particularly in simulated intrusion that coupled playback of soft song with a mount specimen.Conclusions: We discuss the cost of producing soft song and the potential benefit of the unreliable use of soft song and propose a new hypothesis for under-signaling with soft song; i.e., under-signaling territory owners might benefit from taking the initiative in fights.  相似文献   
7.
Background: The COVID-19 pandemic has put enormous pressure on hospital resources, and has affected all aspects of patient care. As operative volumes decrease, cancer surgeries must be triaged and prioritized with careful thought and attention to ensure maximal benefit for the maximum number of patients. Peritoneal malignancies present a unique challenge, as surgical management can be resource intensive, but patients have limited non-surgical treatment options. This review summarizes current data on outcomes and resource utilization to help inform decision-making and case prioritization in times of constrained health care resources. Methods: A rapid literature review was performed, examining surgical and non-surgical outcomes data for peritoneal malignancies. Narrative data synthesis was cross-referenced with relevant societal guidelines. Peritoneal malignancy surgeons and medical oncologists reviewed recommendations to establish a national perspective on case triage and mitigating treatment strategies. Results and Conclusions: Triage of peritoneal malignancies during this time of restricted health care resource is nuanced and requires multidisciplinary discussion with consideration of individual patient factors. Prioritization should be given to patients where delay may compromise resectability of disease, and where alternative treatment options are lacking. Mitigating strategies such as systemic chemotherapy and/or surgical deferral may be utilized with close surveillance for disease stability or progression, which may affect surgical urgency. Unique hospital capacity, and ability to manage the complex post-operative course for these patients must also be considered to ensure patient and system needs are aligned.  相似文献   
8.
9.
ABSTRACT

This phenomenological study engaged an availability sample of eight, long-term, adult burn survivors living a primarily rural burn center catchment area of the U.S. in face-to-face interviews focused on their holistic health since their burn injuries occurred. Criteria for the primary study involved females (n = 1) and males (n = 7) with an age range of 18 to 65 years and a minimum of 20% total body surface area (TBSA) injuries that required hospitalization in a specialized burn center. The mean age of participants at the time of interviews was 54.38 years. Burns ranged between 20% and 98% TBSA and one to 22 years since burn injuries occurred. Thematic data analysis revealed resilient protective factors as contributing to participants’ post-burn health and recoveries. Resilient factors included resourcefulness, achievement motivation, optimism, spirituality, and empathy. Increased understanding of resilient protective factors and how they impacted long-term burn recovery in this sample may aid social workers in development and implementation community-based interventions in rural communities that promote resilience, health/mental health and long-term recovery for this population and others who have experienced trauma.  相似文献   
10.
This qualitative interview study brings the voices of 27 public health leaders, health communication experts, and artists who work in public health in Uganda together to articulate the principles and practices that make the country a shining example of effective, evidence-based use of the arts for health communication. The specific aim of the study was to identify best practices, theoretical foundations, and other factors that contribute to the success of arts-based health communication campaigns in Uganda.

The study presents four primary themes related to use of the arts for health communication in Uganda: (1) the arts empower health communication; (2) the arts engage people emotionally; (3) effective programs are highly structured; and (4) professionalism is critical to program effectiveness. The findings suggest that the arts humanize, clarify, and empower health communication. The arts can attract attention and engage target populations, reduce hierarchical divisions and tensions that can challenge communication between health professionals and community members, make concepts clearer and more personally and culturally relevant, and communicate at an emotional level wherein concepts can be embodied and made actionable. The findings articulate why and how the arts are an effective means for health communication and can guide best practices.  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