全文获取类型
收费全文 | 1292篇 |
免费 | 233篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 53篇 |
妇产科学 | 8篇 |
基础医学 | 139篇 |
口腔科学 | 9篇 |
临床医学 | 427篇 |
内科学 | 136篇 |
皮肤病学 | 2篇 |
神经病学 | 217篇 |
特种医学 | 7篇 |
外科学 | 124篇 |
综合类 | 68篇 |
一般理论 | 3篇 |
预防医学 | 245篇 |
药学 | 31篇 |
中国医学 | 3篇 |
肿瘤学 | 56篇 |
出版年
2024年 | 25篇 |
2023年 | 119篇 |
2022年 | 134篇 |
2021年 | 155篇 |
2020年 | 151篇 |
2019年 | 132篇 |
2018年 | 75篇 |
2017年 | 98篇 |
2016年 | 91篇 |
2015年 | 81篇 |
2014年 | 81篇 |
2013年 | 140篇 |
2012年 | 42篇 |
2011年 | 34篇 |
2010年 | 30篇 |
2009年 | 15篇 |
2008年 | 24篇 |
2007年 | 28篇 |
2006年 | 8篇 |
2005年 | 14篇 |
2004年 | 13篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有1533条查询结果,搜索用时 15 毫秒
51.
Chanwoong Kim Kyung Hye Park Eun Kyung Eo Young-Min Kim Soo Kyung Eo JaeHun Han 《Yonsei medical journal》2022,63(4):372
PurposeThis study aimed to investigate burnout and resilience among emergency physicians (EPs) at university teaching hospitals during the coronavirus disease (COVID-19) pandemic.Materials and MethodsIn April to May 2021, a survey was administered to 331 and 309 emergency medicine specialists and residents, respectively, from 31 university teaching hospitals in Korea. Data on the respondents’ age, sex, designation, working area, experience with treating COVID-19 patients, and personal experience with COVID-19 were collected. Based on the participants’ characteristics, quality of life (compassion satisfaction, burnout, and secondary traumatic stress), resilience, emotional content, and self-image were analyzed.ResultsA total of 247 responses were analyzed. Compared to specialists, compassion satisfaction and resilience in residents were not good, burnout was severe, and emotional content and self-image were less positive. Experiences with treating COVID-19 patients did not cause any difference in quality of life, resilience, emotional content, and self-image among participant subgroups. Personal COVID-19 experiences were associated with poor compassion satisfaction, resilience, less positive emotional content and self-image, and severe burnout. Compassion satisfaction, secondary traumatic stress, and resilience can definitively affect burnout.ConclusionThe quality of life and resilience of EPs in university teaching hospitals in Korea during the COVID-19 pandemic have been low. Supportive measures to improve resilience can prevent burnout among emergency staff, particularly residents and EPs, with personal experiences related to COVID-19. 相似文献
52.
彭阳 《中国健康心理学杂志》2013,21(8):1244-1246
目的对流动与非流动初中生积极心理品质:自立人格、心理韧性、正性-负性情绪进行比较,为推动流动初中生心理健康发展提供依据。方法采用青少年自立人格量表、青少年心理韧性量表、正性-负性情绪量表对深圳某中学658名初中1~3年级的学生进行抽样调查,以筛选出的392名流动初中生为研究组,其他学生为对照组。利用SPSS16.0统计软件对调查结果进行统计分析。结果①流动与非流动初中生在自立人格各因子及正性-负性情绪上无显著差异;②流动初中生在心理韧性的积极认知上得分显著高于非流动初中生(F=4.078,P<0.05),其它因子无显著差异。结论流动对流动初中生积极心理品质发展的影响并不明显,可通过教育发挥流动的积极意义。 相似文献
53.
Zachary Randell Michael Kenner Joseph Tomoleoni Julie Yee Mark Novak 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(8)
The factors that determine why ecosystems exhibit abrupt shifts in state are of paramount importance for management, conservation, and restoration efforts. Kelp forests are emblematic of such abruptly shifting ecosystems, transitioning from kelp-dominated to urchin-dominated states around the world with increasing frequency, yet the underlying processes and mechanisms that control their dynamics remain unclear. Here, we analyze four decades of data from biannual monitoring around San Nicolas Island, CA, to show that substrate complexity controls both the number of possible (alternative) states and the velocity with which shifts between states occur. The superposition of community dynamics with reconstructions of system stability landscapes reveals that shifts between alternative states at low-complexity sites reflect abrupt, high-velocity events initiated by pulse perturbations that rapidly propel species across dynamically unstable state–space. In contrast, high-complexity sites exhibit a single state of resilient kelp–urchin coexistence. Our analyses suggest that substrate complexity influences both top-down and bottom-up regulatory processes in kelp forests, highlight its influence on kelp-forest stability at both large (island-wide) and small (<10 m) spatial scales, and could be valuable for holistic kelp-forest management.Kelp-forest ecosystems exhibit rich and varied spatiotemporal dynamics. Prominent among these are dramatic shifts between kelp-dominated forests and so-called urchin barrens from which macroalgae are almost entirely absent due to intense urchin grazing (1, 2). Phase shifts between kelp and barren states have long been associated with structural changes to kelp-forest communities, such as the addition or removal of sea-urchin predators (3, 4) or changes in the environment such as shifting water temperatures (4–7). Kelp forests are also subject to stochastic perturbations such as large wave, marine disease, and anomalous warm water events that might perturb kelp forests between alternative stable states (8, 9). However, distinguishing phase shifts and alternative stable states is a major challenge (10). This is partially because both slow environmental change and relatively rapid stochastic perturbations often appear to act synergistically and with episodic urchin recruitment events that, due to their large regional extent, decouple rates of urchin grazing from the local density-dependent regulation of their populations (11, 12).Although consensus is emerging that the maintenance of kelp-dominated forests is driven by a combination of top-down and bottom-up processes, the mechanisms underlying these processes—and hence the optimal means to control and avoid tipping points to the urchin-barren state—appear varied and often unclear (1, 13). For example, top-down processes contributing to kelp-forest stability include the effects of predators and disease on urchin grazing behavior and mortality rates (14–18), emphasizing the need for management strategies that preserve or restore top-down forms of urchin control (19, 20). On the other hand, bottom-up processes affecting kelp growth and senescence rates, and the retention of drift algae that urchins prefer to consume, are also known to contribute to kelp-forest stability, emphasizing management strategies that differ from those of direct urchin control (21–25). We hypothesize that substrate complexity modifies both top-down and bottom-up processes structuring urchin–kelp interactions, e.g., provisioning habitat for urchin predators and increasing the retention of drift algae for urchins.Here we apply the perspective of stochastic dynamical systems to the study of kelp forests not to determine the specific mechanisms or feedbacks that underlie kelp-forest dynamics but rather to infer an environmental variable that influences their relative strength and net expression. The dynamical-systems perspective conceptualizes a system’s community states and dynamics using the ball-in-cup heuristic of stability and resilience (26, 27), formally described by a (quasi-)potential stability landscape (28, 29). A system with alternative stable states exhibits a multimodal landscape with two or more basins of attraction (cups) over which it travels in time due to endogenous drivers (e.g., species interactions) and external perturbations. Because most perturbations are directionally random and small, communities spend more time in states at the bottom of the attracting basins than they do on their slopes and cusps, with deeper and steeper-sloped basins corresponding to more stable and resilient community states whose dynamics are dominated by negative feedbacks (28). Previous work has utilized this characteristic of stochastic dynamical systems to make use of large-scale spatial variation in community structure to infer what biotic and environmental conditions may alter the stability of various ecological systems, including tropical and temperate forests and desert biomes (4, 30–32). For example, Scheffer et al. (33) used satellite-derived spatial variation in the frequency distributions of percentage of tree cover values to infer that boreal biomes exhibit between one and three different alternative stable states whose number and nature depend on mean July temperature, where empirical system–state frequency histograms represent negative potential (i.e., a mirror image of a ball-in-cup stability landscape reflected across the x axis). Similarly, Ling et al. (4) combined spatial survey data with translocation experiments to infer bistability in response to urchin densities in Tasmanian kelp forests. The approach underlying these inferences has been referred to as potential analysis (34).Using spatially fixed and replicated long-term time series of kelp-forest community dynamics around San Nicolas Island, CA, we extended the application of potential analysis to include the temporal domain to more rigorously infer their condition-dependent stability landscapes and shifts in community structure. Our analyses reveal kelp-forest communities around San Nicolas Island to exhibit dramatic, perturbation-induced shifts between kelp-dominated forests and urchin-barren states only when the complexity of the underlying substrate is low and that similarly perturbed high-complexity substrates permit only a single persistent state of resilient kelp–urchin coexistence. We infer that substrate complexity at San Nicolas Island controls the relative strength of the many negative and positive feedbacks that have been described in kelp forests and that a greater understanding of its influences is likely to increase the effectiveness of management efforts seeking to conserve and restore their existence. 相似文献
54.
Isabelle Laurin Flicia Brochu Gabriel Bordeleau-Gervais 《Canadian journal of public health. Revue canadienne de santé publique》2022,113(4):528
SettingFrom April 2020, in sight of child care reopening, the Direction régionale de santé publique de Montréal (DRSPM) conducted a situational analysis with its child care (CC) partners in order to learn about the challenges they envisioned in their role in preventing and managing COVID-19. The CC partners requested access to preferred public health support.InterventionThe DRSPM established a service consisting of three components: (1) telephone support available 6 to 7 days/week for CC managers facing a COVID-19 situation; (2) a regional committee combining four Montreal representatives of CC associations and one from the Ministère de la Famille; (3) prevention brigades formed by front-line health workers from the Centres intégrés universitaires de santé et de services sociaux (CIUSSS).OutcomesThis health promotion intervention (1) enabled CC services to handle the pandemic with better capability and confidence through facilitating access to accurate and positive information; (2) supported the commitment and collaboration of CC services by acting as a mediator between them and decision-makers; and (3) responded to the psychosocial needs of community members.ImplicationsThis service helped to adjust public policy and promote community resilience by raising awareness of the importance of balancing COVID-19 prevention and the collateral impacts of the pandemic. 相似文献
55.
Eliya Farah Maria El Bizri Radmila Day Lavina Matai Fred Horne Timothy P. Hanna David Armstrong Susan Marlin Olivier Jrme Darren R. Brenner Winson Cheung Laszlo Radvanyi Eva Villalba Natalie Leon Chana Cohen Karine Chalifour Ronald Burkes Sharlene Gill Scott Berry Brandon S. Sheffield Pamela Fralick Barry D. Stein 《Current oncology (Toronto, Ont.)》2022,29(3):1723
(1) Background: The COVID-19 pandemic illuminated vulnerabilities in the Canadian health care system and exposed gaps and challenges across the cancer care continuum. Canada is experiencing significant disruptions to cancer-related services, and the impact these disruptions (delays/deferrals/cancellations) have on the health care system and patients are yet to be determined. Given the potential adverse ramifications, how can Canada’s health care systems build resilience for future threats? (2) Methods: To answer this question, CCC facilitated a series of four thought-leadership roundtables, each representing the views of four different stakeholder groups: patients, physicians, health care system leaders, and researchers. (3) Results: Six themes of strength were identified to serve as a springboard for building resilience including, (1) advancing virtual care and digital health technologies to prevent future interruptions in cancer care delivery. (2) developing real-time data metrics, data sharing, and evidence-based decision-making. (3) enhancing public–private-non-profit partnerships to advance research and strengthen connections across the system. (4) advancing patient-centricity in cancer research to drive and encourage precision medicine approaches to care. (5) investing in training and hiring a robust supply of health care human resources. (6) implementing a national strategy and infrastructure to ensure inter-provincial collaborative data sharing (4). Conclusions: A resilient health care system that can respond to shocks and threats is not an emergency system; it is a robust everyday system that can respond to emergencies. 相似文献
56.
57.
《The British journal of oral & maxillofacial surgery》2020,58(3):364-365
The number of women studying in medical schools is increasing, and the relative proportion of female consultants in surgical and leadership roles is lagging behind, relatively, and so a new drive for promoting and supporting women in surgery has evolved. A part of this was the creation of the Society of Women in Oral and Maxillofacial Surgery. This short communication gives proceedings of the inaugural conference of SWiMS and discusses the need for greater promotion of women in the speciality (and the profession at large) and how the society has addressed the need for resilience and community in surgical training and beyond. 相似文献
58.
Xi Zhang Rui Gao Jin Ling Lin Ning Chen Qin Lin Gui Fang Huang Long Wang Xiao Huan Chen Fang Qin Xue Hong Li 《Journal of clinical nursing》2020,29(13-14):2196-2208
59.
60.