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   13129篇
  免费   898篇
  国内免费   263篇
耳鼻咽喉   1530篇
儿科学   277篇
妇产科学   188篇
基础医学   837篇
口腔科学   335篇
临床医学   2193篇
内科学   1124篇
皮肤病学   101篇
神经病学   460篇
特种医学   1075篇
外科学   1093篇
综合类   1628篇
现状与发展   2篇
一般理论   4篇
预防医学   1367篇
眼科学   111篇
药学   1041篇
  10篇
中国医学   611篇
肿瘤学   303篇
  2024年   27篇
  2023年   208篇
  2022年   382篇
  2021年   720篇
  2020年   569篇
  2019年   529篇
  2018年   505篇
  2017年   472篇
  2016年   555篇
  2015年   497篇
  2014年   996篇
  2013年   1008篇
  2012年   821篇
  2011年   801篇
  2010年   703篇
  2009年   655篇
  2008年   603篇
  2007年   615篇
  2006年   546篇
  2005年   402篇
  2004年   347篇
  2003年   311篇
  2002年   246篇
  2001年   243篇
  2000年   196篇
  1999年   174篇
  1998年   131篇
  1997年   120篇
  1996年   94篇
  1995年   74篇
  1994年   114篇
  1993年   58篇
  1992年   69篇
  1991年   42篇
  1990年   58篇
  1989年   43篇
  1988年   44篇
  1987年   33篇
  1986年   30篇
  1985年   45篇
  1984年   43篇
  1983年   26篇
  1982年   41篇
  1981年   18篇
  1980年   16篇
  1979年   13篇
  1978年   21篇
  1977年   7篇
  1976年   6篇
  1975年   7篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Zusammenfassung Es wird anhand einer konsekutiven Serie über eine modifizierte fortlaufende Nahttechnik am Colon berichtet, die gerade bei älteren Patienten eine sichere und rasche Methode der Anastomosierung darstellt. Die klinisch relevante Insuffizienzrate sowie auch die Letalitätsrate betrugen in dieser Serie je 2%, wobei die Ursachen für die Letalität aber keine Folge der Insuffizienz waren. Die Komplikationsrate betrug 11%, die urologischen Komplikationen mit 6% standen hierbei im Vordergrund.
A consecutive series of 100 resections of the colon using a modified technique of continuous (running away) suture
Summary Based on a consecutive series it is reported about a modified type of continuous suture on the colon, used especially in elderly patients for being a secure and prompt method of anastomosing. The rate of insufficiency and mortality, as far as the clinical relevance is concerned, turns out to be 2% each and there was no relation between mortality and insufficient anastomosis. The complication rate was 11%, whereby the urological complications predominated with 6% of the total.
  相似文献   
82.
目的 对广州市于第二波新冠疫情及时开展疫情防控以及大规模核酸检测进行卫生经济学评价。方法 基于全社会角度,从相关部门及文献中收集数据,对广州市的所有常住居民构建改进SEIR模型,通过构建不同情景,分析真实世界情景及疫情防控措施分别推迟3天与7天的情景下的结果产出值,并对广州市四轮大规模核酸检测行成本效益分析。结果 真实世界情境下,本轮疫情的总经济负担约为344.02亿元人民币。与及时开展疫情防控措施相比,推迟3天开展疫情防控措施会带来1 391例累计确诊病例、43例死亡以及额外的141.91亿元人民币的经济负担。而推迟7天开展疫情防控措施会带来26 237例累计确诊病例、882例死亡以及额外的294.62亿元人民币的经济负担。四轮大规模核酸检测的净收益为221.82亿元人民币,效益成本比为24.23。结论 面对疫情时及时开展疫情防控措施能够极大地减少经济负担,且进行大规模核酸检测具有良好的经济性。  相似文献   
83.
【目的】 分析国际顶级综合类科技期刊公众传播模式及特点,为我国科技期刊公众传播能力建设提供建议。【方法】 以Altmetric Top 100入选论文数量最多的NatureScience和PNAS三刊为研究对象,剖析其在公众传播产品、媒体传播体系和新闻媒体人才支撑等方面的模式和特征。对照分析我国最有影响力的综合类科技期刊《国家科学评论》和《科学通报》的公众传播特点。【结果】 以《国家科学评论》和《科学通报》为代表的我国综合类科技期刊的公众传播能力提升迅速,但仍存在新闻传媒人才短缺、期刊集约化程度不高、公众传播机制尚未建立等问题。【结论】 我国综合类科技期刊需要着力增强传媒人才培育、集约化品牌发展、公众传播机制建设,以促进我国科技期刊公众传播能力提升。  相似文献   
84.
目的:探讨乳腺癌改良根治术中应用超声引导下胸椎旁神经阻滞(TPVB)复合全身麻醉对患者术后认知功能的影响。方法:选择信阳市中心医院2020年1月至2021年12月期间收治的56例乳腺癌改良根治术患者,以随机数字表法分为观察组(超声引导下TPVB联合全身麻醉)和对照组(全身麻醉),各28例。比较两组患者的麻醉前(T0)、切皮时(T1)、手术开始60 min(T2)、术毕时(T3)的血流动力学指标变化情况,记录术中两组患者的麻醉药物用量,记录术前、术后1 d两组患者的神经功能状况,比较两组术后不良反应发生情况。结果:T1~T3时观察组患者的平均动脉压(MAP)、心率(HR)与T0时比较,差异无统计学意义(P> 0.05);T1~T3时对照组患者的MAP、HR高于T0时,差异具有统计学意义(P <0.05);T1~T3时观察组患者的MAP、HR低于同时段对照组,差异具有统计学意义(P <0.05)。观察组患者的术中丙泊酚、瑞芬太尼用量低于对照组,差异具有统计学意义(P <0.05)。术后1 d两组患者的简易智力状态检查量表(MMSE)评分均低于术前,且术后1 d观察组...  相似文献   
85.
Social media platforms have become part of many people’s lives. Users are spending more and more time on these platforms, creating an active and passive digital footprint through their interaction. This footprint has high research potential in many research areas because understanding people’s communication on social media is essential in understanding their values, attitudes, experiences and behaviors. Researchers found that the use of social networking sites impacts adolescents’ eating behavior. If we define adolescents as individuals between ages 10 and 24 (WHO’s definition), 76% of USA young people at age 18–⁠24 use Instagram, so the Instagram social network analysis is important for understanding young people’s expressions in the context of healthy food. This study aims to identify the main topic associated with healthy food on the Instagram social network via hashtag and community analysis based on 2,045,653 messages created by 427,936 individual users. The results show that users most associate Healthy food with healthy lifestyle, fitness, weight loss and diet. In terms of food, these are foods that are Vegan, Homemade, Clean and Plant-based. Given that young people change their behavior in relation to people’s behavior on social networks, it is possible to use this data to predict their future association with healthy food characteristics.  相似文献   
86.
Young adults are constantly exposed to energy-dense, nutrient-poor food and beverages, particularly through advertising. Exposure can influence poor food choices and negatively impact health. This study aimed to understand young adults’ attitudes and experiences associated with food-related advertisements, particularly on social media. This qualitative analysis involved n = 166 Australian 18 to 24-year-olds who were involved in a four-week online conversation on different areas relating to health, social media, and eating. Inductive thematic analysis was utilised on two forums on the recall and perceptions of food-related advertisements. Young adults commonly mentioned aspects of the marketing mix (promotion, product, price, and place) in food advertisements. Participants were more readily able to recall energy-dense, nutrient-poor food advertisements compared to healthy food-related advertisements. Digital advertisements were often discussed alongside the use of ad-blockers and algorithms which tailored their social media viewing to what they like. Participants felt constant exposure to unhealthy food advertisements hindered their ability to realise healthy eating behaviours and created feelings of guilt. This current analysis highlights the need to provide an advertising environment that appropriately motivates healthy eating and a food environment that allows healthy food to be the affordable and convenient option.  相似文献   
87.
BackgroundPatients use Facebook as a resource for medical information. We analyzed posts on idiopathic pulmonary fibrosis (IPF)-related Facebook groups and pages for the presence of guideline content, user engagement, and usefulness.ObjectiveThe objective of this study was to describe and analyze posts from Facebook groups and pages that primarily focus on IPF-related content.MethodsCross-sectional analysis was performed on a single date, identifying Facebook groups and pages resulting from separately searching “IPF” and “idiopathic pulmonary fibrosis.” For inclusion, groups and pages needed to meet either search term and be in English, publicly available, and relevant to IPF. Every 10th post was assessed for general characteristics, source, focus, and user engagement metrics. Posts were analyzed for presence of IPF guideline content, useful scientific information (eg, scientific publications), useful support information (eg, information about support groups), and potentially harmful information.ResultsEligibility criteria were met by 12 groups and 27 pages, leading to analysis of 523 posts. Of these, 42% contained guideline content, 24% provided useful support, 20% provided useful scientific information, and 5% contained potentially harmful information. The most common post source was nonmedical users (85%). Posts most frequently focused on IPF-related news (29%). Posts containing any guideline content had fewer likes or comments and a higher likelihood of containing potentially harmful content. Posts containing useful supportive information had more likes, shares, and comments.ConclusionsFacebook contains useful information about IPF, but posts with misinformation and less guideline content have higher user engagement, making them more visible. Identifying ways to help patients with IPF discriminate between useful and harmful information on Facebook and other social media platforms is an important task for health care professionals.  相似文献   
88.
BackgroundSocial media has become a ubiquitous part of daily life during the COVID-19 pandemic isolation. However, the role of social media use in depression and suicidal ideation of the general public remains unclear. Related empirical studies were limited and reported inconsistent findings. Little is known about the potential underlying mechanisms that may illustrate the relationship between social media use and depression and suicidal ideation during the COVID-19 pandemic.ObjectiveThis study tested the mediation effects of social loneliness and posttraumatic stress disorder (PTSD) symptoms on the relationship between social media use and depressive symptoms and suicidal ideation, as well as the moderation effect of age on the mediation models.MethodsWe administered a population-based random telephone survey in May and June 2020, when infection control measures were being vigorously implemented in Hong Kong. A total of 1070 adults (658 social media users and 412 nonusers) completed the survey. Structural equation modeling (SEM) and multigroup SEM were conducted to test the mediation and moderation effects.ResultsThe weighted prevalence of probable depression was 11.6%; 1.6% had suicidal ideation in the past 2 weeks. Both moderated mediation models of depressive symptoms (χ262=335.3; P<.05; comparative fit index [CFI]=0.94; nonnormed fit index [NNFI]=0.92; root mean square error of approximation [RMSEA]=0.06) and suicidal ideation (χ234=50.8; P<.05; CFI=0.99; NNFI=0.99; RMSEA=0.02) showed acceptable model fit. There was a significantly negative direct effect of social media use on depressive symptoms among older people (β=–.07; P=.04) but not among younger people (β=.04; P=.55). The indirect effect via PTSD symptoms was significantly positive among both younger people (β=.09; P=.02) and older people (β=.10; P=.01). The indirect effect via social loneliness was significant among older people (β=–.01; P=.04) but not among younger people (β=.01; P=.31). The direct effect of social media use on suicidal ideation was not statistically significant in either age group (P>.05). The indirect effects via PTSD symptoms were statistically significant among younger people (β=.02; P=.04) and older people (β=.03; P=.01). Social loneliness was not a significant mediator between social media use and suicidal ideation among either age group (P>.05).ConclusionsSocial media may be a “double-edged sword” for psychosocial well-being during the COVID-19 pandemic, and its roles vary across age groups. The mediators identified in this study can be addressed by psychological interventions to prevent severe mental health problems during and after the COVID-19 pandemic.  相似文献   
89.
90.
【目的】 探析医学科技期刊新媒体爆款文章的特征及生成策略。 【方法】 以《协和医学杂志》为例,筛选出其在今日头条平台2018年10月至2020年12月阅读量为“10万+”的爆款文章,分析文章特征,并从资源挖掘、内容生产及推广传播环节提出有效策略。 【结果】 医学科技期刊新媒体爆款文章具有话题热、标题靓、排版精、互动深的特点;借力平台优势、融合科普定位、发挥“意见领袖”作用、巧搭新闻热点事件、精心设计版式以及多网媒滚筒式传播均为医学科技期刊新媒体爆款文章生成的有力之举。 【结论】 医学科技期刊新媒体深挖优势资源,把好内容及传播环节,策略性运营,可为爆款文章生成提供保障,进而提升期刊品牌影响力和新媒体综合实力。  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