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   1696572篇
  免费   126785篇
  国内免费   3786篇
耳鼻咽喉   21771篇
儿科学   55787篇
妇产科学   46217篇
基础医学   242071篇
口腔科学   48910篇
临床医学   151593篇
内科学   333976篇
皮肤病学   38946篇
神经病学   131693篇
特种医学   64133篇
外国民族医学   242篇
外科学   257764篇
综合类   38961篇
现状与发展   4篇
一般理论   531篇
预防医学   124301篇
眼科学   40224篇
药学   123931篇
  7篇
中国医学   4476篇
肿瘤学   101605篇
  2021年   12866篇
  2019年   13575篇
  2018年   20052篇
  2017年   15292篇
  2016年   16736篇
  2015年   19063篇
  2014年   26365篇
  2013年   38120篇
  2012年   52972篇
  2011年   55632篇
  2010年   32901篇
  2009年   30829篇
  2008年   51717篇
  2007年   55015篇
  2006年   55477篇
  2005年   52751篇
  2004年   50969篇
  2003年   48356篇
  2002年   46579篇
  2001年   91967篇
  2000年   93770篇
  1999年   77114篇
  1998年   19796篇
  1997年   17316篇
  1996年   17434篇
  1995年   16800篇
  1994年   15330篇
  1993年   14125篇
  1992年   57473篇
  1991年   55367篇
  1990年   53070篇
  1989年   50828篇
  1988年   46201篇
  1987年   45005篇
  1986年   42294篇
  1985年   40051篇
  1984年   29413篇
  1983年   24960篇
  1982年   13938篇
  1979年   25592篇
  1978年   17614篇
  1977年   14948篇
  1976年   13897篇
  1975年   14598篇
  1974年   17668篇
  1973年   16991篇
  1972年   15697篇
  1971年   14485篇
  1970年   13451篇
  1969年   12536篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
191.
One unreported case of extended-spectrum-beta-lactamase (ESBL)-producing Salmonella enterica serovar Typhi was identified, whole-genome sequence typed, among other analyses, and compared to other available genomes of S. Typhi. The reported strain was similar to a previously published strain harboring blaSHV-12 from the Philippines and likely part of an undetected outbreak, the first of ESBL-producing S. Typhi.  相似文献   
192.
IntroductionPain is highly prevalent in patients with multiple sclerosis (MS); it is chronic in 50% of cases and is classified as nociceptive, neuropathic, or mixed-type. Pain affects quality of life, sleep, and the activities of daily living. Electrotherapy is an interesting alternative or complementary treatment in the management of pain in MS, with new innovations constantly appearing.Material and methodsThis study evaluates the effectiveness of treatment with monopolar dielectric transmission of pulsed electromagnetic fields (PEMF) for pain associated with MS. We performed a randomised, placebo-controlled clinical trial including 24 patients, who were assessed with the Brief Pain Inventory, the Multiple Sclerosis International Quality of Life questionnaire, the Beck Depression Inventory, and the Modified Fatigue Impact Scale.ResultsStatistically significant improvements were observed in maximum and mean pain scores, as well as in the impact of pain on work, personal relationships, and sleep and rest. Not significant differences were found between the treatment and placebo groups.ConclusionsTreatment with PEMF may be effective in reducing pain in patients with MS, although further research is necessary to confirm its effectiveness over placebo and to differentiate which type of pain may be more susceptible to this treatment.  相似文献   
193.
PurposeTwitter is an increasingly popular social media platform within the health care community. The objective of this analysis is to characterize the profile of radiation oncology–related tweets and Twitter users over the past 6 years.Methods and MaterialsUsing the web-based social media analytics platform Symplur Signals, we filtered tweets containing at least 1 of the following hashtags or key words: #radonc, #radiationoncology, "rad onc," or "radiation oncology." We evaluated radiation oncology–related Twitter activity between October 2014 and March 2020 for tweet frequency, tweet content, and individuals or groups posting tweets. We identified the most influential Twitter users contributing to radiation oncology–related tweets.ResultsFrom 2014 to 2020, the quarterly volume of radiation oncology–related tweets increased from 5027 to 29,763. Physicians contributed the largest growth in tweet volume. Academic radiation oncologists comprise 60% of the most influential Twitter accounts responsible for radiation oncology–related content. The number of radiation-oncology resident physicians on Twitter increased from 25 to 328 over the past 6 years, and 20% of radiation-oncology residency programs have a Twitter account. Seventy-one percent of radiation oncology–related tweets generated direct communication via mentions, and 59% of tweets contain links to external sources, including scientific articles.ConclusionsThe number of physicians contributing radiation oncology–related Twitter content has increased significantly in recent years. Academic radiation oncologists are the primary influencers of radiation oncology–related Twitter activity. Twitter is used by radiation oncologists to both professionally network and discuss findings related to the field. There remains the opportunity for radiation oncologists to broaden their audience on Twitter to encompass a more diverse community, including patients.  相似文献   
194.
BackgroundVenoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used as a life-saving therapy for patients with cardiovascular collapse, but identifying patients unlikely to benefit remains a challenge.Methods and ResultsWe created the RESCUE registry, a retrospective, observational registry of adult patients treated with VA-ECMO between January 2007 and June 2017 at 3 high-volume centers (Columbia University, Duke University, and Washington University) to describe short-term patient outcomes. In 723 patients treated with VA-ECMO, the most common indications for deployment were postcardiotomy shock (31%), cardiomyopathy (including acute heart failure) (26%), and myocardial infarction (17%). Patients frequently suffered in-hospital complications, including acute renal dysfunction (45%), major bleeding (41%), and infection (33%). Only 40% of patients (n = 290) survived to discharge, with a minority receiving durable cardiac support (left ventricular assist device [n = 48] or heart transplantation [n = 7]). Multivariable regression analysis identified risk factors for mortality on ECMO as older age (odds ratio [OR], 1.26; 95% confidence interval [CI], 1.12–1.42) and female sex (OR, 1.44; 95% CI, 1.02–2.02) and risk factors for mortality after decannulation as higher body mass index (OR 1.17; 95% CI, 1.01-1.35) and major bleeding while on ECMO support (OR, 1.92; 95% CI, 1.23–2.99).ConclusionsDespite contemporary care at high-volume centers, patients treated with VA-ECMO continue to have significant in-hospital morbidity and mortality. The optimization of outcomes will require refinements in patient selection and improvement of care delivery.  相似文献   
195.
196.
197.
198.
199.
200.
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