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   31542篇
  免费   1141篇
  国内免费   366篇
耳鼻咽喉   930篇
儿科学   1019篇
妇产科学   508篇
基础医学   2637篇
口腔科学   444篇
临床医学   2354篇
内科学   6637篇
皮肤病学   439篇
神经病学   3242篇
特种医学   691篇
外科学   2919篇
综合类   3784篇
一般理论   1篇
预防医学   1679篇
眼科学   231篇
药学   1791篇
  10篇
中国医学   3260篇
肿瘤学   473篇
  2023年   234篇
  2022年   585篇
  2021年   1333篇
  2020年   966篇
  2019年   2844篇
  2018年   2387篇
  2017年   1623篇
  2016年   615篇
  2015年   560篇
  2014年   1673篇
  2013年   1385篇
  2012年   1433篇
  2011年   1253篇
  2010年   1099篇
  2009年   1008篇
  2008年   883篇
  2007年   825篇
  2006年   688篇
  2005年   557篇
  2004年   413篇
  2003年   387篇
  2002年   303篇
  2001年   261篇
  2000年   208篇
  1999年   155篇
  1998年   117篇
  1997年   98篇
  1996年   68篇
  1995年   86篇
  1994年   74篇
  1993年   52篇
  1992年   44篇
  1991年   54篇
  1990年   40篇
  1989年   33篇
  1988年   33篇
  1987年   33篇
  1985年   641篇
  1984年   1065篇
  1983年   813篇
  1982年   812篇
  1981年   794篇
  1980年   727篇
  1979年   714篇
  1978年   645篇
  1977年   441篇
  1976年   554篇
  1975年   461篇
  1974年   439篇
  1973年   381篇
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
1.
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area.  相似文献   
2.
BackgroundFindings on the usefulness of massage therapy (MT) in postoperative pain management are often inconsistent among studies.ObjectivesThis study’s aim is to conduct a meta-analysis of randomized controlled trials (RCT) to clarify the effects of massage therapy in the treatment of postoperative pain.MethodsThree databases (PubMed, Embase, and Cochrane Central Register of Controlled Trials) were searched for RCTs published from database inception through January 26, 2021. The primary outcome was pain relief. The quality of RCTs was appraised with the Cochrane Collaboration risk of bias tool. The random-effect model was used to calculate the effect sizes and standardized mean difference (SMD) with 95 % confidential intervals (CIs) as a summary effect. The heterogeneity test was conducted through I2. Subgroup and sensitivity analyses were used to explore the source of heterogeneity. Possible publication bias was assessed using visual inspection of funnel plot asymmetry.ResultsThe analysis included 33 RCTs and showed that MT is effective in reducing postoperative pain (SMD, −1.32; 95 % CI, −2.01 to −0.63; p = 0.0002; I2 = 98.67 %). A similar significant effect was found for both short (immediate assessment) and long terms (assessment performed 4–6 weeks after the MT). Remarkably, we found neither the duration per session nor the dose had an impact on the effect of MT and there seemed to be no difference in the effects of different MT types. In addition, MT seemed to be more effective for adults. Furthermore, MT had better analgesic effects on cesarean section and heart surgery than orthopedic surgery.LimitationsPublication bias is possible due to the inclusion of studies in English only. Additionally, the included studies were extremely heterogeneous. Double-blind research on MT is difficult to implement, and none of the included studies is double-blind. There was some heterogeneity and publication bias in the included studies. In addition, there is no uniform evaluation standard for the operation level of massage practitioners, which may lead to research implementation bias.ConclusionsMT is effective in reducing postoperative pain in both short and long terms.  相似文献   
3.
目的:观察评判性护理干预对乳腺癌手术后患者疼痛和睡眠质量的影响。方法:选取2019年1月至2020年5月蚌埠医学院第一附属医院肿瘤内科收治的乳腺癌手术患者126例作为研究对象,按照随机数字表法分为观察组和对照组,每组63例。对照组给予常规护理干预,观察组给予评判性护理干预。采用抑郁自评量表(Self-rating Depression Scale,SDS)、焦虑自评量表(Self-rating Anxiety Scale,SAS)比较2组患者干预前后抑郁、焦虑状态改善情况,采用匹兹堡睡眠指数量表(Pittsburgh Sleep Quality Index,PSQI)比较2组患者睡眠质量变化,同时观察2组患者并发症发生率、中度、重度疼痛患者所占比例。结果:干预后,观察组SAS评分、SDS评分显著低于对照组,观察组PSQI评分显著低于对照组,患者中度、重度疼痛比例降低,并发症发生率降低,观察组的干预效果优于对照组,2组比较差异有统计学意义(P<0.05)。结论:对乳腺癌患者手术后采用评判性护理,可有效缓解患者手术后疼痛程度,改善患者睡眠质量,降低患者焦虑及抑郁情绪,降低并发症发生风险,值得推广使用。  相似文献   
4.
5.
《Vaccine》2022,40(7):1001-1009
Vaccination guidelines for dogs and cats indicate that core vaccines (for dogs, rabies, distemper, adenovirus, parvovirus; for cats, feline parvovirus, herpes virus-1, calicivirus) are essential to maintain health, and that non-core vaccines be administered according to a clinician’s assessment of a pet’s risk of exposure and susceptibility to infection. A reliance on individual risk assessment introduces the potential for between-practice inconsistencies in non-core vaccine recommendations. A study was initiated to determine non-core vaccination rates of dogs (Leptospira, Borrelia burgdorferi, Bordetella bronchiseptica, canine influenza virus) and cats (feline leukemia virus) in patients current for core vaccines in veterinary practices across the United States. Transactional data for 5,531,866 dogs (1,670 practices) and 1,914,373 cats (1,661 practices) were retrieved from practice management systems for the period November 1, 2016 through January 1, 2020, deidentified and normalized. Non-core vaccination status was evaluated in 2,798,875 dogs and 788,772 cats that were core-vaccine current. Nationally, median clinic vaccination rates for dogs were highest for leptospirosis (70.5%) and B. bronchiseptica (68.7%), and much lower for canine influenza (4.8%). In Lyme-endemic states, the median clinic borreliosis vaccination rate was 51.8%. Feline leukemia median clinic vaccination rates were low for adult cats (34.6%) and for kittens and 1-year old cats (36.8%). Individual clinic vaccination rates ranged from 0 to 100% for leptospirosis, B. bronchiseptica and feline leukemia, 0–96% for canine influenza, and 0–94% for borreliosis. Wide variation in non-core vaccination rates between clinics in similar geographies indicates that factors other than disease risk are driving the use of non-core vaccines in pet dogs and cats, highlighting a need for veterinary practices to address gaps in patient protection. Failure to implement effective non-core vaccination strategies leaves susceptible dogs and cats unprotected against vaccine-preventable diseases.  相似文献   
6.
7.
8.
9.
10.
IntroductionEvidence for the relationship between movement behaviors and mental health among adolescents is inconclusive. We aimed to identify profiles of digital media use (including related bedtime delay) and leisure-time physical activity (LTPA) in adolescence, and to examine whether preadolescent mental health predicted later behavior profiles.MethodsThis study included 1285 participants assessed at 11 years of age, and followed-up four years later. Participants completed the Self-Perception Profile for Children (SPPC), Center for Epidemiological Studies Depression Scale for Children (CES-DC) and Screen for Child Anxiety-Related Emotional Disorders (SCARED) at baseline, and reported digital media use (active and passive use, gaming, and related bedtime delays) and LTPA at follow-up. A latent class approach was employed to identify behavior profiles, membership of which was then predicted with mental health and covariates, including baseline digital media use and LTPA.ResultsWe identified four behavior profiles: 1) high digital media use/moderate LTPA (20% of adolescents; 78% boys), 2) moderate digital media use/high LTPA (31%; 28%), 3) high digital media use/high LTPA (26%; 15%), 4) high passive digital media use and gaming/low LTPA (23%; 89%). After adjusting for covariates, higher LTPA and better perception of athletic competence at baseline associated with higher odds of belonging to any other profile than to the unhealthiest profile (4) at follow-up. Symptoms of depression or anxiety did not associate with later behavior profiles.ConclusionsLTPA and related self-esteem seem to be stronger predictors of future digital media use and LTPA behavior during adolescence than mental health symptoms alone.  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