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   36635篇
  免费   3393篇
  国内免费   401篇
耳鼻咽喉   332篇
儿科学   2079篇
妇产科学   391篇
基础医学   3961篇
口腔科学   533篇
临床医学   3339篇
内科学   2528篇
皮肤病学   221篇
神经病学   15595篇
特种医学   341篇
外科学   1127篇
综合类   2795篇
现状与发展   2篇
一般理论   1篇
预防医学   3044篇
眼科学   129篇
药学   2988篇
  7篇
中国医学   808篇
肿瘤学   208篇
  2024年   116篇
  2023年   860篇
  2022年   1216篇
  2021年   1850篇
  2020年   1767篇
  2019年   1701篇
  2018年   1565篇
  2017年   1648篇
  2016年   1672篇
  2015年   1473篇
  2014年   2458篇
  2013年   3430篇
  2012年   1922篇
  2011年   2369篇
  2010年   1789篇
  2009年   1770篇
  2008年   1838篇
  2007年   1680篇
  2006年   1383篇
  2005年   1149篇
  2004年   931篇
  2003年   845篇
  2002年   733篇
  2001年   530篇
  2000年   427篇
  1999年   372篇
  1998年   407篇
  1997年   337篇
  1996年   256篇
  1995年   212篇
  1994年   184篇
  1993年   167篇
  1992年   159篇
  1991年   153篇
  1990年   132篇
  1989年   126篇
  1988年   112篇
  1987年   84篇
  1986年   50篇
  1985年   103篇
  1984年   79篇
  1983年   53篇
  1982年   78篇
  1981年   46篇
  1980年   48篇
  1979年   33篇
  1978年   33篇
  1977年   27篇
  1976年   25篇
  1974年   13篇
排序方式: 共有10000条查询结果,搜索用时 553 毫秒
51.
Objective: To determine serotonin system abnormalities related to major depression or previous suicidal behavior.

Methods: [11C]WAY100635, [18F]altanserin and positron emission tomography were used to compare 5-HT1A and 5-HT2A binding in MDD patients divided into eight past suicide attempters (>4yrs prior to scanning) and eight lifetime non-attempters, and both groups were compared to eight healthy volunteers.

Results: The two receptor types differed in binding pattern across brain regions from each other, but there were no differences in binding between healthy volunteers and the two depressed groups or between depressed suicide attempters and non-attempters. No effects of depression severity or lifetime aggression were observed for either receptor.

Conclusion: Limitations of this study include small sample size and absence of high lethality suicide attempts in the depressed attempter group. No trait-like binding correlations with past suicide attempt or current depression were observed. Given the heterogeneity of nonfatal suicidal behavior, a larger sample study emphasizing higher lethality suicide attempts may find the serotonin biological phenotype seen in suicide decedents.  相似文献   

52.
消化道术后胃肠功能紊乱影响着患者们的生活质量。张立平教授认为术后胃肠功能紊乱,证属本虚标实,临床治疗当从调理中焦-脾胃肝为切入点,强调"脾胃为本""中焦一体"的治疗思路,总结出脾胃虚弱、肝郁脾虚两个证型,临证时以培土达木为基本治疗原则,辨证论治,临床疗效显著。  相似文献   
53.
目的 探讨思维导图在本科护生精神科实习带教中的应用效果。方法 选取2018年6月至12月31名本科护生为试验组,采用思维导图进行带教;选取2019年4月至7月32名本科护生作为对照组,采用传统的带教方法进行带教。比较两组前后评判性思维能力、对带教方法的评价,以及两组护生的理论、操作考试成绩。采用SPSS 20.0进行t检验、卡方检验和秩和检验。结果 试验组在评判性思维能力量表各项得分明显提高,由带教前的(248.09±24.45)分提高至(331.03±14.31)分,且高于对照组(P<0.05)。试验组在带教方法肯定性评价各项得分均高于对照组,差异均有统计学意义(P<0.05)。试验组带教后理论成绩为(88.35±7.71)分、操作考试成绩为(86.45±5.03)分,对照组带教后理论成绩为(74.41±10.27)分、操作考试成绩为(81.02±6.64)分,两组比较差异有统计学意义(P<0.05)。结论 运用思维导图对精神科护生进行临床带教,提高了护生学习积极性,学习由被动变主动,同时促进了护生评判性思维能力培养,值得临床推广。  相似文献   
54.
《Clinical neurophysiology》2020,131(1):213-224
ObjectiveSystematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations).MethodsPubmed, ISI Web of Knowledge and BIORXIV were searched for the relevant articles according to PRISMA standards.ResultsERP components are generally delayed across all sensory modalities both in RTT patients and its animal model, while findings on ERPs amplitude strongly depend on stimulus properties and presentation rate. Studies on RTT animal models uncovered the abnormalities in the excitatory and inhibitory transmission as critical mechanisms underlying the ERPs changes, but showed that even similar ERP alterations in auditory and visual domains have a diverse neural basis. A range of novel approaches has been developed in animal studies bringing along the meaningful neurophysiological interpretation of ERP measures in RTT patients.ConclusionsWhile there is a clear evidence for sensory ERPs abnormalities in RTT, to further advance the field there is a need in a large-scale ERP studies with the functionally-relevant experimental paradigms.SignificanceThe review provides insights into domain-specific neural basis of the ERP abnormalities and promotes clinical application of the ERP measures as the non-invasive functional biomarkers of RTT pathophysiology.  相似文献   
55.
56.

Purpose

To quantify eating disorder (ED) stability and diagnostic transition among a community-based sample of adolescents and young adult females in the United States.

Methods

Using 11 prospective assessments from 9,031 U.S. females ages 9–15 years at baseline of the Growing Up Today Study, we classified cases of the following EDs involving bingeing and purging: bulimia nervosa (BN), binge ED, purging disorder (PD), and subthreshold variants defined by less frequent (monthly vs. weekly) bingeing and purging behaviors. We measured number of years symptomatic and probability of maintaining symptoms, crossing to another diagnosis, or resolving symptoms across consecutive surveys.

Results

Study lifetime disorder prevalence was 2.1% for BN and roughly 6% each for binge ED and PD. Most cases reported symptoms during only one survey year. Twenty-six percent of cases crossed between diagnoses during follow-up. Among participants meeting full threshold diagnostic criteria, transition from BN was most prevalent, crossing most frequently from BN to PD (12.9% of BN cases). Within each disorder phenotype, 20%–40% of cases moved between subthreshold and full threshold criteria across consecutive surveys.

Conclusions

Diagnostic crossover is not rare among adolescent and young adult females with an ED. Transition patterns from BN to PD add support for considering these classifications in the same diagnostic category of disorders that involve purging. The prevalence of crossover between monthly and weekly symptom frequency suggests that a continuum or staging approach may increase utility of ED classification for prognostic and therapeutic intervention.  相似文献   
57.
Bernard–Soulier syndrome (BSS) is a rare autosomal recessively inherited bleeding disorder. Pregnancy in patients with BSS is characterized by ante‐, intra‐, or postpartum haemorrhage, which may be delayed and severe. There is no consensus in the management of BSS in pregnancy and so far only 16 pregnancies in nine patients have been described. We report a further three pregnancies in two women with the syndrome. We also outline our management of pregnant patients with BSS.  相似文献   
58.
59.
北京市50家综合医院门诊患者抑郁障碍的调查   总被引:11,自引:0,他引:11  
目的 了解北京地区综合医院门诊患者抑郁障碍的患病率。方法 随机抽取50家各级综合医院为调查现场,由精神科护士用自制抑郁筛选量表调查各科门诊患者2877例,由精神科医师对筛选阳性和10%的筛选阴性者以美国精神障碍诊断与统计手册第4版(DSM—Ⅳ)为金标准做出诊断。结果 (1)符合DSM—Ⅳ重性抑郁发作者为73例,现患病率为2.54%。其中内、外科患者的患病率(分别为3.03%和3.12%)高于其他科(1.58%);而性别分布的差异无统计学意义。(2)抑郁障碍总的现患率、年患率和终生患病率分别为3.09%、3.65%和6.16%;其中,重性抑郁障碍分别为1.97%、2.53%和4.48%。(3)检出的73例重性抑郁发作患者中,仅10例(14%)因抑郁求助和接受医生提供的服务,并被正确识别。结论北京综合医院非心理科门诊患者抑郁障碍的现患率为3.09%;患者对抑郁问题而求助医生的比例低。  相似文献   
60.
BACKGROUND: The validity of parent reports regarding children's attention-deficit/hyperactivity disorder (ADHD) symptoms has been questioned. This study assessed whether parent reports were as sensitive as teacher reports to document change in ADHD symptoms during clinical trials with atomoxetine. METHODS: Data were compared from two randomized, double-blind, placebo-controlled clinical trials of atomoxetine using different versions (parent or teacher) of the same rating scale (Attention-Deficit/Hyperactivity Disorder Rating Scale-IV [parent or teacher] Version: Investigator Administered and Scored - ADHD RS). Exclusion criteria included history of bipolar disorder, psychosis, seizures, alcohol abuse, or positive drug screen. Patients (6-16 years old) were treated with atomoxetine (titrated to a maximum dose of 1.8 mg/kg/day) administered once daily for up to 7 weeks. Parent and teacher ratings were compared using an analysis of covariance (ANCOVA) model. RESULTS: The analysis (n = 318) showed that treatment effects (mean change, baseline to endpoint) were similar between parent and teacher ratings (total, p = .762; inattention, p = .519; hyperactive/impulsive, p = .955). Effect sizes also were similar based on total scores (parent ratings = .69; teacher ratings = .63). CONCLUSIONS: Parent reports are as sensitive as teacher reports in assessing the efficacy of long-acting pharmacologic treatment for ADHD in children during clinical trials using the nonstimulant atomoxetine.  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