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   36241篇
  免费   3812篇
  国内免费   1113篇
耳鼻咽喉   582篇
儿科学   404篇
妇产科学   602篇
基础医学   5276篇
口腔科学   1063篇
临床医学   4565篇
内科学   3961篇
皮肤病学   175篇
神经病学   11782篇
特种医学   1198篇
外科学   3063篇
综合类   2880篇
预防医学   1477篇
眼科学   431篇
药学   2005篇
  15篇
中国医学   1248篇
肿瘤学   439篇
  2024年   108篇
  2023年   803篇
  2022年   1036篇
  2021年   2037篇
  2020年   1823篇
  2019年   1613篇
  2018年   1492篇
  2017年   1524篇
  2016年   1387篇
  2015年   1381篇
  2014年   2270篇
  2013年   2550篇
  2012年   1733篇
  2011年   2027篇
  2010年   1621篇
  2009年   1593篇
  2008年   1593篇
  2007年   1545篇
  2006年   1412篇
  2005年   1159篇
  2004年   1085篇
  2003年   1023篇
  2002年   859篇
  2001年   680篇
  2000年   563篇
  1999年   498篇
  1998年   502篇
  1997年   443篇
  1996年   399篇
  1995年   342篇
  1994年   350篇
  1993年   244篇
  1992年   296篇
  1991年   253篇
  1990年   233篇
  1989年   222篇
  1988年   179篇
  1987年   186篇
  1986年   174篇
  1985年   271篇
  1984年   239篇
  1983年   180篇
  1982年   192篇
  1981年   177篇
  1980年   171篇
  1979年   149篇
  1978年   124篇
  1977年   96篇
  1976年   90篇
  1974年   57篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
51.
52.
53.
54.
55.

Context

Family caregivers constitute a critical component of the end-of-life care system with considerable cost to themselves. However, the joint association of terminally ill cancer patients' symptom distress and functional impairment with caregivers' subjective caregiving burden, quality of life (QOL), and depressive symptoms remains unknown.

Objectives/Methods

We used multivariate hierarchical linear modeling to simultaneously evaluate associations between five distinct patterns of conjoint symptom distress and functional impairment (symptom-functional states) and subjective caregiving burden, QOL, and depressive symptoms in a convenience sample of 215 family caregiver–patient dyads. Data were collected every 2 to 4 weeks over patients' last 6 months.

Results

Caregivers of patients in the worst symptom-functional states (States 3–5) reported worse subjective caregiving burden and depressive symptoms than those in the best two states, but the three outcomes did not differ between caregivers of patients in State 3 and States 4–5. Caregivers of patients in State 5 endured worse subjective caregiving burden and QOL than those in State 4. Caregivers of patients in State 4 suffered worse subjective caregiving burden and depressive symptoms but comparable QOL to those in State 2.

Conclusion

Patients' five distinct, conjoint symptom-functional states were significantly and differentially associated with their caregivers' worse subjective caregiving burden, QOL, and depressive symptoms while caring for patients over their last 6 months.  相似文献   
56.
目的:探讨可调式外固定支具治疗第5掌骨颈骨折的可行性及有效性。方法:选取2014年1月~2017年6月我院收治的54例第5掌骨颈骨折患者作为研究对象,随机分为A组和B组,每组27例。A组行闭合复位交叉克氏针固定,B组行手法整复可调式外固定支具固定,比较两组末次随访第5掌指关节活动度和主观满意度。结果:随访4~10个月,两组患者第5掌指关节活动度(ROM)值相比较,差异无统计学意义,P0.05;两组的主观满意度相比较,差异无统计学意义,P0.05。结论:手法整复可调式外固定支具固定可为第5掌骨颈骨折提供可靠、有效的固定,有助于患者的早期功能恢复,是一种有效的治疗方法。  相似文献   
57.
58.
Most studies investigating the effect of childhood trauma on the brain are retrospective and mainly focus on maltreatment, whereas different types of trauma exposure such as growing up in a violent neighborhood, as well as developmental stage, could have differential effects on brain structure and function. The current magnetic resonance imaging study assessed the effect of trauma exposure broadly and violence exposure more specifically, as well as developmental stage on the fear neurocircuitry in 8‐ to 14‐year‐old children and adolescents (N = 69). We observed reduced hippocampal and increased amygdala volume with increasing levels of trauma exposure. Second, higher levels of violence exposure were associated with increased activation in the amygdala, hippocampus, and ventromedial prefrontal cortex during emotional response inhibition. This association was specifically observed in children younger than 10 years. Finally, increased functional connectivity between the amygdala and brainstem was associated with higher levels of violence exposure. Based on the current findings, it could be hypothesized that trauma exposure during childhood results in structural changes that are associated with later risk for psychiatric disorders. At the same time, it could be postulated that growing up in an unsafe environment leads the brain to functionally adapt to this situation in a way that promotes survival, where the long‐term costs or consequences of these adaptations are largely unknown and an area for future investigations.  相似文献   
59.
《Brain stimulation》2020,13(5):1159-1167
BackgroundInhibitory control refers to a central cognitive capacity involved in the interruption and correction of actions. Dysfunctions in these cognitive control processes have been identified as major maintaining mechanisms in a range of mental disorders such as ADHD, binge eating disorder, obesity, and addiction. Improving inhibitory control by transcranial direct current stimulation (tDCS) could ameliorate symptoms in a broad range of mental disorders.ObjectiveThe primary aim of this pre-registered meta-analysis was to investigate whether inhibitory control can be improved by tDCS in healthy and clinical samples. Additionally, several moderator variables were investigated.MethodsA comprehensive literature search was performed on PubMed/MEDLINE database, Web of Science, and Scopus. To achieve a homogenous sample, only studies that assessed inhibitory control in the go-/no-go (GNG) or stop-signal task (SST) were included, yielding a total of 75 effect sizes from 45 studies.ResultsResults of the meta-analysis indicate a small but significant overall effect of tDCS on inhibitory control (g = 0.21) which was moderated by target and return electrode placement as well as by the task. The small effect size was further reduced after correction for publication bias.ConclusionBased on the studies included, our meta-analytic approach substantiates previously observed differences between brain regions, i.e., involvement of the right inferior frontal gyrus (rIFG) vs. the right dorsolateral prefrontal cortex (rDLPFC) in inhibitory control. Results indicate a small moderating effect of tDCS on inhibitory control in single-session studies and highlight the relevance of technical and behavioral parameters.  相似文献   
60.
目的研究双重排粪造影方式应用在结肠功能性便秘诊断当中的效果。方法文章所选择的调查对象来自2017年10月-2018年12月,均为在此期间本院收治的60例经临床病理诊断确诊为结肠功能性便秘患者,分析双重排粪造影方式和排粪造影的符合性。结果采用双重排粪造影方式诊断结肠功能性便秘59例得到确诊,占98.33%,和排粪造影相比,差异有统计学意义(P<0.05)。结论通过双重排粪造影方式进行结肠功能性便秘诊断,可以有效的提升诊断的效率,对于具体症型的确认也具有重要意义。  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