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   43782篇
  免费   4687篇
  国内免费   856篇
耳鼻咽喉   309篇
儿科学   916篇
妇产科学   614篇
基础医学   3155篇
口腔科学   1528篇
临床医学   4310篇
内科学   5581篇
皮肤病学   504篇
神经病学   3303篇
特种医学   1305篇
外国民族医学   3篇
外科学   3764篇
综合类   5052篇
现状与发展   5篇
一般理论   2篇
预防医学   7259篇
眼科学   610篇
药学   3530篇
  26篇
中国医学   4452篇
肿瘤学   3097篇
  2024年   38篇
  2023年   963篇
  2022年   970篇
  2021年   1692篇
  2020年   1811篇
  2019年   1816篇
  2018年   1790篇
  2017年   1691篇
  2016年   1561篇
  2015年   1395篇
  2014年   3307篇
  2013年   3290篇
  2012年   2658篇
  2011年   2824篇
  2010年   2160篇
  2009年   2084篇
  2008年   2323篇
  2007年   2372篇
  2006年   2121篇
  2005年   1761篇
  2004年   1439篇
  2003年   1381篇
  2002年   1066篇
  2001年   962篇
  2000年   760篇
  1999年   654篇
  1998年   451篇
  1997年   465篇
  1996年   359篇
  1995年   414篇
  1994年   361篇
  1993年   302篇
  1992年   298篇
  1991年   263篇
  1990年   223篇
  1989年   207篇
  1988年   195篇
  1987年   155篇
  1986年   123篇
  1985年   115篇
  1984年   101篇
  1983年   68篇
  1982年   65篇
  1981年   62篇
  1980年   58篇
  1979年   32篇
  1978年   29篇
  1977年   26篇
  1976年   19篇
  1975年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
摘 要 目的 探讨传统膀胱截石位与改良膀胱截石位对超声评估前盆腔相关参数的影响。方法 应用交叉设计二阶段法,将100例行盆底超声检查的患者随机分为两组(每组各50例),A组采用先传统体位后改良体位规范盆底超声,B组采用先改良体位后传统体位规范盆底超声检查,对比分析两种体位检查的成功率、静息状态、最大Valsalva动作时各盆腔参数的差异。结果 改良体位获得最大Valsalva动作的成功率大于传统体位(96% vs 90%),差异有统计学意义(χ2=4.348,P=0.037)。两种体位在静息状态时膀胱颈到参考线的距离、膀胱后角、尿道倾斜角比较差异均无统计学意义;改良体位在最大Valsalva动作时的膀胱后角、膀胱颈移动度、尿道旋转角均大于传统体位,差异均有统计学意义(P<0.05),且上述参数受实验顺序影响不明显,改良体位下尿道漏斗形成率大于传统体位,差异有统计学意义(P<0.05)。结论 体位因素对评估前盆腔相关参数具有影响,改良体位法获得的前盆腔相关参数与传统体位有一定差异,在临床应用中应注意合理解析。  相似文献   
24.
背景 糖尿病肾脏病(DKD)的发病率逐年升高,已成为全世界终末期肾病的主要病因。然而DKD起病隐匿,进入临床蛋白尿期后进展迅速,当肾功能明显受损后,常规治疗难以延缓疾病进展。因此,探究能够延缓晚期DKD疾病进展的切实有效的治疗方法是亟待解决的临床问题。王耀献教授针对DKD晚期浊毒与癥瘕为主的病机特点,提出泄浊消癥法治疗晚期DKD,在临床实践中取得了良好疗效。 目的 以"伏热"理论和"肾络癥瘕"理论为基础,探讨泄浊消癥法治疗晚期DKD的临床疗效。 方法 采用基于真实世界的前瞻性队列研究设计,2016—2020年,于北京中医药大学东直门医院、中国中医科学院广安门医院、首都医科大学附属北京中医医院、中国中医科学院望京医院、中国中医科学院西苑医院、北京市中西医结合医院、北京市房山区中医医院就诊并符合本课题纳入标准的DKD患者为研究对象,以泄浊消癥法作为暴露因素,分为对照组和试验组。对照组予西医基础治疗,试验组在西医基础治疗的基础上联合泄浊消癥法治疗。观察周期为24周,分别于0、4、12、24周时检测两组血肌酐(Scr)、尿素氮(BUN)、24小时尿蛋白定量(24 hUTP)、总胆固醇(TC),计算估算肾小球滤过率(eGFR),记录中医症状积分;于0、12、24周时检测两组糖化血红蛋白(HbA1c)。记录试验期间记录不良事件,评价安全性。 结果 本研究共59例患者完成试验,其中试验组36例、对照组23例。时间对两组受试者eGFR、Scr、BUN水平主效应显著(P<0.05)。组间与时间对两组受试者中医症状积分变化存在交互作用(P<0.05)。组内比较发现,相较于0周,对照组在24周时Scr水平、中医症状积分升高,在12周和24周时BUN水平升高(P<0.05);相较于0周,试验组在4周时eGFR水平升高(P<0.05)。组间比较发现,24周时试验组eGFR水平高于对照组,Scr、BUN水平和中医症状积分低于对照组(P<0.05)。对照组不良事件发生率为21.74%(5/23),试验组不良事件发生率为8.33%(3/36),两组间不良事件发生率比较,差异无统计学意义(χ2=2.15,P=0.14)。 结论 在晚期DKD治疗中,泄浊消癥法联合西医常规治疗相较于单纯西医常规治疗在延缓eGFR降低,减缓Scr、BUN水平升高,保护肾脏功能,降低热证积分,改善中医症状方面具有优势,能够提高临床疗效。  相似文献   
25.
26.
Childhood acute lymphoblastic leukaemia (ALL) is suggested to result from a dysregulated immune response to infections in children with a preleukaemic state. Childcare in early life supposedly may protect against childhood ALL by facilitating sufficient exposure to infections to stimulate and ensure normal maturation of the immune system. We assessed the association between childcare attendance before age 2 years and risk of childhood ALL in a register-based cohort study, including all children aged 2 to 14 years born in Denmark during 1991 to 2014 with available childcare information recorded in the Danish Childcare Database (n = 1 116 185). Cox regression was used to estimate hazard ratios (HRs) comparing children enrolled in childcare and children not enrolled before age 2 years. Further, we assessed the association according to age at enrolment, type of childcare facility and specific ALL subtypes. During 10 460 811 person-years of follow-up, 460 children developed ALL at ages 2 to 14 years. Of these, 57 (12.4%) never attended childcare before age 2 years compared with 10.6% in the total cohort. Compared with homecare, childcare attendance before age 2 years was associated with a statistically non-significantly, marginally decreased risk of childhood ALL with adjusted HR = 0.87 (95% confidence interval [CI]: 0.65-1.16). Risk estimates did neither vary statistically significantly by age at enrolment nor by type of childcare facility and also not between childhood ALL subtypes, including frequently prenatally initiated ALL subtypes. Results from this large, nationwide register-based study provided no evidence that childcare attendance in the first years of life protects against childhood ALL.  相似文献   
27.
We carried out a longitudinal study on the associations between residential greenness and depression risk in urban areas in Finland. Residential greenness indicators were estimated within various buffer sizes around individuals' home locations (selected n = 14424) using time-series of normalized differential vegetation index (NDVI) and CORINE land cover data (CLC). We estimated individuals’ cumulative exposure to residential greenness over a 5-years and 14-years follow-up. We used doctor-diagnosed depression and Beck Depression Inventory for depression assessment. Our multi-logistic model showed an inverse association between residential greenness and depression, implying lowered depression risk for individuals with higher residential greenness. The association was particularly evident when using NDVI-based residential greenness (within a buffer of 100 m radius) and doctor-diagnosis depression data, adjusted with individual-level covariates. The odds ratio was 0.56 (95% CI 0.33 to 0.96) for the 5-years follow-up, and 0.54 (95% CI 0.30 to 0.98) for the 14-years follow-up. The associations between CLC-based total residential green space and depression varied across the different buffer sizes. In general, all the associations depended on the type of depression assessment, quality of greenness indicators, and the spatial scale of analysis. The associations also varied across the socio-demographic groups and neighborhood socioeconomic disadvantage level.  相似文献   
28.
Demographic situation, changes in the role of women in society and growing demand for long-term care (LTC) of older people have challenged the ability to meet the growing LTC needs in most developed countries. In countries where responsibility for LTC is still largely laid on families, it is, however, even more critical and calls for improvements in formal LTC systems. More intensive stakeholder collaboration in LTC policy development, organising and delivery are of primary importance in improving LTC systems. Such collaboration, however, is not always successful; thus, it is critical to understand what makes it effective and efficient. In this paper, we specifically look into multistakeholder collaboration in LTC in Lithuania, one of the fastest ageing countries in the EU, with the demand for LTC services growing fast and exceeding the supply despite rising business and NGO engagement. To determine facilitators of such collaboration, we build on the data obtained through eight focus group discussions with all key stakeholder representatives (LTC policymakers, organisers and service providers [public, private and NGOs], 54 participants in total). Our findings indicate that in addition to national and organisational level facilitators studied in prior research, there are important individual level factors, such as meaningfulness at work, concern and care for others, possibility for personal growth and development, satisfaction with supervision, a sense of belonging and role clarity. On the other hand, our results show that collaboration is constrained by a shortage of human resources, increased workload caused by growing LTC demand, bureaucratic requirements, legal restrictions, lack of awareness of LTC service availability among elder persons, and prevailing social norms and attitudes to institutionalised care. Interestingly, a lack of financial resources is not perceived as a major constraint.  相似文献   
29.
30.
随着蒙医药临床与实验科学的快速发展,关于肝损伤的实验研究也逐渐增多,其研究内容从最初的药物对实验动物生化指标的影响发展到组织病理形态学改变以及分子生物,免疫蛋白测定等。本文章通过查阅与总结从1992年至今关于蒙药治疗肝损伤实验研究,总结多种蒙药复方、单药及其提取物对不同模型导致肝损伤的作用及影响,为蒙药治疗肝损伤的进一步研究发展提供最初的信息资源。  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