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   20480篇
  免费   2218篇
  国内免费   384篇
耳鼻咽喉   120篇
儿科学   1025篇
妇产科学   123篇
基础医学   1553篇
口腔科学   364篇
临床医学   3283篇
内科学   4180篇
皮肤病学   185篇
神经病学   1066篇
特种医学   427篇
外科学   1101篇
综合类   3473篇
现状与发展   1篇
预防医学   2406篇
眼科学   119篇
药学   2153篇
  37篇
中国医学   842篇
肿瘤学   624篇
  2024年   22篇
  2023年   423篇
  2022年   601篇
  2021年   1140篇
  2020年   1578篇
  2019年   881篇
  2018年   820篇
  2017年   903篇
  2016年   987篇
  2015年   928篇
  2014年   1628篇
  2013年   1815篇
  2012年   1354篇
  2011年   1393篇
  2010年   1083篇
  2009年   899篇
  2008年   869篇
  2007年   946篇
  2006年   742篇
  2005年   594篇
  2004年   557篇
  2003年   519篇
  2002年   319篇
  2001年   264篇
  2000年   205篇
  1999年   177篇
  1998年   156篇
  1997年   125篇
  1996年   115篇
  1995年   126篇
  1994年   108篇
  1993年   75篇
  1992年   88篇
  1991年   86篇
  1990年   70篇
  1989年   79篇
  1988年   47篇
  1987年   42篇
  1986年   37篇
  1985年   67篇
  1984年   43篇
  1983年   27篇
  1982年   29篇
  1981年   29篇
  1980年   18篇
  1979年   13篇
  1978年   9篇
  1977年   11篇
  1976年   11篇
  1975年   7篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
目的 探讨新生儿肺部超声在早产儿肺部感染评价中的价值。 方法 选取肺部感染早产儿80例为观察组,无肺部感染的早产儿80例为对照组,均给予新生儿肺部超声检查,比较2组肺部超声评分、氧合指数、呼吸指数,比较观察组不同病情、预后患儿肺部超声评分、氧合指数、呼吸指数,分析肺部超声评分和氧合指数、呼吸指数的相关性。 结果 观察组肺部超声评分、氧合指数低于对照组,呼吸指数高于对照组,差异有统计学意义(P<0.05)。观察组极危重患儿肺部超声评分、氧合指数低于危重和非危重患儿,呼吸指数高于危重和非危重患儿,危重患儿肺部超声评分、氧合指数低于非危重患儿,呼吸指数高于非危重患儿,差异有统计学意义(P<0.05)。肺部超声评分与呼吸指数呈负相关(r=-0.455,P<0.05),与氧合指数呈正相关(r=0.470,P<0.05)。观察组死亡患儿肺部超声评分、氧合指数低于存活患儿,呼吸指数高于存活患儿,差异有统计学意义(P<0.05)。肺部超声评分预测患儿预后的ROC曲线下面积为0.874,高于呼吸指数和氧合指数(P<0.05),其截断值为20分时,敏感度和特异度为88.50%和75.00%。 结论 新生儿肺部超声在早产儿肺部感染评价中有较好的效果,值得临床使用。  相似文献   
2.
3.
4.
Childhood community acquired pneumonia (CAP) is the leading cause of mortality in children under 5 years worldwide. Clinical practice guidelines (CPGs) may be limited by method of development, scope of recommendations and the quality of supporting evidence. This study systematically identified, appraised and compared the recommendations of CPGs for the management of paediatric CAP using the AGREE II tool.The systematic review yielded 1409 non-duplicate results, of which 14 CPGs were appraised. Four of the fourteen CPGs were deemed high quality. Most CPGs were considered low-medium quality with ‘rigour of development’ and ‘applicability’ the weakest domains. These areas should be considered in deriving CPGs in the future. Recommendations were generally similar across all guidelines; however, there was notable heterogeneity in three areas. This suggests the need for further evidence to guide management decisions on oxygen saturation thresholds for admission, the utility of investigations such as acute phase reactants, and the duration of antibiotic therapy.  相似文献   
5.
ObjectivesCancer can have long-term biopsychological impacts for young people that persist for years. To promote adjustment, it is essential to understand how young people cope, yet this is relatively understudied.MethodsThis study explored the coping strategies using semi-structured interviews with 16 young people with cancer aged 15–24 years. Eligible participants were diagnosed within the previous 24 months and recruited through Australian Youth Cancer Services. Transcribed interviews were analysed using content analysis.ResultsCoping strategies included: seeking support; controlling the focus; avoiding negatives and staying positive; meaning making and; changes with time. During treatment, seeking support, focussing on the present, distraction and avoidance were commonly applied. Following treatment, planning for the future, avoidance of re-traumatising situations and meaning making were used.ConclusionFindings support the concept of coping as a dynamic process where different strategies are used depending on the stressor, available resources and previous experiences.Practice ImplicationsComprehensive, developmentally appropriate psychosocial assessments, open communication, education and information provision, as well as appropriate referral for support are essential, particularly for young cancer survivors identified at risk.  相似文献   
6.
7.
目的 研究社区获得性肺炎(community acquired pneumonia,CAP)患儿血清维生素A(vitamin A,VA)水平及与免疫功能的相关性,为肺炎病情评估提供一定参考。方法 以入住新乡医学院第一附属医院PICU的63例重度社区获得性肺炎(severe community acquired pneumonia, SCAP)患儿(SCAP组)、普通儿科病区的30例轻度社区获得性肺炎(mild community acquired pneumonia, MCAP)患儿(MCAP组),以及同期体检的30名健康儿童(对照组)为研究对象,检测其血清中VA和免疫球蛋白(immunoglobulin,Ig)G、IgA、IgM水平,及SCAP组体内T淋巴细胞亚群(总T淋巴细胞、CD4、CD8、CD4/CD8),并对SCAP组体内VA水平及以上指标的相关性进行分析。结果 3组性别和年龄差异无统计学意义;血清中VA的平均含量分别为0.36、0.25和0.19 mg/L,CAP组VA的含量较对照组明显降低,且SCAP组明显低于MCAP组( P<0.05)。根据WHO推荐的VA诊断标准,3组VA临床缺乏/亚临床缺乏率分别为10.00%、36.67%和61.90%,差异有统计学意义( P<0.05)。CAP组血清中Ig水平较对照组明显降低,且SCAP组明显低于MCAP组( P<0.05)。SCAP组血中总T淋巴细胞、CD4、CD8和CD4/CD8的平均水平分别为53.28%、30.26%、20.24%和1.59;分析VA水平与免疫相关指标关系发现VA水平与Ig(IgG、IgA、IgM)水平、总T淋巴细胞、CD4呈正相关,与CD8水平不相关。结论 肺炎患儿血清VA水平与病情严重程度及机体免疫功能相关。  相似文献   
8.
9.
10.
《Drug discovery today》2022,27(1):223-233
Approaches based on animal and two-dimensional (2D) cell culture models cannot ensure reliable results in modeling novel pathogens or in drug testing in the short term; therefore, there is rising interest in platforms such as organoids. To develop a toolbox that can be used successfully to overcome current issues in modeling various infections, it is essential to provide a framework of recent achievements in applying organoids. Organoids have been used to study viruses, bacteria, and protists that cause, for example, respiratory, gastrointestinal, and liver diseases. Their future as models of infection will be associated with improvements in system complexity, including abilities to model tissue structure, a dynamic microenvironment, and coinfection.Teaser.Organoids are a flexible tool for modelling viral, bacterial and protist infections. They can provide fast and reliable information on the biology of pathogens and in drug screening, and thus have become essential in combatting emerging infectious diseases.  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