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   1387篇
  免费   166篇
  国内免费   16篇
耳鼻咽喉   14篇
儿科学   349篇
妇产科学   67篇
基础医学   119篇
口腔科学   2篇
临床医学   165篇
内科学   103篇
皮肤病学   7篇
神经病学   41篇
特种医学   18篇
外科学   109篇
综合类   129篇
预防医学   256篇
眼科学   8篇
药学   161篇
  1篇
中国医学   6篇
肿瘤学   14篇
  2024年   8篇
  2023年   24篇
  2022年   52篇
  2021年   69篇
  2020年   80篇
  2019年   54篇
  2018年   46篇
  2017年   77篇
  2016年   59篇
  2015年   65篇
  2014年   64篇
  2013年   117篇
  2012年   57篇
  2011年   66篇
  2010年   49篇
  2009年   52篇
  2008年   49篇
  2007年   54篇
  2006年   40篇
  2005年   49篇
  2004年   36篇
  2003年   38篇
  2002年   27篇
  2001年   29篇
  2000年   17篇
  1999年   17篇
  1998年   15篇
  1997年   25篇
  1996年   24篇
  1995年   18篇
  1994年   25篇
  1993年   19篇
  1992年   13篇
  1991年   16篇
  1990年   10篇
  1989年   16篇
  1988年   3篇
  1987年   16篇
  1986年   8篇
  1985年   7篇
  1984年   5篇
  1982年   11篇
  1981年   4篇
  1980年   8篇
  1979年   5篇
  1978年   7篇
  1976年   6篇
  1975年   3篇
  1973年   5篇
  1967年   1篇
排序方式: 共有1569条查询结果,搜索用时 0 毫秒
1.
目的 探讨早产胎膜早破 (pretermprematureruptureofmembranes ,PPROM)的妊娠结局。方法 对 6 5例PPROM进行回顾性分析。结果  6 5例PPROM中以流产引产史、感染及胎位不正多见。孕 2 8~ 34+ 6w 与孕35~ 36 + 6wPPROM比较 ,前者剖官产率明显低于后者 (P <0 .0 1) ,而新生儿发病率明显高于后者 (P <0 .0 1)。结论 对孕 2 8~ 34+ 6w 的PPROM宜采用期待疗法 ,以减少新生儿的并发症 ,降低新生儿的发病率及死亡率  相似文献   
2.
ABSTRACT. Background: Several designs of plastic blanket heat shields are in use. This study was done to compare different designs for their efficiency in reducing heat loss. Methods: Four heat shield designs were tested by sequentially covering each of 14 infants (wt. 640–2030 g) cared for under radiant warmers. The power consumption of the radiant warmers was measured as a surrogate for. heat loss. All designs were tested for a total of 20 min on all infants. Results were calculated as percent change in power consumption from shield to shield. The most efficient design was further modified and evaluated in another group of 14 infants (wt. 700–1180 g). Results: The relative reductions in power consumption were: no shield (control) –0%, a plastic foil over the side rails: –17%, a single layer close to the infant but excluding the head: –34%, the same as double layer –37% and the most efficient one, a single layer covering the whole infant –42%. A modification of this design, tested in the second group of infants, reduced power consumption by 13% (95% CI –5.9/–19.7), ( p < 0.004) when compared to the single layer covering the whole infant. It was tucked under the connecting tubes to the ventilator. It also reduced the risk for displacement and allowed for the endotracheal tube to be suctioned without removing the blanket. Conclusion: Modifications of the design of heat shield blankets for infants resulted in significant increases in efficiency.  相似文献   
3.
目的 为探讨硫酸镁治疗新生儿重症肺炎的临床效果及对血气血镁的影响。方法 采用 96例新生儿重症肺炎患儿随机分成治疗组 4 8例 ,对照组 4 8例 ,治疗组加用硫酸镁 30~ 5 0mg/(kg·d)加入 5 %葡萄糖 2 0ml静滴 ,持续 1h ,疗程3~ 8d ,同时监测血气血镁。结果 治疗组总有效率 79.2 % ,对照组总有效率 5 0 .0 % (P <0 .0 1) ,硫酸镁在改善症状 ,消除肺部体征及缩短住院时间和提高治愈率等方面优于对照组 ,治疗组病死率下降 ,同时血气恢复正常优于对照组 ,血镁含量治疗前后无变化。结论 硫酸镁治疗新生儿重症肺炎疗效显著 ,未发现明显副作用。  相似文献   
4.
新生儿呼吸机选择的要素   总被引:1,自引:1,他引:0  
根据新生儿和成人之间呼吸生理的不同,认为新生儿呼吸机与儿童、成人呼吸机无论从那方面来讲都有较大的区别,并从新生儿呼吸生理的特点出发,提出购买新生儿呼吸机时要注意的几个要素。  相似文献   
5.
The thermal responses of neonates during a cool acclimation period were studied with regard to sleep stages. Sleep stages, body temperatures and metabolic rate (VO2) were studied for seven neonates nursed in incubators and exposed to a cool temperature (thermoneutrality minus 2 degrees C) for 75 h. Each recording session lasted 3 h in the morning: firstly under thermoneutral baseline conditions, then during the first and last 3-h periods of the cool acclimation and finally during the last 3 h of a 24-h recovery period. Sleep structure was modified during the initial hours of cool exposure: the percentage of active sleep increased (AS: +13%, P = 0.028) at the expense of quiet sleep (QS: -11%, P = 0.043). This alteration in sleep structure persisted at the end of the acclimation period. Metabolic heat production only increased in the later period of cool acclimation. Throughout the cool exposure, VO2 increased more (P = 0.040) in QS (+33%) than in AS (+20%) so that by the end of the cool period, VO2 levels were similar in both sleep stages. During cool acclimation, the maintenance of homeothermy is related not only to a change in sleep organization but also to modifications in the thermoregulatory processes in both sleep stages. Considering the importance of AS/QS patterns in the neurobehavioral development of neonates, the present results could have clinical implications for the thermal management of neonates.  相似文献   
6.
人胚胎胃的组织发生   总被引:3,自引:0,他引:3  
张薇  何素云 《解剖学报》1992,23(3):325-329
  相似文献   
7.
ABSTRACT  The technique for gavage administration to rat nurslings was improved to allow determination of the direct effects of chemical substances in the nurslings. Rat neonates were treated with distilled water from postnatal day 1 through 20 using this technique. The viability of neonates during the administration period was comparable to that of untreated neonates. No adverse effects of this technique on the development of neonates were found, and no histological alterations of the esophagus or pharynx. Therefore, we conclude that use of our improved gavage administration method will contribute to ensuring successful neonatal development and thus allowing accurate assessment of the toxicological effects of test compounds on rat nurslings.  相似文献   
8.
BACKGROUND: Within an ongoing birth cohort study (LISA) the cytokine production of cord blood T cells was compared between neonates from Leipzig (East Germany) and Munich (West Germany). The aim of this study was to analyse regional differences and influencing factors of the immune status. METHODS: Cytokine production was measured in a randomly selected subgroup of 158 children from the LISA (Life style - Immune system - Allergy) cohort by intracellular cytokine staining. Information on family "atopy" history (FAH) and home characteristics was obtained from questionnaires. RESULTS: Reduced numbers of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) producing T cells were found in association with biparental FAH and housing renovation during pregnancy. In addition, cytokine production was influenced by season. In Munich, the frequency of biparental FAH and of renovation measures during pregnancy was significantly higher as compared to Leipzig. Neonates from Munich showed significantly decreased amounts of IFN-gamma and TNF-alpha and elevated levels of interleukin-4 (IL-4) producing T cells. Differences in cytokine production between Munich and Leipzig were influenced by season (IL-4) and housing renovation (IFN-gamma, TNF-alpha). CONCLUSIONS: Since differences in the T cell cytokine production of neonates in Munich and Leipzig are independent from FAH our findings may provide evidence for the impact of environmental factors upon the fetal immune system.  相似文献   
9.
The immunogenicity of a full dose (20 μg) of recombinant DNA yeast-derived hepatitis B vaccine (Engerix-B) was assessed in healthy neonates in order to compare three candidate vaccination schemes. After randomization 162 newborns of hepatitis B surface antigen (HBsAg) negative mothers entered the study. Neonates received hepatitis B vaccine according to a fourdose vaccination scheme starting either at month 3 (scheme I: months 3,4,5, and 11) or at birth (scheme III: months 0,1,2, and 11). Another group of neonates received hepatitis B vaccine according to a three-dose scheme starting at birth (scheme II: months 0, 1, and 6). Serious adverse reactions were not observed; 2.5% of the vaccinated newborns suffered mild transient local symptoms. The vaccine was highly immunogenic irrespective of vaccination scheme; all infants developed anti-HBs levels ≥10 IU/L, 97% ≥100 IU/L. The immunogenicity of hepatitis B vaccine after primary and booster vaccinations, administered in the four-dose scheme started at birth, was significantly higher (P< 0.05) than in the three-dose scheme started at birth. Hepatitis B vaccination according to the four-dose scheme started at month 3 produced significantly higher (P < 0.05) antibody levels in comparison to the four-dose scheme started directly after birth. This study showed that a fourdose hepatitis B vaccination scheme starting at month 3 resulted in the highest antibody levels of the three schemes investigated and can be recommended for incorporation in the Expanded Programme on Immunization in The Netherlands.  相似文献   
10.
本文就新生儿尿布皮炎发生的危险因素及预防的研究进展,从完善新生儿皮肤监测系统、ABCDE皮肤护理方案的实施和采用家长参与式护理模式等3个方面进行阐述,以期为降低新生儿尿布皮炎的发生率,提高患儿的舒适度,降低医疗花费,为保障新生儿家庭的护理安全提供参考和指导。  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