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   11101篇
  免费   903篇
  国内免费   419篇
耳鼻咽喉   109篇
儿科学   65篇
妇产科学   516篇
基础医学   707篇
口腔科学   235篇
临床医学   1346篇
内科学   585篇
皮肤病学   41篇
神经病学   540篇
特种医学   230篇
外科学   912篇
综合类   1876篇
预防医学   1571篇
眼科学   50篇
药学   1983篇
  16篇
中国医学   1524篇
肿瘤学   117篇
  2024年   35篇
  2023年   177篇
  2022年   321篇
  2021年   603篇
  2020年   446篇
  2019年   392篇
  2018年   396篇
  2017年   414篇
  2016年   461篇
  2015年   420篇
  2014年   854篇
  2013年   1026篇
  2012年   789篇
  2011年   840篇
  2010年   622篇
  2009年   533篇
  2008年   564篇
  2007年   559篇
  2006年   434篇
  2005年   394篇
  2004年   335篇
  2003年   317篇
  2002年   213篇
  2001年   186篇
  2000年   167篇
  1999年   118篇
  1998年   115篇
  1997年   87篇
  1996年   73篇
  1995年   69篇
  1994年   57篇
  1993年   45篇
  1992年   54篇
  1991年   38篇
  1990年   34篇
  1989年   38篇
  1988年   29篇
  1987年   31篇
  1986年   15篇
  1985年   21篇
  1984年   16篇
  1983年   18篇
  1982年   14篇
  1981年   14篇
  1980年   11篇
  1979年   7篇
  1978年   7篇
  1977年   6篇
  1975年   2篇
  1973年   2篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
11.
Objective: A multidisciplinary vocational rehabilitation programme, the Vocational Enablement Protocol (VEP) was developed to address the specific needs of employees with hearing difficulties. In the current study we evaluated the process of implementing the VEP in audiologic care among employees with hearing impairment. Design: In conjunction with a randomized controlled trial, we collected and analysed data on seven process parameters: recruitment, reach, fidelity, dose delivered, dose received and implemented, satisfaction, and perceived benefit. Study sample: Sixty-six employees with hearing impairment participated in the VEP. The multidisciplinary team providing the VEP comprised six professionals. Results: The professionals performed the VEP according to the protocol. Of the recommendations delivered by the professionals, 31% were perceived as implemented by the employees. Compliance rate was highest for hearing-aid uptake (51%). Both employees and professionals were highly satisfied with the VEP. Participants rated good perceived benefit from it. Conclusions: Our results indicate that the VEP could be a useful treatment for employees with hearing difficulties from a process evaluation perspective. Implementation research in the audiological setting should be encouraged in order to further provide insight into parameters facilitating or hindering successful implementation of an intervention and to improve its quality and efficacy.  相似文献   
12.
目的:研究阳春砂小花假合蕊柱的形成过程。方法:将阳春砂小花自0. 5 cm长度至开花后一天划分为8个生长时期,对小花鲜样解剖并制作石蜡切片,测定花药腔的高度,花粉囊裂口夹角,花粉囊缝隙宽度,花柱直径,花丝与唇瓣的夹角(α),花丝与花药的夹角(β)。结果:花粉囊夹角在开花前无明显变化,开花时从32°缩小为17°。两对花粉囊间的缝隙宽度在第5时期增大至约0. 29 mm,同时期的花柱直径约0. 32 mm,两者比例达92%。相比开花前一天,开花时α角从83°减小为42°,β角从186°减小为147°。花丝的远轴侧比近轴侧多1至5层细胞,花柱的近轴侧比远轴侧多1至6层细胞。结论:远、近轴侧细胞结构的不对称性是花丝、花柱运动的基础。在第5时期,花粉囊间的缝隙增大至几乎与花柱等径,花柱运动嵌入花粉囊间。开花时花粉囊夹角缩小,将花粉囊间隙出口封闭,花柱留在花粉囊间,同时角α,β剧烈减小,雄蕊将雌蕊夹在其中向唇瓣弯曲,最终形成半包于唇瓣内的假合蕊柱结构。  相似文献   
13.
ObjectiveTo determine the effect of obesity on the onset of spontaneous labor, scheduled delivery rates and perinatal outcomes in term pregnancies.Material and methods242 obese and 244 non-obese pregnant women ≥37 gestational weeks were compared in terms of the onset of spontaneous labor, scheduled delivery rates and perinatal outcomes.ResultsObese pregnant women had statistically significantly lower onset of spontaneous labor and higher rates of scheduled delivery. No difference was determined in respect of the type of delivery, 1st and 5th minutes APGAR scores and the need for intensive care. Higher values of birth weight, large for gestational age, macrosomia, gestational diabetes mellitus and preeclampsia were determined in obese women.ConclusionThe onset of spontaneous labor rates in term obese pregnancies were lower and scheduled delivery rates were higher than in the non-obese pregnancies. However, more extensive studies are needed to better understand this relationship.  相似文献   
14.
15.
Clinical decisions are often made with incomplete information, yet patient care decisions are made every day. Patients vary clinically, uncertainty exists in diagnostic and prognostic information, and many preventive and treatment alternatives have not been formally assessed for their effectiveness. Because scientific information will never answer all clinical questions, clinical decisions are partially based on probabilistic information.
This paper describes how to apply clinical decision making to diagnosing and managing dental caries and periodontal diseases. By using explicit information to quantify probabilities and outcomes, clinical decision making analyzes decisions made under uncertain conditions and the uncertain impact of clinical information.
Clinical decision making incorporates concepts for preventing, diagnosing and treating dental caries and periodontal diseases: risk assessment, evidence-based dentistry, and multiple oral health outcomes. This information can serve as a tool for clinicians to augment clinical judgment and expertise.  相似文献   
16.
17.
刘春旺 《医疗设备信息》2004,19(8):27-27,51
简述AGFA2050/S多幅相机工作原理,并就工作过程详细阐述,最后简单介绍控制电路。  相似文献   
18.
目的研究17β-雌二醇(17β-E2)对子宫内膜异位症(内异症)患者在位子宫内膜间质细胞β-catenin mRNA和蛋白表达的影响,探讨Wnt/β-catenin信号通路在介导雌激素促进内异症发生发展的作用。方法体外分离培养内异症患者在位子宫内膜间质细胞。用不同浓度17β-E2处理子宫内膜间质细胞48 h;此后选用10-10mol/L 17β-E2处理子宫内膜间质细胞12、24和48 h,逆转录聚合酶链反应(RT-PCR)和免疫印迹法(Western blotting)检测17β-E2处理前后子宫内膜间质细胞β-catenin mRNA和蛋白的表达水平。同法分析雌激素受体拮抗剂ICI182,780(10-6mol/L)对17β-E2促进β-catenin mRNA和蛋白表达的影响。免疫组织化学染色观察17β-E2作用后β-catenin在子宫内膜间质细胞中的定位。结果17β-E2能明显促进内异症患者在位子宫内膜间质细胞β-catenin mRNA和蛋白的表达,并呈剂量和时间依赖性,于10-10mol/L作用48 h最明显。雌激素受体拮抗剂ICI182,780能明显抑制17β-E2对子宫内膜间质细胞β-catenin mRNA和蛋白的表达。免疫组织化学染色发现17β-E2能促进β-catenin在子宫内膜间质细胞核内的表达。结论雌激素可能通过激活Wnt/β-catenin信号通路促进内异症在位子宫内膜的异位种植。  相似文献   
19.
部分NANDA护理诊断缺陷分析及对策   总被引:1,自引:0,他引:1  
刘丽萍 《护理学报》2006,13(10):27-29
NANDA护理诊断给中国护理带来了巨大进步,但在教学和临床应用时,有些护理诊断名称与医学名词相同而内涵不同,有些护理诊断缺乏定量判断而不够严谨,有些护理诊断概念不同但诊断依据和护理措施几乎类似,有些疾病的主要症状体征没有相应的护理诊断。改进护理诊断的对策:一是继续提升对护理诊断的认识,护理诊断很重要、很必要,更要不断发展;二是确立护理诊断的指导思想,起源于医学,为医学分支,症状护理较符合医学逻辑;三是提高护理诊断用语的准确性、公认性;四是在中国建立护理诊断认可程序,完善后编入护理教材,为世界护理事业发展再添中国色彩。  相似文献   
20.
Cylindrical matrices were prepared by compression either of polyvinyl alcohol 100000 or mixtures of the excipient and a drug (sodium salicylate or theophylline). To modify the cylindrical shape, a hole was bored in the centre of the flat surface through both sides of the matrices. Different swellable systems were obtained applying an impermeable coating to one, two or three surfaces of the perforated matrices. The swelling of the perforated matrices was modified according to the number and the position of the coated surfaces (selective coating) and the loaded drug. Pseudo-zero order kinetics were obtained when the interior hole was the only uncoated surface.  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