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   12066篇
  免费   1192篇
  国内免费   199篇
耳鼻咽喉   777篇
儿科学   153篇
妇产科学   158篇
基础医学   844篇
口腔科学   684篇
临床医学   2075篇
内科学   903篇
皮肤病学   135篇
神经病学   752篇
特种医学   199篇
外国民族医学   1篇
外科学   1019篇
综合类   1604篇
一般理论   9篇
预防医学   2464篇
眼科学   86篇
药学   759篇
  42篇
中国医学   422篇
肿瘤学   371篇
  2024年   28篇
  2023年   214篇
  2022年   305篇
  2021年   509篇
  2020年   571篇
  2019年   469篇
  2018年   419篇
  2017年   461篇
  2016年   509篇
  2015年   517篇
  2014年   855篇
  2013年   1057篇
  2012年   850篇
  2011年   902篇
  2010年   688篇
  2009年   659篇
  2008年   622篇
  2007年   622篇
  2006年   517篇
  2005年   385篇
  2004年   343篇
  2003年   296篇
  2002年   271篇
  2001年   207篇
  2000年   199篇
  1999年   148篇
  1998年   144篇
  1997年   110篇
  1996年   102篇
  1995年   57篇
  1994年   61篇
  1993年   47篇
  1992年   47篇
  1991年   29篇
  1990年   26篇
  1989年   22篇
  1988年   27篇
  1987年   20篇
  1986年   18篇
  1985年   24篇
  1984年   20篇
  1983年   10篇
  1982年   11篇
  1981年   18篇
  1980年   11篇
  1979年   11篇
  1978年   8篇
  1977年   4篇
  1976年   3篇
  1974年   2篇
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
81.
Chemoreceptors in the ventral medulla contribute to the respiratory response to hypercapnia. Do they ‘sense’ intracellular pH (pHi)? We measured pHi in the ventral medulla or cortex (control) using 31P-NMR obtained via a novel 3×5 mm2 surface coil in anesthetized rats breathing air or 7% CO2. During air breathing over 240 min, pHi decreased slightly from 7.13±0.02 to 7.05±0.02 (SEM; n=5; 2 cortex, 3 ventral medulla). During 180 min of hypercapnia, cortical pHi (n=4) decreased from 7.17±0.02 to 6.87±0.01 by 90 min and recovered by 150 min. Ventral medulla pHi showed no such regulation. It decreased from 7.11±0.02 to 6.88±0.02 at 90 min and recovered only after cessation of hypercapnia (n=5), results consistent with pHi being the chemoreceptor stimulus. However, non-chemoreceptor neurons that contribute to our medullary NMR signal also do not appear to regulate pHi in vitro. Regional differences in pHi regulation between cortex and ventral medulla may be due to both chemosensitive and non-chemosensitive neurons.  相似文献   
82.
The fossa navicularis is a relatively rare anatomic variation of the skull base. Awareness of its existence will avoid misinterpretations of radiological images and unnecessary investigations. This study describes the appearance of the fossa navicularis, and investigates its incidence and whether it is related to pathology at the basiocciput. We studied 492 dry human skulls and 525 computer tomography (CT) images of patients. Dry skulls showing a fossa navicularis were investigated by CT scan, whereas patients identified as having a fossa navicularis were further examined with magnetic resonance imaging (MRI). To document the position of the fossa more precisely, measurements were made between the fossa navicularis and certain anatomic landmarks such as the foramen ovale, the pharyngeal tubercle, the posterior border of the vomer, the foramen lacerum, the carotid canal, and the occipital condyle. Upon examination, 26 of 492 skulls (5.3%) were found to have a fossa navicularis. Twelve were <2 mm in depth and the other 14 had a depth of >/=2 mm. Of the 525 patients, 16 (3.0%) were identified as having a fossa navicularis in CT images. Evaluation of MRIs showed no soft tissue lesions in any of these patients. Comprehensive anatomic details of the fossa navicularis have not been reported in the literature. The results of this study may be useful to radiologists, anatomists, and surgeons interested in the skull base.  相似文献   
83.
Anatomical variations of the ten triangles around the cavernous sinus   总被引:5,自引:0,他引:5  
The dimensions of the 10 triangles around the cavernous sinus were measured to define the anatomical characteristics of the triangles and to compare their consistency in shape and area. Twelve tissue blocks containing the bilateral cavernous sinuses and medial two-thirds of the middle cranial fossae were obtained from Japanese adults at autopsy, fixed to a stereotactic frame, and examined with an operative microscope. The dimensions of each triangle were measured with calipers and compared, based on the same point and border. The anteromedial triangle and the superolateral (Parkinson's) triangle were more consistent in shape than the paramedial and oculomotor triangles, but the oculomotor triangle was larger in area than these other triangles. The posteromedial (Kawase's) triangle was more consistent in shape and larger than the anterolateral, lateral, and the posterolateral (Glasscock's) triangles. The anteromedial and superolateral (Parkinson's) triangles are important for the combined epi- and subdural approach to cavernous sinus lesions. The posteromedial (Kawase's) triangle is important for gaining access to the posterior cranial fossa from the middle cranial fossa.  相似文献   
84.
Summary In blood of 21 anemic patients and 8 normal subjects (N) thre oxygen dissociation curves each were measured at different pH values to calculate Bohr coefficients after acidification with CO2 (BCCO 2) or fixed acid (BCFA), and other important parameters of oxygen affinity. The patients had either low hemoglobin or red cell production (L:n=11, 7.3 g/dl Hb) or high erythrocyte production combined with high loss (H:n=10, 7.8 g/dl Hb). The standard half saturation pressure P50 (pH 7.4, 37°C) was equally elevated in both anemic groups (L:30.5, H:30.8, N:26.7 mmHg), as well as the diphosphoglycerate concentration (DPG) (L:18.7, H:18.6, N:12.7 mol/g Hb). The red cell pH of the anemics was lower than for the N (approximately 0.045 units) causing part of the difference in P50. Hill's ntended to high values in the anemics except at low O2-saturation in the H. For BCCO 2 no significant difference among the groups was observed. BCFA, however, increased in the H at low SO 2 compared to the N and L. The cause for most of the changes in hemoglobin oxygen affinity in anemics was the high [DPG]. The combination of high P50 and high n value as in the L seems to be most advantageous for tissue oxygenation.The measurements were performed during a stay as visiting professor at the Universidad del Valle, supported by Deutscher Akademischer Austauschdienst VS 931 509 0013  相似文献   
85.
摘 要:2019年8月,重庆市荣昌区作为全国567个紧密型县域医共体建设试点县之一,以“人通、医通、财通”为抓 手,加快整合医疗卫生资源,促进医疗卫生工作重心下移和资源下沉,积极推动分级诊疗制度建设,为辖区内居民提供全方 位的健康服务。  相似文献   
86.
目的:运用知识图谱技术将诊疗指南中的辨证论治过程构建为可视化的知识图谱,通过程序将输入临床表现到输出相应的中医诊断和处方用药的过程进行可视化,为中医医师直观地显示诊疗过程和数据关系,为中医药诊治冠心病的标准化和规范化提供助力,为中医药诊疗的传承和推广提供技术依托。方法:采用Neo4j联合py2neo知识图谱技术,以中华中医药学会心血管病分会发布的《冠心病稳定型心绞痛中医诊疗指南》为模式构建知识图谱,通过编程实现以临床表现的输入调用知识图谱,可视化展示冠心病稳定型心绞痛的中医规范化诊疗过程。结果:使用py2neo库调用Neo4j,从诊疗指南中提取整理好的结构化数据导入Neo4j,构建基于冠心病稳定型心绞痛中医诊疗指南的知识图谱,且该知识图谱支持图数据库查询功能。结论:该研究结合目前中医诊疗经验传承中存在的问题,针对冠心病稳定型心绞痛这个单一病种,笔者提出了一种基于凝结了中医行业专家经验和循证证据所形成的诊疗指南,实现基于中医诊疗指南和专家经验的知识图谱可视化展示过程,为直观地展现从症状输入到遣方用药的整个中医诊疗过程和辅助中医经验传承提供助力,为中医的标准化和规范化诊疗提供了一种可参考的...  相似文献   
87.
目的对比分析实施PDCA循环前后医疗绩效管理的效果。方法医院每季度进行一次绩效管理考核,分为核心制度、病历质量、用药情况、耗材情况和医疗效率5个维度。2019年第一季度绩效管理开始引入PDCA循环,以第一季度各维度得分作为基础值,对比分析引入PDCA循环前后各维度得分,以手术科室为例,进行统计分析。结果核心制度、病历质量、耗材情况维度得分比较,均P<0.05,差异具有统计学意义;用药情况、医疗效率维度得分比较,均P>0.05,但各季度得分相比基础值均逐渐升高,第四季度与基础值比较差异具有统计学意义(P<0.05)。结论医疗绩效管理中实施PDCA循环,能有效提升管理水平,促进医疗质量螺旋上升。  相似文献   
88.
Modelling and simulation methods can play an important role in guiding public health responses to infectious diseases and emerging health threats by projecting the plausible outcomes of decisions and interventions. The 2003 SARS epidemic marked a new chapter in disease modelling in Canada as it triggered a national discussion on the utility and uptake of modelling research in local and pandemic outbreaks. However, integration and application of model-based outcomes in public health requires knowledge translation and contextualization. We reviewed the history and performance of Pan-InfORM (Pandemic Influenza Outbreak Research Modelling), which created a national infrastructure in Canada with a mandate to develop innovative knowledge translation methodologies to inform policy makers through modelling frameworks that bridge the gaps between theory, policy, and practice. This review demonstrates the importance of a collaborative infrastructure as a “Community of Practice” to guide public health responses, especially in the context of emerging diseases with substantial uncertainty, such as the COVID-19 pandemic. Dedicated resources to modelling and knowledge translation activities can help create synergistic strategies at the global scale and optimize public health responses to protect at-risk populations and quell socioeconomic and health burden.  相似文献   
89.
This paper sets out a structured process for the co-production of knowledge between researchers and societal partners and illustrates its application in an urban health equity project in Accra, Ghana. The main insight of this approach is that research and knowledge co-production is always partial, both in the sense of being incomplete, as well as being circumscribed by the interests of participating researchers and societal partners. A second insight is that project-bound societal engagement takes place in a broader context of public and policy debate. The approach to co-production described here is formed of three recursive processes: co-designing, co-analysing, and co-creating knowledge. These ‘co-production loops’ are themselves iterative, each representing a stage of knowledge production. Each loop is operationalized through a series of research and engagement practices, which we call building blocks. Building blocks are activities and interaction-based methods aimed at bringing together a range of participants involved in joint knowledge production. In practice, recursive iterations within loops may be limited due of constraints on time, resources, or attention. We suggest that co-production loops and building blocks are deployed flexibly.  相似文献   
90.
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