全文获取类型
收费全文 | 9735篇 |
免费 | 733篇 |
国内免费 | 185篇 |
专业分类
耳鼻咽喉 | 108篇 |
儿科学 | 180篇 |
妇产科学 | 230篇 |
基础医学 | 1116篇 |
口腔科学 | 529篇 |
临床医学 | 1552篇 |
内科学 | 1031篇 |
皮肤病学 | 102篇 |
神经病学 | 513篇 |
特种医学 | 564篇 |
外科学 | 1128篇 |
综合类 | 801篇 |
预防医学 | 1933篇 |
眼科学 | 191篇 |
药学 | 406篇 |
2篇 | |
中国医学 | 120篇 |
肿瘤学 | 147篇 |
出版年
2023年 | 162篇 |
2022年 | 274篇 |
2021年 | 339篇 |
2020年 | 341篇 |
2019年 | 385篇 |
2018年 | 333篇 |
2017年 | 315篇 |
2016年 | 313篇 |
2015年 | 296篇 |
2014年 | 522篇 |
2013年 | 784篇 |
2012年 | 402篇 |
2011年 | 418篇 |
2010年 | 392篇 |
2009年 | 372篇 |
2008年 | 445篇 |
2007年 | 449篇 |
2006年 | 403篇 |
2005年 | 376篇 |
2004年 | 351篇 |
2003年 | 302篇 |
2002年 | 255篇 |
2001年 | 240篇 |
2000年 | 192篇 |
1999年 | 172篇 |
1998年 | 149篇 |
1997年 | 166篇 |
1996年 | 168篇 |
1995年 | 142篇 |
1994年 | 119篇 |
1993年 | 108篇 |
1992年 | 103篇 |
1991年 | 82篇 |
1990年 | 63篇 |
1989年 | 53篇 |
1988年 | 63篇 |
1987年 | 55篇 |
1986年 | 55篇 |
1985年 | 56篇 |
1984年 | 66篇 |
1983年 | 52篇 |
1982年 | 43篇 |
1981年 | 36篇 |
1980年 | 28篇 |
1979年 | 24篇 |
1978年 | 36篇 |
1977年 | 34篇 |
1976年 | 40篇 |
1975年 | 27篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
1.
《Archivos de la Sociedad Espa?ola de Oftalmología》2022,97(8):432-442
PurposeTo develop and evaluate an automated method to measure the foveal avascular zone (FAZ) area in healthy eyes on Heidelberg Spectralis Optical Coherence Tomography Angiography (HS-OCTA). This method is referred to as the modified Kanno-Saitama macro (mKSM) which is an evolution of the Kanno-Saitama macro (KSM) approach.MethodsThis cross-sectional study included 29 eyes of 25 healthy volunteers who underwent HS-OCTA at the macular area twice at the same time. Regardless of the quality of the images, all of them were included. Macular data on the superficial vascular plexus, intermediate capillary plexus (ICP) and deep capillary plexus were processed by mKSM. The FAZ area was measured twice automatically using the mKSM and KSM and twice manually by two independent examiners.ResultsFrom 174 images, KSM could not measure correctly 31% while mKSM could successfully measure all of them. Intrascan intraclass coefficient ranged from 0.948 to 0.993 for manual measurements and was 1 for mKSM method. Despite that the difference between human examiners is smaller than between human examiners and mKSM according to Bland-Altman plots, the scatterplots show a strong correlation between human and automatic measurements. The best results are obtained in ICP.ConclusionsWith mKSM, the automated determination of the FAZ area in HS-OCTA is feasible and less human-dependent. It solves the inability of KSM to measure the FAZ area in suboptimal quality images which are frequent in daily clinical practice. Therefore, the mKSM processing could contribute to our understanding of the three vascular plexuses. 相似文献
2.
3.
4.
《Journal of Medical Imaging and Radiation Sciences》2015,46(3):309-316
ObjectivesThe purposes of this study were to (1) investigate the limits of measurements on scout view in three computed tomography axes, x, y and z and (2) develop a model to provide better understanding of measurement accuracy.MethodsFor the first objective, anteroposterior and lateral scout views of a Catphan phantom 200 mm in diameter and length were acquired with a GE scanner at 21 different table heights. Phantom measurements on scout view were performed by two experienced readers. The comparison of their measures provided estimation of precision. The accuracy was assessed by determining the bias, calculated as the difference between the values measured on scout view and the real phantom size. Second, a model was developed investigating the relationship between the dimensions of the object, its image, and the table height. This relationship was tested on our data.ResultsScout view measurements were precise, with less than 0.53% difference between readers. In addition, small biases of about 1 mm were detected in the z-axis, whatever the table height. In the other axes, serious biases from −13 to +73 mm were measured. Furthermore, at isocentre, overestimations up to 7 mm were shown. The results also indicated that biases in scout view measurements are because of the geometrical projection related to the object-detector distance.ConclusionsMeasurements in the table movement axis are precise and accurate, conferring to scout views an added value for preoperative planning in orthopedic surgery. 相似文献
5.
6.
教育测量与评价对实现教育目标具有重要作用。科学的教育评价既促进学生学习,又为教育决策提供依据,以实现持续质量改进。"健康中国2030"的整体目标、医学科学的发展及人民的健康需求,对新时代护理人才的培养提出了更高、更具体的要求。高等护理院校应以国家和社会对护理人才需求、院校培养目标为导向,以测量理论为基础,制定完善的学业评定标准,科学地开展毕业考核,保证人才"出口"质量。毕业考核作为终结性评价,测试内容在评价质量中起核心作用,应符合国家护理学专业培养标准,并与院校培养目标、课程目标契合。院校应关注护理本科生毕业考核质量,在保障测试信度的同时,做到实施公平、评价适当、标准一致,以确保测试的效度。教育管理部门及各院校应优化评价体系,加强对护理本科生毕业管理,在充分开展系统调查与分析的基础上,基于胜任力导向和结果导向,建立综合性评价体系,在教学过程中进行全方位反馈评价管理。文章结合国内外护理学专业本科生毕业考核的现状,从考核目的、内容、方式、评价主体、质量控制等方面进行综述与分析,为我国加强护理学本科教育,完善护理学专业本科生毕业评价体系建设提供借鉴。 相似文献
7.
8.
目的通过线性法测量皮质下缺血性血管病(SIVD)患者脑萎缩,分析其与认知功能损害的相关性。方法共纳入SIVD组50例,健康对照组50例。所有入组对象均完成一般情况评定、Mo CA量表评估认知功能、头颅MRI检查,线性法进行脑萎缩测量。结果 SIVD组代表脑室系统横径的测量值及脑沟测量值,除桥池宽度外,均较对照组显著增大(P 0. 05)。SIVD组的脑萎缩测量相对值除脑干指数外,均显著高于对照组(P 0. 05)。SIVD组双侧侧脑室两额角间最宽距离、双侧侧脑室额角两侧尾状核头间最小距离、第三脑室宽度、双侧侧脑室腰部外侧壁最小距离与Mo CA评分呈显著负相关(P 0. 05)。SIVD组脑萎缩测量相对值中的额角指数、尾状核指数、哈氏值、第三脑室宽度与视空间能力、计算力、延迟记忆和定向力均呈负相关(P 0. 05)。结论 SIVD患者存在明显的皮质和皮质下萎缩,并与认知功能损害相关。哈氏值、额角指数、尾状核指数、第三脑室宽度可作为SIVD患者脑萎缩的预测指标,提示执行功能/视空间及计算力、记忆力的损害。 相似文献
9.
10.