全文获取类型
收费全文 | 7693篇 |
免费 | 497篇 |
国内免费 | 126篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 50篇 |
妇产科学 | 37篇 |
基础医学 | 802篇 |
口腔科学 | 663篇 |
临床医学 | 653篇 |
内科学 | 738篇 |
皮肤病学 | 178篇 |
神经病学 | 411篇 |
特种医学 | 948篇 |
外国民族医学 | 1篇 |
外科学 | 759篇 |
综合类 | 1360篇 |
一般理论 | 2篇 |
预防医学 | 949篇 |
眼科学 | 136篇 |
药学 | 240篇 |
13篇 | |
中国医学 | 99篇 |
肿瘤学 | 237篇 |
出版年
2024年 | 40篇 |
2023年 | 240篇 |
2022年 | 353篇 |
2021年 | 431篇 |
2020年 | 369篇 |
2019年 | 246篇 |
2018年 | 263篇 |
2017年 | 248篇 |
2016年 | 219篇 |
2015年 | 266篇 |
2014年 | 402篇 |
2013年 | 465篇 |
2012年 | 445篇 |
2011年 | 543篇 |
2010年 | 397篇 |
2009年 | 418篇 |
2008年 | 430篇 |
2007年 | 372篇 |
2006年 | 350篇 |
2005年 | 309篇 |
2004年 | 249篇 |
2003年 | 167篇 |
2002年 | 167篇 |
2001年 | 132篇 |
2000年 | 114篇 |
1999年 | 72篇 |
1998年 | 71篇 |
1997年 | 83篇 |
1996年 | 54篇 |
1995年 | 63篇 |
1994年 | 43篇 |
1993年 | 26篇 |
1992年 | 35篇 |
1991年 | 30篇 |
1990年 | 27篇 |
1989年 | 15篇 |
1988年 | 25篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 34篇 |
1984年 | 20篇 |
1983年 | 14篇 |
1982年 | 5篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1973年 | 4篇 |
排序方式: 共有8316条查询结果,搜索用时 15 毫秒
71.
Philippe A. Puech Loïc Boussel Samir Belfkih Laurent Lemaitre Philippe Douek Régis Beuscart 《Journal of digital imaging》2007,20(2):122-130
DicomWorks is freeware software for reading and working on medical images [digital imaging and communication in medicine (DICOM)].
It was jointly developed by two research laboratories, with the feedback of more than 35,000 registered users throughout the
world who provided information to guide its development. We detail their occupations (50% radiologists, 20% engineers, 9%
medical physicists, 7% cardiologists, 6% neurologists, and 8% others), geographic origins, and main interests in the software.
The viewer’s interface is similar to that of a picture archiving and communication system viewing station. It provides basic
but efficient tools for opening DICOM images and reviewing and exporting them to teaching files or digital presentations.
E-mail, FTP, or DICOM protocols are supported for transmitting images through a local network or the Internet. Thanks to its
wide compatibility, a localized (15 languages) and user-friendly interface, and its opened architecture, DicomWorks helps
quick development of non proprietary, low-cost image review or teleradiology solutions in developed and emerging countries. 相似文献
72.
Unsharp masking is a widely used image-enhancement method in medical imaging. Hardware-based solutions can be developed to support high computational demand for unsharp masking, but they suffer from limited flexibility. Software solutions can easily incorporate new features and modify key parameters, such as filtering kernel size, but they have not been able to meet the fast computing requirement. Modern programmable mediaprocessors can meet both fast computing and flexibility requirements, which will benefit medical image computing. In this article, we present fast adaptive unsharp masking on two leading mediaprocessors or high-end digital signal processors, Hitachi/Equator Technologies MAP-CA and Texas Instruments TMS320C64x. For a 2k × 2k 16-bit image, our adaptive unsharp masking with a 201 × 201 boxcar kernel takes 225 ms on a 300-MHz MAP-CA and 74 ms on a 600-MHz TMS320C64x. This fast unsharp masking enables technologists and/or physicians to adjust parameters interactively for optimal quality assurance and image viewing. 相似文献
73.
脑动脉DSA形态分析及其意义 总被引:3,自引:0,他引:3
目的:探讨脑血管造影各主要动脉的投影规律及其分支的显示率,为脑血管疾病的影像诊断和介入治疗提供重要参考。方法:随机抽取140例全脑血管DSA系列图像,选择其中无脑血管疾病的51例进行观察。分别统计颈内动脉和椎动脉造影时正常脑血管各主要分支的显示率;归纳大脑前动脉A1段、大脑中动脉M1段及大脑后动脉P1段在平面上的投影规律并分析总结了脑动脉的正常解剖学特征及其变异。结果:①脑底动脉变异较大;②颈内动脉照影时OA、AChA、ACoA、PCoA、ACA和MCA的显示率分别为96.1%、92.2%、52.9%、69.6%、100%和100%;③椎动脉造影时PICA、AICA、BA、SCA、PCA和PCoA的显示率分别为66.7%、62.7%、100%、70.6%、80.4%和41.2%。结论:①尽管脑底血管实际解剖关系较为复杂,但造影时反映到平面上可简捷的用“水平、上升、下降”等来描述血管的形态和走行;②虽然是平面图像,通过调整投照体位仍可非常逼真的反映血流的动态变化。 相似文献
74.
目的为了方便快捷地实时监测心律失常,设计一种基于PDA的嵌入式ECG监护分析仪。方法仪器功能包括低功耗MSP430系列单片机控制心电信号的采集、放大、滤波、转换和在PDA上实时显示、存储和分析,并实现心电数据的远程传输。对仪器工作原理进行分析,把监护分析仪总体结构划分为子模块,并具体介绍各子模块的功能与实现。结果与结论与医院现有的三导全自动心电图机、Holter动态心电图机进行对照,本监护分析仪携带方便、操作简单、接收的心电信号无失真,连续工作时间大于20h等。各高频干扰信号对ECG信号无影响;软件可对心电信号进行实时显示,可连续记录15h的原始心电数据。 相似文献
75.
A five generation family with type 4 preaxial polydactyly is reported. The 21 affected individuals demonstrated variability in expression without apparent sex influence and penetrance which was complete. The deformities were more severe in the feet than the hands. Anteroposterior flatness of the thumbs was the only manifestation of the trait in the hands of several affected family members. 相似文献
76.
目的 在肺癌微波消融治疗中探究基于CT的三维数字化导航技术的应用价值。方法 回顾性分析我院收治的92例肺癌患者,随机进行三维数字化导航微波消融或传统CT引导下微波消融,分为三维导航组和传统组,依据肿瘤位置、大小(最大径差值≤2 mm)及微波消融条件不同两两配对,共46对,比较2组手术时间、微波针穿刺次数、CT剂量指数、术中并发症发生率、术后病灶控制情况。结果 三维导航组与传统组的手术时间分别为(30.07 ± 6.36)min、(47.20 ± 9.65)min、穿刺次数分别为(1.72 ± 0.69)次、(7.13 ± 3.00)次、CT剂量指数分别为(11.16 ± 2.20)mGy、(26.67 ± 8.72)mGy、术中并发症发生率分别为10.87%、34.78%,以上3个指标三维导航组均低于传统组,三维导航组治疗有效率(93.48%)高于传统组(71.74%),差异均有统计学意义(P < 0.05)。结论 CT引导下利用三维数字化导航技术行肺癌微波消融治疗,使介入穿刺手术的操作更加精准安全。 相似文献
77.
Olubusola Oladeji Chi Zhang Tiam Moradi Dharmesh Tarapore Andrew C Stokes Vukosi Marivate Moinina D Sengeh Elaine O Nsoesie 《JMIR Public Health and Surveillance》2021,7(4)
BackgroundThe prevalence of chronic conditions such as obesity, hypertension, and diabetes is increasing in African countries. Many chronic diseases have been linked to risk factors such as poor diet and physical inactivity. Data for these behavioral risk factors are usually obtained from surveys, which can be delayed by years. Behavioral data from digital sources, including social media and search engines, could be used for timely monitoring of behavioral risk factors.ObjectiveThe objective of our study was to propose the use of digital data from internet sources for monitoring changes in behavioral risk factors in Africa.MethodsWe obtained the adjusted volume of search queries submitted to Google for 108 terms related to diet, exercise, and disease from 2010 to 2016. We also obtained the obesity and overweight prevalence for 52 African countries from the World Health Organization (WHO) for the same period. Machine learning algorithms (ie, random forest, support vector machine, Bayes generalized linear model, gradient boosting, and an ensemble of the individual methods) were used to identify search terms and patterns that correlate with changes in obesity and overweight prevalence across Africa. Out-of-sample predictions were used to assess and validate the model performance.ResultsThe study included 52 African countries. In 2016, the WHO reported an overweight prevalence ranging from 20.9% (95% credible interval [CI] 17.1%-25.0%) to 66.8% (95% CI 62.4%-71.0%) and an obesity prevalence ranging from 4.5% (95% CI 2.9%-6.5%) to 32.5% (95% CI 27.2%-38.1%) in Africa. The highest obesity and overweight prevalence were noted in the northern and southern regions. Google searches for diet-, exercise-, and obesity-related terms explained 97.3% (root-mean-square error [RMSE] 1.15) of the variation in obesity prevalence across all 52 countries. Similarly, the search data explained 96.6% (RMSE 2.26) of the variation in the overweight prevalence. The search terms yoga, exercise, and gym were most correlated with changes in obesity and overweight prevalence in countries with the highest prevalence.ConclusionsInformation-seeking patterns for diet- and exercise-related terms could indicate changes in attitudes toward and engagement in risk factors or healthy behaviors. These trends could capture population changes in risk factor prevalence, inform digital and physical interventions, and supplement official data from surveys. 相似文献
78.
Kyohei Itamura Arthur Wu Elisa Illing Jonathan Ting Thomas Higgins 《JMIR Public Health and Surveillance》2021,7(1)
BackgroundReal-time polymerase chain reaction using nasopharyngeal swabs is currently the most widely used diagnostic test for SARS-CoV-2 detection. However, false negatives and the sensitivity of this mode of testing have posed challenges in the accurate estimation of the prevalence of SARS-CoV-2 infection rates.ObjectiveThe purpose of this study was to evaluate whether technical and, therefore, correctable errors were being made with regard to nasopharyngeal swab procedures.MethodsWe searched a web-based video database (YouTube) for videos demonstrating SARS-CoV-2 nasopharyngeal swab tests, posted from January 1 to May 15, 2020. Videos were rated by 3 blinded rhinologists for accuracy of swab angle and depth. The overall score for swab angle and swab depth for each nasopharyngeal swab demonstration video was determined based on the majority score with agreement between at least 2 of the 3 reviewers. We then comparatively evaluated video data collected from YouTube videos demonstrating the correct nasopharyngeal swab technique with data from videos demonstrating an incorrect nasopharyngeal swab technique. Multiple linear regression analysis with statistical significance set at P=.05 was performed to determine video data variables associated with the correct nasopharyngeal swab technique.ResultsIn all, 126 videos met the study inclusion and exclusion criteria. Of these, 52.3% (66/126) of all videos demonstrated the correct swab angle, and 46% (58/126) of the videos demonstrated an appropriate swab depth. Moreover, 45.2% (57/126) of the videos demonstrated both correct nasopharyngeal swab angle and appropriate depth, whereas 46.8% (59/126) of the videos demonstrated both incorrect nasopharyngeal swab angle and inappropriate depth. Videos with correct nasopharyngeal swab technique were associated with the swab operators identifying themselves as a medical professional or as an Ear, Nose, Throat–related medical professional. We also found an association between correct nasopharyngeal swab techniques and recency of video publication date (relative to May 15, 2020).ConclusionsOur findings show that over half of the videos documenting the nasopharyngeal swab test showed an incorrect technique, which could elevate false-negative test rates. Therefore, greater attention needs to be provided toward educating frontline health care workers who routinely perform nasopharyngeal swab procedures. 相似文献
79.
目的探讨D7S2 1位点在河北汉族人群分布的多态性 ,为DNA指纹数据库的构建及其法医学应用提供基础资料。方法应用MVR PCR方法和聚丙烯酰胺梯度凝胶电泳银染法对 12 4名河北汉族人群无关个体D7S2 1位点进行了快速检测 ,并进行数字编码。结果每一个体平均得到 3 6个数字编码 ,未发现任何两个无关个体所有编码相同 ,两无关个体 3 6个编码相同的机率为 3 .4 8× 10 -18。三种重复单位a 型、t 型和o 型出现的机率分别为 4 8.5 %、4 9.5 %和 2 .1%。该位点杂合度为 0 .9876,非父排除率为 0 .974 6,多态性信息含量为 0 .9872。结论D7S2 1位点在河北汉族人群中具有高度的多态性 ,聚丙烯酰胺梯度凝胶电泳银染法简便、快速 ,具有一定的实用价值 相似文献
80.
急性顽固性鼻出血的病人治疗起来非常棘手 ,经过多次后鼻道填塞仍不能达到有效止血 ,病人出血比较凶险 ,往往需要结扎颈外动脉 ,若遇到两侧颌内动脉均出血的病人 ,又不能同时结扎两侧颈外动脉 ,因此 ,用多种方法均达不到彻底止血的目的 ,DSA检查可清晰的看到出血动脉的部位和范围 ,了解其与周围血管的交通情况 ,通过导管技术可用多种栓塞材料做靶血管栓塞 ,并且可以随时复查栓塞效果 ,此方法创伤小 ,疗效肯定 ,可大力推广之。1 资料和方法5例患者 ,其中 2例有高血压史 ,1例为外伤 ,1例动脉硬化性动脉出血 ,1例动静脉畸形出血。年龄30岁… 相似文献