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1.
BACKGROUND: Past receiver operating characteristic (ROC) studies have demonstrated that single photon emission computed tomography (SPECT) perfusion imaging by use of iterative reconstruction with combined compensation for attenuation, scatter, and detector response leads to higher area under the ROC curve (A(z)) values for detection of coronary artery disease (CAD) in comparison to the use of filtered backprojection (FBP) with no compensations. A new ROC study was conducted to investigate whether this improvement still holds for iterative reconstruction when observers have available all of the imaging information normally presented to clinical interpreters when reading FBP SPECT perfusion slices. METHODS AND RESULTS: A total of 87 patient studies including 50 patients referred for angiography and 37 patients with a lower than 5% likelihood for CAD were included in the ROC study. The images from the two methods were read by 4 cardiology fellows and 3 attending nuclear cardiologists. Presented for the FBP readings were the short-axis, horizontal long-axis, and vertical long-axis slices for both the stress and rest images; cine images of both the stress and rest projection data; cine images of selected cardiac-gated slices; the CEQUAL-generated stress and rest polar maps; and an indication of patient gender. This was compared with reading solely the iterative reconstructed stress slices with combined compensation for attenuation, scatter, and resolution. With A(z) as the criterion, a 2-way analysis of variance showed a significant improvement in detection accuracy for CAD for the 7 observers (P = .018) for iterative reconstruction with combined compensation (A(z) of 0.895 +/- 0.016) over FBP even with the additional imaging information provided to the observers when scoring the FBP slices (A(z) of 0.869 +/- 0.030). When the groups of 3 attending physicians or 4 cardiology fellows were compared separately, the iterative technique was not statistically significantly better; however, the A(z) for each of the 7 observers individually was larger for iterative reconstruction than for FBP. Compared with results from our previous studies, the additional imaging information did increase the diagnostic accuracy of FBP for CAD but not enough to undo the statistically significantly higher diagnostic accuracy of iterative reconstruction with combined compensation. CONCLUSIONS: We have determined through an ROC investigation that included two classes of observers (experienced attending physicians and cardiology fellows in training) that iterative reconstruction with combined compensation provides statistically significantly better detection accuracy (larger A(z)) for CAD than FBP reconstructions even when the FBP studies were read with all of the extra clinical nuclear imaging information normally available.  相似文献   
2.
本文从信息经济学的角度出发,分析了病案信息的经济价值、市场需求及其开发利用,揭示了病案信息利用对相关市场参与者的利润、效用、福利增进的机制及在疾病控制中的重大作用,指明了加强病案信息开发的重要性和紧迫性,并提出建议。  相似文献   
3.
The ability to cluster different perfusion compartments in the brain is critical for analyzing brain perfusion. This study presents a method based on a mixture of multivariate Gaussians (MoMG) and the expectation-maximization (EM) algorithm to dissect various perfusion compartments from dynamic susceptibility contrast (DSC) MR images so that each compartment comprises pixels of similar signal-time curves. This EM-based method provides an objective way to 1) delineate an area to serve as the in-plane arterial input function (AIF) of the feeding artery for adjacent tissues to better quantify the relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT); 2) demarcate regions with abnormal perfusion derangement to facilitate diagnosis; and 3) obtain parametric maps with supplementary information, such as temporal scenarios and recirculation of contrast agent. Results from normal subjects show that perfusion cascade manifests (in order of appearance) the arteries, gray matter (GM), white matter (WM), veins and sinuses, and choroid plexus mixed with cerebrospinal fluid (CSF). The averaged rCBV, rCBF, and MTT ratios between GM and WM are in good agreement with those in the literature. Results from a patient with cerebral arteriovenous malformation (CAVM) showed distinct spatiotemporal characteristics between perfusion patterns, which allowed differentiation between pathological and nonpathological areas.  相似文献   
4.
目的 了解住院患者尊严期望现状,为针对性干预提供参考.方法 采用普通话版住院患者尊严量表对442例住院患者进行问卷调查.结果 住院患者尊严期望值为48.00(40.00,53.00)分,尊严满意度为71.00(61.00,75.00)分;回归分析结果显示,性别、家庭人均月收入、住院科室是住院患者尊严期望值影响因素(均P<0.05);近年住院经历、经济负担、文化程度是住院患者尊严满意度影响因素(均P<0.05).结论 住院患者尊严期望值处于中度水平,满意度较高.临床护士应根据不同尊严期望值和尊严满意度患者提供个性化和针对性干预,满足其尊严期望和尊严满意度.  相似文献   
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Attenuation coefficient maps (-maps) are a useful way to compensate for non-uniform attenuation when performing single photon emission tomography (SPET). A new method was developed to record single photon transmission data and a-map for the brain was produced using a four-head SPET scanner. Transmission data were acquired by a gamma camera opposite to a flood radioactive source attached to one of four gamma cameras in the four-head SPET scanner. Attenuation correction was performed using the iterative expectation maximization algorithm and the-map. Phantom studies demonstrated that this method could reconstruct the distribution of radioactivity more accurately than conventional methods, even for a severely non-uniform-map, and could improve the quality of SPET images. Clinical application to technetium-99m hexamethylpropylene amine oxime (HMPAO) brain SPET also demonstrated the usefulness of this method. Thus, this method appears to be promising for improvement in the image quality and quantitative accuracy of brain SPET.This work was presented in part at the World Congress on Medical Physics and Biomedical Engineering, 7–12 July 1991, Kyoto, Japan  相似文献   
7.
文章指出中国医学流入美国约50年,美国学者对此古老医学非常崇敬,认为中医学有很高的价值,中西医结合是未来医学发展之趋势,中医西医学化,中医新科技化,是大家必须去研讨之路。同时认为,中医要进一步发展必须改进传统观念,以学术科学为主,以传统经典为考,改进而不忘本,中医才能更加发扬光大。  相似文献   
8.
目的了解终末期肾病患者住院期间对护理人员提供社会支持的体验及需求,为护士实施全面有效的社会支持提供依据。方法采用立意抽样法选取14例终末期肾病住院患者为研究对象,采用半结构式访谈提纲进行深入访谈并按三维度叙事分析法进行转录和分析。结果患者住院期间感受到的护理专业性社会支持主要有:护理帮助支持、情感支持、沟通和信息支持;患者期望获得及时的评价支持,更多的情感支持,针对性、多样化的沟通信息支持。结论护理人员为终末期肾病患者提供专业性社会支持时应关注患者的期望,提升护理服务效能。  相似文献   
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《The journal of pain》2014,15(12):1282-1293
Expectations and beliefs shape the experience of pain. This is most evident in context-induced, placebo analgesia, which has recently been shown to interact with the trait of magical thinking (MT) in adults. In children, placebo analgesia and the possible roles that MT and gender might play as modulators of placebo analgesia have remained unexplored. Using a paradigm in which heat pain stimuli were applied to both forearms, we investigated whether MT and gender can influence the magnitude of placebo analgesia in children. Participants were 49 right-handed children (aged 6–9 years) who were randomly assigned—stratified for MT and gender—to either an analgesia-expectation or a control-expectation condition. For both conditions, the placebo was a blue-colored hand disinfectant that was applied to the children's forearms. Independent of MT, the placebo treatment significantly increased both heat pain threshold and tolerance. The threshold placebo effect was more pronounced for girls than boys. In addition, independent of the expectation treatment, low-MT boys showed a lower tolerance increase on the left compared to the right side. Finally, MT specifically modulated tolerance on the right forearm side: Low-MT boys showed an increase, whereas high-MT boys showed a decrease in heat pain tolerance. This study documented a substantial expectation-induced placebo analgesia response in children (girls > boys) and demonstrated MT and gender-dependent laterality effects in pain perception. The findings may help improve individualized pain management for children.PerspectiveThe study documents the first experimental evidence for a substantial expectancy-induced placebo analgesia response in healthy children aged 6 to 9 years (girls > boys). Moreover, the effect was substantially higher than the placebo response typically found in adults. The findings may help improve individualized pain management for children.  相似文献   
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