基于组稀疏残差去噪的磁共振图像重构

为了克服磁共振图像重构精度低的问题,方便医生诊断与治疗,提出一种将组稀疏残差去噪和近似消息传递相结合的磁共振图像重构算法.在基于迭代软阈值的去噪近似消息传递(D-AMP)重构算法中,滤波的去噪算法将使用基于组稀疏残差约束(GSRC)的图像去噪实现.实验结果表明,基于组稀疏残差去噪的磁共振图像重建算法可有效缓解重建图像局...     

Engineering biocompatible TeSex nano-alloys as a versatile theranostic nanoplatform

Photothermal nanotheranostics, especially in the near infrared II (NIR-II) region, exhibits a great potential in precision and personalized medicine, owing to high tissue penetration of NIR-II light. NIR-II-photothermal nanoplatforms with high biocompatibility as well as high photothermal effect are urgently needed but rarely reported so far. Te nanomaterials possess high absorbance to NIR-II light but also exhibit high cytotoxicity, impeding their biomedical applications. In this work, the controllable incorporation of biocompatible Se into the lattice of Te nanostructures is proposed to intrinsically tune their inherent cytotoxicity and enhance their biocompatibility, developing TeSe_x nano-alloys as a new kind of theranostic nanoplatform. We have uncovered that the cytotoxicity of Te nanomaterials primarily derives from irreversible oxidation stress and intracellular imbalance of organization and energy, and can be eliminated by incorporating a moderate proportion of Se (x = 0.43). We have also discovered that the as-prepared TeSe_x nano-alloys have extraordinarily high NIR-II-photothermal conversion efficiency (77.2%), ⁶⁴Cu coordination and computed tomography contrast capabilities, enabling high-efficacy multimodal photothermal/photoacoustic/positron emission tomography/computed tomography imaging-guided NIR-II-photothermal therapy of cancer. The proposed nano-alloying strategy provides a new route to improve the biocompatibility of biomedical nanoplatforms and endow them with versatile theranostic functions.     

Committing to Memory: A Project to Publish and Preserve California Local History Digital Resources

SUMMARY

This article highlights the LSTA-grant funded California Local History Digital Resources Project (LHDRP) as a case study of a collaborative statewide program involving three primary groups: cultural heritage institutions, grant funding agencies, and digital library service providers. It explores how the infrastructure of the California Digital Library (CDL) is utilized to preserve and promote public access to digitized local history collections, and discusses challenges and technical solutions to integrating heterogeneous resources into METS-based repositories. Project building blocks are also discussed, including digital object encoding and transmission tools, scanning services, metadata and imaging standards, and training programs.     

Muscle cross-sectional areas and performance power of limbs and trunk in the rowing motion

Although it is clear that rowers have a large muscle mass, their distribution of muscle mass and which of the main motions in rowing mediates muscle hypertrophy in each body part are unclear. We examine the relationships between partial motion power in rowing and muscle cross-sectional area of the thigh, lower back, and upper arms. Sixty young rowers (39 males and 21 females) participated in the study. Joint positions and forces were measured by video cameras and rowing ergometer software, respectively. One-dimensional motion analysis was performed to calculate the power of leg drive, trunk swing, and arm pull motions. Muscle cross-sectional areas were measured using magnetic resonance imaging. Multiple regression analyses were carried out to determine the association of different muscle cross-sectional areas with partial motion power. The anterior thigh best explained the power demonstrated by leg drive (r ² = 0.508), the posterior thigh and lower back combined best explained the power demonstrated by the trunk swing (r ² = 0.493), and the elbow extensors best explained the power demonstrated by the arm pull (r ² = 0.195). Other correlations, such as arm muscles with leg drive power (r ² = 0.424) and anterior thigh with trunk swing power (r ² = 0.335), were also significant. All muscle cross-sectional areas were associated with rowing performance either through the production of power or by transmitting work. The results imply that rowing motion requires a well-balanced distribution of muscle mass throughout the body.     

Sport imagery ability predicts trait confidence,and challenge and threat appraisal tendencies

Abstract

The present study investigated the interplay among athletes' sport imagery ability, trait confidence, and tendency to appraise situations as a challenge and threat. The potential mediating role of trait confidence was also tested. A total of 207 athletes (M _age =19.44; s=1.26; 90 female, 117 male) completed the Sport Imagery Ability Questionnaire to assess ease of imaging skill, strategy, goal, affect and mastery imagery, the confidence subscale of the Competitive Trait Anxiety Inventory to measure trait confidence, and the Cognitive Appraisal Scale to assess tendencies to appraise sport situations as a challenge and as a threat. Structural equation modelling supported a model wherein mastery and goal imagery ability both positively predicted confidence, which in sequence positively predicted challenge appraisal and negatively predicted threat appraisal tendency. Partial support was found for confidence mediating the relationship between mastery imagery ability and appraisal tendencies. In addition, ease of imaging mastery and affect imagery directly predicted challenge appraisal tendency (positive direction), and ease of imaging mastery imagery directly predicted threat appraisal tendency (negative direction). Results highlight the importance of motivational imagery ability and the need to assess athletes' ability to image different content.     

The Functional Equivalence Between Movement Imagery,Observation, and Execution Influences Imagery Ability

Abstract

Based on literature identifying movement imagery, observation, and execution to elicit similar areas of neural activity, research has demonstrated that movement imagery and observation successfully prime movement execution. To investigate whether movement and observation could prime ease of imaging from an external visual-imagery perspective, an internal visual-imagery perspective, and kinesthetic modality, 36 participants (M age = 20.58; SD = 3.11; 18 women and 18 men) completed an adapted version of the Movement Imagery Questionnaire-Revised under four modes of delivery (movement prime, external observation prime, internal observation prime, and image-only). The results revealed that ease of imaging was significantly greater during the movement and observation prime conditions compared to the image-only condition (p < .05). Specifically when priming external visual imagery and internal visual imagery, observation facilitated ease of imaging only when the perspective was congruent with the imagery perspective. The results support the use of movement and observation to facilitate ease of imaging, but highlight the importance of considering the visual perspective when using observation.     

E-Learning Three-Dimensional Anatomy of the Brainstem: Impact of Different Microscopy Techniques and Spatial Ability

Polarized light imaging (PLI) is a new method which quantifies and visualizes nerve fiber direction. In this study, the educational value of PLI sections of the human brainstem were compared to histological sections stained with Luxol fast blue (LFB) using e-learning modules. Mental Rotations Test (MRT) was used to assess the spatial ability. Pre-intervention, post-intervention, and long-term (1 week) anatomical tests were provided to assess the baseline knowledge and retention. One-on-one electronic interviews after the last test were carried out to understand the students’ perceptions of the intervention. Thirty-eight medical students, (19 female and 19 males, mean age 21.5 ± SD 2.4; median age: 21.0 years) participated with a mean MRT score of 13.2 ± 5.2 points and a mean pre-intervention knowledge test score of 49.9 ± 11.8%. A significant improvement in both, post-intervention and long-term test scores occurred after learning with either PLI or LFB e-learning module on brainstem anatomy (both P < 0.001). No difference was observed between groups in post-intervention test scores and long-term test scores (P = 0.913 and P = 0.403, respectively). A higher MRT-score was significantly correlated with a higher post-intervention test score (r_k = 0.321; P < 0.05, respectively), but there was not a significant association between the MRT- and the long-term scores (r_k = −0.078; P = 0.509). Interviews (n = 10) revealed three major topics: Learning (brainstem) anatomy by use of e-learning modules; The “need” of technological background information when studying brainstem sections; and Mnemonics when studying brainstem anatomy. Future studies should assess the cognitive burden of cross-sectional learning methods with PLI and/or LFB sections and their effects on knowledge retention.     

Evaluation of an Augmented Reality Application for Learning Neuroanatomy in Psychology

Neuroanatomy is difficult for psychology students because of spatial visualization and the relationship among brain structures. Some technologies have been implemented to facilitate the learning of anatomy using three-dimensional (3D) visualization of anatomy contents. Augmented reality (AR) is a promising technology in this field. A mobile AR application to provide the visualization of morphological and functional information of the brain was developed. A sample of 67 students of neuropsychology completed tests for visuospatial ability, anatomical knowledge, learning goals, and experience with technologies. Subsequently, they performed a learning activity using one of the visualization methods considered: a 3D method using the AR application and a two-dimensional (2D) method using a textbook to color, followed by questions concerning their satisfaction and knowledge. After using the alternative method, the students expressed their preference. The two methods improved knowledge equally, but the 3D method obtained higher satisfaction scores and was more preferred by students. The 3D method was also more preferred by the students who used this method during the activity. After controlling for the method used in the activity, associations were found between the preference of the 3D method because of its usability and experience with technologies. These results found that the AR application was highly valued by students to learn and was as effective as the textbook for this purpose.     

Evaluating the integration of body donor imaging into anatomical dissection using augmented reality

Augmented reality (AR) has recently been utilized as an integrative teaching tool in medical curricula given its ability to view virtual objects while interacting with the physical environment. The evidence for AR in medical training, however, is limited. For this reason, the purpose of this mixed method study was to evaluate the implementation of overlaying donor-specific diagnostic imaging (DSDI) onto corresponding body donors in a fourth-year, dissection-based, medical elective course entitled anatomy for surgeons (AFS). Students registered in AFS course were separated into groups, receiving either DSDI displayed on Microsoft HoloLens AR head-mounted display (n = 12) or DSDI displayed on iPad (n = 15). To test for the change in spatial ability, students completed an anatomical mental rotation test (AMRT) prior to and following the AFS course. Students also participated in a focus group discussion and completed a survey at the end of AFS, analyzed through thematic triangulation and an unpaired, Mann Whitney U test respectively, both addressing dissection experience, DSDI relevancy to dissection, and use of AR in anatomical education. Although statistically significant differences were not found when comparing student group AMRT scores, survey and discussion data suggest that the HoloLens had improved the students' understanding of, and their spatial orientation of, anatomical relationships. Trunk dissection quality grades were significantly higher with students using the HoloLens. Although students mentioned difficulties with HoloLens software, with faculty assistance, training, and enhanced software development, there is potential for this AR tool to contribute to improved dissection quality and an immersive learning experience.     

颗粒成像技术用于絮体分形结构研究

利用颗粒成像技术对硫酸铝形成的高岭土和腐殖酸絮体在破碎后重新生长形成的絮体结构动态变化进行了研究。结果表明,在絮体生长一破碎一再生长过程中,腐殖酸存在时会导致絮体分形维数减小。絮体在生长过程中的分形维数随着粒径增加从1．60增加到1．80,破碎后絮体分形维数重新回到1．60。絮体重新生长形成的絮体的分形维数跟破碎强度有关,较长时间破碎形成的絮体分形维数没有明显变化,短时间破碎形成的絮体分形维数和生长阶段稳定阶段一致。絮体破碎后重构不是生长阶段絮体分形维数增加的原因,而是跟絮体分形尺度不变性及存在多级结构有关。