Actin filament organization in aligned prefusion myoblasts

The organization of the actin cytoskeleton in prefusion aligning myoblasts is likely to be important for their shape and interaction. We investigated actin filament organization and polarity by transmission electron microscopy (TEM) in these cells. About 84% of the filaments counted were either found in a subplasmalemma sheet up to 0.5 microm thick that was aligned with the long axis of the cell, or in protrusions. The remaining filaments were found in the cytoplasm, where they were randomly orientated and not organized into bundles. The polarity of the subplasmalemma filaments changed progressively from one end of the cell to the other. At the ends of the cells and in protrusions, the majority of filaments were organized such that their barbed ends faced the tip of the protrusion. We did not find any actin filament bundles or stress fibres in these cells. Time-lapse phase microscopy demonstrated that aligned cells were still actively migrating at the time of our TEM observations, and their direction of movement was restricted to the long axis of the cell group. The ability of these cells to locomote actively in the absence of actin filament bundles suggests that in these cells the subplasmalemma actin sheet contributes not only to cell shape but also to cell locomotion.     

HealthTrust: a social network approach for retrieving online health videos

Background

Social media are becoming mainstream in the health domain. Despite the large volume of accurate and trustworthy health information available on social media platforms, finding good-quality health information can be difficult. Misleading health information can often be popular (eg, antivaccination videos) and therefore highly rated by general search engines. We believe that community wisdom about the quality of health information can be harnessed to help create tools for retrieving good-quality social media content.

Objectives

To explore approaches for extracting metrics about authoritativeness in online health communities and how these metrics positively correlate with the quality of the content.

Methods

We designed a metric, called HealthTrust, that estimates the trustworthiness of social media content (eg, blog posts or videos) in a health community. The HealthTrust metric calculates reputation in an online health community based on link analysis. We used the metric to retrieve YouTube videos and channels about diabetes. In two different experiments, health consumers provided 427 ratings of 17 videos and professionals gave 162 ratings of 23 videos. In addition, two professionals reviewed 30 diabetes channels.

Results

HealthTrust may be used for retrieving online videos on diabetes, since it performed better than YouTube Search in most cases. Overall, of 20 potential channels, HealthTrust’s filtering allowed only 3 bad channels (15%) versus 8 (40%) on the YouTube list. Misleading and graphic videos (eg, featuring amputations) were more commonly found by YouTube Search than by searches based on HealthTrust. However, some videos from trusted sources had low HealthTrust scores, mostly from general health content providers, and therefore not highly connected in the diabetes community. When comparing video ratings from our reviewers, we found that HealthTrust achieved a positive and statistically significant correlation with professionals (Pearson r ₁₀ = .65, P = .02) and a trend toward significance with health consumers (r ₇ = .65, P = .06) with videos on hemoglobinA_{1 c}, but it did not perform as well with diabetic foot videos.

Conclusions

The trust-based metric HealthTrust showed promising results when used to retrieve diabetes content from YouTube. Our research indicates that social network analysis may be used to identify trustworthy social media in health communities.     

红外眼震视频瞳孔寻迹

针对眼震红外视频图像灰度分布不均匀造成瞳孔边缘检测精度不高的状况,介绍了一种基于形态学和Canny算法实现瞳孔中心定位方法,运用形态学去除一些无意义的区域,使目标瞳孔平滑,分离和提取最大连通区域瞳孔,再根据所设计的Canny算法实现瞳孔边缘提取,通过计算获取瞳孔中心位置坐标,实时地把每帧图像得到的瞳孔中心坐标通过曲线拟合出来,得到瞳孔的运动轨迹,从而获得眼震临床所期望的诊断信息。实验结果表明,该方法能够很好地适应不同实验对象灰度值差别,进行准确的边缘提取,拟合的瞳孔运动轨迹良好地反映眼睛运动情况,为国内视频眼震瞳孔中心定位的研究提供一种可借鉴的实用方法。     

压力传感器信号调理电路设计

详细介绍了循环式氦氧混合气辅助呼吸装置压力传感器信号调理电路传感器接入、电流源、差分放大器、输出放大器、非线性调整环、频率响应等功能模块的设计,明确给出了信号调理电路差分放大器及零点调整电路中电阻的计算方法.测试结果表明:该压力传感器信号调理电路在实现大电压信号满量程输出、输出电压与输入压力保持线性关系、零点电压提升等功能方面取得了很好的效果.     

Continuous axial contraction wave in the free wall of the guinea pig left ventricle

We studied the variation from the simultaneous contraction of the normal left ventricle (LV). The pattern of the contraction along the LV long axes was assessed on the LV free wall on seven guinea pig hearts in situ with ultra fast video system and epicardial markers by means of the latitude and the size of the areas defined by markers. We found that the contraction occurs as a continuous contraction wave from the apex towards the base, which might yield functional adaptation of these two regions to diastolic and systolic function, respectively.     

基于SoC的医用内窥镜高清视频显示系统

目的 开发一种基于SoC的医用内窥镜高清视频显示系统,以满足高分辨率和高实时显示的要求.方法 使用CMOS摄像头采集视频数据.使用集成有双核ARM Crotex-A9处理器和FPGA的SoC芯片作为核心,利用SoC的HPS搭建嵌入式系统实现人机交互,利用FPGA实现视频数据的处理和缓存.使用ARM AMBA AXI总线桥接宽带系统连接HPS和FPGA,以实现缓存的视频数据经编码后在显示屏上的实时显示.结果 搭建了一个基于SoC的高清视频显示系统,实现了高清视频数据采集、处理及实时显示、视频冻结等功能.结论 结果表明该方案有效可行,并具有可定制性、可多次开发、视频显示实时性好等优点.     

Evaluation of nursing-specific drug information PDA databases used as clinical decision support tools

Background

Nursing is arguably the most organizationally diverse healthcare profession. Educational backgrounds may vary, even among similarly credentialed nurses. Drug information databases used as clinical decision support tools can improve access to pharmacologic information at point-of-care when housed on personal digital assistants. They may also help address the disparity in drug information and pharmacology education between nurses.

Objectives

To evaluate nursing-specific drug information database content on personal digital assistants (PDAs).

Methods

Seven nursing-specific PDA databases were evaluated for scope (absence or presence of an answer) and completeness (three-point scale) via the use of 80 general category and 80 subspecialty drug information questions. Erroneous information was also tracked. Individual scope and completeness scores were delineated by rank order and chi square was performed to determine differences in scope and completeness scores between the databases.

Results

Davis's Drug Guide for Nurses (DDGN) and Nursing Lexi-Drugs (NLD) tied for the highest scores for scope, including each answering 72.5% of the 160 evaluation questions. No significant differences existed between their scores and those earned by Nursing2008 Drug Handbook (p < 0.05). The highest scores for completeness were earned by NLD with 58.1% and DDGN at 57.1%. Saunders Nursing Drug Handbook was the only database that showed a significantly lower score in completeness as compared to the other six databases (p < 0.05). A 4.2% overall error rate was found among database answers.

Discussion

Significant differences were found among the performances in the databases evaluated in this study for their ability to answer commonly encountered drug information issues in nursing practice. All databases contained some erroneous information and even the top performers failed to provide answers to more than one-fourth of the questions posed. The availability of accurate and timely drug information at point-of-care can play a vital role in patient management and outcomes, but current resources that are available need to be improved.     

The Effect of Ambient Illumination on Handheld Display Image Quality

Handheld devices such as smartphones and tablets are becoming useful in the medical field, as they allow physicians, radiologists, and researchers to analyze images with the benefit of mobile accessibility. However, for handheld devices to be effective, the display must be able to perform well in a wide range of ambient illumination conditions. We conducted visual experiments to quantify user performance for testing the image quality of two current-generation devices in different ambient illumination conditions while measuring ambient light levels with a real-time illuminance meter. We found and quantified that due to the high reflectivity of handheld devices, performance deteriorates as the user moves from dark areas into environments of greater ambient illumination. The quantitative analysis suggests that differences in display reflection coefficients do not affect the low illumination performance of the device but rather the performance at higher levels of illumination.     

Improving youth question-asking and provider education during pediatric asthma visits

Objective

We conducted a pragmatic randomized controlled trial to test the effectiveness of an asthma question prompt list with video intervention to increase youth question-asking and provider education during visits.