Understanding the association between psychomotor processing speed and white matter hyperintensity: A comprehensive multi‐modality MR imaging study

Cognitive processing speed is crucial for human cognition and declines with aging. White matter hyperintensity (WMH), a common sign of WM vascular damage in the elderly, is closely related to slower psychomotor processing speed. In this study, we investigated the association between WMH and psychomotor speed changes through a comprehensive assessment of brain structural and functional features. Multi‐modal MRIs were acquired from 60 elderly adults. Psychomotor processing speeds were assessed using the Trail Making Test Part A (TMT‐A). Linear regression analyses were performed to assess the associations between TMT‐A and brain features, including WMH volumes in five cerebral regions, diffusivity parameters in the major WM tracts, regional gray matter volume, and brain activities across the whole brain. Hierarchical regression analysis was used to demonstrate the contribution of each index to slower psychomotor processing speed. Linear regression analysis demonstrated that WMH volume in the occipital lobe and fractional anisotropy of the forceps major, an occipital association tract, were associated with TMT‐A. Besides, resting‐state brain activities in the visual cortex connected to the forceps major were associated with TMT‐A. Hierarchical regression showed fractional anisotropy of the forceps major and regional brain activities were significant predictors of TMT‐A. The occurrence of WMH, combined with the disruption of passing‐through fiber integrity and altered functional activities in areas connected by this fiber, are associated with a decline of psychomotor processing speed. While the causal relationship of this WMH‐Tract‐Function‐Behavior link requires further investigation, this study enhances our understanding of these complex mechanisms.     

慢性HCV感染DAA应答特点和长期预后观察研究

目的 本研究旨在观察不同疾病进展阶段的HCV感染者直接抗病毒药物(direct-acting antiviral agents,DAA)治疗的应答特点和长期预后.方法 纳入2016年7月—2017年3月就诊于我中心的慢性HCV感染者127例,其中慢性丙型肝炎(chronic hepatitis C,CHC)患者85例,代偿期肝硬化(compensated-liver cirrhosis,CLC)患者32例,失代偿期肝硬化(decompensated-liver cirrhosis,DLC)患者10例.DAA治疗12或24周.比较3组患者HCV RNA转阴时间、停药后12周持续病毒学应答(sustained virologic response 12,SVR12)率以及停药后2年的转归情况.结果 所有CHC、CLC、DLC患者均完成DAA治疗.CHC、CLC和DLC患者的SVR12率分别为98.82％(84/85)、96.88％(31/32)和100％(10/10);CHC患者HCV RNA转阴时间明显早于CLC和DLC患者(P均<0.05).在2年随访期间,1例CLC患者发生病毒学复发,2例DLC患者分别出现肝功能恶化和肝细胞癌.结论 目前常用的DAA治疗方案对CHC、CLC和DLC的患者均有高效的抑制病毒复制的作用,并且SVR12率在96％～100％之间,有很高治愈率.对于肝硬化患者停药后仍须监测肝癌的发生或个别病例HCV复发等情况.     

基于MEMS传感器的可穿戴式老年人跌倒监测系统的设计

为了缩短老年人跌倒后的救助时间和提高安全保障,我们设计了一种基于加速度和角速度传感器的跌倒监测装置。该装置结合机械微电子系统(microelectro mechanical system,MEMS)传感器、数字信号处理及无线传输技术应用于智能手机上。为区分人体跌倒事件和日常行为,结合人体三轴加速度和角速度联合对跌倒事件进行判断,通过大量实验选取合适阈值。针对老年人的生活特点,数据通过蓝牙装置发送至手机上进行处理,通过手机语音报警、手机GPS定位系统和短信通知医院和用户监护人,使得老年人跌倒后能够在第一时间获得救治,减小伤害。经过大量的实验测试结果统计,相比较于传统的三轴加速度判断跌倒事件,结合三轴加速度和加速度联合判断使该系统的准确率从84.29%提高至100%。结果表明:基于MEMS传感器的可穿戴式跌倒监测系统具有便捷、准确、功耗低的特点,能够准确监测出跌倒事件并进行报警。     

Regional differences in extracellular ascorbic acid levels in the rat brain determined by high speed cyclic voltammetry

High speed cyclic voltammetry was used in combination with pressure ejection of ascorbate oxidase for the determination of extracellular ascorbic acid within the brain of the anaesthetized rat. Large variations in absolute levels of ascorbate were found between animals although distribution patterns showed a good degree of reproducibility. Ascorbate levels in the white matter of the corpus callosum were found to be higher than in adjacent areas of grey matter (striatum and cortex).     

高速逆流色谱快速分离制备石椒草中高纯度芦丁对照品

[目的]建立高速逆流色谱法高效、快速分离制备石椒草中芦丁的新方法.[方法]石椒草的乙醇提取物经大孔吸附树脂柱初步分离后,直接进行高速逆流色谱分离,所用两相溶剂体系为乙酸乙酯-正丁醇-水(2:1:3,v/v/v),上相为固定相,下相为流动相,流速1.5 mL/min,转速830 r/min,检测波长254 nm,所得产物的纯度经HPLC检测,结构经UV和Ms鉴定.[结果]经一步分离从200 mg石椒草粗提物中得到纯度高于99%的芦丁,分离时间短于2 h.[结论]由该法制备芦丁简便、快速,所得产物纯度高,适合于芦丁对照品的大规模制备.     

Relationship between sarcopenia,six‐minute walk distance and health‐related quality of life in liver transplant candidates

Sarcopenia, or loss of skeletal muscle mass, is associated with increased mortality and morbidity in liver transplant (LT) candidates. Six‐minute walk distance (6MWD) and health‐related quality of life (HRQOL) as assessed by short form 36 scores (SF‐36) also impact clinical outcomes in these patients. This study explored the relationship between the sarcopenia, 6MWD, and HRQOL in LT candidates. Sarcopenia was evaluated based on skeletal muscle mass index (SMI) quantified from abdominal computed tomography. Patients were followed until death, removal from the wait list or the end of the study period. Two hundred and thirteen patients listed for LT were included. The mean SMI, 6MWD and mean gait speed were 54.3 ± 9.7, 370.5 m and 1 m/s, respectively. Sarcopenia was noted in 22.2% of LT candidates. There was no correlation between sarcopenia, 6MWD, and SF‐36 scores. The 6MWD, but not sarcopenia, was an independent predictor of mortality (hazard ratio = 2.1 [0.9–4.7]). In summary, sarcopenia did not emerge as a significant predictor of waitlist mortality and also failed to correlate with either functional capacity or HRQOL in LT candidates. In patients with ESLD awaiting LT, 6MWD appears to be a more useful prognostic indicator than the presence of sarcopenia.     

推拿对颈椎病患者等速运动中最大力矩角度的影响*

[目的]探讨正常人和颈椎病患者颈部肌肉最大力矩角度(APT)的特征及推拿干预机制.[方法]采用等速肌力测仪评估等速运动状态颈椎病颈部肌肉APT特性,分颈椎病组(40例)和正常对照组(39例),每组按性别、年龄相匹配分青、中和老年3个亚组.推拿治疗10次,分别在推拿治疗前、第1次推拿后即刻及第10次以后进行评估.[结果]正常人APT值比较恒定,随年龄改变不明显,90°/s角速度前屈和后伸APT多位于距离中立位偏后10°～25°,25°～40°;180°/s角速度前屈和后伸APT多分别位于距离中立位偏后15°～20°,20°～30°;颈椎病患者后伸APT值与正常人有显著差异,其值多位于中立位前后10°左右;推拿可以改善最大力矩角度,尤其是后伸APT值.[结论]正常人可以作为评估颈椎病颈部肌肉功能的有效参数;推拿可以通过改善以整体恢复颈部肌肉的力学平衡.     

采用高速离心及ExoQuick-TC法提取小鼠骨髓间充质干细胞来源外泌体比较及鉴定

比较及鉴定超高速离心法及ExoQuick-TC法提取小鼠骨髓间充质干细胞来源外泌体.采用BCA蛋白检测可见ExoQuick-TC法提取的外泌体蛋白含量高于超高速离心法提取的蛋白含量.Exosome Antibodies,Array & ELISA Kits检测可见ExoQuick-TC法提取外泌体的纯度优于超高速离心法提取的纯度.两种方法提取的外泌体电镜下形状无差异,随机选取3个电镜视野进行计数可见ExoQuick-TC法提取外泌体数量多于超高速离心法提取外泌体. ExoQuick-TC法提取的外泌体具有更高的产量及纯度.     

The Effects of Word Completion and Word Prediction on Typing Rates Using On-Screen Keyboards

Word prediction is often recommended by therapists as a means to improve typing speed for clients with physical limitations. Although literature suggests that word prediction does have an effect on writing proficiency, increased speed is not one of its benefits when used with a standard keyboard. One reason given for the failure of word prediction to accelerate typing is that the user must look away from any source document to scan the prediction list during typing. Looking away from the source document may slow the typist more than any acceleration offered by word prediction. For input methods that already require the typist to look away from the copy, this effect might be irrelevant. The focus of this research was to determine whether word completion or word prediction programs would increase typing speed when used with an input method (an on-screen keyboard) that also requires looking away from the source document. Ten people, five men and five women, aged 20 to 38 years, participated in this study. The study used a single-subject, successive intervention design to test typing speed and accuracy using an on-screen keyboard with integrated word prediction software. Seven participants had their fastest typing speed with word prediction. Two participants had their fastest typing speed with word completion. Only one participant demonstrated no improvement in speed when using these two programs. Overall, these results show that the use of word prediction and word completion may assist on-screen keyboard users to improve typing speed.