Functional imaging and localization of electromagnetic brain activity

Functional imaging of electric brain activity requires specific models to transform the signals recorded at the surface of the human head into an image. Two categories of model are available: single-time-point and spatio-temporal methods. The instantaneous methods rely only on the few voltage differences measured at one sampling point. To create a spatial image from this limited information, they require strict assumptions that rarely conform with the underlying physiology. Spatio-temporal models create two kinds of images: first, a spatial image of discrete equivalent multiple dipoles or regional sources, and second, an image of source current waveforms that reflect the temporal dynamics of the brain activity in circumscribed areas. The accuracy of the spatial image is model dependent and limited, but it can be validated from the spatio-temporal data by the "regional source imaging" technique, introduced here. The source waveforms are linear combinations of the scalp waveforms, and thus, specific derivations which image local brain activities at a macroscopic level. Brain source imaging of somatosensory evoked potentials revealed temporally overlapping activities from the brainstem, thalamus and from multiple sources in the region of the contralateral somatosensory projection areas.     

1995～2004年广东省医院管理研究文献量的统计分析

引用中国生物医学光盘数据库(CBMdisc)收录全国及广东省十年间医院管理发表的文献量、全国10大城市医院管理的文献量排名和广东省内21个省市级医院发表医院管理文献量排名等进行统计分析,并且提出建议。     

精制E型肉毒类毒素免疫原不同配制比例实验

目的为获得高效价的马血浆,选择最佳E型肉毒类毒素免疫原配制比例。方法用3种不同配制比例配制E型肉毒类毒素免疫原,免疫原1、2、3分别为V（羊毛脂）：V（液体石蜡）：V（精制E型肉毒类毒素抗原）=1：2：6,1：2：3,1：2：2。将24匹马分为3组,分别用3种免疫原按常规法免疫,采用小鼠中和试验方法检测马血浆效价。结果用免疫原2免疫的马匹,马血浆平均效价比用免疫原1、3平均效价提高了36．3％,且马匹表现状况好于免疫原1、3。结论免疫原2的配制比例使用安全、稳定性良好、马匹免疫效果较好,为目前抗毒素生产用免疫原最佳配制比例。     

Left Ventricular Abnormality and Covert Atrial Fibrillation in Embolic Stroke of Undetermined Source

Aims: The relationship between left ventricular (LV) function and AF detection in embolic stroke of undetermined source (ESUS) patients with insertable cardiac monitors (ICMs) remains unclear. We investigated the association between LV function and AF detection in patients with ESUS after ICMs implantation. Methods: We enrolled patients with ESUS who underwent ICMs implantation from September 2016 to September 2020 using a single-center, prospective registry. LV systolic and diastolic functions were assessed on precordial echocardiography by LV fractional shortening (LVFS) and average E/e’, respectively. Associations between characteristics of LV function and detection of AF by ICMs were analyzed. Results: Participants comprised 101 patients (median age, 74 years; male, 62%). During a median follow-up period of 442 days (interquartile range (IQR), 202–770 days), AF was detected in 24 patients (24%). Median duration from ICMs implantation to AF detection was 71 days (IQR, 13–150 days). When LVFS and E/e’ were dichotomized by cutoff value, each of low LVFS (＜35.5%; adjusted hazard ratio (HR), 4.77; 95% confidence interval (CI), 1.77–12.9) and high E/e’ (≥ 8.65; adjusted HR, 4.56; 95%CI, 1.17–17.7) were independently associated with AF detection after adjusting for age and sex. When patients were divided into four groups according to dichotomized LVFS and E/e’, the combination of low LVFS and high E/e’ was independently associated with AF. Conclusions: In patients with ESUS after ICMs implantation, the LV characteristics of low LVFS and high E/e’ were associated with AF detection.     

A Low-Cost Wireless Bite Force Measurement Device

Assessing maximum voluntary bite force is important to characterize the functional state of the masticatory system. Due to several factors affecting the estimation of the maximum bite force, a unique solution combining desirable features such as reliability, accuracy, precision, usability, and comfort is not available. The aim of the present study was to develop a low-cost bite force measurement device allowing for subject-specific customization, comfortable bite force expression, and reliable force estimation over time. The device was realized using an inexpensive load cell, two 3D printed ergonomic forks hosting reusable subject-specific silicone molds, a read-out system based on a low-cost microcontroller, and a wireless link to a personal computer. A simple model was used to estimate bite force taking into account individual morphology and device placement in the mouth. Measurement reliability, accuracy, and precision were assessed on a calibration dataset. A validation procedure on healthy participants was performed to assess the repeatability of the measurements over multiple repetitions and sessions. A 2% precision and 2% accuracy were achieved on measurements of forces in the physiological range of adult bite forces. Multiple recordings on healthy participants demonstrated good repeatability (coefficient of variation 11%) with no significant effect of repetition and session. The novel device provides an affordable and reliable solution for assessing maximum bite force that can be easily used to perform clinical evaluations in single sessions or in longitudinal studies.     

双源64层CT的工作原理及其临床应用

本文对双源64层CT的基本结构、工作原理及其临床应用做了介绍。     

纵行神经束内电极与周围神经生物相容性的实验研究

目的　研究纵行神经束内电极长期植入家兔坐骨神经神经束中的生物相容性 ,并探讨应用纵行神经束内电极记录的周围神经束的信号对电子假手控制的可能性。方法　将纵行神经束内电极长期植入 12只新西兰大白兔坐骨神经的神经束内 ,分别作为记录和刺激电极 ,通过经颅刺激系统 ,在术后不同时间记录运动诱发电位 (MEP)和皮层体感诱发电位 (CSEP) ,观察电极长期植入神经束内所记录到的信号的变化 ;术后 6个月信号记录结束后 ,取电极植入处的神经束进行组织学检查 ,了解电极对神经束的影响。然后 ,将纵行神经束内电极植入一名前臂残肢志愿受试者残肢的三条主要神经的神经束中 ,记录志愿受试者在意识控制中完成不同手的动作时的信号 ,并将其应用于电子假肢的实时控制。结果　不同时间记录的MEP和CSEP潜伏期间的差异均具有显著性意义 (方差分析 ,均P <0 .0 0 1)。经组间比较 ,MEP和CSEP的潜伏期在术后 1个月内无明显变化 ,以后明显延长 ,但 3个月以后趋于稳定 ;不同时间记录的MEP峰间波幅间的差异有显著意义 (方差分析 ,P <0 0 0 1)。经组间比较 ,在术后 1个月内变化不明显 ,以后明显降低 ,3个月后又趋于平稳。不同时间记录的CSEP峰间波幅虽然随时间延长有下降的趋势 ,但其间的差异无显著意义 (方差分析 ,P >0 0     

四种污染源气体颗粒物对大鼠血清肌红蛋白和脑钠肽的影响

【摘要】 目的 观察四种不同污染源气体颗粒物对大鼠血清肌红蛋白和脑钠肽水平的影响。方法 将70只成年SD大鼠随机分为对照组10只、汽车尾气组15只、煤烟组15只、燃烧秸秆组15只和自然空气组15只;按1mg/ml的相同的浓度气管内分别滴注汽车尾气、煤烟、燃烧秸秆、自然空气颗粒物悬液每天1次,一次01ml,连滴10天后,采用化学发光法动态检测5组的血清肌红蛋白（Mb）和脑钠肽（BNP）水平;计算HM/BM;CCK 8法检测大鼠心肌细胞的存活率,并观察心肌细胞的病理变化。结果 各研究组大鼠血清Mb的水平均有所升高,均在一定时间内达到峰值。血清中BNP水平也存在此类波动变化,BNP达到峰值的时间及恢复正常水平的时间比Mb水平晚,但升高的幅度大。汽车尾气组、煤烟组和自然空气组大鼠HM/BM明显升高,出现了不同程度的心肌细胞浸润、水肿、变性、坏死、纤维化;心肌细胞存活率明显下降;秸秆组大鼠HM/BM变化不明显,心肌病理出现了轻度的心肌细胞水肿、变性,HM/BM无明显升高,心肌细胞存活率下降不明显。结论 高浓度的汽车尾气、煤烟、燃烧秸秆、自然空气颗粒均可以引起大鼠的心肌损害。检测大鼠血清中肌红蛋白(Mb)和脑钠肽 (BNP)的水平对判断污染物对大鼠心肌损害程度具有重要意义。     

护理老年骨质疏松性骨折 ——护士压力源相关因素调查分析及对策

目的 随着生物-心理-社会医学模式的转变,全新护理老年骨质疏松性骨折对骨科护士身心健康所造成的压力及危害的压力源,为骨科护士减轻压力、提高护士生活质量提供依据。方法 自行设计骨科临床一线护士压力源调查表进行调查。调查表包括5个方面共13种压力源,在相对范围内对80%以上护士造成压力的压力源作为共同压力源。结果 骨科临床一线护士共同压力源来自 超负荷及紧张的工作状态,工作量大,护理人员紧缺,医院优质护理服务要求严格,注重专科内涵,社会支持保障不足,年轻护士专科知识不过硬,心理,自我提升（考试、晋升、考核）,家庭社会,以及工作环境压力等。结论 医院护理管理者在注重提高优质护理服务质量的同时,必须关注护士的身心健康,制定有效的减压措施,以维护骨科护理队伍的稳定。