Direct Chill Casting and Extrusion of AA6111 Aluminum Alloy Formulated from Taint Tabor Scrap

AA6111 aluminum automotive body-sheet alloy has been formulated from 100% Taint Tabor scrap aluminum. Direct chill casting with and without high shear melt conditioning (HSMC) was used to produce the AA6111 alloy billets. Both homogenized and non-homogenized billets were extruded into sheets. The optical micrographs of the melt conditioned direct chill (MC-DC) samples showed refined equiaxed grains in comparison to direct chill (DC) cast and direct chill grain refined (DC-GR) samples. Optical metallography showed extensive peripheral coarse grain (PCG) for the DC, DC-GR and MC-DC planks extruded from the homogenized standard AA6111 billets while planks extruded from modified AA6111 billets (with recrystallization inhibitors) showed thin PCG band. The co-addition of recrystallization inhibitors Mn, Zr, and Cr with elimination of the billet homogenization step had a favorable impact on the microstructure of the AA6111 alloy following the extrusion process where a fibrous grain structure was retained across the whole section of the planks. The mechanical properties of as-cast planks extruded from non-homogenized billets were similar to those extruded from homogenized billets. Eliminating the homogenization heat treatment step prior to extrusion has important ramifications in terms of processing cost reduction.     

A ‘Third Way’ for lay involvement: what evidence so far?

Aims and objectives  This article considers evidence regarding lay involvement in the NHS, following the White Paper's commitment to rebuild public confidence in an NHS 'accountable to patients and open to the public and shaped by their views'. It looks at two aspects of lay involvement: the lay board member's involvement in primary care group (PCG) decision-making and the engagement of the PCG with the wider public.
Methods  The paper analyses data from the first sweep of the annual Tracker Survey of a sample of PCGs in England, led by the National Primary Care Research and Development Centre in collaboration with the King's Fund between September and December 1999. It draws specifically from the postal questionnaires sent to lay members. Firstly, however, it contextualizes this data by reviewing the history of lay involvement before 1997 in the NHS and particularly in primary care.
Conclusions  The paper concludes that, during the first 6 months of their operation, the lay voice was faintly heard in PCGs. The lay member's role in decision-making at board-level was peripheral. The majority rated their involvement in key aspects of decision-making as low and their influence on decision-making below that of other board members including the Chief Officer, the chair and the GP board members. Beyond the arena of the board, what little contact there was with the lay voice has taken the shape of informing rather than consulting. Mitigating factors include the early stage at which the survey was completed and the lack of precedents for lay involvement in primary care in a broad sense on which PCGs can draw.     

Towards classifying non-segmented heart sound records using instantaneous frequency based features

Abstract

Heart sound and its recorded signal which is known as phonocardiograph (PCG) are one of the most important biosignals that can be used to diagnose cardiac diseases alongside electrocardiogram (ECG). Over the past few years, the use of PCG signals has become more widespread and researchers pay their attention to it and aim to provide an automated heart sound analysis and classification system that supports medical professionals in their decision. In this paper, a new method for heart sound features extraction for the classification of non-segmented signals using instantaneous frequency was proposed. The method has two major phases: the first phase is to estimate the instantaneous frequency of the recorded signal; the second phase is to extract a set of eleven features from the estimated instantaneous frequency. The method was tested into two different datasets, one for binary classification (Normal and Abnormal) and the other for multi-classification (Five Classes) to ensure the robustness of the extracted features. The overall accuracy, sensitivity, specificity, and precision for binary classification and multi-classification were all above 95% using both random forest and KNN classifiers.     

Dissection of perceptual,motor and autonomic components of brain activity evoked by noxious stimulation

In the past two decades, functional brain imaging has considerably advanced our knowledge of cerebral pain processing. However, many important links are still missing in our understanding of brain activity in relation to the regulation of pain-related physiological responses. This fMRI study investigates the cerebral correlates of pain (rating), motor responses (RIII-reflex) and autonomic activity (skin conductance response; SCR) evoked by noxious electrical stimulation. Stimulus intensity was adjusted individually based on the RIII threshold to control for differences in peripheral processes and baseline spinal activation. Covariance analyses were used to reveal individual differences in brain activity uniquely associated with individual differences in pain, RIII and SCR. Shock-evoked activity in cingulate, medial orbitofrontal and parahippocampal regions predicted pain sensitivity. Moreover, lateral orbitofrontal and cingulate areas showed strong positive associations with individual differences in motor reactivity but negative associations with autonomic reactivity. Notably, individual differences in OFC activation was almost fully accounted by the combination of individual measures of autonomic and motor reactivity (R² = 0.93). Additionally, trial-to-trial fluctuations of RIII-reflex and SCR (within-subjects) were proportional to shock-evoked responses in subgenual cingulate cortex (RIII), anterior insula (SCR) and midcingulate cortex (SCR and RIII). Together, these results confirm that individual differences in perceptual, motor, and autonomic components of pain reflect robust individual differences in brain activity. Furthermore, the brain correlates of trial-to-trial fluctuations in pain responses provide additional evidence for a partial segregation of sub-systems involved more specifically in the ongoing monitoring, and possibly the regulation, of pain-related motor and autonomic responses.     

Direct evidence of intra- and interhemispheric corticomotor network degeneration in amyotrophic lateral sclerosis: an automated MRI structural connectivity study

Although the pathogenesis of amyotrophic lateral sclerosis (ALS) is uncertain, there is mounting neuroimaging evidence to suggest a mechanism involving the degeneration of multiple white matter (WM) motor and extramotor neural networks. This insight has been achieved, in part, by using MRI Diffusion Tensor Imaging (DTI) and the voxelwise analysis of anisotropy indices, along with DTI tractography to determine which specific motor pathways are involved with ALS pathology. Automated MRI structural connectivity analyses, which probe WM connections linking various functionally discrete cortical regions, have the potential to provide novel information about degenerative processes within multiple white matter (WM) pathways. Our hypothesis is that measures of altered intra- and interhemispheric structural connectivity of the primary motor and somatosensory cortex will provide an improved assessment of corticomotor involvement in ALS. To test this hypothesis, we acquired High Angular Resolution Diffusion Imaging (HARDI) scans along with high resolution structural images (sMRI) on 15 patients with clinical evidence of upper and lower motor neuron involvement, and 20 matched control participants. Whole brain probabilistic tractography was applied to define specific WM pathways connecting discrete corticomotor targets generated from anatomical parcellation of sMRI of the brain. The integrity of these connections was interrogated by comparing the mean fractional anisotropy (FA) derived for each WM pathway. To assist in the interpretation of results, we measured the reproducibility of the FA summary measures over time (6 months) in control participants. We also incorporated into our analysis pipeline the evaluation and replacement of outlier voxels due to head motion and physiological noise. When assessing corticomotor connectivity, we found a significant reduction in mean FA within a number of intra- and interhemispheric motor pathways in ALS patients. The abnormal intrahemispheric pathways include the corticospinal tracts involving the left and right precentral gyri (lh.preCG, rh.preCG) and brainstem (bs); right postcentral gyrus (rh.postCG) and bs; lh.preCG and left posterior cingulate gyrus (lh.PCG); rh.preCG and right posterior cingulate gyrus (rh.PCG); and the rh.preCG and right paracentral gyrus (rh.paraCG). The abnormal interhemispheric pathways included the lh.preCG and rh.preCG; lh.preCG and rh.paraCG; lh.preCG and right superior frontal gyrus (rh.supFG); lh.preCG and rh.postCG; rh.preCG and left paracentral gyrus (lh.paraCG); rh.preCG and left superior frontal gyrus (lh.supFG); and the rh.preCG and left caudal middle frontal gyrus (lh.caudMF). The reproducibility of the measurement of these pathways was high (variation less than 5%). Maps of the outlier rejection voxels, revealed clusters within the corpus callosum and corticospinal projections. This finding highlights the importance of correcting for motion artefacts and physiological noise when studying clinical populations. Our novel findings, many of which are consistent with known pathology, show extensive involvement and degeneration of multiple corticomotor pathways in patients with upper and lower motor neuron signs and provide support for the use of automated structural connectivity techniques for studying neurodegenerative disease processes.     

人体心电心音信号定征分析系统设计

目的：设计人体动态心电心音信号定征分析系统。方法：设计了一套以内置A／D的单片机为控制核心,结合信号调理电路和USB通信接口传输的同步采集系统及VC＋＋6．0开发的心电心音定征分析系统,整个系统包括模拟电路、数字电路和PC客户定征分析软件等3个部分。结果：采用双通道、双采样率采集方法实现了动态心音和心电信号的同步采集、实时存储,并可从复杂的带噪原始信号中精确检测提取出心电信号的QRS波、P波、ST段等以及心音信号的各成分。结论：整个系统操作简便、测量准确、功耗低、体积小、数据分析处理功能强大,可在家庭和医院使用。     

SXG－7000心脏工作站原理与方法

ＳＸＧ—７０００心脏工作站兼有检查和监护功能，可检查病人的十二导联心电图，心电心音图、颈动脉博动图，心尖博动图，心电向量图，时间心向量图，连续心向量图，心室晚电位和心电监护共十项功能。每一项均可实现实时彩色记忆示波，并具有流动显示和冻结功能。仪器使用八笔彩色记录仪，描记标准病历报告单，每一项的图形及自动分析测算结果均可由绘图仪一并描出。本文就系统原理、硬件和软件方法以及临床试用情况进行了介绍。     

中国原发性先天性青光眼患者CYP1B1基因突变的系统评价

目的了解中国人群原发性先天性青光眼患者CYP1B1基因突变及其分布情况。方法检索Pub Med、Web of Science、CNKI、万方等数据库,收集公开发表的有关中国人群原发性先天性青光眼患者CYP1B1基因突变筛查研究文献。采用系统评价的方法评价文献质量,提取相关数据,运用Freeman-Tukey双反正弦变换法对基因突变率进行合并计算,收集并获得我国原发性先天性青光眼患者的CYP1B1基因突变谱。结果共纳入9篇文献,包括434例原发性先天性青光眼患者,其中69例存在CYP1B1基因突变,合并突变率为15.2%(95%可信区间11.8%~19.0%)。共发现43种突变,基因突变谱分散,以7990C>T(L385F)、8006G>A(R390H)、4124C>G(L107V)三种突变频率最高,比较发现L107V是中国原发性先天性青光眼人群CYP1B1基因特有的变异位点。结论中国原发性先天性青光眼患者的CYP1B1基因突变率较低,提示该人群中存在除CYP1B1基因以外的其他致病基因。收集获得的CYP1B1基因突变谱可为今后原发性先天性青光眼人群基因突变筛查提供参考。     

原发性先天性青光眼患者长期手疗效比较分析

目的 评价原发性先天性青光眼患者长期手术疗效.方法 对过去11年间(1997年9月至2008年9月)收入中山大学中山眼科中心首次行手术治疗,并能长期随访到的48例81只眼原发性先天性青光眼患者进行回顾性分析.结果 所有患者在小梁切除术、小梁切开术与联合手术者间手术成功率无明显差异(P=0.492);在随访超过4年者中:Kaplan-Meier分析显示行小梁切除术与联合手术者成功率曲线下降较平稳,其中联合手术者成功率曲线下降最缓慢,但小梁切开术曲线下降较明显(P=0.022).结论 长期随访(≥4年)能更好地评价原发性先天性青光眼术后长期临床疗效;三种手术方式治疗原发性先天性青光眼患者远期成功率均随着时间的延长而下降,但以联合手术组成功率曲线下降最缓慢,其次是小梁切除术组,小梁切开术组成功率曲线下降最明显.术后远期的手术成功率与术后患者随访的依从性相关,患者依从性好术后远期的手术成功率高.     

变形链球菌表面蛋白P1粘膜免疫动物模型的建立及霍乱毒素的免疫增强作用

用共价偶联的方法 ,将变形链球菌表面蛋白 P1与霍乱毒素 B亚单位或前霍乱原类毒素进行偶联后 ,用灌胃的方法将不同的免疫剂进行大鼠免疫实验 ,检查不同时间大鼠体内特异抗体的产生情况。结果证实了霍乱毒素 B亚单位的佐剂效果 ,同时发现前霍乱原类毒素具有强的胃肠免疫增强作用。