Sensory brain activation during rectal balloon distention: a pilot study in healthy volunteers to assess safety and feasibility at 1.5T

Objective

Although increasing evidence suggests a central mechanism of action for sacral neuromodulation, the exact mechanism remains unclear. We set up a scanning paradigm to measure brain activation related to various stages of rectal filling using rectal balloon distention.

Materials and Methods

Six healthy volunteers underwent rectal balloon distention during MRI scanning at a 1.5T scanner with a Tx/Rx head coil. MR images were collected at four levels of distention: empty balloon (EB), first sensation volume (FSV), desire to defecate volume (DDV), maximum tolerable volume (MTV). Data were analyzed using BrainVoyager 20.4. Whole brain and ROI-based fixed-effects general linear model analyses were performed on the fMRI time-course data from all participants.

Results

Rectal filling until FSV evoked the most blood-oxygen-level-dependent responses in several clusters throughout the cortex, followed by the responses evoked by rectal filling until DDV. Interestingly, rectal filling until MTV evoked negative responses compared to baseline throughout the cortex. No negative side effects were found.

Discussion

This study shows that a standardized paradigm for functional MRI combined with rectal filling is feasible and safe in healthy volunteers and is ready to be used in fecal incontinent patients to assess whether their brain activity differs from healthy controls.

     

存款单作为电费质押担保的可行性及其实践

银行存款单质押作为保证债权实现的一种预防性措施,有着一般担保形式无法比拟的优越性,是一种手续简便、安全性高、变现成本小的物的担保。通过银行存款单质押对电费进行担保,能够有效降低供电企业电费回收的风险。将此种担保推而广之,更有助于解决电费回收难的困境,对促进市场交易有着积极的意义。     

A feasibility study of a direct-mapping parallel processing method to solve linear equations in load-flow calculation

With the growing size and complexity of power systems, system analysis—such as transients calculation—takes much time. Hence, fast calculation methods are required. Although parallel processing is a hopeful method, there have been difficulties in the parallel solution of linear equations which appear in power-flow calculations by the Newton-Raphson method. This paper aims at the fast calculation of the power-flow problem by means of parallel processing. In order to improve the suitability to the parallel solution of the differential equation in transients calculation, we assume the use of a direct-mapping parallel processing machine to map directly the network of a power system onto a network of processors. Under this assumption, we propose a new parallel-processing-oriented method in which the linear equation is solved by linear iterations between nodes with Aitken acceleration. We simulate the method on three model power systems and compare this Parallel Iterative Method (PIN) with a Parallel Direct Method (PDM) which uses the banded matrix according to the number of operations required. As a result, we can expect that PIM may solve linear equations faster than PDM with m processors, although the PIM might be inferior to the PDM with m × m processors, where m denotes the half-band width of the banded matrix.     

模糊理论在新型接地故障选择装置中的应用

基于对小电流系统单相接地故障特征的分析,采用模糊理论计算各线路对故障的可信度。据此设计以微型机为平台的小电流系统接地故障选择装置,从而保证装置对参数变化具有鲁棒性。     

The use of a rotlin field in the dielectrophoretic separation ofdifferent types of bioparticle

For the purpose of bringing about the separation of bioparticles by means of dielectrophoresis, a field is considered which at any given point is constant in magnitude, and rotating at a fixed angular velocity. The field pattern causing this behavior exhibits a two-dimensional variation in the xy plane, and moves in the x direction at a fixed velocity; at all times, the field is zero everywhere in the z direction. Because a rotating field is produced from the linear motion of the field pattern, it is termed a `rotlin field'. The way in which a rotlin field may be produced is explained. It is evident that spatial harmonics will be present, and that these might affect bioparticle behavior. A bioparticle in such a field will experience both rotational and dielectrophoretic effects. A change in the angular velocity of the rotating field set up at each point by the rotlin field, and a change in the permittivity or conductivity or both of the immersion medium, can cause some particles to exhibit negative, while others exhibit positive, dielectrophoresis. The resulting difference in their movement can be used to bring about their separation     

一种矢量原子磁力仪中旋转磁场的设计及实验验证

目前国内外报道了几种矢量原子磁力仪的技术方案,其中基于磁场旋转调制法的矢量原子磁力仪可实现对矢量磁场的连续测量。本文对磁场旋转调制法矢量原子磁力仪的工作原理进行了阐述,对“旋转磁场”的设计、产生以及标定方法进行了介绍,在此基础上基于抽运-检测型原子磁力仪对旋转磁场和矢量磁场的叠加磁场进行了实验测量,验证了实测磁场的平均值、峰峰值与理论计算结果的符合情况,分析了实测磁场的平均值与理论平均值的偏差起源,并通过实验验证了矢量原子磁力仪的连续测量能力。本文研究内容为连续测量型矢量原子磁力仪的研制奠定了技术基础。     

The 3-D calculations of the leakage magnetic field and the short-circuit reactance in a transformer with disk windings

Contents A three-dimensional analysis of the quasistationary leakage magnetic field of a three-phase transformer with disk windings is presented. A simplified mathematical model of the transformer based on Maxwell's equations has been applied. Computational results of the short-circuit reactance for the symmetrical and asymmetrical disk windings have been compared with analytical ones according to Richter's formulas [8]. For the magnetic field calculation, the finite difference method with the application of fast calculating subroutines has been used.

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Dreidimensionale Berechnung des magnetischen Streufeldes und Kurzschlussreaktanz eines Transformators mit Scheibenwicklungen

Übersicht Es wird eine dreidimensionale Analyse des quasistationären magnetischen Streufeldes eines dreiphasigen Transformators mit Scheibenwicklung dargestellt. Dazu wird ein vereinfachten mathematisches Modell eines Transformators auf der Basis der Maxwell-Gleichungen angewandt. Die numerischen Ergebnisse der Kurzschlußreaktanz für symmetrische und unsymmetrische Scheibenwicklung wurden mit den analytischen Ergebnissen nach R. Richter [8] verglichen.Für die Berechnung des magnetischen Feldes wurde ein Differenzenverfahren mit schnellen numerischen Prozeduren verwendet.

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The first author is on leave from the Technical University in Opole (Poland) under the Alexander von Humboldt Grant.     

A review of studies on the electric field and the current induced in a human body exposed to electromagnetic fields

How high an electric field or current is induced inside a human body when exposed to an electromagnetic field has recently attracted much attention. The background for this is twofold; concern about the possible health effects of electromagnetic fields (usually called ‘EMF issues’), and their positive application to medical treatment or new research subjects. This paper reviews various aspects related to this topic in terms of the following items: basic formulas for field calculation, effect of electromagnetic fields, calculation methods, an Investigation Committee in the IEEJ, and future research subjects. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

家用空调压缩机故障分析

在简要介绍相关背景知识的基础上 ,对某次家用空调压缩机的故障进行了调查分析 ,判明了原因 ,分析了影响 ,提出了对策     

某高加三通阀自动切换失效的原因及技控措施

某电厂2#机高压加热器进口三通阀(进口阀门)出现不能正常切换等问题,为保证同类问题的及时解决和确保机组的正常运行,通过对特殊阀门的结构分析,明确了三通阀结构部件的作用与工作原理,提出了处理方案。通过与对阀门解体对比发现,两者吻合,说明了处理方案的可行性,及时消除了缺陷,保证了机组安全运行。     

山西省实施污水资源化亟待解决的问题

对山西省实施污水资源化面临的主要问题进行了分析 ,提出了从体制、政策方面解决障碍的建议 ,对工程具体实践中存在的问题进行了剖析 ,并设计了解决措施     

长期洪水浸泡对地基土影响分析

本文通过静力触探试验及静载荷试验等手段评价了长期洪水浸泡对地基承载力指标的影响,从卸载及地基土膨胀性等因素分析了承载力降低的原因,同时结合地基土的特性对基坑的开挖与维护提供了相关建议。     

The Design and Evaluation of an Ion-Drag Dielectric Pump to Enhance Cooling in a Small Oil-Filled Transformer

An ion-drag dielectric pump consisting of a closed loop of glass tubing has been used to investigate the pumping of transformer oil. The velocity of the oil has been measured with a multiplicity of design variables: electrode spacing and density of field enhancing points, cofield temperature gradients, waveshape, and pressure heads. The observed velocities under our experimental conditions are severalfold higher (-10x) than the flow rates computed for convective oil flow in a 25-kVA distribution transformer (=0.6 cm/s).     

The role of energy conservation technologies in selecting a rational scheme for supplying heat to large towns

We present the results from a comprehensive analysis of power engineering of a town, using Moscow as an example; statistical initial data; and results obtained from surveys and calculations, as well as preliminary conclusions on how efficiently energy resources are produced, transported, distributed, and used by end consumers.     

爆炸冲击荷载作用下横观各向同性半无限弹性介质的动力响应

本文视土岩介质为横观各向同性均匀弹性体,用正弦波的半周期模拟爆炸冲击荷载的情况,利用三维弹性动力学的基本原理研究了爆炸冲击荷载作用下半无限弹性介质的动力响应,并给出了算例的解析解结果。该方法可用于解决土木工程基础开挖中预留保护层及建筑物爆破振动防护的问题。     

逆变器短路控制式串级调速系统在发电厂排煤粉机90kW绕线式异步电动机上的应用

本文介绍了逆变器短路控制式串级调速系统在本钢发电厂排煤粉机00kW绕线式异步电机上的应用,文中介绍了该串调系统的工作原理,实际构成,工业实验结果及体会。     

加装试验开关的某型号矿用隔爆型真空电磁起动器机械联锁机构设计

简要阐述了某型号矿用隔爆型真空电磁起动器加装试验开关后,机械联锁机构的设计。     

湖南电网近期建设220 kV GIS设计选型

0　前　言　　随着国民经济的不断发展 ,城市用电量、负荷增加 ,特别是城市的经济发展和人民生活水平的不断提高 ,对供电可靠性要求也越来越高。加上城区电网改造项目的实施及城市工业区内电厂项目的上马 ,我省 2 2 0 k V电压等级的城区变电所将越来越多。由于城市内 2 2 0 k V变电所占地面积受到很大限制 ,工业区内变电站电气设备受工业污染腐蚀严重 ,且目前网络容量越来越大 ,因而对 2 2 0 k V配电装置的布置方式和设备提出了更高的要求。因此 ,湖南电力系统首先在高岭 2 2 0 k V变采用了 GIS的设计 ,为我省电网 2 2 0 k V GIS的采用…     

线缆质量水平长期处于低位国内企业亟需自救

2008年9月16日,国家质检总局发布了对天津、河北、内蒙古(不涉及出口产品)等15个省、直辖市120家企业生产的120种电线电缆产品质量的国家监督抽查结果,产品实物质量抽样合格率为93.7%.这个结果让生产总值占我国GDP1.5%以上的整个电线电缆产业感到欣慰.然而, "2008中国电线电缆行业大会"上,国家电线电缆质量检验中心副主任吴长顺在<国内电线电缆质量状况分析及提高产品质量对策>的报告中却指出,我国电线电缆质量问题重重.……