Postoperative management of hypothermia of intra-operative origin--experience with a forced-air convective warming device

Hypothermia develops during the intra-operative period partly as a result of disordered thermoregulation induced by anaesthesia, and partly because of the nature of the operation or injury and the surgical environment. Both the hypothermic state and the consequences of physiological attempts to return the core temperature to normal, which take place during the postoperative period, are associated with non-beneficial effects. Attempts to prevent an intra-operative decline in core temperature are a part of anaesthesia management. However, most of the traditional options available are inefficient or ineffective, especially if used as a single intervention and particularly in adults. This study evaluates the performance of a new device, the forced-air convective warmer, in the management of the postoperative hypothermic state. Results show that the device made a significant difference to the thermal state of a group of hypothermic postoperative patients when compared with a hypothermic control group, but only if used for at least 2 hours after the operation.     

便携式结晶器振动监测系统的设计与应用

根据炼钢连铸结晶器的特点,设计并实现了便携式结晶器振动监测系统。系统实现了三维振动动画模型的建立、振动频率辨识与计算、振动相位计算、振动幅值及偏差计算和相关工艺参数计算。经过在炼钢厂的现场应用,系统设计满足工业现场的使用要求,能精确地测量结晶器的振动幅值、频率、相位和相关工艺参数,为结晶器的安全生产提供了科学依据,有较好的工程应用价值。     

Design and evaluation of head unit for wheelchair control by quadriplegic patients

A control unit was designed to allow persons who have lost hand and arm function to control the speed, steering, reversal and on-off switching of an electric wheelchair by means of backward movement and rotation of the head. When possible, shoulder movement was used to control both reversal and on-off switching. Clinical evaluation in 10 patients with quadriplegia and 2 with severe neuromuscular disease showed that the unit neither interfered with nor restrained the patients' residual body movements, permitted use of natural head movements for smooth and fast control of the wheelchair, and was well accepted by and integrated into the life of the patients.     

基于STC单片机的便携式里氏硬度计的研究与设计

介绍基于STC12C5A60S2单片机的便携式里氏硬度计的研究与设计,详细介绍了里氏硬度计的设计原理、硬件结构图、实现里氏硬度测量的主程序流程,同时,给出了部分程序代码和实际的测试数据.     

Effect of beta blockade on the erythrocyte transport of Na+: evaluation during stimulation by cold pressure test in patients with essential hypertension

Several studies have shown in essential hypertension alterations of the transmembrane red blood cells sodium fluxes, as an involvement, especially in the early phases, also of the adrenergic system. In this study we evaluated the behaviour of red blood cells fluxes of sodium before, during and after the cold pressor test, a method used also to evoke an adrenergic stimulation, in twenty hypertensive subjects, 14 males and 6 females, with an average age of 43.2 +/- 5.7 years, with normal weight and without cardiovascular complications and metabolic diseases. The behaviour of the Na+ total efflux (Na+ TE), of the Na+/K+ pump, of the Na+K+ cotransport (Na+/K+ CT), of the Na+/Li+ counter transport (Na+/Li+ Cnt), of the Na+ passive permeability (Na+ PP), of the intracellular Na+ (I Na+) and of the plasmatic noradrenaline (NE) was evaluated basally, at the third minute during cold pressor test (CPT) and 20 minutes after the end of the test. The test, which the same method, was repeated after a 30 day treatment with propranolol at the dose of 240 mg/day in three daily administrations. The beta-blockade caused, besides the reduction of both the systolic and diastolic pressure values, a significant increase in the Na+/K+ CT (from 248 +/- 41 to 314 +/- 71 mmol/l/cells/h, p < 0.001) and a decrease in the Na+ PP (from 0.039 +/- 0.004 to 0.023 +/- 0.007 hr-1, p < 0.00001), probably directed towards the reduction of the accumulation of intracellular Na+, that could compete, among the other mechanisms, with the anti-hypertensive action of the beta-blockers. The CPT caused, before the beta-blockade, a significant depression of the Na+/K+ pump (from 2057 +/- 149 to 1610 +/- 101 mmol/l/cells/h, p < 0.00001) and of the Na+ TE (from 2640 +/- 397 to 2032 +/- 179 mmol/l/cells/h, p < 0.00001) inversely correlated to the levels of NE (r = -0.60, p < 0.003), with a consequent increase in I Na+ (from 6.2 +/- 0.6 to 7.5 +/- 1.5 mmol/l/cells, p < 0.001), showing how the adrenergic activation in hypertensive subjects is able to interfere with the systems of transmembrane transport with an inhibitory attitude, that is expressed by an increase in the levels of I Na+. The beta-blockade was able to outweigh the depression of the Na+/K+ pump (from 1843 +/- 584 to 1728 +/- 640 mmol/l/cells/h, p: ns) and the reduction of the Na+ TE, preventing the accumulation of I Na+ (from 6.3 +/- 1.6 to 6.6 +/- 1.3 mmol/l/cells, p: ns). Such data show an increased susceptibility of the Na+ transport systems to the adrenergic stimuli in hypertensive subjects with a tendency to favor the accumulation of I Na+ and that the beta-blockade is able to antagonize the effects, with a maintenance of the intracellular levels of Na+.     

结晶器便携式振动监测系统的设计与应用

根据炼钢连铸结晶器的特点,设计并实现了结晶器便携式振动监测系统。采用附加测试件方法消除结晶器表面对信号的影响,提高原始信号质量;通过自适应放大及带通滤波进一步消除干扰信号,提高A／D量化精度;采用多通道同步采样,确保各通道无相移。系统软件具有数据采集与管理、采样组态、测点定义与管理、时域波形显示、波形放大、历史波形回放、历史波形比较、振动相位检测、振动频率检测、报表生成、特征数据采集和振动三维动画显示等功能。     

Combined evaluation of pupillary and cardiovascular responses to cold pressor test in cluster headache patients

Little is known about the structures and mechanisms involved in the pathophysiology of cluster headache (CH). In this study, pupillary and cardiovascular responses to the cold pressor test (CPT) were monitored in CH patients during either an active phase of disease or a remission period in order to evaluate the oculocephalic and cardiovascular functioning of the autonomic nervous system in this form of idiopathic headache. CH patients showed a specific pattern of pupillary response on both sides during both phases of the disease. This response differed from that of controls because of an absent miosis. The pressor response to CPT was more marked in CH patients than in controls. Naloxone pretreatment caused specific and selective changes in both the pupillary and cardiovascular responses of CH patients. These data suggest a systemic sympathetic hyperactivation in response to CPT in CH patients. An oculocephalic sympathetic hypofunction is possibly associated as well as an altered opioid neuromodulation.     

Development and evaluation of a compliance test for patients taking disulfiram

A breath test for carbon disulfide, a major excretion product of disulfiram, is described and evaluated. All breath excretions were standardized by collecting a fixed amount based on CO2 control. Excretion of CS2 falls rapidly (half life 8 to 18 hours), so that 20 to 30 hours following the last dose of disulfiram the test becomes negative. Approximately 300 tests in hospitalized patients taking disulfiram were positive; 40 tests in patients not taking this drug were negative. In an active disulfiram outpatient clinic more than one third of the patients who claimed to have taken disulfiram on the previous day had, as determined by this test, failed to do so. Of subjects judged by the professional staff to be almost certainly compliant 20% were not taking medication. Of the total of 52 patients tested in clinic only 25 were taking disulfiram.     

冷轧带钢针孔在线检测系统设计与应用

介绍一套基于光电检测技术的冷轧薄带钢针孔在线检测系统,该系统可有效识别直径≥15μm的针孔。高亮度LED光源照射在带钢上表面,光电接收器对透过针孔的光线进行汇聚,再被光电倍增管接收,转化为电信号,信号处理电路对电信号进行识别分类,最终由采集卡采集;边部针孔检测模块对边部进行精确跟踪和遮挡,保证系统在趋零盲区情形下实现边部针孔检测。运行证明,系统具有较高的实时性、可靠性和精确性。     

Detection and evaluation mechanism of cold rolling strip edge shape

The edge shape problem of strip has great influence on the shape control precision, so it is extremely necessary to establish the high-precision strip edge shape model. Based on the theoretical analysis and the practical engineering, a new high-precision shape detection model, which consists of wide channels in the middle of detection roll and narrow channels on both sides, is established to analyse the problem of strip edge shape. Instance data showed that the strip lateral thickness difference was directly related with the shape state of strip, and the strip edge coverage rate and the strip deviation amount had important influences on the shape detection precision, the pattern recognition accuracy and the shape control effect, so the strip edge shape model has become one of the key factors to improve industrial application effect of the shape closed-loop control system in the present situation.     

冷轧中锰钢的超塑性与组织结构演化行为

 为了研究含铝冷轧中锰钢的超塑性能和在超塑性变形下的组织结构演化过程,对冷轧含铝中锰钢在800 ℃进行了高温拉伸试验和不同变形量下的微观组织结构表征。研究结果表明,0.05C5Mn2Al、0.10C5Mn2Al和0.15C5Mn3Al钢伸长率分别达到了740%、850%和350%,都获得了超塑性现象,EBSD表征结果表明0.05C5Mn2Al、0.10C5Mn2Al两种冷轧组织均匀细小,在高温拉伸过程中具有较高的稳定性,拉伸过程中铁素体与原奥氏体均匀长大,且最大晶粒尺寸小于10 μm;但0.15C5Mn3Al冷轧组织存在条带状的铁素体,该组织易于通过吞并细小的铁素体和原奥氏体晶粒而异常长大,高温拉伸后的尺寸达到了20 μm。通过对3种含铝冷轧中锰钢的超塑性行为与微观组织结构演化关系分析,认为初始均匀一致的冷轧组织具有高的组织稳定性而有利于超塑性,而具有粗大条带状的铁素体组织易于发生异常长大而不利于超塑性。     

冷连轧机轧制数据管理系统的设计与实现

主要介绍了某650 mm四辊四机架冷连轧机轧制数据管理系统的设计方案、结构特点和功能实现。该系统以SQL Server数据库服务器为中心,通过网络与过程控制系统连接,共享数据,并对数据进行统一管理。投运后,有效地满足了生产和管理的需求,给企业带来了显著的经济和社会效益。     

全连续冷连轧机自动控制系统的设计与实现

河北中钢1250mm八辊五机架全连续冷连轧机组是我国首条自主研制开发的全连续冷连轧生产线，北京科技大学高效轧制国家工程研究中心承担了自动控制系统的设计开发。本文介绍了该系统过程控制级、基础自动化级和现场执行级的主要功能、硬件组成、网络结构及软件设计思想。该系统已在河北中钢五机架级冷连轧机组投入使用，证明是安全、可靠和稳定的。     

四辊轧机板形测控系统的设计

介绍了东北大学轧制技术及连轧自动化国家重点实验室三机架四辊连轧机板形测量与控制系统的设计，并对板形（平直度）的测控原理进行了阐述。通过板形在线检测系统的投入，使被轧带材板形的质量有了较大程度的提高。     

双机架可逆冷连轧机自动控制系统设计与应用

随着现代工业的迅速发展，冷轧带钢产品需求日益增加，对其质量的要求也日益提高。由于双机架可逆冷连轧机具有许多优点，已成为冷轧带钢领域的一种重要机型。针对高效轧制国家工程研究中心新建的一套双机架可逆冷连轧机，作者开发了其自动控制系统。     

Design and evaluation of a device for measuring three-dimensional micromotions of press-fit femoral stem prostheses

Implant micromotion is considered to be a major factor in the loosening of cementless total hip replacements. Translational micromotion at the bone-implant interface generally occurs in all three spatial directions. Under physiological loading, the interfacial micromotion consists of a cyclic amplitude and changes in the mean, which, in the cranio-caudal direction, represents subsidence of the prosthesis. Existing measurement strategies, which are based on dial gauges, extensometers, LVDTs, hall-effect transducers or strain gauge techniques provide information about only one component of the general three-dimensional micromovement. Moreover, in the majority of the studies, the data are difficult to interpret due to the measured motions being composed of interfacial micromotion and femoral strains. A new transducer was designed that allows the accurate measurement of all three isolated components of micromotion. An optoelectronic approach, based on silicon position-sensitive detectors (PSD) in combination with high precision mechanical parts, was chosen. To exclude thermodrifts during long-term testing, a thermistor was integrated in the sensor. Validation experiments on a precision positioning table indicated the high precision and resolution of the developed sensors. Furthermore, in-vitro tests on a standard press-fit prosthesis demonstrated the easy handling and reliability of the system.