Wave propagation in the silicon tube: comparison of the two-point and three-point pressure methods.

The values of the propagation coefficient measured on a silicon rubber tube in the frequency range 1-15 Hz were compared, using four different equations. The first formula is based on three simultaneous pressure measurements performed at equidistant points; the remaining three equations are original, and make use of only two of the three pressure measurements together with a no-flow condition at the terminal tube section. The results of our trials demonstrate that the experimental phase velocity, obtained with all equations, settles at a value about 25% in excess of the theoretical one computed with a classic linear mathematical model. This result may be explained by an increase in the dynamical Young modulus with respect to that measured in static conditions. However, the three-point method introduces great errors in the results in the frequency range 11-14 Hz where the spectrum of the second signal becomes minimum. In all cases, the experimental value of attenuation per wavelength at mid-high frequencies is greater than the theoretical one valid for a purely elastic tube. The attenuation values obtained with the two-point method can be explained by introducing a small contribution of wall viscoelasticity (2-3 degrees) into the linear model. Attenuation per wavelength computed with the three-point methods turns out about threefold that computed with each of the two-point formulas. This result supports the idea that the accuracy of the three-point method may be insufficient to achieve correct estimation of wave attenuation, especially when the distance between transducers is small compared to wavelength.     

多聚甲醛固定对大鼠椎骨黏弹性影响的实验研究

目的观察多聚甲醛固定对大鼠椎骨黏弹性力学性能的影响,从生物力学角度寻找松质骨样品的最佳保存方式。方法选择8周龄健康雌性SD大鼠20只,手术分离获得完整的腰椎L4和L5共40只,随机平均分为固定组和对照组,固定组置于4%多聚甲醛中固定72 h,对照组置于5 m L EP管内-20℃冷冻保存。两组随机各取10只分别行应力松弛和蠕变实验,7 200 s后收集样品并通过显微CT分析其微观结构变化。结果固定组松弛蠕变曲线相比对照组更加平滑,达到稳态的时间较短,且500 s和7 200 s的松弛蠕变总量明显降低(P0.01)。显微CT结果显示松弛蠕变实验会引起骨小梁断裂,且固定组比对照组骨小梁破坏更加严重。结论多聚甲醛固定法显著降低大鼠椎骨的黏弹性,在力学负荷下更易造成其微观结构破坏,不利于松质骨保存。     

Measurements of wave speed and compliance in a collapsible tube during self-excited oscillations: a test of the choking hypothesis

Indirect evidence links self-excited oscillation of flow through collapsed tubes with choking, defined by the cross-sectionally averaged fluid speed u reaching the local speed of small pressure waves c. This was tested by measuring both c-u and c as functions of tube cross-sectional area during self-excited oscillation, using small superimposed high-frequency wave packets. The wavespeed c was derived from the local slope of the pressure/area relationship, measured at both high and low frequency, while c-u was taken as the upstream propagation rate of the pressure disturbances. When u=0, these were shown to agree with each other. The propagation results showed that choking did not occur at high frequency. At the low frequency of the self-excited oscillation the results were less conclusive, because of dispersion and indirect methodology, but choking appeared not to happen at the modest flow rate of the oscillation investigated. Results on the attneuation of the wave packets were successfully explained using a model of the tube throat consisting of two equal and opposite reflection sites.     

Nerve repair using a polyglactin tube and nerve graft: An experimental study in the rabbit

Defects in a sectioned tibial nerve were bridged by a new method using a polyglactin mesh-tube and compared with conventional nerve grafting in the rabbit The capability of healing was evaluated by morphometrical observations and repeated EMG-recordings. Only minor differences between the two different techniques were observed and the possible advantage of the polyglactin method is discussed.     

Effects of a computerized decision support system on care planning for pressure ulcers and malnutrition in nursing homes: An intervention study

BackgroundNursing documentation is essential for facilitating the flow of information to guarantee continuity, quality and safety in care. High-quality nursing documentation is frequently lacking; the implementation of computerized decision support systems is expected to improve clinical practice and nursing documentation.AimThe present study aimed at investigate the effects of a computerized decision support system and an educational program as intervention strategies for improved nursing documentation practice on pressure ulcers and malnutrition in nursing homes.Design, setting and participantsAn intervention study with two intervention groups and one control group was used. Fifteen nursing homes in southern Norway were included. A convenience sample of electronic healthcare records from 46 units was included. Inclusion criteria were records with presence of pressure ulcers and/or malnutrition. The residents were assessed before and after an intervention of a computerized decision support system in the electronic healthcare records. Data were collected through a review of 150 records before (2007) and 141 records after the intervention (2009).MethodsThe nurses in intervention group 1 were offered educational sessions and were trained to use the computerized decision support system, which they used for eight months in 2008 and 2009. The nurses in intervention group 2 were offered the same educational program but did not use the computerized decision support system. The nurses in the control group were not subject to any intervention. The resident records were examined for the completeness and comprehensiveness of the documentation of pressure ulcers and malnutrition with three data collection forms and the data were analyzed with non-parametric statistics.ResultsThe implementation of the computerized decision support system and the educational program resulted in a more complete and comprehensive documentation of pressure ulcer- and malnutrition-related nursing assessments and nursing interventions.ConclusionThis study provides evidence that the computerized decision support system and an educational program as implementation strategies had a positive influence on nursing documentation practice.     

基于声学不均匀特性的磁感应磁声成像声压解析

目的 依据人体声学参数,探索磁声耦合成像声信号在声学非均匀媒介中的传播对检测结果的影响.方法 参考人体组织声学特性建立仿真模型,借助有限元分析工具进行电磁场仿真,采用时域有限差分方法求解磁声信号在仿真模型中的传播,并在自由空间采集声压信号.最后,对比研究磁声信号在声学均匀模型和声学非均匀模型中的传播过程.结果 在两个声学模型中声源分布相同,声学非均匀模型中采集的声压信号峰值数量多于声源边界,且声压峰值间的时间间隔与声源边界之间的距离不匹配.结论 初步揭示了声学非均匀特性对磁感应磁声成像的影响,为声学非均匀媒介的重建算法研究奠定了一定基础.     

The impact of numeracy on reactions to different graphic risk presentation formats: An experimental analogue study

Objectives. Numeracy, the ability to process basic mathematical concepts, may affect responses to graphical displays of health risk information. Displays of probabilistic risk information using grouped dots are easier to understand than displays using dispersed dots. However, dispersed dots may better convey the randomness with which health threats occur, so increasing perceived susceptibility. We hypothesized that low numeracy participants would better understand risks presented using grouped dot displays, while high numeracy participants would have good understanding, regardless of display type. Moreover, we predicted that dispersed dot displays, in contrast to grouped dot displays, would increase risk perceptions and worry only for highly numerate individuals. Design and method. One hundred and forty smokers read vignettes asking them to imagine being at risk of Crohn's disease, in a 2(display type: dispersed/grouped dots)×3(risk magnitude: 3%/6%/50%)×2(numeracy: high/low) design. They completed measures of risk comprehension, perceived susceptibility and worry. Results. More numerate participants had better objective risk comprehension, but this effect was not moderated by display type. There was marginally significant support for the predicted numeracy × display type interaction for worry about Crohn's disease, but not for perceived susceptibility to the condition. Conclusions. Dispersed dot displays somewhat increase worry in highly numerate individuals, but only numeracy influenced objective risk comprehension. The most effective display type for communicating risk information will depend on the numeracy of the population and the goal(s) of the communication.     

负压吸引联合局部氧疗治疗压疮效果的研究

目的探讨负压吸引联合局部氧疗对压疮的治疗效果。 方法将2015年1月至2016年12月于空军总医院烧伤整形科住院的60例Ⅲ期压疮患者按随机数字表法分为3组：常规换药组、负压吸引组、联合治疗组,每组各20例,常规换药组与负压吸引组分别给予常规换药法、负压伤口疗法治疗,联合治疗组采用负压吸引结合创面局部氧疗。观察入院后即刻,治疗后第1、2、3、4、5、6、7、8周创面最大长度、宽度、深度,渗出情况,组织类型及创面缩小程度。对数据进行单因素方差分析和LSD法。 结果负压吸引组在压疮的长度、宽度、深度上较常规换药组均明显减小,联合治疗组的减小效果更为显著,差异均有统计学意义(P值均小于0.05)。治疗后第8周常规换药组压疮的长、宽、深度分别为(3.04±0.43)、(3.63±0.88)、(1.55±0.77) cm,负压吸引组分别为(2.14±0.71)、(2.65±1.27)、(1.05±0.62) cm,而联合治疗组为(1.17±0.28)、(1.39±2.37)、(0.58±0.45) cm。负压吸引组压疮的渗出明显减少,压疮肉芽组织生长明显增多,创面缩小程度更为显著,联合治疗组的以上治疗效果明显优于负压吸引组,差异均有统计学意义(P值均小于0.05)。 结论负压吸引联合局部氧疗治疗Ⅲ期压疮能显著促进创面愈合,减少渗出,促进肉芽组织生长,效果优于单独负压吸引治疗,将来可以作为一种新的有效的治疗手段来推广应用。     

兔动脉粥样硬化易损斑块模型的建立

目的利用血管内超声(IVUS)的影像学特点分析建立的兔模型的易损斑块。方法16只雄性新西兰纯种兔,通过球囊损伤腹主动脉和高脂(1%胆固醇)饲料喂养8周,建立动脉粥样硬化易损斑块的兔模型。应用IVUS分别测量腹主动脉同一血管段中多个病变部位及其参考部位的各项指标,然后给予中国斑点蝰蛇毒(CRVV)和组胺药物触发,造成实验性斑块破裂和血栓形成。结果破裂与未破裂斑块相比较,破裂斑块具有较大的偏心性(P<0.05),破裂斑块呈现明显的正性重构,而未破裂斑块主要表现为负性重构。结论IVUS应用于已建立的动脉粥样硬化易损斑块的动物模型上,能够准确地识别动脉粥样硬化易损斑块,为以后实验性大样本研究药物稳定易损斑块的治疗奠定了基础。     

Effect of electronic toilet system (bidet) on anorectal pressure in normal healthy volunteers: influence of different types of water stream and temperature

Although bidets are widely used in Korea, its effects on anorectal pressures have not been studied in detail in terms of the water settings used. Twenty healthy volunteers were placed on a toilet equipped with a bidet, and anorectal pressures were measured with a manometry catheter inserted into the rectum and anal canal before and after using the bidet at different water forces (40, 80, 160, 200 mN), temperatures (24°C vs 38°C), and water jet widths (narrow vs wide). The pressure at anal high pressure zone decreased from 96.1 ± 22.5 to 81.9 ± 23.3 mmHg at water jet pressure of 40 mN and 38°C wide water jet (P < 0.001), from 94.3 ± 22.4 to 80.0 ± 24.1 mmHg at water jet pressure of 80 mN and 38°C narrow water jet (P < 0.001), and from 92.3 ± 22.4 to 79.6 ± 24.7 mmHg at a water jet pressure of 80 mN and 38°C wide water jet (P < 0.001). At other settings, no significant changes were observed. Our results indicate that, in addition to cleansing effect, bidet could be used to reduce anal resting pressure in the same manner as the traditional warm sitz bath under the conditions of low or medium water jet pressure, a warm water temperature, and a wide type water jet.     

硫酸镁神经保护作用的实验研究

目的：探讨硫酸镁对新生鼠缺氧缺血性脑损伤的神经保护作用。方法：结扎7日龄Wistar大鼠左侧颈总动脉后吸入8％浓度氧和92％浓度氮气混合气体2小时,制成动物模型。将其随机分组,应用苏木素－伊红（HE）染色和生物化学手段,观察和比较各组动物脑组织中组织病理学形态改变、SOD活力和丙二磷MDA含量。结果：应用MgSO4后脑组织中MDA含量较缺氧缺血组显著降低（P＜0．001）,神经细胞变性坏死减少。结论：MgSO4对新生鼠缺氧缺血性脑损伤有神经保护作用,其作用与抗自由基有关。     

高速投射物压力波致大鼠肝损伤的实验研究

本实验旨在通过压力波作用于大鼠，观察压力波能否引起肝脏的功能改变，为临床上高速投射物伤的诊治提供参考。结果发现：压力波致伤后，大鼠肺脏、肝脏表面有出血点片，可见肠穿孔及肝脏表面裂口等改变。     

下肢不等长对步态影响的实验分析

目的采用正常人体单侧增高模拟下肢不等长,分析下肢不等长步态特征,研究下肢不等长对步态的影响,为下肢假肢穿戴者因下肢不等长引起的慢性疾病提供理论依据。方法通过单侧穿鞋增高人为制造下肢不等长,利用三维动态捕捉系统和地面反力采集设备采集受试者在正常步态和下肢不等长步态下的时空参数、地面反力和关节角度,并进行对比分析。结果下肢不等长步态与正常步态在步长、步长时间和单侧支撑期存在显著差异。下肢不等长步态左右腿足跟着地期垂直方向地面反力均大于正常步态,髋、膝、踝角度存在明显变化。结论下肢不等长是造成行走步态异常的重要原因,可能是下肢假肢穿戴者产生腿部关节疾病的原因。     

双侧峡部裂对腰椎稳定性影响的实验研究

目的：研究双侧峡部裂对腰椎三维稳定性的影响。方法：实验材料为８具成人新鲜腰椎标本,切断Ｌ２双侧峡部,通过脊柱三维运动试验机,对标本施加前屈／后伸、侧弯和轴向旋转等６种力偶矩（１０Ｎ．ｍ）,由脊柱三维运动分析系统得到腰椎节段的运动范围。结果：双侧峡部断裂后,腰椎前屈／后伸及左／右旋转运动范围分别增加２６．６％、５５．９％、１００．９％、１１５．８％,较正常标本有显著性增大,而左／右侧弯变化不大。结论：峡部对腰椎三维稳定具有重要的力学作用,双侧峡部裂导致腰椎不稳。     

异种松质骨支架体内移植免疫的实验研究

观察异种松质骨支架植入后宿主动态免疫应答,为进一步改进材料和临床应用提供实验依据。采用物理化学方法对异种(猪)松质骨进行处理得到猪松质骨支架,对猪松质骨进行蛋白提取,考马斯亮蓝法测定蛋白浓度,用提取的蛋白作抗原包被ELISA条板备用。将异种(猪)松质骨支架植入兔背部近头侧皮下,分别于移植后1周、2周、4周、8周、12周五个时间点作支架周围组织的组织学检查(HE)及外周血清抗体检测(ELISA)。结果:异种(猪)松质骨及松质骨支架的蛋白质浓度分别为(1.242±0.26)mg/ml和(0.024±0.004)mg/ml。异种(猪)松质骨蛋白抗原液经聚丙烯酰胺凝胶(SDS-PAGE)电泳分离后可清楚显示十条不同相对分子质量大小的蛋白条带(从15000到180000),异种(猪)松质骨支架蛋白抗原液经SDS-PAGE电泳分离后10000 Mr以上的蛋白条带消失,说明松质骨支架不含有效激发免疫反应的抗原蛋白成分。外周血中特异抗体水平在移植术后1周达最高,与处理前有明显差异(P<0.05),2~4周时逐渐降低,8~12周时维持在较低水平,与移植前无显著差异(P>0.05)。植术后1周,植入物周围组织光学显微镜下可见大量炎症细胞浸润,以淋巴细胞和单核细胞为主,2周以后炎症细胞浸润逐渐减轻,4周时未见明显炎性细胞浸润,术后12周,组织内炎性细胞罕见。异种(猪)松质骨支架不含有效激发免疫反应的抗原蛋白成分,植入后表现为一过性轻度的炎性细胞反应。     

人巨细胞病毒先天性潜伏感染老龄小鼠肺组织的实验研究

目的 观察HCMV先天性潜伏感染老龄小鼠肺组织的病理改变，为进一步研究HCMV潜伏感染再激活与肺部疾病的关系提供初步依据。方法HCMV AD169株感染BALB／c小鼠雌雄配对，所生子鼠饲养18个月后随机取6只腹腔注射环磷酰胺为病毒激活组，另取6只为病毒潜伏组；同样方法设立DMEM激活组和DMEM未激活组为对照。取各组小鼠肺组织进行病毒分离与鉴定、PCR和RT-PCR检测HCMVUL83基因及其转录产物、HE染色等。结果 病毒激活组小鼠肺组织病毒分离、PCR及RT-PCR均为阳性；HE染色可见肺泡间隔增宽，有大量炎性细胞浸润，肺泡腔有渗出，可观察到HCMV特征性包涵体。病毒潜伏组仅PCR为阳性，其余均为阴性。对照组小鼠所有结果均为阴性。结论HCMV AD169株可引起小鼠先天性肺组织潜伏感染，并在免疫抑制剂作用下可能激活转变为活动性感染造成肺组织病理损伤。     

An experimental electron microscopic study on the striatonigral projection in the cat

Summary The ultrastructure of the cat's substantia nigra was investigated from 2–21 days following large lesions of the caudate nucleus and the putamen. From 4 days on a large number of degenerating boutons and degenerating unmyelinated fibers are seen in the substantia nigra, in the pars compacta as well as the pars reticulata. Both parts, mainly the latter, receive striatal afferents. The degeneration in the substantia nigra following striatal lesions is of the dark type. Most of the degenerating boutons apparently are of the type I (see Rinvik and Grofová, 1970) and end on all parts of the nigral cell surface, including the dendritic spines. One instance of a degenerating presynaptic bouton in an axo-axonic synapse has been found. Some degenerating boutons also probably belong to the type II bouton, while degenerating boutons of type III were never seen following the striatal lesions. The electron microscopic identification of early axonal degeneration in the central nervous system, is discussed with reference to the paper of Cohen and Pappas (1969). Problems concerning the pars compacta versus the pars reticulata of the substantia nigra are taken up. The possible sources of origin of the different types of boutons in the cat's substantia nigra, is discussed.On leave of absence from the Anatomical Institute of the Medical Faculty, Charles' University in Prague, with an IBRO grant nr. E. 29.99-1.A preliminary report of some of the observations was presented at the XIIth Congress for Morphologists in Prague, October '69.We gratefully acknowledge the valuable technical assistance of Mrs. J. L. Vaaland and the skilful help by Mrs. B.E. Branil in the preparation of the microphotographs.