高压对耳蜗的影响

目的研究高压环境对人耳蜗的影响,弥补试验手段不足导致的耳蜗在高压环境下听力行为特征研究的缺失,为今后对耳蜗进行针对性研究提供新的思路。方法基于健康人耳蜗CT扫描图像,结合自编程序,利用PATRAN软件建立三维螺旋耳蜗有限元模型。应用NASTRAN软件进行流固耦合频率响应分析和瞬态响应分析,通过数值模拟方法研究高压对耳蜗的影响。结果基底膜12 mm处与镫骨底板中心(卵圆窗的中心)处位移比值模拟结果与已报道的试验结果相吻合,验证了所建模型的正确性。高压环境下,耳蜗中基底膜特征频率点的幅值随着压强的增大而不断减小。结论高压环境最终导致人耳听力的降低。研究结果为临床上研制防治高压的缓冲装置提供理论支撑。     

溶血标本对生化检验结果的影响分析

目的研究溶血标本对生化检验结果的影响，为检验人员和临床医生对溶血标本的生化检验结果进行正确的分析提供依据。方法取未溶血标本的血清进行相关的生化项目检验．然后通过搅拌使标本发生轻度溶血、重度溶血，并分离出溶血标本的血清进行相同的生化项目检验，对未溶血、轻度溶血及重度溶血标本的检验结果进行统计分析。结果轻度溶血标本对ALT、AST、TP、AMY、ALP、LDH、CK、CK-MB、HBDH、UREA、GLU、CRE、UA、LDHC、IP、Fe、Mg、Zn、K、Na、Cl的检验结果产生显著性的影响；标本重度溶血时，除对轻度溶血产生显著性影响的项目外，还对ALB、HDLC、APOA1，Ca、IgG的检验结果也产生显著性影响。结论标本溶血对大部分生化检验项目的检验结果可产生显著性的影响，但在分析溶血标本的生化检验结果时．无论是检验人员还是临床医生均应将该项目的统计学结果、实验允许误差、医学决定水平结合起来分析，同时以本单位实验室公布的受影响的实验项目为参考背景，才能最大限度地利用溶血标本的检测结果，为临床医生的诊疗提供正确的分析。     

离体猪气管异向力学特性及数值模拟研究

目的 研究猪气管和主支气管各向异性的力学性能,通过有限元数值模拟确定描述气管变形的本构模型。方法 将收集的猪气管沿轴向剖开并展成平面,以展开后的气管长度方向0°为起始角度,逆时针方向获得30°、60°、90°、120°、150°、180°共6个角度方向的标本。利用电子万能试验机分别对6个角度方向标本进行单轴拉伸试验,获得标本在不同角度方向的应力和应变。采用Mooney-Rivilin超弹性模型对实验数据进行非线性拟合,得到模型材料特性参数,建立气管和主支气管有限元模型,并进行拉伸数值模拟。结果 不同角度的气管标本拉伸呈现出不同的应力-应变;在气管中,30°、120°和150°方向样本的应力范围为1.0~1.5 MPa,60°和90°方向标本的应力范围为0.5~1.0 MPa,180°方向标本的应力范围为2.5~3.0 MPa;在主支气管中,30°、60°和150°方向标本的应力范围为0.8~1.0 MPa,90°和180°方向标本的应力范围为1.4~1.8 MPa,120°方向标本的应力范围为0.4~0.6 MPa,气管与主支气管有着明显的差异。经有限元模拟验证,Mooney-Rivilin本构模型适合于描述气管的小变形行为。结论 猪气管呈现较强的各向异性,Mooney-Rivilin模型可以表征气管小变形行为。研究结果为临床治疗中气管切除重建及支气管镜等手术器械介入治疗提供理论依据。     

不同时段不同类型临床标本微生物检验结果阳性率分布

目的对不同时段不同类型临床标本微生物检验结果阳性率分布进行分析,探讨临床标本微生物检验应注意的事项。方法对医院2010年1月~2011年12月及2012年1月~2013年12月两个时间段共4141份临床检验标本为对象,系统分类后通过全自动细菌鉴定药敏分析仪对其阳性率进行检验。结果两个时期的不同类型临床标本的阳性率存在差异。2012年1月~2013年12月的呼吸道标本和非呼吸道及粪便标本的阳性率均低于2010年1月~2011年12月的标本,而血培养标本的阳性率则高于2010年1月~2011年12月阶段,差异具有统计学意义(<0.05)。结论对微生物检验中存在的问题,医院应范标本采集步骤,提高医护人员的专业素养,以促进整体诊疗水平和诊治效果的提高。     

PDCA循环管理在降低临床尿常规检验标本不合格率中的应用

目的探讨PDCA循环管理法在降低临床尿常规检验标本不合格率中的应用效果。方法对首都医科大学附属北京中医医院2017年7月至2018年6月住院患者尿常规检验不合格标本进行数量统计,进一步分析标本不合格原因,随后采用PDCA循环管理法对住院患者尿常规检验标本进行持续性质量改进,比较PDCA循环管理法实施前后的标本不合格率。结果实施PDCA循环管理法后,住院患者尿常规检验标本不合格率显著降低(P<0.05),由实施前的24.18%降为实施后的8.8%,在后期的效果维持阶段,住院患者尿常规检验标本不合格率仍维持在较理想水平(不合格率为9.3%)。结论应用PDCA循环管理法可显著降低住院患者尿常规检验标本不合格率,有效保证检验分析前阶段标本质量,提高检验结果准确性。     

研究比较临床细菌检验各项目的正确性

目的 对临床细菌检验各项目的正确性进行比较分析,提升临床检验水平.方法 选取2012年8月～2014年8月在我院行临床检验的2460例标本为研究对象,根据标本类型,分为血液标本、尿液标本、粪便标本、脓性分泌物类标本、生殖道分泌物类标本、痰液标本六大类,分别为530例,491例,361例,265例,224例,589例.采用常规K-B法行药敏试验,分析比较各检验项目的正确性.结果 本次研究结果显示各类标本的合格率均比较好,从高到低依次如下:尿液标本(98.98％)、粪便标本(98.61％)、脓性分泌物类标本(98.11％)、血液标本(97.92％)、生殖道分泌物类标本(95.54％)、痰液标本(93.04％).结论 临床细菌检验对疾病的防控具有重要意义,需要严格按照操作标准来执行,保障每个环节的均符合要求,保障检验结果正确性.     

基于3D打印和CT三维重构数值模拟上呼吸道气流状态的研究方法

目的建立物理模型实验和数值模拟相结合的方法,用于研究上呼吸道气流状态。方法基于网上公开CT医学图像,重建人体上呼吸道三维模型。基于3D打印技术,建立上呼吸道实验模型,进行呼吸的流量过程测量实验;通过对上呼吸道三维模型进行网格划分,采用湍流Realizable k-ε数值模型进行计算。结果首先进行与实验工况对应的数值模拟对比研究,得到与实验吻合的结果。数值模拟结果表明,呼吸过程中的气流的流动轨迹呈抛物线形状,呼气和吸气阶段的流场、壁面压力和涡结构分布很大区别,呼吸交换过程中上下鼻道有空气残留。另外,通过脉线、压力分布和涡结构分布情况,初步分析气流对上呼吸道生理环境的影响。结论该方法具有针对性、快速性和准确性的特点,充分发挥了物理实验可靠和数值模拟精细的优点,适用于不同个案上呼吸道不同问题的研究,对临床个性化诊疗具有价值。     

放射治疗下实体肿瘤演变的数学模型和数值模拟

目的数值模拟研究放射治疗下放射敏感性系数、治疗频率、肿瘤细胞成熟年龄等因素对实体肿瘤放射治疗效果的影响。方法建立放射治疗下实体肿瘤演变的连续-离散混合数学模型,模型考虑肿瘤的微环境(氧、细胞外基质、基质降解酶)以及自身行为(增殖、凋亡、黏附)对肿瘤演变的影响,并引入线性二次模型描述肿瘤对放射治疗的响应,采用数值模拟方法模拟不同条件下肿瘤演变的过程,评价放射治疗的疗效。结果肿瘤的放射治疗效果与放射敏感性系数、肿瘤细胞成熟年龄正相关,而在放射剂量总量不变的情况下,高频治疗和低频治疗效果并没有特别明显的区别。结论模拟结果与临床结果相吻合,可为肿瘤放射治疗的理论及临床研究提供一种新的方法。     

溶血标本对酶联免疫吸附试验检测乙型肝炎表面抗原影响的分析

目的：探讨溶血标本对酶联免疫吸附试验检测乙型肝炎表面抗原结果的影响。方法对400份不同的血清标本采用酶联免疫吸附试验(ELISA)进行乙型肝炎表面抗原(HBsAg)的测定，其中阴性标本217份，强阳性标本95份，弱阳性标本88份；用人为方法造成溶血，对溶血标本重新测定，对2次检测结果进行比较。结果217例HBsAg阴性标本和95例HBsAg强阳性标本，非溶血标本和溶血标本血清检测结果(阴性或强阳性)全部一致，非溶血标本和溶血标本血清的HBsAg的OD值无统计学意义；88例HBsAg弱阳性标本，溶血标本血清检测出现假阳性率为7.95%(7/88)，非溶血标本和溶血标本血清的乙型肝炎表面抗原(HBsAg)的OD值具有统计学意义。结论溶血对乙型肝炎表面抗原(HBsAg)阴性及乙型肝炎表面抗原(HBsAg)强阳性的标本影响不大，而对乙型肝炎表面抗原(HBsAg)弱阳性标本的检验结果具有一定影响，甚至可能造成假阴性。     

临床标本阳性率检验结果探析

目的对临床标本阳性率检验结果进行分析探讨，为今后的临床检验和防治工作提供可靠的理论依据。方法采集2012年1月~2013年12月我院临床标本1098份，将其根据标本采集时间和类型进行分组，对不同时间段和不同类型标本的阳性率进行统计分析。结果对比2012年1月~12月和2013年1月~12月的数据发现，13年标本各种临床标本阳性率较12年发生明显降低(P<0.05)；不同临床标本的阳性率比较“存在差异(P<0.05)。结论临床标本检验结果阳性可为疾病的诊断和治疗方法的选择等提供可靠的参考信息。     

Mixing enhancement of the passive microfluidic mixer with J-shaped baffles in the tee channel

This study proposed a new design of a passive micromixer employing several J-shaped baffles in the tee channel to enhance mixing. The mixing performance of the device was investigated experimentally and by numerical simulation. The in-plane structured micromixer was fabricated using micromolding of SU-8 photoresist and PDMS. The mixing performance was demonstrated using image analysis to quantify the concentration distribution in the microchannel. The percentage of mixing increased as the number of baffles increased. The simulated and experimental results showed that the mixer with J-shaped baffles exhibited better mixing performance, and the percentage of mixing was about 1.2 to 2.2 times higher when compared to those without baffles, in the range of Reynolds number (Re) 5 to 350. The improvement in mixing performance was especially apparent at the short axial distance and at the lower Reynolds numbers. The results revealed that the J-shaped baffles could result in lateral convection in the main channel, resulting in improved mixing.     

Rapid circular microfluidic mixer utilizing unbalanced driving force

This paper proposes a novel rapid circular microfluidic mixer for micro-total-analysis-systems (μ-TAS) applications in which an unbalanced driving force is used to mix fluids in a circular chamber at low Reynolds numbers (Re). The microfluidic mixer has a three-layered structure and is fabricated on low-cost glass slides using a simple and reliable fabrication process. Using hydrodynamic pumps, fluids are driven from two inlet ports into a circular mixing chamber. Each inlet port separates into two separate channels, which are then attached to opposite sides of the 3-dimensional (3-D) circular mixing chamber. The unequal lengths of these inlet channels generate an unbalanced driving force, which enhances the mixing effect in the mixing chamber. Numerical simulations are performed to predict the fluid phenomena in the mixing chamber and to estimate the mixing performance under various Reynolds number conditions. The numerical results are verified by performing flow visualization experiments. A good agreement is found between the two sets of results. The numerical and experimental results reveal that the mixing performance can reach 91% within a mixing chamber of 1 mm diameter at a Reynolds number of Re = 3. Additionally, the results confirm that the unbalanced driving force produces a flow rotation in the circular mixer at low Reynolds numbers, which significantly enhances the mixing performance. The novel micromixing method presented in this study provides a simple solution for mixing problems in Lab-on-a-chip systems.     

Helminth egg analysis platform (HEAP): An opened platform for microscopic helminth egg identification and quantification based on the integration of deep learning architectures

BackgroundMillions of people throughout the world suffer from parasite infections. Traditionally, technicians use manual eye inspection of microscopic specimens to perform a parasite examination. However, manual operations have limitations that hinder the ability to obtain precise egg counts and cause inefficient identification of infected parasites on co-infections. The technician requirements for handling a large number of microscopic examinations in countries that have limited medical resources are substantial. We developed the helminth egg analysis platform (HEAP) as a user-friendly microscopic helminth eggs identification and quantification platform to assist medical technicians during parasite infection examination.MethodsMultiple deep learning strategies including SSD (Single Shot MultiBox Detector), U-net, and Faster R-CNN (Faster Region-based Convolutional Neural Network) are integrated to identify the same specimen allowing users to choose the best predictions. An image binning and egg-in-edge algorithm based on pixel density detection was developed to increase the performance. Computers with different operation systems can be gathered to lower the computation time using our easy-to-deploy software architecture.ResultsA user-friendly interface is provided to substantially increase the efficiency of manual validation. To adapt to low-cost computers, we architected a distributed computing structure with high flexibilities.ConclusionsHEAP serves not only as a prediction service provider but also as a parasitic egg database of microscopic helminth egg image collection, labeling data and pretrained models. All images and labeling resources are free and accessible at http://heap.cgu.edu.tw. HEAP can also be an ideal education and training resource for helminth egg examination.     

Mixing of acrylic bone cement: effect of oxygen on setting properties

The present study investigates the effect of different mixing methods on the setting properties of bone cement. It was found that vacuum mixing decreased the setting time of the bone cement by nearly 2 min (10%), compared to mixing in air. Two additional experiments, in which the bone cement powders were purged with argon or oxygen, and mixed with the methyl methacrylate monomer, revealed that oxygen concentrations in the bone cement had a great effect on the setting time. The setting time increases significantly as the oxygen concentration increases, which suggests that the decrease in the setting time by vacuum mixing may be attributed to the lower oxygen levels present in the mixer. No significant effect was observed on dough time or maximum exothermic temperature by varying oxygen concentrations in the bone cement mixer.     

血管生物反应器流场的数值分析

目的 研究一种新型小口径血管生物反应器在不同工况下的流场分布。方法 采用数值方法模拟反应器外筒单独旋转、内筒单独旋转和内外筒同向等速旋转情况下其内部的流场分布,对流速和切应力等参数进行比较分析。结果 血管生物反应器工作时,培养液随内外筒的旋转而旋转流动,速度分布均匀;可为培养液内的细胞提供非破坏性的低切应力环境;并且反应器内部的切应力大小与转速呈二次函数关系。结论 该反应器能为血管培养提供良好的培养环境,本研究可为其实验研究提供指导意见和理论基础。     

Numerical optimization of a three-channel radiofrequency coil for open, vertical-field, MR-guided, focused ultrasound surgery using the hybrid method of moment/finite difference time domain method

The numerical optimization of a three-channel radiofrequency (RF) coil with a physical aperture for the open, vertical-field, MR-guided, focused ultrasound surgery (MRgFUS) system using the hybrid method of moment (MoM)/finite difference time domain (FDTD) method is reported. The numerical simulation of the current density distribution on an RF coil with a complicated irregular structure was performed using MoM. The electromagnetic field simulation containing the full coil-tissue interactions within the region of interest was accomplished using the FDTD method. Huygens' equivalent box with six surfaces smoothly connected the MoM and FDTD method. An electromagnetic model of the human pelvic region was reconstructed and loaded in the FDTD zone to optimize the three-channel RF coil and compensate for the lower sensitivity at the vertical field. In addition, the numerical MoM was used to model the resonance, decoupling and impedance matching of the RF coil in compliance with engineering practices. A prototype RF coil was constructed to verify the simulation results. The results demonstrate that the signal-to-noise ratio and the homogeneity of the B(1) field were both greatly improved compared with previously published results.     

经水平和冠状切的后半部颅骨表面包埋方法探讨

目的　使用环氧树脂AB胶对最容易损坏的经水平切和冠状切的后半部分颅骨表面进行薄层包埋,使颅骨骨质薄的结构变得坚硬,且其孔、缝、管保存完好。 方法　将48个颅骨标本随机分成8组,每组按照不同时间段逐个浸没于有机玻璃盒的环氧树脂AB胶中,每个浸泡时可看见有气体排出,约1 min左右,没有明显的大气泡产生,即用止血钳夹住较厚的颅骨壁边缘取出颅骨,在有机玻璃盒上方停留一会并轻轻晃动,待颅骨表面流动的胶基本流干后,将颅骨水平切面朝下放置于硅胶板上,静置24 h。 结果 标本透明度高,颅骨壁光滑,可清楚辨认标本结构,易碎部分骨骼受力明显增强,较容易脱落骨骼与颅骨整体连接更加紧密,搅拌充分后60 min内包埋的颅骨标本的各管、孔没有明显堵塞,表面没有出现结块现象。 结论　在室温下,环氧树脂AB胶搅拌充分后60 min以内为适宜的颅骨表面包埋时间。经表面包埋后的颅骨标本较好的解决了在实验教学过程中不易损坏,要求不能触摸的两难问题。     

基于负压吸引式冷冻溶脂降温效果的仿真及实验

目的:评估冷冻溶脂治疗过程的降温效果,为临床治疗提供理论依据。方法:依据负压吸引式冷冻溶脂装备结构建立物理模型,通过数值模拟的方法评估不同溶脂温度以及血液灌注率对降温效果的影响,并进行实验验证了模型的准确性。结果:模拟结果表明,不同制冷温度下,低于溶脂温度的脂肪厚度占比为10.11%~40.32%,与临床的减脂效果10.7%~37.5%相比,模拟结果与临床结果较为一致。较小的脂肪血液灌注率会提升降温效果,但当脂肪血液灌注率小于1.44×10-4 s-1时,冷冻溶脂降温效果的提升较小。实验结果表明,模拟值与实验值降温趋势一致,在最终时刻温度相差1~2 ℃,证实数值模拟结果的准确性。结论:研究结果可以为临床评估及优化冷冻溶脂效果提供可靠的理论依据。     

瑞氏染液混配机的设计

目的设计一种可替代传统人工操作的瑞氏染液混配机。方法瑞氏染液混配机由混配罐、水箱、电机、电控箱和基座等构成。工作模式采用动力电机减速驱动混配罐翻转,借助于混配罐内壁摩擦撞击和研磨材料碰撞,使粉粒状瑞氏色素粉碎分散溶解成均一的极细小的微粒以至混配成瑞氏染液。通过实际配液和染色比较瑞氏染液混配机配液与人工配液的差异。结果瑞氏染液混配机混配的染液色素颗粒微细,质量优良,染色效果好,便于标本片的会诊和图像采集,避免了人工配制造成的染液质量不稳定和甲醇的毒副作用。结论该设计装备结构简单,设计合理,配液效率高,是一种特别适宜配制瑞氏染液的实验室实用新型设备。     

Numerical and experimental characterization of a novel modular passive micromixer

This paper reports a new low-cost passive microfluidic mixer design, based on a replication of identical mixing units composed of microchannels with variable curvature (clothoid) geometry. The micromixer presents a compact and modular architecture that can be easily fabricated using a simple and reliable fabrication process. The particular clothoid-based geometry enhances the mixing by inducing transversal secondary flows and recirculation effects. The role of the relevant fluid mechanics mechanisms promoting the mixing in this geometry were analysed using computational fluid dynamics (CFD) for Reynolds numbers ranging from 1 to 110. A measure of mixing potency was quantitatively evaluated by calculating mixing efficiency, while a measure of particle dispersion was assessed through the lacunarity index. The results show that the secondary flow arrangement and recirculation effects are able to provide a mixing efficiency equal to 80?% at Reynolds number above 70. In addition, the analysis of particles distribution promotes the lacunarity as powerful tool to quantify the dispersion of fluid particles and, in turn, the overall mixing. On fabricated micromixer prototypes the microscopic-Laser-Induced-Fluorescence (μLIF) technique was applied to characterize mixing. The experimental results confirmed the mixing potency of the microdevice.