微波激励热声成像中微波源参数选择的理论分析

分析了微波激励热声成像中激励源参数对成像质量和对比度的影响,探讨使用理论和计算方法来选择微波激励源参数.首先从理论上分析微波激励源参数对成像质量的影响和微波源参数的选择标准,然后从微波热声成像的自身特点、微波对于人体的安全标准以及工程应用的可行性的角度出发,对一些关键参数进行理论计算得出参数选择的参考范围,同时指出进行参数选择时的关键影响因素.     

病态噪声识别特征参数的优化选择

为提高病态嗓声识别效率,本研究首次采用主分量分析方法对目前常用的27个噪声特征参数进行了优化分析,考察了仅用少数主分量参数的识别效果及其分量数对结果的影响;同时根据参数对病态噪声信息敏感程度,使用正交试验法优选出9个较优特征参数,其识别率即可达到原27个参数的识别结果.经两种方法对参数进行优选后识别率分别达到97.23%和98.10%,显著高于未经优选、使用全部27个参数的92.10%识别率.研究结果表明:原27个参数中,2/3的参数不能很好地反映嗓声的病态变化特征,使用优选的含有大量病态嗓声信息的少量特征参数即可大幅提高病态嗓声识别效率.     

中国人股骨上段几何特征研究

目的研究股骨近端几何形态的统计规律,以改善现有的人工关节设计.方法成人尸体股骨480根,正侧位X光片摄片获得原始成像,用计算机数字图像技术结合测量21个参数,对股骨上段髓腔曲线进行拟合和统计.对股骨髓腔截面形态进行自动提取,并采用圆锥曲线拟合、二次曲线简化、形心曲线拟合等数学方法,将股骨髓腔截面形态简化为长短轴、形心轴线等几个参数.结果获得480例股骨上段参数的统计数据,150例股骨上段髓腔截面的长短轴以及截面形心的曲线拟合方程并对截面的长短轴和形心曲线方程进行了分类.讨论本研究对股骨髓腔21个参数做了大量统计分析,应用模式识别的方法将曲线形状参数以分类定为6种,并选出截面形心的曲线拟合方程,这些都为假体柄部的设计提供了科学的依据,为三维建模提供了基础,使得CAD优化设计成为可能.     

表面肌电信号的时变AR模型参数估计及其在下腰痛评估中的应用研究

本文针对表面肌电信号的非平稳特性,采用时变参数AR模型对表面肌电信号进行分析,将线性非平稳问题转化为线性时不变问题,并采用递推最小二乘算法求解模型的时变参数.在此基础上,提出了结合奇异值分解进行参数优化,进而进行模式分类的方法.能够成功地区分下腰痛患者治疗前后的状态,为下腰痛的诊断、治疗与康复判定奠定了一定的基础.     

利用LabVIEW构建血管生物反应器数据采集系统

对组织工程血管的参数监测在血管的培养过程中有着重要的意义.传统的仪表硬件系统能对反应器部分参数进行测量,但仍存在一些不足之处,本文通过分析确定血管生物反应器的监控参数,并利用虚拟仪器技术及LabVIEW软件开发平台构建了血管组织工程参数监测系统,该系统在实际应用中表明:系统简捷、运行稳定,能够监测血管的体外培养并达到了预定的精度要求.Labview的     

表面肌电信号的时变AR模型参数评估肌疲劳程度的研究

目的 本研究针对表面肌电信号的非平稳特性,采用时变参数AR模型的方法对表面肌电信号进行分析,实现对短时表面肌电信号的肌肉疲劳快速评估.方法 应用时变参数模型对10名受试者疲劳前、后的肌电信号进行特征提取,建立时变参数AR模型,并采用递推最小二乘算法求解模型的时变参数,将线性非平稳问题转化为线性时不变问题.结果 以时变参数AR模型的第一个时变参数的均值作为肌肉疲劳的快速指针.实验证明时变参数比传统的中值频率对疲劳反应的灵敏度高（提高范围为37.80%到324.46%）.结论 该方法可以实现对短时表面肌电信号的肌肉疲劳快速评估,为腰肌劳损的诊断和康复治疗,以及人体工效学的研究提供一个可靠的工具.     

一个中国汉族精神分裂症高发家系的全基因组连锁分析

目的 对一个汉族精神分裂症高发家系进行全基因组连锁分析,对易感基因进行定位.方法 抽取受试者外周血4 mL,用常规酚氯仿法提取基因组DNA,选择Illumina Infinium Linkage-24 BeadChips芯片对样本进行单核苷酸多态性检测及分型.用Illumina BeadStudio软件处理原始数据后,对分型结果应用Merlin软件进行两点非参数连锁分析和两点参数连锁分析.结果 用Merlin软件进行两点非参数连锁分析,共发现27个连锁值较高的位点(连锁值在0.63～0.75之间,P＜0.05),其中3个单核苷酸多态性(rs993694、rs992690、rs1861577)位于12p12.3区,剩余的位点均位于4p12-q22区.在显性模型下的两点参数连锁分析得到了几乎一致的结果.结论 染色体4p12-q22区以及12p12.3区可能包含精神分裂症的易感基因.     

图像处理工具箱测定卵泡的形态参数

目的:数字图像处理被广泛的应用在生物医学领域,并取得一些成果,但对卵泡形态参数进行测量的系统报道不多.本文研究利用计算机图像处理技术,对促排卵治疗患者的卵泡形态参数进行测量,在生殖医学的临床诊断方面有重要的现实意义和广阔的应用前景.方法:使用The MathWorks公司的MATLAB软件中的图像处理工具箱(image pro-eessing toolbox)编写程序.先将获取的原始卵泡图像先进行四步预处理:一、提取原始图像,二、估计背景亮度,三、调整背景,四、调整对比度;然后再进行四步图像分割:一、提取图片,二、图像二值化,三、面积围封,四、确定边界.最后对得到所需样本.测量卵泡面积、周长、最大直径、等效圆直径、似圆度五个形态参数.结果:测出比较理想的卵泡的面积、周长、最大直径、等效圆直径、似圆度五个形态参数.结论:应用图像处理工具箱(image processing toolbox)可对卵泡形态参数的实现简便的测量.     

脉冲电磁场辅助骨细胞培养装置的研制

目的 根据脉冲电磁场对骨细胞的作用机制,设计了能够产生均匀磁场、参数可调的脉冲电磁场发生装置和磁场作用板;叙述了实验装置的硬件构成、软件控制功能以及磁场作用板的设计,并通过试验测试,观察记录了在未加入磁性材料和加入磁性材料后磁场的分布情况.方法 设计了强度为4～6 mT、频率8 Hz的参数可调的脉冲电磁场发生装置和专用的适合细胞培养的磁场作用装置,并对产生的磁场进行了实验测定.结果 实验装置运行时,对各参数检测表明,实验装置满足设计的要求:在加入磁性材料后,磁场作用表面的磁场分布均匀.结论 实验装置满足设计要求,可为进一步进行骨细胞培养提供可靠的实验手段.     

实时在位皮肤光学吸收系数与优化散射系数规律的研究

为了解皮肤光学吸收系数和散射系数的规律,利用双通道血氧测试仪(OXI Meter)对志愿者上表皮肤进行实时在位光学参数测量,得到了光学吸收系数与优化散射系数的变化规律.通过对不同个体的不同部位研究,发现皮肤光学参数与性别、年龄、体态和肤色有密切关系,为皮肤病的诊断和美容提供了重要的参考依据.     

Dual-chamber cardiac pacemaker tester

To investigate the operation of dual-chamber cardiac pacemakers, a pacemaker tester is developed that is able to examine pacemaker parameters, demand modes and rate-adaptive modes. The tester generates simplified electrograms and responds to pacemaker pulses in a closed-loop simulation. The authors describe the hardware and the software algorithm of the tester. To demonstrate the capabilities of the tester, four tests are presented, together with their results on a rate-adaptive dual-chamber pacemaker.     

人眼时空调制传递函数测试系统

本文介绍在激光视网膜空间ＭＴＦ测试装置基础上，增加时间ＭＴＦ测试，自动打印和显示ＩＶＡ、ＭＴＦ、频率等参数；打印不同频率下的ＭＴＦ－ＩＶＡ曲线的单片机控制系统。     

基于MSP430F435的低氧浓度测试仪的研制

研制一种专用于低氧实验中氧浓度测试仪器。该装置以低功耗单片机MSP430F435为控制核心,采用的德国I-01型电化学氧传感器具有性能稳定、寿命长以及输出线性好的特点,同时该装置具备高低限氧浓度报警功能。低氧浓度测试仪研制为医学低氧实验环境中氧浓度监测提供了便捷的解决方案,保证了医学低氧实验的安全与准确。     

Detection of TEM-induced reciprocal translocations in F1 sons of CD-1 male mice: comparison of sequential fertility evaluation and cytogenetic analysis

To determine the positive and negative classification error rates associated with the HTA in our laboratory, F1 sons of TEM-exposed CD-1 male mice were evaluated by the sequential fertility method with subsequent cytogenetic analysis. Males who sired three litters of size 10 or less when mated to primiparous females from either the B6C3F1 or the BCF1 strain were classified as partial steriles. When meiotic chromosome analyses revealed the presence of at least two cells containing multivalent figures, males were classified as translocation heterozygotes. When the fertility evaluation and the cytogenetic analysis were compared, normal fertility was observed on 5 of 83 (6.02%) translocation-bearing F1 males mated to B6C3F1 tester females and on 3 of 83 (3.61%) F1 males mated to BCF1 tester females. Thus, the false-negative error rates were 6.02% and 3.61% with these two tester strains. Multivalent figures were not observed in the meiotic chromosomes of 410 F1 males. Of these, 12 (2.93%) had reduced fertility when mated to the B6C3F1 tester strain as did 7 (1.71%) mated to the BCF1 strain. Thus, the false-positive error rates with these two tester strains were 2.93% for the B6C3F1 strain and 1.71% for the BCF1 strain. Our results indicate that non-zero error rates, both false-positive and false-negative, are associated with the sequential mating method HTA. In addition, the magnitude of these error rates was influenced not only by the tester female strain but also by the genotype of the F1 male.     

Mutagenic potential of Mancozeb in Salmonella typhimurium.

Mancozeb, a dithiocarbamate fungicide, was examined for its possible mutagenic activity using Salmonella typhimurium tester strains TA97a, TA98, TA100, and TA102. We found that Mancozeb exhibited toxic effects at the dose of 40 microg/plate and higher with all tester strains. Mancozeb showed dose-dependent increases in the number of revertants with and without metabolic activation when it was dissolved in DMSO or acetone with strain TA97a; however, the number of revertants at the highest dose was less than two-fold compared to control values. We postulate that the true mutagenic potential of Mancozeb may be masked by its toxic effect to the tester strain used.     

Mutagenic and cytotoxic potencies of a series of anthracycline derivatives as measured by His+ reversion, 8-azaguanine resistance and direct plating cytotoxicity tests in Salmonella typhimurium

His+ reversion at multiple his- loci, 8-azaguanine resistance, and a previously reported direct plating cytotoxicity test were used to measure the genotoxic potencies of a series of anthracycline derivatives in Salmonella typhimurium. N-demethylated amino sugar monosaccharide anthracyclines reverted most his- tester strains and were positive with 8-azaguanine selection. Reversion of strain TA98 was the most sensitive end point for measuring the mutagenic activity of the N-demethylated anthracyclines. N,N-dimethyl amino sugar derivatives of Adriamycin and daunomycin were negative as measured by His+ reversion in tester strain TA98, but generated positive responses in tester strain TA102 that were equal to or greater than those of the demethylated parent compounds. Similarly, N,N-dimethyl amino sugar derivatives of pyrromycinone and 1-deoxypyrromycinone had no mutagenic activity as measured by His+ reversion except in tester strains TA102 and TA104. These later compounds also gave positive responses with 8-azaguanine selection. In view of these results, the importance of amino sugar dialkylation and anthracycline mechanisms of mutagenesis are discussed.     

A tester for nickel cadmium defibrillator batteries

A microprocessor-controlled tester for nickel cadmium batteries is described. This versatile instrument allows up to three cycles of charge and discharge to be performed automatically, with results presented in hard-copy form. The tester determines whether defective cells are present in a battery by comparing the discharge characteristics with previously established values. Batteries can also be discharged in a way which simulates their use in defibrillators.     

女性特殊工种矿工心理测量与比较分析

目的探讨我国矿山女性特殊工种员工安全生产相关心理特征及其与男性特殊工种员工之间存在的岗位职能心理差异。方法运用声光反应时测定仪EP204,运动反应时测定仪EP206-P,注意力集中测试仪EP701C,注意力分配测试仪EP708A和EPQ人格问卷对中煤矿建(集团)公司1600余名各类特殊工种员工进行心理测量,测量数据使用SPSS17.0统计软件对男女特殊工种员工多项心理特征进行比较分析。结果女性特殊工种员工声光反应准确性、运动反应准确性均显著优于男性矿工(P<0.01,P<0.05)。女性特殊工种员工注意力稳定性、情绪稳定性均显著优于男性矿工(P<0.01,P<0.05)。结论女性矿工具有良好的岗位职能心理特征。研究开发女性矿工心理资源有利于提高矿山劳动工效,增强矿山生产安全心理保障,同时有利于促进矿山人际和谐及矿工群体心理卫生水平的优化、提高。     

Issues in the genetics of social behavior: Revisited

Though social behavior has not been overlooked by behavior geneticists, the number of studies is small when compared to those on individual traits. One reason for the neglect may be the difficulty of making connections between genes and social behaviors, which by definition involve the interaction of two or more organisms. Fuller and Hahn (1976) addressed this issue and described three means of establishing social groups that would facilitate genetic analysis. We survey the literature on agonistic behavior in mice from 1976 through 1994 and describe interesting uses of those three methods. One of those methods (the standard tester design) often employs a “noninteractive” social partner. We present data showing that the standard tester design may be more valuable when using an evocative and interactive standard tester.     

An electric tooth pulp vitality tester

A simple battery-powered constant-current pulse generator able to supply up to 200 μA at a maximum of 250 V is described. The tester incorporates a battery status indicator and an overload, incorrect operation and fault condition audible alarm. A simple test routine helps to ensure that the instrument is operating correctly before each application. For enhanced patient co-operation and comfort the tester is activated by the patient.