应用Power Builder进行人类精子库信息系统的开发

随着辅助生殖技术的开展和人类精子库的建立，应用供精人工授精治疗男性不育尤其是无精子症的需求增多，各精子库的精源更是供不应求。面对日趋繁琐的供精者和受精者信息，人类精子库信息系统在精子库的管理中也起着越来越重要的地位。Power Builder是目前公认的最优秀的数据库前端开发工具之一，具有开发速度快、成本低、质量高、功能强等特点。本文介绍利用Power Builder 9．0软件进行人类精子库信息系统的开发。     

人工晶体植入屈光度的术前预选法：眼科超声仪36例对比研究

根据公认的眼科解剖学数据，提出后房型人工晶体植入屈光度的术前预测方法：IOL（D）=1．02（＋21D＋2X）。经人工晶体专用眼科A超36眼实测对比，无显著差异，认为在地市级医院和县级医院后房型人工晶体植入术推广中具有积极意义。     

Multivariable non-linear controller for a synchronous generator

The problem of multivariable controller synthesis for a turbogenerator is considered. Using the feedback linearization approach for multi-input non-linear systems, the existence of a linearizing state feedback for the improved reduced-order model of a turbogenerator is proved and the simplest form of this feedback is derived. Application of the obtained non-linear controller to the multivariable control of a turbogenerator provides very good results not only for the reduced-order model but also for the ‘exact’ (Park's) model of a turbogenerator. Simulations of fault and post-fault conditions in the obtained nonlinear control system confirm its superiority over a system with a voltage regulator and power system stabilizer.     

低强度超短波对小鼠体质及智力的影响

本实验探讨了低强度超短波对小鼠连续三代辐射,对学习、记忆、拉力、运动耐力和周围血象的影响。用81MHz,10～12V/m 的超短波进行辐射,每天辐射2小时,每周6天。结果表明:经过超短波辐射的各代小鼠与对照组相比,学习能力、记忆能力、拉力及运动耐力有明显的降低,且运动耐力有进行性降低的趋势,而经过辐射的三代小鼠红细胞、血红蛋白含量及白细胞数均明显增高,每个红细胞的血红蛋白含量则低于对照组。     

Force-time parameters during explosive isometric grip correlate with muscle power

Although explosive isometric contraction provides little work toward the outside, force-time parameters of the rising phase of the force-time curve may be able to predict muscle power. The purpose of this study was to examine the relationship between muscle power with work (power grip) and force-time parameters during the rising phase in explosive isometric grip. Fifteen healthy young adult males participated in this study. Power grip was measured using loads of 20%–50% of maximal voluntary contraction (MVC) (peak isometric force). Subjects pulled explosively on a grip bar held with the second digital joints without the thumb. Peak power was calculated from peak velocity and load. Explosive isometric grip was measured using a hand dynamometer. Time-series data of both tests were sampled by an analog-to-digital interface. Both tests were performed with the subjects seated with a sagittal and horizontal position of the arm supported by an armrest. Peak power in the power grip test tended to be larger with an increase of the load, but there was no significant difference between 40% and 50% MVC. Only the peak power in 50% MVC significantly correlated with peak grip force (r=0.52, p<0.05). The force-time parameters related to the peak rate of the rising force phase in explosive isometric grip significantly correlated with the peak powers (30%–50% MVC, r=|0.58−0.78|). Peak rate of the rising force phase in explosive isometric grip may be useful for predicting muscle power with loads between 30%–50% MVC.     

完全随机设计的方差分析中检验效能的估计

在实验设计时应保证一定的检验效能；当统计检验结果是阴性时，应估计其检验效能。本文探讨了完全随机设计的方差分析中检验效能的估计方法。结果表明，检验效能与样本含量的大小及样本均数间的差别有关。同时，用医学实例说明其应用。     

Stability of Late Event-Related Potentials: Topographical Descriptors of Motor Control Compared with the P300 Amplitude

The P300-amplitude evoked with an acoustic oddball-paradigm is considered the most stable late event-related potential (ERP). This amplitude-index has become a standard parameter in electrophysiology. Recently, a robust ERP-parameter (NoGo-anteriorization, NGA) has been introduced, which reflects spatial brain electrical changes in relation to execution and inhibition of a motor response elicited with a Continuous Performance Test (CPT). The current study refers to the stability of this new topographical ERP-parameter compared to the stability of the classical P300-amplitude. For that purpose, 12 healthy subjects were investigated with both paradigms during recording of a 21-channel EEG. Analysis of the resulting ERPs revealed a very high stability for both, topographical and amplitude index: In every single subject, the brain electrical fields were characterized by a more anterior location in the NoGo- compared to the Go-condition (=NGA) and by higher amplitudes after target compared to distractor condition. T-tests, analyses of the effect size and of the power revealed equivalent differences between the two contrasting conditions for the topographical compared to the amplitude index. These results indicate that the stability of the topographical ERP-parameters elicited with the CPT is sufficient for an electrophysiological standard-index. The possibility to elicit a robust and specific spatial brain activation with the CPT is an ideal completion to the classical P300 amplitude effect and, therefore, hopefully will be a useful expansion of the standard paradigms in electrophysiological laboratories.     

Application of classical and model-based spectral methods to ophthalmic arterial Doppler signals with uveitis disease

In this study, Doppler signals recorded from ophthalmic artery of 75 subjects were processed by PC-computer using classical and model-based methods. The classical method (fast Fourier transform) and three model-based methods (Burg autoregressive, moving average, least-squares modified Yule–Walker autoregressive moving average methods) were selected for processing ophthalmic arterial Doppler signals with uveitis disease. Doppler power spectra of ophthalmic arterial Doppler signals were obtained by using these spectrum analysis techniques. The variations in the shape of the Doppler spectra as a function of time were presented in the form of sonograms in order to obtain medical information. These Doppler spectra and sonograms were then used to compare the applied methods in terms of their frequency resolution and the effects in determination of uveitis disease.     

Isokinematic muscle mechanics in four groups of women of increasing age

Summary The purpose of this study was to evaluate the effects of age on dynamic muscle attributes of the knee extensors and flexors in postmenopausal women. Young healthy women (3rd decade,n = 15; 4th decade,n = 5) and older healthy women (6th decade,n = 9; 7th decade,n = 6) were tested at six angular velocities from 60° · s^–1 to 400° · s^–1. The 3rd and 4th decade groups produced greater extensor and flexor values for strength related variables at all angular velocities (peak torque, angle specific torque, work, power) than both the 6th and 7th decade groups (P<0.05). However, relative changes in these variables, with increments in angular velocity, were equivalent among the groups. Analysis of the flexor: extensor ratios for these variables demonstrated a differential loss in flexor function with increased age, perhaps indicative of type II motor unit loss or muscle fibre atrophy. It is suggested that such changes may be present even within 4th decade subjects.     

EMG power spectra of elbow extensors during ramp and step isometric contractions

Summary The goal of the present study was to compare electromyogram (EMG) power spectra obtained from step (constant force level) and ramp (progressive increase in the force level) isometric contractions. Data windows of different durations were also analysed for the step contractions, in order to evaluate the stability of EMG power spectrum statistics. Fourteen normal subjects performed (1) five ramp elbow extensions ranging from 0 to 100% of the maximum voluntary contraction (MVC) and (2) three stepwise elbow extensions maintained at five different levels of MVC. Spectral analysis of surface EMG signals obtained from triceps brachii and anconeus was performed. The mean power frequency (MPF) and the median frequency (MF) of each power spectrum were obtained from 256-ms windows taken at 10, 20, 40, 60 and 80% MVC for each type of contraction and in addition on 512-, 1024-and 2048-ms windows for the step contractions. No significant differences (P>0.05) were found in the values of both spectral statistics between the different window lengths. Even though no significant differences (P>0.05) were found between the ramp and the step contractions, significant interactions (P<0.05) between these two types of contraction and the force level were found for both the MPF and the MF data. These interactions point out the existence of different behaviours for both the MPF and the MF across force levels between the two types of contraction.