Risk behaviors and its association with caries activity and dental caries in Japanese children

The aim of this study was to assess risk behaviors and its association with caries activity and dental caries in Japanese children. The subjects were 392 young Japanese children who underwent dental health check-up at 18, 30 and 42 months of age. Oral examinations, Cariostat tests and dental health questionnaires were carried out at each time. The caries prevalence of children was 1.5% at 18 months, 9.9% at 30 months and 28.1% at 42 months. Caries activity based on the Cariostat scores of children was correlated with caries status (caries-free/carious) at 42 months. In children with caries during each examination period at 42 months, eating snacks while playing was ranked as the most important behavioral risk (P < 0.001), followed by breast-feeding (P < 0.01), non setting of time for snacks (P < 0.05) and frequency of snacks (P < 0.05) at 18 months old; non brushing by mother (P < 0.05) and eating snacks while playing (P < 0.05) were ranked highest at 30 months old. In addition, eating snacks while playing (P < 0.001) at 42 months old was the only a significant factor for children with caries. Caries activity and risk behaviors were associated with caries experience at different age periods of childhood.     

On information field of clinical diagnosis

“Field” is a universal phenomenon existing in both nature and society, and determines the existence and significance of all materials or information. The man being has always been generating and carrying a large quantity of life information in his whole life. Each piece of life information has an independent information field. The life information field includes such three subfields as bioinformation field, psychoinformation field and psycho-bioinformation field.The clinical diagnosis information field which is a specific information field within the information field of human activities consists of all information concerning man‘s health. Only after we have cognized and ascertained the clinic diagnosis information field, can we accurately utilize its function to serve the human being.     

Partial distortion entropy maximization for online data clustering

Competitive learning neural networks are regarded as a powerful tool for online data clustering to represent a non-stationary probability distribution with a fixed number of weight vectors. One difficulty in practical applications of competitive learning neural networks to online data clustering is that most of them require heuristically-predetermined threshold parameters for balancing a trade-off between convergence accuracy, i.e. error minimization performance, and speed of adaptation to the changes in source statistics. Although adaptation acceleration is achievable by relocating a “useless” node so that it becomes useful, excessive relocation often disturbs error minimization. Hence, both of the adaptation speed and the error minimization performance sensitively depend on threshold parameters to determine whether a node should be relocated or not. In general, it is difficult to know adequate threshold parameters a priori. This paper proposes a novel criterion for decision making of node relocation without heuristically predetermined thresholds. According to the proposed criterion, a node is relocated only if the relocation task improves partial distortion entropy, which is an online optimality metric reliable from the viewpoint of error minimization. Hence, node relocation is carried out without disturbing error minimization. As a result, both quick adaptation and error minimization are simultaneously accomplished without any carefully predefined parameters. Experimental results clarify the validity of the proposed criterion. Competitive learning with the criterion is clearly superior to other representative algorithms in terms of both quick adaptation and error minimization performance.     

红外多波长无创人体血糖检测阵列模型的研究

无创血糖监测不仅可以减少患者的痛苦，还能进行连续测量，从而降低并发症的发生，它是一种不需收集血样进行体内血糖浓度测量的新技术。本文根据朗伯-比尔定律(The Lambert—Beer Law)原理，为克服无创血糖检测研究中的难点和缺陷，详细分析了血糖红外光谱的吸收特性，利用阵列技术设计了红外多波长无创血糖检测传感器阵列模型，对关键技术进行了讨论。用ME算法建立了信号检测和标定数学模型，结合了人体各种影响因素，使红外无创血糖检测的精度和稳定性得到了改善。列举了详细的实验实施步骤，同时叙述了系统调试的详细过程，讨论了无创血糖检测中需要注意的问题。     

Client feedback on physiotherapy counselling in primary health care

The extent of rehabilitation services is adequate, but little feedback is available on these services and service users. This paper is based on a client feedback survey of physiotherapy services conducted in Spring 2000. The purpose of the paper is to compare patients' perceptions of the physiotherapy instruction they received in a private outpatient facility and in a public physiotherapy facility. The results of the study showed that physiotherapy clients were satisfied with the therapy and instruction they received. They felt they received an adequate amount of instructions and advice. The rehabilitee's strong commitment to care, high motivation and a support network are important to independent rehabilitation in the future. As for the point of contact, the majority of clients in the private physiotherapy facility were gainfully employed while the health centre had almost as many retired clients. Client instruction was not dependent on the point of contact.     

Dissolution response of hydroxyapatite coatings to residual stresses

The effect of residual stress on the dissolution of hydroxyapatite (HA) coatings was investigated. The examined coatings of 80-, 110-, and 200-microm thickness were prepared by a plasma-spraying technique under identical conditions. Residual stresses in the coatings were measured with a hole-drilling method. Dissolution of the coatings was monitored along with an examination of the phase composition. The results showed that both tensile residual stress and amorphous HA existed throughout the entire depth of the coatings and tended to increase from the surface to the interface of the coating and substrate. The thicker the coatings were, the higher the maximum residual stress was. Correspondingly, the pH value and calcium concentration of the solutions tended to increase with the coating thickness. On the basis of these phenomena and a thermodynamic analysis of the dissolution of the HA subjected to stresses, we concluded that besides structural effects, residual stress was also an important intrinsic factor influencing dissolution of HA coatings, and the dissolution can be delayed or even restrained by compressive residual stress.     

遗传算法在256阵元相控阵高强度聚焦超声治疗系统多焦点控制中的应用

阐述了遗传算法优化多点超声聚焦的方法以及球面相控阵声场计算方法。对实验室研发的256阵元相控阵聚焦超声治疗系统作了简介。利用此遗传算法和声场计算方法，对轴上和离轴单焦点以及轴对称六焦点和非轴对称四焦点进行了256阵元相控阵的声场仿真，并观察了实验室研发的256阵元相控阵聚焦超声治疗系统作用于有机玻璃和透明仿体的实验结果。用遗传算法和声场计算方法的仿真和系统实验结果表明，此方法可在实际聚焦手术中准确地控制3维单焦点和3维多焦点。