Effect of the helmet act for motorcyclists in Thailand

OBJECTIVES: This study investigated the effect of the helmet act for motorcyclists on increasing helmet use and reducing motorcycle-related deaths and severe injuries in Thailand. METHODS: Data were derived from a trauma registry at the Khon Kaen Regional Hospital in the northeast Thailand. Helmet use and outcome in motorcycle crashes were compared 2 years before (1994-1995) and after (1996-1997) enforcement of the helmet act. During the study period, there were 12002 injured motorcyclists including 129 death cases in the municipality of Khon Kaen Province who were brought to the regional hospital. RESULTS: After enforcement of the helmet act, helmet-wearers increased five-fold while head injuries decreased by 41.4% and deaths by 20.8%. Those who had head or neck injuries or died were less likely wearing a helmet. Compliance of helmet use was lower at night. Fatality of injured motorcyclists did not significantly decrease in the post-act period and among helmet-wearers. CONCLUSION: Enforcement of the helmet act increased helmet-wearers among motorcyclists but helmet use did not significantly reduce deaths among injured motorcyclists. Motorcyclists should be instructed to properly and consistently wear a helmet for their safety.     

Linear electrostatic actuators: Gap maintenance via fluid bearings

This paper addresses a novel actuator for manufacturing applications, the “electrostatic artificial muscle.” Artificial muscle is composed of a dense array of small linear actuators. Its promise lies in the prospect of high performance (e.g. higher force-to-weight ratio and peak acceleration than a comparable magnetic motor), clean, quiet operation, and design versatility (especially the elimination of transmissions in many applications). The characteristics of artificial muscle are particularly appealing for applications in robotics and high-speed automation.A model of a linear electrostatic induction motor is presented to illustrate the potential for high performance as well as the difficulty of “gap maintenance.” Gap maintenance refers to the demanding task of preserving a uniform, narrow gap between “slider” and stator in the presence of destabilizing electrostatic forces. A novel approach to gap maintenance, the use of dielectric fluid bearings, is presented. Analysis of a simple, 2-D motor model shows that gap maintenance and motor efficiency may be characterized by two nondimensional parameters: a levitation number, and a gap aspect ratio. It is shown that achieving both low-speed levitation and high efficiency requires long, narrow gaps (high aspect ratio). The results of this analysis are extended to a more complex model featuring an unconstrained, rigid slider. An experimental study of fluid bearings is also presented.     

Artificial Neural Network Approach to Data Matrix Laser Direct Part Marking

Certain applications have recently appeared in industry where a traditional bar code printed on a label will not survive because the item to be tracked has to be exposed to harsh environments. Laser direct-part marking is a manufacturing process used to create permanent marks on a substrate that could help to alleviate this problem. In this research, artificial neural networks were employed to model the laser direct-part marking process of Data Matrix symbols on carbon steel substrates. Several experiments were conducted to study the laser direct-part marking process and to generate data to serve as training, validation and testing data sets in the artificial neural networks modeling process. Two performance measures, mean squared error and correlation coefficient, were utilized to assess the performance of the artificial neural network models. Single-output artificial neural network models corresponding to four performance measures specific to the Data Matrix bar code symbology were found to have good learning and predicting capabilities. The single-output artificial neural network models were compared to equivalent multiple linear regression models for validation purposes. The prediction capability of the single-output artificial neural network models with respect to laser direct-part marking of Data Matrix symbols on carbon steel substrates was superior to that of the multiple linear regression models.     

Temporal distribution of motorcyclist injuries and risk of fatalities in relation to age, helmet use, and riding while intoxicated in Khon Kaen, Thailand

This study investigated the temporal distribution of risky behaviors among injured motorcyclists, that is, riding unhelmeted or while intoxicated, and showed how they are associated with risk of fatal injuries. Data of motorcyclists injured in Khon Kaen municipality in northeastern Thailand and transferred to Khon Kaen Regional Hospital were obtained from the trauma registry system of the hospital. Case fatalities were compared by time of day, age group, helmet use, and alcohol intoxication. Unhelmeted riding peaked late in the evening and riding while intoxicated peaked around midnight. Both were associated with increased fatality risk after stratification by time of day; the odds ratios were 3.49 (95% confidence interval (CI) = 1.48-9.36) and 3.01 (CI = 1.71-5.19), respectively. Nighttime injuries were not significantly associated with increased fatality risk after stratification by helmet use or alcohol intoxication. Unhelmeted driving was prevalent and associated with higher fatality risk among younger drivers, whereas intoxicated driving was less prevalent among teens but associated with increased risk among those aged 20-39 years. This study shows that riding unhelmeted or while intoxicated can explain the increased fatality risk at night, suggesting that safety education or enforcements should be targeted at specific age groups and appropriate times.     

Glucose-installed biodegradable polymeric micelles for cancer-targeted drug delivery system: synthesis,characterization and <Emphasis Type="Italic">in vitro</Emphasis> evaluation

Glucose metabolism of cancer can be used as a strategy to target cancer cells which exhibit altered glycolytic rate. The facilitated glucose transporter (Glut) plays an important role in enhancement glycolytic rate resulting in increased glucose uptake into cancer cells. ¹⁸FGD-PET image is an example for using Glut as a targeting to diagnose the high glycolytic rate of tumor. Thus, Glut may be adapted to target cancer cells for drug delivery system. Herein, biodegradation polymeric micelles target cancer cells by Glut was fabricated. The amphiphilic block copolymer of poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL) was synthesized where terminal group of the PEG chain was installed with glucose molecules. The ¹H-NMR confirmed the existence of glucose moiety from two distinct peaks (5.2 and 4.7 ppm) of protons at anomeric carbon of glucose. Glucose-PEG-b-PCL spontaneously forms micelles in an aqueous solution. The size and zeta potential were 22?nm and -7 mv, respectively. Glucose-micelles have high stability, and no evidence of cytotoxicity was found after incubation for 7 days. Doxorubicin, used as a fluorescent probe, was loaded into glucose-micelles. The enhanced amount of doxorubicin as a result of glucose-micelles in PC-3, MCF-7 and HepG2 was evaluated by fluorescence microscopy and flow cytometer. Glucose molecules on the surface of micelles increased internalization and enhanced uptake of micelles via bypassing endocytosis pathway. These results show the use of glucose as a targeting ligand on the micelle surface to target cancer cells via Glut.

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