The humic acid contents in drinking water and soil in Kaschin-Beck disease areas were found more than that of non-disease areas in this research. Changes of free radical concentration in drinking water were agreed with that of humic acid contents in drinking water of Kaschin-Beck disease areas. A positive correlation of free radical concentration and humic acid content in drinking water has been shown (r=0.913) . The structure of I. R. spectra of humic acid under ultraviolet light has been changed. Thus it indicated that free radical was resulted from benzoqiunonyl groups of humic acid in environment. 相似文献
In order to investigate the correlation between the prevalence of Kashin-Back disease (KBD) and Se concentrations, natural
soil samples and cultivated soil samples were collected from southeastern Tibet, China; and the soil Se concentrations were
measured by atomic fluorescent spectrophotometer. It was found that the mean Se concentrations of natural soil samples in
KBD areas, from the first layer to the third layer, were 0.17 mg/kg, 0.11 mg/kg, and 0.10 mg/kg, respectively, and in nondisease
areas were 0.21 mg/kg, 0.24 mg/kg, and 0.13mg/kg, respectively. The mean Se concentrations of cultivated soil samples were
0.10 mg/kg in KBD areas and 0.23 mg/kg in non-disease areas, respectively. Soil Se concentrations in KBD areas were lower
than that in non-disease areas, and the mean concentrations of soil Se in Tibet were lower than the average of China (0.29
mg/kg). Therefore, there is a close relationship between soil Se concentrations and KBD in Tibet. More studies should be concentrated
on the impacts of Se deficiency in soils and its relationship with Se concentrations in food-grain and the human body in Tibet
areas. 相似文献
Objective: The aim of this study was to explore whether varying levels of operational and tactical driving task demand differentially affect drivers with Parkinson's disease (PD) and control drivers in their sign recall.
Methods: Study participants aged between 50 and 70 years included a group of drivers with PD (n = 10) and a group of age- and sex-matched control drivers (n = 10). Their performance in a sign recall task was measured using a driving simulator.
Results: Drivers in the control group performed better than drivers with PD in a sign recall task, but this trend was not statistically significant (P =.43). In addition, regardless of group membership, subjects' performance differed according to varying levels of task demand. Performance in the sign recall task was more likely to drop with increasing task demand (P =.03). This difference was significant when the variation in task demand was associated with a cognitive task; that is, when drivers were required to apply the instructions from working memory.
Conclusions: Although the conclusions drawn from this study are tentative, the evidence presented here is encouraging with regard to the use of a driving simulator to examine isolated cognitive functions underlying driving performance in PD. With an understanding of its limitations, such driving simulation in combination with functional assessment batteries measuring physical, visual, and cognitive abilities could comprise one component of a multitiered system to evaluate medical fitness to drive. 相似文献