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1.
Environ Sci Pollut Res Int ; 30(59): 123832-123842, 2023 Dec.
Article En | MEDLINE | ID: mdl-37991619

Epidemiological studies have reported that the frequency of nuclear cataracts (NUCs) is high among the elderly and in tropical countries. Ultraviolet (UV) irradiation and lens temperature are considered as key physical contributors, although their precise quantification is difficult. The aim of this study is to investigate the association of NUC prevalence with UV irradiation and heat load. First, we assessed the lens temperature using thermodynamic modeling considering the thermophysiological response. We then conducted a multivariate linear regression analysis for the epidemiological analysis of NUC prevalence across five cities. A strong correlation was observed between NUC prevalence and the combined effects of UV irradiation and cumulative equivalent minutes at 43 °C (CEM43°C) derived from the computed lens temperature (adjusted R2 = 0.933, p < 0.0001). Heat load significantly contributed to the prevalence at 52%, surpassing the contributions of UV irradiation (31%) and the decline in DNA repair capacity in the lens (17%). These results suggested that both UV radiation and heat load are associated with NUC, with heat load contributing more. Our findings provided important implications for future interventions, particularly in the context of global warming.


Cataract , Ultraviolet Rays , Humans , Aged , Hot Temperature , Prevalence , Cities , Cataract/epidemiology
2.
Front Public Health ; 11: 1061135, 2023.
Article En | MEDLINE | ID: mdl-36875384

The number of patients with heat illness transported by ambulance has been gradually increasing due to global warming. In intense heat waves, it is crucial to accurately estimate the number of cases with heat illness for management of medical resources. Ambient temperature is an essential factor with respect to the number of patients with heat illness, although thermophysiological response is a more relevant factor with respect to causing symptoms. In this study, we computed daily maximum core temperature increase and daily total amount of sweating in a test subject using a large-scale, integrated computational method considering the time course of actual ambient conditions as input. The correlation between the number of transported people and their thermophysiological temperature is evaluated in addition to conventional ambient temperature. With the exception of one prefecture, which features a different Köppen climate classification, the number of transported people in the remaining prefectures, with a Köppen climate classification of Cfa, are well estimated using either ambient temperature or computed core temperature increase and daily amount of sweating. For estimation using ambient temperature, an additional two parameters were needed to obtain comparable accuracy. Even using ambient temperature, the number of transported people can be estimated if the parameters are carefully chosen. This finding is practically useful for the management of ambulance allocation on hot days as well as public enlightenment.


Heat Stress Disorders , Humans , Japan , Temperature , Climate
3.
Sci Rep ; 10(1): 14480, 2020 09 02.
Article En | MEDLINE | ID: mdl-32879341

Mosquito legs have a unique highly water-repellent surface structure. While being beneficial to mosquitoes, the water-repellence of the tarsi enhances the wettability of hydrophobic substances such as oils. This high wettability induces strong attraction forces on a mosquito's legs (up to 87% of the mosquito's weight) towards the oil. We studied the landing behaviour of mosquitoes on oil-coated surfaces and observed that the mosquito contact time was reduced compared to that on hydrophilic-liquid-coated surfaces, suggesting that the oil coating induces an escape response. The observed escape behaviour occurred consistently with several hydrophobic liquids, including silicone oil, which is used globally in personal care products. As the repellent effect is similar to multiple hydrophobic substances, it is likely to be mechanically stimulated owing to the physical properties of the hydrophobic liquids and not due to chemical interactions. On human skin, the contact time was sufficiently short to prevent mosquitoes from starting to blood-feed. The secretion of Hippopotamus amphibius, which has physical properties similar to those of low-viscosity silicone oil, also triggered an escape response, suggesting that it acts as a natural mosquito repellent. Our results are beneficial to develop new, safe, and effective mosquito-repellent technologies.


Aedes/drug effects , Hydrophobic and Hydrophilic Interactions , Insect Repellents/chemistry , Insect Repellents/pharmacology , Skin/drug effects , Animals , Artiodactyla , Dimethylpolysiloxanes , Female , Humans , Microscopy, Atomic Force , Nylons , Silicones , Stress, Mechanical , Surface Tension , Viscosity , Water/chemistry , Wettability
4.
Org Lett ; 17(12): 3114-7, 2015 Jun 19.
Article En | MEDLINE | ID: mdl-26042936

Zwitterionic protonated-dipyrrin 1 bearing a phosphate unit was synthesized from the N2O2-type tetradentate dipyrrin ligand. Compound 1 is in equilibrium with the deprotonated form 1' with a pKa value of 5.8. Compound 1 exhibited a pH-responsive fluorescence under physiological conditions; the fluorescence intensity increased in aqueous media as the pH increased. In living cells, 1 also exhibited emission responsive to pH. Thus, 1 should be applicable as a pH probe for detecting tumor cells.


Fluorescent Dyes/chemistry , Hydrogen-Ion Concentration , Nitrous Oxide/chemistry , Phosphates/chemistry , Pyrroles/chemistry , Pyrroles/chemical synthesis , Ligands , Molecular Structure , Spectrometry, Fluorescence
5.
Neural Netw ; 20(7): 819-31, 2007 Sep.
Article En | MEDLINE | ID: mdl-17683903

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.


Algorithms , Artificial Intelligence , Cluster Analysis , Electronic Data Processing/methods , Entropy , Neural Networks, Computer , Computer Simulation , Decision Support Techniques , Fuzzy Logic , Information Storage and Retrieval , Information Theory , Normal Distribution , Numerical Analysis, Computer-Assisted , Signal Processing, Computer-Assisted , Stochastic Processes
6.
J Biosci Bioeng ; 98(1): 34-9, 2004.
Article En | MEDLINE | ID: mdl-16233663

The growth and ammonium uptake of the aerial microalga Coelastrella striolata var. multistriata, which was isolated from the surface of rocks, were characterized in this study. The specific growth rate of the alga was mu=0.3 d(-1), as calculated in the growth logarithmic phase. The algal cells were able to remove almost 100% of the ammonium ions from medium in 5 d, with the removal rate of ammonium-N being 0.4 mg/l/h. It was shown that the alga has a unique ability to be a reddish orange to green color depending on the nitrogen source concentration in the medium. Astaxanthin, adonixanthin, canthaxanthin, and beta-carotene were found in the reddish orange cells of the alga. The assessment of water pollution was attempted using this aerial microalga. When the reddish orange alga was incubated in the experimental medium with added ammonium-, nitrate-, or urea-N as a nitrogen source, an approximately linear relationship existed between the nitrogen concentration and chlorophyll formation. Using the chlorophyll formation of the alga, for example, it was possible to estimate spectrophotometrically the total nitrogen content in water collected from aquatic systems. Biofunctional materials for environmental biomonitoring using photosynthetic microorganisms are called green devices in this study.

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