Objective Current perception threshold (CPT) measurement is a noninvasive, easy, and semi‐objective method for determining sensory function using transcutaneous electrical stimulation. Previous studies have shown that CPT is determined by physical characteristics, such as sex, age, physical sites, and presence of neuropathy. Although the CPT reported in males is clearly higher than that in females, the reason for this difference remains unclear. This study investigates the cause of sex‐based differences in CPT and suggests an adjustment method, which may suppress the sex difference in CPT. Materials and Methods Electrical stimulation was applied with PainVision® via five sizes of circular surface electrodes. Seventy healthy participants were examined thrice under each electrode. The relationship among body water percentage, body fat percentage, and CPT was then analyzed. Results CPT values are higher in males than that in females, with statistically significant sex differences with each electrode pairs (EL 1: p < 0.001; EL 2: p = 0.006; EL 3: p < 0.001; EL 4: p < 0.001; EL 5: p < 0.001). By adjusting for body fat percentage or body water percentage, the log‐transformation values (CPT values) no longer exhibit sex differences with any electrode pairs (body fat: p = 0.09; body water: p = 0.08). Conclusion We conclude that sensitivity for perceiving electrical stimulation can be influenced by the subjects' characteristics, such as body fat or body water percentages.

Sweating, the intermittent secretion of uid from the sweat glands, is an indispensable mechanism for the regulation of body temperature. The methods used to measure the sweat rate include an iodine starch test, a weight assay, and an ion electric conductivity method. The ventilation capsule method is another method for quanti cation of sweat rate. However, this method has a problem in that the subject s physical activity is restricted by the rmly attached measurement probes. SNT-200, a wearable sweat meter developed by Rousette Strategy Inc., is already commercially available. This sweat meter contains silica gel that serves as an absorbent for sudoriferous steam and uses a temperature-humidity sensor to detect humidity changes in the device caused by sweating. However, the accuracy of the measurement has not yet been suf ciently investigated. This study was designed to provide evidence to validate the underlying measurement principle and accuracy of the device. We simulated various sweating conditions and performed simulated sweating measurements using SNT-200. In the rst experiment, continuous sweating over a wide body surface was simulated. The calculated absorbed steam volume was 1.84 times greater than the real transpiration rate. In the second experiment, sweating was simulated in the form of water drops, and the sweat meter absorbed the generated steam. In the second experiment, the data obtained using SNT-200 was in good accord with the volume dispensed by a micropipette. These experiments provided convincing evidence that the total area of four steam holes (A1, in the equation for calculating the sweat rate) required correction. We therefore modeled the effective absorption area of the sweat meter as one circle encompassing the four holes (8 mm in diameter; 52 mm 2) instead of a summation of the areas of four steam holes. De ning the effective absorption area by this method modi ed the value calculated in the rst experiment, which agreed with the transpiration rate. In addition, the modi ed moisture absorption volume in the sweat meter converged within ± 20% error of the actual measurement, except at 30 C.

A kinetic study of capsaicin (CAP) toward radicals has been performed using stopped-flow spectrophotometry in detail. The second-order rate constants (k2) for the reaction of CAP toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) and galvinoxyl have been measured in methanol, ethanol, 2-propanol/water (5:1, v/v), and aqueous micellar suspensions containing 5% Triton X-100 (pH 4.0 to 10.0), respectively. The decay rates of DPPH and galvinoxyl for the reaction with CAP increased linearly in a concentration-dependent manner in homogeneous solutions and aqueous micellar suspensions. However, the k2 for CAP obtained in an aqueous micellar suspension showed notable pH dependence; that is, the reactivity of CAP increased with an increasing pH value from 4 to 10. In addition, a good correlation between the k2 value and the molar fraction of CAP (phenolate anion (CAP-O(-))/undeprotonated form (CAP-OH)) was observed. These properties are associated with the pKa of CAP. Furthermore, it was found that the CAP-O(-) reacts with galvinoxyl about 6 times as fast as the CAP-OH. These results indicate that sequential proton loss electron transfer from the phenolic hydrogen of CAP may be responsible for the scavenging of radicals in an aqueous micellar suspensions.

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