Following direct exposure to sunlight while pursuing leisure activities, many have noticed a strong sense of fatigue in the evening. In this regard, our results of a survey of awareness showed that the development of fatigue from solar exposure of the body was generally recognized. On the other hand, a tool for objective and quantitative determination of mental fatigue has recently been reported. Known as the Advanced Trail Making Test (ATMT), it is a method of evaluating brain function. In the present study, we attempted to determine fatigue development caused by exposure of the human body to solar radiation using ATMT results. For 3 days in the summer season, 15 male subjects (26 to 41 years old) received exposure to the sun equivalent to 100kJ/cm² of ultraviolet radiation 3 to 4 times each day. During the periods of exposure, the subjects wore short-sleeved shirts and short pants, and covered their heads with a towel. Following the 3-day period, they were divided into 2 groups based on their subjective evaluation of a sense of tiredness, fatigued (n=10) and non-fatigued (n=5). In the fatigued group, a significant increase in the subjective score for fatigue sense was observed in the evening of all 3 days following sun exposure, as well as in the morning of the third day, as compared with those in the non-fatigued group. Further, a significant increase in average ATMT value was also observed in the fatigued group in the evening of the first and second days following sun exposure, as well as in the morning of the third day. These results indicate that ATMT may be a useful evaluation tool for quantitative and objective measurement of mental fatigue caused by exposure to sunlight.

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Today, it is said that the formula design of cosmetics from ingredients of plant origin is an indispensable way and trend. From this consideration, cosmetic materials made from animal and synthetic petroleum ingredients are becoming less usable. Instead, cosmetic materials are designed from ingredients of plant origin and many and various botanical ingredients are being developed. Lanolin, which is one of the animal-based ingredients, is said to have ideal functions as a cosmetic oil, and it has been used in many fields such as make-up cosmetics as well as hair and skin care products for a long time. However, unfortunately, lanolin is an animal-based ingredient; therefore, the development of a botanical ingredient to replace lanolin was desired. Polyglyceryl-8 Decaerucate/Isostearate/Ricinoleate, which we have developed, is an ester oil originating from plants and has an equivalent or higher function than lanolin. We have confirmed that our developed ester oil has various excellent characteristics such as a water-holding capability 2.5 times higher than that of lanolin, high air permeability, moisture keeping in dermal layers, protection of hair from changes in external environmental humidity, and excellent gloss and excellent dispersability of pigments. Thus, this newly developed ester oil is expected to be a promising new botanical cosmetic ingredient which can be applied in various fields.

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Transparency of the skin is an important keyword that is frequently used in questionnaires related to the female skin condition and skin consciousness, as well as an index for “before and after” comparisons of the effect of cosmetics. However, the concept of “transparency” has not been concretely defined. In the present study, we investigated the importance of “transparent skin” and the relationship between transparency and other expressions for skin condition comparing the young with middle-aged and elderly women. Furthermore, we also analyzed the correlation between the subjective assessment score of transparency of panels made by evaluators and the skin physiological parameters of those panels, and compared the difference of their relationship when the young and middle-aged and elderly women were employed as evaluators. Regarding the consciousness of the young women, the importance of “transparent skin” was ranked in the top position while “skin roughness” was the chief worry of the middle-aged and elderly women. On the other hand, both age groups indicated that transparent skin is a complex concept composed of skin texture, color, and moisture. Analysis of the relationship between the subjective assessment and the skin physiological parameters showed that the uneven dispersion of b in the skin color (standard deviation), the water content of stratum corneum, and the skin surface configuration (depth of furrows, amount of furrows) closely correlated with the judgment of skin transparency in the young group, in contrast to the uneven dispersion of L and a in the skin color (standard deviation) in the middle-aged and elderly women. These results suggest that there may be no differences between the different age groups in the linguistic concept of transparency, while there may be differences in the physiological characteristics of skin that are utilized in making the judgment of transparency.

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There is great interest in the cosmetic field in improving the shape of the face, which is determined by the amount of bone, muscle and subcutaneous fat. We examined the amount of facial subcutaneous fat in healthy women by magnetic resonance imaging (MRI), and investigated the distribution of fat in relation to the body shape. Thirty-eight healthy women, 10 lean, 18 normal and 10 obese subjects, were examined by cephalometric MRI to obtain T 1-weighted images, by which fat regions can be clearly observed. The area of subcutaneous fat was greater in obese subjects than in normal subjects, and was decreased in lean subjects. At 45 measured points, the thickness of subcutaneous fat was greater in the cheek near the nose independently of the body shape, and the surface of the masseter muscle and lower jaw increased according to the body mass index (BMI). This research suggested that there are two types of regions, one type maintains fat mass and the other type increases with BMI.

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