Thermoreversible morphological transition (MT) of a poly(styrene-Wocfe-isoprene) diblock copolymer was studied by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The cylindrical and spherical microdomains of polystyrene (PS) which are embedded in the polyisoprene matrix were thermoreversibly observed at 150 and 200 °C, respectively. As far as we know, this work may be the first to show that the cylindrical and spherical morphologies can reversibly change with temperature. Using experimentally determined interaction parameters x> we compared SAXS and TEM results with the theory in the weak segregation limit presented by Leibler, which predicts the thermoreversible MT between spheres and cylinders. Consequently, (x-N)t < (x-Wmo °c < (\N), < (xA)i < (x-Wwo "c was obtained, where ixN)t, ixN)" and (xN)i denote the theoretical values of product at the microphase separation transition (MST), at the spinodal point of the MST, and at the MT between spheres and cylinders, respectively, and N is the degree of polymerization of the copolymer.

The grain boundary morphology of lamellar microdomains in block copolymers was investigated by means of transmission electron microscopy. Avariety of patterns which can be successfullyreproduced by the computer simulation using Scherk's first surface or deformed Scherk's first surfaces as a calculation model were observed. This implies that the microdomains with lamellar morphology which locally have only two-dimensional continuity are topologically continuous in three dimensional space as a whole through the grain boundaries, but the lamellae are essentially flat within the grains.

The influences of chronic UVB exposure on epidermal differentiation have been poorly studied compared to dermal photo-aging although those effects are very important in terms of photo-damage to the skin. The purpose of this study was to investigate the effects of chronic UVB exposure on keratin expression in the epidermis. The effects on murine skin of chronic exposure to weak UVB (below 1 MED) was examined by immunoblotting for keratins K10, K5, K6, and K16, by immunohistochemistry using antibodies to K6, K16, and Ki67 as well as by conventional HE staining of skin sections. Alterations of keratin expression induced by the chronic UVB exposure were distinct from those elicited by a single acute UVB exposure. The expression of keratins K6 and K16 was quite long-lasting, continuing for 7 weeks after 6 weeks of chronic UVB exposure and for 6 weeks after 9 weeks of chronic UVB exposure. In contrast, K6 and K16 expression induced by a single UVB exposure at 0.5 MED or 3 MED almost ceased within 2 weeks after that exposure. Furthermore, the expression of the constructive keratins, K5 and K10, remained almost unchanged by chronic UVB exposure. Epidermal thickness was increased significantly immediately after the 9 weeks of chronic UVB exposure; however, it had returned to normal level 6 weeks later. The alterations in keratin expression accompanied the marked disruption of the ordered ultrastructure of keratin intermediate filaments, which were observed by TEM. Thus, chronic exposure to UVB has a deep impact on the biosynthetic regulation of different keratins in the epidermis, thereby interfering with the ordered ultrastructure of keratin intermediate filaments. Those events could have relevance to the mechanism of photo-damage, such as fine wrinkles observed in chronically UV-exposed skin in addition to dermal photo-aging.

Background/purpose: This study aimed to reveal genderdependent differences in the degree of facial wrinkles. Methods: Subjects comprised 173 Japanese men and women, divided into four groups according to age. Photographs were taken from nine facial regions and used to classify the intensity of wrinkles into five grades. In addition, replicas were taken from five facial sites and used to measure surface roughness. Data were compared between men and women within each age group. Results: In all age groups, men showed increased forehead wrinkles compared with women. In contrast, no gender-dependent differences were found in upper eyelid wrinkles. Other facial wrinkles were greater in men than in women in all except the oldest group (age, 65-75 years), in which wrinkles in women were greater than or equal to those in men. Conclusion: Our results showed that gender-dependent differences exist in the degree of facial wrinkles. In general, men tend to have more severe wrinkles than women. This tendency disappeared or was reversed in some regions of the face and in individuals more than 60 years old.

The grain boundary morphology of lamellar microdomains in block copolymers was investigated by means of transmission electron microscopy. A variety of patterns which can be successfully reproduced by the computer simulation using Scherk's first surface or deformed Scherk's first surfaces as a calculation model were observed. This implies that the microdomains with lamellar morphology which locally have only two-dimensional continuity are topologically continuous in three dimensional space as a whole through the grain boundaries, but the lamellae are essentially flat within the grains.