The ultrafast photodynamics of porphyrin-fullerene dyads in which the distance between the porphyrin and C 60 moieties is varied systematically at close proximity has been examined using fluorescence up-conversion and pump-probe transient absorption techniques with time resolutions of ca. 100 fs. The porphyrin-fullerene dyads examined are MP-D-C 60 (M ) Zn and 2H) in which the C 60 moiety is directly connected with the porphyrin ring at the meso position and MP-O-C 60 , MP-M-C 60 , and MP-P-C 60 in which the C 60 moiety is linked with porphyrin moieties through the benzene ring at the ortho, meta, and para positions, respectively. The charge transfer (CT) bands are observed for MP-D-C 60 and MP-O-C 60 , whereas no CT band is seen for MP-M-C 60 and MP-P-C 60 . Time-resolved absorption spectral measurements indicate that the photoexcitation of ZnP-D-C 60 in benzonitrile (PhCN) results in formation of the exciplex, which decays to the ground state without forming the charge-separated state. The strong interaction between the ZnP and the C 60 moieties due to the short linkage distance in ZnP-D-C 60 as indicated by the observation of the strongest CT band at the ground state results in formation of the exciplex. The energy of the exciplex is lower than that of the chargeseparated state even in a polar solvent such as PhCN. In contrast, the photoexcitation of the dyad with longer linkage, ZnP-O-C 60 , in PhCN results in formation of the charge-separated state via the exciplex formation, which is higher in energy than the charge-separated state. The photodynamics of exciplex formation of porphyrin-C 60 -linked dyads with a short linkage is characterized by the extremely fast formation rate from the singlet excited states of porphyrins involving both the second and first excited states due to the interaction between the porphyrin and C 60 moieties, which are placed at close proximity. In the case of MP-D-C 60 , the exciplex formation from the first singlet excited state of MP occurs at an ultrafast time scale with a time constant of 160 fs and that from the second singlet excited state occurs faster with a time constant less than 50 fs.

A very interesting phenomenon has been observed in which foam formed from an aqueous fatty acid potassium salt solution spontaneously absorbs liquid oil immediately upon contact without defoaming. Although this phenomenon initially appeared to be based on capillary action, it was clarified that the liquid oil that flows in foam film did not wet the air/water interface. In this study, it is discussed why aqueous foam can spontaneously soak up liquid oil without defoaming using equilibrium surface tension, dynamic oil/water interfacial tension, and image analysis techniques. The penetration of oil was attributed both to the dynamic decrease in the surface tension at the oil/water interface and to Laplace pressure, depending on the curvature of the plateau border. Therefore, the foam does not absorb the oil, but the oil spontaneously penetrates the foam. This interesting behavior can be expected to be applied to aqueous detergents for liquid oil removal.

Water-soluble components in the outermost layer of human skin are called natural moisturizing factor (NMF). NMF is one of the most important factors of skin moisturizing mechanisms. It is known that individuals with psoriasis, atopic dermatitis, and ichthyosis possess skin with lower-than-normal NMF content. Therefore, a noninvasive method for NMF content measurement of the human skin would be very useful to both dermatologists and cosmetic chemists. We attempted to measure the NMF content by focusing on the infrared wavelengths that are commonly absorbed by most NMF components. In order to estimate the intensity of absorption that is common to NMF components, we simulated the attenuated total reflection (ATR)-infrared (IR) spectrum of human skin by the combination of multiple Gaussian peaks. The spectroscopic signal of NMF linearly correlated with the actual NMF content measured by chromatographic methods. Therefore, we concluded that we can determine the skin surface NMF content from the ATR-IR spectrum of skin. This noninvasive and simple method is useful for studying NMF in a wide variety of skin regions and under various skin conditions.

ObjectiveDespite the application of skin care treatments, many infants have skin problems such as dryness and erythema. We proposed a new combination skin care for infants which consisted of a foaming cleanser with lower surfactant activity and moisturizers that contained pseudo-ceramide.Subjects and methodsA total of 50 infants (age: 3–24 months) with insignificant levels of dry skin were enrolled in this usage trial. The parents washed the infants with the test cleanser while bathing and then applied the moisturizer (lotion or cream) containing pseudo-ceramide. Prior to and following the 4-week usage period, visual evaluation of the skin condition was conducted by a dermatologist, in addition to instrumental analysis.ResultsErythema and papule, accompanied by dryness, were commonly observed at week 0. However, by week 4, these symptoms significantly improved; the condition of none of the subjects deteriorated. The number of infants with lower cutaneous barrier function and higher skin pH decreased. The parents of the infants recognized improvements in the skin symptoms and were appreciative of the test materials.ConclusionThe combined usage of the foaming cleanser with lower surfactant activity and a moisturizer containing pseudo-ceramide may be effective in maintaining healthy infant skin and ameliorating the skin symptoms.

Wet soap foam spontaneously imbibes liquid oil without defoaming when it is brought into contact. The kinetics behind this recently observed phenomenon was studied experimentally, with focus on the origin of the suction force and on the oil front dynamics. Using an aqueous foam with an air volume fraction slightly greater than the critical value ϕ, we show that the pumping pressure of oil and/or miscible liquid into the wet foam is attributed to the interfacial distortion of the bubble surfaces. Two distinct regimes along time t were observed in the oil imbibition dynamics. The proceeding oil front evolves with t dependency in the early imbibition time in accordance with the classical theory of penetration of a porous medium, whereas it departs into t at late imbibition time. The latter process is attributed to the elongation of an oil branch trapped inside the foam when pumping of the exterior oil has ceased.

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It was previously found that a cationic amphiphilic peptide, Ac-(Leu-Ala-Arg-Leu)3-NHCH3 (4(3)), caused the destabilization of a phospholipid membrane and showed strong antibacterial activity [Lee et al. Biochim. Biophys. Acta 1986; 862: 211-219]. In order to investigate the effect of changing alpha-helix propensity, hydrophobicity and basicity in 4(3) on the peptide conformation and activity, the 4(3) analogs, [Gly (or Val)6]4(3), [Gly (or Val)2,6]4(3), [Gly (or Val)2,6,10]4(3), [Gln3]4(3), [Gln3,7]4(3) and [Gln3,7,11]4(3) were synthesized. Except for [Val2,6]4(3) and [Val2,6,10]4(3), which mainly formed a beta-structure, other peptides formed an alpha-helix and showed moderate membrane-perturbing activity toward neutral and acidic lipid vesicles. All the peptides other than [Val2,6,10]4(3) and [Gln3,7,10]4(3) had the antibacterial activity comparable with that of 4(3). The relationship between the membrane-perturbing activity and the antibacterial activity was not always parallel. Conclusively, the Ala-->Val substitution in 4(3) causes the change of peptide conformation and the presence of a cationic amino acid residue is necessary for the antibacterial activity.

Foam produced using matcha is of great interest because it comprises gas and liquid forms, as well as a solid form. We investigated the foaming properties and foam stability of foam produced from matcha and measured the median diameter of the foam in terms of particle size. The results show that the foaming property is derived from conjoining of the matcha soluble ingredients and the matcha fine particles. Foam stability did not appear to be affected by differences in particle size or matcha concentration. However, the soluble ingredients did contribute to foam stability. The median diameter of foam did not change with the milling method or particle size of the matcha. Thus, the matcha particles localized along the foam membrane.