In this paper, surface degradation of hair is reviewed. Surface properties such as hydrophobicity and surface friction change as surface structures of hair fiber, that is, 18-methyleicosanoic acid (18-MEA) and epicuticle, degrade. Comparison of contact angle and amount of 18-MEA from root to tip of the sampled hair fibers clarified the contribution of not only 18-MEA but also epicuticle to surface properties. It was found that chemical treatment by itself, such as bleaching, is not enough to cause complete loss of hydrophobic nature even after 18-MEA is removed. Additional weathering processes, such as repeatedly shampooing, are required. A technology for the deposition of a persistent hydrophobicity to bleached and weathered hair surfaces using 18-MEA is presented. Combination of 18-MEA with specific cationic surfactants (Stearoxypropyldimethylamine: SPDA) made the bleached and weathered hair surface hydrophobic, and its hydrophobicity was maintained even after shampooing. Characterization of adsorbed layers of 18-MEA/SPDA on a mica surface, as a possible hydrophilic surface model, was performed using atomic force microscopy (AFM) and angle-resolved X-ray photoelectron spectroscopy (AR-XPS). The effects of the anteiso-branch moiety of 18-MEA to create a persistent hydrophobicity with 18-MEA/SPDA were investigated using controlled AFM. It was revealed that the anteiso-branch moiety of 18-MEA in the 18-MEA/SPDA system produces a persistent hydrophobicity by providing higher fluidity to the upper region of the 18-MEA/SPDA layer. The contribution to hair beauty and sensory feeling as one of the practical functions of the hair surface is described in this paper. The hydrophobic nature of the hair surface reduces surface friction in a wet state, which reduces hair disorder alignment. It is also revealed that the moisturized or dried out feeling strongly depends on the hair shape (meandering and diameter) which depends on hair surface properties in a wet environment.

Phenylglycine undergoes transamination with 2-oxoglutaric acid in the presence of N-dodecylpyridoxal chloride (DPL) and hexadecyltrimethylammonium chloride (CTACl) under mild conditions. This is the first example of nonenzymatic overall transamination realized in the absence of metal ions.

and MMP-9 activities from its lowest concentration, and MMP-1 and MMP-2 at its higher concentrations, which implies a greater protective effect on elastin. It dramatically increased the expression of types I, III, and V collagens, and elastin, fibrillin-1, and fibrillin-2 in dermal fibroblasts. The effects were similar to those of ascorbic acid. This is the first report identifying xanthohumol's potential to improve skin structure and firmness: it simultaneously inhibits the activities of elastase/MMPs and stimulates the biosynthesis of fibrillar collagens, elastin, and fibrillins.pp. 133-145 Comparison of hydration, tyrosinase resistance, and antioxidant activation in three kinds of pearl powders by

In this study, we investigated how the lipids bound to the outermost surface of human hair are affected by chemical treatments such as hair bleach and ultraviolet (UV) radiation using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Many lipid components are bound covalently via a thioester or ester linkage on the outermost surface of hair. We studied how these components are changed by chemical treatment. It was found that the fatty acids covalently bound via a thioester linkage are removed more easily than those with an ester linkage. Eighty percent of the 18-MEA (18-methyleicosanoic acid), which is a major component of lipids, was removed in a single bleach treatment, and most had vanished entirely after three treatments. We also investigated the influence of UV radiation and found that the amount of 18-MEA decreased with the radiation time. More than 90% of the 18-MEA was removed by UV radiation with corresponding exposure of three summer months. Copyright

Background: Although it is well known that chemical oxidation with alkaline hydrogen peroxide damages human hair, little is known about the effects of bleaching during daily life activities which may alter hair components. Objective: To determine the effects of bleaching combined with daily weathering on lipids and amino acids in hair. Methods: Levels of lipids and amino acids were analyzed by chromatography in scalp hair fibers collected from three different females and in experimentally treated hair. Results: Bleaching combined with daily weathering induced the loss of 18-methyleicosanoic acid (18-MEA) and the conversion of half-cystine (H-CYS) to cysteic acid (CYS-A), which were the most remarkable changes among all lipids and amino acids tested. Although a single bleaching had no effect, repeated bleaching combined with daily weathering elicited significant decreases in other intrinsic endogenous lipids and alterations in amino acids that are characteristic for the cuticle. Conclusion: Hair damage, eventually leading to the worst damage such as splitting, is caused by bleaching during daily life activities and is mainly attributable to the loss of 18-MEA as well as the conversion of H-CYS to CYS-A.