Accueil
Détail de l'auteur
Auteur Binhua Yang |
Documents disponibles écrits par cet auteur
Ajouter le résultat dans votre panier Affiner la recherche
Cuticular damage to african-american hair during relaxer treatments - A microfluorometric and SEM study - / Sigrid B. Ruetsch in IFSCC MAGAZINE, Vol. 11, N° 2 (04-05/2008)
[article]
Titre : Cuticular damage to african-american hair during relaxer treatments - A microfluorometric and SEM study - Type de document : texte imprimé Auteurs : Sigrid B. Ruetsch, Auteur ; Binhua Yang, Auteur ; Yash K. Kamath, Auteur Année de publication : 2008 Article en page(s) : p. 131-137 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'African-American hair' 'Lye-based' 'No-lye relaxers' 'Relaxer solutions' 'Commercial relaxer systems' 'Relaxer-induced surface changes/damage' 'Surface chemistry' 'Physical nature' 'Microfluorometry' Résumé : In earlier publications [1,2,3 we discussed several in-depth studies of characterization and quantification of damage done to European dark brown hair fibres by photochemical and cosmetic-chemical oxidation (bleaching) and reduction (perming) processes. These earlier studies established considerable changes in surface chemistry such as an increase in acidity and hydrophilicity. We discussed in detail the breakdown of the lipid domains (delipidation) of the outer ®-layer of the exposed scale faces and generation of anionic (sulphonic acid) groups (acidification) on the hair surface caused by these oxidative and reduction processes. The goal of this current study is to characterize and quantify the level of chemical and physical changes in the surface of African-American hair caused by various »lye-based« and »no-lye« relaxer treatments [4]. This study attempts to establish which product delivers the best »hair straightening« performance while resulting in the least chemical and physical changes in the hair surface. We again use a microfluorometric technique with the help of the cationic fluorochrome Rhodamine B to detect, map and quantify relaxer-induced changes in the surface chemistry of human hair fibre. In addition, we also use SEM at various magnifications to highlight relaxer-induced changes in the physical nature of the hair surface. We attempt to associate the level of increase in fluorescence intensity, which represents an increased level of delipidation/acidification of the hair surface, with the damage level to the hair topography, and thus, determine the least damaging cosmetic chemical process. Damage to the physical nature of the hair topography as observed by SEM shows a clear difference between treatments involving lab-made relaxer solutions and commercial relaxer systems. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10373
in IFSCC MAGAZINE > Vol. 11, N° 2 (04-05/2008) . - p. 131-137[article]Réservation
Réserver ce documentRole of melanin and artificial hair color in preventing photo-oxidative damage to hair / Sigrid B. Ruetsch in IFSCC MAGAZINE, Vol. 7, N° 2 (04-05-06/2004)
[article]
Titre : Role of melanin and artificial hair color in preventing photo-oxidative damage to hair Type de document : document électronique Auteurs : Sigrid B. Ruetsch, Auteur ; Binhua Yang, Auteur ; Yash K. Kamath, Auteur Année de publication : 2004 Article en page(s) : p.127-135 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cheveux -- Détérioration
Cheveux -- Teinture
Colorants
Electrophorèse capillaire
Mélanine
Photo-oxydation
Photodétérioration
SpectrophotométrieIndex. décimale : 668.5 Parfums et cosmétiques Résumé : This research is a multifaceted study which investigates not only the role of melanin in providing photostability to natural hair color and hair proteins, but also the claim that the presence of specific artificial colors in hair slows down the rate of photodegradation of hair proteins. In earlier studies, the extractability of protein from photodegraded hair was investigated and showed that many of the cleaved proteins could not be extracted because of photo-oxidative cross-linking. The current study investigates the effect of the amount of melanin in hair of different ethnicity and the presence of artificial hair colors on the extractability of the main classes of hair proteins. Furthermore, the data are used in the interpretation of the effect of these components in being able to prevent photo-oxidative damage to hair proteins.
When exposed to sunlight, hair undergoes changes in chemical, mechanical and morphological properties. The UVB and UVA regions of the solar spectrum are the most damaging to human hair. Of these two, the UVA region is predominant in the solar spectrum at low altitudes. Hair of different ethnicity responds differently to the damaging radiation of the solar spectrum, because of different amounts of melanin present in hair. Melanin absorbs the impinging radiation (especially at the lower wavelengths (254–350 nm), and converts it by some complex internal mechanism into heat. Because of this, melanin provides a photochemical protection to natural hair color and hair proteins and prevents their photodegradation. However, the melanin pigments act sacrificially and become themselves degraded in the process of protecting the proteins from light. As a result, this «protective» effect of the melanin pigments does not last during long-term intense exposure, when, regardless of the amount of melanin in hair, most matrix, intermediate filament and high molecular weight hair proteins undergo photo-oxidative cross-linking into higher molecular weight species, and their extractability from hair decreases significantly.
The goal of this study is to demonstrate how UV-radiation affects natural and artificial hair color during long-term exposures. Bright-field and UV-microspectrophotometry and an electrophoretic separation technique (SDS-PAGE) were chosen as investigative techniques for these studies, because they are well-suited to accurately and reproducibly investigate the initial properties of a specific hair sample and the changes in these properties as a result of long-term light-exposure. The goal of this paper is not to relate this to the content and type of melanin in hair. Electrophoresis, while not measuring the exact quantitative amount of protein extracted, is a semi-quantitative method, where increases in brightness of the bands represent increased amounts of proteins that were extracted of that specific protein from hair. This electrophoretic study attempts to determine whether the presence of natural or artificial color in hair influences the protein extractability in unaltered hair and the photo-oxidative cross-linking during light-exposure.
The bright-field microspectrophotometric study showed that high concentrations of melanin provide protection to the melanin itself and that they prevent loss of natural hair color during light-exposure. However, neither large amounts of melanin in hair of different ethnicity, nor artificial hair colors (even a dye with an absorption in the UV region) provide protection to the hair proteins against photodegradation under the conditions used in this study.
UV-microspectrophotometry has suggested the formation of high levels of photo-oxidized proteins as a result of light-exposure. Electrophoresis revealed photo-oxidative cross-linking of most matrix, intermediate filament and high molecular weight hair proteins into their higher molecular weight analogues, rendering them less extractable due to their lowered diffusivity. Only very low levels of low molecular weight matrix proteins could be extracted.Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10527
in IFSCC MAGAZINE > Vol. 7, N° 2 (04-05-06/2004) . - p.127-135[article]Réservation
Réserver ce document