Antioxidation activity of cysteine and cystine prepared from sheep wool / Ján Matyasovsky in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXV, N° 5 (05/2020)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXV, N° 5 (05/2020) . - p. 166-175 Titre : Antioxidation activity of cysteine and cystine prepared from sheep wool Type de document : texte imprimé Auteurs : Ján Matyasovsky, Auteur ; Ján Sedliacik, Auteur ; Simon Peter, Auteur ; Igor Novák, Auteur ; Peter Jurkovic, Auteur ; Peter Duchovic, Auteur ; Mariana Sedliacikovà, Auteur ; Zuzana Cibulkovà, Auteur ; Matej Micusík, Auteur ; Angela Kleinová, Auteur Année de publication : 2020 Article en page(s) : p. 166-175 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Adhésifs -- Teneur en formaldéhyde Antioxydants Caractérisation Colles:Adhésifs Contreplaqué Copolymère urée formaldéhyde Cystéine La cystéine (abréviations IUPAC-IUBMB : Cys et C), du grec ancien κύστις ("vessie"), est un acide α-aminé dont l'énantiomère L est l'un des 22 acides aminés protéinogènes, encodé sur les ARN messagers par les codons UGU et UGC. Elle n'est pas considérée comme essentielle pour l'homme mais peut être produite en quantité insuffisante par l'organisme selon l'état de santé des individus — notamment dans le cas de certaines maladies métaboliques et de syndromes de malabsorption — ainsi que chez les enfants et les personnes âgées. Il s'agit d'un acide α-aminé naturel caractérisé par la présence d'un groupe sulfhydryle –SH formant un thiol ; la sélénocystéine et la tellurocystéine en sont des analogues dont l'atome de soufre est remplacé respectivement par un atome de sélénium et de tellure. La cystéine est présente en petites quantités dans la plupart des protéines. Sa présence dans les protéines est très importante, notamment parce qu'elle permet la formation de ponts disulfure. Le groupe thiol est très fragile car il s'oxyde facilement. Son oxydation conduit à la cystine, qui consiste en deux molécules de cystéine unies par un pont disulfure. Un oxydant plus énergique peut oxyder la cystéine sur son soufre en donnant l'acide cystéique HO3S–CH2–CH(NH2)COOH, à l'origine de la taurine, produit de décarboxylation présent dans la bile sous forme de taurocholate. Cystine La cystine est un acide aminé composé de deux unités cystéine liées par un pont disulfure. Essais (technologie) Formulation (Génie chimique) Laine de mouton Panneaux muraux préfabriqués Résistance au cisaillement Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Amino acid cysteine and its oxidized dimer form, cystine, can be found in hair, nails, hoofs, feather, wool, etc. The main focus of this research was the preparation of cysteine and cystine from wool and testing of its antioxidation properties in the reduced and oxidized forms. Preparation technology was optimized on a laboratory scale and the samples were characterized by FTIR-ATR spectroscopy and X-ray photoelectron spectroscopy (XPS). Antioxidation activity of cysteine and cystine was studied in a ; polyethylene glycol (PEG) matrix employing the non-isothermal differential scanning calorimetry (DSC). In the data treatment, the Berthelot-Hood equation was chosen as the temperature function. The kinetic parameters enabled the assessment of the induction period of oxidation for application temperatures. For the comparison of the stabilizing effect, the protection factors and antioxidant efficiency were calculated. The results show that the antioxidant activity of the samples depends on the preparation procedure, purity, etc. Protection factors decreased with increasing temperature and decreasing concentration. In the second part of the study, cysteine was tested in its reduced and oxidized form for the model polycondensation system of the urea-formaldehyde formulations. The quality parameters of these adhesive mixtures were verified on wood-based panels to determine formaldehyde emission and physical and mechanical properties. The results showed ca. 44% decrease of formaldehyde emission and increase of the shear strength of glued joint for all modifications in comparison wit ; the reference sample. Note de contenu : - EXPERIMENTAL : Materials and chemicals - Cysteine - Methods of testing - ATR-FTIR spectroscopy measurements - Elemental and mass analysis - DSC calorimeter Perkin-Elmer DSC7 - Plywood panels manufacturing - Formaldehyde emissons - Plywood strength testing - RESULTS AND DISCUSSION : Infrared FTIR-ATR spectroscopy - Elemental analysis and mass spectra measurement - Antioxidation activity - Reduction of formaldehyde emission - Shear strength of plywood panels DOI : https://doi.org/10.34314/jalca.v115i5.3810 En ligne : https://drive.google.com/file/d/1W268sG_XnoG22kJg5tbv96o_-W1EMVgQ/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34162 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
21742	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Fungal biotransformation of bovine hair. Part 2 : Biomass and proteases produced as a function of incubation time. Assessment of hair waste digestion / B. C. Galarza in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 90, N° 4 (07-08/2006)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 90, N° 4 (07-08/2006) . - p. 169-172 Titre : Fungal biotransformation of bovine hair. Part 2 : Biomass and proteases produced as a function of incubation time. Assessment of hair waste digestion Type de document : texte imprimé Auteurs : B. C. Galarza, Auteur ; L. M. Goya, Auteur ; M. L. Garro, Auteur ; J. Mercerat, Auteur ; R. A. Hours, Auteur ; Carlos S. Cantera, Auteur Année de publication : 2006 Article en page(s) : p. 169-172 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux Cystine La cystine est un acide aminé composé de deux unités cystéine liées par un pont disulfure. Déchets -- Valorisation Détérioration fongique Epilage Microscopie Peptidases Poils -- Biodégradation Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Unlike the conventional hair-saving unhairing processes, the modern processes considerably reduce the organic load from the beamhouse liquid effluent and yet a partially degraded 'hair waste' is generated, which has to be properly disposed of. It is estimated that a tannery processing 25 ton of salted cow hides will recover about 2.5 ton of wet hair per day. As was mentioned in the first part of the series 'Fungal biotransformation of bovine hair' the aim of our activities is to produce structural changes in the ‘hair waste’ using it as a solid substrate for the growth of the fungal species Trichophyton ajelloi and therefore weakening the keratinís resistance to hydrolysis processes. A strain of this microorganism, which was isolated from a Yak yard, has proved to be able to generate an enzymatic system capable of degrading hair keratin by means of specific proteases: the keratinases. Fungal activity also gave place to an enzymatic extract with activity upon the protein substrates of the epidermis and dermis of bovine hide. It should be noted that reports on fungal pathogenesis indicated that Trichophyton ajelloi presents no pathogenicity for men or animals. Upgrading the 'hair waste' by fungal biotransformation implies considering it as a raw material and not taking the current modality of 'throwing away proteins' to the soil (cost of transport and disposal of waste in landfills). Biodegradation offers on the one hand the attractive concept of 'feedback' since hair is the solid substrate upon which fungi act generating a degraded organic waste and a protein extract with proteolytic activity (keratinolytic among others) whose unhairing activity is evaluated. On the other hand an intermediate stage would be generated in the transformation of the ‘hair waste’ with potential uses in vermiculture and vermicompost. Note de contenu : - OBJECTIVES - MATERIALS AND METHODS : Culture conditions of the microorganism - Analytical techniques - Assessment of the degree of digestion of the ‘hair waste’ - RESULTS AND DISCUSSION : Microscopy observations - Assessment of digestibility - Cystine assessment in the ultrafiltered crude extract - Final remarks - Table 1 : Hair digestibility En ligne : https://drive.google.com/file/d/1fYmDuf6dOPGGOroT0Iv-Raf9r9NFKTRb/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39116 [article]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

A highly resistant structure between the cuticle and the cortex of human hair III : Characterization of the structure CARB / Toshie Takahashi in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 43, N° 2 (04/2021)  

[article]  inINTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 43, N° 2 (04/2021) . - p. 254-262 Titre : A highly resistant structure between the cuticle and the cortex of human hair III : Characterization of the structure CARB Type de document : document électronique Auteurs : Toshie Takahashi, Auteur Année de publication : 2021 Article en page(s) : p. 254-262 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse spectrale Caractérisation Cheveux -- Anatomie Cheveux -- Biologie Cheveux -- Croissance Cheveux -- Teinture Colorants Cortex (poil) Cosmétiques Cuticule Cystine La cystine est un acide aminé composé de deux unités cystéine liées par un pont disulfure. Glycolipides Statistique Index. décimale : 668.5 Parfums et cosmétiques Résumé : - Objective : It was previously reported that a highly resistant structure, which functions as a barrier against the penetration of dyes, is present at the interface between the cuticle and the cortex of human hair. That structure was named CARB, cuticle anchored resistant base. The goal of this study was to clarify the formation and composition of the structure CARB. - Methods : Cuticular substructures were observed from the keratinized area of each hair to its root end. The positions where the CARB structure appeared were isolated, and the barrier ability before and after that structure was evaluated. The distributions of glycolipid and cystine were measured using a nano-IR and a transmission electron microscope (TEM). - Results : Cuticular substructures were fully constructed several mm from the hair bulb of the hairs observed. The results show that keratinization at the distal side of the cuticle cell precedes that of the proximal side, and CARB is fully constructed last among the substructures. Glycolipid was preferentially distributed at CARB in the keratinized area. The cystine content of CARB is lower than that of the A-layer; however, it is slightly higher than that of the exocuticle and the inner layer. - Conclusion : These results demonstrate that CARB is produced in the final stage of keratinization of the cuticle layers. The rich contents of glycolipid and cystine might contribute to its resistant property. Note de contenu : - MATERIALS AND METHODS : Hair samples - Chemicals - Observations of cuticular substructures and dye penetration - Distribution of glycolipid - Distribution of SS bonds - Statistical analysis - RESULTS : Development process of cuticular substructures - Barrier level before and after the structure completion - Distribution of glycolipid before and after the structure completion - Distribution of cystine - Table 1 : Distances of points observed from the root end of the hair samples DOI : https://doi.org/10.1111/ics.12691 En ligne : https://drive.google.com/file/d/1opcBVJVwL1svUT8HMLNhEL9IO8wxgPBF/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35877 [article]

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité
aucun exemplaire

Protective effect of calcium hydroxide in hair-saving unhairing process / Hu Yang in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 97, N° 5 (09-10/2013)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 97, N° 5 (09-10/2013) . - p. 200-206 Titre : Protective effect of calcium hydroxide in hair-saving unhairing process Type de document : texte imprimé Auteurs : Hu Yang, Auteur ; Lan Liu, Auteur ; Dan Weihua, Auteur ; Dan Nianhua, Auteur Année de publication : 2013 Article en page(s) : p. 200-206 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chaux Cuirs et peaux -- Défauts Cystine La cystine est un acide aminé composé de deux unités cystéine liées par un pont disulfure. Epilage Immunisation (épilage) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : To better understand the mechanism of alkali-induced hair immunization, in this work native bovine hair was selected as the direct research subject rather than fresh salted bovine hide. The state of hair was evaluated, both before and after having undergone the procedure of immunization by measuring the changes of active groups, thermal stability, surface morphology, strength, calcium content and cystine content. The result indicates that the immunization is indeed caused by the interaction between calcium hydroxide and the cystine active center. Meanwhile, the optimum condition for immunization was: calcium hydroxide 15g/I and treatment time 90 minutes. This work may, to some extent, provide theoretical support for searching for the balance between the dehairing [hair burning] and hair saving process. Note de contenu : - IMMUNIZATION PHENOMENON - EXPERIMENTAL PROCEDURE : Raw materials and chemicals - Tests for hair characterization - Analysis of waste liquor - ASSAYS : Protective effect of immunization against the attack of reducing agent - Hair characterization - Pollution evaluation of the hair-saving unhairing En ligne : https://drive.google.com/file/d/1q7gZWIMmjuSJ327BMFmwfx82EZWa1BXX/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19568 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
15601	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 4 / 4)