Orientador: Inés Joekes / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-19T10:48:43Z (GMT). No. of bitstreams: 1 Richena_Marina_M.pdf: 1581549 bytes, checksum: cea715827b6e69afa186bff163d1c821 (MD5) Previous issue date: 2011 / Resumo: O cabelo branco se torna amarelo com o tempo, apesar de não possuir melanina, o pigmento responsável pela coloração. Este amarelecimento gera insatisfação nas pessoas. Neste trabalho estudamos em profundidade as mudanças de cor e as propriedades mecânicas do cabelo branco após exposição ao UV, Vis e IV, e os fatores que afetam o amarelecimento, incluindo descoloração com H2O2 e a presença de umidade, e tentamos identificar os cromóforos amarelos. Usamos cabelos brancos de dois tipos: cabelo padrão (blenda de várias cabeças), mais amarelado (valor da coordenada de azul-amarelo, b* = 20), e cabelo comum (cabelo de uma cabeça), menos amarelo (b* = 10). Os resultados mostram que a coloração inicial interfere no comportamento frente à exposição ao UV - Vis: após exposição numa lâmpada de mercúrio por cerca de 200 h, o cabelo padrâo desamarela (Db* = - 6), e o cabelo comum amarela (Db* = 2). Entretanto, quando o cabelo padrâo é descolorido com H2O2 (b* = 8), amarela após poucas horas de irradiação (Db* = 3). Expondo apenas ao Vis ocorre desamarelecimento, independentemente da coloração inicial, tanto no cabelo padrão (Db* = - 9), quanto no cabelo comum (Db* = - 3). Os resultados de variação de cor do cabelo branco exposto ao sol concordam com os resultados de exposição à lâmpada de mercúrio. Já a radiação IV na temperatura de 81°C amarela tanto o cabelo branco comum (Db* = 9), quanto o cabelo branco padrão (Db* = 3). O cabelo padrão irradiado em 100% de umidade relativa não mostra variação de cor após 88 h de irradiação. Além disso, o cabelo que foi irradiado, mas lavado com solução de lauril sulfato de sódio após cada período de irradiação, manteve o valor de Db*. O cabelo não lavado continuou menos amarelo após a armazenagem; entretanto, um amarelecimento (Db* > 1,5) foi observado após 1 ano. A única alteração significativa observada nas propriedades mecânicas foi a redução da tensão máxima em 17% depois de 480 h de exposição ao Vis da lâmpada. Medidas de absorbância no UV - Vis de soluções de cabelo branco com diferentes tonalidades de amarelo mostram absorção em toda a faixa do visível, comportamento decorrente do amarelecimento. Há ainda a formação de uma banda forte em 320 nm após irradiação UV. Contrariamente ao mostrado na literatura de lã, que também é uma estrutura formada por queratina, esta banda não está relacionada com a formação dos cromóforos amarelos. Demonstramos que o amarelecimento inicial do cabelo é um fator determinante na sua variação de cor após irradiação UV e que este amarelecimento é decorrente da ação do calor. Ademais, após a irradiação são formados radicais livres responsáveis pelas reações de degradação no escuro, em que a água tem um papel importante na desativação destes radicais / Abstract: White hair turns yellow after time, but it has no melanin, the pigment responsible for hair color. This yellowing upsets people. In this work we study in depth the color changes and mechanical properties in white hair after exposure to UV, Vis and IR, and the factors that effect the yellowing, including bleaching with H2O2 and the presence of moisture, and try to identify the yellow chromophores. We use two types of white hair, blended hair (blend of several heads), initially yellowish (value of color coordinate blue-yellow, b* = 20), and single head hair (hair of one head), lesser yellow initially (b * = 10). The results show that the initial color affects the behavior by exposuring to UV - Vis: after exposure to a mercury lamp for 200 h, the blended hair turns less yellow (Db * = - 6), and the single head hair turns yellowier (Db * = 2). However, when the blended hair is bleached with H2O2 (b * = 8), turns yellowier after a few hours of irradiation (Db * = 3). By exposing only the Vis turns less yellow independently of initial color, both in blended hair (Db * = - 9) and in the single head hair (Db * = - 3). The results of color changes in white hair after sun irradiation agree with the results of exposure to mercury lamp. The IR radiation at 81°C turns hair yellowier both single head white hair (Db * = 9) and blended white hair (Db * = 3). The blended hair irradiated at 100% relative humidity shows no color variation after 88 h of irradiation. Still, the hair that has been irradiated, but washed with a sodium lauryl sulfate solution after each irradiation period, kept the Db* value. The without washings hair continued less yellow after storage, however, a yellowing (Db* > 1.5) was observed after 1 year. The only significant change in mechanical properties was observed in the reduction of maximum stress by 17% after 480 h of exposure to Vis lamp. UV - Vis absorbance measurements in the white hair solutions with different shades of yellow show absorption in the visible range, these behavior is due to the yellowing, and the formation of a strong band at 320 nm after UV irradiation. Unlike shown in the wool literature, which is also a structure formed by keratin, this band is not related to the formation of yellow chromophores. We demonstrate that the initial hair yellowing is a determining factor in their color variation after UV radiation, and this yellowing is caused by heat action. Still, after irradiations are formed free radicals responsible for the degradation reactions in the dark, in which water plays an important role in the deactivation of these radicals / Mestrado / Físico-Química / Mestre em Química

Orientador: Ines Joekes / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-07T21:43:58Z (GMT). No. of bitstreams: 1 Wagner_RitadeCassiaComis_D.pdf: 5300466 bytes, checksum: b220b80949a0b5e00e05ecef6360d5ac (MD5) Previous issue date: 2006 / Resumo: O cabelo é uma estrutura protéica de queratina formada por quatro estruturas principais: as cutículas, o córtex, o cimento intercelular (CMC) e a medula. Esta última nem sempre está presente no fio e, por acreditar-se que sua influência nas propriedades da fibra é negligenciável, foi pouco estudada. Este trabalho almeja esclarecer as estruturas da medula e verificar sistematicamente se ela afeta alguma propriedade na fibra. Os fios medulados e sem medula provenientes do mesmo couro cabeludo foram identificados e separados em mechas utilizando um micro-estereoscópio. Encontraram-se dois tipos de medula (fina e grossa) que foram diferenciadas por microscopia eletrônica de varredura (MEV) e de transmissão (MET). A medula tem uma estrutura esponjosa composta por três unidades principais: a fibrilar (desalinhada com as fibrilas do córtex), os glóbulos e uma camada de CMC na interface com o córtex. Por MET constatou-se que a medula fina é morfologicamente diferente da medula grossa. A medula fina apresenta contraste, interface limitada pelo CMC, nenhum grânulo de melanina e menor diâmetro. A medula grossa apresenta mais glóbulos, bem como maiores dimensões das cavidades, alguns grânulos de melanina disformes e organização gradual das células de fora para dentro. Essas características morfológicas sugerem que a medula seria um córtex em estágio atrasado de formação. Utilizando-se um espectrofotômetro de refletância difusa (ERD), verificou-se que os fios com medula são mais escuros, menos vermelhos e menos amarelos que os fios sem medula oriundos do mesmo couro cabeludo. Sugere-se que as cavidades da medula causem o espalhamento e o confinamento de luz pela diferença de índice de refração com o córtex, diminuindo, então, a reflexão externa da fibra, já que praticamente não possui melanina. Para a mecha estudada, a diferença de cor total está em 4,7 unidades de cor e é visível a olho nu. A medula, então, deve ser considerada em estudos de cor, juntamente com as melaninas e as condições de preservação das cutículas. Já nas propriedades mecânicas, a medula causa uma maior heterogeneidade nas curvas de tensão-deformação, mas não muda os valores médios das propriedades estudadas. Os fios medulados são mais espessos que fios sem medula. Descontando-se o valor do diâmetro da medula do diâmetro total da fibra, têm-se valores aproximados aos dos fios sem medula. A heterogeneidade observada é proveniente da diferença percentual que o diâmetro da medula representa do diâmetro total da fibra. Observaram-se mudanças estruturais quando o cabelo com medula fina é submetido à imersão em SDS 10 % e à 75 °C, transformando-se em medula grossa após os tratamentos / Abstract: Human hair is a keratinous material divided into four main units: cuticles, cortex, intercellular cement (CMC) and medulla. The last one could be present or not in the shafts. There are few studies about it mainly because it is believed to have small or no influence on any hair property. The present work aims to clarify the medulla structure and to systematically verify if mechanical or color properties are affected by its presence in the fiber. Medullated and unmedullated fibers from the same scalp were identified by stereo-microscopy and separated into tresses. Two kinds of medulla were found: thin and thick medulla. Their morphology was characterized by scanning (SEM) and transmission (TEM) electron microscopy. Medulla has a sponge structure composed by three units: fibril (not aligned longitudinally as in the cortex), globular and CMC layer in the interface with the cortex. Thin and thick medullas are different in TEM. Thin medulla has contrast, CMC limited interface, no melanin and smaller diameter. Thick medulla has more globular structures, larger cavities, some elliptical melanin granules and a gradual organization from the outside to the inner side of the medulla. These data suggest that medulla is in an earlier stage of the differentiation process compared to the cortex. Color data obtained using a diffuse reflectance spectrophotometer showed that unmedullated fibers are clearer, redder and yellowier than medullated fibers. Once that medulla presents no melanin, we suggest that the medulla cavities cause scattering and confinement of light by the difference with the refractive index of cortex which decreases the external reflectance of the fiber. For the studied tress, the total color difference was 4.7 (visible to naked eyes). Thus, medulla together with melanin and cuticles must now be considered in studies of hair color. Average values of the mechanical properties are similar for unmedullated and medullated fibers. However, higher dispersion in data for medullated fibers is observed. Unmedulated fibers are more uniform and show smaller diameters. These data indicate that the air cavities in medulla could act as defects but do not interfere in the crystalline character of the fiber. Thus, the heterogeneity observed might be attributed to the difference between the medulla diameter with the whole fiber diameter. Thin medulla regions became thick medulla after immersion in SDS 10 % and after 24 h at 75 °C / Doutorado / Físico-Química / Doutor em Ciências

Orientador: Inés Joekes / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T11:57:45Z (GMT). No. of bitstreams: 1 Alves_ScheilaDaianaFausto_M.pdf: 2196472 bytes, checksum: c6f04b6d2db3f6b1a2f50a2fabb1e67f (MD5) Previous issue date: 2013 / Resumo: Os cabelos tingidos, como é de conhecimento comum, desbotam com o passar do tempo. Estudos mostram que tanto cabelos naturais quanto tingidos apresentam desbotamento quando expostos à radiação ultravioleta, e este mesmo fenômeno também é observado em outras fibras naturais. Além disso, o processo de lavagem tem grande influência nesta perda de cor. No entanto, há poucos estudos que combinem os efeitos da radiação ao de tensoativos, utilizados no processo de lavagem. Neste trabalho, estudamos a permanência da cor em cabelos Caucasianos tingidos frente à exposição à radiação UV-Vis e a três diferentes tensoativos, coco glucosídeo, cocoil sarcosinato de sódio e coco sulfato de sódio, de mesma cadeia apolar e diferente grupo polar. Cabelos castanhos foram oxidados antes do tingimento. Cabelos loiros foram tingidos sem oxidação prévia. Cabelos castanhos e loiros sem tingir foram usados como controles. Foram simulados danos diários por meio de irradiação em lâmpada de vapor de mercúrio e lavagens, em 30 ciclos sequenciais de 8 h de irradiação e uma lavagem. As diferenças de cor foram medidas por espectrofotometria de reflectância difusa.. Foram obtidos espectros no UV-Vis das soluções de lavagem com os diferentes tensoativos. Como esperado, todas as mechas, naturais e tingidas, apresentaram diferença de cor. No caso das mechas sem tingir, os espectros das soluções de lavagem correspondem aos das melaninas. No caso das mechas tingidas, as soluções de lavagem têm o mesmo perfil de absorbância que as soluções de tintura. As mechas oxidadas e tingidas desbotaram mais que as que foram apenas tingidas. Observou-se diferença entre o efeito dos tensoativos apenas nas mechas que foram tingidas. Tanto para o cabelo castanho oxidado e tingido quanto para o cabelo loiro tingido, a ordem de extração do pigmento é: coco sulfato de sódio > cocoil sarcosinato de sódio > coco glucosídeo, concordando com o respectivo índice HLB / Abstract: It is well known that dyed hair fades with time. There are studies showing that dyed and natural hair, besides other natural fibers, have their color lightened when exposed to ultraviolet radiation. Futhermore, shamppoing has a big effect on this color lightening. However, there are few studies combining the effects of radiation and surfactants. In this work, we studied the color durability in dyed Caucasian hair when exposed to radiation and three surfactants, coco glucoside, sodium cocoyl sarcosinate and sodium coco sulfate, with same carbonic chain and different polar groups. Brown hair was chemically bleached before dyeing and blond hair was dyed without previous oxidation. Brown and blond hair with no dyeing was used as control. Simulation of diary damages was done by a mercury vapor lamp and washing cycles, in 30 sequential cycles of 8 h of irradiation and one shampooing. Color changes were measured by diffuse reflectance spectroscopy (DRS), using CIELab system. UV-Vis spectra were obtained from washing solutions with the different surfactants. All tresses, natural and dyed, showed color changes. UV-Vis spectra of the washing solutions of the hair without dyeing are consistent with melanin spectra. Dyed hair washing solutions spectra have the same profile of the dye solutions. The chemically bleached and dyed tresses faded more than the only dyed ones. Differences among the surfactants were observed only in the dyed tresses The pigment removal order for both, oxidized and dyed and only dyed tresses is: sodium coco sulfate > sodium cocoyl sarcosinate > coco glucoside, agreeing with their HLB index / Mestrado / Físico-Química / Mestra em Química

Numerous studies have described that physical traits correlate with psychological personal characteristics. However, associations between congenital hair characteristics and personality have not been studied yet. Such studies have focused only on the association of hair color with a few specific psychological characteristics or emotions. The aim of this study was to reveal whether people with different hair darkness, redheadedness or curliness vary in personality and sexual traits. We have found significant connection of these traits with hair darkness and especially with redheadedness and curliness for men and women. These hair characteristics were associated with self-rated personality characteristics, Big Five personality traits and sexual orientation and preferences. We have excluded the mediating role of some physical and psychological factors for many associations. However, in many cases the connections disappeared when controlling for these factors, thus there is a possibility of a mediating role of these factors in observed associations. The hypothesis concerning the effect of stereotypes based on different types of hair and self-fulfilling prophecy was also considered.

no / The biochemistry of hair pigmentation is a complex field involving a plethora of protein and peptide mechanisms. The in loco factory for melanin formation is the hair follicle melanocyte, but it is common knowledge that melanogenesis results from a fine tuned concerted interaction between the cells of the entire dermal papilla in the anagen hair follicle. The key enzyme is tyrosinase to initiate the active pigmentation machinery. Hence, an intricate understanding from transcription of mRNA to enzyme activity, including enzyme kinetics, substrate supply, optimal pH, cAMP signaling, is a must. Moreover, the role of reactive oxygen species on enzyme regulation and functionality needs to be taken into account. So far our knowledge on the entire hair cycle relies on the murine model of the C57BL/6 mouse. Whether this data can be translated into humans still needs to be shown. This article aims to focus on the effect of H2O2-redox homeostasis on hair follicle pigmentation via tyrosinase, its substrate supply and signal transduction as well as the role of methionine sulfoxide repair via methionine sulfoxide reductases A and B (MSRA and B).

Minority phenotype preference, or the negative frequency-dependent selection is a type of selection, where a feature is more preferred, the lower it's frequency is in the population. Even a weak effect in other-preference based sexual selection can result in a sustainable polymorphism. This study reviews the phenomenon in the context of human visual facial features. Common trends in attractiveness shape the morphology of the human face towards uniformity. Individual recognition however, as a condition for most social relations, uses the wast variability of different features. This variability could be formed and maintained by minority phenotype preference. In our study we tested the effect of minority phenotype preference in the selection for rare hair and eye colors. In 120 unique sets, each containing six photographs, we experimentally manipulated the frequency of each color type. These sets were then shown to 226 human raters. We tested whether the relative frequency of each color type affected the rating of individual stimuli. In hair color, significant effect of minority phenotype preference was detected when females rated the photographs of men. When males rated the photographs of females, the effect was significant in eye color only. Key words: face perception, sexual selection,...

Indiana University-Purdue University Indianapolis (IUPUI) / In the past, the present and the future, Lebanon has been an important link between the East and the West. It was always known as the ‘Switzerland of the East’. Over the years, it was a hotspot for different civilizations that uniquely shaped the genomic backbone of the current Lebanese. It is also a good representation of genetically admixed individuals with diverse phenotype characteristics and unique features. Lebanon, quite like other Middle Eastern populations, lacks sufficient genetic studies that helps to better comprehend the complex genomic composition of different traits and diseases. The lack of good representation of the Middle East and North Africa (MENA) region in global studies has led to ambiguity in discovering special ancestry markers and patterns in the Lebanese genome. Yet, in this study, a thorough investigation into a Lebanese collection shows new patterns that potentially would be helpful in forensic and genealogical applications. The investigation into the autosomal and Y-STRs revealed unique alleles that would be valuable in future forensic investigation analysis. In addition, the assessment of phenotype prediction models to predict eye, hair and skin color showed promising results in terms of prediction performance. Those results encourage the future use of intelligence tools in the regions that in return would aid in serving justice and furthering science research. In fact, ancestry and genetic distance studies confirms the presence of admixture within Lebanon between Europe and North Africa. / 2029-06-01

Senile graying of human hair has been the subject of intense research since ancient times. Reactive oxygen species have been implicated in hair follicle melanocyte apoptosis and DNA damage. Here we show for the first time by FT-Raman spectroscopy in vivo that human gray/white scalp hair shafts accumulate hydrogen peroxide (H(2)O(2)) in millimolar concentrations. Moreover, we demonstrate almost absent catalase and methionine sulfoxide reductase A and B protein expression via immunofluorescence and Western blot in association with a functional loss of methionine sulfoxide (Met-S=O) repair in the entire gray hair follicle. Accordingly, Met-S=O formation of Met residues, including Met 374 in the active site of tyrosinase, the key enzyme in melanogenesis, limits enzyme functionality, as evidenced by FT-Raman spectroscopy, computer simulation, and enzyme kinetics, which leads to gradual loss of hair color. Notably, under in vitro conditions, Met oxidation can be prevented by L-methionine. In summary, our data feed the long-voiced, but insufficiently proven, concept of H(2)O(2)-induced oxidative damage in the entire human hair follicle, inclusive of the hair shaft, as a key element in senile hair graying, which does not exclusively affect follicle melanocytes. This new insight could open new strategies for intervention and reversal of the hair graying process.

Die Lichtensteinhöhle ist eine Klufthöhle im Berg Lichtenstein in den Harzausläufern. Im anthropogenen Teil der Höhle wurden größere Mengen disoloziert vorliegender Menschenknochen gefunden. Über assoziierte archäologische Artefakte und 14C-Datierungen erfolgte eine Einordnung ins 10.–9. Jh. v. Chr.. Aufgrund eines Überzuges mit Gipssinter und konstant niedriger Temperaturen war ein herausragend guter Erhaltungszustand der Knochen und der enthaltenen aDNA gegeben. Dies ermöglichte umfangreiche anthropologische Forschungsarbeiten an den menschlichen Überresten aus der Lichtensteinhöhle. Eine zentrale Fragestellung zu Beginn der Forschungsarbeiten war, ob es sich um eine Opferstätte oder einen Bestattungsplatz handelt. Es konnte für die zunächst identifizierten 40 Individuen ein ausgewogenes Geschlechterverhältnis und eine Altersverteilung über alle Altersklassen hinweg nachgewiesen werden. Zudem konnten mittels molekulargenetischer Methoden verwandtschaftliche Beziehungen zwischen den Individuen aufgedeckt werden. Die Verwandtschaftsrekonstruktion ergab den Stammbaum eines Familienclans. Damit lagen eindeutige Hinweise für eine Nutzung als Bestattungsplatz vor. Während molekulargenetischer Reihenuntersuchungen verschiedener Skelettelemente und morphologischer Zuordnungen von Skelettelementen zu Individuen wurde deutlich, dass Knochen von mehr Individuen als den 40 bislang identifizierten vorhanden waren. Zudem deutete sich an, dass für nahezu alle Individuen nicht alle Knochen in der Höhle aufgefunden worden waren. Das Fehlen von Skelettelementen warf die Frage auf, ob es sich bei der Lichtensteinhöhle nicht um einen Primär- sondern um einen Sekundärbestattungsplatz handeln könnte. Im aktuell durchgeführten Forschungsprojekt wurden, unter Verwendung morphologischer und molekulargenetischer Methoden, die Zuordnungen der dislozierten Knochen zu Individuen zu Ende geführt. Die rekonstruierten Individuen wurden umfassend morphologisch und molekulargenetisch untersucht, mit dem Ziel, die demografische Struktur der Population zu erschließen und die Verwandtschaftsrekonstruktion auszuweiten. Zudem wurde den Fragen der Nutzungsdauer und der genauen Nutzungsart der Höhle nachgegangen. Es konnten 60 Individuen identifiziert werden. Nur für zwei der Individuen wurden alle bei den Zuordnungen berücksichtigten Skelettelemente vorgefunden. An den Knochen zeigten sich nur wenige Fälle degenerativer Veränderungen. Dies ließ darauf schließen, dass die in der Lichtensteinhöhle bestatteten Menschen nicht übermäßig harter körperlicher Belastung ausgesetzt waren. Spuren massiver Gewalteinwirkung fehlten vollständig. Dies macht es unwahrscheinlich, dass die bestattete Population in kriegerische Auseinandersetzungen involviert war. Einige wenige verheilte Frakturen an Rippen oder Schlüsselbein lassen sich problemlos auf Alltagsunfälle zurückführen. Spuren von Mangel- oder Stressphasen waren nur in Einzelfällen nachweisbar. Dies deutet darauf hin, dass die Bestatteten zu Lebzeiten kontinuierlichen Zugang zu ausreichenden Nahrungsressourcen hatten. Das Geschlechterverhältnis war ausgewogen und die Altersverteilung entsprach in den Grundzügen der für eine historische Population zu erwartenden. Eine fesgestellte Unterrepräsentanz von Individuen der Altersklasse Infans I könnte als Hinweis darauf interpretiert werden, dass tatsächlich Sekundärbestattungen praktiziert wurden und die sehr kleinen, fragilen Knochen der Infans I Individuen zum Zeitpunkt der Umbettungen bereits vergangen waren. In begleitenden Arbeiten durchgeführte statistischen Analysen verschiedener Merkmale, wie z.B. Unterschiede im Grad der DNA-Degradierung, lieferten weitere Hinweise in die Richtung, dass es sich bei der Lichtensteinhöhle um einen Sekundärbestattungsplatz handeln dürfte. Für alle neu identifizierten Inividuen wurden mittels molekulargenetischer Analysen die genetischen Fingerabdrücke sowie die mitochondraialen und Y-chromosomalen Haplotypen bestimmt. Die anschließende Verwandtschaftsrekonstruktion ergab einen erweiterten Stammbaum, in dem für 47 der 60 Individuen entweder direkte Verwandtschaft oder aber Verwandtschaft in mütterlicher oder väterlicher Familienlinie belegt ist. Der Stammbaum umfasst insgesamt sechs Generationen. Dies entspricht – bei einer angenommenen Generationendauer von 20 Jahren – einer Nutzungsdauer von 120 Jahren und passt somit gut zum archäologisch ermittelten Nutzungszeitraum. Die Auswertung der Diversität der mitochondrialen und Y-chromosomalen Haplotypen ergab Hinweise auf eine patrilokale Gesellschaftsform. In begleitenden Arbeiten wurden weitere genetische Marker – z.B. für die Augen- und Haarpigmentierung, die immungenetische Ausstattung oder auch für den Laktosetoleranzstatus – analysiert. Insgesamt zeigte sich, dass sich in vielerlei Hinsicht die genetische Ausstattung heutiger Populationen im Vergleich zu der vor 3.000 Jahren nicht grundlegend unterscheidet. Lediglich für die Frequenz des Laktosetoleranz verursachenden Allels war eine deutliche Zunahme seit der Bronzezeit zu verzeichnen.