Cognitive and noncognitive variables that predict Florida community college radiography program graduates' success on the Registry

This study examined the predictive merits of selected cognitive and noncognitive variables on the national Registry exam pass rate using 2008 graduates (n = 175) from community college radiography programs in Florida. The independent variables included two GPAs, final grades in five radiography courses, self-efficacy, and social support. The dependent variable was the first-attempt results on the national Registry exam. The design was a retrospective predictive study that relied on academic data collected from participants using the self-report method and on perceptions of students' success on the national Registry exam collected through a questionnaire developed and piloted in the study. All independent variables except self-efficacy and social support correlated with success on the national Registry exam ( p < .01) using the Pearson Product-Moment Correlation analysis. The strongest predictor of the national Registry exam success was the end-of-program GPA, r = .550, p < .001. The GPAs and scores for self-efficacy and social support were entered into a logistic regression analysis to produce a prediction model. The end-of-program GPA (p = .015) emerged as a significant variable. This model predicted 44% of the students who failed the national Registry exam and 97.3% of those who passed, explaining 45.8% of the variance. A second model included the final grades for the radiography courses, self efficacy, and social support. Three courses significantly predicted national Registry exam success; Radiographic Exposures, p < .001; Radiologic Physics, p = .014; and Radiation Safety & Protection, p = .044, explaining 56.8% of the variance. This model predicted 64% of the students who failed the national Registry exam and 96% of those who passed. The findings support the use of in-program data as accurate predictors of success on the national Registry exam.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Seawater carbonate chemistry, pigments and biological processes during experiments with coralline alga Corallina sessilis

Previous studies have shown that increasing atmospheric CO2 concentrations affect calcification in some planktonic and macroalgal calcifiers due to the changed carbonate chemistry of seawater. However, little is known regarding how calcifying algae respond to solar UV radiation (UVR, UVA+UVB, 280-400 nm). UVR may act synergistically, antagonistically or independently with ocean acidification (high CO2/low pH of seawater) to affect their calcification processes. We cultured the articulated coralline alga Corallina sessilis Yendo at 380 ppmv (low) and 1000 ppmv (high) CO2 levels while exposing the alga to solar radiation treatments with or without UVR. The presence of UVR inhibited the growth, photosynthetic O2evolution and calcification rates by13%, 6% and 3% in the low and by 47%, 20% and 8% in the high CO2 concentrations, respectively, reflecting a synergistic effect of CO2 enrichment with UVR. UVR induced significant decline of pH in the CO2-enriched cultures. The contents of key photosynthetic pigments, chlorophyll a and phycobiliproteins decreased, while UV-absorptivity increased under the highpCO2/low pH condition. Nevertheless, UV-induced inhibition of photosynthesis increased when the ratio of particulate inorganic carbon/particulate organic carbon decreased under the influence of CO2-acidified seawater, suggesting that the calcified layer played a UV-protective role. Both UVA and UVB negatively impacted photosynthesis and calcification, but the inhibition caused by UVB was about 2.5-2.6 times that caused by UVA. The results imply that coralline algae suffer from more damage caused by UVB as they calcify less and less with progressing ocean acidification.

Seawater carbonate chemistry and Emiliania huxleyi biological processes during experiments, 2010

The calcifying phytoplankton species, coccolithophores, have their calcified coccoliths around the cells, however, their physiological roles are still unknown. Here, we hypothesized that the coccoliths may play a certain role in reducing solar UV radiation (UVR, 280-400 nm) and protect the cells from being harmed. Cells of Emiliania huxleyi with different thicknesses of the coccoliths were obtained by culturing them at different levels of dissolved inorganic carbon and their photophysiological responses to UVR were investigated. Although increased dissolved inorganic carbon decreased the specific growth rate, the increased coccolith thickness significantly ameliorated the photoinhibition of PSII photochemical efficiency caused by UVR. Increase by 91% in the coccolith thickness led to 35% increase of the PSII yield and 22% decrease of the photoinhibition of the effective quantum yield by UVR. The coccolith cover reduced more UVA (320-400 nm) than UVB (280-315 nm), leading to less inhibition per energy at the UV-A band.

Tracing the Chromospheric and Coronal Magnetic Field with AIA, IRIS, IBIS, and ROSA Data

The aim of this study is to explore the suitability of chromospheric images for magnetic modeling of active regions. We use high-resolutionimages (≈0.2"-0.3"), from the Interferometric Bidimensional Spectrometer in the Ca II 8542 Å line, the Rapid Oscillations in the Solar Atmosphere instrument in the Hα 6563Å line, the Interface Region Imaging Spectrograph in the 2796Å line, and compare non-potential magnetic field models obtainedfrom those chromospheric images with those obtained from images of the Atmospheric Imaging Assembly in coronal (171 Å, etc.) and inchromospheric (304 Å) wavelengths. Curvi-linear structures are automatically traced in those images with the OCCULT-2 code, to which we forward-fitted magnetic field lines computed with the Vertical-current Approximation Nonlinear Force Free Field code. We find that the chromospheric images: (1) reveal crisp curvi-linear structures (fibrils, loop segments, spicules) that are extremely well-suited for constraining magnetic modeling; (2) that these curvi-linear structures arefield-aligned with the best-fit solution by a median misalignment angle of μ2 ≈ 4°–7° (3) the free energy computed from coronal data may underestimate that obtained from chromospheric data by a factor of ≈2–4, (4) the height range of chromospheric features is confined to h≲4000 km, while coronal features are detected up to h = 35,000 km; and (5) the plasma-β parameter is β ≈ 10^-5 - 10^-1 for all traced features. We conclude that chromospheric images reveal important magnetic structures that are complementary to coronal images and need to be included in comprehensive magnetic field models, something that is currently not accomodated in standard NLFFF codes.

Synergistischer photoinduzierter Schadstoffabbau mittels eines Porphyrazin-Titandioxid-Hybrids

Die zunehmende Luftverschmutzung aufgrund des steigenden Energiebedarfs und Mobilitätsanspruchs der Bevölkerung, insbesondere in urbanen Gebieten, erhöht das Gefährdungspotential für die Gesundheit und verschlechtert so die Lebensqualität. Neben der Vermeidung von Emissionen toxischer Gase als mittel- und langfristig optimale Maßnahme zur Verbesserung der Luftqualität, stellt der Abbau emittierter Luftschadstoffe ein geeignetes und kurzfristig wirksames Mittel dar. Ein solcher Abbau kann durch Photokatalyse erzielt werden, allerdings nutzen Photokatalysatoren, die auf dem Halbleiter Titandioxid (TiO2) basieren, das solare Emissionsspektrum nur geringfüfig aus und sind in Innenräumen und anderen UV-schwachen Bereichen nicht wirksam. Um diese Nachteile zu überwinden, wurde ein Photokatalysator entwickelt und hergestellt, der aus TiO2 (P25) als UV-aktiver Photokatalysator und als Trägermaterial sowie einem seinerseits im Vis-Bereich photoaktiven Porphyrazin-Farbstoff als Beschichtung besteht. Die sterisch anspruchsvollen und in der Peripherie mit acht Bindungsmotiven für TiO2 versehenen Farbstoffmoleküle wurden zu diesem Zweck auf der Halbleiteroberfläche immobilisiert. Die so gebildeten Porphyrazin-Titandioxid-Hybride wurde ausführlich charakterisiert. Dabei wurden unter anderem die Bindung der Farbstoffe auf der Titandioxidoberfläche mittels Adsorptionsisothermen und die UV/Vis-spektroskopischen Eigenschaften des Hybridmaterials untersucht. Zur Bestimmung der photokatalytischen Aktivitäten der Einzelkomponenten und des Hybridmaterials wurden diese auf die Fähigkeit zur Bildung von Singulett-Sauerstoff, Wasserstoffperoxid und Hydroxylradikalen hin sowie in einem an die ISO-22197-1 angelehnten Verfahren auf die Fähigkeit zum Abbau von NO hin jeweils bei Bestrahlung in drei Wellenlängenbereichen (UV-Strahlung, blaues Licht und rotes Licht) geprüft. Darüber hinaus konnte die Aktivität des Hybridmaterials bei der Photodynamischen Inaktivierung (PDI) von Bakterien unter UV- und Rotlichtbestrahlung im Vergleich zum reinen Ttandioxid bestimmt werden. Die Charakterisierung des Hybridmaterials ergab, dass die Farbstoffmoleküle in einer neutralen Suspension nahezu irreversibel in einer monomolekularen Schicht mit einer Bindungsenergie von -41.43 kJ/mol an die Oberfläche gebunden sind und das Hybridmaterial mit hohen Extinktionskoeffizienten von bis zu 105 M-1cm-1 in großen Bereichen des UV/Vis-Spektrums Photonen absorbiert. Das Spektrum des Hybridmaterials setzt sich dabei additiv aus den beiden Einzelspektren zusammen. Die Auswirkungen der Charakterisierungsergebnisse auf die Bildung reaktiver Sauerstoffspezies wurden ausführlich diskutiert. Der Vergleich der Aktivitäten in Bezug auf die Bildung der reaktiven Sauerstoffspezies zeigte, dass die Aktivität des Hybridmaterials bis auf die bei der Bildung von Hydroxylradikalen unter UV-Bestrahlung in allen Versuchen deutlich höher war als die Aktivität des reinen Titandioxids. Im Gegensatz zu reinem Titandioxid erzeugte das Hybridmaterial in allen untersuchten Wellenlängenbereichen Mengen an Singulett-Sauerstoff, die photophysikalisch eindeutig detektierbar waren. Zur Erklärung und Deutung dieser Beobachtungen wurde eine differenzierte Diskussion geführt, die die Ergebnisse der Hybridpartikelcharakterisierung aufgreift und implementiert. Der Vergleich der NO-Abbaueffizienzen ergab bei allen Experimenten durchgängig deutlich höhere Werte für das Hybridmaterial. Zudem wurden durch das Hybridmaterial nachgewiesenermaßen wesentlich geringere Mengen des unerwünschten Nebenprodukts des Abbaus (NO2) gebildet. Im Zuge der Diskussion wurden verschiedene mögliche Mechanismen der „sauberen“ Oxidation zu Nitrat durch das Hybridmaterial vorgestellt. Untersuchungen zur Photodynamischen Inaktivierung verschiedener Bakterien ergaben, dass das Hybridmaterial neben einer zu P25 ähnlichen Aktivität unter UV-Bestrahlung, anders als P25, auch eine PDI verschiedener Bakterien unter Rotlichtbestrahlung erreicht.

Solar coronal jets: observations, theory, and modeling

Coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of significant mass and energy input to the upper solar atmosphere and the solar wind. While the energy involved in a jet-like event is smaller than that of “nominal” solar flares and coronal mass ejections (CMEs), jets share many common properties with these phenomena, in particular, the explosive magnetically driven dynamics. Studies of jets could, therefore, provide critical insight for understanding the larger, more complex drivers of the solar activity. On the other side of the size-spectrum, the study of jets could also supply important clues on the physics of transients close or at the limit of the current spatial resolution such as spicules. Furthermore, jet phenomena may hint to basic process for heating the corona and accelerating the solar wind; consequently their study gives us the opportunity to attack a broad range of solar-heliospheric problems.

Lääkeaineiden poisto yhdyskuntajätevesistä katalyyttisillä membraaneilla

Lääkeaineiden poistaminen jätevedestä on tärkeää lääkeainejäämien ympäristöön pääsyn ehkäisemiseksi. Tämän työn tavoitteena on selvittää, soveltuvatko katalyyttiset membraanit lääkeaineiden poistoon jätevedestä ja saadaanko membraanisuodatusta tehostettua katalyyttisellä prosessilla. Työ käsittelee katalyyttisistä prosesseista fotokatalyysiä, joka perustuu valoa absorboivan katalyytin käyttöön. Kirjallisuustyössä tarkastellaan kahden erilaisen fotokatalyyttisen prosessin toimivuutta membraanisuodatuksen kanssa lääkeaineiden poistossa jätevedestä. Lisäksi tutkitaan fotokatalyysissä käytettävän katalyytin ja ultraviolettisäteilyn vaikutusta membraaniin. Tutkimukset ovat osoittaneet, että katalyyttisillä membraaneilla voidaan poistaa lääkeaineita jätevedestä tehokkaasti. Parhaan lääkeaineiden poistotehokkuuden saamiseksi katalyytin määrä on optimoitava hajotusprosessin kannalta. Myös katalyytin sijainti membraanissa vaikuttaa tehokkuuteen. Katalyytti voi sijaita membraanista myös erillään. Tällöin saadaan käsiteltyä myös jatkuvatoimisessa membraanisuodatuksessa syntyvä lääkeaineita sisältävä konsentraattivirta. Kun katalyyttisellä membraanilla hajotetaan lääkeaineita, täytyy prosessin turvallisuuden kannalta olla hyvin selvillä mahdollisista syntyvistä myrkyllisistä välituotteista. Tutkimuksissa on myös todettu, että katalyyttisen membraanin käyttö vähentää membraanin likaantumista.

Effects in ultrafast laser micromachining PMMA-based optical fibre grating

Ultrafast laser owns extreme small beam size and high pulse intensity which enable spatial localised modification either on the surface or in the bulk of materials. Therefore, ultrafast laser has been widely used to micromachine optical fibres to alter optical structures. In order to do the precise control of the micromachining process to achieve the desired structure and modification, investigations on laser parameters control should be carried out to make better understanding of the effects in the laser micromachining process. These responses are important to laser machining, most of which are usually unknown during the process. In this work, we report the real time monitored results of the reflection of PMMA based optical fibre Bragg gratings (POFBGs) during excimer ultraviolet laser micromachining process. Photochemical and thermal effects have been observed during the process. The UV radiation was absorbed by the PMMA material, which consequently induced the modifications in both spatial structure and material properties of the POFBG. The POFBG showed a significant wavelength blue shift during laser micromachining. Part of it attributed to UV absorption converted thermal energy whilst the other did not disappear after POFBG cooling off, which attributed to UV induced photodegradation in POF.

Modeling chemistry in massive star forming regions with internal PDRs

Over the past decades star formation has been a very attractive field because knowledge of star formation leads to a better understanding of the formation of planets and thus of our solar system but also of the evolution of galaxies. Conditions leading to the formation of high-mass stars are still under investigation but an evolutionary scenario has been proposed: As a cold pre-stellar core collapses under gravitational force, the medium warms up until it reaches a temperature of 100 K and enters the hot molecular core (HMC) phase. The forming central proto-star accretes materials, increasing its mass and luminosity and eventually it becomes sufficiently evolved to emit UV photons which irradiate the surrounding environment forming a hyper compact (HC) and then a ultracompact (UC) HII region. At this stage, a very dense and very thin internal photon-dominated region (PDR) forms between the HII region and the molecular core. Information on the chemistry allows to trace the physical processes occurring in these different phases of star formation. Formation and destruction routes of molecules are influenced by the environment as reaction rates depend on the temperature and radiation field. Therefore, chemistry also allows the determination of the evolutionary stage of astrophysical objects through the use of chemical models including the time evolution of the temperature and radiation field. Because HMCs host a very rich chemistry with high abundances of complex organic molecules (COMs), several astrochemical models have been developed to study the gas phase chemistry as well as grain chemistry in these regions. In addition to HMCs models, models of PDRs have also been developed to study in particular photo-chemistry. So far, few studies have investigated internal PDRs and only in the presence of outflows cavities. Thus, these unique regions around HC/UCHII regions remain to be examined thoroughly. My PhD thesis focuses on the spatio-temporal chemical evolution in HC/UC HII regions with internal PDRs as well as in HMCs. The purpose of this study is first to understand the impact and effects of the radiation field, usually very strong in these regions, on the chemistry. Secondly, the goal is to study the emission of various tracers of HC/UCHII regions and compare it with HMCs models, where the UV radiation field does not impact the region as it is immediately attenuated by the medium. Ultimately we want to determine the age of a given region using chemistry in combination with radiative transfer.

Caracterización de las condiciones de salud y de trabajo y su relación con lesiones cutáneas en los orfebres artesanales de Mompox Bolivar-Colombia 2015

INTRODUCCIÓN Las alteraciones de la salud relacionadas con el trabajo (enfermedades y accidentes), pueden prevenirse desde las actividades bien enfocadas del Sistema de Gestión de Seguridad y Salud en el Trabajo (SGSST), realizando la identificación y control de los agentes causales en el ambiente de trabajo y la vigilancia de la salud de la población trabajadora. El proyecto desarrollado va dirigido a un grupo específico de artesanos orfebres en la ciudad de Mompox, Bolivar, en la que esta labor artesanal se centra en el arte de la filigrana, transmitido generacionalmente desde antaño En esta ciudad los artesanos orfebres, aunque corresponden a un sector informal de la economía, se encuentran agremiados principalmente en tres asociaciones ubicadas en la cabecera municipal. En el desempeño de sus labores, estos profesionales del arte de la filigrana manipulan agentes químicos como el ácido nítrico, el ácido sulfúrico, la plata y el mercurio, los cuales se utilizan en las diferentes etapas del proceso que incluye técnicas propias de esta labor. Teniendo en cuenta que la información disponible en la literatura científica describe principalmente los efectos de agentes químicos en otros oficios diferentes a la población orfebre y conociendo que la exposición a estas sustancias químicas puede generar variados efectos en el organismo, el interés de este proyecto se centra específicamente en las alteraciones cutáneas posiblemente relacionadas con las condiciones de trabajo de esta población del sector informal. MATERIALES Y METODOS La presente investigación es un estudio de corte trasversal, el cual realizó una selección por conveniencia de 114 trabajadores de orfebres Momposinos con el fin de identificar la relación de las condiciones de trabajo con la presencia de alteraciones cutáneas de los trabajadores que laboran en la orfebrería artesanal en la ciudad de Mompox, departamento de Bolívar, en el año 2015, de tal manera que dejando a consideración la descripción de los hallazgos encontrados, se posibiliten futuras y precisas investigaciones e intervenciones en este colectivo de trabajadores. Los instrumentos empleados para la recolección de la información y para el cumplimento de los objetivos fueron la encuesta Nacional de Condiciones de Trabajo del Instituto Nacional de Seguridad e Higiene en el trabajo de España (INSHT) que permite recolectar información sobre la caracterización de la población a nivel sociodemográfico y ocupacional, y para la determinación de patologías dermatológicas relacionadas con el trabajo se utilizó el Cuestionario NOSQ-2002 Nórdico- Enfermedades Cutáneas de origen Laboral, en su versión validada en español. Se describieron las variables categóricas con porcentajes y las continuas (cuantitativas) con medidas de tendencia central y dispersión La asociación entre los hallazgos de exposición ocupacional y los síntomas y signos en piel, fue estimada mediante riesgos relativos. RESULTADOS El 75,4% del total de la población correspondió al género masculino y el 67,5% reportó realizar sus labores como trabajadores independientes. Respecto a la identificación de condiciones de salud, la percepción por parte de los orfebres fue positiva, reportando muy buena salud en el 34% de los mismos. El 8% de la población manifestó alteraciones dermatológicas tipo eczema en los últimos seis meses y el 11% las presentó principalmente en manos. Respecto de la iniciación del eczema, el 97% de los trabajadores reportó que se iniciaba al contacto con sustancias químicas y el 98,7% manifestó que se encontraban realizando la labor de orfebrería cuando inició el eczema. La lesión prevalente fue mancha roja sin edema (8%), seguida de ronchas o manchas y ampollas pequeñas (3%) y de piel seca con escamas (2%). CONCLUSIONES Los resultados de la presente investigación mostraron la prevalencia de alteraciones cutáneas principalmente en las manos, tipo eczema (manchas rojas) o prurito (picor). Se recomienda la disminución de los tiempos de exposición, adecuación de jornadas y tiempos de descanso, sistemas de protección personal adecuados y la implementación de un programa de educación y participación para el control integral del riesgo.

Morphological and chemical characterization of tintypes and ambrotypes

The present work was done on two ambrotypes and two tintypes. It aimed evaluate their chemical and physical characteristics, especially their degradation patterns. Moreover, to understand the materials used for their production and cross-check analytical and historical information about the production processes. To do so multi-analytical, non-destructive methods were applied. Technical photography highlighted the surface morphology of the objects and showed the distribution of the protective coatings on their surfaces through UV radiation, which were very different between the four pieces. OM allowed for a detailed observation of the surfaces along with the selection of areas of interest to be analysed with SEM-EDS. SEM-EDS was the technique used most extensively and the one that provided the most insightful results: it allowed to observe the morphology of the image forming particles and the differences between highlights, dark areas and the interfaces between them. Also, elemental point analysis and elemental maps were used to identify the image forming particles as silver and to detect the presence of compounds related to the production, particularly gold used to highlight jewellery, iron as the red pigment and traces of the compounds used in the photographic process containing Ag, I, Na and S . Also, some degradation compounds were analysed containing Ag, Cu, S and Cl. With μ-FT-IR the presence of collodion was confirmed and the source of the protective varnishes was identified, particularly mastic and shellac, in either mixtures of the two or only one. μ-Raman detected the presence of metallic silver and silver chloride on the objects and identified one of the red pigments as Mars red. Finally, μ-XRD showed the presence of metallic silver and silver iodide on both ambrotypes and tintypes and hematite, magnetite and wuestite on the tintypes; RESUMO: O presente estudo foi desenvolvido sobre dois ambrótipos e dois ferrótipos. O propósito consiste em estudar as suas características químicas e físicas, dando particular ênfase aos padrões de degradação. Também é pretendido compreender os materiais usados na sua produção e relacionar esta informação analítca com dados históricos de manuais técnicos contemporâneos à produção dos objectos. Para tal foram utilizadas técnicas multi-analíticas e não destrutivas. O uso da fotografia técnica permitiu uma observação da morfologia das superficies dos objectos e da distribuição das camadas de verniz através da radiação UV, muito diferente entre os quatro. A microscopia óptica proporcionou uma observação detalhada das superfícies assim como a selecção de pontos de interesse para serem analisados com SEM-EDS. SEM-EDS foi a técnica usada mais extensivamente e a que proporcionou os resultados mais detalhados: observação da morofologia das partículas formadoras da imagem e as diferenças entre zonas de altas luzes, baixas luzes e as interfaces entre elas. A análise elemental e os mapas elementares foram usados para detectar prata nas partículas formadoras da imagem e a presença de compostos relacionados com a produção, em particular ouro utilizado para realçar joalharia, ferro no pigmento vermelho e vestígios de compostos utilizados no processo fotográfico incluindo Ag, I, Na e S. Do mesmo modo, alguns compostos de degradação foram analisados contendo Ag, Cu, S e Cl. Com μ-FT-IR a presença de colódio foi confirmada e identificada a origem dos vernizes, mástique e goma-laca, tanto em misturas dos dois como apenas um. Com μ-Raman foi detectada a presença de prata metálica e de cloreto de prata e identificado um dos pigmentos vermelhos como Mars red. Finalmente, μ-DRX revelou a presença de prata metálica e iodeto de prata tanto nos ambrótipos como nos ferrótipos e hematite, magnetite e wuestite nos ferrótipos.

Photoprotective potential of emulsions formulated with Buriti oil (Mauritia flexuosa) against UV irradiation on keratinocytes and fibroblasts cell lines

Considering the belief that natural lipids are safer for topical applications and that carotenoids are able to protect cells against photooxidative damage, we have investigated whether topical creams and lotions, produced with Buriti oil and commercial surfactants, can exert photoprotective effect against UVA and UVB irradiation on keratinocytes and fibroblasts. Cell treatment was divided into two steps, prior and after exposition to 30 min of UVA plus UVB radiation or to 60 min of UVA radiation. Emulsions prepared with ethoxylated fatty alcohols as surfactants and containing alpha-tocopherol caused phototoxic damage to the cells, especially when applied prior to UV exposure. Damage reported was due to prooxidant activity and phototoxic effect of the surfactant. Emulsions prepared with Sorbitan Monooleate and PEG-40 castor oil and containing panthenol as active ingredient, were able to reduce the damages caused by radiation when compared to non-treated cells. When the two cell lines used in the study were compared, keratinocytes showed an increase in cell viability higher than fibroblasts. The Buriti oil emulsions could be considered potential vehicles to transport antioxidants precursors and also be used as adjuvant in sun protection, especially in after sun formulations. (C) 2009 Elsevier Ltd. All rights reserved.

O estudo da aplicação de acabamentos funcionais de barreira UV em fibras previamente ativadas por plasma

Tese de Doutoramento Engenharia Têxtil

Water-filtered infrared-A radiation (wIRA) is not implicated in cellular degeneration of human skin

Rapport de synthèse : Introduction : le vieillissement cutané est un processus biologique complexe auquel participe une exposition excessive au rayonnement ultraviolet du soleil. En particulier, les longueurs d'onde des rayons ultraviolets A et B (UV-A et UV-B) peuvent induire une augmentation de la synthèse de protéases, comme la métalloprotéinase matricielle 1 (MMP-1), qui est impliquée dans le processus de vieillissement. La thermothérapie par infrarouges, dont les longueurs d'onde sont plus longues que celles des UV, est largement utilisée à des fins thérapeutiques ou cosmétiques. Or, il a été démontré que les infrarouges en filtration aqueuse (IRFA) pouvaient induire une augmentation de la production de MMP-1 et par conséquent être nocifs. Il serait donc intéressant d'évaluer les effets des IRFA au niveau cellulaire et moléculaire. But Expérimental : étudier les effets des lampes à infrarouges en filtration aqueuse utilisées en clinique sur des fibroblastes cutanés humains en culture, afin d'analyser l'expression du gène codant pour la protéine MMP-1. Méthode : des fibroblastes cutanés humain ont été irradiés d'une part avec approximativement 88% d'IRFA (780-1400 nm) et 12% de lumière rouge (LR, 665-780 nm) avec 380 mW/cm2 IRFA(+LR) (333 mW/cm2 IRFA) et d'autre part avec des UV-A comme contrôle. Des courbes de survie cellulaire ont été établies après une exposition allant de 15 minutes à 8 heures au IRFA(+LR) (340-10880 J/cm2 wIRA(+RL), 300-9600 J/cm2 wIRA) ou de 15 à 45 minutes aux UV-A(+BL) (25-75 J/cm2 UV-A(+BL). L'induction de l'ARNm du gène de la MMP-1 a été analysé dans les fibroblastes cutanés humain à deux températures physiologiques (30°C et 37°C) lors d'expositions uniques de 15 à 60 minutes aux IRFA(+LR) (340-1360 J/cm2 IRFA(+LR), 300-1200 J/cm2 IRFA) ou de 30 minutes aux UV-A(+BL) (50 J/cm2 UVA(+BL)). De plus, nous avons effectué des irradiations répétées, une a chaque passage cellulaire jusqu'au passage. 10 de 15 minutes d'IRFA(+LR) 340 J/cm2 IRFA(+LR), 300 J/cm2 IRFA) . Résultats : une exposition unique aux UV-A (+BL) entraîne chez des fibroblastes cutanés humains une augmentation de la mort cellulaire, ainsi qu'une forte augmentation de l'expression du gène codant pour la MMP-1. L'augmentation mise en évidence pour cet ARNm varie en fonction de la technique utilisée : elle est de 11 ± 1 fois par RT-PCR classique, de 76 ± 2 fois par RT-PCR quantitative à 30°C, et de 75 ± 1 fois par RT-PCR quantitative à 37°C. Par contre, une exposition unique ou répétée aux IRFA (+LR) n'induit aucune augmentation de la mort cellulaire, ni de l'expression de l'ARNm de la MMP-1 chez ces fibroblastes. Conclusions : les résultats de cette étude montrent que, contrairement aux rayons ultraviolets, les IRFA (+LR) ne semblent impliqués ni dans le vieillissement, ni dans la mort cellulaire, même utilisés à des doses très élevées. Ces résultats sont en accord avec certaines investigations in vivo montrant une induction de MMP-1 par des UV et non des infrarouges. Ces dernières études suggèrent d'ailleurs plutôt un rôle protecteur des IRFA (+LR).