<p> UV radiation disinfection technology is an advantageous method of wastewater disinfection as it avoids the formation of chemical by-products typically found from chlorination. One challenge with this technology is avoiding fouling on the quartz sleeves in which the UV lamps are housed. In this study, using a model fouling system, the roles in fouling of light, and the constitution of the fouling media, are examined. The systematic determination of fouling by various mixtures of human serum albumin, humic acid, Ca^2+, and Fe^3+ was carried out on quartz slides in the presence and absence of UV (254nm) light. Fouling was assessed by the reduction in transmission of UV light through the quartz slides over time. It was determined that the most important factors were the concentration of..iron and protein, which apparently act synergistically to foul the surface. Other contributing factors to the magnitude of fouling include the flow rate and the age of the fouling solution. Most important was the presence of UV light. In all solutions examined, fouling was observed to a lower degree when the system was exposed to light. On the other hand, XPS analysis has demonstrated differences in the nature of the fouling layer on the surface exposed to UV light compared to that in the dark. </p> <p> It is generally accepted that low energy surfaces are less easily fouled than polar surfaces. Therefore, hydrophobic modification of the quartz by a series of different silane coupling agents was undertaken. Irrespective of the nature of the coating (alkylamine, alkyl, aryl, fluorocarbon, silicone), the rate and magnitude of fouling on the surface were comparable to the unmodified quartz. However, the more hydrophobic surfaces were easier to clean. </p> / Thesis / Master of Science (MSc)

Yes / Cutaneous science has seen considerable development in the last 25 years, in part due to the -Omics revolution, and the appreciation that this organ is hardwired into the body’s key neuroimmuno- endocrine axes. Moreover, there is greater appreciation of how stratification of skin disorders will permit more targeted and more effective treatments. Against this has been how the remarkable extension in the average human life-span, though in the West at least, this parallels worrying increases in lifestyle-associated conditions like diabetes, skin cancer etc. These demographic trends bring greater urgency to finding clinical solutions for numerous age-related deficits in skin function caused by extrinsic and intrinsic factors. Mechanisms for aging skin include the actions of reactive oxygen species (ROS), mtDNA mutations, and telomere shortening, as well as hormonal changes. We have also significantly improved our understanding of how to harness the skin’s considerable regenerative capacity e.g., via its remarkable investment of stem cell subpopulations. In this way we hope to develop new strategies to selectively target the skin’s capacity to undergo optimal wound repair and regeneration. Here, the unsung hero of the skin regenerative power may be the humble hair follicle, replete with its compliment of epithelial, mesenchymal, neural and other stem cells. This review introduces the topic of human skin aging, with a focus on how maintenance of function in this complex multi-cell type organ is key for retaining quality of life into old age.

No description available.

This report presents results from a series of experiments in which YAG samples (undoped, as well as doped with Nd and Cr3+) were exposed to ionizing radiation (gamma rays and UV). These experiments were performed for the purpose of investigating the various phtodarkening processes taking place in these materials in response to the ionizing radiation. The purpose of this investigation was to establish whether and how co-doping YAG with Cr3+ improves the material's resistance to photodarkening due to the ionizing radiation. The experiments tracked time-resolved transmittance of the samples at 1064 nm in immediate response a pulsed exposure to the ionizing radiation, as well as steady-state spectrally-resolved changed in the samples' optical absorption after the irradiation. The investigation revealed a number of photodarkening processes occurring in the samples in response to the ionizing radiation, both transient and permanent. It was further revealed that inclusion of Cr3+ ions in YAG significantly reduces these photodarkening processes, improving the material's radiation resistance. It was observed that materials containing at least 0.5 at% Cr3+ are essentially radiation-hardened, resisting both transient and steady-state changes in transmittance observed in the materials not containing Cr3+.

Foram estudadas trinta e uma cepas fúngicas não identificadas, as quais foram denominadasX1 a X31. O potencial fotoprotetor foi avaliado pela medida espectrofotométrica da absorçãodos extratos na região do UV (280-400 nm). Os extratos com os melhores perfis de absorção em cultura estacionária foram X1, X2, X6, X12, X13, X18, X19, X22, X24 e X31 e, em cultura agitada X4 e X17. A reprodutibilidade do processo foi avaliada e as cepas fúngicas que apresentaram coeficiente de variação menor que 15% foram selecionadas para o estudo de fotoestabilidade. A fotoestabilidade dos extratos foi avaliada pela medida da viabilidade celular de fibroblastos L929 tratados com extratos previamente irradiados sob radiação UVA (11,2 J/cm2) e UVB (3,43 J/cm2) e extratos não irradiados, bem como, pela comparação das áreas sob as curvas de absorção na região do UV dos extratos irradiados e não irradiados. Os extratos selecionados para o estudo de fotoestabilidade foram X4, X12, X19, X22, X24 e X31. Os extratos não irradiados apresentaram os seguintes valores deIC50 para viabilidade celular (citotoxidade): X4-130µg/ml, X19-20µg/ml, X22-10 µg/ml e X24-60µg/ml. Após a radiação UVA e UVB, os extratos apresentaram redução significativa da viabilidade celular em relação ao IC50 dos extratos não irradiados. Sob luz UVB, os extratos X12 (IC50 35µg/ml) e X31 (IC50 70µg/ml) mantiveram a mesma porcentagem de redução da viabilidade celular quando comparado ao IC50 dos extratos não irradiados. No entanto após exposição à luz UVA, o extrato X12 aumentou a viabilidade celular de 50% (quando não irradiado) para 75% (irradiado). Enquanto que o extrato X31, mesmo após a radiação UVA, manteve a mesma redução de 50% da viabilidade celular. Nessa etapa os extratos selecionados foram os X12 e X31. O espectro de absorção na região do UV obtido para o extrato X12 mostrou uma redução da absorbância de 28,3% sob radiação UVB e de 60% sob radiação UVA em relação ao extrato não irradiado. O extrato X31 apresentou uma redução da absorbância de 17,6% e30% sob radiação UVB e UVA respectivamente, em relação ao extrato não irradiado. Os fungos selecionados foram identificados por PCR, sugerindo que o fungo X12 seja o Aspergillus terreus e o X31 seja o Talaromyces pinophilus. Por fim, foi feita a identificação da substância ativa do extrato X12 empregando a técnica de desreplicação, a qual fez o uso da instrumentação analítica acoplada UHPLC-DAD-(ESI)-HRMS associada ao banco de dados Chapman& Hall\'s Dictionary of Natural Products (DNP). No extrato X12 o composto majoritário foi identificado como sendo a citreoviridina. Assim, os resultados do presente trabalho permitiu estabelecer um procedimento para a seleção de fungos produtores de compostos absorvedores de radiação UV, que poderia ser aplicado na obtenção de novos filtros orgânicos naturais para protetores solares. / It were studied thirty-one fungal strains not identified, which were named X1 to X31. The photoprotective potential was assessed spectrophotometrically by measuring absorption of the extract in the UV region (280-400 nm). The extracts that presented the best absorption profiles in stationary culture were X1, X2, X6, X12, X13, X18, X19, X22, X24 and X31, and X4 and X17 in stirred culture. The reproducibility of the process was evaluated and fungal strains that showed a coefficient of variation lower than 15% were selected for the study of photostability. The photostability of the extracts was assessed by measuring cell viability of L929 fibroblasts treated with extracts previously irradiated under UVA light (11,2 J/cm2) and UVB (3,43 J/cm2) and not irradiated extracts, as well as by comparison of the areas under the curves of absorption in the UV region of the irradiated and non-irradiated extracts. The extracts selected for the study of photostability were X4, X12, X19, X22, X24 and X31. The non-irradiated extracts showed the following IC50 values for cell viability (cytotoxicity): X4- 130?g/ml X19-20?g/ml, X22-10/ml and X24-60?g/ml. After UVA and UVB radiation, the extracts showed significant reduction in cell viability compared to the IC50 of the unirradiated extracts. Under UVB light, the X12 extracts (IC50 35?g/ml) and X31 (IC50 70mg/ml) maintained the same percentage of cell viability reduction when compared to the IC50 of the unirradiated extracts. However after exposure to UVA light, X12 extract increased the cell viability from 50% (when not irradiated) to 75% (irradiated). While X31 extract even after the UVA irradiation, remained the same 50% of reduction in cell viability. At this stage the selected extracts were X12 and X31. The absorption spectrum in the UV region obtained for X12 extract showed a decrease in absorbance of 28.3% under UVB and 60% under UVA radiation relative to non-irradiated extract. The X31extract showed a reduction in absorbance of 17.6% and 30% in UVA and UVB radiation, respectively, compared to non-irradiated extract. The selected fungi were identified by PCR, suggesting that X12 fungus is Aspergillus terreus and X31 is the Talaromyces pinophilus. Finally it was identified the active substance of X12 extract employing dereplication technique which makes use of coupled analytical instrumentation UHPLC-DAD- (ESI) HRMS associated to the Chapman and Hall\'s Dictionary of Natural Products (DNP) database. The majority compound of X12 extract was identified as the citreoviridin. Thus, the results of this study allowed us to establish a procedure for the selection of producers of UV absorbing compounds from fungi, which could be applied in obtaining new natural organic filters for sunscreens.

Biometeorologinė informacija suteikia išankstinius perspėjimus apie sveikatai gresiantį pavojų, kaip meteorologinių sąlygų kompleksas veiks žmonių sveikatos būklę ar komfortiškumą. Šio darbo tikslas - nustatyti orų poveikį Lietuvos gyventojų sveikatai ir atlikti biometeorologinių sąlygų šalies teritorijoje vertinimą. Darbe atliktas Lietuvos gyventojų jautrumo orams sociologinis vertinimas. Nustatytas orų sąlygų poveikis širdies-kraujagyslių ligų kartojimuisi Vilniuje ir išskirtos meteojautriausios ligos ir jų priklausomybė nuo esamų meteorologinių sąlygų. Analizuota biometeorologinį šalčio poveikį nusakančio Vėjo žvarbumo ir karščio poveikį – „Humidex“ indekso kaita Lietuvoje. Įvertintas karščio poveikis Vilniaus gyventojų mirtingumui ir nustatyti indikatoriai tinkantys teikti karščio perspėjimus Lietuvoje. Atlikta Kauno MS išmatuotų ultravioletinės spinduliuotės dydžių kalibraciją bei įvertintas modelio STAR tinkamumas ultravioletinės spinduliuotės intensyvumo Lietuvoje prognozei. Disertacinio darbo rezultatai gali būti naudojami biometeorologinėms prognozėms sudaryti. Remiantis šiuo darbu, galima tobulinti egzistuojančią išankstinių perspėjimų apie stichinius, katastrofinius ir kitus pavojingus hidrometeorologinius reiškinius sistemą. / Biometeorological information provides early warnings about health risks and possible effects of complex meteorological conditions on human health or comfortability. The aim of the present research is to determine the weather impact on human health in Lithuania and accomplish evaluation of biometeorological conditions in the country. In the research a sociological evaluation of weather sensitivity of Lithuanian population was carried out. There also was measured the impact of the weather conditions on cardiovascular disease recurrent in Vilnius and the most meteo sensitive diseases were identified as well as their dependence on the current weather conditions. The change of indices describing biometeorological cold (Wind Chill) and heat („Humidex“) effects was analysed. The impact of heat on mortality of Vilnius residents was evaluated and appropriate indicators were determined to provide heat warnings in Lithuania. There was performed a calibration of ultraviolet radiation values measured in Kaunas MS and assessed the appropriateness of STAR model for forecasting of UV radiation intensity in Lithuania. The results of dissertation can be used to make biometeorological forecasts. On the basis of this work, the system of existing early warnings about elemental, catastroffic and other hazardous weather events could be improved.

Biometeorological information provides early warnings about health risks and possible effects of complex meteorological conditions on human health or comfortability. The aim of the present research is to determine the weather impact on human health in Lithuania and accomplish evaluation of biometeorological conditions in the country. In the research a sociological evaluation of weather sensitivity of Lithuanian population was carried out. There also was measured the impact of the weather conditions on cardiovascular disease recurrent in Vilnius and the most meteo sensitive diseases were identified as well as their dependence on the current weather conditions. The change of indices describing biometeorological cold (Wind Chill) and heat („Humidex“) effects was analysed. The impact of heat on mortality of Vilnius residents was evaluated and appropriate indicators were determined to provide heat warnings in Lithuania. There was performed a calibration of ultraviolet radiation values measured in Kaunas MS and assessed the appropriateness of STAR model for forecasting of UV radiation intensity in Lithuania. The results of dissertation can be used to make biometeorological forecasts. On the basis of this work, the system of existing early warnings about elemental, catastroffic and other hazardous weather events could be improved. / Biometeorologinė informacija suteikia išankstinius perspėjimus apie sveikatai gresiantį pavojų, kaip meteorologinių sąlygų kompleksas veiks žmonių sveikatos būklę ar komfortiškumą. Šio darbo tikslas - nustatyti orų poveikį Lietuvos gyventojų sveikatai ir atlikti biometeorologinių sąlygų šalies teritorijoje vertinimą. Darbe atliktas Lietuvos gyventojų jautrumo orams sociologinis vertinimas. Nustatytas orų sąlygų poveikis širdies-kraujagyslių ligų kartojimuisi Vilniuje ir išskirtos meteojautriausios ligos ir jų priklausomybė nuo esamų meteorologinių sąlygų. Analizuota biometeorologinį šalčio poveikį nusakančio Vėjo žvarbumo ir karščio poveikį – „Humidex“ indekso kaita Lietuvoje. Įvertintas karščio poveikis Vilniaus gyventojų mirtingumui ir nustatyti indikatoriai tinkantys teikti karščio perspėjimus Lietuvoje. Atlikta Kauno MS išmatuotų ultravioletinės spinduliuotės dydžių kalibraciją bei įvertintas modelio STAR tinkamumas ultravioletinės spinduliuotės intensyvumo Lietuvoje prognozei. Disertacinio darbo rezultatai gali būti naudojami biometeorologinėms prognozėms sudaryti. Remiantis šiuo darbu, galima tobulinti egzistuojančią išankstinių perspėjimų apie stichinius, katastrofinius ir kitus pavojingus hidrometeorologinius reiškinius sistemą.

Ultraviolet radiation reaching the Earth’s surface (UVR, 280-400 nm) may penetrate deep into the clear oligotrophic waters influencing a large part of the euphotic layer. Marine heterotrophic bacteria at the surface of the oceans are especially sensitive to the damaging solar radiation due to their haploid genome with little or no functional redundancy and lack of protective pigmentation. In a context of climate change and ozone depletion, it is clearly important to understand the physiology and underlying molecular UVR responses of abundant marine bacteria species. We chose the marine ultramicrobacterium Sphingopyxis alaskensis as a reference species to study the impact of solar radiation due to its numerical abundance in oligotrophic waters and its photoresistance, previously reported. For this purpose, we focused on the formation of the two major UVB-induced DNA photoproducts (CPDs and 6-4PPs) as well as the differential protein expression under solar radiation. We first demonstrated that the GC content of prokaryotic genome had a major effect on the formation of UVB-induced photoproducts, quantified by HPLC-MS/MS. Due to its high GC content, S. alaskensis presented a favoured formation of highly mutagenic cytosine-containing photoproducts and therefore would be more susceptible to UVinduced mutagenesis. By comparing S. alaskensis to another marine bacterium Photobacterium angustum, we observed for the latter strain a remarkable resistance to high UVB doses associated with a decrease in the rate of formation of CPDs explained by a non-conventional activity of photolyase. We also demonstrated that DNA damage in S. alaskensis was markedly modulated by growth temperature and time spent in stationary phase. In order to assess the effects that environmental UV-R had on regulatory networks and pathways of S. alaskensis, and determine how the cell’s physiology was affected, a quantitative proteomics investigation was performed. Changes in proteome were analyzed, with the recent and powerful mass spectrometry based approach using iTRAQ methodology. Approximately, one third of the proteome of S. alaskensis was identified, with 119 statistically and significantly differentially abundant proteins. Cellular processes, pathways and interaction networks were determined and gave us unique insight into the biology of UV response and adaptation of S. alaskensis.

Ultraviolet radiation reaching the Earth’s surface (UVR, 280-400 nm) may penetrate deep into the clear oligotrophic waters influencing a large part of the euphotic layer. Marine heterotrophic bacteria at the surface of the oceans are especially sensitive to the damaging solar radiation due to their haploid genome with little or no functional redundancy and lack of protective pigmentation. In a context of climate change and ozone depletion, it is clearly important to understand the physiology and underlying molecular UVR responses of abundant marine bacteria species. We chose the marine ultramicrobacterium Sphingopyxis alaskensis as a reference species to study the impact of solar radiation due to its numerical abundance in oligotrophic waters and its photoresistance, previously reported. For this purpose, we focused on the formation of the two major UVB-induced DNA photoproducts (CPDs and 6-4PPs) as well as the differential protein expression under solar radiation. We first demonstrated that the GC content of prokaryotic genome had a major effect on the formation of UVB-induced photoproducts, quantified by HPLC-MS/MS. Due to its high GC content, S. alaskensis presented a favoured formation of highly mutagenic cytosine-containing photoproducts and therefore would be more susceptible to UVinduced mutagenesis. By comparing S. alaskensis to another marine bacterium Photobacterium angustum, we observed for the latter strain a remarkable resistance to high UVB doses associated with a decrease in the rate of formation of CPDs explained by a non-conventional activity of photolyase. We also demonstrated that DNA damage in S. alaskensis was markedly modulated by growth temperature and time spent in stationary phase. In order to assess the effects that environmental UV-R had on regulatory networks and pathways of S. alaskensis, and determine how the cell’s physiology was affected, a quantitative proteomics investigation was performed. Changes in proteome were analyzed, with the recent and powerful mass spectrometry based approach using iTRAQ methodology. Approximately, one third of the proteome of S. alaskensis was identified, with 119 statistically and significantly differentially abundant proteins. Cellular processes, pathways and interaction networks were determined and gave us unique insight into the biology of UV response and adaptation of S. alaskensis.

Orientador: Marian Rosaly Davolos / Banca: Sergio Antonio Marques de Lima / Banca: Kassandra Azevedo Tadini / Resumo: A preocupação com a radiação ultra-violeta (UV) do espectro eletromagnético que atinge a superfície terrestre, devido ao aumento do índice de câncer de pele, tem incentivado a pesquisa de produtos para a proteção da pele. Este trabalho tem como objetivo a obtenção e estudo do filtro inorgânico ZnO:Ti4+ com 1, 5, 10, 20, 40, 50% em mol do dopante e a associação dos filtros dopados obtidos com o filtro orgânico 1-(4-terc-butilfenil)-3-(4- metoxifenil)propano-1,3-diona ou butil metoxi dibenzoil metano (bmdm), comercialmente denominado Eusolex 9020. Os filtros dopados foram obtidos pelo método sol-gel, com razão de hidrólise de 0,1 e de 0,01. As amostras foram caracterizadas por espectroscopia de absorção através de medidas de refletância difusa (RD), espectroscopia na região do infravermelho (IV), espectroscopia na região do ultravioleta - visível (UV-Vís), difratometria de raios X (DRX), colorimetria, medidas de potencial zeta, razão UVA/UVB e comprimento de onda crítico foram calculados para conhecer o desempenho dos filtros na região do UVA. Os resultados de DRX indicam a formação da fase ZnO wurtzita para dopagens de até 10%. Acima dessa porcentagem de "dopante", observa-se a formação de fases de titanatos de zinco (Zn2TiO4 e ZnTiO3). Os espectros no IV apresentam bandas referentes à ligação metaloxigênio deslocadas para maiores números de onda com o aumento da quantidade de dopante, devido ao efeito da força de ligação e do tamanho do íon de titânio em relação ao de zinco nas interações metal-oxigênio. Os espectros de RD apresentam deslocamento das bandas para a região do visível. Os filtros dopados obtidos foram, então, associados com o filtro orgânico bmdm. Os filtros associados foram caracterizados pelas mesmas técnicas acima descritas. Nos espectros IV dos filtros... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The concern with UV radiation of the electromagnetic spectrum that reaches the earth's surface has encouraged the research of products for skin protection due to increased rates of skin cancer. This study aims to obtain and study the inorganic filter ZnO:Ti4+ with 1, 5, 10, 20, 40, 50 at% of doping and the association with doped filters developed through organic filter 1 - (4-tert- butyl phenyl) -3 - (4-methoxyphenyl) propane-1 ,3-dione or butyl methoxy dibenzoyl methane (bmdm), trade name Eusolex 9020®. Doped filters were obtained by the sol-gel method, with hydrolysis ratio of 0.1 and 0.01. The samples were characterized by absorption spectroscopy using diffuse reflectance (DR), infrared (IR) spectroscopy, ultraviolet - visible (UV-Vis), X-ray diffraction (XRD), colorimetric and zeta potential measurements. UVA/UVB ratio and critical wavelength were calculated to know the filter's performance in the UVA region. XRD results indicate the ZnO wurtzite phase formation step for doping levels up to 10%. Above this percentage of doping, phases of zinc titanates (Zn2TiO4 and ZnTiO3) we observed. The IR spectra show bands of the metal-oxygen shifted to higher wave numbers and an increasing amount of dopant due to the bond strength and size effects of the titanium ion compared to zinc ion in metaloxygen interactions. The RD spectra show shifts of bands for the visible region. Doped filters were then associated with the bmdm organic filter. The associated filters were characterized by the same techniques just described above. In the IR spectra of the associated filters, there is also the band on the metal-oxygen, splitting and shifting of the band related to the carbonyl group when compared with the free bmdm, that indicates an association between the filters. The absorption bands of doped filters do not cover... (Complete abstract click electronic access below) / Mestre