As propriedades dos extratos vegetais vêm sendo cada vez mais investigadas, suscitando o interesse em aliar o potencial destes para minimizar efeitos do fotoenvelhecimento da pele decorrentes da ação dos radicais livres à fotoproteção proporcionada pelos filtros solares. Apesar do uso difundido de vários extratos vegetais, alguns deles, como a Matricaria chamomilla, ainda carecem de estudos acerca de suas propriedades e efeitos biológicos na pele, especialmente quando este é veiculado em formulações dermocosméticas. Assim, esse trabalho teve por objetivo a avaliação da estabilidade e da eficácia pré-clínica de formulações fotoprotetoras contendo o extrato de Matricaria chamomilla ou dos componentes isolados do vegetal, a-bisabolol e apigenina, na proteção de danos causados pela radiação ultravioleta (UV). Para tal, verificou-se a estabilidade dos ativos veiculados em formulação com FPS previamente determinado, bem como outras formulações de protetor solar foram desenvolvidas e a estas adicionadas extrato de camomila ou alfa-bisabolol, sendo testados por centrifugação, pH e análise visual. A estabilidade física das formulações mais estáveis foi analisada por estudos reológicos. A estabilidade química de formulações contendo extrato de camomila, apigenina e bisabolol foi determinada por Cromatografia Líquida de Alta Eficiência (HPLC). Estas formulações acrescidas de apigenina, extrato de camomila, ou alfa-bisabolol finalmente foram avaliadas no que tange à eficácia pré-clínica. Neste estudo, camundongos foram submetidos à radiação UV e o efeito protetor das formulações foi avaliado através de técnicas de biofísica nãoinvasiva e análise de imagem, que forneceram medidas de eritema, o teor de água do estrato córneo, a perda de água transepidérmica, ecogenicidade e espessura da derme. Os resultados permitiram selecionar as formulações fisicamente estáveisl para ambas as combinações de filtros UV associados contendo as substâncias ativas em estudo. No estudo de estabilidade química, a apigenina foi mais estável quando comparada às outras substâncias ativas em estudo e o bisabolol mostrou estabilidade química baixa. Todas as formulações foram eficazes na redução da perda de água transepidérmica. Os efeitos destas formulações na pele foram muito positivos, pois todas elas levaram a aumentos ecogenicidade e valores menores de espessura quando comparada às regiões irradiadas. Esses resultados mostraram efeitos significativos na melhoria do processo inflamatório causado pela radiação. Finalmente, as formulações desenvolvidas foram estáveis e eficazes na proteção da pele. Além disso, quando o extrato de camomila ou apigenina esteve presente na formulação fotoprotetora os efeitos foram mais pronunciados. / Particular plant extracts are being increasingly studied for their properties, in order to combine their potential to minimize skin photoaging effects from the action of free radicals with photoprotection provided by sunscreens. Despite of the widespread use of various plant extracts, some of them as it is the case of Matricaria chamomilla still need mored detailed studies especially on their properties and biological effects on skin, especially in dermocosmetic formulations. The aim of the present study was to assess the stability and the preclinical efficacy of sunscreen formulations containing M. chamomilla extract or its isolated components, alpha-bisabolol and apigenin, in the protection from damage caused by ultraviolet radiation. For this purpose, the physical stability in a pre-determined SPF formulation added of the active substances under study was determinated. Other sunscreen formulations were developed and supplemented with chamomile extract or alpha-bisabolol, and these were tested for centrifugation stability, pH and visual analysis. Physical stability of the most stable formulations was estimated by rheological measurements. The chemical stability of the formulations containing chamomile extract, apigenin, and bisabolol was determinated by High Efficiency Liquid Chromatography (HPLC). These formulations with chamomile extract, apigenin or alpha-bisabolol were finally evaluated in terms of preclinical efficacy. In this study, hairless mice were submitted to UV radiation and the protective effect of the formulations was evaluated using noninvasive biophysics techniques and image analysis, in which we obtained measures of erythema, the water content of stratum corneum, transepidermal water loss, the echogenicity and the thickness of the dermis. The results allowed selecting physicallystable formulations for both the combinations of UV-filters associated containing the actives substances under study. In the chemical stability study, the apigenin present in the extract was more stable when compared to the other active substances under study and the bisabolol showed a low chemical stabilitity. All the formulations were effective in the transepidermic water-loss reduction. The effects of these formulations on skin were very positive since all of them led to ecogenicity increases and lower thickness values when compared to irradiated regions. These results showed significant effects in the improvement of the inflammatory process caused by radiation. Finally, the formulations developed were stable and effective in the skin protection. In addition, when the chamomile extract or apigenin was present in the formulation the photoprotective effects were more pronounced.

Ever since the first observations of diffuse ultraviolet radiation by Hayakawa et al. (1969) and Lillie & Witt (1976), there has been an effort to understand its distribution and its origin. Unfortunately, because of the difficulty of the observations and the faintness of the background, many of the early observations were conspicuous more by their disagreements than by the light they shed on the topic. The state of the observations and theories before 1990 have been reviewed by Bowyer (1991) and Henry (1991). There has been significant progress in more recent years, particularly in the far ultraviolet (< 1200˚A) where Murthy et al. (1999) and Murthy & Sahnow (2004) have used spectroscopic data from the Voyager and FUSE (Far Ultraviolet Spectroscopic Explorer) spacecraft, respectively, to trace the radiation field over many different locations in the sky. There have also been a number of observations at longer wavelengths, most recently by the SPEAR instrument (Ryu et al. 2008, and references therein), but no systematic study of the UV background. The Galaxy Evolution Explorer (GALEX) offers us the opportunity to extend coverage of the diffuse background to a significant fraction of the sky with a sensitivity of better than 100 photons cm−2 sr−1 s−1 ˚A−1 . In this work, we will report on one such observation, that of the nebulosity observed near M82 by Sandage (1976). These GALEX observations are the first to probe the diffuse UV background at a spatial resolution comparable to other surveys of dust emission, notably the IR. We obtain a quantitative estimate of the Airglow, the Zodiacal Light and the Extragalactic Background Radiation. We have modelled the data with our monte carlo scattering simulation program, and inferred an estimate of albedo and scattering phase function parameter of the dust in Sandage region. In this thesis the methods and results of these deductions are explained in detail.

This diploma thesis deals with a study of kinetics of photochemical reactions in a thin printed polymer layer. The experimental part deals with the composition preparation and layers coating. The prepared layers were exposed and subsequently studied for their colour response to the light. The aim of this work was to prepare a photosensitive layer with a significant colour change between individual doses of radiation, to improve the mechanical resistance of the layers, to adjust the sensitivity of the compositions to UVB radiation and to study the kinetics of the photochemical reaction used.

Ultraviolet (UV) light has been used for disinfection purposes for over 100 years. Irradiation by UV light is a method to disinfect surfaces in order to prevent microbiological growth. At Tetra Pak this is of great importance as they are manufacturer of filling machines. Those filling machines must ensure a certain level of sterility on all packages produced. The irradiation process can be simulated using Geant4 which is a software package that tracks particles through matter. The simulation model used today does not consider the absorption of photons inside of medium-pressure UV lamps. By understanding the absorption that takes place in the lamp, one can quantify how changes in the design would impact the emitter output. In this master's thesis, the aim is to develop a model that can describe the interaction of photons with a medium-pressure UV lamp. An absorption model was suggested and developed with the assumption of local thermodynamical equilibrium and existing Hg radiative data. A simulation including the collision process in Geant4 was used. In this collision process the non-radiative transition probabilities were assumed to be the same as that of the radiative, this was done in order to demonstrate how it can be done. It resulted in collisions populating other states allowing more transitions to be present in the final output spectrum. The collision process and a method for computing the Einstein's emission coefficient with the software package General Relativistic Atomic Structure Package is proposed as future work. / I över 100 år har ultraviolet (UV) ljus använts till desinficering. UV bestrålning är en metod för att desinficera ytor med målet att förhindra mikrobiologisk tillväxt. För Tetra Pak som är ledande inom tillverkning av fyllmaskiner är det extra viktigt. Förpackningarna inuti fyllningsmaskinerna måste garantera en viss nivå av sterilitet för alla förpackningar. Dagens simuleringar av medeltrycks UV lampa utförs i Geant4 som är ett mjukvarupaket som möjliggör följandet av partiklar genom olika medium. Detta görs utan att ta hänsyn till absorptionen av fotoner. Genom att förstå absorptionen som sker i lampans gas kan man kvantifiera hur förändringar i design skulle påverka emittorns utgående effekt. I detta examensarbete är målet att utveckla en modell som kan beskriva hur fotoner växelverkar med gasen i en medeltrycks UV lampa. En modell utvecklas och föreslås med antagandet att lokalt termodynamisk jämvikt råder och att enbart Hg strålnings data används. En simulering med en kollisionsprocess i Geant4 inkluderades. I denna kollisionsprocess antas den icke-optiska övergångssannolikheten vara densamma som för de optiska övergångarna. Detta inkluderades för att demonstrera hur en sådan process kan gå till. Detta resulterade i att kollisionerna populerade andra tillstånd vilket gjorde att dessa övergångar visade sig i utgående spektrum. Kollisionsprocessen och en metod för att beräkna Einsteins emissions koefficient med mjukvarupaketet General Relativistic Atomic Structure Package föreslås även som framtida arbete.

<p>Predmet istraživanja ove disertacije je monitoring i analiza ultraljubičastog zračenja, toplotnih indeksa i zagađujućih materija u vazduhu većih naselja na teritoriji Vojvodine. Cilj istraživanja je da se prostornom i vremenskom analizom posmatranih parametara dođe do &scaron;to optimalnijih saznanja o stanju kvaliteta životne sredine na području Vojvodine kao i stvaranje jedinstvene baze podataka koja će služiti za buduća istraživanja. U radu je ispitan odnos između sunčevog globalnog i UV zračenja, izvedena i verifikovana empirijska jednačina za procenu dnevnih suma UV-B zračenja u osam naselja za period 1981-2008, analizirane koncentracije pet zagađujućih materija u sedam naselja za period 2001-2008. godina i analizirani toplotni indeksi u sedam naselja u periodu od 1992. do 2008. Analiza pokazuje da rekonstruisane vrednosti dnevnih suma UV-B zračenja i srednji godi&scaron;nji toplotni indeksi u svim naseljima pokazuju tendenciju rasta i da dominantan uticaj na kvalitet vazduha u naseljima Vojvodine imaju čestice. Napravljena je jedinstvena baze podataka sa vrednostima koncentracija zagađivača vazduha, toplotnih indeksa, UV i globalnog zračenja.</p> / <p>This study analyzes UV radiation, heat indexes and air pollution in town in Vojvodina region. Objective of the thesis is to provide scientific facts about environmental quality in Vojvodina, as well as, to generate unique data base for the future research. The relationship between UV-B and global radiation has been studied and correlation equation for estimating UV-B from global radiation has been deduced. Equation was used for UV-B radiation calculation in eight towns in Vojvodina region during the period 1981-2008. This study also analyzes concentrations of five air pollutant in during the period 2001-2008, and heat index during the period 1992-2008. in seven towns in Vojvodina. The results from this study show growth UV-B radiation and heat index in all towns, and denote particulate maters as main air pollutants in Vojvodina towns.</p>

A primary emulsion with whey protein isolate (WPI) and hexanoic acid was prepared, and chitosan (Ch) (0.01%, 0.02%, and 0.03%) was added to evaluate its impact on particle size distribution of the emulsion. NaCl (0, 20, 40, and 80 mM) was added to increase ionic interactions to stabilize the multilayer emulsion. Lecithin (0.5%, 1%, 2%, 3 %, w/v) was mixed with the primary emulsion in order to form a multilayer, and casein hydrolysate (CH) was used to stabilize the tertiary emulsion system without the use of NaCl for 28 d at 4 °C. Stable O/W nanoemulsions were generated for use as nano-vesicular vehicles (NVV) to carry Curcumin (CU). Two important variables, (1) addition of casein hydrolysate (CH) (1:50, w/w WPI) and, (2) use of high pressure (140 and 210 MPa), were studied for their effect on the stabilization of monodispersed NVV and persistence of antioxidant activity of the CU as cargo in the NVV throughout storage. Addition of CH reduced nano-particle size and increased emulsion stability with UHPH pressure. The nanoparticle distribution was not changed by the addition of CU. Addition of casein hydrolysate reduced particle size as well as enhanced the positive functional properties of the NVV. Similar trends were observed in zeta-potential, surface energy, contact angle and antioxidant efficacy of the NVV, both with and without CU when UHPH was applied. The effect of Ultraviolet (UV) radiation (254 nm) on the stability of O/W nanoemulsion systems was investigated. A nano vesicular vehicle (NVV) was generated using ultra-high pressure homogenization (UHPH) that was stabilized using whey protein isolate (WPI) (1%, w/v), Tween 20 (20% w/w WPI) and casein hydrolysate (CH) (1:50 of WPI, w/w). Coarse emulsions were prepared by blending for three min. The coarse emulsion was exposed to UV radiation (0-60 min), followed by a single-pass of UHPH at 140 and 210 MPa. The UHPH treated NVV-CU had greater (P<0.05) short and long term antioxidant properties. After 28 d of storage, the CU-NVV treated at 210 MPa retained 7.0 and 1.4% greater AA and AP, respectively, when compared to the unpressurized CU-NVV.

No description available.

No description available.

Ultraviolet (UV) radiation has been demonstrated in numerous studies to be a major risk factor for non-melanoma skin cancer development. Despite the emergence of current UV-preventative strategies, such as sunscreens and skin-protective clothing, the incidence of non-melanoma skin cancer has continued to rise. This has encouraged investigations on alternative methods for UV prevention. In particular, bovine milk sphingomyelin has been studied for its potential in protecting human skin against UV photodamage. While the previous studies have suggested that sphingomyelin exhibits UV-protective properties in a human skin equivalent model, the exact mechanisms behind sphingomyelin’s photoprotective effects are yet unknown. This thesis aims to further investigate the UV-protective effects of sphingomyelin in normal human epidermal keratinocytes, using nuclear p21 expression as a marker for UV photodamage. Keratinocytes were incubated for 24 hours in a 0.1% sphingomyelin solution and then exposed to 40mJ/cm2 of 302nm UV radiation. After 24 hours of post-UV incubation, nuclear p21 expression was evaluated using immunofluorescence. Confocal images were analyzed for their mean nuclear p21 fluorescence intensity measured in grayscale (0-255). Keratinocytes treated with sphingomyelin showed approximately a 50% decrease in UV-induced mean nuclear p21 intensity compared to keratinocytes with no sphingomyelin treatment (via Tukey’s test; p

Water is essential for life on earth. Human society is challenged to sustain sufficient water quantity of good quality. This objective is reflected in sustainable development goal 6, “clean water and sanitation”. Water monitoring is part of sustainable water management and aims to evaluate the physical, chemical and biological status of a water body. Regular monitoring in the catchment area of Indalsälven (Sweden) is conducted by the Indalsälven Water Conservation Association (IWCA). In this area counts of Escherichia coli (E. coli) between 0 and 500 colony forming units (CFU) were monitored from 1993 – 2022 at the closest monitoring station Enkroken. This implies that drinking water quality standards were exceeded during many occasions (≥10 E. coli CFU/100ml). It is known that survival of E. coli in aquatic environments is dependent on nutrient levels, turbidity, sedimentation, pH level, predation, microbial community composition, temperature, and solar radiation. Low water depth and clear water with poor nutrient level in Enan and Handölan, tributaries to Indalsälven, are believed to cause solar radiation to be the main driver for inactivation of E. coli. Inactivation behaviour of indicator bacteria for faecal contamination such as E. col, is assumed to reflect on other bacteria that were excreted in the same way. The objective of the research was to investigate to which extent river color and river depth under the influence of sunlight affected E. coli inactivation in pristine like conditions such as the upper catchment area of Indalsälven. In this study, conditions from the research area were mimicked in 4 laboratory experiments. Results showed that neither 10 nor 35µW/cm2 led to additional inactivation due to sunlight. In a following experiment the liquid depth was reduced, with as a result that the inactivation of bacteria started to be influenced by sunlight when the depth was reduced to 14.4cm or lower. A fourth experiment was conducted at 14.4cm depth and additional color concentration 50 and 100 mg/l Pt. Results indicated that inactivation influenced by sunlight was reduced at color level 50 or more to a level that was equal to no sunlight radiation. A median depth of 0.2 cm and median color level of 15 mg/l Pt in the catchment area of Indalsälven suggests that inactivation of E. coli is very likely influenced by the sun, upstream the measuring point Enkroken and at points where the river is as shallow 14.4cm or less. Sunlight radiation might be underestimated in the conducted laboratory experiments, therefore continuous on-site research is suggested. / <p>2022-06-19</p>