• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 134
  • 108
  • 33
  • 6
  • 6
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • Tagged with
  • 402
  • 402
  • 107
  • 99
  • 47
  • 43
  • 33
  • 26
  • 23
  • 23
  • 19
  • 18
  • 18
  • 17
  • 17
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Caracterizacao e padronizacao de um sistema dosimetrico termoluminescente para radiacoes ultravioleta e laser utilizando o CaSO sub(4):Dy

GROSSI, FABIO H. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:46:32Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:07Z (GMT). No. of bitstreams: 1 08286.pdf: 4148498 bytes, checksum: f9d73111bc4c47c409ba95ffcaec8d14 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:99/06632-0
202

Estudo compreensivo da fotodissociacao do ion OHsub(-) nos haletos alcalinos e sua interacao com centros de cor

GOMES, LAERCIO 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:32:05Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:51Z (GMT). No. of bitstreams: 1 02301.pdf: 3265642 bytes, checksum: ef5be621c56bae7b751bf5bc812f0c07 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
203

Avaliacao dos efeitos causados por inclusoes, solarizacao e modificadores na transmitancia optica no vidro 40BaO. 60Psub(2)Osub(5)

PRISON, JOSE M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:48:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:10Z (GMT). No. of bitstreams: 1 09303.pdf: 5478849 bytes, checksum: 91eea1ce1127d155b27d04ee87ec86c7 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
204

Desinfecção solar da água: avaliação da técnica "SODIS" aplicada a águas de chuva, poço e manancial superficial, nas condições climáticas de verão na região de Porto Alegre, RS

Carvajal, Ruth Angelic Reyes January 2015 (has links)
SODIS (Solar Water Disinfection) é uma tecnologia simples para tratamento de água no pontode- uso, sendo uma alternativa importante para disponibilizar água em situações de emergência ou onde não há acesso à água potável. A ação concomitante entre a temperatura e a radiação ultra violeta do sol provoca a morte dos microorganismos presentes na água. Este estudo avaliou a eficiência de inativação de coliformes totais e Escherichia coli pela técnica SODIS para as águas de chuva (coletada em telhado), de poço freático e de manancial superficial (reservatório), sob as condições climáticas de verão de Porto Alegre, RS. Foram ainda, realizados ensaios para verificar se ocorreu o recrescimento dos microorganismos após 24 e 48 horas do término da exposição ao sol. Também foram determinadas as constantes de decaimento das bactérias utilizando a Lei de Chick para representar o declínio dos microorganismos. Os ensaios de SODIS foram realizados em batelada, utilizando garrafas PET transparentes de 1,5 L, expostas ao sol por um período de 6 h. O mesmo número de garrafas era mantido à sombra pelo mesmo período, como controle. As temperaturas do ar e da água e a radiação ultravioleta foram monitoradas ao longo dos ensaios. Os valores médios de remoção de concentrações de E. coli no SODIS nas amostras das águas analisadas variaram entre 98,8 a maior do que 99,99%; para coliformes totais as reduções médias nas amostras variaram entre 90,00 – 99,99%. Não houve recrescimento de microorganismos após 24 e 48 horas seguindo-se ao término da exposição solar. As constantes de decaimento para coliformes totais e E. coli foram, respectivamente, 0,2979 h-1 e 0,9397 h-1, confirmando as observações de que E. coli é mais sensível a desinfecção. Os coeficientes de determinação para a equação da Lei de Chick foram de 0,938 (E. coli) e 0,877 (coliformes totais). Os resultados da pesquisa indicam que as águas de chuva e de poço freático tratadas com SODIS atingiram os padrões microbiológicos recomendados pela Organização Mundial da Saúde, o que não ocorreu com as amostras de água do reservatório superficial estudado. / SODIS (Solar Water Disinfection) is a simple techhnology for point-of-use drinking water treatment, and can be used during emergencies or in sites without running water. The joint action of high temperature and ultraviolet radiation causes the die-off of microrganisms. This study evaluated the removal of total coliforms and Escherichia coli using SODIS to disinfect water from rain (collected in roofs), from well and from surface water (reservoir) under the climate conditions of Porto Alegre, RS. Essays were also conducted to see if bacteria regrowth occurred after 24 and 48 h after the end of the SODIS test. In addition, bacterial decay coefficients were calculated using the Chick´s Law as model. SODIS essays were performed in batch reactors using 1.5 L transparent PET bottles exposed to the sunlight for 6 h.The same number of bottles were kept in the shadow, as a control. Air and water temperatures and ultraviolet radiation were monitored hourly. E. coli mean removals in samples from the three sources of water varied between 98,8% to greater than 99,99%. The mean reductions for total coliforms varied between 90.0% to 99.99%. Microorganism regrowth was not observed after 24 and 48 h. Decay coefficients for coliforms and E. coli were, respectively, 0.2979 h-1 e 0.9397 h-1, confirming the observation that E. coli is more sensitive than total coliforms to SODIS. Coefficients of determination for Chick´s Law equation were 0.938 (E. coli) and 0.877 (total coliform). The results from this research indicate that water from rain and well , but not reservoir, achieved the World´s Health Organization drinking water guidelines for drinking water with low risk of disease acquisition.
205

Avaliação de sistema de tratamento da água cinza e reúso da água no semiárido brasileiro

Feitosa, Alex Pinheiro 22 November 2016 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-05-16T22:25:01Z No. of bitstreams: 1 AlexPF_TESE.pdf: 2520880 bytes, checksum: aa5cf94e61b1275420710fe08e340aba (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-05-17T11:03:43Z (GMT) No. of bitstreams: 1 AlexPF_TESE.pdf: 2520880 bytes, checksum: aa5cf94e61b1275420710fe08e340aba (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-05-17T11:04:01Z (GMT) No. of bitstreams: 1 AlexPF_TESE.pdf: 2520880 bytes, checksum: aa5cf94e61b1275420710fe08e340aba (MD5) / Made available in DSpace on 2017-05-17T11:04:19Z (GMT). No. of bitstreams: 1 AlexPF_TESE.pdf: 2520880 bytes, checksum: aa5cf94e61b1275420710fe08e340aba (MD5) Previous issue date: 2016-11-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The inadequacy of sewage systems in Brazil has compromised the health of rural and urban populations and the environmental quality. Considering this scenario and together with the scarcity of good quality water, it has been stimulated the agricultural use of wastewater for production of vegetables as well as other agricultural crops. This work aimed at the evaluation of a treatment plant for gray water using ultraviolet (UV) radiation in the disinfection of effluents and the hydraulic performance of drippers using gray water. A plant for the treatment of gray water was constructed in the Monte Alegre I Settlement Project, municipality of Upanema, midwestern region of the state of Rio Grande do Norte, and a reactor was equipped with ultraviolet lamps and installed in the Zoobotanical Park (PZO) of the Federal Rural University of the SemiArid Region (UFERSA), in Mossoró, state of Rio Grande do Norte. The treatment plant consisted of a passage box, a septic tank, an organic filter and a storage reservoir, and the artificial ultraviolet reactor was built in brick masonry in the dimensions of 1.08 m width, 1.18 m length and 0.40 m depth, containing two germicidal lamps (30 W, 254 nm). The treatments used to analyze the effect of UV radiation consisted of three slides (0.10 m, 0.20 m and 0.30 m) and five exposure times of (0, 1, 2, 3 and 4 h). For evaluation of the treatment system, we collected samples of the effluents at different sites of the system and analyzed them for physical, chemical and microbiological characteristics; the effect of UV radiation was investigated through the decay of the microorganisms. Data were evaluated using parametric (univariate) and non-parametric (multivariate) statistics, according to the complexity of the data set. During the experimental period, the performance of the irrigation system was analyzed by means of the mean flow (Q), flow variation coefficient (CVQ), distribution uniformity coefficient (CUD) and statistical uniformity coefficient (Us). The treatment plant was efficient in removing most of the characteristics analyzed, since they were within the standards set forth by the current legislation. The evaluation of the irrigation system evidenced the development of a biofilm in the dripper as well as the presence of microorganisms. The radiation effect was satisfactory however the radiation dose has to be calculated to improve the efficiency of the treatment. The set a passage box, septic tank, organic filter and ultraviolet radiation reactor provide a degree of gray water treatment that allows the irrigation of vegetables through a drip irrigation system, but drip clogging control measures are required to ensure maximum performance / A inadequação dos sistemas de esgotamento sanitário no Brasil tem comprometido a saúde das populações rurais e urbanas e a qualidade do ambiente. Diante desse cenário, e juntamente com a escassez da água de boa qualidade, tem-se estimulado o aproveitamento agrícola das águas residuárias na produção de hortaliças, bem como de outros cultivos agrícolas. Este trabalho objetivou a avaliação de uma estação de tratamento para água cinza empregando radiação ultravioleta (UV) na desinfecção do efluente e o desempenho hidráulico de gotejadores com água cinza. Sendo construída uma estação para tratamento de água cinza localizada no Projeto de Assentamento (P.A.) Monte Alegre I no município de Upanema-RN, microrregião médio Oeste potiguar e um reator com lâmpadas ultravioletas foi instalado no Parque Zoobotânico (PZO) da Universidade Federal Rural do Semi-Árido (UFERSA) Campus Mossoró-RN. A estação de tratamento foi composta por uma caixa de passagem, tanque séptico, um filtro orgânico e um reservatório de armazenamento, já o reator ultravioleta artificial foi construído em alvenaria de tijolos nas dimensões de 1,08 m de largura por 1,18 m de comprimento e 0,40 m de profundidade, onde e foram instaladas duas lâmpadas germicidas UV de 30 W e 254 nm cada. Os tratamentos utilizados na análise do efeito da radiação UV consistiram de três lâminas (0,10 m, 0,20 m e 0,30 m) e cinco tempos de exposição de (0, 1, 2, 3 e 4 h). Para fins de avaliação do sistema de tratamento adotou-se por meio de coleta e análise físico-químicas e microbiológicas dos efluentes coletados em distintos pontos do sistema e o efeito da radiação UV por meio do decaimento do nível populacional de microrganismos. Os dados foram avaliados mediante uso da estatística paramétrica (univariada) e não paramétrica (multivariada), de acordo com a complexidade do grupo de dados. Durante o período experimental foi analisado o desempenho do sistema de irrigação por meio dos indicadores vazão média (Q), coeficiente de variação de vazão (CVQ), coeficiente de uniformidade de distribuição (CUD) e coeficiente de uniformidade estatística (Us). A estação de tratamento foi eficiente na remoção da maioria das características analisadas, visto que estavam dentro dos padrões da legislação vigente. Na avaliação do sistema de irrigação foi notado a formação de biofilme no gotejador e presença de microrganismos. O efeito da radiação foi satisfatório, entretanto evidenciou-se a necessidade do cálculo da dose de radiação, com vistas a melhorar a eficiência do tratamento. O conjunto caixa de passagem, tanque séptico, filtro orgânico e reator com radiação ultravioleta permite obter um nível de tratamento da água cinza que possibilite a irrigação de hortaliças, via sistema de irrigação por gotejamento, no entanto medidas de controle da obstrução dos gotejadores são necessárias para garantir o máximo desempenho do equipamento / 2017-05-16
206

TOXICITY OF SEDIMENTS CONTAINING COAL-TAR PAVEMENT SEALANTS TO NOTOPHTHALMUS VIRIDESCENS AND AMBYSTOMA MACULATUM, SURROGATE SPECIES FOR EURYCEA SOSORUM

Bommarito, Thomas 01 January 2009 (has links)
The Barton Springs salamander (Eurycea sosorum) is a federally endangered species that is endemic to Barton Springs in Austin, Texas. Development within the Barton Springs watershed threatens the continued existence of E. sosorum. A factor that may be contributing to its decline is contamination from polycyclic aromatic hydrocarbons (PAHs). Nearby asphalt parking lots paved with coal-tar and asphalt sealants can be sources of PAHs. Unaltered parent compounds of PAHs can have toxic effects, but oxidation and ultraviolet radiation can create degradation products 100 times more toxic than the parent compounds. The objective of this project was to determine if PAHs are potentially harmful to E. sosorum using two surrogate species. Adult eastern newts (Notophthalmus viridescens) and larval spotted salamanders (Ambystoma maculatum) were exposed to sediments with nominal concentrations of total PAHs that ranged from 0 to 1500 mg/kg under UV (290 - 400 nm) and visible (400 - 700 nm) light to determine concentration/response relationships. No statistically significant mortality occurred under any treatment. Exposure to both coal-tar sealant and UV light resulted in sublethal effects such as decreased righting ability and swimming speed. Difficulty in performing such movements would make it difficult to catch prey and increase susceptibility to predation. Exposure to UV light also resulted in elevated numbers of micronucleated erythrocytes and white blood cells. This study shows that simultaneous exposure to PAHs and UV light result in sublethal effects that could make the population of E. sosorum vulnerable to further decline.
207

Desinfecção solar da água: avaliação da técnica "SODIS" aplicada a águas de chuva, poço e manancial superficial, nas condições climáticas de verão na região de Porto Alegre, RS

Carvajal, Ruth Angelic Reyes January 2015 (has links)
SODIS (Solar Water Disinfection) é uma tecnologia simples para tratamento de água no pontode- uso, sendo uma alternativa importante para disponibilizar água em situações de emergência ou onde não há acesso à água potável. A ação concomitante entre a temperatura e a radiação ultra violeta do sol provoca a morte dos microorganismos presentes na água. Este estudo avaliou a eficiência de inativação de coliformes totais e Escherichia coli pela técnica SODIS para as águas de chuva (coletada em telhado), de poço freático e de manancial superficial (reservatório), sob as condições climáticas de verão de Porto Alegre, RS. Foram ainda, realizados ensaios para verificar se ocorreu o recrescimento dos microorganismos após 24 e 48 horas do término da exposição ao sol. Também foram determinadas as constantes de decaimento das bactérias utilizando a Lei de Chick para representar o declínio dos microorganismos. Os ensaios de SODIS foram realizados em batelada, utilizando garrafas PET transparentes de 1,5 L, expostas ao sol por um período de 6 h. O mesmo número de garrafas era mantido à sombra pelo mesmo período, como controle. As temperaturas do ar e da água e a radiação ultravioleta foram monitoradas ao longo dos ensaios. Os valores médios de remoção de concentrações de E. coli no SODIS nas amostras das águas analisadas variaram entre 98,8 a maior do que 99,99%; para coliformes totais as reduções médias nas amostras variaram entre 90,00 – 99,99%. Não houve recrescimento de microorganismos após 24 e 48 horas seguindo-se ao término da exposição solar. As constantes de decaimento para coliformes totais e E. coli foram, respectivamente, 0,2979 h-1 e 0,9397 h-1, confirmando as observações de que E. coli é mais sensível a desinfecção. Os coeficientes de determinação para a equação da Lei de Chick foram de 0,938 (E. coli) e 0,877 (coliformes totais). Os resultados da pesquisa indicam que as águas de chuva e de poço freático tratadas com SODIS atingiram os padrões microbiológicos recomendados pela Organização Mundial da Saúde, o que não ocorreu com as amostras de água do reservatório superficial estudado. / SODIS (Solar Water Disinfection) is a simple techhnology for point-of-use drinking water treatment, and can be used during emergencies or in sites without running water. The joint action of high temperature and ultraviolet radiation causes the die-off of microrganisms. This study evaluated the removal of total coliforms and Escherichia coli using SODIS to disinfect water from rain (collected in roofs), from well and from surface water (reservoir) under the climate conditions of Porto Alegre, RS. Essays were also conducted to see if bacteria regrowth occurred after 24 and 48 h after the end of the SODIS test. In addition, bacterial decay coefficients were calculated using the Chick´s Law as model. SODIS essays were performed in batch reactors using 1.5 L transparent PET bottles exposed to the sunlight for 6 h.The same number of bottles were kept in the shadow, as a control. Air and water temperatures and ultraviolet radiation were monitored hourly. E. coli mean removals in samples from the three sources of water varied between 98,8% to greater than 99,99%. The mean reductions for total coliforms varied between 90.0% to 99.99%. Microorganism regrowth was not observed after 24 and 48 h. Decay coefficients for coliforms and E. coli were, respectively, 0.2979 h-1 e 0.9397 h-1, confirming the observation that E. coli is more sensitive than total coliforms to SODIS. Coefficients of determination for Chick´s Law equation were 0.938 (E. coli) and 0.877 (total coliform). The results from this research indicate that water from rain and well , but not reservoir, achieved the World´s Health Organization drinking water guidelines for drinking water with low risk of disease acquisition.
208

Interaction of UVA (320-380 nm) radiation with human skin cells

Watkin, Richard David January 2000 (has links)
No description available.
209

Ação da luz ultravioleta e da riboflavina na inativação da Leishmania infantum chagasi em sangue canino conservado em bolsas para transfusão

Sacco, Soraya Regina [UNESP] 13 November 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-11-13Bitstream added on 2014-06-13T18:41:57Z : No. of bitstreams: 1 000740733.pdf: 2604673 bytes, checksum: 0a046e576f0e604892305395adc3f265 (MD5) / É de extrema importância para a medicina transfusional que haja segurança no procedimento de transferência de hemocomponentes, minimizando a ocorrência da transmissão de patógenos. O presente trabalho visa caracterizar as possíveis alterações hematológicas e bioquímicas, ocorridas durante o período de 21 dias de armazenamento das amostras de sangue canino colhidas em bolsas plásticas para transfusão, investigando ainda a eficiência do tratamento destas bolsas com luz ultravioleta e riboflavina na inativação de Leishmania infantum chagasi. Para isto, realizou-se hemograma, teste de fragilidade osmótica, determinação da concentração sérica de sódio e potássio, testes sorológicos e moleculares, comparando-se um grupo de bolsas de sangue colhidas de cães parasitados com L. infantum chagasi, com um grupo de bolsas de sangue obtidas de cães hígidos. Após as análises laboratoriais in vitro, o sangue canino parasitado foi submetido ao tratamento com riboflavina e luz UV por 30 e 45 minutos e inoculado em hamsters. O sangue de cães com leishmaniose armazenado em bolsas para transfusão demonstrou: anemia, hiperproteinemia, trombocitopenia, hipercalemia, diminuição do pH, 100% das RIFIs positivas (título 1:640) e PCR convencional positiva em 20% dos animais, demonstrando a importância do hemograma, exames bioquímicos e dos testes laboratoriais de diagnóstico da leishmaniose na seleção dos doadores. O sangue parasitado não perdeu a capacidade de produzir a infecção após o período de armazenamento. Os hamsters inoculados com sangue tratado com riboflavina e luz UV por 30 e 45 minutos apresentaram PCR positiva, apesar de não apresentarem sinais e sintomas clínicos da enfermidade. Na qPCR pode-se identificar que a associação da riboflavina com a luz UV reduziu o número de leishmanias, diminuindo a carga parasitária, porém não eliminou completamente os parasitas / Providing safety during the transfusion of blood products is of major importance in transfusion medicine; this requires a proper blood to minimize the occurrence of pathogen transmission. The present work aims to characterize the possible hematological and biochemical changes that occurr during the 21 days of storage of canine blood samples collected in plastic bags for transfusion and to investigate the treatment efficiency of these bags with ultraviolet light and riboflavin in inactivating Leishmania infantum chagasi. Total blood count, osmotic fragility test, determination of serum sodium and potassium, serological and molecular tests were performed comparing a group of bags of blood taken from dogs infected with L. infantum chagasi, with a group of bags of blood obtained from healthy dogs. After this, the parasitized canine blood was subjected to the treatment with riboflavin and UV light for 30 to 45 minutes and inoculated in hamsters. The blood of dogs with leishmaniasis stored in bags for transfusion showed anemia, hyperproteinemia, thrombocytopenia, hyperkalemia, decreased pH, 100 % of RIFIs positive (1:640 title) and conventional PCR positive in 20% of animals, demonstrating the importance of blood count, biochemical tests and laboratory tests for the diagnosis of leishmaniasis in blood donor selection. The parasitized blood has not lost the ability to produce infection after the storage period. Hamsters inoculated with blood treated with riboflavin and UV light for 30 and 45 minutes were PCR positive, although not presenting clinical signs and symptoms of the disease. The qPCR can identify that the combination of riboflavin with UV light reduced the number of Leishmania, reducing the parasitic load, but did not completely eliminate parasites
210

The risks and benefits of cutaneous sunlight exposure

Felton, Sarah Jane January 2016 (has links)
Background: Recommendations to restrict summer sunlight exposure to prevent skin cancer apparently conflict with requirements to protect bone health through adequate 25-hydroxyvitamin D (25[OH]D) levels, as provided by cutaneous ultraviolet (UV)B exposure. Furthermore, sunlight exposure promotes a feeling of euphoria that is felt to drive further sun-seeking behaviour. Objectives: My principal objective was to examine health risk (DNA damage) and health benefits (25[OH]D gain, and potential cutaneous photoprotection) following low-level summer sunlight exposures in people of light (phototype II) and darker (phototype V) skin. A further objective was to evaluate serum endocannabinoid levels, potential drivers of mood elevation, following these exposures, and to assess for evidence of tanning addiction in a cross-section of psoriasis patients who had received similar low dose UV exposures, as medical phototherapy. Methods: During wintertime, 10 white Caucasians and 6 South Asians aged 18 to 60 years, from Greater Manchester, UK, received a simulated summer's sunlight exposures, specifically 1.3 standard erythemal dose, thrice weekly for 6 weeks, whilst casually dressed. Serum and urine samples and skin colour measurements were taken at baseline, Monday, Wednesday and Friday of week 1 and then weekly, and buttock skin that had received differential UVR exposures was biopsied for immunohistochemical analysis. Phototype II individuals, who are at higher risk of sunburn, were subsequently challenged with 2X minimal erythema dose (MED) UVB on small areas of simulated summer-exposed and photoprotected skin. Separately, a link to an online tanning questionnaire survey was sent to all members of the National Psoriasis Foundation (USA) during my USA field trip. Results: The simulated summer resulted in 50% gain in 25(OH)D for both phototype groups, but significantly more cutaneous DNA damage (cyclobutane pyrimidine dimers, CPD) in phototype II than V (p<0.0001). There was no accumulation of cutaneous CPD after 6 weeks compared with a single UVR exposure in either group, while phototype V individuals had repaired a greater proportion of their CPD 24 hours after final UVR exposure (p<0.0001). Urinary oxidative DNA damage was higher in phototype II throughout the simulated summer (p=0.002) and unaffected by UVR. All individuals had significant skin darkening, and in phototype II, stratum corneum thickness increased significantly (p<0.05). This tanning response provided significant photoprotection against a pro-inflammatory UVB (2X MED) challenge, as shown by reduced erythema and neutrophil influx in skin exposed to the simulated summer than in photoprotected skin (p<0.05 for both). Serum endocannabinoid (2-arachidonoyl glycerol) levels increased significantly during the simulated summer in both phototype groups (p<0.01), peaking at week 2-3. The cross-sectional study of 1,832 psoriasis patients revealed 34% had used sunbeds; 11% of current users fulfilled diagnostic criteria for addictive-like tanning behaviour: female sex, younger age, younger age at psoriasis diagnosis, severe disease and prior phototherapy were significant risk factors for addiction. Discussion: These findings should assist public health guidance on safe sunlight exposure and highlight the need for distinct guidance targeted to different phototype groups. Furthermore, individuals with psoriasis, in particular those who previously received regular UVR exposure, are at high risk of tanning addiction that may be driven by the endocannabinoid system.

Page generated in 0.0357 seconds