332 research outputs found

    Evaluation of iris color stability in ocular prosthesis

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    Accurate iris reproduction in the fabrication of ocular prosthesis in order to match the remaining eye is a key factor to mask the loss and achieve an esthetic outcome for anophthalmic patients. This study evaluated the stability of acrylic paints used for replicating iris color in ocular prostheses by the analysis of two factors: the temperature of the acrylic resin polymerization cycle during prosthesis fabrication and the incidence of sun light, which is the main photodegrading agent undermining the longevity of ocular prostheses. An accelerated aging assay was used for both analyses. Specimens simulating the prosthetic iris in the colors blue, yellow, black, brown and green were fabricated, and were submitted to a colorimetric reading before and after undergoing the thermal conditions of acrylic resin polymerization. Next, the specimens were submitted to an artificial accelerated aging assay with ultraviolet radiation A and weekly colorimetric readings during a 3-week period. The color change (??*) values for the four specimens painted with the same color paint were averaged and the resulting values were considered for statistical analysis. Levine's test and Student's t-test were used to analyze the influence of the temperature of the polymerization cycle during prosthesis fabrication on the color stability of each acrylic resin paint. Friedman's test for three dependent samples was used for analysis of color photodegradation as function of time. Significance level was set at 0.05 for all analyses. It was observed that, after the action of the temperature of the polymerization cycle, alteration above clinically acceptable level of ??*> 3.3 was observed only for the yellow color. After the accelerated aging assay, there were statistically significant differences (p<0.05) as a function of time in the green, brown, black and blue colors. Changes were clinically acceptable for the brown and black colors; slightly above the clinically acceptable limit for the green color; and significantly high and impracticable from a clinical standpoint for the blue color. There was no statistically significant differences (p>0.05) for the yellow color, which presented color change only a little above the clinically acceptable limit. In conclusion: 1. Only the yellow color presented alterations above the clinically acceptable levels after the polymerization cycle; 2. After accelerated aging, there was no changes in the yellow color above the clinically acceptable levels; 3. For the green color, degradation was significant and slightly above the clinically acceptable levels; 4. The black, brown and blue colors presented significant alterations as function of time; the alterations of the brown and black colors were within acceptable clinical levels, while the blue color presented a more accentuated degradation over time.A fiel reprodução da íris do olho remanescente através da pintura na confecção da prótese ocular é fator fundamental no resultado estético e na dissimulação da perda para os pacientes afetados. Decidiu-se, então, avaliar a estabilidade das cores da tinta acrílica utilizada na pintura da mesma, sob a ação de dois fatores: a temperatura do ciclo de polimerização da resina acrílica e a incidência da luz solar, principal agente de fotodegradação que compromete a longevidade das próteses oculares, através de teste de envelhecimento acelerado. Foram assim, confeccionados corpos de prova simulando a íris protética, nas cores azul, amarelo, preto, marrom e verde, submetidos a uma leitura colorimétrica inicial e outra após as condições térmicas do ciclo de polimerização. Posteriormente os mesmos foram testados durante três semanas através de ensaio de envelhecimento acelerado artificialmente com radiação ultravioleta A e leituras colorimétricas semanais. Através dos valores da alteração de cor (DE*) foi obtida uma média para as quatro amostras pintadas com a mesma cor e os valores resultantes foram submetidos à análise estatística. Os testes de Levine e t de Student foram utilizados para analisar a influência da temperatura do processo de polimerização na estabilidade de cada cor utilizada na fabricação das próteses. O teste de Friedman para três amostras dependentes foi usado para analisar a degradação de cor em função do tempo. O nível de significância foi de 0,05 para todas as análises. Após a ação da temperatura do ciclo de polimerização, observou-se que somente na cor amarelo ocorreu alteração acima do nível clinicamente aceitável (p<0,05). Após o ensaio de envelhecimento, ocorreram diferenças estatisticamente significantes em função do tempo nas cores verde, marrom, preto e azul. A variação de cor ocorreu em níveis considerados clinicamente aceitáveis para as cores marrom e preto; levemente acima dos níveis clinicamente aceitáveis para a cor verde; e em níveis elevados, inviáveis clinicamente para a cor azul. Na cor amarelo não houve diferenças estatisticamente significantes (p>0,05), com alteração apenas um pouco acima do limite considerado clinicamente aceitável. Em conslusão: 1. Somente a cor amarelo apresentou alteração acima dos níveis clinicamente aceitáveis após o ciclo de polimerização; 2. Após o envelhecimento artificial, não houve alterações na cor amarelo acima dos níveis clinicamente aceitáveis; 3. Para a cor verde, a degradação foi significante e um pouco acima dos níveis clinicamente aceitáveis; 4. As cores preto, marrom e azul apresentaram diferenças significantes em função do tempo; as alterações das cores marrom e preto foram em níveis clinicamente aceitáveis, enquanto a cor azul apresentou um elevado índice de degradação de cor em todo tempo

    Implementation of HPV tests in Latin America: what we learned; what should we have learned, and what can we do better?

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    Cervical cancer is caused by HPV. Although it is the fourth most common type of cancer diagnosed and the fourth cause of cancer death, cervical cancer is nearly completely preventable because of the vaccination and screening available. The present review aims to map the initiatives conducted to implement or evaluate the implementation of HPV testing in Latin American countries. We performed the review by searching on PubMed in the English language and on grey literature, as most of the information about the guidelines used was found in governmental websites in the Spanish language. We only found information in eight countries concerning HPV testing as primary screening. Only Mexico has established HPV-based screening in all territories. There are three countries with regional implementation. Two countries with pilot studies indicated results that supported implementation. Finally, there are another two countries with a national recommendation. We have learned that HPV implementation is feasible and a very promising tool for reducing cervical cancer morbidity and mortality. The costs associated with saving lives and reducing suffering due to morbidity of a preventable disease must be pragmatically evaluated by the Latin America governments, and improving outcomes must be a mandatory priority for those that are responsible for addressing an organized system of cervical cancer screening.This research was funded by the São Paulo Research Foundation (FAPESP), grant number 2020/00445-6 and 2018/22017-6

    Cohort study protocol of the Brazilian collaborative research network on COVID-19 : strengthening WHO global data

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    Introduction: with the COVID-19 pandemic, hospitals in low-income countries were faced with a triple challenge. First, a large number of patients required hospitalisation because of the infection’s more severe symptoms. Second, there was a lack of systematic and broad testing policies for early identification of cases. Third, there were weaknesses in the integration of information systems, which led to the need to search for available information from the hospital information systems. Accordingly, it is also important to state that relevant aspects of COVID-19’s natural history had not yet been fully clarified. The aim of this research protocol is to present the strategies of a Brazilian network of hospitals to perform systematised data collection on COVID-19 through the WHO platform. Methods and analysis: this is a multicentre project among Brazilian hospitals to provide data on COVID-19 through the WHO global platform, which integrates patient care information from different countries. From October 2020 to March 2021, a committee worked on defining a flowchart for this platform, specifying the variables of interest, data extraction standardisation and analysis. Ethics and dissemination: this protocol was approved by the Research Ethics Committee (CEP) of the Research Coordinating Center of Brazil (CEP of the Hospital Nossa Senhora da Conceicao), on 29 January 2021, under approval No. 4.515.519 and by the National Research Ethics Commission (CONEP), on 5 February 2021, under approval No. 4.526.456. The project results will be explained in WHO reports and published in international peer-reviewed journals, and summaries will be provided to the funders of the study

    Management of early-stage vulvar cancer

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    Vulvar cancer is a rare gynecological malignancy since it represents 4% of all cancers of the female genital tract. The most common histological type is squamous cell carcinoma (90%). This type can be classified into two clinicopathological subtypes according to the etiology. The first subtype is associated with persistent human papillomavirus infection and is usually diagnosed in younger women. The second subtype is associated with lichen sclerosus condition, and in most cases is diagnosed in postmenopausal women. Currently, an increase in first subtype cases has been observed, which raised the concern about associated mortality and treatment morbidity among young women. Vulvar cancer treatment depends on histopathology grade and staging, but surgery with or without radiotherapy as adjuvant treatment is considered the gold standard. In recent decades, sentinel lymph node biopsy has been incorporated as part of the treatment. Therefore, we sought to review and discuss the advances documented in the literature about vulvar cancer focusing on the treatment of early-stage disease. Relevant articles, such as the GROINS-V studies and the GOG protocols, are presented in this review. Additionally, we discuss key points such as the evolution of treatment from invasive surgery with high morbidity, to more conservative approaches without compromising oncologic safety; the role of sentinel lymph node mapping in the initial staging, since it reduces the complications caused by inguinofemoral lymphadenectomy; the recurrences rates, since local recurrence is common and curable, however, groin-associated, or distant recurrences have a poor prognosis; and, finally, the long-term follow-up that is essential for all patients.This study was partially supported by Public Ministry of Labor Campinas (Research, Prevention and Education of Occupational Cancer, Brazil) and the Barretos Cancer Hospital

    Toxicidade ocular induzida pelo tamoxifeno: uma revisão de literatura : Tamoxifen induced ocular toxicity: a review of literature

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    O tamoxifeno é um agente antiestrogênico que atua diretamente nas mamas, se ligando com receptores dos estrógenos e impedindo assim a sua ligação com o hormônio em questão, e é usado amplamente no tratamento do câncer de mama estrogênio positivo. Apesar de sua eficácia e baixos índices de efeitos colaterais, essa droga possui a capacidade de induzir toxicidade ocular em pacientes que fazem o seu uso diário, mesmo que em baixas doses. O objetivo desse estudo foi analisar quais são os principais efeitos colaterais oculares induzidos pelo tamoxifeno, bem como sua incidência e manejo. Para a confecção desse estudo, foram realizadas buscas em bases de dados e selecionados inicialmente 29 artigos, dentre os quais 17 se enquadraram nos critérios pré-estabelecidos. Como justificativa para a realização da pesquisa, destaca-se a escassez de estudos acerca desse tema na literatura mundial – sendo este estudo um dos poucos realizados por pesquisadores brasileiros – e a relevância clínica do problema em questão.&nbsp;&nbsp; O uso do tamoxifeno está relacionado diretamente com a toxicidade ocular, sendo a principal manifestação a retinopatia, seguida por alterações na córnea e neurite óptica. Apesar de rara, a potencial toxicidade ocular do tamoxifeno pode levar a eventos graves como diminuição irreversível da acuidade visual e até perda da visão

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Patologias atuais: a compulsão e a sociedade dos excessos: Current pathologies: compulsion and the society of excesses

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    O artigo em tela tem por objetivo analisar os aspectos biopsicossociais da conduta compulsiva de consumo. Propõe-se a apresentar os elementos psicológicos contidos nesse comportamento, além de verificar quais são os resultados decorrentes dessa compulsão. O consumo compulsivo, também chamado de oniomania, é um transtorno causado pela ansiedade despertada pela necessidade de comprar e saciada, somente, quando é materializada a aquisição daquilo que se deseja comprar. O estudo em questão pode ser classificado como sendo de cunho bibliográfico, a partir da análise de documentos publicados em forma de artigos científicos e livros em formato digital

    Mapping density, diversity and species-richness of the Amazon tree flora

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    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution
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