23 research outputs found

    Fluorescent patterning of paper through laser engraving

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    While thermal treatment of paper can lead to the formation of aromatic structures via hydrothermal treatment (low temperature) or pyrolysis (high temperature), neither of these approaches allow patterning the substrates. Somewhere in between these two extremes, a handful of research groups have used CO2 lasers to pattern paper and induce carbonization. However, none of the previously reported papers have focused on the possibility to form fluorescent derivatives via laser-thermal engraving. Exploring this possibility, this article describes the possibility of using a CO2 laser engraver to selectively treat paper, resulting in the formation of fluorescent compounds, similar to those present on the surface of carbon dots. To determine the most relevant variables controlling this process, 3 MM chromatography paper was treated using a standard 30 W CO2 laser engraver. Under selected experimental conditions, a blue fluorescent pattern was observed when the substrate was irradiated with UV light (365 nm). The effect of various experimental conditions (engraving speed, engraving power, and number of engraving steps) was investigated to maximize the fluorescence intensity. Through a comprehensive characterization effort, it was determined that 5-(hydroxymethyl)furfural and a handful of related compounds were formed (varying in amount) under all selected experimental conditions. To illustrate the potential advantages of this strategy, that could complement those applications traditionally developed from carbon dots (sensors, currency marking, etc.), a redox-based optical sensor for sodium hypochlorite was developed.Fil: Clark, Kaylee M.. Clemson University; Estados UnidosFil: Skrajewski, Lauren. Clemson University; Estados UnidosFil: Benavidez, Tomás Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Clemson University; Estados UnidosFil: Mendes, Letícia F.. Universidade de Sao Paulo; BrasilFil: Bastos, Erick L.. Universidade de Sao Paulo; BrasilFil: Dörr, Felipe A.. Universidade de Sao Paulo; BrasilFil: Sachdeva, Rakesh. Clemson University; Estados UnidosFil: Ogale, Amod A.. Clemson University; Estados UnidosFil: Paixão, Thiago R. L. C.. Universidade de Sao Paulo; BrasilFil: Garcia, Carlos D.. Clemson University; Estados Unido

    Baixa estatura em crianças nascidas com muito baixo peso entre as idades de 4 a 8 anos

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    Introdução: O crescimento em recém-nascidos de muito baixo peso ao nascer tem sido associado com anormalidades futuras no desenvolvimento neurológico e doenças cardiovasculares e metabólicas na vida adulta. Objetivo: Avaliar o crescimento de crianças com idades entre 4 e 8 anos acompanhados em ambulatório de seguimento e que tinham muito baixo peso ao nascer. Métodos: Foram avaliadas 87 crianças nascidas com muito baixo peso (33 pequenas e 54 adequadas para a idade gestacional). Foi calculado o índice de massa corporal, assim como os escores-Z de peso para idade e gênero; a idade óssea foi determinada através da radiografia do punho esquerdo. O ponto de corte usado para calcular a prevalência de baixa estatura para idade e gênero foi – 2 desvios padrão da média na curva de referência do National Center for Health Statistics. Resultados: A prevalência de baixa estatura foi 4,6% (N 4/87, 95% IC 3,6–5,4). Índice de massa corporal baixo foi encontrado em 23% das crianças (20/87). Idade óssea um ano menor em relação à idade cronológica foi encontrada em 43,7 % das crianças (38/87). Conclusão: Este estudo mostrou que algumas crianças nascidas prematuras e de muito baixo peso podem manter baixa estatura e baixo índice de massa corporal até a idade pré-escolar e escolar, indicando que o acompanhamento após a alta da unidade deve ser mantido durante a infância.Palavras-chaves: Crescimento. Prematuro. Muito Baixo Peso.Abstract Introduction: Growth in newborns of very low birth weight has been associated with future abnormalities in the neurological development as well as in cardiovascular and metabolic diseases in the adulthood. Objective: To evaluate the growth of children with four to eight years of age that were born with very low birth weight. Methods: 87 children with very low birth weight were studied (33 small babies and 54 with appropriate size for their gestational age). The body mass index was calculated as well as the Z-scores for weight to age and gender. Bone age was determined through the X-ray of the left wrist. The cutoff point used for calculating the prevalence of short stature to age and sex was a standard deviation of two below the mean from the National Center of Health Statistics growth reference chart. Results: The prevalence of short stature was 4.6% (N 4/87, 95% CI 3.6–5.4). Low body mass index was found in 23% of the children (20/87). 43.7 % of the children (38/87) had a bone age one year below the chronological age. Conclusion: This study showed that some children who are born prematurely may have short stature and low body mass index until preschool and school ages. This shows that the follow up of these children after leaving hospital should be done during childhood.Keywords: Growth. Premature. Very Low Birth Weigh

    Genomic history of coastal societies from eastern South America

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    Sambaqui (shellmound) societies are among the most intriguing archaeological phenomena in pre-colonial South America, extending from approximately 8,000 to 1,000 years before present (yr bp) across 3,000 km on the Atlantic coast. However, little is known about their connection to early Holocene hunter-gatherers, how this may have contributed to different historical pathways and the processes through which late Holocene ceramists came to rule the coast shortly before European contact. To contribute to our understanding of the population history of indigenous societies on the eastern coast of South America, we produced genome-wide data from 34 ancient individuals as early as 10,000 yr bp from four different regions in Brazil. Early Holocene hunter-gatherers were found to lack shared genetic drift among themselves and with later populations from eastern South America, suggesting that they derived from a common radiation and did not contribute substantially to later coastal groups. Our analyses show genetic heterogeneity among contemporaneous Sambaqui groups from the southeastern and southern Brazilian coast, contrary to the similarity expressed in the archaeological record. The complex history of intercultural contact between inland horticulturists and coastal populations becomes genetically evident during the final horizon of Sambaqui societies, from around 2,200 yr bp, corroborating evidence of cultural change

    Perspectivas epidemiológicas, clínicas e terapêuticas do transtorno bipolar em comorbidade com o uso de drogas: revisão de sistemática: Epidemiological, clinical and therapeutic perspectives of bipolar disorder in comorbidity with drug use: a systematic review

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    Conhecida como transtorno maníaco-depressivo, atualmente possui um novo nome: Transtorno Afetivo Bipolar, visto que com o passar do tempo foi se percebendo que esse transtorno não se tratava de uma alteração psicótica, e mais de um prejuízo afetivo. O transtorno bipolar possui alguns tipos, não se caracterizando em apenas uma forma, sua manifestação varia conforme o indivíduo e suas tendências, disforia e/ou euforia porém independente da forma expressa o paciente bipolar pode ter sua vida social comprometida, se não tratada, visto a irregularidade no estado de humor; bem como pode fazer uso de substâncias psicoativas, o que prejudica a sua condição clínica. Objetivo central da pesquisa é de apresentar a correlação do transtorno bipolar com o uso de drogas, mediante uma revisão de literatura integrativa realizada entre os meses de março de 2022 a julho de 2022, através da busca de artigos científicos nos bancos de dados online PubMed, Scielo e Google Acadêmico, utilizando como critério de refinamento de pesquisa artigos de todas as línguas publicados entre os anos 2000 e 2022

    Uso de AAS em pacientes cardiopatas e ocorrência de Úlcera Perfurada quais as melhores soluções? uma revisão sistemática com metánalise

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    A administração do ácido acetilsalicílico (AAS) é uma das medidas indicadaspelos médicos em caso de suspeita de infarto agudo do miocárdio. De acordo com os especialistas, o medicamento serve para diminuir a agregação de plaquetas e inibir a formação de coágulos no interior das artérias. O objetivo deste estudo é verificar na literatura o uso do Ácido Acetilsalicílico (AAS) em pessoas cardiopatas e sua possível relação com o aparecimento de úlcera. Trata-se de uma revisão sistemática com base em publicações, dos último cinco anos, que essa temática, extraídas de bases de dados eletrônicas como Scielo, PubMed, Lilacs, BVS, Embase e Medline, em língua inglesa e portuguesa. Dos estudo que se aproximaram do objetivo da pesquisa, muitos não relataram a estreita relação entre o uso AAS e o surgimento de úlcera. Assim, espera-se que este estudo sirva de incentivo para que mais estudos sejam realizados sobre essa temática afim de estabelecer e conhecer se há alguma relação entre o fármaco e a doença

    Pervasive gaps in Amazonian ecological research

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    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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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost
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