84 research outputs found
Synthetic Oil Gels With Organoclays In The Formulation Of Magnetorheological Fluids
Magnetorheological fluids (MRF) are smart composite materials that, under an
external magnetic field, show a reversible solid-liquid transition in less than
10 ms. This study aimed to evaluate which organoclays would jellify a synthetic
oil for the formulation of MRF. Three dispersant additives for carbonyl iron
powder were evaluated. Fifteen different gelling additives from four clay
families, bentonites, hectorites, montmorillonites, and mixed mineral
thixotropes (MMT), were dispersed in oil only, keeping the same concentration,
without iron particles. The gels were then tested through amplitude and
frequency sweeps in oscillatory rheometry to evaluate their viscoelastic
behavior. All the MRFs were prepared using carbonyl iron powder HS in oil gels
with the same organoclay. All three dispersant additives showed a thixotropic
recovery above 100% in the three-interval test. Regarding the dispersibility
after one year, the MRF formulations with octan-1-amine and lecithin were
reproved, as they reached normal force peaks of 19 and 24 N, while the work was
28 and 415 mJ, respectively. The best MRF was formulated with octan-1-ol, and
resulted in a normal force of 0.33 N and 3.4 mJ at 35 mm of vane penetration.
Therefore, we conclude that the MRF with octan-1-ol and montmorillonite #6
showed a better balance between thixotropy, MR effect, and, above all, good
redispersibility
From Cow Manure to Bioactive Carbon Dots: A Light-up Probe for Bioimaging Investigations, Glucose Detection and Potential Immunotherapy Agent for Melanoma Skin Cancer
Bioactive carbon dots (C-dots) with ca. 4 nm were successfully produced with singular photophysical properties, low-toxicity and interesting immunological response. The optical properties of the C-dots were investigated and the “light-up” behaviour enabled them to be explored in glucose detection and bioimaging experiments (mitochondrial selective probe). C-dots were not selective to the tumour region and several fluorescent spots were visualized spread on animal bodies. The histology investigations showed that cancer-bearing mice treated with C-dots presented a large number of regions with necrosis and inflammatory infiltrates, which were not identified for cancer-bearing mice without the treatment. These results suggested that C-dots have the potential to be explored as an immune therapy agent for melanoma skin cancer
PREVENÇÃO E MANEJO DO RN ASFIXIADO: REVISÃO DE LITERATURA
To evaluate the profile of newborns with gestational age ≥ 35 weeks with perinatal anoxia in the Neonatal Intensive Care Unit (NICU) of a private maternity hospital in Aracaju, Sergipe. Methodology: This is an observational clinical study, descriptive and cross-sectional. A convenience sample was used, consisting of all newborns with a gestational age ≥ 35 weeks admitted to the NICU from January 1, 2019 to December 31, 2020. Neonates outside the gestational age of the study and incomplete medical records were excluded. An Apgar score less than 7 at the 5th minute was used to define neonatal anoxia (NA). The analysis used Pearson's Chi-Square, Fisher's exact, Shapiro-Wilk, Mann-Whitney and Kruskal-Wallis tests, in addition to descriptive data. A significance level of 5% was applied. Results: The final sample consisted of 127 children, mostly male (63.7%), with normal birth weight (75.2%) and adequate weight for gestational age (79.6%). The mean weight and mean gestational age were 2,982.7 grams (± 649.5) and 37.5 weeks (± 1.6), respectively. The groups with and without AN did not show significant epidemiological differences. A higher risk of anoxia was found in those born vaginally (p=0.001) and in those with acute perinatal events (p=0.003). Small size for gestational age was a risk factor for the outcome of death. Conclusion: Acute perinatal events and vaginal birth are risk factors for AN. Newborns who are small for gestational age have worse outcomes. Future studies discriminating the types of birth to analyze the association with AN may be useful.Avaliar o perfil dos neonatos com idade gestacional ≥ 35 semanas com anóxia perinatal na Unidade de Terapia Intensiva Neonatal (UTIN) de uma maternidade privada de Aracaju, Sergipe. Metodologia: Trata-se de um estudo clínico observacional, de caráter descritivo e transversal. Utilizou-se amostra de conveniência, composta por todos os recém-nascidos com idade gestacional ≥ 35 semanas internados na UTIN de 01 janeiro de 2019 até 31 de dezembro de 2020. Foram excluídos os neonatos fora da idade gestacional do estudo e prontuários incompletos. O escore de Apgar menor que 7 no 5º minuto foi utilizado para definir anóxia neonatal (AN). A análise utilizou os testes Qui-Quadrado de Pearson, exato de Fisher, Shapiro-Wilk, Mann-Whitney e Kruskal-Wallis, além de dados descritivos. Aplicou-se nível de significância de 5%. Resultados: A amostra final foi de 127 crianças, majoritariamente do sexo masculino (63,7%), com peso normal ao nascer (75,2%) e peso adequado para idade gestacional (79,6%). O peso médio e idade gestacional média foram 2.982,7 gramas (± 649,5) e 37,5 semanas (± 1,6), respectivamente. Os grupos com e sem AN não apresentaram diferenças epidemiológicas significativas. Foi encontrado maior risco de anoxia em nascidos por via vaginal (p=0,001) e naqueles com eventos perinatais agudos (p=0,003). Tamanho pequeno para idade gestacional foi fator de risco para o desfecho óbito. Conclusão: Eventos perinatais agudos e parto vaginal são fatores de risco para AN. Recém-nascidos pequenos para idade gestacional apresentam piores desfechos. Futuros estudos discriminando os tipos de parto para análise de associação com AN podem ser úteis
Erica: Prevalences Of Hypertension And Obesity In Brazilian Adolescents
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)To estimate the prevalence of arterial hypertension and obesity and the population attributable fraction of hypertension that is due to obesity in Brazilian adolescents. METHODS: Data from participants in the Brazilian Study of Cardiovascular Risks in Adolescents (ERICA), which was the first national school-based, cross-section study performed in Brazil were evaluated. The sample was divided into 32 geographical strata and clusters from 32 schools and classes, with regional and national representation. Obesity was classified using the body mass index according to age and sex. Arterial hypertension was defined when the average systolic or diastolic blood pressure was greater than or equal to the 95th percentile of the reference curve. Prevalences and 95% confidence intervals (95% CI) of arterial hypertension and obesity, both on a national basis and in the macro-regions of Brazil, were estimated by sex and age group, as were the fractions of hypertension attributable to obesity in the population. RESULTS: We evaluated 73,399 students, 55.4% female, with an average age of 14.7 years (SD = 1.6). The prevalence of hypertension was 9.6% (95% CI 9.0-10.3); with the lowest being in the North, 8.4% (95% CI 7.7-9.2) and Northeast regions, 8.4% (95% CI 7.6-9.2), and the highest being in the South, 12.5% (95% CI 11.0-14.2). The prevalence of obesity was 8.4% (95% CI 7.9-8.9), which was lower in the North region and higher in the South region. The prevalences of arterial hypertension and obesity were higher in males. Obese adolescents presented a higher prevalence of hypertension, 28.4% (95% CI 25.5-31.2), than overweight adolescents, 15.4% (95% CI 17.0-13.8), or eutrophic adolescents, 6.3% (95% CI 5.6-7.0). The fraction of hypertension attributable to obesity was 17.8%. CONCLUSIONS: ERICA was the first nationally representative Brazilian study providing prevalence estimates of hypertension in adolescents. Regional and sex differences were observed. The study indicates that the control of obesity would lower the prevalence of hypertension among Brazilian adolescents by 1/5.501Brazilian Department of Science and Technology at the Secretariat of Science and TechnologyStrategic Inputs of the Ministry of Health (Departamento de Ciencia e Tecnologia da Secretaria de Ciencia e Tecnologia e Insumos Estrategicos do Ministerio da Saude - Decit/SCTIE/MS)Health Fund Sector (Fundo Setorial de Saude - CT-health) at the Ministry of science, Technology and Innovation (Ministerio da Ciencia, Tecnologia e Inovacao - MCTI)FINEP [01090421]CNPq [2010/565037-2]hospital research incentive fund for Clinics in Porto Alegre (fundo de incentivo a Pesquisa do Hospital de Clinicas de Porto Alegre - HCPA) [405,009/FIPE-2012-7]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Erica: Prevalence Of Metabolic Syndrome In Brazilian Adolescents
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)To determine the prevalence of metabolic syndrome and its components in Brazilian adolescents. METHODS: We evaluated 37,504 adolescents who were participants in the Study of Cardiovascular Risks in Adolescents (ERICA), a cross-sectional, school-based, national study. The adolescents, aged from 12 to 17 years, lived in cities with populations greater than 100,000 inhabitants. The sample was stratified and clustered into schools and classes. The criteria set out by the International Diabetes Federation were used to define metabolic syndrome. Prevalences of metabolic syndrome were estimated according to sex, age group, school type and nutritional status. RESULTS: Of the 37,504 adolescents who were evaluated: 50.2% were female; 54.3% were aged from 15 to 17 years, and 73.3% were from public schools. The prevalence of metabolic syndrome was 2.6% (95% CI 2.3-2.9), slightly higher in males and in those aged from 15 to 17 years in most macro-regions. The prevalence was the highest in residents from the South macro-region, in the younger female adolescents and in the older male adolescents. The prevalence was higher in public schools (2.8% [95% CI 2.4-3.2]), when compared with private schools (1.9% [95% CI 1.4-2.4]) and higher in obese adolescents when compared with nonobese ones. The most common combinations of components, referring to 3/4 of combinations, were: enlarged waist circumference (WC), low HDL-cholesterol (HDL-c) and high blood pressure; followed by enlarged WC, low HDL-c and high triglycerides; and enlarged WC, low HDL-c, high triglycerides and blood pressure. Low HDL was the second most frequent component, but the highest prevalence of metabolic syndrome (26.8%) was observed in the presence of high triglycerides. CONCLUSIONS: ERICA is the first Brazilian nation-wide study to present the prevalence of metabolic syndrome and describe the role of its components. Despite the prevalence of Metabolic Syndrome being low, the high prevalences of some components and participation of others in the syndrome composition shows the importance of early diagnosis of this changes, even if not grouped within the metabolic syndrome.501Department of Science and Technology of the Secretariat of Science, Technology and Strategic Inputs of the Ministry of Health (Decit/SCTIE/MS)Health Sectorial Fund (Fundo Setorial de Saude - CT-Saude) of the Ministry of Science, Technology and Innovation (MCTI)FINEP [01090421]CNPq [2010/565037-2]Research Incentive Fund of the Hospital de Clinicas de Porto Alegre - (Fundo de Incentivo a Pesquisa do Hospital de Clinicas de Porto Alegre - FIPE-HCPA) [405.009/2012-7]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
As particularidades clínicas da otite média: Clinical features of otitis media
A otite média é um processo inflamatório de evolução abrupta, acompanhado pelo quadro clínico típico de inflamação na orelha média, sendo sua incidência prevalente em crianças, culminando em leves repercussões clínicas, mas que deve ser adequadamente diagnosticada e tratada. Este evento clínico pode ser agudo, subagudo ou crônico com aparições típicas, evolução e manejo clínico diferenciados. O seguinte artigo é uma revisão narrativa de literatura que visa analisar a respeito das principais particularidades clínicas da Otite Média. Diante das informações coletadas, pode se elucidar que a otite média é o fator causal para implicações negativas e antibioticoterapia em crianças, logo é essencial medidas para diagnose precoce para evitar repercussões na saúde destes
O perfil semiológico do paciente portador de hemorragia digestiva alta
OBJETIVO: O seguinte estudo objetivou descrever a semiologia do paciente portador de hemorragia digestiva alta, considerando como determinante na avaliação de potencias focos hemorrágicos. METODOLOGIA: Foram realizadas buscas nas plataformas do SciELO, LILACS, PubMed, Scopus e Google Scholar,utilizando os descritores gastrointestinal bleeding, peptic ulcerous disease e varicose hemorrhage, sendo identificados 35 estudos, dos quais foram incluídos 13 artigos completos. Desses estudos, 5 avaliaram as principais etiologias, 2 o surgimento de novos testes diagnósticos, 2 analisaram os aspectos epidemiológicos e 1 a sintomatologia apresentada pelo acometimento da hemorragia digestiva alta. Observou-se inicialmente a abundâncias de informações conceituais sobre o sangramento, como um transtorno clínico comum, acompanhada de inúmeras manifestações, considerando que o foco hemorrágico pode ocorrer em qualquer porção do trato gastrointestinal. Neste estudo, todas as publicações eleitas apresentaram o quadro semiológico composto por algia abdominal, indícios de choque hipovolêmico e taquicardia, alguns exibiram quedas abruptas da pressão arterial, odinofagia, êmese, náuseas e estado ictérico. Os pacientes implicados, cronicamente, já manifestaram ocorrências prévias, devido ao caráter recidivante torna-se essencial investigar a existência de varizes, fístula aorto-entérica, angiodisplasia e doença ulcerosa. CONCLUSÃO: Elucida-se que a hemorragia digestiva alta representa a principal causa de sangramento do trato gastrointestinal, majoritamente manifesta-se como hematêmese ou melena e cursam com o quadro sintomatológico que auxilia na avaliação da gravidade deste e o embasamento de potenciais focos de sangramento e que contribuam para disseminação de informações e intervenções futuras
Os aspectos semiológicos do acidente vascular encefálico: uma abordagem neurológica
O Acidente Vascular Encefálico (AVC) é um evento neurológico súbito, com um foco de isquemia ou hemorragia. Ambos, qualificados pelo déficit neurológico focal abrupto. Ressaltando, que estes déficits podem ocorrer, sendo a ocorrência espontânea, perduração de 15 minutos, autoresolutiva é denominada como Ataque Isquêmico Transitório (AIT), no entanto, toda insuficiência neural que não melhorar pós esse período deve ser manejado como AVC. O artigo objetivou descrever os principais aspectos clínicos do AVC. O AVC é uma emergência para a saúde pública, em razão de ser um potencial em gerar morbimortalidades para os portadores e prejuízos para os sistemas de saúde. O AVC do tipo isquêmico representa a maioria das ocorrências, o quadro clínico do paciente é correspondente ao tecido neural afetado, inicialmente a tomografia computadorizada sem contraste é o primeiro exame, por ser crucial para descartar a etiologia hemorrágica, a condução terapêutica se baseia em medidas neuroprotetoras através da estabilização da glicemia, temperatura e sódio, adequar os níveis pressóricos, mediante o prazo estipulado impor terapia antitrombótica. A manifestação hemorrágica, pode ocorrer por torção de aneurisma sacular originando o sangramento subaracnóideo ou por hipertensão gerando o sangramento intraparenquimatoso. A partir da análise das informações coletadas, elucida-se que o diagnóstico precoce e o período transcorrido até o manejo terapêutico são cruciais para o desfecho clínico do portador, ou seja, é possível a normalização ou ocorrer sequelas neurais e óbito
A reatividade negativa oriunda da poliquimioterapia imposta na Hanseníase
Introdução: A hanseníase é uma doença infectocontagiosa, que devido às repercussões clínicas e aos dados epidemiológicos é considerada de notificação compulsória. Contudo, esse transtorno quando é precocemente identificado e adequadamente manejado, evita consideravelmente o círculo vicioso de contágio e as manifestações clínicas que tornam a doença tão alvo de estigma. Objetivo: Descrever a reação negativa oriunda da poliquimioterapia imposta na hanseníase. Metodologia: Trata-se de uma revisão narrativa de literatura, fundamentada nas plataformas do Scielo, Pubmed, Lilacs e demais literaturas pertinentes ao tema, utilizando-se os seguintes descritores: Reação Hansênica, Efeitos Adversos e Poliquimioterapia, no período de janeiro de 2023. Resultados e Discussão: Atualmente, o protocolo terapêutico voltado para a Hanseníase é a poliquimioterapia e possui boa eficácia e tolerância pela maioria dos pacientes. No advém, a minoria destes apresenta reações adversas que variam de leve a exacerbadas e que devem ser devidamente classificados e orientados para outras opções farmacológica, objetivando impedir que o paciente abandone o tratamento, junto às enormes repercussões oriundas deste, e propiciar melhor qualidade de vida. Conclusão: Estima-se que o tratamento da Hanseníase é algo importante e indispensável para evitar problemas de saúde pública, mas este se baseia em uma alta carga associada de remédios potentes, a qual alguns portadores possuem sensibilidade e se orientados, podem continuar o tratamento até o alcance da cura. 
Consistent patterns of common species across tropical tree communities
Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe
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