78 research outputs found

    Análisis de perfiles radiales de temperatura para lechos fijos de baja relación de aspecto por fluidodinámica computacional

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    En trabajos previos se ha presentado el Modelo de Dos Zonas (MDZ) para la transferencia de calor en lechos fijos. Este modelo permite la simulación ágil de reactores de lecho fijo de baja relación de aspecto, como es el caso de los reformadores de gas natural, considerando que el lecho está conformado por dos regiones: una zona anular, adyacente a la pared del tubo y de un espesor de un radio de partícula, y una segunda zona denominada central, abarcando el resto del lecho. Los parámetros térmicos que el modelo introduce son: el coeficiente de transferencia de calor sobre la pared, el coeficiente de transferencia de calor entre las dos zonas del modelo y la conductividad térmica efectiva radial que caracteriza a la zona central del lecho. Se ha discutido en contribuciones previas la evaluación del coeficiente de transferencia de calor sobre la pared. En este trabajo se profundiza dicho análisis con el estudio de los perfiles de temperatura de la zona central del lecho, con el objetivo principal de evaluar el coeficiente de transferencia de calor entre las dos zonas y la conductividad térmica efectiva radial. El sistema analizado consiste en un conjunto de partículas sólidas ubicadas en una celda, conforme a diferentes arreglos espaciales. Las celdas están limitadas por dos planos paralelos sobre los que se especifica la misma temperatura y dos fronteras periódicas en las posiciones de entrada y salida de la corriente de fluido. Una corriente gaseosa con temperatura predefinida atraviesa el lecho, completándose la celda de cálculo con condiciones de simetría en las caras laterales paralelas al flujo. Se utilizó la licencia académica del programa FLUENT 6.3.16 y su generador de mallas GAMBIT 2.4.6., llevándose a cabo numerosas simulaciones con el objeto de obtener los perfiles de temperatura para diferentes configuraciones geométricas y valores del número de Reynolds. Este estudio se centra en la evaluación del transporte de calor en la zona central, que en el modelo se representa por medio de un enfoque continuo y pseudohomogéneo. A partir de un análisis de regresión de los perfiles de temperatura de dicha zona, se obtienen -como parámetros de ajuste- los valores de la conductividad efectiva radial y del coeficiente de transferencia de calor entre zonas. Se presentan y analizan los valores obtenidos de la conductividad efectiva radial y se los compara con valores calculados a partir de correlaciones propuestas por otros autores. Adicionalmente, para los valores obtenidos del coeficiente de transferencia de calor entre las dos zonas se propone una correlación que permite una rápida evaluación de dicho parámetro para su utilización en el MDZ.Centro de Investigación y Desarrollo en Ciencias Aplicada

    Quinone oxidoreductase from Staphylococcus aureus

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    Funding Information: Helena Gaspar is acknowledged for the HPLC analyses and Bruno Victor for advice on modelling. F.M.S. and M.S.S. are recipients of fellowships by Fundação para a Ciência e a Tecnologia (PD/BD/128213/2016 and PD/BD/128202/2016, respectively, both within the scope of the PhD program Molecular Biosciences PD/00133/2012). A.B. is recipient of a fellowship by Fundação para a Ciência e a Tecnologia UI/BD/153052/2022. The work was funded by Fundação para a Ciência e a Tecnologia ( PTDC/BIA-BQM/2599/2021 to M.M.P). The project was further supported by UIDB/04046/2020 and UIDP/04046/2020 Centre grants from FCT , Portugal (to BioISI), by LISBOA-01-0145-FEDER-007660 cofunded by FEDER through COMPETE2020-POCI and by Fundação para a Ciência e a Tecnologia and by UIDB/04612/2020 and UIDP/04612/2020 research unit grants from FCT (to Mostmicro). The NMR spectrometers are part of the National NMR Network (PTNMR) and are supported by Infrastructure Project N° 022161 (co-financed by FEDER through COMPETE 2020, POCI, and PORL and FCT through PIDDAC). Funding Information: Helena Gaspar is acknowledged for the HPLC analyses and Bruno Victor for advice on modelling. F.M.S. and M.S.S. are recipients of fellowships by Fundação para a Ciência e a Tecnologia (PD/BD/128213/2016 and PD/BD/128202/2016, respectively, both within the scope of the PhD program Molecular Biosciences PD/00133/2012). A.B. is recipient of a fellowship by Fundação para a Ciência e a Tecnologia UI/BD/153052/2022. The work was funded by Fundação para a Ciência e a Tecnologia (PTDC/BIA-BQM/2599/2021 to M.M.P). The project was further supported by UIDB/04046/2020 and UIDP/04046/2020 Centre grants from FCT, Portugal (to BioISI), by LISBOA-01-0145-FEDER-007660 cofunded by FEDER through COMPETE2020-POCI and by Fundação para a Ciência e a Tecnologia and by UIDB/04612/2020 and UIDP/04612/2020 research unit grants from FCT (to Mostmicro). The NMR spectrometers are part of the National NMR Network (PTNMR) and are supported by Infrastructure Project N° 022161 (co-financed by FEDER through COMPETE 2020, POCI, and PORL and FCT through PIDDAC). Publisher Copyright: © 2022 The Author(s)Staphylococcus aureus is an opportunistic pathogen and one of the most frequent causes for community acquired and nosocomial bacterial infections. Even so, its energy metabolism is still under explored and its respiratory enzymes have been vastly overlooked. In this work, we unveil the dihydroorotate:quinone oxidoreductase (DHOQO) from S. aureus, the first example of a DHOQO from a Gram-positive organism. This protein was shown to be a FMN containing menaquinone reducing enzyme, presenting a Michaelis-Menten behaviour towards the two substrates, which was inhibited by Brequinar, Leflunomide, Lapachol, HQNO, Atovaquone and TFFA with different degrees of effectiveness. Deletion of the DHOQO coding gene (Δdhoqo) led to lower bacterial growth rates, and effected in cell morphology and metabolism, most importantly in the pyrimidine biosynthesis, here systematized for S. aureus MW2 for the first time. This work unveils the existence of a functional DHOQO in the respiratory chain of the pathogenic bacterium S. aureus, enlarging the understanding of its energy metabolism.publishersversionpublishe

    Low-Intensity, High-Frequency Grazing Positively Affects Defoliating Behavior, Nutrient Intake and Blood Indicators of Nutrition and Stress in Sheep

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    The intensity and frequency of grazing affect the defoliating strategy of ruminants, their daily nutrient intake, thus nutrition and physiological status. Italian ryegrass (Lolium multiflorum Lam.) pastures were grazed by sheep either under a low-intensity/high-frequency grazing strategy (Rotatinuous stocking; RN) with nominal pre- and post-grazing sward heights of 18 and 11 cm, respectively, or under a high-intensity/low-frequency strategy (traditional rotational stocking; RT) with nominal pre- and post-grazing sward heights of 25 and 5 cm, respectively. Treatments were arranged under a complete randomized design and evaluated over two periods, in different years. In 2017, the aim was to depict the type of bites that sheep perform during the grazing-down and associate them to the grazing management strategy according to their relative contribution to the diet ingested. In 2018 we estimated the total nutrient intake and evaluated blood indicators of the nutritional status and immune response to stress of sheep. The bite types accounting the most for the diet ingested by RN sheep were those performed on the “top stratum” of plants with around 20, 15, and 25 cm, whereas the type of bites accounting the most for the diet of RT sheep were those performed on “grazed plants” with around 10, 5, and ≤ 3 cm. In 2018, the RN sheep increased by 18% the total organic matter (OM) intake and by 20–25% the intake of soluble nutrients (i.e., crude protein, total soluble sugars, crude fat), digestible OM and of metabolizable energy, and had 17.5, 18, and 6.1% greater blood concentration of glucose, urea nitrogen (BUN) and albumin, respectively, but 17% lower blood neutrophil-to-lymphocyte (N:L) ratio. Sheep grazing vegetative Italian ryegrass pastures under the low-intensity/high-frequency grazing strategy (RN) ingested a diet of better quality from bites allocated on the top stratum of plants, had greater intake of soluble nutrients and blood parameters positively associated with nutritional status and immune response to stress

    An introduction to violence against women as a human rights and public health problem

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    O objetivo deste artigo é apresentar àqueles(as) que se iniciam no estudo da violência praticada contra as mulheres uma breve contextualização histórica do modo como, gradualmente, este se tornou um tema do campo dos Direitos Humanos e da Saúde Pública. Partimos da Declaração Universal dos Direitos dos Homens para, em seguida, discutirmos sua importância para o campo dos Direitos Humanos e analisarmos a polêmica entre direitos humanos versus direitos das mulheres. Posteriormente, apresentamos as diversas convenções e tratados internacionais de proteção dos direitos das mulheres e sua importância para a conscientização da Saúde Pública, com relação ao fenômeno da violência. Inicialmente abordada como "causas externas" de morbidade e mortalidade, devido à grande incidência e aos elevados prejuízos sociais, econômicos e de saúde (física e psicológica), atualmente a violência é reconhecida como um campo específico e urgente de intervenção sob a perspectiva da Saúde Pública. De modo particular, a violência praticada contra as mulheres é um problema de proporções mundiais, que atinge pessoas de todas as classes sociais, religiões e etnias. Afirmamos que, a partir da inclusão da violência contra as mulheres na arena dos direitos humanos e da Saúde Pública, começaram a ocorrer transformações mais efetivas nas políticas legais de muitos países, como a criação de programas de intervenção e outros suportes. Por fim, apresentamos a situação do Brasil com relação à igualdade de gênero.The aim of this paper is to show to those who are beginning to study the subject of violence against women a brief historical overview of the way it gradually became a theme of the fields of Human Rights and Public Health. We start with the Universal Declaration of Human Rights to discuss its importance for the field of Human Rights and to analyze the polemic between human rights versus women's rights. After that, we present the international treaties and conventions that protect women's rights and their importance to raise the awareness of the Public Health field about violence. Initially seen as "external causes" of morbidity and mortality, because of its high incidence and several social, economic and health (physical and psychological) damages, nowadays violence is seen as a specific domain of the Public Health field that needs urgent intervention. In particular, violence against women is a global problem that reaches people of all social classes, religions and ethnic groups. We claim that, since the inclusion of violence against women in the fields of Human Rights and Public Health, more effective transformations in the legal policies of several countries have begun to occur, like the creation of interventional programs and other supports. At the end, we show Brazil's position about gender equality.info:eu-repo/semantics/publishedVersio

    Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

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    Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

    Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

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    There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

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    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

    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

    Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

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    Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI &lt;18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school&#x2;aged children and adolescents, we report thinness (BMI &lt;2 SD below the median of the WHO growth reference) and obesity (BMI &gt;2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

    Pervasive gaps in Amazonian ecological research

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