Modeling and multivariate analysis of the production process of alpha-hydroxy acids and hydrogen by electro-oxidation of glycerol / Modelagem e análise multivariada do processo de produção de alfa-hidroxiácidos e hidrogênio por eletro-oxidação de glicerol

The electro-oxidation of alkaline solutions of glycerol to obtain alpha-hydroxy acids and hydrogen is a sustainable procedure of a renewable nature, with the raw material derived from the co-production of biodiesel. The system is composed of a stirred tank electrochemical reactor built "ad-hoc" with a cell separated by ceramic where oxygen is generated to produce acids and hydrogen. The present studies were conducted by controlling the variables: temperature (0C), molar ratio (mol/mol) and current density (mA/cm2), based on experimental design and cyclic voltammogram. The empirical model and multivariate analysis were obtained through data collected by HPLC with a refractive index detector. This analysis presents the conversion of glycerol to tartronic and oxalic acid associated with the current density corresponding to factor1. Factor2 reveals the productivity of glyceric acid and glycolic acid related to molar ratio. The accumulated percentage of the two factors were more than 75% representative.  The empirical model built from experimental planning had  an error of less than 5%. The best phenomenological model experienced had an average error of less than 7%. From this model, the amount of hydrogen generated in the NTP was calculated

Design de experimento no estudo comparativo de adsorção de corante sintético em quitosana e em carvão ativado comercial / Design of experiment in the comparative study of synthetic dye adsorption on chitosan and on commercial activated carbon

Neste trabalho experimental, foi realizado um estudo comparativo da adsorção de corante Remazol Brilliant Blue R (RB) em quitosana e carvão ativado como adsorventes, e avaliação da cinética de adsorção do corante RB em quitosana, segundo os modelos de pseudo-primeira ordem e pseudo-segunda ordem. Resultados mostraram que, dependendo das condições experimentais, a quitosana mostrou capacidade de remoção tão altas como o carvão ativado, chegando a >99% de remoção do corante da fase aquosa. Estudo dos gráficos de Pareto e de superfície de resposta mostraram que o pH e a dosagem de adsorvente foram os parâmetros que mais influenciaram no processo de adsorção com a quitosana. O modelo de pseudo-segunda ordem foi o mais adequado para descrever a cinética do processo adsortivo

Avaliação experimental da cinza da casca de arroz como suporte catalítico de níquel-rutênio para hidrogenação da sacarose / Experimental evaluation of rice husk ash as a nickel-ruthenium catalytic support for sucrose hydrogenation

O presente trabalho avaliou a eficiência da cinza de casca de arroz (CCA) como suporte catalítico de níquel-rutênio (Ni-10%-Ru-1%/CCA) aplicado ao processo de hidrogenação da sacarose com produção seletiva em manitol e sorbitol. Sob condições de processo de 5,0 g de catalisador foram misturados a 0,70 L de uma solução aquosa de 60 g.L-1 a 265 g.L-1 de sacarose, submetidos a  pressão de 700 psi em reator de leito de lama, com agitação mecânica de 500 rpm, funcionando semi-aberto para a fase gasosa (H2) e fechado para as fases líquida (solução de sacarose) e sólida (catalisador), nas temperaturas de 130°C, 140°C e 150°C. Nos resultados obtidos, destacou-se a temperatura de 150°C com a conversão de 100%  e seletividade de 72% para o sorbitol e 28% para o manitol para um tempo de reação de 3 horas e 60 g.L-1 de sacarose

Das considerações acerca do paciente politraumatizado com ênfase em trauma cranio encefalico: Considerations about the polytrauma patient with emphasis on head trauma

A morte decorrente do trauma é um grande problema de saúde no mundo inteiro, resultando em quase 14 mil mortes diariamente, o trauma se evidencia entre as cinco principais causas de morte. Nos últimos 10 anos, mais de 1 milhão de pessoas ficaram inválidas devido a traumas mecânicos no Brasil, sendo os acidentes de trânsito os principais responsáveis por estas taxas. Além do aumento do número de veículos em circulação, a desorganização, a deficiência geral da fiscalização, as péssimas condições de muitos veículos, o comportamento dos usuários e a impunidade dos infratores fizeram com que nas últimas décadas o Brasil se colocasse entre os campeões mundiais de acidentes de trânsito. As lesões cerebrais constituem uma causa importante de morte, especialmente em adultos jovens, e uma causa importante de incapacidade. Atualmente estão cada vez mais disseminados os agentes causais de lesões nos seres humanos, tais como: os meios de transportes, o maquinário agrícola e industrial, o aumento da agressividade das armas de fogo, entre outros. Se por um lado o aumento tecnológico tem contribuído para o aumento da qualidade de vida, por outro ameaça a sobrevivência dos cidadãos. Esta pesquisa se enquadra como revisão de literatura, do tipo sistemática de caráter exploratório e abordagem qualitativa. O grande objetivo desta pesquisa foi elaborar atualização acerca das informações acerca do trauma cranioencefálico de forma a fomentar atualização em saúde

Pervasive gaps in Amazonian ecological research

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

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Pervasive gaps in Amazonian ecological research

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