Pesquisa | SciELO

The objective of the present work was to apply self-organizing feature maps (SOFM) and multilayer perceptron (MLP) to evaluate the protective capacity of tert-butylhydroquinone (TBHQ), butylhydroxyanisole (BHA), and butylhydroxytoluene (BHT) antioxidants against the biodiesel oxidation reaction. For this, the antioxidant concentration and the biodiesel compliance parameters were used as continuous input variables and the type of antioxidant as a categorical. The SOFM proved to be an adequate tool for the classification of biodiesel samples containing antioxidants. The performance of the 5 most active networks of the model ranged from 89 to 99% for training, testing, and validation with an error below 1.42 × 10-4. Statistical tests applied to validate the model showed no significant difference between predicted and experimental values. The global sensitivity analysis showed that the relative protection factor (RPF) contributed with 34.89%, the antioxidant with 31.49%, the induction period with 10.69%, the water content with 6.00%, and the others all together with 16.93% in the construction of the regression models by MLP.

https://doi.org/10.21577/0103-5053.20220139

Simulation of the diffusion process of NaCl and KCl in olive pulp using the finite element method
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Clemente, Marco A. J.

; Silva, Heloisa H. P.

; Silva, Nathan F.

; Campos, Julia W.

; Sousa, Eduardo G. de

; Silva, Hágata C.

; Mantovani, Ana C. G.

; Angilelli, Karina B.

; Borsato, Dionisio

Química Nova

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2023, Volume 46 Nº 3 Páginas 229 - 235

Resumo: En | Texto: En | PDF: En

The simultaneous diffusion of inorganic components in the olive pulp in wet brine was modeled based on Fick’s generalized 2nd Law and simulated using the finite element method. The main and crossed diffusion coefficients, the film coefficient and the Biot number were determined, with the application of the simplex optimization method, through the minimization of the percentage errors. The errors between the simulated and experimental data were 5.35% for NaCl and 4.77% for KCl and the adjusted main diffusion coefficients were 0.4358 × 10-12 m2 s-1 for NaCl and 0.5408 × 10-12 m2 s-1 for KCl. The system developed to simulate diffusion allows the control and modulation of the salts content that diffuses through the olive pulp.

https://doi.org/10.21577/0100-4042.20230005

Air velocity spatial variability in open Compost-Bedded Pack Barn system with positive pressure ventilation
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OLIVEIRA, CARLOS EDUARDO A.

; TINÔCO, ILDA DE FÁTIMA F.

; DAMASCENO, FLÁVIO A.

; OLIVEIRA, VICTOR C. DE

; RODRIGUES, PEDRO HENRIQUE M.

; FERRAZ, GABRIEL A.S.

; SOUSA, FERNANDA C. DE

; ANDRADE, RAFAELLA R.

; NASCIMENTO, JOÃO ANTÔNIO C. DO

; SILVA, LEONARDO F. DA

Anais da Academia Brasileira de Ciências

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2023, Volume 95 Supl. 1 elocation e20220415

Resumo: En | Texto: En | PDF: En

Abstract In Compost-Bedded Pack Barn (CBP) systems, air velocity is linked with the thermal comfort of housed dairy cattle and bedding quality and, therefore, assessing ventilation efficiency is essential. In this context, the objective of this study was to evaluate and characterize dependence and spatial distribution of air velocity at the 1.5 m height (vair,M) and at bedding level (vair,B) in an open CBP system with positive pressure ventilation. The study was conducted in 2021, in a facility located in the Zona da Mata region, Minas Gerais, Brazil. The facility area was divided into a mesh composed of 55 equidistant points, where vair,M and vair,B data were collected in the morning (09:00 a.m.) and afternoon (03:00 p.m.) periods, during three weeks in Brazilian winter. Geostatistics techniques were used to assess dependence and spatial distribution. In both periods evaluated, there were a strong occurrence of spatial dependence and non-uniform vair,M and vair,B distributions. The vair,M and vair,B values were lower than recommended (1.8 m∙s–1) in more than 65.0% of the area. Adequate ventilation levels were observed only in the first 20.0 m of the facility, from Southeast to Northwest, because of the fan lines present.

https://doi.org/10.1590/0001-3765202320220415

DIFFUSION STUDY OF NaCl AND KCl AT THE SOLUTION/OLIVE INTERFACE: MATHEMATICAL MODELING USING THE FINITE ELEMENT METHOD AND SELF-ORGANIZING FEATURE MAP (SOFM)-TYPE NEURAL NETWORKS
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Borsato, Dionisio

; Clemente, Marco A. J.

; Silva, Heloisa H. P.

; Silva, Nathan F.

; Campos, Julia W.

; Sousa, Eduardo G. de

; Silva, Hágata C.

; Angilelli, Karina B.

; Mantovani, Ana C. G.

; Mantovani, Rafael G.

Química Nova

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2023, Volume 46 Nº 8 Páginas 785 - 790

Resumo: En | Texto: En | PDF: En

Olive samples were subjected to the salting process in brine containing 1196 mol m−3 of NaCl and 402 mol m−3 of KCl. Samples were collected during 60 h and salt concentration values were determined. With the finite element method (FEM) and the minimization of the errors percentage between the simulated and experimental values, the mass transfer coefficients in the film (hm) were obtained, being 1.0072 × 10−8 and 1.2499 × 10−8 for NaCl and KCl, respectively. The salts concentration at the olive/brine interface was simulated by FEM and analyzed via SOFM. A network with 4 × 4 topology and 10000 training epochs was used. It was observed that the influence of the stationary film formed on the surface of the olives during the salting process depends on the position, the salt involved in the diffusion and that the concentration of the salts, at each point, varies according to the immersion time.

https://doi.org/10.21577/0100-4042.20230053

Multidisciplinary Scientific Cruises for Environmental Characterization in the Santos Basin – Methods and Sampling Design
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Moreira, Daniel L.

; Dalto, Adriana G.

; Figueiredo JR, Alberto G.

; Valerio, Aline M.

; Detoni, Amalia M. S.

; Bonecker, Ana C. T.

; Signori, Camila N.

; Namiki, Cláudia

; Sasaki, Dalton K.

; Pupo, Daniel V.

; Silva, Danilo A.

; Kutner, Deborah S.

; Duque-Castaño, Diana C.

; Marcon, Eduardo H.

; Gallotta, Fabiana D. C.

; Paula, Fabiana S.

; Gallucci, Fabiane

; Roque, Gabriela C. F.

; Campos, Giulia S.

; Fonseca, Gustavo

; Mattos, Gustavo

; Lavrado, Helena P.

; Silveira, Ilson C. A. da

; Costa, Jessica O.

; Santos Filho, João R. dos

; Carneiro, Juliane C.

; Moreira, Julio C.F.

; Rozo, Laura

; Araujo, Leandro F.M.

; Lazzari, Letícia

; Silva, Letícia O. da

; Michelazzo, Luan S.

; Fernandes, Luciano F.

; Dottori, Marcelo

; Araújo Jr., Marcus A. G. de

; Chuqui, Mateus G.

; Ceccopieri, Milena

; Borges-Silva, Milton

; Kampel, Milton

; Bergo, Natascha M.

; Silva, Paulo V. M.

; Tura, Pedro M.

; Moura, Rafael B. de

; Romano, Renato G.

; Martins, Renato P.

; Carreira, Renato S.

; Toledo, Rodrigo G.A.

; Bonecker, Sérgio L.C.

; Disaró, Sibelle T.

; Rodrigues, Silvana V.

; Corbisier, Thais N.

; Vicente, Thaisa M.

; Paiva, Vitor G. de

; Pellizari, Vivian H.

; Belo, Wellington C.

; Brandini, Frederico P.

; Sousa, Silvia H.M

Ocean and Coastal Research

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2023, Volume 71 Supl. 3 elocation e23022

Resumo: En | Texto: En | PDF: En

Abstract The Santos Basin (SB) is the main petroliferous basin in the Brazilian continental margin and one of the most studied marine areas in Brazil. However, historical data suggest that new efforts should be carried out to acquire quantitative biological data, especially in the deep sea, to establish the baseline of essential ocean variables in different ecosystems for future monitoring programs. The Brazilian energy company Petrobras planned and executed 24 oceanographic cruises over a period of 2 years to assess the benthic (SANSED cruise) and pelagic (SANAGU cruise) systems of the SB (356 days at sea in 2019 and 2021/2022). These efforts were part of the Santos Project, which comprised a comprehensive environmental study aimed at investigating benthic and pelagic variables to characterize ecology, biogeochemistry, thermohaline properties of water masses, and ocean circulation patterns, geomorphology, and sedimentology, as well as organic and inorganic chemistry. Here we present the detailed sampling designs and the field methods employed on board, during the SB scientific cruises. All sampling protocols were based on standardized approaches. For the benthos analyses, triplicate sediment samples were performed using a GOMEX-type box corer (0.25 m²) or a large modified Van Veen grab (0.75 m²) at 100 stations ranging from 25 to 2400 m depth. At each station, 25 geochemical and physico-chemical parameters were analyzed in addition to micro-, meio-, and macrofauna and living foraminifera samples. For the pelagic system, 60 stations were selected to investigate the plankton community, ranging in size from pico- to macroplankton, through vertical, horizontal, and oblique net hauls (20, 200, and 500 μm mesh size), as well as 25 biogeochemical parameters collected with an aid of a CTD-rosette sampler. Part of this scientific information also serves the Regional Environmental Characterization Project (PCR-BS) in support of Petrobras’ Santos Basin drilling licensing process led by the Brazilian Environmental Agency – IBAMA. This project contributes to the sustainable development of the SB, in line with the guidelines of the United Nations Decade of Ocean Science for Sustainable Development.

https://doi.org/10.1590/2675-2824071.22072dlm

Hydrogel as mitigator of salt stress during the establishment of Tagetes patula L. seedlings
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Sousa, Naara I. G.

; Sousa, Alan B. O. de

; Lacerda, Claudivan F. de

; Sales, Jonnathan R. da S.

; Mesquita, Rosilene O.

; Cavalcante, Eduardo S.

; Canjá, Juvenaldo F.

; Camara, Wembley A. R.

Revista Brasileira de Engenharia Agrícola e Ambiental

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Nov 2022, Volume 26 Nº 11 Páginas 807 - 814

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

RESUMO Os hidrogéis favorecem a retenção de umidade no substrato e podem atenuar os efeitos do estresse salino na produção de plantas em vaso. Nesse contexto, buscou-se avaliar o uso do hidrogel para mitigar os danos causados pela salinidade da água de irrigação na emergência, crescimento e índice térmico de mudas de Tagetes patula L. A pesquisa foi realizada em casa-de-vegetação, em setembro de 2020, no município de Fortaleza, estado do Ceará, Brasil. O delineamento utilizado foi em blocos casualizados em parcelas subdivididas. As parcelas corresponderam a sete níveis de condutividades elétricas da água de irrigação - CEa (0,5, 1,0, 2,0, 3,0, 4,0, 5,0 e 6,0 dS m-1) e as subparcelas corresponderam a quatro concentrações de hidrogel (0, 1,0, 2,0 e 3,0 g L-1), com cinco repetições e cada subparcela foi composta por 27 sementes. A aplicação de 3,0 g de hidrogel L-1 de substrato favoreceu a produção de folhas e reduziu o estresse térmico nas plantas associado ao aumento da salinidade do substrato até 6,0 dS m-1. A utilização de 3,0 g L-1 de hidrogel incrementou a altura das plântulas, massa seca da folha e massa seca total em comparação aos tratamentos sem o polímero retentor de água, mesmo em níveis moderados (2,0 a 3,0 dS m-1) e altos de salinidade (4,0 a 6,0 dS m-1), indicando assim possível efeito mitigador dos danos causados pela salinidade da água de irrigação. Entretanto, a intensidade desse efeito mitigador deminui nos maiores níveis de estresse salino.

ABSTRACT Hydrogels favor moisture retention in the substrate and can attenuate the effects of salt stress on the production of potted plants. In this context, this research sought to evaluate the use of hydrogel to mitigate the damage caused by the salinity of irrigation water on the emergence, growth, and thermal index of Tagetes patula L. seedlings. The research was carried out in a greenhouse, in September 2020, in the municipality of Fortaleza, Ceará State, Brazil. The design used was randomized blocks in a split plot. The plots corresponded to seven levels of electrical conductivity of the irrigation water - ECw (0.5, 1.0, 2.0, 3.0, 4.0, 5.0, and 6.0 dS m-1) and the subplots corresponded to four hydrogel concentrations (0, 1.0, 2.0, and 3.0 g L-1), with five replicates and each subplot consisted of 27 seeds. The application of 3.0 g hydrogel L-1 of substrate favored the production of leaves and reduced the thermal index in plants associated with the increase in the salinity of the substrate up to 6.0 dS m-1. The use of 3.0 g L-1 hydrogel increases seedling height, leaf dry mass, and total dry mass compared to treatments without water-retaining polymer, even at moderate (2.0 to 3.0 dS m-1) and high (4.0 to 6.0 dS m-1) salinity levels, thus indicating a possible effect of mitigation of damage caused by the salinity of the irrigation water. However, the intensity of this mitigating effect decreases at higher levels of salt stress.

https://doi.org/10.1590/1807-1929/agriambi.v26n11p807-814

Synthesis of 1,2,3-Triazole Benzophenone Derivatives and Evaluation of in vitro Sun Protection, Antioxidant Properties, and Antiproliferative Activity on HT-144 Melanoma Cells
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Dias, Maria C. F.

; Sousa, Bianca L. de

; Ionta, Marisa

; Teixeira, Róbson R.

; Goulart, Thiago Q.

; Ferreira-Silva, Guilherme Á.

; Pilau, Eduardo J.

; Santos, Marcelo H. dos

Journal of the Brazilian Chemical Society

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Mar 2021, Volume 32 Nº 3 Páginas 572 - 587

Resumo: En | Texto: En | PDF: En

Benzophenones display several biological activities, including antioxidant, anticancer, and photoprotective. Furthermore, antioxidants can minimize both ultraviolet absorption and tumor development. In the present investigation, a series of twenty-six 1,2,3-triazole-benzophenone derivatives were synthesized and had their antioxidant, anticancer, and photoprotective effects evaluated. For the compounds synthesis, 4,4’-dihydroxybenzophenone (1a) and 2,4-dihydroxybenzophenone (1b) were propargylated, affording the alkynes bis(4-(prop-2-yn-1-yloxy))benzophenone (2a) and (2-hydroxy-4-(prop-2-yn-1-yloxy))benzophenone (2b), respectively. The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between the compounds 2a/2b and several benzyl azides gave the 1,2,3-triazole-benzophenone derivatives with yields ranging from 35 to 95%. The 1,2,3-triazole-benzophenone derivatives at the concentration of 0.2 μg mL-1 (a no-cytotoxic concentration) exhibited a solar protection factor (SPF) comparable to positive control benzophonen-3 (BP-3). Concerning their antioxidant and cytotoxic effects, the derivatives from 1b showed high in vitro antioxidant effects as well as cytotoxicity against A549 (lung carcinoma), MCF-7 (breast carcinoma), and HT-144 (metastatic melanoma) cell lines, without significant cytotoxicity to a non-cancerous cell line. Derivatives 19, 20, and 24 induced cell death and cell cycle arrest at G1/S in HT-144 melanoma cells.

https://doi.org/10.21577/0103-5053.20200211 324 downloads

Er3+/Yb3+-Doped GdVO4 Obtained by the Non-Hydrolytic Sol-Gel Route and Potential Application as Up-Conversion Thermometer
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Ferreira, Maria F.

; Sousa, Kalil Z. R. de

; Massarotto, Wagner L.

; Ricci, Emiliane G.

; Faria, Emerson H. de

; Ciuffi, Katia J.

; Sevic, Dragutin

; Rocha, Lucas A.

; Nassar, Eduardo J.

Journal of the Brazilian Chemical Society

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Fev 2021, Volume 32 Nº 2 Páginas 376 - 384

Resumo: En | Texto: En | PDF: En

The properties of lanthanides allow them to be used as contrast agents for magnetic resonance imaging, thereby helping to differentiate between tissues, organs, and pathologies more efficiently. Lanthanides contain thermosensitive energy levels that aid identification of cancer and healthy cells. This work investigates the GdVO4 matrix obtained by the non-hydrolytic sol-gel methodology and doped with the lanthanide ions Er3+ and Yb3+ at a 1:1 molar ratio. The efficiency of the optical parameters was analyzed on the basis of the Er3+ green emission after excitation in the infrared region, namely 980 nm. The temperature-dependent fluorescence intensity ratio (FIR) between the thermally coupled Er3+ levels (2H11/2 and 4S3/2 → 4I15/2) was evaluated. The Er3+ emission depended on the laser power. The calculated number of photons was 2 in this case. Temperatures ranging from 298.3 to 374.5 K were assessed, and the sensitivity varied from 1.2 to 1.9% K-1, respectively. The initial temperature was estimated.

https://doi.org/10.21577/0103-5053.20200189 227 downloads

INCORPORAÇÃO DE RODAMINA B EM MEMBRANA DE POLIAMIDA PELO MÉTODO DA ADSORÇÃO
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Sousa, Kalil Z. R. de

; Faria, Emerson H. de

; Marçal, Liziane

; Ciuffi, Katia J.

; Ricci, Emiliane G.

; Rocha, Lucas A.

; Nassar, Eduardo J.

; Silva, Jorge V. L.

; Oliveira, Marcelo F.

; Maia, Izaque A.

Química Nova

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Fev 2021, Volume 44 Nº 2 Páginas 154 - 160

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

We have incorporated rhodamine into polyamide membranes by additive manufacture selective laser sintering technology. Incorporation into 0.5 cm2 membranes was conducted at different pH values and constant temperature of 25 oC. The amounts of incorporated dye were determined by a calibration curve, and analyses showed rhodamine incorporation in the order of 10-6 mol L-1. The absorption spectra of the solutions and membranes after rhodamine incorporation showed maximum absorption at 553 nm and a shoulder at 522 nm, which indicated that a dimer was formed. Photoluminescence presented maximum emission at 575 nm for the sample incorporated with rhodamine in acid pH. The membranes that were treated with acid presented shorter adsorption time and demanded 180 min to reach equilibrium, whereas the non-treated membrane and the membranes that were treated with base required 1440 min to reach equilibrium. Polyamide membrane has proven to be an excellent material for the incorporation of dyes and compounds for application as luminescent sensors.

https://doi.org/10.21577/0100-4042.20170670 134 downloads

10.

Synergistic Supramolecular Effect on the Electro-Oxidation of Biological Relevant Molecules: A Novel Sensor for Simultaneous Determination of Epinephrine and Uric Acid in Human Urine Using MWCNT and a Copper(II) Complex
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Ferraz, Bruno R. L.

; Leite, Fernando R. F.

; Gomes, Eliziana S.

; Sousa, Marcus L.

; Arruda, Eduardo G. R. de

; Bonacin, Juliano A.

; Malagutti, Andréa R.

; Formiga, André L. B.

Journal of the Brazilian Chemical Society

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Nov 2020, Volume 31 Nº 11 Páginas 2396 - 2408

Resumo: En | Texto: En | PDF: En

In this paper a novel supramolecular strategy to improve the efficiency of a voltammetric sensor to determine two biologically relevant molecules (epinephrine (EP) and uric acid (UA)) is presented. The strategy is based on the use of a glassy carbon electrode modified with a copper(II) complex ([Cu(H2dimpy)Cl]PF6) adsorbed on multi-walled carbon nanotubes (MWCNTs). The [Cu(H2dimpy)Cl]PF6/MWCNT composite-supported electrode was characterized by electrochemical impedance spectroscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The electrocatalytic oxidation of EP and UA using the sensor was investigated by cyclic voltammetry and square wave voltammetry. Under optimized conditions, voltammetric peak currents showed a linear response for the EP and UA concentrations in the ranges 0.5-159.2 and 0.2-58.5 µmol L−1, whereas the limits of detection were 0.2 and 0.05 µmol L−1, respectively. The sensor was successfully applied in the selective and simultaneous determination of EP and UA in human urine samples. Thus, our results showed that the supramolecular strategy was successful to build an efficient sensor for simultaneous detection of these molecules in biological samples.

https://doi.org/10.21577/0103-5053.20200154 272 downloads

11.

THE FUNDAMENTAL IMPORTANCE OF BASIC SCIENCE: EXAMPLES OF HIGH-IMPACT DISCOVERIES FROM AN INTERNATIONAL CHEMISTRY NETWORK
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Lopes, Luiz G. F.

; Sadler, Peter J.

; Bernardes-Génisson, Vânia

; Moura, José J. G.

; Chauvin, Remi

; Bernhardt, Paul V.

; Sousa, Eduardo H. S.

Química Nova

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Set 2020, Volume 43 Nº 8 Páginas 1176 - 1189

Resumo: En | Texto: En | PDF: En

During the last 150 years or more, society has witnessed many key scientific discoveries and inventions, which have dramatically improved not only our quality of life, but our lifespan. However, the motivation of scientists to provide scientific advances has generally not been the achievement of these goals, but mainly driven by research curiosity. Fundamental scientific studies, also known as basic science, have paved the way to a society of knowledge by means of continuously evolving education systems, and have led to applied science and technological breakthroughs changing the World. However, without basic science such life-changing advances would not happen, which is poorly understood by the society. Having this in mind, chemists and biochemists working in a chemistry network highlight here examples of how basic science has played a crucial role and led to major breakthroughs. In seven short stories, the authors describe cases and historical events where basic research discoveries have advanced science, and opened avenues for future achievements. Investment in basic science is crucial for a nation’s health and wealth. The support of scientists driven by curiosity ultimately can benefit the whole of society, not only in innovative products, but also in the improvement of the understanding of our own lives.

https://doi.org/10.21577/0100-4042.20170584 5062 downloads

12.

Atualização das Diretrizes em Cardiogeriatria da Sociedade Brasileira de Cardiologia – 2019
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Feitosa Filho, Gilson Soares

; Peixoto, José Maria

; Pinheiro, José Elias Soares

; Afiune Neto, Abrahão

; Albuquerque, Afonso Luiz Tavares de

; Cattani, Álvaro César

; Nussbacher, Amit

; Camarano, Ana Amelia

; Sichinels, Angela Hermínia

; Sousa, Antonio Carlos Sobral

; Alencar Filho, Aristóteles Comte de

; Gravina, Claudia F.

; Sobral Filho, Dario Celestino

; Pitthan, Eduardo

; Costa, Elisa Franco de Assis

; Duarte, Elizabeth da Rosa

; Freitas, Elizabete Viana de

; Moriguchi, Emilio Hideyuki

; Mesquita, Evandro Tinoco

; Fernandes, Fábio

; Fuchs, Felipe Costa

; Feitosa, Gilson Soares

; Pierre, Humberto

; Pereira Filho, Ilnei

; Helber, Izo

; Borges, Jairo Lins

; Garcia, Jéssica Myrian de Amorim

; Souza, José Antonio Gordillo de

; Zanon, José Carlos da Costa

; Alves, Josmar de Castro

; Mohallem, Kalil Lays

; Chaves, Laura Mariana de Siqueira Mendonça

; Moura, Lídia Ana Zytynski

; Silva, Márcia Cristina Amélia da

; Toledo, Maria Alice de Vilhena

; Assunção, Maria Elisa Lucena Sales de Melo

; Wajngarten, Mauricio

; Gonçalves, Mauro José Oliveira

; Lopes, Neuza Helena Moreira

; Rodrigues, Nezilour Lobato

; Toscano, Paulo Roberto Pereira

; Rousseff, Pedro

; Maia, Ricardo Antonio Rosado

; Franken, Roberto Alexandre

; Miranda, Roberto Dischinger

; Gamarski, Roberto

; Rosa, Ronaldo Fernandes

; Santos, Silvio Carlos de Moraes

; Galera, Siulmara Cristina

; Grespan, Stela Maris da Silva

; Silva, Teresa Cristina Rogerio da

; Esteves, William Antonio de Magalhães

Arquivos Brasileiros de Cardiologia

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Mai 2019, Volume 112 Nº 5 Páginas 649 - 705

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

https://doi.org/10.5935/abc.20190086 15622 downloads

13.

Fitossociologia dos componentes lenhoso e herbáceo em uma área de caatinga no Cariri Paraibano, PB, Brasil
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Lima, Jacira R.

; Silva, Rômulo G. da

; Tomé, Maysa P.

; Sousa Neto, Eduardo P. de

; Queiroz, Rubens T.

; Branco, Mário Sérgio D.

; Moro, Marcelo F.

Hoehnea

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2019, Volume 46 Nº 3 elocation e792018

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

RESUMO Caatinga sensu stricto é a vegetação típica do semiárido brasileiro, adaptada à forte sazonalidade das chuvas e às altas temperaturas. Possui alta riqueza de espécies e alto nível de diversidade beta. O objetivo do estudo foi documentar a flora e fitossociologia das plantas lenhosas e herbáceas de uma área de caatinga. Para isso, amostramos um hectare na Reserva Particular do Patrimônio Natural Fazenda Almas (Estado da Paraíba). A área apresentou diversidade florística de 114 espécies (34 lenhosas/80 herbáceas), semelhante a outros estudos realizados nessa vegetação. O componente lenhoso apresentou densidade absoluta de 4822 ind.ha-1 e área basal de 38,851 m2.ha-1. Para plantas herbáceas foi registrada uma variação na densidade, percentual de cobertura do solo e riqueza de espécies entre as estações seca e chuvosa. Apesar da alta biodiversidade, a caatinga continua passando por extensos processos de degradação ambiental. O presente trabalho documentou a estrutura de um trecho conservado de caatinga que pode ser uma referência para futuros projetos de restauração.

ABSTRACT The caatinga sensu stricto is a typical vegetation type of the Brazilian semiarid region and is adapted to strong seasonality in rainfall and high temperatures. It has a high species richness and a high level of beta diversity. The objective of this study was to document the flora and structure of woody and herbaceous plant assemblages of a site with caatinga vegetation. We sampled one hectare in the Reserva Particular do Patrimônio Natural Fazenda Almas (Paraíba State, Brazil). Our study recorded 114 species (34 woody/80 herbaceous), which is similar to other studies conducted in this vegetation type. The woody component presented density of 4822 ind.ha-1 and a basal area of 38,851 m2.ha-1. For the herbaceous plants, we recorded variation in density, percentage of soil cover, and species richness between the dry and rainy seasons. Despite the high biodiversity, the caatinga still undergoes extensive environmental degradation processes. The present study documented the structure of a conserved tract of caatinga that can be a reference for future restoration projects.

https://doi.org/10.1590/2236-8906-79/2018 1904 downloads

14.

Systematic review of childhood and adolescence sedentary behavior: analysis of the Report Card Brazil 2018
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Silva, Kelly Samara

; Bandeira, Alexsandra da Silva

; Santos, Priscila Cristina dos

; Malheiros, Luís Eduardo Argenta

; Sousa, Ana Caroline F. C. de

; Barbosa Filho, Valter Cordeiro

Revista Brasileira de Cineantropometria & Desempenho Humano

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Ago 2018, Volume 20 Nº 4 Páginas 415 - 445

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Resumo Objetivou-se sintetizar estudos que estimaram a prevalência de comportamento sedentário (CS) em crianças e adolescentes. Revisão sistemática conduzida em oito base de dados (PubMed, Scopus, Web of Science, LILACS, SPORTDiscus, BIREME, Scielo, and Google Scholar). Os critérios utilizados foram: artigos originais; amostras incluindo crianças e adolescentes; levantamentos de base escolar e populacional; estudos observacionais usando diferentes medida do CS; estudos mostrando a prevalência de pelo menos um componente do CS. Dos 205 estudos incluídos, 104 foram analisados. Houve maior concentração de estudos nas regiões Sul (n=41) e Nordeste (n=18). Os componentes mais investigados foram assistência à TV (n=36) e tempo de tela (n=32). Somente três estudos incluíram dados de crianças com menos de sete anos, e a maioria investigou adolescentes de 10 a 19 anos. A maioria dos estudos usou questionários e apresentou variabilidade no ponto de corte utilizado (de 2 a 4 horas). A prevalência de adolescentes que atendiam às recomendações de CS (<2 horas/dia) variou de 9,4% a 68,0%. A prevalência de adolescentes que assistiam TV (<2 horas/dia) foi de 16,8% a 67,2%. Para o uso de computador, a prevalência variou de 39,1% a 97,7%; e de 47,7% a 98,0% para o videogame. Na maioria dos estudos menos da metade dos adolescentes atendeu às recomendações de CS e de tempo de TV. Por outro lado, mais da metade deles apresentou tempo inferior a duas horas por dia para o uso de computador e videogame.

Abstract The aim of this study was to summarize studies examining the prevalence of sedentary behavior among Brazilian children and adolescents. A systematic review conducted on eight databases (PubMed, Scopus, Web of Science, LILACS, SPORTDiscus, BIREME, Scielo, and Google Scholar). The criteria applied were: original research; samples including Brazilian children and adolescents; to be a school- or population-based survey; observational studies using different measures of sedentary behavior; studies showing the prevalence of at least one component of sedentary behavior. Of the 205 studies included, 104 were analyzed. There was a greater concentration of studies in the southern (n=41) and northeastern (n=18) regions. The components more frequently investigated were watching TV (n=36) and screen time (n=32). Only three studies included children under seven years, and the age range more investigated was 10 to 19 years. Most of the studies used a self-reported questionnaire and showed variability in the cut-off point applied (from 2 to 4 hours/day). The prevalence of adolescents who met recommendations ranged from 9.4% to 68.0% for sedentary behavior (<2 hours/day) and from 16.8% to 67.2% for TV viewing (<2 hours/day). The prevalence ranged from 39.1% to 97.7% for computer use and from 47.7% to 98.0% for videogame use. Most of the studies reported that less than half of the adolescents met the recommendations of sedentary behavior and TV viewing. On the other hand, more than half of them devoted less than two hours a day to computer and videogame use.

https://doi.org/10.5007/1980-0037.2018v20n4p415 1538 downloads

15.

CHROMATOGRAPHIC INVESTIGATION OF RUTHENIUM NITROSYL COMPLEX: NO INTERCONVERSION AND REACTIONS WITH BIOLOGICAL REDUCTANTS
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Silva, Francisco O. N. da

; Penha, Dayana P. S.

; Alencar, Ana E. V. de

; Pontes, Daniel de L.

; Pontes, Ana C. F. de B.

; Sousa, Eduardo H. S.

; Lopes, Luiz G. F.

Química Nova

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Abr 2018, Volume 41 Nº 4 Páginas 400 - 404

Resumo: En | Texto: En | PDF: En

One experimental strategy to prepare a nitrosyl metal complex is based on the acid-base conversion of NO2- into NO+. Here, we employed UV-vis absorption and FTIR spectroscopies to investigate the reaction of cis-[Ru(NO2)(bpy)2(imN)]PF6 with H3O+, which produced cis-[Ru(NO)(bpy)2(imN)](PF6)3 complex. Chromatographic studies were carried out and showed that immediately after nitrite complex was dissolved only one species was present with retention time(tR) of 6.81 minutes. Addition of H3O+ to nitrite complex led to the formation of one major peak with tR of 3.92 min supporting nitrosyl complex formation. The reaction of nitrosyl complex with cysteine was also monitored by HPLC and it showed clearly the formation and followed decrease of a peak at 3.38 minute with maximum absorption at 380 nm, consistent with an intermediate complex. Later, it was observed the appearance of a peak at 4.15 minute with absorption band at 470 nm. In contrast to the reaction with cysteine, methionine did not show the formation of any intermediate. The use of HPLC was an important tool to support mechanistic assumptions for nitrosyl reactions.

https://doi.org/10.21577/0100-4042.20170181 538 downloads

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