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Assessment of Vulnerability of Oxisols to Compaction in the Cerrado Region of Brazil

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Pedosphere 2010年第2期20卷 252-260页

作者： A.E.AJAYI m.S.DIAS JUNIOR N.CURI A.OKUNOLA T.T.TEIXEIRA SOUZA B.silva PIRES Department of Agricultural Engineering Federal University of Technology Departamento de Ci encia do Solo Universidade Federal de Lavras Federal College of Agriculture Fundacao de Ensino Superior de Passos Universidade do Estado do Minas Gerais

The Cerrado region of Brazil,one of the fastest-growing agricultural areas in the world,is undergoing very rapid mechanization;this development is good for the country's economy but may also snowball into substantial loss of agricultural land and other environmental degradation if the soil susceptibility and vulnerability to compaction is not well *** this study we explored different techniques for estimating soil intrinsic abilities to withstand applied pressure using the prevalent Oxisols of the Cerrado region under native *** samples were collected from three sites within the region and subjected to 1) compressibility test;2) manual penetration resistance test;3) automated penetration resistance test;and 4) packing density *** four methods produced analogous *** results showed the significant influence of soil structure on the inherent strength and compaction susceptibility of the *** also established the association of soil structure with the mineralogy of the *** is noteworthy that the packing density which was developed from very simple and easily obtained parameters could give a picture of the tendency of the soil to ***,this approach would be useful in developing compaction susceptibility maps for the *** could be concluded that most of the Oxisols in the Cerrado region would support mechanized agricultural production very ***,there is need for careful management of the mechanization process to avert *** management techniques should include conservationist practices such as no till in order to maintain as much as possible the favorable structure and drainage of these very old soils.

关键词： compressibility packing density penetration resistance soil structure

Raman probing carbon&aqueous electrolytes interfaces and molecular dynamics simulations towards understanding electrochemical properties under polarization conditions in supercapacitors

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Journal of Energy Chemistry 2021年第9期30卷 279-292页

作者： Rafael Vicentini Leonardo m.Da silva Débora V.Franco Willian G.Nunes Juliane Fiates Gustavo Doubek Luís F.m.Franco Renato G.Freitas Cristiano Fantini Hudson Zanin Advanced Energy Storage Division Carbon Sci-Tech LabsUniversity of CampinasAv Albert Einstein 400CampinasSP 13083-852Brazil Department of Chemistry Federal University of Jequitinhonha and Mucuri’s ValleyRodovia MGT 367km 5835000Alto da Jacuba39.100-000 DiamantinaMGBrazil Advanced Energy Storage Division Center for Innovation on New EnergiesLaboratory of Advanced BatteriesSchool of Chemical EngineeringUniversity of Campinas(UNICAMP)CampinasSP 13083-852Brazil Department of Chemistry Federal University of Mato GrossoICET-UFMT78060-900 CuiabáMTBrazil Departamento de Física ICExUniversidade Federal de Minas GeraisBelo HorizonteMG 31270-901Brazil

Raman probing of carbon electrode and electrolyte under dynamic conditions is performed here using different aqueous electrolytes to elucidate the fundamental events occurring in electrochemical supercapacitor during charge–discharge *** areal capacitance ranges from 1.54 to 2.31μF cm^(-2)μm and it is determined using different *** findings indicate that the Helmholtz capacitance governs the overall charge-storage process instead of the space charge(quantum)capacitance commonly verified for HOPG electrodes in the range of~3 to 7μF cm^(-2).molecular dynamics simulations are employed to elucidate the origin of the reversible Raman spectral changes during the charge–discharge processes.A correlation is verified between the reversible Raman shift and the surface excesses of the different ionic species.A theoretical framework is presented to relate the effect of the applied potential on the Raman shift and its correlation with the surface ionic *** is proposed that the Raman shift is governed by the interaction of solvated cations with graphite promoted by polarization *** is the first time that a comparative study on different aqueous electrolyte p H and cation ion size has been performed tracking the Raman spectra change under dynamic polarization conditions and contrasting with comprehensive electrochemistry and dynamic molecular simulations *** study shines lights onto the charge-storage mechanism with evidence of Kohn anomaly reduction in the carbon electrode during the reversible adsorption/desorption and insertion/extraction of ionic species.

关键词： Defect reorganization in graphite Surface excess of charge Operando Raman studies Electrical double-layer capacitors

Continuous positive airway pressure acutely increases exercise duration in children with severe therapy-resistant asthma:a randomized crossover trial

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World Journal of Pediatrics 2021年第2期17卷 189-196页

作者： Claudia silva Schindel Daniele Schiwe Joao Paulo Heinzmann-Filho Natalia Evangelista Campos Paulo marcio Pitrez marcio Vinicius Fagundes Donadio Laboratory of Pediatric Physical Activity Centro Infant.Pontiffcia Universidade Catolica do Rio Grande do Sul(PUCRS)Av.Ipiranga6690.2°andarPorto AlegreRS CEP 90610-000.Brazil Hospital moinhos de Vento Porto AlegreBrazil and Centro InfantPontiffcia Universidade Catolica do Rio Grande do Sul(PUCRS)Porto Alegre.Brazil

Background Lower exercise tolerance is an important component of asthma and the possible effects of non-invasive ven-tilation on exercise capacity in individuals with severe therapy-resistant asthma(STRA)are *** study aimed to evaluate the immediate effect of continuous positive airway pressure(CPAP)on exercise tolerance in children with *** We performed a controlled,randomized,crossover clinical trial including subjects aged 6 to 18 years old diagnosed with ***,anthropometric and lung function data were *** participants in the intervention group(IG)used CPAP(PEEP 10cmH2O and FiO20.21)for a period of 40 *** in the control group(CG)used CPAP with mini-mum PEEP at 1 cmH20 also for 40 ***,subjects from both groups underwent cardiopulmonary exercise testing(CPET).After a 15-day washout period,on a subsequent visit,subjects participated in the opposite group to the initial *** Thirteen subjects with a mean age of 12.30±1.7 years were *** variables of peak expiratory flow(PEF)and forced expiratory volume in the first second(FEV1)before using CPAP and after performing CPET did not show sig-nificant *** CPET results,there was no significant difference(P=0.59)between groups at peak exercise for oxygen consumption—VO2(CG:33.4±6.3 and IG:34.5±5.9,mL kg^(-1)min^(-1)).However,the IG(12.4±2.1)presented a total test time(min)significantly(P=0.01)longer than the CG(11.5±1.3).Conclusion The results suggest that the use of CPAP before physical exercise increases exercise duration in children and adolescents with STRA.

关键词： Asthma Non-invasive ventilation Oxygen consumption Exercise test Exercise tolerance Exercise-induced bronchospasm

Advances in Tropical Soil Characterization via Portable X-Ray Fluorescence Spectrometry

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Pedosphere 2019年第4期29卷 468-482页

作者： Elen A. silva David C. WEINDORF Sergio H. G. silva Bruno T. RIBEIRO Giovana C. POGGERE Teotonio S. CARVALHO mariana G. m. GONQALVES Luiz R. G. GUILHERmE Nilton CURI Department of Soil Science Federal University of Lavras Lavras 37200-000 (Brazil) Department of Plant and Soil Science Texas Tech University Texas 79409-2122 (USA)

Portable X-ray fluorescence(pXRF) spectrometers can be used to determine the elemental composition easily, rapidly, and without using chemical reagents, which is very important for tropical regions due to the lack of detailed soil characterization data. moreover,pXRF data can be used to predict the results of more expensive, time-consuming, and conventional laboratory analyses. This study sought to determine the elemental composition of various soil profiles using pXRF. Two operational modes(Trace mode and General mode) and two scanning time(30 and 60 s) were assessed to determine their effects on the correlation of pXRF dataset with respect to conventional inductively coupled plasma(ICP)-optical emission spectrometry analysis. This relationship has been reported in previous studies, however, few studies were performed on tropical soils, which are unique. Furthermore, such relationships establish the viability of developing prediction models directly from pXRF data. Linear regression was applied to develop calibration models for the prediction of ICP analysis results and exchangeable and available elemental contents based on pXRF data. High coefficients of determination(R^2) were obtained for Ca(0.87), Cu(0.90), Fe(0.95), mn(0.85), Cr(0.95), V(0.72), and Ni(0.90), with adequate validation. Statistically significant results were not found for Al, K, Zn, Ti, and Zr. The models predicting the exchangeable Ca based on the total Ca from p XRF reached an R^2 of up to 0.85. Operational modes influenced the pXRF results. Our results illustrate that pXRF holds great promise for tropical soil characterization and the development of prediction models, justifying the need for larger-scale studies in tropical countries worldwide.

关键词： elemental composition exchangeable Ca inductively coupled plasma operational mode prediction models scanning time soil analysis total elemental content

melatonin prevents oxidative stress,inflammatory activity,and DNA damage in cirrhotic rats

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World Journal of Gastroenterology 2022年第3期28卷 348-364页

作者： Josieli R Colares Renata m Hartmann Elizângela G Schemitt Sandielly R B Fonseca marilda S Brasil Jaqueline N Picada Alexandre S Dias Aline F Bueno Cláudio A marroni norma P marroni medical Sciences Program Universidade Federal do Rio Grande do SulPorto Alegre 90050-170Brazil Marilda S BrasilNorma Biological Sciences Program Universidade Federal do Rio Grande do SulPorto Alegre 90050-170Brazil Cellular and molecular Biology Program Lutheran University of Brazil(ULBRA)Canoas 92425-900Brazil Pneumological Sciences Program Universidade Federal do Rio Grande do SulPorto Alegre 90050-170Brazil Posgraduate Program in Hepatology Universidade Federal de Ciências da Saúde de Porto AlegrePorto Alegre 90050-170Brazil

BACKGROUND Cirrhosis is an important health problem characterized by a significant change in liver *** animals,this can be reproduced by an experimental model of bile duct ligation(BDL).melatonin(mLT)is a physiological hormone synthesized from serotonin that has been studied for its beneficial properties,including its antioxidant *** To evaluate mLT’s effects on oxidative stress,the inflammatory process,and DNA damage in an experimental model of secondary biliary *** male Wistar rats were divided into 4 groups:Control(CO),CO+mLT,BDL,and BDL+*** was administered(20 mg/kg)daily beginning on day 15 after biliary *** day 29 the animals were *** samples,liver tissue,and bone marrow were collected for further *** BDL caused changes in biochemical and histological parameters and markers of inflammatory *** acid(0.46±0.01)reactive substance levels,superoxide dismutase activity(2.30±0.07)and nitric oxide levels(2.48±0.36)were significantly lower(Pmage was also lower(PmLT-treated groups(171.6±32.9)than the BDL-only group(295.5±34.8).Tissue damage and the expression of nuclear factor kappa B,interleukin-1β,Nrf2,NQO1 and Hsp70 were significantly lower in animals treated with mLT(Pministered to rats with BDL-induced secondary biliary cirrhosis,mLT effectively restored the evaluated parameters.

关键词： Antioxidants Secondary biliary cirrhosis Oxidative stress melatonin Bile duct ligation

Coating independent cytotoxicity of citrate-and PEG-coated silver nanoparticles on a human hepatoma cell line

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Journal of Environmental Sciences 2017年第1期29卷 191-201页

作者： Veronica Bastos Jose m.P.Ferreira-de-Oliveira Joana Carrola Ana L.Daniel-da-silva Iola F.Duarte Conceicao Santos Helena Oliveira CESAm&Laboratory of Biotechnology and Cytomics Department of BiologyUniversity of Aveiro3810-193 AveiroPortugal CICECO-Aveiro Institute of materials Department of ChemistryUniversity of Aveiro3810-193 AveiroPortugal Department of Biology Faculty of SciencesUniversity of Porto4169-007 PortoPortugal

The antibacterial potential of silver nanoparticles（AgNPs） resulted in their increasing incorporation into consumer,industrial and biomedical ***,human and environmental exposure to AgNPs（either as an engineered product or a contaminant）supports the emergent research on the features conferring them different toxicity *** this study,30 ran AgNPs coated with citrate or poly（ethylene glycol）（PEG） were used to assess the influence of coating on the effects produced on a human hepatoma cell line（HepG2）,namely in terms of viability,apoptosis,apoptotic related genes,cell cycle and cyclins gene *** types of coated AgNPs decreased cell proliferation and viability with a similar toxicity *** the concentrations used（11 and 5 μg/mL corresponding to IC50 and-IC10 levels,respectively） the amount of cells undergoing apoptosis was not significant and the apoptotic related genes BCL2（anti-apoptotic gene）and BAX（pro-apoptotic gene） were both ***,both AgNPs affected HepG2 cell cycle progression at the higher concentration（11 μg/mL） by increasing the percentage of cells in S（synthesis phase） and G2（Gap 2 phase） *** the cell-cycle related genes,the expression of cyclin B1 and cyclin E1 genes were ***,this work has shown that citrate- and PEG-coated AgNPs impact on HepG2 apoptotic gene expression,cell cycle dynamics and cyclin regulation in a similar *** research is needed to determine the properties that confer AgNPs at lower toxicity,since their use has proved helpful in several industrial and biomedical contexts.

关键词： Silver nanoparticles(AgNPs) Citrate Polyethylene glycol)(PEG) HepG2 cells Cytotoxicity Nanotoxicology

High prevalence of vitamin A deficiency in Crohn's disease patients according to serum retinol levels and the relative dose-response test

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World Journal of Gastroenterology 2015年第5期21卷 1614-1620页

作者： márcia Soares-mota Tianny A silva Luanda m Gomes marco AS Pinto Laura mC mendon?a maria Lúcia F Farias Tiago Nunes Andrea Ramalho Cyrla Zaltman Instituto de Nutricao Josué de Castro Federal University of Rio de JaneiroRio de Janeiro 21941-913Brazil Departamento de Clínica médica Hospital Universitário Clementino Fraga FilhoFederal University of Rio de JaneiroRio de Janeiro 21941-901Brazil Nutrition and Immunology Chair ZIEL Research Center for Nutrition and Food SciencesTechnical University of MünchenFreising-Weihenstephan80333 MünchenGermany

AIm:To assess the vitamin A status of patients with Crohn's disease(CD) by evaluating serum retinol levels and the relative dose response(RDR) test(liver retinol stores).mETHODS:Vitamin A nutritional status was measured by serum retinol obtained by high performance liquid chromatography and the RDR test for evaluation of the hepatic *** composition was performed by densitometry by dual-energy X-ray *** A dietary intake was assessed from a semiquantitative food frequency ***:This study included 38 CD patients and 33 *** serum retinol concentrations were detected in 29% of CD patients vs 15% in controls(P min A stores(P minosis A had lower BmI and body fat compared with those without this *** was no association between vitamin A deficiency and its dietary intake,ileal location,presence of disease activity and prior bowel ***:Patients with CD have higher prevalence of vitamin A deficiency,as assessed by two independent methods.

关键词： Crohn's disease Vitamin A Serum retinol Relative dose response test Body composition

超声波与人工智能在现场绝缘诊断中的应用(英文)

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高电压技术 2012年第8期38卷 1842-1847页

作者： Ferreira T V Germano A D silva K m Costa E G Department of Electrical Engineering Federal University of Campina GrandeCampina Grande Institute for High Voltage Technology and Power Transmission Technische Universitt München Department of Electrical Engineering University of Brasília

This work studies the feasibility of implementing a system for diagnosis of electrical insulation in the field based on ultrasonic noise and artificial neural *** system,proved functional under laboratory conditions,extracts spectral information from the ultrasonic noise emitted by the corona discharges in electric equipments,and correlates it with previously defined degrees of *** achieve this classification,artificial neural networks are *** results show the viability of the method in the site;nevertheless they also show that its reliability is proportional to the size and diversity of the available database.

关键词：局部放电射频信号放电量高电压技术

Appropriate search techniques to estimate Weibull function parameters in a Pinus ***

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Journal of Forestry Research 2021年第6期32卷 2423-2435页

作者： Lais Almeida Araujo Rafael menali Oliveira mario Dobner Jr Carolina Souza Jarochinskie silva Lucas Rezende Gomide Department of Forest Sciences Federal University of LavrasLavrasMinas GeraisBrazil Department of Agriculture Biodiversity and ForestsFederal University of Santa CatarinaCuritibanosSanta CatarinaBrazil

The Weibull function,a continuous probability distribution,is widely used for diameter distribution modelling,in which parameter estimation performance is affected by stand attributes and fitting *** Weibull cumulative distribution function is nonlinear,and classical fitting methods may provide a not optimal *** the use of artificial intelligence by metaheuristics is reasonable for this optimisation ***,aimed and compared(1)the metaheuristics genetic algorithm and simulated annealing performance over the moment and percentile methods;(2)the hybrid strategy merging the metaheuristics tested and the percentile method and,(3)the metaheuristics fitness functions under basal area and density errors.A long-term experiment in a Pinus taeda stand subjected to crown thinning was *** to our findings,all methods have a similar performance,independent of the thinning regimes and *** pattern of the estimated parameters tends to be acceptable,as b increases over time and c increases after ***,our findings suggest that methods based on metaheuristics have a higher precision than classical methods for estimating Weibull *** to the classification test,the methods that involved simulated annealing stood *** hybrid method involving this metaheuristic also stood out,with accurate *** methods showed the poorest performance,and we therefore suggest the use of simulated annealing due to its faster processing time and high-quality solution.

关键词： Forest management Diameters distribution Weibull function Genetic algorithm Simulated annealing