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Tribologically induced nanostructural evolution of carbon materials: A new perspective

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Friction 2024年第1期12卷 144-163页

作者： Guilherme oliveira NEVES Nicolás ARAYA Diego Berti SALVARO Thiago de Souza LAMIM Renan Oss GIACOMELLI Cristiano BINdeR Aloisio Nelmo KLEIN JoséDaniel Biasoli de mello Laboratório de Materiais Universidade Federal de Santa CatarinaSanta Catarina 88040-900Brazil departamento de Ingeniería Mecánica Facultad de IngenieríaUniversidad del Bío-BíoConcepcion 4070-386Chile Universidad de Concepción Concepcion 4070-386Chile SENAI Innovation Institute for Laser Processing Santa Catarina 89218-153Brazil Universidade Federal de Uberlândia Minas Gerais 38408-100Brazil

Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes *** the macroscale,these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem *** a recently developed advanced Raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants,from graphite and carbide-derived carbon particles to multi-layer graphene and carbon *** addition,these materials were tested under various dry sliding conditions,with different geometries,topographies,and solid-lubricant application *** of the initial tribosystem conditions and allotrope level of atomic ordering,there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.

关键词： carbon nanostructures tribology Raman spectroscopy defects quantification tribolayer solid lubrication

Behavior of wood basic density according to environmental variables

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Journal of Forestry Research 2022年第2期33卷 497-505页

作者： Gabriel Marcos Vieira oliveira JoséMárcio de mello Carlos Rogério de mello JoséRoberto Soares Scolforo Eder Pereira Miguel Thiago Campos Monteiro Brazil Institute of Agricultural and Forestry defense of Espírito Santo(IDAF) Av.Lourival Lugon Moulinnº300CentroJerônimo MonteiroES CEP:29.550-000Brazil department of Forestry Sciences Universidade Federal de Lavras-UFLACaixa Postal 3037LavrasMG CEP:37.200-000Brazil Engineering department Universidade Federal de Lavras-UFLACaixa Postal 3037LavrasMG CEP:37.200-000Brazil Forestry Engineering department Faculdade de TecnologiaUniversity of Brasilia-UnBCampus Universitário Darcy RibeiroCaixa Postal 4357Asa Norte-BrasíliaDF CEP:70910-900Brazil department of Forestry Engineering and Technology Universidade Federal do Paraná-UFPRAv.Pref.Lothário Meissner632Jardim BotânicoCuritibaPR CEP:80.210-170Brazil

The relationships between climate conditions and wood density in tropical forests are still poorly *** quantify spatial dependence of wood density in the state of Minas Gerais(MG,Brazil),map spatial distribution of density,and correlate density with climate variables,we extracted data from the Forest Inventory of Minas Gerais for 1988 trees scaled throughout the territory and measured wood density of discs removed from the *** variables were extracted from the database of the Ecological-Economic Zoning of Minas *** spatial analysis,tree densities were measured at 44 georeferenced sampling *** data were subjected to exploratory analysis,variography,cross-validation,model selection,and ordinary *** relationships between wood density and environmental variables were calculated using dispersion matrices,linear correlation,and *** density proved to be highly spatially dependent,reaching a correlation of 96%,and was highly continuous over a distance of 228 *** distribution of wood density followed a continuous gradient of 514-659 kg m^(−3),enabling corre-lation with environment *** was correlated with mean annual precipitation(−0.57),temperature(0.63),and evapotranspiration(0.83).Geostatistical methods proved useful in predicting wood density in native tropical forests with different climate *** results confirmed the sensitivity of wood density to climate change,which could affect future carbon stock in forests.

关键词： Biomass Climate variables Geostatistics Hardwood Forest inventory Minas Gerais

decontamination of mobile phones and electronic devices for health care professionals using a chlorhexidine/carbomer 940■gel

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Frontiers of Chemical Science and Engineering 2019年第1期13卷 192-198页

作者： Rafael Muniz de oliveira Nereida mello da Rosa Gioppo Jancineide oliveirade Carvalho Francilio Carvalho oliveira Thomas Jay Webster Fernanda Roberta Marciano Anderson oliveira Lobo University Hospital of the West of Parana State University of West of Parana Cascavel PR Brazil University Center for Health. Humanities and Technology of Piaui (UNINOVAFAPI). Piaui Brazil Science and Technology Institute Brasil University Itaquera SP Brazil Nanomedicine Laboratory Department of Chemical Engineering Northeastern University MA 02115 USA Materials Science and Engineering graduation program Technology Center Federal University of Piaui. PI Brazil

Though they reduce microorganism growth, current hospital disinfectants also damage many of today’s modern electronic devices such as tablets and smartphones. Herein, the efficacy of a new chlorhexidine digluconate gel (CDG) was tested as a disinfectant for mobile and electronic devices in a clinical environment. Specifically, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and methicillin resistant Staphylococcus aureus were used to infect the screen of eight smartphones. The CDG was prepared at concentrations of 2%, 4% and 6%, and tested on paper disks infected with these bacteria before being tested on the smartphones. The devices were disinfected with the CDG gel (4%) at two times: immediately and after 5 min of the bacterial contamination. In all cases, the CDG gel eliminated 100% of gram-positive and gram-negative microorganisms compared to the control (without any agent). In addition, the gel did not damage the smartphones. Therefore, our study suggests that the CDG gel may be applied to disinfect a wide range of electronic devices for health care professionals in the hospital environment.

关键词： smartphones disinfection clinical environment chlorhexidine bacteria

Effects of Soluble Silicate and Nanosilica Application on Rice Nutrition in an Oxisol

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Pedosphere 2018年第4期28卷 597-606页

作者： Rita de Cassia FELIX ALVAREZ Renato de mello PRADO Guilherme FELISBERTO Angelica Cristina FERNANdeS deUS Raimundo Leonardo LIMA de oliveira Federal University of Mato Grosso do Sul Chapadao do Sul 79560-000 (Brazil) University of the State of Sao Paulo UNESP School of Agronomic Sciences Department of Soils and Fertilizers Jaboticabal 14884-900 (Brazil)

Silicon （Si） has been supplied to plants via application of calcium silicate to soil; however, high doses of calcium silicate are required because of its low solubility. Nanoparticles can reduce Si doses and be applied to seeding furrows. This study investigated the effects of liquid Si sources, i.e., highly soluble silicate （115.2 g L^-1 Si and 60.5 g L^-1 Na20） and nanosilica （〈 200 nm）, on Si uptake by rice plants, plant lignification, plant C：N：P stoichiometry, plant physiology, and grain yield using an Oxisol under greanhouse condistions. The treatments included the application of nanosilica and soluble silicate to seeding furrows at Si doses of 0, 605, 1210, and 2 420 g ha^-1. Plant uptake and treatment effects were evaluated by measuring C and lignin contents, Si, N, and P accumulation, physiological characteristics, and grain yield of rice. The deposition of silica bodies and amorphous silica in the flag leaves was analyzed using scanning electron microscopy. Application of liquid Si increased Si accumulation in rice by 47.3% in relation to the control （0 g ha^-1 Si）, regardless of the Si sources used. Nanosilica application increased leaf lignin content by 112.7% when compared to that in the control. Silicon moderately affected the net C assimilation （increased by 1.83%） and transpiration rates （increased by 48.3%）; however, Si influenced neither plant growth nor grain yield of rice. These results are explained by the lack of biotic or abiotic stress in rice plants during the experiment. To the best of our knowledge, in Brazilian agriculture, this is the first report on the use of nanosilica as a Si fertilizer and its effect on plant nutrition. This study provides evidence that rice plants absorb and accumulate nanoparticles; however, further studies are required to investigate the use of nanoparticles in other plant species.

关键词： C:N:P stoichiometry grain yield leaf lignin net C assimilation plant physiology silicon source

Time-dependent impact of a high-fat diet on the intestinal barrier of male mice

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World Journal of Methodology 2024年第1期14卷 114-123页

作者： Carolline Santos Miranda Daiana Araujo Santana-oliveira Isabela Lopes Vasques-Monteiro Nathan Soares Dantas-Miranda Jade Sancha de oliveira Glauser Flavia Maria Silva-Veiga Vanessa Souza-mello department of Anatomy Rio de Janeiro State UniversityRio de Janeiro 20551030Brazil

BACKGROUND Excessive saturated fat intake compromises the integrity of the intestinal mucosa,leading to low-grade inflammation,impaired mucosal integrity,and increased intestinal permeability,resulting in the migration of lipopolysaccharide(LPS)to other *** To evaluate the chronic effects(at 10 and 16 wk)of a high-fat diet(HFD)(with 50%energy as fat)on the phylogenetic gut microbiota distribution and intestinal barrier structure and protection in C57BL/6 *** Forty adult male mice were divided into four nutritional groups,where the letters refer to the type of diet(control and HFD or HF)and the numbers refer to the period(in weeks)of diet administration:Control diet for 10 wk,HFD for 10 wk,control diet for 16 wk,and HFD for 16 *** sacrifice,biochemical,molecular,and stereological analyses were *** The HF groups were overweight,had gut dysbiosis,had a progressive decrease in occludin immunostaining,and had increased LPS *** progression reduced the number of goblet cells per large intestine area and Mucin2 expression in the HF16 group,consistent with a completely disarranged intestinal ultrastructure after 16 wk of HFD *** Chronic HFD intake causes overweight,gut dysbiosis,and morphological and functional alterations of the intestinal barrier after 10 or 16 ***-dependent reductions in goblet cell numerical density and mucus production have emerged as targets for countering obesity-driven intestinal damage.

关键词： High-fat diet Intestine Ultrastructure Goblet cells Gut microbiota

Effect of temperature and atmosphere on the tribological behavior of a polyether ether ketone composite

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Friction 2015年第4期3卷 259-265页

作者： Felipe Darabas RZATKI Diego Vinicius Dalevedo BARBOZA Renan Muller SCHROEdeR Guilherme Mariz de oliveira BARRA Cristiano BINdeR Aloisio Nelmo KLEIN JoséDaniel Biasoli de mello Federal University of Santa Catarina-UFSC Mechanical Engineering DepartmentMaterials LaboratoryFlorianópolisSCBrazil Whirlpool/Embraco JoinvilleSCBrazil

Polyether ether ketone(PEEK)is a high-performance thermoplastic,which is often selected for high-temperature tribological applications under chemically aggressive *** present work investigates the tribological behavior of a high-performance PEEK composite under conditions that are often found inside hermetic ***,an AMTI tribometer equipped with a hermetic chamber and a heating system was used to conduct sliding tests of PEEK cylinders on AISI 304 stainless steel polished discs(S_(q)der atmospheric air,with a 25%decrease in the friction coefficient associated with a 100%increase in the wear ***,the friction measured from the samples tested under a tetrafluoroethane atmosphere showed no significant temperature dependence.

关键词： solid lubricant thermoplastics environment temperature

Anterior transhepatic approach for total caudate lobectomy including spigelian lobe,paracaval portion and caudate process:A Brazilian experience

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Hepatobiliary & Pancreatic Diseases International 2018年第4期17卷 371-373页

作者： Eduardo de Souza Martins Fernandes Carlo Alberto Pacilio Felipe Pedreira Tavares de mello Ronaldo de oliveira Andrade Leandro Moreira Savattone Pimentel Camila Liberato Girão Hepato-Pancreato-Biliary and Transplant Surgery Hospital Adventista SilvestreRio de JaneiroBrazil Hospital Universitario Clementino Fraga Filho Universidade Federal do Rio De Janeiro(UFRJ)Rio de JaneiroBrazil

To the Editor:Nowadays,because of the infiltration of cholangiocarcinoma to the parenchyma and/or bile ducts of the caudate lobe,the inclusion of caudate lobe combined with a major hepatectomy remains the gold standard approach for a resectable hilar *** the last years of the 20th century,some authors have begun to report isolated caudate lobe resection for hepatocellular

关键词： HCC Anterior transhepatic approach for total caudate lobectomy including spigelian lobe paracaval portion and caudate process:A Brazilian experience

Autoregressive spatial analysis and individual tree modeling as strategies for the management of Eremanthus erythropappus

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Journal of Forestry Research 2016年第3期27卷 595-603页

作者： Henrique Ferraco Scolforo Jose Roberto Soares Scolforo Jose Marcio de mello Anto nio Carlos Ferraz Filho Diogo Francisco Rossoni Thiza Falqueto Altoe Antonio Donizette oliveira Renato Ribeiro de Lima department of Forest Science Federal University of Lavras PO Box: 3037 Lavras MG 37200-000 Brazil department of Statistics State University of Maringa Av. Colombo 5.790 Jd. Universitario Bloco E90 Maringa PR 87020-900 Brazil department of Statistics Federal University of Lavras PO Box: 3037 Lavras MG 37200-000 Brazil

The objectives of this study were to apply statistical techniques to discriminate fertilization treatments of Eremanthus erythropappus（DC.） Mac *** autoregressive modeling, and to develop individual tree models for diameter and crown area（CA） projection to define management strategies for candeia plantations subjected to different fertilization treatments. This is an important tree species originating from the Brazilian Atlantic Rain forest and Savannah biomes, intensively used in the cosmetic industry. Nonetheless, to date, research has not addressed the management of natural stands or plantations of the species. Our experiment was located in Baependi, Minas Gerais, Brazil, and comprised of four randomized blocks and 13 treatments. The treatments consisted of 12 different regimes of fertilization plus a control. Each sample plot was composed of 50 plants plus two border plants in a planting spacing of 2.5 9 2.0 m and undergoing pruning at 5 and 6 years of age. Starting in the second year, total tree height（H） and circumference（at 1.30 m from the ground or breast height, CBH） were measured every 6 months. Starting in the fifth year CA was measured. Tree growth varied by fertilization *** were detected by using an autoregressive approach, considering that standard statistical methods were not powerful enough to detect significant *** growth groups were formed, and maximum growth was obtained for treatment 10（NPK, 8-28-16）. Management guidelines are provided based on individual tree models for different fertilization levels.

关键词： Management strategies Candeia Fertilization level Brazil Crown area

development of Active Films with Collagen Fiber and Polyvinyl Alcohol Mixture and Incorporation of Oregano and Rosemary Essential Oils in Their Matrix

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Food and Nutrition Sciences 2023年第7期14卷 601-625页

作者： Suslin Raatz Thiel Mari Silvia Rodrigues de oliveira Vinícius Badia Stephanie Reis Ribeiro Roger Wagner Tatiana Emanuelli Rosa Cristina Prestes renius mello department of Food Science and Technology Federal University of Santa Maria Santa Maria Brazil department of Food Engineering and Chemical Engineering Santa Catarina State University Pinhalzinho Brazil

The aim was to develop films with a new mixture of collagen fiber plus polyvinyl alcohol added of oregano or rosemary essential oils at different levels (0%, 2%, 4% and 6%), as well as to assess the antimicrobial activity, physical, optical, microstructure and molecular properties in the films. An interaction between the ingredients was observed at the molecular level by FTIR. The amide II and amide III bands, which are important to verify collagen conformation, showed intense peaks in the films. The formation of a network through collagen fibers was produced, acting as a reinforcement in matrix. The films with essential oil had an expressive antimicrobial activity by the steam contact method (micro-atmosphere), mainly for Escherichia coli and Staphylococcus aureus. The mixture of collagen fiber plus polyvinyl alcohol added of essential oils is a promising matrix for application in food as active packaging.

关键词： Antimicrobial Activity Biodegradable Packaging Bioactive Volatile Compounds Fourier Transformed Infrared Spectroscopy Scanning Electron Microscopy Sustainable Packaging