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Preparation of Polycarbonate/Clay Nanocomposite and Characterization by X-Ray, Thermal Analyzes and Low-Field Nuclear Magnetic Resonance

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材料科学与工程（中英文A版） 2011年第5X期1卷 671-677页

作者： Pedro Paulo Merat Maria Ines Bruno Tavares emerson oliveira da silva Instituto de Macromoleculas Professora Eloisa Mano Universidade Federal do Rio de Janeiro Centro de Tecnologia Bloco J Rio de Janeiro RJ CEP 21945-970 Brazil Instituto Federal de Educacao Ciencia e Tecnologia Rio de Janeiro Avenida Republica do ParaguaL 120 Sarapui Duque de Caxias Rio de Janeiro RJ CEP 25050-100 Brazil

The nanocomposites based on polycarbonate and organophilic montmorillonite were prepared by solvent cast method, using different ratios of organophilic montmorillonite. The intermolecular interactions and molecular dynamics of the nanocomposites obtained have been evaluated by spin-lattice relaxation time determined by nuclear magnetic resonance. They have also been characterized by X-ray diffraction to confirm the changes in the organoclay structure after being incorporated in the polymeric matrix. The thermal stability of both polymer and nanocomposites were also studied by thermogravimetric analysis. The glass transition temperature was determined by differential scanning calorimetry. The sum of all results indicates that nanocomposites obtained presented a predominant intercalated morphology.

关键词：纳米复合材料 X射线衍射分析低场核磁共振聚碳酸酯热分析制备差示扫描量热法玻璃化转变温度

Application of NMR Relaxometry to Study Nanostructured Poly(vinyl alcohol)/MMT/Cephalexin Materials for Use in Drug Delivery Systems

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Materials Sciences and Applications 2016年第7期7卷 380-387页

作者： Antonio de Pádua Castelo Branco Cunha Maria Inês Bruno Tavares emerson oliveira da silva Instituto de Macromoléculas Professora Eloisa Mano da Universidade Federal do Rio de Janeiro CT Bloco J Cidade Universitária Ilha do Fundao Rio de Janeiro Brazil

Polymers containing nanoparticles dispersed and distributed in the matrix can be used for control of drug release. In this work, hydrophilic matrix systems were prepared using poly(vinyl alcohol) and unmodified clay containing the same amount of cephalexin. The materials were obtained through in situ polymerization and were characterized by the conventional technique of FTIR and NMR relaxometry, through determination of proton spin-lattice relaxation time, in order to understand the molecular behavior of the new materials. The NMR relaxometry data showed that the new materials containing low quantities of clay (0.25% and 0.75%) and the same amount of cephalexin (0.5 g) had very good dispersion and distribution of the clay and drug in the polymer matrix. The combination of clay and cephalexin formed a more homogenous material with a narrow domain curve and low relaxation values. The material containing 0.25% clay presented a mixed morphology, with part exfoliated and part intercalated, as could be seen from the relaxation domain distribution, which was larger than that for material with 0.75% clay.

关键词： Polymer Relaxometry NMR Nanotechnology

Polymer Nanocomposites Used as Scaffolds for Bone Tissue Regeneration

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Materials Sciences and Applications 2018年第8期9卷 679-697页

作者： Raquel Couto de Azevedo Goncalves Mota emerson oliveira da silva Lívia Rodrigues de Menezes Instituto de Macromoléculas Professora Eloisa Mano Universidade Federal do Rio de JaneiroRio de JaneiroBrazil

Scaffolds are three-dimensional biocompatible structures that can mimic the properties of the extracellular matrix (ECM) of a given tissue, like mechanical support and bioactivity, which provides a platform for cellular adherence, proliferation and differentiation. Consequently, scaffolds are frequently used in tissue engineering with the intention of assisting the regeneration of a damaged tissue, and a major application in bone regeneration. An ideal scaffold needs to be biodegradable, biocompatible, and needs to match the biomechanical properties of bone. Polymers are widely used in this field because they fulfil the first two requirements. However, no polymeric material can achieve mechanical properties similar to the bone. For that reason, polymeric nanocomposites, which consist of ceramic/metallic nanoparticles dispersed in a polymer matrix, are being considered for bone scaffold fabrication in order to overcome this problem, since nanoparticles are known to improve composite mechanical strength, and enhance other properties.

关键词： Scaffolds Polymer Nanocomposites Nanoparticles Bone Tissue Engineering

Effect of the Addiction of Metal Oxide Nanoparticles on the Physical, Chemical and Thermal Properties of PVA Based Nanocomposites

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Materials Sciences and Applications 2018年第5期9卷 473-488页

作者： Raquel Couto de Azevedo Gonç alves Mota emerson oliveira da silva Lí via Rodrigues de Menezes Instituto de Macromolé culas Professora Eloisa Mano Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil

In this study, poly(vinyl alcohol) (PVA)-based nanocomposites consisting of metallic oxide nanoparticles (TiO2, ZnO, ZrO2) were obtained from an aqueous solution of 7% PVA, in order to compare the microstructural, and physical properties of bionanocomposite films reinforced with various loading contents (0.1%, 0.2% and 0.3% w/w). They were evaluated regarding their molecular toughness through Nuclear Magnetic Resonance (NMR), regarding their chemical structural through Fourier Transform Infrared Spectroscopy (FTIR), regarding their crystallinity throught X-ray Diffraction (XRD), and regarding termal properties through Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The NMR results showed that the smallest concentrations of these oxides have a tendency to disperse better in the polymeric matrix, improving the structural toughness. Besides, changes in the termal resistance of the material were found with the use of TGA and DSC.

关键词： Poly(vinyl alcohol) Nanocomposites Metallic Oxides Titanium Oxide Zirconium Oxide Zinc Oxide

3D Printed Scaffolds as a New Perspective for Bone Tissue Regeneration: Literature Review

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Materials Sciences and Applications 2016年第8期7卷 430-452页

作者： Raquel Couto de Azevedo Gonçalves Mota emerson oliveira da silva Felipe Fortes de Lima Lívia Rodrigues de Menezes Antonio Carlos Santos Thiele Instituto de Macromoléculas Professora Eloisa Mano Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil Universidade Federal do Rio de Janeiro Pólo Xerém Estr. de Xerém 27-Xerém Duque de Caxias-RJ Rio de Janeiro Brazil

Due to the high incidence of bone fractures in the population, it became necessary to produce scaffolds that are able to assist in tissue regeneration. It is necessary to find an appropriate balance between the mechanical and biological properties, in order to mimic the natural tissue, these properties are directly related to the architecture and their degree of porosity, as well as the size of their pores and their interconnectivity. In this perspective, the 3D printing stands out, where the structure is obtained layer by layer, according to a predetermined computational model which provides a greater control of architecture and scaffold geometry and overcomes, in this way, the limitations of traditional techniques of scaffolds manufacturing. In this way, the objective of this seminar is to present the state of the art of the polymer scaffolds produced by 3D printing and applied to bone tissue regeneration, highlighting the advantages and limitations of this process.

关键词： Scaffolds 3D Printing Tissue Engineering Bone Tissue

Chronological Age and Performance in Paralympic Powerlifters: Differences Between Sexes, Competition, and Weight Categories

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Journal of Science in Sport and Exercise 2023年第1期5卷 53-61页

作者： João Paulo Lopes-silva Dillon Richardson emerson Franchini Applied Research Group Performance and Health CESMAC University CenterMaceióAlagoasBrazil International Paralympic Committee(IPC) BonnGermany Sport Department School of Physical Education and SportUniversity of Sao PauloSao PauloBrazil

Purpose We quantified the chronological age and performance of Paralympic powerlifters competing at the elite level in the World Championships(WC)and Paralympic Games(PG),and examined the age-related differences between sexes,weight categories,and competition *** This was a retrospective study involving 3107 athletes who took part in the last eight WC and six *** pow-erlifters were divided by sex,chronological age,weight category,and competition *** Overall,males were older(33 years)and stronger(lifting 168 kg)than female(32 years and lifting 96 kg,respec-tively)para powerlifters(Pdallists were younger(31 and 30 years for females and males,respectively)than non-medallists(33 and 32 years for females and males,respectively)(Pdallists were younger(31 and 30 years)than non-medallists(33 and 32 years)for females and males,respectively.

关键词： data analysis Para athletes Sports performance Gender

Ecological intensification of cropping systems enhances soil functions,mitigates soil erosion,and promotes crop resilience to dry spells in the Brazilian Cerrado

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International Soil and Water Conservation Research 2021年第4期9卷 591-604页

作者： Lucas de Castro Moreira da silva Junior Cesar Avanzi Devison Souza Peixoto Marina Neves Merlo emerson Borghi Alvaro Vilela de Resende Salvador Francisco Acuna-Guzman Bruno Montoani silva Department of Soil Science Federal University of Lavras(UFLA)37200-900LavrasMGBrazil Department of Water Resources Federal University of Lavras(UFLA)37200-900LavrasMGBrazil Embrapa Maize and Sorghum Brazilian Agricultural Research Corporation(EMBRAPA)PO Box:28535701-970Sete LagoasMGBrazil Department of Physics Federal University of Lavras(UFLA)37200-900LavrasMGBrazil Center for Engineering and Industrial Development(CIDESI) Pie de la Cuesta 702Desarrollo San PabloQuerétaroQro.76125Mexico

Water scarcity threatens global food security and agricultural systems are challenged to achieve high yields while optimizing water *** deficit can be accentuated by soil physical degradation,which also triggers water losses through runoff and consequently soil *** soil health in cropping systems within the Brazilian Cerrado biome have been surveyed throughout the years,information about soil erosion impacts and its mitigation are still not well understood;especially concerning the role of cropping system diversification and its effects on crop ***,the aim of this study was to assess whether ecological intensification of cropping systems-inclusion of a consorted perennial grass and crop rotation-could promote soil coverage and consequently decrease water erosion and soil,water,and nutrient *** work studied the effects of crop rotation and consorted Brachiaria,along with different levels of investment in fertilization on soil physical quality and on soil,water,and nutrient losses,and crop *** proved that soybean monoculture(SS)is a system of low sustainability even under no-till in the Brazilian Cerrado *** exhibited high susceptibility to soil,water,and nutrient losses,causing low crop *** results showed that water losses in SS cropping system were approximately 10%of the total annual rainfall,and total K losses would require an additional 35%of K ***,ecological intensification of cropping systems resulted in enhanced soil environmental and agronomic functions,increased grain yield,and promoted soil and water conservation:high soil cover rate,and low soil,water and nutrient *** intensification proved to be an adequate practice to boost crop resilience to water deficit in the Brazilian Cerrado.

关键词： Crop rotation Grain production Nutrient losses Soil physical quality Tropical region

Nutritional Quality of Olives and Olive oil Produced in the Serra da Mantiqueira from Brazil

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Agricultural Sciences 2017年第7期8卷 518-526页

作者： Angelo Alberico Alvarenga Joyce Ludimila da Cruz Adelson Francisco de oliveira Luiz Fernando de oliveira da silva emerson Dias Goncalves Paulo Marcio Norberto Researchers/Scholarship BIP FAPEMIG/EPAMIG SulBrazil Scholarship PIBIC FAPEMIG/EPAMIG SulBrazil

The olive tree (Olea europaea L.) is one of the oldest fruits grown by man. Its fruit can be processed into olive oil or treated properly and serve directly for the in natura consumption in the form of olives. Extracted from the olive, the olive oil is highly valued in the market, for its nutritional benefits and also for its unique and delicate flavor. Brazil is the second largest importer of olive oil in the world, but technology is already available and the expansion of the crop has been taking place in the south-southeast regions, where the climate is favorable, in order to serve this market. The objective of this work was to evaluate the physical and chemical qualities of the olives and characterize, sensorially and chemically, olive oils from different olive cultivars planted in the Region of Serra da Mantiqueira. The olives and olive oils produced from the cultivars Arbequina, Arbosana, Grapolo 541, Koroneiki and Maria da Fé were evaluated at the EPAMIG Experimental Field of Maria da Fé, Minas Gerais, and Brazil. In the first experiment the olives harvested in February of 2015 were analyzed in terms of weight, volume, transverse and longitudinal diameter of the fruit and the lump and the relation of the olive/lump and the chemical (protein, lipid, moisture and ashes). In the second experiment the olives were processed by the grinding, beating and centrifugation method to obtain the oils. The olive oils were analyzed for acidity, peroxide index and absorbance in the ultraviolet region at 274 nm, 270 nm, 266 nm and 232 nm. After this characterization the olive oils produced in the Serra da Mantiqueira were then submitted to sensorial analysis. The results were submitted to analysis of variance and the means were compared by the Tukey test at 5% of probability. The interpretation of the data from the sensorial analysis was done using the software sensomaker. Differences were observed between olives and olive oils produced by different cultivars in the Serra da M

关键词： Diet Health Cooking

Association between Helicobacterpylori, Epstein-Barr virus, human papillomavirus and gastric adenocarcinomas

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World Journal of Gastroenterology 2018年第43期24卷 4928-4938页

作者： Carolina Rosal Teixeira de Souza Marcelli Carolini Alves Almeida Andre Salim Khayat emerson Lucena da silva Paulo Cardoso Soares Luiz Claudio Chaves Rommel Mario Rodriguez Burbano Laboratory of Human Cytogenetics Institute of Biological Sciences Federal University of Para Belem Para 66075-110 Brazil Oncology Research Center Federal University of Para Joao deBarros Barreto University Hospital Belem Para 66073-000Brazil Ophir Loyola Hospital Belem Para 66060-281 Brazil

AIM To correlate Helicobacter pylori(H. pylori), Epstein-Barr virus(EBV) and human papillomavirus(HPV) with gastric cancer(GC) cases in Pará State, *** Tissue samples were obtained from 302 gastric adenocarcinomas. A rapid urease test was used to detect the presence of H. pylori, and the presence of the cagA gene in the HP-positive samples was confirmed by PCR. An RNA in situ hybridization test designed to complement Eber1 RNA was used to detect the presence of EBV in the samples, and the L1 region of HPV was detected using nested PCR. Positive HPV samples were genotyped and analyzed for E6 and E7 viral gene expression. Infections were also correlated with the clinical and pathological characteristics of the *** The majority of the 302 samples analyzed were obtained from men(65%) aged 55 years or older(67%) and were classified as the intestinal subtype(55%). All three pathogens were found in the samples analyzed in the present study(H. pylori : 87%, EBV: 20%, HPV: 3%). Overall, 78% of the H. pylori-positive(H. pylori+) samples were cag A +(H. pylori-cag A+), and there was an association between the cytotoxic product of this gene and EBV. Coinfections of H. pylori-cagA+ and EBV were correlated with the most advanced tumor stages. Although only 20% of the tumors were positive for EBV, infection with this virus was associated with distant metastasis. Only the HPV 16 and 18 strains were found in the samples, although no expression of the E6 and E7 oncoproteins was detected. The fundus of the stomach was the region least affected by the *** HPV was not involved in gastric tumorigenesis. Prophylactic and therapeutic measures against H. pylori and EBV may prevent the development of GC, especially the more aggressive forms.

关键词：乳头状瘤病毒协会腺癌胃区域检测测试设计 HPV EBV