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Chemical Characterization of Auriferous Ores from the Brazilian State of Paraiba

Journal of Minerals and Materials Characterization and Engineering 2015年第1期3卷 9-14页

作者： marcelo rodrigues do nascimento Artur M.G.Lourenco Instituto Federal de Educacao Ciencia e Tecnologia da ParaibaLaboratorio de FlotacaoCampina GrandeBrazil Universidade Federal de Campina Grande Programa de Pos-Graduacao em Engenharia CivilCampina GrandeBrazil

One of the most important problems facing the gold industry is that the placer and free milling gold ores are almost terminating. Hence, the use of refractory ores has been increased during the recent years. In general, gold refractory ores occurs in various types of deposits associated with a range of minerals. Among the refractory ores, the sulfide type is the most common. The methodology employed in the mining process depends on the mode of occurrence of the ore and on the particle size, shape and degree of purity of the auriferous species. We have undertaken a mineralogical investigation of a representative sample of a complex gold mining ore collected in the municipality of Princesa Isabel, Paraiba, Brazil, using X-ray fluorescence spectrometry, X-ray diffractometry, infrared spectroscopy, inductively coupled plasma-atomic emission spectrometry and the Fire Assay. The results showed that the arsenic content of the ore was closely related to the gold content, and that the occurrence of “invisible gold” was associated primarily with pyrite and secondarily with arsenopyrite. The sulfur content of the ore was directly related to its refractoriness. It is concluded that gold mineralization in the study area is mainly of the gold-quartz-sulfide veins (lode gold), while the gold found in the mini-fractures of the deposits is probably associated with the hydrothermal processes that occurred in the region.

关键词： Auriferous Ore Chemical Characterization X-Ray Fluorescence Spectrometry X-Ray Diffractometry Inductively Coupled Plasma-Atomic Emission Spectrometry

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Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on Si(111) substrates

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Journal of Semiconductors 2024年第9期 34-42页

作者： Leonarde do nascimento rodrigues Wesley Fiorio lnoch Marcos L.F.Gomes Odilon D.D.Couto Jr. Bráulio S.Archanjo Sukarno Olavo Ferreira Physics Department Federal University of Vi?osa Instituto de Física Gleb Wataghin Universidade Estadual de Campinas National Institute of Metrology Quality and Technology (Inmetro) Materials Metrology Division (DIMAT)

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2D character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.

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Concerns about the application of resistance exercise with blood-flow restriction and thrombosis risk in hemodialysis patients

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Journal of Sport and Health Science 2024年第4期13卷 548-558,F0003页

作者： Hugo de Luca Correa Lysleine Alves Deus Dahan da Cunha nascimento Nicholas Rolnick Rodrigo Vanerson Passos Neves Andrea Lucena Reis Thais Branquinho de Araujo Carmen Tzanno-Martins Fernanda Silveira Tavares Luiz Sinesio Silva Neto Claudio Avelino rodrigues Santos Paolo Lucas rodrigues-Silva Fernando Honorato Souza Vitoria Marra da Motta Vilalva Mestrinho Rafael Lavarini dos Santos Rosangela Vieira Andrade Jonato Prestes Thiago dos Santos Rosa Post-graduate Program of Physical Education Catholic University of BrasıliaBrasılia 71966-700Brazil The Human Performance Mechanic Lehman CollegeNew YorkNY 10011USA Clinical Group Home Dialysis Center and RenalClass Sao Paulo 01239-040Brazil Department of Medicine Catholic University of BrasıliaBrasılia 71966-700Brazil Faculty of Medicine Federal University of TocantinsTocantins 77001-090Brazil Embrapa Genetic Resources and Biotechnology Brasılia 70770-917Brazil Graduate Program of Genomic Sciences and Biotechnology Brasılia 71966-700Brazil

Background:Hemodialysis(HD) per se is a risk factor for *** the growing body of evidence on blood-flow restriction(BFR) exercise in HD patients,identification of possible risk factors related to the prothrombotic agent D-dimer is required for the safety and feasibility of this training *** aim of the present study was to identify risk factors associated with higher D-dimer levels and to determine the acute effect of resistance exercise(RE) with BFR on this ***:Two hundred and six HD patients volunteered for this study(all with a glomerular filtration rate of 70 years old),and HD ***,RE+BFR significantly increases D-dimer after 4 *** with borderline baseline D-dimer levels(400-490 ng/mL) displayed increased risk of elevating D-dimer over the normal range(≥500 ng/mL).Conclusion:These results identified factors associated with a heightened prothrombotic state and may assist in the screening process for HD patients who wish to undergo RE+BFR.D-dimer and/or other fibrinolysis factors should be assessed at baseline and throughout the protocol as a precautionary measure to maximize safety during RE+BFR.

关键词： Blood-flow restriction Chronic kidney disease Coagulation Hemodialysis Vascular occlusion exercises

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Response to Commentary by Dr. Matthew J. Clarkson on

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Journal of Sport and Health Science 2024年第5期13卷 670-671页

作者： Hugo de Luca Corrêa Lysleine Alves Deus Dahan da Cunha nascimento Nicholas Rolnick Rodrigo Vanerson Passos Neves Andrea Lucena Reis Thais Branquinho de Araújo Carmen Tzanno-Martins Fernanda Silveira Tavares Luiz Sinésio Silva Neto Cláudio Avelino rodrigues Santos Paolo Lucas rodrigues-Silva Fernando Honorato Souza Vitória Marra da Motta Vilalva Mestrinho Rafael Lavarini dos Santos Rosangela Vieira Andrade Jonato Prestes Thiago dos Santos Rosa Post-graduate Program of Physical Education Catholic University of BrasıliaBrasılia 71966-700Brazil The Human Performance Mechanic Lehman CollegeNew YorkNY 10011USA Clinical Group Home Dialysis Center and RenalClass Sao Paulo 01239-040Brazil Department of Medicine Catholic University of BrasıliaBrasılia 71966-700Brazil Faculty of Medicine Federal University of TocantinsTocantins 77001-090Brazil Embrapa Genetic Resources and Biotechnology Brasılia 70770-917Brazil g Graduate Program of Genomic Sciences and Biotechnology Brasılia 71966-700Brazil

Dear editor:We sincerely thank Matthew *** for his insightful commentary1 on our recent publication in the Journal of Sport and Health Science.2 Clarkson's pioneering work in the development and application of blood flow restriction (BFR) exercise protocols has undeniably laid the groundwork for subsequent investigations in this field,including our own.(3-6)His commentary not only highlights the relevance and timeliness of our study but also offers valuable perspectives on refining safety considerations for intradialytic BFR exercise among hemodialysis patients.

关键词： patients application flow

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Sex recognition does not modulate aggression toward nest intruders in a paper wasp

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Current Zoology 2023年第3期69卷 324-331页

作者： Andre rodrigues de Souza Wilson Franca Amanda Prato Fabio Santos do nascimento Departamento de Biologia Faculdade de Filosofia Ciencias e Letras de Ribeirao PretoUniversidade de Sao PauloSao PauloBrazil

During social interactions,the behavior of an individual often depends on the sex of its social *** animal societies have males and females that play very different behavioral roles,although they coexist and interact *** specific phases of the colony cycle,social wasp females and males are contemporaries within a nest,they often interact,although mating occurs mostly off the nest,therefore providing an opportunity to test sex discrimination in contexts other than classical sexual *** performed a lure presentation experiment to test if Mischocyttarus metathoracicus discriminate between conspecifics of the 2 sexes during on-nest social *** wasps discriminated conspecific sex during experimentally simulated nest *** and chemical cues may account for this sex *** sex discrimination(evidenced by differential inspective behavior from the nest females toward the female and the male lures),female wasps were as aggressive toward lures of both *** the female-dominated hymenopteran societies,males are often subordinate and not aggressive on nest,resulting in females directing less aggression to them compared to other ***,*** males and females are both aggressive toward nestmates,so they might be perceived as similar threat during on-nest social interactions.

关键词： chemical cues Mischocyttarus sex discrimination social interactions social wasps visual cues

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Tree structure and diversity of lowland Atlantic forest fragments：comparison of disturbed and undisturbed remnants

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Journal of Forestry Research 2016年第3期27卷 605-609页

作者： Fabricio Alvim Carvalho Joao marcelo Alvarenga Braga marcelo Trindade nascimento Departamento de Botanica Universidade Federal de Juiz de Fora. Campus Universitario s/n Sao PedroJuiz de Fora-MG 36036-900 Brazil Instituto de Pesquisas do Jardim Botanico do Rio de Janeiro. Rio de Janeiro-RJ Brazil Laboratorio de Ciencias Ambientais CBB Universidade Estadual do Norte Fluminense Campos dos Goytacazes-RJ 28013-602 Brazil

This study describes the tree community structure of three moist lowland Atlantic Forest fragments in Rio de Janeiro State, southeastern Brazil. Two fragments were disturbed and an undisturbed one was used as reference. Our hypothesis was that disturbed fragments show distinct structural patterns in comparison with undisturbed stands due to past disturbance practices and forest fragmentation. Four 100 ×5 m sampling plots were demarcated in each fragment and all live and dead trees with DBH C 5 cm were located, measured and identified. The results supported our hypothesis, due to the high values found for standing dead trees, an increase of dominance of a few pioneer species, lower values of large trees and species richness in disturbed fragments in comparison with the undisturbed one. The advanced fragmentation process in the Southern Brazilian lowland areas and the high species richness in undisturbed areas highlight these forest fragments as priority areas for conservation and management.

关键词： Phytosociology Tree community Forestfragmentation . Hotspot Brazil

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In vitro antileishmanial effects of Physalis angulata root extract on Leishmania infantum

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Journal of Integrative Medicine 2018年第6期16卷 404-410页

作者： Bruno Jose Martins Da Silva Sandro Wilson Gomes Pereira Ana Paula Drummond rodrigues Jose Luiz Martins do nascimento Edilene Oliveira Silva Laboratory of Structural Biology Institute of Biological SciencesFederal University of PardBelemPard 66075-110Brazil National Institute of Science and Technology in Structural Biology and Bioimaging(INCT-INBEB) Rio de Janeiro 21941-901Brazil Laboratory of Electron Microscopy Department of Health SurveillanceMinistry of HealthEvandro Chagas InstituteBelemPard 66087-082Brazil Laboratory of Molecular and Cellular Neurochemistry Institute of Biological SciencesFederal University of PardBelemPard 66075-110Brazil National Institute of Science and Technology in Neuroimmunomodulation(INCT-NIM) Rio de Janeiro 21040-360Brazil

Objective： In the present study, we evaluated the effects of the aqueous extract of Physalis angulata root （AEPa） on Leishmania infanturn proliferation, morphology, and the driving mechanism in leishmanicidal activity and modulatory action on macrophages. Methods： I., infantum promastigotes were treated with 50 and 100 μg/mL AEPa for 72 h and then antipro- mastigote assay was performed by counts in a Newbauer chamber, morphological changes were analyzed by transmission electron microscopy and the mechanism of the leishmanicidal activity was detected. In addition, macrophages were infected with L. infantum and were used to evaluate anti-amastigote activity of AEPa and effects of AEPa on cytokine secretion after 72-hour treatment. Results： Treatment with AEPa reduced the numbers ofL infantum promastigotes （50% inhibitory concen- tration （ICso） = 65.9μg/mL; selectivity index （SI）= 22.1） and amastigotes （ICso = 37.9 μg/mL; SI = 38.5） compared with the untreated control. Amphotericin B reduced 100% of the promastigote numbers after 72 h of treatment （IC50 = 0.2μg/mL）. AEPa induced several morphological changes and increased the production of reactive oxygen species and apoptotic death in promastigotes after treating for 72 h. AEPa （100 μg/mL） promoted tumor necrosis factor-α secretion in macrophages infected with L. infantum after 72 h of treatment, but did not induce an increase in this cytokine in noninfected macrophages. In addition, AEPa showed no cytotoxic effect on J774-A1 cells （50% cytotoxic concentration 〉1000μg/mL）. Conclusion： AEPa presented antileishmanial activity against the promastigotes and amastigotes of I.. infantum without macrophage cytotoxicity; these results show that natural products such as P. angulata have leishmanicidal potential and in the future may be an alternative treatment for leishmaniasis.

关键词： Leishmanicidal activity Leishmania infantum Reactive oxygen species Apoptosis Physalis angulata

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Environmental and Durability Perspective of the Use of Curaua Fiber Treated in Mortars

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Journal of Renewable Materials 2022年第9期10卷 2409-2429页

作者： Afonso R.G.de Azevedo marcelo nascimento Dirlane do Carmo Markssuel T.Marvila Gustavo de C.Xavier Sergio Neves Monteiro UENF-State University of the Northern Rio de Janeiro LECIV-Civil Engineering LaboratoryCampos dos GoytacazesBrazil UFF-Federal Fluminense University TER-Department of Agricultural EngineeringNiteróiBrazil UENF-State University of the Northern Rio de Janeiro LAMAV-Advanced Materials LaboratoryCampos dos GoytacazesBrazil IME-Military Institute of Engineering Department of Materials ScienceRio de JaneiroBrazil

The use of natural lignocellulosic fibers(NLFs)as a reinforcement mechanism for cementitious composites,such as mortar,has been investigated in the last ***,their application has often been restricted to technological evaluation research.A NLF with great potential the curaua,which after treatment with NaOH solution,proved to be technologically feasible for mortars reinforcement based on cement and *** objective of this research was the comparative evaluation between a traditional mortar,based on cement and lime,with 1:1:6:0.8 ratio of cement:lime:sand:water,and a modified mortar with addition of 2 wt.%treated curaua fiber in cement mass by evaluating environmental and durability *** a curing time for 28 days,environmental assessments were carried out and durability methodologies were *** tests performed were:(i)attack by chlorides and sulfate,(ii)the wetting and drying cycles,and(iii)slake durability *** results showed that the mortar with the addition of curaua fiber presented a similar behavior to the reference mixture,both in terms of environmental and durability *** modified mortar is able to be used in internal and external environments,the latter with some ***,it also contributes to the promotion of sustainable use of curaua fiber.

关键词： Natural lignocellulosic fibers curaua mortar durability environmental aspects

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Perspectives on new biomarkers in gastric cancer: Diagnostic and prognostic applications

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World Journal of Gastroenterology 2014年第33期20卷 11574-11585页

作者： Danilo do Rosário Pinheiro Wallax Augusto Silva Ferreira Mariceli Baia Leo Barros Mariana Diniz Araújo Symara rodrigues-Antunes Bárbara do nascimento Borges Master Program of Animal Health and Production Federal Rural University of Amazonia Belém PA 66077-530 Brazil Molecular Biology Laboratory Biological Science Institute Federal University of Pará Belém PA 66075-110 Brazil Center of Agropecuary Technology Socio-environmental and Hydric Resources Institute Federal Rural University of Amazonia Belém PA 66077-530 Brazil

Gastric cancer is considered one of the most deadly tumors worldwide. Even with the decline in its incidence, the mortality rate of this disease has remained high, mainly due to its late diagnosis and to the lack of precise prognostic markers. The main purpose of this review is to present genetic, epigenetic and proteomic molecular markers that may be used in a diagnostic and prognostic manner and to discuss the pros and cons of each type of marker for improving clinical practice. In this sense, we observed that the use of genetic markers, especially mutations and polymorphisms, should be carefully considered, as they are strongly affected by ethnicity. Proteomic-based markers show promise, but the higher costs of the associated techniques con-tinue to make this approach expensive for routine use. Alternatively, epigenetic markers appear to be very promising, as they can be detected in bodily fluids as well as tissues. However, such markers must be used carefully because epigenetic changes may occur due to environmental factors and aging. Despite the advances in technology and its access, to date, there are few defined biomarkers of prognostic and diagnostic use for gastric tumors. Therefore, the use of a panel of several approaches(genetic, epigenetic and proteomic) should be considered the best alternative for clinical practice.

关键词： Molecular markers Epigenetic Genetic Proteomic Diagnosis Prognosis Gastric tumors

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Rat cardiomyocyte H9c2(2-1)-based sulforhodamine B assay as a promising in vitro method to assess the biological component of effluent toxicity

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Journal of Environmental Sciences 2020年第10期32卷 163-170页

作者： Elsa T rodrigues Susana F nascimento Maria Joao Moreno Paulo J Oliveira Miguel A Pardal University of Coimbra Centre for Functional EcologyDepartment of Life SciencesCalcada Martim de FreitasCoimbra 3000-456Portugal University of Coimbra Coimbra Chemistry CenterDepartment of ChemistryCoimbra 3004-535Portugal Centre for Neuroscience and Cell Biology Uniuersity of CoimbraUC BiotechBiocant ParkCantanhede 3060-197Portugal

The treatment of wastewaters is crucial to maintain the ecological status of receiving waters,and thereby guarantee the protection of aquatic life and human *** quality evaluation is conventionally based on physicochemical parameters,but increasing attention has been paid to integrate physicochemical and biological ***,the regulatory use of fish in biological testing methods has been subject to various ethical and cost concerns,and in vitro cell-based assays have thus become an important topic of ***,the present study intends:(a) to evaluate the efficiency of two different sample pre-concentration techniques (lyophilisation and solid phase extraction) to assess the toxicity of municipal effluents on rat cardiomyoblast H9c2(2-1) cells,and (b) maximizing the use of the effluent sample collected,to estimate the environmental condition of the receiving *** gathered results demonstrate that the H9c2(2-1) sulforhodamine B-based assay is an appropriate in vitro method to assess biological effluent toxicity,and the best results were attained by lyophilising the sample as *** to its response,the H9c2(2-1) cell line might be a possible alternative in vitro model for fish lethal testing to assess the toxicity of municipal *** physicochemical status of the sample suggests a high potential for eutrophication,and iron exceeded the permissible level for wastewater discharge,possibly due to the addition of ferric chloride for wastewater *** general,the levels of carbamazepine and sulfamethoxazole are higher than those reported for other countries,and both surpassed the aquatic protective values for long-term exposure.

关键词： Municipal wastewater treatment plant effluent Lyophilisation Solid phase extraction Cell-based assays H9c2(2-1)cell line SRB assay

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