Silver
Mostrando 13-24 de 1554 artigos, teses e dissertações.
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13. QUANTIFICACAO DE NANOPARTICULAS DE PRATA EM UM PRODUTO FARMACEUTICO POR ESPECTROFOTOMETRIA E POTENCIOMETRIA: UMA PROPOSTA PARA AULAS PRATICAS DE QUIMICA ANALITICA
Spectrophotometry and potentiometry techniques were used to quantify silver in an ophthalmic solution. A standard solution of silver nanoparticles was synthesized, from which an analytical method was developed to quantify silver in the sample. Potentiometric titrations of three samples were made, using an electrochemical cell containing an alternative metall
Quím. Nova. Publicado em: 2021-01
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14. Optimization of the Reaction Conditions for the Synthesis of Dihydrobenzofuran Neolignans
We have optimized the experimental conditions for the silver(I)-promoted oxidative coupling of methyl p-coumarate (I) and methyl ferulate (II), which is the most frequently used methodology to synthesize the bioactive dihydrobenzofuran neolignans 1 ((±)-trans-dehydrodicoumarate dimethyl ester) and 2 ((±)-trans-dehydrodiferulate dimethyl ester). Most of the
J. Braz. Chem. Soc.. Publicado em: 2021-01
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15. Novel N-Heterocyclic Carbene Silver(I) Complexes: Synthesis, Structural Characterization, Antimicrobial and Cytotoxicity Potential Studies
In this study, a series of unsymmetrical N,N-disubstituted benzimidazolium salts were synthesized as N-heterocyclic carbene (NHC) (2a-2j) and their AgI complexes. Their structures were characterized by elemental analyses, 1H and 13C nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy techniques. Further, both the salts and their silver(I)-NHC com
J. Braz. Chem. Soc.. Publicado em: 2020-10
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16. DETERMINATION OF FOUR ARSENIC SPECIES IN ALGAE BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED WITH HYDRIDE GENERATION ATOMIC FLUORESCENCE SPECTROMETRY
A rapid method has been developed for the determination of silver arsenite As(III), dimethylated arsenic DMA, monomethylated arsenic MMA, and arsenate As(V) in algae sample using liquid chromatography coupled with hydride generation atomic fluorescence spectrometry (LC-HG-AFS). Types, flow rate and pH of mobile phase were optimized. Under the optimal conditi
Quím. Nova. Publicado em: 2020-09
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17. Green Synthesis, Characterization and Antimicrobial Evaluation of Silver Nanoparticles for an Intracanal Dressing
Resumo A química verde tem sido aplicada em diferentes áreas devido à crescente demanda por processos renováveis e uma delas é a nanotecnologia. O objetivo deste estudo foi caracterizar uma formulação contendo nanopartículas de prata (AgNPs) produzidas por meio de síntese verde e avaliar sua atividade antimicrobiana. A formulação será usada como
Braz. Dent. J.. Publicado em: 2020-09
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18. Effect of Silver Antibacterial Agents on Bond Strength of Fiber Posts to Root Dentin
Resumo Este estudo foi conduzido para avaliar se a irrigação de pré-tratamento antibacteriano com nanopartículas de prata (SNPs) e fluoreto de diamina de prata (SDF) tem algum efeito na resistência de união de pinos de fibra cimentados com três tipos de cimentos resinosos no espaço do canal radicular. Cinquenta e quatro raízes de incisivos centrais
Braz. Dent. J.. Publicado em: 2020-08
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19. PROCESSING OF A METAL CONCENTRATE FROM GROUND WASTE PRINTED CIRCUIT BOARDS IN ACIDIC MEDIA USING HYDROGEN PEROXIDE AS OXIDANT
The recovery of precious and base metals of a metal concentrate from ground waste printed circuit boards (PCBs) is described in detail. Samples were treated with NaOHaq. to remove the soldering mask. Experiments were performed in acidic medium (HF, H2SO4, CH3COOH or H3PO4) using H2O2 as oxidant. Base metals were leached in high yields (>99 wt.%) at ~40 ºC a
Quím. Nova. Publicado em: 20/07/2020
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20. DEVELOPMENT OF AN ANALYTICAL METHOD FOR THE DETERMINATION OF LEAD BASED ON LOCAL SURFACE PLASMON RESONANCE OF SILVER NANOPARTICLES
Lead is environmental pollutant that even in low trace is harmful for human health and wildlife. In this study we presented a colorimetric method for determination of Pb2+ in water by aggregation of silver nanoparticles capped citrate in the presence of deferoxamine as chelating agent. Silver nanoparticles were prepared by reduction of AgNO3 with NaBH4. In t
Quím. Nova. Publicado em: 2020-06
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21. Case for diagnosis. Keloidal cord-like lesion on the leg,
Abstract We report a 74-year-old male presented to an outpatient dermatology clinic in Manaus, Amazonas, with a one-year history of pruritic, keloidal lesions on his left lower extremity. Histopathology showed round structures in reticular dermis. Grocott methenamine silver stain revealed numerous round yeasts with thick double walls, occurring singly or in
An. Bras. Dermatol.. Publicado em: 2020-06
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22. Minieditorial: Risco de FA após Ablação de Flutter Dependente de Istmo Cavo-Tricuspídeo: Vale a Pena Fazer a Ablação da FA Simultaneamente?
Considering the size of the Amazon region and the need for studies to establish soil trace metal concentrations in natural environments, the objective of this work was to evaluate heavy metal contents in a toposequence of an Amazon State microbasin. Soil samples were collected in three native forest topographic positions. Samples were opened for analysis by
Arq. Bras. Cardiol.. Publicado em: 2020-05
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23. VALORES DE REFERÊNCIA DA CONCENTRAÇÃO DE METAIS PESADOS EM SOLOS NA AMAZÔNIA CENTRAL
Considering the size of the Amazon region and the need for studies to establish soil trace metal concentrations in natural environments, the objective of this work was to evaluate heavy metal contents in a toposequence of an Amazon State microbasin. Soil samples were collected in three native forest topographic positions. Samples were opened for analysis by
Quím. Nova. Publicado em: 2020-05
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24. METHOD DEVELOPMENT AND VALIDATION FOR THE FLUOROQUINOLONES DETERMINATION BY STABILIZED SILVER NANOPARTICLES
Silver nanoparticles (AgNPs) stabilized with glutathione (GSH) were used as nanosensors for the determination of fluoroquinolones such as ciprofloxacin (CIP), norfloxacin (NOR) and enrofloxacin (ENRO) in aqueous systems. The AgNPs were stabilized with GSH (Ag-GSH NPs), whereas the decrease of the surface plasmon resonance (SPR) band at 400 nm and the bathoch
Quím. Nova. Publicado em: 2020-03