JBCS



20:26, seg fev 17

Acesso Aberto/TP



vol. 44, No. 4, 2021



Artigo de Capa
Quim. Nova 2021, 44(4), 473-477

Otimização e validação de método enzimático semiquantitativo simples e de baixo custo para a busca de inibidores de cisteino proteases

Ana Karolina de Souza Andrade; Luana Andrade Santos; Edisleide Silva Menezes; Rafael Ciro Marques Cavalcante; James Almada da Silva*

Simple and low-cost semi-quantitative enzymatic method for searching cysteine proteases inhibitors was optimized and validated using E64 irreversible inhibitor and herb extracts.

http://dx.doi.org/10.21577/0100-4042.20170691

Publicado online: dezembro 10, 2020
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Total access: 849

Artigo de Contra Capa
Quim. Nova 2021, 44(4), 478-483

Optimization of brewing waste's (trub) phenolic compounds extraction by ultrasound assisted using response surface methodology

Bianca C. G. GandolphoI,*; Aline R. AlmeidaI; Gabriel M. GandolphoII; Daniele Z. FreitasI; Otávio C. GaspariniIII; Michelle H. MachadoI; Pedro L. M. BarretoI

The brewing waste (trub) presents high levels of phenolic compounds can be extracted through optimize parameters of UAE by Response Surface Methodology, increasing the byproduct's value, and reducing the process environmental impact.

http://dx.doi.org/10.21577/0100-4042.20170688

Publicado online: dezembro 8, 2020
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Total access: 773

Artigo Quim. Nova 2021, 44(4), 385-390

 

Study on the optimization for the size of fuel cell flow field under inadequate air supply condition

Shi Lei; Zheng Minggang*


The optimization of the flow field size can improve the performance of the PEMFC under the inadequate air supply of cathode and ensure that it is close to the level under the normal air supply.

http://dx.doi.org/10.21577/0100-4042.20170713

Publicado online: fevereiro 4, 2021
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Total access: 924

Quim. Nova 2021, 44(4), 391-401

 

Evaluation of the chemical composition and structure of asphaltenes from three offshore brazilian biodegraded heavy oils

Hemmely Guilhermond de Souza SeverinoI,*; Christiane Béatrice Duyck PintoI; André Luiz Durante SpigolonII; Carlos Siqueira Bandeira de MelloII; Tais Freitas da SilvaIII; Kátia Zaccur LealI


Characterization of purified asphaltenes and complementary analysis suggest biodegradation effects on the asphaltenic structure.

http://dx.doi.org/10.21577/0100-4042.20170697

Publicado online: dezembro 22, 2020
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Total access: 917

Quim. Nova 2021, 44(4), 402-409

 

Quantificação de mullita proveniente de resíduos de caulim da região amazônica: uso do método de rietveld

Marlice C. Martelli; Eric Mochiutti*; João Pedro O. Lima; Roberto de F. Neves


Kaolin residues from the Capim (CC) and Jari (CJ) regions were calcined at 1300 °C, 1400 °C, 1500 °C of temperature, using a muffle furnace, forming mullite and cristobalite. One of these products had their phases quantified using the Rietveld method.

http://dx.doi.org/10.21577/0100-4042.20170696

Publicado online: dezembro 22, 2020
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Total access: 1123

Quim. Nova 2021, 44(4), 410-414

 

Macroalgae Fucus vesiculosus oil: biodiesel production using alkaline transesterification

Bruno Roberto PetryI; Rafael Cardoso RialII,*; Osmar Nunes de FreitasI; Joyce Mara dos Santos BarbosaI; Leandro Fontoura CavalheiroI; Carlos Eduardo Domingues NazárioI; Luíz Henrique VianaI


Methyl biodiesel and ethyl biodiesel obtained from Fucus vesiculosus oil using alkaline catalysis showing to be a potential raw material for the production of biodiesel.

http://dx.doi.org/10.21577/0100-4042.20170704

Publicado online: janeiro 20, 2021
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Total access: 796

Quim. Nova 2021, 44(4), 415-424

 

Modificação química do polipropileno através da introdução de grupos sulfônicos para aplicação como catalisador em reações de esterificação

Bárbara N. AudI,II; Giovani A. LourençoII; Lynicker Y. O. DouradoI; Rosana M. N. AssunçãoIII,*


Chemical modification of polypropylene by treatment with concentrated sulfuric acid and fuming sulfuric acid; Application as a catalyst heterogeneous acid in the reaction of esterification of oleic acid with methanol to produce methyl oleate.

http://dx.doi.org/10.21577/0100-4042.20170690

Publicado online: dezembro 10, 2020
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Total access: 970

Quim. Nova 2021, 44(4), 425-431

 

Preparation of hybrid polymers and use as controlled release delivery vehicle for volatile repellent to control Aedes aegypti

Ygor M. de Oliveira; Ângladis V. Delfino; Cenira M. de Carvalho; Lucia M. Conserva; Fabiane C. de Abreu*


Adsorbent biomaterials based on silica and chitosan were synthesized, characterized and tested in a Y-olfactometer for release of a natural Aedes aegypti mosquito repellent.

http://dx.doi.org/10.21577/0100-4042.20170698

Publicado online: janeiro 20, 2021
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Total access: 826

Revisão Quim. Nova 2021, 44(4), 432-459

 

Desenvolvimento nos métodos de glicosilação: uma chave para acessar suas aplicações na síntese de moléculas bioativas

Pedro R. de Souza Neto; Bruna M. Guimarães; Jucleiton J. R. de Freitas; Ronaldo N. Oliveira#; João R. de Freitas Filho*


In this short review, recent reports of the main glycosylation methods, basic mechanisms, factors influencing the stereoselectivity and their applications in the synthesis of bioactive molecules are described.

http://dx.doi.org/10.21577/0100-4042.20170676

Publicado online: novembro 26, 2020
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Total access: 1217

Quim. Nova 2021, 44(4), 460-472

 

Gases de nitrogênio reativo como precursores do aerossol atmosférico: reações de formação, processos de crescimento e implicações ambientais

Carolina G. Rocha; Arnaldo A. Cardoso*


Creation and emission of reactive nitrogen species have increased dramatically in the last hundred years; such nitrogen compounds act in the atmosphere to produce secondary aerosol, which has deleterious effects to the human health, environment, and climate.

http://dx.doi.org/10.21577/0100-4042.20170692

Publicado online: dezembro 11, 2020
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Total access: 1575

Educação Quim. Nova 2021, 44(4), 484-492

 

Classificação das substâncias químicas: um conceito pouco explorado na educação química

Cintia Maria Carneiro Franco LimaI; José Luis P. B. SilvaII,*


The classification of chemical substances constitutes a large net with classes on the knots and chemical reactions as relations between them.

http://dx.doi.org/10.21577/0100-4042.20170667

Publicado online: novembro 6, 2020
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Total access: 996

Quim. Nova 2021, 44(4), 493-501

 

Sala de aula invertida no ensino da química orgânica: um estudo de caso

Bruna R. F. da SilvaI; Sebastião L. da Silva NetoI; Bruno S. LeiteII*


The application of the flipped classroom in the teaching organic chemistry, specifically NMR, in two classes of a Chemistry degree course is discussed in this article revealing possibilities for the teaching and learning processes.

http://dx.doi.org/10.21577/0100-4042.20170677

Publicado online: novembro 26, 2020
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Total access: 1829

Quim. Nova 2021, 44(4), 502-511

 

Uma proposta para o ensino de laboratório de química analítica qualitativa

Julia Pereira Postigo; Hellen Franciane Gonçalves Barbosa#; Roberta Maura Calefi##; Jany Hellen Ferreira de Jesus; Priscila Cervini; Rafael Martos Buoro; Rosa Lucia Simencio Otero; Éder Tadeu Gomes Cavalheiro*


Example of phenomenon observed when chloride is added to a solution containing the cations of Group I and when the filtrate from the hot solution is added to a solution containing chromate.

http://dx.doi.org/10.21577/0100-4042.20170673

Publicado online: novembro 18, 2020
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Total access: 4879

Quim. Nova 2021, 44(4), 512-518

 

Efeito do Hg2+ e dos íons Cu2+, Fe2+, Ni2+, Sn2+ E Zn2+ na estabilidade de nanopartículas de prata: uma prática interdisciplinar de nanotecnologia experimental

Aline Kaori KatanosakaI; Anne Helene FostierII#; Elias Barros SantosI*


Silver nanoparticles were synthesized using chitosan as a capping agent. The stability of AgNPs colloid was studied in the aqueous medium in the presence of Hg2+ and other ions using UV-vis spectroscopy.

http://dx.doi.org/10.21577/0100-4042.20170679

Publicado online: novembro 27, 2020
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Total access: 770

Assuntos Gerais Quim. Nova 2021, 44(4), 519-535

 

Salitre: o produto químico estratégico no passado do Brasil

Luciano E. FariaI,*; Carlos A. L. FilgueirasII


Carbonate outcrop of the western slope of monte Rorigo, in Santo Hipólito, MG.

http://dx.doi.org/10.21577/0100-4042.20170695

Publicado online: dezembro 15, 2020
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Total access: 1183

Quim. Nova 2021, 44(4), 536-541

 

A visita de Fritz Haber ao Brasil

Cássius Klay NascimentoI,#; João Pedro BragaII,*


This paper is about the visit of Fritz Haber to Brazil, in 1914. The present work tries to recover the historical fact behind the visit of this important scientist to Brazil.

http://dx.doi.org/10.21577/0100-4042.20170707

Publicado online: fevereiro 3, 2021
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Total access: 953

On-line version ISSN 1678-7064 Printed version ISSN 0100-4042
Química Nova
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