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ISSN:0100-4042
ISSN:1678-7064 on line
Volume 38, Número 1, 2015
Artigo
1 A influência da ligação de hidrogênio em reações químicas:
reação de Prileschajew
Mauro A. Bueno e Boaz G. Oliveira
The epoxidation mechanism known as the Prileschajew reaction was reinvestigated
through the formation of hydrogen bonds between C2H4O and HCO2H.
8 The application of automated correlation optimized warping to the quality evaluation of Radix Puerariae thomsonii:
correcting retention time shift in the chromatographic fingerprints
Long Jiao, Shan Bing, Xiaofei Wang, Zhiwei Xue and Hua Li
Automated correlation optimized warping is a practical method for aligning the
chromatographic fingerprints of Radix Puerariae thomsonii. After this alignment,
the quality of Radix Puerariae thomsonii can be correctly evaluated.
14 Biofilms based on canihua flour (Chenopodium Pallidicaule):
design and characterization
Lady M. Salas-Valero, Delia R. Tapia-Blácido and
Florencia C. Menegalli
The flours isolated from canihua grains (Chenopodium Pallidicaule) can form films
that have low water vapor permeability and act as a good barrier to incident
ultraviolet light. Films formed from both varieties of canihua grains used in this
study (cupi and illpa-inia) presented a single vitreous transition temperature
(< 0 °C) and show promise for potential applications in food packaging.
22 Efeito da estrutura molecular de ligantes de superfície em
pontos quânticos de CdTe dispersos em água
Brener R. C. Vale, Kayo O. Vieira, José C. L. Sousa,
Jefferson L. Ferrari e Marco A. Schiavon
With increasing particle sizes of water-soluble mercaptoethylamine-capped
CdTe, the trap band energy stabilizes until the material reaches a critical size.
Thereafter, the TB is not observed in the photoluminescence spectra.
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30 Distribuição e fracionamento do Hg em sedimentos do Rio
Paraíba do Sul – RJ, Brasil
Beatriz F. Araujo, Marcelo G. de Almeida, Thiago P. Rangel
e Carlos E. de Rezende
Our results confirm the key role played by mangroves in controlling the fate of
mercurial compounds in coastal areas. Consequently, mangrove deforestation
should be considered a major source of environmental risk in tropical and
subtropical coastal regions.
37 Di-hidrocucurbitacina B: semi-síntese de novos derivados
glicosilados
Vanessa R. Machado, Karen L. Lang, Fernando J. Durán,
Gabriela M. Cabrera, Jorge A. Palermo, Eloir P. Schenkel
e Lílian S. C. Bernardes
Novel glycoside derivatives of dihydrocucurbitacin B were synthesized under
Köenigs-Knorr and imidate reaction conditions.
42 Chemical study of Hortia superba (Rutaceae) and investigation of the antimycobacterial activity of crude extracts and
constituents isolated from Hortia species
Vanessa G. P. Severino, Afif F. Monteiro, Mª Fátima das G.
F. da Silva, Rodrigo Lucarini and Carlos H. G. Martins
The picture describes the methodology used in the biological evaluation of Hortia
species against Mycobacterium tuberculosis H37Rv, M. kansasii and M. avium, and
the compounds that exhibited promising MIC values against M. tuberculosis H37Rv.
46 Esterificação e transesterificação simultâneas de óleos ácidos
utilizando carboxilatos lamelares de zinco como catalisadores
bifuncionais
Luiz P. Ramos, Ricardo J. Brugnago, Fabiano R. da Silva,
Claudiney S. Cordeiro e Fernando Wypych
Response surface demonstrating the ability of zinc carboxylates to promote the
simultaneous esterification and transesterification of palm oil with 40% in free
fatty acids.
Vol. 38, No. 1
55 Influência do tratamento térmico no nanocompósito fotocatalisador ZnO/TiO2
Mª Terezinha C. Sansiviero e Dalva L. A. de Faria
ZnO/TiO2 nanocomposites were treated at different temperatures, and anatase,
ZnO, and ZnTiO3 were formed when the sample was heated at 600 °C, whereas
the main phases obtained above 750 °C were rutile and ZnTiO3. The presence of
ZnTiO3 in the sample had no significant effect on the nanocomposite photocatalytic
activity.
60 Novos flavonoides de Margaritopsis carrascoana com atividade antioxidante
Raimundo R. G. Nascimento, Jackelyne A. Monteiro,
Antônia T. A. Pimenta, Mª Teresa S. Trevisan, Raimundo
Braz-Filho, Elnatan B. de Souza, Edilberto R. Silveira e
Mary A. S. Lima
Two new flavonoids and other known compounds were obtained from extracts
of the leaves and stems of Margaritopsis carrascoana. All isolated compounds
showed higher antioxidant activity, while the extract of the stems showed strong
AChE inhibition.
66 Volatile components from galls induced by Baccharopelma
dracunculifoliae (Hemiptera: Psyllidae) on leaves of Baccharis dracunculifolia (Asteraceae)
Michele A. Besten, Domingos S. Nunes, Daniel Granato,
Sávio L. Sens, Alberto Wisniewski Jr, Edesio L. Simionatto
and Dilamara Riva-Scharf
This article presents the first GC-MS analyses of volatiles from galls induced by
Baccharopelma dracunculifoliae and the results are compared with those from
healthy Baccharis dracunculifolia leaf samples.
71 Global and local reactivity descriptors for picloram herbicide:
a theoretical quantum study
Luis H. Mendoza-Huizar
The most reactive sites on picloram for electrophilic, free radical, and nucleophilic
attacks have been determined.
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Quim. Nova
77 Avaliação de métodos de solubilização para determinação
de metais em glicerina proveniente da produção de biodiesel
por técnicas de espectrometria atômica
Caroline D. Clasen, Meibel T. Lisboa, Ane M. T. P. Pinto,
Anderson S. Ribeiro e Mariana A. Vieira
Evaluation by atomic spectrometry of simple and fast solubilization methods for
the determination of Ca, Mg, and K in glycerin samples obtained from biodiesel
production.
85 Investigação do uso de eletrodo de carbono vítreo modificado
com hexacianoferrato de rutênio para detecção de procaína
Thalita G. Silva, Maiara O. Salles e Thiago R. L. C. Paixão
The use of a glassy carbon electrode modified with ruthenium hexacyanoferrate
was investigated. The aim was to detect procaine in abused drugs and
pharmaceutical formulations.
91 Nanopartículas de proteína isolada de soja em água: efeito
da força iônica e das concentrações de proteína e surfactante
Samira J. Fayad, Betina G. Z. Ramos, Valdir Soldi e Edson
Minatti
Soy protein isolate nanoparticles were obtained through the coacervation of an
aqueous protein solution. Morphology and stability analyses were followed by
light scattering and microscopy analyses.
Revisão
97 A versatilidade dos compostos de coordenação na produção
de polietilenos: uma revisão dos sistemas catalíticos
Emanoel I. da S. Oliveira, Fernando Silveira, Adelaide Mª
V. Viveiros, Nara R. S. Basso, Zênis N. da Rocha e João H.
Z. dos Santos
Various types of polyethylene can only be obtained because of the possibility
of modulating coordination compounds used as catalysts in the polymerization
process. Both the metal center and the ligands can be tuned, giving versatility
to such systems.
Vol. 38, No. 1
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106 Óxidos de nióbio: uma visão sobre a síntese do Nb2O5 e sua
aplicação em fotocatálise heterogênea
Osmando F. Lopes, Vagner R. de Mendonça, Fernando B.
F. Silva, Elaine C. Paris e Caue Ribeiro
The following scheme depicts the application sequence of niobium oxide
nanoparticles from an appropriate Nb source to heterogeneous photocatalysis.
Aspects such as the morphology, band gap, and surface area are defined by
the nanoparticles’ synthetic parameters, which also influence the catalyst
performance.
118 Arsênio e arroz: toxicidade, metabolismo e segurança alimentar
Juliana M. O. Souza, Maria F. H. Carneiro, Ana C. C.
Paulelli, Denise Grotto, Ariano M. Magalhães Júnior,
Fernando Barbosa Júnior e Bruno L. Batista
Rice plants have the tendency to absorb different arsenic species. This cereal
is a staple food for half of the global population. According to FAO/WHO, the
arsenic level of rice is an increasing concern in food safety. Understanding the
plant’s mechanisms and monitoring its safety are imperative.
Nota Técnica
128 Construção de um reator de plasma descarga corona para
eliminação de compostos orgânicos voláteis
Marina M. Machado, Marília M. Machado, Ana R. de A.
Dutra, Elisa H. S. Moecke e Anelise L. V. Cubas
A cold plasma reactor was built with low-cost materials in order to degrade volatile
organic compounds such as BTEX, known for their adverse effects on human health.
132 Construção de um dispositivo de pressurização a vácuo para
a preparação de fases estacionárias monolíticas via processo
sol-gel
Sandro P. Ribeiro, Fernando A. S. Vaz, Marcone A. L. de
Oliveira, Thiago de O. Mendes e José P. R. F. de Mendonça
This high pressurization device allows the capillary to be filled with a sol solution
through either positive or negative (vacuum) pressure. The latter procedure averts
contact between sol and the syringe thus avoiding damage.
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Quim. Nova
136 Aparato eletroquímico para sistema de aquisição de dados
multicanal com resolução espaço-temporal
Raphael Nagao, Melke A. Nascimento e Hamilton Varela
An electrochemical setup for a multichannel data acquisition system was
developed in order to obtain spatiotemporal resolution during the electrooxidation of small organic molecules.
Educação
144 A formação de professores em comunidades de prática: o
caso de um grupo de professores de química em formação
inicial
Valéria C. Santos e Agnaldo Arroio
This graphical abstract outlines the main elements of the research. The group
represents a community of practice in chemistry teaching.
151 Avoiding first-year university chemistry textbooks’ misrepresentations in the teaching of spontaneous reactions
Ana Quílez-Díaz and Juan Quílez-Pardo
The calculation (and the sign) of DrG establishes the direction of a chemical
reaction. Q–K inequalities are accurate options. However, the use of the sign of
DrGº or Le Châtelier’s principle leads to incorrect predictions.
156 Método de síntese de azidas aromáticas usando vinagre
Kauanna N. Hino e Álvaro T. Omori
A simple and low-cost procedure for preparation of aryl azides is described.
Vinegar (renewable source) can be used as solvent/reagent.
Carta ao Editor
159 Comentário sobre o artigo: “Modificação do polímero condutor polianilina para uso como trocador catiônico”
Retraction Notice
160 Adsorption of a copper (II) complex on calcium phosphate intercalated with 4-aminobenzoic acid – synthesis and electrochemical investigation
Quimica Nova, Vol. 36, No. 8, 1170-1175, 2013
Camila F. N. Silva, Fernando M. de Souza, Jéssica P. Santos, Ana Paula B. Dias, Ana Paula R. Santana, Angélica M. Lazarin, Rosana
L. Sernaglia, Elza I. S. Andreotti and Claudio Airoldi