Publisher: SciELO   (Total: 911 journals)

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Showing 201 - 400 of 911 Journals sorted alphabetically
Cuadernos de Administración (Universidad del Valle)     Open Access   (Followers: 3)
Cuadernos de Contabilidad     Open Access   (Followers: 1)
Cuadernos de Desarrollo Rural     Open Access   (Followers: 1, SJR: 0.154, CiteScore: 0)
Cuadernos de Economía     Open Access   (SJR: 0.115, CiteScore: 0)
Cuadernos de Economía     Open Access   (Followers: 2)
Cuadernos de Economia - Latin American J. of Economics     Open Access   (Followers: 3)
Cuadernos de Historia     Open Access   (Followers: 2)
Cuadernos de Historia de la Salud Publica     Open Access  
Cuadernos de Medicina Forense     Open Access   (Followers: 2, SJR: 0.1, CiteScore: 0)
Cuadernos de Psicologia del Deporte     Open Access   (SJR: 0.423, CiteScore: 1)
Cuadernos del CENDES     Open Access   (SJR: 0.109, CiteScore: 0)
Cuadernos.info     Open Access   (SJR: 0.38, CiteScore: 0)
Cubo. A Mathematical J.     Open Access  
Cuestiones Constitucionales     Open Access   (Followers: 2, SJR: 0.1, CiteScore: 0)
Cuicuilco     Open Access   (Followers: 1)
Cuicuilco. Revista de Ciencias Antropológicas     Open Access   (Followers: 1)
Cultivos Tropicales     Open Access   (Followers: 1)
Cultura y Representaciones Sociales     Open Access   (Followers: 1)
Culturales     Open Access   (Followers: 3)
Dados - Revista de Ciências Sociais     Open Access   (SJR: 0.37, CiteScore: 0)
De Jure     Open Access   (Followers: 1)
DELTA : Documentação de Estudos em Lingüística Teórica e Aplicada     Open Access   (SJR: 0.133, CiteScore: 0)
Dementia & Neuropsychologia     Open Access   (Followers: 11, SJR: 0.205, CiteScore: 0)
Dental Press J. of Orthodontics     Open Access   (Followers: 5, SJR: 0.489, CiteScore: 1)
Desacatos     Open Access   (Followers: 1)
Desacatos : Revista de Antropología Social     Open Access   (Followers: 1)
Desarrollo y Sociedad     Open Access   (Followers: 3, SJR: 0.109, CiteScore: 0)
Diálogo Andino - Revista de Historia, Geografía y Cultura Andina     Open Access   (Followers: 1, SJR: 0.116, CiteScore: 0)
Diánoia     Open Access   (Followers: 1)
Dimensión Empresarial     Open Access  
Discusiones Filosóficas     Open Access   (Followers: 1)
Dynamis : Acta Hispanica ad Medicinae Scientiarumque Historiam Illustrandam     Open Access   (Followers: 3, SJR: 0.131, CiteScore: 0)
e-J. of Portuguese History     Open Access   (Followers: 2, SJR: 0.101, CiteScore: 0)
e-Pública : Revista Eletrónica de Direito Público     Open Access   (Followers: 1)
Earth Sciences Research J.     Open Access   (Followers: 1)
Eclética Química     Open Access   (Followers: 1)
Ecología en Bolivia     Open Access  
Economia Aplicada     Open Access   (SJR: 0.208, CiteScore: 0)
Economia e Sociedade     Open Access  
Economía Mexicana. Nueva Época     Open Access   (Followers: 1)
EconoQuantum     Open Access  
Educação & Sociedade     Open Access   (Followers: 3)
Educação & Realidade     Open Access  
Educação e Pesquisa     Open Access   (Followers: 1, SJR: 0.163, CiteScore: 0)
Educação em Revista     Open Access  
Educación Matemática     Open Access  
Educación Médica     Open Access   (Followers: 1, SJR: 0.236, CiteScore: 0)
Educación Médica Superior     Open Access   (Followers: 1, SJR: 0.237, CiteScore: 0)
Educación y Educadores     Open Access  
Educar em Revista     Open Access  
EDUMECENTRO     Open Access  
Eidos     Open Access   (SJR: 0.119, CiteScore: 0)
En-Claves del pensamiento     Open Access   (Followers: 1, SJR: 0.194, CiteScore: 0)
Encuentros     Open Access  
Ene : Revista de Enfermería     Open Access  
Enfermería Global     Open Access   (Followers: 3, SJR: 0.165, CiteScore: 0)
Enfermería Nefrológica     Open Access   (Followers: 1, SJR: 0.198, CiteScore: 0)
Enfoques     Open Access  
Engenharia Agrícola     Open Access   (SJR: 0.305, CiteScore: 1)
Engenharia Sanitaria e Ambiental     Open Access   (SJR: 0.218, CiteScore: 0)
Ensaio Avaliação e Políticas Públicas em Educação     Open Access   (Followers: 1, SJR: 0.254, CiteScore: 0)
Ensayos de Economía     Open Access   (Followers: 1)
Ensayos Revista de Economía     Open Access  
Entomologia y Vectores     Open Access   (Followers: 2)
Entre Ciencia e Ingeniería     Open Access   (Followers: 1)
Epidemiologia e Serviços de Saúde     Open Access  
Escritos de Psicología : Psychological Writings     Open Access   (Followers: 2)
Espacios en Blanco : Revista de educación     Open Access  
Estudios Atacameños     Open Access   (Followers: 2, SJR: 0.446, CiteScore: 1)
Estudios Constitucionales     Open Access   (Followers: 5, SJR: 0.319, CiteScore: 0)
Estudios de Cultura Maya     Open Access   (Followers: 2, SJR: 0.272, CiteScore: 0)
Estudios de Economía     Open Access   (SJR: 0.121, CiteScore: 0)
Estudios de historia moderna y contemporánea de México     Open Access   (SJR: 0.101, CiteScore: 0)
Estudios Economicos     Open Access  
Estudios Filologicos     Open Access   (SJR: 0.107, CiteScore: 0)
Estudios Fronterizos     Open Access   (Followers: 1)
Estudios internacionales     Open Access   (Followers: 5)
Estudios Pedagogicos (Valdivia)     Open Access   (Followers: 1, SJR: 0.338, CiteScore: 0)
Estudios Políticos     Open Access  
Estudios Sociales     Open Access   (Followers: 2)
Estudios sociales : Revista de alimentación contemporánea y desarrollo regional     Open Access   (Followers: 1)
Estudios Socioterritoriales : Revista de Geografía     Open Access  
Estudios y Perspectivas en Turismo     Open Access   (Followers: 2)
Estudos Afro-Asiáticos     Open Access   (Followers: 2)
Estudos Avançados     Open Access   (SJR: 0.232, CiteScore: 0)
Estudos de Psicologia (Campinas)     Open Access   (Followers: 1, SJR: 0.233, CiteScore: 0)
Estudos de Psicologia (Natal)     Open Access   (SJR: 0.117, CiteScore: 0)
Estudos Econômicos     Open Access   (SJR: 0.204, CiteScore: 0)
Estudos Históricos     Open Access   (Followers: 1)
EURE (Santiago) - Revista Latinoamericana de Estudios Urbano Regionales     Open Access   (SJR: 0.38, CiteScore: 1)
Ex aequo     Open Access  
FEM : Revista de la Fundación Educación Médica     Open Access  
Fides et Ratio : Revista de Difusión Cultural y Científica     Open Access   (Followers: 1)
Fisioterapia e Pesquisa     Open Access  
Fisioterapia em Movimento     Open Access  
Fitosanidad     Open Access  
Floresta e Ambiente     Open Access   (Followers: 1, SJR: 0.3, CiteScore: 0)
Folios     Open Access  
Food Science and Technology (Campinas)     Open Access   (Followers: 1, SJR: 0.467, CiteScore: 1)
Formación Universitaria     Open Access   (Followers: 4, SJR: 0.213, CiteScore: 1)
Frónesis     Open Access   (Followers: 1)
Frontera Norte     Open Access  
Gaceta Médica Boliviana     Open Access  
Gaceta Médica Espirituana     Open Access  
Galáxia (São Paulo)     Open Access  
Gayana (Concepcion)     Open Access   (SJR: 0.236, CiteScore: 0)
Gayana. Botanica     Open Access   (SJR: 0.234, CiteScore: 0)
Genetics and Molecular Biology     Open Access   (Followers: 15, SJR: 0.638, CiteScore: 2)
Geofísica internacional     Open Access   (SJR: 0.312, CiteScore: 1)
Gerokomos     Open Access   (Followers: 1, SJR: 0.257, CiteScore: 0)
Gestão & Produção     Open Access   (SJR: 0.156, CiteScore: 0)
Gestión y Política Pública     Open Access   (Followers: 2, SJR: 0.106, CiteScore: 0)
Hacia la Promoción de la Salud     Open Access  
Hallazgos     Open Access   (Followers: 1)
Hidrobiológica     Open Access   (SJR: 0.166, CiteScore: 0)
Historia     Open Access   (Followers: 2)
Historia (Santiago)     Open Access   (Followers: 1, SJR: 0.162, CiteScore: 0)
História (São Paulo)     Open Access   (SJR: 0.11, CiteScore: 0)
História, Ciências, Saúde - Manguinhos     Open Access   (Followers: 2, SJR: 0.144, CiteScore: 0)
Hoehnea     Open Access  
Horizonte Sanitario     Open Access   (Followers: 1)
Horizontes Antropológicos     Open Access   (Followers: 3, SJR: 0.233, CiteScore: 0)
Horticultura Brasileira     Open Access   (SJR: 0.605, CiteScore: 1)
HTS Theological Studies     Open Access   (Followers: 8, SJR: 0.448, CiteScore: 0)
Humanidades Médicas     Open Access  
IDESIA : Revista de Agricultura en Zonas Áridas     Open Access   (SJR: 0.223, CiteScore: 0)
Iheringia. Série Zoologia     Open Access   (Followers: 1, SJR: 0.26, CiteScore: 1)
Íkala : Revista de Lenguaje y Cultura     Open Access   (SJR: 0.112, CiteScore: 0)
Image & Text     Open Access   (Followers: 1)
Index de Enfermeria     Open Access   (Followers: 7, SJR: 0.113, CiteScore: 0)
Indo-Pacific J. of Phenomenology     Open Access   (Followers: 1)
Infectio     Open Access   (SJR: 0.133, CiteScore: 0)
Información Tecnológica     Open Access   (SJR: 0.197, CiteScore: 0)
Ingeniare : Revista Chilena de Ingenieria     Open Access   (Followers: 1, SJR: 0.239, CiteScore: 0)
Ingeniería Electrónica, Automática y Comunicaciones     Open Access  
Ingeniería Hidráulica y Ambiental     Open Access  
Ingeniería Industrial     Open Access  
Ingeniería Mecánica     Open Access   (Followers: 4)
Ingenieria Mecánica. Tecnologia y Desarrollo     Open Access   (Followers: 3)
Ingeniería y Competitividad     Open Access  
Ingeniería y Desarrollo     Open Access  
Ingenieria y Universidad     Open Access   (Followers: 1, SJR: 0.161, CiteScore: 1)
Ingeniería, Investigación y Tecnología     Open Access   (Followers: 1)
Innovar     Open Access   (SJR: 0.118, CiteScore: 0)
Interações (Campo Grande)     Open Access  
Interface - Comunicação, Saúde, Educação     Open Access   (Followers: 1, SJR: 0.417, CiteScore: 0)
Intersticios Sociales     Open Access   (Followers: 1)
Intervención     Open Access   (Followers: 1)
Intervención Psicosocial     Open Access   (SJR: 0.381, CiteScore: 1)
Intl. Brazilian J. of Urology     Open Access   (Followers: 5, SJR: 0.367, CiteScore: 1)
Intl. J. of Morphology     Open Access  
Intl. J. of Odontostomatology     Open Access   (Followers: 1)
Intl. Law: Revista Colombiana de Derecho Internacional     Open Access   (Followers: 3)
Investigación Administrativa     Open Access   (Followers: 1)
Investigación Bibliotecológica     Open Access   (Followers: 6, SJR: 0.274, CiteScore: 0)
Investigación Económica     Open Access   (Followers: 4, SJR: 0.132, CiteScore: 0)
Investigación y Desarrollo     Open Access   (Followers: 1)
Investigación y Educación en Enfermería     Open Access   (Followers: 1, SJR: 0.198, CiteScore: 0)
Investigaciones Geográficas     Open Access   (SJR: 0.246, CiteScore: 0)
Investigaciones Marinas     Open Access  
Iteckne     Open Access  
Iuris Tantum Revista Boliviana de Derecho     Open Access  
Ius et Praxis     Open Access   (SJR: 0.283, CiteScore: 0)
Izquierdas     Open Access   (SJR: 0.188, CiteScore: 0)
Iztapalapa : Revista de ciencias sociales y humanidades     Open Access   (Followers: 1)
J. of Applied Oral Science     Open Access   (SJR: 0.645, CiteScore: 2)
J. of Applied Research and Technology     Open Access   (SJR: 0.255, CiteScore: 1)
J. of Coloproctology     Open Access   (SJR: 0.167, CiteScore: 0)
J. of Energy in Southern Africa     Open Access   (Followers: 3, SJR: 0.249, CiteScore: 1)
J. of Epilepsy and Clinical Neurophysiology     Open Access   (Followers: 7)
J. of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 11, SJR: 0.146, CiteScore: 1)
J. of Seed Science     Open Access   (Followers: 1)
J. of Soil Science and Plant Nutrition     Open Access   (Followers: 12, SJR: 0.823, CiteScore: 2)
J. of Technology Management & Innovation     Open Access   (Followers: 5, SJR: 0.271, CiteScore: 1)
J. of the Brazilian Chemical Society     Open Access   (Followers: 2, SJR: 0.357, CiteScore: 1)
J. of the Brazilian Society of Mechanical Sciences     Open Access   (Followers: 2)
J. of the Chilean Chemical Society     Open Access   (Followers: 2, SJR: 0.201, CiteScore: 1)
J. of the Mexican Chemical Society     Open Access   (Followers: 2, SJR: 0.214, CiteScore: 1)
J. of the Selva Andina Research Society     Open Access   (Followers: 3)
J. of the South African Institution of Civil Engineering     Open Access   (Followers: 2, SJR: 0.174, CiteScore: 0)
J. of the Southern African Institute of Mining and Metallurgy     Open Access   (Followers: 6)
J. of Theoretical and Applied Electronic Commerce Research     Open Access   (Followers: 1, SJR: 0.477, CiteScore: 2)
J. of Venomous Animals and Toxins     Open Access   (Followers: 2)
JISTEM : J. of Information Systems and Technology Management     Open Access   (Followers: 7)
Jornal Brasileiro de Nefrologia     Open Access   (SJR: 0.334, CiteScore: 1)
Jornal Brasileiro de Patologia e Medicina Laboratorial     Open Access   (SJR: 0.143, CiteScore: 0)
Jornal Brasileiro de Pneumologia     Open Access   (SJR: 0.448, CiteScore: 1)
Jornal Brasileiro de Psiquiatria     Open Access   (Followers: 3, SJR: 0.224, CiteScore: 0)
Jornal da Sociedade Brasileira de Fonoaudiologia     Open Access  
Jornal de Pneumologia     Open Access  
Jornal Vascular Brasileiro     Open Access   (SJR: 0.136, CiteScore: 0)
Justicia Juris     Open Access  
Kriterion: Revista de Filosofia     Open Access   (Followers: 1, SJR: 0.114, CiteScore: 0)
Kronos : Southern African Histories     Open Access   (Followers: 6)
La ventana. Revista de estudios de género     Open Access  
La zaranda de ideas     Open Access   (Followers: 1)
Laboreal     Open Access  
Lankesteriana     Open Access   (SJR: 0.458, CiteScore: 1)
Latin American Applied Research     Open Access   (Followers: 1)
Latin American J. of Aquatic Research     Open Access   (SJR: 0.289, CiteScore: 1)

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Journal of the Brazilian Chemical Society
Journal Prestige (SJR): 0.357
Citation Impact (citeScore): 1
Number of Followers: 2  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0103-5053 - ISSN (Online) 1678-4790
Published by SciELO Homepage  [911 journals]
  • Study of the Effect of Inhibitors Solutions on the Chemical Composition of
           Waxes by Rheology Tests and High Resolution Mass Spectrometry

    • Abstract: Wax deposit is of a great concern in the petroleum industry and causes partial or total blockage of the pipelines. In this work, four Brazilian crude oils (P1-P4) and five inhibitors solutions (I1-I5) were used associating rheology results to understand, at a molecular level, the characteristics of the saturated fractions by high-resolution mass spectrometry (Orbitrap coupled to atmospheric pressure chemical ionization (APCI) source) and two-dimensional gas chromatography coupled to mass spectrometry (GC × GC-MS). The effectiveness of wax inhibitors can be demonstrated by the viscosity decrement. The characterization of the saturated fractions by GC × GC-MS and high resolution mass spectrometry showed that is possible to conclude that inhibitor I1 favored the inhibition process of paraffins when oils have a smaller and monocyclic saturated chain hydrocarbon (HC) profiles, whereas for oils with larger amounts of polycyclic chain HCs, the inhibitor I4 appeared to be the alternative.
       
  • Upconversion 3D Printed Composite with Multifunctional Applications for
           Tissue Engineering and Photodynamic Therapy

    • Abstract: Upconversion nanoparticles (UCNPs) are suitable materials for bioapplications due to their ability to emit visible light under near infrared (NIR) excitation, in the biological transparency range. Polycaprolactone(PCL)-based scaffolds are widely used in tissue engineering in combination with inorganic compounds to improve bioactivity and osteoconductive properties. This work proposes a 3D printed composite scaffold with upconversion property aiming at biomedical applications in therapy-stimulated bone repair and photodynamic therapy (PDT). The system combines PCL polymer, UCNPs-apatite and a PDT photosensitizer. Thermal and rheological behaviors of the composite were similar to pure PCL polymer. Mechanical properties were improved by adding UCNPs-apatite. The 3D printable composite presented upconversion property and potential for PDT application, which was demonstrated by singlet oxygen generation under 980 nm excitation. Cytotoxicity, genotoxicity and mutagenicity assays indicated no toxicological effects at low concentrations of rare earth elements. Taken together, a potential multifunctional material is proposed for biomedical applications.
       
  • Potential Slow Release Fertilizers Based on K2MgSiO4 Obtained from
           Serpentinite

    • Abstract: In this work, a potassium magnesium silicate mineral based on phase K2MgSiO4 was prepared from serpentinite rock and studied as a potential K and Mg slow-release fertilizer. The material was prepared by impregnation of serpentinite/KOH and calcination at 700 °C to produce K2MgSiO4 phase, olivine and forsterite. The release patterns of K and Mg in the stirred-flow trial and leaching through the soil columns showed that K2MgSiO4-based materials released K on lower rates than KCl and MgSO4.7H2O, however, there was no evidence of Mg release. The extraction with 1 mol L-1 NH4OAc showed a considerable content of Mg and K for K2MgSiO4-based materials, due to exchange of NH4+ and Mg2+. X-ray diffraction (XRD) analysis of materials impregnated with K and calcined showed peaks relative to K2MgSiO4. After leaching, the peaks intensity diminished, supporting that part of K leached. Therefore, the samples showed great potential as slow-release K-fertilizers when compared with KCl source.
       
  • A Protocol for Fish Lipid Analysis Using Nuclear Magnetic Resonance
           Spectroscopy

    • Abstract: This article reports on an easy-to-follow methodology for fish lipids analysis, including the biological sample collection, lipid extraction, sample preparation, nuclear magnetic resonance (NMR) spectroscopy analysis and statistical data analysis, with details on parameters used for the NMR analysis and the care needed in each step execution. As an example of the biological matrix of lipids, for the entire procedure, we have used two Amazonian fish samples. Phenotype factor was taken into account when lipid contents of the Amazonian fish samples were evaluated, such as fish-eating habits in distinct Amazon seasonal periods, the flood and the drought. Results demonstrated the applicability of NMR as a powerful and useful tool for fish oil analysis. The omnivorous (T. elongatus) and the piscivorous (C. monoculus) Amazonian fish differ in composition and distribution of lipids, which show differences not only because of the different eating habits between the two species, but also by the availability and quantity of food along the year, i.e., during the flood and drought Amazon periods.
       
  • Geochemical Investigation of Tar Balls Collected in a Brazilian Beach
           Using Biomarkers, Ni/V, δ13C Ratios and Ultra-High Resolution FT-ICR Mass
           Spectrometry

    • Abstract: Representative tar balls collected in two distinct years (2012 and 2014) in a beach along the State of Bahia, northeastern Brazil, were geochemically characterized in order to identify correlations between them and investigate potential sources. Terpanes and steranes biomarkers (detected by gas chromatography coupled to mass spectrometry, GC-MS), carbon stable isotope ratio (δ13C), Ni and V ratios and polar compounds by Fourier transform ion cyclotron resonance mass spectrometry using electrospray ionization in negative mode (ESI(-) FT-ICR MS) were evaluated. Three Brazilian oil samples from distinct sources were assessed as possible spill sources, comparing their results with the tar ball samples. Using chemometric techniques, it was verified correlation between the two set of tar ball samples, suggesting same source. However, no correlation with the oil samples was observed, with different geochemical profile among them. The heteroatom class distribution displayed severe degradation levels for tar balls and its seems that photo-oxidation and biodegradation processes were further relevant. Tar ball samples show multiple classes, most oxygenated, and with one sample showing considerable relative abundance of N1 class, suggesting it is from a more recent oil spill. In brief, our results suggest that the region, with very sensitive ecosystem, is possibly subjected to frequent spills from the same source.
       
  • Spatial and Temporal Effects of Decommissioning a Zinc Smelter on the
           Sediment Quality of an Estuary System: Sepetiba Bay, Rio de Janeiro,
           Brazil

    • Abstract: Sepetiba Bay, Rio de Janeiro, Brazil, was home to a zinc smelter until its shutdown in 1998, and during 2011 the remains of the smelter were decommissioned. This study investigates the impact of decommissioning on metal concentrations in the bottom sediments of the bay. In addition to Zn and Cd, Cr, Cu, Ni and Pb are also quantified. The results show that over these 15 years, Cd and Zn concentrations have decreased by 100 and 70%, respectively. Temporal effects are also studied by applying five dated 210Pb cores, which are validated using the Zn and Cd profiles. The observed decrease in the Zn concentration in oysters is correlated with its reduction in the sediment. It was possible to verify the impact of Cr, Cu, Ni and Pb on the sediment quality due to the remaining metallurgical industries in the Sepetiba Bay basin.
       
  • Near-Infrared Luminescence from Visible-Light-Sensitized
           Ruthenium(II)-Neodymium(III) Heterobimetallic Bridged Complexes Containing
           Alkoxy(silyl) Functional Groups

    • Abstract: New infrared emitting d-f (ruthenium(II)-neodymium(III)) heterobimetallic complexes with alkoxy(silyl) functional groups have been prepared. Visible excitation evidenced energy transfer processes from the ruthenium(II) donor to neodymium(III) acceptors leading to infrared emission. Energy transfer rates (kEnT) and efficiency of energy transfer (ηEnT) are, respectively, 0.61 × 107s-1 and 44% for RuL1-NdL3 complex. Larger values of kEnT (3.04 × 107 s-1) and ηEnT (84%) were detected for RuL2-NdL4 complex. RuL1-NdL3 and RuL2-NdL4 complexes were fully characterized by elementary analysis (EA), mass spectrometry (MS), Fourier transform infrared spectroscopy (FTIR) and Fourier transform Raman spectroscopy (FT-Raman). Total correlation spectroscopy (TOCSY1D), 1H{13C} heteronuclear single quantum correlation (HSQC) and 1H{13C} heteronuclear multiple bond correlation (HMBC) nuclear magnetic resonance (NMR) analyses were also carried out to characterize NdL3 and RuL1-NdL3 complexes. The presence of trialkoxysilyl-substituted ligands would allow further grafting onto any silica or silicated surface aiming at applications as new luminescent near infrared (NIR)-emitting biosensors or biomarkers.
       
  • New Allyldithiocarbimates: Synthesis, Structure and Antifungal Activity
           against Phakopsora pachyrhizi and Hemileia vastatrix

    • Abstract: Twelve tetraphenylphosphonium allyldithiocarbimates were synthesized and fully characterized by high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), infrared and nuclear magnetic resonance (NMR) spectroscopies. The spectroscopic data indicated that the allyldithiocarbimate anions present Z configuration, as confirmed by X-ray crystallography. These new compounds inhibited the germination of Phakopsora pachyrhizi and Hemileia vastatrix at very low doses, with IC50 (concentration to achieve 50% of inhibition of spore germination) values ranging from 0.028 to 0.166 mmol L-1, and IC90 (concentration to achieve 90% of inhibition of spore germination) values varying from 0.156 to 0.528 mmol L-1. Allyldithiocarbimate salts are lead compounds for the development of new antifungals for coffee leaf rust and Asian soybean rust, devastating plant diseases with limited control options.
       
  • Chemometric Optimization of the Methodology for Determination of
           Molybdenum in Soils and Plants by Square Wave Adsorptive Stripping
           Voltammetry

    • Abstract: The method is based on the adsorptive accumulation of complex molybdenum(VI) with 8-hydroxyquinoline, using voltammetric square wave cathodic stripping voltammetry. The composition and concentration of the supporting electrolyte, frequency (Hz), amplitude (mV) and deposition time (s), were optimized by factorial design in relation to current reduction of molybdenum(VI). The optimum methodology provided the following values for the process variables: scan increase (0.5 mV), pulse amplitude (127 mV), frequency (96 Hz), adsorption time (80 s) and drop size (0.60 mm2), the concentration of KNO3 (2.0 mol L-1), acetate buffer (0.5 mol L-1) and 8-hydroxyquinoline (0.01 mol L-1). The results obtained after optimization showed a linear response in the range from 1.0 to 6.0 mg L-1 and limits of detection and quantification, respectively equal to 0.02 and 0.08 mg L-1. The molybdenum contained in the samples were determined using the optimized methodology, with values consistent with the values determined by atomic emission spectrometry with inductively coupled plasma (ICP-AES).
       
  • Metabolization of Insecticidal Amides from Leaves of Piper tuberculatum by
           Heraclydes hectorides and Naupactus bipes

    • Abstract: Amides have been recognized as potent insecticidal natural products but, despite their variety of targets and mechanisms of action, their metabolic fate in insects is virtually unknown. The currently accepted hypothesis is that specialist herbivores are capable of biotransforming xenobiotics rendering them more polar and excretable while generalist insects do not have comparable capacity. The leaves from Piper tuberculatum, rich in insecticide amides, were offered to two insect species found on Piper leaves under natural conditions and also to four generalist grasshoppers in order to compare their capacity of biotransforming xenobiotics. The amides 1-7 were identified in the P. tuberculatum leaves and their corresponding carboxylic acids 8-13 were detected in frass samples of two host insects suggesting that these species promote the amides hydrolysis. The four generalist grasshoppers when offered P. tuberculatum leaves, starved to death after 72 h, indicating a strong antifeedant activity of P. tuberculatum leaves.
       
  • The Comparative Investigation of Corrosion and Passivation for X65 Carbon
           Steel in pH 1 to 5 HNO3 Solutions without and with 0.01 mol L-1 NaNO2

    • Abstract: The influence of 0.01 mol L-1 NaNO2 addition on the corrosion and passivation of X65 carbon steel in pH 1 to 5 HNO3 solutions was investigated and compared by electrochemical methods and microstructural techniques. In the pH 1 to 5 solutions without NaNO2, the X65 steel presented the electrochemical characteristic of active dissolution, and the corrosion rate of X65 carbon steel decreased gradually with the raise of pH value. By contrast, with the addition of 0.01 mol L-1 NaNO2 in pH 1 to 5 HNO3 solutions, the electrochemical characteristic of X65 carbon steel transferred from the active dissolution in the pH 1 to 5 solutions without NaNO2 to the anodic passivation in the corresponding pH solutions with NaNO2. For the X65 steel in the pH 1 to 5 solutions with NaNO2, with the raise of pH value, the corrosion rate also decreased gradually but the passivation capability strengthened obviously. The corrosion and passivation of X65 carbon steel in pH 1 to 5 HNO3 solutions without and with 0.01 mol L-1 NaNO2 were related to the cathodic reactions of H+ reduction, O2 reduction and NO2-/HNO2 reduction.
       
  • Fast and Ecological Liquid-Liquid Separation Method for Preparing Quinones
           Enriched Extract from Nigella sativa Oil

    • Abstract: A fast, inexpensive, and ecological method based on liquid-liquid extraction principle has been developed for preparation of extract with high content of Nigella sativa (N. sativa) quinones. The gas chromatography-mass spectrometry (GC-MS) analysis showed that oil extraction using 70% ethanol for 6 h yielded extract containing 50% of thymoquinone (TQ) and 13% of thymohydroquinone (THQ).
       
  • Ultrasound-Promoted Synthesis, Structural Characterization and in vitro
           Antimicrobial Activity of New
           5-Aryl-3-(2-hydroxyphenyl)-4,5-dihydro-1H-pyrazole-1-carboximidamides

    • Abstract: This work aims the synthesis of amidino pyrazolines by the cyclocondensation reaction between 3-(hetero)aryl-1-(2-hydroxyphenyl)enones and aminoguanidine hydrochloride under sonochemical conditions. Thirteen new compounds were synthesized in 15-83% of yield after sonication for 30 min without purification by chromatography. Furthermore, antimicrobial activities of the synthesized compounds were investigated by in vitro minimum inhibitory concentration (MIC) in a panel of four bacterial strains and four Candida yeasts. As result, the 5-(4-bromophenyl)-3-(2-hydroxyphenyl)-4,5-dihydro-1H-pyrazole-1-carboximidamide hydrochloride was identified as the most active against gram-positive S. aureus and E. faecalis with MIC of 7.8 µg mL−1, similar to the value showed by chloramphenicol, which was used as standard.
       
  • Residue-Based CaO Heterogeneous Catalysts from Crab and Mollusk Shells for
           FAME Production Via Transesterification

    • Abstract: The production of fatty acid methyl esther (FAME) via transesterification was studied, assessing the influence of CaO heterogeneous catalysts obtained from four different fishery residues: sururu, crab, clam and mussel. Characterization and properties of the residues were obtained via thermogravimetric analysis, X-ray diffraction, X-ray fluorescence, Fourier transform infrared (FTIR) spectra, nitrogen adsorption/desorption, chemical composition and scanning electron microscopy (SEM). Catalytic activities and reaction kinetics of FAME synthesis from the transesterification of soybean oil were performed. FAME yield was determined by 1H nuclear magnetic resonance (NMR). A higher efficiency and reaction rate were observed for the catalysts obtained from the sururu residues with 93.7% FAME yield after 3.5 h of reaction at the first usage, reducing only to 91.0% after four consecutive cycles of reuse. The best activities were assigned to the presence of SrO, to smaller particle size, higher pore volumes and the higher Ca leaching, yielding Ca-diglyceroxide which is an important active phase for transesterification.
       
  • Ab initio Study of 17α-Ethinylestradiol and Estrone Molecules Interacting
           with Single Wall Carbon Nanotube

    • Abstract: In this work, a systematic study of 17α-ethinylestradiol and estrone molecules interacting with single wall carbon nanotube is presented by means of first principle calculations. The structural properties, binding energy, charge transfer, and electronic properties were calculated and analyzed to characterize the effect of interaction of 17α-ethinylestradiol and estrone molecules on the nanotube surface. Results show that the molecular structure and electronic character of single wall carbon nanotube were not affected due to the presence of the molecules. It is observed via binding energy calculated that ethinylestradiol and estrone molecules interact weakly with the nanotube. The results are very interesting once that they suggest that nanotubes are sensitive to 17α-ethinylestradiol and estrone molecules which can lead to confection of sensor to detect these molecules.
       
  • Metabolomics-Based Discovery of Biomarkers with Cytotoxic Potential in
           Extracts of Myracrodruon urundeuva

    • Abstract: Myracrodruon urundeuva (“aroeira-do-sertão”) is a species threatened with extinction due to anthropogenic exploitation. Phytochemical analysis of bark, branch and leaf extracts revealed the presence of several compounds such as flavonoids, phenols, tannins, quercetin derivatives and anacardic acids. Dereplication methodology was performed to tentatively identify 50 compounds analyzed by ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry operating in MSE mode (UPLC-QTOF-MSE). The extracts exhibited anti-tumor effect in cancer cells HCT-116 (colorectal), SF-295 (glioblastoma), HL-60 (leukemia), and RAJI (leukemia). Also, these results correlate with the principal component analysis (PCA) data that identified three distinct groups indicating, efficiently, metabolic differences between organs of M. urundeuva. Through discriminatory analysis of the orthogonal partial least squares (OPLS-DA), the variable of importance in the projection (VIP) and S-Plot, we were able to determine 30 potential biomarkers. The fingerprint of hydroethanolic extracts was correlated with the cytotoxicity assay and demonstrated a significant difference in the composition of plant extract.
       
  • Study of Thermoplastic Extrusion and Its Impact on the Chemical and
           Nutritional Characteristics and Two Sorghum Genotypes SC 319 and BRS 332

    • Abstract: The use of sorghum in human nutrition has been expanded due to its nutritional composition and its functional potential. Extrusion has been used to improve the quality of sorghum. The aim of this work was to assess the effect of extrusion in the nutritional composition, phenolic compounds content of two sorghum, and characterize the profile of chemical constituents by paper spray mass spectrometry (PS-MS). Extrusion increased the carbohydrate and fiber contents and reduced moisture, lipids and ashes, and enabling a higher degree of liberation of phenolic compounds and antioxidant activity. The fingerprint obtained in both ionization modes had been influenced by extrusion, allowing for a greater compounds’ identification on the extruded samples. The analysis of sorghum samples’ main components made distinguishing of the main constituents possible, as well as highlighted the extrusion effect and the influence of the genotypes. This study demonstrated that extrusion enabling a higher liberation of phenolic compounds, which were identified by the PS-MS technique.
       
  • Chitosan-Sodium Alginate Polyelectrolyte Complex Coating Pluronic® F127
           Nanoparticles Loaded with Citronella Essential Oil

    • Abstract: Pluronic® F127 nanoparticles were loaded with citronella essential oil (CEO) and then covered with chitosan-sodium alginate polyelectrolyte complex (PEC). The system was characterized according to size, zeta potential and stability over time. Dynamic light scattering (DLS) in different proportions of water/ethanol as a dispersive medium was important in confirming that PEC covered the F127 nanoparticles. Infrared spectroscopy also indicated interaction of F127 with PEC. The nanoparticle size evaluated by transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) corroborated the value observed in DLS (hydrodynamic radius (RH) range of 100-200 nm). Encapsulation efficiency of 80% for CEO was determined by UV-Vis spectroscopy. The release profile of the CEO was evaluated in phosphate buffer saline (PBS) containing 20% of ethanol and in simulated sweat fluid, achieving 74 and 81%, respectively. The releasing mechanism fitted the Korsmeyer-Peppas mathematical model, indicating Fickian diffusion behavior for both studied media.
       
  • Insecticidal and Acaricidal Activity of Essential Oils Rich in
           (E)-Nerolidol from Melaleuca leucadendra Occurring in the State of
           Pernambuco (Brazil) and Effects on Two Important Agricultural Pests

    • Abstract: Essential oils from the leaves, stems, flowers and fruits of Melaleuca leucadendra growing in the state of Pernambuco, Brazil, were analyzed using gas chromatography-mass spectrometry (GC-MS). The effects of the oils and their major constituent were evaluated on the agricultural pests Tetranychus urticae and Plutella xylostella in different stages of development. The analysis revealed a M. leucadendra chemotype rich in (E)-nerolidol (81.78 ± 0.90 to 95.78 ± 1.20%). P. xylostella was more susceptible to the oils and major constituent than T. urticae. The fruit oil was 1.5-fold more toxic than the leaf oil to T. urticae eggs. (E)-Nerolidol was 5.5-fold and 4.5-fold more toxic to T. urticae adults than the leaf and fruit oils, respectively. Azamax® used as the positive control was more efficient than the oils and (E)-nerolidol against T. urticae. However, the oils and (E)-nerolidol were more toxic to P. xylostella than Azamax®.
       
  • Synthesis of Glycerol-Derived 4-Alkyl-Substituted 1,2,3-Triazoles and
           Evaluation of Their Fungicidal, Phytotoxic, and Antiproliferative
           Activities

    • Abstract: Herein, the synthesis of nine novel glycerol-derived 4-alkyl-substituted 1,2,3-triazoles, using the CuI-catalyzed alkyne-azide cycloaddition reaction as the key step, is reported. The triazoles were characterized by infrared and nuclear magnetic resonance (NMR 1H and 13C) spectroscopy and mass spectrometry. The nine prepared compounds were evaluated with regard to their phytotoxic, antiproliferative, and fungicidal activities. The fungicidal activity was assessed on Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. All compounds presented high efficiency (comparable to the commercial fungicide tebuconazole) in inhibiting C. gloeosporioides sporulation. The phytotoxicity of the triazoles was assessed against Lactuca sativa. Germination was the less-affected parameter, whereas the most pronounced effects of the triazoles were on the germination speed index and root growth of the L. sativa seedlings. As indicators of antiproliferative activity, the mitotic index was evaluated along with chromosomal and nuclear alterations, all of which were influenced to different degrees by the triazoles. In addition, all derivatives demonstrated aneugenic and clastogenic actions in meristematic cells of L. sativa roots. Therefore, these 4-alkyl-substituted triazoles may represent a scaffold to be explored for the development of new fungicidal agents.
       
  • Structural and Functional Stabilization of Sericin from Bombyx mori
           Cocoons in a Biopolysaccharide Film: Bioorigami for Skin Regeneration

    • Abstract: Development and optimization of a bioorigami film with silk sericin was pursued for skin regeneration. Several formulations were produced, with varying integrated sericin contents, viz. 0, 1, 2, 5, 10, 20 and 50 mgsericin mLfilm-1. The physico-chemical characteristics of the bioorigami films produced were evaluated via infrared spectrophotometry, X-ray diffraction, X-ray transmission, X-ray fluorescence, thermogravimetry, differential scanning calorimetry, transdermal protein permeation, kinetics of protein release from the bioorigami films and free radical scavenging activities. The mechanical resistance was also evaluated. The results by 2,2-diphenyl-1-picryl-hydrazil (DPPH) assay suggest that the bioorigami films integrating crude sericin extract had capacity to sequester free radicals, exhibited prolonged release of the bioactive protein, good physico-chemical characteristics and adequate mechanical resistance. Specifically, the bioorigami film with 10 mgsericin mLfilm-1 proved to be able to release all the bioactive protein in a 12 h timeframe. The results suggest potential for use in biopharmaceutical application, specifically, as material for use in hydrogels.
       
  • Isolation, in vitro and in silico Evaluation of Phenylethanoid Glycoside
           from Arrabidaea brachypoda as Lipoxygenase Inhibitor

    • Abstract: Lipoxygenase (LOX) plays an important role in inflammatory processes and Arrabidaea brachypoda (DC.) Bureau (Bignoniaceae) has been described as presenting anti-inflammatory activity. Therefore, the objective of this study was to develop a high-performance liquid chromatography (HPLC) procedure to directly recognize LOX inhibitor compounds in A. brachypoda crude extract, facilitating the isolation, characterization of bioactive compounds, evaluation of natural compounds using an in vitro 15-LOX assay and prediction of the most probable binding modes of their main constituent through molecular docking simulations. The chemical analysis was performed by ethanol crude extract microfractionation using HPLC-DAD (diode array detector) associated to a fraction collector. The bioactive chromatogram displayed a peak with 50.9% LOX inhibition at 13.6 min retention time. The extract was purified and conandroside was isolated, presenting a LOX inhibitory activity with an inhibitory concentration (IC50) of 7.8 ± 1.1 µM, close to standard quercetin (IC50 7.6 ± 0.3 µM). Additionally, conandroside was not cytotoxic to normal cells (GM07492A). The LOX-conandroside complex displayed a slightly higher docking score (92.7) than quercetin (71.5). These results together suggest that conandroside could be explored as lipoxygenase inhibitor.
       
 
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