Chemical And Spectroscopic Techniques
Mostrando 1-12 de 66 artigos, teses e dissertações.
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1. Spectroscopic techniques combined with chemometrics to study organic matter in tropical soils with different degrees of pedogenetic evolution
Understanding of the organomineral interactions in soil can elucidate the humic substances (HS) formation and the humification process. This study aimed to structurally characterize the humic acids (HA) formed in tropical soils with different pedogenesis degrees. The HA fraction was extracted from soil samples in the superficial horizons of an Inceptisol and
Química Nova. Publicado em: 2022
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2. Individuals with untreated psychiatric disorders and suicide in the COVID-19 era
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
Braz. J. Psychiatry. Publicado em: 2021-06
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3. Reduced Graphene Oxide/Ruthenium Oxide Hexacyanoferrate Nanocomposite for Electrochemical Determination of Ethanol in Commercial Samples
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
J. Braz. Chem. Soc.. Publicado em: 2021-06
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4. Increased depression and anxiety during the COVID-19 pandemic in Brazilian mothers: a longitudinal study
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
Braz. J. Psychiatry. Publicado em: 2021-06
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5. ANÁLISE ESPECTROSCÓPICA DA MATÉRIA ORGÂNICA NO SEDIMENTO SUPERFICIAL DA BAÍA DE SEPETIBA, RIO DE JANEIRO, BRASIL
Spectroscopic techniques are powerful tools for molecular organic matter assessment in sediments, which analysis request low sample mass and are cheap, fast and easy to obtain. The aim of this work was to evaluate the elemental (C, N) and molecular composition of the organic matter in relation to the grain-size distribution over surface sediments from Sepeti
Quím. Nova. Publicado em: 2020-05
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6. Iridoides, triterpenos e outros constituintes das cascas do caule e flores de Tabebuia caraiba Bignoniaceae
The trunk bark of Tabebuia caraiba Bignoniaceae was found to contain four novel iridoids, 6-O-E-p-coumaroyljioglutin D (2), 6-O-E-p-coumaroyl-3-demethyl-3-O-ethyljioglutin D (3), 6-O-E-p-coumaroyl-1-demethyl-1-O-ethyljioglutin D (4), 7-O-E-p-coumaroyljiofuranaldehyde (5), three known iridoids, including one iridoid glucoside, jioglutin D (1), rehmaglutin D (
Quím. Nova. Publicado em: 2020-04
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7. Chemical constituents from the fruits of Schisandra sphenanthera and their cytotoxicity activity
Abstract Schisandra sphenanthera Rehder & E.H. Wilson, Schisandraceae, is well known as a type of traditional medicine for the treatment of hepatitis, diarrhea and insomnia in Asia. It was also reported to have antiviral and anti-HIV activities. Using various chromatographic resins and isolation techniques, a new lignan (1), erythro-4-(3,4-dimethoxyphenyl)-4
Rev. bras. farmacogn.. Publicado em: 09/12/2019
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8. Chronic hypoglycemic effect and phytochemical composition of Smilax moranensis roots
ABSTRACT Smilax moranensis M.Martens & Galeotti, Smilacaceae, root is a medicinal plant used among the Chatinos in Oaxaca, Mexico, to control type 2 diabetes. The objectives of the study were to isolate the bioactive compounds from the roots of Smilax and evaluate the chronic hypoglycemic effect of the ethanol–water extract. The main compounds were isolate
Rev. bras. farmacogn.. Publicado em: 27/05/2019
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9. Flavonol Tri-O-glycoside and Other Chemical Constituents from Flowers of Aristolochia trulliformis
A new flavonol triglycoside, named kaempferol-3-O-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside, was isolated from flowers of Aristolochia trulliformis (Aristolochiaceae) together with 15 known compounds, including six flavonoids and four lignans. The structures of the compounds were determined by spectroscopic analyses, inclu
J. Braz. Chem. Soc.. Publicado em: 08/04/2019
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10. NEW DEGRADED QUINONE DITERPENOID FROM THE STEMS OF Byrsonima coccolobifolia Kunth. (Malpighiaceae)
A chemical investigation of two specimens of Byrsonima coccolobifolia collected in the southeast cerrado and from central Brazil was performed. A new degraded diterpenoid, byrsonimaquinone, was isolated from the stems along with known compounds. This is the first study on the roots of B. coccolobifolia, and several triterpenes, such as α-amyrin, β-amyrin,
Quím. Nova. Publicado em: 2018-02
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11. Influence of reaction time on the structure of polyaniline synthesized on a pre-pilot scale
Abstract The aim of this work is to follow the structural variations of polyaniline (PAni) obtained by chemical oxidation on a pre-pilot scale, with different reaction times. Synthesis of PAni is well known, but when it is carried out on a pre-pilot scale, several factors can lead to structural changes and understanding these changes is important to improve
Braz. J. Chem. Eng.. Publicado em: 2018-01
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12. Using Magnetized (Fe3O4 / Biochar Nanocomposites) and Activated Biochar as Adsorbents to Remove Two Neuro-Active Pesticides from Waters
This work describes the removal of pesticides from water using activated and magnetized biochars produced from exhausted husk, and dry tannin from barks of black wattle (Acacia mearnsii De Wild.). These materials were characterized using chemical, spectroscopic, thermal, solid structure and surface area techniques. The activated and magnetized biochars were
J. Braz. Chem. Soc.. Publicado em: 2017-10