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Sol-Gel Relative Humidity Sensors: Impact of Electrode Geometry on Performance in Soil Suction Measurements

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Journal of Sensor Technology 2017年第1期7卷 1-23页

作者： rafaela cardoso Gabriele Sarapajevaite Oleksandr Korsun Susana cardoso Laura Ilharco Instituto Superior Técnico (IST) Universidade de Lisboa Lisbon Portugal Civil Engineering Research Innovation and Sustainability (CERIS) Institute of Construction Structures and Territory of IST (ICIST) Lisbon Portugal INESC-MN Microsystems and Nanotechnologies Lisbon Portugal CQFM Centro de Química-Física Molecular Instituto Superior Técnico (IST) Lisbon Portugal

This paper describes the experimental procedure followed to fabricate and validate sol-gel based RH sensors which will be incorporated in soil specimens for standard laboratorial tests. It is the first time such sensors were used for soil suction measurement. They are microfabricated relative humidity sensors (footprint area 11,000 μm × 22,000 μm) operating based on changes in electrical resistivity detected by a cerium doped silica titania film deposited using a sol-gel technique. Their design required gathering experts in several engineering specialties. The working principle of the sensors is based on water vapour equilibrium between the air in the soil and in the sol-gel pores, due to the contact between the two porous materials. The spacing between interdigitated aluminium electrodes was optimized to improve the sensing properties of the sol-gel. The calibration of the different prototypes was done against compacted clay, varying the spacing between 100 and 700 μm. The sensors were also incorporated in soil samples for suction measurement during wetting and drying paths. They were validated by comparing the readings with those from a water dew point potentiometer. From this study it was possible to determine the optimum electrodes spacing of 200 μm. Error was explained by sol-gel heterogeneity effect and by the resolution of the sensing area provided by the electrodes spacing. When comparing with other sensors operating inside soil specimens in standard laboratorial tests, these sol-gel sensors extend the operation range available with the alternative technologies: while conventional tensiometers measure suction ranges from 0 to 1.8 MPa, our sensors demonstrate good results between 1 to 10 MPa (and higher).

关键词： Microfabricated Interdigitated Electrodes Humidity Sensors Suction Unsaturated Soils

Initial Growth and Gas Exchanges of Plants of Colored Cotton Submitted to Saline Stress

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Agricultural Sciences 2018年第12期9卷 1652-1663页

作者： Hallyson Oliveira Ronaldo do Nascimento Samuel Silva José Alberto Ferreira cardoso rafaela Felix Basílio Guimaraes Elka Costa Santos Nascimento Post-Graduated of Agricultural Engineer Federal University of Campina GrandeCampina GrandeBrazil

The objective of the research was to evaluate the effects of saline stress on the initial growth and physiological parameters of three varieties of cotton plants, being two cultivars of colored fiber (BRS Topázio and BRS Verde) and one of white fiber (BRS 286). The experiment was conducted under greenhouse conditions. After chemical depletion with sulfuric acid, five seeds were seeded in polyethylene pots of 20 kg, leaving only one plant per pot after thinning. The experimental design was completely randomized, with a factorial scheme of 3 × 5, with five replications, totaling 75 plots, being three cotton varieties and five saline stress treatments—1.1;3.1;5.1;7.1;9.1 dS m−1. The evaluations occurred at 15 and 30 days after the beginning of the treatments (DAT) for growth variables (plant height, stem diameter, number of leaves and leaf area) and gas exchange (stomatal conductance, net photosynthesis rate and transpiration. The variety that was most resistant to the salt stress levels studied was BRS 286, followed by BRS Topazio and BRS Verde.

关键词： Photosynthesis Stomatal Conductance Dry Mass Resistance Cultivars

Essential Oils from Mentha piperita,Cymbopogon citratus,Rosmarinus officinalis,Peumus boldus and Foeniculum vulgare:Inhibition of Phospholipase A_(2) and Cytotoxicity to Human Erythrocytes

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American Journal of Plant Sciences 2017年第9期8卷 2196-2207页

作者： Danubia Aparecida de Carvalho Selvati Rezende Maria das Gracas cardoso rafaela Vieira Souza Maria Luisa Teixeira rafaela Magalhaes Brandao Vanuzia Rodrigues Fernandes Ferreira Jéssica Oliveira e Nogueira Maisa Lamounier Magalhaes Silvana Marcussi David Lee Nelson Departamento de Química Universidade Federal de Lavras Lavras Brasil Departamento de Ciência dos Alimentos Universidade Federal de Lavras Lavras Brasil Universidade Federal do Vale do Jequitinhonha e Mucuri Diamantina Brasil

The essential oils from Mentha piperita, Cymbopogon citratus, Rosmarinus officinalis, Peumus boldus and Foeniculum vulgare were extracted by hydrodistillation and characterized and quantified by GC-MS and GC-DIC. The oils induced hemolysis with all the doses evaluated (0.6 to 1.8 μL), and the diameters of the halos varied between 9 and 15 mm. Pre-incubation of P. boldus oil with Bothrops jararacussu venom resulted in potentiation of venom-induced hemolysis (30%) (proteases and phospholipases A2). The essential oil from M. piperita (0.6 μL) inhibited venom-induced hemolysis by 45%, whereas 0.6 μL of R. officinalis oil increased the hemolysis by 20%. For the essential oil from F. vulgare, 100% inhibition of activity (0.6 and 1.2 μL) was observed. The application of C. citratus oil induced hemolysis with all the volumes evaluated. Phospholipase activity induced by the venom was only inhibited (10%) with the 0.6 μL volume of R. officinalis oil. The oils from M. piperita and F. vulgare (1.8 μL) and C. citratus oil (0.6 μL) potentiated the phospholipase activity. The results highlight the need for a broad characterization and regulation of the use of natural products, because they can have therapeutic or toxic actions.

关键词： Natural Products Snake Venoms Hemolysis Pharmacological Potential

Evaluation of the Coagulating Potential of the Crude Extract from the Barbatimão Bark for the Treatment of Dairy Effluents

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American Journal of Plant Sciences 2016年第13期7卷 1685-1692页

作者： Vanuzia Rodrigues Fernandes Ferreira Josefina Aparecida de Souza Maria das Graças cardoso Luiz Gustavo de Lima Guimarães rafaela Magalhães Brandão rafaela Vieira Souza Luana Isac Soares Jéssica Oliveira e Nogueira Francielli D’Carlos Cravo David Lee Nelson Department of Chemistry Federal University of Lavras Lavras Brazil Federal University of Sao Joao Del Rei Sao Joao Del Rei Brasil Pro-Reitoria de Pesquisa e Pós-Graduacao Federal University of Vales de Jequitinhonha and Mucuri Diamantina Brazil

The coagulating potential of the crude extract from the barbatimao bark for the treatment of dairy effluent was assessed and compared with industrial coagulants such as aluminum sulfate (inorganic coagulant), the crude extract of black wattle bark (used in the manufacture of natural organic coagulants), and gallic acid (the main constituent of condensed tannins). The aqueous extract of barbatimao was obtained by refluxing for 12 h, and the black wattle was provided by a producer of natural coagulants. The determinations of total phenolic compounds and tannins in the extracts were performed by the Folin-Ciocalteu method and precipitation with casein, respectively. The treatment of the effluent with coagulant was performed by the Jar-Test. After testing, the effluent was evaluated for turbidity, total solids, and biochemical oxygen demand (BOD). A higher content of phenolic compounds (19.81% mg of gallic acid/g extract) was observed in the barbatimao extract than in the black wattle extract (14.24% mg of gallic acid/g extract). However, the extracts contained the same amount of tannins, 13.95% for the barbatimao extract and 12.89% for the black wattle extract. A 63%, reduction in BOD was observed for the effluent treated with barbatimao extract, 35% for the black wattle extract, 58% for gallic acid and 60.59% for the treatment with aluminum sulfate. Treatment with gallic acid caused a 98% reduction in the turbidity of the effluent;with aluminum sulfate, a 97% reduction was obtained;with barbatimao extract, 96%, and with black wattle extract, 93%. The barbatimao extract was shown to be a potential coagulant for dairy effluents.

关键词： Stryphnodendron adstringens Acacia mearnsii Tannins

Essential Oils from the Leaves and Flowers of Callistemon viminalis:Chemical Characterization and Evaluation of the Insecticide and Antifungal Activities

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American Journal of Plant Sciences 2017年第10期8卷 2516-2529页

作者： Thais Aparecida Sales Maria Das Gracas cardoso Luiz Gustavo De Lima Guimaraes Karen Caroline Camargo Danúbia Aparecida De Carvalho Selvati Rezende rafaela Magalhães Brandao rafaela Vieira Souza Vanúzia Rodrigues Fernandes Ferreira Ana Ermelinda Marques Maísa Lamounier Magalhaes David Lee Nelson epartment of Chemistry Federal University of LavrasLavrasBrazil Department of Natural Science Federal University of Sao Joao Del ReiSao Joao Del ReiBrazil Department of Food Science Federal University of LavrasLavrasBrazil Pro-Reitoria de Pesquisa e Pós-Graduacao Federal University of the Jequitinhonha and Mucuri ValleysDiamantinaBrazil

The chemical compositions of the essential oils from the leaves and flowers of Callistemon viminalis and their insecticide and fungitoxic activities were determined. The essential oil was extracted by the hydrodistillation method using a modified Clevenger apparatus. The chemical characterization was performed by GC-MS and GC-FID. The evaluation of the insecticidal activity was performed with the Myzus persicae aphid, and the antifungal potential was determined via the inhibition of the mycelial growth of Alternaria alternata, Fusarium oxysorum and Botrytis cinérea phytopathogenic fungi. The principal components of the essential oils from the leaves and flowers were eucalyptol (84.60% and 61.47%), α-pinene (10.28% and 21.48%) and α-terpineol (2.59% and 2.79%), respectively. The use of a 0.5% concentration of the essential oil from the flowers influenced the preference of aphids and their reproduction. The number of adult aphids decreased within a period of 48 hours in the presence of the essential oil from the leaves. In the test with no chance of choice, the mean number of adults decreased with both oils within 48 hours. No inhibition of the mycelial growth of the A. alternate microorganism was observed in any of the treatments with the two essential oils. However, the growth of F. oxysporum and B. cinerea fungi was inhibited. The mycelial growth of F. oxysporum was inhibited with the concentration of 100 μL·Lˉ1 of the oil from the flowers and 250 μL·Lˉ1 of the oil from the leaves. The inhibition of the growth of B. cinerea was observed at concentrations of 500 and 100 μL·Lˉ1 for the oils from the flowers and leaves, respectively. The essential oils presented insecticidal and antifungal potentials. However, further studies are needed for these oils to be used in integrated pest management.

关键词： Myzus persicae Biological Activity Phytopathogenic Fungi Natural Products

Comparison and Quantification of the Development of Phenolic Compounds during the Aging of Cachaca in Oak(Quercus sp)and Amburana(Amburana cearensis)Barrels

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American Journal of Plant Sciences 2014年第21期5卷 3140-3150页

作者： Wilder D.Santiago Maria das G.cardoso Juliana de A.Santiago Marcos S.Gomes Leonardo M.A.Rodrigues rafaela M.Brandao Rodolfo R.cardoso Gabriel B.d’Avila Bruno L.da Silva Alex R.S.Caetano Department of Chemistry Federal University of LavrasLavrasBrazil Department of Food Science Federal University of LavrasLavrasBrazil

Aging is a stage of the cachaça production process in which several chemical reactions occur between compounds extracted from the wood and other compounds present on the beverage. In an attempt to establish a profile regarding the chemical characterization of aged cachaças, phenolic compounds have been studied because of the specific characteristics of each wood species and their known antioxidant properties. This work sought to assess and compare the development of 12 phenolic compounds in cachaças aged in oak (Quercus sp) and amburana (Amburana cearenses) barrels during a period of 12 months. There was a progressive increase in the concentration of phenolic compounds in the beverage for both of the types of wood. The principal compounds encountered in the cachaça aged in oak barrels were gallic acid, syringaldehyde and syringic acid, while vanillic acid, syringaldehyde, sinapic acid and gallic acid were isolated from that aged in amburana barrels.

关键词： Beverage Aging Phenolic Compounds Liquid Chromatography

Essential Oils from Mentha viridis(L).*** Mentha pulegium L.:Cytogenotoxic Effects on Human Cells

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American Journal of Plant Sciences 2017年第6期8卷 1423-1437页

作者： Lucilene Fernandes Silva Maria das Gracas cardoso Paulo Sérgio Castilho Preté Maria Luisa Teixeira David Lee Nelson Maísa Lamounier Magalhaes Vanuzia Rodrigues Fernandes Ferreira rafaela Vieira Souza Luana Isac Soares Silvana Marcussi Departamento de Química Universidade Federal de LavrasCampus UniversitárioLavrasMinas GeraisBrasil Departamento de Química Universidade Federal dos Vales do Jequitinhonha e MucuriCampus UniversitárioDiamantinaMinas GeraisBrasil Departamento de Ciência dos Alimentos Universidade Federal de LavrasCampus UniversitárioLavrasMinas GeraisBrasil

The essential oils from Mentha viridis (L). L. and Mentha pulegium L. were studied to assess their inhibitory potential on phospholipase from snake venoms and to determine their cytogenotoxic action on human cells. These essential oils were able to inhibit the breakdown of phospholipids induced by venoms of snakes of the Bothrops genus. Both oils presented hemolytic activity, although the Mentha viridis (L). L. oil induced hemolysis only at the highest concentrations (14.6 and 29 μL·mL-1). The essential oil from M. viridis induced 3.9;8.6 and 16.2 times greater damage to human leukocyte DNA than that observed with the positive control (100 μg·μL-1 doxorubicin) at concentrations of 0.25;0.5 and 1.0 μL·mL-1, respectively. A similar effect was observed for the oil from M. pulegium (2.1, 2.5 and 15.8 times greater damage). The results extend the characterization of these essential oils and demonstrate their potential use in industries.

关键词： Essential Oils Mentha viridis(L).L. Mentha pulegium L. Hemolysis Comet Assay

Characterization of the Biological Potential of the Essential Oils from Five Species of Medicinal Plants

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American Journal of Plant Sciences 2017年第2期8卷 154-170页

作者： Danubia Aparecida Carvalho Selvati Rezende rafaela Vieira Souza Maisa Lamounier Magalh?es Alex Rodrigues Silva Caetano Marcos Schleiden Sousa Carvalho Ellen Cristina de Souza Luiz Gustavo de Lima Guimaraes David Lee Nelson Luís Roberto Batista Maria das Gra?as cardoso Departamento de Química Universidade Federal de LavrasLavrasBrasil Departamento de Ciencia dos Alimentos Universidade Federal de LavrasLavrasMGBrasil Departamento de Ciência dos Alimentos Universidade Federal de LavrasLavrasMGBrasil Departamento de Agricultura Universidade Federal de LavrasLavrasMGBrasil Universidade Federal de Sao Joao del-Rei Sao Joao del-ReiBrasil Universidade Federal do Vale do Jequitinhonha e Mucuri DiamantinaMGBrasil

Essential oils from Mentha piperita, Cymbopogon citratus, Rosmarinus officinalis, Peumus boldus and Foeniculum vulgare were extracted by hydrodistillation, chemically characterized and quantified by GC/MS and GC/FID. The principal componentes in the essential oil of M. piperita (carvone and limonene), C. citratus (geranial, neral and myrcene), R. officinalis (1,8-cineole, camphor and α-pinene), P. boldus (α-terpinyl formate, p-cymene and 1,8-cineole) and F. vulgare (methyl chavicol, limonene and fenchone) were identified. The oils were tested for antioxidant activity employing the DPPH (2,2-diphenyl-1-picryl-hydrazyl) radical-capture method, the oxidation of the β-carotene/linoleic acid system, and the ABTS radical-capture method. The essential oils were not effective. The antioxidant activities of the oils were determined by the hydroxyl method, and the highest activity (62.80%) was observed with the essential oil from M. piperita. Activities of 1.54 and 1.82 μg μg-1, respectively, were observed for the essential oils from C. citratus and P. Boldus using the phosphomolybdenum method. No activity was observed with respect to reducing power. The essential oil from C. citratus was effective in inhibiting the growth of L. monocytogenes (15.63 mg·L-1), S. choleraesuis (15.63 mg·L-1) and E. coli (31.25 mg·L-1), and the essential oil from P. boldus inhibited the growth of S. aureus (62.5 mg·L-1). No essential oil inhibited the growth of P. aeruginosa. A low antioxidant activity and a promising antibacterial activity were observed for these essential oils.

关键词： Natural Products Antioxidant Antibacterial Activity

Chemical Characterization and in Vitro Antitumor Activity of the Essential Oils from the Leaves and Flowers of Callistemon viminalis

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American Journal of Plant Sciences 2015年第16期6卷 2664-2671页

作者： Christiane Maria de Oliveira Maria das Gracas cardoso Marisa Ionta Marisi Gomes Soares Juliana de Andrade Santiago Guilherme álvaro Ferreira da Silva Maria Luisa Teixeira Danúbia Aparecida de Carvalho Selvati Rezende rafaela Vieira de Souza Luana Isac Soares David Lee Nelson Marcos Schleiden Sousa Carvalho Department of Chemistry Federal University of LavrasLavrasBrazil Institute of Biomedical Sciences Federal University of AlfenasAlfenasBrazil Department of Chemistry Federal University of AlfenasAlfenasBrazil Federal University of Vales de Jequitinhonha e Mucuri DiamantinaBrazil Department of Agriculture Federal University of LavrasLavrasBrazil

The objective of this study was to characterize and verify the in vitro antitumor activity of essential oils (EOs) extracted from the leaves and flowers of Callistemon viminalis. The EOs were extracted by hydrodistillation using a modified Clevenger apparatus. The identification and quantification of constituents were performed on a gas chromatograph coupled to a mass spectrometer and a gas chromatograph with a flame ionization detector. The antitumoral activity was evaluated by a colorimetric assay (MTS) using different cell lines derived from human tumors (breast, lung, glioblastoma, and melanoma). The major constituents of the EOs of leaves and flowers were similar, only quantitative differences being observed. The compounds 1,8-cineole, α-pinene and α-terpineol were found in concentrations of 50.4%, 25.8% and 8.7% in the EOs obtained from the leaves and 48.8%, 24.5% and 3.9% in the EOs obtained from the flowers, respectively. The cytotoxic activity of the EOs was observed only in melanoma cultures (HT144). Cultures treated for 48 h with EOs from leaves and flowers (200 μg·mL-1) reduced the viability by 40% and 25%, respectively. Thus, the antiproliferative activity of the EO from leaves was more pronounced than the EO from flowers in cells derived from melanoma.

关键词： Cancer Volatile Oil Escova-de-Garrafa(Bottle Brush)