Artículos Científicos

URI permanente para esta comunidadhttps://hdl.handle.net/20.500.13053/4496

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Examinando Artículos Científicos por Autor "Aguilar Vitorino, Hector"

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  • Miniatura
    PublicaciónAcceso abierto
    Bioherbicide from Azadirachta indica Seed Waste: Exploitation, Efficient Extraction of Neem Oil and Allelopathic Effect on Senna occidentalis
    (MDPI, 2023-05-24) De Paulo Barbosa, Larissa Macelle; Oliveira Santos, Jorge; Mouzinho de Sousa, Rayssa Carolinne; Barros Furtado, Jomar Livramento; Vidinha, Pedro; Suller Garcia, Marco Aurelio; Aguilar Vitorino, Hector; Fossatti Dall’Oglio, Daiane
    “Bioherbicides are an alternative to minimize the damage caused to the environment using agrochemicals. This study had the objective of extracting neem oil from ripe waste fruits that Azadirachta indica A. Juss and optimizing the process using solvents (or a mixture of solvents) with different polarities. Then, through a solid-liquid extraction system (Soxhlet), the solvents hexane, methanol/hexane (1:1), ethanol, and hexane/ethanol (1:1) were used to determine the process with the highest yield and most efficiency. The physicochemical parameters of the extracted oil (density, acidity value, iodine value, saponification value, esters value, and molecular weight) and the % of free fatty acids were determined. In addition, the allelopathic properties of the oil (0%, 2%, 3%, and 4% m/v) on septic weed Senna occidentalis seeds were evaluated, analyzing their growth and development parameters (germination, germination speed, hypocotyl, and radicle length). Hexane was the most efficient (4 h) in neem oil extraction, with the highest yield (43%). It also provided a better oleic and linoleic acid content (41.3% and 18.6%), similar to ethanol extraction (41.1% and 20.22%). Moreover, the allelopathic properties were more prominent for the oils extracted with hexane and hexane/ethanol. This optimized process provides an efficient alternative to obtain a natural herbicidal potential for strategically controlling harmful plants“
  • Miniatura
    PublicaciónAcceso abierto
    Bioherbicide from Azadirachta indica Seed Waste: Exploitation, Efficient Extraction of Neem Oil and Allelopathic Effect on Senna occidentalis
    (MDPI, 2023-05-24) De Paulo Barbosa, Larissa Macelle; Oliveira Santos, Jorge; Mouzinho de Sousa, Rayssa Carolinne; Barros Furtado, Jomar Livramento; Vidinha, Pedro; Suller Garcia, Marco Aurelio; Aguilar Vitorino, Hector; Dall’Oglio, Daiane Fossatti
    “Bioherbicides are an alternative to minimize the damage caused to the environment using agrochemicals. This study had the objective of extracting neem oil from ripe waste fruits that Azadirachta indica A. Juss and optimizing the process using solvents (or a mixture of solvents) with different polarities. Then, through a solid-liquid extraction system (Soxhlet), the solvents hexane, methanol/hexane (1:1), ethanol, and hexane/ethanol (1:1) were used to determine the process with the highest yield and most efficiency. The physicochemical parameters of the extracted oil (density, acidity value, iodine value, saponification value, esters value, and molecular weight) and the % of free fatty acids were determined. In addition, the allelopathic properties of the oil (0%, 2%, 3%, and 4% m/v) on septic weed Senna occidentalis seeds were evaluated, analyzing their growth and development parameters (germination, germination speed, hypocotyl, and radicle length). Hexane was the most efficient (4 h) in neem oil extraction, with the highest yield (43%). It also provided a better oleic and linoleic acid content (41.3% and 18.6%), similar to ethanol extraction (41.1% and 20.22%). Moreover, the allelopathic properties were more prominent for the oils extracted with hexane and hexane/ethanol. This optimized process provides an efficient alternative to obtain a natural herbicidal potential for strategically controlling harmful plants.“
  • Miniatura
    PublicaciónAcceso abierto
    Effect of Diet on Growth Performance of First Crab Stage Callinectes sapidus Rathbun, 1896 (Brachyura: Portunidae): A Comparison of Three Different Regimens
    (Animals, 2023-04-03) Gencer, Övgü; Aguilar Vitorino, Hector
    “This study aimed to supply three foods to the crab Callinectes sapidus in its juvenile stage and compare their effects on its growth. For that, crab larvae were cultured from oviparous adult female crabs. The larvae (z1–z8) were fed with rotifers, previously cultured with microalgae and megalopae (Meg.) with live Artemia salina larvae, obtained from fresh cysts until they reached juvenile development (c1, first crab). Then, 270 animals (c1) were analyzed in three groups of 90, with different diets: shrimp (Penaeus vannamei; Group 1), squid (Mastigoteuthis flammea; Group 2), and tilapia fish (Oreochromis niloticus; Group 3). After 90 days of feeding regimens, the sizes of juvenile crabs were measured by microscopy, and the following relationship was found (p < 0.001): Group 1 (20.8 0.7) > Group 2 (14.5 0.9) > Group 3 (10.4 0.6). The nutritional factor played an essential role in this size differentiation. This intelligent and differentiated feeding strategy showed us that shrimp could be an essential source for the growth of crabs in the juvenile stage. This new approach to safe and efficient roost feeding can classify crabs by size for further hormonal, molting, and reproductive studies.“
  • Miniatura
    PublicaciónAcceso abierto
    Effect of Diet on Growth Performance of First Crab Stage Callinectes sapidus Rathbun, 1896 (Brachyura: Portunidae): A Comparison of Three Different Regimens
    (Animals, 2023-04-03) Gencer, Övgü; Aguilar Vitorino, Hector
    “This study aimed to supply three foods to the crab Callinectes sapidus in its juvenile stage and compare their effects on its growth. For that, crab larvae were cultured from oviparous adult female crabs. The larvae (z1–z8) were fed with rotifers, previously cultured with microalgae and megalopae (Meg.) with live Artemia salina larvae, obtained from fresh cysts until they reached juvenile development (c1, first crab). Then, 270 animals (c1) were analyzed in three groups of 90, with different diets: shrimp (Penaeus vannamei; Group 1), squid (Mastigoteuthis flammea; Group 2), and tilapia fish (Oreochromis niloticus; Group 3). After 90 days of feeding regimens, the sizes of juvenile crabs were measured by microscopy, and the following relationship was found (p < 0.001): Group 1 (20.8 0.7) > Group 2 (14.5 0.9) > Group 3 (10.4 0.6). The nutritional factor played an essential role in this size differentiation. This intelligent and differentiated feeding strategy showed us that shrimp could be an essential source for the growth of crabs in the juvenile stage. This new approach to safe and efficient roost feeding can classify crabs by size for further hormonal, molting, and reproductive studies.“
  • Miniatura
    PublicaciónAcceso abierto
    Electrochemical Sensitivity Improvement by the Cooperation between Pt and Ru for Total Antioxidant Evaluation in Natural Extracts
    (MDPI, 2023-04-23) Carvalho Diniz, Gustavo; Pinheiro Gome, Vinicius Tribuzi Rodrigues; De Assis, Marcelo; Santiago José, Alejandro Figueroa; Ferreira Torquato, Igor; De Freitas Borges, Luiz Gustavo; Aguilar Vitorino, Hector; Batista de Lima, Roberto; Suller Garcia, Marco Aurélio; De Araujo Rodrigues, Isaíde
    “Herein, a straightforward electrochemical method was used to evaluate the total phenolic antioxidant capacity in natural extracts prepared from pomegranate, hibiscus, and pitaya. In light of this, the well-known electrochemical index (EI), a screening protocol for natural antioxidant properties evaluation, was determined using differential pulse voltammetry. Initially considering rutin and catechin as standards, we found that the system’s sensitivity greatly increased by using platinum (Pt) and platinum/ruthenium (Pt/Ru) nanoparticles (NPs) immobilized on Vulcan XC-72 to modify screen-printed carbon electrodes (SPCEs). When such modifications were applied to natural fruit/plant extracts, their electrochemical ability proved highly superior to the bare SPCE, even considering a very small amount of materials for electrode preparation. However, with an optimized ratio, the bimetallic counterpart was more sensitive to detection. When the pomegranate extract was used, for example, EI values of 52.51 ± 6.00 and 104.79 ± 6.89 µA/V were obtained using Pt and Pt/Ru (with an optimized ratio) electrocatalysts, showing the remarkable sensitivity increase obtained in our bimetallic protocol. Thus, based on physicochemical and electrochemical characterizations, we found that the ruthenium content was essential for the achievements. In due course, XPS analysis suggested that the Pt2+/Pt0 species ratio could have improved the system’s sensitivity, which significantly changed when ruthenium was used in the material. “
  • Miniatura
    PublicaciónAcceso abierto
    Electrochemical Sensitivity Improvement by the Cooperation between Pt and Ru for Total Antioxidant Evaluation in Natural Extracts
    (MDPI, 2023-05-23) Carvalho Diniz, Gustavo; Rodrigues Pinheiro Gomes, Vinicius Tribuzi; De Assis, Marcelo; Figueroa, Santiago José Alejandro; Ferreira Torquato, Igor; De Freitas Borge, Luiz Gustavo; Aguilar Vitorino, Hector; Batista de Lima, Roberto; Suller Garcia, Marco Aurélio; De Araujo Rodrigues, Isaíde
    Herein, a straightforward electrochemical method was used to evaluate the total phenolic antioxidant capacity in natural extracts prepared from pomegranate, hibiscus, and pitaya. In light of this, the well-known electrochemical index (EI), a screening protocol for natural antioxidant properties evaluation, was determined using differential pulse voltammetry. Initially considering rutin and catechin as standards, we found that the system’s sensitivity greatly increased by using platinum (Pt) and platinum/ruthenium (Pt/Ru) nanoparticles (NPs) immobilized on Vulcan XC-72 to modify screen-printed carbon electrodes (SPCEs). When such modifications were applied to natural fruit/plant extracts, their electrochemical ability proved highly superior to the bare SPCE, even considering a very small amount of materials for electrode preparation. However, with an optimized ratio, the bimetallic counterpart was more sensitive to detection. When the pomegranate extract was used, for example, EI values of 52.51 ± 6.00 and 104.79 ± 6.89 µA/V were obtained using Pt and Pt/Ru (with an optimized ratio) electrocatalysts, showing the remarkable sensitivity increase obtained in our bimetallic protocol. Thus, based on physicochemical and electrochemical characterizations, we found that the ruthenium content was essential for the achievements. In due course, XPS analysis suggested that the Pt2+/Pt0 species ratio could have improved the system’s sensitivity, which significantly changed when ruthenium was used in the material.