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Institution

Universidade Federal de Viçosa

EducationViçosa, Brazil
About: Universidade Federal de Viçosa is a education organization based out in Viçosa, Brazil. It is known for research contribution in the topics: Population & Dry matter. The organization has 16012 authors who have published 26711 publications receiving 353416 citations.


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Journal ArticleDOI
TL;DR: In this paper, Vermelho-Amarelo et al. evaluated the efeitos da adubacao com N, Mo and Zn sobre a producao e qualidade de graos de milho, and avaliar a epocaso mais adequada for amostragem e analise foliar de N nas formas de N orgânico, N-NO3- e N total (NO3 + N orgÃnico) and relacionar a composicao mineral das folhas
Abstract: A adubacao e um dos fatores que mais contribui para o aumento da produtividade do milho, podendo influenciar a qualidade dos graos. Este trabalho foi conduzido num Argissolo Vermelho-Amarelo distrofico, visando avaliar os efeitos da adubacao com N, Mo e Zn sobre a producao e qualidade de graos de milho, sob o aspecto proteico e teor de nutrientes minerais; avaliar a epoca mais adequada para amostragem e analise foliar de N nas formas de N orgânico, N-NO3- e N total (NO3- + N orgânico) e relacionar a composicao mineral das folhas e dos graos de milho. Utilizou-se um delineamento em blocos ao acaso com quatro repeticoes, em esquema fatorial com quatro doses de N (0, 70, 140 e 210 kg ha-1), duas doses de Mo (0 e 90 g ha-1) e duas de Zn (0 e 3 kg ha-1). As amostras de folhas foram retiradas aos 25, 45 e aos 63 dae (dias apos emergencia). No material vegetal obtido (folhas e graos) foram determinados os teores de N orgânico, N-NO3-, N total, proteina, P, K, Ca, Mg, S, Cu, Fe, Mn, e Zn. O numero de espigas por planta, peso das espigas com palha, peso das espigas sem palha, peso de mil graos e a producao de graos aumentaram com o incremento nas doses de N, obtendo-se a maxima producao de graos (8,58 t ha-1) na dose de 201,2 kg ha-1 de N. Os teores de proteina e nutrientes nos graos aumentaram com as doses de N. A adubacao com Mo elevou o teor de proteina e a com Zn aumentou o teor desse nutriente nos graos. Os niveis criticos de N total foram 2,73 e 2,00 dag kg-1, aos 45 e 63 dae. A melhor caracteristica para ser utilizada como indice de diagnose nutricional e de producao de graos foi o teor de N orgânico aos 45 dae (antes do pendoamento), utilizando-se na analise quimica a ultima folha completamente aberta. A composicao mineral dos graos, em geral, apresentou alta correlacao positiva com a composicao mineral das folhas, aos 63 dae.

90 citations

Journal ArticleDOI
TL;DR: Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses, which could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories.

90 citations

Journal ArticleDOI
TL;DR: Ethanol extracts from wild plants collected in three different regions of Brazil and from plants cultivated in various soil conditions were tested, and the wild plants were the most active, indicating a good candidate for pre‐clinical tests as a phytotherapeutic agent or for chemical isolation of the active compounds.
Abstract: Bidens pilosa (Asteraceae), a medicinal plant used worldwide, has antimalarial activity as shown in previous work. This study tested ethanol extracts from wild plants collected in three different regions of Brazil and from plants cultivated in various soil conditions. The extracts were active in mice infected with P. berghei: doses of < or =500 mg/kg administered by oral route reduced malaria parasitaemia and mouse mortality; higher doses were found to be less effective. Tested in vitro against three P. falciparum isolates, two chloroquine resistant and one mefloquine resistant, the plants cultivated under standard conditions, and in humus enriched soil, were active; but the wild plants were the most active. Analysis using thin layer chromatography demonstrated the presence of flavonoids (compounds considered responsible for the antimalarial activity) in all plants tested, even though at different profiles. Because B. pilosa is proven to be active against P. falciparum drug-resistant parasites in vitro, and in rodent malaria in vivo, it is a good candidate for pre-clinical tests as a phytotherapeutic agent or for chemical isolation of the active compounds with the aim of finding new antimalarial drugs.

90 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of wall material concentration, inlet temperature, and feed rate on the properties of rosemary oil microencapsulated by spray-drying, with gum arabic as carrier, was evaluated.
Abstract: This study evaluated the influence of wall material concentration (10–30%), inlet temperature (135–195°C), and feed rate (0.5–1.0 L · h−1) on the properties of rosemary oil microencapsulated by spray-drying, with gum arabic as carrier. Powder recovery, surface oil, oil retention, and hygroscopicity varied from 17.25%–33.96%, 0.03%–0.15%, 7.15%–47.57%, and 15.87%–18.90%, respectively. The optimized conditions were determined to be a wall material concentration of 19.3%, an inlet air temperature of 171°C, and a feed flow rate of 0.92 L · h−1. At this condition, particles presented no fissures and the compositions of pure and microencapsulated oil were similar. The sorption isotherms could be described by the GAB model.

90 citations


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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202346
2022320
20212,074
20202,208
20191,941
20181,865