Consulta: creatorFacets:"Guerra,Fernando"
Registros recuperados: 4
Data/hora: 12/06/2024 12:31:02

Saponin production from Quillaja genus species. An insight into its applications and biology
Provedor de dados: 63
Autores: Guerra,Fernando; Sepúlveda,Sebastián.
ABSTRACT: Quillaja genus (Quillajaceae family) is endemic to South America, where is represented by two species, Quillaja saponaria and Quillaja brasiliensis. One outstanding characteristic of these forest tree species is their production of saponins, a family of amphipathic glycosides, involved in the defensive response of plants against biotic and abiotic factors. Saponins are metabolites of economic importance due to their chemical and physical properties. Basic and applied research efforts performed during the last decades, mainly on Q. saponaria, have placed these compounds as an important raw material in industrial areas, such as food and beverage, cosmetics, vaccine production, biopesticides, among others. In this review, we summarize information on...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Triterpenes; Secondary metabolism; Chemical structure; Biosynthesis pathway; Genes.
Ano: 2021
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162021000501802

Heavy metals in vegetables and potential risk for human health
Provedor de dados: 63
Autores: Guerra,Fernando; Trevizam,Anderson Ricardo; Muraoka,Takashi; Marcante,Nericlenes Chaves; Canniatti-Brazaca,Solange Guidolin.
Ingestion of vegetables containing heavy metals is one of the main ways in which these elements enter the human body. Once entered, heavy metals are deposited in bone and fat tissues, overlapping noble minerals. Slowly released into the body, heavy metals can cause an array of diseases. This study aimed to investigate the concentrations of cadmium, nickel, lead, cobalt and chromium in the most frequently consumed foodstuff in the São Paulo State, Brazil and to compare the heavy metal contents with the permissible limits established by the Brazilian legislation. A value of intake of heavy metals in human diets was also calculated to estimate the risk to human health. Vegetable samples were collected at the São Paulo General Warehousing and Centers Company,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Contamination; Food chain; Potentially toxic element; Daily intake; Consumption habit.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162012000100008

Cadmium phytoavailability in soils and evaluation of extractant effectiveness using an isotope technique
Provedor de dados: 63
Autores: Guerra,Fernando; Trevizam,Anderson Ricardo; Fior,Rafael Carvalho; Muraoka,Takashi.
Large areas of land are nowadays contaminated by heavy metals and, it is therefore, important to monitor their levels in soils. Vegetables act as transfer mechanisms of such contaminants from soils to higher levels in the food chain. In this study, we aimed to evaluate the effectiveness of chemical extractants by the L-value method for Cd phytoavailability using the 109Cd radionuclide. In a greenhouse experiment, rocket plants (Eruca sativa L.) were cultivated in pots with samples from Typic Hapludox and Typic Quartzipsamment soils. Cadmium concentrations ranging from 0 to 16 mg kg-1 were added to a 200 mL solution containing 148 kBq 109Cd. The available Cd in the soil was extracted by DTPA, Mehlich-1, Mehlich-3, and a mixture of organic acids (acetic,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Potentially toxic element; L-value; Radioactive tracer; Weathered tropical soils; Soil contamination.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162014000500010

Past and present land use influences on tropical riparian zones: an isotopic assessment with implications for riparian forest width determination
Provedor de dados: 49
Autores: Salemi,Luiz Felippe; Lins,Silvia Rafaela Machado; Ravagnani,Elizabethe de Campos; Magioli,Marcelo; Martinez,Melissa Gaste; Guerra,Fernando; Vidas,Natassia Bonini; Fransozi,Aline; Ferraz,Silvio Frosini de Barros; Martinelli,Luiz Antonio.
Abstract In this article, by using carbon stable isotopes, we assessed the past and present land use influences that riparian areas are subject within agricultural landscapes. Emphasis is given to the understanding of the effects of the 2012 Brazilian Forest Act on such areas. We selected five riparian areas within a highly C4 dominated agricultural landscape. Three of them had 30 meters native riparian forest buffer (NRFB) and two of them had 8 meter and no NRFB. We used three 100 meter-transects located 5, 15 and 30 meters relative to stream channel to obtain soil samples (0 - 10 cm). All riparian areas presented soil carbon isotopic signatures that are not C3 (native forests) irrespective of having or not 30 meters NRFB. Two cases presenting less than...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Watershed; Soil degradation; Organic matter; Sediment; Carbon cycling.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032016000200210