Search results for "STRESS"
showing 10 items of 6278 documents
Oxidative stress neuroinflammation and cellular stress response in sensorineural hearing loss: novel nutritional therapeutical approaches
2016
This study is intended to validate the hypothesis that changes in the redox state of glutathione, the major endogenous antioxidant, associated with the abnormal expression and activity of cytoprotective vitagenes, which in normal conditions are expressed only at low level may represent a critical factor, involved in the physiopathological changes associated to degenerative damage occurring in cochlear diseases. Moreover modulation of stress responsive vitagenes by nutritional antioxidants can be an effective therapeutic strategy to minimize consequences of oxidative stress associated to the pathogenesis and course of sensorineural hearing loss. One therapeutic approach can be antioxidant su…
Experimental and Numerical Study on the Flow Field and Friction Factor in a Pressurized Corrugated Pipe
2015
An experimental campaign including measurement of pressure drops and velocity profiles was conducted on the pressurized flow in a commercial corrugated pipe. The results show that the empirical graphs suggested by Morris in the fifties may produce inaccurate assessments of the friction factor, in particular, for low Reynolds numbers. The experimental data was then reproduced by means of a numerical model with the large eddy simulation (LES) technique. The friction factor behavior for low and relatively high Reynolds numbers was thus investigated. The numerical simulations were in good agreement with the experimental results, showing the LES suitability to predict the effect of the pipe wall…
Friction Stir Processing: thermo-mechanical loads and consequent effects on the local material characteristics
2008
The present article is focused on the correlation between the applied thermal and mechanical loads and the consequent effects on the material in friction stir processing (FSP) operations. On one hand, the actions exerted in FSP are split compared to the results obtained with a tool without the pin at its end to a traditional one with a cylindrical pin. In this way, the thermal flux determined by the frictional forces at the tool—shoulder—workpiece interface is secluded from the mechanical stirring action made by the tool pin. On the other hand, the processed specimens are analysed in terms of residual stress state, microhardness, and average grain size values. An in-process heat treatment …
A carbon budget model to predict branch carbohydrate deficiencies as a function of water stress and crop load in pistachio (Pistacia veraL.)
2018
The effect of irrigation and crop load on alternate bearing was studied in pistachio tree using a “branch carbon budget model” developed to calculate branch carbohydrate balance. Experiences were conducted in Sicily (37°26’N, 14°03’E, 360 m a.s.l.) on female trees of ‘Bianca’. Two treatments were applied: rainfed (T0) and 100 mm of irrigation (T100). At 29, 44, 65, 86, 103 and 121 DAFB, on one fully expanded leaf selected on three trees per treatment, were monitored leaf gas exchanges. At 15 days interval, three branches treatment-1 were excised and, in the lab, the following parameters were measured: total photosynthetically active leaf surface; number of leaves, fruits, shoot fresh weight…
In Candida parapsilosis the ATC1 Gene Encodes for an Acid Trehalase Involved in Trehalose Hydrolysis, Stress Resistance and Virulence
2014
An ORF named CPAR2-208980 on contig 005809 was identified by screening a Candida parapsilosis genome data base. Its 67% identity with the acid trehalase sequence from C. albicans (ATC1) led us to designate it CpATC1. Homozygous mutants that lack acid trehalase activity were constructed by gene disruption at the two CpATC1 chromosomal alleles. Phenotypic characterization showed that atc1Δ null cells were unable to grow on exogenous trehalose as carbon source, and also displayed higher resistance to environmental challenges, such as saline exposure (1.2 M NaCl), heat shock (42°C) and both mild and severe oxidative stress (5 and 50 mM H2O2). Significant amounts of intracellular trehalose were …
Homozygous deletion of ATC1 and NTC1 genes in Candida parapsilosis abolishes trehalase activity and affects cell growth, sugar metabolism, stress res…
2015
A double homozygous atc1Δ/atc1Δ/ntc1Δ/ntc1Δ mutant (atc1Δ/ntc1Δ KO) was constructed in the pathogen opportunistic yeast Candida parapsilosis by disruption of the two chromosomal alleles coding for NTC1 gene (encoding a neutral trehalase) in a Cpatc1Δ/atc1Δ background (atc1Δ KO strain, deficient in acid trehalase). The Cpatc1Δ/ntc1Δ KO mutant failed to counteract the inability of Cpatc1Δ cells to metabolize exogenous trehalose and showed a similar growth pattern on several monosaccharides and disaccharides. However, upon prolonged incubation in either rich medium (YPD) or nutrient-starved medium the viability of Cpatc1Δ cells exhibited a sensitive phenotype, which was augmented by further Cp…
Isolation, purification, LC–MS/MS characterization and reactive oxygen species induced by fumonisin B1 in VERO cells
2010
Fumonisins are mycotoxins produced by Fusarium verticillioides that commonly contaminate maize and maize products. The present work shows the results of a comparative study of three different fermentation's techniques (solid and liquid medium of corn and a solid agarized medium) for the production of fumonisins B-1, B-2 and B-3 with strains of F. verticillioides. The solid medium of corn was the most effective in the production of fumonisins, being Fumonisin B-1 the one produced with higher concentration, so the extract obtained by solid fermentation process was used for FB1 purification. Fumonisins characterization and quantification were performed with reversed-phase high-performance liqu…
Isolation and purification of enniatins A, A1, B, B1, produced by Fusarium tricinctum in solid culture, and cytotoxicity effects on Caco-2 cells
2010
Enniatins (ENs) are antibiotic compounds of hexadepsipeptidic structure produced by several strains of Fusarium spp. The ENs A, A(1), B, B-1 were purified from extracts of Fusarium tricinctum grown on a solid medium of corn, by a low pressure liquid chromatography (LPLC) on reverse phase of Amberlite XAD-7 followed by semipreparative LC. The purity and the structure of the isolated compounds were confirmed by LC-MS/MS. The technique of the purification of the fungal extract enabled complete separation of the ENs A, A(1), B, B-1 with a mean purity of 97% for all the compounds. The cytoxicity of the ENs was tested in the cell lines of human origin (epithelial colorectal adenocarcinoma cells, …
Migrant Women-experiences from the Mediterranean Region
2019
Introduction: The phenomenon of migration is characterized and influenced by a number of different variables; and the different stages of journey are related to different levels and types of psychological distress. Women, in particular, are exposed to further specific risks during migration. Aim: To determine the factors that affect the psychological health of migrant women during the different stages of the migration journey. Methods: We provide a narrative review of the literature around the experiences of women during migration process, with a geographical focus on women migrating to the Mediterranean area. Results: Little data is currently available on the burden of mental health disor…
As2O3-induced oxidative stress and cycle progression in a human intestinal epithelial cell line (Caco-2)
2007
Foods and drinking water are the main routes for human exposure to inorganic arsenic, the intestinal epithelium being the first barrier against such exogenous toxicants. The present study evaluates the effect of As(III) (0.5-25 microM) upon Caco-2 cells as an intestinal epithelia model. Cell viability, intracellular formation of reactive oxygen species (ROS), mitochondrial membrane potential (Deltapsim) changes, and cell cycle distribution in exposed cultures were evaluated. The intracellular production of ROS was seen to increase in a non-dose dependent manner at all concentrations tested, with impairment of cell mitochondrial enzyme function secondary to a loss of Deltapsim. Concentration…