Search results for "stress effect"
showing 6 items of 6 documents
Analysis of the Diffusion-Induced Stress Effect on the Oxidation in Finely Divided Vanadium Ferrites
1999
L'oxydation isotherme des cations fer(II), vanadium(II) et vanadium(III) pour les ferrites spinelles finement divises, lesquels sont oxydes en phases deficitaires en cations, a ete etudiee par thermogravimetrie. La faible temperature de cinetique d'oxydation de chaque cation oxydable a ete expliquee en considerant que l'oxydation genere des contraintes qui en modifie la cinetique ou les cations a la surface sont plus oxydes que dans le volume. Pour cela, il at ete considere que le coefficient de diffusion chimique est donne par la relation D = D 0 exp [-(E' a + pV a )/RT] ou D 0 represente le facteur pre-exponentiel, E' a l'energie d'activation, V a le volume d'activation et p la pression i…
Identification, cloning and environmental factors modulation of a αβ defensin from the lessepsian invasive mussel Brachidontes pharaonis (Bivalvia: M…
2015
International audience; Immunological effectors of invasive species playing a role in addressing new colonization are still poorly studied. In the present study the cDNA sequence of the defensin from a Lessepsian invasive species, the Red Sea mussel Brachidontes pharaonis, was cloned using RACE method. Defensins are a class of widely known antimicrobial peptides (AMPs), oligopeptides with a broad spectrum of targeted organisms ranging from viruses to parasites. Analysis of BpDef sequence (262 bp) revealed the presence of an ORF coding for 81 amino acids. The full-length amino acid sequence showed the highest similarity to antimicrobial peptides MGD1 and MGD2 sequence from Mytilus galloprovi…
Photo‐Induced Polymerization and Stress Effects in Fullerite C60
2005
Abstract Modifications of the structure and hardness of fullerite C60 crystals under stresses generated during photo‐induced polymerization are investigated.
Fine–grained spinel ferrites: From the reactivity to magnetic properties
1998
The oxidation at low temperature of fine-grained ferrites containing oxidizable cations such as Cu + , Fe 2+ , Mn 2+ , Mo 3+ , V 3+ , has led to new mixed-valent cation deficient ferrites with a large number of vacancies. It has been demonstrated by DTG analysis that each cation oxidizes at a specific temperature in close relation with the cation-oxygen distance. The kinetics oxidation of each oxidizable cation has been explained on the basis of a diffusion-induced stress effect when these stresses are generated by the chemical gradient induced during the oxidation process. When fine-grained ferrites contain some Co-cations, it has been revealed that the stresses have a significant influenc…
Pesticide Effects on Eel Metabolism
1995
Previous works on endosulfan eel toxicology in this laboratory demonstrated that 0.041 mg/liter of endosulfan was the 50% lethal concentration of 96 hr exposure. Eels of species Anguilla anguilla were exposed to two sublethal endosulfan concentrations: 8.2 μg/liter (1/5 LC50) and 4.1 μg/liter (1/10 LC50), and the experiment was done at different exposure times: 12, 24, 48, 72, and 96 hr. Muscle glycogen content decreased significantly (P < 0.05) at 24, 48, 72, and 96 hr exposure to 8.2 μg/liter pesticide; levels did not decline at any time when animals were exposed to 4.1 μg/liter. Muscle lactate levels in fish did not change significantly while lactate levels in eel blood increased at 12, …
An experimental approach to oxidative stress effect on sperm motility and DNA fragmentation
2018
En el estudio de la fertilidad masculina en todas las especies animales, la movilidad espermática, junto a la concentración y morfometría son los parámetros principales y más básicos en la evaluación de la calidad de los espermatozoides. La infertilidad masculina habitualmente se asocia con tasas anormales de estos parámetros seminales. Aún teniendo, los espermatozoides tasas adecuadas de todos estos parámetros no se puede garantizar la capacidad de fertilizar y/o desarrollar un cigoto. Por lo tanto, está claro que el examen rutinario del semen y los espermatozoides en la eyaculación no puede evaluar otros parámetros importantes en el proceso de fecundación como es capacitación espermática …