Kinetic modelling of total organic carbon degradation in dairy wastewater.

Several treatment strategies have been proposed to minimize the environmental impact of dairy wastewaters. However, their complex and variable composition makes it difficult to predict the degradation kinetics of organic compounds. In this study, we used a mathematical approach to describe the kinetics of total organic carbon degradation in real dairy wastewater by photo-Fenton oxidation.

Solar photo-Fenton oxidation of mature landfill leachate: empirical model and chemical inferences.

In this study, a stochastic model was applied to investigate the degradation of landfill leachate by solar photo-Fenton processes. The coefficient of determination () between experimental and predicted data ranged from 0.9958-0.

Applications of an electronic nose in the prediction of oxidative stability of stored biodiesel derived from soybean and waste cooking oil.

Waste cooking oil (WCO) is a valuable feedstock for the synthesis of biodiesel but the product exhibits poor oxidative stability. Techniques available for assessing this parameter are generally expensive and time-consuming, hence the purpose of this study was to develop and validate a rapid and reliable predictive system based on signals from the sensors of a commercial hand-held e-nose instrument. Biodiesels were synthesized from soybean oil and six samples of WCO, and their physicochemical characteristics and oxidative stabilities determined before and after storage in different types of containers for 30 or 60 days at room temperature or 43 °C.

Carbonaceous decomposition of a recalcitrant effluent treated by the photo-Fenton process: a kinetic approach.

Natural effluents with marked variation in their chemical composition over decomposition time in the matrix from which they are generated have a complex composition and are not totally known in most cases. Landfill leachate can be considered an effluent with complex composition, requiring imminent and more comprehensive studies on organic load degradation. Such complexity of numerous organic compounds (most of them recalcitrant humic and fulvic substances) demands a large number of kinetic equations to satisfactorily describe the temporal evolution of such conversion.

Effects of photobiomodulation therapy (PBMT) on bovine sperm function.

Fertilization rates and subsequent embryo development rely on sperm factors related to semen quality and viability. Photobiomodulation therapy (PBMT) is based on emission of electromagnetic waves of a laser optical system that interact with cells and tissues resulting in biological effects. This interaction is mediated by photoacceptors that absorb the electromagnetic energy.

Evaluation of Lasting Effects of Heat Stress on Sperm Profile and Oxidative Status of Ram Semen and Epididymal Sperm.

Higher temperatures lead to an increase of testicular metabolism that results in spermatic damage. Oxidative stress is the main factor responsible for testicular damage caused by heat stress. The aim of this study was to evaluate lasting effects of heat stress on ejaculated sperm and immediate or long-term effects of heat stress on epididymal sperm.

Induced lipid peroxidation in ram sperm: semen profile, DNA fragmentation and antioxidant status.

Action of reactive oxygen species, protamination failures and apoptosis are considered the most important etiologies of sperm DNA fragmentation. This study evaluated the effects of induced lipid peroxidation susceptibility on native semen profile and identified the mechanisms involved in sperm DNA fragmentation and testicular antioxidant defense on Santa Ines ram sperm samples. Semen was collected from 12 adult rams (Ovis aries) performed weekly over a 9-week period.

Sperm Oxidative Stress Is Detrimental to Embryo Development: A Dose-Dependent Study Model and a New and More Sensitive Oxidative Status Evaluation.

Our study aimed to assess the impact of sperm oxidative stress on embryo development by means of a dose-dependent model. In experiment 1, straws from five bulls were subjected to incubation with increasing H2O2 doses (0, 12.5, 25, and 50 μM).

System for evaluation of oxidative stress on in-vitro-produced bovine embryos.

This study proposed a quantitative evaluation of oxidative status (OS) in bovine embryos. Sixteen-cell stage embryos, cultured under 5% O2, were treated with oxidative stress inducer menadione (0, 1, 2.5 and 5 µmol/l) for 24 h.

Influence of bovine sperm DNA fragmentation and oxidative stress on early embryo in vitro development outcome.

Sperm chromatin fragmentation may be caused by a number of factors, the most significant of which is reactive oxygen species. However, little is known about the effect of sperm oxidative stress (OS) on DNA integrity, fertilization, and embryonic development in cattle. Therefore, the goal of this study was to evaluate the influence of sperm OS susceptibility on the DNA fragmentation rate and in vitro embryo production (IVP) in a population of bulls.