Search results for "Gradation"

A combined experimental and theoretical study of the thermal cycloaddition of aryl azides with activated alkenes.

2011

International audience; Reactions were performed from aryl azides on the one hand, and activated alkenes coming from β-dicarbonyl compounds or malonodinitrile on the other hand, either with recourse to conventional heating or to microwave activation, to afford 1-aryl-1H-1,2,3-triazoles. The mechanism and the regioselectivity of the reactions involving β-dicarbonyl compounds have been theoretically studied using DFT methods at the B3LYP/6-31G* level: they are domino processes comprising a tautomeric equilibrium of the β-dicarbonyl compounds with their enol forms, a 1,3-dipolar cycloaddition of the enol forms with the aryl azides (high activation energy), and a dehydration process (lower acti…

2020

BAG3, a multifunctional HSP70 co-chaperone and anti-apoptotic protein that interacts with the ATPase domain of HSP70 through its C-terminal BAG domain plays a key physiological role in cellular proteostasis. The HSP70/BAG3 complex determines the levels of a large number of selective client proteins by regulating their turnover via the two major protein degradation pathways, i.e. proteasomal degradation and macroautophagy. On the one hand, BAG3 competes with BAG1 for binding to HSP70, thereby preventing the proteasomal degradation of its client proteins. By functionally interacting with HSP70 and LC3, BAG3 also delivers polyubiquitinated proteins to the autophagy pathway. BAG3 exerts a numbe…

Protein quality control during aging involves recruitment of the macroautophagy pathway by BAG3.

2009

The Hsc/Hsp70 co-chaperones of the BAG (Bcl-2-associated athanogene) protein family are modulators of protein quality control. We examined the specific roles of BAG1 and BAG3 in protein degradation during the aging process. We show that BAG1 and BAG3 regulate proteasomal and macroautophagic pathways, respectively, for the degradation of polyubiquitinated proteins. Moreover, using models of cellular aging, we find that a switch from BAG1 to BAG3 determines that aged cells use more intensively the macroautophagic system for turnover of polyubiquitinated proteins. This increased macroautophagic flux is regulated by BAG3 in concert with the ubiquitin-binding protein p62/SQSTM1. The BAG3/BAG1 ra…

Response of the PCB-contaminated soil bacterial community to applied bioremediation treatments

2011

For full field implementation of the bioremediation as a strategy for cleaning PCB-contaminated soils, the impact of the applied treatment on the microbial community needs to be clarified. An ideal bioremediation should have positive effects on PCB-removal but should pose no treats to the health of the soil ecosystem. Microbes, playing an essential role in maintenance of the soil ecosystem, are the first indicators of a negative impact of soil manipulation to ecosystem. A small-scale bioremediation experiment was conducted in order to get insight into behavior of the microbial community during bioremediation of PCB-contaminated soil, targeting both functional PCB-degrading community (by bph…

Kinetics of Thermoascus aurantiacus solid-state fermentation on sugar-beet pulp-polysaccharide alteration and production of related enzymatic activit…

1996

International audience; The fungal solubilization of cell wall components of sugar-beet pulp, during solid-state fermentation of Thermoascus aurantiacus, is reported here. The extracellular fungal enzyme activities related to the substrate degradation were also studied. In 120 h, more than 60% of the main sugar-beet pulp polysaccharides, i.e. pectins, arabinose- and glucose-containing polysaccharides, were rapidly brought into solution by the fungus. The slow accumulation of monosaccharides compared to the fast degradation of the polysaccharides suggested that most of the released sugars were consumed by the fungus. The analysis of the enzymes present in the water extracts of the solid-stat…

Amino polyphosphonates - chemical features and practical uses, environmental durability and biodegradation

2012

Growing concerns about the quality of the environment led to the introduction of complex system of safety assessment of synthetically manufactured and commonly applied chemicals. Sometimes, however, our knowledge of consequences that result from the usage of these substances, appears far later, than at the beginning of their application. Such situation is observed in the case of aminopolyphosphonates being an important subgroup of organophosphorus compounds. The increasing industrial and household applications, led to introduce thousand tons of polyphosphonates every year into the environment. These substances are difficult to determine in environmental samples because of lack of appropriat…

Novel performance-based technique for predicting maintenance strategy of bitumen stabilised ballast

2018

Abstract Despite being the most used worldwide, railway ballasted tracks presents high maintenance cost related to ballast settlement and particle degradation. With the aim of reducing life cycle costs, bitumen stabilised ballast (BSB) has been recently proposed as a relatively cheap alternative maintenance solution to be applied to existing tracks. This study aims at assessing the potential advantages of this technology, defining a novel maintenance strategy of traditional ballasted track-beds. A protocol for the application of the BSB technology and its associated maintenance strategy is defined. To estimate minor and major maintenance operations of BSB scenario in comparison to tradition…

A New High-Efficiency Procedure for Aggregate Gradation Determination of the Railway Ballast by Means Image Recognition Method

2013

Abstract The mechanical characteristics of the railway superstructure are related to the properties of the ballast, and especially to the particle size distribution of its grains. Under the constant stress-strain of carriages, the ballast can deteriorate over time, and consequently it should properly be monitored for safety reasons. The equipment which currently monitors the railway superstructure (like the Italian diagnostic train Archimede) do not make any “quantitative” evaluation of the ballast. The aim of this paper is therefore to propose a new methodology for extracting railway ballast particle size distribution by means of the image processing technique. The procedure has been teste…

Digital image analysis technique for measuring railway track defects and ballast gradation

2018

Abstract In order to guarantee safety and driving comfort and to maintain an efficient railway infrastructure, the first step is to carefully monitor the track geometry and wear level of the materials constituting the superstructure. To that end diagnostic trains are widely used on main lines, in that they can detect several geometric track parameters and rail wear, but under no circumstances they can yet detect ballast gradation. Due to the practical implications for the planning of maintenance operations on the railway network, this article presents a “DIP” digital image processing technique for measuring the transverse profile and corrugations of the rails as well as ballast gradation. T…

Removal of pharmaceuticals from municipal wastewaters at laboratory scale by treatment with activated sludge and biostimulation.

2017

Abstract Municipal wastewater containing 21 pharmaceutical compounds, as well as activated sludge obtained from the aeration tank of the same wastewater treatment plant were used in lab-scale biodegradation experiments. The concentrations of pharmaceutical compounds were determined by high-performance liquid chromatography coupled to Orbitrap high-resolution mass spectrometry and ranged from 13.2 ng/L to 51.8 μg/L. Activated sludge was characterized in the terms of phylogenetic and catabolic diversity of microbial community, as well as its morphology. Proteobacteria (24.0%) represented the most abundant phylum, followed by Bacteroidetes (19.8%) and Firmicutes (13.2%). Bioaugmentation of was…