Search results for "CPA"
showing 10 items of 53 documents
Effect of pH on the mobility of the herbicide MCPA in a sand-goethite column: 1D and 2D reactive transport modeling
2018
Abstract Adsorption and transport of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) in a homogeneous sand-goethite system were investigated as a function of pH. Interaction of MCPA with the solid surface was geochemically modeled according to the charge distribution multisite complexation (CD-MUSIC) approach. Based on this calibration, retardation of MCPA transport in column experiments was significantly underestimated by conventional 1D simulations. As a new approach, Positron Emission Tomography (PET) was employed to analyze the flow field, using 18F− as a radiotracer. The observed heterogeneity was reproduced in 2D simulations assuming increased permeability and porosity at the…
Adsorption of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) by goethite.
2014
Interaction between the goethite surface and 4-chloro-2-methylphenoxyacetic acid (MCPA) herbicide was studied using density functional theory (DFT) calculations combined with molecular dynamics (MD). The important step made here lies in the use of a periodic DFT method enabling the study of a mineral surface of different protonation states, in strong contrast with previous molecular modeling studies limited to single protonation state corresponding to the point of zero charge. Different surface OH groups and MCPA proton states were used to mimic the strong effects of pH on the outer- and inner-sphere surface complexes that are theoretically possible, together with their binding energies, an…
The effects of woodchip- and straw-derived biochars on the persistence of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) in soils
2014
Sorption and degradation are the primary processes controlling the efficacy and runoff contamination risk of agrochemicals. This study assessed the influence of two biochars, made from woodchips and straw at a pyrolysis temperature of 725°C and applied to a loamy sand and a sandy soil in the concentration of 5.3 g 100 g(-1) sandy soil and 4.1 g 100 g(-1) loamy sand soil, or 53 t ha(-1) for both soil types, on degradation of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA). Soils were spiked with 50 mg MCPA kg(-1) soil. In the sandy soil, significantly more MCPA remained after 100 days if amended with straw-derived biochar in comparison to wood-derived biochar. Both biochars types si…
Metabolic Consequences of Obstructive Sleep Apnea
2022
The effects of OSA on metabolism are quite complex, and obesity, diabetes, nonalcoholic fatty liver disease and dyslipidemia often coexist with OSA, making it difficult to tease out the independent effects of OSA on metabolic variables. There is firm experimental evidence of a detrimental impact of OSA on adipose tissue dysfunction, with intermittent hypoxia, sympathetic hyperactivity, and oxidative stress as the most important intermediate mechanisms. Sleep fragmentation or deprivation may also contribute to the metabolic dysfunction of OSA. This work reviews the current knowledge on this topic, as well as the results of studies on the effects of CPAP treatment.
Intellectual Capital Management in Local Public Utilities
2012
The competitive advantage of companies is increasingly focused on Intellectual Capital (IC) and on its management. Factors such as skills, innovation, stakeholders' relation, development and sharing of knowledge have become key success factors. These aspects are important for Local Public Utilities. These organizations produce goods and services operating in competitive markets in a utility function for the local community using technological and organizational infrastrutture resources. In the past, in these organizations, IC was critica1 to reach objectives such as to satisfy citizen needs. Local Public Utilities focused their assets on the technical components of management including plan…
Commentaire CA d'Angers (renvoi de cassation), 7 octobre 2005, D. 2006, Jur. 1733
2006
International audience
Guanosine-Mediated Anxiolytic-Like Effect: Interplay with Adenosine A1 and A2A Receptors
2020
Acute or chronic administration of guanosine (GUO) induces anxiolytic-like effects, for which the adenosine (ADO) system involvement has been postulated yet without a direct experimental evidence. Thus, we aimed to investigate whether adenosine receptors (ARs) are involved in the GUO-mediated anxiolytic-like effect, evaluated by three anxiety-related paradigms in rats. First, we confirmed that acute treatment with GUO exerts an anxiolytic-like effect. Subsequently, we investigated the effects of pretreatment with ADO or A1R (CPA, CCPA) or A2AR (CGS21680) agonists 10 min prior to GUO on a GUO-induced anxiolytic-like effect. All the combined treatments blocked the GUO anxiolytic-like effect, …
Quantification of fibrosis by collagen proportionate area predicts hepatic decompensation in hepatitis C cirrhosis.
2015
SummaryBackground It is unclear whether the course of cirrhosis and its prognosis are related to the amount of collagen in the liver. Aim To determine whether fibrosis, assessed by collagen proportionate area (CPA) in patients with compensated cirrhosis, is associated with the presence of oesophageal varices, and predict disease decompensation during the follow-up period. Methods We prospectively evaluated 118 consecutive patients with compensated cirrhosis to correlate fibrosis, assessed by CPA in liver biopsies, with the presence of oesophageal varices (OV) and with the rate of liver decompensation (LD) development during a median follow-up of 72 months. Results At baseline 38 (32.2%) pat…
Toxicity of 5- chloro- 3- methyl- catechol to rat: Chemical observations and light microscopy of the tissue
1979
5-chloro-3-methyl-catechol was first time described by GAUNT and EVANS (1961) as a metabolite of MCPA (4-chloro-2-methylphenoxyacetic aci~which is the most widely used herbicide in the Nordic countries. The toxicity of the metabolite 5-chloro-3-methylcatechol bas hot been studied so far. Other catechols like 3,5dichlorocatechol has been shown to be a metabollte of 2,4-D (BOLLAG et ai. 1968a, BOLLAG et ai. 1968b), and it has been proven to be toxic to cells by HORVATH (1971). The catechols are metabolized by bacteria finally to muconic semialdehyde (HORVATH 1970, HORVATH and ALEXANDER 1970). In this work the toxicity of 5-chloro-3-methyl-catechol to maie rats was studied in acute and subchro…
Modeling interactions between Human Equilibrative Nucleoside Transporter-1 and other factors involved in the response to gemcitabine treatment to pre…
2014
Background Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy, characterized by largely unsatisfactory responses to the currently available therapeutic strategies. In this study we evaluated the expression of genes involved in gemcitabine uptake in a selected cohort of patients with PDAC, with well-defined clinical-pathological features. Methods mRNA levels of hENT1, CHOP, MRP1 and DCK were evaluated by means of qRT-PCR in matched pairs of tumor and adjacent normal tissue samples collected from PDAC patients treated with gemcitabine after surgical tumor resection. To detect possible interaction between gene expression levels and to identify subgroups of patients a…