36 research outputs found
Microscopic model of diffusion limited aggregation and electrodeposition in the presence of levelling molecules
A microscopic model of the effect of unbinding in diffusion limited
aggregation based on a cellular automata approach is presented. The geometry
resembles electrochemical deposition - ``ions'' diffuse at random from the top
of a container until encountering a cluster in contact with the bottom, to
which they stick. The model exhibits dendritic (fractal) growth in the
diffusion limited case. The addition of a field eliminates the fractal nature
but the density remains low. The addition of molecules which unbind atoms from
the aggregate transforms the deposit to a 100% dense one (in 3D). The molecules
are remarkably adept at avoiding being trapped. This mimics the effect of
so-called ``leveller'' molecules which are used in electrochemical deposition
Sensitive Detection of Organophosphorus Pesticides Using a Needle Type Amperometric Acetylcholinesterase-based Bioelectrode. Thiocholine Electrochemistry and Immobilised Enzyme Inhibition
International audienceAn acetylcholinesterase (AChE) based amperometric bioelectrode for a selective detection of low concen¬ trations of organophosphorus pesticides has been developed. The amperometric needle type bioelectrode consists of a bare cavity in a PTFE isolated Pt-Ir wire, where the AChE was entrapped into a photopolymerised polymer of polyvinyl alcohol bearing styrylpyridinium groups (PVA-SbQ). Cyclic voltammetry, performed at Pt and AChE/Pt disk electrodes, confirmed the irreversible, monoelectronic thiocholine oxidation process and showed that a working potential of + 0.410 V vs. Ag/AgCl, KClSat was suitable for a selective and sensitive amperometric detection of thiocholine. The acetylthio-choline detection under enzyme kinetic control was found in the range of 0.01-0.3 U cm~" of immobilised AChE. The detection limit, calculated for an inhibition ratio of 10%, was found to reach 5 jxM for dipterex and 0.4 jaIVI for paraoxon. A kinetic analysis of the AChE-pesticide interaction process using Hanes-Woolf or Lineweaver-Burk linearisations and secondary plots allowed identification of the immobilised enzyme inhibition process as a mixed one (non/uncompetitive) for both dipterex and paraoxon. The deviation from classical Michaelis Menten kinetics induced from the studied pesticides was evaluated using Hill plots
Statistic evaluation of cysteine and allyl alcohol as additives for Cu-Zn coatings from citrate baths
Gemcabene downregulates inflammatory, lipid-altering and cell-signaling genes in the STAM™ model of NASH
<div><p>Background and aims</p><p>Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) can advance, if untreated, to liver fibrosis, cirrhosis, hepatocellular carcinoma, liver failure and liver-related death. In the United States, NASH affects approximately 2–5% of the population and an additional 10–30% have NAFLD. The number of drugs in development for NASH is growing steadily, along with nonclinical models to support prediction of clinical success. Here we evaluate gemcabene, a first-in-class clinical candidate for dyslipidemia, for its potential utility, based on its combined lipid-lowering and anti-inflammatory efficacy in clinical trials, in a preclinical model of NASH.</p><p>Methods</p><p>Gemcabene was evaluated in the STAM™ murine model of NASH. Gemcabene intervention in mice made diabetic with streptozotocin and fed a high fat high-caloric diet was assessed for changes in plasma, and hepatic histological and mRNA markers of lipid metabolism and inflammation.</p><p>Results</p><p>Gemcabene significantly downregulated hepatic mRNA markers of inflammation (TNF-α, MCP-1, MIP-1β, CCR5, CCR2, NF-κB), lipogenesis and lipid modulation (ApoC-III, ACC1, ADH-4, Sulf-2), and fibrosis (TIMP-1 and MMP-2). These effects are important for the prevention of steatosis, inflammation, and hepatocyte ballooning (<i>i</i>.<i>e</i>., the components of the NAFLD Activity Score or NAS), and inhibition of fibrosis progression, and were observed following treatment with gemcabene.</p><p>Conclusions</p><p>These non-clinical findings corroborate with existing clinical data to support the clinical evaluation of gemcabene as a potential new treatment for NASH.</p></div
Gemcabene downregulates inflammatory, lipid-altering and cell-signaling genes in the STAM™ model of NASH - Fig 5
<p>A) NAS Score; B) Fibrosis area.</p
Representative photomicrographs of Sirius red-stained liver sections.
<p>Representative photomicrographs of Sirius red-stained liver sections.</p
Gemcabene downregulates inflammatory, lipid-altering and cell-signaling genes in the STAM™ model of NASH - Fig 6
<p>Oil Red-O Staining Analysis: A—Representative photomicrographs of Oil Red Stained Liver Sections; B—Fat Deposition Area.</p
Representative photomicrographs of hematoxylin and eosin-stained liver sections.
<p>Representative photomicrographs of hematoxylin and eosin-stained liver sections.</p
Overview of the NAFLD Activity Score (NAS).
<p>Overview of the NAFLD Activity Score (NAS).</p