Search results for "Acetic Acid"
showing 10 items of 427 documents
Effect of vasoactive intestinal polypeptide on the release of serotonin from the in vitro vascularly perfused small intestine of guinea pig.
1989
Isolated segments of the guinea pig small intestine were vascularly perfused and the release of endogenous serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) into the portal vein was measured. All test substances were intraarterially perfused. Vasoactive intestinal polypeptide (VIP, 1 pmol/l-100 nmol/l) inhibited the spontaneous release of 5-HT and 5-HIAA. The maximal inhibitory effect (about 60%) was seen at 100 pmol/l. The effect of VIP on the spontaneous release of 5-HT and 5-HIAA was not changed in the presence of 1 mumol/l tetrodotoxin (TTX). Raising intraluminal pressure by 500 Pa for 5 min increased the release of 5-HT and 5-HIAA by about 25%. Raising the intralu…
Characterization of the muscarine receptors involved in the modulation of serotonin release from the vascularly perfused small intestine of guinea pi…
1989
Isolated small intestinal segments of the guinea pig were arterially perfused and the release of 5-hydroxytryptamine (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) into the portal venous effluent measured by HPLC with electrochemical detection. Test substances were applied via the arterial perfusion medium. McN-A-343, pilocarpine and oxotremorine inhibited concentration-dependently the outflow of 5-HT and 5-HIAA. Pirenzepine (0.03-0.1 mumol/l) which can discriminate between M1 and M2-receptor subtypes antagonized completely this inhibitory effect. In the presence of 1 mumol/l tetrodotoxin (TTx), all three muscarine receptor agonists increased the outflow of 5-HT and 5-HIAA. O…
A novel dimer of oxo-di(acetato)-bridged manganese(III) dimers complex of potential biological significance
2000
[EN] Assembly of the tetranuclear oxomanganese(III) acetato cluster [Mn4O2(O2CMe)(7)(phen)(2)](BF4) from the dinuclear oxo-di(acetato)bridged manganese(III) species [Mn2O(O2CMe)(2)(H2O)(2)(phen)(2)](BF4)(2) . 3H(2)O in aqueous/acetic acid MeOH solution occurs via the new 'dimer of dimers' Mn-III complex [Mn2O(O2CMe)(3)(H2O)(phen)(2)](BF4) . MeOH possesing an unprecedent [Mn-4(mu-O)(2)(mu-O2Me)(4) (mu-(OH2O2CMe)-O-...)(2)] core.
Multifunctional derivatives of dimethoxy-substituted triphenylamine containing different acceptor moieties
2020
This project has received funding from the Research Council of Lithuania (LMTLT), Agreement No. [S-LZ-19-2]. This research was funded by the Région Centre, the Tunisian ministry of research, University of Monastir and the French ministry of Higher Education and Research. J. Bouclé would like to thank the Sigma-Lim LabEx environment for financial supports, and the PLATINOM facility at XLIM laboratory regarding device fabrication and characterizations. DG acknowledges the Lithuanian Academy of Sciences for the financial support.
Structure and thermal properties of a chitosan coated polyethylene bilayer film
2012
The thermal and the structural properties of chitosan coated polyethylene (PE) films were studied. The coating process did not significantly influence the thermal stability and the PE surface structure and/or composition of the polyolefin. Dehydration temperature of chitosan films reflected the strength of water/acetic acid/chitosan chains interactions. Glycerol, used as a plasticizer, formed new hydrophilic centres in the film matrix. Moreover it was better integrated in the CSEGLY than in CSAGLY network. Besides, the addition of a plasticizer in the chitosan films decreased the film degradation temperature. There were two main steps for the PE chitosan coated films degradation. The first …
A zinc-doped endodontic cement facilitates functional mineralization and stress dissipation at the dentin surface
2018
Objective: The purpose of this study was to evaluate nanohardness and viscoelastic behavior of dentin surfaces treated with two canal sealer cements for dentin remineralization. Material and Methods: Dentin surfaces were subjected to: i) 37% phosphoric acid (PA) or ii) 0.5 M ethylenediaminetetraacetic acid (EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite), respectively. Samples were stored in simulated body fluid during 24 h or 21 d. The intertubular and peritubular dentin were evaluated using a nanoindenter to assess nanohardness (Hi). The load/displacement responses were used f…
The development and validation of a rapid method for the determination of antimicrobial agent residues in milk and meat using ultra performance liqui…
2014
Abstract A new multi-class method has been developed for the identification and quantification of the residues of 26 antibiotics from different classes (sulfonamides, macrolides, tetracyclines, penicillins, and quinolones) in milk and meat by ultra performance liquid chromatography coupled to hybrid quadrupole – high resolution Orbitrap mass spectrometry (UPLC–qOrbitrap). The sample preparation included extraction of two analytical portions with acetonitrile and 5% trichloroacetic acid, respectively, followed by centrifugation and filtration. The method was validated over three days at 50% of MRL (maximum residue limit) set in the European Union. Experiments on spiked meat and milk samples …
Guanidinoacetate-creatine in secondary progressive multiple sclerosis: a case report.
2022
Acute secondary progressive multiple sclerosis (SPMS) is characterized by escalating neurological disability, with limited disease-modifying therapeutic options. A 48-year-old woman with acute SPMS being treated with interferon beta-1a and oral corticosteroids presented as a clinical outpatient with no disease-modifying effects after treatment. A decision was made to treat her with a combination of guanidinoacetate and creatine for 21 days. She had made clinical progress at follow-up, with the intensity of fatigue dropping from severe to mild. Magnetic resonance spectroscopy revealed increased brain choline, creatine, N-acetylaspartate, and glutathione. Patients with SPMS may benefit from …
Adducts of free-base meso-tetraarylporphyrins with trihaloacetic acids: Structure and photostability
2020
Abstract Four diverse meso-tetraarylporphyrins in the form of diprotonated adducts with trifluoro-, trichloro-, tribromoacetic acids and acetic acid were investigated in benzene solution. Despite similar structural distortion of the chromophore system due to protonation, the respective adducts demonstrated different photostability when exposed to UV irradiation. The trifluoro- and trichloroacetic adducts, and the acetic acid one, showed some common features both molecular and in the mechanism of photodegradation. However, the tribromo-derivative decayed according to a different kinetic scheme, revealing a considerable impact of the bromine atoms upon the pyrrole units of the porphyrin macro…
Test of isotopic fractionation during liquid-liquid extraction of volatile components from fruits
1995
Fruits constitute a natural source of flavoring molecules. Nevertheless, an isotopic fractionation could be induced by the extraction of volatile molecules from fruits. After the addition of six volatile molecules to Italia grape (hexyl acetate, acetic acid, linalool, butanoic acid, 3-hydroxy-2-methyl-4-pyrone, and methyl cinnamate) and five volatile molecules to Primofiori lemon (hexanal, trans-2-hexenyl acetate, 1-hexanol, trans-2-hexenol, and 4-decanolide) before extraction, it has been established that, for a particular extraction procedure, there is no significant difference between the 13 C enrichments of these molecules before and after extraction. Nothing has been concluded for acet…