Letteratura scientifica selezionata sul tema "Inhibiteur de tartre"

Une nappe d'eaux fossiles à grande profondeur (800 à 2 700 mètres) a été mise en exploitation dans le Sud-Tunisien pour alimenter une usine d'osmose inverse située à Gabès ayant une production de 15 000 m3 /jour, afin de lutter contre la désertification par irrigation et d'assurer le chauffage de serres pour la production de primeurs. La grande dureté (TH de l'ordre de 100 à 140 °F) de ces eaux géothermales a pour conséquence le colmatage rapide des conduites de distribution : 40 à 50 tonnes de tartre par forage, constitué essentiellement de carbonate de calcium, précipitent chaque année. Ce tartre est constitué d'aragonite comme le montrent la microscopie électronique à balayage et la diffraction des rayons X. Une technique électrochimique, la chronoélectrogravimétrie, permet d'étudier l'inhibition de l'entartrage par des composés de la famille des phosphates inorganiques, des phosphonates organiques et des polycarboxylates. La concentration efficace de chacun de ces inhibiteurs agissant par effet de seuil a été déterminée : elle est de l'ordre de 1,1 à 1,5 mg.l-1 pour l'eau du forage de EL HAMMA. Un essai sur le site de EL MANSOURA a été effectué en privilégiant un inhibiteur produit industriellement dans le Sud-Tunisien, le triphosphate de sodium. A la concentration de 1 mg.l-1 il évite l'entartrage du système de refroidissement de type cascade - piscines et des conduites de distribution.

Carvacrol is a major component of thyme and oregano essential oils and has potential uses as a food preservative. The effect of carvacrol on the growth of Listeria monocytogenes was investigated in vitro and in steak tartare. Carvacrol had strong antilisterial activity in growth medium (MIC = 1.6 mM), but no effect was observed when carvacrol was tested in steak tartare. There were two reasons for this reduced activity: the antilisterial activity of carvacrol was strongly reduced at lower temperatures (10 versus 30°C), and the presence of food components interfered with the activity of carvacrol. Both bovine serum albumin and egg yolk inhibited carvacrol activity at >0.2% (wt/vol) in growth medium. For the first time, carvacrol was found to bind to albumin, suggesting that the reduced antilisterial activity of carvacrol in foods such as dairy products and uncooked meats is the result of fewer free unbound carvacrol molecules available to interact with bacteria.

The aim of this study was to determine if the activity of tartrate-resistant acid phosphatase (TRAP) in the synovial fluid (SF) and serum can be used as a marker for diagnosing the early stages of osteoarthritis (OA). We also wished to determine if identifiable differences in the concentrations of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) could be detected in SF between normal joints and OA joints for the diagnosis of early OA. Ten skeletally mature beagle dogs underwent a unilateral surgical transection of the cranial cruciate ligament and medial meniscectomy. Five sham-operated beagle dogs were used as controls. The synovial fluid was collected in 1, 2 and 3 months and examined by western blotting for MMP-2 and ELISA for TIMP-2. The activity of TRAP in the SF and serum was measured using a spectrophotometer. In addition, the presence of TRAP positive cells in the synovium was identified by enzyme histochemistry. The level of the activity of TRAP and MMP-2 in the SF from the induced OA dogs was significantly higher than that of the control over a three-month period (P < 0.05). The TIMP-2 level in the SF was significantly lower in the induced OA dogs than in the control. However, there was no difference in TRAP activity in the serum. Histochemistry revealed a higher number of TRAP positive cells in the synovium from the induced OA dogs. Based on these data, we conclude that the activity of TRAP, MMP-2 and TIMP-2 in SF can be used as a biomarker to diagnose and monitor the early stages of OA.

The inhibitive performance of Trisodium Phosphate (TSP) in controlling corrosion of rebar steel immersed in simulated concrete pore solution prepared in well water in the absence and presence of Zn2+ has been evaluated by the weight loss method. The formulation consisting of 250 ppm of TSP and 50 ppm of Zn2+ offers 95 % inhibition efficiency to rebar steel. Potentiodynamic polarization and electrochemical impedance studies confirmed that a TSP -Zn2+ system function as an anodic inhibitor and the formulation controls the anodic reaction predominantly. Surface analysis by CV, SEM and AFM confirmed the formation of protective layer on the rebar steel surface.

Abstract Abstract 4453 Object Ursolic acid(UA), a pentacyclic triterpenoid derived from many kinds of medicinal plants, exhibits potent anticancer activity in many kinds of cancer cells. However, the anticancer mechanism of UA is not clearly understood. Method The toxic action of UA in K562 cells was assessed using CCK-8. K562 cells trested by UA were incubated with FITC-conjugated Annexin V and counterstained with PI in order to allow exclusion of necrotic cells, then were subsequently analyzed using a flow cytometer. Pro-caspase-3, cleaved caspase-3, Procaspase-9, cleaved caspase-9, Akt and Akt phosphorylation were analyzed by Western Blotting. The expression of PTEN gene is analyzed by Quantitative real-time RT-PCR. Result Here we showed that UA could cause growth inhibition, and induce apoptosis in human chronic myelogenous leukemia cell line K562 cells. The expression of PTEN gene is rejected in many kinds of cancers including leukemia, then the PI3K/Akt pathway is actived. So the PTEN gene and PI3K/Akt pathway become the central targer for cancer therapy. UA treatment can up-regulate the expression of PTEN gene, inhibite the activity of Akt kinase, change the mitochondrial transmembrane potential, then induce the reduce of cytochrome C and the active of caspase family. Conclusion These results suggest that UA might exhibit its strong antitumor effects via the up-regulation of PTEN gene and the inhibited the activity of PI3K/Akt pathway. Disclosures: No relevant conflicts of interest to declare.

<p style="text-align: justify;"><strong>Aims</strong>: Inhibition of potassium hydrogen tartrate (KHT) crystallization by carboxymethylcellulose (CMC) is tested in a model solution and in wines. Tartaric acid salt crystallization risk is assessed by computing the supersaturation, saturation temperature and excess KHT with respect to the saturation equilibrium using MEXTAR® (Mesure de l’EXces de TARtre) software.</p><p style="text-align: justify;"><strong>Materials and results</strong>: Firstly, the time for crystals to appear was recorded by monitoring the conductivity in a model solution and in a wine, and the inhibition ratio was computed. At 11,5 °C, 0,5 mg.L^-1 CMC inhibited KHT crystallization. The inhibitory effect increased exponentially with increasing CMC concentration and was several times greater than that of polysaccharides and polyphenols, the protective colloids in wine (Gerbaud et al., 1997). At 2 °C, 30 mg.L^-1 CMC had the same inhibitory effect than 10 mg.L^-1 at 11.5°C.Secondly, 20 red and white wines were refrigerated for 3 weeks at -4 °C with CMC or metatartaric acid. Results show that the addition of 20 mg.L^-1 CMC has an inhibitory effect at least equivalent to 100 mg.L^-1 metatartaric acid. Furthermore, for 10 wines preheated for 8 days at 30 °C and then refrigerated for 2 months at 0 °C, 5 and 20 mg. L^-1 CMC maintains its inhibitory efficiency, unlike metatartaric acid which is hydrolysed</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: The OIV-OENO 366-2009 and OIV-OENO 02/2008 resolutions recently authorized the use of CMC to prevent tartaric acid salt precipitation. With no impact on health, and stable under heating and in acid solution, CMC is an efficient candidate for tartaric stabilization. The optimal concentration of 20 mg.L^-1 (2 g.hL^-1) should however be adapted to local wine storage conditions and KHT crystallization risk.</p>

Ce projet concerne le développement de différents revêtements hybrides (organiques-inorganiques) fonctionnalisés, élaborés par le procédé sol-gel, pour lutter contre l'entartrage, un problème majeur causé par la précipitation de minéraux, principalement le carbonate de calcium (CaCO3). Contrairement aux méthodes classiques basées sur l'ajout de molécules antitartres dans l'eau, ces revêtements offrent une solution durable en inhibant directement la formation du tartre à la surface d'un matériau. Les performances antitartres de ces films ont été évaluées avec précision grâce à un ensemble d'outils basés sur la microbalance à cristal de quartz (QCM), une technique très sensible capable de détecter les faibles masses déposées à la surface d'un résonateur à quartz. Les résultats ont montré une amélioration significative des performances antitartres des surfaces revêtues par rapport aux surfaces métalliques nues. L'influence de l'hydrophobicité sur l'inhibition du tartre a été étudiée en utilisant des réactifs et des précurseurs plus hydrophobes pour la synthèse des revêtements. Les résultats ont confirmé le rôle important de ce paramètre dans la lutte contre l'entartrage, démontrant que le film le plus hydrophobe présentait les meilleures performances antitartres. Enfin, les propriétés antitartres de films hybrides ont été étudiées, après avoir été imprégnés d'un inhibiteur, l'acide diéthylènetriamine-pentaméthylène phosphonique (DTPMPA). Cette stratégie a permis d'obtenir une inhibition totale de la formation de CaCO3 avec une valeur de l'énergie de formation du tartre, estimée par QCM, très élevée. Ce résultat a montré le potentiel prometteur de ces revêtements comme une alternative durable aux méthodes classiques d'inhibition du tartre, offrant une protection totale de la surface tout en préservant la qualité de l'eau
This project is focused on the development of functionalized hybrid coatings (organic-inorganic) prepared by the sol-gel process for antiscaling applications. Scale, a major issue caused by mineral precipitation, mainly the calcium carbonate (CaCO3), poses significant problems in various industries. These coatings offer a durable solution by directly inhibiting scale formation on the surface, unlike conventional scale inhibition methods that involve the addition of antiscalants directly into water. The antiscaling performance of these films was accurately assessed using a set of tools based on the quartz crystal microbalance (QCM), a highly sensitive technique to detect small masses of deposits on the surface. The results demonstrated a significant improvement in the antiscaling efficiency of coated surfaces compared to uncoated surfaces. The influence of the hydrophobicity on scale inhibition was investigated by using more hydrophobic reagents and precursors for coating elaboration. The results confirmed the fundamental role of this parameter in the scaling process, as the most hydrophobic film exhibited the best anti-scaling performance. The final phase of the project involved studying the antiscaling properties of hybrid coatings impregnated with an inhibitor, diethylenetriamine pentamethylene phosphonic acid (DTPMPA). This strategy successfully achieved total inhibition of CaCO3 formation on the surface, as the energy of scale formation, estimated through QCM measurements, showed the highest value. This outcome highlighted the great potential of these coatings as a sustainable alternative to conventional scale inhibition methods, allowing total inhibition of scaling without compromising water quality

Nous avons caractérisé les propriétés de la liaison in vivo du [3H]GBR12783 dans le cerveau de souris après son injection à dose traceuse par voie systémique. Le surcroît de liaison striatale est diminué par les seuls inhibiteurs de la capture de la dopamine (DA). La liaison est déplacée de façon stéréospécifique par l'énantiomère actif de l'inhibiteur de capture de la DE la nomifensine. Après administration intraveineuse de doses croissantes de GBR12783, nous avons observé une bonne corrélation entre le niveau d'occupation des sites de liaison du [3H]GBR12783 et le score obtenu dans une épreuve de mesure de l'activité locomotrice. Cependant, après l'administration systémique de divers inhibiteurs de capture des monoamines, l'occupation de 50% des sites de liaison in vivo du [3H]GBR12783 se traduit par un effet stimulant moteur d'intensité variable selon l'inhibiteur considéré: la dexamphétamine, un substrat du transporteur neuronal de la DA, et les plus sélectifs du système de capture de la DA induisent une hyperactivité locomotrice tandis que les inhibiteurs non sélectifs sont inactifs dans cette épreuve. Ces résultats suggèrent que des propriétés pharmacologiques associées pourraient jouer un rôle important dans la modulation de leurs effets stimulants moteurs. Finalement, nous avons montré que l'occupation du site de liaison du [3H]GBR12783 in vivo chez la souris intervient pour des doses de dexamphétamine similaires à celles qui induisent les effets stimulants caractéristiques

Nous avons comparé le profil neuropsychopharmacologique de trois agonistes catécholaminergiques indirects, la (+) amphétamine, le GBR 12783 et le GK 13, possédant des propriétés neurochimiques différentes, en nous adressant à des épreuves comportementales mettant en jeu les transmissions catécholaminergiques. La (+) amphétamine inhibe la capture de DA et de NA et induit une libération de DA. Le GBR 12783 est un inhibiteur puissant et sélectif de la capture de DA. Le GK 13 inhibe la capture de DA et de NA. Les trois agents se comportent comme des agonistes dopaminergiques indirects: ce sont des psychostimulants qui induisent chez le rat dont la substance noire est lésée unilatéralement, des rotations ipsilatérales au côté lésé. Ils reversent la catalepsie induite par le halopéridol. L'effet stimulant moteur de la (+) amphétamine est antagonisé à de plus faibles doses de halopéridol que celui évoqué par le GBR 12783 ou le GK 13. La (+) amphétamine, dont l'effet libérateur/stimulant s'appuie sur un pool cytosolique de DA, restaure la transmission dopaminergique, quels que soient l'état des stocks vésiculaires de DA et le niveau de l'activité neuronale; l'effet stimulant du GBR 12783 et du GK 13 nécessite la libération de DA par exocytose, à partir d'un pool vésiculaire de DA. Le GBR 12783 s'avère globalement inactif sur diverses épreuves prédictives d'une activité antidépressive. Le GK 13 et certains de ses dérivés pourraient constituer une série chimique originale de molécules pourvues d'activité antidépressive potentielle, douées de propriétés psychostimulantes

Underground injection of acid gas has been studied for several decades for oil field applications, such as enhanced oil recovery (EOR), but is now being studied as a solution to climate change. This research aims to simulate underground conditions at injection sites, such as the pilot scale injection site located near the site of a coal fired power facility in the Black Warrior Basin of Alabama. This proposed carbon capture and sequestration (CCS) location would involve injection of liquid CO2 into a carbonaceous saline aquifer. The objective of this study was to investigate carbonate surface treatments that alter the kinetics and mechanism of mineral dissolution resulting from the injection of an acid gas (CO2) into a geologic formation. A variety of mineral coatings were tested in an attempt to preserve mineral integrity under acidic conditions. Surface active chemicals were first tested, including scale inhibitors, followed by a novel acid induced surface treatment that precipitates an inorganic layer on the calcite to preserve the acid soluble mineral. These experiments are the first to investigate the use of scale inhibitors for mineral preservation, although were found ultimately to have little impact on dissolution kinetics. However, anions of moderate to strong acids induced surface coatings that were determined to effectively inhibit dissolution. Additionally, a novel, high pressure flow-through experimental apparatus was developed to simulate pressure and temperature conditions relevant to injection sites. Similar mineralogical studies in the literature have used pressurized, unstirred, batch systems to simulate mineral interactions. Solids with an acid induced surface coating were tested in the high pressure column and no calcium was found to leave the column.