Nox2 and p47phox modulate compensatory growth of primary collateral arteries

The role of NADPH oxidase (Nox) in both the promotion and impairment of compensatory collateral growth remains controversial because the specific Nox and reactive oxygen species involved are unclear. The aim of this study was to identify the primary Nox and reactive oxygen species associated with early stage compensatory collateral growth in young, healthy animals. Ligation of the feed arteries that form primary collateral pathways in rat mesentery and mouse hindlimb was used to assess the role of Nox during collateral growth. Changes in mesenteric collateral artery Nox mRNA expression determined by real-time PCR at 1, 3, and 7 days relative to same-animal control arteries suggested a role for Nox subunits Nox2 and p47phox. Administration of apocynin or Nox2ds-tat suppressed collateral growth in both rat and mouse models, suggesting the Nox2/p47phox interaction was involved. Functional significance of p47phox expression was assessed by evaluation of collateral growth in rats administered p47phox small interfering RNA and in p47phox−/− mice. Diameter measurements of collateral mesenteric and gracilis arteries at 7 and 14 days, respectively, indicated no significant collateral growth compared with control rats or C57BL/6 mice. Chronic polyethylene glycol-conjugated catalase administration significantly suppressed collateral development in rats and mice, implying a requirement for H2O2. Taken together, these results suggest that Nox2, modulated at least in part by p47phox, mediates early stage compensatory collateral development via a process dependent upon peroxide generation. These results have important implications for the use of antioxidants and the development of therapies for peripheral arterial disease

Amino-borate complexation for controlling transport phenomena of penetrant molecules into polymeric matrices

The development of new high performance materials, coatings, composites and adhesives relies on insight into the origin of performance on a molecular level. This research explores a new type of epoxy-amine-borate (EAB) hybrid material for control of penetrant solvent molecules into cross-linked thermoset polymer networks. The properties of these materials are explored through material and mechanical testing and model studies are used to probe the mode-of-action through which EAB materials deliver their improved performance properties

Novel Method to Assess Arterial Insufficiency in Rodent Hindlimb

BACKGROUND: Lack of techniques to assess maximal blood flow capacity thwarts the use of rodent models of arterial insufficiency to evaluate therapies for intermittent claudication. We evaluated femoral vein outflow (VO) in combination with stimulated muscle contraction as a potential method to assess functional hind limb arterial reserve and therapeutic efficacy in a rodent model of subcritical limb ischemia. MATERIALS AND METHODS: VO was measured with perivascular flow probes at rest and during stimulated calf muscle contraction in young, healthy rats (Wistar Kyoto, WKY; lean Zucker rats, LZR) and rats with cardiovascular risk factors (spontaneously hypertensive [SHR]; obese Zucker rats [OZR]) with acute and/or chronic femoral arterial occlusion. Therapeutic efficacy was assessed by administration of Ramipril or Losartan to SHR after femoral artery excision. RESULTS: VO measurement in WKY demonstrated the utility of this method to assess hind limb perfusion at rest and during calf muscle contraction. Although application to diseased models (OZR and SHR) demonstrated normal resting perfusion compared with contralateral limbs, a significant reduction in reserve capacity was uncovered with muscle stimulation. Administration of Ramipril and Losartan demonstrated significant improvement in functional arterial reserve. CONCLUSIONS: The results demonstrate that this novel method to assess distal limb perfusion in small rodents with subcritical limb ischemia is sufficient to unmask perfusion deficits not apparent at rest, detect impaired compensation in diseased animal models with risk factors, and assess therapeutic efficacy. The approach provides a significant advance in methods to investigate potential mechanisms and novel therapies for subcritical limb ischemia in preclinical rodent models

Coating method for surfaces in chemical installations

The invention pertains to a method for providing a metallic or concrete surface of a chemical installation with a coating, which comprises the steps of - providing a two-pack coating composition wherein the first pack comprises an epoxy resin and the second pack comprises an amine curing agent for the epoxy resin, the coating composition further comprising an organoboron compound of the formula BX1 X2X3, wherein X1, X2, and X3 are independently selected from -Y1 and -OY2, wherein Y1 is independently selected from monovalent C1-C12 alkyl groups and monovalent C6-C12 aryl groups, and Y2 is independently selected from monovalent C1-C12 alkyl groups and monovalent C6-C12 aryl groups, and wherein at least one of X1, X2, and X3 is an -OY2 group, - combining the first pack and the second pack to form a coating composition, - applying the coating composition to the surface of a chemical installation to form a coating layer, and - allowing the coating layer to cure at a temperature in the range of 0 to 50°C. A chemical installation provided with a lining of a cured coating composition as specified above, and a suitable coating composition, are also claimed. It has been found that the coating composition as specified herein has a wide application spectrum, and a high chemical resistance

Process for the manufacture of an epoxy-functional polyester, epoxy-functional polyester obtained by such process and coating composition comprising such epoxy-functional polyester

The present invention relates to a process for the manufacture of an epoxy- functional polyester. The process according to the invention comprises the steps of a)providing a polyester having functional groups selected from hydroxyl groups and carboxylic acid groups, or mixtures thereof, b)reacting the functional groups of the polyester with an epihaloalkane to obtain an epoxy- functional polyester dissolved in a liquid phase, c) optionally adding an organic solvent to the liquid phase obtained in step b); d) precipitating the epoxy- functional polyester from the liquid phase obtained in step b) or in step c); and e) isolating the precipitated epoxy-functional polyester from the liquid phase by a solid-liquid separation technique. The thus obtained resin is in particular useful for use in powder coatings. The invention further relates to a solid epoxy- functional polyester obtainable by such process and to a coating composition, in particular a powder coating composition, comprising such solid epoxy-functional polyester

Coating method for surfaces in chemical installations

The invention pertains to a method for providing a metallic or concrete surface of a chemical installation with a coating, which comprises the steps of - providing a coating composition comprising epoxy-functional resin, and amine curing agent for the epoxy-functional resin, wherein the coating composition comprises an organic silicon-containing compound selected from the group of organosilanes and organosiloxanes, with the molar ratio between the silicon atoms of the organic silicon-containing compound and the epoxy-groups in the coating composition being in the range of 0.20- 0.75:1.00, - applying the coating composition to a metallic or concrete surface of a chemical installation to form a coating layer, and - allowing the coating layer to cure at a temperature in the range of 0 to 50°C. The invention also pertains to a chemical installation comprising a metallic or concrete surface provided with a lining of a cured coating composition and to a coating composition suitable for providing a metallic or concrete surface of a chemical installation with a coating. It has been found that the coating composition of the present invention shows a wide application spectrum and a high chemical resistance

Coating method for surfaces in chemical installations

The invention pertains to a method for providing a metallic or concrete surface of a chemical installation with a coating, which comprises the steps of: - providing a two-pack coating composition wherein the first pack comprises an epoxy resin and the second pack comprises an amine curing agent for the epoxy resin, the coating composition further comprising an organoboron compound of the formula (I), wherein X is an organic group having 1 to 24 carbon atoms and is linked to the boron atom via a carbon-boron bond, and wherein Y is an at least divalent organic group having 2 to 16 carbon atoms, combining the first pack and the second pack to form a coating composition, - applying the coating composition to the surface of a chemical installation to form a coating layer, and - allowing the coating layer to cure at a temperature in the range of -10 to 50ºC. A chemical installation provided with a lining of a cured coating composition as specified above, and a suitable coating composition, are also claimed. It has been found that the coating composition as specified herein has a wide application spectrum, and a high chemical resistance

Amino-diol borate complexation for controlling transport phenomena of penetrant molecules into polymeric matrices

The development of new high performance materials, coatings, composites and adhesives relies on insight into the origin of material performance on a molecular level. This paper explores a new type of epoxy-amine-borate (EAB) hybrid material for control of penetrant solvent molecules into cross-linked thermoset polymer networks

A highly diastereoselective chloride-mediated dynamic kinetic resolution at phosphorus on-route to a key intermediate in the synthesis of GSK2248761A

A highly diastereoselective chloride-mediated dynamic kinetic resolution at phosphorus has been developed to access a key intermediate in the synthesis of GSK2248761A. This procedure utilises a soluble chloride source and a cheap readily available chiral auxiliary. The practicality of this transformation is demonstrated on a multi-gram scale