Abstract: Described here are devices, systems, and methods for closing the left atrial appendage. The methods described here utilize a closure device for closing the left atrial appendage and guides or expandable elements with ablation or abrading elements to ablate or abrade the left atrial appendage. In general, these methods include positioning a balloon at least partially within the atrial appendage, positioning a closure assembly of a closure device around an exterior of the atrial appendage, inflating the balloon, partially closing the closure assembly, ablating the interior tissue of the atrial appendage with the inflated balloon, removing the balloon from the atrial appendage, and closing the atrial appendage with the closure assembly.

Abstract: A method is invented to remove lead based paint from a large outdoor steel structure without emission of the lead fragments to the environment. The method of this invention protects the surroundings from contamination by the lead contained in the paint material. The method of this invention utilizes the different thermal expansion coefficients of the paint and the steel structure. Adhesive materials, including but not limited to, epoxy resin monomers, sand particles, grout, are added on the surface of an existing lead based paint layer. A protection layer, including but not limited to a paper and fabrics, is laid on the top of the slurry to soak the monomers in. The epoxy resin is cured firmly by proper activator of, including but not limited to, heat and peroxide. Liquid nitrogen, which is supplied through a rubber hose, is sprayed on the surface of protection layer of, including but not limited to, a “Chang Ho Ji” paper.