Abstract: A blood pump for placement in an incision in an aorta is provided that after placement contacts blood passing through the aorta. The pump inflates and deflates in order to provide left ventricular assistance. The pump has an elongated shell with a generally elliptical shape, an outer convex surface and an inner concave surface. A peripheral side edge located between the inner and outer surfaces terminates in a bead edge. A passage is provided through the shell to provide fluid communication between the outer surface and inner surface. A flexible airtight membrane has a membrane edge bonded to the outer shell surface adjacent to the bead edge to form an enclosed internal chamber in fluid communication with the passage. Preforming the membrane edge looped with a maximum linear span of curvature that is greater than a maximal transverse linear extent of the bead edge, membrane operational wear during inflation and deflation cycles is reduced in the region around the bead edge.

Abstract: The formation of inactive, insoluble forms of peptide can be minimized or, alternatively, inactive, insoluble forms of peptide compounds, if present, can be converted into more physiologically active, soluble forms by dissolving peptide samples in aqueous base and then acidifying the aqueous mixture to precipitate the peptide in the presence of at least one of a salt and a co-solvent. Preferably, both a salt and co-solvent are present. By carrying out the precipitation relatively rapidly (at least in a first stage of acidifying in which the pH of the alkaline medium is reduced to a pH in the range of 6 to 7.5, after which acidification to a final desired pH, e.g., 3 to 6, can occur more slowly) at relatively low temperature, the dissolution characteristics of the resultant precipitated peptide are even further improved. The process is robust, consistent, and suitable for commercial scale manufacture of peptides.