Compressible flow structures interaction with a two-dimensional ejector: a cold-flow study

An experimental study has been conducted to examine the interaction of compressible flow structures such as shocks and vortices with a two-dimensional ejector geometry using a shock-tube facility. Three diaphragm pressure ratios ofP4 =P1 = 4, 8, and 12 have been employed, whereP4 is the driver gas pressure andP1 is the pressure within the driven compartment of the shock tube. These lead to incident shock Mach numbers of Ms = 1:34, 1.54, and 1.66, respectively. The length of the driver section of the shock tube was 700 mm. Air was used for both the driver and driven gases. High-speed shadowgraphy was employed to visualize the induced flowfield. Pressure measurements were taken at different locations along the test section to study theflow quantitatively. The induced flow is unsteady and dependent on the degree of compressibility of the initial shock wave generated by the rupture of the diaphragm

Autoantibodies to the heat-shock protein hsp90 in systemic lupus erythematosus.

Patients with systemic lupus erythematosus (SLE) develop multiple autoantibodies to self-antigens. Analysis of autoantibody systems in this and related autoimmune disorders can provide information of etiologic and pathogenetic significance. We report here a previously unrecognized autoantibody to the 90,000-D heat-shock protein, hsp90, a molecule thought to have important functions in the cellular response to stress, virus-induced transformation, steroid hormone receptor action, and cellular activation. Autoantibodies to hsp90 were exclusively of the IgG class, and were detected in approximately 50% of unselected patients with SLE and 2/6 patients with idiopathic polymyositis. Anti-hsp90 antibodies were not detected in sera from 10 normal subjects, 10 patients with rheumatoid arthritis, or 7 patients with scleroderma. The identity of this major intracytoplasmic antigen was established by its specific removal from nonionic detergent cell lysates following immunoabsorption with monospecific rabbit anti-hsp90, and by demonstration of increased synthesis following a 10-min 45 degrees C heat shock. These data define the frequent occurrence of a novel autoantibody to a major heat-shock protein in patients with SLE