Serum biochemical analysis was undertaken to study the pathophysiological details of emaciation disease of the tiger puffer fish Takifugu rubripes (Temminck and Schlegel). Serum parameters were measured by biochemical analysis using automated dry chemistry and gas chromatography/mass spectrometry (GC/MS). Serum concentrations of albumin, amylase, calcium, creatinine, glucose and total protein were significantly lower in the emaciated fish when compared with those of normal fish. Regression analyses found close correlation between concentrations of total protein, albumin, amylase, glucose and progress of the disease. In contrast, serum alanine aminotransferase increased significantly in emaciated fish indicating liver function disorder. Further, GC/MS metabolic profiling of the puffer serum showed that the profile of the emaciated fish was distinct to that of non-infected control. The serum content of amino acids including glycine, 5-oxo-proline and proline, and ascorbic acid, fumaric acid and glycerol increased significantly in serum in moderately emaciated fish. The serum glucose, linolenic acid and tyrosine level decreased significantly in the late phase of the disease. Our results clearly show that prolonged intestinal damage caused by myxosporean infection impairs absorption of nutrients, resulting in extreme emaciation.

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A new conceptual combination of Brayton and inverted Brayton cycles with a heat sink by intercooling, which is dubbed the mirror gas turbine, has been evaluated and proposed in this paper. Prior to such evaluations, a preliminary test on the inverted cycle without intercooling was made experimentally to confirm the actual operation. The conventional method of recuperation in gas turbines can be replaced by the mirror gas turbine with a low working temperature of about 450°C at heat exchanger. The combined cycle of Brayton/Rankine for electricity generation plant may be improved by our concept into a system with steam turbines completely removed and with still high thermal efficiency. Ultra-micro turbines will be possible, producing the output power less than 10 kW as well as thermal efficiency of 20 percent.

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