The growth rate of the energy demand in the world has been lowered recently, however, the essenciality of the development of nuclear power generation has not been changed. Because of the limited resources of terrestrial uranium, the techniques of the extraction of uranium from sea water as the practically unlimited resources of uranium have been developed in Japan and other countries like F. R. Germany, Sweden, United States and others. Many fundamental results in the above field have been accumulated as well as some design studies and cost estimations have been conducted. In the last October, the International Meeting on Recovery of Uranium from Seawater was held in Japan organized by AESJ and IAEA. At this time moment, the up-to-date status of the studies including the selection of the chemical processes, development of adsorbents, design studies and cost estimations will be reviewed.

Contact between blood and biomaterial triggers a complex series of events including protein adsorption, leukocyte adhesion and activation, and complement activation. In this article, a series of fluorinated polyimides cured at a different temperatures was prepared, and the biocompatibility of the membranes was evaluated using in vitro protein adsorption, neutrophil adhesion, and complement activation experiments under static conditions. We found that protein adsorption, neutrophil adhesion, and complement activation for the polyimides significantly depends on the curing temperature and decreases with an increase in the temperature and that the polyimide has a good biocompatibility compared with poly(styrene) and polydimethylsiloxane. We concluded that the rearrangement of molecules such as CF(3), sulfone, and ketone at the outermost surface occurs because of curing, which induces an increase in the hydrophobicity and that the cured polyimide suppresses protein adsorption, neutrophil adhesion, and complement activation because of its high hydrophobicity and low surface free energy.

The growth rate of the energy demand in the world has been lowered recently, however, the essenciality of the development of nuclear power generation has not been changed. Because of the limited resources of terrestrial uranium, the techniques of the extraction of uranium from sea water as the practically unlimited resources of uranium have been developed in Japan and other countries like F. R. Germany, Sweden, United States and others. Many fundamental results in the above field have been accumulated as well as some design studies and cost estimations have been conducted. In the last October, the International Meeting on Recovery of Uranium from Seawater was held in Japan organized by AESJ and IAEA. At this time moment, the up-to-date status of the studies including the selection of the chemical processes, development of adsorbents, design studies and cost estimations will be reviewed.

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Aromatic fluorinated polyimide (6FDA-6FAP) derived from 2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) and 2,2'-bis(4-aminophenyl) hexafluoropropane (6FAP) have been synthesized with chemical imidation for a novel membrane oxygenator. In this study we investigated the interactions of the fluorinated polyimide with plasma protein, platelets, neutrophils, and complement, which influence thrombus formation and the activation of the immune system. The immunogold labeling technique was used for the detection of adsorbed proteins. One of the key findings is that the adsorption of albumin (Alb) and fibrinogen (Fib) from plasma on the surface of the heat-treated polyimide was significantly suppressed. However, the adsorption of y-globulin (IgG) with an isoelectric point of approximately pH 7 onto the polyimide surface was selectively facilitated. The orientation of the adsorbed IgG was determined by using anti-human IgG (Fab')2, and it was determined that almost all the IgG was adsorbed on the surface of the polyimide through the Fc fragment by hydrophobic interaction. These findings will be partially associated with the strong surface negativity combined with hydrophobicity of the polyimide surface, and elucidate the results of the suppressed platelet adhesion and Fc-mediated immune activation of the polyimide.