To study nano-scale manufacturing using highly charged ion beams, a facility to produce and irradiate heavy ion beams has been installed at Kochi University of Technology ͑KUT͒. The facility includes an ECR ion source ͑ECRIS͒, a beam transport and analysis system, and an irradiation system. The first beam was extracted from ECRIS in January 2003. To evaluate the performance of ECRIS, the measurements of the current and mass spectrum of ion beams as a function of the voltage for the beam extraction and of the rf power have been carried out. It is concluded from the present results that the combined use of the ECRIS and acceleration system with the transport and analysis system build at KUT works normally.

SummaryWe determined the changes in the sources of energy supply

The malaria parasite (Plasmodium sp.) contains a plastid-derived organelle called the apicoplast, which is essential for the growth of the parasite. In this organelle, a redox system comprising plant-type ferredoxin (Fd) and Fd:NADP(H) oxidoreductase (FNR) supplies reducing power for the crucial metabolic pathways. Electron transfer between P. falciparum Fd (PfFd) and FNR (PfFNR) is performed with higher affinity and specificity than those of plant Fd and FNR. We investigated the structural basis for such superior protein-protein interaction by focusing on the Plasumodium-specific regions of PfFd. Significant contribution of the C-terminal region of PfFd for the electron transfer with PfFNR was revealed by exchanging the C-terminal three residues between plant Fd and PfFd. Further site-directed mutagenesis of the PfFd C-terminal residues indicated that the presence of aromatic residue at positions 96 and 97 contributes to the lower Km for PfFNR. Physical binding analyses using fluorescence and calorimetric measurements supported the results. A mutation from Asp to Tyr at position 97 of PfFd was recently reported to be strongly associated with P. falciparum resistance to artemisinin, the front line anti-malarial drug. Thus, the enhanced interaction of PfFd D97Y protein with PfFNR could be involved in artemisinin resistance of human malaria parasites.

In this study, by conducting the creep-fatigue crack growth tests using circular notched round bar specimens for Alloy 617, the crack growth behaviour was characterized on the basis of crack growth data obtained from the direct current potential drop (DCPD) method, which results in the assurance of the high accuracy of crack length measurement. Furthermore, on the basis of catastrophe theory, an attempt is made to predict theoretically the threshold temperature of creep crack growth related to the diffusion creep mechanism.

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