In the decommissioning process of nuclear power plants, Ni-59, Ni-63 and Fe-55 present in radioactive waste are crucial radionuclides used as fundamental indicators in determining waste treatment methods. However, due to their low-energy emissions, the chemical separation of these two radionuclides is essential compared to others. Therefore, this study aims to evaluate the suitability of various pre-treatment methods for decommissioning waste materials by conducting characteristic assessments at each chemical separation stage. The goal is to find the most optimized pre-treatment method for the analysis of Ni-59, Ni-63 and Fe-55 in decommissioning waste. The comparative evaluation results confirm that the chemical separation procedures for Fe and Ni are very stable in terms of stepwise recovery rates and the removal of interfering radionuclides. However, decommissioning waste materials, which mainly consist of concrete, metals, etc., possess unique properties, and a significant portion may be low-radioactivity waste suitable for on-site disposal. Considering that the chemical behavior and reaction characteristics may vary at each chemical separation stage depending on the matrix properties of the materials, it is considered necessary to apply cascading chemical separation or develop and apply individual chemical separation methods. This should be done by verifying and validating their effectiveness on actual decommissioning waste materials.

To minimize cultivation costs, prevent insect-pest infestation, and improve the production efficiency of thermophilic mushrooms, plant substrates obtainedfrom local areas in Cambodia were used for production of both spawn and mushrooms. In this experiment, different sawdusts different organic wastes and grain ingredients and analyzed for improvement of spawnproduction efficiency. Four thermophilic mushroom species, Pleurotus sajor-caju (oyster mushroom, Sambok), Ganoderma lucidum (deer horn shaped), Auricularia auricula (ear mushroom), and Lentinula edodes (shiitake), were used to identify efficient new substrates for spawn and mushroom production. Although the mycelia in the rubber tree sawdust medium showed a slightly slower growth rate (10.9 cm/15 days) than mycelia grown in grains (11.2 cm/15 days in rice seeds), rubber tree sawdust appeared to be an adequate replacement for grain spawn substrates. Th findings indicate that rubber tree sawdust, sugarcane bagasse, and acaciatree sawdust supplemented with rice bran and calcium carbonate could be new alternative the substrates for . Although sugarcane bagasse and rubber tree sawdust showed similarly high biological efficiencies (BE) of 60% and 60.8%, respectively, acacia tree sawdust exhibited relatively a low biological efficiency of 22.4%. However, it is expected that acacia sawdust has potential for the mushroom cultivation when supplemented with currently used sawdust substrates in Cambodia, because of its relatively low price. The price of the sawdust (20 kg sawdust= 6500 Riel or 1.6 USD) currently used was 6.5 times higher than the price of acacia sawdust (201000 Riel or 0.25 )USD). Therefore, utilization for acacia sawdust for mushroom cultivation could become feasible as it would reduce by producing costs of mushrooms in rural areas of Cambodia.

Genus Litochila Momoi belonging to the tribe Hemigasterini is represented by eight species from Korea, China, Japan, Taiwan and India. Modern taxonomic revision of this genus was carried out by Kaur (1988). He and Chen (1996) enlarged the genus by adding one species, L. guizhouensis He & Chen from the oriental part of China. They provided a key to Chinese species and descriptions without including L. sinensis Kaur which was previously reported from Fujian, China by Kaur (1988). As a part of a large revisionary work of the subfamily Cryptinae, four species, L. nohirai (Uchida), L. carbonaria (Smith), L. jezonica (Uchida) and L. sinensis, are recognized from Korea. L. carbonaria. L. sinensis and L. jezonica are reported from Korea for the first time. The species L. guizhouensis is synonymized with L. sinensis. The distinction of females of two closely resembling species, L. carbonaria and L. jezonica, is possible by the number of flagellar segments, the shape of mesopleurum and second tergite, but males are difficult to identify. Momoi and Okamoto (1965) relied on the number of tyloids to identify them, and Kaur (1988) used the shape of postpetiole except for such character. However, our observations revealed these characters are not useful in relating these males, because many variations were found in these characters. Therefore, further DNA studies will be required to resolve this controversy.

Xylitol is a sugar alcohol with a variety of functions including bactericidal and anticariogenic effects. However, the cellular mechanisms underlying the role of xylitol in bone metabolism are not yet clarified. In our present study, we exploited the physiological role of xylitol on osteoclast dif-ferentiation in a co-culture system of osteoblastic and RAW 264.7 cells. Xylitol treatment of these co-cultures reduced the number of tartrate-resistant acid phosphatase (TRAP)- positive multinucleated cells induced by 10 nM 1α,25(OH)2 D3 in a dose‐dependent manner. A cell viability test revea-led no marked cellular damage by up to 100 mM of xylitol. Exposure of osteoblastic cells to xylitol decreased RANKL, but not OPG, mRNA expression in the presence of 10-8 M 1α,25(OH)2D3 in a dose‐dependent manner. Furthermore, bone resorption activity, assessed on bone slices in the co- culture system, was found to be dramatically decreased with increasing xylitol concentrations. RANKL and OPG proteins were assayed by ELISA and the soluble RANKL (sRANKL) concentration was decreased with an increased xylitol con-centration. In contrast, OPG was unaltered by any xylitol con-centration in this assay. These results indicate that xylitol inhibits 1α,25(OH)2D3-induced osteoclastogenesis by reducing the sRANKL/OPG expression ratio in osteoblastic cells.