산화물 사용 후 핵연료를 처리하는 전해환원공정에서는 LiCl 용융염계에서 산소가 생성되는 반응을 수반하게 되 며, 생성된 산소로 인해 반응기의 구조재료를 상당히 부식시킬 수 있는, 화학적으로 심각한 반응환경을 조성한다. 따라서, 고온 용융염을 다루는 전해환원 공정장치를 위해서는 최적의 재료를 선택하는 것이 필수적이다. 본 연구에 서는 리튬용융염, 675℃, 216시간동안 산화분위기에서 코팅이 안 된 초합금과 코팅된 초합금 시편의 고온 부식연구 를 수행하였다. IN713LC 초합금 시편에 aluminized NiCrAlY bond 코팅 후 Y2O3 top 코팅을 하였다. 코팅이 안 된 초 합금은 부식층의 빠른 성장응력과 열적응력에 의한 부식층의 박리로 명확한 무게손실을 보인다. 탑 코팅의 화학적 및 열적 안정성으로 인해 고온 리튬용융염을 다루는 구조재료의 부식 저항성이 증가함을 확인할 수 있었다

고온 용융염 전해환원 공정은 후행핵연료 주기의 대안 공정인 파이로공정의 산화물 사용후핵연료의 확대 를 위해 필수적인 공정이다. 사용후핵연료는 다성분 산화물로 이루어져 있으며 각 산화물은 전해환원 공정 에서 화학적 특성에 따라 산소를 잃게 된다. 본 연구에서는 건식분말화 공정 이후 전해환원 반응기에 도입되 는 사용후핵연료 조성을 기준으로 각 금속-산소 시스템을 독립적인 이상고용체로 가정하여 전해환원 반응거동을 계산하였다. 전해환원을 Li의 환원과 이어지는 Li과의 화학반응의 결합으로 산정하여 U을 비롯한 금 속 환원 거동을 계산하였다. 계산결과 대부분의 산화물들은 전해환원 공정에 의해 금속으로 전환되는 것으 로 예상되었다. 란타나이드 원소들의 경우 Li2O의 농도가 낮아지면 금속 전환율이 높아지나 대부분 산화물로 존재하는 것으로 나타났다. 추가적으로 U3O8의 전해환원 거동에 대해 Li의 확산과 Li과의 화학반응을 고려하 여 반실험적 모델이 제시되었다. 실험데이터를 활용하여 매개변수를 결정하였으며 시간에 대한 환원율 및 전류에 대한 99.9% 환원 시간을 계산하였다.

Carnosine is a dipeptide (β-alanyl-L-histidine) found in mammalian brain, eye, olfactory bulb and skeletal muscle at high concentrations. Its biological functions include antioxidant and anti-glycation activities. The objectives of this study were to investigate anti-diabetic effects of carnosine as determined by blood glucose levels in glucose tolerance test (GTT) and insulin tolerance test (ITT), insulin level and serum biochemical and lipid levels in male C57BL/6J db/db mice. There were five experimental groups including normal (C57BL/6J), control (vehicle), and three groups of carnosine at doses of 6, 30, and 150 mg/kg b.w. Carnosine was orally administered to the diabetic mice everyday for 8 weeks. There was no significant difference in body weight changes in carnosine-treated groups compared to the control. The treatments of carnosine significantly decreased the blood glucose level in the diabetic mice compared with the control (p < 0.05) after 5 weeks. The treatments of carnosine also significantly decreased the blood glucose levels in GTT and ITT and glycosylated hemoglobin (HbA1c), compared with the control (p < 0.05). Carnosine at the dose of 6 mg/kg significantly decreased the serum insulin level compared to the control (p < 0.05). Carnosine significantly increased total proteins but significantly decreased lactate dehydrogenase and blood urea nitrogen compared with the control (p < 0.05). Carnosine also significantly decreased glucose, LDL, and triglyceride in the serum of diabetic mice compared to the control (p < 0.05). These results suggest that carnosine has a hypoglycermic effect resulting from reduction of glucose and lipid levels and that high carnosine-containing diets or drugs may give a benefit for controlling diabetes mellitus in humans.

Phytic acid (PA) (Inositol hexaphosphate, IP6) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plants and mammalian cells. Recently PA has received much attention for its role in anticancer activity. In the present study, the preventive effects of PA on colon carcinogenesis were investigated. Six-week old Fisher 344 male rats were fed a AIN-93G purified diet and PA (0.5% or 2% PA in water) for 8 weeks. The animals received two (1st and 2nd week) injections of azoxymethane (AOM, 15 mg/kg b.w.) to induce colonic aberrant crypt foci (ACF). After sacrifice, the total numbers of aberrant crypts (AC) and ACF in colonic mucosa were examined after staining with methylene blue. Blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. AOM induced the total numbers of 142.3 ± 22.3 ACF/colon and 336.6 ± 55.1 AC/colon. PA at the doses of 0.5 and 2% decreased the numbers of ACF and AC/colon in a dosedependent manner. The numbers of ACF/colon and AC/colon by PA at the dose of 0.5% were 124.4 ± 28.5 and 302.7 ± 67.3, respectively. PA at the dose of 2% significantly decreased the ACF and AC numbers to 109 ± 18.1 and 254.8 ± 50.6, respectively (p < 0.01). Especially, 2% PA significantly reduced the number of large ACF ( ≥ 4 AC/ ACF) from 26.8 ± 6.2 ACF/colon to 15 ± 6.7 ACF/colon (p < 0.01). Although some parameters in blood counts and serum chemistry were changed compared with the control, no specific toxicity was found. These findings suggest that phytic acid can be a chemopreventive agent for colon carcinogenesis resulting from inhibition of the development of ACF in the F344 rat.

The aim of this study was to examine the promoting effect of herbal extracts on hair regrowth in C3H/HeJ mice. The herbal extracts were obtained from the Damo-cosmetics Inc. There were four experimental groups including distilled water (D. W., negative control), 20% ethanol (EtOH, vehicle control), 3% minoxidil (MXD, positive control), and herbal extract (Ext). The herbal extract included the mixture of water and alcohol extract from Pleuropterus multflorus, Lonicera japonica Thunberg, Phellinus linteus, and Phaseolus radiatus. Test compounds were applied to the shaved dorsal skin of mice mouse for 3 weeks. The photograph of hair regrowth was taken at day 0, 4, 7, 10, 14, 17, and 21. The herbal extract group showed faster hair regrowth than negative control group or 20% EtOH groups after 10 and 14 days of treatments. The elongation of hair follicles in MXD and the herbal extract groups were observed. The activities of alkaline phosphatase (ALP) and γ-glutamyl transpeptidase were sfanificantly (γ-GT) increased in MXD and herbal extract groups compared with negative control group (p＜0.05). The expression of epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) were also sfanificantly hfaher in MXD and herbal extract group than negative control group (p＜0.05), althouah there were no sfanificant differences amoularhe groups of 20% EtOH, MXD, and herbal extract. These results suagest that the herbal extract used in this study may have grpromoting effect on hair regrowth by increasing activities of ALP and γ-GT and expression of EGF and VEGF.

Anti-wrinkle effect of herbal extracts was investigated on the skin of in a model of animal irradiated by ultraviolet rey B (UVB). The female albino hairless mice (HR/ICR) were randomly allocated to the normal control group (NC-non irradiated-vechicle), positive control group (PC, UVB irradiated vehicle) and herbal extract (HE) group. The herbal extract included the mixture of water and alcohol extract from Pleuropterus multflorus, Lonicera japonica Thunbert, Phellinus linteus, and Phaseolus radiatus. The herbal extract was treated dorsally with 0.2 ml per mouse five times a week for 12 weeks. At fifth week of the treatment, the animals were exposed to UVB irradiation for subsequent eight weeks three times a week. The intensity of irradiation was gradually increased from 30 mJ/㎠ to 240 mJ/㎠ (1MED: 60 mJ/㎠). Dorsal skins were obtained and stained with H&E to examine histological changes and epidermal/dermal thckness. The collagen fiber was also observed in Masson-Trichrome staining. Hydroxyproline assay and western blot analysis were also carried out to detect the change of collagen amount and to investigate MMP-1 expression, respectively. The HE group showed a better appearance and weak wrinkling, compared to PC group, The treatment of herbal extract significantly increased the thickness of dermis and the amount of collagen fibers compared to PC group (p＜0.05). The treatment of HE significantly increased the hydroxyproline amount compared to PC group (p＜0.05). The chronic UVB irradiation to hairless mice skin increased expression of MMP-1 but the treatment of HE decreased the expression of MMP-1. These results indicate that the herbal extract used in this study have a preventive effect on the UVB-induced wrinkle in a hairless mice model, partly due to the reduction of MMP-1 expression and increment of collagen amount.