• The Korea Swine Journal
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• v.10 no.5 s.105
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• pp.118-123
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• 1988

• Railway Journal
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• v.20 no.5
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• pp.37-54
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• 2017

• Water for future
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• v.45 no.5
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• pp.74-79
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• 2012

• Construction Engineering and Management
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• v.19 no.5
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• pp.3-6
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• 2018

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.42-52
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• 2024

Antimalarial drugs are an urgently need and crucial tool in the campaign against malaria, which can threaten public health. In this study, we examined the cytotoxicity of the 9 antimalarial compounds chemically synthesized using SKM13-2HCl. Except for SKM13-2HCl, the 5 newly synthesized compounds had a 50% cytotoxic concentration (CC₅₀) >100 μM, indicating that they would be less cytotoxic than SKM13-2HCl. Among the 5 compounds, only SAM13-2HCl outperformed SKM13-2HCl for antimalarial activity, showing a 3- and 1.3-fold greater selective index (SI) (CC₅₀/IC₅₀) than SKM13-2HCl in vitro against both chloroquine-sensitive (3D7) and chloroquine -resistant (K1) Plasmodium falciparum strains, respectively. Thus, the presence of morpholine amide may help to effectively suppress human-infectious P. falciparum parasites. However, the antimalarial activity of SAM13-2HCl was inferior to that of the SKM13-2HCl template compound in the P. berghei NK65-infected mouse model, possibly because SAM13-2HCl had a lower polarity and less efficient pharmacokinetics than SKM13-2HCl. SAM13-2HCl was more toxic in the rodent model. Consequently, SAM13-2HCl containing morpholine was selected from screening a combination of pharmacologically significant structures as being the most effective in vitro against human-infectious P. falciparum but was less efficient in vivo in a P. berghei-infected animal model when compared with SKM13-2HCl. Therefore, SAM13-2HCl containing morpholine could be considered a promising compound to treat chloroquine-resistant P. falciparum infections, although further optimization is crucial to maintain antimalarial activity while reducing toxicity in animals.

• TTA Journal
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• s.126
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• pp.102-105
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• 2009

• 한국도로학회지:도로
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• v.5 no.3 s.17
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• pp.5-16
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• 2003

• The Journal of Society for e-Business Studies
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• v.24 no.2
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• pp.125-141
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• 2019

This paper provides economic analysis for a residential photovoltaic (PV) power system of 5 districts in China and Thailand, using SAM (System Advisor Model) data. Unlike existing literature, the analysis is conducted from the investment timing perspective, as applying to a real option model which can incorporate the cost uncertainty of the PV system and a resident's option to delay the investment. This study shows that the gap of optimal investment times between a real option model and a generally used net present value model ranges from about 6 to 14 years. Also, we found a contracting result for a particular district that, while the investment is appropriate according to the net present value model, it is more reasonable to delay the PV system investment in terms of the real option model.

• Journal of Nutrition and Health
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• v.42 no.5
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• pp.423-433
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• 2009

Folate and vitamin $B_{12}$ are essential cofactors for homocysteine (Hcy) metabolism. Homocysteinemia has been related with cardiovascular and neurodegenerative disease. We examined the effect of folate and/or vitamin $B_{12}$ deficiency on biomarkers of one carbon metabolism in blood, liver and brain, and analyzed the correlation between vitamin biomarkers in mild and moderate homocysteinemia. In this study, Sprague-Dawley male rats (5 groups, n = 10) were fed folatesufficient diet (FS), folate-deficient diet (FD) with 0 or 3 g homocystine (FSH and FDH), and folate-/vitamin $B_{12}$-deficient diet with 3 g homocystine (FDHCD) for 8 weeks. The FDH diet induced mild homocysteinemia (plasma Hcy 17.41 ${\pm}$ 1.94 nmol/mL) and the FDHCD diet induced moderate homocysteinemia (plasma Hcy 44.13 ${\pm}$ 2.65 nmol/mL), respectively. Although liver and brain folate levels were significantly lower compared with those values of rats fed FS or FSH (p < 0.001, p < 0.01 respectively), there were no significant differences in folate levels in liver and brain among the rats fed FD, FDH and FDHCD diet. However, rats fed FDHCD showed higher plasma folate levels (126.5 ${\pm}$ 9.6 nmol/L) compared with rats fed FD and FDH (21.1 ${\pm}$ 1.4 nmol/L, 22.0 ${\pm}$ 2.2 nmol/L)(p < 0.001), which is the feature of "ethyl-folate trap"by vitamin $B_{12}$ deficiency. Plasma Hcy was correlated with hepatic folate (r = -0.641, p < 0.01) but not with plasma folate or brain folate in this experimental condition. However, as we eliminated FDHCD group during correlation test, plasma Hcy was correlated with plasma folate (r = -0.581, p < 0.01), hepatic folate (r = -0.684, p < 0.01) and brain folate (r = -0.321, p < 0.05). Hepatic S-adenosylmethionine (SAM) level was lower in rats fed FD, FDH and FDHCD than in rats fed FS and FSH (p < 0.001, p < 0.001 respectively) and hepatic S-adenosylhomocysteine (SAH) level was significantly higher in those groups. The SAH level in brain was also significantly increased in rats fed FDHCD (p < 0.05). However, brain SAM level was not affected by folate and/or vitamin $B_{12}$ deficiency. This result suggests that dietary folate- and vitamin B12-deficiency may inhibit methylation in brain by increasing SAH rather than decreasing SAM level, which may be closely associated with impaired cognitive function in nutritional homocysteinemia.

• Journal of Life Science
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• v.21 no.1
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• pp.96-101
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• 2011

S-Adenosyl-L-methionine synthtase (SAM-s) catalyzes the biosynthesis of SAM from ATP and L-methionine. SAM plays important roles in the primary and secondary metabolism of cells. A metK encoding a SAM-s was searched from Streptomyces natalensis producing natamycin, a predominantly a strong antifungal agent, inhibiting the growth of both yeasts and molds and preventing the formation of aflatoxin in filamentous fungi. To obtain the metK of S. natalensis, PCR using primers designed from the two highly conserved regions for metK genes of Streptomyces strains was carried out, and an intact 1.2-kb metK gene of S. natalensis was cloned by genomic Southern hybridization with PCR product as a probe. To identify the function of the cloned metK gene, it was inserted into pSET152ET for its high expression in the Streptomyces strain, and then introduced into S. lividans TK24 as a host by transconjugation using E. coli ET12567(pUZ8002). The high expression of metK in S. lividans TK24 induced actinorhodin production on R5 solid medium, and its amount in R4 liquid medium was 10-fold higher than that by exconjugant including only pSET152ET.