• Advances in concrete construction
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• v.5 no.5
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• pp.513-537
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• 2017

In this study, the fracture toughness $K_{IC}$ of high performance concrete (HPC) was investigated by conducting three-point bending tests on a total of 240 notched beams of $500mm{\times}100mm{\times}100mm$ subjected to heating temperatures up to $450^{\circ}C$ with exposure times up to 16 hours and various heating and cooling rates. For a heating rate of $3^{\circ}C/min$, $K_{IC}$ for the hot concrete sustained a monotonic decrease trend with the increasing heating temperature and exposure time, from $1.389MN/m^{1.5}$ at room temperature to $0.942MN/m^{1.5}$ at $450^{\circ}C$ for 4-hour exposure time, $0.906MN/m^{1.5}$ for 8-hour exposure time and $0.866MN/m^{1.5}$ for 16-hour exposure time. For the cold concrete, $K_{IC}$ sustained a two-stage decrease trend, dropping slowly with the heating temperature up to $150^{\circ}C$ and then rapidly down to $0.869MN/m^{1.5}$ at $450^{\circ}C$ for 4-hour exposure time, $0.812MN/m^{1.5}$ for 8-hour exposure time and $0.771MN/m^{1.5}$ for 16-hour exposure time. In general, the $K_{IC}$ values for the hot concrete up to $200^{\circ}C$ were larger than those for the cold concrete, and an inverse trend was observed thereafter. The increase in heating rate slightly decreased $K_{IC}$, and at $450^{\circ}C$ $K_{IC}$ decreased from $0.893MN/m^{1.5}$ for $1^{\circ}C/min$ to $0.839MN/m^{1.5}$ for $10^{\circ}C/min$ for the hot concrete and from $0.792MN/m^{1.5}$ for $1^{\circ}C/min$ to $0.743MN/m^{1.5}$ for $10^{\circ}C/min$ for the cold concrete after an exposure time of 16 hours. The increase in cooling rate also slightly decreased $K_{IC}$, and at $450^{\circ}C$ $K_{IC}$ decreased from $0.771MN/m^{1.5}$ for slow cooling to $0.739MN/m^{1.5}$ for fast cooling after an exposure time of 16 hours. The fracture energy-based fracture toughness $K_{IC}$' was also assessed, and similar decrease trends with the heating temperature and exposure time existed for both hot and cold concretes. The relationships of two fracture toughness parameters with the weight loss and the modulus of rapture were also evaluated.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.280-284
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• 2017

'Hwaweon 6' was developed from a cross between 'Hwaseongbyeo' and a wild species, Oryza minuta L. (Acc. No. 101154) based on marker-assisted selection and backcrossing. The recurrent parent 'Hwaseongbyeo' is a high grain quality cultivar with medium maturity. Hwaweon 6 is nearly isogenic to Hwaseongbyeo except a small O. minuta introgressed segment on chromosome 7 harboring genes related with spikelets per panicle. The preliminary and replicated yield trial was conducted at Chungnam National University and Chungcheongnamdo Agricultural Research & Extension (CARES), Yesan in 2009 and 2010. The local adaptability test was carried out by the National Seed Management Office (NSMO) in 2011 and 2012. This cultivar was registered to NSMO with a cultivar designated as Hwaweon 6. This cultivar averaged 80cm in culm length and has a medium growth duration. Milled rice of Hwaweon 6 is translucent and the grain quality traits are comparable to those of the recurrent parent. The average yield potential of Hwaweon 6 in grain was about 6.57 MT/ha at the ordinary fertilizer level for two years about 3.0% higher than that of Hwaseongbyeo due to an introgression of the quantitative trait locus (QTL) for spikelets per panicle (qSPP7) from O. minuta. This variety is comparable to Hwaseongbyeo in low temperature germinability and cold tolerance. The qSPP7 QTL would be useful in enhancing yield potential in rice breeding program.

• Journal of Life Science
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• v.31 no.1
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• pp.1-9
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• 2021

Brown seaweeds have been shown to decrease blood glucose levels and improve insulin sensitivity previously. In this study, we investigated the effect of fucoidan, a complex polysaccharide derived from brown seaweeds, on glucose uptake to improve insulin resistance, and examined its mechanism of action in 3T3-L1 adipocytes. We observed that fucoidan significantly increased glucose uptake and it was related to an increased expression of plasma membrane-glucose transporter 4 (PM-GLUT4) in 3T3-L1 adipocytes. Fucoidan treatment increased the activation of phosphatidylinositol-3-kinase (PI3K) and the phosphorylation of insulin receptor substrate 1 (IRS1tyr) compared with that of the control cells. Fucoidan also promoted the phosphorylation of Akt and protein kinase C (PKC)-λ/ζ compared to that of the control cells. Moreover, fucoidan significantly upregulated acetyl-CoA-carboxylase (ACC) and adenosine monophosphate - activated protein kinase (AMPK) phosphorylation. As a result, translocation of GLUT4 was significantly enhanced in 3T3-L1 adipocytes, which significantly promoted glucose uptake via the PI3K/AMPK pathways. The elevation of glucose uptake by fucoidan was blocked by inhibitor of PI3K and inhibitor of AMPK in 3T3-L1 adipocytes. These findings indicate that fucoidan might ameliorate glucose uptake through GLUT4 translocation to the plasma membrane by activating the PI3K/Akt and AMPK pathways in 3T3-L1 adipocytes. Fucoidan is thought to be of high material value to diabetes treatments and functional foods.

• Herbal Formula Science
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• v.29 no.2
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• pp.71-80
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• 2021

Objectives : This study investigated cellular-protective effects of Nardotidis seu Sulculii Concha water extract (NSCE) against oxidative stress induced by arachidonic acid (AA)+iron or tert-butylhydroperoxide (tBHP). Methods : In vitro, MTT assay was assessed for cell viability, and immunoblotting analysis was performed to detect expression of AMP-activated kinase (AMPK) signaling pathway and autophagy related proteins. In vivo, mice were orally administrated with the aqueous extract of NSCE of 500 mg/kg for 3 days, and then injected with CCl₄ 0.5 mg/kg body weight to induce acute damage. The level of liver damage was measured by serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) analysis. Results : Treatment with NSCE inhibited cell death induced by AA+iron and tBHP. NSCE induced the phosphorylation of AMPK, and this compound also induced the phosphorylation of LKB1, an upstream kinase of AMPK, and Acetyl-CoA carboxylase (ACC), a primary downstream target of AMPK. NSCE increased the protein levels of autophagic markers (LC3II and beclin-1) and decreased the phosphorylation of mammalian target of rapamycin (mTOR) and simultaneously increased the phosphorylation of unc-51-like kinase-1 (ULK-1) in time-dependent manner. Conclusions : NSCE has the ability 1) to protect cells against oxidative stress induced by AA+iron or tBHP. NSCE 2) to activate AMP-activated protein kinase (AMPK), and 3) to regulate autophagy, an important regulator in cell survival.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.564-573
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• 2022

Calcium carbonate (CaCO₃) exhibits three polymorphs: calcite with arhombohedral, vaterite with a spherical, and aragonite with a needle-like structure. Qualitative and quantitative analyses of the morphology of CaCO₃ are very important to investigate the synthesis of single-crystal vaterite and aragonite. In this work, the polymorphs of calcium carbonate were quantitatively analyzed using XRD. Pure vaterite and pure aragonite were synthesized and the peak distribution of a single phase was analyzed. The vaterite fraction of a mixture of calcite and vaterite was calculated based on the intensity of a specific diffraction peak, and compared to the results based on the peak area. The mean value of f_sV (the correction factor for the peak area of vaterite) was 0.654. The phase analysis of calcite-aragonite mixtures was performed, and the mean value of f_sA (the correction factor for the peak area of aragonite) was obtained as 0.6713. Using these factors, Eq. (24)~Eq. (32) for the quantitative analysis based on the total peak area of XRD were derived to calculate the phase contents of ternary phase CaCO₃. And three-component XRD section was defined considering overlapping sections.

• Journal of Life Science
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• v.32 no.10
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• pp.762-770
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• 2022

Hyperglycemia in type 2 diabetes can be alleviated by promoting cellular glucose uptake. Betulinic acid (3β,-3-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic lupane-type triterpenoid compound. Although there have been studies on the antidiabetic activity of betulinic acid, studies on cellular glucose uptake are lacking. We investigated the effects of betulinic acid on glucose uptake and its mechanism of action in 3T3-L1 adipocytes. Betulinic acid significantly stimulated glucose uptake in 3T3-L1 adipocytes by increasing the phosphorylation of the insulin receptor substrate 1-tyrosine (IRS-1tyr) in the insulin signaling pathway, which in turn stimulated the activation of phosphoinositide 3-kinase (PI3K) and the phosphorylation of protein kinase B (Akt). The activation of PI3K and Akt by betulinic acid translocated glucose transporter 4 to the plasma membrane (PM-GLUT4), thereby increasing the expression of PM-GLUT4 and thus stimulating cellular glucose uptake. Betulinic acid also significantly increased the phosphorylation/activation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. The activation of PI3K and AMPK by betulinic acid was confirmed using the PI3K inhibitor wortmannin and the AMPK inhibitor compound C. The increase in glucose uptake induced by betulinic acid was significantly decreased by wortmannin and compound C in the 3T3-L1 adipocytes. These results suggest that betulinic acid stimulates glucose uptake by activating PI3K and AMPK in 3T3-L1 adipocytes.

• The Korea Journal of Herbology
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• v.33 no.6
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• pp.43-60
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• 2018

Objectives : This study was conducted to compare the effect of Achyranthis Bidentatae Radix on antioxidant changes and antihyperlipidemics in hypercholesterolemic rats according to changes in the number of steams. Methods : The experimental animals were divided into six groups: normal (Nor), high cholesterol diet (Veh), high cholesterol diet with Simvastatin 5 mg/kg (Sim), high cholesterol diet with AR0 extract 200 mg/kg (AR0), high cholesterol diet with AR6 extract 200 mg/kg (AR6) and high cholesterol diet plus AR9 extract 200 mg/kg (AR9). I measured HDL, LDL TC, TG contents and ROS from each serums and compared them. I analyzed antioxidant-related protein expressions and cholesterol-related protein expressions in each liver tissues. I also performed optical microscopic analysis through liver tissue staining. Results : The Antioxidant activity of Achyranthis Bidentatae Radix was increased by steaming processes. In vivo, AR0 decreased liver weight in hyperlipidemic rats. LDL TC, TG, AI and CRF were decreased but HDL was increased in AR0. AST, ALT, creatinine, and BUN were decreased in AR0. ROS was decreased in AR0, AR6, and AR9. SOD, catalase and GPx were decreased by steaming processes. p-AMPK was decreased but SREBP-2, p-ACC, and HMGCR were increased by steaming processes. Histologic analysis showed that AR0 decreased liver fat accumulation. Conclusion : In conclusion, AR0 can be developed as a treatment for hyperlipemia. And it is required to research on antioxidant effect changes among different times steamed Achyranthis Bidentatae Radix.

• The Korea Journal of Herbology
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• v.33 no.6
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• pp.61-70
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• 2018

Objectives : Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of hepatic triglycerides (TG) that leads to inflammation and fibrosis. Crataegi Fructus ethanol extract (CE) is a korean traditional herb that used for digestive diseases. It has been investigated that CE has the effect that prevent hepatotoxicity caused by CCl4 or GaIN and regulate the inflammatory in several organs. However, a hypolipidemic effect of CF has not been reported. Methods : The purpose of this study is that examine the lipid accumulation inhibitory effect of CE on NAFLD. We checked the body and liver weight change of MCD-diet induced mice with/without administration of CE. The blood lipid levels of C57BL/6J mice were checked by biochemistry. Also we observed the liver histology of MCD-diet induced mice and investigate the molecular mechanisms in MCD-diet-induced NAFLD in C57BL/6J mice. Results : CE improved MCD-diet-induced lipid accumulation and TG and TC levels. Also, CE decreased hepatic lipogenesis such as SREBP-1, $C/EBP{\alpha}$, $PPAR{\gamma}$, ACC and FAS. Besides, we also found out that CE increased AMPK phosphorylation. These results indicated that CE has the same ability to activate AMPK and then reduce SREBP-1, and FAS expression, finally leading to inhibit hepatic lipogenesis and hepatic antioxidative ability. Conclusions : In this report, we found CE exerted a regulatory effect on lipid accumulation by decreasing lipogenesis in MCD-diet induced NAFLD model. Therefore, CE extract may be active in the prevention of fatty liver.

• The Korea Journal of Herbology
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• v.33 no.5
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• pp.89-103
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• 2018

Objectives : This study is aimed to compare the changes in Antioxidative capacity of Liriopis Tuber by steaming process and to compare the effects in hyperlipidemia induced rats fed high cholesterol diet between Simvastatin and Liriopis Tuber by steaming process. Methods : The SD rats were divided into six groups: normal diet (Nor), high cholesterol diet (Veh), high cholesterol diet plus Simvastatin 5 mg/kg (Sim), high cholesterol diet plus LT0 extract 200 mg/kg (LT0), high cholesterol diet plus LT6 extract 200 mg/kg (LT6) and high cholesterol diet plus LT9 extract 200 mg/kg (LT9). We compared the total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL) contents and reactive oxygen species (ROS) from each serums. Protein expression in liver tissues related to antioxidant and cholesterol was analyzed. Results : The Antioxidant activity of Liriopis Tuber increased by steaming process. In vivo, TC, TG, LDL-c, atherogenic index (AI) and cardiac risk factor (CRF) decreased and HDL-c increased with increasing steaming frequency. aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and blood urea nitrogen (BUN) decreased with increasing steaming frequency. ROS decreased only in LT9, and SOD, catalase and glutathione peroxidase (GPx) increased with increasing steaming frequency. phospho-AMP-activated protein kinase (p-AMPK) increased and sterol regulatory element-binding protein 2 (SREBP-2), Phospho-Acetyl-CoA Carboxylase (p-ACC) and HMG-CoA reductase (HMGCR) decreased with increasing steaming frequency. Liver staining showed a decrease in hepatic fat accumulation of LT9. LT9 showed significant results in all experiments. Conclusions : LT9 showed significance of anti-lipid effect and improved fatty liver of hyperlipemia induced rats fed on high cholesterol diet, In conclusion, LP9 can be effectively used for the treatment of hyperlipidemia.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.35 no.4
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• pp.31-46
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• 2022

Objectives : The purpose of this study is to analyze outpatients who visited for treatment for sudden sensorineural hearing loss in ophthalmology & otolaryngology & dermatology clinic of Daejeon Korean medical hospital from January 1st, 2013 to December 31th, 2021. Methods : We retrospectively analyzed outpatients who visited for treatment for sudden sensorineural hearing loss in ophthalmology & otolaryngology & dermatology clinic of Daejeon Korean medical hospital from January 1st, 2013 to December 31th, 2021. according to year, season, gender, age, clinical symptoms, number of visits and initial degree of hearing loss. The statistical analysis performed using IBM SPSS 25.0 for Windows. Results : The results of analyzing the medical records of 194 patients are as follows. 1. The number of patients showed a gradual increase from 2014 to 2021 and spring was highest in season. Acc ording to gender, women visited more than men and the age group that visited the most was middle-aged, including 40s and 50s. 2. Patients experienced 13 symptoms and the average number was 4.06. In the analysis of the major symptoms according to gender, hyperacusis and headache were found to be more common in female. 3. The average of initial hearing loss was 52.54dB and was higher in male. The loss was relatively higher in 60s or older than in the younger age group. Conclusions : If treatment and management methods that reflect these symptoms are developed, it is thought that it will greatly helpful to improve the quality of life of patients with sudden hearing loss.