• Journal of Life Science
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• 제19권12호
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• pp.1836-1840
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• 2009

Recently, hydroxymethylfurfrual (HMF) has been highlighted as a key intermediate for the production of liquid biofuels and other valuable compounds. We used sesame roots as a biocatalyst to synthesize HMF using flask cultures. The synthesis of HMF was identified by GC-mass analysis. The highest root growth was observed in cultures with 1.0 mg/l NAA at $30^{\circ}C$, while root growth was not found in those without NAA treatment. When silver nitrate ($AgNO_3$) was added, the root growth was greatest in those treated with 0.5 mg/l $AgNO_3$ and cultured at $30^{\circ}C$. In the case of HMF synthesis, its highest yield was obtained in those treated with 0.5 mg/l NAA at $25^{\circ}C$, but low HMF was detected in those treated without naphthaleneacetic acid (NAA). The addition of $AgNO_$ to the culture medium showed a 8-10% reduction in HMF yield compared to that of the control, indicating its inhibitory effect on the synthesis of HMF. On the whole, an optimal culture temperature for HMF synthesis seemed to be between $25-30^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• 제29권2호
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• pp.145-152
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• 2016

This study investigated the changes in chemical components, antioxidant compounds, and activity before (BG) and after germinated (AG) brown rice in order to promote the availability of these beneficial factors. The GABA content of BG and AG brown rice were 0.07~6.61 and 11.13~49.72 mg/100 g, respectively. The ${\alpha}$-amylase activity of AG brown rice was 1.77~70.25 unit/g fold higher than it was in BG brown rice. Total polyphenol and flavonoid contents, which are known to be related to antioxidation, were higher in BG brown rice than in AG brown rice. The total polyphenol contents of BG and AG brown rice were 10.52~36.38 and 11.38~26.33 mg/100 g, and the total flavonoid contents were 3.55~13.39 and 3.52~9.78 mg/100 g, respectively. Also, DPPH radical scavenging activity was 57.64~251.34 and 50.49~213.35 mg TE/100 g, respectively. ABTS radical scavenging activity and total tannin content showed a similar trend to DPPH radical scavenging activity. We expect that this data will be useful in the manufacturing of food products.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제11권2호
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• pp.143-149
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• 2008

Purpose: To estimate the long-term therapeutic efficacy and safety of adefovir dipivoxil in children and adolescents with chronic hepatitis B who have developed lamivudine resistance. Methods: Sixteen patients (12 boys and 4 girls; ages 4.3~20.9 years; mean age 14.2 years) with chronic hepatitis B infection resistant to lamivudine therapy received adefovir (0.3 mg/kg/day, maximal dose 10 mg) orally for at least 9 months between March 2004 and April 2008. Each patient was followed up for a mean period of 27 months (range 9~49 months) until April 2008 at Kyungpook National University Hospital in Korea. Therapeutic responses to adefovir were evaluated at 12, 24, 36, and 48 months from the initiation of therapy using the Kaplan-Meier method. Response measurements included ALT normalization, HBV DNA negativization, 2 $log_{10}$ IU/mL decrement of HBeAg titer, HBeAg loss, and HBeAg/Ab seroconversion rate. Results: Three (18.8%) of the 16 patients treated with adefovir showed HBeAg/Ab seroconversion. Kaplan-Meier estimates of cumulative ALT normalization were 12.5% (12 months), 43.8% (24 months), 63.5% (36 months), and 92.7% (48 months), respectively. Cumulative HBV DNA negativization was 6.7%, 30.0%, 45.6%, and 78.2% at 12, 24, 36, and 48 months, respectively. Cumulative 2 $log_{10}$ copies/mL decrement of HBeAg titer was 12.5%, 43.8%, 56.3%, and 86.9% at 12, 24, 36, and 48 months, respectively. Cumulative HBeAg loss and HBeAg/Ab seroconversion were 6.7% (12 months) and 22.2% (24 months), respectively. Conclusion: The long-term therapeutic efficacy of adefovir dipivoxil was favorable in children and adolescents with chronic hepatitis B who had developed lamivudine resistance. The long-term use of adefovir should be safe in children.

• Journal of Bio-Environment Control
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• 제16권1호
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• pp.21-26
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• 2007

This study was carried out to investigate the effects of tree-spray of calcium formate compound extracted from oyster shell with several active agents on the calcium concentration, fruit skin shape and quality of 'Fuji' apple. The tree-spray of calcium formate compound extracted from oyster shell (Os-CaF, $52.4\;mg{\cdot}kg^{-1}$) appeared to have more effectiveness on the calcium translocation into leaves, fruit skin and flesh than control. Addition of adjuvants to Os-CaF increased calcium concentration of 'Fuji' apple when sprayed three times before harvest. Among the active agents examined, the treatment ascorbic acid and poly-vinyl alcohol (PVA) in leaves, Ag-colloidal and PVA in fruit skin, ascorbic acid, Ag-colloidal, and PVA in fruit flesh exhibited highest effectiveness. Fruit qualities (fruit weight, firmness, soluble solids, acidity and Hunter value) were not affect by Os-CaF on different concentrations and solutions of active agents.

• Korean Journal of Pharmacognosy
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• 제45권2호
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• pp.154-160
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• 2014

The aim of this study was to determine the incidence and contamination levels of aflatoxin in Medicinal Herbs for Food and Medicine at Yakyeang market in seoul. 191 Samples 11 items medicinal herbs for food and medicine were evaluated for the aflatoxin contamination. in result 41 samples 10 items (21.5%) were detected in the alfatoxin, a high incidence of aflatoxins items are cassiae semen (50.0%), testudinis plastrum (43.8%) and Batryticatus Bombyx (40.0%), Polygalae Radix (31.2%), Zizyphi Semen (23.5%), Dolichoris Semen, Myristicae Semen (20.0%), Nelumbinis Semen (15.8%), Glycyrrhizae Radix et Rhizoma (7.4%), Hoveniae Semen Cum Fructus (4.3%). AFB1 were detected 27 cases (14.1%), AFB2, AFG1 and AFG2 were detected 18cases (9.4%), 16cases (8.4%) and 5cases (2.6%). The excess cancer risk estimated using the cancer potency of aflatoxin B1 (7(mg/kg/day)-1 for HBsAg-and 230(mg/kg/day)-1 HBsAg+) was N.D ~ $3.79{\times}10^{-6}$ for hepatits B surface antigen negative (HBsAg-) and N.D ~ $9.68{\times}10^{-5}$ hepatits B surface antigen positive (HBsAg+) respectively.

• Journal of the Korean Chemical Society
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• 제41권11호
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• pp.590-593
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• 1997

Square-wave anodic stripping voltammetry was applied to the germanium(IV)- Morin complex in 0.5 M sulfuric acid as a supporting electrolyte. The peak potential appeared at - 0.606 V vs. Ag/AgCl. Effects of sulfuric acid concentration, Morin concentration, accumulation potential, and accumulation time on the stripping peak current for the complex of germanium(IV)-Morin were studied. Interferences by other metal cations that affect on stripping peak current were also investigated. The detection limit was found to be $3.76{\times}10^{-7}M(27 {\mu}g/L)$ for germanium(IV) using 60 seconds of accumulation time. The relative standard deviation (n=8) for 0.4 mg/L($5.5{\times}10^{-6}$ M) germanium(IV) was 3.2%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.873-876
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• 2000

Characteristics of piezoelectric thick films prepared by screen printing method were investigated. The piezoelectric thick films were printed using Pb(Mg,Nb)O$_3$-Pb(Zr,Ti)O$_3$system. The lower electrodes were coated with various thickness of Ag-Pd by screen printing to investigate the effect as a diffusion barrier and deposited with Pt by sputtering on Ag-Pd. The ceramic paste was prepared by mixing powder and binder with various ratios using three roll miller. The fabricated thick films were burned out at 650$^{\circ}C$ and sintered at 950$^{\circ}C$ in the O$_2$condition for each 20, 60min after printing with 350mesh screen. The thickness of piezoelectric thick film was 15∼20 $\mu\textrm{m}$ and the Ag-Pd electrode acted as a diffusion barrier above 3 $\mu\textrm{m}$ thickness. When the lower electrode Ag-Pd was 6 $\mu\textrm{m}$ and the piezoelectric thick films were sintered by 2nd step (650$^{\circ}C$/20min and 950$^{\circ}C$/1h) using paste mixed Pb(Mg,Nb)O$_3$-Pb(Zr,Ti)O$_3$$.$ MnO$_2$+ Bi$_2$O$_3$. V$_2$O$\_$5/ and binder in the ratio of 70:30, the remnant polarization of thick film was 9.1 ${\mu}$C /cm$^2$.

• Journal of the Korean Society for Heat Treatment
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• 제5권2호
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• pp.103-110
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• 1992

This study is aimed to investigate the effect of various thermomechanical treatments($T_6$, $T_8$ and ITMT) on the microstructure and mechanical properties of an Al-Cu-Li-Ag-Mg-Zr alloy (Weldalite 049) which has been known to strong natural aging response, good weldablity and high strength in $T_6$ sand $T_8$ temper. This experiment was performed by means of differential scaning calorimetry, tensile test, optical and transmission electron microscopy. The tensile strength in the peak aged condition shows 620, 650 MPa in $T_6$ and $T_8$(40% cold work), respectively. Also, The tensile strength is increased with cold working in $T_8$ but decreased at 60% cold working. However, the tensile strength of the intermediate thermomechanical treated speciman(ITMT) is lower than that of $T_6$ temper about 20% but the elongation is higher than two times. It might be predicted that the ITMT is effective processing to improve the toughness of this alloy. In $T_6$, $T_8$ and ITMT, the major strengthening phase is $T_1(Al_2CuLi)$ phases. and the fine $T_1$ phase which are homogeneously precipited in matrix was observed much more in $T_8$ than $T_6$ and ITMT.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3723-3729
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• 2010

We investigated the high-excitation voltage cathodoluminescence (CL) performance of blue light-emitting (ZnS:Ag,Al,Cl) and green light-emitting (ZnS:Cu,Al) phosphors coated with metal oxides ($SiO_2$, $Al_2O_3$, and MgO). Hydrolysis of the metal oxide precursors tetraethoxysilane, aluminum isopropoxide, and magnesium nitrate, with subsequent heat annealing at $400^{\circ}C$, produced $SiO_2$ nanoparticles, an $Al_2O_3$ thin film, and MgO scale-type film, respectively, on the surface of the phosphors. Effects of the phosphor surface coatings on CL intensities and aging behavior of the phosphors were assessed using an accelerating voltage of 12 kV. The MgO thick film coverage exhibited less reduction in initial CL intensity and was most effective in improving aging degradation. Phosphors treated with a low concentration of magnesium nitrate maintained their initial CL intensities without aging degradation for 2000 s. In contrast, the $SiO_2$ and the $Al_2O_3$ coverages were ineffective in improving aging degradation.

• Biomolecules & Therapeutics
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• 제9권2호
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• pp.131-139
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• 2001

Lamivudine, an oral nucleoside analogue, effectively inhibits hepatitis B virus replication and reduces hepatic necroinflammation in patients with chronic hepatitis B. Although lamivudine has shown a promise in patients with chronic hepatitis B, a long-term data on Korean patients with hepatitis B are lacking. The purpose of this study is to evaluate the effects and safety of 52-week lamivudine therapy in Korean patients with chronic hepatitis B, A total of twenty-nine patients (27 male and 2 female) who had received 100 mg of oral lamivudine daily for 52 weeks were evaluated, retrospectively. The mean age of 29 patients in the study group was 37.7 $\pm$ 8.9 years (range 19-54). Pretreatment HBV PCR and HBsAg were positive in all 29 patients, and HBeAg were positive in 25 patients (86%). The serum HBV DNA of 28 patients (97%) significantly fell to undetectable levels (<5 pg/ml) within 12 weeks of therapy and it remained undetectable in 24 patients (83%) by the end of 52-week therapy (p<0.001). Mean serum ALT levels of 29 patients declined to the normal range within 12 weeks and remained within the normal range during the evaluative period (p<0.05). The proportions of patients with HBeAg seroconversion (loss of HBeAg, development of antibody to HBeAg, and undetectable HBV DNA) were 42% after 52-week therapy. The differences of response to lamivudine therapy in HBeAg- positive and HBeAg-negative patients were negligible (p>0.05). Furthermore, the study showed that pretreatment serum HBV DNA and ALT levels have no effect to the efficacy of lamivudine therapy (p>0.05). Further comparison of lamivudine's efficacy showed that lamivudine is just as efficacious in patients with cirrhosis as without cirrhosis (p>0.05). In conclusion, lamivudine is an effective and safe therapy for the treatment of chronic hepatitis B in Korean patients.