• Bulletin of the Korean Chemical Society
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• v.26 no.7
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• pp.1017-1024
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• 2005

Elimination reactions of $XC_6H_4CH_2CO_2C_6H_3-2-Y-4-NO_2$ have been studied under various conditions. When X was moderately electron-withdrawing, Y = H, and base-solvent was $R_2$NH-MeCN, the reaction proceeded by the E2 mechanism via an E1cb-like transition state. Concave downward curve was noted in the Hammett plots. When X = 4-$NO_2$, Y = Cl, $CF_3,\;NO_2$, and the base-solvent was ${R_2NH/R_2NH_2}^+$ in 70 mol % MeCN(aq), the reaction proceeded by the E2 mechanism. The mechanism changed to a competing E2 and E1cb when X = 4-$NO_2$ and Y = H, MeO, and to the E1cb when X = 2,4-($NO_2)_2$, and Y = $NO_2$. From these results, a plausible pathway of the change of the mechanism from E2 to the E1cb extreme is proposed.

• Korean Journal of Veterinary Service
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• v.16 no.1
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• pp.41-50
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• 1993

This study was undertaken the bioserotype and drug resistance of Salmonella and Escherichia coli isolated from feces for the prevention and treatment of salmonellosis and colibacillosis in zoological animals. The results obtained from the research were as follows 1. Salmonella were isolated 19, or 4.7% from 408 samples and E. coli were isolated 12, or 40.0% from 30 diarrheal samples. 2. The biotypes in 19 Salmonella were Subspecies 1. 3. The serogroups of Salmonella isolated were 47.4% in B group, 31.6% in C, 5.3% in D and 15.8% in other, and serotype of E. coli was 100% in 0127a. 4. The antibiotic resistance of Salmonella and E. coli isolated were 13, or 68.4% and 7, or 58.3% strains, respectively 5. The multiple resistant patterns of antibiotics in Salmonella were 2drugs- and 3 drugs-resistance 30.8%, respectively, and those in E. coli were mono drug-, 2 drugs- and 7 drugs-resistance 28.6%, respectively. 6. The transferred rate of resistance to recipients (E. coli ML 1410 NA$^{r}$ ) in Salmonella was 38.5%, but that in E. coli was 71.4%.

• Journal of Nutrition and Health
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• v.50 no.5
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• pp.483-493
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• 2017

Purpose: The purpose of this study was to determine trends in dietary vitamin E intakes and contributing food groups among Korean adults. Methods: This study included 66,695 subjects aged ${\geq}19years$ who completed a nutrition survey as part of the Korea National Health and Nutrition Examination Survey (1998, 2001, 2005, 2007~2009, 2010~2012, 2013~2015). We estimated individual daily intakes of ${\alpha}-$, ${\beta}-$, ${\gamma}-$, ${\delta}-tocopherol$, and total vitamin E by linking food consumption data with a vitamin E database of commonly consumed foods. Results: Daily vitamin E intake significantly increased from $6.4mg\;{\alpha}-TE/d$ in 1998 to $7.7mg\;{\alpha}-TE/d$ in 2013~2015 (p for trend < 0.0001) among men as well as from $5.4mg\;{\alpha}-TE/d$ in 1998 to $6.5mg\;{\alpha}-TE/d$ in 2013~2015 among women (p for trend < 0.0001). However, the intake of vitamin E was lower than the adequate intake (AI) of Dietary Reference Intakes for Koreans 2015 (2015 KDRI). In 2013~2015, men consumed 6.5 mg/d of ${\alpha}-tocopherol$, 0.5 mg/d of ${\beta}-tocopherol$, 6.0 mg/d of ${\gamma}-tocopherol$, and 3.9 mg/d of ${\delta}-tocopherol$, whereas women consumed 5.7 mg/d of ${\alpha}-tocopherol$, 0.4 mg/d of ${\beta}-tocopherol$, 4.8 mg/d of ${\gamma}-tocopherol$, and 2.8 mg/d of ${\delta}-tocopherol$. The major food groups contributing to vitamin E intake were vegetables (men: 23.3%, women: 22.7%), grains (men: 14.5%, women: 13.9%), and eggs (men: 13.0%, women: 12.5%). Conclusion: This study provides scientific evidence for vitamin E intake in Korean adults. Since the current intake of vitamin E was lower than the reference intakes set by 2015 KDRI, dietary vitamin E intake should be monitored regularly among Korean adults.

• Reproductive and Developmental Biology
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• v.30 no.1
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• pp.65-70
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• 2006

This study investigated apoptosis and in vitro development of parthenogenetic preimplantation porcine embryos. In vitro matured oocytes for $42{\sim}44h$ were used. Apoptotic cell death was analyzed by using a terminal deoxynucleatidyl transferase mediated deoxyuridine 5-triphosphate nick-end tabling (TUNEL) assay. In experiment 1, oocytes were activated with two electric pulses (CH) of 1.2 kV/cm for $30{\mu}sec$ (E), E + 6-dimethylaminopurine (6-DMAP) or E + cycloheximide (CH) and cultured in PZM-3 under 5% $CO_2$ in air at $38.5^{\circ}C$. In experiment 2, oocytes were activated by E and cultured in PZM-3 or NCSU-23 under a gas atmosphere of 20% $O_2$ ($5%\;CO_2$, in air) or 5% $O_2$ $(5%\;CO_2,\;5%\;O_2\;90%\;N_2)\;at\;38.5^{\circ}C$. Oocytes activated with E+6-DMAP or E+CH showed higher blastocyst rates (36.3% and 32.5%) compared to E alone (27.7%). The frequency of apoptosis according to treatments were 5.3%, 7.7% and 7.1% respectively. Oocytes activated with E alone showed lower (P<0.05) frequency of apoptosis compared to other groups. In experiment 2, parthenotes cultured in PZM-3 showed slightly higher blastocyte rates (28.2% and 29.7%) compared to NCSU-23 (22.6% and 24.4%) regardless of atmosphere. Blastocysts generated in PZM-3 showed lower (P<0.05) apoptosis rate under 20% $O_2$ (9.2% vs 16.9%), whereas those in NCSU-23 had slightly lower apoptosis rate under 5% $O_2$ (14.0% vs 18.4%). This result represents that activation method and culture condition could affect the frequency of apoptosis as well as in vitro developmental rate.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.238-245
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• 2009

Pure culture experiments were conducted to assess the bacteriostatic and bactericidal effects of phlorotannins (PT) isolated from Ascophyllum nodosum (brown seaweed) on Escherichia coli O157:H7. In Exp. 1, one non-O157:H7 strain (25922) and three strains of E. coli O157:H7 (3081, EDL933 and E318N) were cultured in M9 medium with PT included at 0 (control), 25, 50 or $100{\mu}g/ml$ (n = 3). Bacterial growth was monitored by $OD_{600}$ at 0, 4, 6, 12 and 24 h, and by dilution plating at 0, 4, 6 and 24 h. All strains were inhibited (p<0.001) by PT to varying degrees. At 50 or $100{\mu}g/ml$, PT prevented growth of all four strains. At $25{\mu}g\;PT/ml$, growth of 25922, 3081, E318N and EDL933 was inhibited for 6, 12 and 24 h, respectively, but 25922 and 3081 resumed growth by 12 and 24 h. Direct plating confirmed bactericidal effects of PT on all four strains at $100{\mu}g/ml$, and on EDL933 and E318N at $50{\mu}g/ml$. In Exp. 2, strains 25922 and 3081 were incubated with no tannins or with $50{\mu}g/ml$ of PT, purified condensed tannins (CT) from Quebracho (Schinopsis balansaei), or purified tannic acid from Rhus semialata (Anacardiaceae) as hydrolysable tannins (HT). Strain 3081 was unaffected by HT or CT, but was completely inhibited (p<0.001) by PT at 4, 6 and 24 h. Strain 25922 was unaffected by HT, slightly inhibited by CT, and almost eradicated by PT at 4 and 6 h. Transmission electron microscopy revealed tannin-mediated alterations to bacterial cell walls. Phlorotannins from A. nodosum exhibit growth-inhibiting and bactericidal effects in vitro against the strains of E. coli O157:H7 investigated. Anti-E. coli efficacy of A. nodosum PT is superior to that of terrestrial tannins purified from Quebracho and from Rhus semialata.

• Journal of the Korean GEO-environmental Society
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• v.25 no.8
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• pp.13-19
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• 2024

In this study, to reinforce the surface layer of weathered soil slopes where erosion and collapse of surface layer occur, compression strength tests were conducted by mixing carbon fiber and eco-friendly stabilizer (E.S.B.) To determine the optimal mixing ratio of E.S.B. and carbon fiber, E.S.B. was set at conditions of 10%, 20%, and 30%, and carbon fiber at 0.3%, 0.6%, 0.9%, and 1.2%. Additionally, to analyze the changes in compressive strength according to dry density and curing period, 85% and 95% of the maximum dry unit weight were applied, and curing periods were set to 3 days, 7 days, and 28 days. The standard strength for surface layer reinforcement of slopes is proposed as 4 MPa at 7 days and 6 MPa at 28 days according to ACI 230.1R-09 (2009). The compression test results showed that the unconfined compressive strength of E.S.B. reinforced soil met the standard strength at an E.S.B. mixing ratio of 10% or more for 95% compaction. Moreover, when carbon fiber was mixed with E.S.B. reinforced soil, a ductile fracture pattern was observed after the yield point due to compressive strength, indicating that the mixture could compensate for post-yield failure. It was analyzed that the maximum strength is exhibited at a carbon fiber mixing ratio of 0.6%. The unconfined compressive strength of carbon fiber reinforced soil increases by approximately 54-70% compared to the condition without carbon fiber.

• Microbiology and Biotechnology Letters
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• v.45 no.1
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• pp.19-26
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• 2017

Effects of resveratrol glucosylation on the immunomodulation properties of resveratrol and on the viability of macrophage cells have been studied by using murine macrophage RAW 264.7 cells. Nitric oxide (NO) and interleukin 6 (IL-6) expression in macrophages in vitro were studied after treatment with different concentrations of (E)-resveratrol, (E)-resveratrol 3-O-${\beta}$-${\small{D}}$-glucoside (R-3-G), or (E)-resveratrol 4'-O-${\beta}$-${\small{D}}$-glucoside (R-4'-G). In vitro viability of RAW 264.7 cells after treatment with the aforementioned three compounds was also studied. As demonstrated by macrophage cell viability assays, two different resveratrol monoglucosides, R-3-G and R-4'-G, exhibited 50-80% reduced cytotoxicity in comparison to (E)-resveratrol in A549 and HepG2 cells. Compared to the resveratrol aglycon, both glucosylated resveratrol derivatives positively modulated NO and IL-6 production in macrophages positively via transcriptionally up-regulating IL-6 and iNOS expression. Conjugation of a glucose moiety on resveratrol was found to enhance the immunomodulating activity of resveratrol and the viability of RAW 264.7 cells.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.3
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• pp.294-300
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• 2019

To investigate the inhibition effect on pathogenic microbes and the antimicrobial resistance of probiotics, a total of 140 probiotics were isolated from 35 kinds of Korean commercially available Kimchi. Of those, L. plantarum was identified from 53 strains (37.9%), E. faecium from 27 strains (19.3%), and L. rhamnosus from 7 strains (5.0%) using 16S rRNA gene sequencing. Sixty nine strains (49.3%) showed overall antimicrobial activity against pathogenic microbes, namely S. Typhi, S. Enteritidis, E. coli O157:H7, S. flexneri, NAG Vibrio, Listeria monocytogenesis, Y. enterocolitica, S. aureus, S. pyogenes, G. vaginalis, C. albicans, and P. acne. The proportions of L. plantarum, E. faecium, and L. rhamnosus strains to pathogenic microbes were 75.5%, 40.7%, and 28.6%, respectively. In addition, a resistance test with 18 antimicrobial agents using a disk diffusion assay revealed a resistance incidence of 98.6% for nalidixic acid, 83.6% for streptomycin, 75.7% for gentamicin 73.6% for vancomycin, 72.1% for norfloxacin, and 67.9% for ciprofloxacin. In conclusion, L. plantarum, L. sakei, and E. faecium strains with various antimicrobial activities and broad antibiotic resistance are useful for treating diarrhea in long-term inpatients and for the alternative use for treating Candida species female vaginitis.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.235-238
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• 2006

Interface formation between $12CaO{\cdot}7Al_2O_3(C12A7:e^-)$ and Alq3 was investigated using in-situ ultra-violet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS). The work function and vacuum level shift of $C12A7:e^-$ were change by different surface treatment from 2.6eV to 4.2eV. Also vacuum level shift $(\Delta)$ at the interface were from +0.3eV to -0.3eV.

• Journal of the Korean Wood Science and Technology
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• v.47 no.5
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• pp.587-596
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• 2019

This study aimed to determine the antimalarial effect of the Strychnos ligustrina (SLW) wood extracts and to analyze its phytochemicals. The SLW powder samples were macerated with 100% ethanol (E100), 75% ethanol (E75), 50% ethanol (E50), 25% ethanol (E25), and aqueous (A100). The extracts were analyzed by LCMS/MS, and its in-vitro antimalarial activity was tested with Plasmodium falciparum. The results showed that the extract yields of E100, E75, E50, E25, and A100 were 4.3, 5.2, 5.3, 4.7, and 3.6%, respectively. The antimalarial activities of the A100, E25, E50, and E75 extracts were classified as active with $IC_{50}$ values of 38.6, 42.6, 42.9, and $43.7{\mu}g/mL$, respectively. But, the antimalarial activity of the E100 extract was classified as slightly active with $IC_{50}$ values of $87.4{\mu}g/mL$. The dominant compounds contained in the extracts of A100, E25, E50, E75, and E100 was the alkaloid compound, namely brucine with relative concentrations of 24.96, 24.55, 21.33, 11.79, and 11.62%, respectively.