• Title/Summary/Keyword: K-12

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Preparation and Characterization of $Li_4Ti_5O_{12}$ using Sol-Gel Method for Lithium Secondary Battery (Sol-Gel 방법을 이용한 리튬이차전지용 $Li_4Ti_5O_{12}$의 제조 및 특성)

  • Oh, Mi-Hyun;Kim, Han-Joo;Kim, Gyu-Sik;Kim, Young-Jae;Son, Won-Keun;Lim, Kee-Joe;Park, Soo-Gil
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.1989-1991
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    • 2005
  • Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. $Li_4Ti_5O_{12}$ based spinel-framework structures are of great interest material for lithium-ion batteries. We describe here $Li_4Ti_5O_{12}$ a zero-strain insertion material was prepared by novel sol-gel method and by high energy ball milling (HEBM) of precursor to from nanocrystalline phases. According to the X-ray diffraction and scanning electron microscopy analysis, uniformly distributed $Li_4Ti_5O_{12}$ particles with grain sizes of 100nm were synthesized. Lithium cells, consisting of $Li_4Ti_5O_{12}$ anode and lithium cathode showed the 173 mAh/g in the range of $1.0{\sim}3.0V$. Furthermore, the crystalline structure of $Li_4Ti_5O_{12}$ didn't transfer during the lithium intercalation and deintercalation process.

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Studies on Triterpenoid Corticomimetics (V) - Oxidation of Presenegenin with Chromium Trioxide-Acetic Acid to Yield 11-Keto and 12-Keto Derivatives

  • Han, Byung-Hoon;Han, Yong-Nam
    • Archives of Pharmacal Research
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    • v.8 no.4
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    • pp.229-236
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    • 1985
  • Oxidation of presenegenin dimethyl ester triacetate with chromium trioxide in acetic acid yielded two compounds, 11-ketone (IV) and 12-ketone (IV) derivatives. The latter was a main product. On mild alkaline hydrolysis, IV afforded 11-keto-presenegenin dimethyl ester (V), mp 232-$234^{\circ}$, $C_{32}H_{48}O_{8}$, whereas VI did 12-keto-presenegenin dimethyl ester 12, 27-hemiketal (VIII), mp 240-$242^{\circ}$, $C_{32}H_{50}O_{8}$.

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Antifungal Mechanism of Antifungal Peptide Derived from Cecropin A(1-8)- Melittin(1-12) Hybrid against Aspergillus fumigatus

  • Lee, Dong-Gun;Jin, Zhe-Zhu;Maeng, Cheol-Young;Shin, Song-Yub;Seo, Moo-Yeol;Kim, Kil-Lyong;Hahm, Kyung-Soo
    • Journal of Microbiology and Biotechnology
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    • v.9 no.2
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    • pp.168-172
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    • 1999
  • The antifungal mechanism of the antifungal peptide against Aspergillus fumigatus, $K^{18,19}$-CA(l-8)-ME(l-12), derived from cecropin A(l-8)-melittin(l-12) was investigated by confocal laser scanning microscopy, cell wall regeneration, ATPase activity inhibition, and released potassium ion. By confocal laser scanning microscopy, $K^{18,19}$-CA(l-8)-ME(l-12) was detected on the surface of A. fumigatus, while cecropin A used as a negative control peptide was not detected. The protoplast of A. fumigatus treated with$K^{18,19}$-CA(1-8)-ME(1-12) failed to regenerate the fungal cell walls. Compared with cecropin A, the amount of potassium ion released by $K^{18,19}$-CA(l-8)-ME(l-12) was increased. Furthermore, $K^{18,19}$-CA(l-8)-ME(l-12) inhibited the ATPase activity on the plasma membrane. These results suggested that $K^{18,19}$-CA(l-8)-ME(1-12) acts on the plasma membrane of A. fumigatus and its antifungal action is due to the ion channel or pore formation on the plasma membrane.

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Investigation of gene expression of GX-12, a new DNA vaccine for HIV infection, in reproductive organs in SD rats

  • Kang, Kyung-Koo;Park, Min-Seul;Ahn, Kook-Jun;Baik, Dae-Hyun;Sohn, Yong-Sung;Lee, Dong-Sup;Park, Jae-Hun;Ahn, Byoung-Ok;Kim, Won-Bae
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.11b
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    • pp.201-201
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    • 2002
  • GX-12 is a naked DNA vaccine developed by Dong-A pharmaceutical company for the treatment of mv infection. GX-12 consists of four separate plasmids. This study was performed to evaluate the biodistribution and expression of GX-12 mRNA in gonadal tissues, and to investigate the histopathological changes in rats after repeated intramuscular injection.(omitted)

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Cultural Adaptation and Reliability Testing of Korean Version of the World Health Organization Disability Assessment Schedule 2.0 : 12-item versions (세계보건기구 기능제약평가목록 2.0 : 12항목-버전의 한글도구 개발과 신뢰도 검사)

  • Lee, Hae-Jung;Kim, Da-Jeong
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.4
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    • pp.475-488
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    • 2011
  • Purpose: The aims of the study were to develop and to establish reliability in Korean versions of World Health Organization Disability Assessment Schedule 2.0(KWHODAS 2.0): 12 item-self(12-self) and 12 item-interviewer(12-interviewer) versions. Methods: KWHODAS 2.0: 12-item versions were developed in idiomatic modern Korean with a process involving independent translation, synthesis of the translations, independent back translation, and review by an expert committee to achieve equivalence with the original English. 88 participants were included in the study. 33 of participants filled the 12-self version twice to examine test-retest reliability and 55 of participants were assessed simultaneously by four interviewers using the 12-interviewer version. Intra-rater reliability was evaluated using the intra-class correlation coefficient(ICC) and inter-rater reliability was evaluated using both the ICC and k statistic. Results: Test-retest reliability for the 12-self version was excellent with $ICC_{(2,1)}$ value ranged from 0.94(CI 0.88-0.98) to 0.96(CI 0.90-0.98). Inter-rater reliability for the 12-interviewer version showed excellent agreement with $ICC_{(2,1)}$ from 0.94(CI 0.91-0.96) to 1(CI 1.0-1.0). K value was observed from 0.95 to 1. Conclusion: KWHODAS 2.0: 12-self and 12-interviewer versions were successfully translated and both scales showed excellent reliability. It is now suitable for use in clinical and research applications.

Study on the Effects of Supplemented Factors on the Production of Vitamin $B_{12}$ by Propionibacterium shermanii (Propionibacterium shermanii에 의한 비타민 $B_{12}$의 생성에 영향을 미치는 배지첨가물들에 대한 연구)

  • Kim, Ji-Young;Kim, Kong-Hwan;Kim, Kyoung-Ja;Goo, Yang-Mo
    • YAKHAK HOEJI
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    • v.38 no.5
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    • pp.614-620
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    • 1994
  • Following the study on the fermentation conditions influencing the production of vitamin $B_{12}$ by Propionibacterium shermanii(Korean J Biotechnol. Bioeng. 7,126-131, 1992), the effects of some factors supplemented in the medium on the production of vitamin $B_{12}$ were studied. Maximum production of vitamin $B_{12}$ was observed when $Co^{+2}$ was supplemented at the concentration of 2-4 ppm in the fermentation medium. Increase of the supplemented $Co^{+2}$ to 12 ppm did not inhibit the growth of the organism, but it accelerated the lysis of the organism. In the literature, peptone was reported to activate the biosynthesis of vitamin $B_{12}$. Examination of the effect of peptone on the growth and the production of vitamin $B_{12}$ showed that at early stage more vitamin$B_{12}$ was observed in the supplemented medium, but no difference was observed in the later stage of fermentation. Examination of the time for addition and the amount of 5,6-dimethylbenzimidazole, a precursor known to influence the production of vitamin $B_{12}$, showed that a maximum yield of vitamin $B_{12}$ was observed when 15 mg/L was added to the fermentation medium after 2 days' incubation. The effect was comparable with the increase of the production of vitamin $B_{12}$ when the fermentation condition was changed to aerobic condition after 2 days' culture under anaerobic condition.

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Herbal Extracts as a NF-kappaB Inhibitor (NF-kappaB 프로모터 활성을 억제하는 식물추출물)

  • Park, Deok-Hoon;Lee, Jong-Sung;Jung, Eun-Sun;Hyun, Chang-Gu;Lee, Ji-Young;Hur, Sung-Ran;Koh, Jae-Sook;Lee, Hee-Kyung;Baek, Ji-Hwoon;Yoo, Byung-Sam;Moon, Ji-Young;Kim, Ju-Ho
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.32 no.3 s.58
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    • pp.135-140
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    • 2006
  • Nuclear factor-kappaB (NF-kappaB) is a critical transcription factor for maximal expression of many of the cytokines that are involved in the pathogenesis of inflammatory diseases. In this study, we found that 12 plant extracts among 200 plants, namely, Forsythia koreana, Capsicum annuum L, Mentha arvenis, Duchesnea chrysantha, Morus alba, Saururus Chinenis (Lour) Baill, Pine needle, Zingiber mioga (Thunb.), Roscoe, Houttuynia, Prunus yedoenis, Sasa quelpaertenis, significantly inhibited LPS- induced NF-kappaB activation in a concentration-dependent manner. Additionally, 12 plant extracts were found to have antioxidant activities in DPPH assay Therefore, we have attempted to determine whether 12 herbal extracts could inhibit the expression of cytokines possessing NF-kappaB promoter in their promoter regions. Consistently 12 herbal extracts inhibited LPS-induced production of TNF alpha and interleukin-8 (IL-8). These results show that 12 herbal extracts suppresses the production of pro-inflammatory mediators through the inhibition of the NF-kappaB signaling pathway, we suggest that 12 herbal extracts can be used as a anti-inflammatory and soothing agent.

Thermal Stability and Behavior of Isothermal Crystallization in Fe-P-C-B-(AI-Ge) Amorphous Alloys (Fe-P-C-B-(AI-Ge)계 비정질합금의 열적 안정성과 등온결정화 거동)

  • Jeon, U-Yong;Guk, Jin-Seon;Bae, In-Seong;Seol, Gyeong-Won
    • Korean Journal of Materials Research
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    • v.8 no.11
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    • pp.1026-1030
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    • 1998
  • Thermal properties of Fe- base amorpous alloys were investigated. $Fe_{80}P_6C_{12}B_{12}$ and $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloys were fabricated by melt spinning method and thermal analysis was done by differential scanning calorimeter. After isothermal crystallization. the Avrami exponents of $Fe_{80}P_6C_{12}B_{12}$ and $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloys were 1.8-2.2 and 2.5-4.0, respectively. It means the former alloy shows diffusion controlled growth and the latter one shows interface controlled growth. For $Fe_{80}P_6C_{12}B_{12}$ and $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloys. the activation energies of isothermal crystallization was 353 and 371kJlmol. Also the activation energies of nucleation and growth were 301, 324kJlmol and 273. 30lkJ/mol, respectively. Thus $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloy is considered to be more stable than $Fe_{73}P_{11}C_6B_4AI_4Ge_2$ amorphous alloy.

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Effect of trichostatin A on NF-κB DNA binding activity and myogenesis in C2Cl2 skeletal muscle Precursor cell (C2C12 근육아세포에서 trichostatin A에 의한 NF-κB DNA 결합 활성과 근육발생에 미치는 영향)

  • 임운기;김경창;신혜자
    • Journal of Life Science
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    • v.12 no.1
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    • pp.55-60
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    • 2002
  • The differentiation of skeletal muscle precursor cells in culture is marked by the transcriptional activation of muscle-specific genes and the morphological differentiation of myoblast into multinucleate myotube. In this study, we examined the effect of TSA (Trichostatin A) on WF-kB DNA binding activity and muscle cell fusion in the process of myogenesis. Under TSA treatment, C2C12 myoblast could not fuse to myotube and its NF-kB DNA binding activity was also blocked. To investigate whether these phenomenons were affected by TSA in direct or not, differentiation media (DM) used to differentiate cells without TSA was concentrated and added to C2C12 myoblast with TSA simultaneously. C2C12 myoblast was fused to myotube and NF-kB DNA binding activity was recovered. These results suggest that TSA affects on the differentiation of myoblast, perhaps through several factors, by inhibiting myoblst fusion and blocking NF-kB DNA binding activity.

Synthesis of TAME, ETBE, and MTBE Using Heteropolyacid Catalyst (헤테로폴리산 촉매를 이용한 TAME, ETBE 및 MTBE 합성반응의 연구)

  • Park, Jin-Hwa;Yi, Yong-Woo
    • Applied Chemistry for Engineering
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    • v.8 no.4
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    • pp.582-588
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    • 1997
  • Synthetic reaction of TAME, ETBE, and MTBE compounds used largely for gasoline octane number enhancer to prevent air pollution was investigated using heteropolyacid catalyst in a fixed bed flow reactor. In the synthetic reaction of TAME, ETBE and MTBE, after hetero atom being replaced with poly atom, the activity of the catalyst, $H_4SiW_{12}O_{40}$ with coordinated bond with W and an hetero atom of Si was the highest among the catalysts tested. Also the activity depended upon the metals replaced which are related to the catalyst acidity. $FeHPW_{12}O_{40}$ and $K_3PM_{o12}O_{40}$ catalysts showed high activity in TAME synthesis, while they were not effective in ETBE and MTBE synthesis. In this study catalysts showing high activity were selected and mixed with equal weight combination of $H_4SiW_{12}O_{40}$ and $Sr_2SiW_{12}O_{40}$ ;$H_4SiW_{12}O_{40}$ and $NaH_2PW_{12}O_{40}$ ; $Fe_{1.5}PW_{12}O_{40}$ and $Mg_2SiW_{12}O_{40}$ ; $Mg_2SiW_{12}O_{40}$ and $Ba_2SiW_{12}O_{40}$. The mixed heteropolyacid catalysts showed higher TBA conversion rate and better selectivity of ETBE and MTBE than the single catalysts.

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