• 제목/요약/키워드: ${\alpha}-SiC$

검색결과 529건 처리시간 0.035초

TI-I-174, a Synthetic Chalcone Derivative, Suppresses Nitric Oxide Production in Murine Macrophages via Heme Oxygenase-1 Induction and Inhibition of AP-1

  • Kim, Mi Jin;Kadayat, Taraman;Kim, Da Eun;Lee, Eung-Seok;Park, Pil-Hoon
    • Biomolecules & Therapeutics
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    • 제22권5호
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    • pp.390-399
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    • 2014
  • Chalcones (1,3-diaryl-2-propen-1-ones), a flavonoid subfamily, are widely known for their anti-inflammatory properties. Propenone moiety in chalcones is known to play an important role in generating biological responses by chalcones. In the present study, we synthesized chalcone derivatives structurally modified in propenone moiety and examined inhibitory effect on nitric oxide (NO) production and its potential mechanisms. Among the chalcone derivatives used for this study, TI-I-174 (3-(2-Hydroxyphenyl)-1-(thiophen-3-yl)prop-2-en-1-one) most potently inhibited lipopolysaccharide (LPS)-stimulated nitrite production in RAW 264.7 macrophages. TI-I-174 treatment also markedly inhibited inducible nitric oxide synthase (iNOS) expression. However, TI-I-174 did not significantly affect production of IL-6, cyclooxygenase-2 (COX-2) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), implying that TI-I-174 inhibits production of inflammatory mediators in a selective manner. Treatment of macrophages with TI-I-174 significantly inhibited transcriptional activity of activator protein-1 (AP-1) as determined by luciferase reporter gene assay, whereas nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activity was not affected by TI-I-1744. In addition, TI-I-174 significantly inhibited activation of c-Jun-N-Terminal kinase (JNK) without affecting ERK1/2 and p38MAPK, indicating that down-regulation of iNOS gene expression by TI-I-174 is mainly attributed by blockade of JNK/AP-1 activation. We also demonstrated that TI-I-174 treatment led to an increase in heme oxygenase-1 (HO-1) expression both at mRNA and protein level. Transfection of siRNA targeting HO-1 reversed TI-I-174-mediated inhibition of nitrite production. Taken together, these results indicate that TI-I-174 suppresses NO production in LPS-stimulated RAW 264.7 macrophages via induction of HO-1 and blockade of AP-1 activation.

탄소섬유강화복합재료의 마식에 관한 연구 (Study on Erosion of Carbon Fiber Reinforced Plastic Composite)

  • 김엄기;김일현
    • 한국산학기술학회논문지
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    • 제9권2호
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    • pp.291-297
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    • 2008
  • 일방향 탄소섬유 강화 복합재료(CFRP)의 고체입자 마식 거동을 다양한 충돌각도 (${\alpha}$), 속도 (V) 및 섬유 방향 (${\beta}$)에 대하여 연구하였다. 실험결과 30o 충돌각도에서 최대 마식률을 나타내었고, 마식률은 멱함수 법칙 $E{\propto}\;V^n$에 따라 충돌속도에 크게 의존하였다. 본 연구에서는 이상의 결과로부터 일방향 탄소섬유 강화 복합재료의 마식률을 충돌속도, 충돌각도 및 섬유방향 각도로부터 예측하는 방법을 제안하였다.

Effect of Water-impregnation on Steam Explosion of Pinus densiflora

  • Jung, Ji Young;Ha, Si Young;Yang, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • 제47권2호
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    • pp.189-199
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    • 2019
  • This study addresses the biorefinery feedstock from Pinus densiflora. This raw material is a major tree species in the Republic of Korea; it is renewable, has cost-effective, and is readily available. In this study, steam explosion of P. densiflora was performed in a reactor at $225^{\circ}C$ and with 1 to 13 min reaction times with or without previous water impregnation. The combined severity factor (Ro), which is an expression relating the reaction temperature and reaction time used in the steam explosion treatment, ranged from 3.68 to 4.79. The influence of both impregnation and steam explosion conditions were investigated by examining color variations, chemical composition, and mass balance on the pretreated solids. The results showed that steam-exploded P. densiflora that was not impregnated with water exhibited significantly darker color (chroma 28.8-41.4) than water-impregnated and steam-exploded P. densiflora (chroma 18.8-37.3). The increased ${\alpha}$-cellulose and lignin contents were detected as the severity factor increased. Furthermore, the ${\alpha}$-cellulose and lignin contents in the non-impregnated/steam-exploded P. densiflora were higher than those in the water-impregnated/steam-exploded P. densiflora. However, the decreased holocellulose content was detected as the severity factor increased. In mass balance, the holocellulose yield from water-impregnated/steam-exploded P. densiflora was higher than that from the non-impregnated P. densiflora.

RNA-Seq explores the functional role of the fibroblast growth factor 10 gene in bovine adipocytes differentiation

  • Nurgulsim Kaster;Rajwali Khan;Ijaz Ahmad;Kazhgaliyev Nurlybay Zhigerbayevich;Imbay Seisembay;Akhmetbekov Nurbolat;Shaikenova Kymbat Hamitovna;Omarova Karlygash Mirambekovna;Makhanbetova Aizhan Bekbolatovna;Tlegen Garipovich Amangaliyev;Ateikhan Bolatbek;Titanov Zhanat Yeginbaevich;Shakoor Ahmad;Zan Linsen;Begenova Ainagul Baibolsynovna
    • Animal Bioscience
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    • 제37권5호
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    • pp.929-943
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    • 2024
  • Objective: The present study was executed to explore the molecular mechanism of fibroblast growth factor 10 (FGF10) gene in bovine adipogenesis. Methods: The bovine FGF10 gene was overexpressed through Ad-FGF10 or inhibited through siFGF10 and their negative control (NC) in bovine adipocytes, and the multiplicity of infection, transfection efficiency, interference efficiency were evaluated through quantitative real-time polymerase chain reaction, western blotting and fluorescence microscopy. The lipid droplets, triglycerides (TG) content and the expression levels of adipogenic marker genes were measured during preadipocytes differentiation. The differentially expressed genes were explored through deep RNA sequencing. Results: The highest mRNA level was found in omasum, subcutaneous fat, and intramuscular fat. Moreover, the highest mRNA level was found in adipocytes at day 4 of differentiation. The results of red-oil o staining showed that overexpression (Ad-FGF10) of the FGF10 gene significantly (p<0.05) reduced the lipid droplets and TG content, and their down-regulation (siFGF10) increased the measurement of lipid droplets and TG in differentiated bovine adipocytes. Furthermore, the overexpression of the FGF10 gene down regulated the mRNA levels of adipogenic marker genes such as CCAAT enhancer binding protein alpha (C/EBPα), fatty acid binding protein (FABP4), peroxisome proliferator-activated receptor-γ (PPARγ), lipoprotein lipase (LPL), and Fas cell surface death receptor (FAS), similarly, down-regulation of the FGF10 gene enriched the mRNA levels of C/EBPα, PPARγ, FABP4, and LPL genes (p<0.01). Additionally, the protein levels of PPARγ and FABP4 were reduced (p<0.05) in adipocytes infected with Ad-FGF10 gene and enriched in adipocytes transfected with siFGF10. Moreover, a total of 1,774 differentially expressed genes (DEGs) including 157 up regulated and 1,617 down regulated genes were explored in adipocytes infected with Ad-FGF10 or Ad-NC through deep RNA-sequencing. The top Kyoto encyclopedia of genes and genomes pathways regulated through DEGs were the PPAR signaling pathway, cell cycle, base excision repair, DNA replication, apoptosis, and regulation of lipolysis in adipocytes. Conclusion: Therefore, we can conclude that the FGF10 gene is a negative regulator of bovine adipogenesis and could be used as a candidate gene in marker-assisted selection.

Leuconostoc mesenteroides에서 分離한 Glucose-6-phosphate Dehydrogenase의 特性 (Characteristics of Glucose-6-phosphate Dehydrogenase from Leuconostoc mesenteroides)

  • 변시명;최양도;한문희
    • 대한화학회지
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    • 제23권4호
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    • pp.248-258
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    • 1979
  • 저자들은 Cibacron Blue F3G-A Separose 컬럼 어피니티크로마토그래피에 의하여 GIn-cose-6-phosphate dehydrogenase를 Leuconostoc mesenteroides로부터 순수 분리한 바 있다. 이 효소를 사용하여 효소특성을 조사한 결과 분자량은 Sephadex G-200 컬럼에 의해 112,000이었으며 최적온도는 50$^{\circ}$, 활성화에너 지는 8.36kcal/mole 불활성화에너지는 -58.2kcal/mole로 나타났다. $NADP^+$를 조효소로 사용하였을때 최적 pH7.8에서 K_{G6p}:76.9${\mu}$M, ${\alpha}K_{NADP}:\;7.46{\mu}M,\;{\alpha}KNNADP:\;7.l4{\mu}M$이었으며 같은 조건에서 $NAD^+$를 조효소로 사용하였을때 $K_{G6P}:\;53.65{\mu}M,\;K_{NAD}:\;115.2{\mu}M\;{\alpha}K_{NAD}:\;707.2{\mu}M$이었다. 따라서 $NADP^+$$NAD^+$를 조효소로 사용한 경우에 있어서 ${\alpha}$ 값은 각각 1과 6으로 나타났다. pH변화에 따른 반응속도상수의 변화에 의하면 $NAD^+$를 조효소로 하였을때 최적 pH는 7.8 이었고 pKa가 7.2인 활성기와 ${\mu}Kb$가 9.0∼9.6인 활성기가 효소와 기질의 상호작용에 관여함을 알았다. 이중 pKa 7.2인 활성기를 밝히기 위하여 효소를 광산화와 carboxymethylation을 시킨결과 histidine의 imidazole기임을 알수 있있다.

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TRPM7 Is Essential for RANKL-Induced Osteoclastogenesis

  • Yang, Yu-Mi;Jung, Hwi-Hoon;Lee, Sung Jun;Choi, Hyung-Jun;Kim, Min Seuk;Shin, Dong Min
    • The Korean Journal of Physiology and Pharmacology
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    • 제17권1호
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    • pp.65-71
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    • 2013
  • The transient receptor potential melastatin type 7 (TRPM7) channel is a widely expressed non-selective cation channel with fusion to the C-terminal alpha kinase domain and regarded as a key regulator of whole body $Mg^{2+}$ homeostasis in mammals. However, the roles of TRPM7 during osteoclastogenesis in RAW264.7 cells and bone marrow-derived monocyte/macrophage precursor cells (BMMs) are not clear. In the present study, we investigate the roles of TRPM7 in osteoclastogenesis using methods of small interfering RNA (siRNA), RT-PCR, patch-clamp, and calcium imaging. RANKL (receptor activator of NF-${\kappa}B$ ligand) stimulation did not affect the TRPM7 expression and TRPM7-mediated current was activated in HEK293, RAW264.7, and BMM cells by the regulation of $Mg^{2+}$. Knock-down of TRPM7 by siTRPM7 reduced intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) increases by 0 mM $[Mg^{2+}]_e$ in HEK293 cells and inhibited the generation of RANKL-induced $Ca^{2+}$ oscillations in RAW264.7 cells. Finally, knock-down of TRPM7 suppressed RANKL-mediated osteoclastogenesis such as activation and translocation of NFATc1, formation of multinucleated cells, and the bone resorptive activity, sequentially. These results suggest that TRPM7 plays an essential role in the RANKL-induced $[Ca^{2+}]_i$ oscillations that triggers the late stages of osteoclastogenesis.

수산 지역의 규회석과 그 용해 거동 (Wollastonite from and Its Dissolution Behaviors)

  • 김수진;현성필;이성근
    • 한국광물학회지
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    • 제9권1호
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    • pp.1-6
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    • 1996
  • Woolastonite from Susan occurs as intercalations in limestone beds of Lower Paleozoic Joseon Supergroup. It is a thermal metamorphic product of impure limestone. Electron microprobe analysis shows that it is considerably pure wollastonite. It has triclinic cell with a=7.932$\AA$, b=7.328$\AA$, c=7.069$\AA$, $\alpha$=89.995$^{\circ}$, $\beta$=$95.255^{\circ}$, and $ \Upsilon=103.367^{\circ}$.Dissolution behaviors of wollastonite have been studied conducting three different dissolution experiments; two different reactions with HC1 (one batch and one re-initialization experiment) and one traction with distilled water. In the batch type powder wollastonite-HCl reaction, pH of solution rapidly increases in the early stage and then its rate of increase slows down to reach plateau resulting in parabolic relationship with time. It is represented by the early rapid rise and fall in pH giving a sharp pH-edge and succeeding slow rise in the re-initialization experiment. The early rapid rise in pH is due to the rapid sorption of H- in solution to oxygens on the reactive surface of wollastonite and the fall in pH means that all reactive surface sites are occupied by H- ions and no more H- adsorption occurs. The slow rise in pH following the pH- edge is due to the dissolution of wollastonite as evidenced by the correlation of pH variation and cation concentration. Dissolution of powder wollastonite in HCl shows linear trend with time. Si is dissolved predominantly over Ca at a constant rate. Ca is dissolved predominantly in the very early stage. Dissolution rate of coarse-grained wollastonite fragments in distilled water is parabolic with times howing a rapid reaction in the early stage and a slow reaction in the advanced stage. The Ca/Si ratio in solution is high in the case of coarse-grained wollastonite fragment as compared with powder wollastonite. The coarse-grained wollastonite fragment-water (acid) reaction resulted in the solution with an elevated constant pH value (alkaline) giving an important significance on the environmental view point.

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전해도금 공정온도가 Co-Pt 합금 박막의 미세구조 및 자기적 특성에 미치는 영향 (Effects of process temperature on the microstructure and magnetic properties of electrodeposited Co-Pt alloy thin films)

  • 이창형;정근희;박정갑;이광근;서수정
    • 한국결정성장학회지
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    • 제18권2호
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    • pp.87-90
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    • 2008
  • Co-Pt 합금 박막은 amino-citrate 기반의 전해액에서 Ru(30 nm)/Ta(5 nm)/Si(100)구조의 작업 전극을 사용하여 정전류 전해도금 방법으로 증착 하였다. (0002) 우선 성장된 Ru의 buffer layers를 사용하여 Co-Pt 합금 박막의 결정구조와 우선 성장을 조절하였다. 본 실험에서는 도금액 온도를 변화시킴에 따른 Co-Pt 합금 박막의 자기적 성질과 미세구조에 미치는 영향을 고찰하였다. Co-Pt 합금 박막의 형상과 조성은 FESEM 과 EDS로 확인하였고, XRD로 결정구조를 분석하였다. 자기적 성질은 진동 시료 자력계와 토오크 자력계로 분석하였다. Co-Pt 합금 박막은 박막표면과 수직한 방향에서 열처리 없이 각각 6527 Oe의 높은 보자력과 0.93의 높은 각형비를 나타내었다.

졸-겔 공정으로 합성된 코디어라이트를 이용하여 알루미나의 표면개질 (Surface Modification of Alumina Ceramic with Mg2Al4Si5O18 Glass by a Sol-Gel Process)

  • 최필규;추민철;배동식
    • 한국재료학회지
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    • 제24권1호
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    • pp.48-52
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    • 2014
  • The Mg-enriched magnesium aluminum silicate (MAS) glass is known for its higher mechanical strength and chemical resistance. Among such glasses, cordierite ($Mg_2Al_4Si_5O_{18}$) is well known to have a low thermal expansion and low melting point. Polycrystalline engineering ceramics such as alumina can be strengthened by a surface modification with low thermal expansion materials. The present study involves the synthesis of cordierite by a sol-gel process and investigates the effect of glass penetration on the surface of alumina. The cordierite powders were prepared from $Al(OC_3H_7)_3$, $Mg(OC_2H_5)_2$ and tetraethyl orthosilicate by hydrolysis and condensation reaction. The cordierite powders were characterized by X-ray diffraction (XRD, Rigaku), scanning electron microscope (SEM, JEOL: JSM-5610), energy dispersive spectroscopy (EDS, JEOL: JSM-5610), and universal testing machine (UTM, INSTRON). The X-ray diffraction patterns showed that the synthesized particles were ${\mu}$-cordierite calcined at $1100^{\circ}C$ for 1 h. The shape of synthesized cordierite was changed from ${\mu}$-cordierite to ${\alpha}$-cordierite with increasing calcination temperature. Synthesized cordierite was used for surface modification of alumina. Cordierite powders penetrated deeply into the alumina sample along grain boundaries with increasing temperature. The results of surface modification tests showed that the strength of the prepared alumina sample increased after surface modification. The strength of a surface modified with synthesized cordierite increased the most, to about 134.6MPa.

포도 추출물로부터 C/EBP 전사인자 활성 비교 (Comparison of Anti-Adipogenesis Activity by Several Grape Extracts)

  • 이시림;박철홍;권은영;루옌칭;김홍;김기찬;손형우;이현진;허진철;이상한
    • 한국식품저장유통학회지
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    • 제18권1호
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    • pp.119-123
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    • 2011
  • In order to compare what kinds of transcription factors are associated with the inhibition of preadipocyte cell proliferation, we prepared several grape extracts and tested the expression patterns by reverse transcription-polymerase chain reaction. As a result, 50% ethanol extract of Campbell early seed inhibited adipogenesis derived from the MDI solution. Extract of Campbell early seed was significantly inhibited lipid droplet formation and expression of molecular factors C/EBP-alpha and delta in 3T3-L1 cells. It is suggested that grape extracts of fractions would be a good candidate for the development of regional skin fat modulator.