• 제목/요약/키워드: MN9D

검색결과 211건 처리시간 0.024초

Involvement of Corticotropin-releasing Factor Receptor 2β in Differentiation of Dopaminergic MN9D Cells

  • Jin, Tae-Eun;Jang, Miae;Kim, Hyunjung;Choi, Yu Mi;Cho, Hana;Chung, Sungkwon;Park, Myoung Kyu
    • Molecules and Cells
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    • 제26권3호
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    • pp.243-249
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    • 2008
  • Corticotropin releasing factor (CRF) mediates various responses to stress through CRF receptors 1 and 2. CRF receptor 2 has two forms, $2{\alpha}$ and $2{\beta}$ each of which appears to have distinct roles. Here we used dopaminergic neuron-derived MN9D cells to investigate the function of CRF receptor 2 in dopamine neurons. We found that n-butyrate, a histone deacetylase inhibitor, induced MN9D cell differentiation and increased gene expression of all CRF receptors. CRF receptor $2{\beta}$ was minimally expressed in MN9D cells; however, its expression dramatically increased during differentiation. CRF receptor $2{\beta}$ expression levels appeared to correlate with neurite outgrowth, suggesting CRF receptor $2{\beta}$ involvement in neuronal differentiation. To validate this statement, we made a CRF receptor $2{\beta}$-overexpressing $MN9D/CRFR2{\beta}$ stable cell line. This cell line showed robust neurite outgrowth and GAP43 overexpression, together with MEK and ERK activation, suggesting MN9D cell neuronal differentiation. From these results, we conclude that CRF receptor $2{\beta}$ plays an important role in MN9D cell differentiation by activating the MEK/ERK signaling pathway.

Oxidation of Fe-(5.3-29.8)%Mn-(1.1-1.9)%Al-0.45%C Alloys at 550-650 ℃

  • Park, Soon Yong;Xiao, Xiao;Kim, Min Ji;Lee, Geun Taek;Hwang, Dae Ho;Woo, Young Ho;Lee, Dong Bok
    • Corrosion Science and Technology
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    • 제21권1호
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    • pp.53-61
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    • 2022
  • Alloys of Fe-(5.3-29.8)%Mn-(1.1-1.9)%Al-(0.4-0.5)%C were oxidized at 550 ℃ to 650 ℃ for 20 h to understand effects of alloying elements on oxidation. Their oxidation resistance increased with increasing Mn level to a small extent. Their oxidation kinetics changed from parabolic to linear when Mn content was decreased and temperature was increasing. Oxide scales primarily consisted of Fe2O3, Mn2O3, and MnFe2O4 without any protective Al-bearing oxides. During oxidation, Fe, Mn, and a lesser amount of Al diffused outward, while oxygen diffused inward to form internal oxides. Both oxide scales and internal oxides consisted of Fe, Mn, and a small amount of Al. The oxidation of Mn and carbon transformed γ-matrix to α-matrix in the subscale. The oxidation led to the formation of relatively thick oxide scales due to inherently inferior oxidation resistance of alloys and the formation of voids and cracks due to evaporation of manganese, decarburization, and outward diffusion of cations across oxides.

Mn-SnO2/Ag/Mn-SnO2 3중 다층막의 성능지수와 밴딩 특성 (Figure of merit and bending characteristics of Mn-SnO2/Ag/Mn-SnO2 tri-layer film)

  • 조영수;장건익
    • 한국결정성장학회지
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    • 제31권4호
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    • pp.190-195
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    • 2021
  • 상온에서 PET 기판 위에 Mn-SnO2/Ag/Mn-SnO2 3중 다층막을 RF/DC 마그네트론 스파터링 방식으로 제조하였다. EMP 시뮬레이션 결과에 따라 Mn-SnO2의 막 두께는 40 nm, Ag 막 두께는 13 nm로 고정하였다. 550 nm 파장대역에서 측정한 3중막의 투과율은 82.9에서 88.1 % 범위였으며 면저항은 5.9에서 6.9 Ω/☐로 변화하였다. 가장 높은 성능지수(ϕTC)는 48.1 × 10-3 Ω-1로 나타났다. 곡률반경 4, 5 mm 조건에서 inner 밴딩과 out 밴딩의 굽힘시험을 10,000회 실시한 결과 Mn-SnO2/Ag/Mn-SnO2 3중막의 저항변화율은 약 1.5 %로 탁월한 기계적 유연성을 보였다.

AZ91 합금 용탕내 Mn과 Fe의 상호용해도 측정 및 AZ91D 재생지금의 성분조정에의 활용 (Mutual Solubility of Mn and Fe in AZ91 Alloy Melts and Its Application to Composition Control of AZ91D Recycled Ingots)

  • 권순일;변지영;김선진;심재동
    • 한국재료학회지
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    • 제13권9호
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    • pp.619-624
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    • 2003
  • This paper describes a method to control Mn and Fe contents in recycled AZ91D ingots, based on the mutual solubility of Mn and Fe in AZ91 alloy melts. For this purpose, Fe solubility with the change of Mn content and temperature was investigated in the homogenized and re-precipitated liquid AZ91 alloy. The increase of the amount of Mn added to the melt resulted in the decrease of Fe content. The data obtained in this study was adopted to the pilot plant for recycling of the scrap. As a result, Mn and Fe contents measured in the recycled ingot were in good agreement with ASTM B93 standard.

Mn3O4를 첨가한 Al2O3 세라믹스의 소결 및 광학 특성 (Sintering and the Optical Properties of Mn3O4-added Al2O3)

  • 김진호;백승우
    • 한국전기전자재료학회논문지
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    • 제29권9호
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    • pp.539-545
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    • 2016
  • Alumina added with Mn3O4 up to 7.5 cat% of Mn was prepared by conventional ceramic processing, and the sintering behavior and the optical properties of which were studied as functions of Mn content. Densification and grain growth of alumina were enhanced by Mn addition up to 0.75 cat% but was leveled off at higher concentrations. XRD revealed that $Al_2MnO_4$(galaxite) was formed as a second phase in the specimens with more than 0.75 cat% of Mn. Thus it is believed that either the solid solution effect of Mn or the Zener effect of $Al_2MnO_4$ becomes predominant in the sintering of Mn-added $Al_2O_3$ according to the additive concentration. UV-VIS reflectivity(SCI) spectra of Mn-added $Al_2O_3$ consisted of smooth bottoms in 300~550 nm wavelength range and plateaus at wavelengths longer than 650 nm. The reflectivity spectrum continuously moved downward, and the specimen color became darker and thicker with increasing Mn content. The CIELAB color change with respect to standard white was also dependent on the amount of Mn added: ${\Delta}L^*$(D65) negatively increased and ${\Delta}E_{ab}^*$(D65) positively increased with increasing Mn content, probably due to Mn substitution to Al and/or the mixing effect of black $Al_2MnO_4$ as a second phase.

니켈 치환된 스피넬 LiMn2O4 박막의 구조적, 광학적 성질 (Structural and optical properties of Ni-substituted spinel $LiMn_2O_4$ thin films)

  • 이중한;김광주
    • 한국진공학회지
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    • 제15권5호
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    • pp.527-533
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    • 2006
  • 졸-겔(sol-gel) 방법을 이용하여 스피넬(spinel) 구조를 가지는 $LiNi_xMn_{2-x}O_4$ 박막을 x = 0.9까지 합성하였다. 니켈 치환된 박막은 작은 x 값에서는 cubic 구조가 유지되지만, $x{\geq}0.6$ 범위에서는 tetragonal 구조로 상전이가 일어남이 발견되었다. 이와 같은 cubic-tetragonal 상전이는 low-spin $(t_{2g}^6,e_g^1)$ 상태를 가지는 $N^{3+}(d^7)$ 이온이 팔면체 자리를 차지하게 됨으로써 나타나는 Jahn-Teller 효과에 의한 것으로 해석된다. 이와 같은 Ni 이온들은 +3 및 +2의 원자가를 가지고 존재함이 X-ray photoelectron spectroscopy 분석을 통하여 확인되었다. $LiNi_xMn_{2-x}O_4$ 박막들에 대하여 가시광선-자외선 영역에서 spectroscopic ellipsometry(SE)를 이용하여 광학적 성질을 조사하였고, 그 결과 분석을 통하여 화합물 전자구조에 대하여 고찰하였다. SE 측정된 유전함수 스펙트럼은 주로 전하이동(charge-transfer, CT) 전이(transition)에 의한 넓은 에너지 영역을 가지는 1.9, 2.3, $2.8{\sim}3.0$, $3.4{sim}3.6eV$ 근처의 흡수구조 들로 이루어져 있는데, $O^{2-}$에서 $Mn^{4+}$ 이온의 $t_{2g}$ (1.9 eV)와 $e_g$ $(2.8{\sim}3.0\;eV)$로의 전이 즉, $O^{2-}(2p){\rightarrow}Mn^{4+}(3d)$$O^{2-}$에서 $Mn^{3+}$ 이온의 $t_{2g}$ (2.3 eV)와 $e_g$ ($3.4{\sim}3.6$ eV)로의 전이 즉, $O^{2-}(2p){\rightarrow}Mn^{3+}(3d)$ 등에 의한 것으로 해석된다. 또한, 1.6, 1.8, 1.9 eV 부근에서 관측된 좁은 에너지 영역의 흡수구조 들은 팔면체 $Mn^{3+}$ 이온 내에서의 d-d 결정장(crystal-field) 전이에 의한 것으로 해석된다. 이러한 흡수구조는 Ni 치환량이 증가함에 따라 그 강도가 감소한다. x = 0.6의 경우 $e_g$ 상태와 관련된 CT 전이구조 들이 $t_{2g}$ 상태와 관련된 전이구조 들에 비하여 큰 폭으로 감소하는데 이것은 Jahn-Teller 효과에 의해서 격자상수가 tetragonal 구조로 확장됨에 따라 $e_g$ 상태와 $O^{2-}(2p)$ 상태 간의 파동함수 중첩이 감소한 것에 기인하는 것으로 해석된다.

$MnO_2$치환된 PMN계 세라믹스의 유전특성 (A study on Dielectric Properties usig PMN Ceramics with $MnO_2$ substitution)

  • 지승한;유도현;이은학;김영일;박광현;이덕출
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 C
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    • pp.1537-1539
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    • 1997
  • In this study, the dielectric properties of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$ Ceramics have been investigated as a addition of the amount of $MnO_2(0{\leq}x{\leq}0.9wt%)$. The Temperature-dependant dielectric characteristics of 0.9PMN-0.1PT relaxor ferroelectric system were improved by enhencing the extent of the diffuse phase transition(DPT). The maximum dielectric permittivity decreased by substitution $MnO_2$ and the dielectric loss decreased with increasing $MnO_2$ substitution amount. It is expected decreasing in inner heat energy for temperature with increasing $MnO_2$ substitution.

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Plasma Concentrations of Fe, Cu, Mn, and Cr of Maternal and Umbilical Cord Blood during Pregnancy

  • Lee, Jong-Im;Lim, Hyeon-Sook;Cho, Young-Sook
    • Preventive Nutrition and Food Science
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    • 제7권3호
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    • pp.282-286
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    • 2002
  • Anemia is prevalent among pregnant women in Korea, and Fe deficiency anemia is a major nutritional problem throughout the world. Because studies of Cu, Mn, and Cr levels excluding Fe are rare, we were interested in changes in the nutritional status of these trace minerals and their relationship to hematogenesis. Accordingly, we determined the changes in plasma Fe, Cu, Mn, and Cr concentrations of maternal and umbilical cord blood during pregnancy, and evaluated the relationships between them at different time points during pregnancy. A total of 81 women participated in the study: 26 subjects in the first trimester, 23 in the second, and 32 in the third trimester. Plasma Fe levels were lower significantly (p<0.05) in the third trimester. Plasma Cu level ($\mu\textrm{g}$/dL) in each trimester were 86.6$\pm$13.8, 111.6$\pm$27.9, and 114.0$\pm$29.7, respectively; with significant increases (p<0.()5) in the second and third trimester. Plasma Mn concentrations (pg/dL) in each trimester were 212.6$\pm$89.0, 234.0$\pm$140.0, and 240.3$\pm$166.0, respectively and tended to increase, though not significantly, as the pregnancies progressed. The plasma concentrations of Cr (pg/dL) in each trimester were 3.7$\pm$2.0, 3.1$\pm$1.0, and 2.4$\pm$1.2, respectively; and was significantly lower (p<0.05) in the third trimester. In umbilical cord blood, the plasma level of Fe was 194.8$\pm$74.6 $\mu\textrm{g}$/dL, Cu was 57.5$\pm$10.9 $\mu\textrm{g}$/dL, Mn was 482.4$\pm$111.1 pg/dL, and Cr was 9.3$\pm$2.8 pg/dL. Plasma concentrations of Fe, Cu, Mn, and Cr of cord blood were 300 %, 50 %, 200 %, and 370% as compared to those of maternal blood in the third trimester. These results suggest that an active transport mechanism for the transport of Fe, Mn, and Cr from mother to fetus may exist, whereas, for Cu, the placenta appears to have a blocking effect on the transport from mother to baby.

Ruminal Solubility of Trace Elements from Selected Philippine Forages

  • Serra, S.D.;Serra, A.B.;Ichinohe, T.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • 제10권4호
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    • pp.378-384
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    • 1997
  • The ruminal solubility of copper (Cu), manganese (Mn), molybdenum (Mo), and zinc (Zn) in eight Philippine forages was studied. These forages were: 1) grasses: paragrass (Brachiaria mutica (Forsk.) Stapf), stargrass (Cynodon plectostachyum Pilger), and napiergrass (Pennisetum purpureum Schumach.); 2) creeping legumes: calopogonium or calopo (Calopogonium muconoides Desv.) and centrocema (Centrocema pubescens Benth.); 3) tree lequmes: gliricidia or kakawate (Gliricidia sepium (Jacq.) Walp.), leucaena or ipil-ipil (Leucaena leucocephala (Lam.) de Wit.), and sesbania or katuray (Sesbania grandiflora (L.) Poir). Nylon bags with samples were incubated for 0, 3, 6, 12, 24, 48 and 72h in three rumen cannulated sheep fed with timothy hay (Phleum pratense L.) at 2% body weight/d. The 0-h bags were washed with deionized water. There were species differences (p < 0.05) on the different solubilities of trace elements. At O-h incubation, the trend of solubility was Mo (54%) > Zn (43%) > Cu (38.7%) > Mn (29.5%). At 3-h incubation, all the elements except Mn had an average solubility above 50%. Combining particulate passage rate (1.9%/h) and various trace elements disappearance rates, the effective ruminal solubilization (ERS) of trace elements were computed. The ERS across species ranged from 44.6 to 89.9% for Cu, 29.9 to 84% for Mn, 66 to 95.1% for Mo, and 30.1 to 82.3% for Zn resulting to a trend of Mo > Zn > Cu > Mn.

Mn4+ 도핑된 형광체, Sr1-xBaxGe4O9:MnMn4+0.005 (0.00 ≤ x ≤ 1.00)의 Color Tuning (Color Tuning of a Mn4+ Doped Phosphor : Sr1-xBaxGe4O9:MnMn4+0.005 (0.00 ≤ x ≤ 1.00))

  • 박운배
    • 대한화학회지
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    • 제61권4호
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    • pp.163-167
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    • 2017
  • 백색 LED 기술이 발달함에 따라 적색 형광체는 산업 및 학계에서 점차 중요성이 커지고 있으며, 시장에서 수요는 꾸준히 증가했다. 적색 형광체는 고효율 및 고연색의 LED 조명에 사용된다. 그러나 $Eu^{2+}$ 활성제를 사용한 적색 형광체는 4f-5d 전이로 발생하는 녹색 또는 황색 스펙트럼 영역에서의 강한 재흡수로 인해 백색 LED 칩에서 색상 변경 및 발광 강도의 저하를 유발했다. 이러한 단점이 없고 연색성 지수(CRI)를 더 향상할 수 있는 $Mn^{4+}$ 도핑된 형광체가 현재 매우 중요하다. 그러나 $Mn^{4+}$ 도핑된 형광체는 $^2E_g{\rightarrow}^4A_2$ 전이로 인하여 발광 파장이 모체에 따라 결정된다는 단점이 있다. 본 연구는 동일구조의 $SrGe_4O_9$$BaGe_4O_9$ 모체를 합성하여 $Sr_{1-x}B_axGe_4O_9:Mn^{4+}{_{0.005}}$ (x = 0, 0.25, 0.5, 0.75 and 1)를 얻었다. 이로 인해 LED 기술의 다양한 색상 조정이 가능해졌다.