The gep oncogenes, Gα₁₂ and Gα₁₃, upregulate the transforming growth factor-β1 gene

Lee, S J,Yang, J W,Cho, I J,Kim, W D,Cho, M K,Lee, C H,Kim, S G Macmillan Publishers Limited 2009 Oncogene Vol.28 No.9

Transforming growth factor-β1 (TGFβ1) plays a role in neoplastic transformation and transdifferentiation. Gα<SUB>12</SUB> and Gα<SUB>13</SUB>, referred to as the gep oncogenes, stimulate mitogenic pathways. Nonetheless, no information is available regarding their roles in the regulation of the TGFβ1 gene and the molecules linking them to gene transcription. Knockdown or knockout experiments using murine embryonic fibroblasts and hepatic stellate cells indicated that a Gα<SUB>12</SUB> and Gα<SUB>13</SUB> deficiency reduced constitutive, auto-stimulatory or thrombin-inducible TGFβ1 gene expression. In contrast, transfection of activated mutants of Gα<SUB>12</SUB> and Gα<SUB>13</SUB> enabled the knockout cells to promote TGFβ1 induction. A promoter deletion analysis suggested that activating protein 1 (AP-1) plays a role in TGFβ1 gene transactivation, which was corroborated by the observation that a deficiency of the G-proteins decreased the AP-1 activity, whereas their activation enhanced it. Moreover, mutation of the AP-1-binding site abrogated the ability of Gα<SUB>12</SUB> and Gα<SUB>13</SUB> to induce the TGFβ1 gene. Transfection of a dominant-negative mutant of Rho or Rac, but not Cdc42, prevented gene transactivation and decreased AP-1 activity downstream of Gα<SUB>12</SUB> and Gα<SUB>13</SUB>. In summary, Gα<SUB>12</SUB> and Gα<SUB>13</SUB> regulate the expression of the TGFβ1 gene through an increase in Rho/Rac-dependent AP-1 activity, implying that the G-protein-coupled receptor (GPCR)-Gα<SUB>12</SUB> pathway is involved in the TGFβ1-mediated transdifferentiation process.Oncogene (2009) 28, 1230–1240; doi:10.1038/onc.2008.488; published online 19 January 2009

Power supply system for KSTAR neutral beam injector

Cho, W.,Bae, Y.S.,Han, W.S.,Jeong, J.H.,Kim, J.S.,Park, H.T.,Yang, H.L.,Oh, Y.K.,Kwak, J.G. Elsevier 2015 Fusion engineering and design Vol.96 No.-

<P><B>Abstract</B></P> <P>The power supply system in KSTAR neutral beam injector consists of low voltage and high current DC power supplies for plasma generator of ion source and high voltage and high current DC power supply for accelerator grid system. The arc discharge is initiated by an arc power supply supplying the arc voltage between the chamber wall and 12 filaments which are heated by individual filament power supply. The negative output of arc power supply is common to each positive output of 12 filament power supplies. To interrupt the arc discharging for the fault condition of the arc current unbalance, DCCT current monitor is placed at the positive output cable of the filament power supply. The plasma grid (G1) power supply has the maximum capability of 120kV/70A which consists of low voltage regulator with IGBT-switched chopper array system for the voltage control in unit of 600V and the high voltage rectified transformers to supply DC voltage of 20kV, 30kV, and 50kV. The output voltage of the G1 power supply is also connected to the input of the voltage divider system which supplies the gradient voltage to the gradient grid (G2) in the range of 80–90% of G1 voltage by changing tap of winding resistors in unit of 1%. The charged G1 voltage is turned on and off by the high voltage switch (HVS) system consisting of MOSFET fast semiconductor switches which can immediately be opened less than 1μs when the ion source grid breakdown occurs. The decelerating grid (G3) power supply is inverter system using capacitor-charge power supply to supply maximum −5kV/5A. The important component in power supply system is the surge absorber near the ion source to limit the arc energy deposited to accelerator grid. This paper presents configuration and features of power supply system, main controller, and interlock system of KSTAR NBI.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The power supply system in KSTAR NBI consists of DC power supplies for ion source. </LI> <LI> For operation NBI, DC High Voltage based on the low voltage transformer with chopper. </LI> <LI> The surge absorber near the ion source limit the energy deposited to accelerator grid. </LI> </UL> </P>

LIGA-like 공정을 이용한 마이크로 부품 복제용 Ni과 Ni-W 금형 제조 및 특성

황완식,박준식,강영철,조진우,박순섭,이인규,강성군,Hwang, W.S.,Park, J.S.,Kang, Y.C.,Cho, J.W.,Park, S.S.,Lee, I.G.,Kang, S.G. 한국재료학회 2003 한국재료학회지 Vol.13 No.1

Electroplated Ni and Ni-W micro-molds using LIGA-like process for replication of micro-components such as microfluidic parts and micro optical parts have been investigated. In general, it is hard to produce micro-parts using conventional mechanical processes. Micro-mold formed by LIGA-like process could fabricate micro-parts with high aspect ratio. In this paper, fabrication and properties of electroplated Ni molds with varying applied current types as well as those of Ni-W molds were investigated. Ni molds fabricated under pulse-reverse current showed the highest hardness value of about 160 Hv. Ni-W molds showed the hardness of about 500 Hv which was much harder than that of Ni electroplated molds. The above results suggested that high quality micro-molds could be fabricated by using Ni electroplating of pulse-reverse type for core molds and sequential Ni-W alloys coating.

Simulation of single grid-based phase-contrast x-ray imaging (g-PCXI)

Lim, H.W.,Lee, H.W.,Cho, H.S.,Je, U.K.,Park, C.K.,Kim, K.S.,Kim, G.A.,Park, S.Y.,Lee, D.Y.,Park, Y.O.,Woo, T.H.,Lee, S.H.,Chung, W.H.,Kim, J.W.,Kim, J.G. Elsevier BV * North-Holland 2017 Nuclear Instruments & Methods in Physics Research. Vol. No.

<P><B>Abstract</B></P> <P>Single grid-based phase-contrast x-ray imaging (g-PCXI) technique, which was recently proposed by Wen et al. to retrieve absorption, scattering, and phase-gradient images from the raw image of the examined object, seems a practical method for phase-contrast imaging with great simplicity and minimal requirements on the setup alignment. In this work, we developed a useful simulation platform for g-PCXI and performed a simulation to demonstrate its viability. We also established a table-top setup for g-PCXI which consists of a focused-linear grid (200-lines/in strip density), an x-ray tube (100-μm focal spot size), and a flat-panel detector (48-μm pixel size) and performed a preliminary experiment with some samples to show the performance of the simulation platform. We successfully obtained phase-contrast x-ray images of much enhanced contrast from both the simulation and experiment and the simulated contract seemed similar to the experimental contrast, which shows the performance of the developed simulation platform. We expect that the simulation platform will be useful for designing an optimal g-PCXI system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> It is proposed for the single grid-based phase-contrast x-ray imaging (g-PCXI) technique. </LI> <LI> We implemented for a numerical simulation code. </LI> <LI> The preliminary experiment with several samples to compare is performed. </LI> <LI> It is expected to be useful to design an optimal g-PCXI system. </LI> </UL> </P>

Full-length genomic analysis of porcine G9P[23] and G9P[7] rotavirus strains isolated from pigs with diarrhea in South Korea

Kim, H.H.,Matthijnssens, J.,Kim, H.J.,Kwon, H.J.,Park, J.G.,Son, K.Y.,Ryu, E.H.,Kim, D.S.,Lee, W.S.,Kang, M.I.,Yang, D.K.,Hyun, B.H.,Park, S.I.,Park, S.J.,Cho, K.O. Elsevier Science 2012 INFECTION GENETICS AND EVOLUTION Vol.12 No.7

Group A rotaviruses (RVAs) are agents causing severe gastroenteritis in infants and young animals. G9 RVA strains are believed to have originated from pigs. However, this genotype has emerged as the fifth major human RVA genotype worldwide. To better understand the relationship between human and porcine RVA strains, complete RVA genome data are needed. For human RVA strains, the number of complete genome data have grown exponentially. However, there is still a lack of complete genome data on porcine RVA strains. Recently, G9 RVA strains have been identified as the third most important genotype in diarrheic pigs in South Korea in combinations with P[7] and P[23]. This study is the first report on complete genome analyses of 1 G9P[7] and 3 G9P[23] porcine RVA strains, resulting in the following genotype constellation: G9-P[7]/P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1. By comparisons of these genotype constellations, it was revealed that the Korean G9P[7] and G9P[23] RVA strains possessed a typical porcine RVA backbone, similar to other known porcine RVA strains. However, detailed phylogenetic analyses revealed the presence of intra-genotype reassortments among porcine RVA strains in South Korea. Thus, our data provide genetic information of G9 RVA strains increasingly detected in both humans and pigs, and will help to establish the role of pigs as a source or reservoir for novel human RVA strains.

확산펌프 기반의 BCl<SUB>3</SUB> 축전결합 플라즈마를 이용한 GaAs와 AlGaAs의 건식 식각

이성현,박주홍,노호섭,최경훈,송한정,조관식,이제원,Lee, S.H.,Park, J.H.,Noh, H.S.,Choi, K.H.,Song, H.J.,Cho, G.S.,Lee, J.W. 한국진공학회 2009 Applied Science and Convergence Technology Vol.18 No.4

본 논문은 확산펌프 기반의 축전 결합형 $BCl_3$ 플라즈마를 사용하여 GaAs와 AlGaAs를 건식 식각한 연구에 관한 것이다. 실험에서 사용한 압력 범위는 $50{\sim}180$ mTorr, CCP 파워는 $50{\sim}200\;W$, $BCl_3$ 가스 유량은 $2.5{\sim}10$ sccm 이었다. 식각 후에 GaAs와 AlGaAs의 식각 속도와 표면 거칠기분석은 표면 단차 측정기를 이용하여 하였다. GaAs의 식각 벽면과 표면 상태는 전자현미경으로 분석하였다. 식각 중 플라즈마의 광 특성 분석은 광학 발광 분석기를 이용하였다. 본 실험을 통하여 5 sccm의 소량의 $BCl_3$ 가스 유량으로 공정 압력이 130 mTorr이내인 경우에는, 100 W CCP 파워의 조건에서 GaAs는 약 $0.25{\mu}m$/min 이상의 우수한 식각 속도를 얻을 수 있었다. AlGaAs의 경우는 GaAs의 식각 속도보다 조금 낮았다. 그러나 같은 유량에서 공정압력이 180 mTorr로 높아지면 GaAs와 AlGaAs의 식각 속도가 급격히 감소하여 거의 식각되지 않는 것을 알 수 있었다. 또한 CCP 파워의 경우에는 50 W의 파워에서는 GaAs와 AlGaAs 모두 거의 식각되지 않았다. 그러나 $100{\sim}200\;W$의 조건에서는 $0.3{\mu}m$/min 이상의 높은 식각 속도를 주었다. 두 결과를 보았을 때 축전결합형 $BCl_3$ 플라즈마 식각에서 GaAs와 AlGaAs의 식각 속도는 CCP 파워가 $100{\sim}200\;W$ 범위에 있으면 그 값에 비례하지 않고 거의 일정한 값이 된다는 사실을 알았다. 75mTorr, 100 W의 CCP 파워 조건에서 $BCl_3$의 유량 변화에 따른 GaAs와 AlGaAs의 식각 속도의 경우, $BCl_3$의 유량이 2.5 sccm의 소량일 때는 GaAs는 식각 속도가 높았지만 AlGaAs는 거의 식각되지 않는 흥미로운 결과를 얻었다. 플라즈마 발광 특성을 보면 $BCl_3$ 축전 결합 플라즈마는 주로 $500{\sim}700\;mm$ 범위를 가지는 넓은 분자 피크만 만든다는 것을 알 수 있었다. 전자 현미경 사진 결과에서는 5 sccm과 10 sccm의 $BCl_3$ 플라즈마 모두 식각 중에 GaAs의 벽면을 언더컷팅 하였으며, 10 sccm의 $BCl_3$유량을 사용하였을 때 언더컷팅이 더 심했다. We report the etch characteristics of GaAs and AlGaAs in the diffusion pump-based capacitively coupled $BCl_3$ plasma. Process variables were chamber pressure ($50{\sim}180$ mTorr), CCP power ($50{\sim}200\;W$) and $BCl_3$ gas flow rate ($2.5{\sim}10$ sccm). Surface profilometry was used for etch rate and surface roughness measurement after etching. Scanning electron microscopy was used to analyze the etched sidewall and surface morphology. Optical emission spectroscopy was used in order to characterize the emission peaks of the $BCl_3$ plasma during etching. We have achieved $0.25{\mu}m$/min of GaAs etch rate with only 5 sccm $BCl_3$ flow rate when the chamber pressure was in the range of 50{\sim}130 mTorr. The etch rates of AlGaAs were a little lower than those of GaAs at the conditions. However, the etch rates of GaAs and AlGaAs decreased significantly when the chamber pressure increased to 180 mTorr. GaAs and AlGaAs were not etched with 50 W CCP power. With $100{\sim}200\;W$ CCP power, etch rates of the materials increased over $0.3{\mu}m$/min. It was found that the etch rates of GaAs and AlGaAs were not always proportional to the increase of CCP power. We also found the interesting result that AlGaAs did not etched at 2.5 sccm $BCl_3$ flow rate at 75 mTorr and 100 W CCP power even though it was etched fast like GaAs with more $BCl_3$ gas flow rates. By contrast, GaAs was etched at ${{\sim}}0.3{\mu}m$/min at the 2.5 sccm $BCl_3$ flow rate condition. A broad molecular peak was noticed in the range of $500{\sim}700\;mm$ wavelength during the $BCl_3$ plasma etching. SEM photos showed that 10 sccm $BCl_3$ plama produced more undercutting on GaAs sidewall than 5 sccm $BCl_3$ plasma.

정밀 튜닝기반의 고효율 에너지 하비스터

조성원(S. W. Cho),최병근(B. G. Choi),손종덕(J. D. Son),양보석(B. S. Yang) 한국소음진동공학회 2008 한국소음진동공학회 학술대회논문집 Vol.2008 No.4

CFRP드론 프레임의 R값에 따른 구조안정성 개선을 위한 해석적 연구

황규완(G. W. Hwang),조재웅(J. U. Cho),이정호(J. H. Lee),박재웅(J. W. Park),김재원(J. W. Kim),오범석(B. S. Oh),국정한(J. H. Kook),전성식(S. S. Cheon),한문식(M. S. Han),김은도(E. D. Kim),최계광(K. K. Choi) 한국기계가공학회 2017 한국기계가공학회 춘추계학술대회 논문집 Vol.2017 No.10

Micro-Pulse 하전식 집진기용 초고압 전원장치 개발

김원호(W. H. Kim),강유리(I. Kang),김종수(J. S. Kim),임근희(G. H. Rim),김종화(J. W. Kim),조창호(C. H. Cho) 대한전기학회 1998 대한전기학회 학술대회 논문집 Vol.1998 No.7

산업용 적외선온도센서 교정용 고정밀 흑체 개발

박성욱(S.W. Park),조혁진(H. J. Cho),서희준(H. J. Seo),문귀원(G.W. Moon) 한국정밀공학회 2015 한국정밀공학회 학술발표대회 논문집 Vol.2015 No.12월