• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.175-175
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• 2010

The etching characteristics with etch rate of ITO thin films in an $O_2/BCl_3$/Ar plasma were investigated. The etch rate of ITO thin films increased with increasing $O_2$ content from 0 to 10 % in $BCl_3$/Ar plasma, whereas that of ITO decreased with increasing $O_2$ content from 10 % to 30 % in $BCl_3$/Ar plasma. The maximum etch rate of 65.9 nm/min for the ITO thin films was obtained at 10 % $O_2$ addition. The etch conditions were the RF power of 500 W, bias power of 200 W, and process pressure of 2 Pa. The analysis of x-ray photoelectron spectroscopy (XPS) was carried out to investigate the chemical reactions between the surfaces of ITO thin films and etch species.

• Tuberculosis and Respiratory Diseases
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• v.61 no.4
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• pp.366-373
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• 2006

Background: Paraquat is extremely toxic chemical material, which generates reactive oxygen species (ROS), causing multiple organ failure. In particular, paraquat leads to irreversible progressive pulmonary fibrosis. Exaggerated cell deaths exceeding the normal repair of type II pneumocytes leads to mesenchymal cells proliferation and fibrosis. This study examined the followings; i) whether or not paraquat induces cell death in lung epithelial cells; ii) whether or not paraquat-induced cell deaths are apoptosis or necrosis; and iii) the effects of N-acetylcysteine, dexamethasone, and bcl-2 on paraquat-induced cell deaths. Methods: A549 and BEAS-2B lung epithelial cell lines were used. The cell viability and apoptosis were evalluated using a MTT assay, Annexin V staining was monitored by fluorescence microscopy, The level of bcl-2 inhibition was examined by establishing stable A549 pcDNA3-bcl-2 cell lines throung the transfection of pcDNA3-bcl-2 with the mock. Results: Paraquat decreased the cell viability in A549 and BEAS-2B cells in a dose and time dependent manner. The Annexin V assay showed that apoptosis was the type of paraquat-induced cell death. Paraquat-induced cell deaths was significantly inhibited by N-acetylcysteine, dexamethasone, and bcl-2 overexpression. The cell viability of A549 cells treated with N-acetylcysteine, and dexamethasone on the paraquat-induced cell deaths were increased significantly by 10 ~ 20%, particularly at high doses. In addition, the cell viability of A549 pcDNA3-bcl-2 cells overexpressing bcl-2 was significantly higher than the untransfected A549 cells. Conclusion: Paraquat induces apoptotic cell deaths in lung epithelial cells in a dose and time dependent manner. The paraquat-induced apoptosis of lung epithelial cells might occur through the mitochondrial pathway.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.416-422
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• 1999

The characteristics of inductively coupled Cl$_2$/BCl$_3$ plasmas during the GaN etching were studied using plasma mass spectrometry by measuring the relative amounts of reactive ions, neutrals, and etch products. GaN etch rates increased with the increase of pressure and showed a maximum near 25mTorr for the pure $Cl_2$ and near 30mTorr for $Cl_2$$BCl_3$. The addition of$ BCl_3$ to $Cl_2$ also was increased GaN etch rates until 50%BCl$_3$ was mixed to $Cl_2$. The GaN etching with pure $Cl Cl_2$ appears to be related to the combination of Cl$_2^{+}$ ion bombardment and the chemical reaction of Cl radicals. In the case of the GaN etching with Cl$_2$/BCl$_3$, in addition to the combined effect of$_2^{ +}$ ions and Cl radicals, $_BCl2^{+ }$ ions appear to be responsible for some of GaN etching even though they do not have significant effect on the GaN etching compared to $Cl_2^{+}$ and Cl. $Ga^{+ }$ , $GaCl^{+}$ , $GaCl_2^{+}$ , and $N_2^{+}$ were observed as the positive ions of etch products, and the intensities of these etch products showed the same trends as those of GaN etch rate. Among the etch products, Ga and $N_2$ appear to be the main etch products.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.62-62
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• 2003

고밀도 유도결합 플라즈마(high density inductively coupled plasma) 식각은 GaAs 이종접합 양극성 트랜지스터(HBTs)와 고속전자 이동도 트랜지스터(HEMTs)와 같은 GaAs 기반 반도체의 정교한 패턴을 형성하는데 더욱 많이 이용되고 있다 본 연구는 고밀도 플라즈마 소스(source)인 평판형(planar) 고밀도 유도결합 플라즈마 식각장치를 이용하여 $BCl_3$ 와 $BCl_3/Ar$ 가스에 따른 GaAs 식각결과를 비교 분석하였다. 공정변수는 ICP 소스 파워를 0-500W, RIE 척(chuck) 파워를 0-150W, 공정압력을 0-15 mTorr 이었다. 그리고 가스 유량은 20sccm(standard cubic centimeter per minute)으로 고정시킨 상태에서 Ar 첨가 비율에 따른 GaAs의 식각결과를 관찰하였다. 공정 결과는 식각률(etch rate), GaAs 대 PR의 선택도(selectivity), 표면 거칠기(roughness)와 식각후 표면에 남아 있는 잔류 가스등을 분석하였다. 20 $BCl_3$ 플라즈마를 이용한 GaAs 식각률 보다 Ar이 첨가된 (20-x) $BC1_3/x Ar$ 플라즈마의 식각률이 더 우수하다는 것을 알 수 있었다. 식각률 증가는 Ar 가스의 첨가로 인한 GaAs 반도체와 Ar 플라즈마의 충돌로 나타난 결과로 예측된다. $BCl_3$ 와 $BC1_3/Ar$ 플라즈마에 노출된 GaAs 반도체 모두 표면이 평탄하였고 수직 측벽도 또한 우수하였다. 그리고 표면에 잔류하는 성분은 Ga와 As 이외에 $Cl_2$ 계열의 불순물이 거의 발견되지 않아 매우 깨끗함을 확인하였다. 이번 발표에서는 $BCl_3$ 와 $BCl_3/Ar$ 플라즈마를 이용한 GaAs의 건식식각 비교에 대해 상세하게 보고 할 것이다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.261-261
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• 2011

펄스 직류 전원 $BCl_3/SF_6$ 플라즈마를 이용하여 GaAs/$Al_{0.2}Ga_{0.8}As$의 선택적 식각을 연구하였다. 식각 주요 공정 변수는 $BCl_3/SF_6$ 플라즈마에서 $SF_6$ 가스 유량(0~50%)이었다. $BCl_3/SF_6$의 총 가스 유량은 20 sccm이었다. 다른 공정 조건인 공정 압력(100 mTorr), 펄스 파워(500 V), 펄스 주파수(200 kHz), 리버스 시간 (0.7 ${\mu}s$)은 일정하게 고정시켰으며 기계적 펌프만을 이용하여 공정을 진행하였다. 오실로스코프(Oscilloscope) 데이터에 의하면 가스의 조성 변화에도 척에 걸리는 입력 전압과 전류가 거의 변화가 없었다. $BCl_3/SF_6$ 가스가 10%의 조성에서 GaAs와 $Al_{0.2}Ga_{0.8}As$의 식각 선택비가 약 48 : 1로 우수한 결과를 나타내었다. 그러나 $BCl_3/SF_6$ 가스의 증가는 GaAs의 식각율과 선택도를 감소시켰다. 그리고 $SF_6$ 가스의 조성비가 30% 이상일 경우에는 GaAs와 $Al_{0.2}Ga_{0.8}As$가 식각되지 않았다. 식각 후에 GaAs의 표면 거칠기(RMS surface roughness)는 0.7~1.3 nm로 나타났다. 위의 결과들을 종합적으로 보면 펄스 직류 전원 $BCl_3/SF_6$의 조성비가 10%일 때 가장 좋은 식각 선택비를 얻을 수 있었다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.41-42
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• 2008

본 논문에서는 As-doped ZnO 박막의 플라즈마 식각 특성 및 메커니즘에 관하여 실험을 수행 하였다. As-doped ZnO 박막 식각 실험은 유도 결합 플라즈마 식각 장비(inductively coupled plasma;ICP)와 $BCl_3$/Ar 플라즈마에 첨가된 $Cl_2$가스의 비, RF 전력, DC bias voltage, 공정 압력에 대한 식각 속도의 변화를 관찰 하였다. $BCl_3$/Ar 플라즈마에 $Cl_2$ 가스 첨가량 6 sccm 까지는 증가하지만 그 이후 $Cl_2$ 가스의 첨가량이 증가할 때 식각속도가 감소하였다. 이는 플라즈마 내에서 Cl 라디칼의 밀도가 증가함에 따라서 $Ar^+$의 에너지가 감소와 비휘발성 식각 부산물의 증가에 의하여 효과적인 물리적 식각이 이루어 지지 못한 것으로 판단된다. OES를 이용하여 플라즈마 내에서 라디칼들의 빛의 세기를 측정하였고, 식각 후 As-type ZnO 박막 표면에서의 화학적 결합을 보기위해 XPS 분석을 실행하였다.

• Advances in pediatric surgery
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• v.19 no.2
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• pp.122-129
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• 2013

Immature ganglion cell (IGC) is known for its relationship with intestinal motility and its impact on postoperative functional outcomes of Hirschsprung's disease (HD). There are few studies on the relationship between intestinal dysmotility and IGC in HD patients. 67 patients pathologically diagnosed with HD and who received definitive operation in Seoul National University Children's Hospital from 2010 to 2011 were included. 10 patients were excluded due to inadequate immunohistochemical staining results. The proximal end of resected ganglionic segment was evaluated with immunohistochemistry examination with MAP-2, a marker of ganglionic cells and bcl-2, a marker of IGCs The median age at operation was 155 (15-4678) day-old. 55 (96.5%) patients positive for bcl-2, were regarded as having IGC, and 2 (3.5%) patients positive for MAP-2 but negative for bcl-2, were regarded as having only mature ganglion cells. In the bcl-2 positive group, there were 7 patients (12.7%) with constipation, 15 patients (27.3%) with soiling, 3 patients (5.5%) with perianal excoriation and 6 patients (10.9%) with medication use. In bcl-2 negative group, intestinal dysmotility was not seen. There was no statistical significance in the two groups. Considering that HD is diagnosed at a young age, the rate of IGC present is very high and it might be inappropriate to relate IGC to functional outcome at young ages.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.75-79
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• 2003

We studied InP etch results in high density planar inductively coupled $BCl_3$ and $BCl_3$/Ar plasmas. The investigated process parameters were ICP source power, RIE chuck power, chamber pressure and $BCl_3$/Ar gas composition. It was found that increase of ICP source power and RIE chuck power raised etch rate of InP, while that of chamber pressure decreased etch rate. Etched InP surface was clean and smooth (RMS roughness < 2 nm) with a moderate etch rate ($300\;{\sim}\;500\;{\AA}/min$) after the planar $BCl_3/Ar$ ICP etching. It may make it possible to open a new regime of InP etching with $CH_4/H_2$ - free plasma chemistry. Some amount of Ar addition (< 50%) also improved etch rates of InP, while too much Ar addition reduced etch rates of InP.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4599-4602
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• 2013

We intended to study the mechanism of the inhibitory action of curcumin on human non-small cell lung cancer A549 cell. The cell growth was determined by CCK-8 assay, and the results indicated that curcumin inhibited the cell proliferation in a concentration dependent manner. And to further confirm the relative anti-cancer mechanism of curcumin, RT-PCR was carried out to analysis the expression of relative apoptotic proteins Bax, Bcl-2. We found that curcumin could up-regulate the expression of Bax but down-regulate the expression of Bcl-2 in A549 cells. In addition, curcumin affect the mitochondrial apoptosis pathway. These results suggested that curcumin inhibited cancer cell growth through the regulation of Bcl-2/Bax and affect the mitochondrial apoptosis pathway.

• BMB Reports
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• v.51 no.2
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• pp.92-97
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• 2018

B cell leukemia/lymphoma 3 (Bcl3) plays a pivotal role in immune homeostasis, cellular proliferation, and cell survival, as a co-activator or co-repressor of transcription of the $NF-{\kappa}B$ family. Recently, it was reported that Bcl3 positively regulates pluripotency genes, including Oct4, in mouse embryonic stem cells (mESCs). However, the role of Bcl3 in the maintenance of pluripotency and self-renewal activity is not fully established. Here, we report the dynamic regulation of the proliferation, pluripotency, and self-renewal of mESCs by Bcl3 via an influence on Nanog transcriptional activity. Bcl3 expression is predominantly observed in immature mESCs, but significantly decreased during cell differentiation by LIF depletion and in mESC-derived EBs. Importantly, the knockdown of Bcl3 resulted in the loss of self-renewal ability and decreased cell proliferation. Similarly, the ectopic expression of Bcl3 also resulted in a significant reduction of proliferation, and the self-renewal of mESCs was demonstrated by alkaline phosphatase staining and clonogenic single cell-derived colony assay. We further examined that Bcl3-mediated regulation of Nanog transcriptional activity in mESCs, which indicated that Bcl3 acts as a transcriptional repressor of Nanog expression in mESCs. In conclusion, we demonstrated that a sufficient concentration of Bcl3 in mESCs plays a critical role in the maintenance of pluripotency and the self-renewal of mESCs via the regulation of Nanog transcriptional activity.