• 한국전기전자재료학회논문지
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• 제25권9호
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• pp.681-685
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• 2012

We investigated the dry etching characteristics of TiN in $TiN/Al_2O_3$ gate stack using a inductively coupled plasma system. TiN thin film is etched by BCl3/He plasma. The etching parameters are the gas mixing ratio, the RF power, the DC-bias voltages and process pressures. The highest etch rate is in $BCl_3/He$ (25%:75%) plasma. The selectivity of TiN thin film to $Al_2O_3$ is pretty similar with $BCl_3/He$ plasma. The chemical reactions of the etched TiN thin films are investigated by X-ray photoelectron spectroscopy. The intensities of the Ti 2p and the N 1s peaks are modified by $BCl_3$ plasma. Intensity and binding energy of Ti and N could be changed due to a chemical reaction on the surface of TiN thin films. Also we investigated that the non-volatile byproducts such as $TiCl_x$ formed by chemical reaction with Cl radicals on the surface of TiN thin films.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.26.2-26.2
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• 2009

이 논문은 반응성 $BCl_3$ 플라즈마로 GaAs의 건식 식각을 진행한 후 그 결과에 대하여 연구 분석 한 것이다. 이 때 사용한 식각 공정 변수는 $BCl_3$ 플라즈마에서의 가스유량, 공정 압력과 RIE 척 파워의 변화이다. 먼저 공정 압력을 75 mTorr 고정시킨 후 $BCl_3$ 유량을 변화 (2.5~10 sccm)해서 실험하였다. 또한 BCl3의 유량을 5 sccm으로 고정시킨 후 공정압력을 변화(47~180 mTorr)해서 식각 실험을 실시하였다. 마지막으로 47 mTorr와 100 mTorr 의 각각의 공정압력에서 RF 척 파워를 변화시켜 (50~200 W) 실험하였다. GaAs 플라즈마 식각이 끝난 후 표면단차 측정기 (Surface profiler)를 사용하여 표면의 단차와 거칠기를 분석하였다. 그 후 그 결과를 이용하여 식각율 (Etch rate), 식각 표면 거칠기 (RMS roughness), 식각 선택비 (Selectivity) 등의 식각 특성평가를 하였다. 또한 식각 공정 중에 샘플 척에 발생하는 자기 바이어스와 $BCl_3$ 플라즈마 가스를 광학 발광 분석기 (Optical Emission Spectroscopy)를 이용하여 플라즈마의 상태를 실시간으로 분석하였다. 이 실험 결과에 따르면 공정 압력의 증가는 샘플 척의 자기 바이어스의 값을 감소시켰다. $BCl_3$ 압력 변화에 의한 GaAs의 식각 결과를 정리하면 5 sccm의 $BCl_3$ 가스유량과 RF 척 파워를 100 W로 고정시켰을 때 식각율은 47 mTorr에서 가장 높았으며, 그 값은 $0.42{\mu}m/min$ 이었다. GaAs의 식각 속도는 공정압력이 증가할수록 감소하였으며 180 mTorr에서는 식각율이 $0.03{\mu}m/min$로 거의 식각되지 않았다. 또한 공정압력을 75 mTorr, RF 척 파워를 100 W로 고정시키고, $BCl_3$ 가스유량을 2.5 sccm에서 10 sccm까지 변화시켰을 때, 10 sccm 의 $BCl_3$ 가스유량에서 가장 높은 식각율인 $0.87{\mu}m/min$이 측정되었다. 압력에 따른 GaAs의 식각 후 표면 거칠기는 최대 2 nm 정도로 비교적 매끈하였으며, 거의 식각되지 않은 180mTorr의 조건에서는 약 1 nm로 낮아졌다. 본 실험 조건에서 GaAs의 감광제에 대한 식각 선택비는 최대 약 3:1 이내였다.

• Molecules and Cells
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• 제38권6호
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• pp.535-539
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• 2015

Olfactory stimulation activates multiple signaling cascades in order to mediate activity-driven changes in gene expression that promote neuronal survival. To date, the mechanisms involved in activity-dependent olfactory neuronal survival have yet to be fully elucidated. In the current study, we observed that olfactory sensory stimulation, which caused neuronal activation, promoted activation of the phosphatidylinositol 3'-kinase (PI3K)/Akt pathway and the expression of Bcl-2, which were responsible for olfactory receptor neuron (ORN) survival. We demonstrated that Bcl-2 expression increased after odorant stimulation both in vivo and in vitro. We also showed that odorant stimulation activated Akt, and that Akt activation was completely blocked by incubation with both a PI3K inhibitor (LY294002) and Akt1 small interfering RNA. Moreover, blocking the PI3K/Akt pathway diminished the odorantinduced Bcl-2 expression, as well as the effects on odorant-induced ORN survival. A temporal difference was noted between the activation of Akt1 and the expression of Bcl-2 following odorant stimulation. Blocking the PI3K/Akt pathway did not affect ORN survival in the time range prior to the increase in Bcl-2 expression, implying that these two events, activation of the PI3K pathway and Bcl-2 induction, were tightly connected to promote post-translational ORN survival. Collectively, our results indicated that olfactory activity activated PI3K/Akt, induced Bcl-2, and promoted long term ORN survival as a result.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.88-88
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• 2003

Optical Emission Spectroscopy(OES) is a very important technology for real-time monitoring of plasma in a reactor during dry etching process. OES technology is non-invasive to the plasma process. It can be used to collect information on excitation and recombination between electrons and ions in the plasma. It also helps easily diagnose plasma intensity and monitor end-point during plasma etch processing. We studied high density planar inductively coupled BCl$_3$ and BCl$_3$/Ar plasma with an OES as a function of processing pressure, RIE chuck power, ICP source power and gas composition. The scan range of wavelength used was from 400 nm to 1000 nm. It was found that OES peak Intensity was a strong function of ICP source power and processing pressure, while it was almost independent on RIE chuck power in BCl$_3$-based planar ICP processes. It was also worthwhile to note that increase of processing pressure reduced negatively self-induced dc bias. The case was reverse for RIE chuck power. ICP power and gas composition hardly had influence on do bias. We will report OES results of high density planar inductively coupled BCl$_3$ and BCl$_3$/Ar Plasma in detail in this presentation.

• BMB Reports
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• 제51권2호
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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.

• Journal of Chest Surgery
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• 제31권10호
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• pp.924-927
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• 1998

연구배경 : 심근의 허혈 또는 재관류에 의한 세포사에는 괴사 이외에 세포고사가 존재함이 알려져 있다. Bcl-2 단백은 세포질에 존재하는 단백으로 세포고사를 억제하는 기능을 하며 정상심근에서는 발현되지 않으나 심근경색의 급성기에서 발현됨이 보고되어 있다. 본 연구는 가토 허혈-재관류 심근에서 Bcl-2 단백의 발현 여부와 재관류의 시간에 따른 발현의 변화를 알아보고자 하였다. 방법: 평균 무게가 2.9Kg(1.5-4.8Kg)인 가토 39마리를 이용하였다. 허혈-재관류 모델의 각 실험동물에서 좌전하행지를 30분간 결찰한 다음 1, 4, 8, 12, 24시간, 3, 7일 동안 재관류시켰다. 이후 즉시 실험동물을 희생시킨 다음 심장을 적출하여 심근조직을 얻고 10% buffered formalin에 고정하였다. Bcl-2 단백의 발현은 파라핀에 포매된 조직에서 단일클론항체를 이용한 면역조직화학적 염색으로 확인하였다. 결과: 허혈-재관류 심근 중 12, 24시간, 3일 재관류군에서 Bcl-2 단백의 발현을 관찰할 수 있었으며, 특히 24시간 재관류 심근에서 잘 관찰되었다. Bcl-2 양성염색의 심근세포는 위험부위의 구제심근에서 관찰되었다. 결론: Bcl-2 단백은 심근의 허혈-재관류에서 급성기의 비교적 후기에 발현되며, 이는 재관류 초기에서 보다는 후기에서 세포고사를 억제하는데 일부 역할을 할 것으로 사료된다.

• Reproductive and Developmental Biology
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• 제36권3호
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• pp.167-172
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• 2012

The key regulators of apoptosis are the interacting protein of the Bcl-2 family. Bcl-2, an important member of this family, blocks cytochrome C release by sequestering pro-apoptotic BH3-only proteins such as Bid, Bad, Bax and Bim. The pro-survival family members (Bcl-2, Bcl-XL, Bcl-W) are critical for cell survival, since loss of any of them causes cell death in certain cell type. However, its role during early porcine embryonic development is not sufficient. In this study, we traced the effects of Bcl-2 inhibitor, ABT-737, on early porcine embryonic development. We also investigated several indicators of developmental potential, including gene expression (apoptosis-related genes) and apoptosis, which are affected by ABT-737. Porcine embryos were cultured in the PZM-3 medium with or without ABT-737 for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without ABT-737 ($14.7{\pm}3.0$ vs $30.3{\pm}4.8%$, p<0.05). TUNEL assay showed that the number of containing fragmented DNA at the blastocyst stage increased in the ABT-737 treated group compared with control (4.7 vs 3.7, p<0.05). The mRNA expression of the pro-apoptotic gene Bax increased in ABT-737 treated group (p<0.05), whereas expressions of the anti-apoptotic Bcl-2 family members (Bcl-2, Bcl-XL, Bcl-W) decreased (p<0.05). Also, expressions of the ER stress indicator genes (GRP78, XBP-1 and sXBP-1) increased in ABT-737 treated group (p<0.05). In conclusion, Bcl-2 is closely associated with of apoptosis- and ER stress-related genes expressions and developmental potential in pig embryos.

• Molecules and Cells
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• 제41권7호
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• pp.684-694
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• 2018

Upregulation of human telomerase reverse transcriptase (hTERT) expression is an important factor in the cellular survival and cancer. Although growing evidence suggests that hTERT inhibits cellular apoptosis by telomere-independent functions, the mechanisms involved are not fully understood. Here, we show that hTERT contains a BH3-like motif, a short peptide sequence found in BCL-2 family proteins, and interacts with anti-apoptotic BCL-2 family proteins MCL-1 and BCL-xL, suggesting a functional link between hTERT and the mitochondrial pathway of apoptosis. Additionally, we propose that hTERT can be categorized into the atypical BH3-only proteins that promote cellular survival, possibly due to the non-canonical interaction between hTERT and antiapoptotic proteins. Although the detailed mechanisms underlying the hTERT BH3-like motif functions and interactions between hTERT and BCL-2 family proteins have not been elucidated, this work proposes a possible connection between hTERT and BCL-2 family members and reconsiders the role of the BH3-like motif as an interaction motif.

• Molecules and Cells
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• 제24권3호
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• pp.378-387
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• 2007

The Bcl-2 family of proteins interacts at the mitochondria to regulate apoptosis. However, the anti-apoptotic Bcl-2 and $Bcl-X_L$ are not completely localized to the mitochondria. In an attempt to generate Bcl-2 and $Bcl-X_L$ chimeras that are constitutively localized to the mitochondria, we substituted their C-terminal transmembrane tail or both the C-terminal transmembrane tail and the adjacent loop with the equivalent regions from Bak or Bax mutant (BaxS184V) as these regions determine the mitochondrial localization of Bak and Bax. The effects of these substitutions on subcellular localization and their activities were assessed following expression in HeLa and CHO K1 cells. The substitution of the C-terminal tail or the C-terminal tail and the adjacent loop of Bcl-2 with the equivalent regions from Bak or the Bax mutant resulted in its association with the mitochondria. This change in subcellular localization of Bcl-2 chimeras triggered cells to undergo apoptotic-like cell death. The localization of this Bcl-2 chimera to the mitochondria may be associated with the disruption of mitochondrial membrane potential. Unlike Bcl-2, the loop structure adjacent to the C-terminal tail in $Bcl-X_L$ is crucial for its localization. To localize the $Bcl-X_L$ chimeras to the mitochondria, the loop structure next to the C-terminal tail in $Bcl-X_L$ protein must remain intact and cannot be substituted by the loop from Bax or Bak. The chimeric $Bcl-X_L$ with both its C-terminal tail and the loop structure replaced by the equivalent regions of Bak or Bax mutant localized throughout the entire cytosol. The $Bcl-X_L$ chimeras that are targeted to the mitochondria and the wild type $Bcl-X_L$ provided same protection against cell death under several death inducing conditions.

• Journal of Chest Surgery
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• 제32권8호
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• pp.726-731
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• 1999

목적 및 배경: 세포사를 조절하는 암유전자 산물인 bcl-2 단백과 암억제유전자 산물인 p53 단백은 암의 발생 에 관여하는 것으로 알려져 있다. 최근 종양 조직내에서 bcl-2 단백 및 p53 단백의 발현과 종양의 악성도 및 예후와의 관련성에 대한 연구가 활발하게 진행되고 있으나 흉선종에서의 연구는 미흡한 실정이다. 대상 및 방법: 1984년부터 1997년까지 고신대학교 복음병원 흉부외과에서 수술 치험한 흉선상피종 중 병리 조직의 보관이 비교적 양호하고 병록 기록지가 충실한 30례를 대상으로 Rosai씨 분류법 및 Masaoka 병기와 중증근 무력증의 동반 여부에 따라 분류하고 종양조직을 이용하여 면역조직화학 검사를 시행하여 각 분류에 따른 bcl-2 단백과 p53 단백의 발현율, 그리고 bcl-2 단백과 p53 단백의 발현간에 상관관계를 조사하였다. 결과: bcl-2 단백은 비침습성 흉선종에는 발현된 경우가 없었고 침습성 흉선종 10례 중 3례(30%), 흉선암 11례 중 8 례(61.5%)에서 발현되어 악성도가 높을수록 발현율이 높게 나타났다(p=0.021). p53 단백은 비침습성 흉선종에 서 1례(14.3%), 침습성 흉선종 5례(50%), 흉선암 8례(61.5%)에서 발현되어 악성도가 높을수록 발현율이 높아 지는 경향을 보였으나 통계학적 유의성은 없었다(p=0.126). 17례의 흉선종의 Masaoka 병기(1기 5례, 2기 7례, 3기 2례, 4a기 3례)에 따른 bcl-2 단백은 1기와 4a기에서는 발현 예가 없었고, 2기 1례(14.3%), 3기 2례(100%) 에서 발현되어 병기가 진행할 수록 높은 발현율을 보였고(p=0.011), p53 단백은 1기 1례(20%), 2기 2례 (28.6%), 3기 2례(100%), 4a기 1례(33.3%) 발현되어 p53 단백 역시 병기가 진행할 수록 발현율이 높아지는 경 향을 보였으나 통계학적 유의성은 없었다(p=0.229). 중증근무력증의 동반 여부와 bcl-2단백, p53 단백의 발현 과는 무관하였다. bcl-2 단백과 p53 단백의 발현간의 상관관계는 bcl-2 단백과 p53 단백의 발현이 일치하는 경우가 23례(76.7%), 불일치하는 경우가 7례(23.3%)로 상관관계가 있는 것으로 나타났다(kappa치=0.525). 결 론: 흉선상피종 조직내 bcl-2 단백의 발현은 종양의 악성도를 반영하는 것으로 나타났고 p53 단백은 종양의 악성도와 관련이 없는 것으로 나타났다. 그럼에도 두 단백의 발현간에 상관관계가 있는 것으로 나타나 이의 규명을 위해서는 향후 p53 단백의 유전자 변이와 두 단백의 발현과 환자의 생존율과의 상관관계에 대한 연 구가 요할 것으로 사료된다.