• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.114-114
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• 1999

Boron nitride (BN)는 매우 뛰어난 물리적, 화학적 성질을 가지고 있는 재료로 많은 연구가 진행되고 있다. hexagonal 형태의 hBN의 경우 큰 전기 저항과 열 전도도를 가지고 있고 열적 안정성을 가지고 있어 반도체 소자에서 절연층으로 쓰일 수 있다. 또한 X-ray와 가시광선을 투과시키기 때문에 X-ray와 가시광선을 투과시키기 때문에 X-ray lithography이 mask 기판으로 사용될 수 있다. Boron-carbon-nitrogen (BCN) 역시 뛰어난 기계적 성질과 투명성을 가지고 있어 보호 코팅이나 X-ray lithography에 이용될 수 있다. 또한 원자 조성이나 구성을 변화시켜 band gap을 조절할 수 있는 가능성을 가지고 있기 때문에 전기, 광소자의 재료로 이용될 수 있다. 본 연구에서는 여러 합성 조건 변화에 따른 hBN 막의 합성 거동을 관찰하고, 카본 농도변화에 따른 BCN 막의 기계적 성질과 구조의 변화, 그리고 실리콘 첨가에 의한 물성 변화를 관찰하였다. BN박막은 실리콘 (100) 기판 위에 r.f. plasma assisted CVD를 이용하여 합성하였다. 합성 압력 0.015 torr, 원료 가스로 BCl3 1.5 sccm, NH3 6sccm을 Ar 15 sccm을 사용하여 기판 bias (-300~-700V)와 합성온도 (상온~50$0^{\circ}C$)를 변화시켜 BN막을 합성하였다. BCN 박막은 상온에서 기판 bias를 -700V로 고정시킨 후 CH4 공급량과 Ar 가스의 첨가 유무를 변화시켜 합성하였다. 또한 SiH4 가스를 이용하여 실리콘을 함유하는 Si-BCN 막을 합성하였다. 합성된 BN 막의 경우, 기판 bias와 합성 온도가 증가할수록 증착속도는 감소하는 경향을 보여 주었다. 기판 bias와 합성온도에 따른 구조 변화를 SEM과 Xray로 분석하였다. 상온에서 합성한 경우는 표면형상이 비정질 형태를 나타내었고, X-ray peak이 거의 관찰되지 않았다. 합성온도가 증가하게 되면 hBN (100) peak이 나타나게 되고 이것은 합성된 막이 turbostratic BN (tBN) 형태를 가지고 있다는 것을 나타낸다. 50$0^{\circ}C$의 합성 온도에서 기판 bias가 -300V에서 hBN (002) peak이 관찰되었고, -500, -700 V에서는 hBN (100) peak만이 관찰되었다. 따라서 고온에서의 큰 ion bombardment는 합성되는 막의 결정성을 저해하는 요소로 작용한다는 것을 확인 할 수 있었다. 합성된 BN 막은 ball on disk type의 tribometer를 이용하여 마모 거동을 관찰한 결과 대부분 1이상의 매우 큰 friction coefficient를 나타내었고, nano-indenter로 측정한 BN막의 hardness는 매우 soft한 막에서부터 10 GPa 정도 까지의 값을 나타내었고, nano-indenter로 측정한 BN 막의 hardness는 매우 soft한 막에서부터 10GPa 정도 까지의 값을 가지며 변하였다. 합성된 BCN, Si-BCN 막은 FT-IR, Raman, S-ray, TEM 분석을 통하여 그 구조와 합성된 상에 관하여 분석하였다. FT-IR 분석을 통해 B-N 결합과 C-N 결합을 확인할 수 있었고, Raman 분석을 통하여 DLC의 특성을 분석하였다. 마모 거동에서는 BCN 막의 경우 0.6~0.8 정도의 friction coefficient를 나타내었고 Si-BCN 막은 0.3이하의 낮은 friction coefficient를 나타내었다. Hardness는 carbon의 함유량과 Ar 가스의 첨가 유무에 따라 각각을 측정하였고 이것은 BN 막 보다 향상된 값을 나타내었다.

• Nutrition Research and Practice
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• 제11권6호
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• pp.445-451
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• 2017

BACKGROUND/OBJECTIVES: Endoplasmic reticulum (ER) stress is positively associated with atherosclerosis via elevating macrophage cell death and plaque formation, in which oxidative stress plays a pivotal role. Antioxidative, lipid-lowering, and anti-atherogenic effects of kimchi, a Korean fermented vegetable, have been established, wherein capsaicin, ascorbic acid, quercetin, 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid, and lactic acids were identified. In this study, mechanisms of action of kimchi methanol extracts (KME) on fatty streak formation via suppression of ER stress and apoptosis in aorta were examined in low-density lipoprotein receptor knockout mice. MATERIALS AND METHODS: Mice fed a high cholesterol diet with an oral administration of KME (KME group, $200 mg{\cdot}kg-bw^{-1}{\cdot}day^{-1}$) or distilled water (control group) for 8 weeks (n = 20 for group). Plasma lipid and oxidative stress levels were evaluated. Protein expression was measured by western blot assay. Fatty streak lesion size and the degree of apoptosis were examined in the aorta. RESULTS: Compared to the control group, in the KME group, plasma lipids levels were decreased and oxidative stress was alleviated (P < 0.05). Protein expression levels of nuclear factor (erythroid-derived 2)-like 2-mediated antioxidants in aorta were increased whereas those for ER stress markers, glucose regulated protein 78, phospho-protein kinase RNA-like ER kinase, phospho-eukaryotic initiation factor 2 subunit ${\alpha}$, X-box binding protein 1, and C/EBP homologous protein were decreased in the KME group (P < 0.05). Moreover, apoptosis was suppressed via downregulation of phospho-c-Jun N-terminal kinase, bcl-2-associated X protein, caspases-9, and -3 with a concomitant upregulation of anti-apoptotic protein, B-cell lymphoma 2 (P < 0.05). Fatty streak lesion size was reduced and the degree of apoptosis was less severe in the KME group (P < 0.05). CONCLUSIONS: In conclusion, antioxidant activity of KME might prevent fatty streak formation through, in part, inhibition of ER stress and apoptosis in aortic sinus where macrophages are harbored.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권3호
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• pp.143-154
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• 2013

Purpose: This study was to find efficacy of integrin alpha2 (${\alpha}_2$) and epidermal growth factor receptor (EGFR) as tumor marker of oral squamous cell carcinoma (SCC) and clarify the selective cell death effect of anti-integrin ${\alpha}_2$ and anti-EGFR on SCC cells, additionally testify conjugated gold nanoparticles (GNP) with air plasma for selective cell death of oral SCC. Methods: Expression of integrin ${\alpha}_2$, EGFR on human SCC cells (SCC25) were examined by western blot. SCC25 cells were treated with anti-integrin ${\alpha}_2$, anti-EGFR and analysed by Hemacolor staining, immunoflorescence staining, FACS flow cytometry. Conjugated GNP with integrin ${\alpha}_2$, EGFR antibody were treated by air plasma on SCC cells. Results: Integrin ${\alpha}_2$ and EGFR were over-expressed on SCC25 cells than normal lung WI-38 cells. The cell viability rate of SCC25 cells treated with anti-integrin ${\alpha}_2$, anti-EGFR was lower than WI-38 cells. The concentration changes of nucleus, releasing cytochrome c and apoptosis inducing factor (AIF) from mitochondria to cytosol were observed. The changes of proteins related with apoptosis were observed. Increase of bax, bcl-xL, activation of caspase-3, -7, -9, and fragmentation of PARP, DFF45 and decrease of lamin A/C in SCC25 cells were observed. In FACS, increase of sub-$G_1$ and S phase was observed. Cell cycle related proteins, Such as cyclin D1, cyclin dependent kinase (CDK) 4, cyclin A, cyclin E, CDK 2, p27 were decreased. After SCC25 cells treated with conjugatged GNP-Integrin ${\alpha}_2$, GNP-EGFR, additionally air plasma, the cell death rate was significantly increased. Conclusion: Integrin ${\alpha}_2$, EGFR were over-expressed in oral SCC cells. Anti-integrin ${\alpha}_2$, anti-EGFR in SCC25 cells induced apoptosis selectively. When GNP-anti integrin ${\alpha}_2$, GNP-anti EGFR were treated with air plasma on SCC25 cells, cancer cells were died more selectively. GNP-anti integrin ${\alpha}_2$, GNP-anti EGFR with air plasma could be treatment choice of oral SCC.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1355-1363
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• 2009

In the present study, the neuroprotective effects of astaxanthin on $H_2O_2$-mediated apoptotic cell death, using cultured mouse neural progenitor cells (mNPCs), were investigated. To cause apoptotic cell death, mNPCs were pretreated with astaxanthin for 8 h and followed by treatment of 0.3 mM $H_2O_2$. Pretreatment of mNPCs with astaxanthin significantly inhibited $H_2O_2$-mediated apoptosis and induced cell growth in a dose-dependent manner. In Western blot analysis, astaxanthin-pretreated cells showed the activation of p-Akt, p-MEK, p-ERK, and Bcl-2, and the reduction of p-P38, p-SAPK/JNK, Bax, p-GSK3b, cytochrome c, caspase-3, and PARP. Because $H_2O_2$ triggers caspases activation, this study examined whether astaxanthin can inhibit caspases activation in $H_2O_2$-treated mNPCs. After $H_2O_2$ treatment, caspases activities were prominently increased, but astaxanthin pretreatment significantly inhibited $H_2O_2$-mediated caspases activation. Astaxanthin pretreatment also significantly recovered the ATP production ability of $H_2O_2$-treated cells. These findings indicate that astaxanthin inhibits $H_2O_2$-mediated apoptotic features in mNPCs. Inhibition assays with SB203580 ($10\;{\mu}M$, a specific inhibitor of p38) and PD98059 ($10\;{\mu}M$, a specific inhibitor of MEK) clearly showed that astaxanthin can inhibit $H_2O_2$-mediated apoptotic death via modulation of p38 and MEK signaling pathways.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1325-1335
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• 2018

Objective: This study investigated whether spermine supplementation could regulate cell cycle, apoptosis, and amino acid transporter-related genes expression in the thymus and spleen of early weaned piglets. Methods: Eighty female piglets were randomly distributed to receive adequate nutrients supplemented with spermine (0.4 mmol/kg body weight/24 h) or to be provided with restricted nourishment supplemented with normal saline for 7 h or 3, 6, or 9 d in pairs. Results: Regardless of administration time, spermine supplementation significantly up-regulated cyclin A2 gene expression but down-regulated p21 and cyclin D3 mRNA levels in the thymus and spleen and reduced cyclin E2 gene expression in the thymus of piglets (p<0.05). Irrespective of the treatment period, the reduced Bax and caspase-3 gene expressions and improved Bcl-2 mRNA level were observed in the thymus and spleen of spermine-administrated piglets (p<0.05). Regardless of supplementation time, spermine intake significantly enhanced the expressions of amino acid transporter-related genes (SLC1A1, SLC1A5, SLC7A1, SLC7A7, and SLC15A1) in both thymus and spleen, as well as SLC7A9 in the spleen of piglets (p<0.05). In addition, extended spermine administration also markedly promoted cell proliferation, depressed apoptosis and modulated amino acid transport (p<0.05), and such effects were the greatest during prolonged spermine supplementation (6 d) compared to the other time periods (p<0.05). Conclusion: Spermine supplementation may regulate cell cycle during the G1/S phase, suppress apoptosis and modulate amino acid transport. A period of 6 d of spermine supplementation is required to produce the optimal effects on nutritional implications.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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• pp.283-289
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• 2015

This study surveys the improvement characteristics in old-aged muscular mitochondria by bio-active materials coated fabric (BMCF). To observe the effects, the fabric (10 and 30%) was worn to old-aged rat then the oxygen consumption efficiency and copy numbers of mitochondria, and mRNA expression of apoptosis- and mitophagy-related genes were verified. By wearing the BMCF, the oxidative respiration significantly increased when using the 30% materials coated fabric. The mitochondrial DNA copy number significantly decreased and subsequently recovered in a dose-dependent manner. The respiratory control ratio to mitochondrial DNA copy number showed a dose-dependent increment. As times passed, Bax, caspase 9, PGC-$1{\alpha}$ and ${\beta}$-actin increased, and Bcl-2 decreased in a dose-dependent manner. However, the BMCF can be seen to have had no effect on Fas receptor. PINK1 expression did not change considerably and was inclined to decrease in control group, but the expression was down-regulated then subsequently increased with the use of the BMCF in a dose-dependent manner. Caspase 3 increased and subsequently decreased in a dose-dependent manner. These results suggest that the BMCF invigorates mitophagy and improves mitochondrial oxidative respiration in skeletal muscle, and in early stage of apoptosis induced by the BMCF is not related to extrinsic death-receptor mediated but mitochondria-mediated signaling pathway.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.406-406
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• 2010

일반적으로, 나노스케일의 MOS 소자에서는 게이트 절연체 두께가 감소함에 따라 tunneling effect의 증가로 인해 PID (plasma induced damage)로 인한 소자 특성 저하 현상을 감소하는 추세로 알려져 있다. 하지만 요즘 많이 사용되고 있는 high-k 게이트 절연체의 경우에는 오히려 더 많은 charge들이 trapping 되면서 PID가 오히려 더 심각해지는 현상이 나타나고 있다. 이러한 high-k 게이트 식각 시 현재는 주로 Hf-based wet etch나 dry etch가 사용되고 있지만 gate edge 영역에서 high-k 게이트 절연체의 undercut 현상이나 PID에 의한 소자특성 저하가 보고되고 있다. 본 연구에서는 이에 차세대 MOS 소자의 gate stack 구조중 issue화 되고 있는 metal gate 층과 gate dielectric 층의 식각공정에 각각 중성빔 식각과 중성빔 원자층 식각을 적용하여 전기적 손상 없이 원자레벨의 정확한 식각 조절을 해줄 수 있는 새로운 two step 식각 공정에 대한 연구를 진행하였다. 먼저 TiN metal gate 층의 식각을 위해 HBr과 $Cl_2$ 혼합가스를 사용한 중성빔 식각기술을 적용하여 100 eV 이하의 에너지 조건에서 하부층인 $HfO_2$와 거의 무한대의 식각 선택비를 얻었다. 하지만 100 eV 조건에서는 낮은 에너지에 의한 빔 스케터링으로 실제 패턴 식각시 etch foot이 발생되는 현상이 관찰되었으며, 이를 해결하기 위하여 먼저 높은 에너지로 식각을 진행하고 $HfO_2$와의 계면 근처에서 100 eV로 식각을 해주는 two step 방법을 사용하였다. 그 결과 anistropic 하고 하부층에 etch stop된 식각 형상을 관찰할 수 있었다. 다음으로 3.5nm의 매우 얇은 $HfO_2$ gate dielectric 층의 정확한 식각 깊이 조절을 위해 $BCl_3$와 Ar 가스를 이용한 중성빔 원자층 식각기술을 적용하여 $1.2\;{\AA}$/cycle의 단일막 식각 조건을 확립하고 약 30 cycle 공정시 3.5nm 두께의 $HfO_2$ 층이 완벽히 제거됨을 관찰할 수 있었다. 뿐만 아니라, vertical 한 식각 형상 및 향상된 표면 roughness를 transmission electron microscope(TEM)과 atomic force microscope (AFM)으로 관찰할 수 있었다. 이러한 중성빔 식각과 중성빔 원자층 식각기술이 결합된 새로운 gate recess 공정을 실제 MOSFET 소자에 적용하여 기존 식각 방법으로 제작된 소자 결과를 비교해 본 결과 gate leakage current가 약 one order 정도 개선되었음을 확인할 수 있었다.

• Nutrition Research and Practice
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• 제15권3호
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• pp.294-308
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• 2021

BACKGROUD/OBJECTIVES: Allomyrina dichotoma larva (ADL), one of the many edible insects recognized as future food resources, has a range of pharmacological activities. In a previous study, an ADL extract (ADLE) reduced the hepatic insulin resistance of high-fat diet (HFD)-induced diabetic mice. On the other hand, the associated molecular mechanisms underlying pancreatic beta-cell dysfunction remain unclear. This study examined the effects of ADLE on palmitate-induced lipotoxicity in a beta cell line of a rat origin, INS-1 cells. MATERIALS/METHODS: ADLE was administered to high-fat diet treated mice. The expression of apoptosis-related molecules was measured by Western blotting, and reactive oxidative stress generation and nitric oxide production were measured by DCH-DA fluorescence and a Griess assay, respectively. RESULTS: The administration of ADLE to HFD-induced diabetic mice reduced the hyperplasia, 4-hydroxynonenal levels, and the number of apoptotic cells while improving the insulin levels compared to the HFD group. Treatment of INS-1 cells with palmitate reduced insulin secretion, which was attenuated by the ADLE treatment. Furthermore, the ADLE treatment prevented palmitate-induced cell death in INS-1 cells and isolated islets by reducing the apoptotic signaling molecules, including cleaved caspase-3 and PARP, and the Bax/Bcl2 ratio. ADLE also reduced the levels of reactive oxygen species generation, lipid accumulation, and nitrite production in palmitate-treated INS-1 cells while increasing the ATP levels. This effect corresponded to the decreased expression of inducible nitric oxide synthase (iNOS) mRNA and protein. CONCLUSIONS: ADLE helps prevent lipotoxic beta-cell death in INS-1 cells and HFD-diabetic mice, suggesting that ADLE can be used to prevent or treat beta-cell damage in glucose intolerance during the development of diabetes.

• 농업과학연구
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• 제49권2호
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• pp.175-184
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• 2022

The present study investigated the neuroprotective effects of Coreopsis lanceolate extract against hydrogen-peroxide (H₂O₂)-induced oxidative damage and cell death in pheochromocytoma 12 (PC12) cells. Reactive oxygen species (ROS), 2,2'-azinobis (3-ethylbebzothiazoloine-6-sulfonic acid) diammonium salt, and 1,1-diphenyl-2-picrrylhydrazyl radical scavenging activities, as well as the expression levels of proteins associated with oxidative damage and cell death were investigated. According to the results, C. lanceolate extract exhibited inhibitory activity against intracellular ROS generation and cell-damaging effects induced by hydroxyl radicals in a dose-dependent manner. Total phenolic and flavonoid contents were 22.3 mg·g^-1 gallic acid equivalent and 16.2 mg·g^-1 catechin equivalent, respectively. Additionally, a high-performance liquid chromatography (HPLC) assay based on the internal standard method used to detect phenolic compounds. The phenolic compounds identified in C. lanceolata extract contained (+)-catechin hydrate (5.0 ± 0.0 mg·g^-1), ferulic acid (1.6 ± 0.0 mg·g^-1), chlorogenic acid (1.5 ± 0.0 mg·g^-1), caffeic acid (1.2 ± 0.0 mg·g-1), naringin (0.9 ± 0.0 mg·g^-1), and p-coumaric acid (0.5 ± 0.0 mg·g^-1). C. lanceolata extract attenuated pro-apoptotic Bax expression levels and enhanced the expression levels of anti-apoptotic Bcl-2, caspase-3, and caspase-9 proteins. Therefore, C. lanceolata is a potential source of materials with neuroprotective properties against neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases.

• 한국수정란이식학회지
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• 제29권1호
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• pp.73-81
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• 2014

돼지 수정란의 체외 생산 효율성 향상을 위해서는 배발생율과 더불어 고품질의 배를 조기에 선별해야 한다. 체외 배 발생율에 대한 보고는 많지만, 고품질의 배를 선별할 수 있는 기술에 대한 연구는 거의 없었다. 본 연구에서는 돼지 난포란 유래 수정란의 체외배양에 있어서 배반포로의 배 발달과 생존에 미치는 Vitamin $K_1$(vit $K_1$) 첨가 농도, 시기 및 시간의 효과를 검토하였다. $1.0{\mu}M$, $3.0{\mu}M$ 및 $6.0{\mu}M$ vit $K_1$을 배양 1일째 24시간 첨가한 결과, 배반포 발달율이 시험군이 $14.5{\pm}4.3$, 0.0 및 0.0%로써 대조군의 $35.5{\pm}3.2%$에 비하여 유의하게 낮았고(p<0.05), 배반포의 생존율도 대조군이 $31.8{\pm}2.6%$로써 시험군의 $22.2{\pm}2.9$, 0.0 및 0.0%에 비하여 유의하게 높았다(p<0.05). 상기 첨가 농도에서 첨가 시간을 달리한 결과, $1.0{\mu}M$ 농도에서 6시간 처리군의 배반포 발달율과 생존율이 각각 $26.5{\pm}2.9%$ 및 $47.2{\pm}2.8%$로써 가장 높았고 특히, 12시간 처리군보다 유의하게 높았다(p<0.05). $3.0{\mu}M$ 농도에서는 대조군의 배발달율이 $36.4{\pm}3.1%$로 가장 높았으나, 생존율은 3.0시간 첨가군이 $41.7{\pm}3.2%$로 대조군에 비하여 유의하게 높았다(p<0.05). $6.0{\mu}M$ 농도에서도 배발달율은 대조군($32.0{\pm}2.8%$), 생존율은 0.5시간 첨가군($42.9{\pm}1.8%$)이 가장 높았다. 각각의 vit $K_1$ 첨가 농도와 시간을 기준으로 서로 다른 배양 시기에 첨가한 결과, $1.0{\mu}M$ 6시간 첨가군에서는 배반포 발달율은 배양 4일째 첨가군, 생존율은 배양 2일째 첨가군이 가장 높았다. 한편, $3.0{\mu}M$ 3.0시간 및 $6.0{\mu}M$ 0.5시간 첨가군에서는 배양 4일째 첨가군의 배반포 발달율($59.5{\pm}4.1%$ 및 $50.0{\pm}3.6%$)과 생존율($72.7{\pm}5.4%$ 및 $79.2{\pm}4.0%$)이 대조군과 다른 시험군에 비하여 유의하게 높았다(p<0.05). 한편, vit $K_1$ 첨가에 따른 배반포의 세포 수를 조사한 결과, 첨가군($1.0{\mu}M$ 6시간 배양 2일째, $3.0{\mu}M$ 3.0시간 배양 4일째 및 $6.0{\mu}M$ 0.5시간 배양 6일째)이 $53.4{\pm}5.8$, $49.4{\pm}3.8$ 및 $51.5{\pm}4.5$개로써 대조군의 $40.2{\pm}2.3$개에 비하여 유의하게 많았다(p<0.05). 그러나 사멸세포 수는 시험군이 $3.2{\pm}0.9{\sim}3.7{\pm}2.1$개로써 대조군의 $4.2{\pm}1.2$개보다 적었으나, 유의차는 없었다. 세포 사멸 유도 유전자인 Bax mRNA 발현은 처리군과 대조군은 비슷하였으나, 세포 사멸 억제 유전자인 Bcl-xL mRNA 발현은 처리군이 대조군보다 높았고 특히, $6.0{\mu}M$ 0.5시간 배양 4일째 첨가군이 가장 높았다. 이상의 결과로부터 돼지 미성숙 난포란 유래 수정란의 체외 배양에 vit $K_1$의 첨가는 배반포의 생존율과 세포수 증가에 효과적이었다. 그 이유에 대해서는 아직 많은 부분이 밝혀져야 되겠지만, 고품질의 배반포 조기 선발에는 활용이 가능할 것으로 생각된다.