• 한국재료학회지
• /
• 제23권8호
• /
• pp.405-422
• /
• 2013

Atomic layer deposition(ALD) is a promising deposition method and has been studied and used in many different areas, such as displays, semiconductors, batteries, and solar cells. This method, which is based on a self-limiting growth mechanism, facilitates precise control of film thickness at an atomic level and enables deposition on large and three dimensionally complex surfaces. For instance, ALD technology is very useful for 3D and high aspect ratio structures such as dynamic random access memory(DRAM) and other non-volatile memories(NVMs). In addition, a variety of materials can be deposited using ALD, oxides, nitrides, sulfides, metals, and so on. In conventional ALD, the source and reactant are pulsed into the reaction chamber alternately, one at a time, separated by purging or evacuation periods. Thermal ALD and metal organic ALD are also used, but these have their own advantages and disadvantages. Furthermore, plasma-enhanced ALD has come into the spotlight because it has more freedom in processing conditions; it uses highly reactive radicals and ions and for a wider range of material properties than the conventional thermal ALD, which uses $H_2O$ and $O_3$ as an oxygen reactant. However, the throughput is still a challenge for a current time divided ALD system. Therefore, a new concept of ALD, fast ALD or spatial ALD, which separate half-reactions spatially, has been extensively under development. In this paper, we reviewed these various kinds of ALD equipment, possible materials using ALD, and recent ALD research applications mainly focused on materials required in microelectronics.

• 대한본초학회지
• /
• 제31권5호
• /
• pp.47-53
• /
• 2016

Objectives : Mori Follium (Morus alba L. leaf) has been cultivated in many Asian countries. Especially, mulberry leaf has been used as an anti-diabetic remedy in oriental medicine. However, anti-obesity effect of mulberry has not been unknown. In this study, our objectives of study is to investigate the anti-adipogenic effect of mulberry water extract (MLE) and to reveal potential molecular anti-obesity mechanism in 3T3-L1 adipocytes differentiation model.Methods : The cytotoxicity of MLE in 3T3-L1 was examined by MTT assay. Anti-adipogenic effect of MLE was evaluated by Oil Red O (ORO) staining. To elucidate the molecular mechanism, inhibitor assay was employed. The mRNA expression levels of adipogenic transcriptional factors such as PPARγ and fatty acid synthase (FAS) were analyzed by reverse transcription-polymer chain reaction (RT-PCR) analysis.Results : The MLE treatment for 24 h did not affect to the 3T3-L1 cells at concentrations of 1, 10, 100, 200, 400, 800 and 1,000 ㎍/㎖. Thus, non-toxic concentration rages of MLE were used during adipogenesis period (day -2 to 7). Intracellular lipid accumulation in MLE-treated 3T3-L1 adipocytes (day 6) were quantitatively evaluated by ORO staining. The MLE treatment significantly and dose-dependently suppressed 3T3-L1 adipogenesis by 60.42%, 38.24%, and 5.97% at 10, 100, and 200 ㎍/㎖, respectively. In addition, our inhibitor assay and RT-PCR analysis revealed that the MLE-inhibited 3T3-L1 adipogenesis through inhibition of PPARγ mediated by Wnt/β-catenin signaling pathway.Conclusions : In conclusion, these findings indicate that the MLE could be used in prevent and/or treatment of obesity-related diseases.

• Journal of Yeungnam Medical Science
• /
• 제34권1호
• /
• pp.43-54
• /
• 2017

Background: Extracellular sulfatases (Sulfs), sulfatase 1 (Sulf1) and sulfatase 2 (Sulf2), play a pivotal role in cell signaling by remodeling the 6-O-sulfation of heparan sulfate proteoglycans on the cell surface. The present study examined the effects of Sulfs on angiotensin II (Ang II)-induced hypertensive mediator expression and vascular smooth muscle cells (VSMCs) proliferation in spontaneously hypertensive rats (SHR). Methods: Ang II receptors, 12-lipoxygenase (12-LO), and endothelin-1 (ET-1) messenger RNA (mRNA) expressions in SHR VSMCs were analyzed by real-time polymerase chain reaction and Western blotting. VSMCs proliferation was determined by [$^3H$]-thymidine incorporation. Results: Basal Sulfs mRNAs expression and enzyme activity were elevated in SHR VSMCs. However, Sulfs had no effect on the basal or Ang II-induced 12-LO and ET-1 mRNA expression in SHR VSMCs. The inhibition of Ang II-induced 12-LO and ET-1 expression by blockade of the Ang II type 2 receptor ($AT_2\;R$) pathway was not observed in Sulf1 siRNA-transfected SHR VSMCs. However, Sulf2 did not affect the action of $AT_2\;R$ inhibitor on Ang II-induced 12-LO and ET-1 expression in SHR VSMCs. The down-regulation of Sulf1 induced a reduction of $AT_2\;R$ mRNA expression in SHR VSMCs. In addition, the inhibition of Ang II-induced VSMCs proliferation by blockade of the $AT_2\;R$ pathway was mediated by Sulf1 in SHR VSMCs. Conclusion: These findings suggest that extracellular sulfatase Sulf1 plays a modulatory role in the $AT_2\;R$ pathway that leads to an Ang II-induced hypertensive effects in SHR VSMCs.

• Archives of Pharmacal Research
• /
• 제27권9호
• /
• pp.947-953
• /
• 2004

The antioxidative and hepatoprotective potentials of two anthraquinones, alaternin (2-hydroxy-emodin) and emodin, to scavenge and/or inhibit hydroxyl radicals generated by the Fenton reaction and to protect tacrine-induced cytotoxicity in human liver derived HepG2 cells were evaluated, respectively. The inhibitory activity on hydroxyl radical generated in a cell-free chemical system (FeSO$_4$/$H_2O$$_2$) was investigated by a fluorescence spectrophotometer using a highly fluorescent probe, 2$^1$,7$^1$-dichlorofluorescein. The hydroxyl radical scavenging activity was determined by electron spin resonance spectroscopy using 5,5-dimethy-1-pyrroline-N-oxide as hydroxyl radicals trapping agents. Tacrine-induced HepG2 cell toxicity was determined by a 3-［4,5-dimethylthiazole-2yl］-2,5-diphenyltertrazolium bromide assay. Although the scavenging activity of alaternin on hydroxyl radical was similar to that of emodin in dose-dependent pat-terns, the inhibitory activity exhibited by the former on hydroxyl radical generation was stron-ger than that of the latter, with $IC_{50}$/ values of 3.05$\pm$0.26 $\mu$M and 13.29$\pm$3.20 $\mu$M, respectively. In addition, the two anthraquinones, alaternin and emodin showed their hepatoprotective activ-ities on tacrine-induced cytotoxicity, and the EC$_{50}$ values were 4.02 11M and 2.37 $\mu$M, respec-tively. Silymarin, an antihepatotoxic agent used as a positive control exhibited the EC$_{50}$ value of 2.00 $\mu$M. These results demonstrated that both alaternin and emodin had the simultaneous antioxidant and hepatoprotective activities.ies.

• Archives of Pharmacal Research
• /
• 제28권9호
• /
• pp.1073-1078
• /
• 2005

A presenilin 2 mutation is believed to be involved in the development of Alzheimer's disease. In addition, transgenic mice with a presenilin 2 mutation have been reported to have learning and memory impairments. In this study, exposing PC12 cells expressing mutant presenilin 2 to $50{\mu}M\;A{\beta}_{25-35},\;30mM$ L-glutamate and $50{\mu}M\;H_2O_2$ caused a significant increase in acetylcholine esterase activity. An in vivo study revealed high levels of this enzyme activity in the mutant presenilin 2 transgenic brains compared with the wild type presenilin 2 transgenic and non-transgenic samples. These results suggest that a mutant presenilin 2-induced neurodegeneration in Alzheimer's disease might be involved in the increase in acetylcholinesterase activity. These findings might help in the development of an appropriate therapeutic intervention targeting mutant presenilin 2-induced Alzheimer's disease.

• Bulletin of the Korean Chemical Society
• /
• 제34권10호
• /
• pp.2900-2904
• /
• 2013

We present the synthesis and characterization of DTPA-bis(histidylamide) (1a), DTPA-bis(aspartamide) (1b), and their gadolinium complexes of the type $[Gd(L)(H_2O)]$ (2a:L = 1a; 2b:L = 1b). Thermodynamic stabilities and $R_1$ relaxivities of 2a-b compare well with Omniscan$^{(R)}$, a well-known commercial, extracellular (ECF) MRI CA which adopts the DTPA-bis(amide) framework for the chelate: $R_1$ = 5.5 and 5.1 $mM^{-1}$ for 2a and 2b, respectively. Addition of the Cu(II) ion to a solution containing 2b triggers relaxivity enhancement to raise $R_1$ as high as 15.3 $mM^{-1}$, which corresponds to a 300% enhancement. Such an increase levels off at the concentration beyond two equiv. of Cu(II), suggesting the formation of a trimetallic ($Gd/Cu_2$) complex in situ. Such a relaxivity increase is almost negligible with Zn(II) and other endogenous ions such as Na(I), K(I), Mg(II), and Ca(II). In vivo MR images and the signal-to-noise ratio (SNR) obtained with an aqueous mixture of 2b and Cu(II) ion in an 1:2 ratio demonstrate the potentiality of 2 as a copper responsive MRI CA.

• 대한기계학회논문집A
• /
• 제36권8호
• /
• pp.829-833
• /
• 2012

대체천연가스(SNG)는 에너지 안보 차원에서 에너지 수급 안정화 방안의 하나로 많은 관심을 받고 있다. 또한 HCNG (또는 $H_2CNG$)는 배기가스 내의 유해 성분을 현저히 줄이고 열효율도 높일 수 있어서 내연기관이나 가정용 연료로 사용될 것으로 기대되고 있다. 그러나 SNG나 HCNG에 포함되어 있는 수소는 재료에 침투하여 그 재료의 역학적 특성을 크게 저하시키는 것으로 알려져 있다. 따라서 SNG나 HCNG를 안전하고 효율적으로 수송 공급하려면 이를 위해 운용되는 인프라의 안전성과 신뢰성 확보가 선결되어야 한다. 본 연구에서는 중공 시험편을 이용한 인장시험법을 통하여 CNG 저장용기용 저합금강이 나타내는 고압 수소 분위기에서의 인장 특성 변화에 대하여 조사하였다.

• 한국토양비료학회지
• /
• 제37권6호
• /
• pp.383-387
• /
• 2004

농가에서 관리하는 9년생 후지품종의 사과 과수원에 패화석과 석회고토의 중화량를 시용하여 작물생육과 토양 화학성 변화를 조사한 결과는 다음과 같았다. 석회를 시용하지 않은 처리구의 토양은 시험전후 pH가 5.6으로 차이가 없었으나, 패화석과 석회고토 처리구에서는 Ca, Mg 함량이 증가되고 pH가 5.6에서 6.8로 높아져 패화석은 석회고토 처리구와 동등의 산도교정 효과가 있었다. 패화석과 석회고토 시용으로 사과나무 신초의 초장과 신초수, 신초경이 증가되었으며, 석회 무시용에 비해 간경과 주지경의 직경이 연간 0.7 및 1.0 mm 증가하였고, 부주지경의 증가는 패화석과 석회고토 시용이 각각 1.7 및 1.8 mm 증가하여 사과나무의 생육에 효과가 있는 것으로 나타났다. 패화석과 석회고토 처리로 시기별 엽록소함량은 차이가 없었으나 건물중 변화는 10월 23일 조사시 무시용27.3% 대비 패화석과 석회고토 시용이 각각 33.1 및 31.0%로서 높았다. 시기별 엽중 무기성분으로 질소함량은 무시용 대비 패화석과 석회고토 시용으로 함량이 증가하였으며, CaO 함량은 큰 차이가 없었고, Mn 함량이 높았다. 사과의 당도, 경도 및 산도에 대한 패화석 시용효과는 무처리와 비교해 차이가 나타나지 않았으며, 석회고토 처리시 경도는 석회 무시용에 비해 낮았다. 패화석 시용시 색도는 황색도가 약간 높았으나 적색도에서는 낮았으며, 선명도는 처리간 차이가 나타나지 않아 패화석 시용이 사과의 품질 향상에는 영향을 미치지 못하였고 수량은 $37,000kg\;ha^{-1}$로 무시용 대비 5% 증수되었다.

• 한국식품과학회지
• /
• 제50권2호
• /
• pp.209-215
• /
• 2018

치자 추출물의 극성에 따른 분획-헥세인, 에틸아세테이트와 뷰탄올 분획의 폴리페놀 함량을 평가한 결과, 에틸아세테이트 분획이 다량의 폴리페놀을 함유함을 하였고, DPPH와 ABTS 라디칼 제거와 환원력 실험에서 강력한 라디칼 제거와 환원능력을 나타냈다. 또한 치차 에틸아세테이트 분획(GJ-EA)의 라디칼 제거 활성을 세포수준에서 평가한 결과, LPS로 활성화된 BV-2 미세아교세포에서 발생하는 과량의 산화질소 생성을 억제하였고, 과산화수소를 처리한 췌장암 세포주의 증식과 이동성에 대해 억제효과를 나타내었다. 따라서 치자 에틸아세테이트 분획(GJ-EA)이 라디칼 제거효과, 과산화수소 유도형 암세포의 증식과 이동성에 대한 억제효과를 가진다는 것을 확인하여 치자 에틸아세테이트 분획(GJ-EA)을 이용한 기능성 식품소재 개발을 위한 기초자료로 활용될 수 있음을 제시하였다.

• 미생물학회지
• /
• 제40권3호
• /
• pp.232-236
• /
• 2004

Streptomyces coelicolor A3(2)의 acetyl xylan esterase (AxeA)가 Escherichia coli의 과산화수소 저항성에 미치는 영향을 알아보고자 하였다. AxeA 발현은 isopropyl-$\beta$-thiogalactoside로 유도되었고 생산된 AxeA는 SDS-polyacrylamide gel electrophoresis방법으로 확인하였다. AxeA 발현에 따른 과산화수소 저항성의 변화를 E. coli의 생장곡선과 생존율을 통하여 조사하였다. AxeA가 발현되지 않으면 모든 처리 농도 (1 mM, 2.5mM, 5mM)에서 균의 사멸이 일어났다. AxeA가 발현되는 조건에서는 5mM을 제외한 과산화수소 1mM와 2.5mM에서 E. coli의 사멸이 저지되었다. 또한 1.5mM의 과산화수소에 대한생존율이 59%에서 74%로 높다졌다. 동시에 E. coli의 최고생장온도에서에 근접한 $45^{\circ}C$에서의 생존율도 증가되는 결과를 얻었다. 그러므로 AxeA 단백질은 산화적 스트레스와 온도스트레스에 대해 교차 저항성을 나타내는 역할을 한다고 결론지었다.