• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1199-1202
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• 2008

High mobility bottom gate thin film transistors (TFTs) with an amorphous gallium tin zinc oxide (a-GSZO) channel layer have been produced by rf magnetron cosputtering using a gallium zinc oxide (GZO) and tin (Sn) targets. The effect of the post annealing temperatures ($200^{\circ}C$, $250^{\circ}C$ and $300^{\circ}C$) was evaluated and compared with two series of TFTs produced at room temperature and $150^{\circ}C$ during the channel deposition. From the results it was observed that the effect of pos annealing is crucial for both series of TFTs either for stability as well as for improving the electrical characteristics. The a-GSZO TFTs operate in the enhancement mode (n-type), present a high saturation mobility of $24.6\;cm^2/Vs$, a subthreshold gate swing voltage of 0.38 V/decade, a turn-on voltage of -0.5 V, a threshold voltage of 4.6 V and an $I_{ON}/I_{OFF}$ ratio of $8{\times}10^7$, satisfying all the requirements to be used in active-matrix backplane.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1664-1674
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• 2016

This research analyzed the effect of ${\beta}$-glucan that is expected to alleviate the production of the inflammatory mediator in macrophagocytes, which are processed by the lipopolysaccharide (LPS) of Escherichia. The incubated layer was used for a nitric oxide (NO) analysis. The DNA-binding activation of the small unit of nuclear factor-${\kappa}B$ was measured using the enzyme-linked immunosorbent assay-based kit. In the RAW264.7 cells that were vitalized by Escherichia coli (E. coli) LPS, the ${\beta}$-glucan inhibited both the combatant and rendering phases of the inducible NO synthase (iNOS)-derived NO. ${\beta}$-Glucan increased the expression of the heme oxygenase-1 (HO-1) in the cells that were stimulated by E. coli LPS, and the HO-1 activation was inhibited by the tin protoporphyrin IX (SnPP). This shows that the NO production induced by LPS is related to the inhibition effect of ${\beta}$-glucan. The phosphorylation of c-Jun N-terminal kinases (JNK) and the p38 induced by the LPS were not influenced by the ${\beta}$-glucan, and the inhibitory ${\kappa}B-{\alpha}$ ($I{\kappa}B-{\alpha}$) decomposition was not influenced either. Instead, ${\beta}$-glucan remarkably inhibited the phosphorylation of the signal transducer and activator of transcription-1 (STAT1) that was induced by the E. coli LPS. Overall, the ${\beta}$-glucan inhibited the production of NO in macrophagocytes that was vitalized by the E. coli LPS through the HO-1 induction and the STAT1 pathways inhibition in this research. As the host immune response control by ${\beta}$-glucan weakens the progress of the inflammatory disease, ${\beta}$-glucan can be used as an effective immunomodulator.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.71-71
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• 1993

Carboxylesterase is widely distributed in the tissues of vertebrates, insects, plants and mycobacteria. Among various tissues of animals and humans, the highest esterase activity with various substrates is found in the liver. Kidney has moderate carboxylesterase activity in the proximal tubules. Considerable esterase activity is also found in the small intestine epithet elial cells and serum of mammals. Besides these tissues, carboxylesterase has been found in the lung, testis, adipose tissue, nasal mucosa and even in the central nervous system. Hepatic microsomal carboxylesterase catalyzes the hydrolysis of a wide variety of endogenous and exogenous compounds such as carboxylester, thioester and aromatic amide. Since carboxylesterases are important for metabolic activation of prodrugs and detoxification of xenobiotics, differences in substrate specificity and immunological properties of this enzyme are important in connection with choosing a suitable laboratory animal for the evaluation of biotransformation and toxicity of drugs. On the other hand, liver, kidney, intestine and serum were found to contain multiple forms of carboxylesterases in animal species and humans. In fact, we have purified more than fifteen isoforms of carboxylesterases from microsomes of liver, kidney and intestinal mucosa of nine animal species and humans. and characteristics of these isoforms were compared each other in terms of their physical and immunochemical properties. On the other hand, we have reported that hepatic microsomal carboxylesterases are induced by many exogenous compounds such as phenobarbital, polycyclic aromatic hydrocarbons, Aroclor 1254, aminopyrine and clofibrate. Later, we showed that some isoforms of hepatic carboxylesterase were induced by glucocorticoids such as dexamethasone and 16 ${\alpha}$-carbonitrile, but other isoforms were rather inhibited by these compounds. These findings indicate that involvement of carboxylesterases in the metabolism and toxicity of drugs should be explained by the isoforms involved. Since 1991, we have carried out detailed research investigating the types of carboxylesterases involved in the metabolic activation of CPT-11, a derivative of camptothecin, to the active metabolite, SN-38. The results obtained strongly suggest that some isoforms of carboxylesterase of liver microsomes and intestinal mucosal membrane are exclusively involved in CPT-11 metabolism. In this symposium, the properties of carboxylesterase isoforms purified from liver, kidney and intestine of animal species and humans are outlined. In addition, metabolism of CPT-11, a novel antitumor agent, by carboxylesterases in relation to the effectiveness will also be discussed.

• Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.241-250
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• 2012

Polycyclic aromatic hydrocarbons (PAHs), butyltins (BTs), nonylphenol (NP), and fecal sterols concentrations in sediments were investigated from Gunsan coast of Korea to evaluate organic pollution from anthropogenic activities. Sediment toxicity was also examined by bacterial bioluminescence toxicity test (Vibrio fischeri). The concentrations of 16 PAHs in sediments ranged from 67.9 to 425 ng/g dry wt; BTs ranged from 2.79 to 14.1 ng Sn/g dry wt; NP ranged from 20.7 to 2171 ng/g dry wt; and coprostanol, a fecal sterol, ranged from 7.60 to 245 ng/g dry wt. Effective concentration 50% ($EC_{50}$) of sediments ranged from 0.38 to 23.8 mg/mL. Most of the chemicals were present at levels lower than or comparable to the previously reported values from Korea. However, NP levels in the present study were in the high range of levels reported from the Korean coast, and 40% of the measured samples exceeded screening and ecotoxicological values of NP suggested by the Netherlands and Canada. This suggests that an ongoing source of NP is a serious concern in the Gunsan coast. High levels of contaminants were found in the proximity of potential sources, such as the outfall of a wastewater treatment plant for NP, an anthracite-fired power plant for PAHs, and ports for BTs, fecal sterols, and sediment toxicity. This indicates that Gunsan coast has various potential sources of marine sediment contaminants.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.77.1-77.1
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• 2013

WouldYouLike[우주:라이크]는 연세대학교 천문우주학과와 생활디자인과 학생들을 중심으로 천문우주학 대중화를 위해 활동하는 단체이다. 비영리 학생 단체인 만큼 학생들 스스로가 학습한 내용을 직접 요약하고 이를 바탕으로 일반 대중들이 쉽게 접하고 읽을 수 있는 천문우주학 콘텐츠를 제작하는 것을 목표로 하고 있다. 지난 해 봄 약 500여명의 연세대와 이화여대 학생들에게 시행한 관련 설문조사를 시작으로 6월과 12월에 약 30여 페이지 분량의 천문우주관련 소식을 담은 잡지를 발간하였다. 창간호 1300여부와 2호 550부는 연세대를 중심으로 주변 대학교에 배부되었으며 SNS를 이용한 온라인 버전도 약 1900여명의 사람들에게 공개되었다. 천문우주과학의 최신 소식을 전하고 천체사진을 찍는 방법을 소개하는 등 대중의 관심을 끌 내용부터 명왕성의 행성 직위 박탁, 천문대 탐방, IAU 탐방 등 다양한 관련 내용을 담았다. 현재는 3호를 제작중이며 4월말 발간을 목표로 하고 있다. 여기서는 지금까지의 활동 및 앞으로의 계획을 소개하고 천문우주학 전공자들의 의견을 받아 추후의 활동에 반영할 수 있도록 한다.

• Korean Journal of Agricultural Science
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• v.40 no.1
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• pp.35-45
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• 2013

The fat content, fatty acid composition, trans fatty acid content and triacylglycerol (TAG) composition of 22 chocolates (domestics 8, foreigns 14) collected from the Korea distribution markets were investigated. The crude fat was extracted by acid hydrolysis method and analyzed by gas chromatography (GC) and reversed-phase HPLC for fatty acid and TAG compositions, respectively. The crude fat content of all chocolates varied between 30.11% and 49.59%. The major fatty acids in most of the chocolates were palmitic acid (19.36~31.15 wt%), stearic acid (5.11~36.32 wt%) and oleic acid (18.77~36.68 wt%). Whereas lauric acid (approximately 35.43 wt%) was detected in chocolate fat of sample No. 18. High oleic acid content was observed for the sn-2 position fatty acid with a range from 64.91% to 86.93%. Trans fatty acid contents in domestic chocolates (sample No. 1~8) and foreign chocolates (sample No. 9~22) were 0.03~0.59 wt% (0.01~0.19 g/100g chocolate) and 0.05~6.32 wt% (0.02~1.99 g/100g chocolate), respectively. In TAG composition, TAGs such as POP/PPO(1,3(2)-palmitoyl-2(3)-oleoyl glycerol, PN=48), POS/PSO(palmitoyl-oleoyl-stearoyl glycerol or palmitoyl-stearoyl-oleoyl glycerol, PN=50), SOS/SSO(1,3(2)-stearoyl-2(3)-oleoyl glycerol, PN=50) were mainly detected in most of the chocolates. The peaks of TAG with low PN (ex, 32-34, 36-38, and 40-42) were detected in No. 18 chocolate fat because of containing short chain fatty acid such as lauric acid.

• Toxicological Research
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• v.28 no.4
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• pp.209-216
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• 2012

The biological activity of particles is largely dependent on their size in biological systems. Dispersion in the aqueous phase has been both a critical impediment to and a prerequisite for particle studies. Carbon black has been used as a surrogate to investigate the biological effects of carbonaceous particles. Here, biocompatible methods were established to disperse carbon black into ultrafine and fine particles which are generally distinguished by the small size of 100 nm. Carbon black with a distinct particle size, N330 and N990 were suspended in blood plasma, cell culture media, Krebs-Ringer's solution (KR), or physiological salt solution (PSS). Large clumps were observed in all dispersion preparations; however, sonication improved dispersion - averaged particle sizes for N330 and N990 were $85.0{\pm}42.9$ and $112.4{\pm}67.9$ nm, respectively, in plasma; the corresponding sizes in culture media were $84.8{\pm}38.4$ and $164.1{\pm}77.8$ nm. However, sonication was not enough to disperse N330 less than 100 nm in either KR or PSS. Application of Tween 80 along with sonication reduced the size of N330 to less than 100 nm, and dispersed N990 larger than 100 nm ($73.6{\pm}28.8$ and $80.1{\pm}30.0$ nm for N330 and $349.5{\pm}161.8$ and $399.8{\pm}181.1$ nm for N990 in KR and PSS, respectively). In contrast, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) exhibited little effect. Electron microscopy confirmed the typical aciniform structure of the carbon arrays; however, zeta potential measurement failed to explain the dispersibility of carbon black. The methods established in this study could disperse carbon black into ultrafine and fine particles, and may serve as a useful model for the study of particle toxicity, particularly size-related effects.

• Korean Journal of Metals and Materials
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• v.47 no.8
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• pp.482-487
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• 2009

In order to investigate the effects of intermediate heat treatment between cold rolling passes on the hardness and corrosion properties of a Zr alloy incorporating Nb (Zr-1.49Nb-0.38Sn-0.20Fe-0.11Cr) strip, three different intermediate heat treatment processes ($580^{\circ}C{\times}4hrs$, $600^{\circ}C{\times}2hrs$ and $620^{\circ}{\times}1hrs$) were designed based on a recrystallization map and an accumulated annealing parameter. Test samples from the different processes were investigated by a hardness test, corrosion test, and microstructure analysis and appropriate heat-treatment conditions were thereupon proposed. The sample subjected to an intermediate heat treatment of $580^{\circ}C{\times}4hrs$ was harder than that undergoing $600^{\circ}C{\times}2hrs$ and $620^{\circ}C{\times}1hr$ while the corrosion resistance of the sample that received an intermediate heat treatment of $580^{\circ}C{\times}4hrs$ was superior to that of the other specimens. Considering the trade-off of hardness and corrosion resistance, an intermediate heat treatment process of $600^{\circ}C{\times}2hrs$ is proposed to improve the manufacturing process of the alloy strip.

• Korean Journal of Metals and Materials
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• v.47 no.8
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• pp.474-481
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• 2009

The effects of final heat treatment on the mechanical and corrosion properties of a Zr alloy strip incorporating Nb were investigated. The chemical composition of the strip was Zr-1.49Nb-0.38Sn-0.20Fe-0.11Cr, and strip specimens were subjected to final heat treatment in a temperature range of $580{\sim}700^{\circ}C$. Tensile tests at room temperature and $316^{\circ}C$, along with corrosion tests in a simulated PWR loop and a 70 ppm LiOH solution environment at $360^{\circ}C$, were performed on the specimens. The mechanical properties of the strip were saturated when the specimens received final heat treatment at an elevated temperature of more than $640^{\circ}C$. However, the corrosion resistance of the strip in the simulated PWR loop and in the 70 ppm LiOH solution environment was improved with a decrease of the final annealing temperature. It is recommended that the alloy strip be finally heat-treated at a temperature of less than $620^{\circ}C$ for longer than 10 minutes in order to obtain fully recrystallized microstructures, and thereby attain enlarged tensile elongation, and to prevent the precipitation of ${\beta}-Zr$, which is known to deteriorate the corrosion resistance.

• Clean Technology
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• v.28 no.1
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• pp.38-45
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• 2022

CuCl₂-loaded V₂O₅-WO₃/TiO₂ catalyst showed excellent activity in the catalytic oxidation of elemental mercury to oxidized mercury even under SCR condition in the presence of NH₃, which is well known to significantly inhibit the oxidation activity of elemental mercury by HCl. Moreover, it was confirmed that, when SO₂ was present in the reaction gas together with HCl, excellent elemental mercury oxidation activity was maintained even though CuCl₂ supported on the catalyst surface was converted to CuSO₄. This is thought to be because not only HCl but also the SO₄ component generated on the catalyst surface promotes the oxidation of elemental mercury. However, in the presence of SO₂, the total mercury balance before and after the catalytic reaction was not matched, especially as the concentration of SO₂ increased. In order to understand the cause of this, further studies are needed to investigate the effect of SO₂ in the SnCl₂ aqueous solution employed for mercury species analysis and the effect of sulfate ions generated on elemental mercury oxidation. It was confirmed that SO₂ also promotes NO_x removal activity, which is thought to be because the increase in acid sites by SO₄ generated on the catalyst surface by SO₂ facilitates NH₃ adsorption. The composition change and structure of the components present on the catalyst surface under various reaction conditions were measured by XRD and XRF. These measurement results were presented as a rational explanation for the results that SO₂ enhances the oxidation activity of elemental mercury and the NO_x removal activity in this catalyst system.