• Journal of Rhinology
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• v.60 no.1
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• pp.20-28
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• 2022

Background: Whether the use of electronic cigarettes (ECs) is associated with upper airway diseases, including chronic rhinosinusitis (CRS) and allergic rhinitis (AR), remains unclear. Methods: We analyzed data from the nationwide cross-sectional surveys: the Korea National Health and Nutrition Examination Survey VI (2013-2015), VII (2016-2018), and VIII (2019). Logistic regression analysis was performed to assess the association between EC use and CRS or AR. Results: Among a total of 38,413 participants, 6.4% were former EC users and 2.5% were current EC users. Former EC users and current EC showed a significantly increased OR for CRS or AR compared with never EC users. In the subgroup analysis, the "current CC (conventional cigarette)-current EC" and the "current CC-formal EC" group had a significantly higher OR for CRS or AR than the "current CC-never EC" group. In addition, former CC smokers who currently use ECs showed a significantly higher OR for AR than former CC smokers without EC use. Conclusions: EC use is significantly associated with a high prevalence of CRS and AR in the adult population. These results indicate that the use of ECs may increase the risk of upper airway disease.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.645-654
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• 2020

We present the K-Ar age dating results of <0.1㎛ fraction of the selected fault rocks from the Yangsan fault in the Yeonghae area. Based on the mineralogical characterization, the <0.1㎛ fractions were mostly composed of 1Md illite polytype, or I-S interstratified mineral, which should be formed by fault activation. Therefore, we determined the timings of fault activation events by analyzing K-Ar age-dating for the <0.1㎛ fractions. Accordingly, the activation timings of Yangsan Fault in the Yeonghae area were determined as 45.5±1.1 Ma, 50.9±1.2 Ma, 58.2±1.3 Ma, 60.8±1.4 Ma, 65.3±1.6 Ma, 66.8±1.5 Ma, 67.1±1.5 Ma, and 75.1±1.7 Ma. These results indicate that at least 5-times of major fault events occurred in the Yangsan fault from late Mesozoic to Cenozoic Era. In the outcrop, age dating results tend to be younger age from the location of the oldest sample(75.1±1.7 Ma) toward to the both sides. From the results, it suggests that the fault activation extends from the location of oldest age saple to both sides. This geochronological research of the multiple fault activation ages for the Yangsan Fault will provide crucial information for establishing the tectonic evolution model in the southeastern part of the Korean Peninsula.

• Journal of the Korean Vacuum Society
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• v.11 no.4
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• pp.194-200
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• 2002

MOCVD(metal-organic chemical vapor deposition) copper thin film was annealed at various conditions and the eletrical properties and micro-structures were investigated to find the optimal annealing condition and its effect. Cu thin film annealed at Ar 1 torr, $400^{\circ}C$ had the most improved resistivity of 1.98 $\mu\Omega$cm, and texture; the ratio of $I_{(111)}/I_{(200)}$ was varied from 2.03 to 3.11, and Cu thin film annealed at Ar 1 torr, $450^{\circ}C$ had the largest grain size and uniformity. After the annealing, the EM(electromigration) test was followed to ensure the improved properties by annealing. Compare to other conditions, Cu patterns annealed at Ar 1 torr, $400 ^{\circ}C$ had the most improved properties when it came to the EM resistance, which was due to the low resistivity, the preferential evolution of texture to (111) plane, and the reduction of surface roughness of annealed copper film.

• Advances in materials Research
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• v.6 no.3
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• pp.303-316
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• 2017

In this article, novel olefin polymerization catalyst with lower cost and simple synthetic process were developed, $ArOTiCl_3$ complexes [$(2-OMeC_6H_4O)TiCl_3(C1)$, $(2,4-Me_2C_6H_3O)TiCl_3(C2)$, $TiCl_3(1,4-OC_6H_4O)TiCl_3(C3)$, $TiCl_3(1,4-OC_6H_2O-Me_2-2,5)$ $TiCl_3(C4)$] and corresponding $(ArO)_2TiCl_2$ complexes [$TiCl_2(OC_6H_4-OMe-2)_2(C5)$ and $TiCl_2(OC_6H_3-Me_2-2,6)_2(C6)$] have been synthesized by the reaction of $TiCl_4$ with phenol, all these complexes were well characterized with $^1H$ NMR, $^{13}C$ NMR, MASS and EA. When combined with methylaluminoxane (MAO), the $ArOTiCl_3/MAO$ system shows high activity for ethylene copolymerization with 1-octene and copolymer was obtained with broaden molecular weight distribution (MWD). The $^{13}C$ NMR result of polymer indicates that the 1-octene incorporation in polymer reached up to 8.29 mol%. The effects of polymerization temperature, concentration of polymerization monomer and polymerization time on the catalytic activity have been investigated.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.11
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• pp.18-24
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• 2000

(Ba,Sr)$TiO_3$ thin films have attracted great interest as new dielectric materials of capacitors for ultra-large-scale integrated dynamic random access memories (ULSI-DRAMs) such as 1 Gbit or 4 Gbit. In this study, inductively coupled $BCl_3/Cl_2/Ar$ plasmas was used to etch (Ba,Sr)$TiO_3$ thin films. RF power/dc bias voltage=600 W/-250 V and chamber pressure was 10 mTorr. The $Cl_2/(Cl_2+Ar)$ was fixed at 0.2 the (Ba,Sr)$TiO_3$ thin films were etched adding $BCl_3$. The highest (Ba,Sr)$TiO_3$ etch rate is $480{\AA}/min$ at 10 % $BCl_3$ to $Cl_2/Ar$. The change of Cl, B radical density measured by optical emission spectroscopy(OES) as a function of $BCl_3$ percentage in $Cl_2/Ar$. The highest Cl radical density was shown at the addition of 10% $BCl_3$ to $Cl_2/Ar$. To study on the surface reaction of (Ba, Sr)$TiO_3$ thin films was investigated by XPS analysis. Ion bombardment etching is necessary to break Ba-O bond and to remove $BaCl_2$. There is a little chemical reaction between Sr and Cl, but Sr is removed by physical sputtering. There is a chemical reaction between Ti and Cl, and $TiCl_4$ is removed with ease. The cross-sectional of (Ba,Sr)$TiO_3$ thin film was investigated by scanning electron microscopy (SEM), the etch slope is about 65~70$^{\circ}$.

• The Korean Journal of Financial Studies
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• v.8 no.1
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• pp.1-20
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• 2002

이 논문에서는 1991년 1월부터 2000년 12월까지의 납세 후 CD수익률 자료와 소비자물가지수 자료를 사용하여 우리 나라 금융시장에서 단기적 피셔효과가 존재하는지를 검증하고자 시도하였다. Fama(1975)의 방법에 따라 3개월 물가상승률을 CD수익률에 관해 회귀분석한 결과, CD수익률이 미래 물가상승률의 예측치로서 충분한 역할을 하지 못한다는 결과를 얻었다. 단기적 피셔효과를 검증하기 위하여 CD수익률을 기대물가상승률에 관하여 회귀분석하였다. 기대물가상승률은 상수 및 시간추세와 계절성을 반영하는 부분과 확률적 부분으로 구분하고, 확률적 부분이 랜돔워크 모형에 따르는 경우와 AR(1) 모형에 따르는 경우에 대해 기대물가상승률을 구하였다. 랜돔워크모형에 의해 예측하든 AR(1)에 의해 예측하든 기대물가상승률의 회귀계수는 유의한 양(+)의 값이긴 1보다는 훨씬 작은 값으로 추정되었다. 이것은 우리나라의 CD수익률에 단기 피셔효과가 부분적으로만 존재하고 있다는 것을 의미한다. 그리고 AR(1)을 사용하여 예측한 기대물가상승률이 랜돔워크모형을 사용한 경우보다 나은 추정결과를 보여주고 있다.

• Journal of the Korean Statistical Society
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• v.26 no.3
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• pp.383-395
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• 1997

This paper proves that the standard bootstrap approximation for the least absolute deviation (LAD) estimate of .beta. in AR(1) processes with infinite variance error terms is asymptotically valid in probability when the bootstrap resample size is much smaller than the original sample size. The theoretical validity results are supported by simulation studies.

• Journal of the Korean Vacuum Society
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• v.19 no.2
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• pp.128-133
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• 2010

ZnO:Al films were deposited by DC-pulsed magnetron sputtering using a two-step process involving the control of the oxygen pressure. The seed layers were prepared with various Ar to oxygen flow ratios and the bulk layers were deposited under pure Ar. As the oxygen pressure during the deposition of the seed layer increased, the crystallinity and degree of (002) texturing increased. The resistivity gradually decreased with increasing crystallinity from $4.7\times10^4\Omega{\cdot}cm$ (no seed) to $3.7\times10^4\Omega{\cdot}cm$ (Ar/$O_2$ = 9/1). The etched surface showed a crater-like structure and an abrupt morphology change appeared as the crystallinity was increased. The sample deposited at an Ar/$O_2$ flow ratio of 9/1 showed a very high haze value of 88% at 500 nm, which was explained by the large feature size of the craters, as shown in the AFM image.

• Korean Journal of Acupuncture
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• v.24 no.3
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• pp.179-204
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• 2007

Objectives & Methods : The purpose of this study is to observe the effects of Angelicae Radix Pharmacopuncture(AR-P) at Joksamni(ST36) on collagen II induced arthritis in DBA/1J mice. The authors evaluated arthritis index, arthritis incidence and joint edema, and measured body weight, spleen size and stenosis rate, serum cytokine level, serum antibody level, immune cell populations In spleen, lymph node, and knee joint, and performed histological analysis of CIA mouse joint. Results : In the AR-P group, arthritis index, arthritis incidence and joint edema were decreased, and the enlargement, malformation and stenosis of spleen and the malformation of joint appeared milder than the control group. In AR-P group, the levels of $IL-1{\beta}$, IL-6, $TNF-{\alpha}$, $IFN-{\gamma}$ in serum were significantly decreased. And the level of anti-collagen II in serum was maintained lower in AR-P group than in the control group. In AR-P group, the level of $IFN-{\gamma}$ and IL-10, and $IFN-{\gamma}/IL-4$ ratio were significantly decreased, and the ratios of $CD3e^+$ cells to $CD45^+$ cells, $CD4^+$ cells to $CD8^+$ cells in spleen were similarly maintained as those of the normal group. In the AR-P group, the populations of $CD4^+/CD25^+$ cells in spleen and lymph nodes, $CD45R^+/CD69^+$ cells in lymph nodes, $CD3^+/CD69^+$ cells and $CD11b^+/Gr-1^+$ cells in knee joint were decreased. In the histological analysis, the cartilage destruction, synovial cell proliferation and the collagen fiber destruction were decreased in the AR-P group Conclusions : The results suggest that AR-P at right ST36 has a therapeutic effect on collagen-induced arthritis in mice.

• Journal of Nutrition and Health
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• v.44 no.3
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• pp.196-202
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• 2011

Epigallocatechin gallate (EGCG), or epigallocatechin 3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin. EGCG may be therapeutic for many disorders including diabetics and some types of cancer. However it is unknown whether EGCG can induce transdifferentiation of pancreatic cells in pancreatitis. The aim of this study was to investigate the effects of EGCG on the expression of pancreatic regenerating related markers in pancreatic AR42J cells, a model of pancreatic progenitor cells. AR42J cells, differentiated with betacellulin and activin A, were cultured with/without EGCG in a time-dependent manner. Cell growth rate, levels of mRNA, and protein expression were examined with the MTT assay, quantitative PCR, and Western blots, respectively. The results showed that AR42J cell growth rates were inhibited by EGCG in a dose-dependent manner. mRNA and protein expression of amylase, insulin and neurogenin 3 (ngn 3) increased in AR42J cells treated with EGCG. Additionally, we demonstrated that the signal transduction pathway of mitogen-activated protein (MAP) kinase is active in EGCG-treated AR42J cells. ERK and JNK phosphorylation decreased in cells treated with EGCG but not p38 phosphorylation. Activation of the p38 MAP kinase pathway was confirmed by specific MAP kinase pathways inhibitors: U0126 for ERK, SP600126 for JNK, and SB203580 for p38. Activated p38 phosphorylation was inhibited by the specific p38 inhibitor SB203580 but p38 phosphorylation was inhibited with increased EGCG treatment. The ERK and JNK MAP kinase pathways were not affected by EGCG treatment. Although further studies are needed, these results suggest that EGCG affects the induction of pancreatic cell regeneration by increasing the ngn 3 protein and mRNA expression and activating the p38 MAP kinase pathway.