SrTiO₃첨가에 따른 (x)BaTiO₃-(1-x)SrTiO₃의 유전적, 전기적 특성

정해덕,장동환,김덕근,홍경진,최창주 木浦大學校 工業技術硏究所 1998 工業技術硏究誌 Vol.8 No.-

In this paper, a ferroelectric material BaTiO3 was added to SrTiO3, then (x)BaTiO3-(1-x)SrTiO3(0.7≤x≤1) ceramics were fabricated with stable electrical properties in high voltage. Microstructures and electrical properties were investigated according to mixing conditions of addition material SrTiO3. As a result of the investigation of all experiments, the shrinkage was excellent in 0.9BaTioO3-0.1SrTiO3. The grain size was increased, the curie temperature was shifted low temperature. The 0.9BaTiO3-0.1SrTiO3 was appeared stable property in temperature vs. permittivity. Also, 0.9BaTiO3-0.1SrTiO3 was showed stable dielectric properties at 25~85[C]. V-I properties of specimen were observed in the temperature range of 21~143[C], were divided into three regions. the region I below 10[kV/cm] was shown Ohmic conduction, the region II from 10 to 30[kV/cm] was explained by the poole-Frenkel emission theory and the region III above 30[kV/cm] was analysed by the tunneling effect.

정전 열 접합을 이용한 Multi-Substrate Bonding

이덕중,주병권,최우범,한정인,조경익,이광배,장진,오명환 경북대학교 센서기술연구소 1997 센서技術學術大會論文集 Vol.8 No.1

We performed silicon-to-glass bonding using silicon direct bonding followed by anodic bonding(SDAB). Initial bonding between glass and silicon was caused by the hydrophilic surfaces of silicon and glass ensemble using silicon direct bonding(SDB) method. We found that the bonded specimen using SDAB process had higher strength than one using anodic bonding process only. We performed multiple layer bonding by SDAB, which is glass- silicon -glass as sandwich structure. In the silicon wafer, the (1mm x 2mm x 500μm)-sized cavity was formed by the anisotropic etching of the silicon substrate in EPW(Ethylendiamin-Pyrocatechol-Water). And, the cavity was sealed with glass wafers by SDAB method.

원적외선 온열요법이 혈액투석 환자의 혈관통로 기능에 미치는 효과

최향미 ( Hyang Mi Choi ),최은덕 ( Eun Duck Choi ),장소형 ( So Hyeong Jang ),김은희 ( Eun Hee Kim ),최미정 ( Mi Jung Choi ),백송이 ( Song Yi Back ),한복희 ( Bok Hee Han ) 병원간호사회 2015 임상간호연구 Vol.21 No.2

Purpose: For hemodialysis, a vascular access which can maintain a certain speed for a long time is required. The prevention of the vascular access dysfunction is very important to decrease morbidity and to improvethe quality of life of patients receiving hemodialysis It is reported that far infrared heat increases the blood flow by expanding capillaries and micro-arteriovenouses. This study aimed to evaluate the effect of far infrared heat therapy as a new nursing intervention for maintaining vascular access function and improving the blood flow of patients receiving hemodialysis. Methods: The quasi-experimental research of nonequivalent control group pre-post test design was carried out for 59 patients receiving hemodialysis 3 times per week at K medical center. A far infrared heat was applied to the experimental group for 3 months. Results: The arteriovenous fistula blood flow of the experimental group (far infrared heat therapy group) increased significantly when compared to the control group (p=.047). However, static intra-access pressure ratio(SIAPR)was not different statistically (p=.101). Conclusion: The far infrared therapy could be considered as nursing intervention of choice as it demonstrated increase in the arteriovenous fistula blood flow in the patients receiving hemodialysis.

국내 유통 소금 중의 포타슘시아니이드와 페로시아나이드염의 분석에 관한 연구

허숙진,소유섭,최장덕,이화정,최선희,성준현,임무혁,김광수,최용훈,오해성,최정희,최정실,허옥순,이진하,신동우,신현수,문병우 식품의약품안전청 2001 식품의약품안전청 연보 Vol.5 No.-

본 연구는 국내 유통 소금중의 안전성을 규명하기 위하여 천일염 54건, 재제염 보건, 가공염 33건 등 총 143건에 대하여 숲행하였다. HPLC, ICP, Mercury Analyzer 등을 이용하여 KCN, 페로시아나이드 염, 납 등 6개 성분의 항량을 측정하였으며 그 결과는 다음과 같다. [rdn-max(mean) ; m곱3 ; f(CN : ND-ND(ND), 페로시아나이드염 : ND-ND(ND), Pb . ND-1.30 (0.331), Cd :ND-0.23(0.070), Hg ND-0.35(0,035), As :ND-1.52fo.062). 또한, 신속하고도 효율적이 면서 기존의 환경부 시안분석법의 단점을 보완할 수 있는 KCN과 페로시아나이드염의 분석 조건을 계시하였으며, 천일염, 재제염, 가공염 뿐만아니라 소금이 첨가된 식품까지도 적용하기 위한 기초 자료로 활용이 가능할 것으로 사료된다. This study was conducted to confirm the safety in a total of 143 samples of salts. The contents of potassium cyanide(KCN), potassium ferrocyanide(K_(4)Fe(CN)_(6)), lead(Pb), cadmium(Cd), mercury(Hg), and arsenic(As) were determined using a high performance liquid chromatograph(HPLC), inductively coupled plasma spectrometer(ICP), and mercury analyzer. The values of cyanide complexes and metal elements in salts were as follow [min-max(mean);mg/kg] ; KCN : ND-ND(ND), Ferrocyanide salt : ND-ND(ND), Pb : ND-1.30(0.331), Cd: ND-0.23(0.070), Hg : ND-0.35(0.035), As : ND-1.52(0.062). In this study, we established efficient

The Effect of Mycophenolate Mofetil versus Cyclosporine as Combination Therapy with Low Dose Corticosteroids in High-risk Patients with Idiopathic Membranous Nephropathy: a Multicenter Randomized Trial

Choi, Ji-Young,Kim, Dong Ki,Kim, Yang-Wook,Yoo, Tae-Hyun,Lee, Jung Pyo,Chung, Hyun Chul,Cho, Kyu Hyang,An, Won Suk,Lee, Duk-Hyun,Jung, Hee-Yeon,Cho, Jang-Hee,Kim, Chan-Duck,Kim, Yong-Lim,Park, Sun-Hee The Korean Academy of Medical Sciences 2018 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.33 No.9

<P><B>Background</B></P><P>Appropriate immunosuppressive therapy for patients with idiopathic membranous nephropathy (MN) remains controversial. The effect of mycophenolate mofetil (MMF) versus cyclosporine (CsA) combined with low-dose corticosteroids was evaluated in patients with idiopathic MN in a multi-center randomized trial (NCT01282073).</P><P><B>Methods</B></P><P>A total of 39 biopsy-proven idiopathic MN patients with severe proteinuria were randomly assigned to receive MMF combined with low-dose corticosteroids (MMF group) versus CsA combined with low-dose corticosteroids (CsA group), respectively, and followed up for 48 weeks. Complete or partial remission rate of proteinuria and estimated glomerular filtration rate (eGFR) at 48 weeks were compared.</P><P><B>Results</B></P><P>The level of proteinuria at baseline and at 48 weeks was 8.9 ± 5.9 and 2.1 ± 3.1 g/day, respectively, in the MMF group compared to 8.4 ± 3.5 and 3.2 ± 5.7 g/day, respectively, in the CsA group. In total, 76.1% of the MMF group and 66.7% of the CsA group achieved remission at 48 weeks (95% confidence interval, −0.18 to 0.38). There was no difference in eGFR between the two groups. Anti-phospholipase A2 receptor Ab levels at baseline decreased at 48 weeks in the complete or partial remission group (<I>P</I> = 0.001), but were unchanged in the no-response group. There were no significant differences between the two groups in changes in the Gastrointestinal Symptom Rating Scale and Gastrointestinal Quality of Life Index scores from baseline to 48 weeks.</P><P><B>Conclusion</B></P><P>In combination with low-dose corticosteroids, the effect of MMF may not be inferior to that of CsA in patients with idiopathic MN, with similar adverse effects including gastrointestinal symptoms.</P><P><B>Trial Registration</B></P><P>ClinicalTrials.gov Identifier: NCT01282073</P>

Nafamostat Mesilate as an Anticoagulant During Continuous Renal Replacement Therapy in Patients With High Bleeding Risk : A Randomized Clinical Trial

Choi, Ji-Young,Kang, Yun-Jeong,Jang, Hye Min,Jung, Hee-Yeon,Cho, Jang-Hee,Park, Sun-Hee,Kim, Yong-Lim,Kim, Chan-Duck Williams & Wilkins Co 2015 Medicine Vol.94 No.52

<P><B>Abstract</B></P><P>Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has been used increasingly as an anticoagulant during continuous renal replacement therapy (CRRT). However, there, are limited data from randomized studies on NM use in patients with a bleeding tendency. This prospective study evaluated the efficacy and safety of NM use during CRRT in patients with acute kidney injury (AKI) patients at high risk of bleeding.</P><P>Patients with AKI at high risk of bleeding were randomized into the NM and no anticoagulant (NA) groups. The primary outcome was the treatment efficacy represented by the filter lifespan. Several parameters, including safety and patient survival rates at 30 and 90 days, were analyzed as secondary outcomes.</P><P>Fifty-five patients were included in this study (NM group = 31, NA group = 24). The baseline characteristics did not significantly differ between the groups. The mean filter lifespan was significantly longer in the NM group than in the NA group (31.7 ± 24.1 versus 19.5 ± 14.9 hours; <I>P</I> = 0.035). The most common cause of filter failure was filter clotting, which was significantly more frequent in the NA group than in the NM group (59.6% versus 37.7%, <I>P</I> = 0.024). The Cox proportional hazards model showed a 42.2% longer filter lifespan in the NM group compared with the NA group (hazard ratio, 0.578; 95% confidence interval, 0.362–0.923; <I>P</I> = 0.022). There were no significant differences in the frequencies of transfusions and major bleeding between the groups. Patient survival rates at 30 and 90 days after CRRT initiation were comparable between the groups.</P><P>Nafamostat mesilate is a safe and effective anticoagulant for CRRT and allows sufficient filter survival without increasing the risk of bleeding in critically ill patients with AKI and bleeding tendencies.</P>

Furongian trilobites from the Asioptychaspis and Quadraticephalus zones of the Hwajeol Formation, Taebaeksan Basin, Korea

Jang Won Sohn,Duck K. Choi 한국지질과학협의회 2007 Geosciences Journal Vol.11 No.4

This paper describes the upper Furongian trilobites from the Hwajeol Formation and, based on these trilobite faunal assemblages, proposes formally two trilobite biozones, the Asioptychaspis and Quadraticephalus zones. A total of 14 species belonging to ten genera are described: i.e., Micragnostus sp., Pseudagnostus planulatus, Koldinioidia sp., Hamashania pulchera, Hamashania sp. cf. H. busiris, Asioptychaspis subglobosa, Changia sp., Quadraticephalus elongatus, ptychaspidid genus and species indeterminate, Lophosaukia orientalis, Lophosaukia? sp., Tsinania canens, Tsinania sp., and Haniwa sosanensis. The Asioptychaspis Zone is characterized by predominance of Asioptychaspis subglobosa, while the succeeding Quadraticephalus Zone is dominated by Quadraticephalus elongatus, Lophosaukia orientalis, Haniwa sosanensis, and Micragnostus sp. The Asioptychaspis and Quadraticephalus zones are well correlated with the Ptychaspis-Tsinania and Changia (or Quadraticephalus) zones of North China, respectively. These two trilobite assemblages of the Hwajeol Formation support a strong paleogeographical link between the Taebaeksan Basin and North China Platform during the late Furongian.

Taebaek Group (Cambrian-Ordovician) in the Seokgaejae section, Taebaeksan Basin: a refined lower Paleozoic stratigraphy in Korea

Duck K. Choi,Sung Kwun Chough,Yi Kyun Kwon,Seung-Bae Lee,Jusun Woo,Imseong Kang,Hyun Suk Lee,Sang Min Lee,Jang Won Sohn,Young Jae Shinn,Dong-Jin Lee 한국지질과학협의회 2004 Geosciences Journal Vol.8 No.2

The Taebaek Group (Cambrian-Ordovician) in theTaebaeksan Basin comprises mixed carbonate-siliciclastic sequenceand is exposed well in the Seokgaejae section located in the central-eastern part of the Korean Peninsula. The group in the Seokgaejaesection consists of in ascending order the Myeonsan, Myobong,and Duwibong formations. This study describes in detail the well-exposed outcrop sections of the Taebaek Group in the SeokgaejaePass in order to refine the lithostratigraphy of the lower Paleozoicstrata in the Taebaeksan Basin, Korea. The refined lithostratigra-phy delineates clearly the lithologic boundary between the Myobongand Daegi formations, the Hwajeol and Dongjeom formations, theDumugol and Makgol formations, and the Makgol and Jigunsanformations. The preliminary information on trilobite faunal asem-blages suggests that the Cambrian-Ordovician boundary can beplaced within the lowermost part of the Dongjeom Formation.

Tree branch-shaped cupric oxide for highly effective photoelectrochemical water reduction

Jang, Youn Jeong,Jang, Ji-Wook,Choi, Sun Hee,Kim, Jae Young,Kim, Ju Hun,Youn, Duck Hyun,Kim, Won Yong,Han, Suenghoon,Sung Lee, Jae The Royal Society of Chemistry 2015 Nanoscale Vol.7 No.17

<▼1><P>The tree branch-shaped CuO, fabricated using the hybrid microwave annealing (HMA) process with a silicon susceptor shows excellent photoelectrochemical water reduction activity.</P></▼1><▼2><P>Highly efficient tree branch-shaped CuO photocathodes are fabricated using the hybrid microwave annealing process with a silicon susceptor within 10 minutes. The unique hierarchical, one-dimensional structure provides more facile charge transport, larger surface areas, and increased crystallinity and crystal ordering with less defects compared to irregular-shaped CuO prepared by conventional thermal annealing. As a result, the photocathode fabricated with the tree branch-shaped CuO produces an unprecedently high photocurrent density of −4.4 mA cm<SUP>−2</SUP> at 0 VRHE under AM 1.5 G simulated sunlight compared to −1.44 mA cm<SUP>−2</SUP> observed for a photocathode fabricated by thermal annealing. It is also confirmed that stoichiometric hydrogen and oxygen are produced from photoelectrochemical water splitting on the tree branch-shaped CuO photocathode and a platinum anode.</P></▼2>

Favorable neointimal coverage in everolimus-eluting stent at 9 months after stent implantation: comparison with sirolimus-eluting stent using optical coherence tomography

Choi, Hyun Hee,Kim, Jung-Sun,Yoon, Duck Hyoung,Hong, Kyung-Soon,Kim, Tae Hoon,Kim, Byeong Keuk,Ko, Young-Guk,Choi, Donghoon,Jang, Yangsoo,Hong, Myeong-Ki Springer-Verlag 2012 The international journal of cardiovascular imagin Vol.28 No.3