<i>In vitro</i> and <i>in vivo</i> evaluation of a novel polymer-free everolimus-eluting stent by nitrogen-doped titanium dioxide film deposition

Park, Dae Sung,Bae, In-Ho,Jeong, Myung Ho,Lim, Kyung Seob,Sim, Doo Sun,Hong, Young Joon,Lee, So-Youn,Jang, Eun Jae,Shim, Jae-Won,Park, Jun-Kyu,Lim, Han Chul,Kim, Han Byul Elsevier 2018 Materials Science and Engineering C Vol.91 No.-

<P><B>Abstract</B></P> <P>Inflammation and thrombosis are linked to the use of polymer-based drug-eluting stents (DES). The aim of this study was to develop a polymer-free everolimus (EVL)-eluting stent using nitrogen-doped titanium dioxide (N-TiO<SUB>2</SUB>) and verify its efficacy by <I>in vitro</I> and <I>in vivo</I> assessment in a porcine coronary model. Various analytical approaches such as scanning electron microscopy and atomic force microscopy, electron spectroscopy, Fourier transform infrared spectrometry and contact angle measurement were employed for the characterization. As a part of biocompatibility assessment, platelet adhesion and smooth muscle cell (SMC) proliferation were examined. Bare metal stent (BMS), N-TiO<SUB>2</SUB> stent, everolimus-eluting N-TiO<SUB>2</SUB> (N-TiO<SUB>2</SUB>-EVL) stent, and commercialized EVL-eluting stent (EES) were randomly placed in forty coronary arteries in twenty pigs. After four weeks of implantation, the stents were subjected to histological and quantitative analysis. The N-TiO<SUB>2</SUB> film used in this study was well coated without any cracks or peeling. Surface hydrophilicity (88.8% of angle decrement) could be associated with the decrease in surface roughness post N-TiO<SUB>2</SUB> deposition (37.0%). The platelet adhesion on the N-TiO<SUB>2</SUB> surfaces was less than that on the BMS surface. The proliferation of SMC was suppressed in the N-TiO<SUB>2</SUB>-EVL group (30.2%) but not in the BMS group. In the animal study, the percent area restenosis was significantly decreased in the N-TiO<SUB>2</SUB>-EVL group compared to that in the BMS group. The results (BMS; 47.0 ± 11.00%, N-TiO<SUB>2</SUB>-EVL; 31.7 ± 10.50%, and EES; 29.1 ± 11.21%, <I>n</I> = 10, <I>p</I> < 0.05) were almost at par with those of the commercialized EVL-eluting stent. The introduction of N-TiO<SUB>2</SUB> deposition during fabrication of polymer-free DES may be an efficient accessorial process for preventing in-stent restenosis and thrombosis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> N-TiO<SUB>2</SUB> surfaces can help to reduce the platelet adhesion. </LI> <LI> In porcine model, N-TiO<SUB>2</SUB> everolimus decreased in-stent restenosis and fibrin deposition. </LI> </UL> </P>

Different Impact of Diabetes Mellitus on In-hospital and 1-Year Mortality in Patients with Acute Myocardial Infarction Who Underwent Successful Percutaneous Coronary Intervention: Results from the Korean Acute Myocardial Infarction Registry

( Keun Ho Park ),( Young Keun Ahn ),( Myung Ho Jeong ),( Shung Chull Chae ),( Seung Ho Hur ),( Young Jo Kim ),( In Whan Seong ),( Jei Keon Chae ),( Taek Jong Hong ),( Myeong Chan Cho ),( Jang Ho Bae ) 대한내과학회 2012 The Korean Journal of Internal Medicine Vol.27 No.2

Background/Aims: The aim of this study was to evaluate the impact of diabetes mellitus (DM) on in-hospital and 1-year mortality in patients who suffered acute myocardial infarction (AMI) and underwent successful percutaneous coronary intervention (PCI). Methods: Among 5,074 consecutive patients from the Korea AMI Registry with successful revascularization between November 2005 and June 2007, 1,412 patients had a history of DM. Results: The DM group had a higher mean age prevalence of history of hypertension, dyslipidemia, ischemic heart disease, high Killip class, and diagnoses as non-ST elevation MI than the non-DM group. Left ventricular ejection fraction (LVEF) and creatinine clearance were lower in the DM group, which also had a significantly higher incidence of in-hospital and 1-year mortality of hospital survivors (4.6% vs. 2.8%, p = 0.002; 5.0% vs. 2.5%, p < 0.001). A multivariate analysis revealed that independent predictors of in-hospital mortality were Killip class IV or III at admission, use of angiotensin converting enzyme inhibitors or angiotensin-II receptor blockers, LVEF, creatinine clearance, and a diagnosis of ST-elevated MI but not DM. However, a multivariate Cox regression analysis showed that DM was an independent predictor of 1-year mortality (hazard ratio, 1.504; 95% confidence interval, 1.032 to 2.191). Conclusions: DM has a higher association with 1-year mortality than in-hospital mortality in patients with AMI who underwent successful PCI. Therefore, even when patients with AMI and DM undergo successful PCI, they may require further intensive treatment and continuous attention.

Clinical impact of admission hyperglycemia on in-hospital mortality in acute myocardial infarction patients

Kim, Eun Jung,Jeong, Myung Ho,Kim, Ju Han,Ahn, Tae Hoon,Seung, Ki Bae,Oh, Dong Joo,Kim, Hyo-Soo,Gwon, Hyeon Cheol,Seong, In Whan,Hwang, Kyung Kuk,Chae, Shung Chull,Kim, Kwon-Bae,Kim, Young Jo,Cha, Kwa Elsevier 2017 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.236 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Acute hyperglycemia on admission is common in acute myocardial infarction (AMI) patients regardless of diabetic status, and is known as one of prognostic factors. However, the effect of hyperglycemia on non-diabetic patients is still on debate.</P> <P><B>Methods</B></P> <P>A total of 12,625 AMI patients (64.0±12.6years, 26.1% female) who were enrolled in Korea Acute Myocardial Infarction Registry-National Institute of Health between November 2011 and December 2015, were classified into 4367 diabetes (65.4±11.6years, 30.4% female) and 8228 non-diabetes (63.3±13years, 23.9% female). Patients were analyzed for in-hospital clinical outcome according to admission hyperglycemic status.</P> <P><B>Results</B></P> <P>In diabetic patients, independent predictors of in-hospital mortality were old age, high HbA<SUB>1</SUB>C, pre-Thrombolysis In Myocardial Infarction (TIMI) flow 0, left ventricle ejection fraction<40%, cardiogenic shock and ventricular tachycardia. In non-diabetic patients, independent predictors of in-hospital mortality were old age, high admission glucose (≥200mg/dL), pre TIMI flow 0, failed percutaneous coronary intervention, low left ventricle ejection fraction<40%, cardiogenic shock, stent thrombosis and decreased Hb≥5g/dL. In hospital mortality was significantly higher in diabetic patients compared to non-diabetic patients (5.0% vs. 3.4%, <I>p</I> <0.001). However, non-diabetic patients with hyperglycemia have significantly higher mortality compared to diabetic patients (17.4% vs. 7.2%, <I>p</I> <0.001). Comorbidity including cardiogenic shock (<I>p</I> <0.001), cerebral hemorrhage (<I>p</I> =0.012), decreased Hb≥5g/dL (<I>p</I> =0.013), atrioventricular block (<I>p</I> <0.001) and ventricular tachycardia (<I>p</I> =0.007) was higher in non-diabetic with hyperglycemia than in diabetic patients.</P> <P><B>Conclusions</B></P> <P>These findings underscore clinical significance of admission hyperglycemia on in-hospital mortality in non-diabetic AMI patients.</P>

Chemical Beam Epitaxy로 성장한 InGaP의 Photoreflectance 특성 연구

김동렬,배인호,박성배,신영남 大邱大學校附設 基礎科學硏究所 1998 基礎科學硏究 Vol.14 No.2

In_(x)Ga(1-x)P/GaAs system were grown by chemical beam epitaxy(CBE). Pure phosphine(PH₃) gases were used as group Ⅴ sources. For the group Ⅲ sources, TEGa, TmIn were used. In_(x)Ga(1-x)P epilayer was grown on SI-GaAs substrate and has a 1- μm thick. We investigated characteristics of In_(x)Ga(1-x)P using photoreflectance(PR) spectroscopy. From PR measurement, the signal of In_(x)Ga(1-x)P shows third-derivative feature whose peaks provide energy gap. The energy gap of In_(x)Ga(1-x)P has deduced composition x. Chemical beam epitaxy(CBE)로 성장한 In_(x)Ga_(1-x)P에 대하여 photoreflectance(PR) 측정을 하였다. 측정결과, 시료의 띠 간격 에너지는 1.872 eV이었다. 이 에너지 값으로부터 In_(x)Ga_(1-x)P의 조성비 x값이 0.5임을 얻었다. 온도변화에 따른 PR 측정으로 온도계수 dE_(g)/dT=-3.773×10^(-4) eV/K 이었고, 또한 온도변화에 따른 ΔE_(8) 값으로부터 Varshni 상수 α와 β 값을 얻을 수 있었다. Bose-Einstein 온도 관계식을 이용하여 interaction의 크기 β_(B)는 19.4 meV이었고, 평균 포논 주파수와 관계되는 θ값은 101.4K 이었다.

In_0.5(Ga_1-xAl_x)_0.5P/GaAs 이중 이종접합 구조의 Contactless Electroreflectance에 관한 연구

김정화,조현준,배인호,Kim, Jeong-Hwa,Jo, Hyun-Jun,Bae, In-Ho 한국진공학회 2010 Applied Science and Convergence Technology Vol.19 No.2

Metal-organic chemical vapour deposition (MOCVD)법으로 성장된 $In_{0.5}(Ga_{1-x}Al_x)_{0.5}P$/GaAs 이중 이종접합 구조의 특성을 contactless electroreflectance (CER) 분광법으로 조사하였다. CER 측정은 변조전압($V_{ac}$), 온도 및 dc 바이어스 전압($V_{bias}$)의 함수로 수행하였다. 상온에서는 5개의 신호가 관측되었는데, 이 신호들은 각각 GaAs, $In_{0.5}Ga_{0.5}P$, $In_{0.5}(Ga_{0.73}Al_{0.27})_{0.5}P$, $In_{0.5}(Ga_{0.5}Al_{0.5})_{0.5}P$ 및 $In_{0.5}(Ga_{0.2}Al_{0.8})_{0.5}P$ 전이에 관련된 것이다. CER 스펙트럼의 온도 의존성으로부터 Varshni 계수 및 평탄인 자를 구하였다. 그리고 인가전압에 따른 신호의 진폭은 순방향 바이어스 전압 인가시 점차로 감소하나, 역방향 바이어스 전압 인가시에는 반대의 경향을 보였다. We have investigated the contactless electroreflectance (CER) properties of $In_{0.5}(Ga_{1-x}Al_x)_{0.5}P$/GaAs double heterostructures grown by metal-organic chemical vapour deposition (MOCVD). The CER measurements on the sample were studied as a function of temperature, modulation voltage ($V_{ac}$), and dc bias voltage ($V_{bias}$). Five signals observed at room temperature are related to the GaAs, $In_{0.5}Ga_{0.5}P$, $In_{0.5}(Ga_{0.73}Al_{0.27})_{0.5}P$, $In_{0.5}(Ga_{0.5}Al_{0.5})_{0.5}P$, and $In_{0.5}(Ga_{0.2}Al_{0.8})_{0.5}P$ transitions, respectively. From the temperature dependence of CER spectrum, the Varshni coefficients and broadening parameters were determined and discussed. In addition, we found that the behavior of the CER amplitude for the reverse bias is larger than that of the forward.

In_xGa_1-xN/GaN 다중양자우물 구조의 광학적 성질 연구

김기홍,김인수,박헌보,배인호,유재인,장윤석,Kim, Ki-Hong,Kim, In-Su,Park, Hun-Bo,Bae, In-Ho,Yu, jae-In,Jang, Yoon-Seok 한국진공학회 2009 Applied Science and Convergence Technology Vol.18 No.1

$In_xGa_{1-x}N$/GaN 다중양자우물 구조의 EL 특성을 온도와 주입전류 변화에 따른 특성을 조사하였다 저전류와 고전류 주입시 EL 효율의 온도 의존 변화는 매우 다르게 나타나는데, 이러한 온도와 전류의 변화에 의한 독특한 EL 효율의 변화는 내부전기장의 존재 하에 순방향 바이어스에 기인한 외부전기장의 영향인 것으로 볼 수 있다. 그리고 $In_xGa_{1-x}N$/GaN 다중양자우물 구조에서 In 성비의 증가는 발광파장위치의 적색이동을 보였다. 15K에서 주입 전류의 증가에 따라 녹색 양자우물 구조는 80 meV와 청색 양자우물 구조는 22 meV의 청색 편이를 하였다. 이는 전류의 증가에 의해 단위 시간당 생성되는 캐리어 수가증가하게 되고 그에 따라 subband가 급격히 채워지는 band filling 현상이 일어나게 되어 짧은 파장에서 재결합이 증가하기 때문이다. 그리고 청색과 녹색 다중 양자우물구조의 짧은 파장 쪽으로의 편이 차이는 In 농도에 기인한 것으로 In 농도가 높으면 양자우물 깊이가 증가되어 더 강한 양자속박효과가 작용하여 캐리어 구속력이 증가하기 때문 것으로 볼 수 있다. Temperature and injection current dependence of electroluminescence(EL) spectral intensity of the $In_xGa_{1-x}N$/GaN multi-quantum wells(MQW) have been studied over a wide temperature range and as a function of injection current level. It is found that a temperature-dependent variation pattern of the EL efficiency under very low and high injection currents shows a drastic difference. This unique EL efficiency variation pattern with temperature and current can be explained field effects due to the driving forward bias in presence of internal(piezo and spontaneous polarization) fields. Increase of the indium content in $In_xGa_{1-x}N$/GaN multiple quantum wells gives rise to a redshift of 80 meV and 22 meV for green and blue MQW, respectively. It can be explained by carrier localization by potential fluctuation of multiple quantum well and MQW structures also shows a keen difference owing to the different indium content in InGaN/GaN MQW.

In_0.49Ga_0.51P/GaAs 이종접합 구조의 표면 광전압 특성

김정화,김인수,배인호,Kim, Jeong-Hwa,Kim, In-Soo,Bae, In-Ho 한국진공학회 2010 Applied Science and Convergence Technology Vol.19 No.5

Metal-organic chemical vapour deposition (MOCVD) 법으로 성장된 $In_{0.49}Ga_{0.51}P$/GaAs 이종접합 구조의 특성을 표면 광전압(surface photovoltage; SPV) 분광법으로 조사하였다. SPV 측정은 입사광의 세기, 변조 주파수, 온도의 함수로 수행하였다. 상온에서 시료의 띠간격 에너지(band gap energy)는 GaAs와 $In_{0.49}Ga_{0.51}P$는 각각 1.400 및 1.893 eV이었다. 광세기를 증가시킴에 따라 SPV 크기는 증가하는 반면에, 변조 주파수를 증가시킴에 따라 SPV 크기는 감소하였다. 그리고 SPV 스펙트럼의 온도 의존성으로부터 GaAs와 $In_{0.49}Ga_{0.51}P$의 띠간격 에너지의 변화를 Varshni 및 Bose-Einstein 표현에 의해 분석하였다. We report the surface photovoltage (SPV) properties of $In_{0.49}Ga_{0.51}P$/GaAs heterostructure grown by metal-organic chemical vapour deposition (MOCVD). The SPV measurements were studied as a function of modulation beam intensity, modulation frequency and temperature. From a line shape analysis of room temperature derivative surface photovoltage (DSPV) spectrum, the band gap energies for GaAs and $In_{0.49}Ga_{0.51}P$ transitions were 1.400 and 1.893 eV respectively. The surface photovoltage (SPV) increases with increasing the light intensity and temperature, whereas the SPV decreases with increasing the modulation frequency. From the temperature variation of the energy gaps, we have analysis by both Varshni and Bose-Einstein type expressions.

췌담관 합류이상이 있는 환자에서 담도계 손상 기전에 대한 연구

정인호,정용식,김지훈,최수윤,김정운,김욱환,홍정,왕희정,유병무,김진홍,한재호,김영배,김재근,김명욱 한국간담췌외과학회 2003 한국간담췌외과학회지 Vol.7 No.2

교정치료 초기 환자의 통제소재와 불쾌감의 관계

백인호,배창,김영호 대한치과교정학회 1994 대한치과교정학회지 Vol.24 No.1

This study was attempted to explore the relationship between locus of control and the discomfort of the patients at the initial stage of the orthodontic treatment. Locus of control was measured by 'Locus of Control(LOC) scale for children' and 'Orthodontic Locus of Control(OLOC) scale for children'. The discomfort was measured by 'discomfort index card' in 52 children and adolescent patients who initiate orthodontic treatment. In addition, locus of control of the patients' mothers was measured by 'Orthodontic Locus of Control (OLOC) scale for parents'. The results were as follow : 1. The test-retest reliability of 'Locus of Control(LOC) scale for children' and 'Orthodontic Locus of Control(OLOC) scale' was in the moderate to high range. 2. Out of 52 patients, 47 showed moderate to severe discomfort following placement of an initial archwire. The patients showed the most severe discomfort on the first day, and most of the discomfort was manifested within the first 3 days, then decreased until the 7th day. There was no significant difference in the discomfort according to sex and age. 3. The discomfort of the patients was the highest in the morning session when a day was divided in the discomfort into 4 sessions, i.e., morning, afternoon, evening, and night. 4. In the score of 'Locus of Control(LOC) scale for children' and 'Orthodontic Locus of Control(OLOC) scale for children', the group of internal locus of control expressed more discomfort than the group of external locus of control. And there was no significant correlation between locus of control of the patients and that of their mothers. 5. There was no significant difference in the score of locus of control according to sex and age. However, the score of boys tended to be lower than of girls and the score of primary school students higher than that of middle and high school students.

Photoreflectance 측정에 의한 InxGa₁-xAs(0.03≤X≤0.11) 에피층의 특성 연구

김인수(In-Soo Kim),손정식(Jeoog-Sik Son),이철욱(Cheul-Wook Lee),배인호(In-Ho Bae),임재영(Jae-Youog Leem),한병국(Byung-Kuk Han),신영남(Young-Nam Shin) 한국진공학회(ASCT) 1998 Applied Science and Convergence Technology Vol.7 No.4

Molecular Beam Epitaxy(MBE)법으로 성장된 In_xGa_(1-x)As/GaAs 에피층에 대해 photoreflectance (PR)실험을 통해 특성을 조사하였다. PR 측정결과 성장된 In_xGa_(1-x)As 에피층의 띠간격 에너지(E。) 신호가 시료의 변형(strain)에 의해 heavy-hole(E。(HH))과 light-hole(E。(LH))로 분리되어 관측되었다. 에피층의 조성과 변형은 각각 시료에서의 E。(HH) 및 Eo(HH)와 Eo(LH)신호의 에너지 차이를 이용하여 구하였다. 또 160 K이하의 온도에서는 Eo(LH)의 신호가 사라짐을 볼 수 있었다. Franz-Keldysh oscillation(FKO) 피크로부터 계산되어진 InGaAs/GaAs 계면전장 (E)은 In 조성의 증가에 따라 0.75×10^5 V/㎝에서 2.66×10^5 V/㎝로 증가하였다. In 조성이 x=0.09인 시료에 대한 PR신호의 온도의존성 실험에서 Varshni 계수와 Bose-Einstein 계수들을 각각 구하였다. Photoreflectance (PR) measurents have been performed on In_xGa_(1-x)As/GaAs grown by molecular beam epitaxy (MBE). Bandgap (E。) of In_xGa_(1-x)As epilayer measured from PR was separated as heavy-hole (E。(HH)) and light-hole (E。(LH)) by strain effect. The compositions and the strains of epilayer were obtained from the energy value of E。(HH) and from enegy difference of E。(HH) and E。(LH), respectively. In addition, the PR signal of E。(LH) was diminished below 160 K. The interface electric field (E) of InGaAs/GaAs was increased from 0.75×10^5 V/㎝ to 2.66×10^5 V/㎝ as In composition increased, which was calculated from Franz-Keldysh oscillation (FKO) peaks. As the temperature dependence of the PR signal at x=0.09 sample, we obtained Varshni and Bose-Einstein coefficients.