Lateral Strain Sensing Characteristics of Carbon Nanotube Network Thin-Films on Flexible Substrates

Seung-Beck Lee 한국진공학회 2008 한국진공학회 학술발표회초록집 Vol.2008 No.8

Atomic layer deposition growth of SnS₂ films on diluted buffered oxide etchant solution-treated substrate

Lee, Namgue,Lee, Gunwoo,Choi, Hyeongsu,Park, Hyunwoo,Choi, Yeonsik,Kim, Keunsik,Choi, Yeongtae,Kim, Jong-Woo,Yuk, Hyunwoo,Sul, Onejae,Lee, Seung-Beck,Jeon, Hyeongtag Elsevier BV * North-Holland 2019 Applied Surface Science Vol.496 No.-

<P><B>Abstract</B></P> <P>In this report, two types of substrates were prepared for deposition of few-layer tin disulfide (SnS<SUB>2</SUB>) via atomic layer deposition (ALD). The first substrate was prepared using a conventional cleaning method, while the second substrate was rinsed with buffered oxide etcher (BOE) solution after conventional cleaning. Changes in the substrate were confirmed by X-ray photoelectron spectroscopy, contact angle measurements, and electron spin resonance. Characteristics of the SnS<SUB>2</SUB> thin films were determined by X-ray diffraction, Raman analysis, Fourier transform-infrared spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. To investigate growth rate, thickness was measured as a function of ALD cycle number by atomic force microscopy, and 2D layered structure was confirmed by transmission electron microscopy. Findings confirmed that surface treatment using BOE solution was related to an increased growth rate during the initial ALD process. Finally, back-gate field effect transistors based on ALD-grown SnS<SUB>2</SUB> film prepared on substrate that received diluted-BOE surface treatment showed marginal improvement in current on/off ratio from 2.9 × 10<SUP>5</SUP> to 6.5 × 10<SUP>5</SUP> and mobility from 0.22 cm<SUP>2</SUP>/Vs to 0.31 cm<SUP>2</SUP>/Vs compared to ALD-grown SnS<SUB>2</SUB> film prepared on bare substrate.</P> <P><B>Highlights</B></P> <P> <UL> <LI> SnS<SUB>2</SUB> thin films were grown by atomic layer deposition. </LI> <LI> Bare and surface treated substrates were used to deposit SnS<SUB>2</SUB>. </LI> <LI> Buffered oxide etchant solution was used to surface treatment. </LI> <LI> Hydrophilicity of two different substrates was investigated. </LI> <LI> Growth rate and transport properties of SnS<SUB>2</SUB> thin films were investigated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

만성 염증성 탈수초 다발성 신경근병증이 동반된 낭창성 신염

이규백(Kyu Beck Lee),김향(Hyang Kim),이상종(Sang Jong Lee),박찬필(Chan Pil Park),박문향(Moon Hyang Park),박범준(Bum Joon Park),김현승(Hyun Seung Kim),이한보(Han Bo Lee),이준(Jun Lee),오재인(Jae In Oh) 대한신장학회 2000 Kidney Research and Clinical Practice Vol.19 No.3

Systemic lupus erythematosus(SLE) is a multisys-temic disease. Peripheral neuropathy occurs in about 10% of patients with SLE. Chronic inflammatory demyelinating polyneurpathy has been reported rarely in SLE. We experienced a case of chronic inflammatory polyneuropathy in lupus nephritis. 32-year-old housewife presented to chronic progressive muscle weakness and heavy proteinuria. Kidney biopsy showed compatible with lupus nephritis (WHO Class V, membranous nephropathy). Nerve conduction studies showed reduction in conduction velocity and sural nerve biopsy revealed demyeli-nating polyneuropathy. Steroid therapy led to improvement in clinical symptoms and proteinuria.

Fabrication of high crystalline SnS and SnS₂ thin films, and their switching device characteristics

Choi, Hyeongsu,Lee, Jeongsu,Shin, Seokyoon,Lee, Juhyun,Lee, Seungjin,Park, Hyunwoo,Kwon, Sejin,Lee, Namgue,Bang, Minwook,Lee, Seung-Beck,Jeon, Hyeongtag IOP Pub 2018 Nanotechnology Vol.29 No.21

<P>Representative tin sulfide compounds, tin monosulfide (SnS) and tin disulfide (SnS<SUB>2</SUB>) are strong candidates for future nanoelectronic devices, based on non-toxicity, low cost, unique structures and optoelectronic properties. However, it is insufficient for synthesizing of tin sulfide thin films using vapor phase deposition method which is capable of fabricating reproducible device and securing high quality films, and their device characteristics. In this study, we obtained highly crystalline SnS thin films by atomic layer deposition and obtained highly crystalline SnS<SUB>2</SUB> thin films by phase transition of the SnS thin films. The SnS thin film was transformed into SnS<SUB>2</SUB> thin film by annealing at 450 °C for 1 h in H<SUB>2</SUB>S atmosphere. This phase transition was confirmed by x-ray diffractometer and x-ray photoelectron spectroscopy, and we studied the cause of the phase transition. We then compared the film characteristics of these two tin sulfide thin films and their switching device characteristics. SnS and SnS<SUB>2</SUB> thin films had optical bandgaps of 1.35 and 2.70 eV, and absorption coefficients of about 10<SUP>5</SUP> and 10<SUP>4</SUP> cm<SUP>−1</SUP> in the visible region, respectively. In addition, SnS and SnS<SUB>2</SUB> thin films exhibited p-type and n-type semiconductor characteristics. In the images of high resolution-transmission electron microscopy, SnS and SnS<SUB>2</SUB> directly showed a highly crystalline orthorhombic and hexagonal layered structure. The field effect transistors of SnS and SnS<SUB>2</SUB> thin films exhibited on–off drain current ratios of 8.8 and 2.1 × 10<SUP>3</SUP> and mobilities of 0.21 and 0.014 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>, respectively. This difference in switching device characteristics mainly depends on the carrier concentration because it contributes to off-state conductance and mobility. The major carrier concentrations of the SnS and SnS<SUB>2</SUB> thin films were 6.0?×?10<SUP>16</SUP> and 8.7?×?10<SUP>13</SUP> cm<SUP>−3</SUP>, respectively, in this experiment.</P>

상염색체 우성 다낭신 환자에서 18F-FDG PET-CT로 진단한 간낭종 감염 1예

심충남 ( Choong Nam Shim ),이태헌 ( Tae Heon Lee ),체재욱 ( Je Wook Chea ),허성은 ( Seung Eun Huh ),김향 ( Hyang Kim ),이규백 ( Kyu Beck Lee ),이영래 ( Young Rae Lee ),홍현표 ( Hyun Pyo Hong ),이은정 ( Eun Jeong Lee ) 대한신장학회 2010 Kidney Research and Clinical Practice Vol.29 No.1

Infection of hepatic cyst is a serious complication of autosomal dominant polycystic kidney disease (ADPKD). Early diagnosis of infected cyst is crucial and usually requires conventional modalities, including ultrasound and computed tomography. However, their contribution is limited because of nonspecific results. We report a case of hepatic cyst infection for which 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) scan allowed the exact localization of the infected cyst and the precise drainage procedure. A 48-year-old woman with ADPKD presented with fever and RUQ pain. Contrast enhanced computed tomography did not show any evidence of complicated or infected cysts in both kidneys and liver. Though she had been treated by antibiotics for 7 days, patient`s symptoms were not improved. However, 18F-FDG PET-CT scan revealed infected cyst in the left lobe of liver exactly. After percutaneous drainage based on 18F-FDG PET-CT imaging, the hepatic cyst infection was controlled. Therefore, 18F-FDG PET-CT imaging could be a valuable tool to identify the exact localization of cyst infection, which may contribute to drain the infected cyst. We report this case with a brief review of relevant literature.

기압소결에 의해 제조된 AIN-hBN계 머시너블 세라믹스의 가공성에 관한연구

백시영,신봉철,이정원,조명우,이은상,조원승 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

Ceramics are very difficult-to-cut materials because of its high strength and hardness. In this study, to give good machinability to the ceramics, hBN powders are added to AIN by volume of 10, 15 and 20%. The effect of content on mechanical properties, crack propagation and machinability of based machinable ceramics were investigate. Also, As a result of rapping test process, the surface have good rough condition fewer than 0.5㎛(Ra). Get results can be used to develop machinable ceramics of good material properties and machinability.

Machining Characteristics of AlN-hBN Composites in End-Milling and Precision Lapping Processes

Beck, Si Young,Shin, Bong Cheol,Cho, Myeong Woo,Lee, Eun Sang,Park, Dong Sam,Yun, Dae Jin,Cho, Won Seung Trans Tech Publications, Ltd. 2008 Key Engineering Materials Vol.368 No.-

<P>In this study, the machining characteristics of developed AlN-hBN composites were investigated in the end-milling and precision lapping processes. To achieve the objectives, material properties of the developed AlN-hBN composites were evaluated according to the variation of hBN contents. And, required experimental works were performed to investigate the machining characteristics of the composites. First, the machiniability of the composite was evaluated in the end-milling process under various cutting conditions, such as spindle speed, feederate, and depth of cut variations. Also, generated micro cracks caused by the cutting process were investigated via SEM photographs. Next, precision lapping experiments were performed under various conditions, and the results were estimated.</P>

유지투석 중인 말기 신부전 환자에서 Cardiac Troponin T(cTnT)와 Cardiac Troponin I(cTnI)치 측정의 의의(예보)

이상일,김향,윤중원,김현승,성기철,이규백,박효순 대한신장학회 2002 Kidney Research and Clinical Practice Vol.21 No.2

목 적: Cardiac troponin T(cTnT)와 cardiac troponin I(cTnI)는 심근손상의 진단 및 예측에 예민한 지표로 알려져 있다. 그러나 말기 신부전 환자에서 troponin T와 troponin I치의 의의에 대해서는 논란이 많다. 이에 저자들은 말기 신부전으로 유지투석 중인 환자에서 cTnT와 cTnI치를 측정하고, cTnT 및 cTnI가 임상 지표들과 상관관계가 있는지 조사하였다. 방 법: 3개월 이상 심근손상의 증거가 없었던 63명의 유지투석 환자(혈액투석 41명, 복막투석22명)에서 혈중 cTnT와 cTnI치를 각각 electrochemiluminescence immunoassay(ELC)법 및 chemilumino immunoassay(CLIA)법을 이용하여 정량 측정하였다. 혈중 요소질소, 크레아티닌, 알부민치와 혈중 CPK, CK-MB, CK index, LDH치를 측정하였으며, 혈중 호모시스테인, 총 콜레스테롤, 중성지방치를 측정하였다. 또한 심전도와 심초음파검사를 시행하였다. 결 과: 총 63명의 환자 중 17명(27%)에서 cTnT치가 분별한계치인 0.1 ng/mL 이상이었다. cTnT 양성을 보인 17명 중 혈액투석 환자는 13명(32%)이었으며 복막투석 환자는 4명(18%)으로 혈액투석 환자에서 더 많이 관찰되었으나 통계적인 의미는 찾아 볼 수 없었다(p>0.05). cTnI는 혈액투석 환자 1명(2%)에서만 분별한계치인 0.1 ng/mL 이상이었다. cTnT 및 cTnI치와 임상지표들 간의 상관관계를 살펴보았을 때 cTnT치와 혈청 알부민치와는 통계적으로 유의한 음의상관관계가 있었다(p<0.05). 말기 신부전의 원인 질환이 당뇨병인 환자군(n=39)에서 당뇨병이 아닌 군(n=24)보다 통계적으로 유의한 cTnT치의 증가를 보였다(39% vs. 8%, p<0.05). cTnI는 당뇨병 환자 1명(3%)에서만 분별한계치인 0.1 ng/mL 이상이었다. cTnT 및 cTnI치와 환자의 성별, 연령, 투석의 방법, 투석기간, 혈중 CPK, CK-MB, CK-index, LDH, 혈중 호모시스테인, 총 콜레스테롤, 중성지방치와는 연관이 없었다. 결 론: 유지투석 중인 말기 신부전 환자에서 cTnT와 혈청 알부민치의 유의한 상관관계와 당뇨병 환자에서 유의하게 증가하였음은 cTnT가 심장사건 예측 지표임을 추정할 수 있다. 그러나 본 연구는 예보로서, 이 결과만으로 cTnI가 cTnT 보다 더 예민한 지표란 결론을 단정지을 수는 없었다. Background : Despite of the high prevalence of cardiac disease, diagnosing and predicting myocardiac infarction in maintenance dialysis patients may be difficult. The availability of cardiac troponin T (cTnT) and cardiac troponin I(cTnI) offered promise for improving the accuracy of myocardial injuries in the ESRD patients. We hypothesized that cardiac troponin T and I might be useful markers of myocardial injury for patients with dialysis. Methods : We examined several clinical parameters to identify factors that determine cTnT and cTnI in dialysis patients. The study included 63 patients who had been on dialysis without evidence of myocardial damage for minimum 3 months. Patients were assessed using demographic, cardiac and atherogenic indices including CPK, CK-MB, CK index, LDH, homocysteine, total cholesterol, triglyceride and serum albumin level. All patients were undertaken EKG and echocardiography. Serum levels of cTnT and cTnI were measured by electrochemiluminescence immunoassay(ECL) and chemilumino immunoassay( CLIA) method. We estimated the correlation between cTnT and cTnI with several parameters by using Pearson correlation, linear correlation and Chisquare analysis. Results : The results are summarized as follows : The positivity of serum cTnT was higher in HD patients than CAPD(32% vs. 18%). But there was no significance statistically. Serum cTnI was elevated(≥ 0.1 ng/mL) in only one HD patient. Serum cTnT inversely correlated with serum albumin levels (p<0.05). The positivity of serum cTnT showed statistically significant correlation with underlying diabetic patients than non-diabetic patients(39% vs. 8%, p<0.05). Serum cTnI was elevated(≥0.1 ng/mL) in only one diabetic patient. We could not find the significant correlation between serum cTnT and cTnI with age, sex, dialysis mode, duration of dialysis, serum CPK, CK-MB, CK index, LDH, homocysteine, total cholesterol and triglyceride. Conclusion : Because cTnT revealed significant correlation with serum albumin and underlying diabetes mellitus. So we speculated that cTnT possibly might be a helpful marker as a predictor of myocardial event and mortality in maintenance dialysis patients. But we can not exclude false positivity of cTnT. And we are currently working to define that cTnI might be more specific marker of myocardial damage than cTnT and the development of cardiac event in cTnT-positive patients. (Korean J Nephrol 2002;21(2):244-250)

급성 A형 간염에 동반된 급성 간질성 신염 2예

이상일,손정일,박문향,김향,김병익,김현승,박범준,송승오,이규백,박찬필 대한신장학회 1999 Kidney Research and Clinical Practice Vol.18 No.6

Although acute renal failure is common in patients with fulminant hepatitis, it has been recognized as a rare complication of non-fulrninant acute hepatitis A. So far about 30 patients have been described in the literature who had acute hepatitis A associated with acute renal failure. Variable renal biopsy findings have been described in previous reports, including mostly acute tubular necrosis, mesangial proliferative glomerulonephritis, and interstitial nephritis. But the exact mechanism by which hepatitis A causes acute renal damage is still obscure. We describe two cases with acute hepatitis A, proven by IgM anti-hepatitis A antibodies complicated by acute renal failure. One patient required hemodialysis. Kidney biopsy findings showed interstitial nephritis with no evidence of glomerular involvement. Our review of these cases and the relevant literature suggests that there is strong evidence to implicate hepatitis A virus as a cause of acute renal failure. It remains to be elucidated why the histologic features are variable in the cases of hepatitis A virus induced acute renal failure and which factors predispose a patients to have immunologic involvement versus interstitial and tubular involvement.

Elevated Inorganic Phosphate Stimulates Akt-ERK1/2-Mnk1 Signaling in Human Lung Cells

Chang, Seung-Hee,Yu, Kyeong Nam,Lee, Yeon-Sook,An, Gil-Hwan,Beck Jr., George R.,Colburn, Nancy H.,Lee, Kee-Ho,Cho, Myung-Haing American Thoracic Society 2006 American journal of respiratory cell and molecular Vol.35 No.5

<P>Inorganic phosphate (Pi) plays a critical role in diverse cellular functions. Among three classes of sodium/phosphate co-transporters (NPTs), two types have been identified in mammalian lung. The potential importance of Pi as a novel signaling molecule and pulmonary expression of NPTs with poor prognosis of diverse lung diseases including cancer have prompted us to begin to define the pathways by which Pi regulates nontumorigenic human bronchial epithelial cells. Pi activates Akt phosphorylation on Thr308 specifically, and activated signal transmits on the Raf/MEK/ERK signaling. Here, we report that Pi controls cell growth by activating ERK cascades and by facilitating the translocation of Mnk1 from cytosol into nucleus through an Akt-mediated MEK pathway. Sequentially, translocated Mnk1 increases eIF4E-BP1 phosphorylation. As a result, Pi stimulates cap-dependent protein translation. Such Akt-mediated signaling of inorganic phosphate may provide critical clues for treatment as well as prevention of diverse lung diseases.</P>