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LaM 상에서 암모니아와 메탄올로부터 메틸아민의 합성시 반응조건이 활성과 선택성에 미치는 영향
하백현,조원동,강동헌 한국화학공학회 1999 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.37 No.4
수소형 모더나이트(HM)와 이를 lanthanum 이온으로 이온교환한 LaM를 만들고 그의 구조적인 특성변화를 XRD, 산성을 IR에 의하여 측정하고 암모니아와 메탄올로부터 메틸아민 반응에서 반응온도, 반응압력, 접촉시간 및 암모니아/메탄올의 비를 변화시키며 활성과 DMA의 선택성을 연구하였다. 두 시료의 경우 모두 활성과 선택성의 변화는 80h 내에서는 일어나지 않았으며 온도상승에 따라 활성이 증가하며 온도에 따라 전화율의 변화가 큰 영역에서 DMA의 선택성이 가장 크다. LaM이 HM보다 활성은 좀 떨어지나 DMA의 선택성비 커서 HM의 30%에 비해 약 최대 50%를 나타내었다. 암모니아/메탄올의 비의 증가에 따라 알코올의 전화율이 증가하고 space velocity의 증가에 따라서는 전화율이 감소하나 space velocity가 2-4h^(-1)이상에서는 거의 변화가 없었다. 반응압력의 증가는 MMA의 생성을 급격히 감소시키며 DMA의 선택성을 증가시켰으나 약 4atm 이상에서는 전화율에 크게 영향을 주지 못했다. Hydrogen mordenite(HM) was ion-exchanged with lanthanum to give LaM and these catalysts were characterized by using XRD for crystallinity and IR for acidities/structures of the catalysts. The effects of reaction conditions such as reaction temperature, pressure, contact time and ratio of ammonia/methanol on the catalytic activity of methylamine synthesis and the selectivity to dimethylamine(DMA) were investigated from ammonia and methanol. The catalytic activity and DMA-selectivity of these catalysts remained for 80 h, and maximum selectivities of DMA were obtained at temperature range of methanol was rapidly converted. The DMA selectivity on LaM was 50% which was larger than that of 30% obtained on HM. The conversion of methanol increased with the ratio of ammonia/methanol and decreased with space velocity, but for the space velocity, 2-4 h^(-1) it was constant. The elevation of reaction pressure rapidly reduced the amount of produced monomethlamine, but increased selectivity of DMA up to 4 atm.
Kim, Dong Sik,Park, Heun,Hong, Soo Yeong,Yun, Junyeong,Lee, Geumbee,Lee, Jin Ho,Sun, Lianfang,Zi, Goangseup,Ha, Jeong Sook Elsevier 2019 APPLIED SURFACE SCIENCE - Vol.471 No.-
<P><B>Abstract</B></P> <P>We report the fabrication of a stretchable array of active-matrix (AM) electrochromic devices (ECDs). The ECD is made of poly(3-methylthiophene) and Prussian blue electrodes with a mixed gel electrolyte of acetonitrile, poly(methyl methacrylate), propylene carbonate, and lithium perchlorate. The ECD displays can express red, green, or blue (RGB) depending on the applied voltage and has a high stability in air. It exhibits low power consumption levels of 331 and 378 μW cm<SUP>−2</SUP> (10 s duration) at −1.0 and 1.0 V, respectively, and a high coloration efficiency of 201.6 cm<SUP>2</SUP> C<SUP>−1</SUP> at 1.0 V. A 4 × 4 AM ECD array is integrated on a deformable Ecoflex substrate via a dry transfer method using patterned liquid metal interconnections. The display shows a mechanical stability under bending and biaxial stretching by 30%. Finite element method analysis of the strain distribution also confirms that strain is not applied to the ECDs, guaranteeing stable operation of the array under deformation. Furthermore, a stretchable 6 × 6 AM ECD array for higher resolution display also exhibits mechanical stability under 30% biaxial stretching. This work demonstrates the high potential of our stretchable ECD array in low power-consuming displays for stretchable electronics, wearable devices, and electronic skin.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Poly(3-methylthiophene) (P3MT) and Prussian blue (PB) are grown on the ITO. </LI> <LI> Low-power consuming and full RGB color electrochromic device (ECD) can be achieved. </LI> <LI> Stretchable active-matrix ECD array exhibits mechanically stable under stretching. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
99mTc-DTPA 신스캔을 이용한 Aminoglycoside의 신독성에 관한 연구
이동원,정현철,이우철,박성민,이창원,이수봉,성은영,곽임수,나하연,송상헌 대한신장학회 1999 Kidney Research and Clinical Practice Vol.18 No.3
Aminoglycoside has a broad-spectrum bactericidal activity and especially excellent effect on gram negative bacteria. But, its harmful effect is existed about kidney and ear. Among these, many studies were done about aminoglycoside nephrotoxicity. Until now, many authors have been reported its incidence was 4.45-45%. We needed parameters monitoring about nephrotoxicity. So, our study was done using 99mTc-DTPA renal scan to evaluate nephrotoxicity. We enrolled forty patients who admitted due to infection. 32 patients received Netilmicin and 8 patients Isepamicin. Mean duration and dosage were 8 days, 200mg daily. We accomplished 99mTc-DTPA renal scan, 24hr urine study and blood sampling before starting antibiotics. After mean 8 days, same procedure was repeated. Aminoglycoside nephrotoxicity(defined as 50% GFR reduction) was presented in only one patient. She didn't have risky factor, such as hepatic dysfunction, hypotension, previous renal problem. However, duration was longer than other patients(13 days). GFR was fallen by 25-50% in 6 patients. This finding represent nephrotoxic effects of aminoglycoside indirectly. Above 6 patients had not any characteristics compared to other 33 patients. In addition to renal scan, sodium excretion was increased compared to pre-antibiotics, and glomerular filtration rate using 99mTc-DTPA renal scan was positively correlated with 24hr urine creatinine clearance, GFR by Cockcroft & Gault equation. I conclude that aminoglycoside has nephrotoxic effect when used for longer period. Thus, I suggest that DTPA renal scan including other many renal monitoring method has usefulness in revealing aminoglycoside nephrotoxicity.
Park, Heun,Kim, Dong Sik,Hong, Soo Yeong,Kim, Chulmin,Yun, Jun Yeong,Oh, Seung Yun,Jin, Sang Woo,Jeong, Yu Ra,Kim, Gyu Tae,Ha, Jeong Sook The Royal Society of Chemistry 2017 Nanoscale Vol.9 No.22
<P>In this study, we report on the development of a stretchable, transparent, and skin-attachable strain sensor integrated with a flexible electrochromic device as a human skin-inspired interactive color-changing system. The strain sensor consists of a spin-coated conductive nanocomposite film of poly(vinyl alcohol)/multi-walled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) on a polydimethylsiloxane substrate. The sensor exhibits excellent performance of high sensitivity, high durability, fast response, and high transparency. An electrochromic device (ECD) made of electrochemically synthesized polyaniline nanofibers and V2O5 on an indium tin-oxide-coated polyethylene terephthalate film experiences a change in color from yellow to dark blue on application of voltage. The strain sensor and ECD are integrated on skin via an Arduino circuit for an interactive color change with the variation of the applied strain, which enables a real-time visual display of body motion. This integrated system demonstrates high potential for use in interactive wearable devices, military applications, and smart robots.</P>
이동원,정현철,이우철,박성민,이수봉,송상헌,나하연,성은영,안준협,곽임수 대한내과학회 1998 대한내과학회지 Vol.55 No.5
The authors report the case of a 25 year old woman with a chronic corticosteroid-refractory nephrotic syndrome complicated by myocardial infarction. The thromboembolism, especially acute myocardial infarction, is the most serious complication of nephrotic syndrome. Until now many mechanisms have been studied about thromboembolism including coronary artery disease in nephrotic syndrome, but not clear. Hypercoagulability and prolonged hyperlipidemia are known as the principal contributing factors in this complication. In addition, use of steroid as therapeutic trial and hypovolemic state induced by vigorous diuretics will affect the thromboembolism, too. In this case, several coagulation abnormality and prolonged hyperlipidemia are observed. On admission day, this patient had deep vein thrombosis and then was complicated by pulmonary thromboembolism. Despite of anticoagulant and thrombolytic therapy, she experienced acute myocardial infarction on fourth day after admission. After onset of myocardial infarction, by thrombolytics and prolonged anticoagulant therapy, this nephrotic patient was relieved and discharged without other serious complication. We recommend anticoagulant and antiplatelet agent therpy in risky patient of nephrotic syndrome. We present this case with review of literature.
Park, Heun,Kim, Jung Wook,Hong, Soo Yeong,Lee, Geumbee,Lee, Hanchan,Song, Changhoon,Keum, Kayeon,Jeong, Yu Ra,Jin, Sang Woo,Kim, Dong Sik,Ha, Jeong Sook American Chemical Society 2019 ACS NANO Vol.13 No.9
<P>Textile-based electronics have attracted much attention as they can perfectly combine the functionality of wearable devices with the soft and comfortable properties of flexible textile fibers. In this work, we report a dynamically stretchable high-performance supercapacitor for powering an integrated sensor in an all-in-one textile system to detect various biosignals. The supercapacitor fabricated with MWCNT/MoO<SUB>3</SUB> nanocomposite electrodes and nonaqueous gel electrolyte, along the course direction of the fabric, exhibits stable and high electrochemical performance under dynamic and static deformation, including stretching in real time, regardless of the strain rate. The strain sensor created along the wale direction of the fabric shows a high sensitivity of 46.3 under an applied strain up to 60%, a fast response time of 50 ms, and high stability over 10 000 cycles of stretching/releasing. Finally, the supercapacitor and strain sensor are integrated into an all-in-one textile system <I>via</I> liquid-metal interconnections, and the sensor is powered by the stored energy in the supercapacitor. This system sewed into cloth successfully detects strain due to joint movement and the wrist pulse. This work demonstrates the high feasibility of utilizing the fabricated stretchable all-in-one textile system for real-time health monitoring in everyday wearable devices.</P> [FIG OMISSION]</BR>