• 멤브레인
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• 제24권2호
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• pp.167-175
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• 2014

수증기 투과성과 DMMP 방호성능을 가지는 cellulose acetate butyrate (CAB)/polyethyleneimine (PEI) 기반의 선택투과막에 대해 여러가지 첨가제를 적용하여 CEES에 대한 방호성능 개선을 시도하였다. 시험결과, CAB/PEI 기반의 선택투과막은 수증기 투과성은 그대로 유지하면서(${\geq}1,800g/m^2/day$), CEES에 대한 방호성능의 개선을 보여주었다($7.1{\sim}11.5{\mu}g/cm^2{\cdot}24hr$). 이 중, $Ag^+$ 이온과 이온교환수지 혼합물을 포함한 CAB/PEI 선택투과막에서 가장 우수한 방호성능을 확보하였다. 그리고 시험한 모든 선택투과막은 생물학작용제를 모사할 수 있는 다양한 크기의 에어로졸 입자($0.005{\sim}3{\mu}m$)에 대해서도 방호성능을 가짐을 확인하였다.

• Korean Chemical Engineering Research
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• 제45권3호
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• pp.291-297
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• 2007

수포작용제의 일종인 sulfur mustard(HD, bis 2-chloroethylsulfide)를 무해한 물질로 전환하기 위한 공정 운영조건을 찾기 위하여 물에 의한 HD 가수분해 반응을 연구하고 분석절차를 수립하였다. 반응은 2단계로 진행하였다. 먼저, HD 10~20 wt%를 $90^{\circ}C$ 물에서 2시간 동안 가수분해 한 후 상온에서 가성소다 수용액(2.1 당량)을 주입하면서 반응시간에 따른 HD의 농도변화를 측정하였다. 이 실험조건에서 HD의 분해효율은 99.99% 이상 이었으며 가수분해 후의 최종 분해물질은 thiodiglycol 68 wt%, 1,2-bis(2-hydroxyethylthio)ethane 8 wt% 및 bis(2-hydroxyethylthioethyl)ether 24 wt% 이었다.

• 센서학회지
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• 제13권5호
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• pp.323-328
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• 2004

N-type semi-conducting oxides such as $SnO_{2}$, ZnO, and $ZrO_{2}$ have been known for the detecting materials of inflammable or toxic gases. Of those materials, $SnO_{2}$-based sensors are well known as high sensitive materials to detect toxic gases. And the sensitivity is improved if catalysts are added. Detecting toxic gases, especially DMMP (di-methyl-methyl-phosphonate) and DPGME (Dipropylene glycol methyl ether), was performed by a mixture of Tin oxide ($SnO_{2}$) and Zirconia ($ZrO_{2}$). The films consist of each three different mass% of Zr (from 1 mass% to 5 mass%), and they were tested by XRD, SEM, TEM, BET. Nano-structure, pore and particle size was controlled to verify the sensor's sensing mechanism. The sensors was evaluated at five different degrees (from $200^{\circ}C$ to $400^{\circ}C$) and three different concentrations (from 500 ppb to 1500 ppb). The sensors had good sensitivity of both simulants, and high selectivity of DMMP.

• Molecules and Cells
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• 제39권12호
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• pp.869-876
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• 2016

Cantharidin (CTD) is an active compound isolated from the traditional Chinese medicine blister beetle and displayed anticancer properties against various types of cancer cells. However, little is known about its effect on human chronic myeloid leukemia (CML) cells, including imatinib-resistant CML cells. The objective of this study was to investigate whether CTD could overcome imatinib resistance in imatinib-resistant CML cells and to explore the possible underlying mechanisms associated with the effect. Our results showed that CTD strongly inhibited the growth of both imatinib-sensitive and imatinib-resistant CML cells. CTD induced cell cycle arrest at mitotic phase and triggered DNA damage in CML cells. The ATM/ATR inhibitor CGK733 abrogated CTD-induced mitotic arrest but promoted the cytotoxic effects of CTD. In addition, we demonstrated that CTD downregulated the expression of the BCR-ABL protein and suppressed its downstream signal transduction. Real-time quantitative PCR revealed that CTD inhibited BCR-ABL at transcriptional level. Knockdown of BCR-ABL increased the cell-killing effects of CTD in K562 cells. These findings indicated that CTD overcomes imatinib resistance through depletion of BCR-ABL. Taken together, CTD is an important new candidate agent for CML therapy.

• The Journal of Advanced Prosthodontics
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• 제7권2호
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• pp.85-92
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• 2015

PURPOSE. This study aimed to investigate the efficacy of cleaning solutions on saliva-contaminated zirconia in comparison to air-abrasion in terms of resin bonding. MATERIALS AND METHODS. For saliva-contaminated air-abraded zirconia, seven cleaning methods)-no contamination (NC), water-spray rinsing (WS), additional air-abrasion (AA), and cleaning with four solutions (Ivoclean [IC]; 1.0 wt% sodium dodecyl sulfate [SDS], 1.0 wt% hydrogen peroxide [HP], and 1.0 wt% sodium hypochlorite [SHC])-were tested. The zirconia surfaces for each group were characterized using various analytical techniques. Three bonded resin (Panavia F 2.0) cylinders (bonding area: $4.5mm^2$) were made on one zirconia disk specimen using the Ultradent jig method [four disks (12 cylinders)/group; a total of 28 disks]. After 5,000 thermocycling, all specimens were subjected to a shear bond strength test with a crosshead speed of 1.0 mm/minute. The fractured surfaces were observed using an optical and scanning electron microscope (SEM). RESULTS. Contact angle measurements showed that groups NC, AA, IC, and SHC had hydrophilic surfaces. The X-ray photoelectron spectroscopy (XPS) analysis showed similar elemental distributions between group AA and groups IC and SHC. Groups IC and SHC showed statistically similar bond strengths to groups NC and AA (P>.05), but not groups SDS and HP (P<.05). For groups WS, SDS, and HP, blister-like bubble formations were observed on the surfaces under SEM. CONCLUSION. Within the limitations of this in vitro study, some of the cleaning solutions (IC or SHC) were effective in removing saliva contamination and enhancing the resin bond strength.