PLLA분해활성을 가진 고온성세균을 우리나라 경작토로부터 분리하였다. 분리된 균주는 그람양성 간균으로 16S rDNA 염기서열분석 결과 Geobacillus caldoxylosilyticus로 동정되었으며, 현재까지 보고되지 않은 새로운 PLLA분해세균으로 밝혀졌다. 조절화된 퇴비화조건에서 멸균퇴비에 분리균주를 접종하고 58℃에서 40일간 분해활성을 측정하였다. 이 균주는 중량평균 분자량이 5000, 11000, 34000 및 2560

The acenaphthene(ACE) or acenaphthylene(ACEL) is one of the most frequently found compound in polycyclic aromatic hydrocarbon (PAH)-contaminated soil. In this study, we make 10mg/L ACE or ACEL in ethanol which is the model washing solvent for contaminated soil. This was followed by Fenton treatment in which 0.2 or 0.3mL of 30% H2O2 and 0.2 ml of 0.5 M Fe2+ were added. The results showed more than 88 or 99% of ACE or ACEL removal efficiency, respectively. Additionally, we employed GC-MS to identify the main oxidation product generated by the optimized Fenton oxidation [i.e., ACE or ACEL degraded in to 21, 34 % 1,8-naphthalic anhydride(NAPAN), repectively]. It is expected that biodegradability of NAPAN is enhanced because NAPAN has three oxygens compared with ACE and ACEL. Therefore the results suggest that the hybrid treatment system (i.e., ethanol washing -Fenton oxidation treatment) can be effectively applied to remove ACE or ACEL from soil..

In order to investigate 95% retained critical current of Bi-2223/Ag tapes under various stress-strain conditions, load cell attached tension and bending apparatus was used. The critical current of stress-strained tape was degraded below 95% retained critical current when tension and bending was simultaneously applied together. But only one of this tension or bending did not degrade the tape below 95% retained critical current. Deformation temperature was important to maintain the 95% retained Ic of Bi-2223/Ag tapes after bending or tension deformation because mechanical strength of tapes can be changed drastically between room temperature and 77 K.

β-catenin is a cytoplasmic protein that participates in the assembly of cell-cell adherens junctions by binding cadherins to the cytoskeleton. In addition, it is a key component of the Wnt signaling pathway. Activation of this pathway triggers the accumulation of β-catenin in the nucleus, where it activates the transcription of target genes. Abnarmal accumulation of β -catenin is characteristic of polyposis coli(APC) or Axin tumor suppressor proteins, which regulates β-catenin degradation, or activating mutations in β-catenin molecule itself. Here we show that overexpression of Sox4 down-regulates wild type β-catenin in HEK 293 cells. The inhibitory effect of Sox4 on wild type β-catenin is apparently mediated by the ubiquitin- proteasoem system and requires an active glycogen synthase kinase 3β(GSK3β). Mutations in the N-terminus of β -catenin(S33Y) which compromise its degradation by the proteasomes or inhibition of GSK3β activity rendered β-catenin resistant to down-regulation by Sox4. In light of recent evidence that Sox4 expression is activated in colon and other tumors with β-catenin dysregulation, our findings suggest that Sox4 is part of a feedback inhibitory pathway for Wnt signaling in normal cells. Moreover, the mutations in APC, Axin or β-catenin in cancer cells appear to render β-catenin resistant to the effects of Sox4 inhibition.

The photocatalytic degradation of methylene blue(MB) was investigated using TiO2 as photocatalyst and UV radiation. TiO2 supported with activated carbon(AC) was prepared by SOL-GEL method and depended on several parameters such as the mass ratio of TiO2/AC, pH and experimental time. The presence of the anatase and rutile crystal phase was determined by XRD analyses of the prepared TiO2. The degradation of MB with TiO2/AC was about 20% higher than that of AC alone. A variation of photodegradation was negligible under UV radiation conditions ( ≥ 40W). It was experimentally showed that the photodegradation rate was increased with increasing the amount of photocatalyst. The optimal catalyst was prepared by impregmation of 5wt%-TiO2 with AC and was calcined at 300℃, and showed about 99% removal efficiency for 3hrs.

비내진 설계된 철근콘크리트 골조는 내진상세의 미확보로 인하여 전단파괴의 가능성이 있다. 이러한 전단파괴를 해석 모델링에 반영하기 위하여 Moehle과 ATC 40을 포함한 4개의 전단강도감소 모델을 선택하고 비교하였으며, 각 모델을 예제 건물에 적용하여 Push-over해석을 수행하였다. 해석용 예제 모델은 3층 규모로 하였으며 국내 콘크리트 설계기준에 따라 설계하였다. 전단강도 감소모델 비교 결과, Moehle의 모델은 NZSEE의 모델보다 전단내력을 작게 평가하고 ATC 40 모델에 비하여 휨 연성도에 따른 내력의 변동이 작으며, 대부분의 경우에 고찰된 모델들의 전단내력은 ACI 318의 공칭 전단강도보다 크게 나타남을 알 수 있었다. 예제 모델의 수치해석 비교 결과, 전단강도 감소모델에 따라 건물의 수평 저항 능력에 큰 차이가 나타나며, 전단스프링에 전단강도 감소를 고려한 모델에 비하여 ATC 40의 횡 소성 변형을 제한하는 모델을 사용하면 횡저항 능력을 과소평가하게 됨을 알 수 있었다.

To induce the enhanced mutants of dinitroaniline herbicide pendimethalin degrading bacterium, Bacillus sp. MS202 was irradiated with gamma radiation at the dose of LD99 (3.35 kGy). Three enhanced mutants (MS202m7, MS202m14, MS202m18) were isolated fr

Activated carbon fiber (ACF) filters are widely used to remove volatile organic compounds (VOCs) in air cleaning devices. The performance of ACF filters could be enhanced combining adsorption process with photodegradation process. In this study, to investigate this enhancement effect, a duct-type reactor was made and TiO2 was i㎜obilized on a co㎜ercialized ACF filter. Benzene, toluene, and m-xylene (BTX) were chosen as target compounds. Removal experiments for BTX were done under different air velocity and upstream concentration conditions. The range of inlet concentration was 200～1,400 ppb and the air velocities were 0.4, 0.7 and 1.0 m/s. Adsorption by an ACF filter alone showed high removal efficiency of BTX, depending on the BTX species, the upstream concentration, and the air velocity. The combination of TiO2 and ACF filter significantly increased removal of benzene which was less removed than other pollutants by an ACF filter alone. It was found that the combination effect was small in removal test of toluene and m-xylene. Removal efficiency in the tested experimental conditions was decreased in order of toluene > m-xylene > benzene.

Room temperature kinetics of degradation of nerve agent simulants and sarin, an actual nerve agent at the surface of different carbon based adsorbent materials such as active carbon grade 80 CTC, modified whetlerite containing 2.0 and 4.0 % NaOH, active carbon with 4.0 % NaOH, active carbon with 10.0 % Cu (II) ethylenediamine and active carbon with 10.0 % Cu (II) 1,1,1,5,5,5-hexafluoroacetylacetonate were studied. The used adsorbent materials were characterized for surface area and micropore volume by N2 BET. For degradation studies solution of simulants of nerve agent such as dimethyl methylphosphonate (DMMP), diethyl chlorophosphate (DEClP), diethyl cyanophosphate (DECnP) and nerve agent, i.e., sarin in chloroform were prepared and used for the uniform adsorption on the adsorbent systems using their incipient volume at room temperature. Degradation kinetics was monitored by GC/FID and was found to be following pseudo first order reaction. Kinetics parameters such as rate constant and half life were calculated. Half life of degradation with modified whetlerite (MWh/NaOH) system having 4.0 % NaOH was found to be 1.5, 7.9, 1206 and 20 minutes for DECnP, DEClP, DMMP and sarin respectively. MWh/NaOH system showed maximum degradation of simulants of nerve agents and sarin to their hydrolysis products. The reaction products were characterized using NMR technique. MWh/NaOH adsorbent was also found to be active against sulphur mustard.