• 한국결정학회:학술대회논문집
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• 한국결정학회 2007년도 추계학술연구발표회 및 정기총회
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• pp.24-24
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• 2007

• Macromolecular Research
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• 제13권6호
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• pp.549-552
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• 2005

• 한국지구과학회지
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• 제38권6호
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• pp.421-426
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• 2017

본 연구에서는 국내 암석을 대표할 수 있는 한국산 지질 표준물질을 제작하기 위해 대상이 되는 시료를 선정하고 암석학적 연구를 실시하였다. 지질 표준물질 대상 암석으로 쥐라기 화강암인 KJG-1와 KJG-2와 함께 백악기 화강암인 KCG-1을 선정하였다. 표준적인 분쇄 과정을 통하여 분말시료를 제조하고, X-선 형광을 위한 유리 비드를 제작하였으며, 최종적으로 시료들의 주성분 원소함량을 구하였다. 분석 자료에는 평균, 표준편차 및 상대 표준편차를 함께 제시하였다. 미국지질조사소(USGS)와 일본지질조사소(GSJ)의 지질표준물질을 함께 분석하여 그들의 참값과의 비교를 통해 5% 내의 정확도를 확인하였으며, 세 시료에 대한 XRF 분석결과 상대표준편차가 3% 내외의 높은 정밀도 역시 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.295-298
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• 2008

Creatine kinase (CK; E.C. 2.7.3.2) is an important enzyme that catalyzes the reversible transfer of a phosphoryl group from ATP to creatine in energy homeostasis. The brain-type cytosolic isoform of creatine kinase (BB-CK), which is found mainly in the brain and retina, is a key enzyme in brain energy metabolism, because high-energy phosphates are transfered through the creatine kinase/phosphocreatine shuttle system. The recombinant human BB-CK protein was overexpressed as a soluble form in Escherichia coli and crystallized at $22^{\circ}C$ using PEG 4000 as a precipitant. Native X-ray diffraction data were collected to $2.2{\AA}$ resolution using synchrotron radiation. The crystals belonged to the tetragonal space group $P4_32_12$, with cell parameters of a=b=97.963, $c=164.312{\AA},\;and\;{\alpha}={\beta}={\gamma}=90^{\circ}$. The asymmetric unit contained two molecules of CK, giving a crystal volume per protein mass $(V_m)$ of $1.80{\AA}^3\;Da^{-1}$ and a solvent content of 31.6%.

• 한국결정학회지
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• 제15권1호
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• pp.40-43
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• 2004

The peptide deformylase from the pathogenic bacterium Staphylococcus aureus has been over-expressed in Escherichia coli and crystallized in the presence of the inhibitor actinonin at 297 K using polyethylene glycol 20000 as a precipitant. X-ray diffraction data have been collected to 2.2 ${\AA}$ resolution. The crystal is trigonal, belonging to the space group $P3_121$ (or its enantiomorph $P3_221$), with unit cell parameters of a = b = 62.70 ${\AA}$ c = 108.23 ${\AA}$, ${\alpha}\;=\;{\beta}\;=\;90^{\circ},\;and\;{\gamma}\;=\;120^{\circ}$. An asymmetric unit contains a monomer of the recombinant enzyme, giving a $V_M$ of 2.84 ${\AA}^3\;Da^_{-1}$ and a solvent content of 56.7%.

• Biodesign
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• 제6권4호
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• pp.100-102
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• 2018

Autophagy is a degradation pathway that targets many cellular components and plays a particularly important role in protein degradation and recycling. This process is very complex and several proteins participate in this process. One of them, P62/SQSTM1, is related to the N-end rule and induces protein degradation through autophagy. The P62/SQSTM1 makes a huge oligomer, and this oligomerization is known to play an important role in its mechanism. This oligomerization takes two steps. First, the PB1 domain of P62/SQSTM1 makes the base oligomer, and then, when the ligand binds to the ZZ domain of P62/SQSTM1, it induces a higher oligomer by the disulfide bond of the two cysteines. To understand the oligomerization mechanism of P62/SQSTM1, we need to know the dimerization of the PB1 domain. In this study, crystals of PB1 dimer were made and the crystals were diffracted by X-ray to collect usable data up to 3.2A. We are analyzing the structure using the molecular replacement (MR) method.

• Molecules and Cells
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• 제19권3호
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• pp.398-401
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• 2005

The bacterial enzyme UDP-N-acetylglucosamine enolpyruvyl transferase catalyzes the first committed step of peptidoglycan biosynthesis, i.e., transfer of enolpyruvate from phosphoenolpyruvate to UDP-N-acetyl-glucosamine. We have overexpressed the enzyme from Haemophilus influenzae in Escherichia coli and crystallized it in the apo-form, as well as in a complex with UDP-N-acetylglucosamine and fosfomycin using ammonium sulfate as the precipitant. X-ray diffraction data from a crystal of the apo-form were collected to $2.8{\AA}$ resolution at 293 K. The crystal quality was improved by co-crystallization with UDP-N-acetylglucosamine and fosfomycin. X-ray data to $2.2{\AA}$ have been collected at 100 K from a flash-frozen crystal of the complex. The complex crystals belong to the orthorhombic space group I222 (or $I2_12_12_1$) with unit-cell parameters of a = 63.7, b = 124.5, and $c=126.3{\AA}$. Assuming a monomer of the recombinant enzyme in the crystallographic asymmetric unit, the calculated Matthews parameter ($V_M$) is $2.71{\AA}^3Da^{-1}$ and solvent content is 54.6%.

• 보존과학회지
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• 제37권3호
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• pp.220-231
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• 2021

문화재 방사선 비파괴 투과 조사 방식은 이미지플레이트(Image Plate, IP)를 사용하는 디지털 방사선영상시스템(Computed Radiography, CR)이 도입되면서 필름방식의 아날로그 이미지에서 점차 디지털 이미지로 교체되고 있다. 방사선 비파괴 투과 조사의 이미지 품질은 촬영 조건(관전압, 관전류, 노출시간), 영상 획득 매체, 촬영 거리, 유물의 두께 등이 영향을 미친다. 이 논문에서는 목재 문화재에 주로 사용되는 수종(소나무, 밤나무, 은행나무, 상수리나무)에 X선 선원의 투과 특성을 GE사(社)의 CR 영상 시스템을 통해 획득된 이미지의 그레이 스케일(Gray Scale)을 분석한 후 신호 대 잡음비(signal to noise ratio) 및 대조도를 평가하고, 이중-선 상질계(Duplex-wire image quality indicator), 구형파 차트(line-pair gauges), 선형 식별계(Image Quality Indicator)를 이용하여 이미지를 분석하였다.

• Asian Journal of Atmospheric Environment
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• 제7권1호
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• pp.1-7
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• 2013

To establish the method for investigating the behavior of aerosol particles deposited on the leaf surface against fog water under natural conditions, scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analysis and wash water analysis by ion chromatography after the washing treatment were performed using leaves of white birch collected from low part of the tree crown and the top of the tree in Sapporo City, Hokkaido, northern Japan. Each of collected leaves was divided into two parts according to the treatment performed: leaf surface (adaxial side) was 1) untreated, and 2) washed with deionized water with a pipette. In untreated samples, many particles of various shapes, including soil particles and organic debris, were deposited on the surface. Particles containing S were found on the surface of samples collected from only low part of the tree crown. After the washing treatment, SEM-EDX analysis revealed that soil particles and particles containing S had been washed off with water, although some particles such as soil particles and organic debris still remained on the leaf surface. The major anion such as $SO{_4}^{2-}$ was detected in wash water of all samples, although the peak of S in X-ray spectra was not detected from samples collected at top of the tree. The combination of SEM-EDX analysis with wash water analysis indicated that $SO{_4}^{2-}$ was deposited on the leaf surface in dissolved state and/or in state of submicron particles. These results suggested that fog water could remove soil particles and particles containing S and $SO{_4}^{2-}$ from the leaf surfaces, but not all particles. There was no difference in sampling position in the tree crown. Our study suggested that combination with SEM-EDX analysis and wash water analysis would be effective for investigation of the behavior of particles on the leaf surface against fog water.

• 천문학논총
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• 제32권1호
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• pp.235-237
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• 2017

The AKARI NEP Deep Field Survey is an international multiwavelength survey over $0.4deg^2$ of the sky. This is the deepest survey made by the InfraRed Camera (IRC) of the infrared astronomical satellite AKARI with 9 filters continuously covering the $2-25{\mu}m$ range, including three filters in the Spitzer gap between the IRAC and MIPS coverages. This enabled us to make sensitive MIR detection of AGN candidates at z~ 1, based on hot dust emission in the AGN torus. It is also efficient in detecting highly obscured Compton-thick AGN population. In this article, we report the first results of X-ray observations on this field. The field was covered by 15 overlapping Chandra ACIS-I observations with a total exposure of ~300 ks, detecting ${\approx}450$ X-ray sources. We utilize rest-frame stacking analysis of the MIR AGN candidates that are not detected individually. Our preliminary analysis shows a marginal detection of the rest-frame stacked Fe $k{\alpha}$ line from our strong Compton-thick candidates.