Simulation of single grid-based phase-contrast x-ray imaging (g-PCXI)

Lim, H.W.,Lee, H.W.,Cho, H.S.,Je, U.K.,Park, C.K.,Kim, K.S.,Kim, G.A.,Park, S.Y.,Lee, D.Y.,Park, Y.O.,Woo, T.H.,Lee, S.H.,Chung, W.H.,Kim, J.W.,Kim, J.G. Elsevier BV * North-Holland 2017 Nuclear Instruments & Methods in Physics Research. Vol. No.

<P><B>Abstract</B></P> <P>Single grid-based phase-contrast x-ray imaging (g-PCXI) technique, which was recently proposed by Wen et al. to retrieve absorption, scattering, and phase-gradient images from the raw image of the examined object, seems a practical method for phase-contrast imaging with great simplicity and minimal requirements on the setup alignment. In this work, we developed a useful simulation platform for g-PCXI and performed a simulation to demonstrate its viability. We also established a table-top setup for g-PCXI which consists of a focused-linear grid (200-lines/in strip density), an x-ray tube (100-μm focal spot size), and a flat-panel detector (48-μm pixel size) and performed a preliminary experiment with some samples to show the performance of the simulation platform. We successfully obtained phase-contrast x-ray images of much enhanced contrast from both the simulation and experiment and the simulated contract seemed similar to the experimental contrast, which shows the performance of the developed simulation platform. We expect that the simulation platform will be useful for designing an optimal g-PCXI system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> It is proposed for the single grid-based phase-contrast x-ray imaging (g-PCXI) technique. </LI> <LI> We implemented for a numerical simulation code. </LI> <LI> The preliminary experiment with several samples to compare is performed. </LI> <LI> It is expected to be useful to design an optimal g-PCXI system. </LI> </UL> </P>

200 GeV/핵자 유황이온과 핵건판핵의 충돌에 의해 생성된 헬륨 파쇄핵의 극한파쇄 연구

김동철,송진섭,윤천실,정성헌,박인곤,김종오,김철수,김태연,이승희,조재희,천병구,김재률,김준원,김태익,박명렬,장한일,임인택 慶尙大學校 기초과학연구소 1992 基礎科學硏究所報 Vol.8 No.-

고에너지 중이온 원자핵과 핵건판의 충돌에서, 200GeV/핵자 유황이온에 의해 생성된 파쇄 헬륨핵(Z=2)의 실험실계의 방출각 분포는 표적핵에 무관한 회귀공식. dN=exp[a+k exp(η-y_b)]d[exp(η-y_b)]로 잘 표현된다. 여기에서 의사신속도 η=-ln[tan(θ/2)]이고, y_b는 실험실계의 입사입자(^32S)의 신속도이다. 이 공식에 의한 적합에서 k=-0.057±0.008로 얻어진다. 즉, 핵건판과 고에너지 중이온의 충돌에서 파쇄 헬륨핵의 exp(η-y_b)의 분포는 "극한파쇄" 현상을 잘 설명하고 있다. The angular distribution of emission angle θ of helium (Z=2) produced in the collisions of incident particles of 200 GeV/nucleon ^32S in nuclear emulsion is well expressed by dN=exp[a+k exp(η-y_b)]d[exp(η-y_b)] where the pseudorapidity is η=-ln[tan(θ/2)], the laboratory system primary rapidity is y_b, and k=-0.057+0.008. The shape of this frequency of occurrence distributions in terms of exp(η-y_b) attests to the validity of the concept of "limiting fragmentation" for helium projectile fragments produced in the projectile fragmentation regions of heavy ion collisions in nuclear emulsion.

Failure of a breakwater founded on a thick normally consolidated clay layer

Chung, S. G.,Kim, S. K.,Kang, Y. J.,Im, J. C.,Prasad, K. N. INSTITUTION OF CIVIL ENGINEERS 2006 Géotechnique Vol.56 No.6

The E3 ubiquitin ligase CHIP selectively regulates mutant epidermal growth factor receptor by ubiquitination and degradation

Chung, C.,Yoo, G.,Kim, T.,Lee, D.,Lee, C.S.,Cha, H.R.,Park, Y.H.,Moon, J.Y.,Jung, S.S.,Kim, J.O.,Lee, J.C.,Kim, S.Y.,Park, H.S.,Park, M.,Park, D.I.,Lim, D.S.,Jang, K.W.,Lee, J.E. Academic Press 2016 Biochemical and biophysical research communication Vol.479 No.2

Somatic mutation in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) is a decisive factor for the therapeutic response to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in lung adenocarcinoma. The stability of mutant EGFR is maintained by various regulators, including heat shock protein 90 (Hsp90). The C terminus of Hsc70-interacting protein (CHIP) is a Hsp70/Hsp90 co-chaperone and exhibits E3 ubiquitin ligase activity. The high-affinity Hsp90-CHIP complex recognizes and selectively regulates their client proteins. CHIP also works with its own E3 ligase activity independently of Hsp70/Hsp90. Here, we investigated the role of CHIP in regulating EGFR in lung adenocarcinoma and also evaluated the specificity of CHIP's effects on mutant EGFR. In HEK 293T cells transfected with either WT EGFR or EGFR mutants, the overexpression of CHIP selectively decreased the expression of certain EGFR mutants (G719S, L747_E749del A750P and L858R) but not WT EGFR. In a pull-down assay, CHIP selectively interacted with EGFR mutants and simultaneously induced their ubiquitination and proteasomal degradation. The expressions of mutant EGFR in PC9 and H1975 were diminished by CHIP, while the expression of WT EGFR in A549 was nearly not affected. In addition, CHIP overexpression inhibited cell proliferation and xenograft's tumor growth of EGFR mutant cell lines, but not WT EGFR cell lines. EGFR mutant specific ubiquitination by CHIP may provide a crucial regulating mechanism for EGFR in lung adenocarcinoma. Our results suggest that CHIP can be novel therapeutic target for overcoming the EGFR TKI resistance.

Geotechnical Characteristics of Marine Clay in Busan New Port

Chung, S.G.,Ryu, C.K.,Beak, S.H.,Huh, D.Y.,Jo, K.Y.,Lee, N.K.,Ninjgarav 東亞大學校建設技術硏究所 2004 硏究論文集 Vol.28 No.1

Since early 1990s reclamation projects in Busan and its vicinity in Nakdong River plain have been performed for industrial and residential complexes. As well it has started to build a new port (Busan Newport) due to increase in overloads of Busan port since late 1990s. In the area the sedimentary deposit is composed of soft clay of about 30m thick, thin sand layer of 3-4m thick, hard clayey soil, and then basal conglomerates and sandy sediments, total thickness of which is about 70m at the maximum under seawater. For the huge project many contract companies have simultaneously performed geotechnical investigations to get design parameters. Based on the harmful experiences gained by the previous projects, it was also required to pay careful attention to sampling and laboratory and field tests for the project. Nevertheless the results of laboratory tests were so scattered and then resulted in difficulty to evaluate the design parameters. Existing data has been reviewed to evaluate the validity or cause of their variation. In addition geological study, sampling and soil tests have been carefully carried out at a few locations. Using the results the clay would be effectively characterized for depositional environment and its relation to soil properties.

암에르고미터 운동시 여유심박수에서의 신체작업능력(PWC%HRR)을 이용한 최대산소섭취량 추정에 관한 연구

정성태,전태원,정덕조,정영수,엄우섭,이동기,윤호섭 한국운동과학회 2000 운동과학 Vol.9 No.1

암에르고미터 운동시 여유심박수에서의 신체작업능력(PWC%HRR)을 이용한 최대산소섭취량 측정에 관한 연구 운동과학. 제 9권 제 1호. (1)-(12), 2000. 본 연구의 목적은 암에르고미터 운동시 여유심박수에서의 신체작업능력(PWC%HRR)을 이용해 최대산소섭취량(O₂_(max))을 추정하는데 있어 그 타당성을 보는데 있다. 이를 위해 본 연구에서는 건강한20대 남자 대학생(21.1±2.77)20명이 참가 하였다. 이들의 안정시 심박수는 5분간 EKG로 측정되었고, 최대산소취량은 암에르고미터에서 50rpm의 속도로 20W에서 운동을 실시하고 매 3분 간격으로 10W씩 증가시켜 피험자가 탈진시까지 운동을 지속시켰다. 여유심박수 계산에 있어서 최대심박수는 수식(HRmax = 210 - age)으로 계산되었다. PWC%HRR의 계산은 점증부하 운동상에서 120≤R≥160의 범위에 발견된 HR과 O₂의 관계식(Y=bx+a)에 의하였다. 강도별 상대적 백분율 범위는 50∼85%사이였으며, 비교대상은 PWC%HRR, O₂R, O₂_(max)이었다. 그 결과 다음과 같은 결과를 얻었다 첫째, %HRR과 O₂R, O₂_(max)간의 회귀분석결과 %HRR은 O₂_(max)보다 O₂R에 가까웠다. 둘째, 각 강도별 PWC%HRR과 O₂R, O₂_(max)간에는 통계적으로 유의한 차이는 없었으나, PWC%HRR은 O₂_(max)보다 O₂R에 보다 가까웠다(P<.05). 셋째, O₂_(max)의 실측치와 PWC%HRR = O₂R에 의한 추정치 사이에는 모든 강도에서 통계적으로 유의한 차이가 없었으나, 상관관계는 PWC%HRR에서 가장 높았다(P<.05). 이상의 결과를 종합해 볼 때 암에르고미터 운동검사 과정에서 만족할 만한 O₂_(max) 발견하지 못했더라도 최소한 60%HRR에 해당하는 심박수가 발견될 때까지 운동을 수행하였다면 일련의 방식에 의해 O₂_(max)의 추정이 가능하다고 본다. The study on Estimation of maximal oxygun uptake through PWC%HRR during Arm Ergometer Exercise. Exercise Science, 9(1): 1-12, 2000. The purpose of this study was to evaluate the validity for estimation of maximal oxygen uptake through PWC%HRR during Arm Ergometer Exercise. The subjects of this study were 20 healthy males(21.2±2.77yrs) college students. Resting heart rate of subjects were recorded by EKG for 5min. the maximal oxygen uptake was determined until subjects were exhausted. The first stage was performed 50rpm, 20W, and then was increased by 10W every 3 minutes on the arm ergometer. HRmax was determined by a numerical formula of HRmax = 210-age. PWC%HRR was assessed by relative equation (Y=bX+a) of HR and V˙O₂ observed in range 120≤R≥160 during the exercise test. Range of relative percentage was between 50% and 85%, comparison factor was examined among PWC%HRR, % V˙O₂R and % V˙O₂_(max). The results of this study are as follows : 1) Result of the regression analysis among PWC%HRR, % V˙O₂R and % V˙O₂_(max), %HRR was equivalent to % V˙O₂R rather than V˙O₂_(max). 2) No significant difference was observed among PWC%HRR, % V˙O₂R and V˙O₂_(max) in the all intensity, But the PWC%HRR was closer to % V˙O₂R rather than V˙O₂_(max)(P<.05). 3) No significant difference was the actual V˙O₂_(max) and the estimation value by PWC%HRR = % V˙O₂R in the all intensity, and the correlation analysis was the most correlated at the estimation value by PWC%60HRR. It was concluded that if the satisfactory V˙O₂_(max) was not found in Arm Ergometer exercise test but heart rate corresponded to 60%HRR, V˙O₂_(max) can be estimated by a series of equation.

OGLE-2016-BLG-0693LB: Probing the Brown Dwarf Desert with Microlensing

Ryu, Y.-H.,Udalski, A.,Yee, J. C.,Albrow, M. D.,Chung, S.-J.,Gould, A.,Han, C.,Hwang, K.-H.,Jung, Y. K.,Shin, I.-G.,Zhu, W.,Cha, S.-M.,Kim, D.-J.,Kim, H.-W.,Kim, S.-L.,Lee, C.-U.,Lee, Y.,Park, B.-G.,P American Astronomical Society 2017 The Astronomical journal Vol.154 No.6

<P>We present an analysis of microlensing event OGLE-2016-BLG-0693, based on the survey-only microlensing observations by the OGLE and KMTNet groups. In order to analyze the light curve, we consider the effects of parallax, orbital motion, and baseline slope, and also refine the result using a Galactic model prior. From the microlensing analysis, we find that the event is a binary composed of a low-mass brown dwarf (49(-18)(+20) Mj) companion and a K- or G-dwarf host, which lies at a distance of 5.0 +/- 0.6 kpc toward the Galactic bulge. The projected separation between the brown dwarf and its host star is less than similar to 5 au, thus it is likely that the brown dwarf companion is located in the brown dwarf desert.</P>

진행성 위선암 환자에서 p53의 예후적 의의

박유환(Y .H .Park),정춘혜(C .H .Chung),조영신(Y .S .Cho),김동규(D .G .Kim),손현화(H .H .Son),서영선(Y .S .Seo),이미자(M .J .Lee) 대한내과학회 2000 대한내과학회지 Vol.58 No.5

N/A Background : The role of oncogenes and tumor suppressor genes in the pathogenesis of gastric carcinoma has recently received considerable attention. The tumor suppressor gene, p53 locus on chromosome 17p, ceases a mitosis in G1/S check point after DNA demage. Abnormality of the p53 tumor suppressor gene plays an important role in alteration of cells and possibly leads to cancer development. The authors investigated the correlation between expression of p53 and prognosis in advanced gastric carcinoma. Methods : Expression of tumor suppresor gene p53 was investigated immunohistochemically in the primary lesion of 34 patients with advanced gastric carcinoma using paraffin embedded surgical specimens and the relationship of p53 immunopositivity with the clinicopathologic variables(Age, Sex, TNM staging, Lauren classification, Borrmann classification), 5-year survivals and life curves were analyzed. Kaplan and Meier's method is used as a life curve and log crank method is used for the analysis of prognostic factor. Results : Total p53 positive rate was 53% (18 of 34) of all cases. p53 immunopositivity was not associated with other clinicopathologic variables. The 5-year survivals were 44% and 11% for patients with p53 negative and positive gastric carcinomas, respectively. Patents with the expression of p53 has predominantly poor results in comparison of life curve(p<0.05) Conclusion : These findings suggest that p53 gene alteration be associated with poor prognosis of advanced gastric adenocarcinoma(Korean J Med 58:568-574, 2000)

High-level extracellular production and characterization of Candida antarctica lipase B in Pichia pastoris

Eom, G.T.,Lee, S.H.,Song, B.K.,Chung, K.W.,Kim, Y.W.,Song, J.K. Society for Bioscience and Bioengineering, Japan ; 2013 Journal of bioscience and bioengineering Vol.116 No.2

The gene encoding lipase B from Candida antarctica (CalB) was expressed in Pichia pastoris after it was synthesized by the recursive PCR and cloned into the Pichia expression plasmid, pPICZαA. The CalB was successfully secreted in the recombinant P. pastoris strain X-33 with an apparent molecular weight of 34 kDa. For 140 h flask culture, the dry cell weight and the extracellular lipase activity reached at 5.4 g/l and 57.9 U/l toward p-nitrophenyl palmitate, respectively. When we performed the fed-batch fermentation using a methanol feeding strategy for 110 h, the dry cell weight and the extracellular lipase activity were increased to 135.7 g/l and 11,900 U/l; the CalB protein concentration was 1.18 g/l of culture supernatant. The characteristics of CalB recovered from the P. pastoris culture were compared with the commercial form of CalB produced in Aspergillus oryzae. The kinetic constants and specific activity, the effects of activity and stability on temperature and pH, the glycosylation extent, the degree of immobilization on macroporous resin and the yield of esterification reaction between oleic acid and n-butanol were almost identical to each other. Therefore, we successfully proved that the Pichia-based expression system for CalB in this study was industrially promising compared with one of the most efficient production systems.

Identification of Novel SNPs in Bovine Insulin-like Growth Factor Binding Protein-3 (IGFBP3) Gene

Kim, J.Y.,Yoon, D.H.,Park, B.L.,Kim, L.H.,Na, K.J.,Choi, J.G.,Cho, C.Y.,Lee, H.K.,Chung, E.R.,Sang, B.C.,Cheong, I.J.,Oh, S.J.,Shin, Hyoung Doo Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.1

The insulin-like growth factors (IGFs), their receptors, and their binding proteins play key roles in regulating cell proliferation and apoptosis. Insulin-like growth factor binding protein-3 (IGFBP3, OMIM #146732) is one of the proteins that bind to the IGFs. IGFBP3 is a modulator of IGF bioactivity, and direct growth inhibitor in the extravascular tissue compartment. We identified twenty-two novel single nucleotide polymorphisms (SNPs) in IGFBP3 gene in Korean cattle (Hanwoo, Bos taurus coreanae) by direct sequencing of full gene including -1,500 bp promoter region. Among the identified SNPs, five common SNPs were screened in 650 Korean cattle; one SNP in promoter (IGFBP3 G-854C), one in 5'UTR region (IGFBP3 G-100A), two in intron 1 (IGFBP3 G+421T, IGFBP3 T+1636A), and one in intron 2 (IGFBP3 C+3863A). The frequencies of each SNP were 0.357 (IGFBP3 G-854C), 0.472 (IGFBP3 G-100A), 0.418 (IGFBP3 G+421T), 0.363 (IGFBP3 T+1636A) and 0.226 (IGFBP3 C+3863A), respectively. Haplotypes and their frequencies were estimated by EM algorithm. Six haplotypes were constructed with five SNPs and linkage disequilibrium coefficients (|D'|) between SNP pairs were also calculated. The information on SNPs and haplotypes in IGFBP3 gene could be useful for genetic studies of this gene.