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>

Characterization of Phosphoinositide-3-kinase, Class 3 (PIK3C3) Gene and Association Tests with Quantitative Traits in Pigs

Kim, J.H.,Choi, B.H.,Lim, H.T.,Park, E.W.,Lee, S.H.,Seo, B.Y.,Cho, I.C.,Lee, J.G.,Oh, S.J.,Jeon, J.T. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.12

This study deals with the characterization of porcine PIK3C3 and association tests with quantitative traits. PIK3C3 belongs to the class 3 PI3Ks that participate in the regulation of hepatic glucose output, glycogen synthase, and antilipolysis in typical insulin target cells such as those in the such as liver, muscle system, and fat. On the analysis of full-length mRNA sequence, the length of the PIK3C3 CDS was recorded as 2,664 bps. As well, nucleotide and amino acid identities between human and pig subjects were 92% and 99%, respectively. Five SNPs were detected over 5 exons. We performed genotyping by using a SNP C2604T on exon24 for 145 F$_2$ animals (from a cross between Korean native boars and Landrace sows) by PCR-RFLP analysis with Hpy8I used to investigate the relationship between growth and fat depot traits. In the total association analysis, which doesn' consider transmission disequilibrium, the SNP showed a significant effect (p<0.05) on body weight and carcass fat at 30 weeks of age as well as a highly significant effect (p<0.01) on back fat. In an additional sib-pair analysis, C allele still showed positive and significant effects (p<0.05) on back fat thickness and carcass fat. Moreover, the effects of C allele on the means of within-family components for carcass fat and back fat were estimated as 2.76 kg and 5.07 mm, respectively. As a result, the SNP of porcine PIK3C3 discovered in this study could be utilized as a possible genetic marker for the selection of pigs that possess low levels of back fat and carcass fat at the slaughter weight.

비만에 따른 요통환자의 체중분포와 요부 근력차이에 관한 비교분석

한길수 ( G. S. Han ),김건도 ( G. D. Kim ),임동춘 ( D. C. Lim ) 한국운동생리학회(구-한국운동과학회) 2010 운동과학 Vol.19 No.4

이 연구의 목적은 비만에 따른 요통환자의 체중분포와 요부 근기능 및 안정화 비율의 차이를 비교·분석하는 데 있다. 서울 강남에 소재한 J병원에 내원한 남성 만성요통환자 60명 중 체질량지수(Body Mass Index: BMI)가 25kg/m² 이상인 G1그룹 30명과 이하인 G2그룹 30명을 대상으로 Tetrax와 MedX를 이용하여 분석한 결과 다음과 같은 결론을 얻었다. 체중분포에서 G1그룹은 왼쪽 발뒤꿈치 1.97%(p>.05), 오른쪽 발뒤꿈치 2.37%에서 높게 나타났고(p>.05), G2그룹에서는 왼쪽 발앞꿈치 2.75%(p>.05), 오른쪽 발앞꿈치 1.97%(p>.05)에서 더 높은 체중이 실리는 것으로 나타났다. 요부 각도별 신전근력에서 G1그룹이 G2그룹에 비해 모든 각도에서 높은 근력을 나타냈고, 0°(p>.05), 12°(p>.05)를 제외한 24°(p<.05), 36°(p<.01), 48°(p<.001), 60°(p<.001), 72°(p<.001)에서 통계적으로 유의한 차이를 나타냈다. 요부 안정화 비율에서는 G1그룹의 경우 2.75+_1.31, G2그룹 2.48+_2.23로 나타났다(p>.05). 결론적으로 요부 각도별 신전근력에서 G1그룹이 G2그룹에 비해 모든 각도에서 근력이 높게 나타냈고. 발의 체중분포에서 G1그룹은 비만에 따른 요추의 전만을 증가시켜 힘의 중심을 더 후방으로 유지하려는 경향을 보이고 있는데, 이는 요부 신전근력의 약화로 이어져 안정화 비율에도 영향을 미치는 것으로 사료된다. This study was aimed to determine the effect for the weight distribution and lumbar extension strength associated with obesity index in male patients of Chronic Low Back Pain. Sixty subjects(obesity group(BMI:25Kg/m2): n=30, non obesity group: n=30) participated on this study. Both group were tested on lumbar extension using by MedX machine. Front heels and back heels were measured twice using by the Tetrax Portable Multiple System. Independent sample t-test was used to analyze the difference between the two groups. Study results showed that the obese back pain group(G1) had more weight loaded on both heels than the normal back pain group(G2), but there was no significant difference between the groups (p>.05). As for the lumbar extension strength at each angle, the obese back pain group appeared higher muscular strength than the normal group at 0°, but was stronger at angles 12°, 24°, 36°, 48°, 60°, and 72°. The ratio of lumbar flexion 72° and 0° angle showed 2.75:1 in G1 group and 2.48:1 in G2 group. Overall, the back pain group of obesity(G1) according to weight distribution tended to maintain their center of force more backwards by increasing the lordosis degree with abdominal distension.

Improvement of high-field J_c of MgB₂ wires by polymethyl-methacrylate doping

Park, G.C.,Hwang, S.M.,Lee, C.M.,Choi, J.H.,Joo, J.,Lim, J.H.,Kang, W.N.,Kim, C.J. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.suppl1

We applied polymethyl-methacrylate (PMMA) as a new doping material for MgB<SUB>2</SUB> and fabricated C-doped MgB<SUB>2</SUB> wires by in situ powder-in-tube (PIT) process. With increasing PMMA doping level, the transition temperature (T<SUB>c</SUB>) decreased and the MgO content increased, whereas the magnetic field dependence of the critical current density (J<SUB>c</SUB>) weakened. The MgB<SUB>2</SUB> wires doped with 3-10wt.% PMMA showed significantly higher J<SUB>c</SUB> by more than one order of magnitude than that of the undoped wire at 5K and 6.6T. These results confirmed the potential of PMMA as a promising material for the effective substitution of B by C in MgB<SUB>2</SUB>.

Fully international system of units-traceable glycated hemoglobin quantification using two stages of isotope-dilution high-performance liquid chromatography-tandem mass spectrometry

Tran, T.T.H.,Lim, J.,Kim, J.,Kwon, H.J.,Kwon, G.C.,Jeong, J.S. Elsevier 2017 Journal of chromatography Vol.1513 No.-

<P>Glycated hemoglobin (HbA(1c)), defined as hemoglobin (Hb) molecules having a stable adduct of glucose on the N-terminal of the beta-chains, has been endorsed as a diagnostic tool for diabetes mellitus and a prediction indicator for the development of diabetes complications. Here we describe an accurate procedure using two stages of isotope dilution-ultra performance liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) for the quantification of HbA(1c) that provides full traceability to International System of Units (SI). First, synthetic peptides representing specific markers of HbA(1c) (G-hexa) and hemoglobin A(0) (Hexa) were certified by amino acid analysis via acid hydrolysis as reference materials (RMs) for the next step. For this peptide certification, three amino acids (proline, valine, and leucine) were determined by hydrolysis with 10 M hydrochloric acid at 130 degrees C for 48 h followed by ID-LC-MS/MS. Then, HbA(1c), content in blood was quantified with the ratio of specific proteolytic peptides from HbA(1c) and HbA(0) via enzyme digestion using ID-LC-MS/MS with the certified peptides as RMs and isotope-labeled peptides as internal standards. Results demonstrate complete traceability to SI-units throughout this procedure. Reliability was confirmed through comparative studies with commercially available RMs for HbA(1c), and other routine HbA(1c) diagnostic methods as well. Following full method validation, we applied this procedure to the certification of candidate hemolysate-certified RMs for HbA(1c) content, as well as 52 real clinical samples. All of the results showed the suitability of this method to act as a primary reference measurement procedure for HbA(1c) in complex biological samples. (C) 2017 Elsevier B.V. All rights reserved.</P>

Structure-Activity Relationship of Xanthones from Mesua daphnifolia and Garcinia nitida towards Human Estrogen Receptor Negative Breast Cancer Cell Line

G. C. L. Ee,C. K. Lim,A. Rahmat 한국생약학회 2005 Natural Product Sciences Vol.11 No.4

Extensive chemical studies on the stem bark extracts of two Guttifereous plants namely Mesuadaphnifolia and Garcinia nitida have led to the isolation of eight xanthones. Mesua daphnifolia gavecudraxanthone G (1), ananixanthone (2), 1,3,5-trihydroxy-4-methoxyxanthone (3) and euxanthone (4) whileGarcinia nitida gave inophyllin B (5), 1,3,7-trihydroxy-2,4-bis (3-methylbut-2-enyl)xanthone (6), 3-isomangostin(7) and rubraxanthone (8). All these compounds were asayed against the MDA-MB-231 (human estrogenreceptor negative breast cancer) cells. A structure-activity relationship study showed that structurally, all the 1, 3-oxygenated xanthones which carried unsaturated prenyl side chains (either 3-methylbut-2-enyl or 1,1-dimethyl-2-propenyl) at carbons C-2 and C-4 in the xanthone ring A are essential for the outstanding activities in the asay.

EFFECT OF LIQUID-PHASE COMPOSITION ON THE HENRY'S CONSTANTS OF VALINE, ISOLEUCINE, AND LEUCINE IN A CAPCELL-PACK C18 CHROMATOGRAPHY

Lim, G.-W.,Nam, H.-G.,Park, C.,Mun, S. Taylor Francis 2013 Journal of liquid chromatography & related technol Vol.36 No.2

C/GFRP 투광 복합재 적용 태양광 LED 볼라드 개발

신형곤(H. G. Shin),유승현(S. H. Yoo),방박(Pang Bo),임철승(C. S. Lim),이한교(H. G. LEE),오제하(J. H. Oh) 한국생산제조학회 2016 한국생산제조시스템학회 학술발표대회 논문집 Vol.2016 No.04

c-Jun N-terminal kinase has a pivotal role in the maintenance of self-renewal and tumorigenicity in glioma stem-like cells

Yoon, C-H,Kim, M-J,Kim, R-K,Lim, E-J,Choi, K-S,An, S,Hwang, S-G,Kang, S-G,Suh, Y,Park, M-J,Lee, S-J Macmillan Publishers Limited 2012 Oncogene Vol.31 No.44

Uncovering the mechanisms that govern the maintenance of stem-like cancer cells is critical for developing therapeutic strategies for targeting these cells. Constitutive activation of c-Jun N-terminal kinase (JNK) has been reported in gliomas and correlates with histological grade. Here, we found that JNK signaling is crucial for the maintenance of ‘stemness’ in glioma cells. Sphere-cultured glioma cells showed more phosphorylation of JNK compared with serum-containing monolayer cultures. Importantly, blockade of JNK signaling with SP600125 or small interfering RNAs targeting JNK1 or JNK2 significantly reduced the CD133<SUP>+</SUP>/Nestin<SUP>+</SUP> population and suppressed sphere formation, colony formation in soft agar, and expression of stem cell markers in sphere-cultured glioma cells. Intriguingly, sphere-cultured glioma cells exhibited enhanced expression of Notch-2, but not Notch-1, -3 or -4, and JNK inhibition almost completely abrogated this increase. Blocking the phosphoinoside 3-kinase (PI3K)/Akt pathway with LY294002 or si-Akt also suppressed the self-renewal of sphere-cultured glioma cells. PI3K, but not Akt, had a role as an upstream kinase in JNK1/2 activation. In addition, treatment with si-JNK greatly increased etoposide- and ionizing radiation (IR)-induced cell death in glioma spheres. Consistent with glioma cell lines, glioma stem-like cells isolated from primary patient glioma cells also had a higher activity of JNK and Notch-2 expression. Importantly, inhibition of JNK2 led to a decrease of Notch-2 expression and suppressed the CD133<SUP>+</SUP>/Nestin<SUP>+</SUP> cell population in patient-derived primary glioma cells. Finally, downregulation of JNK2 almost completely suppressed intracranial tumor formation by glioma cells in nude mice. Taken together, these data demonstrate that JNK signaling is crucial for the maintenance of self-renewal and tumorigenicity of glioma stem-like cells and drug/IR resistance, and can be considered a promising target for eliminating stem-like cancer cells in gliomas.

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.