Dielectric Analysis(DEA)를 이용한 옻칠의 분자완화 및 경화과정에 관한 연구

김현경,유지강,홍진후 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.2

Curing behavior of oriental lacquer has been characterized using the dielectric analysis(DEA). It was found that the oriental lacquer cured to its hardened state most efficiently at moderate temperature in the presence of air at relative humidities of greater than 70%. In order to study the dielectric properties of oriental lacquer film, various films have been prepared differing curing procedures. The glass transition and secondary relaxation temperatures of ordinary oriental lacquer film were observed at 45℃ and -40℃, respectively. On the contrary, the high temperature cured film showed a secondary relaxation at around -50℃. The relationship between thermodynamic properties and chemical structures has been discussed based or, the analysis of the dielectric relaxation behavior using the Cole-Cole plot and the dielectric relaxation intensity

ESPI 기법에 의한 하중을 받는 균열 박판의 진동 특성에 관한 연구

김경석,강기수,최지은,박찬주,홍진후 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.2

대부분의 실제구조물은 인장과 진동 등이 동시에 작용하는 복합하중 상태가 되며 이러한 환경에서 물체의 거동을 해석하는 것이 중요하다. 이 논문에서는 χ축에 대해 45˚결함이 있는 평판이 하중을 받고 있을 때, 진동 특성을 시간평균 electro speckle pattern interferometry(ESPI)를 이용하여 해석하였다. 결함이 있는 박판 시험편에 인장력을 증가하면서 물체의 고유진동수 변화와 모드의 형태 변화를 동시에 관찰하였다. 실험결과에서 결함은 저차모드에서는 진동모드에 영향을 주지 않았으나, 고차모드에서는 진동모드에 변화를 주었으며, 특정 진동모드에서 결함의 영향으로 현저하게 고유주파수가 낮아지는 경향을 보였다. 또한 실험결과는 유한요소해석과 비교하여 주파수 비교에서는 5%이내의 오차율을 보였으며, 진동모드 비교에서는 완전히 일치하였다. This paper presents the vibration characteristics of a rectangular plate with 45˚ oblique crack subjected to a uniaxial tension. The experiment is adopted by the time-average Electronic Speckle Pattern Interferometry(ESPI) method. The natural frequency and mode shape are considered accurately according to the increase of tensile load. When tensile load is zero, the vibration modes are agreed with the smooth and the 45˚ obliquely cracked plate. But according to the increasement of load, it is shown that vibration modes are extremely varied. The effects of the crack under the vibration are discussed in detail. It is indicated that the increase of load makes the variation of the frequencies and modes complicate in the range of even a small load. The results are agreed with the FEM analysis within 5%.

Branched-chain amino acids sustain pancreatic cancer growth by regulating lipid metabolism

Ji Hyeon Lee,조영라,Ji Hye Kim,Jong Wook Kim,남혜윤,Seong Who Kim,Jaekyoung Son 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Branched-chain amino acid (BCAA) catabolism and high levels of enzymes in the BCAA metabolic pathway have recently been shown to be associated with cancer growth and survival. However, the precise roles of BCAA metabolism in cancer growth and survival remain largely unclear. Here, we found that BCAA metabolism has an important role in human pancreatic ductal adenocarcinoma (PDAC) growth by regulating lipogenesis. Compared with nontransformed human pancreatic ductal (HPDE) cells, PDAC cells exhibited significantly elevated BCAA uptake through solute carrier transporters, which were highly upregulated in pancreatic tumor tissues compared with normal tissues. Branched-chain amino-acid transaminase 2 (BCAT2) knockdown markedly impaired PDAC cell proliferation, but not HPDE cell proliferation, without significant alterations in glutamate or reactive oxygen species levels. Furthermore, PDAC cell proliferation, but not HPDE cell proliferation, was substantially inhibited upon knockdown of branched-chain α-keto acid dehydrogenase a (BCKDHA). Interestingly, BCKDHA knockdown had no significant effect on mitochondrial metabolism; that is, neither the level of tricarboxylic acid cycle intermediates nor the oxygen consumption rate was affected. However, BCKDHA knockdown significantly inhibited fatty-acid synthesis, indicating that PDAC cells may utilize BCAAs as a carbon source for fatty-acid biosynthesis. Overall, our findings show that the BCAA metabolic pathway may provide a novel therapeutic target for pancreatic cancer.

Multi-atlas cardiac PET segmentation

Kim, Sally Ji Who,Seo, Seongho,Kim, Hyeon Sik,Kim, Dong-Yeon,Kang, Keon Wook,Min, Jung-Joon,Lee, Jae Sung Elsevier 2019 Physica Medica Vol.58 No.-

<P><B>Abstract</B></P> <P><B>Purpose</B></P> <P>We propose a multi-atlas based segmentation method for cardiac PET and SPECT images to deal with the high variability of tracer uptake characteristics in myocardium. In addition, we verify its performance by comparing it to the manual segmentation and single-atlas based approach, using dynamic myocardial PET.</P> <P><B>Methods</B></P> <P>Twelve left coronary artery ligated SD rats underwent ([<SUP>18</SUP>F]fluoropentyl) triphenylphosphonium salt PET/CT scans. Atlas-based segmentation is based on the spatial normalized template with pre-defined region-of-interest (ROI) for each anatomical or functional structure. To generate multiple left ventricular (LV) atlases, each LV image was segmented manually and divided into angular segments. The segmentation methods performances were compared in regional count information using leave-one-out cross-validation. Additionally, the polar-maps of kinetic parameters were estimated.</P> <P><B>Results</B></P> <P>In all images, the highest <I>r</I> <SUP>2</SUP> template yielded the lowest root-mean-square error (RMSE) between the source image and the best-matching templates ranged between 0.91–0.97 and 0.06–0.11, respectively. The single-atlas and multi-atlas based ROIs yielded remarkably different perfusion distributions: only the multi-atlas based segmentation showed equivalent high correlation results (<I>r</I> <SUP>2</SUP> = 0.92) with the manual segmentation compared with the single-atlas based (<I>r</I> <SUP>2</SUP> = 0.88). The high perfusion value underestimation was remarkable in single-atlas based segmentation.</P> <P><B>Conclusions</B></P> <P>The main advantage of the proposed multi-atlas based cardiac segmentation method is that it does not require any prior information on the tracer distribution to be incorporated into the image segmentation algorithms. Therefore, the same procedure suggested here is applicable to any other cardiac PET or SPECT imaging agents without modification.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A multi-atlas based segmentation method for cardiac PET and SPECT images. </LI> <LI> Remarkably different perfusion between single-atlas and multi-atlas based ROIs. </LI> <LI> High correlation results between multi-atlas based and manual segmentations. </LI> </UL> </P>

Compartmental Modeling and Simplified Quantification of [11C]sertraline Distribution in Human Brain

Ji Who Kim,이동수,이재성,Su Jin Kim,Lathika Hoigebazar,Kwang-Hee Shin,Kyung-Sang Yu,Wonsik Ahn,정재민 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.9

Sertraline hydrochloride (Zoloft®, Pfizer) is an antidepressant drug of the selective serotonin reuptake inhibitor (SSRI). The aims of this study were evaluating its in vivo distribution and kinetic models in human brain. Also, this study was to determine optimal scan duration of dynamic positron emission tomography (PET) for accurate [11C]sertraline kinetic parameters and the feasibility of semi-quantitative approach for assessing distribution volume ratio (DVR). [11C]sertraline dynamic PET and magnetic resonance imaging (MRI) scans were performed in 5 healthy males. Blood sampling were collected for the input function. Tissue time-activity curves (TAC) were obtained in 7 brain regions using MRI. Goodness-of-fit for TAC using simple tissue compartment model (2C2P) and 3-compartment models with irreversible (3C3P) and reversible (3C4P) were compared. Total distribution volume (DV) for each region of interest (ROI) and DVR were calculated. Also, ratio between the standard uptake value (SUV) of each ROI and that of cerebellum (SUVr) was computed and correlated with the DVR. Akaike information criteria analysis showed that the 2C2P was the most suitable model. Average values of K1 (mL/min/g) and k2 (1/min) were 0.54 and 0.012 in putamen. PET scan time longer than 50 min was required for the accurate estimation of DV. SUVr in 50-90 min was well correlated with DVR.

Comparative evaluation of the algorithms for parametric mapping of the novel myocardial PET imaging agent ¹⁸ F-FPTP

Kim, Ji Who,Seo, Seongho,Kim, Hyeon Sik,Kim, Dong-Yeon,Lee, Ho-Young,Kang, Keon Wook,Lee, Dong Soo,Bom, Hee-Seung,Min, Jung-Joon,Lee, Jae Sung Springer Japan 2017 Annals of nuclear medicine Vol.31 No.6

<P><B>Objective</B></P><P>(<SUP>18</SUP>F-fluoropentyl)triphenylphosphonium salt (<SUP>18</SUP>F-FPTP) is a new promising myocardial PET imaging tracer. It shows high accumulation in cardiomyocytes and rapid clearance from liver. We performed compartmental analysis of <SUP>18</SUP>F-FPTP PET images in rat and evaluated two linear analyses: linear least-squares (LLS) and a basis function method (BFM) for generating parametric images. The minimum dynamic scan duration for kinetic analysis was also investigated and computer simulation undertaken.</P><P><B>Methods</B></P><P><SUP>18</SUP>F-FPTP dynamic PET (18 min) and CT images were acquired from rats with myocardial infarction (MI) (<I>n</I> = 12). Regions of interest (ROIs) were on the left ventricle, normal myocardium, and MI region. Two-compartment (<I>K</I><SUB>1</SUB> and <I>k</I><SUB>2</SUB>; 2C2P) and three-compartment (<I>K</I><SUB>1</SUB>–<I>k</I><SUB>3</SUB>; 3C3P) models with irreversible uptake were compared for goodness-of-fit. Partial volume and spillover correction terms (<I>V</I><SUB><I>a</I></SUB> and <I>α</I> = 1 − <I>V</I><SUB><I>a</I></SUB>) were also incorporated. LLS and BFM were applied to ROI- and voxel-based kinetic parameter estimations. Results were compared with the standard ROI-based nonlinear least-squares (NLS) results of the corresponding compartment model. A simulation explored statistical properties of the estimation methods.</P><P><B>Results</B></P><P>The 2C2P model was most suitable for describing <SUP>18</SUP>F-FPTP kinetics. Average <I>K</I><SUB>1</SUB>, <I>k</I><SUB>2</SUB>, and <I>V</I><SUB><I>a</I></SUB> values were, respectively, 6.8 (ml/min/g), 1.1 (min<SUP>−1</SUP>), and 0.44 in normal myocardium and 1.4 (ml/min/g), 1.1 (min<SUP>−1</SUP>), and 0.32, in MI tissue. Ten minutes of data was sufficient for the estimation. LLS and BFM estimations correlated well with NLS values for the ROI level (<I>K</I><SUB>1</SUB>: <I>y</I> = 1.06<I>x</I> + 0.13, <I>r</I><SUP><I>2</I></SUP> = 0.96 and <I>y</I> = 1.13<I>x</I> + 0.08, <I>r</I><SUP><I>2</I></SUP> = 0.97) and voxel level (<I>K</I><SUB>1</SUB>: <I>y</I> = 1.22<I>x</I> − 0.30, <I>r</I><SUP><I>2</I></SUP> = 0.90 and <I>y</I> = 1.26<I>x</I> + 0.00, <I>r</I><SUP><I>2</I></SUP> = 0.92). Regional distribution of kinetic parametric images (<I>αK</I><SUB>1</SUB>, <I>K</I><SUB>1</SUB>, <I>k</I><SUB>2</SUB>, <I>V</I><SUB>a</SUB>) was physiologically relevant. LLS and BFM showed more robust characteristics than NLS in the simulation.</P><P><B>Conclusions</B></P><P>Fast kinetics and highly specific uptake of <SUP>18</SUP>F-FPTP by myocardium enabled quantitative analysis with the 2C2P model using only the initial 10 min of data. LLS and BFM were feasible for estimating voxel-wise parameters. These two methods will be useful for quantitative evaluation of <SUP>18</SUP>F-FPTP distribution in myocardium and in further studies with different conditions, disease models, and species.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s12149-017-1171-6) contains supplementary material, which is available to authorized users.</P>

검은비늘버섯 분말을 첨가한 쿠키의 품질특성 및 항산화활성

김지원(Ji Won Kim),김상희(Sang Hee Kim),윤향식(Hyang-Sik Yoon),송달님(Dal Nym Song),김민자(Min Ja Kim),장후봉(Who-Bong Chang),송인규(In Gyu Song),엄현주(Hyun-Ju Eom) 한국식품영양과학회 2013 한국식품영양과학회지 Vol.42 No.12

Pholiota adiposa is an edible as well as medicinal mushroom cultured in China and Japan with anti-tumor, anti-microbial, anti-hypertensive, and anti-hyperlipidemic activities. This study was carried out to investigate the quality characteristics of cookies added with Pholiota adiposa powder. Chemical composition of Pholiota adipose powder was as follows: 3.8% moisture, 6.9% ash, 1% crude lipids, 3% protein, 53.3% carbohydrates, and 31.9% crude dietary fiber. To analyze quality characteristics during the manufacture of cookies, pH, texture, color, antioxidant activity, total polyphenol content, and sensory evaluation were determined. As the content of Pholiota adiposa powder increased, the pH of cookies decreased from 6.7 to 6.02. Hardness of cookies decreased with increasing Pholiota adiposa powder content, and cookies added with 5% powder were softer than the control. Regarding surface color, L-value decreased with increasing powder content compared to that of the control, whereas in surface color among various powder levels was not significantly different. As the content of Pholiota adiposa powder increased, both antioxidant activity and total polyphenol content increased. In the sensory evaluation, cookies added with 3% Pholiota adiposa powder showed remarkably higher values compared to control and other amples in all aspects.

ZBTB7A suppresses glioblastoma tumorigenesis through the transcriptional repression of EPB41L5

Jeong Ji-Hoon,Park Seung-Ho,Kim Hyunhee,Nam Hae Yun,Kim Sung-Hak,Jeong Minseok,Kong Min-Jeong,Son Jihyun,Jeong Ji-Eun,Song Ji-Hye,Kim Seong Who,Choi Kyung-Chul 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Glioblastoma multiforme (GBM), the most aggressive and malignant glioma, has a poor prognosis. Although patients with GBM are treated with surgery, chemotherapy, and radiation therapy, GBM is highly resistant to treatment, making it difficult and expensive to treat. In this study, we analyzed the Gene Expression Profiling Interactive Analysis dataset, the Cancer Genome Atlas dataset, and Gene Expression Omnibus array data. ZBTB7A (also called FBI1/POKEMON/LRF) was found to be highly expressed in low-grade glioma but significantly downregulated in patients with GBM. ZBTB7A is a transcription factor that plays an important role in many developmental stages, including cell proliferation. The activation of epithelial-mesenchymal transition (EMT) is a key process in cancer progression and metastasis. Erythrocyte membrane protein band 4.1 like 5 (EPB41L5) is an essential protein for EMT progression and metastasis in various types of cancer. We found that ZBTB7A depletion in U87 cells induced GBM progression and metastasis. Based on RNA sequencing data, ZBTB7A directly binds to the promoter of the EPB41L5 gene, reducing its expression and inhibiting GBM progression. We demonstrated that ZBTB7A dramatically inhibits GBM tumor growth through transcriptional repression of EPB41L5. Thus, both ZBTB7A and EPB41L5 may be potential biomarkers and novel therapeutic targets for GBM treatment. Overall, we discovered the role of a novel tumor suppressor that directly inhibits GBM progression (ZBTB7A) and identified EPB41L5 as a therapeutic target protein for patients with GBM.

Endothelial dysfunction induces atherosclerosis: increased aggrecan expression promotes apoptosis in vascular smooth muscle cells

( Sang-min Kim ),( Jae-wan Huh ),( Eun-young Kim ),( Min-kyung Shin ),( Ji-eun Park ),( Seong Who Kim ),( Wooseong Lee ),( Bongkun Choi ),( Eun-ju Chang ) 생화학분자생물학회 2019 BMB Reports Vol.52 No.2

Endothelial dysfunction-induced lipid retention is an early feature of atherosclerotic lesion formation. Apoptosis of vascular smooth muscle cells (VSMCs) is one of the major modulating factors of atherogenesis, which accelerates atherosclerosis progression by causing plaque destabilization and rupture. However, the mechanism underlying VSMC apoptosis mediated by endothelial dysfunction in relation to atherosclerosis remains elusive. In this study, we reveal differential expression of several genes related to lipid retention and apoptosis, in conjunction with atherosclerosis, by utilizing a genetic mouse model of endothelial nitric oxide synthase (eNOS) deficiency manifesting endothelial dysfunction. Moreover, eNOS deficiency led to the enhanced susceptibility against pro-apoptotic insult in VSMCs. In particular, the expression of aggrecan, a major proteoglycan, was elevated in aortic tissue of eNOS deficient mice compared to wild type mice, and administration of aggrecan induced apoptosis in VSMCs. This suggests that eNOS deficiency may elevate aggrecan expression, which promotes apoptosis in VSMC, thereby contributing to atherosclerosis progression. These results may facilitate the development of novel approaches for improving the diagnosis or treatment of atherosclerosis. [BMB Reports 2019; 52(2): 145-150]

유리체강내 덱사메타손 임플란트 삽입 후 발생한 수술이 필요했던 합병증

김소희(So Hee Kim),최윤아(Youna Choi),최승권(Seung Kwon Choi),이재정(Jae Jung Lee),변익수(Ik Soo Byon),이지은(Ji Eun Lee),박성후(Sung Who Park) 대한안과학회 2021 대한안과학회지 Vol.62 No.5

목적: 유리체강내 덱사메타손 임플란트삽입술 후 수술적 치료가 필요했던 심각한 합병증 발생을 보고하고자 한다. 대상과 방법: 2013년 6월부터 2020년 3월까지 유리체강내 덱사메타손 임플란트삽입술을 받은 환자의 의무기록을 후향적으로 분석하였다. 삽입술 6개월 이내 백내장을 제외한 안내 수술을 시행 받은 경우 중 수술의 원인이 덱사메타손 임플란트 삽입과 분명한 연관성을 보이는 경우를 분석하였다. 원인 질환, 시술 전 눈의 상태, 주사 횟수 등을 분석하였다. 결과: 439명 473안에서 총 1,168회 주사를 시행하여, 1안 평균 2.5회 주사가 시행되었고, 연령은 61.4 ± 11.3세였다. 유리체강내 덱사메타손 임플란트 삽입 후 6회(0.5%)에서 합병증으로 인한 수술적 치료가 필요하였다. 4안은 포도막염, 1안은 당뇨망막병증, 1안은 분지망막정맥폐쇄가 원인 질환이었다. 2안은 안압상승, 2안은 임플란트의 부적절한 위치, 1안은 공막 창상 누출, 1안은 망막박리로 수술이 필요하였다. 이전 유리체절제술의 병력이 있는 경우(p=0.007, Fisher’s exact test)와 원인 질환이 포도막염인 경우에서 수술이 필요한 심각한 합병증의 빈도가 높았다(p=0.007, Fisher’s exact test). 결론: 유리체강내 덱사메타손 임플란트삽입술 후 백내장수술을 제외한 안내 수술이 필요한 심각한 합병증은 0.5% (6회)에서 발생하였고, 유리체절제술이 시행된 경우, 포도막염이 원인 질환인 경우에서 빈도가 높았다. 망막박리 1안을 제외한 5안은 수술 후 양호한 시기능을 회복하였다. Purpose: To report complications requiring surgical management related to intravitreal dexamethasone implant. Methods: The medical records of patients who received intravitreal dexamethasone implant injection from June 2013 to March 2020 were reviewed retrospectively. Patients who had undergone intraocular surgical management within 6 months after implant injection, with the exception of cataract surgery, were included. Of them, only the cases in which the surgery was definitely related to complications with the Ozurdex implant were included. In these patients, underlying disease, intraocular pressure change, and the number of injections were analyzed. Results: A total of 1,168 injections of 473 eyes (439 patients) were enrolled in the study. The mean number of injections was 2.5 per eye. The mean age was 61.4 ± 11.3 years. The complications requiring an additional surgical procedure occurred in six (0.5%) injections. Of them, four, one, and one eyes showed uveitis, diabetic macular edema, and branch retinal vein occlusion, respectively. Surgical management was performed to control the increased intraocular pressure in two eyes, inappropriate implant location in two eyes, scleral wound leakage in one eye, and retinal detachment in one eye. The incidence of severe complications requiring surgical management was high in cases with a history of previous vitrectomy (p = 0.007, Fisher’s exact test) and uveitis (p = 0.007, Fisher’s exact test). Conclusions: Severe complications requiring surgical management occurred in 0.5% of cases (six cases) after intravitreal dexamethasone implant injections. These complications were related to a history of previous vitrectomy and uveitis. Five eyes recovered to favorable visual function after surgery, with the exception of one eye with retinal detachment.