판막 질환에서의 심근 섬유화 : 심근 조직을 이용한 형태학적 연구 및 혈청 생화학적 지표의 분석

강수진,박덕우,송재관,박경민,송종민,강덕현,한기훈,송현,이재원,주석중,송명근,김정선 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.2

Electromagnetic wave absorption properties of multistacked hexaferrite-epoxy composites

Jae-Uk Kim,Young-Min Kang 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.1

We report on electromagnetic wave (EM) absorption properties of multistacked hexaferrite-epoxy composites. Co-Ti substituted M-type hexaferrite powders, SrFe_12-2xCo_xTi_xO₁₉ (x=1.1, 1.2, 1.3) were prepared by conventional solid-state reaction method. Each composition of powder was calcined at 1300°C for 2 hours in air. The calcined powders were ground into fine powders, mixed with 10 wt% of epoxy binder, pressed to form toroidal-shaped (inner and outer diameters of 3.04 and 7.00 mm, respectively) green compacts, and finally cured at 180°C in air for 20 min. The real and imaginary parts of permittivities (ε', ε") and permeabilities (μ', μ") were measured on the toroidal shaped composites using a vector network analyzer (VNA) with an airline kit in the frequency range from 0.1 to 18 GHz. RL spectra for the composites were calculated based on transmission line theory and measured ε', ε" μ', μ" data. Also, the RL spectra were measured from S-parameter method using the VNA with airline kit and one-port Cu threaded hole socket. The minimum RL value (RL_min) < -20 dB could be obtained for the series of composites samples at the optimal thickness. The frequencies of RL_min were 14 GHz, 10 GHz, and 6 GHz for x = 1.1, 1.2, and 1.3 samples, respectively. The RL spectra were also measured on the stacked three samples (A, B, C) with varying stacking orders as ABC, ACB, BAC, BCA, CAB, CBA. The RL spectra were slightly varied depending on the stacking order. However, it was very far from the sum of RL spectra in each sample. The measured RL spectra of the stacked samples were well fitted with calculated RL spectra at total thickness of three samples. Here, the RL calculation was based on volume-averaged ε', ε" μ', and μ" values for each sample.

Purification and Characterization of Helicobacter pylori ${\gamma}$-Glutamyltranspeptidase

Song, Jae-Young,Choi, Yeo-Jeong,Kim, Jeong-Min,Kim, Yoo-Ree,Jo, Jin-Seong,Park, Jin-Sik,Park, Hee-Jin,Song, Yun-Gyu,Lee, Kon-Ho,Kang, Hyung-Lyun,Baik, Seung-Chul,Youn, Hee-Shang,Cho, Myung-Je,Rhee, Kw The Korean Society for Microbiology 2011 Journal of Bacteriology and Virology Vol.41 No.4

Gamma-glutamyltranspeptidase (GGT) was purified to electrophoretic homogeneity from the cell extract of H. pylori. The purified enzyme consisted of heavy and light subunits with molecular weights of 38 kDa and 21 kDa, respectively. N-terminal amino acid sequence of heavy and light subunits revealed that H. pylori GGT was processed into 3 parts for a signal peptide of 27 amino acid residues, a heavy subunit of 352 residues, and a light subunit of 188 residues during translation. The reaction rate for hydrolysis of ${\gamma}$-GpNA was 84.4 ${\mu}mol/min$ per milligram of protein, and that for the ${\gamma}$-glutamyl transfer from ${\gamma}$-GpNA to gly-gly was 23.8 ${\mu}mol/min$ per milligram of protein. The apparent Km values of H. pylori GGT for ${\gamma}$-glutamyl compounds were on the order of $10^{-3}$ to $10^{-4}$ M and those for acceptor peptides and amino acids were on the order of $10^{-1}$ to $10^{-2}$ M. The GGT protein kept approximately 80% of the initial enzymatic activity on incubation at $60^{\circ}C$ for 15 min. The optimum temperature and pH for reactions of both hydrolysis and transpeptidation were $40^{\circ}C$ and 9.0, respectively. The transpeptidation and hydrolysis reactions catalyzed by H. pylori GGT were strongly inhibited by L-Gln and moderately inhibited by L-Ala, L-Ser, ${\beta}$-chloro-L-Ala, and L-Glu. These results demonstrated that the biochemical properties of H. pylori GGT are different from those of other bacterial GGTs. Further, H. pylori GGT might degrade glutathione in the gastric mucous layer of humans if the enzyme could be secreted in the bacterial niches.

P278 : Nonablative fractional laser as a tool to facilitate skin penetration of 5-aminolevulinic acid with minimal skin disruption

( In Jung Kang ),( Jeong Hwee Choi ),( Min Jae Gwak ),( Hee Kyeong Lim ),( Mu Hyoung Lee ),( Min Kyung Shin ) 대한피부과학회 2013 대한피부과학회 학술발표대회집 Vol.65 No.2

Background: Effective penetration of photosensitizer is an essential step in photodynamic therapy (PDT). There have been trials of several methods, including laser treatment, to facilitate prompt and sufficiently deep transdermal drug delivery. Objectives: This study was performed to evaluate the effects of nonablative fractional laser pretreatment on aminolevulinic acid (ALA) penetration of the skin. Methods: Twelve identical treatment areas of 1 × 1 cm2 on the backs of 10 healthy male subjects were mapped. Each area received laser treatment with a different energy and incubation with ALA for different times. Laser treatment was performed with a 1550 nm fractional erbium glass laser, and the laser energy was set to 20 and 50 mJ with a spot density of 50/cm2. ALA incubation time was set to 30, 60, or 180 min. Porphyrin fluorescence was measured. Results: Nonablative fractional laser-pretreated areas showed significantly increased porphyrin fluorescence compared to non-pretreated areas. Laser energy strength and ALA incubation time were positively correlated with ALA absorption. Conclusion: Nonablative fractional laser treatment effectively enhanced ALA skin penetration. Pretreatment with a nonablative fractional laser can be used for ALA-PDT to achieve higher therapeutic efficacy and shortened ALA incubation times with minimal skin barrier disruption compared to ablative laser.

Comparisons of obstetrical outcomes among vaginal, intramuscular progesterone treatment and conservative management for the prevention of preterm birth in twin pregnancies with a short cervix

( Young Li Kim ),( Young Jae Lee ),( Hee Young Cho ),( Eun Ah Kim ),( Min Jung Baek ),( Young Ran Kim ),( Sukho Kang ),( Ji Yeon Lee ) 대한산부인과학회 2016 대한산부인과학회 학술대회 Vol.102 No.-

목적: To determine the differences in pregnancy outcomes among cases treated by vaginal progesterone, intramuscular(IM) progesterone and conservative management in twin pregnancies with a short cervix. 방법: This is a retrospective study of 273 twin pregnancies complicated by a short cervix(<2.5cm) who delivered from 2007 to 2016 in CHA Bundang Medical Center. Women who received cervical cerclage were excluded. Treatment groups included 1) group I; conservative management group without progesterone treatment(n=174), 2) group II; vaginal progesterone suppository group(n=30), 3) group III; IM progesterone injection group(n=69). Primary outcomes were spontaneous birth at <28, 32, 34, or 36 weeks of gestational age(GA). The secondary outcomes included hospitalized for tocolytics or antenatal corticosteroids, small for gestational age and low APGAR score(<7) at 5 min. 결과: Preterm birth before 36 weeks of GA was different among 3 groups(29.3%[51/174] vs.20.0%[6/30] vs.43.5%[30/69], p=0.034). Low APGAR score(<7) at 5min was significantly different among 3 groups(7.8%[27/348] vs.5.0%[3/60] vs.15.2%[21/138], p=0.018). After multivariate analysis, preterm birth(<36 weeks) occurred more frequently in group III than group I(aOR 6.90 95%CI:1.06-45.04, p=0.044). However, there was no significant difference between group II and III. Meanwhile, there were more cases with low APGAR score(<7) at 5 min in group III than group I(aOR 6.58 95%CI:1.43-30.21, p=0.015) and group II(aOR 17.04 95%CI:1.56-185.74, p=0.020) after multivariate analysis. 결론: In twin pregnancies complicated by short cervical length, IM progesterone group showed significantly greater occurrence of preterm birth before 36 weeks of GA in comparison with vaginal progesterone group and conservative management group.

갑상선 기능항진증 환자에서 인슐린감수성 및 인슐린분비능의 변화

최은진,강호철,이태희,정민영,이대호,장연진,박상선,조재현 대한내분비학회 1994 Endocrinology and metabolism Vol.9 No.2

The impairement of glucose metabolism is frequently associated in hyperthyroidism. The present study was performed to determine the effect of the thyroid hormone excess on insulin sensitivity and on insulin secretory function in vivo. Ten newly diagnosed hyperthyroid patients and fifteen healthy control subjects were subjected to frequently sampled intravenous glucose tolerance tests(FSIGT) after an overnight fast. Insulin sensitivity, represented by the insulin sensitivity index(S_1), was assessed by minimal model analysis of FSIGT data. Insulin secretion was measured by the total area under the insulin curve after glucose load. The results were as follows. 1) The K_G values, which represent glucose tolerance, were not different between the hyperthyroid patients and the normals(2.2+-0.3 vs. 2.5+-0.3%/min, p$gt;0.05). 2) S_1 was significantly decreased in the hyperthyroid patients in comparison to the normals(7.5+-1.4 vs. 2.6+-0.3X10^-4 min^-1/uU/ml, p$lt;0.05). 3) The basal insulin concentration was higher in the hyperthyroid patients than in the normals(8.3+-2.4 vs. 4.6+-0.4 uU/ml, p=0.07). In addition, the insulin secretory response to a glucose load was increased in the hyperthyroid patients as evidenced by the peak plasma insulin level(168.2+-30.4 vs. 89.2+-13.9 uU/ml, p$lt;0.05) and by the total area under the insulin curve(2641.1+-443.2 vs. 1696.7+-204.3 min uU/ml, p$lt;0.05). These results clearly demonstrated that insulin sensitivity was impaired in these newly diagnosed hyperthyroid patients. However, glucose tolerance was maintained by the increased insulin secretion (J Kor Soc Endocrinol 9:108-114, 1994).

벤조디아제핀 수용체 영상용 양전자 방출 핵종 표지 플루마제닐 유도체 [F-18](3-(2-Fluoro)flumazenil의 합성과 생체 내 분포

장영수,이숙자,강삼식,홍성현,이명철,이동수,정준기,정재민,조정혁 대한핵의학회 1999 핵의학 분자영상 Vol.33 No.6

Purpose: Radiotracers that bind to the central benzodiazepine receptor are useful for the investigation of various neurological and psychiatric diseases. [C-11]Flumazenil, a benzodiazepine antagonist, is the most widely used radioligand for central benzodiazepine receptor imaging by PET. We synthesized 3-(2-[F- 18]fluoro)flumazenil, a new fluorine-18 (t1/2=110 min) labeled analogue of benzodiazepine receptor imaging agent, and evaluated in vivo for biodistribution in mice. Materials and Methods: Flumazenil (Ro 15-1788) was synthesized by a modification of the reported method. Precursor of 3-(2-[F-18]fluoro)flumazenil, the tosylated flumazenil derivative was prepared by the tosylation of the ethyl ester by ditosylethane. [F-18] labeling of tosyl substitued flumazenil precursor was performed by adding F-18 ion at 85℃ in the hot cell for 20 min. The reaction mixture was trapped by C18 cartridge, washed with 10% ethanol, and eluted by 40% ethanol. Bidistribution in mice was determined after intravenous injection Results: The total chemical yield of tosylated flumazenil derivative was ∼40%. The efficiency of labeling 3-(2-[F-18]fluoro)flumazenil was 66% with a total synthesis time of 50 min. Brain uptakes of 3-(2-[F-18]fluoro)flumazenil at 10, 30, 60 min after injection, were 2.5±0.37, 2.2±0.26, 2.1±0.11 and blood activities were 3.7±0.43, 3.3±0.07, 3.3±0.09%ID/g, respectively. Conclusion: We synthesized a tosylated flumazenil derivative which was successfully labeled with no-carrier-added F-18 by nucleophilic substitution.

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>

Numerical Modeling of Continuous-time Fully Coupled Neural Networks

강민제 濟州大學校工科大學産業技術硏究所 1997 尖端技術硏究所論文集 Vol.8 No.1

This paper discusses numerical performance modeling of fully coupled continuous-time networks utilizing continuous activation functions, finite input resistance of neurons, and other parasitic components within the neural system. Both time-domain performance modeling and static numerical modeling of the networks are characterized and compared.

산전 초음파로 진단된 선천성 수신증 태아의 경험 1례

강민아,김도균,최석철,양회생,배철성,윤혜원,심재철,하달봉 동국대학교 경주대학 1997 東國論集 Vol.16 No.1

Prenatal ultarsound represents an accurate and reliable method for the detection of intrauterine anomalies, especially urinary tract anomalies. Hydronephrosis is the most common congenital condition detected by prenatal ultrasound. Prenatal ultrasonographic diagnosis allows a good condition and therapeutic assessment of the patients prior to serious impairment of renal function so that in most cases the urological surgeon can opt for a parenchymal conserving procedure. The authors have experienced a case of congenital ureteropelvic obstruction with hydronephrosis diagnosed at 32 weeks of pregnancy and report our experience with a brief review of literature.