Chang Kyu Lee

Yonsei University Hospital, Sŏul, Seoul, South Korea

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Publications (63)134.41 Total impact

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    ABSTRACT: Mosaic variegated aneuploidy (MVA) is a recessive condition characterized by mosaic aneuploidies, predominantly trisomies and monosomies, involving multiple chromosomes and tissues. The phenotype of MVA syndrome includes severe microcephaly and growth deficiency, central nervous system anomalies, mental retardation, mild physical anomalies, and predisposition to cancer. We report a case of true fetal mosaicism for variegated aneuploidies detected in amniotic fluid cells. A 33-year-old primigravida woman at 5 weeks 1 day of gestation was referred to our tertiary hospital because of a high-risk pregnancy associated with IgA nephropathy. In a quadruple screening test performed at the 15(th) week of gestation, alpha fetoprotein was 73.4 IU/mL (2.792 MoM), suggesting that she was at high risk of neural tube defect. Following amniocentesis performed at the 17 weeks' gestation, chromosome examination of amniocyte culture showed premature chromatic separation in 63% of the metaphases (58/92) and a high frequency of gain and loss of chromosomes. Repeat amniocentesis at 21 weeks' gestation consistently showed the presence of multiple mosaic autosomal variegated aneuploidies. Ultrasonography at 21 weeks' gestation revealed relatively small head circumference for gestational age (<3%) and vermis defect, suggesting that the fetus would have microcephaly and Dandy-Walker malformation. Cytogenetic analysis with peripheral blood of the parents showed normal karyotype. In summary, we hereby report the cytogenetic analysis and prenatal findings of MVA. © 2015 by the Association of Clinical Scientists, Inc.
    Annals of clinical and laboratory science 12/2015; 45(1):106-9. · 0.84 Impact Factor
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    ABSTRACT: The effect of interleukin (IL)-29, a new therapeutic agent similar to type I interferons (IFNs), on IFN-α secretion of human plasmacytoid dendritic cells (pDCs) has not been studied. Therefore, in this study, we aimed to clarify the effect of IL-29 on IFN-α secretion of pDCs using human peripheral blood mononuclear cells (PBMCs) in the presence of cytosine-phosphate-guanosinemotif-containing oligodeoxy nucleotides (CpG). In this experimental and prospective study, PBMCs were ob- tained from 11 healthy volunteers and divided into four culture conditions: I. control, II. CpG treatment, III. IL-29 treatment and IV. CpG plus IL-29 treatment. The amount of IFN-α secretion was measured from each culture supernatant by flow cytometry using the flowcytomix apparatus (eBioscience, Vienna, Austria). Fractional IFN-α production of the cultured PBMCs was measured by intracellular staining using the cytomics FC 500 system (Beckman Coulter, Brea, CA, USA) with CXP Software. The mean ± standard deviation (SD) of supernatant IFN-α secretion per pDC/μL was 5.7 ± 9.3 pg/mL/count/µL for condition I, 1071.5 ± 1026.6 pg/mL/count/µL for condition II, 14.1 ± 21.1 pg/mL/count/µL for condition III, and 1913.9 ± 1525.9 pg/mL/count/µL for condition IV. There were statistically significant differences between conditions I and II as well as betweenconditions II and IV. Intracellular IFN-α production was only detectable in the pDC fraction from one culture; the production amount was similar between the cells treated with CpG and those treated with CpG plus IL-29. Natural killer (NK) cell production of IFN-α was observed in two out of three cultures and one culture showed IFN- α production in the monocyte fraction. IL-29 alone did not show any effect on IFN-α secretion of PBMCs. However, the addition of CpG along with IL-29 enhanced IFN-α secretion of PBMCs. Given that pDCs are the major secretors of IFN-α in peripheral blood, this result has suggested the possibility that IL-29 has an enhancing effect in human pDC IFN-α secretion. Although the supernatant IFN-α secretion was not directly correlated with pDCs's intracellular IFN-α production in this study, prolonged incubation of pDC and other PB subsets with CpG or IL-29 for over 4 hours could be applied in future studies. These studies would help to elucidate the mechanism of action of IL-29 in human pDCs associated with viral infections.
    Cell Journal 12/2015; 16(4):528-37. · 0.46 Impact Factor
  • Annals of clinical and laboratory science 05/2015; 45(3):352-5. · 0.84 Impact Factor
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    ABSTRACT: In the present study we used an empty zona pellucida derived from hatched blastocysts as an alternative source for embryo aggregation and compared results with the conventional microwell method. Denuded 4-cell stage porcine embryos were aggregated by introduction into an empty zona or placement within a concave microwell. The present study showed that although the rate of aggregate formation was similar, the blastocyst rates and allocation of more cells to the inner cell mass (ICM) in the resultant aggregates were increased significantly more in the empty zona than in the microwell. Notably, using an empty zona showed no limitations with regards to the increased number of embryos aggregated or embryonic stages for aggregation, while partial or no aggregation frequently occurred in the microwell. The discrepancy may be due to the difference of microenvironments where the embryos were placed namely, the presence/absence of zona pellucida. We hypothesize the success of the empty zona in generating aggregates is due to the physical aggregation of individual embryos allowing closer contact between the blastomeres and/or embryos compared with a concave microwell. These results indicate that aggregation conditions could influence overall production efficiency and developmental potential of aggregates, suggesting physical restraint via empty zona that provide three-dimensional pressures is an important factor for successful embryo aggregation.
    PLoS ONE 04/2015; 10(4-4):e0123178-13. DOI:10.1371/journal.pone.0123178 · 3.53 Impact Factor
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    ABSTRACT: Objective To evaluate the accuracy of a new semi-automated method for counting axons in transmission electron microscopic (TEM) images.ProceduresOptic nerve cross sections were obtained from both eyes of Sprague Dawley rats after unilateral induction of chronic ocular hypertension. TEM images (3000× magnification) of cross sections were evaluated by both semi-automated and manual counting methods. The semi-automated counting method was performed using ImageJ software after simple image optimization, and the resulting estimate of axon damage was compared with semiquantitative damage grading scale from light microscopic (LM) images.ResultsAxon counts obtained from the semi-automated method were strongly correlated with those obtained from the manual counting method (Pearson's correlation coefficient r = 0.996, P < 0.001) and from the full manual count from LM images (Spearman's ρ = 0.973, P < 0.001). The semi-automated method measured axonal damage with an error of 0.94 ± 3.16% (mean ± standard deviation), with worse axonal damage associated with greater error. Interobserver and intra-observer variability in axons counts were low (Spearman's ρ = 0.999, P < 0.005). The results of the semi-automated counting method were highly correlated with semiquantitative damage grading scale (Spearman's ρ = 0.965, P < 0.001).Conclusion Results of our semi-automated method for counting axons in TEM images were strongly correlated with those of conventional counting methods and showed excellent reproducibility.
    Veterinary Ophthalmology 01/2015; DOI:10.1111/vop.12247 · 1.09 Impact Factor
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    ABSTRACT: Quantitation of cytomegalovirus (CMV) DNA using real-time PCR has been utilized for monitoring CMV infection. However, the CMV antigenemia assay is still the 'gold standard' assay. There are only a few studies in Korea that compared the efficacy of use of real-time PCR for quantitation of CMV DNA in whole blood with the antigenemia assay, and most of these studies have been limited to transplant recipients. 479 whole blood samples from 79 patients, falling under different disease groups, were tested by real-time CMV DNA PCR using the Q-CMV real-time complete kit (Nanogen Advanced Diagnostic S.r.L., Italy) and CMV antigenemia assay (CINA Kit, ArgeneBiosoft, France), and the results were compared. Repeatedly tested patients were selected and their charts were reviewed for ganciclovir therapy. The concordance rate of the two assays was 86.4% (Cohen's kappa coefficient value=0.659). Quantitative correlation between the two assays was a moderate (r=0.5504, P<0.0001). Among 20 patients tested repeatedly with the two assays, 13 patients were transplant recipients and treated with ganciclovir. Before treatment, CMV was detected earlier by real-time CMV DNA PCR than the antigenemia assay, with a median difference of 8 days. After treatment, the antigenemia assay achieved negative results earlier than real-time CMV DNA PCR with a median difference of 10.5 days. Q-CMV real-time complete kit is a useful tool for early detection of CMV infection in whole blood samples in transplant recipients.
    Annals of Laboratory Medicine 01/2015; 35(1):99-104. DOI:10.3343/alm.2015.35.1.99 · 1.48 Impact Factor
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    ABSTRACT: A recently introduced Sofia RSV FIA was evaluated comparatively with the BinaxNow® RSV Card and the SD Bioline RSV test using 348 respiratory samples. The Sofia, BinaxNow and SD Bioline kits showed sensitivities of 66%, 65%, and 64% for RSV A, and 71%, 63%, and 65% for RSV B, respectively. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
    Journal of Clinical Microbiology 11/2014; 53(2). DOI:10.1128/JCM.03324-14 · 4.23 Impact Factor
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    ABSTRACT: OCT4 encoded by POU5F1 has a crucial role of maintaining pluripotency in embryonic stem cells during early embryonic development and several OCT4 variants have been identified in mouse and human studies. The objective of the present study was to identify different variants of OCT4 and analyze their expression patterns in preimplantation porcine embryos and in various tissues. Here, we showed that POU5F1 transcribes its three variants, namely OCT4A, OCT4B, and OCT4B1. The OCT4B transcript consists of exons identical to the major form of the OCT4 variant, OCT4A, with a differential N-terminal domain coding exon. The structure of OCT4B1 mRNA was same as that of OCT4B mRNA, but harbored a cryptic exon. Based on these findings, the transcription levels was investigated and found that OCT4B and OCT4B1 made up approximately 20% among the variants in embryonic stage and this indicates OCT4A mRNA is dominantly expressed during preimplantation embryos development. Also, OCT4B mRNA was detected in all tissues examined, while OCT4A and OCT4B1 were detected only in testis but not in other tissues examined. OCT4B1 showed inversely correlated expression with SOX2 and NANOG expression. OCT4A protein was specifically localized in the nuclei, whereas OCT4B was mainly localized in the cytoplasm of the porcine embryos at the blastocyst stage. The findings of this study reveal that the porcine OCT4 gene can potentially encode three variants (OCT4A, OCT4B, and OCT4B1), and they are differentially expressed and would have dissimilar roles each other in preimplantation embryos and various adult tissues.
    Reproduction (Cambridge, England) 10/2014; 149(1). DOI:10.1530/REP-14-0403 · 3.26 Impact Factor
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    ABSTRACT: Background: Skin infections with Gram-negative bacteria are sometimes challenging to treat, because these bacteria show multidrug resistance against commonly used antibiotics and patients with Gram-negative bacterial infection overall have deteriorated in conditions in many cases. Studies have shown that epigallocatechin gallate (EGCG) and green tea extracts (GTE) inhibit the growth of several Gram-positive bacteria species. Objective: The purpose of this study was to investigate the minimum inhibitory concentrations (MICs) of EGCG and GTE in Pseudomonas aeruginosa and Escherichia coil, and assess the use of these chemicals as an alternative or adjunct topical antimicrobial agent against P. aeruginosa and E. coil with multidrug resistance. Methods: The MICs of EGCG, GTE, and other tested antibiotics were measured and compared to determine the antibacterial efficacy and the differences in pattern of resistance. Results: The P. aeruginosa and E. coil strains used in this study showed multidrug resistance. EGCG inhibited the growth of P. aeruginosa at a MIC level of 200 similar to 400 mu g/ml. The MIC of GTE was a 1:16 dilution for P. aeruginosa. EGCG showed antimicrobial activity against E. coil at a MIC of 400 mu g/ml. In the case of GTE, the MIC was a dilution between 1: 8 and 1:4 for E. coli. Conclusion: EGCG and GTE showed potential as alternative or adjunct topical antimicrobial agents for infections that are resistant to traditional antibiotic therapy.
    Annals of Dermatology 10/2014; 26(5):564-9. DOI:10.5021/ad.2014.26.5.564 · 0.95 Impact Factor
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    ABSTRACT: Background This study aimed to investigate the impact of preceding respiratory viral infections (RVI) on the clinical severity of pneumococcal pneumonia patients. MethodsA retrospective observational study was conducted at a university hospital from January 2009 to March 2013. Study subjects included adults (aged 18years) with pneumococcal pneumonia who had undergone laboratory tests for RVI. Multivariate logistic regression analysis was performed to identify risk factors associated with severe pneumococcal pneumonia, defined as severity with the Pneumonia Severity Index (PSI) score 91. ResultsIn total, 191 patients with pneumococcal pneumonia were included for analysis and stratified into 2 groups: the severe group with a PSI score 91 (n=99) and the non-severe group with a PSI score <91 (n=92). Preceding RVIs were detected in 48 patients, including influenza A virus (n=20), influenza B virus (n=4), parainfluenza viruses (n=5), metapneumovirus (n=4), rhinovirus (n=4), respiratory syncytial viruses (n=6), coronaviruses (n=2), and mixed viral infections (n=3). In the multivariate logistic regression analysis, preceding RVIs (odds ratio [OR], 249; 95% confidence interval [CI], 110-560), male sex (OR, 258; 95% CI, 124-538), old age (OR, 292; 95% CI, 137-624), hypoalbuminemia (OR, 326; 95% CI, 156-684)], and azotemia (OR, 224; 95% CI, 108-467) were significantly associated with severe pneumococcal pneumonia. Conclusion This study suggests that preceding RVIs might be one of the risk factors affecting the clinical severity of pneumococcal pneumonia.
    Influenza and Other Respiratory Viruses 06/2014; 8(5). DOI:10.1111/irv.12265 · 1.90 Impact Factor
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    ABSTRACT: Human parainfluenza viruses (HPIV) are important causes of respiratory tract infections in young children. To characterize the molecular epidemiology of an HPIV outbreak occurring in Korea during 2006, genetic analysis of 269 cell culture isolates from HPIV-infected children, was conducted using nested reverse transcription-PCR (RT-PCR). HPIV-1 was detected in 70.3% of tested samples (189/269). The detection rate of HPIV-2 and HPIV-3 was 1.5% (4/269) and 9.3% (25/269), respectively. Mixed HPIV-1, -2 and -3 infections were detected in 19.0% (51/269): HPIV-1 and HPIV-2 in 15, HPIV-1 and HPIV-3 in 26, HPIV-2 and HPIV-3 in 6, and HPIV-1, -2 and -3 in 4. Of these positive samples for three different types HIPV-1, -2, and -3, two each representative strains were selected, the full length of hemagglutinin-neuraminidase (HN) gene for HPIV was amplified by RT-PCR, and sequenced. Multiple alignment analysis, based on reference sequence of HPIV-1, -2, and -3 strains available in GenBank, showed that the identity of nucleotide and deduced amino acid sequences was 92.4-97.6% and 92.7-97.9%, respectively, for HPIV-1, 88.5-99.8% and 88.6-100% for HPIV-2, and 96.3-99.5% and 95.0-99.3% for HPIV-3, respectively. Phylogenetic analysis showed that HPIV-1, -2, and -3 strains identified in this study were closely related among the strains in the same type with no significant genetic variability. These results show that HPIV of multiple imported sources was circulating in Korea. J. Med. Virol. © 2014 Wiley Periodicals, Inc.
    Journal of Medical Virology 06/2014; 86(6). DOI:10.1002/jmv.23890 · 2.22 Impact Factor
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    ABSTRACT: Recently, AdvanSureTM kit based on multiplex real-time PCR was developed for simultaneous detection of 14 respiratory viruses. We compared the performance of AdvanSure with those of Seeplex® RV 15 ACE and culture by determining their sensitivity and specificity against a composite reference standard. Four hundred and thirty seven respiratory samples were tested by modified shell vial culture method, RV 15 ACE and AdvanSure. One hundred and fourteen samples (26.2%) out of 437 samples were positive by culture, while additional 91 (20.8%) were positive by AdvanSure or RV15. One hundred twelve of 114 culture positive samples were positive by AdvanSure except 2 samples (1 adenovirus, 1 RSV). Overall, the sensitivities of culture, RV15 and AdvanSure were 74.5%, 89.8%, and 95.1%, respectively. Sensitivities of culture, RV15 and AdvanSure for each virus tested were as follows; 91/100/96% for influenza A, 60/0/100% for influenza B, 63/95/97% for RSV, 69/81/89% for adenovirus, and 87/93/93% for PIV. For viruses not covered by culture, sensitivities of RV15 and AdvanSure were as follows; 77/88% for rhinovirus, 100/100% for coronavirus OC43, 40/100% for coronavirus 229E/NL63, 13/100% for metapneumovirus, and 44/100% for bocavirus. The overall specificities of culture, RV15 and AdvanSure were 100/98.9/99.5%, respectively. Of 45 co-infected specimens, AdvanSure detected 41 specimens (91.1%) as co-infected, while RV15 detected 27 specimens (60.0%) as co-infected. AdvanSure assay demonstrated exquisite performance for the detection of respiratory viruses and will be a valuable tool for the management of respiratory virus infection.
    Diagnostic microbiology and infectious disease 05/2014; 79(1). DOI:10.1016/j.diagmicrobio.2014.01.016 · 2.57 Impact Factor
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    Annals of Laboratory Medicine 03/2014; 34(2):155-8. DOI:10.3343/alm.2014.34.2.155 · 1.48 Impact Factor
  • Myeong In Yeom, Sang Soo Kim, Chang Kyu Lee
    Journal of the Korean Ophthalmological Society 01/2014; 55(8):1261. DOI:10.3341/jkos.2014.55.8.1261
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    ABSTRACT: The aim of this study was to compare the analytical sensitivity and specificity of the recently updated 4th generation Elecsys HIV combi PT assay (Roche Diagnostics GmbH, Germany) to those of the ARCHITECT HIV Ag/Ab Combo assay (Abbott Laboratories, Germany).
    01/2014; 4(3):157. DOI:10.3343/lmo.2014.4.3.157
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    ABSTRACT: Over the past three decades, a total of USD $121 million in economic losses (fish/shellfish kills) has occurred in the Korean aquaculture industry due to harmful algal blooms (HABs). Paralytic shellfish poisoning (PSP) has also been noted almost every year, closing shellfish farms, and 46 people were poisoned including five people killed by consuming wild mussels. Since 1980, PSP has been officially monitored and managed, and the nationwide control of fish/shellfish kills by HAB species began in 1995. Management and control strategies include both precautionary and emergency measures. Precautionary management includes establishing an observation network and prediction system, an early warning system, and mitigating damage to aquafarms. Along with regular HAB monitoring including species, chlorophyll a, and associated water quality and meteorological parameters, automatic HAB alarm systems equipped with chlorophyll a and turbidity sensors are used in aquafarms as early HAB warnings. Emergency management is essential after a HAB outbreak to prevent fisheries damage. This method includes supplying oxygen to fish, stopping feeding, transferring fish to a safe area, and clay dispersal. Clay dispersion is the prime mitigation technique for HABs in Korea, because clay is natural, nontoxic, inexpensive, and easy to use in field operations. Clay is dispersed over the sea surface using a clay dispensing device to efficiently remove HABs. A third generation (3G) clay dispenser has been developed recently, combining an electrolytic water generator and a clay dispenser, significantly reducing the amount of clay used, resulting in high removal efficiencies. Since using this device, the economic losses from HAB fish kills have dropped >80% in Korea, although the frequency of HABs has increased since 1980. Clay is a natural component, but using too much clay may cause negative impacts on marine organisms and environments. In addition, clay dispersal is not an effective method to control poisoning of fish/shellfish from algal toxins that accumulate in fish and shellfish at low density toxic blooms. Future studies of HAB control should include control of HABs using minimum amounts of clay and practical use of biological control agents.
    Harmful Algae 12/2013; 30:S131–S143. DOI:10.1016/j.hal.2013.10.012 · 3.34 Impact Factor
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    ABSTRACT: BACKGROUND: Various kinds of commercial molecular systems have been developed for fast and more accurate detection of respiratory viruses. Anyplex™ II RV16 [RV16] was designed for simultaneous detection of 16 respiratory viruses using multiplex PCR coupled with TOCE™ technology. OBJECTIVES: To compare the performance of RV16 with those of culture and Seeplex(®) RV15 ACE [RV15] by determining their sensitivity and specificity. STUDY DESIGN: Seven hundred and thirty respiratory samples were tested by modified shell vial culture method, RV16, and RV15. For molecular tests, automated nucleic acid extraction and liquid handling system using MICROLAB Nimbus IVD (Hamilton, USA) was adopted to maximize the workflow and accuracy. Performance of each assay was determined against a composite reference standard. RESULTS: Two hundred and one samples (28%) out of 730 samples were positive by culture, while additional 281 (39%) were positive by RV16 or RV15. Sensitivities of RV16, RV15, and culture for virus tested were as follows: 100/93/63% for influenza A, 90/80/69% for influenza B, 98/94/63% for RSV, 98/52/23% for adenovirus, and 100/75/46% for PIV. For viruses not covered by culture, sensitivities of RV16 and RV15 were as follows: 99/81% for rhinovirus, 92/100% for coronavirus OC43, 100/56% for coronavirus 229E/NL63, 92/88% for metapneumovirus, 100/62% for bocavirus, and 91/91% for enterovirus. Overall, the specificities of culture, RV16, and RV15 (Seegene) were 100/99.9/99.9%. CONCLUSIONS: RV16 assay was superior to culture method and RV15 and will be a promising tool for patient management and public health epidemiology.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 06/2013; 57(4). DOI:10.1016/j.jcv.2013.04.014 · 3.47 Impact Factor
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    ABSTRACT: There was a global increase in the prevalence of oseltamivir-resistant influenza viruses during the 2007-2008 influenza season. This study was conducted to investigate the occurrence and characteristics of oseltamivir-resistant influenza viruses during the 2007-2008 and 2008-2009 influenza seasons among patients who were treated with oseltamivir (group A) and those that did not receive oseltamivir (group B). A prospective study was conducted on 321 pediatric patients who were hospitalized because of influenza during the 2007-2008 and 2008-2009 influenza seasons. Drug resistance tests were conducted on influenza viruses isolated from 91 patients. There was no significant difference between the clinical characteristics of groups A and B during both seasons. Influenza A/H1N1, isolated from both groups A and B during the 2007-2008 and 2008-2009 periods, was not resistant to zanamivir. However, phenotypic analysis of the virus revealed a high oseltamivir IC50 range and that H275Y substitution of the neuraminidase (NA) gene and partial variation of the hemagglutinin (HA) gene did not affect its antigenicity to the HA vaccine even though group A had a shorter hospitalization duration and fewer lower respiratory tract complications than group B. In addition, there was no significant difference in the clinical manifestations between oseltamivir-susceptible and oseltamivir-resistant strains of influenza A/H1N1. Establishment of guidelines to efficiently treat influenza with oseltamivir, a commonly used drug for treating influenza in Korean pediatric patients, and a treatment strategy with a new therapeutic agent is required.
    Korean Journal of Pediatrics 04/2013; 56(4):165-75. DOI:10.3345/kjp.2013.56.4.165
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    ABSTRACT: To report the progression of an astrocytic hamartoma of the right optic nerve head as well as the retina, and the progression of retinal nerve fiber defect associated with astrocytic hamartoma in a patient with tuberous sclerosis.
    Journal of the Korean Ophthalmological Society 01/2013; 54(8):1282. DOI:10.3341/jkos.2013.54.8.1282
  • Byung Ju Kang, Chang Kyu Lee, Je Hoon Oh
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    ABSTRACT: The objective of this work is to demonstrate the feasibility of inkjet-printed passive components. All passive components such as resistor, capacitor and inductor were inkjet printed on a polyimide (PI) substrate with various functional inks. For the insulator layer, poly-4-vinylphenol (PVP) and cross linking agent (poly(melamine-co-formaldehyde)) were dissolved in an ethanol. A mixture of poly(3,4-ethylene dioxythiophene) doped with polystyrene sulfonated acid (PEDOT:PSS) and ethylene glycol was used to print a resistor. Barium titanate (BaTiO3) and soft ferrite (Ni–Zn) powders were added to the synthesized insulator solution to improve its dielectric and magnetic characteristics, respectively. An RC circuit was also fabricated based on the results of the printed passive components. The printed electric components and circuit were characterized using LCR meter, function generator and digital oscilloscope. The measured responses of the printed RC circuit were in good agreement with estimated results.
    Microelectronic Engineering 09/2012; 97:251–254. DOI:10.1016/j.mee.2012.03.032 · 1.34 Impact Factor

Publication Stats

519 Citations
134.41 Total Impact Points

Institutions

  • 2015
    • Yonsei University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2006–2015
    • Korea University
      • • Department of Laboratory Medicine
      • • Department of Biomedical Science
      Sŏul, Seoul, South Korea
  • 2005–2014
    • Seoul National University
      • Department of Agricultural Biotechnology
      Sŏul, Seoul, South Korea
    • Seoul National University Hospital
      Sŏul, Seoul, South Korea
  • 2012
    • Hanyang University
      • Division of Mechanical Engineering
      Sŏul, Seoul, South Korea
  • 2010
    • Inje University
      Kŭmhae, Gyeongsangnam-do, South Korea