Y. J. Park

Pohang Accelerator Laboratory, Urusan, Ulsan, South Korea

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Publications (316)646.78 Total impact

  • Cancer Research 05/2014; 73(3 Supplement):B23-B23. DOI:10.1158/1538-7445.TIM2013-B23 · 9.28 Impact Factor
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    F P Li, Y S Lee, S W Kwon, G Li, Y J Park
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    ABSTRACT: This study analyzed 394 Korean rice landrace accessions, including 93 waxy varieties, for polymorphisms using 29 simple sequence repeat (SSR) markers. In total, 381 alleles served as raw data for estimating the genetic diversity (GD) and population structure. The number of alleles per locus ranged from 3 to 44 (average = 13.14). The expected heterozygosity and polymorphism information content (PIC) ranged from 0.0341 to 0.9358 (mean = 0.5623) and from 0.0783 to 0.9367 (mean = 0.5839), respectively. The mean GDs in waxy, low amylose content, intermediate amylose content, and high amylose content (HAC) varieties were 0.6014, 0.5922, 0.5858, and 0.7232, respectively, whereas the mean PIC values for each SSR locus were 0.5701, 0.5594, 0.5550, and 0.6926, respectively. HAC varieties had the highest GD and PIC. Consistent with clustering by genetic distances, a model-based structural analysis revealed 3 subpopulations. Analysis of molecular variance revealed that the between-population component of genetic variance was 22.35%, and that of the within-population component was 77.65%. Significant correlations were observed between eating quality and protein content (r = -0.262), K(+) (r = -0.655), Mg(2+) (r = -0.680), 1000-GW (r = 0.159), and amylose content (r = -0.134). The overall FST value was 0.2235, indicating moderate differentiation among the groups. Analysis of variance of the 3 genetic groups (mean of 9 phenotypic and 5 physicochemical traits) by Duncan's multiple range test showed significant differences in 10 traits. This preliminary study represents a first step toward more efficient conservation and greater utilization of rice landraces to broaden the genetic bases of commercially grown varieties.
    Genetics and molecular research: GMR 04/2014; 13(AOP). DOI:10.4238/2014.April.14.12 · 0.85 Impact Factor
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    ABSTRACT: A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.
    Physical Review Letters 01/2014; 112:034802. · 7.73 Impact Factor
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    ABSTRACT: Aim: Serum antithyroglobulin antibody (TgAb) has been reported as a surrogate marker for differentiated thyroid cancer (DTC) in some conditions. We investigated changes in serum TgAb levels after stimulation with thyroid-stimulating hormone (TSH) and the clinical implications for monitoring DTC. Patients, methods: We retrospectively enrolled 53 DTC patients who had undergone total thyroidectomy and were negative for serum Tg and positive for TgAb. Patients underwent high-dose radioactive iodine treatment, and serum TgAb was measured before (TgAbBAS) and after TSH stimulation (TgAbSTIM). TgAb was followed up 6 to 12 months later (TgAbF/U). The change in TgAb after TSH stimulation (∆TgAbSTIM) was calculated as a percentage of the baseline level. Patient disease status was classified into no residual disease (ND) and residual or recurred disease (RD) by follow-up imaging studies and pathologic data. The characteristics and diagnostic value of serum TgAb levels and ∆TgAbSTIM were investigated with respect to disease status. Results: 38 patients were in the ND group and 15 were in the RD group. TgAbBAS, TgAbSTIM and TgAbF/U were significantly higher in the RD compared to the ND group (p = 0.0008, 0.0002, and < 0.0001, respectively). ∆TgAbSTIM was also significantly higher in the RD group (p = 0.0009). In the patients who presented with obviously high (≥ 50%) or low (< -50%) ∆TgAbSTIM, the proportions in the RD group were markedly different at 100% and 7%, respectively. ∆TgAbSTIM had significant diagnostic value for RD (p < 0.001). Conclusion: The change in serum TgAb level after TSH stimulation is different between the RD and ND groups, and thus, it may be used as a surrogate diagnostic marker for DTC when the serum Tg is negative and TgAb is positive.
    Nuklearmedizin 11/2013; 53(2). DOI:10.3413/Nukmed-0604-13-06 · 1.67 Impact Factor
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    ABSTRACT: The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. This paper describes the high resolution cavity beam position monitor (BPM) system, which is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.423 GHz, and S-band at 2.888 GHz with an increased beam aperture. The cavities, electronics, and digital processing are described. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1 m for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm.
    Review of Modern Physics 01/2013; 15(4). DOI:10.1103/PhysRevSTAB.15.042801 · 42.86 Impact Factor
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    ABSTRACT: This study aims to investigate the combustion characteristics of mixed fuel of liquefied propane gas (LPG) and biodiesel under compression ignition (CI) in an effort to develop highly efficient and environmentally friendly mixed fuelbased CI engines. Although LPG fuel is known to be eco-friendly due to its low CO2 emission, LPG has not yet been widely applied for highly efficient CI engines because of its low cetane number and is usually mixed with other types of CI-friendly fuels. In this study, a number of experiments were prepared with a constant volume chamber (CVC) setup to understand the fundamental combustion characteristics of mixed fuel with LPG and biodiesel in two weight-based ratios and exhaust gas recirculation (EGR) conditions. The results from the current investigations verify the applicability of mixed fuel of LPG and biodiesel in CI engines with a carefully designed combustion control strategy that maximizes the benefits of the mixed fuel. Based on the results of this study, ignition is improved by increasing the cetane value by using higher blending ratios of biodiesel. As the blending ratios of biodiesel increased, CO and HC decreased and CO2 and NOx increases.
    International Journal of Automotive Technology 12/2012; 13(7). DOI:10.1007/s12239-012-0118-0 · 0.82 Impact Factor
  • G Li, S W Kwon, Y J Park
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    ABSTRACT: After complete sequencing of its genome and annotation of the majority of its ~32,000 genes, rice genome has become the model genome among the cereal genomes, and the focus has shifted from structural to functional genomics and application of genomics-derived information in rice breeding. During the past 2 decades, intensive worldwide efforts have led to significant improvements in rice. An abundance of molecular markers and information related to many genes/quantitative trait loci that control agronomically important traits such as yield, quality, and biotic and abiotic stress tolerance have been identified. Bridging the application gap between quantitative trait locus identification and marker-assisted selection breeding is an urgent, arduous, and long-term task. Marker development, allele mining, gene discovery, and molecular breeding have progressed to a great extent because of the rapid development of next-generation sequencing, large-scale high-density genotyping, and genome-wide selection strategies. The availability of high-density markers and the rapidly decreasing cost of genotyping have facilitated marker-assisted selection of many traits that were previously not possible.
    Genetics and molecular research: GMR 09/2012; 11(AOP). DOI:10.4238/2012.September.10.4 · 0.85 Impact Factor
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    ABSTRACT: A theoretical model for the radially dependent effective piezoelectric coefficient and corresponding piezoelectric potential in intrinsic ZnO nanowires (NWs)/nanotubes (NTs) is presented. Substrate-bound ZnO structures oriented along the c-axis with diameters of 100–5000 nm (NWs) and inner diameters of 100–900 nm (NTs; fixed outer diameter, 1000 nm) were examined using finite element method analysis. The piezoelectric potential depended nonlinearly on the NT/NW size, which we explain using the effective piezoelectric coefficient and peak piezoelectric potentials. We propose that this coefficient can be used to judge the degree of enhancement of the piezoelectric potential in ZnO NWs/NTs.
    Applied Physics Letters 07/2012; 101(1). DOI:10.1063/1.4731779 · 3.52 Impact Factor
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    ABSTRACT: Hypermucoviscous (HV) isolates of Klebsiella pneumoniae have been linked to virulence potential in experimental infections. We examined 33 isolates of K. pneumoniae from patients with bacteraemia for the HV phenotype on agar culture, and determined their virulence potential by screening for capsular (K) serotype by polymerase chain reaction and the presence of seven virulence factor genes. Fourteen (42·4%) isolates expressed the HV phenotype and 11 of these were serotype K1 or K2; these serotypes were not identified in HV-negative isolates. The genes rmpA, rmpA2, aerobactin, wabG and allS were significantly more frequent in HV than non-HV isolates. Multilocus sequence typing identified 21 sequence types (ST), eight of which were found in HV-positive isolates and the clonal relatedness of isolates of the most frequent types (ST23 and ST11) from different hospitals was confirmed by pulsed-field gel electrophoresis. The HV phenotype was more associated with community-acquired infection with a lower frequency of fatal underlying illness, but with significantly more focal infections, notably liver abscesses. Clinicians should be aware of such clinical impacts of the HV phenotype.
    Epidemiology and Infection 05/2012; 141(2):1-7. DOI:10.1017/S0950268812000933 · 2.49 Impact Factor
  • Transplantation 01/2012; 94(10S):1190. DOI:10.1097/00007890-201211271-02361 · 3.78 Impact Factor
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    ABSTRACT: Introduction: Plasmodium vivax malaria is one of the most important infectious diseases plaguing humanity and causes significant mortality and morbidity worldwide. The gold standard of P. vivax malaria diagnosis is the microscopy of blood smears. Although microscopy is a rapid, cost‐effective, and readily applicable method, it has many disadvantages, including low sensitivity, specificity, and precision. Therefore, there is a clear need for an effective screening test for P. vivax malaria detection both in high‐prevalence areas and developed countries.Methods: A total of 1761 complete blood count (CBC) samples generated by the automated hematology analyzer (DxH 800™; Beckman Coulter Inc., Miami, FL, USA) were retrospectively analyzed. The sample pool contained 123 samples from 52 P. vivax malaria patients and 1504 nonmalarial samples including 509 patients with leukopenia (white blood cell Results: The P. vivax malaria samples exhibited easily recognizable typical malaria signals on the nucleated red blood cell (nRBC) plots (sensitivity 100%) in DxH 800™. All 1504 samples without P. vivax infection were negative for malaria signal (specificity 100%). The size of P. vivax malaria signals correlated roughly with the parasite burden.Conclusion: DxH800™ provides very sensitive and specific, easily recognizable P. vivax malaria signals on routine CBC without need for the additional reagents or special procedures.
    International Journal of Laboratory Hematology 01/2012; 34(2). · 1.87 Impact Factor
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    ABSTRACT: Plasmodium vivax malaria is one of the most important infectious diseases plaguing humanity and causes significant mortality and morbidity worldwide. The gold standard of P. vivax malaria diagnosis is the microscopy of blood smears. Although microscopy is a rapid, cost-effective, and readily applicable method, it has many disadvantages, including low sensitivity, specificity, and precision. Therefore, there is a clear need for an effective screening test for P. vivax malaria detection both in high-prevalence areas and developed countries. A total of 1761 complete blood count (CBC) samples generated by the automated hematology analyzer (DxH 800™; Beckman Coulter Inc., Miami, FL, USA) were retrospectively analyzed. The sample pool contained 123 samples from 52 P. vivax malaria patients and 1504 nonmalarial samples including 509 patients with leukopenia (white blood cell <2000/μL) and 134 normal subjects. The P. vivax malaria samples exhibited easily recognizable typical malaria signals on the nucleated red blood cell (nRBC) plots (sensitivity 100%) in DxH 800™. All 1504 samples without P. vivax infection were negative for malaria signal (specificity 100%). The size of P. vivax malaria signals correlated roughly with the parasite burden. DxH800™ provides very sensitive and specific, easily recognizable P. vivax malaria signals on routine CBC without need for the additional reagents or special procedures.
    International journal of laboratory hematology 11/2011; 34(2):201-7. DOI:10.1111/j.1751-553X.2011.01383.x · 1.30 Impact Factor
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    ABSTRACT: ATF2 is a final-focus test beam line which aims to focus the low emittance beam from the ATF damping ring to a vertical size of about 37 nm and to demonstrate nanometer level beam stability. Several advanced beam diagnostics and feedback tools are used. In December 2008, construction and installation were completed and beam commissioning started, supported by an international team of Asian, European, and U.S. scientists. The present status and first results are described.
    Physical Review Special Topics - Accelerators and Beams 11/2011; DOI:10.1103/PhysRevSTAB.13.042801 · 1.52 Impact Factor
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    ABSTRACT: UV–vis absorption spectroscopy of uranium in LiCl–KCl eutectic salt at 773K was studied for the on-site use in pyrochemical process. Uranium(III) chloride was electrochemically prepared from uranium metal in LiCl–KCl eutectic salt at 773K by using chronopotentiometry. Three absorption peak positions were selected and calibrated for the quantitative analysis of uranium in the molten salt medium. The molar absorptivity and minimum detectable concentration for the selected wavelength were obtained with a confidence level of 99%.
    Microchemical Journal 11/2011; 99(2):170-173. DOI:10.1016/j.microc.2011.04.013 · 3.58 Impact Factor
  • E. C. Jung, S.-E. Bae, Y. J. Park, K. Song
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    ABSTRACT: The characteristics of the laser-induced fluorescence of Nd3+ in LiCl–KCl eutectic in the wavelength region of 360–900nm were investigated for information concerning the chemical speciation of Nd-chloride complexes. When pumped at either 355 or 532nm, Nd3+ in molten salt emits visible and near-IR fluorescence. The fluorescence peaks at 750nm (4F7/2+4S3/2→4I9/2) and 810nm (4F5/2+2H9/2→4I9/2) were particularly prominent at temperatures above the melting point. The fluorescence decay of these transition lines showed a bi-exponential behaviour of the fluorescence lifetime. These results provide evidence that two different chemical species of Nd3+ coexist in this system.
    Chemical Physics Letters 11/2011; 516(4):177-181. DOI:10.1016/j.cplett.2011.09.093 · 1.99 Impact Factor
  • Clinical otolaryngology: official journal of ENT-UK; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery 10/2011; 36(5):504-9. DOI:10.1111/j.1749-4486.2011.02346.x · 2.27 Impact Factor
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    ABSTRACT: Carbapenem-resistant Acinetobacter baumannii (CRAB) are an increasing infectious threat in hospitals. We investigated the clinical epidemiology of CRAB infections vs. colonization in patients, and examined the mechanisms of resistance associated with elevated minimum inhibitory concentrations (MICs) for carbapenems. From January to June 2009, 75 CRAB strains were collected. CRAB infection was significantly associated with malignancy and a high APACHE II score. The most dominant resistance mechanism was ISAba1 preceding OXA-51, producing strains with overexpression of efflux pump. Strains carrying blaOXA-23-like enzymes had higher carbapenem MICs than those carrying blaOXA-51-like enzymes; however, the presence of multiple mechanisms did not result in increased resistance to carbapenems. There was no difference in the resistance mechanisms in strains from infected and colonized patients. The majority of strains were genetically diverse by DNA macrorestriction although there was evidence of clonal spread of four clusters of strains in patients.
    Epidemiology and Infection 04/2011; 140(1):137-45. DOI:10.1017/S0950268811000744 · 2.49 Impact Factor
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    ABSTRACT: a b s t r a c t Fluorescence spectra and lifetimes originated from both 5 D 3 ! 7 F J and 5 D 4 ! 7 F J transitions of Tb 3þ were measured using time-resolved laser fluorescence spectroscopy in order to investigate the excited state relaxation in a molten salt medium.A cross-relaxation energy transfer of 5 D 3 ! 5 D 4 resulted in rise and decay behaviors in fluorescence signal waveforms of 5 D 4 ! 7 F J transitions.The fluorescence intensity ratios of 5 D 4 ! 7 F 5 to 5 D 3 ! 7 F 4 decreased drastically when the temperature of molten salt increased. This result suggests that the cross-relaxation effect becomes weakened with increasing temperature. In addition, a strong increase of the 5 D 4 emission over the 5 D 3 emission was observed at high Tb 3þ concentration.
    Chemical Physics Letters 01/2011; 501(4-6):300-303. DOI:10.1016/j.cplett.2010.11.039 · 1.99 Impact Factor
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    ABSTRACT: We investigated the interfacial status of ferromagnetic Co84Fe16/insulating barrier Al2O3 of the Al2O3-based magnetic tunnel junction (MTJ) using various x-ray scattering measurements. The results show formation of orthorhombic AlFeO3 magnetic nanoparticles at the interface, which are embedded in the Al2O3 cage. Their thickness and planner size vary with the plasma oxidation time. We also observed an interesting magnetic anomaly with a minimum magnetic coercivity near the AlFeO3 ferrimagnetic TC, which is successfully explained in terms of the AlFeO3 nanoparticles and nanoscale CoFe grains with size distribution.
    Physical review. B, Condensed matter 01/2011; 83. DOI:10.1103/PhysRevB.83.172408 · 3.66 Impact Factor
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    ABSTRACT: The influence of growth sequence on optical and structural properties of InAs/GaAs quantum dots (QD) grown by atomic layer epitaxy was investigated systematically. It is found that growth interruption (GI) after In is more effective than non-GI after In in reducing the density of coalescent dots, and reducing the dot width distribution of the QDs. Meanwhile, dot densities are approximately doubled by non-GI after In. GI after As reduces dot height distribution compared with non-GI after As. Generally, GI after In plays a more critical role than GI after As does in formation of the QDs. The sample grown with In/GI/As/GI sequence shows the lowest 300 K-photoluminescence (PL) linewidth (∼30 meV), high PL peak separation between ground and 1st excited level (∼80 meV). From the result, it is known that In/GI/As/GI is the favorable growth sequence among the sample sets. Temperature dependence of PL linewidth shows that the In/GI/As/GI sample is insensitive to cryostat temperature and it is attributed to weak wetting effect. Thinner wetting layers shown in a cross-sectional TEM image supports this.
    MRS Online Proceeding Library 01/2011; 794. DOI:10.1557/PROC-794-T3.26

Publication Stats

3k Citations
646.78 Total Impact Points

Institutions

  • 1998–2013
    • Pohang Accelerator Laboratory
      Urusan, Ulsan, South Korea
    • Ewha Womans University
      • Department of Electronics Engineering
      Seoul, Seoul, South Korea
    • Yonsei University
      Sŏul, Seoul, South Korea
  • 2012
    • SAIT Polytechnic
      Calgary, Alberta, Canada
  • 2010–2012
    • Kongju National University
      • Department of Plant Resources
      Gongju, Chungcheongnam-do, South Korea
    • Sookmyung Women's University
      • Department of Chemistry
      Sŏul, Seoul, South Korea
  • 2008–2012
    • Kookmin University
      • Graduate School of Automotive Engineering
      Sŏul, Seoul, South Korea
    • Samsung Electro-Mechanics
      Sŏul, Seoul, South Korea
  • 1999–2012
    • Catholic University of Korea
      • • Department of Laboratory Medicine
      • • Department of Internal Medicine
      • • College of Medicine
      Sŏul, Seoul, South Korea
  • 1997–2011
    • Korea Atomic Energy Research Institute (KAERI)
      • Nuclear Chemistry Research Division
      Daiden, Daejeon, South Korea
  • 1995–2011
    • Pohang University of Science and Technology
      • Pohang Accelerator Laboratory
      Antō, North Gyeongsang, South Korea
  • 2001–2008
    • Inha University
      • • Department of Physics
      • • College of Medicine
      Seoul, Seoul, South Korea
    • Pai Chai University
      Sŏul, Seoul, South Korea
    • Kyungpook National University
      • Department of Microbiology
      Daikyū, Daegu, South Korea
    • Electronics and Telecommunications Research Institute
      Sŏul, Seoul, South Korea
    • Chung-Ang University
      Sŏul, Seoul, South Korea
    • Asan Medical Center
      Sŏul, Seoul, South Korea
  • 2000–2008
    • Seoul National University Hospital
      • • Department of Surgery
      • • Department of Internal Medicine
      Sŏul, Seoul, South Korea
    • Children's Cancer Research Institute
      Wien, Vienna, Austria
    • Hongik University
      • Department Electronic and Electrical Engineering
      Sŏul, Seoul, South Korea
  • 2001–2007
    • Sogang University
      • Department of Physics
      Sŏul, Seoul, South Korea
  • 1997–2007
    • Korea Institute of Science and Technology
      • Center for Opto-Electronic Convergence Systems
      Sŏul, Seoul, South Korea
  • 2006
    • University of Seoul
      Sŏul, Seoul, South Korea
  • 1998–2006
    • Korea Advanced Institute of Science and Technology
      • • Department of Materials Science and Engineering
      • • Department of Electrical Engineering
      Sŏul, Seoul, South Korea
    • Samsung Advanced Institute of Technology
      Usan-ri, Gyeonggi Province, South Korea
  • 2005
    • Hankyong National University
      Anjŏ, Gyeonggi Province, South Korea
    • Dongguk University
      • Quantum-functional Semiconductor Research Center
      Sŏul, Seoul, South Korea
  • 2003–2005
    • Hanyang University
      • • Department of Electronics and Computer Engineering
      • • Department of Physics
      Sŏul, Seoul, South Korea
  • 2001–2005
    • Sungkyunkwan University
      • • Samsung Medical Center
      • • Department of Radiation Oncology
      Sŏul, Seoul, South Korea
  • 2004
    • Korea Basic Science Institute KBSI
      Sŏul, Seoul, South Korea
  • 1989–2003
    • Korea University
      • • Department of Physics
      • • College of Nursing
      • • Department of Electrical Engineering
      Sŏul, Seoul, South Korea
  • 1994–2001
    • Seoul National University
      • • Department of Internal Medicine
      • • Department of Surgery
      • • Department of Electrical and Computer Engineering
      Sŏul, Seoul, South Korea