Y. J. Park

Pohang Accelerator Laboratory, Urusan, Ulsan, South Korea

Are you Y. J. Park?

Claim your profile

Publications (295)581.53 Total impact

  • Source
    [Show abstract] [Hide abstract]
    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
  • [Show abstract] [Hide abstract]
    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). · 1.67 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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; · 44.98 Impact Factor
  • [Show abstract] [Hide abstract]
    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; · 2.87 Impact Factor
  • [Show abstract] [Hide abstract]
    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). · 1.29 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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; · 1.57 Impact Factor
  • [Show abstract] [Hide abstract]
    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. · 1.30 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. · 1.87 Impact Factor
  • [Show abstract] [Hide abstract]
    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. · 2.87 Impact Factor
  • [Show abstract] [Hide abstract]
    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. · 2.15 Impact Factor
  • [Show abstract] [Hide abstract]
    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 - MICROCHEM J. 01/2011; 99(2):170-173.
  • E. C. Jung, S.-E. Bae, Y. J. Park, K. Song
    [Show abstract] [Hide abstract]
    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 01/2011; 516(4):177-181. · 2.15 Impact Factor
  • [Show abstract] [Hide abstract]
    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. · 3.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: With 7 figures and 6 tablesAbstractGarlic is widely consumed for its culinary and medical benefits. Six hundred and thirteen accessions of garlic and its relatives with diverse origin were evaluated for genetic diversity at eight recently novel simple sequence repeat loci in this study. A total of 113 alleles were detected, the average allelic richness was 14.1 alleles per locus. Using a heuristic approach, a core set of 95 accessions was successfully developed, which showed 100% coverage of alleles with minimum redundancy. The model-based structure analysis here revealed the presence of four subpopulations in the selected core set, which was basically consistent with clustering based on the genetic distance. The analysis of molecular variance based on this core set showed that between-population component of genetic variance is <15.6% in contrast to 84.4% for the within population component. Overall FST value was 0.1560, indicating a moderate differentiation among the four groups. These results will provide an effective aid for future allele mining, association genetics, mapping and cloning gene(s), germplasm conservation, and improvement programs.
    Plant Breeding 10/2010; 130(1):46 - 54. · 1.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a quantitative and rapid method of sequential separation of Pu, (90)Sr and (241)Am nuclides in environmental soil samples with an anion exchange resin and Sr Spec resin. After the sample solution was passed through an anion exchange column connected to a Sr Spec column, Pu isotopes were purified from the anion exchange column. Strontium-90 was separated from other interfering elements by the Sr Spec column. Americium-241 was purified from lanthanides by the anion exchange resin after oxalate co-precipitation. Measurement of Pu and Am isotopes was carried out using an α-spectrometer. Strontium-90 was measured by a low-level liquid scintillation counter. The radiochemical procedure of Pu, (90)Sr and (241)Am nuclides investigated in this study validated by application to IAEA reference materials and environmental soil samples.
    Applied radiation and isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine 10/2010; 69(2):295-8. · 1.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The present study describes the assessment of genetic diversity and relationships among 79 Job’s tears (Coix lacrymajobi L.) accessions collected from China and Korea using 17 microsatellite markers. A total of 57 alleles were detected with an average of 3.4 alleles per locus. A high frequency of rare alleles (36.3 %) was observed within the collection. Values for observed (HO), expected heterozygosity (HE) and Shannon’s information index (I) within the analysis ranged from 0.00 (GBssrJT183) to 0.81 (GBssrJT130), from 0.01 (GBssrJT170) to 0.65 (GBssrJT130) and from 0.034 (GBssrJt170) to 1.13 (GBssrJT130), respectively. The locus GBJT130 was the most informative marker with the highest values for observed and effective alleles as well as for HO, HE and I. Based on the UPGMA algorithm, the majority of the Chinese accessions grouped in one cluster, whereas all the Korean accessions grouped together in a separate cluster, indicating that Chinese accessions are genetically quite distinct from Korean accessions. No relation between genetic relatedness among Job’s tears accessions and their place of collection was observed. Chinese accessions exhibited greater within population polymorphism (P = 95 %, HE = 0.30, I = 0.52) than the accessions from Korea (P = 68 %, HE = 0.13, I =0.24), indicating their potentiality as a reservoir of novel alleles for crop improvement. However, in general the low diversity within each population indicates a narrow genetic base within our collection. Additional key wordsheterozygosity-Job’s tears-polymorphism-simple sequence repeats
    Biologia Plantarum 01/2010; 54(2):272-278. · 1.69 Impact Factor
  • Transplantation 01/2010; 90. · 3.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The chemical species exiting chamber after an aluminum chemical vapor deposition process using aluminum boro-hydride trimethylamine (ABHTMA) as a precursor were studied with a Fourier transform infrared spectroscope, which was installed in the exhaust line of the chamber. The variation in the absorption spectra of C–H, C–N, B–H, Al–H and Al–N stretching features and the morphology of the deposited films were investigated with varying temperatures using ABHTMA in two different states (normal and decomposed). The dissociation or recombination of ABHTMA in the gas phase and on the surface during deposition resulted in the change in B–H and Al–H peaks. With the information about the peaks, we could measure in real time the purity of ABHTMA and the degree of reaction in the gas phase as a function of deposition conditions.
    Thin Solid Films 01/2010; 518:2228-2233. · 1.87 Impact Factor
  • Transplantation 01/2010; 90. · 3.78 Impact Factor
  • Transplantation 01/2010; 90. · 3.78 Impact Factor

Publication Stats

2k Citations
581.53 Total Impact Points

Institutions

  • 1998–2013
    • Pohang Accelerator Laboratory
      Urusan, Ulsan, South Korea
    • Ewha Womans University
      • Department of Electronics Engineering
      Seoul, Seoul, South Korea
  • 1999–2012
    • Catholic University of Korea
      • • Department of Laboratory Medicine
      • • Department of Internal Medicine
      • • College of Medicine
      Sŏul, Seoul, South Korea
  • 1999–2011
    • Korea Atomic Energy Research Institute (KAERI)
      • Nuclear Chemistry Research Division
      Taiden, Daejeon, South Korea
  • 1998–2011
    • Pohang University of Science and Technology
      • • Pohang Accelerator Laboratory
      • • Department of Physics
      Antō, North Gyeongsang, South Korea
  • 2010
    • Kongju National University
      • Department of Plant Resources
      Gongju, South Chungcheong, South Korea
    • Jiangsu University of Science and Technology
      Chenkiang, Jiangsu Sheng, China
  • 2008
    • Inha University
      • Department of Physics
      Seoul, Seoul, South Korea
  • 1999–2008
    • Seoul National University Hospital
      • Department of Internal Medicine
      Seoul, Seoul, South Korea
  • 2007
    • Yonsei University
      • Department of Materials Science and Engineering
      Seoul, Seoul, South Korea
  • 2001–2007
    • Sogang University
      • Department of Physics
      Sŏul, Seoul, South Korea
    • Pai Chai University
      Sŏul, Seoul, South Korea
    • Asan Medical Center
      Sŏul, Seoul, South Korea
    • Electronics and Telecommunications Research Institute
      Sŏul, Seoul, South Korea
  • 1997–2007
    • Korea Institute of Science and Technology
      • Center for Opto-Electronic Convergence Systems
      Sŏul, Seoul, South Korea
  • 1999–2006
    • Samsung Advanced Institute of Technology
      Usan-ri, Gyeonggi Province, 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
  • 2005
    • Dongguk University
      • Quantum-functional Semiconductor Research Center
      Sŏul, Seoul, South Korea
    • University of Strathclyde
      • Institute of Photonics
      Glasgow, SCT, United Kingdom
    • Hankyong National University
      Anjŏ, Gyeonggi Province, South Korea
  • 2001–2005
    • Sungkyunkwan University
      • • Department of Radiation Oncology
      • • Samsung Medical Center
      Sŏul, Seoul, South Korea
  • 2003
    • Hanyang University
      • Department of Physics
      Seoul, Seoul, South Korea
    • Karpov Institute of Physical Chemistry
      Moskva, Moscow, Russia
    • University of Seoul
      • School of Electrical and Computer Engineering
      Sŏul, Seoul, South Korea
  • 1993–2003
    • Seoul National University
      • • School of Computer Science and Engineering
      • • Department of Electrical and Computer Engineering
      • • Department of Surgery
      • • Department of Internal Medicine
      • • Inter-University Semiconductor Research Center
      Seoul, Seoul, South Korea
  • 1989–2001
    • Korea University
      • • College of Nursing
      • • Department of Electrical Engineering
      • • Department of Physics
      Seoul, Seoul, South Korea
  • 2000
    • University of Cambridge
      Cambridge, England, United Kingdom