• Journal of Korean Neurosurgical Society
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• v.66 no.4
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• pp.382-392
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• 2023

Objective : The use of indocyanine green videoangiography (ICG-VA) to assess blood flow in the brain during cerebrovascular surgery has been increasing. Clinical studies on ICG-VA have predominantly focused on qualitative analysis. However, quantitative analysis numerical modelling for time profiling enables a more accurate evaluation of blood flow kinetics. In this study, we established a multiple exponential modified Gaussian (multi-EMG) model for quantitative ICG-VA to understand accurately the status of cerebral hemodynamics. Methods : We obtained clinical data of cerebral blood flow acquired the quantitative analysis ICG-VA during cerebrovascular surgery. Varied asymmetric peak functions were compared to find the most matching function form with clinical data by using a nonlinear regression algorithm. To verify the result of the nonlinear regression, the mode function was applied to various types of data. Results : The proposed multi-EMG model is well fitted to the clinical data. Because the primary parameters-growth and decay rates, and peak center and heights-of the model are characteristics of model function, they provide accurate reference values for assessing cerebral hemodynamics in various conditions. In addition, the primary parameters can be estimated on the curves with partially missed data. The accuracy of the model estimation was verified by a repeated curve fitting method using manipulation of missing data. Conclusion : The multi-EMG model can possibly serve as a universal model for cerebral hemodynamics in a comparison with other asymmetric peak functions. According to the results, the model can be helpful for clinical research assessment of cerebrovascular hemodynamics in a clinical setting.

• Journal of Preventive Medicine and Public Health
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• v.32 no.4
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• pp.467-472
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• 1999

Objectives: This study was conducted to evaluate the cytotoxicity of gallium arsenide(GaAs), indium phosphide(InP) and indium arsenide(InAs) all of which are used a$ the semiconductor eletments in semiconductor industry. Methods: Cytotoxicity id the alveolar macrophage was evaluated by the measurement of in vitro magnetometry, LDH release assay and histological examination. Results: The relaxation curves by the in vitro magnetometry showed that GaAs has the cytotoxicity for the alveolar macrophage which is more significant in the higher dosages, while this cytotoxicity is not appeared in the groups added with InP or InAs or PBS. In the decay constant for two minutes after magnetization, GaAs-added groups showed a significant decrease with increasing doses, but both InP- and InAs-added groups did not show any significance. The LDH release assay showed a dose-dependent increasing tendency in the GaAs-, InP- and InAs-added groups. In terms of cellular morphological changes, GaAs-added groups revealed such severe cellular damages as prominent destructions in cell membranes and their morphological changes of nucleus, while InP- and InAs-added groups remained intact in intracellular structures, except for cytoplasmic degenerations. Conclusions: It is suggested that GaAs is more influential to cytotoxicity of alveolar macrophages than InP and InAs.

• Journal of Radiation Protection and Research
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• v.11 no.1
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• pp.51-56
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• 1986

It is important to measure and protect from the radiation space dose and induced activity at the high energy medical linear accelerator facilities. These are to consider the additional risk to patients undergoing treatment, machine operators and staff members. Measurements of the space dose distribution and induced radioactivity at the 18 MeV medical linear accelerator facility in the Yonsei Cancer Center. 1. Exposure space dose for 300 rads monitor doses of 18 MeV electron are measured as 50 mR at 1 meter from patients. 2. Exposure space dose for 300 rads monitor doses of 10 MV X-ray are detected as 350 mR at 1 meter from phantom. 3. Induced radioactivity by photonuclear reaction was measured as 0.65 mR/hr from collimater after 30 Gy(3,000 rads) irradiated. 4. Analyzing the decay curves and energy spectrum of induced radioactivity, detected a few materials to be activated by photoneutron reaction, $^{65}Cu({\gamma}{\cdot}n)\;^{64}Cu,\;^{186}W({\gamma}{\cdot}n)\;^{185}W,\;^{181}Ta({\gamma}{\cdot}n)\;^{180}Ta,\;^{199}Au({\gamma}{\cdot}n)\;^{198}Au$.

• Journal of Sensor Science and Technology
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• v.9 no.5
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• pp.341-349
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• 2000

CsI(Br) single crystals doped with 1, 3, 5 or 10 mole% $Br^-$ ions, as an activator, were grown by Czochralski method. The lattice structure of grown CsI(Br) single crystal was bcc and its lattice constant was $4.568\;{\AA}$. The absorption edge of the CsI(Br) single crystals was observed at 243 nm. The spectral range of the luminescence excited by 243 nm of wavelength was $300{\sim}600\;nm$, and its peak emission appeared at 440 nm. The luminescence intensity was maximum when CsI(Br) was doped with 3 mole % $Br^-$ ions. The energy resolutions of the CsI(Br) scintillator doped with 3 mole % $Br^-$ ions were 15.0% for $^{137}Cs$(662 keV), 13.1% for $^{54}Mn$(835 keV), and 18.0% and 6.3% for $^{22}Na$(511 keV and 1275 keV), respectively. The decay curves had fast and slow components, and the fast component was about 41 ns independent on the concentration of the $Br^-$ ions. The time resolution of CsI(Br) scintillators decreased with increasing of the concentration of $Br^-$ ions.

• Nuclear Engineering and Technology
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• v.4 no.4
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• pp.340-344
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• 1972

Isomeric ratios were measured for the capture of thermal neutron by $^{79}$ Br, $^{80}$ Se, $^{103}$ Rh, $^{115}$ In and $^{133}$ Cs as well as those of epi-cadmium neutron by $^{79}$ Br, $^{80}$ Se and $^{l33}$Cs. The measurements were performed by analysing decay curves obtained by ${\gamma}$-ray spectrometry after irradiation. The counting efficiency curve was determined by using the calibrated standard sources with overall uncertainties of about 1%. Isomeric ratios, given in $\sigma$ high spin/($\sigma$ high spin + $\sigma$ low spin), of $^{80, 80m}$Br, $^{81,81m}$Se, $^{014, 104m}$Rh, $^{116,116m}$In and $^{134, 134m}$Cs produced by thermal neutron activation were found to be 0.21$\pm$0.01, 0.14$\pm$0.02, 0.12$\pm$0.02, 0.69$\pm$0.07 and 0.058$\pm$0.004, respectively, Those values of $^{80, 80m}$Br, $^{81,81m}$Se, and $^{134, 134m}$Cs Produced by epi-cadmium neutron were found to be 0.19$\pm$0.02, 0.29$\pm$0.02 and 0.074$\pm$0.011, respectively. The experimental values obtained were compared with the theoretical values deduced from the statistical model. There were the general agreements between the theory and the experiment.t.

• Journal of Life Science
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• v.28 no.3
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• pp.314-319
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• 2018

We analyzed QTLs for alkali-related digestion by using 120 population crossed Cheongcheong and Nagdong derived from anther culture (CNDH). The DNA markers located in the QTLs gene were selected and applied to existing cultivars. As a result of the investigation of the alkali decay degree, brown rice of Cheongcheong and Nagdong was 1.9 and 1.6, respectively, and the CNDH was $3.79{\pm}2.01$, and the distribution of variance was distributed to 7.0-1.0. The milled rice of Cheongcheong and Nagdong was 5.6 and 4.1, respectively. The mean of the CNDH was $4.86{\pm}1.55$, and the distribution of variance was distributed to 7.0-2.0. Variation distribution curves showed continuous variation that was close to non-normal distribution. In the QTLs analysis, qBRA2, qBRA6, and qBRA11 were mapped in 1-2 replications of brown rice. QHRA2-1, qHRA2-2, qHRA2-3, qHRA3, and qHRA8 were mapped in the first replication. QHRA2-1, qHRA2-2, qHRA2-3 and qHRA3 were mapped in the second replicates. And mapped to qHRA5 in 4 replicates. These were found on chromosome 2, 3, 6, 8 and 11, respectively. The phenotypic variations of qBRA2, qBRA6, and qBRA11 on the chromosomes of brown and milled rice were 1-9%. The polymorphism was analyzed for 12 types of the japonica type and six types of the indica type, based on the nine markers found in the QTLs analysis of alkali digestion. Chromosome 11, RM27258, was selected to determine the segregation ratio, which shows the difference in size by the band pattern. The results of this study will be used as basic data for the development of high-quality rice cultivars.