• 한국자기공명학회논문지
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• 제15권2호
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• pp.115-127
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• 2011

A newly developed cost-effective approach to prepare $^{15}N/^{13}C$-labeled protein for NMR studies is presented. This method has been successfully applied to isotopically labeling of PTK6 SH2 domain and MTH 1880 protein. The production method generates cell density using a growing media containing $^{15}NH_4Cl$, $^{12}C_6$-D-glucose. Following a doubling time period for unlabeled metabolite exhaustion and then addition $^{13}C_6$-D-glucose into a M9 growing media, the cells are induced. Our results demonstrate that in order to get full incorporation of $^{13}C$, the isotopes are not totally required during the initial growth phase before induction. The addition of small amounts of $^{13}C_6$-D-glucose to the induction phase is sufficient to obtain more than 95% incorporation of isotopes into the protein. Our optimized protocol is two-thirds less costly than the classical method using $^{13}C$ isotope during the entire growth phase.

• Nuclear Engineering and Technology
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• 제38권3호
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• pp.301-310
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• 2006

Destructive methods were used for the burnup determination of U-Zr alloy nuclear fuel irradiated in the High-flux Advanced Neutron Application Reactor (HANARO) at KAERI. The dissolution rate of unirradiated U-Zr alloy fuel in $HNO_3$/HF mixtures was investigated for the experimental conditions of a different temperature, and initial concentrations of HF and $HNO_3$. The irradiated U-Zr alloy fuel specimen was dissolved in a mixed acid condition of 3 M HNO3 and 1 M HF at $90^{\circ}C$ for 8 hours under reflux. The total burnup was determined from measurement of the Nd isotope burnup monitors. The method includes U, Pu, $^{148}Nd,\;^P{145}Nd+^{146}Nd,\;^{144}Nd+^{143}Nd$ and total Nd isotopes determination by the isotope dilution mass spectrometric method (IDMS) using triple spikes $(^{233}U,\;^{242}Pu\;and\;^{150}Nd)$. The effective fission yield was calculated from the weighted fission yields averaged over the irradiation period. The results are compared with that obtained by the destructive -spectrometric measurement of the $^{137}Cs$ monitor.

• 한국초전도ㆍ저온공학회논문지
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• 제17권3호
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• pp.23-27
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• 2015

Quadruple magnet is an essential component for the accelerator, and the field uniformity in the good field region reflects the quality of quadruple magnet. In this paper, the total magnetic field B was separated into the coil-induced magnetic field $B_s$ and the iron-induced magnetic field $B_c$ to explain why the total magnetic field B has some inhomogeneity. Using Fourier analysis, harmonic components of $B_s$, $B_c$ and B have been analyzed at good field region, respectively. The harmonics of multipole magnet and Fourier analysis are helpful to show the uniformity of magnetic field. Several geometries of yoke and coils were defined to analyze the effect on field uniformity of an HTS quadruple magnet. By the analysis, it was found that the sixth harmonics which is the main factor of field inhomogeneity can be reduced to zero. It means that the sixth harmonics of the magnetic field B can be removed by adjusting the geometry of the magnet pole and the position of coils. We expect that this result can effectively improve the uniformity of an HTS quadruple magnet.

• Journal of Magnetics
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• 제20권3호
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• pp.302-307
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• 2015

The purpose of the study was to identify how isotope and magnetic resonance imaging (MRI) contrast media impact on noise to computed tomography (CT) examination. For the study, divide the phantoms to two groups: 1) saline, saline + different kinds of contrast agent without $^{99m}Tc$ administration; 2) $^{99m}Tc$ administration: saline, saline + different kinds of contrast agent with $^{99m}Tc$ administration. CT contrast agent was used for Iopamidol$^{(R)}$ and Dotarem. And MRI contrast agent was used for Primovist$^{(R)}$ and Gadovist$^{(R)}$. To obtain an image, we used CT scanner. With an obtained image, we set the $1cm^2$ region of interest in the middle of bottle to measure the noise and CT number. As a result, there was no difference in CT number before and after inserting $^{99m}Tc$ into all contrast media including Normal Saline. However, when it comes to Noise, there was a difference before and after inserting $^{99m}Tc$ into every contrast media except MRI contrast media such as Primovist$^{(R)}$ and Gadovist$^{(R)}$.

• 한국지구과학회지
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• 제32권5호
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• pp.437-452
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• 2011

The Steptoean Positive Carbon Isotope Excursion (SPICE) is found in the Machari Formation which was interpreted to have been deposited on the middle to outer carbonate ramp environment. The Machari Formation is the Middle to Late Cambrian in age and distributed in the Yeongweol area, Gangweon Province, Korea. The SPICE event in the Machari Formation begins with the first appearance datum of trilobite Glyptagnostus reticulatus and ends with the first appearance of datum of trilobite Irvingella. The SPICE is found in approximately 120 m thick sequence and ${\delta}^{13}C$ values in the SPICE interval range from 0.6 to 4.4‰. The SPICE in the Machari Formation is interpreted to be caused by burial of organic matter in the sea floor and subsequent increase of $^{13}C$ isotope of the Late Cambrian ocean. The SPICE interval in the Machari Formation corresponds to the highstand to transgressive systems tracts.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.250.1-250.1
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• 2014

A multicusp ion source has been used widely in negative hydrogen cyclotrons mainly for radioisotope productions. The ion source is designed to have cusp geometries of magnetic field inside plasma chamber, where ions are confining and their mean lifetimes increase. The magnetic confinement produced a number of permanent magnetic poles helps to increase beam currents and reduce the emittance. Therefore optimizing the number of magnets confining more ions and increasing their mean lifetime in plasma has to be investigated in order to improve the performance of the ion source. In this work a numerical simulation of the magnetic flux density from a number of permanent magnets is carried to optimize the cusp geometries producing the highest plasma density, which is clearly indicated along the full-line cusp geometry. The effect of magnetic fields and a number of poles on the plasma structure are investigated by a computing tool. The electron confinement effect becomes stronger and the density increases with increasing the number of poles. On the contrary, the escape of electrons from the loss cone becomes more frequent as the pole number increases [1]. To understand above observation the electron and ion's trajectories along with different cusp geometries are simulated. The simulation has been shown that the optimized numbers of magnets can improve the ion density and uniformity.

• Mass Spectrometry Letters
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• 제1권1호
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• pp.29-32
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• 2010

Cross reacting antibodies can cause an overestimation of the results of immunoassays. Therefore, alternative methods are needed for the accurate quantification of steroids. Gas chromatography combined with isotope-dilution mass spectrometry (GC-IDMS) is developed to quantify urinary active androgens, testosterone, epitestosterone and dihydrotestosterone, which are clinically relevant androgens to both hair-loss and prostate diseases. The method devised involves enzymatic hydrolysis with $\beta$-glucuronidase, solid-phase extraction, liquid-liquid extraction using methyl tert-butyl ether and subsequent conversion to pentafluorophenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive and selective analysis in selected-ion monitoring mode. Flophemesyl-TMS derivatization not only eliminates matrix interference but also has a good peak resolution within a 6 min-run. A selective and sensitive GC technique with flophemesyl-TMS derivatives also allows accurate quantitative analysis of three active androgens when combined with IDMS. The limit of quantification of the three analytes was <50 pg/mL, and extraction recoveries ranged from 91.9 to 102.1%. The precision and accuracy were 1.2~6.5% and 89.0~106.7%, respectively. This GC-IDMS method can be useful for evaluating the drug efficacy and monitoring the biological processes responsible for male-pattern baldness and prostate diseases.

• 한국초전도ㆍ저온공학회논문지
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• 제18권2호
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• pp.21-24
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• 2016

In recent years, the iron-dominated high-temperature superconductor (HTS) quadrupole magnets are being developed for heavy ion accelerators. Field analyses for iron-dominated quadrupole magnets were based on the normal-conducting (NC) quadrupole magnet early in the development for accelerators. Some conclusions are still in use today. However, the magnetic field of iron-dominated HTS quadrupole magnets cannot fully follow these conclusions. This study established an HTS quadrupole magnet model and an NC quadrupole magnet model, respectively. The harmonic characteristics of two magnets were analyzed and compared. According to the comparison, the conventional iron-dominated quadrupole magnets can be designed for maximum field gradient; the HTS quadrupole magnet, however, should be considered with varying field gradient. Finally, the HTS quadrupole magnet was designed for the changing field gradient. The field quality of the design was improved comparing with the result of the previous study. The new design for the HTS quadrupole magnet has been suggested.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3228-3232
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• 2010

Malachite green (MG) has been used world-widely in aquaculture as a parasiticide or fungicide. Although MG performed successfully, it has not been permitted for use in aquaculture from European Union, USA, and Canada because of its carcinogenicity and mutagenicity. We developed a sensitive and specific method to determine MG and its principal metabolite, leucomalachite green (LMG), respectively by isotope dilution liquid chromatography mass spectrometry (ID-LC/MS). To enhance the extraction recovery of MG and LMG from fish tissue, an additional step, saponification, was introduced in sample preparation process to remove fat in sample extract, which hampered the performance of SPE columns. The residue of MG and LMG in fish was analyzed using liquid chromatography mass spectrometry in the selected ion monitoring (SIM) mode by monitoring at m/z 329 and 334 for MG and $d_5$-MG and at m/z 331 and 337 for LMG and $^{13}C_6$-LMG, respectively. This method was validated by comparing with the value of the reference material provided by Laboratory Government Chemistry (LGC). The results agreed within the measurement uncertainty and the accuracy was much improved than the provided reference value by LGC.

• 대한디지털의료영상학회논문지
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• 제14권2호
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• pp.75-81
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• 2012

The purpose of this study was administered to the body for examination and treatment, high-energy radioactive isotope(F-18, I-131) in vitro discharge experiments. Increasing exposed dose of radiation to health professionals is caused by the increase of PET/CT use and a radioactive isotope. Therefore, the high-energy isotope F-18 and I-131 after administration about using Metabolite excretion was studied. As a results of this study, patients had plenty of fluids for testing and treatment alone administered radiopharmaceuticals can be more than twice as fast excretion induced emissions. Also was able to get a better image space to reduce the dose rate.