• Investigative Magnetic Resonance Imaging
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• v.12 no.1
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• pp.20-26
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• 2008

Purpose : To present the T1 and T2 relaxation times of the major cerebral metabolites at 1.5T and 3.0T and compare those between 1.5T and 3.0T. Materials and Methods : Using the phantom containing N-acetyl aspartate (NAA), Choline (Cho), and Creatine (Cr) at both 1.5T and 3.0T MRI, the T1 relaxation times were calculated from the spectral data obtained with 5000 ms repetition time (TR), 20 ms echo time (TE), and 11 different mixing time (TM)s using STEAM (STimulated Echo-Acquisition Mode) method. The T2 relaxation times were obtained from the spectral data obtained with 3000 ms TR and 5 different TEs using PRESS (Point-RESolved Spectroscopy) method. The T1 and T2 relaxation times obtained at 1.5T were compared with those of 3.0T. Results : The T1 relaxation times of NAA were $2293\;{\pm}\;48\;ms$ at 1.5T and $2559\;{\pm}\;124\;ms$ at 3.0T (11.6% increase at 3.0T). The T1 relaxation times of Cho were $2540\;{\pm}\;57\;ms$ at 1.5T and $2644\;{\pm}\;76\;ms$ at 3.0T (4.1% increase at 3.0T). The T1 relaxation times of Cr were $2543\;{\pm}\;75\;ms$ at 1.5T and $2665\;{\pm}\;94\;ms$ at 3.0T (4.8% increase). The T2 relaxation times of NAA were $526\;{\pm}\;81\;ms$ at 1.5T and $468\;{\pm}\;74\;ms$ at 3.0T (11.0% decrease at 3.0T). The T2 relaxation times of Cho were $220\;{\pm}\;44ms$ at 1.5T and $182\;{\pm}\;35\;ms$ at 3.0T (17.3% decrease at 3.0T). The T2 relaxation times of Cr were $289\;{\pm}\;47\;ms$ at 1.5T and $275\;{\pm}\;57\;ms$ at 3.0T (4.8% decrease at 3.0T). Conclusion : The T1 relaxation times of the major cerebral metabolites (NAA, Cr, Cho), which were measured at the phantom, were 4.1%-11.6% longer at 3.0T than at 1.5T. The T2 relaxation times of them were 4.8%-17.3% shorter at 3.0T than at 1.5T. To optimize MR spectroscopy at 3.0T, TR should be lengthened and TE should be shortened.

• FLOWER RESEARCH JOURNAL
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• v.18 no.2
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• pp.83-86
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• 2010

This study was conducted to develop in vitro propagation techniques of new cultivar, 'Greenstar', bred by Highland Agriculture Research Center. The multiple shoot induction and plant growth of in vitro plant were analyzed by MS media concentration (1/2 MS, 1 MS and 2 MS medium), plant growth regulators and its proper concentration; CPPU [Forchlorfenuron(N-(2-chloro-4-pridyl)-3-phenylurea) (0, 0.5, 1.0 and $2.0mg{\cdot}L^{-1}$), thidiazuron [(TDZ), (0.01, 0.1, 0.5 and $1.0mg{\cdot}L^{-1}$), zeatin (0, 0.5, 1.0 and $2.0mg{\cdot}L^{-1}$), and BA [6-benzylaminiopurine(BA), (0, 0.5, 1.0 and $2.0mg{\cdot}L^{-1}$)] in MS (3% sugar and 0.8% agar with pH 5.7) media. The highest number of induced shoots, leaves and roots were shown in 1/2 MS medium concentration. On the 1/2 MS medium, shoot numbers, shoot length, leaf numbers and root numbers were 11.0, 1.9 cm, 24.7, and 8.0, respectively. On the absence of CPPU in the 1/2 MS medium, shoot length and root numbers was greater than CPPU treatment, but the highest number of shoots was induced by the $2.0mg{\cdot}L^{-1}$ of CPPU concentration in 1/2MS medium. TDZ, zeatin, and BA treatments were not effective on the induction of multiple shoot in vitro culture. As a result, in vitro culture of new Saxifraga fortunei, 'Greenstar' with $2.0mg{\cdot}L^{-1}$ of CPPU in 1/2 MS medium was most effective for the rapid multiplication.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.110-117
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• 2018

The aim of this study was to develop an analytical method for the quantification of diazepam residues in fishery products, using liquid and gas chromatography-tandem mass spectrometry (LC-MS/MS and GC-MS/MS). The sample utilized in the study was extracted from the fish sample (crucian carp) using 0.1% formic acid in acetonitrile. For the utilization of the purification process, the dispersive solid phase extraction (dSPE) was used for LC-MS/MS, dSPE and SPE was used for GC-MS/MS, respectively. To be sure, the standard calibration curves showed a good linearity as the noted correlation coefficients, $r^2$ was > 0.99. The average recoveries for accuracy ranged in 99.8~124% for the samples which were fortified at three different levels (0.001, 0.002 and 0.010 mg/kg). The correlation coefficient for the precision effect was measured at a range of 4.01~11.8%. The limit of detection (LOD) for the diazepam analysis was 0.0004 mg/kg, and the limit of the quantification (LOQ) was 0.001 mg/kg. The proposed analytical method was characterized with a high accuracy and acceptable sensitivity to meet the established Codex Alimentarius Commission (CAC/GL71-2009) guideline requirements. We therefore established the optimal analysis method for the determination of diazepam in the fishery products using LC-MS/MS and GC-MS/MS. It would be applicable to analyze the diazepam residues in fishery products in further studies on this subject.

• Korean Journal of Plant Tissue Culture
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• v.28 no.6
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• pp.341-346
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• 2001

To investigate the effects of MS medium strength and nitrogen concentration on bulblet formation from bulblet scale segment culture and bulblet growth from bulblet of Lilium oriental hybrid 'Casa Blanca', asiatic hybrid 'Mona', and longiflorum hybrid 'Hinomoto', 0.5∼2.0 strength of MS salts and 30∼120 mM nitrogen concentrations of MS medium were examined in vitro. The number of bulblets from bulb scale segment was favored in the strength of 0.5∼1.0 strength of MS salts or 30 mM total nitrogen concentration of MS medium in three cultivars. But the growth of bulblets formed in vitro was promoted in the 2 strength of MS medium or hight concentration of total nitrogen of MS medium up to 120 mM in three experimented cultivars.

• YAKHAK HOEJI
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• v.60 no.1
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• pp.15-20
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• 2016

Globotriaosylsphingosine (lyso Gb3) is considered as one of the biomarkers for Fabry disease. A rapid and simple UPLC-MS/MS method was developed for the determination of reliable biomarker, lyso Gb3. Total analytical procedure takes only 15 min including sample preparation and MS/MS analysis. Limit of detection was 0.85 ng/ml (S/N=3). The calibration curve was linear over the range of 2.0~400.0 ng/ml ($R^2=0.9999$). Inter-day and intra-day assay accuracy were 93.4~100.6% (RSD, 0.6~6.0%) and 97.5~100.7% (RSD, 3.6~5.2%). Absolute recoveries of 97.6~98.6 showed excellence of a new analytical method. The method was applied to human and mice urines, proved the suitability for the quantification of lyso-Gb3 for screening, diagnosis and therapeutic monitoring of Fabry disease patients.

• Korean Journal of Pharmacognosy
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• v.49 no.1
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• pp.70-75
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• 2018

Acer tegmentosum Maxim (ATM) has been used to treat hepatic disorders in traditional oriental medicine. However, there is little information about phytochemical constituents for quality control of ATM. In this study, we developed and established a simultaneous analytical method of the 10 marker compounds (three coumarins, 3 flavonoids, 1 lignan, 3 phenolics) in ATM using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Chromatographic separation of ten target analytes was achieved with a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$), using a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile with gradient elution. Identifications and quantitation of all analytes were performed using a Q-Exactive UPLC-MS/MS system. Correlation coefficients of the calibration curve for all analytes were ${\geq}0.9986$. The values of limits of detection and quantification of all analytes were 0.5-10.0 and 5.0-50.0 ng/mL, respectively. The established UPLC-MS/MS method successfully identified all target analytes in ATM, and the phytochemicals were 0.01-67.98 mg/g in its lyophilized water extract.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.301-304
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• 1998

Effects of genotype and culture medium on plant regeneration from cotyledon segments of red pepper(Capsicum annuum L.) was investigated. Among combinations of IAA(0.25 and 0.50 mg/L) and zeatin(2.0 and 4.0 mg/L) added to MS medium, combination of 2.0 mg/L zeatin and 0.25 mg/L IAA was shown to be the best for shoot differentiation from cotyledon segments. Shoot regeneration from cotyledon explants took 9 to 25days, depending on genotypes and culture media. Early shooting was observed in Yeongyangjaelae, Putgochw, Karkovskij-A-35, Gris I-A-1 on MS medium containing 2.0 mg/L zeatin and 0.25 IAA mg/L. Percent of explants producing shoots, as also influenced by genotypes and culture media, were over 90% for 621, Yeongyangjaelae, Putgochw, Nikko jacksacgmulgochw, Ch-6-Num-216, and Kajenskij-A-35 when cultured on MS medum supplemented with 2.0 mg/L zeatin and 0.25 mg/L IAA and for Fresno chile, PI 169126, Kajenskij-A-35, jacksacgmulgochw, and PI 297438 on MS medium including 2.0 mg/L BA and 1.0 mg/L IAA.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.626-632
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• 2011

Phoxim, which is one of veterinary drugs, is a well-known antiparasitic agent in wide use. In this paper, phoxim was extracted from cattle and pig tissue using solid-phase extraction (SPE) employing a silica cartridge with acetonitrile. Liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) for the analysis of phoxim from animal tissue was presented. Phoxim was detected on a $C_{18}$ column ($2.1{\times}100\;mm$, $3.5\;{\mu}m$) using a mobile phase of 0.1% formic acid in water and acetonitrile. A linear correlation observed in the calibration curves for cattle (0.0048~2.0 mg/kg) and pig (0.0055~2.0 mg/kg) showed above $r^2$=0.995. Accuracy measured at concentrations ranging from 0.0048 to 0.2 mg/kg was the range of 68.2~106.9%. Limit of detection (LOD) and limit of quantitation (LOQ) were the range of 0.0014~0.0017 mg/kg and 0.0048~0.0055 mg/kg, respectively. The precision (RSD%) was below 11.2%.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.410-418
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• 2016

This study was conducted to improve the analysis method used for N-nitrosamines and to investigate the occurrences of N-nitrosamines in tributaries of the Han-river, intake stations, water treatment plants and tap water used within the city of Seoul. The samples were pretreated through a solid phase extraction and analyzed using a gas chromatography tandem mass spectrometer (GC-MS/MS). The GC-MS/MS in CI mode was compared with the GC-MS/MS in EI mode by the method detection limits (MDLs). MDLs by GC-CI/MS/MS and GC-EI/MS/MS were 0.2 ~ 1.1 ng/L and 0.2 ~ 1.4 ng/L, respectively. Samples were collected from ten tributaries of the Han-river (T1 ~ T10), six intake stations (I1 ~ I6), six water treatment plants (P1 ~ P6) and 25 taps in Seoul city. The maximum levels of N-nitrosodimethylamine (NDMA) were 0.013 μg/L, 0.008 μg/L, 0.006 μg/L and 0.002 μg/L in tributary water, raw water, finished water and tap water samples, respectively. Detected levels were much lower than 0.1 μg/L corresponding to the guideline value of WHO.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.1
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• pp.31-34
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• 2001

When root initiation ratio of cut Italian ryegrass (Lolium multiflorum Lam.) stems was examined in several medium conditions containing different IBA concentration, most higher root initiation ratio was confirmed at 1.0 mg/$\ell$ of IBA and the ratio was 37.5%. When cut Italian ryegrass stems were treated in cold chamber at 4$^{\circ}C$ for 40 days and incubated in growth chamber at 26$^{\circ}C$ for 1 month, the root iniation result was 0.0% at MS-0 medium, 8.3% at MS-0.5IBA medium, 37.5% at MS-1.0IBA medium, 16.7% at MS-1.5IBA medium and 12.5% at MS-2.0IBA medium.