• 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.

• 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.

• Analytical Science and Technology
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• v.6 no.3
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• pp.335-343
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• 1993

The structure of cerebrosides from soybean embryo was determined using fast atom bombardment mass spectrometer (FAB-MS), gas chromatography mass spectrometer (GC-MS) and TLC. The components of cerebroside were determined by GC-MS after acid hydrolysis. The molecular weight distribution of cerebroside was measured by positive mode FAB-MS with LiOH saturated 3-nitrobenzylalcohol(3-NBA) matrix. Structures of individual components of complex mixtures can be determined easily by this process. The major constituent of soybean extracted cerebroside was determined as the glucoside of N-2'-hydroxypalmitoyl-sphingadienine.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.3
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• pp.50-58
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• 1980

A cytoplasmic-genetic male sterile line(MS) in rapes of which fertility is not restored under any temperature regimes and have the better quaility of and oil cake was developed. A MS line named Mokpo-MS, which is form the cross between Tower and Isuzu and its stamens is degenerated completely by interact~g with cytoplasmic and nuclear genes was selected. This MS line was found as a complete cytoplasmic-genetic male sterile having the quality of oil and oil cake were greatly improved by introducing Zero-erucic and Zero-glucosinolate gene from Tower.

• Journal of dental hygiene science
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• v.22 no.4
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• pp.249-255
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• 2022

Background: Sexual dimorphism is important for sex determination in the field of forensics. However, sexual dimorphism is commonly assessed using cone beam computed tomography (CBCT) rather than three-dimensional (3D) modeling software; therefore, studies using a more accurate measurement approach are necessary. This study assessed the sexual dimorphism of the MS using a 3D modeling program to obtain information that could contribute to the fields of surgery and forensics. Methods: The CBCT data of 60 patients (age, 20~29 y; 30 males and 30 females) admitted to the Department of Orthodontics at the Dankook University School of Dentistry were provided in Digital Imaging and Communications in Medicine (DICOM) format. The left MS and right MS were modeled based on the DICOM files using the Mimics (version 22; Materialise, Leuven, Belgium) 3D program and converted to stereolithography (STL) files used to measure the width, length, and height of the MS, infraorbital foramen (IOF), right MS, and left MS. The average of three repeated measurements was calculated, and a reliability test was performed to ensure data reliability (Cronbach's α=0.618). A canonical discriminant analysis was performed using a standard approach (left: Box's M=0.096; right: Box's M=0.115). Results: Males had greater values for all parameters (MS width, MS length, MS height, IOF, right MS, left MS) than females. The discriminant analysis identified six independent variables (MS width, MS height, MS length, IOF, right MS, left MS) that could identify sex. The left MS and right MS correctly identified the sex of 81.7% and 71.7% of the patients, respectively, with the left MS having higher accuracy. Conclusion: This study confirmed that, for Korean individuals, the left MS has a better ability to identify sex than the right MS. These results may contribute to sex identification in the fields of surgery and forensics.

• Mass Spectrometry Letters
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• v.13 no.4
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• pp.177-183
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• 2022

The monomer and dimer structures of the amyloid fragment Aβ(1-16) sequence formed in H₂O were investigated using electrospray ionization mass spectrometry (MS) and tandem MS (MS/MS). Aβ16 monomers and dimers were indicated by signals representing multiple proton adduct forms, [monomer+zH]ⁿ⁺ (=M^z+, z = charge state) and [dimer+zH]^z+ (=D^z+), in the MS spectrum. Fragment ions of monomers and dimers were observed using collision-induced dissociation MS/MS. Peptide bond dissociation was mostly observed in the D1-D7 and V11-K16 regions of the MS/MS spectra for the monomer (or dimer), regardless of the monomer (or dimer) charge state. Both covalent and non-covalent bond dissociation processes were indicated by the MS/MS results for the dimers. During the non-covalent bond dissociation process, the D³⁺ dimer complex was separated into two components: the M¹⁺ and M²⁺ subunits. During the covalent bond dissociation of the D³⁺ dimer complex, the b and y fragment ions attached to the monomer, (M+b_10-15)^z+ and (M+y_9-15)^z+, were thought to originate from the dissociation of the M²⁺ monomer component of the (M¹⁺+M²⁺) complex. Two different D³⁺ complex geometries exist; two distinguished interaction geometries resulting from interactions between the M¹⁺ monomer and two different regions of M²⁺ (the N-terminus and C-terminus) are proposed. Intricate fragmentation patterns were observed in the MS/MS spectrum of the D⁵⁺ complex. The complicated nature of the MS/MS spectrum is attributable to the coexistence of two D⁵⁺ configurations, (M¹⁺+M⁴⁺) and (M²⁺M³⁺), in the Aβ16 solution.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.587-594
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• 2020

In this study, we analyzed glucosinolates and their metabolites in the inner and outer parts of napa cabbage (NC; Brassica rapa subsp. pekinensis) and napa cabbage kimchi (NKC) using UPLC-ESI-MS/MS. In the extracts from NC and NKC, glucobrassicanapin (m/z 386), glucoalyssin (m/z 450), glucobrassicin (m/z 447), 4-methoxyglucobrassicin (m/z 477), and neoglucobrassicin (m/z 477) were detected using the MS scan mode ([M-H]-), and gluconapin (m/z 372→97), progoitrin (m/z 388→97), glucoiberin (m/z 422→97), 4-methoxyglucobrassicin (m/z 477→97), and neoglucobrassicin (m/z 477→447) were detected using the MS/MS MRM mode ([M-H]-). Ascorbigen (m/z 306→130) and indole-3-carboxaldehyde (I3A; m/z 146→118), which were metabolites of glucobrassicins, were detected using the MS/MS MRM ([M+H]+) mode. The peak intensities of ascorbigen in the extract from the inner and outer parts of NC were significantly higher than those of the NKC extract (p<0.05); however, there was no significant difference in I3A peak intensity between the NC and NKC extracts.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.840-842
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• 2007

• Journal of Applied Biological Chemistry
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• v.56 no.1
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• pp.53-57
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• 2013

In here, we investigated the quantitative analysis method of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) with liquid chromatography-mass/mass spectrometry (LC-MS/MS) or gas chromatography-MS. Two ways of clean-up process were investigated for LC-MS/MS instrumental analysis of IAA, but both a simple dilution and hydrophile-lipophile balance (HLB) solid phase extraction (SPE) were not met the optimal recovery rates for quantitative analysis. On the other hand, the clean-up method for GC-MS was finally optimized through HLB-SPE from 250-folds diluted sample and methylation with trimethylsilyl chloride in methanol for 4 h. The limit of detection for methyl ester of IAA and IBA were both 1.4 mg/L, and recovery rates showed 93-107% from the concentrated liquid fertilizer.

• Culinary science and hospitality research
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• v.19 no.3
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• pp.209-217
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• 2013

This study aims to develop mussel stock, which is the base of sauce, soup, etc., using various nourishing elements in mussels. In mussel stock with different heating times, the moisture content was significantly different according to heating times(p < 0.05). For the color value of mussel stock, L value was highest in MS1(35.48), a value in MS1(-2.39), and b value in MS5(-9.49). pH was lowest as 6.56 in MS5, and with increased heating time, pH decreased significantly (p < 0.001). With increased heating time, the sugar content was highest as $4.03^{\circ}Brix$ in MS3 and lowest as $3.37^{\circ}Brix$ in MS1. The salinity content was lowest as 0.71% in MS1, and with increased heating time, the salinity content increased significantly (p < 0.001). The test for characteristic differences of mussel stock showed that its color intensity, transparency, fish flavor, fish taste, and salty taste increased with increased heating time. Savory taste of mussel stock was highest in MS4 with 4.33% According to the results of acceptance test, taste, and overall acceptance test, MS3 showed the best results. In conclusion, mussel stock showed great preference with increased heating time, and the preference has increased when it was heated for 15 min.