• Analytical Science and Technology
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• v.21 no.1
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• pp.34-40
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• 2008

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the quantitative determination of lercanidipine in human plasma. After addition of internal standard (amlodipine), plasma was precipitated with acetonitrile and the supernatant was evaporated. The residues were dissolved in 50 % acetonitrile and analyzed by LC-MS/MS. Using MS/MS with multiple reaction monitoring(MRM) mode, lercanindipine were selectively detected without severe interference from human plasma. The standard calibration curve for lercanidipine was linear (r = 0.9994) over the concentration range 0.05-20.0 ng/mL in human plasma. The intra- and inter-day precision over the concentration range of lercanidipine was lower than 11.7 % (correlation of variance, CV), and accuracy was between 94.4-114.8 %. This method has been successfully applied to the pharmacokinetic study of lercanidipine in human plasma.

• Analytical Science and Technology
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• v.21 no.6
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• pp.535-542
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• 2008

A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) method was developed for the determination and confirmation of clenbuterol in bovine muscle and milk. Clenbuterol and clenbuterol-D9 using as an internal standard in samples were extracted with ethyl acetate after hydrolysis and evaporated to dryness. The extracts were dissolved in 20% methanol and cleaned using HLB solid-phase extraction cartridge. The analytes were detected by LC-ESI/MS/MS on a $C_{18}$ column. Mass spectral acquisition was done in selected reaction monitoring (SRM) in positive ion mode to provide a high degree of sensitivity. Using MS/MS with SRM mode, the transitions (precursor to product) monitored were m/z 277${\rightarrow}$203 for clenbuterol, and m/z 286${\rightarrow}$204 for internal standard. The limits of quantitation (LOQ) and mean recoveries of clenbuterol in bovine muscle were $0.2{\mu}g/kg$ and 84.3~91.1%, respectively. The LOQ and mean recoveries in milk were $0.05{\mu}g/kg$ and 87.7~98.3%, respectively.

• Molecules and Cells
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• v.27 no.5
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• pp.601-608
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• 2009

The 2-deoxystreptamine and paromamine are two key intermediates in kanamycin biosynthesis. In the present study, pSK-2 and pSK-7 recombinant plasmids were constructed with two combinations of genes: kanABK, and kanABKF and kacA respectively from kanamycin producer Streptomyces kanamyceticus ATCC12853. These plasmids were heterologously expressed into Streptomyces lividans TK24 independently and generated two recombinant strains named S. lividans SK-2/SL and S. lividans SK-7/SL, respectively. ESI/ MS and ESI-LC/MS analysis of the metabolite from S. lividans SK-2/SL showed that the compound had a molecular mass of 163 $[M+H]^+$, which corresponds to that of 2-deoxystreptamine. ESI/MS and MS/MS analysis of metabolites from S. lividans SK-7/SL demonstrated the production of paromamine with a molecular mass of $324[M+H]^+$. In this study, we report the production of paromamine in a heterologous host for the first time. This study will evoke to explore complete biosynthetic pathways of kanamycin and related aminoglycoside antibiotics.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.634-640
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• 2016

The objective of this study was to evaluate the effectiveness of using HR-GC/MS for the rapid screening of dieldrin residues in soils. Persistent organic pollutants (POPs) of organochlorine pesticides such as dieldrin, were analyzed in sedimentary rock and granite rock collected from greenhouses, Niigata, Japan. Dieldrin remains in Japanese farming soils, more than 40 years after their use as insecticides was prohibited. The averages in soil moisture ranged from 2.79% to 7.20% in soils derived from sedimentary rock and from 25.59% to 31.40% in soils derived from granite rock. Mean concentrations of dieldrin residues in sedimentary rock and granite rock were $39.7ng\;g^{-1}$ and $40.51ng\;g^{-1}$, respectively. Dieldrin residue was detected at a slightly higher concentration in granite rock than sedimentary rock samples. There was no consistency between the two soils or between surface and subsurface soils. The coefficients of variation of the two soils were 10.6% and 8.7%, respectively. These results suggest that our high-resolution mass spectrometry detector (HR-GC/MS) is effective at analyzing residual organochlorine pesticides in soil. In order to increase the precision and sensitivity for chemical analysis of POPs, high-resolution gas chromatography coupled with a HR-GC/MS is highly recommended.

• Journal of Korean Biological Nursing Science
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• v.15 no.3
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• pp.133-138
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• 2013

Purpose: The purpose of this study was to compare the metabolic syndrome (MS) risk factors, physical activity, and diet habits, between the fifties and sixties in postmenopausal women. Methods: Two hundred and thirty subjects were recruited from the volunteers of a tertiary care hospital located in an urban city of South Korea. MS was defined by the criteria of the American Heart Association, the National Heart, Lung, and Blood Institute, and the International Diabetes Federation, and obesity was determined by waist circumference ${\geq}85cm$. Results: During fifty and sixty years of age, the prevalence of MS was 19.7% and 30.6%, respectively. The waist circumference, triglyceride, blood pressure, and fasting serum glucose levels were significantly higher in the MS group than in the non-MS group during their fifties and sixties. For participants in their sixties, the pulse pressure and fasting serum glucose levels were significantly higher in the MS group than in the non-MS group. Physical activity was significantly lower in the MS group than in the non-MS group in their sixties. Conclusion: These results show that nurses should focus on increased physical activity for patients their sixties, especially MS patients for the improvement of MS risk factors.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.917-921
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• 2013

A simple, quick and reliable analytical method for the confirmation and quantification of propisochlor was developed. The propisochlor was extracted from water, soil and rice (stalks, rice and hull) matrices using acetonitrile, and cleaned up with primary secondary amine and determined by UPLC-MS/MS. The LODs of propisochlor ranged from 0.03 ${\mu}g/kg$ to 0.12 ${\mu}g/kg$, while the LOQs ranged from 0.1 ${\mu}g/kg$ to 0.4 ${\mu}g/kg$ in different matrixes. The mean recoveries of propisochlor at three levels (0.005, 0.01 and 0.05 mg/kg) were in the range of 73.7-94.9% with intra-day relative standard deviations (RSD) of 1.1-13.9% and inter-day $RSD_R$ of 3.3-12.7%. This method is suitable for routine analysis of propisochlor under field conditions. The half-lives of propisochlor in rice stalks, water and soil were 1.7, 1.5 and 2.3 days in Hunan, 5.7, 1.0 and 1.9 days in Anhui and 4.8, 1.0 and 3.1 days in Guangxi.

• Phonetics and Speech Sciences
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• v.7 no.1
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• pp.57-65
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• 2015

This study aimed to identify the development pattern of final stop consonant perception using the gating task. Sixty-four subjects participated in the study: 16 children aged 4 years, 16 children aged 5 years, 17 children aged 6 years, and 15 adults. One-syllable words with consonant-vowel-consonant(CVC) structure, mokㄱ-motㄱ and papㄱ-patㄱ were used as stimuli in order to remove the redundancy of acoustic cues in stimulus words, 40ms-length (-40ms) and 60ms-length (-60ms) from the entire duration of the final consonant were deleted. Three conditions (the whole word segment, -40ms, -60ms) were used for this speech perception experiment. 48 tokens (4 stimuli ${\times}3$ conditions ${\times}4$ trials) in total were provided for participants. The results indicated that 5 and 6 year olds showed final consonant perception similar to adults in stimuli, papㄱ-patㄱ and only the 6-year-old children showed perception similar to adults in stimuli, 'mokㄱ-motㄱ. The results suggested that younger typically developing children require more acoustic information to accurately perceive final consonants than older children and adults. Final consonant perception ability may become adult-like around 6 years old. The study provides fundamental data on the development pattern of speech perception in normal developing children, which can be used to compare to those of children with communication disorders.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.891-894
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• 2014

This study is aimed to investigate the role of paired boxed gene 1 (PAX1) methylation analysis by methylation-sensitive high-resolution melting (MS-HRM) in the detection of high grade lesions in atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion (ASC-H) and compared its performance with the Hybrid Capture 2 (HC2) human papillomavirus (HPV) test. In our study, 130 cases with a diagnosis of ASC-H from the cervical cytological screening by Thinprep cytologic test (TCT) technique were selected for triage. Their cervical scrapings were collected and evaluated by using PAX1 methylation analysis (MS-HRM) and high-risk HPV DNA test (HC2), followed by colposcopy and cervical biopsy. Chi-square test were used to test the differences of PAX1 methylation or HPV infection between groups. In the detection of CIN2+, the sensitivity, specificity, the PPV, NPV and the accuracy of PAX1 MS-HRM assay and high-risk HPV (HR-HPV) tests were respectively 80.6% vs 67.7%, 94.9% vs 54.5%, 83.3%, vs 31.8%, 94.0% vs 84.4%, and 91.5% vs 57.7%. The PAX1 MS-HRM assay proved superior to HR-HPV testing in the detection of high grade lesions (CIN2+) in ASC-H. This approach could screen out the majority of high grade lesion cases of ASC-H, and thus could reduce the referral rate to colposcopy.

• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.239-242
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• 2001

The effects of post-cultural addition of liquid medium addition to stimulate in vitro bulblet growth in Lilium oriental hybrid 'Casa Blanca' were investigated. The sections of bulblets with swollen basal plate (7 mm$\times$12 mm) were cultured on medium containing 60 g/L sucrose and 1 g/L activated charcoal for two months in dark, and then, liquid medium was added into the same vessels. The addition of liquid medium stimulated the growth of bulblets remarkably, compared to no addition of liquid medium. The liquid medium supplemented with 120 g/L sucrose and double strength of MS salts were the most effective on the growth of in vitro bulblets.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.125-141
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• 2011

Melamine has raised international concerns for its catastrophic health effects from tainted infant formula. This report concerns the developmental validation of a sensitive HPLC/MS/MS and GC/MS methods about melamine and cyanuric acid in human urine and serum. Analytical detection ranges of LC/MS was from 0.2 to 5.0 ng/mL and 2.0 to 60.0 ng/mL about melamine and cyanuric acid, respectively. The limits of quantification and confirmation are 0.2 ng/mL for both analytes in human urine and serum by LC/MS/MS. The range of recovery was 91.6%, and 107.6% for cyanuric acid and melamine in urine, respectively. The range of precision coefficient variation was from 2.0%, to 11.8% for cyanuric acid and melamine in urine. The range of recovery was from 94.9%, to 119.0% about cyanuric acid and melamine in serum, respectively. The range of precision coefficient variation from was 3.7%, and 13.5% about cyanuric acid and melamine in serum. Analytical detection ranges of GC/MS were 5.0 to 100.0 ng/mL about melamine and cyanuric acid, respectively. The limits of quantification and confirmation are 5.0 ng/mL for both analytes in human urine and serum by GC/MS. The range of recovery was from 83.7%, to 114.5% for cyanuric acid and melamine in urine, respectively. The range of precision coefficient variation was 3.5%, and 10.7% for cyanuric acid and melamine in urine. The range of recovery was 94.4%, and 110.7% for cyanuric acid and melamine in serum, respectively. The range of precision coefficient variation from was 3.9%, and 13.8% for cyanuric acid and melamine in serum. Several changes were taken to optimize performance by this method.