• 대한방사선기술학회지:방사선기술과학
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• 제41권4호
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• pp.313-319
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• 2018

The purpose of this study was to investigate the influence of metabolic syndrome (MS) on the lower urinary tract symptoms (LUTS), prostate specific antigen (PSA), and prostate volume in Korean men. We analyzed the data from 2654 men over the age of 40 who visited our health promotion center for regular health checkups. Of the total 2654 men, mean age, PSA level, International Prostate Symptom Score (IPSS), and prostate volume were 54.6 years, 1.21ng/ml, 6.2 points, and 27.8ml, respectively. All examinees were divided into MS group (46.5%, 1235 men) and non-MS group (53.5%, 1419). Age and prostate volume were significantly higher in the MS group. The patients were divided into three groups according to their ages: 40's, 50's, and over 60 years old. Prostate volume of the MS group in the younger age groups (40-49 years and 50-59 years) was significantly larger than that of the non-MS group. However, no difference was revealed in the age group of 60-69 years. No significant differences were found in the PSA level and LUTS between the MS and non-MS groups. In the multivariate regression analysis, central obesity was the strongest risk factor for the enlargement of prostate over 30ml among the metabolic components.

• Journal of Plant Biotechnology
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• 제31권3호
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• pp.219-223
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• 2004

두릅나무의 엽병을 1.0 mg/L 2,4-D가 포함된 MS 고체배지에서 배발생캘러스를 유도하였다. 배발생세포와 배발생세포괴는 1.0 mg/L 2.4-D가 포함된 MS 액체배지에서 배발생캘러스를 2주간 현탁배양하여 대량으로 얻었다. 그물망을 통과한 배발생세포는 1.0 mg/L 2.4-D가 포함된 MS 액체배지에서 배양하면 배발생능이 소실되지 않고 지속적으로 유지 및 증식시킬 수 있었다. 그물망을 통과하지 못한 배발생세포괴를 식물생장조절물질이 첨가되지 않은 1/2 MS 액체배지에 옮겨 2주간 배양하면 구상형의 체세포배로 발달하였다. 구상형의 체세포배는 5 L의 bioreactor를 이용하여 배양하면 심장형, 어뢰형, 자엽형의 배와 유식물체로 발달하였다. Bioreactor 배양을 통해 두릅나무의 체세포배를 효과적으로 대량증식 시킬 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.421-429
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• 2011

For precise identification of a Lactobacillus K1 isolate, LC-MS/MS analysis of the putative surface layer protein was performed. The results obtained from LTQ-FT-ICR mass spectrometry confirmed that the analyzed protein spot is the surface layer protein originating from Lb. helveticus species. Moreover, the identified protein has the highest similarity with the surface layer protein from Lb. helveticus R0052. To evaluate the proteomic study, multilocus sequence analysis of selected housekeeping gene sequences was performed. Combination of 16S rRNA sequencing with partial sequences for the genes encoding the RNA polymerase alpha subunit (rpoA), phenylalanyl-tRNA synthase alpha subunit (pheS), translational elongation factor Tu (tuf), and Hsp60 chaperonins (groEL) also allowed to classify the analyzed isolate as Lb. helveticus. Further classification at the strain level was achieved by sequencing of the slp gene. This gene showed 99.8% identity with the corresponding slp gene of Lb. helveticus R0052, which is in good agreement with data obtained by nano-HPLC coupled to an LTQ-FT-ICR mass spectrometer. Finally, LC-MS/MS analysis of surface layer proteins extracted from three other Lactobacillus strains proved that the proposed method is the appropriate molecular tool for the identification of S-layer-possessing lactobacilli at the species and even strain levels.

• Journal of Pharmaceutical Investigation
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• 제37권3호
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• pp.179-186
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• 2007

A simple, sensitive and selective liquid chromatographic/tandem mass spectrometric method (LC-MS/MS) was developed and validated for doxifluridine and 5-fluorouracil (5-FU) quantification in dog heparinized plasma. Sample preparation was based on liquid-liquid extraction using a mixture of isopropanol/ethyl acetate (1/9 v/v) to extract doxifluridine, 5-FU and 5-chlorouracil (5-CU, an internal standard) from plasma. Chromatography was performed on a C-18 analytical column and the retention times were 2.7, 1.5 and 1.7 min for doxifluridine, 5-FU and 5-CU, respectively with shorter analysis time within 5 min than previously reported methods. The ionization was optimized using ESI negative mode and selectivity was achieved by tandem mass spectrometric analysis by multiple reaction monitoring (MRM) using the transformations of m/z 244.8>107.6, 129.0>42.0 and 144.9>42.1 for doxifluridine, 5-FU and 5-CU, respectively. The achieved low limit of quantification was 20.0 ng/mL and the assay exhibited linear range of 20-2000 ng/mL ($R^2>0.99957$ for doxifluridine and $R^2>0.99857$ for 5-FU), using $100{\mu}L$ of plasma. Accuracy and precision of quality control samples for both doxifluridine and 5-FU met KFDA and FDA Guidance criteria of 15% for accuracy with coefficients of variation less than 15%. This method demonstrated adequate sensitivity, specificity, accuracy, precision and stability to support the simultaneous analysis of doxifluridine and 5-FU in dog plasma samples in pharmacokinetic and bioequivalence studies.

• Bulletin of the Korean Chemical Society
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• 제28권7호
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• pp.1187-1194
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• 2007

The three major active isoflavonoids (calycosin-7-O-β -glucoside, isomucronulatol 7-O-β-glucoside, formononetin) and two main saponins (astragaloside I, astragaloside IV) in an extract of Radix Astragali were determined using rapid, sensitive, reliable HPLC/UV and LC-ESI-MS/MS methods. The separation conditions employed for HPLC/UV were optimized using a phenyl-hexyl column (4.6 × 150 mm, 5 μm) with the gradient elution of acetonitrile and water as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 230 nm. The specificity of the peaks was determined using a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) source that was operated in multiple reaction monitoring (MRM) in the positive mode. These methods were fully validated with respect to the linearity, accuracy, precision, recovery and robustness. The HPLC/UV method was applied successfully to the quantification of three major isoflavonoids in the extract of Radix Astragali. The results indicate that the established HPLC/UV and LC-ESI-MS/MS methods are suitable for the quantitative analysis and quality control of multi-components in Radix Astragali.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.821-827
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• 2014

An isotope dilution liquid chromatography tandem mass spectrometry (ID LC-MS/MS) method has been developed and applied to the determination of arsenobetaine (AsB, ${(CH_3)_3}^+AsCH_2COO^-$) from oyster candidate certified reference material (CRM). The exact matching isotope dilution approach was adopted for accurate determination of AsB using $^{13}C_2$-labeled AsB as an internal standard. Efficiencies of different AsB extraction methods were evaluated using a codfish reference material and a simple sonication method was selected as the method of choice for the certification of the oyster candidate CRM. The hydrophilic interaction liquid chromatography (HILIC) combined with electrospray ionization tandem mass spectrometry (ESI/MS/MS) in selected reaction monitoring (SRM) mode was optimized for adequate chromatographic retention and robust quantification of AsB from codfish and oyster samples. By analyzing 12 subsamples taken from each 12 bottles systematically selected from the whole oyster CRM batch, the certified value of AsB was determined as $6.60mg{\cdot}kg^{-1}{\pm}0.31mg{\cdot}kg^{-1}$ and it showed excellent between-bottle homogeneity of less than 0.42%, which is represented by relative standard deviation of 12 bottles from the CRM batch. The major source of uncertainty was the certified value of the AsB standard solution.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.709-714
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• 2014

Protein tyrosine nitration is considered as an important indicator of nitrosative stresses and as one of the main factors for pathogenesis of inflammation and neuronal degeneration. In this study, we investigated various nitrosative modifications of bovine carbonic anhydrase II (CAII) through qualitative and semi-quantitative analysis using the combined strategy of Fourier transformation ion cyclotron resonance mass spectrometry (FT-ICR MS) and ion-trap tandem mass spectrometry (IT-MS/MS). FT-ICR MS and its spectra were used for the search of the pattern of nitrosative modifications. Identification of nitrosatively modified tyrosine sites were executed through IT-MS/MS. In addition, we also tried to infer the reason for the site-specific nitrosative modifications in CAII. In view of the above purpose, we have explored- i) the side chain accessibility, ii) the electrostatic environment originated from the acidic/basic amino acid residues neighboring to the nitrosatively modified site and iii) the existence of competing amino acid residues for nitration.

• 한국환경과학회지
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• 제23권6호
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• pp.1037-1047
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• 2014

A highly sensitive analytical method based on stir bar sorptive extraction (SBSE) technique and gas chromatography/tandem mass spectrometry (GC/MS-MS) has been developed, allowing the simultaneous multi-analyte determination of seven UV filters in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 40 mL of water sample at pH 3 and stirred at 1,100 rpm for 120 min. Other SBSE parameters (salt effect and presence of organic solvent) were optimised. The method shows good linearity (coefficients > 0.990) and reproducibility (RSD < 12.9%). The extraction efficiencies were above 84% for all the compounds. The limits of detections (LOD) and limits of quantification (LOQ) were 2.1~8.6 ng/L and 6.8~27.5 ng/L, respectively. The developed method offers the ability to detect 8 UV filters at ultra-low concentration levels with only 40 mL of sample volume. Matrix effects in tap water, river water, wastewater treatment plant (WWTP) final effluent water and seawater were investigated and it was shown that the method is suitable for the analysis of trace level of 7 UV filters except of benzophenone (BP). The method developed in the present study has the advantage of being rapid, simple, high-sensitive and both user and environmentally friendly.

• 대한기계학회논문집 C: 기술과 교육
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• 제2권1호
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• pp.21-28
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• 2014

MS 엑셀 프로그램은 사업 영역의 다양한 분야에서 활용되고 있는 스프레드시트 프로그램이다. MS 엑셀 프로그램은 대부분의 PC 에서 이용 가능하기 때문에 학생들을 위한 교육적인 목적으로 도 널리 이용되는데, 과학과 공학 분야에서는 주로 수치해석과 공식의 응용 등에 주로 사용된다. 본 논문에서는 기계공학의 필수 과목인 정역학을 교육함에 있어 필수 공식을 활용하기 위한 MS 엑셀 프로그램의 교육사례를 소개한다. 또한, 엑셀 응용 프로그램에 대한 깊은 이해를 위하여 매크로와 비주얼 베이직을 이용하여 응용 프로그램을 개발하는 과정에 대해서도 기술한다. 학생들은 MS 엑셀 프로그램의 기본 함수를 이용하여 정역학 문제를 해결할 수 있었을 뿐만 아니라 매크로와 비주얼 베이직을 이용하여 복잡한 문제를 체계적으로 푸는 방법을 습득하고, 응용프로그램을 작성할 수 있었다.

• 생명과학회지
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• 제14권5호
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• pp.855-858
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• 2004

본 연구는 거베라의 신품종을 육성하여 식물체 재분화 조건을 찾기 위하여 경남농업기술원 화훼육종연구소에서 육성한 화이트데이, 송송이 그리고 러브송 등 3품종을 이용하여 기내배양묘의 엽병으로부터 callus 유도조건 및 식물체 재분화에 미치는 몇 가지 요인을 구명하기 위해 실시되었다. Callus의 유도에 있어서는 3품종 중 '화이트데이'가 다른 품종보다 callus형성이 양호하였다. Callus의 유도를 위한 가장 효과적인 식물생장조절물질의 조건은 MS 기본배지에 NAA 0.1 mg/L＋TDZ 0.5 mg/L의 조건에서 양호하였다. 식물체 재분화를 위한 가장 효과적인 식물생장조절물질의 조건은 MS 기본배지에 IAA 1.0 mg/L＋BA 1.0 mg/L＋Zeatin 0.1 mg/L의 혼용조건에서 양호한 경향이었다. 배양 식물체 재분화를 위한 엽병의 적정 계대배양 기간은 계대배양 후 32일이 경과된 엽병에서 양호한 경향이었다. 또한 식물체 재분화를 위한 적정 MS 배지의 농도는 1/2MS에서 식물체의 분화가 양호하였다.