• Title/Summary/Keyword: $MS^E$

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Inactivation of Escherichia coli and MS2 coliphage by Cu(II)-activated peroxomonosulfate in natural water

  • Kim, Hyung-Eun;Lee, Hye-Jin;Kim, Min Sik;Choi, Joon-Young;Lee, Changha
    • Membrane and Water Treatment
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    • v.10 no.3
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    • pp.231-237
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    • 2019
  • Peroxymonosulfate (PMS) in combination with Cu(II) was examined to inactivate E. coli and MS2 coliphage in natural water. The combined system (i.e., the Cu(II)/PMS system) caused a synergistic inactivation of E. coli and MS2, in contrast with either Cu(II) or PMS alone. Increasing the concentration of PMS enhanced the inactivation of E. coli and MS2, but after a certain point, it decreased the efficacy of the microbial inactivation. In the Cu(II)/PMS system, adding reactive oxidant scavengers marginally affected the E. coli inactivation, but the inhibitory effects of copper-chelating agents were significant. Fluorescent assays indicated that the Cu(II)/PMS system greatly increased the level of reactive oxidants inside the E. coli cells. The sequential addition of Cu(II) and PMS inactivated more E. coli than did adding the two simultaneously; in particular, the inactivation efficacy was much higher when Cu(II) was added first. The observations from the study collectively showed that the microbial inactivation by the Cu(II)/PMS system could be attributed to the toxicity of Cu(I) as well as the intracellular oxidative stress induced by Cu(III) or radical species.

LC-MS/MS-based Proteomic Analysis to Identify Protein Phosphorylation in Emiliania huxleyi

  • Duong, Van-An;Nam, Onyou;Jin, EonSeon;Seo, Jae-Min;Park, Jong-Moon;Lee, Hookeun
    • Mass Spectrometry Letters
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    • v.12 no.4
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    • pp.163-171
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    • 2021
  • Emiliania huxleyi is a marine phytoplankton that plays a critical role in global carbon and sulfur cycling. The genome of E. huxleyi has been sequenced, and an in-depth proteomic profile of this organism has been reported. This study analyzed the phosphoproteome of E. huxleyi and identified its changes under calcium-limited conditions. A TiO2 microcolumn was used for phosphopeptide enrichment, followed by liquid chromatography-tandem mass spectrometry analysis. Overall, we identified 7,010 phosphorylated sites on 3,355 phosphopeptides associated with 2,929 phosphoproteins in E. huxleyi. Quantitative analysis revealed changes in the phosphoproteome in E. huxleyi when ambient conditions changed to calcium-limited conditions, notably the phosphorylation of some transporters was altered. This study provides an overview of protein phosphorylation in E. huxleyi and paves the way for further investigations of its biological functions.

Development of Analytical Method for Determination of Baicalin, Eleutheroside E, and Ligustilide by LC-MS/MS in Raw Materials of Health Functional Foods (LC-MS/MS를 이용한 건강기능식품 원료 중 바이칼린, 엘레우테로사이드 E, 리구스틸라이드 동시분석법 개발)

  • Keum, Eun Hee;Chung, So Young;Lee, Jin Hee;Kim, Meehye
    • Journal of Food Hygiene and Safety
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    • v.32 no.3
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    • pp.193-198
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    • 2017
  • Scutellaria baicalensis, Eleutherococcus senticosus, and Angelica sinensis have been used as raw materials for health functional foods. This study was conducted to develop a novel method to analyze levels of baicalin (Scutellaria baicalensis), eleutheroside E (Eleutherococcus senticosus), and ligustilide (Angelica sinensis) simultaneously in health functional foods. The methanol extracted samples were analyzed and quantified via liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the positive ion mode and the negative ion mode using multiple reaction monitoring. Standard calibration curves confirmed linearity with the correlation coefficient ($r^2$) of > 0.99 at $100-2000{\mu}g/mL$ concentration range. The limits of detection (LODs) and limits of quantitation (LOQs) were in the range of $13.0{\sim}35.2{\mu}g/L$ and $39.3{\sim}106.7{\mu}g/L$, respectively. The recovery results ranged between 91.4~109.9% at 3 different concentration levels with relative standard deviations (RSDs) less than 5%. The proposed analytical method was characterized with high accuracy and acceptable precision. The new method would be an effective tool to analyze baicalin, eleutheroside E, and ligustilide simultaneously in raw materials of health functional foods.

An Adaptive Association Scheme for Fast Handover in IEEE 802.16e (IEEE 802.16e에서 빠른 핸드오버 지원을 위한 선택적인 Association 기법)

  • Park, Jinwook;Oh, Seungtak;Choo, Hyunseung
    • Annual Conference of KIPS
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    • 2009.04a
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    • pp.1120-1123
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    • 2009
  • 다양한 기능의 휴대 단말 기기와 무선 환경의 보급으로 무선 인터넷 서비스에 대한 사용자들의 요구가 증가하고 있다. 이와 관련하여 IEEE 802.16 표준은 사용자에게 대용량 데이터 서비스를 제공하기 위한 무선 기술을 정의하고 있다. 또한, IEEE 802.16에 MS의 핸드오버 절차를 추가한 EEE 802.16e 표준 기술은 MS에 대한 핸드오버 절차를 지원하고 있다. 그러나 이러한 핸드오버 절차는 MS이 Serving BS과의 연결을 종료한 이후, 새로운 Target BS에 대한 핸드오버 절차를 수행하므로 사용자는 일시적인 데이터 전송 중단으로 인한 서비스 지연을 경험한다. 본 논문에서는 이러한 문제를 해결하고, 사용자에 대한 빠른 핸드오버 절차를 지원하기 위해 주변 BS들의 위치 정보를 MOB_NBR-ADV를 통하여 MS에게 전송하고, 이를 통해 각 BS들에 대한 MS의 접근 정도를 평가하여 특정한 BS에 대해서만 Association을 수행할 수 있는 기법을 제안한다.

Comparative analysis of sensory profiles of commercial cider vinegars from Korea, China, Japan, and US by SPME/GC-MS, E-nose, and E-tongue (한국, 중국, 일본, 미국산 시판 사과식초의 관능적 품질 비교를 위한 SPME-GC/MS, 전자코 및 전자혀 분석)

  • Jo, Yunhee;Gu, Song-Yi;Chung, Namhyeok;Gao, Yaping;Kim, Ho-Jin;Jeong, Min-Hee;Jeong, Yong-Jin;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.48 no.5
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    • pp.430-436
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    • 2016
  • Solid phase microextraction and gas chromatography-mass spectrometry (SPME/GC-MS), electronic nose, and electronic tongue were used to characterize the sensory profiles of cider vinegars from Korea (K1-2), China (C1-2), Japan (J1-2), and US (U1-2). SPME-GC/MS detected acetic acid as the common volatile compound in all vinegars, in addition to isovaleric acid, octanoic acid, and phenethyl acetate. Acids and acetic esters were the major components of Korean and US vinegar samples, respectively. Chinese vinegars had high ethyl acetate content, while Japanese samples were characterized by a low content of acetic acid. Principal component analysis (PCA) pattern provided a clear categorical discrimination of Chinese vinegars by E-nose and E-tongue analyses. The instrumental sensory scores and the taste attributes for flavor ($r^2=0.9431$), sourness ($r^2=0.9515$), and sweetness ($r^2=0.8325$) were highly correlated. Therefore, SPME/GC-MS, E-nose, and E-tongue analyses may be useful tools to discriminate the sensory profiles of cider vinegars of different origins.