Characterization of an Unconventional MALDI-MS Peak from DHB/pyridine Ionic Liquid Matrices

Jangmi Hong,김정권 한국질량분석학회 2020 Mass spectrometry letters Vol.11 No.1

Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) analysis of ionic liquid matrices (ILMs) prepared using pyridine and dihydroxybenzoic acid (DHB), such as 2,3-DHB and 2,5-DHB, displayed an unconven-tional peak at m/z 232.0, which was regarded as [DHB+pyridine-H] + . The peak at m/z 232.0 was not observed from other ILMs prepared using other DHB isomers, such as 2,4-DHB, 2,6-DHB, 3,4-DHB, and 3,5-DHB. Two requirements to observe the peak at m/z 232.0 in a DHB/pyridine ILM are suggested. First, carboxyl and hydroxyl groups must be located ortho to each other. Sec- ond, the secondary hydroxyl group must be located at a carbon with a high electron density. Based on these two requirements, a potential mechanism for the generation of the peak at m/z 232.0 is suggested.

Tertiary Matrices for the Analysis of Polyethylene Glycols Using MALDI-TOF MS

Jangmi Hong,Taehee Kim,Jeongkwon Kim 한국질량분석학회 2014 Mass spectrometry letters Vol.5 No.2

The effectiveness of tertiary matrices composed of the combination of three common matrices (dihydrobenzoic acid (DHB), α-cyano-4-hydroxycinnamic acid (CHCA), and sinapinic acid (SA)) was compared with that of single or binary matrices in the analysis of polyethylene glycol (PEG) polymers ranging from 1400 to 10000 Da using matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF MS). A tertiary matrix of 2,5-DHB+CHCA+SA was the most effective in terms of S/N ratios. CHCA and CHCA+SA produced the highest S/N ratios among the single matrices and the binary matrices, respectively. The improvement observed when using a tertiary matrix in analyses of PEG polymers by MALDITOF MS is believed to be due to the uniform morphology of the MALDI sample spots and synergistic effects arising from the mixture of the three matrix materials.

Tertiary Matrices for the Analysis of Polyethylene Glycols Using MALDI-TOF MS

Hong, Jangmi,Kim, Taehee,Kim, Jeongkwon Korean Society for Mass Spectrometry 2014 Mass spectrometry letters Vol.5 No.2

The effectiveness of tertiary matrices composed of the combination of three common matrices (dihydrobenzoic acid (DHB), ${\alpha}$-cyano-4-hydroxycinnamic acid (CHCA), and sinapinic acid (SA)) was compared with that of single or binary matrices in the analysis of polyethylene glycol (PEG) polymers ranging from 1400 to 10000 Da using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A tertiary matrix of 2,5-DHB+CHCA+SA was the most effective in terms of S/N ratios. CHCA and CHCA+SA produced the highest S/N ratios among the single matrices and the binary matrices, respectively. The improvement observed when using a tertiary matrix in analyses of PEG polymers by MALDI-TOF MS is believed to be due to the uniform morphology of the MALDI sample spots and synergistic effects arising from the mixture of the three matrix materials.

일본 초등학교 수영교육 운영 현황 및 시사점

홍장미(Hong Jangmi),박상봉(Park Sangbong) 학습자중심교과교육학회 2020 학습자중심교과교육연구 Vol.20 No.21

본 연구는 선진적인 수영교육이 이루어지고 있는 것으로 평가받고 있는 일본 초등학교의 수영교육 현장을 들여다보고 시사점을 탐색하여 우리나라의 수영교육이 나아갈 방향을 제시하고자 하였다. 이러한 연구목적을 달성하기 위하여 일본의 초등학교를 직접 방문하여 참여관찰, 심층면담, 문서자료 수집 후 이를 분석하였다. 연구 결과, 일본의 초등학교는 대부분 자체 수영장을 보유하고 있었으며 수영 시설이 엄격하게 관리되고 있었다. 그러나 수영장의 노후화 문제에 직면해 있었으며 날씨와 기온의 제약으로 인해 수영장의 가동률이 낮은 것으로 나타났다. 수영 교육과정의 운영 모습을 살펴본 결과, 일본에서 수영교육의 주체는 담임교사이나 한국과 마찬가지로 일본의 교사들도 수영교육의 전문성 부족을 인식하고 있었다. 그러나 학부모 및 교사 공동체의 협력과 지역사회의 인적자원 활용을 통해 이러한 문제들을 극복하기 위한 대안들을 모색하고 있었다. 연구 결과를 토대로 학생들의 실질적인 생존 역량을 기르기 위한 명확한 성취기준 중심의 수영교육과정 운영, 교사의 수영교육 전문성 부족 극복을 위한 제도적 장치 마련, 학교 수영장 건립을 대체할 수영교육 시설 개발 및 확보를 우리나라 수영교육 발전을 위한 시사점으로 제시하였다. This study aimed to look into the actual scene of swimming education in Japanese elementary schools, which are considered to provide advanced swimming education, thus exploring the lessons to be learned in order to propose the direction in which Korea’s swimming education should be developed. In order to achieve these research objectives, I directly visited elementary schools in Japan, conducted participant observation and in-depth interviews, collected documents and material, and analyzed the results. According to the study, most elementary schools in Japan had their own swimming pools and strictly managed their swimming facilities. However, it was found that there were issues due to the aging of the swimming pools, as well as the low operation rate of the swimming pools due to weather and temperature restrictions. According to the observation of practical swimming courses, the homeroom teachers were mainly responsible for swimming education, and Japanese teachers - like Korean teachers - recognized that they lacked expertise in swimming education. However, through the cooperation of the parent and teacher community as well as the utilization of community human resources, the schools were looking for alternatives to overcome these problems. Based on the results of the study, I suggested that the implementation of the swimming curriculum based on clear achievement standards for the purpose of improving students’ actual lifesaving skills, institutional improvement to overcome teachers lack of expertise in swimming education, the development and securement of swimming education facilities in order to replace the school swimming pools are ways that Korea’s swimming education could be improved.

Optimization in Detecting Multiply-charged Protein Ions using MALDI TOF-MS

Lee, Jihyeon,Hong, Jangmi,Kim, Taehee,Kim, Jeongkwon Korean Society for Mass Spectrometry 2013 Mass spectrometry letters Vol.4 No.1

The effects of trifluoroacetic acid (TFA) were evaluated on the generation of multiply charged ions of cytochrome c in a 2-nitrophloroglucinol (2-NPG) matrix in high-vacuum, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The presence of 1% TFA in the 2-NPG matrix solution was more effective in generating multiply charged protein ions than matrix solutions containing 0.1% or 0% TFA. Regarding the matrix itself, with 1% TFA, 2-NPG was significantly more effective in generating multiply charged ions than 2,5-dihydroxybenzoic acid (2,5-DHB). The maximum charge state of cytochrome c was +8 when using a 2-NPG matrix containing 1% TFA.

Optimization in Detecting Multiply-charged Protein Ions using MALDI TOF-MS

Jihyeon Lee,Jangmi Hong,Taehee Kim,Jeongkwon Kim 한국질량분석학회 2013 Mass spectrometry letters Vol.4 No.1

The effects of trifluoroacetic acid (TFA) were evaluated on the generation of multiply charged ions of cytochrome c in a 2-nitrophloroglucinol (2-NPG) matrix in high-vacuum, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The presence of 1% TFA in the 2-NPG matrix solution was more effective in generating multiply charged protein ions than matrix solutions containing 0.1% or 0% TFA. Regarding the matrix itself, with 1% TFA, 2-NPG was significantly more effective in generating multiply charged ions than 2,5-dihydroxybenzoic acid (2,5-DHB). The maximum charge state of cytochrome c was +8 when using a 2-NPG matrix containing 1% TFA.

Microwave-assisted Protein Digestion on Various Locations of a Microplate

Ji Hye Lee,Sehwan Park,이선영,Jangmi Hong,Kyu Hwan Park,김현식,김정권 사단법인 한국질량분석학회 2011 Mass spectrometry letters Vol.2 No.4

The effectiveness of microwave-assisted protein digestion in different well positions of a 96-well microplate wasinvestigated where microwave-assisted protein digestion of bovine serum albumin was performed in 10 different wells of a 96-wellmicroplate in a microwave oven. Similarly increased sequence coverages (~70%) were generally observed for the 10 microwaveassistedprotein digestion samples compared to conventional overnight digestion (63%), which is possibly due to higher miscleavageratios (~53%) of the samples from microwave-assisted protein digestion than conventional overnight digestion (42.1%). The reproducibleresults of microwave-assisted digestions from different well positions demonstrate the potential of high-throughput analysis ofproteins using microwave-assisted protein digestion.

Analysis of Arginine, Glucose, Sucrose, and Polyethylene Glycols using a Wood Charcoal Matrix for MALDI-MS

Sun Young Lee,JinHeeKim,Hyo-Jik Yang,Seongjae Shin,Jangmi Hong,김정권 사단법인 한국질량분석학회 2010 Mass spectrometry letters Vol.1 No.1

Wood charcoal was investigated to determine its potential as an alternative matrix for matrix-assisted laser desorption/ionization of various samples. Wood charcoal was an effective matrix for analyzing glucose, sucrose, arginine, and polyethyleneglycols (PEGs), with detection levels of 100 pmol for glucose, 1 nmol for sucrose, 100 pmol for arginine, 100 pmol for PEG 400,1 pmol for PEG 1540, and 10 pmol for PEG 3350. No analyte signal was observed for peptides or proteins.

Formation of microplastics by polychaetes (<i>Marphysa sanguinea</i>) inhabiting expanded polystyrene marine debris

Jang, Mi,Shim, Won Joon,Han, Gi Myung,Song, Young Kyoung,Hong, Sang Hee Elsevier 2018 Marine pollution bulletin Vol.131 No.1

<P><B>Abstract</B></P> <P>Fragmentation of large plastic debris into smaller particles results in increasing microplastic concentrations in the marine environment. In plastic debris fragmentation processes, the influence of biological factors remains largely unknown. This study investigated the fragmentation of expanded polystyrene (EPS) debris by polychaetes (<I>Marphysa sanguinea</I>) living on the debris. A large number of EPS particles (131 ± 131 particles/individual, 0.2–3.8 mm in length) were found in the digestive tracts of burrowing polychaetes living on EPS debris. To confirm the formation of microplastics by polychaetes and identify the quantity and morphology of produced microplastics, polychaetes were exposed to EPS blocks in filtered seawater under laboratory conditions. Polychaetes burrowed into the blocks and created numerous EPS microplastic particles, indicating that a single polychaete can produce hundreds of thousands of microplastic particles per year. These results reveal the potential role of marine organisms as microplastic producers in the marine environment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Floating marine debris becomes a habitat for marine organisms. </LI> <LI> A lot of EPS particles were found in the feces of polychaetes from EPS debris. </LI> <LI> Polychaetes burrowed into EPS debris and created numerous EPS microplastic particles. </LI> <LI> Marine organisms inhabiting marine debris contribute to microplastic formation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

MMP-1 suppressing activity of high-molecular weight fraction isolated from the roots of <i>Cynanchum wilfordii</i> Hemsley

Jang, Mi,Cho, Chang-Won,Han, Ah-Ram,Rhee, Young Kyoung,Hong, Hee-Do,Kim, Kyung-Tack,Lee, Sung-Young,Lee, Kwang Min,Jung, Sung Keun,Lim, Tae-Gyu Elsevier 2018 Journal of Functional Foods Vol.40 No.-

<P><B>Abstract</B></P> <P> <I>Cynanchum wilfordii</I> Hemsley is a traditional herbal medicine that has been widely used in Asia. In the present study, we investigated the MMP-1 suppressing activity of a high-molecular weight fraction isolated from the roots of <I>C. wilfordii</I> Hemsley (HMF). In human skin tissue, UVB irradiation significantly increased matrix metalloproteinase-1 (MMP-1) expression, while HMF suppressed this effect. The inhibitory effect of HMF was confirmed in both primary human dermal fibroblasts (HDFs) and a human keratinocyte (HaCaT) model. An investigation of the underlying mechanisms responsible revealed that MKK4-JNK, MEK-ERK, and MKK3/6-p38 phosphorylation was downregulated by HMF treatment. HMF also induced a 30–40% increase in DPPH radical scavenging activity and recovered expression levels of the antioxidant enzyme superoxide dismutase. Taken together, these findings suggest that HMF elicits MMP-1 suppressing activity via inhibition of the signaling that drives UVB-induced oxidative stress in human skin.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The anti-wrinkle activity of high-molecular weight fraction isolated from <I>Cynanchum wilfordii</I> Hemsley (HMF) was suggested. </LI> <LI> UVB-suppressed SOD expression was recovered by HMF. </LI> <LI> HMF directly revealed radical scavenging activity. </LI> </UL> </P>