• Title/Summary/Keyword: Ionization development

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Identification and Characterization of Phytochemicals from Peanut (Arachis hypogaea L.) Pods

  • Lee, Jin-Hwan;Baek, In-Youl;Ha, Tae-Joung;Choung, Myoung-Gun;Ko, Jong-Min;Oh, Sea-Kwan;Kim, Hyun-Tae;Ryu, Hyung-Won;Park, Keum-Yong;Park, Ki-Hun
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.475-482
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    • 2008
  • Methanol extracts of peanut (Arachis hypogaea L.) pods were chromatographed, which yielded 3 phytochemicals 1-3 including 5,7-dihydroxychromone (1), eriodictyol (2), and 3',4',5,7-tetrahydroxyflavone (3). To confirm the presence of isolated phytochemicals, the pods extracts were performed by high performance liquid chromatography coupled with a photodiode array detector (HPLC-PDA) and a mass spectrometric detector (MSD) with electrospray ionization (ESI). Optimum extraction conditions for phytochemical contents using peanut germplasm were obtained by employing 90% MeOH for 12 hr at room temperature and phytochemicals 1-3 showed significant differences with concentrations of $407.56{\pm}23.35$, $52.92{\pm}5.11$, and $2,024.34{\pm}134.18\;{\mu}g/g$, respectively. Under this optimal conditions, the contents of phytochemicals 1-3 in peanut pods of 3 Korea cultivars including 'Jakwang', 'Daekwang', and 'Palkwang' exhibited phytochemical 3 was the highest range of $1,338.01-5,162.93\;{\mu}g/g$, followed by phytochemical 1 ($590.13-1,382.10\;{\mu}g/g$), and phytochemical 2 ($25.12-186.85\;{\mu}g/g$), respectively. Moreover, 'Jakwang' exhibited the highest contents of phytochemical (1: $1,362.10{\pm}52.49$, 2: $186.85{\pm}17.69$, and 3: $5,162.93{\pm}148.64\;{\mu}g/g$, respectively), whereas the lowest contents was found in the 'Daekwang' (1: $590.13{\pm}22.23$, 2: $25.12{\pm}2.45$, and 3: $1,338.01{\pm}62.17\;{\mu}g/g$, respectively). These results suggest that the methanol extracts of peanut pods may possess health related benefits to humans owing to various known biological activities of phytochemicals 1-3.

Expression of Antihypertensive Peptide, His-His-Leu, as Tandem Repeats in Escherichia coli

  • Jeong, Do-Won;Shin, Dong-Seok;Ahn, Chang-Won;Song, In-Sang;Lee, Hyong-Joo
    • Journal of Microbiology and Biotechnology
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    • v.17 no.6
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    • pp.952-959
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    • 2007
  • His-His-Leu (HHL), a tripeptide derived from a Korean soybean paste, is an angiotensin-I-converting enzyme (ACE) inhibitor. We report here a method of producing this tripeptide efficiently by expressing tandem multimers of the codons encoding the peptide in E. coli and purifying the HHL after hydrolysis of the peptide multimers. The HHL gene, tandemly multimerized to a 40-mer, was ligated with ubiquitin as a fusion gene (UH40). UH40 was inserted into vector pET29b; the UH40 fusion protein was then produced in E. coli BL21. The recombinant UH40 protein was purified by cation-exchange chromatography with a yield of 17.3mg/l and analyzed by matrixassisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry and protein N-terminal sequencing. Leucine aminopeptidase was used to cleave a 405-Da HHL monomer from the UH40 fusion protein and the peptide was purified using reverse-phase high-performance liquid chromatography (HPLC) on a C18 HPLC column, with a final yield of 6.2mg/l. The resulting peptide was confirmed to be HHL with the aid of MALDI-TOF mass spectrometry, glutamine-TOF mass spectrometry, N-terminal sequencing, and measurement of ACE inhibiting activity. These results suggest that our production method is useful for obtaining a large quantity of recombinant HHL for functional antihypertensive peptide studies.

Antifungal Effect of Triglycerol Monolaurate Synthesized by Lipozyme 435-Mediated Esterification

  • Zhang, Song;Xiong, Jian;Lou, Wenyong;Ning, Zhengxiang;Zhang, Denghui;Yang, Jiguo
    • Journal of Microbiology and Biotechnology
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    • v.30 no.4
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    • pp.561-570
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    • 2020
  • This study was designed to synthesize triglycerol monolaurate (TGML) with Lipozyme 435 as the catalyst, and explore its effects on the growth of Aspergillus parasiticus (A. parasiticus) and Aspergillus flavus (A. flavus) and the secretion of aflatoxin b1. The highest content of TGML (49.76%) was obtained at a molar ratio of triglycerol to lauric acid of 1.08, a reaction temperature of 84.93℃, a reaction time of 6 h and an enzyme dosage of 1.32%. After purification by molecular distillation combined with the washes with ethyl acetate and water, the purity of TGML reached 98.3%. Through characterization by electrospray-ionization mass spectrometry, infrared spectrum and nuclear magnetic resonance, the structure of TGML was identified as a linear triglycerol combined with lauroyl at the end. Finally, the inhibitory effects of TGML on the growths of A. parasiticus and A. flavus and the secretion of aflatoxin b1 were evaluated by measuring the colony diameter, the inhibition rate of mycelial growth and the content of mycotoxin in the media. The results indicated that TGML had a stronger inhibitory effects on colony growth and mycelial development of both toxic molds compared to sodium benzoate and potassium sorbate, and the secretions of toxins from A. parasiticus and A. flavus were completely suppressed when adding TGML at 10 and 5 mM, respectively. Based on the above results, TGML may be used as a substitute for traditional antifungal agents in the food industry.

Comparison of Air Kerma and Absorbed Dose to Water Based Protocols for High Energy Photon Beams: Theoretical and Experimental Study

  • Shin, Dong-Oh;Kim, Seong-Hoon;Seo, Won-Seop;Park, Sung-Yong;Park, Jin-Ho;Kang, Jin-Oh;Hong, Seong-Eon;Ahn, Hee-Kyung
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.241-243
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    • 2002
  • New types of protocols have been recently in development, all based on an absorbed dose-to-water with the aim of improving the accuracy of measurements of absorbed dose to water. IAEA TRS-277, the air-kerma standard-based present protocol, and IAEA TRS-398 and AAPM TG-51, the absorbed dose-to-water standard-based new one, were studied and compared theoretically and experimentally for photon beams of 6, 10, and 15 MV. NE 2571 and 3 Farmer types of ionization chambers in widely commercial use were used to determine an absorbed dose to water at the reference depth in water. Two different kinds of calibration factors were given respectively for every chamber calibrated in $\^$60/CO gamma ray beams from a Korean Secondary Standard Dosimetry Laboratory (KFDA). This work shows that there is around 1 % of difference of absorbed doses measured between two different types of calibration systems owing to different physical parameters and reference conditions used. We hope this work to help form the basis on development of new type of protocol in Korea.

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Purity assignment of 17β-estradiol by mass balance method

  • Lee, Hwa-Shim;Oh, Kwang-Hoon
    • Analytical Science and Technology
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    • v.30 no.5
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    • pp.226-233
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    • 2017
  • In general, quantitative chemical analysis in various areas including food, the environment, in vitro diagnostics, etc., requires traceability in order to increase the reliability of the measurements. Measurement traceability is a property of an unbroken chain of comparisons relating an instrument's measurements to SI units. Purity analysis is the first process for establishing traceability to SI units in chemical measurements. The purpose of this study is to develop and validate a method of purity assignment for establishing the traceability of $17{\beta}$-estradiol measurements in an in vitro diagnostics field. The establishment of this method is very important as it can be applied to the development of CRM and to the analysis of the purity of other hormones. The method of assignment of the purity of $17{\beta}$-estradiol was developed using the mass balance method and was validated through participation in an International comparison. In the mass balance method, impurities are categorized into four classes as follows: total related structure impurities, water, residual organic solvents, and nonvolatiles/inorganics. In this study, total related structure impurities were characterized by a gas chromatography-flame ionization detector (GC-FID) and a high-performance liquid chromatography-ultraviolet (HPLC-UV) detector, water content was determined by a Karl-Fisher coulometer, and total residual solvents and nonvolatiles/inorganics were checked simultaneously by thermogravimetric analysis (TGA). The purity of the $17{\beta}$-estradiol was 985.6 mg/g and the expanded uncertainty was 2.1 mg/g at 95% confidence. The developed method can be applied to the development of certified reference materials, which play a critical role in traceability.

Development of Monitor Chamber Prototype and Basic Performance Testing (모니터 전리함 시작품 개발과 기초 성능 평가)

  • Lee, Mujin;Lim, Heuijin;Lee, Manwoo;Yi, Jungyu;Rhee, Dong Joo;Kang, Sang Koo;Jeong, Dong Hyeok
    • Progress in Medical Physics
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    • v.26 no.2
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    • pp.99-105
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    • 2015
  • The monitor chamber is a real time dosimetry device for the measurement and the control of radiation beam intensity of the linac system. The monitor chamber prototype was developed for monitoring and controlling radiation beam from the linac based radiation generator. The thin flexible printed circuit boards were used for electrodes of the two independent plane-parallel ionization chambers to minimize the attenuation of radiation beam. The dosimetric characteristics, saturation and linearity of the measured charge, were experimentally evaluated with the Co-60 gamma rays. The performance of the developed monitor chamber prototype was in an acceptable range and this study shows the possibility of the further development of the chamber with additional functions.

Analysis of Scutellaria baicaleinsis Georgi (Scutellariae Radix) by LC-DAD and LC-ESI/MS

  • Yu, Youngbob;Choi, Pil-Son;Koo, Sungtae;Chang, Suhwan
    • Korean Journal of Plant Resources
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    • v.31 no.6
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    • pp.652-659
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    • 2018
  • In this study, baicalin, as a marker substance of Scutellariae Radix, was quantitatively analyzed by a high performance liquid chromatography-photodiode array detector (HPLC-DAD). We identified wogonoside, baicalein, and wogonin in the Scutellariae Radix by a high performance liquid chromatography-electrospray ionization-mass spectrometer (HPLC-ESI-MS). The baicalin was separated on a Xterra C18 column ($5{\mu}m$, $4.6{\times}250mm$) using mobile phase consisting of 38% acetonitrile in 0.68% phosphoric acid. The baicalin spectrum in the Scutellariae Radix extracts was coincided by comparing with UV-visible spectrum (200-550 nm) of baicalin standard in the library. The amount of baicalin in Scutellariae Radix was 10.46%, which is higher than KFDA's guideline. The marker substances of Scutellariae Radix showed a strong base peak $[M]^+$ in the positive detection mode following as; baicalin (m/z; $271[MH^+-sugar]^+$, $447[M+H]^+$), wogonoside (m/z; $285[MH^+-sugar]^+$, $461[M+H]^+$), baicalein (m/z; $271\;[M+H]^+$), wogonin (m/z; $285[M+H]^+$). These results are consistent with the fragment pattern and molecular weight of standard components from literature.

Antagonistic Activity of Bacteria Isolated from Apple in Different Fruit Development Stages against Blue Mold Caused by Penicillium expansum

  • Lopez-Gonzalez, Rocio Crystabel;Juarez-Campusano, Yara Suhan;Rodriguez-Chavez, Jose Luis;Delgado-Lamas, Guillermo;Medrano, Sofia Maria Arvizu;Martinez-Peniche, Ramon Alvar;Pacheco-Aguilar, Juan Ramiro
    • The Plant Pathology Journal
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    • v.37 no.1
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    • pp.24-35
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    • 2021
  • Blue mold caused by Penicillium expansum is one of the most significant postharvest diseases of apples. Some microorganisms associated with the surface of ripening apples possess the ability to inhibit the growth of P. expansum. However, the existing literature about their colonization in the stages before ripening is not explored in depth. This study aims to characterize the antagonistic capacity of bacterial populations from five fruit development stages of 'Royal Gala' apples. The results have shown that the density of the bacterial populations decreases throughout the ripening stages of fruit (from 1.0 × 105 to 1.1 × 101 cfu/㎠). A total of 25 bacterial morphotypes (corresponding to five genera identified by 16S RNA) were differentiated in which Bacillus stood out as a predominant genus. In the in vitro antagonism tests, 10 Bacillus strains (40%) inhibited the mycelial growth of P. expansum from 30.1% to 60.1%, while in fruit bioassays, the same strains reduced the fruit rot ranging from 12% to 66%. Moreover, the bacterial strains with antagonistic activity increased in the ripening fruit stage. B. subtilis subsp. spiziennii M24 obtained the highest antagonistic activity (66.9% of rot reduction). The matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis revealed that bacteria with antagonistic activity produce anti-fungal lipopeptides from iturin and fengycin families.

Numerical Simulation on the Formation and Pinching Plasma in X-pinch Wires on 2-D Geometry (자기유체역학 코드를 이용한 축 대칭 엑스 핀치 플라즈마 구조의 2차원 전산해석)

  • Byun, Sangmin;Na, Yong-Su;Chung, Kyoung-Jae;Kim, Deok-Kyu;Lee, Sangjun;Lee, Chanyoung;Ham, Seunggi;Ryu, Jonghyeon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.2
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    • pp.211-218
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    • 2021
  • This paper deals with the computational work to characterize the formation and pinching of a plasma in an X-pinch configuration. A resistive magnetohydrodynamic model of a single fluid and two temperature is adopted assuming a hollow conical structure in the (r,z) domain. The model includes the thermodynamic parameter of tungsten from the corrected Thomas-Fermi EOS(equation of state), determining the average ionization charge, pressure, and internal energy. The transport coefficients, resistivity and thermal conductivity, are obtained by the corrected Lee & More model and a simple radiation loss rate by recombination process is considered in the simulation. The simulation demonstrated the formation of a core-corona plasma and intense compression process near the central region which agrees with the experimental observation in the X-pinch device at Seoul National University. In addition, it confirmed the increase in radiation loss rate with the density and temperature of the core plasma.

The distribution and antimicrobial susceptibility of pathogenic microorganisms isolated from chicken slaughtering and processing procedure (닭 도계 및 가공공정 중 유해미생물의 분포와 항생제 감수성)

  • Seol, Kuk-Hwan;Kim, Ki Hyun;Jo, Su-Mi;Kim, Young Hwa;Kim, Hyun-Wook;Ham, Jun-Sang
    • Korean Journal of Agricultural Science
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    • v.42 no.1
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    • pp.29-35
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    • 2015
  • This study was performed to analyze the distribution and antimicrobial resistance of pathogenic microorganisms isolated from the carcass and environments of chicken processing plant located in Gyeonggi province from October to November in 2010. Chicken slaughterhouse was visited 3 times and totally 40 samples were collected from chicken carcass before and after washing (n=14), chicken cuts (n=7), cooling water (n=8), brine (n=2), cutting knives (n=7) and working plate (n=2). Whole-chicken rinsing technique (for chicken carcasses) and swab technique (for working plate and knives) were used to analyze the distribution of pathogenic microorganisms. In addition, brine and chilling water from storage tanks were gathered using sterilized tubes and used as samples. The matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) for whole cell fingerprinting in combination with a dedicated bioinformatic software tool was used to identify the isolated microorganisms. The pathogenic microorganisms, such as Bacillus cereus (n=8) and Staphylococcus aureus (n=9), were isolated form the chicken processing process (chicken carcasses of before and after chilling, chicken cuts, and working plate). The antimicrobial susceptibility of those isolated microorganisms was analyzed using 21 antimicrobial agents. In the case of B. cereus, it showed 100% of resistance to subclasses of penicillins and peptides, and it also resistant to cephalothin, a member of critically important antimicrobials (CIA), however there was no resistance (100% susceptible) to vancomycin and chloramphenicol. S. aureus showed 100% resistance to subclasses of peptides and some of penicillins (penicillin and oxacillin), however, it showed 100% susceptibility to cephalosporins (cefazolin and cephalothin). All of the tested pathogens showed multi drug resistance (MDR) more than 4 subclasses and one of B. cereus and S. aureus showed resistance to 9 subclasses. After the ban on using the antimicrobials in animal feed in July 2011, there would be some change in microbial distribution and antimicrobial resistance, and it still has a need to be analyzed.