• Title/Summary/Keyword: Ionization development

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Installation and Test Run of Comprehensive Analysis System for SF6 in Power Equipment

  • Lee, Jeong Eun;Kim, Kwang Sin;Kim, Ah Reum;Park, Seoksoon;Kim, Kyeongsook
    • KEPCO Journal on Electric Power and Energy
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    • v.3 no.1
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    • pp.41-47
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    • 2017
  • After $SF_6$, which is being used in power equipment as an insulating material, is classified as one of the 6 major greenhouse gases, the maintenance and the refinement of used $SF_6$ started to get attention. In regard to this, KEPCO Research Institute (KEPRI) is developing $SF_6$ recovery and refinement technology starting with establishing a comprehensive $SF_6$ analysis system. With the analysis system, qualitative and quantitative analyses of the purity and the impurities of $SF_6$ before and after recovery, and before and after refinement have been carried out. The analysis system is comprised of GC-DID (Gas Chromatograph -Discharge Ionization Detector) for trace impurities analysis, GC-TCD (Thermal Conductivity Detector) for analyses of $SF_6$ purity and major impurities concentration from several hundred ppm up to percent range, GC-MSD (Mass Selective Detector) for analyses of impurities not included in standard gas, FT-IR (Fourier Transform-Infrared) Spectrometer for analysis of HF and $SO_2$, and moisture analyzer for analysis of moisture below 100 ppm. With this analysis system, complete analysis method of $SF_6$ has been established. This analysis system is being used in the maintenance of power equipment and the development of $SF_6$ recovery and refinement technologies. In this paper, the analysis results of four samples - gas and liquid phase $SF_6$ samples from a $SF_6$ refinement system before and after refinement are presented.

A design of radiation hardened common signal processing module for sensors in NPP (내방사선 원전센서 공통 신호처리 모듈 설계)

  • Lee, Nam-ho;Hwang, Young-gwan;Kim, Jong-yeol;Lee, Seung-min
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.6
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    • pp.1405-1410
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    • 2015
  • In this study we designed the radiation-hardened sensor signal processing modules that can be commonly used for a variety of sensors during normal operation and even in high-radiation environments caused by an accident. First development module was designed to receive the change of the R and C value from the sensors and to process the signal as a PWM modulation scheme. This module was assessed to have ± 10% error to the Full-Scale in the radiation test in the range of 12 kGy TID. The main cause of the error was analyzed as the annealing of the common circuit in the switching element and the consequent increase in the duty ratio of the pulse width modulation circuit according to the radiation dose increasement. The redesigned module for higher radiation resistivity with Stub transistor circuit was found to have less than 5% error to the Full-scale from the radiation test results for 20.7 kGy TID range.

Identification of Diapause and Non-diapause Associated Proteins in the Eggs of Multivoltine Silkworm Bombyx mori by MALDI MS Analysis

  • Saravanakumar, Ragunathan;Ponnuvel, Kangayam M.;Velu, Dhanikachalam;Koundinya, Panguluri R.;Sinha, Randir K.;Qadri, Syed M. Hussaini
    • International Journal of Industrial Entomology and Biomaterials
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    • v.16 no.2
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    • pp.37-48
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    • 2008
  • The diapause and non diapause associated proteins of multivoltine silkworm eggs were analysed by two dimensional (2D) gel electrophoresis. The study was made at 0 hr, 24 hrs and 48 hrs after oviposition. A total of four protein spots in diapause eggs at 24 hrs of oviposition and two protein spots in non diapause eggs at 0 hrs of oviposition were observed. All the six protein spots were considered to have association with diapause and non diapause characters. The molecular weight (MW) and isoelectric point (PI) of these 6 protein spots were calculated. The protein spots 1 and 2 observed in 0 hr of non diapause eggs were found to have the MW of 67 and 75 KDa and PI of 8.6 and 8.4 respectively. Similarly the four protein spots observed in diapause egg at 24 hrs of oviposition exhibited MW viz., 15, 17,20 and 25 KDa and PI of 5.3, 5.8, 6.5 and 6.0 respectively. All these 6 identified protein spots were subjected to in-gel digestion and resulted tryptic peptides were analyzed by Matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI TOF-MS). Databases searched based on experimentally determined molecular weights of peptides for the determination of the identities of proteins. The identified proteins indicated homology of 34% to 95%. The results indicate that the proteins may playa role in development of diapause and non diapause eggs.

International Standards Activities for ISO/TC 112 Vacuum Technology (ISO/TC 112 Vacuum Technology 국제표준 활동)

  • Hong, S.S.;Shin, Y.H.;Kim, J.T.;Chung, K.H.;Choi, H.K.;Kim, I.S.;Park, W.Y.
    • Journal of the Korean Vacuum Society
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    • v.16 no.6
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    • pp.397-404
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    • 2007
  • International Standardization for Vacuum pumps, vacuum instruments, and vacuum components has been established at ISO/TC 112 which is a technical committee of ISO (International Organization for Standardization) in the area of vacuum technology. This report shortly summarizes the structure of ISO/TC 112 and its activities on the standardization for vacuum technology. Also it introduces the brief contents of "specifications for hot cathode ionization gauges" and"Test procedure for vacuum valves" which are recently accepted as new proposals. These information on ISO/TC 112 would contribute to activate the development of vacuum technology as well as the participation for the international standardization in Korea.

Comparison of Protein Profiles of Proso Millet (Panicum miliaceum) Seeds of Various Korean Cultivars

  • Roy, Swapan Kumar;Kwon, Soo-Jeong;Yu, Je-Hyeok;Sarker, Kabita;Cho, Seong-Woo;Moon, Young-Ja;Jung, Tae-Wook;Park, Cheol-Ho;Woo, Sun-Hee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.62 no.1
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    • pp.40-50
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    • 2017
  • Seed storage proteins are used as carbon and nitrogen sources for the nutritional improvement of seeds. Since the composition of proteins from the Korean cultivars of proso millet is unknown, this study was conducted to obtain a reference map of millet seed proteins and identify the functional characteristics of the identified proteins. Proteins extracted from proso millet seeds of various cultivars were investigated using proteomic techniques such as 2-D electrophoresis coupled with mass fingerprinting; 1152 (differentially expressed) protein spots were detected on the 2-D gels. Among them, 26 reproducible protein spots were analyzed using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry. Out of the 26 proteins, 2 proteins were upregulated in all the millet cultivars, while 13 proteins were upregulated and 11 proteins were downregulated in 2 cultivars. Abundance of most of the identified protein species associated with polysaccharide and starch metabolism, transcription, and pathogenesis was significantly enhanced, while that of other protein species involved in glycolysis, stress response, and transduction was severely reduced. Taken together, the results suggest that the differential expression of the proteins from the four millet cultivars may be cultivar-specific. By conducting a proteomic investigation of millet seeds from different cultivars, we sought to better understand the functional categorization of individual proteins on the basis of their molecular functions. We believe that the identified proteins may help in investigating genetic variations in millet cultivars.

Proteomic Analysis of Outer Membrane Proteins in Salmonella enterica Enteritidis

  • Cho, Youngjae;Park, Soyeon;Barate, Abhijit Kashinath;Truong, Quang Lam;Han, Jang Hyuck;Jung, Cheong-Hwan;Yoon, Jang Won;Cho, Seongbeom;Hahn, Tae-Wook
    • Journal of Microbiology and Biotechnology
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    • v.25 no.2
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    • pp.288-295
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    • 2015
  • Salmonella enterica serovar Enteritidis is the predominant agent causing salmonellosis in chickens and other domestic animals. In an attempt to identify antigenic S. Enteritidis outer membrane proteins (OMPs) that may be useful for subunit vaccine development, we established a proteomic map and database of antigenic S. Enteritidis OMPs. In total, 351 and 301 spots respectively from S. Enteritidis strain 270 and strain 350 were detected by two-dimensional gel electrophoresis. Fifty-one antigen-reactive spots were detected by antisera on two-dimensional immunoblots and identified as 12 specific proteins by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. OmpA and DNA starvation/stationary phase protection protein (Dps) were the most abundant proteins among the identified OMPs, comprising 22 and 12 protein species, respectively. Interestingly, we found that the Dps of S. Enteritidis is also antigenic. OmpW was also verified to have high antigenicity. These results show that OmpA, Dps, and possibly OmpW are antigenic proteins. This study provides new insights into our understanding of the immunogenic characteristics of S. Enteritidis OMPs.

Development of Isotope Dilution LC-MS/MS Method for Accurate Determination of Arsenobetaine in Oyster Certified Reference Material

  • Lee, Woo Young;Yim, Yong-Hyeon;Hwang, Euijin;Lim, Youngran;Kim, Tae Kyu;Lee, Kyoung-Seok
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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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.

A Proteomics Based Approach Reveals Differential Regulation of Visceral Adipose Tissue Proteins between Metabolically Healthy and Unhealthy Obese Patients

  • Alfadda, Assim A.;Masood, Afshan;Al-Naami, Mohammed Y.;Chaurand, Pierre;Benabdelkamel, Hicham
    • Molecules and Cells
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    • v.40 no.9
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    • pp.685-695
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    • 2017
  • Obesity and the metabolic disorders that constitute metabolic syndrome are a primary cause of morbidity and mortality in the world. Nonetheless, the changes in the proteins and the underlying molecular pathways involved in the relevant pathogenesis are poorly understood. In this study a proteomic analysis of the visceral adipose tissue isolated from metabolically healthy and unhealthy obese patients was used to identify presence of altered pathway(s) leading to metabolic dysfunction. Samples were obtained from 18 obese patients undergoing bariatric surgery and were subdivided into two groups based on the presence or absence of comorbidities as defined by the International Diabetes Federation. Two dimensional difference in-gel electrophoresis coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was carried out. A total of 28 proteins were identified with a statistically significant difference in abundance and a 1.5-fold change (ANOVA, $p{\leq}0.05$) between the groups. 11 proteins showed increased abundance while 17 proteins were decreased in the metabolically unhealthy obese compared to the healthy obese. The differentially expressed proteins belonged broadly to three functional categories: (i) protein and lipid metabolism (ii) cytoskeleton and (iii) regulation of other metabolic processes. Network analysis by Ingenuity pathway analysis identified the $NF{\kappa}B$, IRK/MAPK and PKC as the nodes with the highest connections within the connectivity map. The top network pathway identified in our protein data set related to cellular movement, hematological system development and function, and immune cell trafficking. The VAT proteome between the two groups differed substantially between the groups which could potentially be the reason for metabolic dysfunction.

Virus-induced Silencing of the WRKY1 Transcription Factor that Interacts with the SL1 Structure of Potato virus X Leads to Higher Viral RNA Accumulation and Severe Necrotic Symptoms

  • Park, Sang-Ho;Kim, Kook-Hyung
    • The Plant Pathology Journal
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    • v.28 no.1
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    • pp.40-48
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    • 2012
  • $Potato$ $virus$ $X$ (PVX) replication is precisely regulated by regulatory viral sequences and by viral and/or host proteins. In a previous study, we identified a 54-kDa cellular tobacco protein that bound to a region within the first 46 nucleotides (nt) of the 5' non-translated region (NTR) of the viral genome. Optimal binding was dependent upon the presence of an ACCA sequence at nt 10-13. To identify host factors that bind to 5' NTR elements including AC-rich sequences as well as stemloop 1 (SL1), we used northwestern blotting and matrixassisted laser desorption/ionization time-of-flight mass spectrometry for peptide mass fingerprinting. We screened several host factors that might affect PVX replication and selected a candidate protein, $Nicotiana$ $tabacum$ WRKY transcription factor 1 (NtWRKY1). We used a $Tobacco$ $rattle$ $virus$ (TRV)-based virus-induced gene silencing (VIGS) system to investigate the role of NtWRKY1 in PVX replication. Silencing of $WRKY1$ in $Nicotiana$ $benthamiana$ caused lethal apical necrosis and allowed an increase in PVX RNA accumulation. This result could reflect the balancing of PVX accumulation in a systemic $N.$ $benthamiana$ host to maintain PVX survival and still produce a suitable appearance of mosaic and mottle symptoms. Our results suggest that PVX may recruit the WRKY transcription factor, which binds to the 5' NTR of viral genomic RNA and acts as a key regulator of viral infection.

Association of polymorphisms in Pit-1 gene with growth and feed efficiency in meat-type chickens

  • Jin, Sihua;He, Tingting;Yang, Lei;Tong, Yucui;Chen, Xingyong;Geng, Zhaoyu
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.11
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    • pp.1685-1690
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    • 2018
  • Objective: The pituitary specific transcription factor-1 (Pit-1) gene is responsible for pituitary development and growth hormone expression and is regarded as a pivotal candidate gene for growth and production in chickens. Therefore, the aim of this study was to investigate the association of Pit-1 polymorphisms with growth and feed efficiency traits in yellow meat-type chickens. Methods: In the present study, five single nucleotide polymorphisms (SNPs) of Pit-1 were selected and genotyped by high-throughput matrix-assisted laser desorption-ionization time-of-flight mass spectrometry in 724 meat-type chickens. Results: Association analysis showed that rs13687126 of Pit-1 was strongly associated with body weight gain (BWG) and feed intake (FI) (p<0.05), and that rs13687128 was significantly correlated with body weight at 70 days of age (BW70), BWG and feed conversion ratio (FCR) (p<0.05). SNP rs13905622 was strongly related to BW70 and FCR (p<0.05). Furthermore, birds with the GG genotype of rs13687126 had larger BWG and FI than those with the AG genotype (p<0.05). Individuals with the TT genotype of rs13687128 were significantly higher BW70 and BWG than those of the CT and CC genotype, while FCR was just the opposite (p<0.05). For rs13905622, the AA chickens showed strongly larger BW70 and lower FCR compared with the AT and TT chickens (p<0.05). Additionally, an ACA haplotype based on rs13687126, rs13687128, and rs13905622 had significant effects on BW70 and FCR (p<0.05). Conclusion: Our studies thus provide crucial evidence for the relationship between polymorphisms of Pit-1 and growth and feed efficiency traits which may be useful for meat-type chicken breeding programs.