• Title/Summary/Keyword: Molecular Characteristics

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Li-doped p-type ZnS Grown by Molecular Beam Epitaxy

  • Lee Sang-Tae
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.3
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    • pp.313-318
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    • 2005
  • Li-doped ZnS layers were grown by molecular beam epitaxy. It was found that relatively low growth temperature is suitable for effective incorporation of Li acceptors. The layers grown under optimized conditions exhibited photoluminescence spectra dominated by neutral-acceptor-bound excitons. Such layers also showed electrically p-type behavior in capacitance-voltage characteristics. The net acceptor concentration is estimated to be approximately $3{\times}10^{15}\;cm^{-3}$.

Molecular epidemiology of norovirus in South Korea

  • Lee, Sung-Geun;Cho, Han-Gil;Paik, Soon-Young
    • BMB Reports
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    • v.48 no.2
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    • pp.61-67
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    • 2015
  • Norovirus is a major cause of viral gastroenteritis and a common cause of foodborne and waterborne outbreaks. Norovirus outbreaks are responsible for economic losses, most notably to the public health and food industry field. Norovirus has characteristics such as low infectious dose, prolonged shedding period, strong stability, great diversity, and frequent genome mutations. Besides these characteristics, they are known for rapid and extensive spread in closed settings such as hospitals, hotels, and schools. Norovirus is well known as a major agent of food-poisoning in diverse settings in South Korea. For these reasons, nationwide surveillance for norovirus is active in both clinical and environmental settings in South Korea. Recent studies have reported the emergence of variants and novel recombinants of norovirus. In this review, we summarized studies on the molecular epidemiology and nationwide surveillance of norovirus in South Korea. This review will provide information for vaccine development and prediction of new emerging variants of norovirus in South Korea.

Investigation of ultraprecision machining characteristics by molecular statics simulation method (분자정역학 기법을 이용한 초미세 절삭특성에 관한 고찰)

  • 정구현;이성창;김대은
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.3
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    • pp.122-129
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    • 1997
  • Machining technology has emerged to the point of performing atomic-scale fabrication. In tail paper atomic-scale machining characteristics are investigated by using Molecular Statics simulation method. The cutting model used in this work simulates machining with tools such as an AFM. It is shown that built-up edge formation and cutting forces depend on tool tip geometry. Also, the material flow during cutting is shown for various cutting conditions such as depth of cut, rake angle, and edge radius of tool.

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Morphological and Molecular Identification of Penicillium islandicum Isolate KU101 from Stored Rice

  • Oh, Ji-Yeon;Kim, Eui-Nam;Ryoo, Mun-Il;Kim, Ki-Deok
    • The Plant Pathology Journal
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    • v.24 no.4
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    • pp.469-473
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    • 2008
  • We have previously obtained a representative isolate KU101 of the predominant Penicillium species from rice under indoor storage conditions. In this study we attempted to characterize isolate KU101 using its morphological and molecular characteristics. When the micro- and macroscopic characteristics of isolate KU101 were compared with the P. islandicum reference isolate KCCM 34763, isolate KU101 was generally identical to those of isolate KCCM 34763, however, isolate KU101 grew faster and produced more orange to red pigments than isolate KCCM 34763. In a molecular-based identification, the nuclear sequence of the ITS1-5.8S-ITS2 region of isolate KU101 was most closely related to that of P. islandicum. Therefore, these results indicated that isolate KU101 from stored rice could be identified as P. islandicum, some isolates of which are known to produce mycotoxins.

The Enzymatic Characteristics of the Cytidine Deaminase in Salmonella typhimurium

  • Lee, Sang-Mahn
    • Korean Journal of Environmental Biology
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    • v.21 no.1
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    • pp.60-65
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    • 2003
  • The cytidine deaminase was partialy purified with sephadex G-200 and the characteristics of the enzyme were clarified. The molecular mass of the plasmid-encoded protein was identified as about 30 kDa in a minicell system. The native enzyme was estimated to have the molecular mass of 60 kDa by gel filtration. This indicates that the native enzyme may exist as a dimer composed of two identical subunits. The enzyme was reasonably stable in the pH range of 6 to 9, and was labile under high temperature above $50^{\circ}C$. Mercaptoethanol, pCMB, mercury and copper were found to inhibit the enzyme activity. The cytidine analogues of bromo- and iodo-(deoxy)-cytidine were also found to inhibit the activity, while fluorodeoxycytidine and azacytidine were found to activate it. Deoxycytidine, cytidine, ara-C and Methyldeoxycytidine have excellent substrates for the enzyme.

DNA Dynamics under Turbulent Flow

  • Choi, Hyoung-Jin
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.206-206
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    • 2006
  • Polymer induced turbulent drag reduction achieved by adding minute amounts of high molecular weight DNAs in aqueous solution was investigated using a rotating disk apparatus. The DNAs in this study include ${\lambda}-DNA$ and calf-thymus (CT) DNA. By putting emphasis on effect of CT-DNA concentration, its DR characteristics were compared with that of ${\lambda}-DNA$ possessing monodisperse molecular weight characteristics based on both DR efficiency and a mechanical degradation under turbulence. The DNA chains having much higher molecular size than that of ${\lambda}-DNA$ are observed to be more susceptible to mechanical degradation in a turbulent flow. This result was verified via electrophoresis. Furthermore, the coil to globule phase transition of DNA was also investigated under a turbulent flow.

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Characteristics of a Low Molecular Weight Minor Anionic Isoperoxidase $A_{3n}$ from Radish

  • Lee, Mi-Young;Kim, Soung-Soo
    • BMB Reports
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    • v.31 no.6
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    • pp.548-553
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    • 1998
  • A minor anionic isoperoxidase named $A_{3n}$, was isolated from Korean radish (Raphanus sativus L.) root. Purification of the enzyme was accomplished by CMcellulose chromatography, DEAE-Sephacel chromatography, and Sephadex G-75 gel filtration. The enzyme was a glycoprotein with molecular weight of approximately 31,000 as determined by SDS-PAGE and 33,000 by Sepadex G-150 gel filtration, which is by far the smallest among the reported isoperoxidases. The pI value was 3.5. The optimum pH of the enzyme was 6.5 for guaiacol and $H_2O_2$, and the $K_m$ values for guaiacol and $H_2O_2$ were 13.3 mM and 1.5 mM, respectively. Kinetic studies with various substrates revealed that only A3n, unlike other isoperoxidases from radish, did not use scopoletin as a substrate and had very low $K_m$ value of 0.25 mM for ferolic acid among naturally occurring phenolic substrates.

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A Newly Recorded Sea Star of the Genus Luidia (Asteroidea: Paxillosida: Luidiidae) from the Korea Strait, Korea

  • Kim, Donghwan;Kim, Minkyung;Shin, Sook
    • Animal Systematics, Evolution and Diversity
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    • v.33 no.2
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    • pp.131-135
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    • 2017
  • Asteroid specimens of the genus Luidia were collected at a depth of 95-100 m in the Korea Strait by bottom trawling in April 2016. The specimens were identified as Luidia avicularia Fisher, 1913 (Luidiidae: Paxillosida) based on morphological characteristics and molecular phylogenetic analyses, and the species is new to the Korean fauna. A 648-bp partial nucleotide sequence of mitochondrial cytochrome c oxidase I (mt-COI) gene was obtained from Korea, and then was compared to sequences of related species stored in GenBank using molecular phylogenetic analyses. No sequence differences were detected between the L. avicularia mt-COI gene sequences from Korea and China, and the species described in this report was clearly distinct from L. maculata, which was previously reported in Korean fauna. Three Luidia species have been reported in Korea.

A narrative review of genomic characteristics, serotype, immunogenicity, and vaccine development of Streptococcus pneumoniae capsular polysaccharide

  • Ratna Fathma Sari;Fadilah Fadilah;Yustinus Maladan;Rosantia Sarassari;Dodi Safari
    • Clinical and Experimental Vaccine Research
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    • v.13 no.2
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    • pp.91-104
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    • 2024
  • This narrative review describes genomic characteristic, serotyping, immunogenicity, and vaccine development of Streptococcus pneumoniae capsular polysaccharide (CPS). CPS is a primary virulence factor of S. pneumoniae. The genomic characteristics of S. pneumoniae CPS, including the role of biosynthetic gene and genetic variation within cps (capsule polysaccharide) locus which may lead to serotype replacement are still being investigated. One hundred unique serotypes of S. pneumoniae have been identified through various methods of serotyping using phenotypic and genotypic approach. The advantages and limitations of each method are various, emphasizing the need for accurate and comprehensive serotyping for effective disease surveillance and vaccine targeting. In addition, we elaborate the critical role of CPS in vaccine development by providing an overview of immunogenicity, ongoing research of pneumococcal vaccines, and the impact on disease burden.

Morphological and molecular analysis of indigenous Myanmar mango (Mangifera indica L.) landraces around Kyaukse district

  • Kyaing, May Sandar;Soe, April Nwet Yee;Myint, Moe Moe;Htway, Honey Thet Paing;Yi, Khin Pyone;Phyo, Seinn Sandar May;Hlaing, Nwe Nwe Soe
    • Journal of Plant Biotechnology
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    • v.46 no.2
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    • pp.61-70
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    • 2019
  • There is vast genetic diversity of Myanmar Mangoes. This study mainly focused on indigenous thirteen different mango landraces cultivated in central area of Myanmar, Kyauk-se District and their fruit characteristics by 18 descriptors together with genetic relationship among them by 12 SSR markers. Based on the morpho-physical characters, a wide variation among accessions was found. Genetic characterization of thirteen mango genotypes resulted in the detection of 302 scorable polymorphic bands with an average of 4.33 alleles per locus and an average polymorphism information content (PIC) of 0.7. All the genotypes were grouped into two major clusters by UPGMA cluster analysis and a genetic similarity was observed in a range of 61 ~ 85%. This study may somehow contribute insights into the identification of regional mango diversity in Myanmar and would be useful for future mango breeding program.