• Title/Summary/Keyword: Molecular evolution

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ALMA/ACA CO (1-0) observations of group galaxies

  • Lee, Bumhyun;Wang, Jing;Chung, Aeree;Ho, Luis C.;Wang, Ran;Shao, Li;Michiyama, Tomonari;Wang, Shun;Peng, Eric W.;Kilborn, Virginia
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.64.1-64.1
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    • 2020
  • Galaxy groups are the place where many galaxies feel the impact of the surroundings (e.g., merging, tidal interaction, ram pressure stripping) before joining bigger structures like (sub)clusters. A significant fraction of galaxies is quenched in the group environment. Such "pre-processing" of galaxies in groups is likely to affect galaxy evolution tremendously. To better understand how environmental processes in galaxy groups affect molecular gas, star formation activity, and galaxy evolution, we carried out CO imaging observations of group galaxies, using the Atacama Compact Array (ALMA/ACA). We selected all the targets that have been detected in the GEMS-HI survey for two groups, making the sample of 40 galaxies (18 galaxies in IC 1459 group and 22 galaxies in NGC 4636 group). Our ALMA/ACA observation is the first CO imaging survey for two groups. In this work, we present CO images of group galaxies, together with their star formation maps and HI images. Our ACA CO data show the asymmetric distribution of molecular gas in some of our samples. We discuss the impact of the group environment on molecular gas and star formation activity.

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A Study on Physiological conditions for hydrogen evolution by Rhodopseudomonass phaeroides K-7 (Rhodopseudomonas sphaeroides K-7에 의한 수소생성에 미치는 생리적 조건에 관한 연구)

  • Bae, Moo;Lee, Jeong-Kug
    • Korean Journal of Microbiology
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    • v.21 no.3
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    • pp.109-114
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    • 1983
  • Physiological conditions for hydrogen evolution by Rhodopseudomonas sphaeroides K-7 are examined. Larger amount of molecular hydrogen was evolved at $30^{\circ}C$, pH6.8-7.0 under anaerobically illuminated condition of about 12, 000 lux by the organism. The heighest rates of hydrogen evolution were observed in the culture with the organic acids such as acetate, DL-lactate or DL-malate in media containing L-glutamate as a nitrogen source. Hydrogen was also evolved from glucose with the rate of $178.9\;{\mu}l/hr/mg$ cells (dry weight). When glucose was adopted a a sole carbon source, however, conside erable time lag of about 20hours was required for hydrogen evolution. The resting cells stored at $30^{\circ}C$ under argon maintained the rate of hydrogen evolution in nearly about 90% of initial one even 40 days of storation.

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Aptamers as Functional Nucleic Acids: in vitro Selection and Biotechnological Applications

  • You, Kyung-Man;Lee, Sang-Hyun;Aesul Im;Lee, Sun-Bok
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.2
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    • pp.64-75
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    • 2003
  • Aptamers are functional nucleic acids that can specially bind to proteins, peptides, amino acids. nucleotides, drugs, vitamins and other organic and inorganic compounds. The aptamers are identified from random DNA or RNA libraries by a SELEX (systematic evolution of ligands by exponential amplification) process. As aptamers have the advantage, and potential ability to be released from the limitations of antibodies, they are attractive to a wide range of therapeutic and diagnostic applications. Aptamers, with a high-affinity and specificity, could fulfil molecular the recognition needs of various fields in biotechnology. In this work, we reviewed some aptamer Selection techniques, properties, medical applications of their molecules and their biotechnological applications, such as ELONA (enzyme linked oligonucleotide assay), flow cytometry, biosensors, electrophoresis, chromatography and microarrays.

Time-Resolved Infrared Spectroscopy of Molecular Reorientation During FLC Electro-Optic Switching

  • Jang, Won-Gun;Clark, Noel A.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1112-1117
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    • 2003
  • Polarized Fourier transform infrared (IR) absorption is used to probe molecular conformation in a ferroelectric liquid crystal (FLC) during the reorientation induced by the external field. Spectra of planar aligned cells of FLC W314 are measured as functions of IR polarizer orientation and electric field applied to the FLC. The time evolution of the dichroism of the absorbance due to biphenyl core and alkyl tail molecular vibration modes, is observed. Static IR dichroism experiments show a W314 dichroism structure in which the principal axis of dielectric tensor from molecular core vibration are tilted further from the smectic layer normal than those of the tail. This structure indicates the effective binding site in which the molecules are confined in the Sm-C phase has, on average, "zig-zag" shape and this zig-zag binding site structure is rigidly maintained while the molecular axis rotates about the layer normal during field-induced switching.

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A Taxonomic Study on Perinereis nuntia Species Group (Polychaeta: Nereididae) of Korea

  • Park, Tae-Seo;Kim, Won
    • Animal Systematics, Evolution and Diversity
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    • v.23 no.1
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    • pp.75-85
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    • 2007
  • A taxonomic study was carried out on the Perinereis nuntia species group of Korea by using morphological and molecular data (mitochondrial cytochrome c oxidase subunit I: mtCOI). Two species, P. mictodonta (Marenzeller, 1879) and P. wilsoni (Glasby and Hsieh, 2006), are recognized and redescribed. In this study, mtCOI gene showed a good resolution as molecular marker for species identification of the P. nuntia species group of Korea.

The Marine Amphipod Crustaceans of Ulreung Island, Korea : Part II (울릉도 해역의 단각류(갑각류) II)

  • Kim, Won;Kim, Chang-Bae
    • Animal Systematics, Evolution and Diversity
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    • v.7 no.1
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    • pp.13-38
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    • 1991
  • This study on the five families (Anamixidae, Colomastigidae, Eophliantidae, Eusiridae, and Hyalidae) of fammaridean amphipods of Ulreung Island was based on the materials collected at eight localities in Ulreung Island. Nine speices of seven genera were identified. Of these, three (Paranamixis denticulus, Colomastix prionotos, and Hyale bisaeta) were new to science. Three species (Ceinina japonica, Eusiroides monoculoides japonicus, and Allorchestes angusta) were new recordsfor Korean waters. These six species were descirbed with illustrations.

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Two species of Porcellidiidae (Copepoda, Harpacticoida) associated with hermit crabs from Korea (한국산 집게류에 공생하는 요각류 2종)

  • Kim, Sa-Heung;Kim, Won
    • Animal Systematics, Evolution and Diversity
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    • v.12 no.4
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    • pp.375-387
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    • 1996
  • Two species of the family Porcellidiidae associated with hermit crabs are described from Korean seas. These are Porcellidium similis, new species collected from Pagurus similis, Pagurus pectinatus and Porcellidium brevicaudatum Kicks & Webber collected from Dardanus impressus. The new species resemble closely Porcellidium brevicaudatum in general body form, but is clearly distinguished from Porcellidium vrevicaudatum in that the caudal ramus is weakly oblique in tis distal border and the lobe of leg 5 is more slender.

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Verification of Kinetic Theoretical Prediction of Diffusion-influenced Reversible

  • Yang, Min O;Sin, Guk Jae
    • Bulletin of the Korean Chemical Society
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    • v.21 no.1
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    • pp.93-96
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    • 2000
  • A diffusion-influenced pseudo-first order reversible reaction A + B ⇔C + B is investigated by the molecular dynamics (MD) simulation method. Theoretical finding that the temporal evolution of reactants [conditional probabilities] in the reversible system can be expressed by the irreversible survival probability with an effective rate parameter is confirmed even in the presence of solvent particles. We carry out molecular dynamics simulations for both the irreversible and the reversible cases to evaluate the survival and the conditional probabilities for each cases. When the resultant irreversible survival probability is inserted into the proposed relation, the conditional probabilities given by the simulation are exactly reproduced.

Integrated diagnostic approach of pediatric neuromuscular disorders

  • Lee, Ha Neul;Lee, Young-Mock
    • Journal of Genetic Medicine
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    • v.15 no.2
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    • pp.55-63
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    • 2018
  • Clinical and genetic heterogeneity in association with overlapping spectrum is characteristic in pediatric neuromuscular disorders, which makes confirmative diagnosis difficult and time consuming. Considering evolution of molecular genetic diagnosis and resultant upcoming genetically modifiable therapeutic options, rapid and cost-effective genetic testing should be applied in conjunction with existing diagnostic methods of clinical examinations, laboratory tests, electrophysiologic studies and pathologic studies. Earlier correct diagnosis would enable better clinical management for these patients in addition to new genetic drug options and genetic counseling.

Extracting Frequency-Frequency Correlation Function from Two-Dimensional Infrared Spectroscopy: Peak Shift Measurement

  • Kwak, Kyung-Won
    • Bulletin of the Korean Chemical Society
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    • v.33 no.10
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    • pp.3391-3396
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    • 2012
  • Two-dimensional infrared (2D-IR) spectroscopy can probe the fast structural evolution of molecules under thermal equilibrium. Vibrational frequency fluctuation caused by structural evolution produced the time-dependent line shape change in 2D-IR spectrum. A variety of methods has been used to connect the evolution of 2D-IR spectrum with Frequency-Frequency Correlation Function (FFCF), which connects the experimental observables to a molecular level description. Here, a new method to extract FFCF from 2D-IR spectra is described. The experimental observable is the time-dependent frequency shift of maximum peak position in the slice spectrum of 2D-IR, which is taken along the excitation frequency axis. The direct relation between the 2D-IR peak shift and FFCF is proved analytically. Observing the 2D-IR peak shift does not need the full 2D-IR spectrum which covers 0-1 and 1-2 bands. Thus data collection time to determine FFCF can be reduced significantly, which helps the detection of transient species.