• Title/Summary/Keyword: molecular distribution

Search Result 1,397, Processing Time 0.029 seconds

Existence of "25 kDa Thiol Peroxidase" in Retina: Evidence for An Antioxidative Role

  • Cha, Mee-Kyung;Kim, Il-Han
    • BMB Reports
    • /
    • v.31 no.4
    • /
    • pp.409-412
    • /
    • 1998
  • We isolated and sequenced a human retina cDNA fragment that encodes 25 kDa thiol peroxidase. A search of a databank showed that the 25 kDa thiol peroxidase from retina is the same type of thiol peroxidase which exists in human brain and red blood cells. This type of tbiol peroxidase was distributed in all of the tested tissues including retina. This result suggests a physiological role for the 25 kDa thiol peroxidase as an important antioxidant.

  • PDF

Properties of Precursor Pitch Derived from Petroleum Residue

  • Yu, Hae-Il;Lee, Gyu-Dong;Gwon, Yeong-Bae
    • 한국기계연구소 소보
    • /
    • s.15
    • /
    • pp.37-46
    • /
    • 1985
  • Properties of Precursor pitch derived from petroleum residue were studied physical and chemical analysis method for investigation of production of pitch fiber. For preparing of those precursor pitches it was carried out a temperature and time variation experiment i reactor. It was demonstrated the precursor pitch prepared in this study to have a similar properties to Ashland precursor pitch capable of bulk mesophase formation from the results of the basic analysis, that is, molecular weight distribution, coking yield, carbon content, chemical composition, etc.

  • PDF

Intercalation of Ca-montmorillonite with Decylammonium Ion and n-Alcanol (Decylammonium 이온과 n-Alcanol 분자에 의한 Ca-montmorillonite의 Intercalation)

  • 최진호;김창은;형경우
    • Journal of the Korean Ceramic Society
    • /
    • v.20 no.3
    • /
    • pp.205-210
    • /
    • 1983
  • The determination of charge density and charge distribution in montmorillonite are discussed. The method is based on cation exchange of the inorganic interlayer cations against decylammonium ion and molecular intercalation of n-alcanol. The results obtained from Yougil-bentonite show that charge density of 0.37 per unit formula and cation exchange capacity of 102.5 meq/100g.

  • PDF

Analysis of Asphalt Cement Aging Characteristics Using Chromatogram (크로마토그램을 이용한 아스팔트시멘트의 노화형질 분석)

  • 김광우;연규석;박제선
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1991.10a
    • /
    • pp.1-4
    • /
    • 1991
  • Relationship between againg and characteristic change of asphalt is not well known through asphalt rheolopy. Therefore, this study was conducted to evaluate characteristic change of asphalt cement due to againg based on experimental results of chromatogram and selected physical properties. Currently, three virgin asphalt cements were tested for physical properties and chromatograms before and after artificially conditioning for againg. Results in the current study showed that againg caused significant changes of physical properties and increase of larger size molecules and approximately corresponding reduction of smaller size molecule in asphalt cement molecular size distribution.

  • PDF

Fermi Large Area Telescope Observations of the Dark Accelerator HESS J1745-303

  • Yeung, Paul
    • Journal of Astronomy and Space Sciences
    • /
    • v.33 no.4
    • /
    • pp.319-321
    • /
    • 2016
  • Reviewing the two MeV-GeV investigations in the field of the HESS J1745-303 performed using Fermi Large Area Telescope data, we confirmed that the emission peak comfortably coincides with 'Region A' in the TeV regime, which is the brightest part of this feature. The MeV-TeV spectrum can be precisely described by a single power-law. Also, recent investigation has shown that the MeV-GeV feature is elongated from 'Region A' toward the north-west, which is similar to the case of largescale atomic/molecular gas distribution.

Synthesis and Characteristics of Porous Silica Ceramics with Organic Additives(I) (유기물 첨가에 따른 다공성 실리카 세라믹스의 제조 및 특성(I))

  • 신진용;이범재;노재성
    • Journal of the Korean Ceramic Society
    • /
    • v.35 no.9
    • /
    • pp.958-968
    • /
    • 1998
  • Porous silica ceramics were prepared using DCCA(Drying Control Chemical Additives) Such as uncharged polymer(Polyethylene glycol) and protein (Lipase) under H2O/Low-grade TEOS=10 C2H5OH/Low-grade TEOS=1 HC1/Low=grade TEOS=0.01 After Plain which doesn't added DCCA and samples of 11 sorts which varied molecular weight of PEG(Mw=600, 1000, 2000) quantity of Lipase and concentration of wat-er were synthesized gellation time and thermal analysis were investigated. After heat-treated at 600, cry-stal structures analyses of SiO2 polymer and characteristics of pores were investigated. Gellation time was retarded about 2-6 times as compared with plain resulting in addition of DCCA and crystal structures ex-hibited amorphous state. Moreover as increase of water a short gellation time was obtained. The samples added PEG showed increase of specific surface areas up to 20-40% and had micropores while those of Lipase were decreased about 90% and showed broad pore size distribution.

  • PDF

Biogeography and Distribution Pattern of a Korean Wood-eating Cockroach Species, Cryptocercus kyebangensis, Based on Genetic Network Analysis and DNA Sequence Information

  • Park, Yung-Chul;Choe, Jae-Chun
    • Journal of Ecology and Environment
    • /
    • v.30 no.4
    • /
    • pp.331-340
    • /
    • 2007
  • We examined the evolutionary and ecological processes shaping current geographical distributions of a Korean wood-eating cockroach species, Cryptocercus kyebangensis. Our research aims were to understand evolutionary pattern of DNA sequences, to construct genetic network of Cryptocercus kyebangensis local populations and to understand evolutionary and ecological processes shaping their current geographical distribution patterns via DNA sequence information and genetic networks, using sequence data of two genes (ITS-2 and AT region) from local populations of C. kyebangensis. The results suggest that the ITS-2 and AT region are appropriate molecular markers for elucidating C. kyebangensis geographic patterns at the population level. The MSN-A based on the ITS-2 showed two possible routes, the Hwaak-san and Myeongji-san route and the Seorak-san and Gyebang-san route, for migration of ancestral C. kyebangensis into South Korea. The MSNs (MSN-A and -B) elucidate migration routes well within South Korea, especially the route of Group I and Group II.

Distribution of Rhizosphere and Endosphere Fungi on the First-Class Endangered Plant Cypripedium japonicum

  • Gang, Geun-Hye;Cho, Gyeongjun;Kwak, Youn-Sig;Park, Eun-Hee
    • Mycobiology
    • /
    • v.45 no.2
    • /
    • pp.97-100
    • /
    • 2017
  • Endangered native plant habitats and populations are rapidly disappearing because of climate and environmental changes. As a representative, the abundance of the first-class endangered wild plant, Cypripedium japonicum, has been rapidly decreasing in Korea. The purpose of this study was to evaluate the distribution of rhizosphere and endophytic fungi on C. japonicum in its native habitat. A total of 440 rhizosphere and 79 endosphere fungi isolates were isolated and identified on the basis of their molecular characteristics. Sixty-five genera and 119 fungi species were identified in this study. The genus Trichoderma showed the highest abundance among both rhizosphere and endosphere fungi. Mortierella, Hypocrea, and Penicillium spp. were also relatively dominant species on C. japonicum. The community structures of rhizosphere and endosphere fungi were similar, but endosphere fungi showed greater diversity.

Development of Ion Beam Monte Carlo Simulation and Analysis of Focused Ion Beam Processing (이온빔 몬테 카를로 시물레이션 프로그램 개발 및 집속 이온빔 공정 해석)

  • Kim, Heung-Bae
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.29 no.4
    • /
    • pp.479-486
    • /
    • 2012
  • Two of fundamental approaches that can be used to understand ion-solid interaction are Monte Carlo (MC) and Molecular Dynamic (MD) simulations. For the simplicity of simulation Monte Carlo simulation method is widely preferred. In this paper, basic consideration and algorithm of Monte Carlo simulation will be presented as well as simulation results. Sputtering caused by incident ion beam will be discussed with distribution of sputtered particles and their energy distributions. Redeposition of sputtered particles that are experienced refraction at the substrate-vacuum interface additionally presented. In addition, reflection of incident ions with reflection coefficient will be presented together with spatial and energy distributions. This Monte Carlo simulation will be useful in simulating and describing ion beam related processes such as Ion beam induced deposition/etching process, local nano-scale distribution of focused ion beam implanted ions, and ion microscope imaging process etc.