• Title/Summary/Keyword: molecular distribution

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Trace Organic Contaminants in Sediments from Deep-sea Basin near Dokdo, Korea

  • Yim, Un-Hyuk;Oh, Jae-Ryoung;Hong, Sang-Hee;Li, Dong-Hao;Shim, Won-Joon;Choi, Hye-Kyung;Kim, Eun-Soo;Shim, Jae-Hyung
    • Ocean and Polar Research
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    • v.24 no.4
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    • pp.391-398
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    • 2002
  • Trace organic contaminants in deep-sea sediments near Dokdo were analyzed. Total PAMs concentration ranged 14.8-314 ng/g dry weight and high molecular weight PAHs were dominant. The highest PAHs concentration was detected at A19 which located at Ulleung Basin. Most of organochlorines were under detection limit. Among the detected organochlorines, DDT compounds were dominant and followed by HCHs and HCB. Butyltin compounds and most of organophosphorus pesticides were not detected. Vertical distribution of PAHs showed typical sub-surface maximum and decreasing trends depending on depth. The highest PAHs concentration reached 454ng/g. Some organochlorines, DDT, HCH was detected and also showed decreasing trends. Other target organic pollutants were not detected in core sediments. Abnormally high level of PAHs concentration in A19 was discussed and the input sources were inferred to be the transport of sludge derived pollutant dumped at dumping site 'Byung' by deep current.

Performance and antifouling properties of PVDF/PVP and PSf membranes in MBR: A comparative study

  • Hazrati, Hossein;Karimi, Naser;Jafarzadeh, Yoones
    • Membrane and Water Treatment
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    • v.11 no.2
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    • pp.159-166
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    • 2020
  • In this study, the performance and antifouling properties of polysulfone (PSf) and polyvinylidene fluoride/polyvinylpyrrolidone (PVDF/PVP) membranes in a membrane bioreactor (MBR) were investigated. The membranes were prepared via phase inversion method, and then characterized by a set of analyses including contact angle, porosity and water flux and applied in a lab-scale MBR system. Soluble microbial product (SMP), extracellular polymeric substance (EPS), FTIR, gel permission chromatography (GPC) and particle size distribution (PSD) analyses were also carried out for MBR system. The results showed that the MBR with PSf membrane had higher hydrophobic organic compounds which resulted in formation of larger flocs in MBR. However, in this MBR had high compressibility coefficient of cake layer was higher (n=0.91) compared to MBR with PVDF/PVP membrane (n=0.8); hence, the fouling was more profound. GPC analysis revealed that compounds with molecular weight lower than 2 kDa are more formed on PSf membrane more than PVDF/PVP membrane. The results of FTIR analysis confirmed the presence of polysaccharide and protein compounds on the cake layer of both membranes which was in good agreement with EPS analysis. In addition, the results showed that their concentration was higher for the cake on PSf membrane.

Estimated Photodegradation Properties of Acetanilide Using AOPWIN (AOPWIN을 이용한 Acetanilide의 광부해 특성 평가)

  • 권민정;최윤호;송상환;박혜연;구현주;전성환;나진균;박광식
    • Environmental Analysis Health and Toxicology
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    • v.16 no.3
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    • pp.139-142
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    • 2001
  • Acetanilide is a High Production Volume Chemical, which is produced about 2,300 tons/year in Korea as of 1998 survey. Most is used as an intermediate for synthesis of pharmaceuticals and dyes, and the chemical is one of seven chemicals of which human and environmental risk are being assessed by National Institute of Environmental Research under the frame of OECD SIDS program. The Atmospheric Oxidation Program for Microsoft Windows (AOPWIN) is used to estimates the rate constant for the atmospheric, gas-phase reaction between photochemically produced hydroxyl radicals and organic chemicals. It is also used to estimates the rate constant for the gas-phase reaction between ozone and olefinic/acetylenic compounds. The rate constants estimated by the program are then used to calculate atmospheric half-lives for organic compounds based upon average atmospheric concentrations of hydroxyl radicals and ozone. AOPWIN requires only a chemical structure to make these predictions. Structures are entered into AOPWIN by SMILES (Simplified Molecular Input Line Entry System) notations. In this study, one of environmental fate/distribution of the chemical elements, photodegradation of acetanilide was estimated using AOPWIN model based on SMILES notation and chemical name data.

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The Properties of Amylose of Cow Pea Starch (동부 전분의 아밀로오스 특성)

  • Kweon, Mee-Ra;Ahn, Seung-Yo
    • Applied Biological Chemistry
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    • v.33 no.1
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    • pp.39-42
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    • 1990
  • The properties of amylose of cow pea starch were investigated. Amylose content of cow pea was 25.1 % and iodine binding capacity was 20.2 %. The ${\beta}-amylolysis$ limit of the amylose was 82.3%. The limiting viscosity number of the amylose fraction was 204 ml/g and the corresponding average degree of polymerization was 1,510 glucose units. The percent distribution of molecular weight of the amylose by gel chromatography was $1{\times}10^4$(0.7 %), $1{\times}10^4{\sim}4{\times}10^4$(4.1 %), $4{\times}10^4{\sim}5{\times}10^5$(44.6 %), $5{\times}10^5{\sim}4{\times}10^7$(49.6 % ).

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Biodiversity and Conservation of Indian Sheep Genetic Resources - An Overview -

  • Bhatia, S.;Arora, R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.10
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    • pp.1387-1402
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    • 2005
  • Indian subcontinent is a rich source of diverse ovine germplasm, and only very few countries have such a large number of breeds with wide genetic diversity. This vast ovine biodiversity in India is being eroded rapidly and more than 50% of sheep breeds are currently under threat. It is noteworthy that the characterization of Indian sheep breeds was last done in the first half of the century since then no recent estimates are available and surveys in majority of the regions/breeds are far from complete. Starting in 1985 National Bureau of Animal Genetic Resources (NBAGR), Karnal, India, therefore, initiated activities aimed at determining the status and compiling information on indigenous farm animals including sheep. This report represents attempts made to date on the basis of field/literature surveys and additional activities on molecular characterization to ascertain their status including distribution, population changes, breed diversities and risk status. The need, mode and mechanisms of conservation are also described. Involvement of several agencies for evaluation, improvement, conservation programmes and recommendations made for effective characterization and conservation of sheep biodiversity are highlighted. This publication would promote action particularly at national level to improve the information base on domestic Indian breeds of sheep and provide input into national domestic sheep diversity conservation policy decisions.

Phylogeography and Population Genetic Structure of Amur Grayling Thymallus grubii in the Amur Basin

  • Ma, Bo;Lui, Tingting;Zhang, Ying;Chen, Jinping
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.7
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    • pp.935-944
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    • 2012
  • Amur grayling, Thymallus grubii, is an important economic cold freshwater fish originally found in the Amur basin. Currently, suffering from loss of habitat and shrinking population size, T. grubii is restricted to the mountain river branches of the Amur basin. In order to assess the genetic diversity, population genetic structure and infer the evolutionary history within the species, we analysised the whole mitochondrial DNA control region (CR) of 95 individuals from 10 rivers in China, as well as 12 individuals from Ingoda/Onon and Bureya River throughout its distribution area. A total of 64 variable sites were observed and 45 haplotypes were identified excluding sites with gaps/missing data. Phylogenetic analysis was able to confidently predict two subclade topologies well supported by maximum-parsimony and Bayesian methods. However, basal branching patterns cannot be unambiguously estimated. Haplotypes from the mitochondrial clades displayed local homogeneity, implying a strong population structure within T. grubii. Analysis of molecular variance detected significant differences among the different geographical rivers, suggesting that T. grubii in each river should be managed and conserved separately.

Distribution between Air-Soil Concentration of Organochlorine Pesticides (유기염소계 살충제의 대기-토양간 분배)

  • Choi, Min-Kyu;Chun, Man-Young
    • Environmental Analysis Health and Toxicology
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    • v.22 no.4
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    • pp.299-304
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    • 2007
  • This paper was studied to investigate the equilibrium state between organochlorine pesticides (OCPs) concentration of air and soil, and to know whether soil is a secondary pollution source of OCPs in air or not. The OCPs concentration of air ($C_{air}$) and soil ($C_{soil}$) is not related to molecular weight, vapor pressure ($P_L$) and octanol-air partition coefficient ($K_{oa}$). The slope of the regression line between soil-air partition coefficient ($K_{sa}$) and scavenging coefficient ($C_{soil}/C_{air}$) was 0.2952, which the OCPs concentration between air and soil did not reached to the equilibrium state. The soil/air fugacity quotients ($f_{soil}/f_{air}$) of p, p'-DDT/DDD/DDE and ${\beta}-HCH\;(0.30{\sim}0.67$), which is smaller than 1, means the deposit of OCPs from air to soil. However, $f_{soil}/f_{air}$ of heptachlor, heptachlor epoxide, ${\alpha}/{\gamma}-chlordane$, trans-nonachlor, endosulfan sulfate and ${\alpha}/{\gamma}-HCH\;(1.90{\sim}73.25)$, which is greater than 1, means that soil is secondary pollution source of OCPs in air.

A Physicochemical Characteristics and Manufacture of Solubility Collagen Peptide from Flatfish Skin (당가자미 껍질로부터 수용성콜라겐 제조 및 이화학적 특성)

  • Jang, Boo-Sik;Lee, Mi-Jin;Jeong, Noh-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.3
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    • pp.560-566
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    • 2013
  • In this research we extracted water-soluble collagen peptide from flatfish skin and compared it with commercially available collagen peptide extracted from Tilapia scale currently placed on the market in the aspect of physiochemical property. The physical property and nutritional components of FSCP appeared almost similarly to those of TSCP, and also in calorie, FSCP marking 3.82 Kcal showed no differences from TSCP marking 3.84 Kcal. As for forming amino acids, in aspartic acid, serine, histidine, tyrosine, methionine, FSCP had higher content than TSCP, but in OH-proline, proline and alanine FSCP had lower content than TSCP. Especially the content of essential amino acids of FSCP marked 22.74% with a higher content compared with 13.64% of TSCP. In the distribution of molecular weight FSCP with 1,000 Da showed comparatively low compared with TSCP, and in emulsion property and stability FSCP and TSCP showed similar excellent trend.

Purification of a Steroid $\triangle^1$-dehydrogenase from Arthrobacter simplex

  • BAE. MOO;MI-KYUNG LEE
    • Journal of Microbiology and Biotechnology
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    • v.3 no.3
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    • pp.181-187
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    • 1993
  • Steroid $\Delta^1$-dehydrogenase which introduces a double bond into the 1, 2 positions of steroid ring A was purified from Arthrobacter simplex, an excellent biotransformer of hydrocortisone into prednisolone. Hydrocortisone-induced cells were disrupted by vigorous agitation with glass beads, and a solubilized enzyme was obtained after centrifugation at 100, 000$\times$g for 90 minutes. The enzyme was purified 123-fold in three steps of chromatographic procedures with 13% yield. The last step of testosterone-agarose affinity column decisively contributed to the successful purification. The molecular weight of the enzyme was estimated to be 98, 000 by SDS-PAGE and 100, 000 by gel filtration, indicating that this enzyme behaves as a monomer. The enzyme showed demands for artificial electron acceptor, and among the several reagents tested, phenazine methosulfate acted as the most effective electron acceptor. Subcellular distribution of this enzyme was studied by centrifugation experiment. Comparison of the enzyme activities in pelleted membrane and cytosol fractions suggests that the enzyme may be a weakly attached peripheral membrane protein in vivo. But considerable amounts of enzyme was solubilized without any additional treatments for membrane protein.

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Phylogenetic position of Carex splendentissima, a Korean endemic sedge (Cyperaceae)

  • CHUNG, Kyong-Sook;YANG, Sungyu;NAM, Bo-Mi
    • Korean Journal of Plant Taxonomy
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    • v.50 no.3
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    • pp.253-261
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    • 2020
  • Carex splendentissima U. Kang & J. M. Chung, endemic to the Korean peninsula, is characterized by staminate terminal spikes and glabrous elliptic perigynia. Based on its broad leaves, androgynous spikes, and tri-stigmatic features, the species has been placed in Carex sect. Siderostictae Franch. ex Ohwi, an East Asian section and a basal group in the genus. To clarify the monophyly and phylogenetic position of the species, a molecular study using the internal transcribed spacer region of nuclear ribosomal DNA and chloroplast DNA (trnL-F) data was conducted. The DNA sequence data of ten taxa in sect. Siderostictae and closely related taxa (two taxa in sect. Surculosae) with outgroups were analyzed based on maximum parsimony and maximum likelihood (ML) criteria. In the analyses, C. splendentissima was monophyletic and placed within the Siderostictae clade (sect. Siderostictae + two species of sect. Surculosae), forming a clade with C. ciliatomarginata and C. pachygyna (endemic to Japan). The clade (C. splendentissima + C. ciliatomarginata + C. pachygyna) shows evidence of diploidy. Furthermore, C. splendentissima is a sister to C. ciliatomarginata in the ML tree, and the two taxa have staminate terminal spikes. This study also updates the distribution of C. splendentissima and provides keys to the four Korean taxa in sect. Siderostictae. To conserve the endemic species C. splendentissima, further research on its genetic and ecological features should be conducted at the population level.