• Journal of Environmental Science International
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• v.18 no.12
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• pp.1361-1368
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• 2009

The effects of $Cd^{2+}$ ions on the Chl a fluorescence of 5 hydrophytes (e.g. Lemna, Salvinia, Ricciocarp, Nymph, Typha plants) were investigated in order to select $Cd^{2+}$-sensitive plant species and to get informations on physiological responses of plants to $Cd^{2+}$ stress. Lemna plants were most sensitive to cadmium stress, while Nymph plants were tolerant. However, in all $Cd^{2+}$-treated plants, Fv/Fm, the maximum photochemical efficiency of PS II, decreased in proportion to the increase of $Cd^{2+}$ concentration and treatment time. The Chl a fluorescence transient O-J-I-P was also considerably affected by $Cd^{2+}$ ions; the fluorescence yield decreased consid- erably in steps J, I and P in $Cd^{2+}$ treated plants, although it followed a typical polyphasic rise in non-treated plants. In Lemna plants, the functional parameters, ABS/CS, TRo/CS와 ETo/CS and RC/CS, decreased in proportion to the increase of $Cd^{2+}$ concentration, while N, Mo and Kn increased. The structural parameters, ${\Phi}po$, ${\Phi}po$/($1-{\Phi}po$), Plabs, SFlabs, Kp and RC/ABS, also decreased according to the increase of $Cd^{2+}$ concentration. Consequently, Lemna plants will be useful as a experimental model system to investigate responses of plants. And several functional or structural parameters could be applied to determine quantitatively the physiological states of plants under stresses.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.456-456
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• 2008

In the past few years, the deposition and characterization of cadmium sulfide semiconducting thin films has received a considerable amount of interest due to their potential application in the area of electronic and opto-electronic devices fabrications. Polycrystalline CdS thin films posses good optical transmittance, wide band-gap and electrical properties makes it as one of the ideal material for their application to solar cell fabrication. Cadmium sulfate thin films were deposited by the chemical bath deposition method using tartaric acid and triethanolamine as a complexing agent. Deposition parameters such as pH, temperature, deposition time and concentration of the reactant species were optimized so as to obtain reflecting, good adherent uniform thin films on the glass substrate. Reaction mechanism of the thin film formation is also reported. The crystallographic structure and the crystallite size were studied by the X-ray diffraction pattern. The optical band-gap of deposited film is identified by measuring the transmittance in the visible region. Temperature dependence of resistivity confirmed the semiconducting behavior of the film. Scanning electron micrographs (SEM) showed the presence of grain particles of size 50 nm.

• BMB Reports
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• v.40 no.6
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• pp.845-852
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• 2007

The highly evolved flowers of orchids have colorful sepals and fused columns that offer an opportunity to discover new genes involved in floral development in monocotyledon species. In this investigation, we cloned and characterized the homologous PISTALLATA-like (PI-like) gene PhPI15 ($\underline{Ph}alaenopsis$ $\underline{PI}$ STILLATA # $\underline{15}$), from the Phalaenopsis hybrid cultivar. The protein sequence encoded by PhPI15 contains a typical PI-motif. Its sequence also formed a subclade with other monocot PI-type genes in phylogenetic analysis. Southern analysis showed that PhPI15 was present in the Phalaenopsis orchid genome as a single copy. Furthermore, it was expressed in all the whorls of the Phalaenopsis flower, while no expression was detected in vegetative organs. The flowers of transgenic tobacco plants ectopically expressing PhPI15 showed male-sterile phenotypes. Thus, as a Class-B MADS-box gene, PhPI15 specifies floral organ identity in orchids.

• Parasites, Hosts and Diseases
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• v.32 no.2
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• pp.101-110
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• 1994

This report describes the structures of high-mannose-type N-linked oligosaccharides in glycoproteins synthesized by the microfilariae of Diroflcrio immitis. Microfilariae of D. immitis were incubated in vitro in media containing 2-(3H) mannose to allow metabolic radiolabeling of the oligosaccharide moieties of newly synthesized glycoproteins. Glycopeptides were prepared from the radiolabeled glycoproteins by digestion with pronase and fractionation by chromatography on concanavalin A Sepharose. Thirty eight percent of 2- (3H) mannose incorporated into the microalariae of D. immitis glycopeptides was recovered in high mannose-type asparagine-linked oligosaccharides which were bound to the immobilized lectin. Upon treatment of 2-(3H) mannose labeled glycopeptides with endo - β- N- acetylglu co saminidase H , the high mannose type chains were released and their structures were determined by high performance liquid chromatography and exoglycosidase digestion. The major species of high mannose-type chains synthesized by microfilariae of D. immitis have the composition Man5GlcNAc2, Man6ClcNAc2, Man7GlcNAc2, and Man8GlcNAc2. Structural analyses indicate that these oligosaccharides are similar to high mannose-type chains synthesized by vertebrates.

• Parasites, Hosts and Diseases
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• v.50 no.2
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• pp.165-171
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• 2012

Larval excretory-secretory products of Anisakis simplex are known to cause allergic reactions in humans. A cDNA library of A. simplex 3rd-stage larvae (L3) was immunoscreened with polyclonal rabbit serum raised against A. simplex L3 excretory-secretory products to identify an antigen that elicits the immune response. One cDNA clone, designated as ${\alpha}$-methylacyl CoA racemase (Amacr) contained a 1,412 bp cDNA transcript with a single open reading frame that encoded 418 amino acids. A. simplex Amacr showed a high degree of homology compared to Amacr orthologs from other species. Amacr mRNA was highly and constitutively expressed regardless of temperature (10-$40^{\circ}C$) and time (24-48 hr). Immunohistochemical analysis revealed that Amacr was expressed mainly in the ventriculus of A. simplex larvae. The Amacr protein produced in large quantities from the ventriculus is probably responsible for many functions in the development and growth of A. simplex larvae.

• Parasites, Hosts and Diseases
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• v.55 no.3
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• pp.351-355
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• 2017

Hymenolepis nana and Hymenolepis diminuta are globally widespread zoonotic cestodes. Rodents are the main reservoir host of these cestodes. Brown rats (Rattus norvegicus) are the best known and most common rats, and usually live wherever humans live, especially in less than desirable hygiene conditions. Due to the little information of the 2 hymenolepidid species in brown rats in China, the aim of this study was to understand the prevalence and genetic characterization of H. nana and H. diminuta in brown rats in Heilongjiang Province, China. Total 114 fecal samples were collected from brown rats in Heilongjiang Province. All the samples were subjected to morphological examinations by microscopy and genetic analysis by PCR amplification of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene and the internal transcribed spacer 2 (ITS2) region of the nuclear ribosomal RNA gene. In total, 6.1% (7/114) and 14.9% (17/114) of samples were positive for H. nana and H. diminuta, respectively. Among them, 7 and 3 H. nana isolates were successfully amplified and sequenced at the COX1 and ITS2 loci, respectively. No nucleotide variations were found among H. nana isolates at either of the 2 loci. Seventeen H. diminuta isolates produced 2 different COX1 sequences while 7 ITS2 sequences obtained were identical to each other. The present results of H. nana and H. diminuta infections in brown rats implied the risk of zoonotic transmission of hymenolepiasis in China. These molecular data will be helpful to deeply study intra-specific variations within Hymenolepis cestodes in the future.

• Molecules and Cells
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• v.28 no.6
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• pp.575-581
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• 2009

Ornithine decarboxylase (ODC) is a rate-limiting enzyme in the biosynthesis of polyamines, which are essential for cell growth, differentiation, and proliferation. This report presents the characterization of an ODC-encoding cDNA (SlitODC) isolated from a moth species, the tobacco cutworm, Spodoptera litura (Lepidoptera); its expression in a polyamine-deficient strain of yeast, S. cerevisiae; and the recovery in polyamine levels and proliferation rate with the introduction of the insect enzyme. SlitODC encodes 448 amino acid residues, 4 amino acids longer than B. mori ODC that has 71% identity, and has a longer C-terminus, consistent with B. mori ODC, than the reported dipteran enzymes. The null mutant yeast strain in the ODC gene, SPE1, showed remarkably depleted polyamine levels; in putrescine, spermidine, and spermine, the levels were > 7, > 1, and > 4%, respectively, of the levels in the wild-type strain. This consequently caused a significant arrest in cell proliferation of > 4% of the wild-type strain in polyamine-free media. The transformed strain, with the substituted SlitODC for the deleted endogenous ODC, grew and proliferated rapidly at even a higher rate than the wild-type strain. Furthermore, its polyamine content was significantly higher than even that in the wild-type strain as well as the spe1-null mutant, particularly with a very continuously enhanced putrescine level, reflecting no inhibition mechanism operating in the putrescine synthesis step by any corresponding insect ODC antizymes to SlitODC in this yeast system.

• Research in Plant Disease
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• v.22 no.1
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• pp.55-58
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• 2016

A Cucumber mosaic virus (named CMV-Tr1) isolated from the white clover (Trifolium repens) showing mosaic and malformation that found in a pepper field. Cucumber mosaic virus was identified through confirmation with PT-PCR, PCR-restriction fragment length polymorphism, and sequence analysis of coat protein (CP) gene. CMV-Tr1 mosaic symptom on the upper leaves of five tobacco species including Nicotiana benthamiana, Cucumis sativus, Physalis angulata, and Solanum lycopersicon. In Chenopodium quinoa and Vigna unguiculata the isolate showed local lesions in inoculated leaves. CMV-Tr1 compared with CMV-As in the sequence identity of CP gene. CMV-Tr1 showed 98.9% and 99.5% homologies at nucleotide and amino acid levels, respectively. Phylogenetic analysis of the CP gene indicated that CMV-Tr1 belongs to the CMV subgroup IB base on the CP. To our knowledge, this is the first report of CMV in T. repens in Korea.

• Journal of Marine Bioscience and Biotechnology
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• v.9 no.2
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• pp.22-29
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• 2017

A unicellular green alga was axenically isolated from the Port of Jeongja, Ulsan, Korea. Morphological, molecular, and biochemical analyses revealed that the isolate belonged to Heterochlorella luteoviridis. This is the first report of this species in Korea. The microalgal strain was named as H. luteoviridis MM0014 and its growth, lipid composition, and biomass properties were investigated. The strain thrived over a wide range of temperatures ($5-30^{\circ}C$) and withstood up to 0.5 M NaCl. The results of gas chromatography/mass spectrometry analysis showed that the isolate was rich in nutritionally important polyunsaturated fatty acids. Its major fatty acids were linoleic acid (35.6%) and ${\alpha}$-linolenic acid (16.2%). Thus, this indigenous marine microalga is a potential alternative source of ${\omega}3$ and ${\omega}6$ polyunsaturated fatty acids, which are currently obtained from fish and plant oils. Ultimate analysis indicated that the gross calorific value was $19.7MJ\;kg^{-1}$. In addition, the biomass may serve as an excellent animal feed because of its high protein content (51.5%). Therefore, H. luteoviridis MM0014 shows promise for applications in the production of microalgae-based biochemicals and biomass feedstock.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.2
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• pp.1-13
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• 2020

The characterization of aging of the pyrotechnic device is conducted thermally, chemically, and spectroscopically. The device is comprised of two parts: (i) igniter composed of Zr and (ii) pyrotechnic delay composed of ZrNi alloy. The thermally induced chemical reaction is identified through Differential Scanning Calorimetry (DSC) and Thermogravimetry Analysis (TGA). The peak deconvolution of the themo-chemical data is used to estimate the enthalpy change of each metallic fuel component. Laser Induced Breakdown Spectroscopy (LIBS) and X-ray Photoelectron Spectroscopy (XPS) are used for chemical species analysis. The decomposition of oxidants by moisture significantly affected the fuel aging, and the formation of oxide film and metal oxide on the fuel surface gave rise to the thermal energy decrease.