• Title/Summary/Keyword: Molecular structures

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Temperature and the Interfacial Buffer Layer Effects on the Nanostructure in the Copper (II) Phthalocyanine: Fullerene Bulk Heterojunction

  • Kim, Hyo Jung;Kim, Jang-Joo;Jeon, Taeyeol;Kong, Ki Won;Lee, Hyun Hwi
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.275.1-275.1
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    • 2014
  • The effects of the interfacial buffer layer and temperature on the organic bulk heterojunction (BHJ) nanostructures of copper phthalocyanine (CuPc) and fullerene (C60) systems were investigated using real time in-situ x-ray scattering. In the CuPc:C60 BHJ structures, standing-on configured ${\gamma}$-CuPc phase was formed by co-deposition of CuPc and C60. Once formed ${\gamma}$-phase was thermally stable during the annealing upon $180^{\circ}C$. Meanwhile, the insertion of CuI buffer layer prior to deposition of the CuPc:C60 BHJ layer induced lying-down configured CuPc crystals in the BHJ layer. The lying CuPc peak intensity and the lattice parameter were increased by the thermal annealing. This increment of the intensity seemed to be related to the strain at the interface between CuPc:C60 and CuI, which was proportional to the enhancement of the power conversion efficiency of the device.

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Cytotoxic Effects of Furanosesterterpenes, Cyclitol Derivatives, and Bromotyrosine Derivative Isolated from Marine Sponges

  • Sohn, Jae-Hak;Oh, Hyun-Cheol;Jung, Jee-H.;Bae, Song-Ja
    • Preventive Nutrition and Food Science
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    • v.10 no.3
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    • pp.257-261
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    • 2005
  • Marine sponges are known to produce a number of cytotoxic secondary metabolites. In the course of searching for cytotoxic metabolites from marine organisms, we have evaluated cytotoxic activities of six marine secondary metabolites isolated from various sponges. The cytotoxic compounds 1-6 were isolated by the application of various chromatographic methods, including column chromatography and HPLC. The molecular structures were mostly determined using mass spectrometry (MS) and Nuclear Magnetic Resonance (NMR) Spectroscopy. Furanosestererpenes (compounds 1-3) from Psammocinia sp., cyclitol derivatives (compounds 4 and 5) from Sarcotragus sp., and bromotyrosine-type compound (6) from an association of two sponges Jaspis wondoensis and Poecillastra wondoensis were evaluated for their cytotoxic activity against three cancer cell lines; Hep G2, HeLa, and MCF-7. All tested compounds exhibited cyctoxicity at concentrations ranging from $5\;\mug/mL\;to\;25\;\mug/mL.$ Particularly, among the tested compounds, compound 6 showed the highest potency displaying at least $80\%$ of cytotoxicity at $5\;\mug/mL$ level against all three cancer cell lines.

Light-Emitting Properties of Organic Electroluminescent Devices using Zinc Complexes (아연 착체를 이용한 유기 EL 소자의 전계발광 특성)

  • Kim, Hong-Soo;Jeong, Noh-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.4
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    • pp.316-323
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    • 2003
  • Zinc complexes with bis[2-(o-hydroxyphenyl) naphtol [1,2] oxazolato ligands (ZnPBO-4) and its derivatives (ZnPBO-S) were synthesized, and luminescent properties of these materials were investigated. Both the fluorescent emission band and electroluminescent emission band were discussed based on their ligand structure differences. The emission band found that it strongly depends on the molecular structure of introduced ligand. It was tuned from 446 nm to 491 nm by changing the ligand structures. Spreading of the ${\pi}$-conjugation in 2-(o-hydroxyphenyl) group gives rise to a blue shift. The EL properties also showed good consistency with their differences of ligand structure. Bright-blue EL emission with a maximum luminance of 3,100 $cd/m^2$ at 12V, current density, 575 $mA/m^2$ was obtained from the organic light-emitting diodes (OLEDs) using ZnPBO-4 as emitting layer. It was also found that the newly synthesized materials were suitable to be used as emitting materials in organic EL device.

Gamakamide C and D as Two New Analogues of Bitter-Tasting Cyclic Peptide with Hydantoin Structure from Oyster Crassostrea gigas

  • Jang, Jun Ho;Park, Taesung;Lee, Jong Soo
    • Fisheries and Aquatic Sciences
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    • v.18 no.2
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    • pp.131-135
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    • 2015
  • Two new bitter-tasting cyclic peptides comprising six amino acids, namely gamakamide C and D, were isolated from cultured oysters Crassostrea gigas. Dimethylaminoazobenzene sulfonyl-amino acid analysis detected Val and Leu in gamakamide C and Ile and Leu in gamakamide D. The molecular formula of gamakamide C was determined as $C_{43}H_{60}N_{7}O_8S$ by high-resolution fast atom bombardment mass spectroscopy (HR FAB-MS) ($[M+H]^+m/z822.4200{\Delta}-2.4mmu$), and that of gamakamide D was determined as $C_{43}H_{62}N_7O_8S$ by HR FAB-MS ($[M+H]^+m/z836.4379{\Delta}-2.0mmu$). Comparison of amino acid analyses and fragment ions by MS/MS among gamakamide C, D, and E (known), the structures of gamakamide C and D were confirmed $as-{\small{L}}-Val-{\small{L}}-Met(SO)-{\small{L}}-NMe-Phe-{\small{L}}-Leu-{\small{D}}-Lys-{\small{L}}-Phe-$ and $-{\small{L}}-Ile-{\small{L}}-Met(SO)-{\small{L}}-NMe-Phe-{\small{L}}-Leu-{\small{D}}-Lys-{\small{L}}-Phe-$, respectively.

Ab Initio Quantum Mechanical Investigation of H2(An+1X2n)H2(A=C or Si, X=O or S, n = 1-2)]; Energetics, Molecular Structures, and Vibrational Frequencies

  • Choi, Kun-Sik;Kim, Hong-Young;Kim, Seung-Joon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.1
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    • pp.119-126
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    • 2005
  • The geometrical parameters, vibrational frequencies, and relative energies of H$_2$(A$_{n+1}$X$_{2n}$)H$_2$ (A=C or Si, X=O or S, n = 1-2) oligomers have been investigated using high level ab initio quantum mechanical techniques with large basis sets. The equilibrium geometries have been optimized at the self-consistent field (SCF), the coupled cluster with single and double excitation (CCSD), and the CCSD with connected triple excitations [CCSD(T)] levels of theory. The highest level of theory employed in this study is cc-pVTZ CCSD(T). Harmonic vibrational frequencies and IR intensities are also determined at the SCF level of theory with various basis sets and confirm that all the optimized geometries are true minima. Also zero-point vibrational energies have been considered to predict the dimerization and the relative energies.

Spontaneous Vesicle Formation in Aqueous Mixtures of Cationic Gemini Surfactant and Sodium Lauryl Ether Sulfate

  • Cheon, Ho-Young;Jeong, Noh-Hee;Kim, Hong-Un
    • Bulletin of the Korean Chemical Society
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    • v.26 no.1
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    • pp.107-114
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    • 2005
  • Molecular aggregates of surfactant molecules consisting of one or more bilayers arranged in a hollow, closed, usually spherical geometry are termed “esicles”or “iposomes” In recent years it has been found that in certain systems the vesicular structure forms spontaneously and is long lived, and it has been suggested that these structures may in fact constitute the equilibrium state in these cases (as is true of micelles) This paper deals with the mixed CMC, vesicles, phase behavior, phase transition, geometrical structure, their formation and characterization in the aqueous solutions of mixed cationic/anionic surfactants systems. TEM micrographs revealed that the vesicles were of spherical shape and that their size was of around 180 nm. The zeta potentials are positive at CGS1-rich regions and negative at SLES-rich regions. In the region where SLES/CGS1 (6/4), the zeta potentials are very small, implying that the vesicles at this surfactant ratio may be less stable. At other surfactant ratios, the vesicles are thought to be stable, supported by large absolute values of zeta potentials and little change in UV absorbance for several months.

Identification of Two Fungal Endophytes Associated with the Endangered Orchid Orchis militaris L.

  • Vendramin, Elena;Gastaldo, Andrea;Tondello, Alessandra;Baldan, Barbara;Villani, Mariacristina;Squartini, Andrea
    • Journal of Microbiology and Biotechnology
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    • v.20 no.3
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    • pp.630-636
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    • 2010
  • A survey of the endangered orchid Orchis militaris populations was carried out in north-eastern Italy. The occurrence of fungal root endophytes was investigated by light and electron microscopies and molecular techniques. Two main sites of presence were individuated in the Euganean Hills, differing as to the percentage of flowering individuals and of capsules completing maturity. Fluorescence microscopy revealed an intracellular cortical colonization by hyphal pelotons. Two ITS PCR products co-amplified. Sequencing revealed for the former an identity and a high similarity (99%) with a Tulasnellaceae (Basidiomycota) fungus found within tissues of the same host in independent studies in Hungary and Estonia, suggesting an interesting case of tight specificity throughout the Eurosiberian home range. The second amplicon had 99% similarity with Tetracladium species (Ascomycota) recently demonstrated as potential endophytes. TEM revealed two different hyphal structures. Double fungal colonization appears to occur in Orchis militaris and the possible requirement of a specific fungal partner throws light on the causes of this plant's rarity and threatened status.

Analysis for nucleotide sequence of the small membrane (sM) protein gene of porcine epidemic diarrhea virus Chinju99 isolated in Korea

  • Yeo, Sang-Geon;Lee, Changhee
    • Korean Journal of Veterinary Research
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    • v.47 no.2
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    • pp.169-174
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    • 2007
  • To provide information for the molecular pathogenesis and antigenic structures of Korean isolates of porcine epidemic diarrhea virus (PEDV), the small membrane (sM) protein gene of Chinju99 strain, which was previously isolated from piglets suffering from severe diarrhea was characterized and further analyzed with other PEDV strains. The sM gene of Chinju99 generated by reverse transcription and polymerase chain reaction had a single open reading frame with 231 bases consisting of 24.2% adenine, 18.6% cytosine, 18.1% guanine and 39.0% thymine nucleotides. Nucleotide sequence of the gene revealed 97.8% homology to those of Belgian strain CV777 and British strain Br1/87, and 97.0% to Chinese strain LZC. The gene encoded a protein with 76 amino acids, and putative amino acid sequence of the gene revealed 98.7% homology to those of CV777 and Br1/87, and 96.1% to LZC. The amino acids of Chinju99 sM gene consisted of mostly hydrophobic residues, and there were one potential N-myristylation site and one potential threonine (T)-linked phosphorylation site recognized. Also, there was a transmembrane region with 46 amino acids, and Chinju99 was more close to CV777 and Br1/87 than to LZC in phylogenetic analysis on the sM amino acid sequences.

신경줄기세포의 치료응용 전망 : 신경계질환

  • Park, Guk-In
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.6 no.1
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    • pp.108-115
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    • 2006
  • The inherent biology of neural stem cells (NSCs) endows them with capabilities that not only circumvent many of the limitations of other gene transfer vehicles, but that enable a variety of novel therapeutic strategies heretofore regarded as beyond the purview of neural transplantation, Most neurodegenerative diseases are characterized not by discrete, focal abnormalities but rather by extensive, multifocal, or even global neuropathology. Such widely disseminated lesions have not conventionally been regarded as amenable to neural transplantation. However, the ability of NSCs to engraft diffusely and become integral members of structures throughout the host CNS while also expressing therapeutic molecules may permit these cells to address that challenge. Intriguingly, while NSCs can be readily engineered to express specified foreign genes, other intrinsic factors appear to emanate spontaneously from NSCs and, in the context of reciprocal donor-host signaling, seem to be capable of neuroprotective and/or neuroregenerative functions. Stem cells additionally have the appealing ability to "home in" on pathology, even over great distances. Such observations help to advance the idea that NSCs - as a prototype for stem cells from other solid organs - might aid in reconstructing the molecular and cellular milieu of maid eve loped or damaged organs.

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Molecular and Cellular Studies of Seed Storage Proteins from Rice and Wheat

  • Kim, Woo-Taek
    • Applied Biological Chemistry
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    • v.32 no.1
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    • pp.64-72
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    • 1989
  • Near full length cDNA clones encoding the rice seed storage protein, prolamine, were isolated and divided into two homology classes based on cross-hybridization and DNA sequencing analysis. These cDNA clones contain a single open reading frame encoding a putative rice prolamine precursor(M.W.=17,200) possessing atypical 14 amino acid signal peptide. Clones of these two homology classes diverge mainly by insertions/deletions of short nucleotide stretches and point mutations. The deduced primary structures of both types of prolamine polypeptides are devoid of any major tandem repetitive sequences, a feature prevalent in other cereal prolamines. No significant homology teas detected between the rice prolamine and other cereal prolamines, indicating that the rice gene evolved from a different ancestor that gave rise to other cereal prolamine genes. Developing wheat and rice endosperms were examined using ultrathin sections prepared from tissues harvested at various days after flowering. By immunocytochemical localization techniques, wheat prolamines are localized within vesicles from Golgi apparatus and in homogeneous regions of protein bodies. The involvement of the goli apparatus in the packaging of wheat prolamines into protein bodies indicates a pathway which differs from the mode of other cereal prolamines and resembles the mechanism employed for the storage of rice glutelin and legume globulins.

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