• Title/Summary/Keyword: Hybrid strains

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Effects of strain on the optical and magnetic properties of Ce-doped ZnO

  • Xu, Zhenchao;Hou, Qingyu;Guo, Feng;Jia, Xiaofang;Li, Cong;Li, Wenling
    • Current Applied Physics
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    • v.18 no.12
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    • pp.1465-1472
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    • 2018
  • The magnetic and optical properties of Ce-doped ZnO systems have been widely demonstrated, but the effects of different strains of Ce-doped ZnO systems remain unclear. To solve these problems, this study identified the effects of biaxial strain on the electronic structure, absorption spectrum, and magnetic properties of Ce-doped ZnO systems by using a generalized gradient approximation + U (GGA + U) method with plane wave pseudopotential. Under unstrained conditions, the formation energy decreased, the system became stable, and the doping process became easy with the increase in the distances between two Ce atoms. The band gap of the systems with different strains became narrower than that of undoped ZnO without strain, and the absorption spectra showed a red shift. The band gap narrowed, and the red shift became weak with the increase of compressive strain. By contrast, the band gap widened, and the red shift became significant with the increase of tensile strain. The red shift was significant when the tensile strain was 3%. The systems with -1%, 0%, and 1% strains were ferromagnetic. For the first time, the magnetic moment of the system with -1% strain was found to be the largest, and the system showed the greatest beneficial value for diluted magnetic semiconductors. The systems with -3%, -2%, 2%, and 3% strains were non-magnetic, and they had no value for diluted magnetic semiconductors. The ferromagnetism of the system with -1% strain was mainly caused by the hybrid coupling of Ce-4f, Ce-5d, and O-2p orbits. This finding was consistent with Zener's Ruderman-Kittel-Kasuya-Yosida theory. The results can serve as a reference for the design and preparation of new diluted magnetic semiconductors and optical functional materials.

The Hybrid Formation between Aspergillus oryzae var. oryzae and Penicillium chrysogenum by Nuclear Transfer and the Production of Alkaline Protease. (핵전이에 의한 Aspergillus oryzae var. oryzae와 Penicillium chrysogenum의 잡종형성 및 Alkaline Protease생성)

  • 양영기;강희경;임채영;문명님
    • Microbiology and Biotechnology Letters
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    • v.26 no.4
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    • pp.290-296
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    • 1998
  • Interspecific hybrids between Aspergillus oryzae var. oryzae and Penicillium chrysogenum (Tyr$\^$-/), high alkaline protease producing fungi, were obtained by nuclear transfer technique. Nuclei isolated from the wild type Aspergillus oryzae var. oryzae strain were transferred into auxotrophic Penicillium chrysogenum mutants and selected the new strains showing an increased protein degrading capability. Maximum production of protoplasts were obtained by 1% Novozym 234 at $30^{\circ}C$ for 3 hours and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6M KCl. Frequencies of hybrid formation by nuclear transfer were 1.3${\times}$10$\^$-3/∼2.8${\times}$10$\^$-3/. They could be suggested as an aneuploid by the observation of genetic stability, conidial size, DNA content, and nuclear strain. The hybrids showed 1.1~2.2 fold higher alkaline pretense activities than parental strains.

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Papers : Simultaneous Monitoring of Strain and Temperature During and After Cure of Unsymmetric Cross - ply Composite Laminate Using Fiber Optic Sensors (논문 : 비대칭 직교적층 복합재료 적층판의 성형시 및 성형후 광섬유 센서를 이용한 변형률 및 온도의 동시 모니터링)

  • Gang,Hyeon-Gyu;Gang,Dong-Hun;Hong,Chang-Seon;Kim,Cheon-Gon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.30 no.1
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    • pp.49-55
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    • 2002
  • In this paper, we present the simulation monitoring of strain and temperature during and after the cure of unsymmetric composite laminate using fiber optic sensors. Fiber Bragg grating/extrinsic Fabry-Perot interferometric (FBG/EFPI) hybrid sensors are used to measure those measurands. The characteristic matrix of the sensor is analytically derived and measurements can be done without sensor calibration. A wavelength-swept fiber laser is utilised as a lighr source. Two FBG/EFPI sensors are embedded in a graphite/epoxy unsymmetric cross-ply composite laminate in different directions and different locations. We perform a real time monitoring of fabrication strains and temperatures at two points of the composite laminate during cure process in an autoclave. Also, the thermal strains and temperatures of the fabricated laminate are measured in a thermal chamber. Through these experiments, we can provide a basis for the efficient smart processing of composite and know the thermal behavior of unsymmetric cross-ply composite laminate.

Transfer RP4::Mu cts and RP4::mini-Mu from E. coli to Pseudomonas sp. (RP4::Mu cts 및 RP4::mini-Mu Pseudomonas sp.로의 전달)

  • 고윤원;허연주;이영록
    • Korean Journal of Microbiology
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    • v.26 no.3
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    • pp.173-180
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    • 1988
  • Chromosomal gene transferable hybrid plasmids, RP4::Mu cts and RP4::mini-Mu, were transferred by conjugation from E. coli to Pseudomonas strains. In order to use for recipient cells of RP4::Mu cts and RP4:: mini-Mu, plasmid-free Pseudomonas strains were characterized for their antobiotic resistance, aromatic hydrocarbon utility and degradation patterns of chlorinated herbicide. Transfer frequencies of RP4::mini-Mu exhibited about $10^{-2}$ to $10^{-4}$, while those of RP4::Mu cts exhibited very low value of $10^{-7}$ in recipients tested except Pseudomonas aeruginosa KU557. Existance of hybrid plasmids in Pseudomonas transconjugants were identified by their antibiotic resistance and agarose gel electrophoresis. In case of RP4::Mu cts transconjugants it was also confirmed by demonstrating that they were capable of releasing phage and forming plaques at $43^{\circ}C$. Plaque forming unit of the transconjugants was about $10^{5}$. It was shown by the stability test that RP4::Mu cts and RP4::mini-Mu in Pseudomonas were relatively stable.

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Development of a Novel Short Synthetic Antibacterial Peptide Derived from the Swallowtail Butterfly Papilio xuthus Larvae

  • Kim, Seong Ryul;Choi, Kwang-Ho;Kim, Kee-Young;Kwon, Hye-Yong;Park, Seung-Won
    • Journal of Microbiology and Biotechnology
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    • v.30 no.9
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    • pp.1305-1309
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    • 2020
  • Insects possess biological defense systems that can effectively combat the invasion of external microorganisms and viruses, thereby supporting their survival in diverse environments. Antimicrobial peptides (AMPs) represent a fast-acting weapon against invading pathogens, including various bacterial or fungal strains. A 37-residue antimicrobial peptide, papiliocin, derived from the swallowtail butterfly Papilio xuthus larvae, showed significant antimicrobial activities against several human pathogenic bacterial and fungal strains. Jelleines, isolated as novel antibacterial peptides from the Royal Jelly (RJ) of bees, exhibit broad-spectrum protection against microbial infections. In this study, we developed a novel antimicrobial peptide, PAJE (RWKIFKKPFKISIHL-NH2), which is a hybrid peptide prepared by combining 1-7 amino acid residues (RWKIFKK-NH2) of papiliocin and 1-8 amino acid residues (PFKISIHL-NH2) of Jelleine-1 to alter length, charge distribution, net charge, volume, amphipaticity, and improve bacterial membrane interactions. This novel peptide exhibited increased hydrophobicity and net positive charge for binding effectively to the negatively charged membrane. PAJE demonstrated antimicrobial activity against both gram-negative and gram-positive bacteria, with very low toxicity to eukaryotic cells and an inexpensive process of synthesis. Collectively, these findings suggest that this novel peptide possesses great potential as an antimicrobial agent.

Genetic Relationships among the Parental Bombyx mori Strains of the Current F$_1$ Hybrid Silkworm based on RAPD (RAPD를 이용한 장려누에품종의 원종간 유전적 유연관계)

  • 황재삼;이진성;강현아;이상몽;손해룡
    • Korean journal of applied entomology
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    • v.36 no.3
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    • pp.206-214
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    • 1997
  • The genetic relationships among the twenty parental silkworm, Bombyx mori strains authorized in Korea were evaluated using RAPDs-PCR(Random Amplified Polymorphic DNAs-Polymerase Chain Reaction). Twenty-six different 10-mer oligonucleotide primers were used to screen genetic characteristics of parental twenty silkworm strains by RAPD-PCR analysis. 24 primers showed different banding patterns among the strains. Based on these RAPD patterns, the genetic relationships among the silkworm strains were analyzed by UPGMA(Unweighed Pair-Group Method with Arithmetic average) method. The phylogenetic relationships in the twenty silkworm strains were classified into two major sub-groups at the genetic similarity coefficient of 0.60. The first sub-group included Jaml13, Jaml 19, Jaml20, Jam123, Jam1 25 and Jam 127. Jamll4, Jam1 2 I, Jam 122, Jam 124, Jam1 26, Jam 128, Jam129, Jam 130, Jam 131, Jam1 32, Jam133, Jam134, Jam301 and Jam302 were included in the 2nd group. The genetic distance values among Jam1 14, Jam120 and Jam127 were lower than those among the other strains, while Jam129 is very closely related to Jam131 as showing coefficient value of 1 .O.

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UmTco1, a Hybrid Histidine Kinase Gene, Is Essential for the Sexual Development and Virulence of Ustilago maydis

  • Yun, Yeo Hong;Oh, Man Hwan;Kim, Jun Young;Kim, Seong Hwan
    • Journal of Microbiology and Biotechnology
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    • v.27 no.5
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    • pp.1010-1022
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    • 2017
  • Hybrid histidine kinase is part of a two-component system that is required for various stress responses and pathogenesis of pathogenic fungi. The Tco1 gene in human pathogen Cryptococcus neoformans encodes a hybrid histidine kinase and is important for pathogenesis. In this study, we identified a Tco1 homolog, UmTco1, in the maize pathogen Ustilago maydis by bioinformatics analysis. To explore the role of UmTco1 in the survival of U. maydis under environmental stresses and its pathogenesis, ${\Delta}umtco1$ mutants were constructed by allelic exchange. The growth of ${\Delta}umtco1$ mutants was significantly impaired when they were cultured under hyperosmotic stress. The ${\Delta}umtco1$ mutants exhibited increased resistance to antifungal agent fludioxonil. In particular, the ${\Delta}umtco1$ mutants were unable to produce cytokinesis or conjugation tubes, and to develop fuzzy filaments, resulting in impaired mating between compatible strains. The expression levels of Prf1, Pra1, and Mfa1, which are involved in the pheromone pathway, were significantly decreased in the ${\Delta}umtco1$ mutants. In inoculation tests to the host plant, the ${\Delta}umtco1$ mutants showed significantly reduced ability in the production of anthocyanin pigments and tumor development on maize leaves. Overall, the combined results indicated that UmTco1 plays important roles in the survival under hyperosmotic stress, and contributes to cytokinesis, sexual development, and virulence of U. maydis by regulating the expression of the genes involved in the pheromone pathway.

Simultaneous Measurement of Strain and Temperature During and After Cure of Unsymmetric Composite Laminate Using Fiber Optic Sensors (비대칭 복합적층판의 성형시 및 성형후 광섬유 센서를 이용한 변형률 및 온도의 동시 측정)

  • 강동훈;강현규;김대현;방형준;홍창선;김천곤
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.05a
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    • pp.244-249
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    • 2001
  • In this paper, we present the simultaneous measurement of the fabricaition strain and temperature during and after cure of unsymmetric composite laminate uising fiber optic sensors. Fiber Bragg grating/extrinsic Fabry-Perot interferometric (FBG/EFPl) hybrid sensors are used to measure those measurands. The characteristic matrix of sensor is analytically derived and measurements can be done without sensor calibration. A wavelength-swept fiber laser is utilized as a light source. FBG/EFPI sensors are embedded in a graphite/epoxy unsymmetric cross-ply composite laminate at different direction and different location. We perform the real time measurement of fabrication strains and temperatures at two points of the composite laminate during cure process in an autoclave. Also, the thermal strains and temperatures of the fabricated laminate are measured in thermal chamber. Through these experiments, we can provide a basis for the efficient smart processing of composite and know the thermal behavior of unsymmetric cross-ply composite laminate.

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Transfer of RP4:Mu cts from E. coli to Rhizovium leguminosarum (RP4:Mu cts의 E.coli로 부터 Rhizovium leguminosarum으로의 전달)

  • 이인렬;허연주;이영록
    • Korean Journal of Microbiology
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    • v.23 no.2
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    • pp.107-114
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    • 1985
  • In order to use for recipient strains of RP4:Mu cts, 5 strainsof Rhizobium were selected among 32 strains, which were isolated and identified in this study. Hybrid plasmin RP4::Mu cts, which, is temperature sensitive and confers resistance to ampicillin, kanamycin and tetracycline was transfered by conjugation from E. coli to other atrains of C. coli and the symbiotic nitrogen fixer, Rhizobium leguminosarum. Transfer frequencies of RP4::Mu cts plasmid from E. coli to Rhizobium were about $10^{-8}-10^{-7}$ in LB agar and YMA media. The transconjugants were confirmed by demonstrating that the drug-resistant and temperature-sensitive clones isolated were drug-resistant and temperature-sensitive clones isolated were capable of releasing phage and forming plaques. The plaque-forming units of transconjugants were about $10^2\;to\;10^3$. Stability test of RP4::Mucts in Rhizobium represented that most of the transconjugants had drug resistance and produce phage Mu cts.

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Effect of Hydrophobicity of Oyster Mushroom on the Severity of Brown Blotch (느타리 갓 표면의 소수성이 세균갈색무늬병 발병도에 미치는 영향)

  • Lee, Ki-Young;Yang, Seung-Up;Han, Jong-Woo;Yoon, Kun-Sik;Jang, Hoo-Bong;Cha, Jae-Soon
    • The Korean Journal of Mycology
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    • v.38 no.1
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    • pp.69-74
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    • 2010
  • The 2 strains of Pleurotus ostreatus showing very severe and mild symptom of brown blotch were selected, and their F1 hybrid strains were made by mating of their single spore isolates. Hydrophobicity of fruiting body surface and brown blotch severity of the parental and their 11 F1 hybrid strains showing different level of severity of brown blotch were determined. Correlation coefficient (R) between disease severity and hydrophobicity were 0.68 and 0.70 on two independent experiments. Correlation coefficient between disease severity and disease incidence that was determined in the oyster mushroom farm were 0.46 and 0.52 on two independent experiments. When GFP-tagged Pseudomonas tolaasii was monitored with confocal microscope on cap surface of fruiting body, more cells of the pathogen were clustered on the severe strain than the mild strain, which indicates that the bacterial pathogen proliferates more on the severe strain. These results suggest that hydrophobicity of oyster mushroom fruiting body affects disease severity of the brown blotch disease; the longer the bacterial suspension stays on fruiting body surface more severe symptom of the blotch develops.