• Title/Summary/Keyword: Center of resistance

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Agronomic characteristics and field resistance to bacterial soft rot of transgenic potato overexpressing the soybean calmodulin 4 gene (SCaM4) (SCaM4 과발현 형질전환 감자의 농업적 특성 및 감자 무름병 저항성 평가)

  • Sohn, Hwangbae;Cho, Kwangsoo;Cho, Jihong;Gwon, Ohgeun;Cheon, Chunggi;Choi, Jigyeong;Chung, Woosik;Lee, Shin Woo
    • Journal of Plant Biotechnology
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    • v.39 no.4
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    • pp.295-299
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    • 2012
  • We performed in vitro assay and field trials to assess levels of changes in intrinsic properties and resistance against soft rot of the potato cv. Dejima upon the introduction of a soybean calmodulin 4 gene (SCaM4). Field trials with four lines overexpressing SCaM4 gene were conducted over two seasons, and harvested tubers were evaluated in bioassay for resistance to Pectobacterium carotovorum ssp. carotovorum. The SCaM4 transgenic potato lines inoculated with $10^8$ CFU/ml of P. carotovorum ssp. carotovorum showed enhanced resistance compared to control. Among the SCaM4 transgenic lines, the transgenic line SCaM4-4 exhibited the highest tolerance to soft rot in vitro assays, so did in field trials. In the field trial, the soft rot resistance of SCaM4-4 line was more than 5 times higher compared to that of control cultivar, Dejima. The major agronomic characteristics of the SCaM4 transgenic lines were not different from those of the nontransgenic 'Dejima'. The result demonstrated that the transformation of a calmodulin 4 gene was a successful strategy in development of potato cultivar enhanced to soft rot.

EGF Reverses Multi-drug Resistance via the p-ERK Pathway in HepG2/ADM and SMMC7721/ADM Hepatocellular Carcinoma Models

  • Yan, Feng;Bai, Li-Ping;Gao, Hua;Zhu, Chang-Ming;Lin, Li;Kang, Xiang-Peng
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2619-2623
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    • 2014
  • Aim: To investigate signaling pathways for reversal of EGF-mediated multi-drug resistance (MDR) in hepatocellular carcinoma (HCC) models. Materials and Methods: HCC MDR cell strain HepG2/adriamycin (ADM) and SMMC7721/ADM models were established using a method of exposure to medium with ADM between low and high concentration with gradually increasing concentration. Drug sensitivity and reversal of multi-drug resistance by EGF were determined and the cell cycle distribution and apoptosis were analyzed by flow cytometry. Phosphorylation of ERK1, ERK2, ERK5 and expression of Bim were detected by Western blotting. Results: The results showed that HepG2/ADM and SMMC7721/ADM cells were resistant not only to ADM, but also to multiple anticancer drugs. When used alone, EGF had no anti-tumor activity in HepG2/ADM and SMMC7721/ADM cells in vitro, while it increased the cytotoxicity of ADM. EGF induced cell apoptosis and G0/G1 phase cell cycle arrest in HepG2/ADM And SMMC7721/ADM cells, while enhancing activity of p-ERKs and up-regulated expression of BimEL. Conclusions: EGF might enhance the chemosensitivity of HepG2/ADM and SMMC7721/ADM cells via up-regulating p-ERKs and BimEL protein.

Microstructure Analysis of Fe Thin Films Prepared by Ion Beam Deposition (이온빔 증착법에 의해 제조된 철박막의 미세조직 분석)

  • Kim, Ka Hee;Yang, Jun-Mo;Ahn, Chi Won;Seo, Hyun Sang;Kang, Il-Suk;Hwang, Wook-Jung
    • Korean Journal of Metals and Materials
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    • v.46 no.7
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    • pp.458-463
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    • 2008
  • High purity Fe thin films were prepared by the ion beam deposition method with $^{56}Fe^{+}$ions on the Si substrate at the room temperature. The Fe thin films were deposited at the ion energy of 50 eV and 100 eV. Microstructural properties were investigated on the atomic scale using high-resolution transmission electron microscopy (HRTEM). It was found that the Fe thin film obtained with the energy of 50 eV having an excellent corrosion resistance consists of the amorphous layer of ~15 nm in thickness and the bcc crystalline layer of about 30 nm in grain size, while the thin film obtained with the energy of 100 eV having a poor corrosion resistance consists of little amorphous layer and the defective crystalline layer. Furthermore the crystal structures and arrangements of the oxide layers formed on the Fe thin films were analyzed by processing of the HRTEM images. It was concluded that the corrosion behavior of Fe thin films relates to the surface morphology and the crystalline structure as well as the degree of purification.

Effects of ring number and baffled-ring distances on ultrafiltration in the tubular membrane inserted concentrically with a ring rod

  • Yeh, Ho-Ming;Ho, Chii-Dong;Li, Cha-Hsin
    • Membrane and Water Treatment
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    • v.3 no.1
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    • pp.51-62
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    • 2012
  • The permeate flux declination along an ultrafilter membrane is due mainly to the concentration-polarization resistance increment and the decline in transmembrane pressure. It was found in previous works that the concentration polarization resistance could be reduced in a ring-rod tubular membrane ultrafilter using the turbulent behavior. In the present study, the performance was further improved by properly and gradually decreasing the baffled-ring distance along the cross-flow channel coupled with properly adjusting the number of baffled rings. This theoretical analysis is based on the mass and momentum balances as well as the application of the resistance-in-series model. The correlation predictions are confirmed with the experimental results for dextran T500 aqueous solution ultrafiltration.

Single Crystalline CoFe/MgO Tunnel Contact on Nondegenerate Ge with a Proper Resistance-Area Product for Efficient Spin Injection and Detection

  • Jeon, Kun-Rok;Min, Byoung-Chul;Lee, Hun-Sung;Shin, Il-Jae;Park, Chang-Yup;Shin, Sung-Chul
    • Proceedings of the Korean Magnestics Society Conference
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    • 2010.06a
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    • pp.96-96
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    • 2010
  • We report the proper resistance-area products in the single crystalline bcc CoFe/MgO tunnel contact on nondegenerate n-Ge desirable for efficient spin injection and detection at room temperature. The electric properties of the crystalline CoFe(5 nm)/MgO(1.5,2.0,2.5 nm)/n-Ge(001) tunnel contacts have been investigated by I-V-T and C-V measurements. Interestingly, the tunnel contact with the 2-nm MgO exhibits the ohmic behavior with low resistance-area products, satisfying the theoretical conditions required for significant spin injection and detection. This result is ascribed to the presence of MgO layer between CoFe and n-Ge, enhancing the Schottky pinning parameter as well as shifting the charge neutrality level.

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The fabrication of electrodes with low resistance and fine pattern for PDP

  • Cho, Soo-Je;Ryu, Byung-Gil;Park, Myung-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.107-108
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    • 2000
  • We propose the method which is possible to fabricate the electrodes with the fine pattern and low resistance by photolithography and electroplating. The widths of pattern fabricated were 30, 50, 70 and 100um and the thickness could be up to $10{\mu}m$. The resistivity of the copper electrode electroplated was below $2.0{\mu}{\Omega}$ cm which is about half of photosensitive silver electrode. Dielectric layer was coated on the electrodes by screen printing and the pores harmful to the discharge were not formed after heat treatment. In the viewpoint of resistance and patterning, this method has much higher potential for large area display than other methods like screen printing, photosensitive conductive paste method and sputtering.

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Thermal Transient Characteristics of Die Attach in High Power LED Package

  • Kim Hyun-Ho;Choi Sang-Hyun;Shin Sang-Hyun;Lee Young-Gi;Choi Seok-Moon;Oh Yong-Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.4 s.37
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    • pp.331-338
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    • 2005
  • The rapid advances in high power light sources and arrays as encountered in incandescent lamps have induced dramatic increases in die heat flux and power consumption at all levels of high power LED packaging. The lifetime of such devices and device arrays is determined by their temperature and thermal transients controlled by the powering and cooling, because they are usually operated under rough environmental conditions. The reliability of packaged electronics strongly depends on the die attach quality, because any void or a small delamination may cause instant temperature increase in the die, leading sooner or later to failure in the operation. Die attach materials have a key role in the thermal management of high power LED packages by providing the low thermal resistance between the heat generating LED chips and the heat dissipating heat slug. In this paper, thermal transient characteristics of die attach in high power LED package have been studied based on the thermal transient analysis using the evaluation of the structure function of the heat flow path. With high power LED packages fabricated by die attach materials such as Ag paste, solder paste and Au/Sn eutectic bonding, we have demonstrated characteristics such as cross-section analysis, shear test and visual inspection after shear test of die attach and how to detect die attach failures and to measure thermal resistance values of die attach in high power LED package. From the structure function oi the thermal transient characteristics, we could know the result that die attach quality of Au/Sn eutectic bonding presented the thermal resistance of about 3.5K/W. It was much better than those of Ag paste and solder paste presented the thermal resistance of about 11.5${\~}$14.2K/W and 4.4${\~}$4.6K/W, respectively.

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Extensional and Complex Viscosities of Linear and Branched Polycarbonate Blends

  • Park, Jung-Hoon;Hyun, Jae-Chun;Kim, Woo-Nyon;Kim, Sung-Ryong;Ryu, Seung-Chan
    • Macromolecular Research
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    • v.10 no.3
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    • pp.135-139
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    • 2002
  • Blends of the linear bisphenol-A polycarbonate (L-PC) and randomly branched bisphenol-A polycarbonate (Br-PC), prepared by co-rotating twin screw extrusion, were investigated using differential scanning calorimetry (DSC), sag resistance time tester, extensional rheometry, and advanced rheometric expansion system (ARES). From the DSC results, the glass transition temperature (T$_{g}$) of the L-PC/Br-PC blend was increased with the increase of Br-PC in the blend, and the blend showed a single T$_{g}$, which suggests a miscible blend. The sag resistance time of the L-PC/Br-PC blend was increased with the increase of Br-PC in the blends. From the results of rheological measurements of the L-PC/Br-PC blends, the extensional viscosity and the complex viscosity of the blends were found to increase with the increase of Br-PC in the blends. The increase of extensional viscosity and complex viscosity was related with the increase of sag resistance time with the Br-PC in the L-PC/Br-PC blends.nds.

Correlation between the Salmonella seroprevalence on farms and the isolation rate from slaughtered pigs and antimicrobial resistance from the isolates (양돈장 살모넬라 혈청 양성율과 도축돈 살모넬라균 분리율의 상관관계 및 분리 균주의 항생제 내성)

  • Kim, Kyung-Eon;An, Jong-Min;Yang, Byung-Hun;Park, Yeong-Hee;Park, Mi-Young;Jung, Joon-Yong
    • Korean Journal of Veterinary Service
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    • v.37 no.4
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    • pp.233-240
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    • 2014
  • Salmonella spp. are one of the most common bacteria that causes heavy losses in swine industry and have implications for public health. In this study, the correlation between Salmonella seroprev-alence on farms and the isolation rate from slaughtered pigs was analyzed and the antimicrobial resistance of the isolated Salmonella spp. was investigated. A total of 3,001 serum samples for ELISA were collected from 17 farms during two consecutive years (2012-2013). The mean values of ELISA OD% for each 8 age groups were as follows; gilt 27.83 (n=472), sow 23.75 (n=367), 150 days (d) of pig 16.53 (n=278), 130 d 11.87 (n=366), 100 d 9.46 (n=378), 20 d 9.17 (n=394), 70 d 6.56 (n=382), 40 d 3.72 (n=364). From July 2013 to January 2014, a total of 53 (8.0%) Salmonella strains were isolated from 665 slaughtered pigs shipped from those 17 farms. The mean values of ELISA OD% for each age groups serum samples that were collected in the second half of 2013 showed a positive correlation at 100 d (0.61, P<0.05), 130 d (0.45, P<0.1) with the isolation rate of Salmonella spp. in the slaughtered pigs. All the isolates were identified by a real-time PCR and tested for antimicrobial susceptibility. As a result, the predominant serovar was S. Typhimurium (52.8%) and there were 15 strains showing their own antimicrobial resistance pattern. All strains were susceptible to amoxicillin, cefepime, ciprofloxacin and some of them were resistant to streptomycin and tetracycline (60%), ampicillin (53.3%), chloramphenicol (33.3%), respectively.

A Study on the Ship Resistance and Moment Prediction for Running Attitude of 30 Feet Catamaran Sailing Yacht (30ft급 쌍동형 세일링 요트의 항주자세에 따른 실선저항 및 모멘트 추정에 대한 연구)

  • Park, Chung-Hwan;Jang, Ho-Yun;Jeong, Jin-Wook;Lee, Byung-Sung;Chun, Ho-Hwan
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.3
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    • pp.321-327
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    • 2010
  • During sailing by wind-driven thrust on the sail, a catamaran sailing yacht generates leeway and heeling. For estimating resistance and moment prediction of a real ship by changing of running attitude, a model test of the ship has to be carried out. This study aims at establishing experimental techniques for a catamaran sailing yacht by changed attitude during running direction. Through the model test, drag and side force of the real ship are predicted. Also through experiment, rolling and yawing moments were considered.