• Title/Summary/Keyword: Selective growth

Search Result 619, Processing Time 0.034 seconds

Development of a Selective Medium for the Fungal Pathogen Cylindrocarpon destructans Using Radicicol

  • Kang, Yunhee;Lee, Seung-Ho;Lee, Jungkwan
    • The Plant Pathology Journal
    • /
    • v.30 no.4
    • /
    • pp.432-436
    • /
    • 2014
  • The soil-borne ascomycete fungus Cylindrocarpon destructans causes ginseng root rot disease and produces various secondary metabolites such as brefeldin A and radicicol. The slow growth of this fungus compared with other plant pathogenic and saprophytic fungi in soil disturbs isolation of this fungus from soil and infected ginseng. In this study, we developed a selective medium for C. destructans using radicicol produced by this fungus. Supplementing 50 mg/L of radicicol to medium inhibited the mycelia growth of other fungi including Botrytis cinerea, Rhizoctonia solani and Alternaria panax, but did not affect the growth of C. destructans. In addition, conidia germination of other fungal species except for C. destructans was inhibited in submerged culture supplemented with radicicol. This medium provides a very efficient tool for isolating C. destructans and also can be used as an enrichment medium for this fungus.

40 Gb/s Traveling-Wave Electroabsorption Modulator-Integrated DFB Lasers Fabricated Using Selective Area Growth

  • Kwon, Yong-Hwan;Choe, Joong-Seon;Sim, Jae-Sik;Kim, Sung-Bock;Yun, Ho-Gyeong;Choi, Kwang-Seong;Choi, Byung-Seok;Nam, Eun-Soo
    • ETRI Journal
    • /
    • v.31 no.6
    • /
    • pp.765-769
    • /
    • 2009
  • In this paper, we present the fabrication of 40 Gb/s traveling-wave electroabsorption modulator-integrated laser (TW-EML) modules. A selective area growth method is first employed in 40 Gb/s EML fabrication to simultaneously provide active layers for lasers and modulators. The 3 dB bandwidth of a TW-EML module is measured to be 34 GHz, which is wider than that of a lumped EML module. The 40 Gb/s non-return-to-zero eye diagram shows clear openings with an average output power of +0.5 dBm.

Evaluation of Cytotoxicity Effects of Chalcone Epoxide Analogues as a Selective COX-II Inhibitor in the Human Liver Carcinoma Cell Line

  • Makhdoumi, Pouran;Zarghi, Afshin;Daraei, Bahram;Karimi, Gholamreza
    • Journal of Pharmacopuncture
    • /
    • v.20 no.3
    • /
    • pp.207-212
    • /
    • 2017
  • Objectives: Study of the mechanisms involved in cancer progression suggests that cyclooxygenase enzymes play an important role in the induction of inflammation, tumor formation, and metastasis of cancer cells. Thus, cyclooxygenase enzymes could be considered for cancer chemotherapy. Among these enzymes, cyclooxygenase 2 (COX-2) is associated with liver carcinogenesis. Various COX-2 inhibitors cause growth inhibition of human hepatocellular carcinoma cells, but many of them act in the COX-2 independent mechanism. Thus, the introduction of selective COX-2 inhibitors is necessary to achieve a clear result. The present study was aimed to determine the growth-inhibitory effects of new analogues of chalcone epoxide as selective COX-2 inhibitors on the human hepatocellular carcinoma (HepG2) cell line. Methods: Estimation of both cell growth and the amount of prostaglandin E2 (PGE2) production were used to study the effect of selective COX-2 inhibitors on the hepatocellular carcinoma cell. Cell growth determination has done by MTT assay in 24 h, 48 h and 72 h, and PGE2 production has estimated by using ELYSA kit in 48 h and 72 h. Results: The results showed growth inhibition of the HepG2 cell line in a concentration and time-dependent manner, as well as a reduction in the formation of PGE2 as a product of COX-2 activity. Among the compounds those analogues with methoxy and hydrogen group showed more inhibitory effect than others. Conclusion: The current in-vitro study indicates that the observed significant growth-inhibitory effect of chalcone-epoxide analogues on the HepG2 cell line may involve COX-dependent mechanisms and the PGE2 pathway parallel to the effect of celecoxib. It can be said that these analogues might be efficient compounds in chemotherapy of COX-2 dependent carcinoma specially preventing and treatment of hepatocellular carcinomas.

Growth and Etching of Epitaxial Layer and Polysilicon for the Selective Epitaxy (선택적 에피택시를 위한 에피택셜층 및 폴리실리콘의 성장과 에칭)

  • 조경익;김창수
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.22 no.1
    • /
    • pp.34-40
    • /
    • 1985
  • An investigation has been made on the growth phenomena of epitaxial layer and polysilicon from SiH2 Cl2 in H2 and the etch phenomena of them from HCI in H2, at the system pressures of 1.0 atm (atmospheric process) and 0.1 attn (reduced pressure process). From the experimental equations for the growth rates and etch rates. the relevant process conditions for the selective epitaxy are predicted for the case of using mixtures of SiH2Cl2 and HCI in H2. As a result, it is found that selective epitaxial growth region exists in the concentration range investigated for the reduced pressure process but it does not for the atmospheric Process. This is due to the differences in the growth rates and etch rates at atmospheric and reduced pressure.

  • PDF

Analysis of Film Growth in InGaN/GaN Quantum Wells Selective Area Metalorganic Vapor Phase Epitaxy including Surface Diffusion (InGaN/GaN 양자우물의 SA-MOVPE에서 표면확산을 고려한 박막성장 해석)

  • Im, Ik-Tae;Youn, Suk-Bum
    • Journal of the Semiconductor & Display Technology
    • /
    • v.10 no.3
    • /
    • pp.29-33
    • /
    • 2011
  • Film growth rate and composition variation are numerically analyzed during the selective area growth of InGaN on the GaN triangular stripe microfacet in this study. Both the vapor phase diffusion and the surface diffusion are considered to determine the In composition on the InGaN surface. To obtain the In composition on the surface, flux of In atoms due to the surface diffusion is added to the concentration determined from the Laplace equation which is governing the gas phase diffusion. The solution model is validated by comparing the growth rates from the analyses to the experimental results of GaN and InN films. The In composition and resulting wave length are increased when the surface diffusion is considered. The In content is also increased according to the increasing mask width. The effect of mask width to the In content and wave length is increasing in the case of a small open region.

Selective Antiproliferative and Apoptotic Effects of Quercetin in Normal Versus Tumorigenic Hepatic Cell Lines

  • Jeon, Young-Mi;Kim, Jong-Ghee;Lee, Jeong-Chae
    • Natural Product Sciences
    • /
    • v.10 no.3
    • /
    • pp.129-133
    • /
    • 2004
  • Quercetin is a dietary anticancer chemical that is capable of inducing apoptosis in tumor cells. However, little is known about its biological effect in nonmalignant hepatic cells. Using embryonic normal hepatic cell line (BNL CL.2) and its SV40-transformed tumorigenic cell line (BNL SV A.8), we evaluated the effects of quercetin on cell proliferation and apoptosis. As the results, our present study demonstrated that quercetin had a selective growth inhibition in normal versus tumorigenic hepatic cells such that BNL SV A.8 cells were very sensitive to the quercetin-mediated cytotoxicity. In particular, as evidenced by the increased number of positively stained cells in the TUNEL assay, the induction of characteristic nuclear DNA ladders, and the migration of many cells to sub-G1 phase in the BNL SV A.8 cells, quercetin treatment more sensitively induced apoptosis in BNL SV A8 cells than in BNL CL.2 cells. Collectively, our findings suggest that quercetin can be approached as a potential agent that is capable of inducing selective growth inhibition and apoptosis of hepatic cancer cells.

Selective Si Epitaxial Growth by Control of Hydrogen Atmosphere During Heating-up (승온중 수소 분위기 제어에 의한 선택적 Si 에피텍시 성장)

  • Son, Yong-Hun;Park, Seong-Gye;Kim, Sang-Hun;Nam, Seung-Ui;Kim, Hyeong-Jun
    • Korean Journal of Materials Research
    • /
    • v.12 no.5
    • /
    • pp.363-368
    • /
    • 2002
  • we proposed the use of $Si_2H_ 6/H_2$ chemistry for selective silicon epitaxy growth by low-pressure chemical vapor deposition(LPCVD) in the temperature range $600~710^{\circ}C$ under an ultraclean environment. As a result of ultraclean processing, an incubation period of Si deposition only on $SiO_2$ was found, and low temperature epitaxy selective deposition on Si was achieved without addition of HCI. Total gas flow rate and deposition pressure were 16.6sccm and 3.5mtorr, respectively. In this condition, we selectively obtained high-quality epitaxial Si layers of the 350~1050$\AA$ thickness. In older to extend the selectivity, we kept high pressure $H_2$ environment without $Si_2H_6$ gas for few minutes after first incubation period and then we conformed the existence of second incubation period.

Effect of Kimchi ingredients on the growth of pathogenic and lactic acid bacteria (김치부재료의 유산균 증식 및 유해균 억제효과)

  • Kang, Sun-Yi;Han, Myung-Joo
    • Korean journal of food and cookery science
    • /
    • v.21 no.6 s.90
    • /
    • pp.838-843
    • /
    • 2005
  • When ingredients of Kimchi were mixed and stored in $18^{\circ}C$, lactic acid bacteria, such as Leuconostoc mesenteroides and Lactobacillus plantarum, were selectively grown up. Herefore, to understand why lactic acid bacteria were selectively cultured in Kimchi, antibacterial activities of Kimchi ingredients against some pathogens and Kinlchi lactic acid bacteria were investigated. Kimchi mixed with all ingredients significantly inhibited the growth of all tested pathogens: S. typhimurium, S. sonnei, and E. coli. Kimchi without green onion, garlic or ginger inhibited the growth of S. typhimurium, but did not E. coli and S. sonnei. However, Kimchi without red pepper powder did not inhibit the growth of all tested pathogens. All ingredients of Kimchi did not inhibit the growth of L. plantarum and L. mesenteroides. These results suggest that Kimchi ingredients can synergistically inhibit the growth of pathogens and Kimchi may be a selective medium for lactic acid bacteria.

SiGe Nanostructure Fabrication Using Selective Epitaxial Growth and Self-Assembled Nanotemplates

  • Park, Sang-Joon;Lee, Heung-Soon;Hwang, In-Chan;Son, Jong-Yeog;Kim, Hyung-Jun
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • 2009.05a
    • /
    • pp.24.2-24.2
    • /
    • 2009
  • Nanostuctures such as nanodot and nanowire have been extensively studied as building blocks for nanoscale devices. However, the direct growth of the nanostuctures at the desired position is one of the most important requirements for realization of the practical devices with high integrity. Self-assembled nanotemplate is one of viable methods to produce highly-ordered nanostructures because it exhibits the highly ordered nanometer-sized pattern without resorting to lithography techniques. And selective epitaxial growth (SEG) can be a proper method for nanostructure fabrication because selective growth on the patterned openings obtained from nanotemplate can be a proper direction to achieve high level of control and reproducibility of nanostructucture fabrication. Especially, SiGe has led to the development of semiconductor devices in which the band structure is varied by the composition and strain distribution, and nanostructures of SiGe has represented new class of devices such nanowire metal-oxide-semiconductor field-effect transistors and photovoltaics. So, in this study, various shaped SiGe nanostructures were selectively grown on Si substrate through ultrahigh vacuum chemical vapor deposition (UHV-CVD) of SiGe on the hexagonally arranged Si openings obtained using nanotemplates. We adopted two types of nanotemplates in this study; anodic aluminum oxide (AAO) and diblock copolymer of PS-b-PMMA. Well ordered and various shaped nanostructure of SiGe, nanodots and nanowire, were fabricated on Si openings by combining SEG of SiGe to self-assembled nanotemplates. Nanostructure fabrication method adopted in this study will open up the easy way to produce the integrated nanoelectronic device arrays using the well ordered nano-building blocks obtained from the combination of SEG and self-assembled nanotemplates.

  • PDF

Selective Epitaxial Growth of Si and SiGe using Si-Ge-H-Cl System for Self-Aligned HBT Applications (Si-Ge-H-Cl 계를 이용한 자기정렬 HBT용 Si 및 SiGe의 선택적 에피성장)

  • 김상훈;박찬우;이승윤;심규환;강진영
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.7
    • /
    • pp.573-578
    • /
    • 2003
  • Low temperature selective epitaxial growth of Si and SiGe has been obtained using an industrial single wafer chemical vapor deposition module operating at reduced pressure. Epitaxial Si and heteroepitaxial SiGe deposition with Ge content about 20 % has been studied as extrinsic base for self-aligned heterojunction bipolar transistors(HBTs), which helps to reduce the parasitic resistance to obtain higher maximum oscillation frequencies(f$\_$max/). The dependence of Si and SiGe deposition rates on exposed windows and their evolution with the addition of HCl to the gas mixture are investigated. SiH$_2$Cl$_2$ was used as the source of Si SEG(Selective Epitaxial Growth) and GeH$_4$ was added to grow SiGe SEG. The addition of HCl into the gas mixture allows increasing an incubation time even low growth temperature of 675∼725$^{\circ}C$. In addition, the selectivity is enhanced for the SiGe alloy and it was proposed that the incubation time for the polycrystalline deposit on the oxide is increased probably due to GeO formation. On the other hand, when only SiGe SEG(Selective Epitaxial Growth) layer is used for extrinsic base, it shows a higher sheet resistance with Ti-silicide because of Ge segregation to the interface, but in case of Si or Si/SiGe SEG layer, the sheet resistance is decreased up to 70 %.