Effects of In-Situ Annealed Buffer Layers in Oxygen Plasma on Properties of ZnO Epitaxial Layers Grown by Plasma-Assisted Molecular Beam Epitaxy

Min Su Kim,Do Yeob Kim,Ghun Sik Kim,Hyun Young Choi,Min Young Cho,Su Min Jeon,Kwang Gug Yim,Ji Hoon Kim,Dong-Yul Lee,Joo In Lee,Sung Dong Park,Eundo Kim,Myong Hyo Jung,Do-Weon Hwang,Jae-Young Leem 한국진공학회 2009 한국진공학회 학술발표회초록집 Vol.37 No.-

Deep Sequencing Analysis of Apple Infecting Viruses in Korea

Cho, In-Sook,Igori, Davaajargal,Lim, Seungmo,Choi, Gug-Seoun,Hammond, John,Lim, Hyoun-Sub,Moon, Jae Sun The Korean Society of Plant Pathology 2016 Plant Pathology Journal Vol.32 No.5

Deep sequencing has generated 52 contigs derived from five viruses; Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV), Apple stem pitting virus (ASPV), Apple green crinkle associated virus (AGCaV), and Apricot latent virus (ApLV) were identified from eight apple samples showing small leaves and/or growth retardation. Nucleotide (nt) sequence identity of the assembled contigs was from 68% to 99% compared to the reference sequences of the five respective viral genomes. Sequences of ASPV and ASGV were the most abundantly represented by the 52 contigs assembled. The presence of the five viruses in the samples was confirmed by RT-PCR using specific primers based on the sequences of each assembled contig. All five viruses were detected in three of the samples, whereas all samples had mixed infections with at least two viruses. The most frequently detected virus was ASPV, followed by ASGV, ApLV, ACLSV, and AGCaV which were withal found in mixed infections in the tested samples. AGCaV was identified in assembled contigs ID 1012480 and 93549, which showed 82% and 78% nt sequence identity with ORF1 of AGCaV isolate Aurora-1. ApLV was identified in three assembled contigs, ID 65587, 1802365, and 116777, which showed 77%, 78%, and 76% nt sequence identity respectively with ORF1 of ApLV isolate LA2. Deep sequencing assay was shown to be a valuable and powerful tool for detection and identification of known and unknown virome in infected apple trees, here identifying ApLV and AGCaV in commercial orchards in Korea for the first time.

타액선 종양의 임상적 고찰

장은기,김병철,나인국,김형종,노영수,임현준 釜算慶南耳鼻咽喉科學會 1993 임상이비인후과 Vol.4 No.1

거제도 백로와 서식지 환경표본에서 분리한 Salmonella의 Serotypes 분포 조사 및 Molecular Typing

우용구,박진영,이영주,권용국,모인필 한국수의공중보건학회 2001 예방수의학회지 Vol.25 No.3

Since 1997, three large scale unknown death had consecutively appeared in the wild heron flocks in Geo-Je island until 1999. Until now, there has been only a little information on the Salmonella spp. originated from the wild animals in our peninsular. Hence, the objective of this study was to obtain the epidemiological characteristics related to Salmonella strains cultured from wild herons and environmental samples in Geo-Je island using the serotyping, antibiograms, plasmid profiles, and random amplified polymorphic of DNA (RAPD) profiles. A total of fifty-five Salmonella strains were isolated from liver and cecal contents of wild herons captured in Geo-Je island on August in 2000. Among the wild heron species tested, Ardea Cinerea jouyi (Clark) was shown the most high Salmonella isolation frequency (38.5%) and Egretta alba modesta (Gray) was followed as 15.4% (2/13), but any Salmonella could not isolate from the other species. Among the five serotypes identified, S. typhimurium (70.3%) was the most predominant serotype in the wild heron flocks and S. hadar (21.3%), S. wippra (4.3%), S. california (2.2%) and S. chincol (2.2%) were followed in order. S. wippra and S. chincol were reported as the first time among the domestic avian Salmonella serotypes since 1994. Three serotypes including S. typhimurium, S. hadar and S. chincol were commonly cultured from the internal organs of herons, whereas S. wippra was cultured only from the environmental sample, especially in the earth sample. In antimicrobial drug susceptibility test, all Salmonella strains from internal organs of heron were susceptible to all drugs tested, whereas strains from environmental samples were shown the resistance to carbenicillin, doxycyclin, tetracycline and oxytetracycline, respectively. Antibiogram pattern alone could discriminate into two types depending on their isolated origins. The serotype specific plasmid (60 MDa) was found in most of ST isolates (65%) and all strains had also the invA gene (284 bp) by PCR. These two genetic materials (SSP and invA gene) were known as a kind of virulence factors of pathogenic ST strains. The genetic relatedness was also compared between the ST strains from different sources using the random amplified polymorphism of DNA (RAPD) method. As a results, the present method was found as a rapid, efficient and useful tools to differentiate the same Salmonella serotype without specific difficulties in manipulation.

A 50–450 MHz Tunable RF Biquad Filter Based on a Wideband Source Follower With > 26 dBm IIP<tex> $_{3}$</tex>, +12 dBm P<tex> $_{1{\rm dB}}$</tex>, and 15 dB Noise Figure

In-Young Lee,Donggu Im,Jinho Ko,Sang-Gug Lee IEEE 2015 IEEE journal of solid-state circuits Vol.50 No.10

<P>This paper reports a source follower-based active RC filter topology for RF front-ends in wideband systems. In the proposed active RC filter, the noise figure and bandwidth are improved through adopting the proposed sub-1 Ω Z<SUB>out</SUB> source follower, which replaces the conventional operational amplifier-based unity gain buffer and through simply changing its location in the filter. Applying the proposed scheme to the conventional Sallen-Key filter also improves the stopband rejection performance. Furthermore, the proposed filter topology ultimately suppresses the DC offset voltage and flicker noise of the unity gain buffer, which is the only active circuit in the filter. The proposed biquad filter is implemented in 0.18 μm CMOS and the measurements exhibit >26 dBm IIP<SUB>3</SUB>, +12 dBm input P<SUB>1dB</SUB>, and 15 dB noise figure over 50-450 MHz of a 6 bit tunable frequency range. The proposed biquad filter consumes 14 mA from a 1.8 V supply and the chip occupies 1000 ×500 μm<SUP>2</SUP>.</P>

Spur Reduction Techniques With a Switched-Capacitor Feedback Differential PLL and a DLL-Based SSCG in UHF RFID Transmitter

In-Young Lee,Seungjin Kim,Sang-Sung Lee,Jeongki Choi,Jinho Ko,Sang-Gug Lee IEEE 2015 IEEE transactions on microwave theory and techniqu Vol.63 No.4

<P>This paper presents a robust spur reduction technique using a switched-capacitor feedback differential phase-locked loop (PLL) and a delay-locked-loop (DLL)-based spread-spectrum clock generation in a UHF-band RF identification transmitter (TX). The proposed differential PLL is characterized by adopting a switched-capacitor common-mode feedback and distributed varactor biasing scheme to the differential charge pump and voltage-controlled oscillator designs, respectively, which results in down to 94 dBc in reference spur rejection with all digital parts off. Additionally, by adopting an 8-bit DLL and Hershey-Kiss modulated profile together, the proposed spread-spectrum clock generator shows more than 20-dB electromagnetic-interference reduction while providing up-, down-, and center-spread modes. Implemented in a 0.18m CMOS process, the proposed TX achieves <; - 80-dBc spur suppression with 25-dBm transmit power at 920 MHz, which complies with the most stringent regulatory spectral mask without a surface acoustic wave filter.</P>

Mice 소장의 Cajal 세포에서 기록되는 향도잡이 전류의 특성

장성종 ( Jang Seong Jong ),조은택 ( Jo Eun Taeg ),허광식 ( Heo Gwang Sig ),박찬국 ( Park Chan Gug ),김만우 ( Kim Man U ),장인엽 ( Jang In Yeob ),신무경 ( Sin Mu Gyeong ),차경훈 ( Cha Gyeong Hun ),염철호 ( Yeom Cheol Ho ),전제열 ( 대한소화기학회 2003 대한소화기학회지 Vol.42 No.2

Background/Aims: Gastrointestinal motility is initiated by the periodic generation of slow waves. Interstitial cells of Cajal (ICC) are pacemaker cells that generate slow waves and drive spontaneous mechanical contractions of the gastrointestinal smooth muscle. Slow waves generate the periodic activation of spontaneous inward currents (pacemaker currents). The aim of this study was to investigate the characterization of pacemaker currents of ICC. Methods: The ICC in mice small intestine were cultured with stem cell factor for 2 days, and then we recorded pacemaker currents and slow waves using a whole-cell patch clamp technique. Results: Under voltage clamp at -80 mV of holding potential, ICC generated pacemaker currents. Tetrodotoxin and nifedipine did not affect on the pacemaker currents. In addition, tetraethylammonium, 4-aminopyridine and glibenclamide did not affect on the pacemaker currents. The reduction of external Na+ concentrations inhibited pacemaker currents. Moreover, these currents were completely abolished in the external Ca2+-free condition. Gadolinium and flufenamic acid, inhibitors of non-selective cationic currents, inhibited pacemaker currents. Thapsigargin and cyclopiazoic acid, inhibitors of Ca2+-ATPase in endoplasmic reticulum, abolished pacemaker currents. Carbachol depolarized membrane potential and increased inward currents. Conclusions: These results suggest that pacemaker currents are mediated by the activation of non-selective cation channel and become a target of neurotransmitters in regulation of intestinal motility. (Korean J Gastroenterol 2003;42:121-127)

First report of Cucumber mosaic virus in African Impatiens (Impatiens walleriana) in Korea

Choi, Seung Kook,Choi, Gug-Seoun,Kwon, Sun-Jung,Cho, In-Sook,Yoon, Ju-Yeon The Korean Society of Plant Pathology 2015 식물병연구 Vol.21 No.4

Virus-like symptoms including stunt, severe mosaic with malformation of leaves, fern-like leaves and abnormal petals were observed from an African impatiens (Impatiens walleriana) grown in a plant nursery in Icheon, Korea. Serological analysis using immuno-strip kits for viruses reported in African impatiens indicated that Cucumber mosaic virus (named CMV-Im) was a causal agent for the symptomatic African impatiens. Biological properties of CMV-Im were analyzed using responses of host plant species, suggesting that CMV-Im is a typical strain that belongs to CMV subgroup I. RT-PCR analysis verified CMV-Im infection from naturally infected African impatiens or mechanically inoculated some host species. Analysis of multiple alignments of CMV capsid protein (CP) sequences showed that CMV-Im shared high CP amino acids identities with other CMV strains. Phylogenetic tree analysis for the CP sequences of CMV-Im and representative CMV strains confirmed that CMV is a typical member of CMV subgroup I. To our knowledge, it is the first report of CMV in African impatiens in Korea.

Construction of Infectious cDNA Clone of a Chrysanthemum stunt viroid Korean Isolate

Yoon, Ju-Yeon,Cho, In-Sook,Choi, Gug-Seoun,Choi, Seung-Kook The Korean Society of Plant Pathology 2014 Plant Pathology Journal Vol.30 No.1

Chrysanthemum stunt viroid (CSVd), a noncoding infectious RNA molecule, causes seriously economic losses of chrysanthemum for 3 or 4 years after its first infection. Monomeric cDNA clones of CSVd isolate SK1 (CSVd-SK1) were constructed in the plasmids pGEM-T easy vector and pUC19 vector. Linear positive-sense transcripts synthesized in vitro from the full-length monomeric cDNA clones of CSVd-SK1 could infect systemically tomato seedlings and chrysanthemum plants, suggesting that the linear CSVd RNA transcribed from the cDNA clones could be replicated as efficiently as circular CSVd in host species. However, direct inoculation of plasmid cDNA clones containing full-length monomeric cDNA of CSVd-SK1 failed to infect tomato and chrysanthemum and linear negative-sense transcripts from the plasmid DNAs were not infectious in the two plant species. The cDNA sequences of progeny viroid in systemically infected tomato and chrysanthemum showed a few substitutions at a specific nucleotide position, but there were no deletions and insertions in the sequences of the CSVd progeny from tomato and chrysanthemum plants.

400km/h급 전차선로 터널 하수강 구조안전성 분석

유향복(Hyang-Bok Ryoo),정상국(Sang-Gug Jeong),이인희(In-Hee Lee),송정관(Jung-Koan Song),우대현(Dai-Hyun Woo) 한국철도학회 2013 한국철도학회 학술발표대회논문집 Vol.2013 No.5

고속철도 건설과 차량개발에 대한 우리나라의 현재 수준은 차세대고속열차(HEMU-430X)를 개발하여 경부고속철도 구간에서 증속 시험운행중에 있으며, 400km/h급의 전차선로 시스템은 호남고속철도의 일부 구간을 시범적으로 선정하여 설치할 계획에 있다. 400km/h급의 전차선로는 상시 가선장력이 올라가 각종 지지물에 가해지는 상정하중이 증가하게 된다. 시범구간에는 터널이 존재하며 터널용 하수강을 사용하게 되며 터널 라이닝에 사전 매립된 C-챤넬에 고정하게 된다. 국내에서 처음 설계/시공되어지는 특성상 하수강의 구조적 안전성과 C-챤넬의 인발하중을 검토할 필요성이 있다. 본 연구에서는 토목공사에 반영된 C-챤넬의 규격, 공장시험결과, 시공상세도와 터널 하수강의 설계자료를 토대로 구조적 안전성을 분석하였다. In Korea, the newest technology concerning high-speed train construction and vehicle development is the next generation high-speed train (HEMU-430X). There is testing being done on the train in the Gyeongbu high-speed train section. The 400km/hour class track system is to be installed in the subinterval of Honam high-speed rail and will act as an example of how the train works. In the 400km/hour-class track, the weight that is on the supports increases because of growing real time stringing tension. In that section there is a tunnel which has vertical drop supports. It also has a c-channel fixing system, which had been previously installed in the tunnel. It is necessary to review the structural safety of the vertical drops and the pull out load of the c-channel. In this study we analyzed the structural safety by observing the quality of the c-channel based on engineering work, factory test results, and construction detail drawings. We also considered the design data of the vertical drop supports in the tunnel for our analyzation.