• Title/Summary/Keyword: Novel Structure

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Design of Novel Ras Farnesyltransferase Inhibitors Based on Virtual Screening and Docking Studies

  • Jung, Kang-Rae;Park, Hyung-Yeon;Kim, Chan-Kyung;Lee, Bon-Su
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.175.2-175.2
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    • 2003
  • Inhibition of the protein-modifying enzyme farnesyltransferase is considered as a major emerging strategy in cancer therapy because of the involvement of farnesylated proteins in oncogensis. We studied the structure-activity relationship of a novel class of CAAX-peptidomimetic farnesyltransferase inhibitors based on the benzophenone scaffold. FlexX docking of inhibitors confirmed reasonable fit of the molecule into the peptide binding site of farnesyltransferase. We also performed a virtual screening with LeadQuest chemical library databases to idenfity novel inhibitors of farnesyltransferase. (omitted)

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Dynamic Characterization of Sub-Scaled Building-Model Using Novel Optical Fiber Accelerometer System

  • Kim, Dae-Hyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.6
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    • pp.601-608
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    • 2011
  • This paper presents the damage assessment of a building structure by using a novel optical fiber accelerometer system. Especially, a sub-scaled building model is designed and manufactured to check up the feasibility of the optical fiber accelerometer for structural health monitoring. The novel accelerometer exploits the moir$\acute{e}$ fringe optical phenomenon and two pairs of optical fibers to measure the displacement with a high accuracy, and furthermore a pendulum to convert the displacement into acceleration. A prototype of optical fiber accelerometer system has been successfully developed that consists of a sensor head, a control unit and a signal processing unit. The building model is also designed as a 4-story building with a rectangular shape of $200{\times}300$ mm of edges. Each floor is connected to the next ones by 6 steel columns which are threaded rods. Basically, a random vibration test of the building model is done with a shaker and all of acceleration data is successfully measured at the assigned points by the optical fiber accelerometer. The experiments are repeated in the undamaged state and the damaged state. The comparison of dynamic parameters including the natural frequencies and the eigenvectors is successfully carried out. Finally, the optical fiber accelerometer is proven to be prospective to evaluate dynamic characteristics of a building structure for the damage assessment.

Identification of a novel type of small molecule inhibitor against HIV-1

  • Kim, Byung Soo;Park, Jung Ae;Kim, Min-Jung;Kim, Seon Hee;Yu, Kyung Lee;You, Ji Chang
    • BMB Reports
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    • v.48 no.2
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    • pp.121-126
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    • 2015
  • Here we report a new chemical inhibitor against HIV-1 with a novel structure and mode of action. The inhibitor, designated as A1836, inhibited HIV-1 replication and virus production with a 50% inhibitory concentration ($IC_{50}$) of $2.0{\mu}M$ in an MT-4 cell-based and cytopathic protection antiviral assay, while its 50% cytotoxic concentration ($CC_{50}$) was much higher than $50{\mu}M$. Examination of the effect of A1836 on in vitro HIV-1 reverse transcriptase (RT) and integrase showed that neither were molecular targets of A1836. The characterization and re-infection assay of the HIV-1 virions generated in the presence of A1836 showed that the synthesis of early RT products in the cells infected with the virions was inhibited dose-dependently, due in part to abnormal protein formation within the virions, thus resulting in an impaired infectivity. These results suggest that A1836 might be a novel candidate for the development of a new type of HIV-1 inhibitor.

SABA (secondary structure assignment program based on only alpha carbons): a novel pseudo center geometrical criterion for accurate assignment of protein secondary structures

  • Park, Sang-Youn;Yoo, Min-Jae;Shin, Jae-Min;Cho, Kwang-Hwi
    • BMB Reports
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    • v.44 no.2
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    • pp.118-122
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    • 2011
  • Most widely used secondary structure assignment methods such as DSSP identify structural elements based on N-H and C=O hydrogen bonding patterns from X-ray or NMR-determined coordinates. Secondary structure assignment algorithms using limited $C{\alpha}$ information have been under development as well, but their accuracy is only ~80% compared to DSSP. We have hereby developed SABA (Secondary Structure Assignment Program Based on only Alpha Carbons) with ~90% accuracy. SABA defines a novel geometrical parameter, termed a pseudo center, which is the midpoint of two continuous $C{\alpha}s$. SABA is capable of identifying $\alpha$-helices, $3_{10}$-helices, and $\beta$-strands with high accuracy by using cut-off criteria on distances and dihedral angles between two or more pseudo centers. In addition to assigning secondary structures to $C{\alpha}$-only structures, algorithms using limited $C{\alpha}$ information with high accuracy have the potential to enhance the speed of calculations for high capacity structure comparison.

Synthesis and Properties of Novel Flame Retardant Poly(butylene terephthalate)

  • Park Jong Min;Park Yun Heum
    • Macromolecular Research
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    • v.13 no.2
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    • pp.128-134
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    • 2005
  • The phosphorus comonomer [(6-oxido-6H-dibenz<1,2>oxaphosphorin-6-yl)methyl]-methyl butane-dioate (DOP-MBDA) was synthesized through the addition reaction of dimethyl itaconate (DMI) with 9,10-dihydro­9-oxa-10-phosphaphenan threne-10-oxide (DOP). A series of novel flame retardant poly(butylene terephthalate)s (PBTs) containing different amounts of phosphorus were prepared using DOP-MBDA as a comonomer. These novel polymers were characterized by $^{1}H-NMR$, IR, and differential scanning calorimetry (DSC). The novel phosphorus­containing poly(butylene terephthalate)s, referred to as FR-PBTs, exhibited interesting thermal and mechanical behavior, as well as superior flame retardancy. These properties are attributed to the effect of incorporating the rigid structure of DOP-MBDA and the pendant phosphorus group into the poly(butylene terephthalate) (PBT) homopolymer. The UL 94-V2 rating could be achieved with this novel flame retardant PBT, which has a phosphorus content as low as $0.5 wt\%$, and the FR-PBTs emitted less fumes and toxic gases than the PBT homopolymer.

Self-Pulsation in Multisection Distributed Feedback Laser Diode with a Novel Dual Grating Structure

  • Park, Kyung-Hyun;Leem, Young-Ahn;Yee, Dae-Su;Baek, Yong-Soon;Kim, Dong-Churl;Kim, Sung-Bock;Sim, Eun-Deok
    • ETRI Journal
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    • v.25 no.3
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    • pp.149-155
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    • 2003
  • A self-pulsating multisection distributed-feedback laser diode (DFB LD) can potentially realize all-optical clock extraction. This device generally consists of three sections, two DFB sections and one waveguide section. The most important variable in this device is detuning, which is the relative spectral position between the stop bands of two DFB sections. We fabricated a novel structure in which two gratings were located one over and one under the active layers. Each grating structure was independently defined in processing so that detuning, which is the prerequisite for self-pulsation, could be easily controlled. Observing various self-pulsating phenomena in these devices under several detuning conditions, we characterized the phenomena as dispersive Q-switching, mode beating, and self-mode-locking.

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Performance Evaluation and Comparison of Conventional 12/8 and Novel 6/5 Switched Reluctance Motors (기존 12/8 및 새로운 6/5 SRM의 성능분석 및 비교)

  • Xu, Zhenyao;Lee, Dong-Hee;Ahn, Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2016.07a
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    • pp.517-518
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    • 2016
  • In this paper, a novel 6/5 switched reluctance motor (SRM) with segmental rotor is proposed for vehicle cooling fan application. Unlike conventional SRMs, the proposed motor adopts hybrid stator poles and segmental rotor structures, thereby making the motor operate in short flux paths and parts of the flux paths magnetically isolated between the phases. Therefore, compared with conventional SRMs, the proposed structure could improve the output torque density and reduce the core loss, thereby improving the electric utilization of the motor. To verify the proposed structure, the performance of the proposed structure is evaluated. Meanwhile, a conventional 12/8 SRM which has been used for vehicle cooling fan application is also evaluated. Finally, the effectiveness of the proposed SRM is demonstrated by the simulation and experimental results.

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Investigation of Hg free Electrodeless inductively capacitive tubular discharge (무수은 무전극 유도-용량형 직관형 램프 방전에 관한 연구)

  • 이태일;박해일;백홍구
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2002.11a
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    • pp.191-196
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    • 2002
  • In this paper we introduce novel electrode structure for high efficiency discharge. We operate discharge tube under the 0.16 torr pure Xe and apply the sinusoidal wave power to the lamp with 60kHz. We measure the electric power dissipation, plasma parameters, and 828 nm IR intensity. From these data we determine the discharge efficiency, IR intensity/watt, EEDF(Electron energy distribution function). As a result we obtain that the novel electrode structure has better performance in efficiency than that of conventional external electrode system. Also we determine the EEDF for each type of electrode structure by Boltzmann stover, EELNDIF code. The result of Boltzmann equation solving show that the noble electrode system has many high energy electrons compared with the conventional system.

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Crystal Structure of MJ0684 from Methanococcus jannaschii, a Novel Archaeal Homolog of Kynurenine Aminotransferase

  • Yang, Jin-Kuk
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.173-176
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    • 2008
  • MJ0684 from Methanococcus jannaschii is a hypothetical protein belonging to the subfamily Ig of amino acid aminotransferases. In the present study, the crystal structure of MJ0684 has been determined at 2.2 resolution. It reveals that MJ0684 has an overall structure similar to subfamily Ig aminotransferases and its active site architecture is most similar to that of kynurenine aminotransferases among several kinds of aminotransferases in the subfamily Ig?. It has two hydrophobic active site residues conserved in the kynurenine aminotransferases for recognizing hydrophobic substrates. In addition, the absence of any basic residue for recognizing the side chain carboxylic group of the aspartate in the active site rules out the possibility that MJ0684 would act as an aspartate aminotransferase. These structural observations collectively imply that MJ0684 is a novel archaeal homolog of the subfamily Ig kynurenine aminotransferase.

A novel self-aligned offset gated polysilicon thin film transistor without an additional offset mask (오프셋 마스크를 이용하지 않는 새로운 자기 정합 폴리 실리콘 박막 트랜지스터)

  • 민병혁;박철민;한민구
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.5
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    • pp.54-59
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    • 1995
  • We have proposed a novel self-aligned offset gated polysilicon TFTs device without an offset mask in order to reduce a leakage current and suppress a kink effect. The photolithographic process steps of the new TFTs device are identical to those of conventional non-offset structure TFTs and an additional mask to fabricate an offset structure is not required in our device due to the self-aligned process. The new device has demonstrated a lower leakage current and a better ON/OFF current ratio compared with the conventional non-offset device. The new TFT device also exhibits a considerable reduction of the kink effect because a very thin film TFT devices may be easily fabricated due to the elimination of contact over-etch problem.

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