• Title/Summary/Keyword: sciences

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Synthesis of N,N',N"-Trisubstituted Thiourea Derivatives and their Antagonistic Effect on the Vanilloid Receptor

  • Park, Hyeung-Geun;Park, Mi-Kyung;Choi, Ji-Yeon;Choi, Sea-Hoon;Lee, Ji-Hye;Suh, Young-Ger;Cho, Ha-Won;Oh, Uh-Taek;Lee, Jee-Woo
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.253.1-253.1
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    • 2003
  • Twenty-seven N,N',N"-trisubstituted thiourea derivatives were prepared. Among them, 1- [3-(4'-hydroxy-3'-methoxy-phenyl)-propyl] -1,3-diphenethyl-thiourea (81, IC$\sub$50/= 0,32 $\mu\textrm{m}$), showed 2-fold higher antagonistic activity than that of capsazepine (3, IC$\sub$50/= 0,65 $\mu\textrm{m}$) against the vanilloid receptor in a Ca$\^$2+/ -influx assay.

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Conformational change of organic cofactor PLP is essential for catalysis in PLP-dependent enzymes

  • Ngo, Ho-Phuong-Thuy;Nguyen, Diem Quynh;Park, Hyunjae;Park, Yoon Sik;Kwak, Kiwoong;Kim, Taejoon;Lee, Jang Ho;Cho, Kyoung Sang;Kang, Lin-Woo
    • BMB Reports
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    • v.55 no.9
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    • pp.439-446
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    • 2022
  • Pyridoxal 5'-phosphate (PLP)-dependent enzymes are ubiquitous, catalyzing various biochemical reactions of approximately 4% of all classified enzymatic activities. They transform amines and amino acids into important metabolites or signaling molecules and are important drug targets in many diseases. In the crystal structures of PLP-dependent enzymes, organic cofactor PLP showed diverse conformations depending on the catalytic step. The conformational change of PLP is essential in the catalytic mechanism. In the study, we review the sophisticated catalytic mechanism of PLP, especially in transaldimination reactions. Most drugs targeting PLP-dependent enzymes make a covalent bond to PLP with the transaldimination reaction. A detailed understanding of organic cofactor PLP will help develop a new drug against PLP-dependent enzymes.

Design of RF coupler for KIRAMS-13;Korea Institute of Radiological & Medical Sciences-13

  • Jung, In-Su;An, Dong-Hyun;Kim, Yu-Seok;Yang, Tae-Gun;Kim, Jea-Hong;Jang, Hong-Seok;Hong, Bong-Hwan;Lee, Min-Yong;Hong, Sung-Seok;Chai, Jong-Seo;Oh, Bong-Hun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2203-2205
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    • 2003
  • KIRAMS-13, the first medical cyclotron developed by domestic technique, is used to produce radio-isotope such as $^{18}F$ whose life time is relatively short through test operation. For high-power operation of charged particle accelerators, the power coupler must withstand enormous stresses due to charging induced by high RF power passing through. High-power RF testing with peak power in excess of 30kW has been performed on prototype power coupler for KIRAMS-13 normal conducting cavities. CST MICROWAVE STUDIO(CST MWS) is used for fundamental RF Design, and power coupler is manufactured according to fundamental power coupler design requisite. The qualification of the couplers has occurred for the time being only in a limited set of conditions as the available RF system and control instrumentation are under improvement.

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Identification and Molecular Characterization of PERV Gamma1 Long Terminal Repeats

  • Huh, Jae-Won;Kim, Dae-Soo;Ha, Hong-Seok;Ahn, Kung;Chang, Kyu-Tae;Cho, Byung-Wook;Kim, Heui-Soo
    • Molecules and Cells
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    • v.27 no.1
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    • pp.119-123
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    • 2009
  • Porcine endogenous retroviruses (PERVs) gamma1 in the pig genome have the potential to act as harmful factors in xenotransplantation (pig-to-human). Long terminal repeats (LTRs) are known to be strong promoter elements that could control the transcription activity of PERV elements and the adjacent functional genes. To investigate the transcribed PERV gamma1 LTR elements in pig tissues, bioinformatic and experimental approaches were conducted. Using RT-PCR amplification and sequencing approaches, 69 different transcribed LTR elements were identified. And 69 LTR elements could be divided into six groups (15 subgroups) by internal variation including tandem repeated sequences, insertion and deletion (INDEL). Remarkably, all internal variations were indentified in U3 region of LTR elements. Taken together, the identification and characterization of various PERV LTR transcripts allow us to extend our knowledge of PERV and its transcriptional study.

Evaluation of energy correction algorithm for signals of PET in heavy-ion cancer therapy device

  • Niu, Xiaoyang;Yan, Junwei;Wang, Xiaohui;Yang, Haibo;Ke, Lingyun;Chen, Jinda;Du, Chengming;Zhang, Xiuling;Zhao, Chengxin;Kong, Jie;Su, Hong
    • Nuclear Engineering and Technology
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    • v.52 no.1
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    • pp.101-108
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    • 2020
  • In order to solve the contradiction between requirements of high sampling rate for acquiring accurate energy information of pulses and large amount of data to be processed timely, the method with an algorithm to correct errors caused by reducing the sampling rate is normally used in front-end read-out system, which is conductive to extract accurate energy information from digitized waveform of pulse. The functions and effects of algorithms, which mainly include polynomial fitting with different fitting times, double exponential function fitting under different sampling modes, and integral area algorithm, are analyzed and evaluated, and some meaningful results is presented in this paper. The algorithm described in the paper has been used preliminarily in a prototype system of Positron Emission Tomography (PET) for heavy-ion cancer therapy facility.