• Title/Summary/Keyword: Lee Sam

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The Effect of Electrical Stimulation Applied in Dominant Forearm on Autonomic Nervous System Response of Both Hands (우세측 전완에 적용한 전기자극이 양쪽 손 자율신경계 반응에 미치는 효과)

  • Lee, Dong-Geol;Seo, Sam-Ki;Lee, Jeong-Woo
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.7 no.1
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    • pp.7-10
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    • 2009
  • Purpose : The purpose of this study was to investigate the effect of electrical stimulation applied in dominant forearm on autonomic nervous system response of both hands. Methods : Fourteen healthy subjects (women) received low frequency-high intensity electrical stimulation to one forearm. The subjects assigned to two groups; a ipsilateral stimulation group (n=7) and a contralateral stimulation group (n=7). The electrode attachment was arranged on the forearm of the dominant arm and the electricity stimulus time was set as 15 minutes. Measuring items were the skin conduction velocity, the blood flow, and the pulse rate, which were measured total 3 times (pre, post, and post 10 min.). Results : The skin conduction velocity showed a significant difference according to the change of the time in both hands, but there was no significant difference according to time in the blood flow, and the change of the pulse frequency regardless of stimulus side. Conclusion : These results demonstrate that the low frequency-high intensity electrical stimulation applied dominant forearm can increase selectively only with the skin conduction velocity, which may be helpful for the activation of the sudomotor function of both hands by the activation of sympathetic nerve.

Analogs of Periplanetasin-4 Exhibit Deteriorated Membrane-Targeted Action

  • Lee, Heejeong;Hwang, Jae Sam;Lee, Dong Gun
    • Journal of Microbiology and Biotechnology
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    • v.30 no.3
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    • pp.382-390
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    • 2020
  • Periplanetasin-4 is an antimicrobial peptide with 13 amino acids identified in cockroaches. It has been reported to induce fungal cell death by apoptosis and membrane-targeted action. Analogs were designed by substituting arginine residues to modify the electrostatic and hydrophobic interactions accordingly and explore the effect of periplanetasin-4 through the increase of net charge and the decrease of hydrophobicity. The analogs showed lower activity than periplanetasin-4 against gram-positive and gram-negative bacteria. Similar to periplanetasin-4, the analogs exhibited slight hemolytic activity against human erythrocytes. Membrane studies, including determination of changes in membrane potential and permeability, and fluidity assays, revealed that the analogs disrupt less membrane integrity compared to periplanetasin-4. Likewise, when the analogs were treated to the artificial membrane model, the passage of molecules bigger than FD4 was difficult. In conclusion, arginine substitution could not maintain the membrane disruption ability of periplanetasin-4. The results indicated that the attenuation of hydrophobic interactions with the plasma membrane caused a reduction in the accumulation of the analogs on the membrane before the formation of electrostatic interactions. Our findings will assist in the further development of antimicrobial peptides for clinical use.

Synthesis and Biocompatibility of the Hydroxyapatite Ceramic Composites from Tuna Bone(III) - SEM Photographs of Bonding Properties between Hydroxyapatite Ceramics Composites in the Simulated Body Fluid- (참치 뼈를 이용한 Hydroxyapatite 세라믹 복합체의 합성 및 생체 친화성(제3보) -인공체액에서의 Hydroxyapatite 세라믹 복합체간의 결합의 전자현미경 관찰-)

  • Kim, Se-Kwon;Choi, Jin-Sam;Lee, Chang-Kook;Byun, Hee-Guk;Jean, You-Jin;Lee, Eung-Ho;Park, In Yong
    • Applied Chemistry for Engineering
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    • v.9 no.3
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    • pp.322-329
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    • 1998
  • Chemical bonding was investigated in the simulated body fluid of several selected hydroxyapatite-containing composites. The hydroxyapatite-containing composites chemically bonded with each other in the simulated body fluid after 4 weeks. Bioglass was strongly bonded in the simulated body fluid, but bonding strength was not depended on composition. Their composite bodies were chemically bonded by heterogeneous nucleation and growth at the interfaces of the specimens in the simulated body fluid.

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Synthesis of 2-(Pyrazol-1-yl)quinoxalines and 2,3-Di(pyrazol-1-yl)quinoxalines (2-(Pyrazol-1-yl)quinoxaline류 및 2,3-Di(pyrazol-1-yl)quinoxaline류의 합성)

  • Kim, Ho-Sik;Jeong, Won-Young;Choi, Kyung-Ok;Lee, Seong-Uk;Kwag, Sam-Tag;Lee, Man-Kil
    • Journal of the Korean Chemical Society
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    • v.46 no.1
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    • pp.37-45
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    • 2002
  • The reaction of 3,6-dichloro-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(8) or 6-chloro-3-hydrazino-2-(3,5-dimethylpyrazol-1-yl)quinoxaline(9) with substituted anilines, sulfa drugs and heteroacyl chlorides gave 2-(pyrazol-1-yl)quinoxalines(10-12). The reaction of compound 9 with alkyl (ethoxymeth-ylene) cyanoacetates resulted in the intramolecular cyclization to give 2,3-di(pyrazol-1-yl)quinoxalines(13).

Surface modification for block copolymer nanolithographyon gold surface

  • Hwang, In-Chan;Bang, Seong-Hwan;Lee, Byeong-Ju;LeeHan, Bo-Ram;Kim, Hyeong-Jun
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.11a
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    • pp.33.2-33.2
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    • 2009
  • Block copolymer lithography has attracted great attention for emerging nanolithography since nanoscaleperiodic patterns can be easily obtained through self-assembly process without conventional top-down patterning process. Since the morphologies of self-assembled block copolymer patterns are strongly dependent on surface energy of a substrate, suitable surface modification is required. Until now, the surface modification has been studied by using random copolymer or self-assembled mono layers (SAMs). However, the research on surface modifications has been limited within several substrates such as Si-based materials. In present study, we investigated the formation of block copolymer on Au substrate by $O_2$ plasma treatment with the SAM of 3-(p-methoxy-phenyl)propyltrichloro-silane [MPTS, $CH_3OPh(CH_2)_3SiCl_3$]. After $O_2$ plasma treatment, the chemical bonding states of the surface were analyzed by X-ray photoelectron spectroscopy (XPS). The static contact angle measurement was performed to study the effects of $O_2$ plasma treatment on the formation of MPTS monolayer. The block copolymer nanotemplates formed on Au surface were analyzed by scanning electron microscopy. The results showed that the ordering of self-assembled block copolymer pattern and the formation of cylindrical nano hole arrays were enhanced dramatically by oxygen plasma treatment. Thus, the oxidation of gold surface by $O_2$ plasma treatment enables the MPTS to form the monolayer assembly leading to surface neutralization of gold substrates.

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Cytologic Features of Glassy Cell Carcinoma of the Uterine Cervix - Three Cases Report - (자궁 경부의 유리질 세포 암종의 세포학적 소견 - 3예 보고 -)

  • Jeon, Seok-Hoon;Paik, Seung-Sam;Lee, Won-Mi;Jang, Se-Jin;Park, Yong-Wook;Park, Moon-Hyang;Lee, Jung-Dal
    • The Korean Journal of Cytopathology
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    • v.7 no.2
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    • pp.197-201
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    • 1996
  • Glassy cell carcinoma is an unusual neoplasm of the uterine cervix that accounts for $1{\sim}2%$ of all cervical malignancy. It is a rapidly progressive and biologically aggressive disease with poor response to therapy. This tumor is considered to be a poorly differentiated mixed adenosquamous carcinoma. The cytologic findings are characterized by tumor cells arranged predominantly in syncytial like aggregates and an inflammatory background. The tumor cells have moderate amounts of eosinophilic or amphophilic cytoplasm, which is often finely granular. The nuclei are relatively large and have fine chromatin with prominent eosinophilic nucleoli. Cytologically, glassy cell carcinoma is most likely to be confused with large cell nonkeratinizing squamous cell carcinoma and with atypical reparative cells. Herein, we report three cases of glassy cell carcinoma of the uterine cervix diagnosed by cervicovaginal smear and confirmed by histologic section with review of literatures.

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BER Simulator Development for Link Compliance Analysis

  • Kang, Hyun-Chul;Kim, Woo-Seop;Lee, Jae-Wook;Jang, Young-Chan;Park, Hwan-Wook;Kim, Jong-Hoon;Lee, Jung-Bae;Kim, Chang-Hyun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.2
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    • pp.150-155
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    • 2008
  • This paper is related to developing new Bit Error Rate (BER) simulator, Sam sung BER simulator (SBERS), in order to evaluate the link compliance and all kinds of effects of link compliance in a real environment. SBERS allows to generate transmit pulse accurately by using the various parameters, and obtain the eye diagram and bathtub curve, which represents the performance of link, by calculating the transmit pulse and the measured frequency response characteristics. SBERS give results as same as real environment after taking account of distribution and value of noise. To verify the accuracy of simulator, we derive the simulated and measured result and compare eye opening. The difference came out to be within 5% error. It is possible to estimate the real environment and design the transmitter and receiver circuit effectively using new BER simulator, SBERS.

Two Flexible Loops in Subtilisin-like Thermophilic Protease, Thermicin, from Thermoanaerobacter yonseiensis

  • Jang, Hyeung-Jin;Lee, Chang-Hun;Lee, Weon-Tae;Kim, Yu-Sam
    • BMB Reports
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    • v.35 no.5
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    • pp.498-507
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    • 2002
  • A gene that encodes a thermostable protease, coined thermicin, has been isolated from Thermoanaerobacter yonseiensis that is expressed and characterized in E. coli.. In order to elucidate the molecular characteristics on thermostability of the enzyme, molecular modeling and mutagenesis technology were applied. In the modeling structure, the structural core, including the active site, was well conserved; whereas, the two loop regions were unique when compared to thermitase. The mutant enzyme with the small loop deleted (D190-I196), based on modeling structural information, showed identical enzyme activity. However, when the large loop was deleted (P233-P244), a little lower $K_m$ and even a lower kcat was found. This indicates that the large loop could influence catalytic activity. However, the unfolding temperature ($T_m$), which was determined by a differential-scanning calorimetry for the mutant enzyme deleted the small loop, was $96^{\circ}C$. This is $14^{\circ}C$ lower than that for the parent thermicin. These results suggest that the small loop may play a role in maintaining the proper folding of the enzyme at high temperatures, whereas the large loop might be related to catalysis.

Molecular Cloning and Expression of a cDNA Encoding Putative Chemosensory Protein from the Mole Cricket, Gryllotalpa orientalis

  • Kim, Iksoo;Lee, Kwang-Sik;Ryu, Kang-Sun;Kim, Jin-Woo;Ahn, Mi-Young;Lee, Heui-Sam;Sohn, Hung-Dea;Jin, Byung-Rae
    • International Journal of Industrial Entomology and Biomaterials
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    • v.6 no.1
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    • pp.87-92
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    • 2003
  • We describe here the cloning, expression and characterization of a cDNA encoding a putative chemosensory protein (CSP) from the mole cricket, Gryllotalpa orientalis. The G. orientalis chemosensory protein cDNA sequences comprised of 384 bp with 128 amino acid residues. The G. orientalis chemosensory protein showed 75.4% protein sequence identity to the Locusta migratoria CSP, Northern blot analysis revealed that signal was stronger in head than leg and cuticle, indicating that the head part containing antennae is a main site for G. orientalis chemosensory protein synthesis. The cDNA encoding G. orientalis chemosensory protein was expressed as approximately 12 kDa polypeptide in baculovirus-infected insect cells.