• Title, Summary, Keyword: NR

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Influence of Initial States of Test Sheets on Adhesion of NR/NR, BR/BR, and NR/BR (시험편의 초기 상태가 NR/NR, BR/BR, 그리고 NR/BR 접착에 미치는 영향)

  • Choi, Sung-Seen;Kim, Jong-Chul;Woo, Chang-Su
    • Elastomers and Composites
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    • v.42 no.2
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    • pp.107-111
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    • 2007
  • Adhesion of NR and BR composites with different initial states of precured or uncured conditions was studied. Adhesion between the NR and BR sheets as well as adhesion between the same rubber sheets was investigated. Adhesion forces of the uncured/uncured specimens were larger than those of the cured/uncured and cured/cured ones. The cured/cured samples and uncured NR/cured BR specimen were fully peeled out by the peel test. When one sheet was broken during the peel test, the sheet having the higher crosslink density was broken irrespective of the rubber types. Adhesion forces of the same rubber sheets were higher than those of the different ones and adhesion force of the cured NR/uncured BR sample was higher than that of the uncured NR/cured BR one. The experimental results were explained with the crosslink density and interdiffusion of rubber chains.

Distribution of N-Methyl-D-Aspartate Receptor Subunits NR2A and NR2B in Chum salmon Brain (연어 뇌에서 N-Methyl-D-Aspartate 수용체 아단위 NR2A와 NR2B의 분포)

  • 진덕희;문일수
    • Journal of Life Science
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    • v.9 no.6
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    • pp.722-727
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    • 1999
  • We carried out immunoblot analyses to study expression and subcellular distribution of the N-methyl-D-aspartate receptor(NR) subunits in salmon (Chum Salmon, Oncorhynchus keta). We prepared subcellular fractions such as brain homogenates, synaptosomes, and postsynaptic density (PSD) from salmon brains, and analyzed protein compositions by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). In a Coomassie-stained 6% SDS-gel, about 20 distinct major protein bands could be identified in the PSD fraction. Immunoblot analyses using antibodies against rat NR subunit 2A and 2B antigens (NR2A and NR2B, respectively) showed weak but evident signals at the 180 kDa positions in the salmon PSD fractions. However, in contrast to rat NRs, the salmon NR2A and NR2B are not recognized by a phosphotyrosine-specific antibody suggesting that the salmon NRs are regulated differently from those of the rat by protein tyrosine kinases. Our results indicate that NR2A and NR2B subunits are expressed in the salmon PSD fraction but not regulated by tyrosine phosphorylation.

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Covulcanization and Ozone resistance for Unsaturated and Saturated Rubbers (불포화 고무와 포화 고무의 공가류 및 내오존성)

  • Lim, Won-Woo;Jung, Il-Taek;Han, Min-Hyun
    • Journal of Adhesion and Interface
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    • v.2 no.4
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    • pp.32-38
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    • 2001
  • Effects of the ratio of rubber composition on covulcanization and ozone resistance were studied in this study. Specimens used in this study were rubber compounds(specimen-A) blended with various ratio of NR, SBR, BR, IIR, and EPDM, unsaturated rubber compounds(specimen-B) with NR/BR/SBR, and saturated rubber compounds(specimen-C) with NR/IIR/EPDM. PAD adhesion specimen was prepared from vulcanizing specimen-A and B, and specimen-A and C, respectively. Using same adhesion specimen, peel strength was measured and tested ozone resistance. In specimen-A, peel strength was higher with increasing NR ratio for NR and BR contained blends. In other specimen-A containing NR and SBR, the peel strength was also increased with increasing SBR ratio. NR/BR/IIR/EPDM rubber compounds had also better adhesion property than NR/SBR/IIR/EPDM compounds. As more unsaturated rubber was blended, the peel strength was higher but ozone resistance was worse. Optimum ratio of unsaturated and saturated rubbers for the peel strength and ozone resistance was 60/40.

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STK Feature Tracking Using BMA for Fast Feature Displacement Convergence (빠른 피쳐변위수렴을 위한 BMA을 이용한 STK 피쳐 추적)

  • Jin, Kyung-Chan;Cho, Jin-Ho
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.8
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    • pp.81-87
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    • 1999
  • In general, feature detection and tracking algorithms is classified by EBGM using Garbor-jet, NNC-R and STK algorithm using pixel eigenvalue. In those algorithms, EBGM and NCC-R detect features with feature model, but STK algorithm has a characteristics of an automatic feature selection. In this paper, to solve the initial problem of NR tracking in STK algorithm, we detected features using STK algorithm in modelled feature region and tracked features with NR method. In tracking, to improve the tracking accuracy for features by NR method, we proposed BMA-NR method. We evaluated that BMA-NR method was superior to NBMA-NR in that feature tracking accuracy, since BMA-NR method was able to solve the local minimum problem due to search window size of NR.

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Effect of Electrochemical Redox Reaction on Biochemical Ammonium Oxidation and Chemical Nitrite Oxidation

  • Jeon, Bo-Young;Seo, Ha-Na;Kang, Seung-Won;Park, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.20 no.3
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    • pp.485-493
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    • 2010
  • A modified graphite felt electrode with neutral red (NR-electrode) was shown to catalyze the chemical oxidation of nitrite to nitrate under aerobic conditions. The electrochemically oxidized NR-electrode (EO-NR-electrode) and reduced NR-electrode (ER-NR-electrode) catalyzed the oxidation of $1,094{\pm}39$ mg/l and $382{\pm}45$ mg/l of nitrite, respectively, for 24 h. The electrically uncharged NR-electrode (EU-NR-electrode) catalyzed the oxidation of $345{\pm}47$ mg/l of nitrite for 24 h. The aerobic bacterial community immobilized in the EO-NR-electrode did not oxidize ammonium to nitrite; however, the aerobic bacterial community immobilized in the ER-NR-electrode bioelectrochemically oxidized $1,412{\pm}39$ mg/l of ammonium for 48 h. Meanwhile, the aerobic bacterial community immobilized on the EU-NR-electrode biochemically oxidized $449{\pm}22$ mg/l of ammonium for 48 h. In the continuous culture system, the aerobic bacterial community immobilized on the ER-NR-electrode bioelectrochemically oxidized a minimal $1,337{\pm}38$ mg/l to a maximal $1,480{\pm}38$ mg/l of ammonium to nitrate, and the community immobilized on the EU-NR-electrode biochemically oxidized a minimal $327{\pm}23$ mg/l to a maximal $412{\pm}26$ mg/l of ammonium to nitrate every two days. The bacterial communities cultivated in the ER-NR-electrode and EU-NR-electrode in the continuous culture system were analyzed by TGGE on the $20^{th}$ and $50^{th}$ days of incubation. Some ammonium-oxidizing bacteria were enriched on the ER-NR-electrode, but not on the EU-NR-electrode.

Identification of a Potential Tyrosine Phosphorylation Site on the NR2B Subunit of the N-methyl-D-aspartate Receptor (NMDA 수용체 아단위 2B의 Tyrosine 인산화 위치의 동정)

  • Il Soo Moon;Yong Wook Jung;Bok Hyun Ko
    • Journal of Life Science
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    • v.8 no.6
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    • pp.654-659
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    • 1998
  • The 2B subunit of N-methyl-D-aspartate (NMDA) receptors (NR2B) is the major phosphotyrosine-containing pro-tein in the postsynaptic density (PSD). In order to identify the site for tyrosine phosphorylation on NR2B, a mass spectrometry was applied on tryptic and endolys-C peptides. The NR2B subunit was isolated from N-octyl glucoside (NOG)-insoluble PSD fraction through SDS-PAGE and electroelution. The eluted protein was confirmed to be NR2B and phosphorylated on tyrosine by its cognate antibody and phosphotyrosine-specific antibody. By matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry of the peptides generated by digesting the eluted NR2B with trysin or endolys-C, a potential site for tyrosine phosphorylation could be identified as Tyr-1304.

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Identification and characteristics of Lactic Acid Bacteria Isolated from Nuruk (누룩으로부터 젖산세균의 분리 및 특성)

  • 이정훈
    • KSBB Journal
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    • v.15 no.4
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    • pp.359-365
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    • 2000
  • Three lactic acid bacteria (C-1 K-3 and T-1 strain) were isolated from Nuruk and characterized subsequently. They were useful strains for production of lactic acid and their growth was inhibited at 10% ethanol pH 4 These strains were identified as lactococcus lactis subsp. lactis NR C-1 Leuconostoc mesenteroides subsp. mesenterides NR K-3 and pediococcus pentosaceus NR T-1 respectively by morphological physiological and biochemical characterization Lac lactis subsp lactis NR C-1 showed the highest lactic acid productivity. Leu measenteroides subsp mesenteroides NR K-3 showed stable lactic acid productivity and its growth was inhibited at pH 4. P pentosaceus NR T-1 had lower lactic acid productivity than the other two bacteria but it could not grow at 10% ethanol pH 4 The lactic acid productivity of these three strains in MRS broth were higher than that in Skim milk media the optimum pH and temperature for the lactic acid production of the three strains were 30-32$^{\circ}C$ and pH 6.0∼6.8 Glucose was the optimal carbon souorce for the lactic acid production. In terms of antagonism lac lactis subsp lactis NR c-1 showed somewhat inhibitory efects against some Gram positive rod and cocci such as Lactobacillus brevis and Streptococcus mitis. And Leu mesenteroides subsp mesenteroides NR K-3 showed the inhibitory effects against Streptococcus mitis but P. pentosaceus NR T-1 didn't show any inhibitory effects against tested strains.

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The Role of Nuclear Receptor Subfamily 1 Group H Member 4 (NR1H4) in Colon Cancer Cell Survival through the Regulation of c-Myc Stability

  • Lee, Yun Jeong;Lee, Eun-Young;Choi, Bo Hee;Jang, Hyonchol;Myung, Jae-Kyung;You, Hye Jin
    • Molecules and Cells
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    • v.43 no.5
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    • pp.459-468
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    • 2020
  • Nuclear receptor subfamily group H member 4 (NR1H4), also known as farnesoid X receptor, has been implicated in several cellular processes in the liver and intestine. Preclinical and clinical studies have suggested a role of NR1H4 in colon cancer development; however, how NR1H4 regulates colon cancer cell growth and survival remains unclear. We generated NR1H4 knockout (KO) colon cancer cells using clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 nuclease (CAS9) technology and explored the effects of NR1H4 KO in colon cancer cell proliferation, survival, and apoptosis. Interestingly, NR1H4 KO cells showed impaired cell proliferation, reduced colony formation, and increased apoptotic cell death compared to control colon cancer cells. We identified MYC as an important mediator of the signaling pathway alterations induced by NR1H4 KO. NR1H4 silencing in colon cancer cells resulted in reduced MYC protein levels, while NR1H4 activation using an NR1H4 ligand, chenodeoxycholic acid, resulted in time- and dose-dependent MYC induction. Moreover, NR1H4 KO enhanced the anti-cancer effects of doxorubicin and cisplatin, supporting the role of MYC in the enhanced apoptosis observed in NR1H4 KO cells. Taken together, our findings suggest that modulating NR1H4 activity in colon cancer cells might be a promising alternative approach to treat cancer using MYC-targeting agents.

A Study on the Mechanical Properties of Organo-clay Filled NR/MMT Nanocomposites (Organo-Clay를 이용한 NR/MMT 나노복합체의 기계적 물성에 관한 연구)

  • Oh, Woo-Taek;Lee, Eun-Kyoung;Choi, Sei-Young
    • Elastomers and Composites
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    • v.44 no.4
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    • pp.455-465
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    • 2009
  • In this study, Organo-montmorillonite(MMT) was synthesized by intercalation of various amine(Octylamine, Dodecylamine, Dimethyldodecylamine, Octadecylamine) compounds into layered silicate. Natural Rubber(NR)/MMT nanocomposites were prepared by reinforcement of Organo-MMT. X-ray diffraction(XRD) and Scanning electron microscope(SEM) were employed to characterize the layer distance of Organo-MMT and the morphology of the NR/MMT nanocomposites. The structures of the synthesized Organo-MMTs were analyzed by the measurement of FT-IR. Cure characteristics, surface free energy and mechanical properties such as tensile strength, modulus and hardness of NR/MMT nanocomposites were carefully studied by contact angle meter, ODR, UTM, and hardness tester. FT-IR analysis showed a insertion of the alkyl and amine chains into the interlayers of the MMT. It was shown that the cure time of the organo-MMT was more decreased than that of $Na^+$-MMT. Surface free energy and tensile strength of the NR/DDA-MMT nanocomposite were the highest. NR/ODA-MMT nanocomposite was the highest in hardness.

Production and Characterization of Nitrate Reductase Deficient Mutants in Petunia parviflora

  • Lee, Cheol-Hee
    • Korean Journal of Plant Resources
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    • v.19 no.6
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    • pp.706-715
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    • 2006
  • Nitrate reductase deficient (NR) mutant lines were selected indirectly by their resistance to 100mM chlorate in cell cultures of P. parviflora. A total of 585 chlorate resistant lines were confirmed by a second passage on a high concentration of chlorate. Frequency of spontaneous mutation was $9.7{\times}10^{-7}$ in 3 month old suspension-cultured cells, and in non-selective media containing amino acids as sole nitrogen source. The frequency of mutation could be increased up to 11-fold by culture for 12 months. Out of 40 randomly selected calli, 22 were fully deficient in NR. The rest of the clones contained a decreased level of NR activity. Further characterization was carried out in 13 mutant lines which were fully deficient in NR and in 5 mutant lines containing residual (0-7.0%) NR activity, as compared to wild-type cells cultured on the same medium. The $NR^-$ mutants were tentatively classified as defective in the NR apoenzyme (nia-type; 11 mutant lines including the 5 with residual NR activity) or in the molybdenum cofactor (cnx-type; 7 mutant lines) by the XDH activity. The cnx-type could be further classified into two groups. In one group (5 mutant lines) of these, the NR activity could be partially restored by nonphysiologically high (1.0mM) molybdate in the culture medium. Both types of $NR^-$ mutants were unable to grow on minimal medium containing nitrate as sole nitrogen source, but grew well on amino acids. They also proved to be extremely sensitive to the standard medium ($MSP_1$) containing nitrate and ammonium. Shoot regeneration was obtained only in the $NR^-$ mutants, which contained residual NR activity, but they so far have failed to grow into plants.