• Title/Summary/Keyword: NR

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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.

Preparation and Characterization of Reduced Graphene Oxide with Carboxyl Groups-Gold Nanorod Nanocomposite with Improved Photothermal Effect (향상된 광열 효과를 갖는 카르복실화된 환원 그래핀옥사이드-골드나노막대 나노복합체의 제조 및 특성 분석)

  • Lee, Seunghwa;Kim, So Yeon
    • Applied Chemistry for Engineering
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    • v.32 no.3
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    • pp.312-319
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    • 2021
  • Photothermal therapy is a treatment that necrotizes selectively the abnormal cells, in particular cancer cells, which are more vulnerable to heat than normal cells, using the heat generated when irradiating light. In this study, we synthesized a reduced graphene oxide with carboxyl groups (CRGO)-gold nanorod (AuNR) nanocomposite for photothermal treatment. Graphene oxide (GO) was selectively reduced and exfoliated at high temperature to synthesize CRGO, and the length of AuNR was adjusted according to the amount of AgNO3, to synthesize AuNR with a strong absorption peak at 880 nm, as an ideal photothermal agent. It was determined through FT-IR, thermogravimetric and fluorescence analyses that more carboxyl groups were conjugated with CRGO over RGO. In addition, CRGO exhibited excellent stability in aqueous solutions compared to RGO due to the presence of carboxylic acid. The CRGO-AuNR nanocomposites fabricated by electrostatic interaction have an average size of ~317 nm with a narrow size distribution. It was confirmed that under radiation with a near-infrared 880 nm laser which has an excellent tissue transmittance, the photothermal effect of CRGO-AuNR nanocomposites was greater than that of AuNR due to the synergistic effect of the two photothermal agents, CRGO and AuNR. Furthermore, the results of cancer cell toxicity by photothermal effect revealed that CRGO-AuNR nanocomposites showed superb cytotoxic properties. Therefore, the CRGO-AuNR nanocomposites are expected to be applied to the field of anticancer photothermal therapy based on their stable dispersibility and improved photothermal effect.

Pulsed-Field Gel Electrophoresis and Monoclonal Antibody Analysis of Leptospira interrogans Isolated in Korea (국내 분리 렙토스피라균의 단클론 항체 및 Genomic DNA의 Pulsed-Field Gel Electrophoresis 분석)

  • 조민기;기선호;김형준;김윤원;장우현;오희복
    • Korean Journal of Microbiology
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    • v.35 no.3
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    • pp.197-204
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    • 1999
  • A total of 22 Leptospiua inlermgans field isolates from the ~ a t s captured in 5 provinces of Korea in 1996, and 6 antigenically closely related relerence serovars of lai, yeonchon, birkini. gem, mwogolo. and canicola were analysed. When the antigenic characteristics were analysed by reactivity with 7 monoclonal antibodies prepared with sh.ains belongng to serogroup Icterohaemorrhagiae. all 22 isolates showed the same reaction pattern with that of serovar lai. Large restriction fragment patterns obtained after cleavage of geno~nic DNAs with infrequently cuttimg restriction enzymes were analyzed by pulsed-field pel electrophoresis(PFGE). Identification of leptospira strains by PFGE with Nor I, Asc I or Iise I digests correlated with their antigenically typed serovars, silh a few exceptions. PFGE of isolates, except for JR89, digested wjth Nor I showed identical pattern w~th serovar lai, showing 13 Cragments between 940 kb and 63 kb. When PFGE pallerns of JR89 were compared with those of serovar lai, Not I digest showed additional two hands of 1000 kb and 460 kb, while Asc I digest showed 650 kb fragment and Fse I digest did not show the fragment of 280 kb. Whereas serovar yeonchon. which was isolated in Korea and identified as a new serovar previously. could be differentiated from serovar lai in antigenic reactivities with monoclonal antibodres. it showed the similar PFGE pattern with serovar lai includin~ reference and field isolates. It was suggested that Korean leptospiral field isolates are closely related in DNA level.

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The Surface Properties of Blend Film of Natural Rubber and Graft Latex by Dipping Process (Dipping법에 의한 천연고무와 그라프트 라텍스 블렌드 필름의 표면특성)

  • Kim, Kong-Soo;Park, Jun-Ha;Eum, Ju-Song
    • Applied Chemistry for Engineering
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    • v.5 no.6
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    • pp.990-997
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    • 1994
  • The vulcanized NR and blend films were prepared with mixing of natural rubber latex (NRL) and methyl methacrylated grafted latex(MGL) with various additives by dipping process. It was investigated the basic properties of vulcanized NR films that is optimum condition of the mature time, swelling degree, cure time at $110^{\circ}C$, and measured the mechanical properties of tensile strength and elongation of its condition. In order to identify the surface structure and the slip properties of blend films contact angles and static and kinetic friction coefficient were measured. Contact angles were decreased with increment of blend ratio of MGL, and static and kinetic friction coefficient were decreased rapidly for the NR/MG and NR-d-MG films than for the NR films. From the results, NR/MG and NR-d-MG films has slip's reinforcement in skin contact surface with increased of blend ratio of MGL.

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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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T0901317 as an Inhibitor of Transcriptional Activation of Constitutive Androstane Receptor (CAR) (Constitutive androstane receptor (CAR)의 전사활성 저해제로서의 T0901317)

  • Kim, Hyun-Ha;Seol, Won-Gi
    • Journal of Life Science
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    • v.21 no.4
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    • pp.481-485
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    • 2011
  • T0901317 is a potent synthetic ligand for liver X receptor (LXR, NR1H2/3), a member of the nuclear receptor superfamily that functions as a transcription factor. However, T0901317 has been also reported to modulate the activity at least four other nuclear receptors (NRs), acting as agonists for farnesoid X receptor (FXR, NR1H4) and pregnane X receptor (PXR, NR1I2) and as antagonists for androgen receptor (AR, NR3C4) and retinoid-related orphan receptor-${\alpha}$ (ROR-${\alpha}$, NR1F1). We report here that T0901317 can also function as an inhibitor for constitutive androstane receptor (CAR, NR1I3). Since CAR is a major player of xenobiotic and cholesterol metabolism in the liver, along with PXR, FXR and LXR, which are reported to be regulated by T0901317, this further complicates the interpretation of potential results with T0901317 in liver cells.

Thermal Aging Properties of NR Vulcanizates with Different Cure Systems (가교 시스템이 다른 NR 가황물의 열노화 특성)

  • Choi, Sung-Seen;Park, Byung-Ho
    • Elastomers and Composites
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    • v.40 no.3
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    • pp.181-187
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    • 2005
  • Changes of physical properties or NR vulcanizates with different cure systems by thermal aging were investigated. Two sulfur cure systems and one resole cure system were employed, and total contents of the curatives were varied. For the NR vulcanizates with sulfur cure systems, hardness and modulus after the thermal aging at $90^{\circ}C$ for 3 days were increased, but elongation at break and tensile strength were decreased. For the NR vulcanizates with resloe cure system, the physical properties after the thermal aging were decreased. The change of physical properties by the thermal aging was explained with the crosslink density change. The crosslink densities or the NR vulcanizates with sulfur cure systems were increased after the thermal aging, but those with resole cure system were decreased. Influence of the migration of antidegradant on the changes of physical properties was also investigated. However, the changes of physical properties by the thermal aging were not explained sufficiently with the migration of antigradant.

Nicotinamide riboside regulates inflammation and mitochondrial markers in AML12 hepatocytes

  • Lee, Hee Jae;Yang, Soo Jin
    • Nutrition Research and Practice
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    • v.13 no.1
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    • pp.3-10
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    • 2019
  • BACKGROUND/OBJECTIVES: The $NAD^+$ precursor nicotinamide riboside (NR) is a type of vitamin $B_3$ found in cow's milk and yeast-containing food products such as beer. Recent studies suggested that NR prevents hearing loss, high-fat diet-induced obesity, Alzheimer's disease, and mitochondrial myopathy. The objective of this study was to investigate the effects of NR on inflammation and mitochondrial biogenesis in AML12 mouse hepatocytes. MATERIALS/METHODS: A subset of hepatocytes was treated with palmitic acid (PA; $250{\mu}M$) for 48 h to induce hepatocyte steatosis. The hepatocytes were treated with NR ($10{\mu}M$ and 10 mM) for 24 h with and without PA. The cell viability and the levels of sirtuins, inflammatory markers, and mitochondrial markers were analyzed. RESULTS: Cytotoxicity of NR was examined by PrestoBlue assay. Exposure to NR had no effect on cell viability or morphology. Gene expression of sirtuin 1 (Sirt1) and Sirt3 was significantly upregulated by NR in PA-treated hepatocytes. However, Sirt1 activities were increased in hepatocytes treated with low-dose NR. Hepatic pro-inflammatory markers including tumor necrosis factor-alpha and interleukin-6 were decreased in NR-treated cells. NR upregulated anti-inflammatory molecule adiponectin, and, tended to down-regulate hepatokine fetuin-A in PA-treated hepatocytes, suggesting its inverse regulation on these cytokines. NR increased levels of mitochondrial markers including peroxisome proliferator-activated receptor ${\gamma}$ coactivator-$1{\alpha}$, carnitine palmitoyltransferase 1, uncoupling protein 2, transcription factor A, mitochondrial and mitochondrial DNA in PA-treated hepatocytes. CONCLUSIONS: These data demonstrated that NR attenuated hepatic inflammation and increased levels of mitochondrial markers in hepatocytes.

Causes and Spatial Characteristics of Neighborhood Relations by Family Life Cycle (생애주기에 따른 이웃관계의 형성요인과 공간적 특성)

  • Joung, You Jin;Choi, Mack Joong
    • Journal of the Korean housing association
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    • v.27 no.1
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    • pp.1-11
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    • 2016
  • Based on residents' survey data in Seoul, this study attempts to empirically answer to four research questions regarding neighborhood relations (NR) which are necessary for community building: How important NR is compared to other social relations, what factors establish NR, how large NR's geographical extent is, and what are major meeting places among neighbors. A series of statistical analyses demonstrates that characteristics of NR vary greatly by family life cycle. In the stage of couple without child, NR has no significant meaning. NR becomes important from the stage of child care, and it is formed through the medium of children, particularly children's schools in the stage of child of elementary school as well as secondary schools. As the result, NR's geographical boundary extends beyond residential block or multi-family housing (apartment) estate while cafe and restaurant serve as dominant meeting places in these life cycle stages. On the contrary, after children are married and leave home, casual encounters resulted from spatial proximity become an important cause of NR. Likewise neighbors' geographical distribution is relatively concentrated within residential block or apartment estate, while community facilities play a role of meeting places as originally planned and designed.

The Experimental Study on the Immuno-regulatory effect of Notopterygii Rhizoma Herbal-acupuncture at Pyesu(BL13) on OVA-induced asthma in mice (폐유(肺兪) 강활약침(羌活藥鍼)이 OVA-induced Asthma Mouse Model의 면역조절(免疫調節)에 미치는 영향)

  • Jang, Suk-Geun;Hong, Kwon-Eui;Lee, Byung-Ryul
    • Korean Journal of Acupuncture
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    • v.22 no.2
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    • pp.107-125
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    • 2005
  • Objectives : The aim of this study was to investigate the asthma-suppressive and immuno-regulatory effect of NR-HA(Notopterygii Rhizoma Herbal-acupuncture) at Pyesu(BL13) on OVA(ovalbumin)-induced asthma in mice. Methods : C57BL/6 mice out of all the experimental sloops, except the Normal group and the NR-HA group, were sensitized and challenged with OVA. The mice in the NR-HA group and the OVA-NR-HA group were treated with NR-HA(1%) at Pyesu(BL13). The mice in the OVA-Saline group were injected with saline at Pyesu(BL13). The mice in the OVA-Needle-prick group were treated with a single prick with an injection needle at Pyesu(BL13). NR-HA, saline injection and needle prick were administered for 8 weeks, three times a week Results : in vitro 1. The populations of granulocytes, $CD3e^-/CCR3^+$cells, $CD69^+/CD3e^+$ cells, $CD4^+\;cells\;and\;CD23^+/B220^+$ cells in the OVA-induced asthmatic mouse lungs decreased significantly by NR-HAS(Notopterygii Rhizoma Herbal-acupuncture solution). 2. The lung weight and total cells in lung of the OVA-NR-HA group decreased significantly compared with those of the OVA-Control group. 3. Total leukocytes and eosinophils in BALF of the OVA-NR-HA group decreas ed significantly compared with those of the OVA-Control group. 4. The collagen accumulation in the lung sections of the OVA-NR-HA group decreased significantly compared with that of the OVA-control group. 5. The concentrations of IL-4, IL-5, IL-13, IgE in BALF and serum of the OVA-NR-HA group decreased significantly compared with those of the OVA- Control group. 6. The numbers of $Gr-1^+/CD11b^+,\;CCR3^+,\;CD3e^+, \;CD19^+,\;CD3e^+/CD69^+$ cells in the OVA-NR-HA group decreased significantly compared with those of the OVA-Control group. 7. The mRNA expressions of $TNF-{\alpha}$, IL-5, IL-4 and IL-13 in lung of the OVA-NR-HA group decreased significantly compared with those of the OVA- Control group. 8. The NR-HA group did not show my considerable difference from the Normal group. The OVA-saline group and the OVA-Needle prick group showed suppressive effects on OVA-induced asthma however they were not statistically significant. Conclusion : These results suggest that NR-HA at Pyesu(BL13) is considered to be effective in treating asthma and to be put to practical use in the future asthma clinic.

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