• 제목/요약/키워드: high molecular components

검색결과 272건 처리시간 0.024초

IMAGING THE CIRCUMSTELLAR ENVELOPES AROUND EVOLVED STARS WITH THE SMA

  • HIRANO NAOMI;CHIU PO-JIAN;MULLER SEBASTIEN;TRUNG DINH-V
    • 천문학회지
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    • 제38권2호
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    • pp.219-222
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    • 2005
  • We present the high-resolution (2"-4") images of the molecular envelopes surrounding the evolved stars, V Hya, VY CMa, and ${\pi}^1$ Gru observed with the Submillimeter Array. The CO J=2-1 and 3-2 images of the carbon star V Hya show that the circumstellar structure of this star consists of three kinematic components; there is a flattened disk-like envelope that is expanding with a velocity of ${\~}16 km\;s^{-1}$, the second component is the medium-velocity wind having a deprojected velocity of 40-120 km $s^{-l}$ moving along the disk plane, and the third one is the bipolar molecular jet having an extreme velocity of 70-185 km $s^{-l}$. The axis of this high velocity jet is perpendicular to the plane of the disk-like envelope. We found that the circumstellar structure of the S-star ${\pi}^1$ Gru traced by the CO J =2-1 resembles that of V Hya quite closely; the star is surrounded by the expanding disk-like envelope and is driving the medium-velocity wind along the disk plane. We also obtained the excellent images of VY CMa with the CO and $^{13}CO$ J=2-1 and $SO\;6_5-5_4$ lines. The maps of three molecular lines show that the envelope has a significant velocity gradient in the east-west direction, suggesting that the envelope surrounding VY CMa is also flattened and expanding along its radial direction. The high-resolution images obtained with the SMA show that some AGB stars are associated with the asymmetric mass loss including the equatorial wind and bipolar jet.

A New Door for Molecular-Based Organic Electroluminescent Devices

  • Jou, Jwo-Huei;Wang, Wei-Ben;Hsu, Mao-Feng;Lai, Wen-Hsuan;Chen, Chin-Ti;Chin, Chih-Lung
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.350-353
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    • 2009
  • While the comparatively high MW would make the employed molecules extremely difficult to vacuum-evaporate, and result in poor device performance, the wet-process has been proven to be quite effective and convenient as usual to the fabrication of high-efficiency OLEDs composing high MW components.

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Improved Thermal Bonding Behaviour of Polypropylene Non-wovens by Blending Different Molecular Weights of PP

  • Deopura, B.L.;Mattu, Ankush;Jain, Anurag;Alagirusamy, R.
    • Fibers and Polymers
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    • 제3권1호
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    • pp.38-42
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    • 2002
  • Polypropylene filaments were spun from a mixture of PP chips of two different Melt Flow Index (MFI) (3 MFI and 35 MFI). A significant difference was observed in the melting characteristics of the resultant filaments from either of the individual components as observed from the DSC. The main difference being in the degree of melting achieved at any temperature in the initial stages of the melting range, which was found to be higher in case of the filaments spun from the b]end. These filaments were then thermally bonded using silicon oil bath and heated roller method. Subsequently the bond strength of the filaments was measured on the Instron Tensile Tester using the loop technique. The values of the world strengths obtained from the blend were compared with those made from the individual component. It was found that the bond strength of the bonds obtained from the blended filament at a given temperature was higher than that of the bonds made from the filaments of either of the individual components, which is also suggested by the DSC curves. The difference in the bond strength was found to be as high as 25% in case of the blend with 60:40 composition ratios of the 3 MFI and 35 MFI components respectively.

한국산(韓國産) 고등(高等) 균류(菌類)의 성분(威分) 연구(硏究)(제48보)(第48報) -노란다발버섯의 독(毒) 성분(成分) 네마톡신- (Studies on Constituents of the Higher Fungi of Korea(XLVIII) -Nematoxin of Naematoloma fasciculare-)

  • 김병각;심미자
    • 한국균학회지
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    • 제12권3호
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    • pp.117-119
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    • 1984
  • 한국에 야생하는 독버섯의 하나인 노란다발버섯을 물로 가열 추출한 후 추출액에 3배의 에탄올을 첨가하여 고분자 물질을 침전시켰으며 이를 다시 투석하여 정제 하였다. 이것을 냉동 건조하여 분말을 얻었으며 60mg/kg 용량을 백서의 복강내에 주사 하였던 바, 6일 후 부터 사망하기 시작하여 7일째에는 7마리중 4마리가 절명하였다. 이 유독 성분을 "네마톡신"이라 명명하고자 한다.

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Influence of Quantum well Thickness Fluctuation on Optical Properties of InGaN/GaN Multi Quantum well Structure Grown by PA-MBE

  • Woo, Hyeonseok;Kim, Jongmin;Cho, Sangeun;Jo, Yongcheol;Roh, Cheong Hyun;Kim, Hyungsang;Hahn, Cheol-Koo;Im, Hyunsik
    • Applied Science and Convergence Technology
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    • 제26권3호
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    • pp.52-54
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    • 2017
  • An InGaN/GaN multiple quantum well (MQW) structure is grown on a GaN/sapphire template using a plasma-assisted molecular beam epitaxy (PA-MBE). The fluctuation of the quantum well thickness formed from roughly-grown InGaN layer results in a disordered photoluminescence (PL) spectrum. The surface morphologies of the InGaN layers with various In compositions are investigated by reflection high energy electron diffraction (RHEED) and atomic force microscopy (AFM). A blurred InGaN/GaN hetero-interface and the non-uniform QW size is confirmed by high resolution transmission electron microscopy (HR-TEM). Inhomogeneity of the quantum confinement results in a degradation of the quantum efficiency even though the InGaN layer has a uniform In composition.

인공무릎관절에 있어서 임플란트의 재료 및 고정방법에 따른 응력분석 (Stress Analysis of Total Knee System Depending on Implant Materials and Fixation Methods)

  • 조철형;조용균;최재봉;최귀원
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.484-488
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    • 1997
  • Three-dimensional finite element analyses were used to compare the stress distribution and the stability of the fixation among seven different tibial components and to investigate the effect due to implant materials in total knee arthroplasty. The components included an intact tibia(Type I), Cemented Cobalt-Chromium tibial tray implanted with a PMMA cemented Co-Cr stem(Type II), Cemented Co-Cr tibial tray with a uncemented Co-Cr stem(Type III), Cemented Ultra High Molecular Weight Polyethylene (UHMWPE) tibial tray with a cemented UHMWPE stem (Type IV), Cemented UHMWPE tray with a uncemented UHMWPE stem(Type V), Cemented Co-Cr tray without a stem(Type VI), and Cemented UHMWPE tray without a stem(Type VII). Uncemented components were assumed to have complete bony in growth and a rigid state of fixation between component and bone. The interface between bone/cement/component of cemented components was also assumed to be fully bonded. Bi-condylar forces were applied. The results indicated that Uncemented stem components provided lower bone stress shielding and stress concentration. The UHMWPE tray and stem component showed better agreement with the intact tibia than the Co-Cr Alloy tray and stem components. If the implant tray can be fixed firmed without a stem, Cemented PE tray without a stem(Type VII) may be recommended to give the best characteristics in the sense of stress distribution and stability.

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細胞의 融合機作에 관한 硏究(1) (Studies on the Fusion Mechanism of the Cell (1))

  • Kang, Man-Sik;Seunhyon Choe;Wookeun Song
    • 한국동물학회지
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    • 제26권4호
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    • pp.235-251
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    • 1983
  • 배양한 계배 근원세포의 융합기작을 밝혀보기 위해서 분화과정에 있는 근세포를 lactoperoxidase를 촉매로 써서 막표면단백질을 iodination하여 본 결과, 융합의 과정에서 막표면단백질의 정성적 및 정량적 변화를 볼 수 있었다. 융합전의 세포에서 12개의 주요단백질을 검출할 수 있었는데, 융합시의 세포에서는 165K와 93K의 단백질이 새롭게 나타났으며 동시에 245K 단백질의 감소와 저분자 단백질의 증가를 볼 수 있었다. 이 고분자 단백질의 감소는 세포주기와 관계가 있는 것으로 생각되고 있는 세포내 cAMP 수준은 융합에 앞서서 현저한 일시적인 증가를 보였는데, 이와같은 결과는 cAMP의 증가가 세포의 융합의 유발과 관계가 있음을 보여 주는 것이었으며, 분화하는 근원세포에서는 고도의 동조성이 보였다. 아울러, 근세포의 융합과정에서 적어도 4 가지의 iodination된 저분자 단백질을 배양액에서 발견할 수 있었는데, 이들은 막단백질의 가수분해산물로 생각되었고, 역시 세포의 융합과정과 유관할 것으로 추정되었다. 세포막 표면단백질의 변화, 분화과정 중에 배양액 속으로 방출되는 단백질, 융합과 유관한 cAMP의 증가 및 융합과 관련되는 외적 요인의 가능성에 관해서 논의하였다.

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Sentinel lymph node mapping using tri-modal human serum albumin conjugated with visible dye, near infrared fluorescent dye and radioisotope

  • Kang, Se Hun;Kim, Seo-il;Jung, So-Youn;Lee, Seeyoun;Kim, Seok Won;Kim, Seok-ki
    • 대한방사성의약품학회지
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    • 제1권1호
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    • pp.62-73
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    • 2015
  • We developed an evans blue-indocyanine green-$^{99m}Tc$-human serum albumin conjugate for sentinel lymph node mapping and we describe its unique potential usage for clinical implications. This conjugate has combined the strengths of visible blue dye, near-infrared fluorescence and radioisotope into one single conjugate without any additional weakness/disadvantage. All the components of evans blue-indocyanine green-$^{99m}Tc$-human serum albumin are safe and of low cost, and they have already been clinically used. This conjugate was stable in the serum, it showed a long retention time in the lymphatic system and the lymph nodes showed a much higher signal-to-noise ratio after the conjugate was injected intradermally into the paw of mice. Both the single-photon emission computed tomography and near-infrared fluorescent images of the mice were successfully obtained at the same time as the excised sentinel lymph nodes showed blue color. The visual color, near-infrared fluorescence and gamma ray from this agent could be complementary for each other in all the steps of sentinel lymph node sampling: exploring and planning sentinel lymph node before excision with visualization of the exact sentinel lymph node location during an operation. Therefore, the triple modal agent will possibly be very ideal for sentinel lymph node mapping because of the high signal-to-noise ratio for non-invasive imaging and its complementary multimodal nature, easy preparation and safety. It is promising for clinical applications and it may have great advantages over the traditional single modal methods.

Genetic Function Approximation and Bayesian Models for the Discovery of Future HDAC8 Inhibitors

  • Thangapandian, Sundarapandian;John, Shalini;Lee, Keun-Woo
    • Interdisciplinary Bio Central
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    • 제3권4호
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    • pp.15.1-15.11
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    • 2011
  • Background: Histone deacetylase (HDAC) 8 is one of its family members catalyzes the removal of acetyl groups from N-terminal lysine residues of histone proteins thereby restricts transcription factors from being expressed. Inhibition of HDAC8 has become an emerging and effective anti-cancer therapy for various cancers. Application computational methodologies may result in identifying the key components that can be used in developing future potent HDAC8 inhibitors. Results: Facilitating the discovery of novel and potential chemical scaffolds as starting points in the future HDAC8 inhibitor design, quantitative structure-activity relationship models were generated with 30 training set compounds using genetic function approximation (GFA) and Bayesian algorithms. Six GFA models were selected based on the significant statistical parameters calculated during model development. A Bayesian model using fingerprints was developed with a receiver operating characteristic curve cross-validation value of 0.902. An external test set of 54 diverse compounds was used in validating the models. Conclusions: Finally two out of six models based on their predictive ability over the test set compounds were selected as final GFA models. The Bayesian model has displayed a high classifying ability with the same test set compounds and the positively and negatively contributing molecular fingerprints were also unveiled by the model. The effectively contributing physicochemical properties and molecular fingerprints from a set of known HDAC8 inhibitors were identified and can be used in designing future HDAC8 inhibitors.

A combined application of molecular docking technology and indirect ELISA for the serodiagnosis of bovine tuberculosis

  • Song, Shengnan;Zhang, Qian;Yang, Hang;Guo, Jia;Xu, Mingguo;Yang, Ningning;Yi, Jihai;Wang, Zhen;Chen, Chuangfu
    • Journal of Veterinary Science
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    • 제23권3호
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    • pp.50.1-50.12
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    • 2022
  • Background: There is an urgent need to find reliable and rapid bovine tuberculosis (bTB) diagnostics in response to the rising prevalence of bTB worldwide. Toll-like receptor 2 (TLR2) recognizes components of bTB and initiates antigen-presenting cells to mediate humoral immunity. Evaluating the affinity of antigens with TLR2 can form the basis of a new method for the diagnosis of bTB based on humoral immunity. Objectives: To develop a reliable and rapid strategy to improve diagnostic tools for bTB. Methods: In this study, we expressed and purified the sixteen bTB-specific recombinant proteins in Escherichia coli. The two antigenic proteins, MPT70 and MPT83, which were most valuable for serological diagnosis of bTB were screened. Molecular docking technology was used to analyze the affinity of MPT70, MPT83, dominant epitope peptide of MPT70 (M1), and dominant epitope peptide MPT83 (M2) with TLR2, combined with the detection results of enzyme-linked immunosorbent assay to evaluate the molecular docking effect. Results: The results showed that interaction surface Cα-atom root mean square deviation of proteins (M1, M2, MPT70, MPT83)-TLR2 protein are less than 2.5 A, showing a high affinity. It is verified by clinical serum samples that MPT70, MPT83, MPT70-MPT83 showed good diagnostic potential for the detection of anti-bTB IgG and M1, M2 can replace the whole protein as the detection antigen. Conclusions: Molecular docking to evaluate the affinity of bTB protein and TLR2 combined with ELISA provides new insights for the diagnosis of bTB.