• 제목/요약/키워드: Molecular probe

검색결과 430건 처리시간 0.03초

Infrared Spectroscopic Study of Molecular Hydrogen Bonding in Chiral Smetic Liquid Crystal

  • Jang, Won-Gun
    • Journal of Information Display
    • /
    • 제2권3호
    • /
    • pp.18-31
    • /
    • 2001
  • We utilize Fourier transform infrared (IR) spectroscopy to probe intramolecular hydrogen bonding in $smectic-C^{\ast}$ liquid crystal phases. Infrared spectra of aligned smectic liquid crystal materials vs. temperature and of isotropic liquid crystal mixtures vs. concentration were measured in homologs, both with and without hydrogen bonding. Hydrogen bonding significantly changes the direction and magnitude of the vibrational dipole transition moments, causing marked changes in the IR dichroic absorbance profiles of hydrogen bonded molecular subfragments. A GAUSSIAN94 computation of the directions, magnitudes, and frequencies of the vibrational dipole moments of molecular subfragments shows good agreement with the experimental data. The results show that IR dichroism can be an effective probe of hydrogen bonding in liquid crystal phases.

  • PDF

Molecular gas properties under ICM pressure : A Case study of NGC4402

  • 한유진;정애리
    • 천문학회보
    • /
    • 제36권2호
    • /
    • pp.117.2-117.2
    • /
    • 2011
  • We probe 12CO J=2-1 and 13CO J=1-0 properties of a Virgo disk galaxy, NGC 4402 which is located near the cluster center. Our goal is to study the impact of intra cluster medium (ICM) on the molecular gas of a galaxy in the cluster environment. It has been believed that cluster galaxies are deficient in atomic hydrogen gas (HI gas) compared to their field counterparts and now there is much evidence that low density ISM can be easily removed by ram pressure caused by ICM wind. Meanwhile, no significant molecular gas deficiency of the cluster galaxy population has been found yet they show overall lower star formation rate than galaxies in the field, and it is still controversy whether dense ISM can be also stripped by the ICM wind or not. NGC 4402 with truncated HI disk($D_{HI}/D_{opt}$ ~ 0.75 and only 36%of HI gas compare to field galaxies of a similar size) and a disturbed gas morphology, appears to have strong ongoing ram pressure. Using high resolution 12 and 13CO data of NGC 4402 from a Sub Millimeter Array (SMA), we probe the molecular gas properties under strong ICM pressure. We discuss how its star formation activity and hence the global color of NGC4402 would be changed in the future.

  • PDF

FAP Inhibitors as Novel Small Molecules for Cancer Imaging using Radionuclide

  • Anvar Mirzaei;Jung-Joon Min;Dong-Yeon Kim
    • 대한방사성의약품학회지
    • /
    • 제9권1호
    • /
    • pp.49-55
    • /
    • 2023
  • Tumors are encircled by various non-cancerous cell types in the extracellular matrix, including fibroblasts, endothelial cells, immune cells, and cytokines. Fibroblasts are the most critical cells in the tumor stroma and play an important role in tumor development, which has been highlighted in some epithelial cancers. Many studies have shown a tight connection between cancerous cells and fibroblasts in the last decade. Regulatory factors secreted into the tumor environment by special fibroblast cells, cancer-associated fibroblasts (CAFs), play an important role in tumor and vessel development, metastasis, and therapy resistance. This review addresses the development of FAP inhibitors, emphasizing the first, second, and latest generations. First-generation inhibitors exhibit low selectivity and chemical stability, encouraging researchers to develop new scaffolds based on preclinical and clinical data. Second-generation enzymes such as UAMC-1110 demonstrated enhanced FAP binding and better selectivity. Targeted treatment and diagnostic imaging have become possible by further developing radionuclide-labeled fibroblast activation protein inhibitors (FAPIs). Although all three FAPIs (01, 02, and 04) showed excellent preclinical and clinical findings. The final optimization of these FAPI scaffolds resulted in FAPI-46 with the highest tumor-to-background ratio and better binding affinity.

Neisseria lactamica 2118의 $\beta$-galactosidase 유전자의 대장균으로의 클로닝 (Molecular Cloning of $\beta$-Galactosidase Gene from Neisseria lactamica 2118 into Escherichia coli MC 1061)

  • 이종수
    • 자연과학논문집
    • /
    • 제5권1호
    • /
    • pp.37-45
    • /
    • 1992
  • Neisseria lactamica 2118 의 $\beta$-galactosidase 유전자를 Southern Hybridization 과 colony hybridization을 통하여 Escherichia coli MC 1061에 클로닝 시켰다. $\beta$-Galactosidase 유전자를 함유하는 6.5 Kb EcoR I 단편과 7.2 Kb BamH I 단편들을 pMC 1871의 lac Z 유전자를 probe로 한 Southern hybridization으로 얻고 이들을 pBR 322에 삽입한후 Escherichia coli MC 1061에 형질전환 시키고 이들 형질전환체들을 동일 probe로 colony hybridization 시켜 최종적으로 3주의 $\beta$-galactosidase positive clone들을 얻었다. 이들의 재조합 plasmid에는 Neisseria lactomica 2118 염색체 DNA의 약 7.2Kb BamH I 단편이 삽입되어 있음을 확인 하였고 probe와 상동성이 가장 강한것으로 추정되는 pNL 24에 대한 제한효소지도를 작성 하였다.

  • PDF

Evaluation of ${\alpha}$-Tubulin as an Antigenic and Molecular Probe to Detect Giardia lamblia

  • Kim, Ju-Ri;Shin, Myeong-Heon;Song, Kyoung-Ju;Park, Soon-Jung
    • Parasites, Hosts and Diseases
    • /
    • 제47권3호
    • /
    • pp.287-291
    • /
    • 2009
  • The ${\alpha}/{\beta}$-tubulin heterodimer is the basic subunit of microtubules in eukaryotes. Polyclonal antibodies specific to recombinant ${\alpha}$-tubulin of Giardia lamblia were made, and found effective as a probe to specifically detect G. lamblia by immunofluorescence assays. Nucleotide sequences of ${\alpha}$-tubulin genes were compared between G. lamblia WB and GS strains, prototypes of assemblage A and assemblage B, respectively. A set of primers was designed and used to amplify a portion of the ${\alpha}$-tubulin gene from G. lamblia. PCR-RFLP analysis of this ${\alpha}$-tubulin PCR product successfully differentiated G. lamblia into 2 distinct groups, assemblages A and B.Theresults indicate that ${\alpha}$-tubulin can be used as a molecular probe to detect G.lamblia.

Direct Fabrication of the Scanning Probe Tip with Multi­Walled Carbon Nanotubes Using Dielectrophoresis

  • Lee Hyung-Woo;Han Chang-Soo;Lee Eung-Sug;Chul Youm;Kim Jae Ho;Kim Soo-Hyun;Kwak Yoon-Keun
    • International Journal of Precision Engineering and Manufacturing
    • /
    • 제6권2호
    • /
    • pp.50-54
    • /
    • 2005
  • We report a simple, low cost, and reliable method for assembling a multi-walled nanotube (MWNT) to the end of a metal coated scanning probe microscopy (SPM) tip. By dropping the MWNT solution and applying an electric field between an SPM tip and an electrode, MWNTs which were dispersed into a dielectric solution were directly assembled onto the apex of the SPM tip due to the attraction by the dielectrophoretic force. The effective measurement of a MWNT -attached SPM tip was demonstrated by direct comparison with AFM images of a standard sample with a bare AFM tip.

MOLECULAR BASIS OF LUBRICATION

  • Hsu, S.M.
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
    • /
    • pp.49-50
    • /
    • 2002
  • Rapid advancements in analytical instrumentations and techniques in the last several decades offer an unprecedented opportunity to analyze the complex chemistry and probe the surfaces for chemical evidence. Recent developments in nanotechnology provide further ability to examine phenomena and mechanisms at the nanometer level. As a result of these advances, our understanding of the complex lubrication system has improved significantly. This paper will attempt to provide a molecular basis of how lubricant and additives function in lubrication.

  • PDF