Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0276640 (TEM)
 20,729 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three nanobiocomposites (PRAg31, PRAg11, and PRAg13; the numbers indicate the weight ratios of poly(o-methoxyaniline) (POMA) and ribonucleic acid (RNA), respectively), produced from the same amount of POMA (P) and silver nitrate (AgNO(3)) with differing proportions of RNA (R) are prepared by aging the aqueous solutions of the mixture for 3 weeks at 30 degrees C. The scanning and transmission electron microscopy (SEM and TEM) indicate Ag nanoparticle formation on the hybrid fiber surface and in the PRAg31 system the hybrid fibrils become coated with metallic Ag, the phenomenon being termed as "nanojacketting". The circular dichroism (CD) spectra indicate a small distortion of RNA conformation from A helix toward B helix. FTIR and UV-vis spectra suggest that POMA (emeraldine base, EB) being doped by Ag(+) become oxidized to its pernigraniline base (PB) form and reduce Ag(+) to metallic Ag. The Ag nanoparticles thus produced become stabilized on the fibril surface by co-ordination through nitrogen atoms of POMA (PB) chains. The much slower red shift of pi band to polaron band transition peak in PRAg31 than that of the other two nanobiocomposites is indicative of difficulty in conformational transitions of POMA chain in the "nanojacketted" hybrid fibrils. The dc-conductivity values of the nanobiocomposites are two orders higher than that of the pure POMA-RNA hybrids. The PRAg31 system exhibits rectification property in the I-V characteristic curves and a probable explanation based on the feasibility of p-n junction formation arising from the transfer of lone pair of electrons of nitrogen of POMA (p-type) to the Ag nanoparticles (n-type) has been offered.
 ...
PMID:RNA-poly(o-methoxyaniline) hybrid templated growth of silver nanoparticles and nanojacketing: physical and electronic properties. 2002 Jul 56

Ultrasound assisted in-situ semi-batch emulsion polymerization has been used for the preparation of polyaniline (PANI) and PANI/ZnMoO4 nanocomposite with different loading of ZnMoO4 (ZM) nanoparticles. ZM nanoparticles were functionalized using Myristic acid (MA) for better compatibility with PANI. The cavitational effects induced due to ultrasonic irradiations have been shown significant enhancement in the dispersion of functionalized ZM nanoparticles into the PANI during ultrasound assisted in-situ emulsion polymerization process. TEM images of PANI/ZM nanocomposite particles give the direct evidence of fine dispersion and encapsulation of MA treated ZM nanoparticles in PANI matrix. The presence of ZM nanoparticles in PANI/ZM nanocomposite shows significant improvement in the mechanical (cross-cut adhesion), thermal, anticorrosion and sensing properties of PANI/ZM nanocomposite/alkyd coatings over PANI/alkyd and neat alkyd resin coating. Fine and uniform dispersion of ZM nanoparticles in PANI matrix using this novel synthesis method (PANI (p-type)/ZM (n-type) hetero-junction) improves LPG sensing ability and minimizes response time to sense LPG significantly compared with neat PANI.
 ...
PMID:Ultrasound assisted synthesis of PANI/ZnMoO4 nanocomposite for simultaneous improvement in anticorrosion, physico-chemical properties and its application in gas sensing. 2546 77