Characterization of Protein in Old Myocardial Infarction by FTIR Micro-spectroscopy

The aim of the present study was to assess whether Fourier transform infrared spectrometry (FTIR) micro-spectroscopy could produce distinct spectral information on protein of old myocardial infarction (OMI) and to set them as molecular markers to diagnose atypical OMI. Paraffin-embedded heart samples were derived from victims dying of OMI. In combination with histological stain, FTIR and infrared micro-spectroscopy, the characteristics of OMI were analyzed morphologically and molecularly. The most relevant bands identified were the amide A, B, Ⅰ and Ⅱ, showing crucial spectral differences between apparent normal region and OMI region, including the peak position blue shift and the increased intensity of OMI, moreover relative increase in α-helix and decrease in β-sheet of protein secondary structures in OMI. Comparing to single spectral band, the I1650/I1550 ratio was increased and rationally used as a molecular marker for diagnosing OMI. These novel preliminary findings supported further exploration of FTIR molecular profiling in clinical or forensic study, and were in accordance with histopathology.

Reaction Mechanism of H2-Assisted C3H6-SCR over Ag-CexZr Catalyst as Investigated by In situ FTIR

A series of silver-doped cerium zirconium oxide(Ag-CevZr)samples was synthesized successfully for selective catalytic reduction of nitric oxide(NO)with hydrogen and propene(H2/C3H6-SCR)under excess oxygen condition.The catalytic activity test proved that Ag-Ce0.4Zr exhibited the best C3H6-SCR activity.Hydrogen(H2)significantly enlianced NO conversion and widened the temperature window.Multi-technology characterizations were conducted to ascertain the properties of fabricated catalysts including X-ray diflraction(XRD),Fourier transform infrared spectrometry(FTIR),scanning electron microscopy(SEM)and H2 temperature programmed reduction(H2-TPR).In situ FTIR results demonstrated that various types of nitrates and chelating nitrite were generated on Ag-CexZr after introduction of NO.Besides,adding H2 could increase the concentration of bidentate nitrate and chelated bidentate nitrate dramatically,especially for Ce0.4Zr catalyst.Transient reaction between pre-adsorbing NO and C3H/C3H6+H2 illuminated that the most active intermediate was chelating nitrite,which was promoted significantly by H2 participation.Furthermore,adding H2 improved the formation of organo-nitro(R-N02),which was the key intennediate in C3H6-SCR.The reaction mechanism over Ag-CexZr catalysts was proposed at 200℃ as follows:nitric oxide(NO)+pr opene(C 3H6)+hy dr ogen(H2)+oxy gen(O2)→chelating nitrite (N O2-)+acry late-type species(CxHyOz)→organo-nitro(R-NO2)→isocyanate(-NCO)+cyanide(—CN)→nitrogen(N2).