Sensitive Gap-Enhanced Raman Spectroscopy with a Perfect Radially Polarized Beam

Gap mode surface-enhanced Raman spectroscopy (SERS) enables high enhancement of Raman signal. However, the polarization of excitation light shows great influence on the excitation of gap mode and hence on the Raman enhancement. Here, we propose a nanoparticle-on-film gap mode SERS accompanying with a new type of excitation source called as perfect radially polarized (PRP) beam. The PRP beam possesses a ring-shaped beam pattern that can be tuned to match the surface plasmon resonance angle under a tight focusing condition, hence improving greatly the excitation efficiency of surface plasmon polaritons, and eventually the sensitivity of gap mode SERS. Such kind of enhanced-Raman system with a PRP beam has a great potential on the applications such as single molecule Raman detection.

     

Determinants of sensitivity to DZNep induced apoptosis in multiple myeloma cells

The 3-Deazaneplanocin A (DZNep), one of S-adenosylhomocysteine (AdoHcy) hydrolase inhibitors, has shown antitumor activities in a broad range of solid tumors and acute myeloid leukemia. Here, we examined its effects on multiple myeloma (MM) cells and found that, at 500 nM, it potently inhibited growth and induced apoptosis in 2 of 8 MM cell lines. RNA from un-treated and DZNep treated cells was profiled by Affymetrix HG-U133 Plus 2.0 microarray and genes with a significant change in gene expression were determined by significance analysis of microarray (SAM) testing. ALOX5 was the most down-regulated gene (5.8-fold) in sensitive cells and was expressed at low level in resistant cells. The results were corroborated by quantitative RT-PCR. Western-blot analysis indicated ALOX5 was highly expressed only in sensitive cell line H929 and greatly decreased upon DZNep treatment. Ectopic expression of ALOX5 reduced sensitivity to DZNep in H929 cells. Furthermore, down-regulation of ALOX5 by RNA interference could also induce apoptosis in H929. Gene expression analysis on MM patient dataset indicated ALOX5 expression was significantly higher in MM patients compared to normal plasma cells. We also found that Bcl-2 was overexpressed in DZNep insensitive cells, and cotreatment with DZNep and ABT-737, a Bcl-2 family inhibitor, synergistically inhibited growth and induced apoptosis of DZNep insensitive MM cells. Taken together, this study shows one of mechanisms of the DZNep efficacy on MM correlates with its ability to down-regulate the ALOX5 levels. In addition, DZNep insensitivity might be associated with overexpression of Bcl-2, and the combination of ABT-737 and DZNep could synergistically induced apoptosis. These results suggest that DZNep may be exploited therapeutically for a subset of MM.     

Correction to: Comparative life cycle assessment of rex rabbit breeding industry chains: benefits of a circular industry chain

The International Journal of Life Cycle Assessment -     

Comparative life cycle assessment of rex rabbit breeding industry chains: benefits of a circular industry chain

The International Journal of Life Cycle Assessment - The environmental impacts of breeding industries have been broadly studied and compared. However, environmental research on the rex rabbit...