Surface plasmon resonance and field enhancement in #-shaped gold wires metamaterial.

A #-shaped gold wires metamaterial is designed for surface enhanced Raman spectroscopy (SERS) and sensing. The tunability of surface plasmon resonance (SPR) excitations, hotspots distribution, localized field enhancement and sensitivity of the structure are investigated. In contrast to most metamaterial, the #-shaped structure exhibits two pronounced SPRs that are insensitive to the polarization of excitation light. Pure electromagnetic Raman enhancement factors of about 10(6) are achieved on the symmetrically distributed field hotspots. It is possible to break the usable wavelength range of conventional gold SERS substrates via higher order excitations of the #-shaped metamaterial. In addition, the sensitivity and the figure of merits are found to be comparable or even higher than those of conventional SERS substrates. All these factors together with the high reproducibility nature of metamaterial and its simple planer structure suggest that this structure is very promising for surface enhanced spectroscopy and sensing applications.

[Influence of electro-stimulation at auriculo-stomach point in electrogastrogram of peptic ulcer patients].

Through observation on electrogastrogramm (EGG) with electro-stimulation at Auriculo-Stomach and Auriculo-Heart points and in 60 gastric and duodenal ulcer patients without any treatment as control. Results showed that after electro-stimulation at Stomach point the EGG amplitude of ulcer patients' gastric antrum and corpus was reduced (P < 0.01). But there was no such effect in that at Heart point and in the control (P > 0.05). There were also no effects of three methods on the EGG frequency of ulcer patients' gastric antrum and corpus (P < 0.05). It proves that electro-stimulation at Stomach point has some therapeutic effect to ulcer patients.