[Study on Raman linear model of human breast tissue].

A linear regression model for Raman spectra of human breast tissue was developed with 10 basis spectra which were derived from the spectra of fat, cell cytoplasm, collagen, beta-carotene, DNA and cholesterol etc. This model was tested statistically with more than 2 000 spectra collected from both normal and tumor breast tissue samples. The confidence of F-test for the model significance was 1 to all the spectra and the average of multiple determination coefficients measuring the fit goodness was 0.95. The normalized fit coefficients reflected, to a certain extent, the relative quantities of the Raman-active components in tissue represented by the basis spectra. In comparison with normal breast tissue, the coefficients of the cell cytoplasm and DNA basis spectra increased apparently for the tumor one, and the coefficient of fat basis spectrum changed reversely, which was easily understood with the known pathological changes in the tissue. Mapping spectra were also fitted with this model. This work is helpful to understanding the biochemical/morphological changes in the breast tumor tissues and to developing the Raman diagnostic method for breast tumor.

[Proof of solid state cathodoluminescence by using brightness waveform].

Three different inorganic-organic hetero-junctions (A: ITO/SiO2/Alq3/Al, B: ITO/Alq3/SiO2/Al and C: ITO/SiO2/Alq3/SiO2/Al) were fabricated. The emission can be observed only under positive bias in devices A and B, but under both biases in device C according to their brightness waveforms. With increasing voltage, the increase in blue emission in devices B and C is faster than that in green emission. This is because that the recombination of hot electrons and holes, i.e., electron-hole pairs, produced blue emission in devices B and C, and the recombination of electrons injected from Al with the accumulated holes, which are excited by hot electrons, produced green emission in device A. Hence, the emissions of the devices are attributed to not only the recombination of electrons and accumulated holes, but also the cathodoluminescence-like (CL-like) emission.