[Research on early diagnosis of esophageal cancer by Raman spectroscopy of human hemoglobin].

The Raman spectrums of hemoglobin from 20 normal persons and 21 esophageal cancer patients were measured and analyzed in the present paper, the results show obvious differences between the Raman spectrums of esophageal cancer patients and normal persons. Compared with normal persons, there are more iron ions in low spin state and less in high spin state in the hemoglobin of esophageal cancer patients. It indicates that some iron ions in high spin state turned to low spin state because of cancerization, and this experimental result coincides with the fact that hemolysis is more likely to occur in cancer patients. Principal component analysis (PCA) was employed to get a three-dimensional scatter plot of PC scores for the health and cancer groups, and it can be learned that they are distributed in separate areas. By using the method of discriminate analysis, it was found that the diagnostic algorithm separates the two groups with sensitivity of 90.5% and diagnostic specificity of 95%, and the overall diagnostic accuracy was 92.7%. The results from this exploratory study demonstrate that Raman spectroscopy combined with multivariate analysis would be an effective method for early diagnosis of esophageal cancer.

[Study the Raman spectroscopy of breast tumor limbic tissue].

The confocal Raman micro-spectra of breast tumor limbic fat tissues of forty cases after surgery were collected. Substantial differences were found among breast infiltrative ductal carcinoma, hyperplasia and fibroadenoma, which is possibly to be used as a character of breast cancer and other breast tumor and offers the evidence for the breast tumor diagnosis. So, the Raman spectroscopy of the breast limbic fat tissue is of great value.

[Stabilising porous silicon luminescence by a novel titanium-doped stain etching approach].

Porous silicon (PS) with good luminescent stability and homogeneity was fabricated by using a novel titanium-doped stain etching approach. The blue shift and degrading of the photoluminescence (PL) were not observed when stored and annealed in ambient air. The good luminescent stability is attributed to the surface passivation of the PS by both oxygen and titanium during fabrication. The PL position is independent of the etching time. The results indicate that the photon excitation process meets the quantum confinement mechanism since the PL intensity reaches its maximum when the particle size-dependent band gap is in resonance with the exciting photon energy. The photon emission process is, however, not a direct band-band transition, rather through a surface state within the band gap, instead.

[Raman spectroscopic study of boron carbonitride nanotubes].

Raman spectra of boron carbonitride (BCN) nanotubes made by thermal decomposition under different temperatures and with different catalysts were analyzed. The intensity ratio of D to G band, I(D)/I(G), increases and then decreases with the increase of the temperature. It was indicated that there exists an optimal temperature under which B and N incorporation is maximum. The catalysts influence also the Raman spectra of the BCN nanotubes. I(D)/I(G) is higher with cobalt/ferrocene and nickel/ferrocene than with cobalt, nickel and cobalt/nickel as catalysts. This means that better BCN nanotubes with B and N contents can be produced with the former. The results were confirmed by TEM observation.

[The study of absorption spectrum for cell substrate].

The authors collected the absorption spectrum of RPMI 1640 and DMEM substrates that cultivated Hela and CNE by UV-3101 spectrophotometer and analysed the absorbability of proteins in the substrate. The absorption peaks of the RPMI 1 640 culture medium that cultivated cells for different times shifted from 227 to 222 or 218 nm and from 278 to 280 nm respectively; while during growing course of cultivated cells, one of the absorption peaks of DMEM culture medium shifted from 224 nm to one near 221 nm, and the absorption peak 278 nm almost had no shift. All of these shifts show that the content of each amino acid such as tryptophan and casein has already changed. That is, during the growing course of cultivating cancer cells, the tryptophan and casein were not depleted equivalently. In the growth period of Hela and CNE, they consumed different amino acid. So they need different component proportion for amino acid.