Yong Ye

Raman scattering properties of human pterygium tissue

Pterygia, caused by fibrovascular growth of conjunctiva, are a common ophthalmic disease. However, the molecular composition of pterygium tissue has not been completely understood, and therefore the aim of this study is to investigate the spectroscopic differences between normal human bulbar conjunctiva and human pterygium tissue using a confocal Raman system. The high signal-to-noise ratio spectra from pterygium and conjunctiva tissue were obtained by this technique without any sample preparation and the time of detection required less than 3 min. Comparing Raman spectra of two types of tissue, there are obvious changes, including intensity decrease at approximately 1585 cm(-1) and intensity increase at approximately 1748, 1156, and 1521 cm(-1) with the lesion of conjunctiva. Additionally, the amide I vibrational mode of proteins in conjunctiva is significantly different than that in pterygium. The use of pathology, immunology, and the peroxidation of the lipids in conjunction with the Raman results indicate that the presence of additional elastic fibers, mast cells, and lymphocytes in pterygium, as compared with normal bulbar conjunctiva, have fewer unsaturated fat acids. The present study demonstrates that Raman spectroscopy can be potentially applied to diagnose pterygia clinically.

Surface-enhanced Raman spectroscopy of some Schiff base complexes and their interaction with DNA

Abstract Surface-enhanced Raman spectroscopy (SERS) in silver colloidal of some new Schiff base complexes derived from 2-chlorobenzaldehyde and alanine as model anticancer compounds and their interaction with DNA were investigated. The effects of DNA binding on the SERS are significantly different for these complexes. Most of the differences in the spectra are explained in terms of the compound affinity for DNA. It seems SER spectra can be inferred as a new method for initial screening of anticancer compounds.

Fourier-transform Raman and infrared spectroscopic analysis of 2-nitro-tetraphenylporphyrin and metallo-2-nitro-tetraphenylporphyrins ☆

The Fourier-transform Raman (FT-Raman) and infrared (FT-IR) spectra of 2-nitro-tetraphenylporphyrin (2-NO(2)-TPP), nickel-2-nitro-tetraphenylporphyrin (Ni-2-NO(2)-TPP), zinc-2-nitro-tetraphenylporphyrin (Zn-2-NO(2)-TPP) and copper-2-nitro-tetraphenylporphyrin (Cu-2-NO(2)-TPP) were acquired for the first time and carefully assigned and discussed. The effects of a beta-NO(2) group and the influence of the central metal on the molecular symmetry and vibrational spectra of the porphyrin macrocycle were also examined. The bands at 1323-1339, 1516-1526 and 961-971 cm(-1) were attributed to the symmetric and asymmetric stretching vibration of the NO(2) group and to the stretching vibration of the C(beta)-N bond, respectively, which connects the NO(2) group with the beta-carbon of the porphyrin macrocycle. These bands can act as a marker to distinguish beta-NO(2) TPPs from other beta-substituent TPPs. Cu-2-NO(2)-TPP has a C(4nu) molecular symmetry, which is different from those of Ni-2-NO(2)-TPP and Zn-2-NO(2)-TPP, i.e. D(4h).

Design of auto-classifying system and its application in Raman spectroscopy diagnosis of gastric carcinoma

A tentative user-friendly auto-classifying system is developed to classify Raman spectra of gastric carcinoma tissues. By combining two efficient fuzzy clustering methods: artificial neural network (ANN) and fuzzy C-means (FCM), the software system integrates high robustness of ANN and strong quantity estimation ability of FCM, and provides more credible classifying results for the Raman spectroscopy auto-diagnosis of gastric carcinoma. Also the system can be applied to classifying of other spectroscopy by some necessary alteration of feature vector.