[Baseline correction of Raman spectrum based on piecewise linear fitting].

The baseline drifts of Raman spectra occur in many types of instrumental measurements. It is an important part and a routine step to correct the baseline drift for the data preprocessing. In the present work, the limitations of the baseline correction method based on polynomial fitting were highlighted and a modified polynomial fitting method, i.

[Identification of Cortex Phellodendri by Fourier-transform infrared spectroscopy and principal component analysis].

Fourier transform infrared spectrometer was used to collect infrared spectra of Cortex Phellodendri from six different regions. Original spectra were preprocessed by carrying out appropriate baseline correction and five-points smoothing, and the averaged spectra of Cortex Phellodendri from the six origins were analyzed. As a result, the averaged spectra looked quite similar.

[Sorting oleaginous yeast by using optical manipulation and Raman spectroscopy].

Extensive research has been carried out in an effort to screen the oleaginous microorganisms. Here, Raman spectroscopy and laser tweezers were used to sort oleaginous yeast from mixed yeast cells. The preprocessing of subtracted background, 17 points S-G smoothing filter, polynomial fitting baseline correction and vector normalization were performed and the main features information of intracellular substances from the Raman spectroscopy of yeast cells was extracted by combining principal component analysis.

[Raman tweezers-based analysis of carotenoid synthesis in Rhodotorula glutinis].

Carotenoid synthesis in Rhodotorula glutinis was investigated with Raman tweezers in order to find the effect of nitrogen and carbon resource on carotenoid yield. The cells in fermentation terminus were harvested, and then divided into two parts, one for UV analysis, the other for Raman tweezers detection. Original spectra were preprocessed by carrying out background elimination and baseline correction, and the averaged spectra of cells cultivated in different fermentation medium were analyzed qualitatively.

[Analysis of components difference of yeast strains based on laser tweezers Raman spectroscopy combined with multistatistical analysis].

The combination of laser tweezers and con-focusing Raman spectroscopy (LTRS) has made it possible to investigate single cells in aqueous media. In our experiments, a modified method of Percoll density gradient centrifugation was developed for isolating synchronous cells from six yeast strains and Raman spectra of single yeast cells were collected by LTRS as well, in which multiple statistical analysis, principal component analyses (PCA) and discriminant function analysis (DFA) were applied to distinguish synchronous cells between yeast strains statistically. The result showed that Raman spectra scattered from the trapping yeast cells could provide intrinsic molecular information, and there were remarkable difference among those of six yeast strains in Raman spectrogram which correspond to various biomacromolecule, the difference of protein as well as lipid were significantly higher than nucleinic acid between two of yeast strains randomly, and among the six strains, synchronized yeast cells can be discriminated using PCA and DFA based on 14 most contribution bands, 706, 862, 918, 997, 1 073, 1 127, 1 269, 1 291, 1 305, 1 429, 1 465, 1 591, 1 602 and 1 652 cm(-1), 10 bands of which were from protein, 3 bands were from lipoid, and 1 band was from nucleinic acid.

[Using Raman spectroscopy to analyze apoptosis of gastric cancer cells induced by cisplatin].

Apoptosis of gastric cancer cells induced by cisplatin was investigated using laser Raman spectroscopy. Gastric cancer cells (SGC7901) were treated with 10 microg x mL(-1) cisplatin for 24, 48 and 72 hours, then were divided into two parts, one for fluorescence staining, the other for collection of Raman spectra by means of scanning. The acquired spectra were then preprocessed by background elimination, smoothing, normalization, baseline correction, and peak fitting.

[The effect of abnormal cell shape on the spectral distinguishing of erythrocytes using laser tweezers Raman spectroscopy].

Erythrocyte is a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues. Erythrocyte, which takes on a biconcave disc that has no nucleus, is flexible and changeful. Erythrocyte is so sensitive to the environment that the shape of cell goes crimpy, even acanthoid.

[Laser tweezers Raman spectroscopy analysis of liver cancer tissue].

Single cell laser tweezers Raman spectroscopy (LTRS) has been applied to biology field. In the present article, the authors measured the spectra of liver cancer cells, para-cancer cells and normal hepatocytes using single cell laser tweezer Raman spectroscopy (LTRS) system and compared their average spectra changes. The results showed that the laser tweezers Raman spectroscopy could differentiate specimens of different pathological changes from liver tissue studied.

[FTIR-HATR to identify beta-thalassemia and its mechanism study].

Fourier transform infrared spectroscopy (FTIR) associated with horizontal attenuated total reflectance (HATR) was firstly used to diagnose beta-thalassemia patients. With excellent linearity (r = 0.997) and reproducibility (RSD < 4%), FTIR-HATR shows an order-of-magnitude increase in IR absorption bands over the single-path transmission FTIR Based on above, spectra from 37 patients' and 68 health samples indicated several observable differences in IR vibrational spectra of the Hb lysates between the beta-thalassemia major patients and control: (1)Because of decreasing hemoglobin, the peak intensities are obviously lower in beta-thalassemia group that is consistent with index from routine hemoglobin diagnosis.

[Study of Raman spectra of single carcinoma of nasopharynx cell].

The Raman spectra from carcinoma of nasopharynx cell lines (CNE2) and normal airway epithelial cell lines (HBE) were investigated using a laser tweezers Raman spectroscopy (LTRS). The Raman scattering measurements were obtained from three different places in every single cell. Visual inspection of the spectra shows that the differences observed in spectra of the cancer cells and normal cells are obvious.

[Raman micro-spectroscopy of single blood platelets].

The authors collected the Raman spectra of single blood platelets of human, pig, rat and rabbit suspended in saline so-lution by using a laser tweezers Raman spectroscopy (LTRS) setup. A single platelet cell was trapped in the focus of a near-infrared laser beam at 785 nm and the excited Raman spectrum was acquired. For each species, the Raman spectra of up to 20 platelet cells were acquired and were used to perform a principal components analysis (PCA) or a discriminate function analysis (DFA).