In Raman detection, the most popular solution for the samples is tri-distilled water. But the effect of aqueous solution
is barely studied in Raman spectroscopy. In fact Raman spectroscopy of solid-state and liquid-state are obvious different.
In addition, FWHM of Raman spectral peaks also change evidently. In this paper, several samples were selected for the
experiment; including sodium nitrate, sodium nitrite, glucose and caffeine. By comparing the Raman spectroscopy
of samples at different concentrations, it is found that the concentration of the sample can affect the strength of Raman
spectroscopy, but it can hardly impact FWHM of Raman spectral peaks. By comparing the Raman spectroscopy of
liquid-state with the Raman spectroscopy of solid-state, it is observed that the FWHM of some Raman spectral peaks
varied obviously; that may be because when the sample was dissolved into the water, the crystal lattice structure was
broken, and for some samples atom form became ion form in aqueous solution. Those structural variations caused the
variation of the FWHM. The Raman spectroscopy of caffeine aqueous solution at very low concentration was also
detected and analyzed. Compared with the Raman spectra of solid-state samples, it is found that some Raman spectral
peaks disappeared when the sample was dissolved in water. It is possible that the low concentration of the sample result
in the weakening of Raman signals and the disappearing of some weak Raman spectral peaks. Then Ag nanoparticles
were added into the caffeine aqueous solution, the results suggest that surface enhanced Raman spectroscopy (SERS) not
only can enhance the Raman spectral signal, but also can reduce the effect of aqueous solution. It is concluded that the
concentration of sample only affects the strength of Raman spectroscopy; the aqueous solution can affect the FWHM of
Raman spectral peaks; and SERS can reduce the effect of aqueous solution.
Surface enhanced Raman spectroscopy (SERS) can provide information of internal structures and chemical components
from different kinds of samples. Laser scanning confocal microscopy (LSCM) can show morphologic information of
samples by high-resolution optical images with different focal planes. In this paper, the dynamic variation of cancer cells
(HELA cells) in the apoptosis was first studied by combining SERS and LSCM. After gold nanoparticles (GNPS) uptake,
HELA cells were divided into two groups, and were respectively studied at six different time points of cell apoptosis
period by SERS and LSCM. The LSCM images of HELA cells obtained at different time points were analyzed, and the
morphology varieties of HELA cells apoptosis were obtained. It suggests that HELA cells apoptosis gradually in the
apoptosis period until they died. In addition, Raman spectra of HELA cells measured at different time points were also
compared. It shows that some Raman signal peaks shift, and FWHM of Raman peaks change too. The variation of
internal structures and chemical constituents were analyzed according to the shifts and FWHM of the Raman peaks. The
internal dynamic information and morphologic varieties from HELA cells apoptosis gained by combining SERS and
LSCM will make us to understand cancer cell apoptosis throughly.
To overcome the drawback of traditional universal tool microscopes, a remanufacturing scheme based on charge coupled devices (CCD) is proposed. In this paper, the remanufacturing of old tool microscopes is replaced gradually by CCD and grating ruler and the development of a novel measuring system designed to directly analyze image of the screw to be measured is discussed. For the analysis of image, such novel image processing methods as adaptive switching median (ASM) filter and edge detection based on the modified Sobel operator are designed. For the line detection algorithm, HOUGH transform also is used to measure the screw parameter. Experiments on screw images demonstrate that the scheme of remanufactured universal tool microscope is of feasibility and the proposed measurement is of validity.
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