Ex vivo diagnosis of lung cancer using a Raman miniprobe.

Lung cancer is the most common cause of cancer death. The conventional method of confirming the diagnosis is bronchoscopy, inspecting the airways of the patient with a fiber optic endoscope. A number of studies have shown that Raman spectroscopy can diagnose lung cancer in vitro. In this study, Raman spectra were obtained from ex vivo normal and malignant lung tissue using a minifiber optic Raman probe suitable for insertion into the working channel of a bronchoscope. Shifted subtracted Raman spectroscopy was used to reduce the fluorescence from the lung tissue. Using principal component analysis with a leave-one-out analysis, the tissues were classified accurately. This novel technique has the potential to obtain Raman spectra from tumors from patients with lung cancer in vivo.

Recycled carbon fiber filled polyethylene composites

Composites of recycled carbon fiber (CF) with up to 30 wt % loading with polyethylene (PE) were prepared via melt compounding. The morphology of the composites and the degree of dispersion of the CF in the PE matrix was examined using scanning electron microscopy, and revealed the CF to be highly dispersed at all loadings and strong interfacial adhesion to exist between the CF and PE. Raman and FTIR spectroscopy were used to characterize the surface chemistry and potential bonding sites of recycled CF. Both the Young's modulus and ultimate tensile stress increased with increasing CF loading, but the percentage stress at break was unchanged up to 5 wt % loading, then decreased with further successive addition of CF. The effect of CF on the elastic modulus of PE was examined using the Halpin-Tsai and modified Cox models, the former giving a better fit with the values determined experimentally. The electrical conductivity of the PE matrix was enhanced by about 11 orders of magnitude on addition of recycled CF with a percolation threshold of 7 and 15 wt % for 500-mu m and 3-mm thick samples. (c) 2007 Wiley Periodicals, Inc.