A general model is presented for the interpretation of the Raman spectra of amorphous carbon nitrides measured at any excitation energy. The Raman spectra can be explained in terms of an amorphous carbon based model, without need of extra peaks due to CN, NN or NH modes. We classify amorphous carbon nitride films in four classes, according to the corresponding N-free film: a-C:N, a-C:H:N, ta-C:...

Toxoplasmosis is an important zoonosis in public health because domestic cats are the main agents responsible for the transmission of this disease in Brazil. We investigate a method for diagnosing toxoplasmosis based on Raman spectroscopy. Dispersive near-infrared Raman spectra are used to quantify anti-Toxoplasma gondii (IgG) antibodies in blood sera from domestic cats. An 830-nm laser is used...

The goal of this study is to characterize the Raman spectra of tungsten trioxide (WO3) at increasing temperatures in the range 30.6–170 ̊C in order to understand the behavior and characteristics of WO3 after adsorption of toxic gases (e.g. NO and SO2) and to provide a database of Raman spectral features for future use in providing an optical complement to semi-conducting metal oxide gas sensor t...

Dielectric stack interference ® lters can be used in conjunction with a high-throughput single-stage spectrograph to facilitate the measurement of high signal-to-noise (S/N) ultraviolet (UV) Raman spectra with 228.9-nm and 244-nm excitation wavelengths. Placed between the sample and the spectrograph, these ® lters re ̄ ect Rayleigh scattering while transmitting Stokes-shifted Raman scattering. W...

The first observation of the vibrational spectrum of the synthetic pyroxene Li-kosmochlor (LiCrSi2O6) is reported herein. The Raman and visible spectra are reported as a function of pressure. Though the pyroxene retains its P21/c symmetry, changes in the Raman spectra are observed between 6.8 and 7.7 GPa, possibly due to the formation of an additional bond between Li and O3 or some other transi...

The Fourier transform gas phase (5000-400 cm), solid phase (4000-400 cm) infrared spectra as well as Raman spectra (3500-50 cm) of 1,3-dimethylbarbituric acid have been recorded. Quantum chemical calculations of energies, geometrical structure and vibrational wave numbers of 1,3-dimethylbarbituric acid have been made by density functional method with 6-31G(d,p) as basis set. The best level of t...

A thiol-modified carotene, 7'-apo-7'-(4-mercaptomethylphenyl)-β-carotene, was used to obtain nonresonant surface-enhanced Raman scattering (SERS) spectra of carotene at an excitation wavelength of 1064 nm, which were compared with resonant SERS spectra at an excitation wavelength of 532 nm. These spectra and surface-enhanced hyper-Raman scattering (SEHRS) spectra of the functionalized carotene ...

Nitrogenated, tetrahedral amorphous carbon (ta-C) ®lms prepared by the ®ltered cathodic vacuum arc (FCVA) technique have been studied using ultraviolet (UV, 244 nm) and visible (514 nm) micro-Raman scattering. The nitrogen ions were produced by a RF ion-beam source with a nitrogen ̄ow-rate varying from 0 to 10.0 sccm, which results in a nitrogen content from 0 to 10.8 at.% in the deposited ®lms...

Breast-conserving surgery (BCS) is increasingly employed for the treatment of early stage breast cancer. One of the key challenges in BCS is to ensure complete removal of the tumour while conserving as much healthy tissue as possible. In this study we have investigated the potential of Raman micro-spectroscopy (RMS) for automated intra-operative evaluation of tumour excision. First, a multivari...

The cellular and matrix cues that induce stem cell differentiation into distinct cell lineages must be identified to permit the ex vivo expansion of desired cell populations for clinical applications. Combinatorial biomaterials enable screening multiple different microenvironments while using small numbers of rare stem cells. New methods to identify the phenotypes of individual cells in cocultu...