We present a compact, fast, and versatile fiber-optic probe system for real-time determination of tissue optical properties from spatially resolved continuous-wave diffuse reflectance measurements. The system collects one set of reflectance data from six source-detector distances at four arbitrary wavelengths with a maximum overall sampling rate of 100 Hz. Multivariate calibration techniques based on two-dimensional polynomial fitting are employed to extract and display the absorption and reduced scattering coefficients in real-time mode. The four wavelengths of the current configuration are 660, 785, 805, and 974 nm, respectively. Cross-validation tests on a 6 x 7 calibration matrix of Intralipid-dye phantoms showed that the mean prediction error at, e.g., 785 nm was 2.8% for the absorption coefficient and 1.3% for the reduced scattering coefficient. The errors are relative to the range of the optical properties of the phantoms at 785 nm, which were 0-0.3/cm for the absorption coefficient and 6-16/cm for the reduced scattering coefficient. Finally, we also present and discuss results from preliminary skin tissue measurements.

Native fluorescence characteristics of blood plasma were studied in the visible spectral region, at two different excitation wavelengths, 405 and 420 nm, to discriminate patients with different stages of oral malignancy from healthy subjects. The fluorescence spectra of blood plasma of oral malignant subjects exhibit characteristic spectral differences with respect to normal subjects. Different ratios were calculated using the fluorescence intensity values at those emission wavelengths that give characteristic spectral features of each group of experimental subjects studied. These fluorescence intensity ratios were used as input variables for a multiple linear discriminant analysis across different groups. Leave-one out cross-validation was used to check the reliability of each discriminant analysis performed. The discriminant analysis performed across normal and oral cancerous subjects classified 94.7% of the original grouped cases and 93.7% of the cross-validated grouped cases. A classification algorithm was developed on the basis of the score of the discriminant functions (discriminant score) resulted in the analyses. The diagnostic potentiality of the present technique was also estimated in the discrimination of malignant subjects from normal and nonmalignant diseased subjects such as liver diseases. In the discriminant analysis performed across the three groups, normal, oral malignancy (including early and advanced stages) and liver diseases, 99% of the original grouped cases and 95.9% of the cross-validated grouped cases were correctly classified. Similar analysis performed across normal, early stage of oral malignancy, advanced oral malignancy and liver diseases correctly classified 94.9% of the original grouped cases and 91.8% of the cross-validated grouped cases.

Influence of cell shape and aggregate formation on the optical properties of flowing whole bloodEnejder, AMK; Swartling, Johannes; Aruna, P; Andersson-Engels, Stefan General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Influence of cell shape and aggregate formation on the optical properties of flowing whole blood Annika M. K. Enejder, Johannes Swartling, Prakasa Aruna, and Stefan Andersson-EngelsWe studied the influence of shape and secondary, or intercellular, organization on the absorption and scattering properties of red blood cells to determine whether these properties are of any practical significance for optical evaluation of whole blood and its constituents. A series of measurements of transmittance and reflectance of light from bovine blood in a flow cuvette was conducted with a 650 -900-nm integrating sphere at shear rates of 0 -1600 s Ϫ1, from which the influence of cell orientation, elongation, and aggregate formation on the absorption ͑ a ͒ and the reduced scattering ͑ s Ј͒ coefficients could be quantified. Aggregation was accompanied by a decrease of 4% in s Ј compared with the value in randomly oriented single cells. Increasing the degree of cell alignment and elongation as a result of increasing shear rate reduced s Ј by 6% and a by 3%, evaluated at a shear rate of 1600 s Ϫ1. Comparison with T-matrix computations for oblate-and prolate-shaped cells with corresponding elongation and orientation indicates that the optical properties of whole blood are determined by those of its individual cells, though influenced by a collective scattering factor that depends on the cell-to-cell organization. We demonstrate that cell morphological changes must be taken into consideration when one is conducting whole blood spectroscopy.

In recent years, the perspective of applying hafnium oxide (HfO 2 ) has geared up in various field of medical science such as neutron detection, bioimplants, biosensors, radiotherapy etc., The present study is to synthesis HfO 2 nanoparticles, and check its cell viability for in vivo applications. Hafnium oxide nanoparticles of different sizes (8.79, 7.16, 6.78 nm) were synthesized by varying the intervals of stirring time (6 h, 8 h, 12 h) by precipitation method. XRD pattern and Raman spectroscopy revealed that this material crystallizes in a monoclinic structure. SEM images and TEM micrographs showed that the HfO 2 NPs were spherical in shape with an average particle size of below 10 nm. The EDAX spectrum showed that the synthesized nanoparticles were HfO 2 . 3T3 fibroblast cell lines were chosen for cytotoxic study as it mimics the human cells. The aim of this study is to compare the toxicity of different sizes of HfO 2 nanoparticles on interaction with 3T3 fibroblast cell lines. From this study we could infer that smaller sized nanoparticles (6.78 and 7.17 nm) have 86% cell viability even at the concentration of 2500 g/mL.

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