Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy

This protocol describes how to make agarose-based tissue-mimicking phantoms and demonstrates how to determine their optical properties using a conventional optical system with an integrating sphere. Measuring systems for the acquisition of the diffuse reflectance and total transmittance spectra are constructed with a broadband white light source, a light guide, an achromatic lens, an integrating sphere, a sample holder, an optical fiber probe, and a multi-channel spectrometer. An acrylic mold consisting of two rectangular acrylic pieces and a U-shaped acrylic piece is constructed to create an epidermal phantom and a dermal phantom with whole blood. The application of a sodium dithionite (Na2S2O4) solution to the dermal phantom enables the researcher to deoxygenate hemoglobin in red blood cells distributed in the dermal phantom. The inverse Monte Carlo simulation with the diffuse reflectance and total transmittance spectra measured by a spectrometer with an integrating sphere is performed to determine the absorption coefficient spectrum µa(λ) and the reduced scattering coefficient spectrum µs'(λ) of each layer phantom. A two-layered phantom mimicking the diffuse reflectance of human skin tissue is also demonstrated by piling up the epidermal phantom on the dermal phantom.

Environmentally persistant toxicant arsenic affects uterus grossly and histologically

The experiment was carried out to determine the gross and microscopic effects of arsenic on uterus of female Black Bengal Goats against control group in the Department of Anatomy and Histology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh-2202. A total of twelve mature female Black Bengal goats were studied, six from arsenic affected areas of Mymensingh district and theother six from Hill Tracts of Bangaldesh which are arsenic free. Gross parameters show slight variations in the morphology (color and shape) and biometry (size and weight) of uterus of arsenic affected Black Bengal goats, but this variation was statistically insignificant (p>0.05). For microscopic study, permanent slide was prepared by Mayer’s Hematoxylin and Eosin stain method. In microscopic level, there were significant variations in arsenic affected group of goats compared to the control group. Arsenic affected group of goats show thickening of uterine horn (p<0.01), uterine gland is lower in amount and diameter(p<0.01), cervical villi length was smaller (p<0.01), cervical wall thickness was higher (p<0.01). This work may be the tip of the iceberg representing the full extent of arsenic exposure to female genital tract. DOI: http://dx.doi.org/10.3329/bjvm.v11i1.13175 Bangl. J. Vet. Med. (2013). 11 (1): 61-68