No abstract

Hydroxy apatite (HA) is a biocompatible material used as bone-substitute materials in both orthopedics and dentistry due to its excellent osteo-conductive and chemical composition similar to that of the inorganic part of bone in comparison with other implant materials . HA (S1) and Cr loaded hydroxy apatite (S2, S3, S4 and S5) of different chromium concentrations have been prepared. many techniques used to analyze the changes occurred due to the substitution. The XRD (X-ray diffraction) and FTIR (Fourier transform infrared radiation )spectroscopy were used as analytical techniques for the prepared HA and Cr loaded HA. The effect of the heat treatment on structural change of the samples was examined by DTA. It was found that all the samples have the same crystalline structure. The crystallinity of the samples decreased as the chromium ions concentration increase

Hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂) is widely used as bio-ceramic materials and as adsorbents for separation of bio-molecules. These materials have also been used as adsorbents for heavy metals, supports and as catalysts in oxidation and dehydrogenation reactions. The catalytic performance of these materials depend on the lattice substitution of Ca sites in Hydroxyapatite structure by varied cations as Na, Mg, Sr and Mn, which result in changes in various structural pro perties as crystallinity and morphology. Pure calcium hydroxyapatite (S1) and Cr loaded hydroxyl apatite (S2, S3, S4 and S5) of different chromium concentrations have been prepared by wet precipitated method. An <i>in-vitro</i> examination is essential to investigate the mechanism of the deficient HA and tissue interface reaction by preparing SBF (Simulated Body Fluid) through the elemental and chemical analysis of Ca, P and Cr. FTIR used to analyze the samples after incubation in SBF for 24 day. PH of the samples also was measured at the first period of immersion time. At high loading of chromium ions, the formation of carbonate apatite decrease. The concentrations of the chromium in the Cr_HA crystal during the soaking in SBF are very safe dose for human

H YDROXYAPATITE is considered as one of the most effective biomaterials with general formula Ca 10 [ PO 4 [ 6 [0H , 2 [many substances have been used for doping hydroxypatite like F, Mg, CO 3 ,Zn, Bi and Na ,to improve the properties of the HA crystal. In this paper, we discuss the influence of magnesium ions on the electrical properties of the HA crystal. Pure HA (S1) and Mg loaded hydroxy apatite (S2 ,S3 and S4) of different magnesium concentrations have been prepared by wet precipitation method .The dielectric parameters) ε ('and) ε (''measured at different temperature ,relaxation time of relaxation process was calculated from the cole cole plot. The advantages of modulus studies were to recognize the conduction process and study the effect on the frequency and estimate the relaxation frequency. Conduction mechanism has been studied using alternating current measurements, analyzing their dependence on temperature and frequency .The exponent (S) was estimated to recognize the type of conduction .The activation energy studied also to confirm the conductivity measurements. The electrical measurements confirmed that as the addition of Mg increased , the conductivity of the substance would increase and this will improve the bioactivity of HA.

In the present study, we have obtained a blood hemoglobin (Hb) sensor using binary defective one-dimensional photonic crystal. The structure is composed of Air/Diamond/SiO2)NHb /Diamond/SiO2)S/SiO2 and the defect layer is filled by hemoglobin solution. The numerical calculations are based on transfer matrix method (TMM). The defect peak showed well shifting of the defect peak frequency by increasing the hemoglobin concentration; the wavelength shifted due to the change of hemoglobin concentration; from 679.5 nm at the 0g/dL to 682.3 nm at 28.7 g/dL. The presented idea is very simple, and can potentially attract a wider audience when one considers the fact of constantly rising interest of the scientific community (especially biologists and physicians) in the diagnostic methods utilizing different types of the optical phenomena.