sorkheh-dizaj apatite-iron oxide deposit is located 32 km southeast of zanjan. the area is situated within the tarom subzone of western alborz-azarbaijan structural zone. the oldest units at the sorkheh-dizaj area are eocene trachyte, trachyandesite, olivine basalt and volcanoclastic brecciate tuff and lapilli tuff which intruded by a quartz-monzonite, monzonite and granite subvolcanic pluton o...

Fission track analysis of apatites from basement rocks of the Wright Valley in southern Victoria Land provides information about the timing. the amount and hence the rate of uplift of the Transantarctic Mountains in this area. Apatite ages increase systematically with elevation, and a pronounced break in the age versus elevation profile has been recognised at about 800 m on Mt. Doody near the m...

Bone tissue at nanoscale is a composite mainly made of apatite crystals, collagen molecules and water. This work is aimed to study the diffusion within bone nanostructure through Monte-Carlo simulations. To this purpose, an idealized geometric model of the apatite-collagen structure was developed. Gaussian probability distribution functions were employed to design the orientation of the apatite...

In continuing search for effective treatments of cancer, the emerging model aims at efficient intracellular delivery of therapeutics into tumor cells in order to increase the drug concentration. However, the implementation of this strategy suffers from inefficient cellular uptake and drug resistance. Therefore, pH-sensitive nanosystems have recently been developed to target slightly acidic extr...

Investigation of modern and fossil teeth from northern and central Kenya, using the ion microprobe, electron microprobe, and transmission electron microscope, confirms that fossil tooth chemistry is controlled not only by the diagenetic precipitation of secondary minerals but also by the chemical alteration of the biogenic apatite. Increases in the concentrations of Fe, Mn, Si, Al, Ba, and poss...

The present study investigates the changes in microstructure and microchemistry (particularly Ca/P ratio) during whisker formation on the surface of TTCP powder in hydrochloric solution. XRD results indicate that the as-fabricated (non-treated) powder has a monolithic TTCP crystal structure. When the powder is treated for 10min in HCl, a DCPD phase appears on TTCP surface, which increases in in...

INTRODUCTION This study aimed to compare the cytotoxicity of MTA Fillapex, AH-26 and Apatite root canal sealers at different times after mixing. METHODS AND MATERIALS In this in vitro study, MTA Fillapex, AH-26 and Apatite root canal sealer were spilled uniformly by 40 µm mesh in a 96-well plate. Then, human fetal foreskin fibroblast cell line (HFFF2) were added to each sealer cell culture me...

Plasma-sprayed hydroxyapatite (HA) coatings were incubated in simulated body fluids (SBFs) for different periods of time to investigate the nucleation and growth of apatite on their surface. The layer that formed was recognized as having similarities to bone apatite because it is poorly crystallized, non-stoichiometric or calcium deficient, and contains carbonate and magnesium. Scanning electro...

Four E. ruminantium 1H12 open reading frames and their proteins known to protect sheep against heartwater needle challenge were encapsulated into, or adsorbed onto poly(d,l-lactide-co-glycolide) microparticles. Microspheres with smooth surface and smaller than 5 μm diameters were produced, with high adsorption and encapsulation efficiencies. Gel electrophoresis showed that neither encapsulation...

Nowadays, there are almost limitless applications for microparticles. Microparticles are used as components in many advanced materials and composites, in the healthcare and personal grooming industries, and in many research and development applications. This review presents an overview of recent and current studies carried out at the Particles, Polymers and Biomaterials Technology Group of the ...