Quantitative analysis of synthetic calcium carbonate polymorphs using FT-IR spectroscopy.

Fourier Transform Infrared Spectroscopy (FT-IR) was used successfully for the simultaneous quantitative analysis of calcium carbonate phases (calcite, aragonite, vaterite) in ternary mixtures. From the FT-IR spectra of pure calcite, aragonite and vaterite powders with KBr, the absorptivities, alpha, of the absorption bands at 713 cm(-1) for calcite, 745 cm(-1) for vaterite, 713 and 700 cm(-1) for aragonite, were determined. In order to overcome the absorption band overlapping a set of equations based on Beer's law was developed.

Modal damping for monitoring bone integrity and osteoporosis.

We applied a noninvasive method to assess bone structural integrity. The method is based on the measurement of the dynamic characteristics of the bone (quality factor and modal damping factor) by applying vibration excitation in the range of acoustic frequencies, in the form of an acoustic sweep signal. Excised sheep femora were tested to detect changes in modal damping, density (kg/m3), bone mineral density (kg/m2) and bone mineral (hydroxyapatite) percentage.

Encrustation of a metal alloy urinary stent: a mechanistic investigation.

Materials And Methods: A section of a metal stent consisting mainly of tantalum coated partially by strongly adhering calcium oxalate monohydrate (COM) crystals was immersed in supersaturated solutions prepared from calcium chloride and sodium oxalate at 37 degrees C and ionic strength 0.15 M in NaCl. Abstract

Objectives: To investigate the kinetics of encrustation of a metall alloy urinary stent system in vitro by calcium oxalate and characterize the crystals forming from solutions supersaturated with respect to all calcium oxalate hydrates.

[Frequency and causes of extraction of permanent teeth. 2. Ten-year (1978-1987) clinicostatistical investigation].

The purpose of this clinical investigation was to analyze the frequency and the causes of mortality (loss) of 59,253 permanent teeth, extracted, during a ten-year (1978-1987) period, in Clinic Exodontia of Dental School University of Athens, at 35,830 population of Greece (15,260 males and 20,570 females). The following conclusions were drawn from the statistical analysis and the interpretation of the results: The mean value of extracted teeth per person was 1.65 and was lower in females (1.

[Tooth extraction on diabetic patients].

Performing extractions on diabetic patients is a complicated problem, which is connected with the type of diabetes and the various complications related to this disease. The main concern is to avoid acute incidents hyper or sub-glycemic comas during the operation and to secure a smooth post- operational course, namely an undisturbed post- extracture healing. In this study, 80 diabetic patients who came for extractions to the escodental department were divided into two categories: patients suffering from diabetes type I and patients suffering from diabetes type II.