Characterization of calcium phosphate coatings doped with Mg, deposited by pulsed laser deposition technique using ArF excimer laser.

Calcium phosphate layers were deposited on Ti6Al4V substrates with TiN buffer layers by use of pulsed laser deposition method. With this technique three pressed pellets consisted of tricalcium phosphate (TCP, Ca(3)(PO(4))(2)), hydroxyapatite (HA, Ca(10)(PO(4))(6)(OH)(2)) and hydroxyapatite-doped with magnesium (HA with 4% of Mg and trace amount of (Ca,Mg)(3)(PO(4))(2)) were ablated using ArF excimer laser (lambda=193 nm). The using of different targets enabled to determine the influence of target composition on the nature of deposited layers. The obtained deposits were characterized by means of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction method (XRD). The obtained Fourier spectras revealed differences in terms of intensity of spectral bands of different layers. The analysis from XRD showed that Mg-doped HA layer has crystalline structure and TCP and HA layers composition is characterized by amorphous nature.

Long-term results of hydroxyapatite application in the treatment of periodontal osseous defects.

The aim of the present study was to evaluate in long-term clinical trials the effectiveness of hydroxyapatite (HA) bioceramics employed in dentistry in the treatment of periodontal osseous defects. The technology of obtaining the studied HA was developed at the Faculty of Material Science and Ceramics, University of Mining and Metallurgy, Cracow, Poland. A population of 90 patients was subjected to implantation of HA granules. The results of initial and final investigations based on periodontal indices, determination of osseous defects depth and X-ray studies were compared. The follow-up was 6 and 12 months, 2, 3 and as much as 4 years. All the studied parameters showed a significant improvement that was confirmed by statistical evaluation. Ceramic HA was found to be a fully and totally useful material in the reconstruction of periodontal defects. As demonstrated by X-ray studies, the reconstruction of osseous defects proceeded faster within the first 2 years and subsequently the process became slower.

[Determination of certain pesticides, nitrates, nitrites, ammonium ions, sulphates, urea and chlorides in surface and underground water and in certain agricultural products. VI]. / Oznaczanie wybranych pestycydów, azotanów, azotynów, jonów amonowych, siarczanów, mocznika i chlorków w wodach powierzchniowych i podziemnych. Cz. VI.

The subject of this study was determination of the residue of pesticides (lindane, methoxychlor, and chlorfenvinphos) nitrates, ammonium ions, sulphates and urea in surface waters and underground waters and in potatoes in 11 localities in the eastern part of the Province of Szczecin in 1987. The pesticides were determined by gas chromatography, while nitrates, nitrites, ammonium ions, sulphates and urea by spectrophotometry, chloride--by precipitation. The obtained results showed that contamination of surface and underground waters with these pesticides was below the permitted value. The concentration of nitrate nitrogen exceeded the permitted in Poland level in 15% of underground water samples. These samples were taken from wells in private farms. Nitrites were demonstrated in all of the samples of surface waters and 78% of underground water samples. The highest concentration of nitrite nitrogen was in the well of a private farm. The concentration of ammonium nitrogen exceeded in 22% of underground water samples the permitted value. Sulphates were detected in all water samples, but their concentrations were not exceeding the permitted level. In none of the analysed potato samples these pesticides were demonstrated. On the other hand high levels of nitrates and nitrites were found.