Effect of Calcium Oxide on Stress Crack Resistance and Light Transmittance in PET Containers for Packaging Carbonated Beverages.

For polyethylene terephthalate (PET) bottles, a material used for food packaging, light transmission and mechanical performance, particularly environmental stress cracking (ESC), are essential characteristics. For this purpose, following extrusion of PET/CaO granules, preforms were manufactured using the injection technique, and bottles were produced by a stretch-blow-molding process. With incorporation of calcium oxide (CaO), light transmittance increased by around 25%, and ESC went from 0.3 to 11 min. In addition, whereas acetaldehyde (AA) and carboxylic acid (COOH) decomposition values rose with increasing CaO content, diethylene glycol and isophthalic acid values did not significantly change. Moreover, the maximum crystallization temperature and crystallinity both exhibited an upward trend with the CaO content.

Boron-doped Biphasic Hydroxyapatite/ß-Tricalcium Phosphate for Bone Tissue Engineering.

Boron-doped hydroxyapatite/tricalcium phosphates (BHTs) were synthesized to study boron uptake and correlate structural alterations of incremental boron addition (0 to 10 mol%). BHTs with a Ca/P ratio of 1.6 were prepared by a wet precipitation/microwave reflux method, sieved (< 70 µm) and characterized. XRD and FTIR analyses revealed that boron slightly distorted apatite crystal, increased crystallinity (95.78 ± 2.08% for 5BHT) and crystallite size (103.39 ± 23.47 nm for 5BHT) and still, boron addition did not show any further detrimental effects. Total surface area (4.05 ± 0.82 m2/g for 10BHT) and mesoporosity (23.90 ± 7.92 µL/g for 10BHT) were expanded as boron content was increased. Moreover, boron addition made grains become smaller (0.21 ± 0.06 µm for 5BHT) and ordered while hardness (10.51 ± 0.86 GPa for 10BHT) increased. Boron incorporation enhanced bioactivity with significantly highest calcium phosphate deposition and protein adsorption (135.29 ± 29.58 µg on 10BHT). In return, boron favored highest alkaline phosphatase activity (4.80 ± 0.40 MALP/ngDNA.min), intracellular calcium (23.61 ± 0.68 g/gDNA), phosphate (31.84 ± 4.68 g/gDNA), and protein (23.70 ± 3.46 g/gDNA) storage in 5BHT without cytotoxicity (128 ± 18% viability compared to pure HT). Compared to literature, it can be pointed out that we successfully employed an optimal procedure for production of BHTs and incorporated significantly higher boron content in HT (5.23 mol%). Additionally, results tended to conclude that 5BHT samples (5 mol% boron in HT) demonstrated a very high potential to be used in composite bone tissue constructs.

Extraction of heavy metal complexes from a biofilm colony for biomonitoring the pollution.

An extraction method was tested for biomonitoring the biofilm samples containing heavy metals. The fractionation of metal complexes was performed via C-18-HPLC-ICP-MS and MALDI-MS, respectively. The extraction power of some reagents was determined for the heavy metal extraction from biofilm samples collected in Erdemli coast in the Mediterranean Sea. The ammonium acetate solution giving the highest extraction results was found as a suitable extraction reagent. The concentration and pH of the ammonium acetate solution were optimized and found as 1 M and 5, respectively. The chromatograms of metal complexes with the C-18-HPLC-ICP-MS system were taken to determine the effect of the pH of the metal complexes. After performing the extraction, metal bounded biomolecules were characterized by MALDI-MS for the fractions in the C18-HPLC system. It was seen that ammonium acetate extraction (1M, pH 5) might be used in biomonitoring studies due to relatively simple procedure, short analysis period, and low cost. The evaluation of the applicability of the method in biomonitoring studies might be supported by further studies with biofilms having similar characteristics.