ABSTRACT. Previous micro-Raman investigations on a wide range of types of microcrystalline silica samples have evidenced the presence of a new silica polymorph, i.e. moganite, in virtually every sample. In order to test the ubiquity of moganite in such geological materials in Romania, micro-Raman measurements were performed on gem-quality microcrystalline quartz (chalcedony, including agate and jasper) and additionally on quasi-amorphous silica (opal, silicified wood) samples from different occurrences.All the studied materials, including the quasi-amorphous varieties contain moganite in variable amounts (from traces up to local concentrations of 75 wt. %). Establishing correlations between colour and texture of the chemically-"pure" microcrystalline silica samples and their mineralogical composition -as traced by microRaman measurements, requires further research.
Background and aimsAlthough dental implants are widely and successfully used, failure rates because of bacterial colonization are still high. Adequate fabrication and sterilization techniques as well as proper management of infectious complications represent a constant field of interest and research. In this study, we focused our attention on implants with controlled porosity produced by Selective Laser Melting (SLM). The difficulty to sterilize porous implantable devices is well known and finding an adequate sterilization protocol represents a challenge worldwide. Before testing the biological and mechanical properties of porous implants, a preliminary study in order to determine a correct sterilization protocol must be conducted.Our aim was to establish a valid sterilization protocol for porous titanium alloy dental implants, as such protocols are not officially available yet.MethodsTwenty dental implants were fabricated from a titanium alloy by SLM. Ten of them were made using a 150W laser beam (porosity of 1% - group A) and the rest using a 75W laser beam (porosity of 23% - Group B), all of them with a non-defined internal structure. The implants were initially sterilized (5 from group A and 5 from group B, using dry heat - 180°C for 2 hours; the rest using steam sterilization - 121 °C for15 min) and then spent 18 hours in culture media with developing bacteria (Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 49444), Enterococcus faecalis (ATCC 29212), Listeria monocytogenes (ATCC 19114), three Gram negative bacteria: Escherichia coli (ATCC 25922), Salmonella typhimurium (ATCC 14028) and Pseudomonas aeruginosa (ATCC 27853). The first ten implants (5 from group A and 5 from group B) were then sterilized with dry heat and the others with steam. After sterilization, they were all placed in sterile culture media in order to observe if any bacterial growth were present.ResultsThe culture media was observed 18 hours after the sterilized implants were placed inside. No bacterial growth was observed.ConclusionsOur tests reached their aims of defining a protocol to sterilize porous implants. Future tests regarding biological and mechanical aspects of these implants may now follow.
Background. Metabolic syndrome (MetS) represents a clustering of metabolic risk factors for cardiovascular disease. Many studies have shown the influence of an unhealthy lifestyle on the risk of MetS, yet some aspects remain controversial. Aim of the study: to investigate the relationship between an unhealthy lifestyle and the risk of MetS. Materials and Methods. The study was conducted using a sample of 181 patients, 54 (29.8%) males and 127 (70.2%) females, aged 59.95±10.8 years. The baseline survey involved the completion of structured questionnaires and clinical examination. Results. Rural environment, lower education level, past smoking, the absence of fruit/vegetables in the diet, carbonated soft drinks, and the consumption of significant amounts of alcohol were risk factors for the MetS. Conclusion. A precise etiology for the MetS remains unclear, but it is known to result from a complex interaction of genetic, metabolic, and socioeconomic and environmental factors.
Part of an indestructible component of any orthodox church, the Imperial Gates represent an important symbol in our cultural heritage. But in many cases the Imperial Gates from the wooden churches were damaged. In order to preserve and restore them, the scientific investigations of the Imperial Gate belonging to Nicula Monastery wooden church were performed by employing nondestructive and destructive methods. The wood essence was established, with its “health” status being investigated by FTIR (Fourier Transform Infrared) spectroscopy and DSC (Differential Scanning Calorimetry) thermal analysis. The painting materials employed by popular artists were determined by FTIR and XRF (X-ray fluorescence) spectroscopy as gypsum, calcite (rear background), lead white (Archangel Clothes), lead-minium (Archangel Clothes, leaf), iron oxide (Imperial Gate frame), malachite (green), Prussian blue (blue), orpiment (yellow), aliphatic, ester, and protein (probably egg yolk degradation products). Using similar colors as in the original artwork (resulting from the scientific investigation of the pigments) a 3D reconstruction has been performed. The restored Imperial Gates are placed in the old Nicula wooden church, being included into a tourist and religious circuit.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.