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Four metal substituted hydroxyapatites (HAPs) were prepared and characterized using energy-dispersive X-ray fluorescence, X-ray diffraction, thermal analysis, and transmission electron microscopy. From the evaluation of the potential applications for antimicrobial properties and the photodegradation of methylene blue, it can be concluded that the two applications seem to be competing. Thus, Mn-substituted HAP, which provided the best degradation efficiency for methylene blue from the substituted materials (approximately 88%), has poor antimicrobial potential against most of the studied microbial lines. The Co-substituted HAP showed favorable antimicrobial properties against all the studied lines, including the lowest values for both minimum inhibitory concentration and a minimal concentration for biofilm eradication of 78.1 µg/mL against Pseudomonas aeruginosa, but exhibited a low degradation efficiency for methylene blue (approximately 42%). This can be explained by the properties of the pure material: pure HAP that showed the highest degradation efficiency of methylene blue (93%) but exhibited no antimicrobial efficiency against the studied lines. Thus, from the performed experiments, a single material cannot be recommended for both applications, but rather a specific material should be employed for each potential use: HAP, Mn- or Sn-substituted HAP for photodegradation, and Co-substituted HAP for antimicrobial applications. [ABSTRACT FROM AUTHOR]

The discovery of metals and alloys greatly contributed to the development of human civilizations; their role in shaping history is recognized by the scientific community even through the denomination of some archaeological periods (Copper Age, Bronze Age, and Iron Age). Archaeometallurgy appeared from the application of usually non destructive analytical techniques for the characterization of cultural heritage objects, with emphasis on metal artifacts. This article presents a case study regarding the application of fast and non-destructive methods (energy dispersive X-ray fluorescence and metallurgical microscopy) for the characterization of selected numismatic artifacts, thus obtaining information regarding their composition, authenticity, and state of preservation. [ABSTRACT FROM PUBLISHER]