Thanks to the continuous development of light-curing resin composites it is now possible to print permanent single-tooth restorations. The purpose of this study was to compare resin composites for milling -Gandio Blocks(GR), Brilliant Crios(CR) and Enamic(EN) with resin composite for 3D printing—VarseoSmileCrown plus(VSC). Three-point bending was used to measure flexural strength (σf) and flexural modulus (Ef). The microhardness was measured using a Vickers method, while fractographic, microstructural, texture and fractal dimension (FD) analyses were performed using SEM, optical microscope and picture analysis methods. The values of σf ranged from 118.96 (±2.81) MPa for EN to 186.02 (±10.49) MPa for GR, and the values of Ef ranged from 4.37 (±0.8) GPa for VSC to 28.55 (±0.34) GPa for EN. HV01 ranged from 25.8 (±0.7) for VSC to 273.42 (±27.11) for EN. The filler content ranged from 19–24 vol. % for VSC to 70–80 vol. % for GR and EN. The observed fractures are typical for brittle materials. The correlation between FD of materials microstructure and Ef was observed. σf of the printed resin depends on layers orientation and is significantly lower than σf of GR and CR. Ef of the printed material is significantly lower than Ef of blocks for milling.
Malaria pigment is generated during the growth of the intraerythrocytic parasite plasmodium. This compound is postulated as a product of haemoglobin degradation and consists of an unknown iron porphyrin compound and an apoprotein. We report here a new spectroscopic investigation on the porphyrin component of intact malaria pigment obtained from in vitro cultures of Plasmodium falciparum without any previous chemical or biochemical treatment of the sample. We demonstrate the use of resonance Raman microspectrometry, electron paramagnetic resonance spectrometry, and magnetic susceptibility measurements that show the iron porphyrin moiety of the malaria pigment to be a high-spin monomeric iron(III) protoporphyrin hydroxide.
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