Influence of Diatomaceous Earth Particle Size on Mechanical Properties of PLA/Diatomaceous Earth Composites.

The fractionation of diatomaceous earth (DE) using sedimentation made it possible to obtain separate unbroken diatom fractions from broken or agglomerated bodies with a range of particle sizes. The produced filler was used to prepare polylactide (PLA)/diatomaceous earth biocomposite samples containing different particle sizes, which were subjected to mechanical testing (tensile strength, flexural strength, impact strength), colloidal testing (contact angle, color change test, SEM/EDS), and thermal testing (TGA, DSC, DMA). Modification of the PLA containing the smallest particle size with diatomaceous earth (Fraction 5) resulted in a higher impact strength compared to both the pure PLA and the PLA/DE composite that contained base diatomaceous earth.

Titanium matrix composites reinforced with biogenic filler.

Novel metal matrix composites (MMCs) have been fabricated with Ti6Al4V matrix and a biogenic ceramic filler in the form of diatomaceous earth (DE). Mixtures of DE and Ti6Al4V powders were consolidated by the spark plasma sintering (SPS) method. Microstructure of the consolidated samples has been investigated with microscopic techniques and XRD.

Gas Chromatography-Mass Spectrometry Based Approach for the Determination of Methionine-Related Sulfur-Containing Compounds in Human Saliva.

Gas chromatography-mass spectrometry technique (GC-MS) is mainly recognized as a tool of first choice when volatile compounds are determined. Here, we provide the credible evidence that its application in analysis can be extended to non-volatile sulfur-containing compounds, to which methionine (Met), homocysteine (Hcy), homocysteine thiolactone (HTL), and cysteine (Cys) belong. To prove this point, the first method, based on GC-MS, for the identification and quantification of Met-related compounds in human saliva, has been elaborated.

Comparison of Dental Stone Models and Their 3D Printed Acrylic Replicas for the Accuracy and Mechanical Properties.

This study was conducted to test possibilities of application of 3D printed dental models (DMs) in terms of their accuracy and physical properties. In this work, stone models of mandibles were cast from alginate impressions of 10 patients and scanned in order to obtain 3D printed acrylic replicas. The diagnostic value was tested as matching of model scans on three levels: peak of cusps, occlusal surface, and all teeth surfaces.

The nexus of hair corticosterone level, immunocompetence, metabolic rates and overwinter survival in the root vole, Microtus oeconomus.

Although corticosterone (CORT) regulates many physiological mechanisms, the associations between CORT levels, immunocompetence, energy expenditures and overwinter survival have not been examined. Here, we studied individual variation in CORT level extracted from hair, immunocompetence quantified as the neutrophil-to-lymphocyte (N/L) ratio, total white blood cells (WBC) and natural antibody levels (NAbs), along with the resting (RMR) and peak metabolic rates (PMR) and mortality during three consecutive winter seasons in a natural population of the root vole, Microtus oeconomus. In early winter, hair CORT level was strongly positively associated with body mass and inversely related to voles' ability to survive.

Effect of the abrasive properties of sedges on the intestinal absorptive surface and resting metabolic rate of root voles.

Recent studies on grasses and sedges suggest that the induction of a mechanism reducing digestibility of plant tissues in response to herbivore damage may drive rodent population cycles. This defence mechanism seems to rely on the abrasive properties of ingested plants. However, the underlying mechanism has not been demonstrated in small wild herbivores.

Immunocompetence and high metabolic rates enhance overwinter survival in the root vole, Microtus oeconomus.

Despite its presumed significance, the association between immune defence, energy expenditures and overwinter survival is rarely studied. We analysed individual variation in immunocompetence quantified as neutrophil-to-lymphocyte ratio (N/L), total white blood cells (WBC) and natural antibody levels, along with resting (RMR) and peak metabolic rates (PMR) and mortality during three consecutive winter seasons in a natural population of the root vole, Microtus oeconomus. In early winter, WBC count was negatively correlated with RMR, whereas N/L ratio was negatively correlated with swim-elicited PMR.

Shaving increases daily energy expenditure in free-living root voles.

Experimental manipulation of energy expenditure has long been recognized as an effective means for identifying causative effects and avoiding confounded interpretations arising from spurious correlations. This approach has been successfully applied mainly to studies on birds, particularly on reproducing adults, whereas manipulations in mammals have proved more problematic. Here, we tested the hypothesis that shaving off 50% of the dorsal pelage should effectively increase energy expenditure in wild root voles (Microtus oeconomus) in their natural environment.

The new locality of Ixodes apronophorus Schulze, 1924 in Biebrza National Park, Poland.

The new locality of Ixodes apronophorus Schulze, 1924 in Biebrza National Park, Poland is recorded. The study was conducted in open wet-meadow habitat (Caricetum appropinquatae), in April 2007. The small mammals were caught in live-traps placed at permanent trap stations.