WC-Co and Cr<Subscript>3</Subscript>C<Subscript>2</Subscript>-NiCr Coatings in Low- and High-Stress Abrasive Conditions

The article deals with the evaluation of abrasive wear resistance and adhesive strength of thermally sprayed coatings. The main attention was paid to differences between low- and high-stress abrasive conditions of the measuring. Conclusions include the evaluation of specific properties of the WC-Co and the Cr₃C₂-NiCr High Velocity Oxygen Fuel coatings and the evaluation of the changes in the behavior of the abrasive media. Mainly, the relationship between the low- and high-stress abrasion conditions and the wear mechanism in the tested materials was described. For the wear test, the abrasive media of Al₂O₃ and SiO₂ sands were chosen. During wear tests, the volume loss of the tested materials and the surface roughness of the wear tracks were measured. The wear tracks on the tested materials and abrasive sands’ morphologies were observed using Scanning Electron Microscopy. It was found that high-stress abrasive conditions change the coatings’ behavior very significantly, particularly that of the Cr₃C₂-NiCr coating. Adhesive-cohesive properties of the coatings and relationships among individual structure particles were evaluated using tensile testing. It was found that the weak bond strength among the individual splats, structure particles, and phases plays a role in the poor wear resistance of the coatings.     

Is seeking bad mood cognitively demanding? Contra-hedonic orientation and working-memory capacity in everyday life.

Hedonism, or wanting to feel good, is central to human motivation. At times, however, people also seek to maintain or enhance negative affect or to dampen positive affect, and this can be instrumental for the later attainment of their goals. Here, we investigate the assumption that such contra-hedonic orientation is cognitively more demanding than prohedonic orientation, above and beyond the effects of momentary affective experience. We provided 378 participants with mobile phones that they carried with them for 3 weeks while pursuing their daily routines. The phones prompted participants at least 54 times to report their current affect-regulation orientation and to work on two trials of a cognitively demanding working memory task. As expected, contra-hedonic orientation was substantially less prevalent than prohedonic orientation. It was reported in 15% of the measurement occasions. Participants who reported on average more contra-hedonic orientation showed lower average working memory performance throughout the study interval. Further, controlling for the effects of accompanying affective experiences, momentary occurrences of contra-hedonic orientation were associated with temporary declines in working memory performance within individuals, and this could neither be explained by lacking task compliance nor by other characteristics of the individual or the situation. Prohedonic orientation showed a considerably smaller association with working memory performance. These findings are consistent with the view that contra-hedonic orientation is accompanied by momentarily more diminished cognitive resources than is prohedonic orientation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Microstructural comparison of porous oxide ceramics from the system Al2O3–ZrO2 prepared with starch as a pore-forming agent

In this paper we show examples of microstructures of porous oxide ceramics prepared by traditional slip casting (TSC) and starch consolidation casting (SCC) and present results obtained using different microstructural characterization techniques; Archimedes method (open and total porosity), shrinkage measurement, mercury intrusion porosimetry (pore size distribution) and microscopic methods – optical microscopy with microscopic image analysis (pore size distribution) and scanning electron microscopy (detailed investigation of the local microstructure). In particular, microstructures are compared for porous ceramics from the system Al₂O₃–ZrO₂ prepared with rice and corn starch. It is shown that maximum values of the total porosity of porous ceramics prepared with starch as a pore-forming agent were approx. 50%. A major finding by using SEM with respect to starch-produced porous ceramics is the existence of pore fillings in the form of small sintered ceramic shell inside the pores, as a result of starch granule shrinkage during the drying and burn-out steps.     

Re-investigation on odour thresholds of key food aroma compounds and development of an aroma language based on odour qualities of defined aqueous odorant solutions

Literature data on odour thresholds of volatile food constituents, and, in particular on their odour quality, may differ significantly. In order to obtain more reliable sensory data, the odour thresholds of eighty-four compounds previously characterised as key food odorants were re-evaluated and compared to literature results. In addition, the odour thresholds of ten odorants are reported here for the first time. On the basis of a distinct protocol, also the aroma attributes of the odorants were evaluated in order to define an aroma language, which can be used for specific purposes, e.g., training of panellists for GC-Olfactometry.     

Quantification of DNA during winemaking by fluorimetry and <Emphasis Type="Italic">Vitis vinifera</Emphasis> L.-specific quantitative PCR

The ability to genotype wine would be of a great benefit to control the varietal wine authenticity. In this paper, we assessed the fate of grapevine DNA and total DNA during vinification to suggest the latest sampling point that would allow genotyping. The total DNA concentration was measured by fluorimetry and the specific Vitis vinifera L. DNA concentration was measured by quantitative PCR in samples obtained from different steps of vinifications of four wines. To elucidate the effect of pre-extraction and extraction steps on DNA yield from wine, several samples from bottle of wine, two precipitation salts, and two DNA extraction solutions were tested. It was found that hundreds of genome equivalents of grapevine DNA can be extracted from every winemaking sample and from wine. In tested samples, differences in DNA yield among wines from different grapevine varieties, differences among extraction methods, and sampling variation in wine were not statistically significant.     

Role of Integrins in Sperm Activation and Fertilization

In mammals, integrins are heterodimeric transmembrane glycoproteins that represent a large group of cell adhesion receptors involved in cell–cell, cell–extracellular matrix, and cell–pathogen interactions. Integrin receptors are an important part of signalization pathways and have an ability to transmit signals into and out of cells and participate in cell activation. In addition to somatic cells, integrins have also been detected on germ cells and are known to play a crucial role in complex gamete-specific physiological events, resulting in sperm-oocyte fusion. The main aim of this review is to summarize the current knowledge on integrins in reproduction and deliver novel perspectives and graphical interpretations presenting integrin subunits localization and their dynamic relocation during sperm maturation in comparison to the oocyte. A significant part of this review is devoted to discussing the existing view of the role of integrins during sperm migration through the female reproductive tract; oviductal reservoir formation; sperm maturation processes ensuing capacitation and the acrosome reaction, and their direct and indirect involvement in gamete membrane adhesion and fusion leading to fertilization.     

A Hierarchical Genotyping Framework Using DNA Melting Temperatures Applied to Adenovirus Species Typing

Known genetic variation, in conjunction with post-PCR melting curve analysis, can be leveraged to provide increased taxonomic detail for pathogen identification in commercial molecular diagnostic tests. Increased taxonomic detail may be used by clinicians and public health decision-makers to observe circulation patterns, monitor for outbreaks, and inform testing practices. We propose a method for expanding the taxonomic resolution of PCR diagnostic systems by incorporating a priori knowledge of assay design and sequence information into a genotyping classification model. For multiplexed PCR systems, this framework is generalized to incorporate information from multiple assays to increase classification accuracy. An illustrative hierarchical classification model for human adenovirus (HAdV) species was developed and demonstrated ~95% cross-validated accuracy on a labeled dataset. The model was then applied to a near-real-time surveillance dataset in which deidentified adenovirus detected patient test data from 2018 through 2021 were classified into one of six adenovirus species. These results show a marked change in both the predicted prevalence for HAdV and the species makeup with the onset of the COVID-19 pandemic. HAdV-B decreased from a pre-pandemic predicted prevalence of up to 40% to less than 5% in 2021, while HAdV-A and HAdV-F species both increased in predicted prevalence.