Search

A prior study developed the Computational Thinking Scale (CTS) for assessing individuals' computational thinking dispositions in five dimensions: decomposition, abstraction, algorithmic thinking, evaluation, and generalization. This study proposed the Developmental Model of Computational Thinking through validating the structural relationships among the five factors of the CTS. To examine the model, a questionnaire including the CTS was administered to 472 middle school students. A confirmatory factor analysis was used to confirm the construct of the measurements, and a PLS-SEM analysis was used to validate the structural relationships among the factors. The results confirmed that the 19-item CTS has good item reliability, internal consistency, and construct reliability for measuring computational thinking (CT). In the Developmental Model of CT, decomposition and abstraction significantly predict all other three CT dispositions, suggesting that they are the two fundamental factors required for CT development. Moreover, a significant linear prediction path was shown starting from algorithmic thinking, evaluation, until generalization. Thus, a multi-level model was confirmed for the conceptual framework of CT. This model suggests a possible sequence for CT development which may provide a guideline for the teaching objectives of CT for different learning stages in different school levels. Decomposition and abstraction are especially suggested to be emphasized in school curricula before teaching algorithmic thinking or algorithm designs. [ABSTRACT FROM AUTHOR]

Left-ventricular assist devices (LVADs) improve outcomes in end-stage heart failure patients. Two centrifugal-flow LVAD systems are currently approved, HeartMate 3 (HM3) and Medtronic/Heartware HVAD (HVAD). Clinical findings suggest differences in thrombogenicity between both systems. We compared markers of platelet activation and aggregation between HM3 and HVAD. We prospectively included 59 LVAD patients (40 HM3, 19 HVAD). Platelet P-selectin expression, activated glycoprotein (GP) IIb/IIIa and monocyte-platelet aggregates (MPA) were assessed by flow-cytometry. Platelet aggregation was measured by light-transmission aggregometry (LTA) and multiple-electrode aggregometry (MEA). Von-Willebrand factor (VWF) antigen (VWF:Ag), VWF activity (VWF:Ac), and VWF multimer pattern analysis were determined. Soluble P-selectin (sP-selectin) was measured with an enzyme-linked immunoassay. P-selectin, GPIIb/IIIa and MPA levels in vivo and in response to arachidonic acid, adenosine diphosphate, and thrombin receptor activating peptide were similar between HM3 and HVAD (all p >.05). Likewise, agonist-inducible platelet aggregation by LTA and MEA did not differ between HM3 and HVAD (all p >.05). VWF:Ag levels and FVIII:C were similar between both systems (both p >.05), but patients with HVAD had significantly lower VWF:Ac (p =.011) and reduced large VWF multimers (p =.013). Finally, sP-selectin levels were similar in patients with HVAD and HM3 (p =.845). In conclusion, on-treatment platelet activation and aggregation are similar in HM3 and HVAD patients. Potential clinical implications of observed differences in VWF profiles between both LVAD systems need to be addressed in future clinical trials. [ABSTRACT FROM AUTHOR]

This systematic review compares polytetrafluoroethylene tape and cotton pellet when used as endodontic spacers underneath provisional restorations. The review followed the PRISMA guidelines and was registered in the PROSPERO database (CRD42020176555). Studies that compared the microbial contamination between polytetrafluoroethylene tape and cotton pellet, when used as spacers, were included. Literature searches of Pubmed, Embase, EBSCOHost Dentistry & Oral Sciences Source, Scopus, and Open Grey databases were conducted from their inception until May 2020 for studies in English or other Latin script languages. Hand searching of reference lists was performed. Three laboratory and three clinical studies were included. The risk of bias of the component studies varied widely. Results from the laboratory studies showed higher bacterial counts for cotton pellets. Results from the clinical studies showed that polytetrafluoroethylene tape was associated with a significantly lower incidence of microbial contamination. Findings were consistent throughout the studies, though the evidence available is scarce and heterogeneous. Polytetrafluoroethylene tape was associated with less microbial contamination when compared with cotton pellets as endodontic spacers and therefore appears to be a more suitable material for the purpose. [ABSTRACT FROM AUTHOR]

Abstract Background Stroke models are essential tools in experimental stroke. Although several models of stroke have been developed in a variety of animals, with the development of transgenic mice there is the need to develop a reliable and reproducible stroke model in mice, which mimics as close as possible human stroke. Methods BALB/Ca-RAG2-/-γc-/- mice were subjected to cauterization or thrombosis stroke model and sacrificed at different time points (48hr, 1wk, 2wk and 4wk) after stroke. Mice received BrdU to estimate activation of cell proliferation in the SVZ. Brains were processed for immunohistochemical and EM. Results In both stroke models, after inflammation the same glial scar formation process and damage evolution takes place. After stroke, necrotic tissue is progressively removed, and healthy tissue is preserved from injury through the glial scar formation. Cauterization stroke model produced unspecific damage, was less efficient and the infarct was less homogeneous compared to thrombosis infarct. Finally, thrombosis stroke model produces activation of SVZ proliferation. Conclusions Our results provide an exhaustive analysis of the histopathological changes (inflammation, necrosis, tissue remodeling, scarring...) that occur after stroke in the ischemic boundary zone, which are of key importance for the final stroke outcome. This analysis would allow evaluating how different therapies would affect wound and regeneration. Moreover, this stroke model in RAG 2-/- γC -/- allows cell transplant from different species, even human, to be analyzed.