Displacement and emission currents from PLZT 8/65/35 and 4/95/5 excited by a negative voltage pulse at the rear electrode

It is shown that non-prepoled PLZT ceramics, both in ferroelectric and antiferroelectric phase, emit intense current bursts when a negative exciting voltage is applied to the rear surface of the cathode. The spontaneous polarization induced in the bulk by applying the field through the cathode disk, creates a sheet of negative charge on the diode boundary of the ferroelectric. This, in turn, induces such a high electric field at the diode dielectric surface that electrons are ejected out from the ceramic surface into the vacuum. The coherent behaviour of the displacement and emitted current shows clearly that the emission is due to a variation of spontaneous polarization. A second effect generated by the application of the high voltage pulse at the rear side is the formation of a surface plasma. Applying a positive voltage to the anode, electrons are readily transferred through the diode gap

Correlation between cognitive functions and motor coordination in children with different cognitive levels

Cognitive development is related with central nervous system maturation and plays a crucial role for the definition of executive functions such as movement imagination, movement planning and problem-solving. In particular, executive functions are required during complex interactions between players/environment and are also fundamental for motor skills coordination. Although the complex interaction between cognitive and physical outcomes was recognized by several authors, few studies examined the magnitude of the relation between executive functions and motor development according to dif- ferent stages of cognitive maturation. Thus the aim was the assessment of the relationships between motor skills coordination and executive functions in children with different cognitive level. Ninety healthy male participants were involved in the study where children affected by Down syndrome were, also, recruited. The participants were divided into three groups according to classi- fication of Piaget: concrete, formal operational groups and Down syndrome individuals. Executive functions were assessed using a validated computerized battery tests while motor skills was evaluated using the K\uf6rperkoordinations Test f\ufcr Kinder. Analysis of variance by ranks (Kruskal-Wallis nonparametric test) and Mann-Whitney U pairwise comparisons with Dunn\u2019s correction for multiple contrasts were applied to assess the differences concerning the two kinds of outcome. The Pearson product-moment correlation coefficient was used to calculate the correlation between physical performance and the outcomes of the cognitive tests. A Spearman correlation was used to analyze the data when the assumption of normality was violated. The three groups showed differences in both executive functions and motor coordination outcomes. The highest number of significant correlations was found in the formal operational group (correlation coefficients ranging between 120.999 and 120.520, and between 0.970 and 0.759, all p values < 0.05) while a small number of correlations were found in the concrete operational group (correlation coefficients equal to 120.527, 120.461, 120.436 and 0.468, all p values < 0.05). No correlations between executive function and motor coordination were found in Down syndrome group. High executive function seems to affect the coordination skills

Allogeneic Umbilical Cord-Derived Mesenchymal Stem Cells as a Potential Source for Cartilage and Bone Regeneration: An in Vitro Study

Umbilical cord (UC) may represent an attractive cell source for allogeneic mesenchymal stem cell (MSC) therapy. The aim of this in vitro study is to investigate the chondrogenic and osteogenic potential of UC-MSCs grown onto tridimensional scaffolds, to identify a possible clinical relevance for an allogeneic use in cartilage and bone reconstructive surgery. Chondrogenic differentiation on scaffolds was confirmed at 4 weeks by the expression of sox-9 and type II collagen; low oxygen tension improved the expression of these chondrogenic markers. A similar trend was observed in pellet culture in terms of matrix (proteoglycan) production. Osteogenic differentiation on bone-graft-substitute was also confirmed after 30 days of culture by the expression of osteocalcin and RunX-2. Cells grown in the hypertrophic medium showed at 5 weeks safranin o-positive stain and an increased CbFa1 expression, confirming the ability of these cells to undergo hypertrophy. These results suggest that the UC-MSCs isolated from minced umbilical cords may represent a valuable allogeneic cell population, which might have a potential for orthopaedic tissue engineering such as the on-demand cell delivery using chondrogenic, osteogenic, and endochondral scaffold. This study may have a clinical relevance as a future hypothetical option for allogeneic single-stage cartilage repair and bone regeneration

Multi-Teaching Styles Approach and Active Reflection: Effectiveness in Improving Fitness Level, Motor Competence, Enjoyment, Amount of Physical Activity, and Effects on the Perception of Physical Education Lessons in Primary School Children

Physical education (PE) researchers sustain that the teaching styles adopted by PE teachers play a key role in defining children's positive experiences during lessons and have a relevant impact on their psychophysical health. However, a limited number of studies has examined the effect of teaching styles on these aspects. The aim of this study was to investigate the effectiveness of an integrated approach mainly based on integration of multi-teaching styles and active reflection (MTA) on the fitness level, motor competence, enjoyment, self-perception, amount of physical activity (PA), and children's perception of PE, in Italian primary school children. Participants were 121 children from three elementary schools. Children were randomly assigned into two groups: (a) an intervention group (IG) that received PE lessons based on MTA provided by specifically trained PE students, and (b) a control group (CG) that received standard PE lessons (S-PE) from primary school classroom teachers. Both groups engaged in two PE lessons per week lasting 1 h each for 12 weeks. The findings revealed an increase in the children's fitness level, motor competence, enjoyment and amount of PA in the IG compared to those in the CG. Furthermore, the children of the IG spent more time being engaged on a task, reflecting on it, and wasted less time during PE compared to the children of the CG. Finally, the children of the IG reported higher levels of satisfaction with PE lessons and teaching styles compared to children of the CG. Integration of different teaching styles lead by specifically trained educators can be suggested as a valuable strategy to provide learning experiences of children of primary school to have positive effects on their physical literacy development promoting healthy lifestyle

A robust and powerful green light photoemission source: The ferroelectric ceramics

The photoemission characteristics of ceramic disks of lead zirconate titanate lanthanum doped (PLZT), have been investigated. We observe 1 nC of extracted charge under an accelerating field of 20 kV/cm in poor vacuum conditions. The emission is clearly limited by space charge effects. The extrapolated quantum efficiency results in ≈10−6. The yield of a PLZT ceramic in the ferroelectric state and its slope versus light intensity have turned out higher than those of antiferroelectric ceramic. Samples in different experimental configurations have shown different nonlinear yields

Indoor mobile mapping system and crowd simulation to support school reopening because of covid-19: a case study

Occupancy analyses represent a crucial topic for building performance. At present, this is even true because of the pandemic emergency due to SARS-CoV-2 and the need to support the functional analysis of building spaces in relation to social distancing rules. Moreover, the need to assess the suitability of spaces in high occupancy buildings as the educational ones, for which occupancy evaluations result pivotal to ensure the safety of the end-users in their daily activities, is a priority. The proposed paper investigates the steps that are needed to secure a safe re-opening of an educational building. A case study has been selected as a test site to analyse the re-opening steps as required by Italian protocols and regulations. This analysis supported the school director of a 2-to-10 year old school and its team in the decision-making process that led to the safe school re-opening. Available plants and elevations of the building were collected and a fast digital survey was carried out using the mobile laser scanner technology (iMMS - Indoor Mobile Mapping System) in order to acquire three-dimensional geometries and digital photographic documentation of the spaces. A crowd simulation software (i.e. Oasys MassMotion) was implemented to analyse end-users flows; the social distance parameter was set in its proximity modelling tools in order to check the compliance of spaces and circulation paths to the social distancing protocols. Contextually to the analysis of users flows, a plan of hourly air changes to maintain a high quality of the environments has been defined

Performance characteristics and clinical utility of an enzymatic method for the measurement of glycated albumin in plasma

Objective: The measurement of plasma glycated albumin is particularly useful in the short-middle term monitoring of glycometabolic control in diabetics. The aim of this work is to evaluate a new enzymatic method for the measurement of glycated albumin in plasma, with particular attention to some selected cases and comparison with other relevant tests (fasting plasma glucose, after glucose load, fructosamine, glycated hemoglobin). Design and methods: We have performed a multicenter study by which sample collection was performed in three different centers (Milano, Padova and Cagliari) and serum samples, frozen at 1280 \ub0C, were then delivered under dry ice to the centralized laboratory in Milano. Glycated plasma albumin was measured with reagents from Asahi Kasei Pharma (Lucica GA-L enzymatic assay; AKP, Tokyo, Japan) on a Modular P Roche system. Fructosamine was assessed by a Roche method and HbA1c (measured separately in the three centers on fresh EDTA blood) by DCCT-aligned HPLC systems. We have investigated 50 type 2 diabetics, 26 subjects with gestational diabetes, 35 subjects with thalassemia major, 10 subjects with cirrhosis, 23 patients with end-stage renal disease subjected to dialysis treatment and 32 healthy adult control subjects. Results: The main analytical performance characteristics of the new GA test were the following: (a) the within-assay reproducibility was between 3.0 and 3.9% (in terms of GA% CV, measured on 2 serum pools and 2 control materials at normal and pathological glycated albumin levels); (b) the between-assays reproducibility was from 2.8 to 4.1%; (c) the linearity was tested in the interval between 13 and 36% and found acceptable (r2=0.9932). Concerning the clinical utility of the new test, we have evaluated the relationships between GA, HbA1c, fructosamine and fasting and post-prandial glucose in several patients, as well as the changes in the abovementioned parameters in a sub-group of type 2 diabetic patients for 18 weeks as they progressed from severe hyperglycemia (HbA1c 6510.0%) toward a better glycemic control. The correlations between glycated albumin and HbA1c were as follows: (a) type 2 diabetics: r2=0.483 (good glycemic control), r2=0.577 (poor control); (b) diabetic patients under dialysis: r2=0.480; (c) liver disease: r2=0.186; (d) transfused non-diabetics with thalassemia: r2=0.004. Glycated albumin, as well as HbA1c and fructosamine, was of little value in the study of women with gestational diabetes, mainly because of the very limited glucose fluctuations in this particular category of subjects. In 11 type 2 diabetic patients under poor metabolic control, GA was better correlated with fasting plasma glucose then HbA1c (r2=0.555 vs. 0.291, respectively), and decreased more rapidly than HbA1c during intensive insulin therapy. Conclusions: The experience we have acquired with the new enzymatic test demonstrates its reproducibility and robustness. We confirm that plasma glycated albumin is better related to fasting plasma glucose with respect to HbA1c. Moreover, glycated albumin is more sensitive than HbA1c with regard to short-term variations of glycemic control during treatment of diabetic patients. This test is also very appropriate when the interpretation of HbA1c is critical

Probing dispersion and re-agglomeration phenomena upon melt-mixing of polymer-functionalized graphite nanoplates

A one-step melt-mixing method is proposed to study dispersion and re-agglomeration phenomena of the as-received and functionalized graphite nanoplates in polypropylene melts. Graphite nanoplates were chemically modified via 1,3-dipolar cycloaddition of an azomethine ylide and then grafted with polypropylene-graft-maleic anhydride. The effect of surface functionalization on the dispersion kinetics, nanoparticle re-agglomeration and interface bonding with the polymer is investigated. Nanocomposites with 2 or 10 wt% of as-received and functionalized graphite nanoplates were prepared in a small-scale prototype mixer coupled to a capillary rheometer. Samples were collected along the flow axis and characterized by optical microscopy, scanning electron microscopy and electrical conductivity measurements. The as-received graphite nanoplates tend to re-agglomerate upon stress relaxation of the polymer melt. The covalent attachment of a polymer to the nanoparticle surface enhances the stability of dispersion, delaying the re-agglomeration. Surface modification also improves interfacial interactions and the resulting composites presented improved electrical conductivity.The authors acknowledge the financial support to Project Matepro Optimizing Materials and Processes, with reference NORTE-07-0124-FEDER-000037 by the Programa Operacional Regional do Norte (ON.2) and Portuguese Foundation for the Science and Technology (FCT) for PEst-C/CTM/LA0025/2013. EC acknowledges FCT for a PhD grant SFRH/BD/87214/2012

Development, explanation, and presentation of the Physical Literacy Interventions Reporting Template (PLIRT)

Background The physical literacy (PL) concept integrates different personal (e.g., physical, cognitive, psychological/ affective, social)determinants of physical activity and has received growing attention recently. Although practical efforts increasingly adopt PL as a guiding concept, latest evidence has shown that PL interventions often lack specification of important theoretical foundations and basic delivery information. Therefore, the goal of the present study was to develop an expert-based template that supports researchers and practitioners in planning and reporting PL interventions. Methods The development process was informed by Moher etal.’s guidance for the development of research reporting guidelines. We composed a group of ten distinguished experts on PL. In two face-to-face meetings, the group first discussed a literature-driven draft of reporting items. In the second stage, the experts anonymously voted and commented on the items in two rounds (each leading to revisions)until consensus was reached. Results The panel recommended that stakeholders of PLinitiatives should tightly interlock interventional aspects with PL theory while ensuring consistency throughout all stages of intervention development. The Physical Literacy Interventions Reporting Template (PLIRT) encompasses a total of 14 items (two additional items for mixed-method