State Anxiety Related to Daily Function Among Older Adults During the COVID-19 Pandemic: Are There Gender Differences? (Preprint)

BACKGROUND Background: Especially among older adults, the Corona virus pandemic (COVID-19) poses a challenge to people's day-to-day functioning and constitutes a meaningful factor related to their emotional and physical health. OBJECTIVE Objective: This study aimed to analyze relationships and gender differences between state anxiety, daily functional actualization, and functional cognition among older adults during the COVD-19 pandemic shelter-in-place. METHODS Methods: We collected online data from a sample of 204 people (102 men and 102 women) aged 60 years and older. In addition to a demographic questionnaire, the State-Trait Personality Inventory was used to assess state anxiety, the Daily Functional Actualization questionnaire was used to evaluate daily functional actualization and the Daily Living Questionnaire to measure functional cognition. RESULTS Results: Significant gender differences were found for state anxiety, t(202) = -2.36, P = .02; daily functional actualization, t(202) = 2.15, P = .03; and several functional cognition components, such as complex tasks, Z = -3.07, P = .002; cognitive symptoms that might be interfering, Z = -2.15, P = .028; executive functions, Z = -2.21, P = .024; and executive function monitoring, Z = -2.21, P = .027. Significant medium correlations were found between both state anxiety level and functional cognition (r = .37–.40, P < .001) and daily functional actualization (r = -.62, P < .001). Furthermore, daily functional actualization predicted 43% of the variance of state anxiety level, F(1, 202) = 155.73, P < .0001. CONCLUSIONS Conclusions: In older adults, anxiety is associated with cognitive decline. It may harm daily functional abilities, in turn leading to social isolation, loneliness, and decreased well-being. Knowledge and self-awareness about the relationships between common and available resources of daily functional actualization and functional cognition with anxiety, especially as related to gender, may serve as a possible strengthening factor in crisis periods such as the COVID-19 pandemic.

Microstructural Evolution and Mechanical Properties of Graphene-Reinforced Ti-6Al-4V Composites Synthesized via Spark Plasma Sintering

Ti-6Al-4V alloy (TC4) with different concentrations of graphene nanoplatelets (GNPs) were fabricated by ball milling and spark plasma sintering (SPS). Microstructure characteristics of the composites were characterized by X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), and Raman. Microhardness and the compressive mechanical properties were also investigated. Experimental results showed that in the process of SPS, most of the GNPs were still retained at high pressure and temperature, and a new phase of TiC was presented due to the in-situ reaction between TiC and GNPs. Also, the strength of the composites was depended on the concentration of GNPs in TC4 matrix. Consequently, the composite with 0.8 wt. % GNPs was increased 18% in microhardness. The maximum yield strength and ductility of the composite were increased by 22.2% and 43.2%, respectively. The strengthening mechanism of the composites was further discussed, and the Orowan strengthening mechanism was the main strengthening factor.

Strength Properties of Nano Silica Recycled Sustainable Concrete

This experiment highlights the salient features of concrete under nanotechnology. Concrete production requires huge amount of cement and aggregates which eventually increases carbon emission and contaminates environment. Hence, incorporation of ‘F’ class fly ash which is partially replaced for cement, recycled aggregate and cactus gel can be done which can reduce dumping issues, carbon emission and cost. However, incorporation of fly ash in ordinary Portland cement deviates its strength consequently. Hence, Nano-silica can be added as an additive to fill up the deviation, thereby increasing its workability and improving the strengthening factor of concrete. In this paper mineral admixture such as Nano-silica were used to increase the strength of concrete and natural polymer substances such as cactus jelly is used to increase the workability of concrete. For the binding material cement were replaced with the fly-ash at the percentage of 60% respectively and for the coarse aggregate quarry aggregate has been replaced with recycled aggregate with the proportion of 40% and 60% respectively. In the investigation three specimens were casted say conventional, replacement of 60% and replacement of 60% with Nano silica and cactus extract solution. The result of compressive and flexural strength were compared. The aim of this experiment is to maintain the economy and environmental effect.

Designing ultrastrong 5d transition metal diborides with excellent stability for harsh service environments

A pressure-induced strengthening strategy can be rationalized by the proposed strengthening factor η.

Mechanical Properties of PM CNT-Dispersed Cu Composite

Microstructural and mechanical properties of powder metallurgy (PM) with carbon nanotube (CNTs) dispersed copper (Cu) composites were investigated in detail. Pure copper powder was coated with un-bundled CNTs by using the zwitterionic surfactant solution containing CNTs. The powder rolling process was applied to increase the powder surface area to be coated with CNTs. The total rolling reduction of Cu-CNT composite powder by 5 steps rolling was about 75%. With increasing the number of rolling steps, the content of CNTs coated on the Cu powder surface increased because of the increment of the flat surface area of flaky Cu rolled powder. As a result, the CNT content was 0.67mass% after 5 steps powder rolling. It was about twice as that of as-coated Cu-CNT composite powder without rolling. The grain size of PM extruded Cu-CNT composite was about one fifth of that of the extruded monolithic Cu material without CNT. Yield stress of the extruded Cu-CNT composite via the rolling process was 192 MPa, which is about twice that of the extruded monolithic Cu material (88 MPa). CNTs distributed at primary particle boundaries were effective to prevent the grain coarsening by their pinning effects, and this grain refinement was the main strengthening factor of the Cu-CNT composite via rolling process.

Experimental Study on Hysteretic Behavior of the Concrete Filled Circular CFRP-Steel Tubular (C-CFRP-CFST) Beam-Columns

Overall 12 specimens were experimentally investigated in this paper to study the hysteretic behaviors of the concrete-filled circular CFRP-steel tubular (C-CFRP-CFST) beam-columns. The test results indicated that CFRP can provide transverse confinement effect and longitudinal strengthening effect for the concrete filled circular steel tubular (C-CFST) beam-columns effectively and the local buckling of the steel tube is deferred. With the increase of the strengthening factor of the longitudinal CFRP, the damage scale reduces.

Studying the Expansion Uniformity of Intravascular Stents by the Effect of Laser Cutting Error

Laser cutting error has large influence on the beam width of intravascular stents. Minor random variation in beam width of stents may significantly impact the expansion uniformity. In this paper, the relevant factors that may affect the beam width during the manufacture are investigated. Based on the randomization model, the pattern how the factors affect expansion uniformity is explored, and the method for calculating uniformity index is proposed. A detailed computation is made on the width randomization for the two expansion elements. The results show that with the increase of the value range of beam width, probability of uniformity index decreases gradually; the strengthening factor has large effect on the expansion uniformity. The method is meaningful for studying how the processing error affects expansion uniformity.

The Effect of Marginal Ridge Thickness on the Fracture Resistance of Endodontically-treated, Composite Restored Maxillary Premolars

Clinical Relevance Preserving the marginal ridge of endodontically-treated composite restored maxillary premolars can act as a strengthening factor and improve fracture resistance.