High Load Levels Research Articles

Enhancing the work engagement of frontline nurses during the COVID-19 pandemic: the mediating role of affective commitment and perceived organizational support

BackgroundOverload and anxiety were common phenomena among frontline nurses during the pandemic. Understanding the potential pathway for fostering engagement in high-stress working conditions can provide evidence of targeted intervention to facilitate nurses’ well-being and safety practices. This study aims to investigate the level of nurses’ work engagement during nucleic acid collection tasks in the COVID-19 pandemic and identify its potential antecedents.MethodsA cross-sectional design was adopted. A sample of 824 nurses who engaged in nucleic acid collection tasks completed an online self-report questionnaire between 1 March and 31 May 2022. Descriptive and path analyses were utilized to analyse the interrelationships among anxiety, perceived workload, affective commitment, perceived organizational support and work engagement. This study was conducted and reported under the guidelines for Strengthening the Reporting of Observational Studies in Epidemiology.ResultsThe results showed that frontline nurses engaged in such tasks reported high levels of anxiety and task load and low levels of work engagement. Path analysis identified anxiety symptoms, perceived workload, perceived organizational support, and affective commitment as associated with work engagement, and among these factors, perceived organizational support and affective commitment played key roles in mediating the relationship of anxiety, workload and work engagement in high-stress working conditions.ConclusionsAffective commitment and perceived organizational support were associated with frontline nurses’ level of work engagement during the COVID-19 pandemic; these two variables might explain how engagement is generated in high-anxiety and high-workload situations. When healthcare organizations give more attention to frontline nurses’ physical and psychological conditions and are able to innovatively motivate affective commitment and facilitate organizational support, nurses’ work engagement in high-level tasks may increase, thus enhancing work safety and personal well-being.

Abstract B122: Association between allostatic load and prostate-specific antigen (PSA) levels in African American men

Abstract Introduction: To further understand cancer health disparities, researchers are utilizing the framework of social determinants of health with a significant factor including physiological factors such as stress. Emerging evidence suggests physiological dysregulation such as high allostatic load to have negative health effects including acting as a driver to cancer risk and development. Understanding the lifetime effects of allostatic load levels within the African American populations is imperative. However, the literature is sparse on allostatic load and prostate cancer in African American men despite high rates of allostatic load and prostate cancer in this population. The goal was to evaluate the association of high allostatic load and prostate cancer within African American men in Chicago. Methods: In 2003-2012, 1200 AA men, over 18 years of age were recruited through yearly community health events in Chicago, Illinois. Allostatic load was defined as the sum of 8 established baseline risk-associated biomarkers, cholesterol, triglyceride, systolic blood pressure, diastolic blood pressure, creatinine, blood urea nitrogen, high-density lipoprotein, low-density lipoprotein, that exceeded specified cut off points adapted from verified scales found in previous literature. Results: The presence of high allostatic load levels was significantly associated with elevated PSA levels in Black men. Participants with high allostatic load scores were 2 times more likely to have elevated PSA levels. [Odds Ratio (OR) 2.129 (95%CI 1.254, 3.614)] Conclusion In conclusion, these results suggest the biological toll of stress in Black men may contribute to higher PSA scores and prostate cancer risks. It is important to understand the complex interplay of the multi-factorial experiences that are unique to Blacks in the United States that may put Black men at higher risk for factors that drive prostate cancer. Further research should be conducted on understanding these socio-biological risk factors to develop effective intervention strategies. Citation Format: Jamirah Y. Chevrin, Rick Kittles. Association between allostatic load and prostate-specific antigen (PSA) levels in African American men [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B122.

Rootstock and Crop Load Effects on ‘Honeycrisp’ Photosynthetic Performance and Carbohydrate Accumulation

Rootstock selection and crop load adjustment are key practices in apple orchard management; nevertheless, the effects of rootstocks and crop load levels on important physiological processes of the scions, such as photosynthetic performance and carbohydrate accumulation, are still unclear. To investigate the impact of different rootstocks and crop load levels on scion photosynthesis and carbohydrate buildup, in 2020, ‘Honeycrisp’ trees grafted on rootstocks ‘G.41’, ‘G.935’, and ‘M.9-T337’ were thinned to low and high crop load levels, and photosynthetic performance and carbohydrate accumulation in leaves and fruit were evaluated. Leaves from ‘G.935’ showed the highest net photosynthesis and electron use efficiency of photosynthesis and the lowest activity for non-net carboxylative processes, all together indicative of enhanced photosynthetic performance. High crop load determined an increase in gas exchange, suggesting a positive feedback of high fruit competition on carbon assimilation. While rootstock ‘M.9-T337’ showed a higher accumulation of starch in leaves, no pattern regarding the composition of leaf-soluble sugars among rootstocks could be identified. Conversely, by the end of the harvest season, leaves from low-cropping trees had higher fructose, glucose, and sorbitol than those from high-cropping trees, but differences in starch content were not significant. Fructose and sorbitol concentrations were affected by rootstock and crop load, respectively. Overall, this study showed that high cropping enhanced photosynthesis in ‘Honeycrisp’ apple and determined lower accumulation of some soluble carbohydrates (fructose, glucose, sorbitol) in leaves. This study also provided insights into how rootstocks affect photosynthetic performance of ‘Honeycrisp’, highlighting ‘G.935’ as the rootstock conferring the highest photosynthetic capacity under the present experimental conditions.

Prolonged Cytopenia Following CAR T-Cell Therapy in Relapsed/Refractory Multiple Myeloma: A Prospective Comprehensive Biomarker Study

Background Chimeric antigen receptor (CAR) modified T-cells are leading to a paradigm shift in the treatment of relapsed/refractory (RR) multiple myeloma (MM). A high proportion of patients treated with CAR T-cells, however, experience prolonged cytopenia, with the mechanism remaining poorly understood. Here, we aimed to explore potential biomarkers that might correlate with cytopenia following CAR T-cell therapy in RRMM. Methods We prospectively collected peripheral blood (PB) of RRMM patients treated with idecabtagen-vicleucel (ide-cel) at the following time points: prior to lymphodepleting chemotherapy (LDC) (baseline), after ide-cel on day 4, 7, 14 and 28, and monthly thereafter. Cytopenia was determined according to the CTCAE version 5.0. Flow cytometry was performed with the following markers: CD45, CD3, CD4, CD8, CD62L, CD45RA, CD19, CD14, CD138, CD38 and a BCMA-CAR-detection marker. Results We included 222 PB samples at different sampling time points from 35 RRMM patients, who were pretreated with a median of 5 therapy lines (range 2-10). All patients were triple-class exposed and, 34 (97%) and 9 (26%) patients underwent autologous and allogeneic stem cell transplant (SCT), respectively. First, we analyzed the relationship between baseline parameters and the duration of grade ≥3 cytopenia after ide-cel (n=35). Notably, patients who received allogeneic SCT or >4 lines of therapy did not develop longer lasting cytopenia than the remaining patients. We found a correlation between the baseline hemoglobin level and the duration of grade ≥3 anemia (r=-0.55, P<0.001). Similarly, low baseline platelet count indicated long duration of grade ≥3 thrombocytopenia (r=-0.48, P=0.003). Moreover, high baseline ferritin level correlated with long duration of grade ≥3 anemia (r=0.52, P<0.001) and thrombocytopenia (r=0.51, P=0.002). Furthermore, the maximum ferritin level after ide-cel was an indicator for long lasting grade ≥3 anemia (r=0.73, P<0.001) and thrombocytopenia (r=0.71, P<0.001). Interestingly, we found significant correlations between the duration of grade ≥3 lymphopenia and baseline CD4+ T-cell frequency (r=0.41, P=0.02), CD8+ T-cell frequency (r=-0.38, P=0.04) and CD4+/CD8+ ratio (r=0.4, P=0.03). Noteworthy, patients with β2-microglobulin level >3.5 mg/l displayed longer duration of grade ≥3 anemia (median: 9 vs 0 day, P=0.007) and neutropenia (median: 43 vs 12 days, P=0.02) compared with the remaining patients, suggesting that high tumor load might be a risk factor for prolonged cytopenia after ide-cel. Second, we divided the follow-up PB samples (n=187) into two groups: early (<d60) and prolonged (≥d60) cytopenia to account for direct toxic effects related to LDC. A high ferritin level was associated with low hemoglobin level (<d60: r=-0.45, P<0.001, ≥d60: r=-0.62, P<0.001) and low platelet count (<d60: r=-0.58, P<0.001, ≥d60: r=-0.81, P<0.001) in both groups. In prolonged cytopenia (≥d60), lymphocyte count correlated with the T-cell count (r=0.7, P<0.001), suggesting that prolonged lymphopenia was mainly attributed to the reduced T-cell count after ide-cel. Of note, the frequency of naïve CD4+ T-cells (CD3+CD4+CD62L+CD45RA+) positively correlated with neutrophil count (r=0.58, P<0.001), hemoglobin level (r=0.37, P=0.03) and white blood cell count (r=0.5, P=0.002) in the ≥d60 group, suggesting that delayed immune reconstruction with reduced naïve CD4+ T-cells might contribute to prolonged cytopenia after ide-cel. Moreover, in the ≥d60 group, lymphocyte count was related with the frequency of CAR+CD4+ (r=-0.58, P<0.001), CAR+CD8+ (r=0.58, P<0.001), CAR-CD4+ (r=-0.72, P<0.001), CAR-CD8+ (r=0.75, P<0.001) T-cells, as well as the ratios of CAR+CD8+/CAR+CD4+ (r=-0.6, P<0.001) and CAR-CD8+/CAR-CD4+ (r=-0.75, P<0.001). Conclusion Here, we present one of the first prospective studies investigating the factors associated with prolonged cytopenia after CAR T-cell therapy in RRMM. High tumor load, preexisting cytopenia and high ferritin level are related with prolonged cytopenia after ide-cel. Delayed immune reconstruction, characterized by reduced naïve CD4+ T-cell count, indicates prolonged cytopenia following ide-cel therapy. Patients with high CD4+/CD8+ ratio are at risk of prolonged lymphopenia (with reduced T-cell count), which may be a risk factor for infectious complications and an issue for subsequent T-cell based immunotherapies.

Simulation and Experimental Investigation of Multi-Step Shot Peening for Surface Crack Repair in Aluminum Alloys

This study explores the impact of shot peening residual compressive stress on repairing surface cracks in the 7075-T651 aluminum alloy. Two models were developed for crack repair via shot peening and fatigue test finite element modeling. A multi-step numerical simulation introduced shot peening-induced residual stress into the fatigue test model, and subsequent simulations analyzed the crack repair mechanism. The research results indicate that increasing pressure and projectile size improve repair effectiveness, but higher pressure causes material damage, and larger projectiles decrease fatigue life. Crack repair effectiveness decreased with higher loading levels, more significantly at higher loads. Experimental and simulation results matched well, validating the simulation model for shot peen repair processes and offering optimization possibilities.

Vinasse processing by electrodialysis combined with nanofiltration: emphasis on process optimization and environmental sustainability.

Vinasse, due to its high organic load, low pH, high corrosivity, and high potassium levels, can cause salinization, acidification, loss of fertility, and leaching of constituents when applied to agricultural soils. In this context, electrodialysis (ED) was used to remove potassium from this effluent, to concentrate it in the cathode concentrate compartment. The cathode concentrate was subjected to nanofiltration (NF), allowing the electrolyte to be reconditioned and simultaneously generating a solution rich in potassium, making it an input for the fertilizer industry. The conditions of NF were optimized by the design of experiments. The optimal conditions obtained were 6 bar pressure, 1.8 L min-1 flow, and 1.6× feed dilution factor. Although the reconditioned electrolyte has been feasible, the raw vinasse (pre-ultrafiltered) was compared and proved to be a sustainable option. The NF permeate had a potassium concentration of 90% and magnesium of 84%, in addition to the annual reduction in magnesium sulfate demand (139,450,988 kg) and distilled water (5,019 m3). It was also possible to obtain an increase of approximately 400% in the rate of the application of vinasse in fertigation without compromising the needs of the plantation, the quality of the soil, and groundwater.

In Vitro Wear Behavior of Knee Implants at Different Load Levels: The Impact of the Test Fluid

Calf serum is defined as a test fluid for in vitro knee wear simulation studies in the ISO standard. However, protein degradation typically occurs during in vitro wear simulation. The current study should indicate whether increased loads change the rheological properties of the test fluid and may, therefore, lead to favorable tribological behavior and reduced wear. Three different load levels were simulated in a displacement-controlled knee wear simulation study. The gravimetric wear rates were determined, pressure measurements were performed, and the dynamic viscosity of the test fluids were analyzed after the simulation of 0.5 × 106 cycles. The lowest load level led to the lowest wear rate, and the lowest contact pressure and contact area, compared to the medium and high-load level. Although, the high-load level led to the highest contact pressure and contact area, the wear rates were comparable to the medium-load level. The rheological measurements revealed the highest dynamic viscosity for the high-load level and no differences could be found between the medium and low loading condition. To perform realistic wear simulation studies, the reproduction of the in vivo interrelationships between the shear forces and wear are necessary.

Correlation Analysis of Various Water Quality Parameters of the Tiru Reservoir, Maharashtra, India

The present study was conducted in the department of Aquatic Environment Management, College of Fishery Science, Udgir, District Latur, Maharashtra, India during August, 2017 to January, 2019 to investigate trophic status of the Tiru reservoir. Twenty (20) water quality parameters had been collected monthly from five sampling sites of Tiru reservoir, Udgir, Latur district, Maharashtra, India. Seasonal trends were analysed and discussed in this chapter. Pearson’s correlation coefficient (r) of eighteen physico-chemical parameters from five study locations were analyzed to know the pollution causing parameters. Water quality analysis showed that Total Phosphorus concentrations was highest in the summer, when reservoir water levels were lowest. Correlation between Total phosphorus and Chl-a was highest at 0.926. Eutrophication was mainly generated by phosphorus available in the water, which increases chlorophyll-a concentration (algal blooms). A positive correlation between temperature and DO might be possible because higher summertime water temperatures boost photosynthetic activity. SDD has shown a substantial negative connection with Chl-a throughout all seasons, since an increase in phytoplankton abundance yields a decrease in water transparency. The negative correlation between SDD and turbidity is primarily caused by the high levels of productivity in the summer, and high levels of suspended organic load due to surface runoff in the monsoon season. The majority of the time throughout the research period, Tiru reservoir was found in the eutrophic state, and in some cases even hyper-eutrophic.

Characterization of hardness and elastic modulus using nanoindentation and correlation with wear behavior of UHMWPE during uniaxial tension

UHMWPE is the material of choice for bearing surfaces in total joint arthroplasty making its wear and mechanical properties important factors of contribution in longevity of prosthetic hip/knee implants. In this study, the variation of hardness and elastic modulus with applied load in textured UHMWPE has been investigated. Texture has been induced through uniaxial tension of UHMWPE modifying its microstructure which in turn influences the wear resistance and hence the mechanical properties of the material. Previous studies have shown hardness to be a major factor influencing wear resistance. However, recently, the ratio of hardness (H) to elastic modulus (E) has been recognized as a more influential parameter of wear resistance. The validity of predicting wear resistance using H/E ratio has been examined in this work. Power law variation with load for the bioimplant material UHMWPE has been investigated at different strain levels. It has been observed that power law exponent of 2 can only be achieved at higher load levels. Overall, this work provides an insight into influencing the properties of bioimplant material UHMWPE by modifying the microstructure of the material through inducing texture which ultimately affects the longevity of the prosthetic implants.

Highly Efficient and Stable Binary Cross-Linkable/ Self-Assembled Organic Nonlinear Optical Molecular Glasses.

The development of electro-optical materials with high chromophore loading levels that possess ultrahigh electro-optic coefficients and high long term alignment stability is a challenging topic. Anthracene-maleimide Diels-Alder (DA) reaction and π-π interaction of Anthracene-pentafluorobenzene and benzene-pentafluorobenzene are developed for making highly efficient binary cross-linkable/self-assembled dendritic chromophores FZL1-FZL4. A covalently or non-covalently cross-linked network is formed by DA reaction or π-π interaction after electric field poling orientation, which greatly improves the long-term alignment stability of the materials. An electro-optic coefficient up to 266pmV-1 and glass transition temperature as high as 178°C are achieved in cross-linked film FZL1/FZL2, and 272-308pmV-1 is achieved for self-assembled films FZL1/FZL4 and FZL3/FZL4 due to high chromophore density (3.09-4.02×1020 moleculescm-3 ). Long-term alignment stability tests show that after heating at 85°C for over 500h, 99.73% of the initial r33 value is maintained for poled crosslinked electro-optic films 1:1 FZL1/FZL2. The poled self-assembled electro-optic films 1:1 FZL1/FZL4 and 1:1 FZL3/FZL4 can still maintain more than 97.11% and 98.23%, respectively, of the original electro-optic coefficient after being placed at room temperature for 500h. The excellent electro-optic coefficient and stability of the material indicate the practical application prospects of organic electro-optic materials.

Macrobending loss in fiber optic wrapped on rubber-spring wire structure under static load-pressure

This work observes rubber-based frame structures for wide helix-shaped-macrobending fiber optic sensors intended for measuring an object with high load levels. In this fiber sensor, the working principle is to measure the power loss (due to bending) of the light traveled in the employed fiber optic. During the applications, it needs a particular mechanical structure to accommodate a reversible fiber bending in the context of load measurement. In this work, a cylindrical-shaped rubber structure mixed with calcium carbonate compound (CaCO3) is constructed as the fiber bending frame (housing) in which a spring wire is inserted into the structure in the two models, i.e., outer and inner-spring structure. Several investigations of static load pressure reveal the optimum structure design for high load measurement. Using the inner-spring model, a rubber structure with 10wt% CaCO3 exhibits the preferable performance with a sensitivity of 0.15 V/Kg.cm2 and measurement load range until 210 Kg.

Cognitive Ergonomics: A Review of Interventions for Outpatient Practice.

Doctoring is difficult mental work, involving many cognitively demanding processes such as diagnosing, decision-making, parallel processing, communicating, and managing the emotions of others. According to cognitive load theory (CLT), working memory is a limited cognitive resource that can support a finite amount of cognitive load. While the intrinsic cognitive load is the innate load associated with a task, the extraneous load is generated by inefficiency or suboptimal work conditions. Causes of extraneous cognitive load in healthcare include inefficiency, distractions, interruptions, multitasking, stress, poor communication, conflict, and incivility. High levels of cognitive load are associated with impaired function and an increased risk of burnout among physicians. Cognitive ergonomics is the branch of human factors and ergonomics (HFE) focused on supporting the cognitive processes of individuals within a system. In health care, where the cognitive burden on physicians is high, cognitive ergonomics can establish practices and systems that decrease extraneous cognitive load and support pertinent cognitive processes. In this review, we present cognitive ergonomics as a useful framework for conceptualizing an oft-overlooked dimension oflaborand apply theory to practice by summarizing evidence-based cognitive ergonomics interventions for outpatient care settings. Our proposed interventions are structured within four general recommendations: 1. minimize distractions, interruptions, and multitasking; 2. optimize the use of the electronic health record (EHR); 3. optimize the use of health information systems (HIS); and 4. support good communication and teamwork. Best practices in cognitive ergonomics can benefit patients, minimize practice inefficiency, and support physician career longevity.

Effect of rivet arrangement on fatigue performance of electromagnetic riveted joint with [formula omitted]10 mm diameter rivet

Electromagnetic riveting (EMR) can effectively form large-diameter rivets and produce high-quality joints. In this paper, the effect of rivet arrangement on fatigue performance of electromagnetic riveted joint was investigated. Quasi-static shear tests, fatigue tests, numerical simulation and microstructure observation were carried out. The results showed that the rivet arrangement had little effect on the shear performance and had a great impact on the fatigue performance of the EMR joint. Specifically, the difference between the average maximum shear load of the V-joints (60.49 kN) and the H-joints (60.41 kN) was small. The fatigue life of the H-joints was higher than that of the V-joints at high fatigue load levels (Fmax>30.225 kN), while the result was opposite at low fatigue load levels (Fmax<30.225 kN). Furthermore, the fatigue fracture analysis showed that there were two typical failure modes for the joints: (I) the rivet fracture, and (II) the sheet fractured on the manufactured head side. The V-joints mainly displayed the coexistence of failure mode I and mode II, while the H-joints displayed failure mode II at all fatigue load levels. At high fatigue load levels, the significant stress concentration in both rivets resulted in the rivet fracture of the V-joints within a relatively short time. Due to multiple extension directions and a smaller extension zone, the fatigue life of H-joints was lower than that of the V-joints at low fatigue load levels. Therefore, the fatigue performance of the component could be improved by choosing a different rivet arrangement.

Tropical peat surface oscillations are a function of peat condition at North Selangor peat swamp forest, Malaysia

Tropical peatland condition across southeast Asia is deteriorating as a result of conversion to agriculture and urban zones. Conversion begins by lowering the water table, which leads to peat decomposition, subsidence and increased risk of large-scale forest fires. Associated changes in mechanical peat properties impact the magnitude and timing of changes in peatland surface motion, making them a potential proxy for peatland condition. However, such a relationship is yet to be observed in a tropical peatland setting. This study aimed to establish whether patterns of tropical peatland surface motion were a function of peat condition at North Selangor Peat Swamp Forest in Selangor, Malaysia. Results showed that subsidence was greatest at fire-affected scrubland sites, whilst the lowest mean water table levels were found at smallholder oil palm sites. Peat condition and magnitude of tropical peat surface oscillation were significantly different between peat condition classes, whilst peat condition differed with depth. More degraded tropical peats with high bulk density throughout the peat profile due to high surface loading and low mean water table levels showed greater surface oscillation magnitudes. The dominant peat surface oscillation mechanisms present at all sites were compression and shrinkage from changes in water table level. Mean water table level and subsidence rate were related to surface oscillation magnitude. However further work towards measuring surface and within-water table range bulk densities and surface loading is required to better understand the controls on surface oscillation magnitudes.

Preparation of granulated powders via freeze drying at different levels of slurry solid loading and comparison of their powder bed quality in roller-compaction-assisted binder jetting

Granulation can improve the flowability of nanopowder and the density of resultant parts printed by binder jetting. Forward-rotating roller compaction has the potential for further improving the density. In this study, for the first time, powder recoating tests of different granulated alumina powders were conducted on a commercially available binder jetting printer equipped with a forward-rotating roller compaction system. Freeze drying was used to prepare the granulated powder. Four different granulated powders were prepared from slurries with different levels of solid loading: 2, 5, 10, and 15 vol%, respectively. Powder bed quality, including defects on powder bed surface and maximum powder bed density without defects, was compared among the granulated powders. When the compaction ratio was too high, granulated powders with low solid loading levels of 2 and 5 vol% showed much fewer compaction-induced defects (including surface ridges and edge ridges) on powder bed surface than those with high solid loading levels of 10 and 15 vol%. As the solid loading level increased from 2 to 15 vol%, the maximum powder bed density without defects decreased from 19.5% to 16.0%. This study showed that a granulated powder prepared from a low level of slurry solid loading could reduce the compaction-induced defects on powder bed surface and enhance the powder bed density in roller-compaction-assisted binder jetting.

Resilience of Medium-to-High-Rise Ductile Coupled Shear Walls Located in Canadian Seismic Zones and Strengthened with Externally Bonded Fiber-Reinforced Polymer Composite: Nonlinear Time History Assessment

Coupled shear walls (CSWs) are structural elements used in reinforced concrete (RC) buildings to provide lateral stability and resistance against seismic and wind forces. When subjected to high levels of seismic loading, CSWs exhibit nonlinear deformation through cracking and crushing in concrete and yielding in reinforcements, thereby dissipating a significant amount of energy, leading to their permanent deformation. Externally bonded fiber-reinforced polymer (EB-FRP) sheets have proven to be effective in strengthening RC structures against various loading and environmental conditions. In addition, their high strength-to-weight ratio makes them an attractive solution as they can be easily applied without significantly increasing the structure’s weight. This study investigates the effectiveness of using EB-FRP sheets to reduce residual displacement in CSWs during severe earthquake loadings. Two series of 15-story and 20-story CSWs in Western and Eastern Canadian seismic zones, which serve as representative models for medium- and high-rise structures, were evaluated through nonlinear time history analysis. The numerical simulation of all CSWs and strengthened elements was carried out using the RUAUMOKO 2D software. The findings of this study provided evidence of the effectiveness of EB-FRP sheets in reducing residual deformation in CSWs. Additionally, significant reductions in the rotation of the coupling beams (CBs) and the inter-story drift ratio were observed. The results also revealed that bonding vertical FRP sheets to boundary elements and confining enhancement by wrapping CBs and wall piers is a very effective configuration in mitigating residual deformations.

Full-scale testing and nonlinear finite element analysis of a pioneering fully prefabricated noise barrier wall system

The structural behavior of a novel fully prefabricated noise barrier wall system was examined experimentally and analytically using nonlinear finite element analysis. The wall components and connectivity details were developed to be a totally precast system for fast-track construction. Two full-scale prototypes were designed, fabricated, assembled, and prepared for full-scale testing at the High-Bay Structural Laboratory at the University of Illinois at Chicago. Each prototype was instrumented with about 40 sensors including strain gauges, linear variable differential transducers, and crack meters at pre-identified critical locations essential for understanding its structural behavior. In addition, a nonlinear finite element analysis model of the wall system prototype was required for future refinement and adjustment of the noise barrier wall system components. With proper calibration based on the experimental results, the nonlinear finite element analysis model will allow for conducting parametric studies on key factors relevant to the wall behavior without the need for costly and time-consuming full-scale testing. The structural behavior of the wall system was analyzed in terms of the load–deflection curves, load–strain curves, cracking, uplift, and failure mode. The experimental results revealed that the wall system was structurally stable up to a high loading level and met the intended serviceability and strength requirements.

The relationship of maternal hepatitis B e antigen and response to vaccination of infants born to women with chronic infection

BackgroundThe relationship of maternal HBeAg and infants’ response to hepatitis B vaccine remains controversial. This study aims to observe the dynamic changes in infant birth HBV markers and study the time-varying effects of maternal HBeAg on vaccination response of infants born to women with chronic HBV infection.Methods3163 infants born to HBsAg positive mothers including 1737 with maternal HBeAg positive in group A and 1426 negative in group B were enrolled eventually. Demographic information and laboratory tests were collected at birth, 7-12th and 24th month. The dynamic changes of infant HBV markers and HBsAb titers at different time points were compared between the two groups.ResultsThe infant HBV markers at birth displayed different modes. During the follow-up, we observed a significant downward trend in the positive rates of HBsAg, HBeAg, HBeAb and HBcAb. The HBsAg of two groups switched to negative at 7–12 months and HBeAg in Group A became negative at 24 months. The HBsAb titers of the infants in the two groups were 576.91(192.8–1000.0) vs 719.67(208.1–1000.0) at 7–12 months (Z = -3.049, P = 0.002) and 783.5(227.8–1000.0) vs 891.4(234.0–1000.0) at 24 months (Z = -0.853, P = 0.394). High HBV DNA viral load (OR 1.260, 95% CI 1.139–1.395, P < 0.001) and maternal HBeAg level (OR 1.003, 95% CI 1.002–1.003, P < 0.001) were associated with the higher HBeAg positive rate of infants.ConclusionsMaternal HBeAg did affect the infants’ immune response to vaccination and reduce the anti-response at 7-12th month temporarily, but these influences were negligible by 24th months after birth, which proved that the maternal HBeAg would not induce immune tolerance of infants from a long-term perspective.

Assessing the Impact of Transport Provision Factors on the Efficiency of a Regional Transportation System

This research presents a correlation regression analysis of the impact of transport provision characteristics on the efficiency of the regional transportation system of the Russian regions. The research showed that the scope of cargo turnover in million tons per kilometer produces the largest positive impact on the efficiency of the regional transportation system. Another significant positive factor is the volume of investment into capital assets of the relevant organizations. Apparently, the growth of capital investment into basic production assets allows increasing the cargo turnover of transportation companies, which is reflected on the scope of transportation services per capita. At the same time, the growth of passenger turnover (million passengers per kilometer) leads to a decrease in the resulting index. In our opinion, this can be due to competition within a sector. Specifically, a high level of roads loading, including with public transport, leads to an increase of unproductive loss of working time for business, delays and, consequently, reduced volume of goods turnover.

Ultrasound versus videos: A comparative study on the effectiveness of musculoskeletal anatomy education and student cognition.

Ultrasound imaging is a dynamic imaging technique that uses high-frequency sound waves to capture live images of the structures beneath the skin. In addition to its growing use in diagnosis and interventions, ultrasound imaging has the potential to reinforce concepts in the undergraduate medical curriculum. However, research assessing the impact of ultrasound on anatomy learning and student cognition is scarce. The purpose of this study was to compare the impact of ultrasound-based instruction versus narrated videos on students' understanding of anatomical relationships, as well as the role of intrinsic motivation, self-efficacy beliefs, and students' attitudes in this process. A booster course on anterior leg and wrist anatomy was offered to second-year medical students. A randomized controlled trial with a cross-over design allocated students to either an ultrasound-based teaching condition (cohort A) or a narrated anatomy video condition (cohort B). Next, participants were crossed to the alternative intervention. At the start of the study (T0), baseline anatomy knowledge, intrinsic motivation, self-efficacy beliefs, and spatial ability were measured. After the first intervention (T1) and at the end of the study (T2), both cohorts were administered an anatomy test, an intrinsic motivation scale, and a self-efficacy scale. In addition, each student was asked to fill out a perception survey after the ultrasound intervention. Finally, building on the cross-over design, the most optimal sequence of interventions was examined. A total of 181 students participated (cohort A: n = 82, cohort B: n = 99). Both cohorts performed comparably on the baseline anatomy knowledge test, spatial ability test, intrinsic motivation, and self-efficacy scale. At T1, cohort B outperformed cohort A on the anatomy test (p = 0.019), although only a small effect size could be detected (Cohen's d = 0.34). Intrinsic motivation and self-efficacy of both cohorts were similar at T1. At T2, the anatomy test, intrinsic motivation, and self-efficacy scale did not reflect an effect after studying either sequence of the interventions. Students reported favorably about the ultrasound experience, but also mentioned a steep learning curve. Medical students found the hands-on ultrasound sessions to be valuable, increasing their interest in musculoskeletal anatomy and ultrasound imaging. However, the addition of ultrasound did not result in superior spatial anatomy understanding compared to watching anatomy videos. In addition, ultrasound teaching did not have a major effect on student cognition. Ultrasound-based teaching of musculoskeletal anatomy is regarded as difficult to learn, and therefore it is hypothesized that too high levels of cognitive load might explain the presented results.