Search Results (183,480)

Background: Whether patients commence haemodialysis with a central venous catheter (CVC), or an arteriovenous fistula (AVF) is used to audit the quality of a vascular access service. However, this crude metric of measurement can miss the increasing nuance and complexity of vascular access planning. We aimed to understand whether commencing haemodialysis with a CVC represented an ‘optimal’ or ‘suboptimal’ outcome and how this could influence the assessment of a vascular access service. Methods: From a prospective clinical database, patients known to nephrology >90 days prior to initiating haemodialysis as first-ever renal replacement therapy (2011–2020) from a single centre were included. Results: A total of 158/254 patients started haemodialysis with a CVC, and 96 with arteriovenous fistula. For 91 patients, the CVC was deemed ‘optimal’ care due to factors such as unpredictable deterioration in renal function (n = 41) and inadequate veins for AVF creation (n = 24). For 67 patients, the CVC was ‘suboptimal’ due to factors such as no/late referral to access assessment (n = 25) and delays in the AVF creation pathway (n = 13). There was no difference in mean survival between the AVF and ‘suboptimal’ groups (2.53 vs. 2.21 years, p = 0.31). There was a survival difference between AVF versus CVC (2.53 vs. 1.97 years, p = 0.002) and ‘suboptimal’ versus ‘optimal’ CVC cohorts (2.21 vs. 1.40 years, p = 0.16). Conclusions: Understanding whether a CVC is ‘optimal’ or ‘suboptimal’ allows a more nuanced analysis of service provision. High mortality in the ‘optimal’ group suggests a frailer cohort where CVC is potentially the best care. Studying ‘suboptimal’ CVC starts helps identify practice and system issues preventing ‘optimal’ care. Full article

This study investigated the influence of the ultraviolet (UV) dose (${\mathrm{D}}^{\mathrm{U}\mathrm{V}}$) on the photodeposition of MnO_x and Pd cocatalysts on 300-nm-thick anatase TiO₂ thin films, which were prepared via sol–gel dip-coating on a glass substrate. MnO_x and Pd were photodeposited using increasing UV doses ranging from 5 to 20 J cm⁻², from 5 mM aqueous electrolytes based on Mn²⁺/IO₃⁻ or Pd²⁺, respectively. The effect of the ${\mathrm{D}}^{\mathrm{U}\mathrm{V}}$ on the MnO_x photodeposition resulted in an increase in Mn²⁺ surface content, from 2.7 to 5.2 at.%, as determined using X-ray photoelectron spectroscopy (XPS). For Pd, increasing the UV dose led to a reduction in the oxidation state, transitioning from Pd²⁺ to Pd⁰, while the overall Pd surface content range remained relatively steady at 2.2–2.4 at.%. Both MnO_x/TiO₂ and Pd/TiO₂ exhibited proportional enhancements in photocatalytic activity towards the degradation of methylene blue. Notably, Pd/TiO₂ demonstrated a significant improvement in photocatalytic performance, surpassing that of pristine TiO₂. In contrast, TiO₂ samples functionalized through wet impregnation and thermal treatment in the same electrolytes showed overall lower photocatalytic activity compared to those functionalized via photodeposition. Full article

The excessive consumption of red meat, such as beef, is a growing global health concern linked to increased risks of cancer and cardiovascular diseases. The health consequences associated with red meat consumption were estimated to cost USD 285 billion globally in 2020, accounting for approximately 0.3% of total health expenditures that year. Understanding the psychological mechanisms behind food choices is crucial for changing consumption habits, fostering healthy behaviors, and achieving sustainable dietary patterns. To address these challenges, this study utilizes virtual reality (VR) as a persuasive tool to examine how empathy, as a psychological mechanism, influences the intention to reduce beef consumption and its impact on dietary attitudes. Using an experimental design with 142 participants, the study found that in the VR context, individuals with higher empathy scores experienced a stronger sense of presence, significantly influencing their attitudes toward beef consumption, mediated by the change in anti-beef-eating attitude (p = 0.029). This suggests that VR can serve as an effective medium to reduce individuals’ willingness to consume beef and consequently prevent health risks associated with excessive meat intake. This study also highlights the importance of considering individual empathy levels when designing VR interventions to maximize their effectiveness and promote healthier dietary habits, ultimately improving public health. However, one limitation of this study is that it only assessed short-term changes in attitudes following the VR intervention, without incorporating long-term follow-ups to determine if these changes are sustained over time. Full article

High-speed segmented annular seals are often subjected to friction and wear, and the groove design on the sealing surface can effectively suppress this loss. For the purpose of improving the sealing performance, the segmented annular seal models of three structures are established, and the accuracy of the calculation model is verified by comparing with the previous results. Through fluid–solid–thermal coupled analysis, the flow field characteristics, opening characteristics, and leakage characteristics of the segmented annular seal under high working condition parameters were studied. The results show that the setting of the shallow groove forms the hydrodynamic effect by squeezing and hindering the flow of fluid in the clearance. The increase in rotational speed and pressure difference can promote the increase in the opening force, while the temperature has no significant effect on the opening of the seal. Seals with ladder-like grooves have the best opening performance, and seals without shallow grooves are already difficult to open under conditions of high pressure difference and large spring forces. Temperature and pressure difference are the main factors affecting the leakage of the seal, while the influence of the rotation speed is small. When the sealed pressure increases from 0.15 MPa to 0.4 MPa, the maximum increase in the leakage of the seal with specific groove design is 4.657 times the original. As the temperature rises from 420 K to 620 K, the maximum decrease in the three structures is up to 22.9%. Among the seals of the three structures, seals with ladder-like grooves have medium leakage. This research will contribute to the improvement of research methods for the sealing performance of segmented annular rings, especially for the evaluation of groove design and opening characteristics. Full article

The Moroccan government has taken several initiatives to improve HR practices in the public sector, with the aim of enhancing the performance of civil servants and thereby improving the quality of public administration services. Therefore, this study employs the PLS-SEM technique to investigate the influence of HRM practices on job satisfaction, affective commitment, and in-role job performance within public administrations. The dataset was collected online from 390 Moroccan civil servants. The results indicate that recruitment and selection (RSE), training (TRA), compensation (COM), employment security (ESE), and internal career opportunities (ICOs) had a positive impact on job satisfaction (JSA). Likewise, RSE, TRA, and ICOs improved affective commitment (ACO). In addition, JSA and ACO enhanced in-role job performance (RJP). These findings provide valuable theoretical implications and practical guidelines for policymakers on how to adapt HR practices to enhance civil servants’ job satisfaction and affective commitment, ultimately improving their in-role job performance levels. Full article

Polyimide (PI) has been widely used as a flexible substrate in the OLED display industry to achieve folding and other functions. However, it has unintended side effects, such as friction-greening, a green screen phenomenon caused by friction after prolonged usage. This is related to drifting TFT characteristics caused by charge accumulating in the PI in combination with the high efficiency of green pixels. In this study, the mechanism of the influence of PI structure on friction-greening was investigated. Increasing the process temperature from 350 °C to 470 °C, the chain segment structure within the PI became more regularized. Thus, the material had higher conductivity and shallower trap energy levels, which was confirmed by X-ray small angle scattering, dielectric, photoluminescence, and other methods. Under prolonged discharge conditions, less charge accumulated within PI, thus effectively mitigating the threshold voltage drift of the thin-film transistor (TFT). These results will contribute to the further optimization of the process and the development of PI materials. Full article

Flood disasters occur frequently and cause great losses. Improving the resilience of urban flood disasters is of great significance to improving disaster prevention and mitigation in the region. The metropolitan area is the center of regional economic development and the key to strengthening the construction of local resilience. However, there is little research on resilience in the metropolitan area. Taking nine cities in the Zhengzhou metropolitan area as the research object, this paper uses the pressure state response (PSR) model to build the evaluation system of the Zhengzhou metropolitan area’s flood disaster resilience and comprehensively uses the entropy weight method, analytic hierarchy process, kernel density estimation method, and factor contribution model to measure the temporal and spatial evolution characteristics of Zhengzhou metropolitan area’s flood disaster resilience from 2010 to 2022, excavating the development trend of the level of flood disaster resilience of members in the Zhengzhou metropolitan area, and explore the driving factors affecting the resilience of the Zhengzhou metropolitan area’s flood disaster. The results show that (1) from 2010 to 2022, the development trend of flood disaster resilience among the Zhengzhou metropolitan area members has obvious differences, the change of pressure resilience is stable, and the state resilience and response resilience increase as a whole; (2) the results show that the resilience of flood disaster in the Zhengzhou metropolitan area has obvious change characteristics in time and space, and the overall trend is to take Zhengzhou as the core to drive the surrounding members’ upward development; (3) in the driving factor analysis, the number of ordinary colleges and universities and the proportion of public security expenditure in fiscal expenditure are the main influencing factors in the resilience evaluation index. The Zhengzhou metropolitan area is the key area of economic development in Henan Province. The research results provide a reference for improving the resilience level of the Zhengzhou metropolitan area and strengthening the prevention and control of flood disasters. Full article

Heme, a complex iron-containing molecule, is traditionally recognized for its pivotal role in oxygen transport and cellular respiration. However, emerging research has illuminated its multifaceted functions in the nervous system, extending beyond its canonical roles. This review delves into the diverse roles of heme in the nervous system, highlighting its involvement in neural development, neurotransmission, and neuroprotection. We discuss the molecular mechanisms by which heme modulates neuronal activity and synaptic plasticity, emphasizing its influence on ion channels and neurotransmitter receptors. Additionally, the review explores the potential neuroprotective properties of heme, examining its role in mitigating oxidative stress, including mitochondrial oxidative stress, and its implications in neurodegenerative diseases. Furthermore, we address the pathological consequences of heme dysregulation, linking it to conditions such as Alzheimer’s disease, Parkinson’s disease, and traumatic brain injuries. By providing a comprehensive overview of heme’s multifunctional roles in the nervous system, this review underscores its significance as a potential therapeutic target and diagnostic biomarker for various neurological disorders. Full article

Chlorophyll-a (Chl-a) serves as a crucial indicator of water quality, making the precise monitoring of its concentration essential for aquatic environment ecosystem protection. Water color retrieval technology has gained prominence in monitoring spatiotemporal variations in water quality. This study evaluated inversion models for Chl-a estimation in urban water bodies using ground-based hyperspectral data in Nanjing, China. The results indicate that the normalizing of water-leaving reflectance significantly enhances the correlation between water-leaving reflectance and measured Chl-a concentration. However, due to the complexity of urban water bodies and the diversity of interfering components, the three ratio algorithms of OC2V4, OC4V4, and TChla using blue–green bands yielded suboptimal inversion results. In contrast, the normalized fluorescence line height (NFH) algorithm exhibited a robust performance, yielding an R² of 0.70. Furthermore, the overall performance of the near-infrared–Red (NIR-red)-band algorithms showed a commendable overall performance (R² > 0.60), and the best four-band algorithm, 4BDA, achieved an R² of 0.72. Other index algorithms, such as the Yang index and the normalized difference Chl-a index (NDCI), also performed well (R² = 0.61). Notably, the classification of Chl-a concentrations did not significantly enhance the inversion accuracy of the empirical and semi-analytical models. Only the NFH algorithm using the fluorescence band greatly improved the inversion accuracy for low Chl-a concentrations (R² = 0.75), likely due to the influence of Chl-a and other substances on fluorescence peak positioning and height. Ultimately, the NFH model is identified as the optimal approach for Chl-a inversion across varying Chl-a concentrations in urban water bodies. This study provides critical technical support for the protection of aquatic environments and the management of urban water resources. Full article

With the growing demand for high-performance polymer composites, conventional single- and twin-screw extruders often fall short of meeting industrial requirements for effective mixing and compounding. This research investigates the kinematic behavior of the plasticization and transport mechanisms in tri-screw extruders when subjected to a vibrational force field. The study specifically examines how applying vibrational force technology can improve the efficiency of polymer mixing. Vibration force field means that in a three-screw mechanism, an axial vibration is applied to the middle screw to produce a vibration force field. Through the development of mathematical and physical models, this study analyzed the motion dynamics of the screw and the influence of a vibrational force field on polymer transport and mixing efficiency. The findings indicate that, in comparison to traditional twin-screw extruders, tri-screw systems can achieve higher shear and elongational rates, leading to enhanced polymer mixing uniformity. Furthermore, applying an axial vibrational force field significantly influenced the shear and elongational strain rates of the material, thereby optimizing its rheological behavior and processing quality. This research not only establishes a theoretical foundation for the design and optimization of tri-screw extruders but also opens new pathways for the efficient processing of high-viscosity composite materials. Full article

In industrial production, 7075 aluminum alloy (A7075) is prized for its strength and light weight. However, heat treatment can reduce its hardness and wear resistance. Therefore, proper surface treatments are often necessary to optimize its mechanical properties. In this work, a hammering tool attached to a robotic arm was employed to impact the surface of A7075 using different impact energies, and the surface hardness, morphology, roughness, and frictional characteristics of samples subjected to machine hammer peening (MHP) treatment were analyzed to explore the strengthening mechanism of MHP. The results indicate that the hardness increased to a maximum value of 235 HV with rising impact energy, whereas the depth of influence (2 mm) was almost unaffected by the impact energy. Microstructural analysis revealed significant grain refinement, especially at 2.7 J. The surface roughness increased significantly to about 7.2 μm, then dropped to around 3.7 μm when the impact energy increased to 2.7 J. Finally, the roughness decreased to ~6.8 μm. In addition, the samples that were strengthened by MHP demonstrated low friction coefficients (about 0.27) and wear volume (minimum value of 7.67/10⁻⁴ mm³), implying that MHP can effectively improve the wear resistance of A7075. Observation by SEM revealed that the corresponding wear mechanism is mainly attributable to mild oxidative wear and three-body wear. Full article

Bone regeneration is a highly dynamic and complex process that involves hematopoietic stem cells and mesenchymal cells, collagen fibers, non-collagenous proteins and biomolecules from extracellular matrices, and different cytokines and immune cells, as well as growth factors and hormones. Some phytochemicals due to antioxidant and anti-inflammatory effects can modulate the bone signaling pathways and improve bone healing and thus can be a good candidate for osteoregeneration. The aim of this study was to analyze the impact of Juglans regia L. extract compared to ellagic acid on bone neoformation in rats. The animals with a 5 mm calvaria defect were divided into four groups (n = 10): group 1 was treated with ellagic acid 1% (EA), group 2 was treated with Juglans regia L. extract 10% (JR), group 3 was treated with a biphasic mix of hydroxyapatite and tricalcium phosphate (Ceraform), and group 4 was treated with vehicle inert gel with carboxymethylcellulose (CMC). After 3 weeks of treatment, blood samples were collected for oxidative stress and inflammation assessment. Additionally, the receptor activator of nuclear factor kappa-Β ligand (RANKL) and hydroxyproline levels were quantified in blood. The skull samples were analyzed by scanning electron microscopy in order to detect the modifications in the four groups. The results suggested that JR extract had relevant anti-oxidant effect and bone protective activity and generated the accumulation of Ca and P, demonstrating the potential therapeutic abilities in bone regeneration. Full article

This study builds on previous research that investigated the triple hybrid wastewater treatment system combining electrocoagulation (EC), zeolite (Z), and ultrasound (US), and it examines the effects of different ultrasonic powers on compost wastewater treatment by analysing several process parameters. In the first part, two levels of US power intensity, corresponding to 20% and 100% of intensity, with and without zeolite addition, were investigated on three different electrode materials. Although satisfactory chemical oxygen demand (COD) reduction was obtained (81.42%–88.90%), better results were obtained for Al and Zn electrodes at 20% US power intensity, while for Fe better resulted were obtained at 100% US power intensity. Deteriorations of the anodic and cathodic surfaces, which were analysed using optical microscope images at 50× and 200× magnification, are generally less pronounced at higher US power intensities. Energy consumption in the range of 3.86–18.78 kWh/m³ showed an increased sequence—Fe < Zn < Al. In the second part, Taguchi optimisation was used to study the influence of US intensity (0%, 20%, 100%), the electrode materials (Al, Fe, or Zn), contact time (10, 20, and 30 min), and mixing speed (150, 250, 350 rpm) on COD decrease, electrode consumption, settling velocity, and voltage (power) consumption. The result shows that increased US power enhances COD reduction, electrode mass preservation, and voltage while decreasing the settling velocity. Full article

This theoretical study investigates the high molecular weight (Mw) production in copolymerization of ethylene and 1-octene using heteroatom-substituted constrained geometry catalysts (CGCs). The research explores the correlation between chain termination reactions and polymer molecular weight, revealing that the Gibbs free energy barrier of the chain termination reactions is positively linked to the molecular weight. Quantitative structure–property relationship models were constructed, indicating that molecular descriptors such as atom charge, orbital energy, and buried volume significantly influence the polymer molecular weight. Full article

Macroautophagy, commonly referred to as autophagy, is an essential cytoprotective mechanism that plays a significant role in cellular homeostasis. It has emerged as a promising target for drug development aimed at treating various cancers and infectious diseases. However, the scientific community has yet to reach a consensus on the most effective approach to manipulating autophagy, with ongoing debates about whether its inhibition or stimulation is preferable for managing these complex conditions. One critical factor contributing to the variability in treatment responses for both cancers and infectious diseases is estrogen, a hormone known for its diverse biological effects. Given the strong correlations observed between estrogen signaling and autophagy, this review seeks to summarize the intricate molecular mechanisms that underlie the dual cytoprotective effects of estrogen signaling in conjunction with autophagy. We highlight recent findings from studies that involve various ligands, disease contexts, and cell types, including immune cells. Furthermore, we discuss several factors that regulate autophagy in the context of estrogen’s influence. Ultimately, we propose a hypothetical model to elucidate the regulatory effects of the estrogen–autophagy axis on cell fate. Understanding these interactions is crucial for advancing our knowledge of related diseases and facilitating the development of innovative treatment strategies. Full article