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The change of the blade tip clearance size has an important impact on the performance of the compressor. Considering that the performance curve of the compressor is often limited by surge and stall boundaries, this paper used the numerical simulation method to investigate the influence mechanism of the blade tip clearance size change on the stall margin of transonic axial flow compressor rotor. By mathematically decomposing the calculation formula of the stall margin of rotor, the approximate calculation formula of the change of rotor's stall margin was obtained. Then, the detailed quantitative analysis of the factors that affect the rotor's stall margin was carried out, the influence weights of various factors on the rotor's stall margin was also obtained. Finally, the physical mechanism of the change of the rotor's performance parameters was obtained by the analysis of rotor tip flow field after the blade tip clearance size change. [ABSTRACT FROM AUTHOR]

A Neural network (NN) is a promising tool for the tomographic inversion of the ionosphere. However, existing research has adopted an unbalanced cost function for training purposes and a preset image for constraint purposes, resulting in the output image being dominated by measurements. To address these problems, we proposed an NN-based tomographic model with a balance cost function and a dynamic correction process (BCDC) for ionosphere inversion. The cost function is composed of two balance terms corresponding to the measurements and the selected constraints, respectively. The produced image in the forward process of the NN is corrected dynamically by fitting each vertical profile with orthogonal basis functions (EOFs) and the Chapman function and then by smoothing the voxels of each layer with a moving window approach horizontally. The corrected image is then used to calculate the slant total electron content (STEC) parameter, which is further translated into the term of the cost for the vertical and horizontal constraints. Experiments were carried out to validate the BCDC method and compared with a recently developed tomographic method and the international reference ionosphere (IRI) model. Results show that the parameters derived from the BCDC model demonstrate good consistency with the observations. Comparing with the reference methods, the BCDC method performs better in the validations of vertical profiles, F2 layer peak density (NmF2), STEC parameter and vertical total electron content map. Further analysis also shows that a balance cost function is of benefit to achieve an image of better quality. [ABSTRACT FROM AUTHOR]

Summary: In this article, the state of charge (SoC) balancing problem of large‐scale electric vehicles (EVs) connected to the utility grid is addressed by designing a novel no circulating current cooperative adaptive SoC balancing control. First, considering different capacities and initial SoCs, an adaptive power distribution algorithm based on distributed dynamic consistency algorithm is blue developed to achieve the SoC balancing of large‐scale EVs connected to the utility grid. Then, considering the shortage of battery life caused by the circulating current during the long‐term charging and discharging process, an adaptive balance rate factor is designed to effectively avoid the generation of the circulating current. Then, an adaptive cooperative fuzzy terminal sliding mode controller is proposed for grid‐connected EVs to improve power tracking accuracy and enhance robustness. Considering the parameters' uncertainties and unmodeled parts of grid‐connected EVs, parameter adaptive estimation and fuzzy algorithm are used to approximate the unmodeled part. In addition, the boundedness of the adaptive estimation is guaranteed by using the projection operator. Finally, the validity and reliability of the designed control strategy are verified by simulations. [ABSTRACT FROM AUTHOR]

The micro-nanoscopic morphology of the contact surfaces directly affects the tribological behavior between the contact surfaces. In this paper, a single crystal copper substrate with nano rough surfaces is characterized based on the fractal theory, and the nano rough contact model which could exist stably at room temperature (298 K) is established. The contact behavior between rigid plane and elasto-plastic rough substrate is analyzed. It is found that only a few higher asperities enter the contact area at the initial contact stage, causing large fluctuations in contact force. However, due to the small interaction between the asperities, the contact area is approximately linear with the contact force. If the ratio of real contact area to nominal contact area is greater than 17%, the contact force and contact area both increase with the increase of indentation depth, but the contact area-contact force curve deviates from the linear relationship gradually due to the intensification of material deformation and the interaction between asperities. [ABSTRACT FROM AUTHOR]

Higher heating value, also known as the coal calorific value, is an important indicator of coal quality. Nevertheless, traditional experimental determination of higher heating value is expensive, tedious, and time-consuming. Some regression models have been commonly used to solve this problem. However, the prediction accuracy still needs to be improved. Accordingly, based on the correlation between proximate analysis of coal and higher heating value, a gradient boosting regression tree model was established in this study to predict the higher heating value as a means to a less intensive procedure to estimate coal heating values. This approach used data from the U.S. Geological Survey Coal Quality database and Kentucky Coal Database to evaluate coal quality. The hyperparameters of the regression tree model were tuned by cross-validation. A comparative study was conducted between the model established in this paper and the existing methods. Experimental results indicate that the coefficient of determination of the gradient boosting regression tree model of two databases achieves 0.9862 and 0.9541 , respectively. Thus, the prediction capability of the gradient boosting regression tree model outperforms the existing methods. [ABSTRACT FROM AUTHOR]

• The impact of the preceding layer stacking on rear filament winding is considered. • An improved cubic spline function approach and a novel parabola method were proposed. • The strength analysis of gas cylinders based on the parabola method was carried out. • The parabola method adapts well to cylinders with varied sizes and ply schemes. Due to the characteristics of changing angle and thickness, predicting the outer contour of the vessel dome has been a challenging task in composite pressure vessel design. The impact of preceding layer fiber stacking on subsequent filament winding has never been considered in existing methods of dome thickness calculation. So we developed an improved cubic spline function approach and a novel parabola method that takes preceding layer fiber stacking into account. The example findings show that the improved cubic spline function approach has a weakness in that the selection of several critical parameters is not clearly described and heavily reliant on actual engineering knowledge. The parabola approach described in our study is not only simple in design, but also adapts well to dome contour of gas cylinders with varied sizes and ply schemes. Moreover, the strength analysis of composite gas cylinders was carried out by finite element method. The results show high consistency with hydraulic burst test results, which clearly demonstrates that the parabola method we proposed can effectively realize the precise modeling of composite pressure vessels and will be very beneficial in the design of composite pressure vessels. [ABSTRACT FROM AUTHOR]

The frequently encountered wastewater contaminations, including soluble aromatic compound and dye pollutants, pathogenic bacteria, and insoluble oils, have resulted in significant environmental and human health issues. It poses a challenge to utilize identical materials for the treatment of complex wastewater. Herein, in this research, multifunctional Ag NPs/guar gum hybrid hydrogels were fabricated using a facile in situ reduction and self-crosslinking method for efficient remediation of complex wastewater. The Ag NPs/guar gum hybrid hydrogel showed remarkable remodeling, adhesive, and self-healing characteristics, which was favorable for its versatile applications. The combination of Ag NPs with the guar gum skeleton endowed the hybrid hydrogel with exceptional catalytic activity for reducing aromatic compounds and dye pollutants, as well as remarkable antibacterial efficacy against pathogenic bacteria. In addition, the Ag NPs/guar gum hybrid hydrogel could be employed to coat a variety of substrates, including cotton fabrics and stainless steel meshes. The hydrogel coated cotton fabrics and meshes presented superhydrophilicity/underwater superoleophobicity, excellent antifouling capacity, and outstanding recyclability, which could be successfully applied for efficient separation of oil-water mixtures. The findings of this work provide a feasible and cost-effective approach for the remediation of intricate wastewater. [ABSTRACT FROM AUTHOR]

• Lps-induced neuroinflammation can lead to cognitive impairment. • Activation of hippocampal microglia by neuroinflammation may lead to reduced inhibitory output of PV interneurons to PY neurons. • Our findings provide a new therapeutic direction for the treatment of neuroinflammation-induced cognitive impairment. The vulnerability of hippocampal pyramidal (PY) neurons played a key role in the onset of cognitive impairment. Multiple researches revealed that neuroinflammation together with microglia activation and parvalbumin (PV) interneurons participated in the pathogenesis of cognitive dysfunction. However, the underlying mechanism was still unclear. This study aimed to determine whether microglia activation would induce PV interneurons impairment and PY neurons disinhibition, and as a result, promote cognitive dysfunction after lipopolysaccharide (LPS) challenge. Male C57BL/6J mice were injected with LPS to establish systemic inflammation model, and animal behavioral tests were performed. For chemogenetics, the virus was injected bilaterally into the CA1 region. Clozapine N-Oxide (CNO) was used to activate the PV interneurons. Whole-cell patch clamp recording was applied to detect spontaneous inhibitory post synaptic current (sIPSC) and spontaneous excitatory post synaptic current (sEPSC) of PY neurons in the CA1 region. LPS induced hippocampal dependent memory impairment, which was accompanied with microglia activation. Meanwhile, PV protein level in hippocampus were decreased, and IPSCs of PY neurons in the CA1 were also suppressed. Minocycline reversed all the above changes. In addition, rescuing PV function with CNO improved memory impairment, sIPSCs of PY neurons and perisomatic PV boutons around PY neurons without affecting microglia activation. Disinhibition of hippocampal parvalbumin interneurons on pyramidal neurons participates in LPS-induced cognitive dysfunction. [ABSTRACT FROM AUTHOR]

Experimental and numerical studies are carried out to investigate the failure behavior of grid stiffeners under tension and flexural loadings. The grid stiffeners with three different typical layup schemes at the intersection were manufactured and tested. A 3D anisotropic damage model based on continuum damage mechanics is developed to modeling the progressive failure behaviors of the grid stiffeners. Besides, the digital image correlation (DIC) technique was adopted to capture the complex deformation and failure process. Results show that introducing discontinuous plies at the intersection could change the failure mechanism and hence improve the mechanical performance of the grid structure. The tensile and flexural strength are improved by 21% and 23% respectively by properly introducing 25% of discontinuous plies at the intersection. This work provides insights on the failure mechanisms of the composite grid stiffeners, and results can be further used towards the optimization design of the grid structure. • Progressive failure behaviors were captured by 3D anisotropic damage model. • Introducing discontinuous ply at intersection improve the mechanical performance. • Digital image correlation technique was adopted to explore flexural failure modes. [ABSTRACT FROM AUTHOR]

• Exploring the pathogenesis of postoperative cognitive dysfunction is essential to improve the prognosis of patients. • The establishment of POCD model in aged mice and related behavioral experiments are more relevant to clinical treatment and have more clinical significance. • The combination of neuroinflammation caused by microglia and complement pathway plays an important role in the destruction of neural network leading to cognitive dysfunction. • The E/I imbalance mediated by the loss of inhibitory synapses is a new mechanism and discovery that leads to cognitive dysfunction. • This finding provides an idea for future research on whether neurons with inhibitory function can be regulated to improve cognitive function. Elderly patients after surgery are prone to cognitive decline known as postoperative cognitive dysfunction (POCD). Several studies have shown that the microglial activation and the increase of complement protein expression in hippocampus induced by surgery may be related to the pathogenesis of POCD. The purpose of this study was to determine whether microglia and complement system were involved in cognitive dysfunction in aged mice. The POCD model was established by exploratory laparotomy in 15-month-old male C57BL/6J mice and animal behavioral tests were performed to test hippocampal-dependent memory capacity. Minocycline was used to suppress the activation of microglia, and complement 3 receptor inhibitor was used to suppress the association between microglia and complement 3. Western blot and immunofluorescence were used to detect the microglial activation, complement protein, and synaptic protein expressions. Operation induced hippocampal-dependent memory impairment (P < 0.01), which was accompanied by microglial activation (P < 0.01). There was also a significant reduction in inhibitory synaptic protein expression in the hippocampus of mice in the surgery group (P < 0.01). However, minocycline, a microglia inhibitor, rescued all the above changes. In addition, C3RI intervention inhibited the phagocytosis of inhibitory synapses by microglia (P < 0.05) and improved the cognitive function of mice (P < 0.01). Microglia participate in postoperative cognitive dysfunction by mediating inhibitory synaptic loss through the complement pathway. [ABSTRACT FROM AUTHOR]

Optical computing, renowned for its light-speed processing and low power consumption, typically relies on the coherent control of two light sources. However, there are challenges in stabilizing and maintaining high optical spatiotemporal coherence, especially for large-scale computing systems. The coherence requires rigorous feedback circuits and numerous phase shifters, introducing system instability and complexity. Here we propose an innovative logic gate using a single light source, with frequency and polarization serving as two virtual inputs. Our design leverages frequency-polarization multiplexed metasurfaces to achieve all basic logic operations by selectively routing surface plasmon polaritons. This single-channel logic gate maintains inherent coherence between frequency and polarization, thereby considerably eliminating stringent light-source specifications and numerous rigid phase controls and resulting in higher stability. Our device showcases unique application potentials in on-chip readout of encryption information by using random sequences as a one-time pad, unlocking fresh prospects for information protection and optical computing with other simple light sources.

Monitoring perioperative tissue perfusion is crucial in clinical anesthesia to protect organs and ensure patient safety. Indicators like hemodynamic parameters, tissue metabolism, and microcirculation markers are used for assessment. Studies show intraoperative hypotension negatively impacts outcomes, though blood pressure alone may not reflect tissue perfusion accurately. Cardiac output is a more direct measure, with adequate levels generally indicating good perfusion. However, some conditions cause adequate cardiac output but inadequate perfusion. Non-quantitative markers like skin color and temperature, and quantitative indicators like tissue oxygen saturation and laser Doppler flowmetry, help assess microcirculation but can't fully evaluate systemic perfusion. Near-Infrared Spectroscopy (NIRS) monitors tissue oxygen metabolism, reflecting oxygen supply and consumption balance. Central venous oxygen saturation offers a better systemic overview but may not always indicate good perfusion, especially in sepsis. Lactic acid levels closely correlate with tissue perfusion and outcomes, with dynamic changes being more indicative than single measurements. Effective monitoring requires evaluating both macro- and microcirculation states and systemic metabolic levels to ensure optimal outcomes. Combining these measures provides a more accurate assessment of tissue perfusion and patient prognosis., Competing Interests: Declarations. Competing interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2025. The Author(s).)

The hygrothermal aging model, based on Fick's second law of diffusion, characterizes the degradation of engineering constants in T700 carbon fiber/epoxy resin composites. It focuses on changes in the tensile modulus, shear modulus, and transverse Poisson's ratio due to moisture absorption and temperature variations. The model validates through mass change observations before and after seawater immersion, along with surface morphology assessments and tensile experiments. The results reveal that the saturated moisture absorption rate for single-layer laminates in seawater immersion is 0.35%. Short-term seawater immersion at room temperature (≤60 days) does not induce cracks or defects (≥10 μm) on the composite's surface. The composite's modulus decreases as moisture absorption increases, with the longitudinal tensile modulus dropping by an order of 10 -5 %, while the other engineering constants decrease by an order of 10 -3 %. The modulus also decreases with rising temperature; the closer the temperature is to the matrix's glass transition, the faster the modulus declines, with the longitudinal tensile modulus decreasing by 0.84%, and the other engineering constants decreasing by 100%. This research provides valuable insights for the engineering applications of composite materials in marine environments.

Purpose: This study aimed to investigate the relationship between intraoperative sleep spindle activity and postoperative sleep disturbance (PSD) in elderly orthopedic surgery patients., Patients and Methods: In this prospective observational cohort study, we collected intraoperative electroencephalography (EEG) data from 212 elderly patients undergoing orthopedic surgery from May 2023 to December 2023. We used the Athens Insomnia Scale to assess sleep quality on postoperative day (POD) 1 and POD 3 and analyzed the correlation between intraoperative sleep spindle activity and PSD through logistic regression., Results: The incidence of PSD was 65.6% on POD 1 and 41.9% on POD 3. On the first day, there were no significant differences in intraoperative sleep spindle characteristics between PSD and non-postoperative sleep disturbance (non-PSD) patients. However, by the third day, PSD patients showed lower sigma power compared to non-PSD patients, as well as lower spindle density in the bilateral frontopolar (Fp1/Fp2) and bilateral temporal (F7/F8) channels, with shorter average spindle duration ( P < 0.05). Multivariate logistic regression analysis suggested that the average spindle density in F7/F8 channels (OR 0.543, 95% CI 0.375-0.786; P = 0.001) was an independent risk factor for PSD on POD 3. Furthermore, Mini-Mental State Examination (MMSE) could independently predict PSD on POD 1 (OR 0.806, 95% CI 0.656-0.991; P = 0.041) and POD 3 (OR 0.701, 95% CI 0.562-0.875; P = 0.002). Pain on movement and at rest were independently associated with PSD on POD 1 (OR 1.480, 95% CI 1.200-1.824; P < 0.001) and POD 3 (OR 1.848, 95% CI 1.166-2.927; P = 0.009), respectively., Conclusion: Intraoperative mean spindle density in the F7/F8 channels was an independent risk factor for PSD on POD 3 in elderly patients undergoing orthopedic surgery. MMSE and postoperative pain also independently increased the risk of PSD., Competing Interests: The authors declare that they have no conflicts of interest., (© 2024 Dai et al.)

Background: Postoperative respiratory adverse events are the most common perioperative complications in pediatric anesthesia, particularly prevalent in children undergoing tonsillectomy and adenoidectomy, with an incidence rate as high as 50%. The choice of anesthetic induction regimen directly influences the incidence of respiratory adverse events during the induction period. However, this effect seems to have minimal impact on postoperative outcomes. The occurrence rate of postoperative respiratory adverse events is likely more closely associated with the anesthetic maintenance phase, yet this relationship remains uncertain at present., Methods: The objective of this study was to assess the impact of different anesthetic maintenance regimens on postoperative respiratory adverse events in pediatric patients undergoing tonsillectomy and adenoidectomy. The AmPRAEC study is a multicenter, randomized, double-blind controlled trial. A total of 717 pediatric patients were recruited from 12 medical centers and randomly assigned to three groups: group A (intravenous maintenance group, receiving propofol infusion); group B (intravenous-inhalational combination group, maintained with 1% sevoflurane combined with propofol); and group C (inhalational maintenance group, maintained with 2-3% sevoflurane inhalation). The primary outcome measure was the incidence rate of postoperative respiratory adverse events., Discussion: This clinical trial aims to elucidate the impact of various anesthetic maintenance regimens on postoperative respiratory adverse events in pediatric patients. The outcomes of this study are anticipated to facilitate anesthesiologists in devising more comprehensive perioperative management strategies, enhancing comfort, and improving the clinical outcomes for this patient population., Trial Registration: Chinese Clinical Trial Registry ( http://www.chictr.org.cn ) ChiCTR2300074803. Registered on August 16, 2023., (© 2024. The Author(s).)

Aim: Postoperative delirium (POD) is a common complication with significant adverse effects in elderly patients. Electroencephalography (EEG) provides a promising approach for predicting the risk of POD. This study aims to elucidate the correlation between intraoperative EEG spectrum and the incidence of POD in elderly patients undergoing orthopedic surgery., Methods: A single-center prospective observational cohort study was conducted at Zhongda Hospital, Southeast University, from September 2022 to March 2023, registered on Chinese Clinical Trail Registry (ChiCTR2300069548). Among the 172 patients who underwent orthopedic surgery, 125 completed the study with available data. Preoperative baseline cognitive function was assessed using the mini-mental state examination (MMSE). An intraoperative 4-channel EEG was recorded. Total power spectra and power spectral density for beta, alpha, theta, and delta bands were calculated. Spectral edge frequency, burst suppression ratio, and patient state index were directly extracted from the EEG monitor. The primary outcome was POD, assessed using a 3-minute Diagnostic Interview for Confusion Assessment Method (CAM)-Defined Delirium scale or the CAM for the Intensive Care Unit. Patients were divided into POD and non-postoperative delirium (non-POD) groups. Logistic regression analysis was conducted to evaluate the independent predictive effect of intraoperative spectral distribution and other quantitative EEG data for POD., Results: The incidence of delirium within 72 hours after surgery was 8.8%. Compared to the non-POD group, the POD group showed significantly lower absolute power in the beta [0.06 (0.03, 0.09) dB vs 0.14 (0.08, 0.26) dB, p < 0.001], alpha [0.41 (0.25, 0.71) dB vs 1.24 (0.55, 2.57) dB, p = 0.008], and theta [0.77 (0.44, 1.01) dB vs 1.19 (0.72, 2.02) dB, p = 0.035] bands. Logistic regression analysis identified several independent risk factors for POD, including lower intraoperative alpha power [odds ratio (OR) 10.210, 95% confidence interval (CI) 1.233-84.568, p = 0.031], advanced age (OR 7.713, 95% CI 1.022-58.204, p = 0.048), preoperative anemia (OR 6.636, 95% CI 1.091-40.358, p = 0.040), and preoperative depression (OR 10.089, 95% CI 1.029-98.909, p = 0.047). In contrast, higher preoperative MMSE scores appeared to be a protective factor for POD (OR 0.130, 95% CI 0.021-0.820, p = 0.030)., Conclusions: Intraoperative EEG frontal low alpha power demonstrated a significant independent association with POD in elderly patients after orthopedic surgery. This parameter may serve as an intraoperative neurophysiological marker of cerebral vulnerability to POD. Additionally, advanced age, lower preoperative MMSE scores, preoperative anemia, and preoperative depression were independent risk factors for POD., Clinical Trial Registration: Chinese Clinical Trial Registry (ChiCTR2300069548).

Phonon-assisted photon upconversion (UPC) is an anti-Stokes process in which incident photons achieve higher energy emission by absorbing phonons. This letter studies phonon-assisted UPC in twisted 2D semiconductors, in which an inverted contrast between UPC and conventional photoluminescence (PL) of WSe 2 twisted bilayer is emergent. A 4-fold UPC enhancement is achieved in 5.5° twisted bilayer while PL weakens by half. Reduced interlayer exciton conversion efficiency driven by lattice relaxation, along with enhanced pump efficiency resulting from spectral redshift, lead to the rotation-angle-dependent UPC enhancement. The counterintuitive phenomenon provides a novel insight into a unique way that twisted angle affects UPC and light-matter interactions in 2D semiconductors. Furthermore, the UPC enhancement platform with various superimposable means offers an effective method for lighting bilayers and expanding the application prospect of 2D stacked van der Waals devices., (© 2023. The Author(s).)