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Abstract Backgroundː Stroke, primarily resulting from ischemic conditions, is the foremost cause of mortality and long-term impairment and is frequently associated with narrowing of the carotid arteries. Although carotid endarterectomy (CEA) is the treatment of choice, it carries the risk of cerebral ischemia and reduced blood flow. Transcranial Doppler (TCD) ultrasound offers a nonintrusive method to assess cerebral blood circulation during CEA, potentially enhancing surgical outcomes. The objective of this study was to assess the clinical utility and safety of TCD monitoring during CEA and to identify factors influencing postoperative complications. Methods This retrospective analysis included 158 CEA patients (from January 2021–August 2023) who underwent TCD monitoring and whose data were compared to historical standard care data. The primary outcomes were operation duration and artery occlusion time. Secondary outcomes included carotid shunt usage, seven-day postoperative complications, and six-month carotid artery patency. Logistic regression identified factors linked to adverse reactions, and a predictive model was evaluated with a receiver operating characteristic (ROC) curve. Resultsː Comparative analysis indicated significant reductions in both the duration of surgery (113.26 ± 7.29 min) and artery occlusion time (21.85 ± 2.92 min) for patients monitored with TCD (P

For service robots， security reconnaissance vehicles， etc. their mobile range is large and working space is complex. The drive system is vulnerable to impact， blocking or overload due to external impact， thereby resulting in tooth fractures and large bending of support shafts. The application of micro servo drive system is greatly limited. Aiming at this problem， a clutch structure is proposed to protect miniature reducer in this study. Using the finite element method， basic parameters of the spring and the protection threshold of the clutch structure is designed. Then， the threshold is captured and verified through the clutch performance test rig. Experimental results show that the miniature reducer can realize the clutch function accurately under the overload condition， and the measured clutch protection threshold is in good agreement with the design threshold. The clutch structure can limit the maximum threshold of the gear load， enable the gears of the miniature reducer to work within the design load range and improve the working reliability of the miniature reducer.

Confined-domain crosslink-enhanced emission effect was first studied to reveal the photoluminescence mechanism of carbonized polymer dots (CPDs). A general strategy was exploited to synthesize CPDs exhibiting tunable photoluminescence properties.

The contact path and transmission error are key indexes for evaluating the meshing performance of spiral bevel gears. The contact path is offset by misalignment，and symmetry and fluctuation amplitude of transmission error change. Therefore，based on installation adjustment，an optimization method for the contact path and transmission error of spiral bevel gears is proposed. The equations are established by the constraining assembly conditions and the initial transmission ratio，and then the theoretical installation adjustment is solved. A tooth contact analysis （TCA） algorithm with the misalignment is built by introducing gear pair misalignment. Taking the misalignment as the design variable and presetting the characteristic parameters of contact path and the transmission error，an objective function is built and solved by the nonlinear optimization algorithm. The optimization results show that the contact path is moved to the small end and the loaded contact area is expanded to the middle of the tooth flank，load bearing contact performance is improved. That the droop deviation and fluctuation amplitude of the transmission error curve are decreased，whichis beneficial to avoid edge contact and improve dynamic performance.

A finite element and discrete element （FEM-DEM） coupling model for shot peening on rough surface is proposed in consideration of the surface roughness of non-peened specimen. The peened and non-peened 45# steel specimens are prepared，and their residual stress on the surface and subsurface are measured. The measured results are used to verify the proposed model，and the effects of shot peening process parameters on the residual stress on the subsurface are studied. The results show that increasing the surface coverage and shot peening intensity can increase the peak value of the compressive residual stress，especially the impact of shot peening is more significant. With the same surface coverage and shot peening intensity，the smaller diameter shot can increase the peak value of the compressive residual stress，while the thickness of the compressive residual stress increases as the diameter of shot becomes larger. If the surface roughness before shot peening is too high，the effect of shot peening can be enhanced by increasing the surface coverage. The research provides a certain theoretical basis for the optimization of shot peening on the rough surface.

Binocular endoscopy is gradually becoming the future of minimally invasive surgery (MIS) thanks to the development of stereo vision. However, some problems still exist, such as the low reconstruction accuracy, small surgical field, and low computational efficiency. To solve these problems, we designed a framework for real-time dense reconstruction in binocular endoscopy scenes. First, we obtained the initial disparity map using an SGBM algorithm and proposed the disparity confidence map as a dataset to provide StereoNet training. Then, based on the depth map predicted by StereoNet, the corresponding left image of each depth map was input into the Oriented Fast and Brief-Simultaneous Localization and Mapping (ORB-SLAM) framework using an RGB-D camera to realize the real-time dense reconstruction of the binocular endoscopy scene. The proposed algorithm was verified in the stomach phantom and a real pig stomach. Compared with the ground truth, the proposed algorithm’s RMSE is 1.620 mm, and the number of effective points in the point cloud is 834,650, which is a significant improvement in the mapping ability compared with binocular SLAM and ensures the real-time performance of the algorithm while performing dense reconstruction. The effectiveness of the proposed algorithm is verified.

Advances in whole-slide images (WSI) technology can promote the pathology environment based on digital imaging and make a very compelling case as part of the clinical workflow. Furthermore, the applications of artificial intelligence (AI) for morphometric image analysis are accelerating the transition of pathology into a more quantitative science. However, several challenges, such as storing, sharing, visualizing, and analyzing large-size WSI files and the acquisition of annotations from pathologists for WSIs still exist in working with WSIs in AI researches. We, therefore, developed a web-based platform PAI-WSIT: Pathologists Annotated and AI-empowered WSI Database for Tumors, which provides storing, sharing, and visualizing services for WSIs with annotations. In addition, PAI-WSIT also supports the management of annotations from different pathologists and integrates an AI service for detecting malignant regions in colorectal WSIs. The platform will provide collaborations between the computer scientists and research pathologists that are of utmost importance for the development of relevant algorithms and computer-aided prognosis. PAI-WSIT is freely accessible from http://www.paiwsit.com.

There are shortcomings of binocular endoscope three-dimensional (3D) reconstruction in the conventional algorithm, such as low accuracy, small field of view, and loss of scale information. To address these problems, aiming at the specific scenes of stomach organs, a method of 3D endoscopic image stitching based on feature points is proposed. The left and right images are acquired by moving the endoscope and converting them into point clouds by binocular matching. They are then preprocessed to compensate for the errors caused by the scene characteristics such as uneven illumination and weak texture. The camera pose changes are estimated by detecting and matching the feature points of adjacent left images. Finally, based on the calculated transformation matrix, point cloud registration is carried out by the iterative closest point (ICP) algorithm, and the 3D dense reconstruction of the whole gastric organ is realized. The results show that the root mean square error is 2.07 mm, and the endoscopic field of view is expanded by 2.20 times, increasing the observation range. Compared with the conventional methods, it does not only preserve the organ scale information but also makes the scene much denser, which is convenient for doctors to measure the target areas, such as lesions, in 3D. These improvements will help improve the accuracy and efficiency of diagnosis.

Throwing light upon the structure-property relationship of the excited state properties for next-generation fluorescent materials is crucial for the organic light emitting diode (OLED) field. Herein, we designed and synthesized three donor-acceptor (D-A) structure compounds based on a strong spin orbit coupling (SOC) acceptor benzo[a, c]phenazine (DPPZ) to research on the three typical types of excited states, namely, the locally-excited (LE) dominated excited state (CZP-DPPZ), the hybridized local and charge-transfer (HLCT) state (TPA-DPPZ), and the charge-transfer (CT) dominated state with TADF characteristics (PXZ-DPPZ). A theoretical combined experimental research was adopted for the excited state properties and their regulation methods of the three compounds. Benefiting from the HLCT character, TPA-DPPZ achieves the best non-doped device performance with maximum brightness of 61,951 cd m−2 and maximum external quantum efficiency of 3.42%, with both high photoluminescence quantum efficiency of 40.2% and high exciton utilization of 42.8%. Additionally, for the doped OLED, PXZ-DPPZ can achieve a max EQE of 9.35%, due to a suppressed triplet quenching and an enhanced SOC.

A new series of tetrahedral heteroleptic copper(I) complexes exhibiting efficient thermally-activated delayed fluorescence (TADF) in green to orange electromagnetic spectral regions has been developed by using D-A type N^N ligand and P^P ligands. Their structures, electrochemical, photophysical, and electroluminescence properties have been characterized. The complexes exhibit high photoluminescence quantum yields (PLQYs) of up to 0.71 at room temperature in doped film and the lifetimes are in a wide range of 4.3–24.1 μs. Density functional theory (DFT) calculations on the complexes reveal the lowest-lying intraligand charge-transfer excited states that are localized on the N^N ligands. Solution-processed organic light emitting diodes (OLEDs) based on one of the new emitters show a maximum external quantum efficiency (EQE) of 7.96%.

In this study, we successfully synthesize palladium-decorated indium trioxide (Pd/In2O3) hybrid nanoclusters (NCs) using an advanced dual-target cluster beam deposition (CBD) method, a significant stride in developing high-performance ethanol sensors. The prepared Pd/In2O3 hybrid NCs exhibit exceptional sensitivity, stability, and selectivity to low concentrations of ethanol vapor, with a maximum response value of 101.2 at an optimal operating temperature of 260 1C for 6 at% Pd loading. The dynamic response of the Pd/In2O3-based sensor shows an increase in response with increasing ethanol vapor concentrations within the range of 50 to 1000 ppm. The limit of detection is as low as 24 ppb. The sensor exhibits a high sensitivity of 28.24 ppm-1/2, with response and recovery times of 2.7 and 4.4 seconds, respectively, for 100 ppm ethanol vapor. Additionally, the sensor demonstrates excellent repeatability and stability, with only a minor decrease in response observed over 30 days and notable selectivity for ethanol compared to other common volatile organic compounds. The study highlights the potential of Pd/In2O3 NCs as promising materials for ethanol gas sensors, leveraging the unique capabilities of CBD for controlled synthesis and the catalytic properties of Pd for enhanced gas-sensing performance. [ABSTRACT FROM AUTHOR]

In this work, a wear prediction model considering the dynamic load is proposed for spur gears in mixed elastohydrodynamic lubrication (EHL). The dynamic load is calculated by gear dynamic model. Combining gear wear model and dynamic model, the wear depth under the dynamic load is determined and compared with that under quasi-static load. The comparative results show that the maximum wear depth under dynamic load is significantly larger than that under quasi-static load near engaging-in point. The effects of fractional film defect coefficient on wear depth are considerable under dynamic load, which is closely related to gear contact temperature. Furthermore, the effects of surface roughness and gear geometrical parameters on wear depth are studied. The investigation reveals that the wear depth decreases with the increased tooth width, module and pressure angle, but increases with the surface roughness. It illustrates that gear wear depth under the dynamic load can be reduced by optimizing gear geometrical parameters. [ABSTRACT FROM AUTHOR]

A tri-armed arylsulfone-based acceptor (SF) linked by triphenylbenzene (TPB) has been developed to construct solution-processable thermally activated delayed fluorescence (TADF) materials with large band gaps. The acceptor suffered limited conjugation due to the tetrahedral geometry of sulfonyl groups, as well as a meta-linkage at the central TPB moiety. By simple conjugation of the SF with appropriate donor units, luminophores SF-DMAC and SF-PXZ capable of producing efficient blue/green emissions were obtained, with peak efficiencies of 11.3% (19.0 cd A-1 and 10.0 lm W-1) and 12.4% (35.6 cd A-1 and 17.8 lm W-1) in the corresponding wet-processed OLEDs. Decent resistance to roll-off at high brightness was noticed in the device based on SF-PXZ, ascribing to reduced intermolecular interactions due to its star-shaped architecture and an efficient reverse intersystem crossing (RISC) process. [ABSTRACT FROM AUTHOR]

This paper provides a method coupling the 2D microtopography filtered by ISO Gaussian filter of spur gears, which is typically used in power transmission devices, and Transmission error (TE) together. A gearbox with certain transmission ratio is selected as a research object for analysis. This gearbox comprises a mathematical model of TE calculation based on the Monte Carlo method and the coordinate transformation method, which couples the 2D microtopography of spur gears and TE. Two TE models are established to study their effects on the coupling results: a) The single TE model, which means only one gear owns TE, and b) the synthetic TE model, which means both gears possess TE. The new model of the 2D microtopography of tooth surfaces can be utilized further to investigate the mechanism of engagement and the approximate contact position of asperities on the tooth surface. The new model is also significant in studying the tooth root bending stress. [ABSTRACT FROM AUTHOR]

The organic–inorganic hybrid catalyst L-Mn-PMoV was prepared simply by combining a schiff base Mn complex (L-Mn, L: N, N′-disalicylidene-1, 6-hexanediamine) with the Keggin-structured molybdovanadophosphoric heteropolyacid (PMoV). The proposed composition and structure of the catalyst were evidenced by TG, elemental analysis, FT-IR, and UV–Vis characterizations. Its catalytic performance was evaluated in the direct hydroxylation of benzene to phenol by molecular oxygen with ascorbic acid as the reducing agent. Various reaction parameters were changed to attain the optimal conditions. The hybrid catalyst has a formula [{Mn(C20H22N2O2)(Cl)}2(H4PMo11VO40)], with the two terminal oxygen atoms in the PMoV Keggin structure coordinately linked to the two Mn(III) ions in two L-Mn units, respectively. It exhibits a remarkably enhanced yield to phenol compared to the pure PMoV due to the synergy effect between the Schiff-base manganese complex and PMoV. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Cyclodextrins (CyDs) complexes with vanadium-substituted heteropoly acids (PMoV n -β-CyDs, n = 1, 2) were prepared by simple mixing and their structures were characterized by FT-IR. Among various catalysts, PMoV1-β-CyDs, an efficient phase transfer catalyst, exhibited the highest yield (13.1%) of phenol without observing the formation of catechol, hydroquinone and benzoquinone in direct hydroxylation of benzene to phenol in 80 vol% aqueous acetic acid with molecular oxygen and ascorbic acid used as the oxidant and the reducing reagent, respectively. The influences of the reaction temperature, the pressure of oxygen, the amount of ascorbic acid, the amount of catalyst, and the reaction time on the yield of phenol were investigated to obtain the optimal reaction conditions for phenol formation. [ABSTRACT FROM AUTHOR]

Pyridine(Py)-modified Keggin-type mono-vanadium-substituted heteropoly acids (Py n PMo11V, n = 1–4) were prepared by a precipitation method as organic/inorganic hybrid catalysts for direct hydroxylation of benzene to phenol in a pressured batch reactor and their structures were characterized by FT-IR. Among various catalysts, Py4PMo11V exhibited the highest catalytic activity (yield of phenol 9.0%) with the high selectivity for phenol, without observing the formation of catechol, hydroquinone and benzoquinone in the reaction with 80 vol% aqueous acetic acid, molecular oxygen and ascorbic acid used as the solvent, oxidant and reducing reagent, respectively. The influences of the reaction temperature, the pressure of oxygen, the amount of ascorbic acid, the amount of catalyst, and the reaction time on the yield of phenol were investigated to obtain the optimal reaction conditions for phenol formation. Pyridine can greatly promote the catalytic activity of the Py-free catalyst (H4PMo11VO40), mostly because the organic π electrons in the hydrid catalyst may extend their conjugation to the inorganic framework of heteropoly acid and thus dramatically modify the redox properties. [ABSTRACT FROM AUTHOR]