Search Results (1,607)

Mycobacterial spindle cell pseudotumors (MSCPs) are rare lesions characterized by the proliferation of spindle-shaped histiocytes caused by mycobacterial infections. MSCPs have been reported in the lung, lymphatic system, and skin of immunodeficient patients. We present the case of a spindle cell pseudotumor of the pancreas in a 30-year-old male with advanced human immunodeficiency virus (HIV) infection, which led to biliary stricture, splenomegaly, chronic pancreatitis, portal hypertension, compression of the hepatic artery and portal vein, and ascites. This was the patient’s third mycobacterial infection diagnosis. The MSCP was diagnosed via endoscopic biopsy after two prior non-diagnostic biopsies of the pancreatic lesion. Following 18 months of tailored antimycobacterial therapy, the pancreatic mass resolved radiographically with normalization of liver tests and sustained clinical improvement, and there has been no relapse more than 8 months after treatment completion. This case highlights the presentation of an MSCP in a unique anatomic location not previously documented and the challenges encountered with diagnosis and management. Full article

Objectives: Oocyte quality is crucial for female fertility, but the underlying molecular mechanisms remain unclear. This study investigates the non-canonical role of the telomerase RNA protein (TERP), whose function in oogenesis is unknown, in safeguarding female gamete quality. Methods: We used gain-of-function (AT) and loss-of-function (D7) mutant mouse lines to assess oocyte quality via morphological and molecular analyses. Key methods included immunofluorescence of meiotic spindles, Western blotting for the autophagy marker LC3B, and qRT-PCR to quantify the perinatal ovarian reserve. Results: Both AT and D7 mutations caused severe meiotic spindle abnormalities, including aberrant morphology and increased size. The D7 mutation, in particular, led to impaired cytoplasmic maturation and reduced autophagy levels in oocytes. Furthermore, loss of TERP function resulted in an abnormally large ovarian reserve in newborn females, which correlated with decreased expression of autophagy and lysosomal markers in the newborn ovary. Conclusions: This study establishes a novel, non-canonical function for TERP as a crucial regulator of oocyte quality. TERP dysregulation compromises meiotic integrity and oocyte maturation by disrupting lysosome-dependent autophagy. Full article

Dermatofibroma is a common mesenchymal skin lesion that typically presents as a firm, slow-growing nodule. Generally, such lesions are asymptomatic; however, they can also cause discomfort in some cases. Ulceration is an uncommon feature of dermatofibroma, and diagnosis in such cases is often difficult. We report a case of a 67-year-old female with multiple comorbidities, including pancreatic cancer undergoing neoadjuvant chemotherapy, who was admitted for acute pulmonary embolism. The patient presented with an incidental medial thigh lesion. The lesion was asymptomatic, ulcerated, and oozing pus one month before presentation. Clinical examination revealed a 3 × 2 cm deep ulcer with a punched-out edge, a dry yellow-white base, and a firm violaceous border. Histopathology confirmed dermatofibroma with epidermal hyperplasia, dermal spindle cell proliferation, histiocytes, and collagen trapping. Immunohistochemistry was positive for CD68, CD10, and Factor XIII. Due to the deteriorating condition of the patient, no intervention was provided to her, and she succumbed to her primary illness. This case is unique due to its atypical ulcerative presentation in a patient with complex systemic illness and emphasizes distinguishing between benign lesions and malignant mimics, especially in cases which have ambiguous clinical presentation. Full article

Meandering river point bar sand bodies, serving as critical reservoir units, exhibit significant lithofacies heterogeneity that governs remaining oil distribution patterns. Taking the Guantao Formation in the Gudao Oilfield as an example, this study integrates core observation, pore-throat structure characterization, and numerical simulation to reveal lithofacies characteristics of point bar sand bodies and their controlling mechanisms on incremental oil recovery distribution during surfactant–polymer (SP) flooding. The results demonstrate that point bar lithofacies display planar grain-size fining from concave to convex banks, with vertical upward-fining sequences (point bar medium sandstone facies → fine sandstone facies → siltstone facies). Physical property variations among lithofacies lead to remaining oil enrichment in relatively low-permeability portions of fine sandstone facies and low-permeability siltstone facies after waterflooding. SP flooding significantly enhances remaining oil mobilization through a “lithofacies-controlled percolation—chemical synergy” coupling mechanisms. The petrophysical heterogeneity formed by vertical lithofacies assemblages in the reservoir directly governs the targeted zones of chemical agent action (with interfacial tension reduction preferentially occurring in high-permeability lithofacies, while viscosity control dominates sweep enhancement in low-permeability lithofacies). This results in a distinct spatial differentiation of the incremental oil recovery, characterized by a spindle-shaped sweep improvement zone and a dam-type displacement efficiency enhancement zone. Full article

This article addresses the monitoring and diagnosis of high-speed spindles (HSM) used in CNC grinding machines, emphasizing the importance of the real-time evaluation of their dynamic behavior during commissioning. Due to the complexity of these dynamic phenomena, especially at high speeds (up to 150,000 RPM), common faults such as bearing wear, imbalance, or misalignment can lead to catastrophic failures and high repair costs. An original method is proposed, based on synchronous envelope vibration analysis (SEVA) using the Hilbert transform, to detect mechanical defects in both low-frequency domains (imbalance, mechanical looseness) and high-frequency domains (bearing faults). The system includes vibration, temperature, and speed sensors, and the experimental protocol involves step-by-step monitoring from 10,000 to 90,000 RPM. Through synchronous FFT analysis and IFFT, critical frequencies and their impacts on machining quality are identified. The method enables the accurate fault diagnosis of new or refurbished spindles under real industrial conditions, reducing downtime and production losses. The method involves both local and remote real-time monitoring and diagnosis using a remote data center protocol. Full article

Cylindrical gears are used extensively due to their significant advantages including high efficiency, high load-bearing capacity, and long lifespan. However, the machining accuracy of cylindrical gears is significantly affected by motion errors and force-induced errors of machine tools. In this study, a motion error model of the machine tools was established based on multi-body system theory and homogeneous coordinate transformation method, quantifying the contributions and variation patterns of 12 key errors in the A and B-axes to workpiece geometric errors. Then, by using the stiffness analytical model and the spatial meshing theory, the influence of the force-induced elastic deformation of the shaft of rolling wheel and the springback of the workpiece tooth flank on the geometric error was revealed. Finally, taking the through rolling of a spur cylindrical gear with a module of 1.75 mm, a pressure angle of 20°, and 46 teeth as an example, the force-induced elastic deformation model of the shaft was verified by the rolling tests. Results show that for 40CrNiMo steel, the total profile deviation, total helix deviation, and single pitch deviation in the X-direction caused by rolling forces are 32.48 μm, 32.13 μm, and 32.13 μm, respectively, with a maximum contact rebound is δ_c = 28.27 μm. The relative error between theoretical and measured X-direction spindle deformation is 8.26%. This study provides theoretical foundation and experimental support for improving the precision of rolling process. Full article

The relationship between sleep and epilepsy involves complex interactions between thalamocortical circuits, circadian mechanisms, and sleep architecture that fundamentally influence seizure susceptibility and cognitive outcomes. Epileptic activity disrupts essential sleep oscillations, particularly sleep spindles generated by thalamic circuits. Thalamic epileptic spikes actively compete with physiological sleep spindles, impairing memory consolidation and contributing to cognitive dysfunction in epileptic encephalopathy. This disruption explains why patients with epilepsy often experience learning difficulties despite adequate seizure control. Sleep stages show differential seizure susceptibility. REM sleep provides robust protection through enhanced GABAergic inhibition and motor neuron suppression, while non-REM sleep, particularly slow-wave sleep, increases seizure risk. These observations reveal fundamental mechanisms of seizure control within normal brain physiology. Circadian clock genes (BMAL1, CLOCK, PER, CRY) play crucial roles in seizure modulation. Dysregulation of these molecular timekeepers creates permissive conditions for seizure generation while being simultaneously disrupted by epileptic activity, establishing a bidirectional relationship. These mechanistic insights are driving chronobiological therapeutic approaches, including precisely timed antiseizure medications, sleep optimization strategies, and orexin/hypocretin system interventions. This understanding enables a paradigm shift from simple seizure suppression toward targeted restoration of physiological brain rhythms, promising transformative epilepsy management through sleep-informed precision medicine. Full article

The increasing demand for energy efficiency in manufacturing has driven the need for advanced modeling techniques to optimize power consumption in machining processes. This study presents a novel approach to modeling power consumption in milling processes using machine learning, leveraging a custom-designed braking device integrated into the milling machine’s main spindle to measure friction forces with high precision. A comprehensive dataset of observations, including parameters such as speed, force, intensity, apparent power, active power, and power factor, was collected under loaded conditions. Nine machine learning models—Linear Regression, Random Forest, Support Vector Regression, Polynomial Regression, Multi-Layer Perceptron with 2 and 3 layers, K-Nearest Neighbors, Bagging, and a hybrid Probabilistic Random Forest—Multi-Layer Perceptron (PIRF–MLP)—were evaluated using 5-fold cross-validation to ensure robust performance assessment. The PIRF–MLP model achieved the highest performance, demonstrating superior accuracy in predicting utile power. The feature importance analysis revealed that force and speed significantly influence power consumption. The proposed methodology, validated on a milling machine, offers a scalable solution for real-time energy monitoring and optimization in machining, contributing to sustainable manufacturing practices. Future work will focus on expanding the dataset and testing the models across diverse machining conditions to enhance generalizability. Full article

To explore the effects of ultrasonic burnishing strengthening technology on the surface morphology and mechanical properties of 40Cr rods for hydraulic applications, a conical transition composite amplitude transformer was designed using ANSYS (Workbench 2024 R1) finite element analysis software, with a frequency of 18,158 Hz, an amplification factor (M_p) of 2.0, and a maximum stress of 122.9 MPa. The ultrasonic burnishing strengthening process was numerically simulated via ABAQUS finite element analysis software. Based on the single-factor analysis method, the influence of spindle speed, ultrasonic amplitude, and burnishing passes on the maximum residual compressive stress of the hydraulic rod was investigated, and key parameters such as surface roughness and microhardness of the rod before and after ultrasonic burnishing strengthening were comparatively analyzed. The results show that ultrasonic burnishing strengthening technology can reduce the surface roughness of the hydraulic rod, enhance its microhardness, and increase the depth of the plastic deformation layer. Ultrasonic amplitude and burnishing passes exert a significant influence on the maximum residual compressive stress on the rod surface, while the effect of spindle speed is relatively minor. When the ultrasonic amplitude is 10 μm, the spindle speed is 120 r/min, and the burnishing passes are 3, the surface residual compressive stress of the hydraulic rod reaches the maximum experimental value of 433.39 MPa. This study reveals the influence law of process parameters on the surface properties of rods for hydraulic applications, verifies the feasibility of the ultrasonic burnishing system, and provides a technical reference for improving the performance of rods for hydraulic applications. Full article

The recycling and remanufacturing of end-of-life (EoL) electric vehicle (EV) batteries are urgent challenges for a circular economy. Disassembly is crucial for handling EoL EV batteries due to their inherent uncertainties and instability. The human–robot collaborative disassembly of EV batteries as a semi-automated approach has been investigated and implemented to increase flexibility and productivity. Unscrewing is one of the primary operations in EV battery disassembly. This paper presents a new method for the robotic unfastening and collecting of screws, increasing disassembly efficiency and freeing human operators from dangerous, tedious, and repetitive work. The design inspiration for this method originated from how human operators unfasten and grasp screws when disassembling objects with an electric tool, along with the fusion of multimodal perception, such as vision and touch. A robotic disassembly system for screws is introduced, which involves a collaborative robot, an electric spindle, a screw collection device, a 3D camera, a six-axis force/torque sensor, and other components. The process of robotic unfastening and collecting screws is proposed by using position and force control. Experiments were carried out to validate the proposed method. The results demonstrate that the screws in EV batteries can be automatically identified, located, unfastened, and removed, indicating potential for the proposed method in the disassembly of EoL EV batteries. Full article

To improve chip removal efficiency and drilling performance in oxygen-free copper, a multi-objective optimization of gun drilling process parameters was conducted using a response surface methodology and a genetic algorithm. The Box–Behnken Design (BBD) response surface analysis method was employed to evaluate the effects of feed rate, cutting speed, and cutting fluid pressure on the chip evacuation coefficient and chip volume ratio. Experimental results indicate that among the three factors, the feed rate has the most significant influence, followed by the cutting speed and the cutting fluid pressure. Additionally, the interaction between the cutting speed and the cutting fluid pressure notably impacts both chip evacuation and chip volume ratio. Using response surface modeling, a three-dimensional predictive model was developed. Based on this fitted model, optimal gun drilling parameters were identified through genetic algorithm optimization, minimizing the chip evacuation coefficient and chip volume ratio to achieve an optimized machining configuration. The optimal drilling parameters were identified as a feed rate of 0.019 mm/r, a spindle speed of 47.1 m/min, and a cutting fluid pressure of 2.4 MPa. Under these conditions, a chip evacuation coefficient of 3.2951 and a chip volume ratio of 3.3345 were achieved. The resulting chips predominantly exhibited a C-shaped morphology, accompanied by smooth and efficient evacuation. Full article

This article presents the wear characteristics of the working surface of WC-Co (Tungsten Carbide–Cobalt) tungsten carbide tools obtained using the innovative U-FAST (Upgraded Field-Assisted Sintering Technology) method for particleboard machining. Three groups of tools with a similar chemical composition but differing WC (Tungsten Carbide) grain sizes were tested. Milling tests were carried out on a CNC (Computer Numerical Control) machine tool with the following cutting parameters: spindle rotation at 15,000 rpm, a feed rate of 0.25 mm per tooth, and a feed rate of 3.75. The experimental results show that tools with submicron WC grit sizes of 0.4 µm and 0.8 µm have the longest tool life. Wear of the cutting edges occurred through the removal of the cobalt bond between the tungsten carbide grains, leading to fracture and mechanical removal of the grains from the cutting edge surface. The similarities in the relative wear characteristics of blades with submicron tungsten carbide grain sizes suggest that micro-abrasion and bond phase extrusion may be the main wear mechanisms under the experimental conditions. Nanometric WC grain size significantly influences tool wear through chipping and cracking. Full article

Histone tail phosphorylation has diverse effects on a myriad of cellular processes, including cell division, and is highly conserved throughout eukaryotes. Histone H3 phosphorylation at threonine 3 (H3T3) during mitosis occurs at the inner centromeres and is required for proper biorientation of chromosomes on the mitotic spindle. While H3T3 is also phosphorylated during meiosis, a possible role for this modification has not been tested. Here, we asked if H3T3 phosphorylation is important for meiotic division by quantifying sporulation efficiency and spore viability in Saccharomyces cerevisiae mutants with a T3A amino acid substitution. The T3A substitution resulted in reduced sporulation efficiency and reduced spore viability. Analysis of two other H3 tail mutants, K4A and S10A, revealed different effects on sporulation efficiency and spore viability compared to the T3A mutant, suggesting that these phenotypes may be due to failures in distinct functions. To determine if the spindle checkpoint promotes spore viability of the T3A mutant, the MAD2 gene was deleted. This resulted in a severe reduction in spore viability following meiosis. Altogether, the data reveal an important function for histone H3 threonine 3 that requires monitoring by the spindle checkpoint to ensure successful completion of meiosis. Full article

Addressing the need to optimize human settlement quality in arid and semi-arid regions under rapid urbanization, this study innovatively constructs an evaluation framework integrating greenness, thermal conditions, impervious surfaces, water bodies, and air transparency. Focusing on 12 prefecture-level cities in Inner Mongolia, Northern China, it systematically reveals the spatial differentiation characteristics and driving mechanisms of human settlement quality. Findings indicate the following: (1) Regional human settlement quality exhibits a spindle-shaped structure dominated by the medium grade (Excellent: 18.13%, High: 23.34%, Medium: 46.48%, Low: 12.04%), with Ulanqab City having the highest proportion of Excellent areas (25.26%) and Ordos City the lowest proportion of Low-grade areas (6.20%), reflecting a critical transition period for regional quality enhancement. (2) Spatial patterns show pronounced east-west gradients and functional differentiation: western arid zones display significant blue-green space advantages but face high-temperature stress and rigid water constraints, eastern humid zones benefit from superior ecological foundations with weaker heat island effects, the core Hetao Plain experiences strong heat island effects due to high impervious surface density, while industrial cities confront prominent air pollution pressures. Consequently, implementing differentiated strategies—strengthening ecological protection/restoration in High/Low-grade zones and optimizing regulation to drive upgrades in Medium-grade zones—is essential for achieving three sustainable pathways: compact development, blue-green space optimization, and industrial upgrading, providing vital decision-making support for enhancing human settlement quality and promoting sustainable development in ecologically fragile cities across northern China. Full article

The spindle motion error significantly affects the surface quality and dynamic precision of machined workpieces. This study proposes a novel detection method for workpiece surface morphology with arbitrary rotation angles. A mathematical model was established for the relationship between the detection signal, spindle error, and workpiece contour when the workpiece rotates at different angles. Unlike traditional reversal methods, this approach allows a flexible selection of workpiece rotation angles and simplifies calculations. Simulation results demonstrate the method’s accuracy, with the slight mean square errors and determination coefficients R² approaching 1. Experimental validation confirms the method’s reliability. Furthermore, the influences of asynchronous errors and sensor errors on measurement results were systematically investigated, highlighting the importance of increasing sampling periods and accurate positioning of sensors. This method offers a cost-effective and versatile solution for precision machining and can be extended to other rotating machinery applications. Full article