Search Results (1,594)

Background: The primary effect of Botulinum toxin (BoNT) is to cause weakness in the injected muscles by inhibiting the release of acetyl choline from presynaptic nerve terminals. Its effect on sensorimotor integration (SMI) has largely been confined to small studies. The aim of this review is to highlight effect of BoNT on SMI in the context of Parkinson’s disease (PD), Cervical dystonia (CD), and Writer’s cramp (WC). Methods: Using keywords “Botulinum toxin” and “sensorimotor integration” or “Freezing of gait (FOG)” or ‘Tremor”or “Cervical dystonia” or “Parkinson’s disease”, or “Writer’s cramp”, PubMed database was searched for relevant articles supporting our view. The abstracts of all resultant articles (case reports, case series, randomized trials, observational studies) were reviewed to look for evidence of effects of botulinum toxin on SMI. The relevant articles were charted in excel sheet for further full text review. Results: In FOG, chronic BoNT injections may alter central motor patterns with inclusion of alternative striatal systems, cerebellum, and its connections. In tremor, the afferent proprioceptive input may be modified with reduction of intracortical facilitation and increment of intracortical inhibition. In CD, BoNT can restore disorganized cortical somatotrophy, the key pathophysiology behind cervical dystonia. Similarly, in WC, both the deficient sensory system and abnormal reorganization of the sensorimotor cortex may be altered following chronic BoNT injections. Conclusions: There is preliminary evidence that BoNT may modulate SMI in PD, CD, and WC by altering inputs from the muscle spindles in short term and modifying circuits/particular anatomic cerebral cortices in the long term. Properly conducted randomized trials comparing BoNT with placebo or prospective large-scale studies to look for effect on various surrogate markers reflective of changes in SMI should be the next step to confirm these findings. Targeting the system of afferents like spindles and golgi tendon organs in muscles may be a better way of injecting BoNT, with lower amounts of toxin needed and potential for lesser side-effects like weakness and atrophy. However, this needs to be proven in controlled trials. Full article

The 7075-T7451 aluminum alloy, widely used in aerospace, aviation, and automotive fields for critical load-bearing components due to its excellent mechanical properties, suffers from residual stresses induced by thermo-mechanical coupling during milling, which deteriorate workpiece performance. This study explores how key milling parameters—spindle speed *n_c*, feed per tooth *f_z*, cutting depth *a_p*, and cutting width *a_e*—affect surface residual stress and cutting force via orthogonal experiments and finite element analysis (FEA). Results show *a_e* is critical for X-direction residual stresses, while *f_z* dominates Y-direction ones. Cutting force increases with *f_z*, *a_p*, and *a_e* but decreases with higher *n_c*. Multivariate regression-based prediction models for residual stress and cutting force were established, which effectively characterize parameter–response relationships with maximum prediction errors of 18.69% (residual stress) and 12.27% (cutting force), showing good engineering applicability. The findings provide theoretical and experimental foundations for multi-parameter optimization in aluminum alloy milling and residual stress/cutting force control, with satisfactory practical effectiveness. Full article

Titanium alloys (Ti-6Al-4V) are widely used in the aerospace field. However, as a typical difficult-to-machine material, titanium alloys have a low thermal conductivity, a high chemical activity, and a significant adiabatic shear effect. In conventional milling (CM), the temperature in the cutting zone rises sharply, leading to tool adhesion, rapid wear, and damage to the workpiece surface. This article systematically investigated the influence of process parameters on the surface roughness, cutting force, and cutting temperature in the ultrasonic-vibration-assisted milling (UAM) process of titanium alloys, based on which multi-objective optimization process of the milling process parameters was conducted, by utilizing the grey relational analysis method. An orthogonal experiment with four factors and four levels was conducted. The effects of various process parameters on the surface roughness, cutting force, and cutting temperature were systematically analyzed for both UAM and CM. The grey relational analysis method was employed to transform the optimization problem of multiple process target parameters into a single-objective grey relational degree optimization problem. The optimized parameter combination was as follows: an ultrasonic amplitude of 6 μm, a spindle speed of 6000 rpm, a cutting depth of 0.20 mm, and a feed rate of 200 mm/min. The experimental results indicated that the surface roughness Sa was 0.268 μm, the cutting temperature was 255.39 °C, the cutting force in the X direction (FX) was 5.2 N, the cutting force in the Y direction (FY) was 7.9 N, and the cutting force in the Z direction (FZ) was 6.4 N. The optimization scheme significantly improved the machining quality and reduced both the cutting forces and the cutting temperature. Full article

An intelligent vehicle hierarchical coordinated control strategy based on time delay state feedback model predictive control (TSMPC) and tire force optimization allocation is presented. Aiming at the problem of insufficient trajectory tracking accuracy and the limited time delay compensation capability of distributed drive intelligent vehicles in complex working conditions, an innovative hierarchical control architecture was designed by establishing vehicle dynamics models and path tracking models. The upper-level controller adopts TSMPC algorithm, which significantly improves the coordinated control ability of path tracking and vehicle stability through incremental prediction model and time–delay state feedback mechanism. The lower-level controller adopts an improved artificial bee colony (IABC) algorithm to optimize tire force allocation, effectively solving the dynamic performance optimization problem of redundant drive systems. Simulation verification shows that compared with traditional model predictive control (MPC) algorithms, TSMPC algorithm exhibits significant advantages in trajectory accurateness, error suppression, and stability control. In addition, the IABC algorithm further improves the trajectory accurateness and stability control performance of vehicles in tire force optimization allocation. Full article

This study investigates a novel approach based on micro-pulse plasma electrolytic oxidation (μPPEO), aiming to improve the control over key parameters such as the Ca/P ratio, the formation of anatase and rutile phases, and the porosity of titanium surfaces—factors that are critical for enhancing bioactivity. By employing electrical micro-pulses with widths of 50 μs or 100 μs, our aim was to restrict the discharge time and subsequent surface/electrolyte reactions. The results demonstrate that μPPEO-treated surfaces exhibit uniform pore diameters, a Ca/P ratio of approximately 1.67, and the better control of anatase/rutile formation. The μPPEO treatment successfully produced hydrophilic surfaces, with the 6Ti50 sample displaying the highest polar component of surface energy. Notably, this sample was the only one to support cell viability comparable to that of the polystyrene surface on the 24-well plate, emphasizing its strong potential for clinical applications. Across all treated surfaces, OFCOL osteoblasts displayed a spindle-like morphology with elongated filopodia, suggesting favorable cell interactions and adaptability to the treated surfaces. This study underscores the promise of PPEO as a valuable technique for biomedical applications, particularly in controlling and optimizing dental implant surfaces. Full article

Interest in surface integrity has grown in the manufacturing industry; indeed, it has become an integral part of the industry. It can be studied by examining surface roughness parameters, hardness variations, and microstructure. However, evaluating all these parameters together can be a challenging task. To address this multi-criteria decision-making model (MCDM), techniques such as Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Grey Relational Analysis (GRA) provide a suitable solution for optimizing the machining parameters that lead to improved product quality. This work investigated surface roughness parameters, including arithmetic average surface roughness (2D) (Ra), mean surface roughness depth (2D) (Rz), area arithmetic mean height (3D) (Sa), and maximum surface height (3D) (Sz), in conjunction with Vickers macrohardness (HV) and optical micrographs, to analyze machined surfaces during the turning of X5CrNi18-10 steel. The results suggest that machining with a spindle speed (N) of 2000 rpm or v_c of 282.7 m/min, a feed rate (f) of 0.1 mm/rev, and a depth of cut of 0.5 mm yields the best surface, achieving an “A” class surface finish. These parameters can be applied in manufacturing industries that utilize chromium–nickel alloys. Additionally, the method used can be applied to rank the quality of the product. Full article

This work investigates the macroscopic behavior of skeletal muscles from a system-theoretic perspective. Based on data available in the literature, we propose an initial evaluation model for isometric force generation, i.e., force produced at a constant muscle length or in quasi-static conditions, as a function of muscle length and neuronal excitation frequency. This model enables a more physics-inspired representation of isometric force by employing a nonlinear spring framework with controllable properties such as stiffness and rest length. Finally, we introduce a hybrid dynamical filter model to describe components of the sensory system responsible for relaying information about muscle length and its rate of change back to the Central Nervous System. As an application case, we present the modeling of the oculomotor system, highlighting the relevance of the proposed modeling approach in a physiologically meaningful control task. Full article

Fruit shape is an important quality and yield trait of pear, and the fruit shape of ‘Laiyang Cili’ presents a spindle shape which seriously affects its commercial value. Calyx excision treatment could change the fruit shape, while the underlying genes and their regulatory mechanism remain poorly understood. In this study, we constructed RNA-seq libraries of pear treated with calyx excision to explore underlying regulatory mechanisms. At the early stage of the calyx excision treatment, the numbers of differentially expressed genes (DEGs) between each comparison group were relatively high and gradually decreased along with fruit development. The expression pattern of the DEGs ranked in the top 30 of the six groups had obvious divergence, and DEGs were mainly distributed in the “after calyx excision treatment (0 days)” (AC0d) and AC2d groups. The DEGs were mainly enriched in plant hormone signal transduction and plant defense response. We identified 17 candidate genes related to fruit shape and tested their expression patterns along with fruit development. Among them, nine candidate genes expression trends were consistent with fragments per kilobase of exon model per million mapped fragment (FPKM) values, including MYB62, outer envelope pore protein 62 (OEP62), auxin response factor 3 (ARF3), auxin-responsive protein 50 (SAUR50), protein phosphatase 2C 51 (PP2C 51), major allergen Pyr c 1 (PYRC1), aquaporin TIP1-3 (TIP1-3), transcription factor TGA4 (TGA4) and auxin-responsive protein 17 (IAA17). And then, weighted gene co-expression network analysis (WGCNA) analysis revealed that the OVATE family protein (OFP) and SUN domain-containing protein (SUN) were divided into the MEblue model, which had a positive correlation with calyx excision treatment, and the expression trend of LOC103960706 (OFP8) appeared cohesive with FPKM values. Pbr014104.1 and Pbr016952.1, which were the ortholog genes of LOC103960706, were further identified from the pear genome, and were found to be highly expressed in pear fruit through RT-PCR analysis. Taken together, the key stage determining the development of fruit shape was in the early stage after calyx excision treatment, and fruit shape regulation and development were co-regulated by multiple genes. Full article

We present a rare case of sympathetic ophthalmia in the fellow eye of a 59-year-old Caucasian male diagnosed with untreated malignant choroidal melanoma. Initially identified with a medium-sized choroidal melanoma, the patient declined recommended brachytherapy and did not seek medical attention for two years. Upon returning, he exhibited signs of sympathetic ophthalmia in the contralateral eye. Treatment with corticosteroid-based immunosuppression was initiated. After consenting to treatment for the melanoma, the affected left eye was enucleated, and histopathology confirmed spindle cell choroidal melanoma. This case underscores the uncommon development of sympathetic ophthalmia without prior ocular trauma or surgery, linked to untreated choroidal melanoma. Full article

Friction stir lap welding has been utilized across research and industry for over a decade. However, difficulties in welding in the lap configuration without an interface-related defect have prevented the process from moving beyond low feed rates (generally less than 1.5 m per minute). As a means of making a huge leap in welding productivity, this study will evaluate friction stir welds made at 10 m per minute (mpm), detailing the changes to tool geometries and weld parameters that result in fully consolidated welds. Characterization of the subsequent material properties, namely through optical microscopy, CT scanning, microhardness testing, tensile and fatigue testing, hermetic seal pressure tests, and electron backscattered diffraction, is presented as a means of demonstrating the quality and repeatability of friction stir lap welds made at 10 mpm. Fully consolidated welds were produced at spindle speeds 5.5% faster and 2.9% slower than nominal values and weld depths ranging from 1% shallower to 8.2% deeper than nominal values. Additionally, the loading direction of the weld had a significant impact on tensile properties, with the advancing side of the weld measured to be 16% stronger in lap-shear tensile and 289% fatigue life improvement under all loading conditions measured when compared to the retreating side. Full article

The persistent challenge of fracture-driven interference (FDI) during large-scale hydraulic fracturing in the southern Sichuan Basin has severely compromised shale gas productivity, while the existing research has inadequately addressed both FDI risk reductions and the optimization of reservoir stimulation. To bridge this gap, this study developed a mechanistic model of the competitive multi-cluster fracture propagation under non-uniform perforation conditions and established a perforation-based design methodology for the mitigation of horizontal well interference. The results demonstrate that spindle-shaped perforations enhance the uniformity of fracture propagation by 20.3% and 35.1% compared to that under uniform and trapezoidal perforations, respectively, with the perforation quantity (48) and diameter (10 mm) identified as the dominant control parameters for balancing multi-cluster growth. Through a systematic evaluation of the fracture communication mechanisms, three distinct inter-well types of FDI were identified: Type I (natural fracture–stress anisotropy synergy), Type II (natural-fracture-dominated), and Type III (stress-anisotropy-dominated). To mitigate these, customized perforation schemes coupled with geometry-optimized fracture layouts were developed. The surveillance data for the offset well show that the pressure interference decreased from 14.95 MPa and 6.23 MPa before its application to 0.7 MPa and 0 MPa, achieving an approximately 95.3% reduction in the pressure interference in the application wells. The expansion morphology of the inter-well fractures confirmed effective fluid redistribution across clusters and containment of the overextension of planar fractures, demonstrating this methodology’s dual capability to enhance the effectiveness of stimulation while resolving FDI challenges in deep shale reservoirs, thereby advancing both productivity and operational sustainability in complex fracturing operations. Full article

Line laser measurement, as a typical method of laser triangulation, makes the acquisition of 3D tooth-surface data more accurate, efficient, and informative. Thus, a line laser 3D measurement model of gears is established, and a specialized polyhedral artifact with specific geometric features is invented to determine the pose parameters of the line laser sensor in measuring space. Based on this, a single-spindle gear-measuring instrument is developed and a series of experimental studies are conducted for gears with different module and flank directions in this instrument, including profile deviation, helix deviation, pitch deviation, topological deviation, etc. A comparative experiment with traditional contact measurement methods validates the correctness of the methods mentioned in this paper for the accurate evaluation of tested gears. In further research, the mining and utilization of big data obtained from the line laser 3D measurement of gears will be an important topic. Full article

Background and Clinical Significance: Blue nevi are a dubious pigmented lesion. While somewhat common throughout the population, they are significantly less common than other melanocytic neoplasms, and both their morphology and development bring them closer to true hamartomas than neoplasms. An exceedingly rare occurrence is the development of melanoma from a preexisting blue nevus. This nosological unit, defined as melanoma arising in a blue nevus, also known as malignant blue nevus, blue naevus–like melanoma, melanoma ex-blue naevus, and melanoma mimicking cellular blue naevus, is required to either originate from an area of previously excised blue nevus or have a blue nevus remnant adjacent to it. Due to the spindle cell morphology of melanoma arising in blue nevus, the terminology is often misused by some authors to include spindle cell melanomas, which exhibit a distinct pathogenesis and, although morphologically similar, have differing molecular profiles as well. Case presentations: The following manuscript discusses comparative morphological features in a case series of blue nevi and melanoma arising in blue nevi. Discussion: Blue nevi present with unique morphological features, with melanomas originating from them having a unique molecular pathology profile, which significantly differs from other cutaneous melanomas and is closer to that of uveal melanomas. Full article

This study introduces a time-efficient rotating bending fatigue testing system featuring 11 dual-end spindles, enabling simultaneous testing of 22 specimens. Designed for high-throughput fatigue life (S–N curve) assessment, the system theoretically allows over 93% reduction in total test duration, with 87.5% savings demonstrated in validation experiments using AISI 304 stainless steel. The PLC-based architecture provides autonomous operation, real-time failure detection, and automatic cycle logging. ER16 collet holders are easily replaceable within one minute, and all the components are selected from widely available industrial-grade parts to ensure ease of maintenance. The modular design facilitates straightforward adaptation to different station counts. The validation results confirmed an endurance limit of 421 MPa, which is consistent with the established literature and within ±5% deviation. Fractographic analysis revealed distinct crack initiation and propagation zones, supporting the observed fatigue behavior. This high-throughput methodology significantly improves testing efficiency and statistical reliability, offering a practical solution for accelerated fatigue life evaluation in structural, automotive, and aerospace applications. Full article

Lacrimal cysts (dacryops), which involve lacrimal tissue, are uncommon in dogs with an obscure/unclear pathogenesis. Compared to the current available literature, this report describes the clinicopathologic and immunohistochemical features of two cases of unusual dacryops in brachycephalic dogs. A three-year-old male Cane Corso was referred with a 1-month history of swelling ventromedial to the left eye associated with blepharospasm and epiphora. Furthermore, a severe lower and upper eyelid entropion and a deep corneal ulcer were present. B-mode ultrasonography and a CT scan revealed a subcutaneous cyst, closely adherent to the maxillary bone. Surgical removal and the correction of entropion were performed. No recurrence and/or complication was detected by seven-year follow-up. Histopathology revealed a cystic structure with single- to double-cell-layered, nonciliated, cuboidal epithelia. Alcian blue stain revealed rare, disseminated goblet cells admixed with epithelial cells. The epithelium was strongly Cytokeratin-positive by immunohistochemistry and appeared lined by several layers of smooth muscle actin (SMA)-positive myoepithelial cells. A 1-year-old male French Bulldog with a 3-month lesion of the third eyelid of the right eye. The lesion (15 mm × 7 mm) beneath the conjunctiva appeared pale-pink, smooth, and multilobulated. Excision was performed by blunt dissection through the conjunctiva on the palpebral surface of the third eyelid. Recovery was uncomplicated, and no recurrence has been noted at three-year follow-up. Cytology of the cystic fluid and histopathology and immunohistochemistry of the cyst wall revealed findings for case 1. To further characterize the SMA-positive spindle cells located directly beneath the cyst-lining epithelium, double-color immunofluorescence for SMA and p63 (a myoepithelial cell marker) was performed on the sample from case 2. The analysis revealed that the SMA-positive cells lacked p63 expression, indicating a non-myoepithelial phenotype. The histological findings in our cases are consistent with previous reports of canine dacryops. The positivity of immunohistochemical staining for SMA in cells directly beneath the epithelium of dacryops in the cases here described in two brachycephalic dogs is consistent with previous reports in dogs and horses but in contrast with a retrospective study about a human dacryops. These results support the conclusion that the pathogenesis of dacryops in dogs should exclude failure of ductular “neuromuscular” contractility. Full article