Search Results (1,529)

Pyonephrosis is a rare, life-threatening suppurative disease of the kidney characterised by the accumulation of purulent exudate within the renal pelvis and the destruction of renal parenchyma. It is typically associated with azotaemia and urinary tract obstruction. Extreme leucocytosis (>100 × 10³/µL), known as a leukemoid reaction, has been rarely reported in feline pyonephrosis. A 13-year-old neutered domestic shorthair female cat was brought to a veterinary clinic with symptoms of lethargy and apathy, as well as a significantly enlarged abdominal cavity. Physical examination revealed dehydration and a large, non-painful mass occupying the left abdominal cavity. Haematology revealed severe leucocytosis of 123.22 × 10³/µL and anaemia with haematocrit (HCT) 18.6% and serum biochemistry showed elevated SDMA 17 µg/dL, AST 97 U/L, with hypokalaemia, hypochloraemia and hypoproteinaemia. Creatinine (1.5 mg/dL) and blood urea nitrogen (BUN) (23 mg/dL) remained within reference values. Abdominal X-ray and ultrasound revealed a large mass of anechoic structure encompassing the entire left side of the abdominal cavity, consistent with pyonephrosis. Microbiological studies of purulent material obtained by ultrasound-guided fine-needle aspiration and culturing revealed the presence of Escherichia coli. The day after admission, the patient underwent surgical laparotomy with unilateral nephrectomy. Histopathology confirmed severe inflammatory infiltration of the mucosa, connective tissue proliferation and fibrosis, with partial glomerular hyalinisation and without cellular atypia. Six days after surgical intervention, the leukocyte count decreased to 44.81 × 10³/µL. The patient was alive and clinically healthy 3 months after surgery. This case illustrates that massive unilateral pyonephrosis can occur in geriatric cats without azotaemia due to the compensatory function of the contralateral kidney. Marked leucocytosis of 123.22 × 10³/µL probably represents a leukemoid reaction secondary to severe suppurative inflammation. Moreover, pyonephrosis should be considered in the differential diagnosis of large abdominal masses in cats, even in the presence of a normal creatinine level. Full article

Background and Objectives: The aim of this study was to evaluate the volume of dental tissue removed during conventional versus microscope-assisted coronal access cavity preparation by an undergraduate student in extracted mandibular incisors, and to compare the volumetric assessment capabilities of cone beam computed tomography (CBCT) and intraoral scanner (IOS) for this application. Materials and Methods: Thirty extracted mandibular incisors were randomly allocated to two equal groups: Group 1 (G1), access cavity preparation without magnification; and Group 2 (G2), access cavity preparation with the aid of an operating microscope. Volumetric analysis was performed using CBCT (RAYSCAN^® Alpha Plus 130) and an intraoral scanner (3Shape TRIOS^® 3) before and after access cavity preparation. Volume loss was calculated for each group. Differences in groups were assessed using the independent-samples Student’s t-test for CBCT data and the Mann–Whitney U test for IOS data. Reproducibility between methods was evaluated using the intraclass correlation coefficient (ICC). Results: The CBCT analysis revealed significantly greater tissue loss in G1 (mean 14.93 mm³, SD 4.42) than in G2 (mean 7.64 mm³, SD 2.72) (mean difference 7.29 mm³, 95% CI, 4.54–10.04; p < 0.001; Cohen’s d = 1.99, 95% CI, 1.10–2.88). The IOS analysis did not detect a statistically significant between-group difference (G1: mean 5.37 mm³ vs. G2: mean 4.55 mm³; p = 0.436). The ICC for volume loss between methods was 0.011 (95% CI: −0.150 to 0.237), below the threshold conventionally used to indicate acceptable reliability; because CBCT and IOS did not sample identical anatomical extents, this should be interpreted as limited agreement specific to the present protocols rather than general evidence of poor concordance between the two imaging methods. Conclusions: Within the limitations of this exploratory, single-operator in vitro study, microscope-assisted access cavity preparation resulted in significantly less CBCT-measured volumetric tissue loss than conventional access in mandibular incisors. Full article

Background: Pleomorphic rhabdomyosarcoma (RMS) is a rare, adult-predominant high-grade sarcoma that usually arises in the deep soft tissues of the extremities. Primary oral pleomorphic RMS is exceptionally rare, and detailed CT and MRI characteristics of oral pleomorphic RMS remain sparsely documented. Case Presentation: A 66-year-old woman presented with a two-month history of lower anterior tooth pain and progressive mandibular swelling, initially misdiagnosed and treated as a dental infection. CT and MRI revealed a 3.8-cm heterogeneously enhancing mass centered in the mandibular gingiva, with aggressive cortical destruction, diffusion restriction, and anterior floor-of-mouth extension; oral cavity cancer (squamous cell carcinoma) was initially favored on imaging. The patient underwent wide excision with segmental mandibulectomy and fibular osteocutaneous free-flap reconstruction. Histopathologic examination confirmed a high-grade pleomorphic RMS with immunoreactivity for desmin and MyoD1. The patient received adjuvant chemotherapy and radiotherapy, with no recurrence at 8-month follow-up. Conclusions: Pleomorphic RMS of mandibular gingiva may be mistaken clinically for odontogenic infection and radiologically for squamous cell carcinoma. Although imaging findings are nonspecific, CT and MRI are essential for defining mandibular and floor-of-mouth involvement and planning resection; definitive diagnosis requires histopathologic and immunohistochemical confirmation. Full article

To address the broadband noise distribution, complex excitation sources, and insufficient low-frequency attenuation of conventional porous acoustic packages in commercial vehicle cabs, this study proposes a PU–six-cavity Helmholtz metamaterial composite acoustic package for broadband noise reduction. The proposed structure consists of a 30 mm PU porous layer for mid-to-high-frequency dissipation and a 30 mm six-cavity Helmholtz metamaterial layer for low-frequency absorption, forming a 60 mm composite acoustic package. A full-vehicle acoustic model of a commercial vehicle cab was established in VA One to identify the A-weighted sound pressure level (SPL) spectrum at the driver position. The results show that the PU porous acoustic package improves the mid- and high-frequency noise response, whereas pronounced peaks remain in the low- and low-to-mid-frequency ranges. To enhance these bands, the six sub-cavities of the Helmholtz metamaterial were tuned to 200, 250, 315, 400, 500, and 630 Hz through spatial partitioning and cavity grouping. COMSOL (version 6.1) simulations and particle velocity distributions confirmed the multi-peak absorption mechanism and the selective excitation of the corresponding sub-cavities. The composite structure was further validated through impedance-tube measurements, full-vehicle acoustic simulations, and in-vehicle tests. The VA One simulation shows that the total A-weighted SPL at the driver position decreases from 68.25 dB for the PU porous package to 66.01 dB after introducing the six-cavity Helmholtz metamaterial, corresponding to an additional reduction of 2.24 dB. A preliminary in-vehicle test under a stationary idling condition shows that the total A-weighted SPL near the driver’s ear decreases from 55.83 dB(A) to 54.56 dB(A). These results demonstrate that the proposed PU–six-cavity Helmholtz metamaterial composite acoustic package combines broadband porous dissipation with low-frequency resonant absorption, providing a feasible solution for broadband noise control in commercial vehicle cabs. Full article

Discrete energy-level dynamics provide a fundamental framework for understanding driven two-state systems. Here, we propose and experimentally demonstrate a classical microwave-photonic analog based on two active fiber loops. Reciprocal electro-optic sidebands coherently couple two independently sustained lasing modes. When the input RF power is increased from 11.7 to 18.7 dBm, the measured oscillation frequency increases from 0.55 to 1.00 MHz, consistent with the modulation-induced coupling predicted by the coupled-mode model. The experiment therefore demonstrates RF-power-controlled Rabi-like oscillation in an active dual-loop system. Because the optical fields and detected intensities are classical, the platform reproduces reduced two-state dynamics rather than quantum-state evolution. This proof-of-concept provides a basis for quantum-inspired microwave-photonic signal processing and future short-cavity implementations. Full article

A high-stability actively mode-locked fiber laser (AMLFL) is proposed and experimentally demonstrated. This AMLFL is based on a distributed feedback laser diode (DFB-LD) injection locking with Fabry-Perot (F-P) etalon frequency stabilization. In this system, a wavelength modulation method is employed to generate the feedback signal for frequency stabilization. The stabilization mechanism utilizes the linear response characteristic of the first-order derivative of the F-P etalon transmission peak. This achieves wavelength stabilization of the DFB-LD. Subsequently, the stabilized light source is injected into the ring cavity of the AMLFL. The proposed system does not require modification to the existing AMLFL cavity. It also features a simple structure and low implementation cost. Experimental results show that, with frequency stabilization, the wavelength drift of a selected spectral line is reduced to within the 10 pm resolution of the OSA. Meanwhile, the standard deviations of the 5 GHz spectral component power fluctuation and the average output optical pulse power are 0.01 dB and 0.01 dB, respectively. Full article

This paper systematically investigates the structural design and numerical characterization of ultra-compact low-loss waveguide bends on lithium niobate-on-insulator (LNOI) thin films via 3D-FDTD simulations. Six 90° bend architectures are analyzed to unravel transmission behaviors and intrinsic loss mechanisms, including three smooth bend optimizations: straight–bend lateral offset, local width tapering, and Euler–circular hybrid curvature modulation, alongside resonant-cavity and corner-mirror L-shaped bends. All structures achieve evident loss reduction within proper parameter windows. At R_eff = 5 μm, optimized smooth bends reach a minimum loss of 0.046 dB/90°, outperforming standard circular bends, while the double-corner-mirror bend exhibits the lowest loss of 0.467 dB/90° among right-angle configurations. Pairwise parametric scans disclose competitive effects among diverse loss-mitigation pathways, demonstrating that simultaneous use of two optimization strategies fails to cut extra loss at equal device dimensions. Broadband and fabrication tolerance simulations verify flat spectral response across the telecom C band; smooth curved bends possess strong robustness against inclined sidewalls, and etch depth acts as the dominant factor governing device loss. This work delivers systematic parametric guidelines for the design and optimization of miniaturized LNOI routing waveguides for photonic interconnects. Full article

To address the technical bottleneck of balancing the wideband noise (100–800 Hz) and aerodynamic performance of multi-blade centrifugal fans in air conditioning indoor units, this paper proposes a “frequency-domain target-driven” parametric design method for micro-perforated silencers. This method began with the precise identification of the 1/3-octave band noise spectrum to determine two noise peak clusters—200–400 Hz and 700–800 Hz—as the target suppression frequency bands. Based on Ma Dayou’s micro-perforated plate theory, a reverse mapping chain of “target frequency range → resonance frequency → structural parameters (hole diameter, perforation rate, rear cavity depth)” was established to enable the quantitative calculation of the silencer’s geometric parameters. Addressing engineering constraints related to manufacturing precision, clogging prevention, and structural stiffness for the theoretically optimal aperture size (0.24 mm), the aperture was adjusted to 1.0 mm through iterative recalculation of the relationship between plate thickness and perforation rate, while maintaining the perforated plate constant k ≈ 1.40 to ensure that the theoretical sound absorption frequency band remained unchanged. Test results show that under semi-anechoic chamber conditions (background noise ≤ 10 dB(A)), the micro-perforated silencer maintains airflow and power without attenuation across all airflow rates; noise peaks in the 200–400 Hz and 700–800 Hz frequency bands are significantly suppressed, and the full-band spectrum tends toward flatness. The average total noise level was reduced by 1 dB(A), and the average peak sound pressure level was reduced by 4 dB(A); the reduction in peak levels was four times that of the total reduction, revealing that the noise reduction mechanism of this method is “frequency-selective resonant absorption” rather than “uniform attenuation across the entire frequency band.” This study provides a quantifiable and reproducible design process for micro-perforated silencers, offering methodological support and engineering references for the development of low-noise compact fan systems in household appliances. Full article

Accurate identification and risk assessment of hidden defects in urban roads are essential for preventing road collapse and ensuring infrastructure safety. Based on a large-scale investigation of urban roads in Hunan Province, China, this study proposed a multi-scale collaborative detection framework integrating three-dimensional ground-penetrating radar (3D GPR) wide-area screening, manual interpretation, two-dimensional (2D) multi-frequency verification, and borehole endoscopic validation. Typical electromagnetic response characteristics of cavity, void, and loose-zone defects were summarized, and qualitative recognition criteria for different defect types were established. A total of 153 endoscopically validated defect cases, including 115 loose zones, 28 voids, and 10 cavities, were analyzed to investigate defect distribution and associated formation factors. The results show that underground pipeline damage, engineering disturbance, and inadequate backfill compaction are the main factors associated with defect development. Inadequate backfill compaction accounts for approximately 70% of all detected defects and is mainly related to early-stage defects, whereas pipeline damage is associated with nearly 90% of cavity cases despite accounting for only 30% of all cases. Risk assessment results show that cavities and voids are mostly high-risk defects, while loose zones are mainly moderate- to low-risk defects. The proposed framework provides a practical basis for subsurface defect identification, risk warning, targeted remediation, and preventive maintenance of urban roads. Full article

Active flow control actuators are critical for improving aerodynamic performance in applications such as aircraft lift enhancement, drag reduction, and maneuverability improvement. However, the plasma synthesis jet actuator (PSJA) is limited by the constraints of electric energy deposition, making it difficult to further improve the jet velocity and mass flow rate. Meanwhile, the jet velocity driven by combustion needs to be further increased. This study preliminarily investigated the characteristics of a combustion-driven SparkJet actuator through experiments; a combustion-driven SparkJet actuator integrates the advantages of plasma actuators and combustion-driven actuators. The actuator employs a continuous methane–air mixture supply ignited by spark discharge. High-speed shadowgraph imaging is used to characterize the jet flow field evolution. The effects of the cavity volume, normalized outlet diameter (d* = d/h), and equivalence ratio on jet performance are systematically examined. As the normalized outlet diameter increases from 0.666 to 1, the jet penetration distance and jet width increase with an increasing normalized outlet diameter, owing to the reduced boundary layer blockage effect at the orifice. However, when the normalized outlet diameter equals 1, both the jet penetration distance and jet width first increase and then decrease with increasing cavity volume; hence, the outlet diameter and cavity have an optimal size. At an equivalence ratio of mixture ≤1, increasing the methane flow rate enhances the volumetric chemical heat release rate, thereby monotonically improving the jet width and penetration distance. The combustion-driven actuator demonstrates a significantly higher jet velocity compared to a conventional plasma actuator under identical geometric parameters; the combustion reaction can effectively amplify the jet energy and velocity of the actuator. Moreover, the combustion-driven SparkJet actuator also has the same working frequency when the actuator volume is the same, indicating that the combustion process does not significantly extend the cycle time. The maximum jet velocity first increases and then decreases with increasing cavity volume; the reason that the maximum jet velocity first increases is that a larger volume results in a greater mixture mass and more released heat; it then decreases due to incomplete combustion occurring in large chambers. These results show that the design standards for the combustion-driven actuator are fundamentally different from those for the plasma actuator, and their optimal performance is related to not only electrical energy density but also combustion performance. The design parameters of the combustion-driven actuator can be optimized to maximize the jet front velocity. The experimental data in this article provides a reference for optimizing the performance of combustion-driven actuators. Full article

Endometriosis affects approximately 10% of women of reproductive age and is associated with infertility in up to half of those diagnosed. Despite decades of research, the molecular basis of its reproductive consequences remains poorly defined. Among the pathophysiological features most consistently documented in affected women, chronic oxidative stress within the peritoneal cavity has attracted sustained attention, yet its relationship to the extracellular vesicle biology that has emerged as central to endometriosis pathogenesis has never been systematically examined. Iron-catalyzed radical chemistry, macrophage-derived superoxide, and mitochondrial electron leak in ectopic stromal cells collectively sustain a peritoneal redox burden that modifies exosomal biogenesis, alters microRNA sorting, and reprograms vesicle lipid and protein cargo. Oxidatively conditioned exosomes skew peritoneal macrophages toward an immunosuppressive M2 phenotype through miR-301a-3p, miR-146a-5p, and miR-196a-5p, suppress natural killer cell cytotoxicity through NKG2D ligand decoy delivery, facilitate peritoneal dissemination and neuroangiogenesis, and compromise oocyte developmental competence through ferroptosis-derived vesicles carrying aberrant miR-122-5p, oxidized phosphatidylethanolamines, and damaged mitochondria. These mechanisms map directly onto the clinical deficits observed in women with endometriosis undergoing assisted reproduction, including reduced oocyte yield, lower fertilization rates, elevated embryo aneuploidy, and impaired implantation. Follicular and peritoneal fluid exosomal microRNA profiles represent promising non-invasive biomarkers, while combinatorial strategies targeting the iron-ROS-exosome axis offer a more coherent therapeutic framework than the single-antioxidant approaches that have so far shown limited benefit. Full article

A plasmonic waveguide coupling cavity structure is proposed, consisting of a bus metal–insulator–metal (MIM) waveguide-coupled single/double D-shaped resonant cavity. The transmission properties, magnetic field distribution, and refractive index sensing performance are simulated using the finite element method (FEM). A clear multi-Fano resonance phenomenon is observed in the transmission spectra. The Fano resonances arise from the interaction between the discrete states of the D-shaped resonant cavity and the continuum state of the bus MIM waveguide. The influence of various structural parameters on the Fano resonance is investigated. Furthermore, the refractive index sensing properties based on the Fano resonance are studied by varying the refractive index of the insulator layer. Maximum sensitivities of 1130 nm/RIU and 1150 nm/RIU are achieved at the fourth Fano resonance dip for the single and double D-shaped resonator cavities, respectively. And a maximum figure of merit of 171 is achieved by the single D-shaped cavity structure. This research can provide new avenues for the design of high-sensitivity sensors as well as novel on-chip sensing structures. Full article

In this study, we propose a novel optical sensor architecture based on two-dimensional photonic crystals for the early detection of cervical cancer (HeLa). The structure consists of a central hollow-disk micro-cavity designed to accommodate biosamples, surrounded by a periodic array of GaAs rods. The detection principle relies on variations in the biosample refractive index, inducing a spectral shift in the resonance. To overcome the limitations of conventional 2D-FDTD method parametric sweeps, an artificial intelligence framework was developed to optimize the geometric parameters of the proposed photonic crystal optical sensor. First, a Random Forest algorithm was employed to identify promising regions of the geometric design space. Next, a multilayer artificial neural network (ANN-MLP) was trained as a high-fidelity surrogate model ($R^2$ = 98.58%) and coupled with a Particle Swarm Optimization (PSO) algorithm to determine the optimal structural configuration. The optimized sensor geometry subsequently achieved an average sensitivity of 5512.91 nm/RIU, a quality factor of 6139.15 and a detection limit of $5.64\times {10}^{-5}$ RIU, demonstrating the effectiveness of the proposed AI-assisted design strategy. The optimized design reduces classical performance trade-offs and exhibits high tolerance to nanometric fabrication deviations below ±20 nm. Full article

Tooth loss and bone resorption of the alveolar cavity caused by dental caries and periodontal disease remain major clinical challenges that compromise oral function. Tissue engineering approaches based on biocompatible scaffolds have emerged as promising strategies for bone regeneration; however, the influence of fabrication methods on scaffold performance remains unclear. This study developed hydroxyapatite/poly (lactic-coglycolic acid)/chitosan scaffolds (HAp/PLGA/CS) using freeze-drying and 3D-printing techniques and evaluated their physicochemical, biological, and biomechanical properties. The morphology, porosity, elemental composition, and mechanical properties of the scaffold were characterized, while the biocompatibility and osteogenic potential were evaluated using human dental pulp stem cells (hDPSCs). Finite element analysis (FEA) using COMSOL Multiphysics^® Version 6.2. was performed to evaluate scaffold behavior under simulated dental implant loading conditions. The 3D-printed scaffolds exhibited significantly higher cell viability than the freeze-dried scaffolds, reaching approximately 85% in the 50% filling group compared with 50% in the freeze-dried group. Microstructural analysis revealed interconnected hierarchical porosity, including macro-, micro-, and submicrometer scale pores. Although the 50% infill scaffold showed the highest cell viability, the 70% infill scaffold demonstrated the most favorable osteogenic profile, with enhanced expression of RUNX2 and OSX. Both types exhibited degradation profiles compatible with early bone regeneration. FEA simulations indicated that further mechanical optimization is required to improve load transfer and reduce deformation at the implant–scaffold interface. Overall, HAp/PLGA/CS scaffolds showed potential as experimental bioactive platforms for bone tissue engineering, with 3D-printed scaffolds providing greater architectural control and favorable early osteogenic responses. However, the translational relevance of these findings remains preliminary and requires validation through long-term degradation studies, in vivo bone regeneration and osseointegration models, cyclic mechanical testing, and implant fixation experiments. Full article

Transvaginal ultrasound (TVS) remains the most frequently performed examination in gynecological patients to evaluate the uterine cavity. Visualization of the endometrium may be limited due to certain uterine positions, particularly axial and retroverted orientations. Alternative diagnostic methods, such as transabdominal ultrasound (TAS) and transrectal ultrasound (TRS), may be useful in patients in whom visualization is suboptimal using the TVS. The aim of the study was to analyze the literature regarding the diagnostic performance of TVS, TAS, and TRS in detecting uterine cavity abnormalities in women with various uterine positions. Studies evaluating ultrasound assessment of uterine cavity pathologies with reference to uterine position were included in this review. The available research suggests that uterine position may influence ultrasound visualization. TAS has been shown to demonstrate lower diagnostic reliability in retroverted or axial uteri, particularly in patients with obesity or when focal lesions are present. TRS may provide improved assessment of endometrial thickness in patients with axial uteri compared with TVS. Uterine position may be a factor affecting the accuracy of evaluation of the uterine cavity in ultrasound. Awareness of these limitations and the use of additional imaging modalities may improve diagnostic accuracy in selected patients. Further studies are needed. Full article