Search Results (36,179)

:Resonant mass sensors based on micro/nanoelectromechanical systems (MEMS/NEMS) offer a promising approach for label-free gravimetric detection. However, practical applications often require not only high sensitivity but also improved loading repeatability and reduced dependence on mass loading position. In this work, a suspended resonant mass sensor based on a 10 nm-thick Hf_0.5Zr_0.5O₂ (HZO) piezoelectric film is proposed. A central silicon loading platform is introduced to provide a mechanically robust and spatially uniform sensing region. A Kirchhoff plate model incorporating residual stress is established to analyze the effects of residual stress and platform geometry on the resonant characteristics. The device is fabricated by combining SOI micromachining with wet transfer of the ultrathin HZO film. Laser Doppler vibrometry measurements show a first-order resonant frequency of 1.303 MHz and a quality factor of 342, corresponding to an extracted residual stress of approximately 1.319 GPa. Finite element simulations calibrated by experimental parameters indicate a uniform first-mode displacement distribution and a linear frequency response to added mass from 0 to 1 ng. The obtained mass sensitivities are 150.7 Hz/pg and 166.8 Hz/pg from finite element and analytical models, respectively. The proposed structure provides a feasible route toward repeatable pg-level resonant mass sensing based on ultrathin piezoelectric films. Full article

The electromagnetic coupling phase at the complex resonance pole is a fundamental property of nucleon excitations. However, its extraction from pion photoproduction data remains model-dependent, particularly for the $\Delta \left(1232\right)$ resonance, where modern multichannel analyses report helicity amplitude phases ranging from $+3^{\circ }$ to $-{18}^{\circ }$. In this Letter, we present a largely model-independent geometric S-matrix formalism that provides a physical constraint for this ambiguity. By imposing Watson’s final-state interaction theorem, a direct consequence of S-matrix unitarity and time-reversal symmetry, on the real energy axis and performing an analytic continuation, we isolate the kinematic threshold barriers of the photoproduction ($k·q$) and elastic ($q^3$) amplitudes. For the dominant $M_{1+}$ multipole transition of the $\Delta \left(1232\right)$, our method yields a kinematically constrained prediction of ${\varphi }_{EM}={-8.5^{\circ }}_{-1.0^{\circ }}^{+0.6^{\circ }}$ for the electromagnetic residue phase. This geometric constraint explains the numerical results of coupled-channel phenomenological fits, validating the extractions by the SAID and Bonn–Gatchina groups, and establishes a theoretical benchmark for evaluating resonance properties. Full article

Spontaneous imbibition plays a critical role in enhancing oil recovery. It also helps optimize fracturing fluid design in tight oil reservoirs. Conventional evaluation methods mainly rely on nuclear magnetic resonance (NMR) experiments on intact core samples. These methods can adequately characterize matrix imbibition behavior. However, they generally neglect the presence of artificial fractures. This limits their applicability for guiding hydraulic fracturing optimization in field development. To address this gap, this study introduces artificial fractures into tight sandstone cores from the Sichuan Basin. It integrates scanning electron microscopy (SEM) with online NMR technology. The imbibition performance of an oil-displacement slickwater system was systematically evaluated. The evaluation considered varying agent concentrations, injection rates, and initial oil saturation conditions. The results demonstrate that using a high-concentration oil-displacement fracturing fluid significantly enhances imbibition efficiency. For example, slickwater containing 0.3% oil-displacement agent increased oil recovery by 12.9%. This was compared with slickwater containing 0.1% agent. The high-concentration fluid also substantially improved oil mobilization from small pores. Furthermore, increasing the injection rate proved particularly beneficial for oil recovery across the micropore to mesopore range. The most pronounced improvement was observed in the micropore range. Initial oil saturation serves as another primary controlling factor for imbibition efficiency. As oil saturation increases, imbibition efficiency improves markedly. The optimized slickwater system developed in this study has been successfully applied in Well NC002. It achieved a tested oil production rate of 32 tonnes per day. This field application validates the effectiveness of the proposed approach. It also provides practical technical support for the efficient development of tight oil resources in the Sichuan Basin. Full article

This study investigates the effects of Ta doping on the elastic, dielectric, piezoelectric, and electromechanical coupling properties of lithium niobate (LiNbO₃, LN) crystals using first-principles calculations. The results show that isovalent substitution of Nb⁵⁺ by Ta⁵⁺ maintains mechanical stability in all doped systems. Ta incorporation enhances the overall stiffness and deformation resistance, while strengthening ionic displacement polarization and the piezoelectric stress response. The piezoelectric strain constant d₃₃ and electromechanical coupling coefficient k₃₃ exhibit different optimal doping concentrations. d₃₃ reaches 9.548 pC/N at 10% Ta doping, corresponding to a 13.6% improvement over intrinsic LN, whereas k₃₃ reaches a maximum of 0.2569 at 3.33% Ta doping and remains high in the 3.33–6.67% range. This separation originates from the competition among polarization enhancement, elastic stiffness hardening, and nonlinear dielectric growth. Enhanced ionic polarization promotes d₃₃, while excessive dielectric energy storage and increased stiffness suppress effective electromechanical energy conversion. These results reveal the microscopic mechanism governing composition-dependent electromechanical tuning in Ta-doped LN crystals. Accordingly, 10% Ta is suitable for improving strain sensitivity, whereas 3.33–6.67% Ta is preferable for optimizing energy conversion efficiency in LN-based sensors, actuators, transducers, and resonators. Full article

In this paper, a simple and compact 1 × 2 decoder based on a two-dimensional photonic crystal structure is proposed, whose operation relies on total internal reflection and photonic band gaps. The designed structure employs a square-lattice configuration of silicon dielectric rods embedded in air. The decoder consists of two input ports, one acting as a Bias port and the other as a logical input port. Numerical modeling and simulations are performed using the plane-wave expansion (PWE) method and the finite-difference time-domain (FDTD) technique. The proposed coupling-resonator structure increases the coupling efficiency at resonant frequencies. The structure has a relatively small footprint, comprising an 18 × 18 array of dielectric rods with a total area of approximately 147 µm². A minimum contrast ratio of about 8.4 dB between logical “1” and “0” states is achieved. The decoder operates at 1.55 µm, making it suitable for photonic and optical communication applications. Due to its compact size, simple architecture, and use of a minimal number of ring resonators, the proposed decoder is well suited for high-speed photonic integrated circuits and future all-optical computing systems. The bit rate of the proposed decoder is estimated to be 2 Tb/s. Full article

Background: In breast cancer diagnosis, while radiological imaging modalities provide important insights into the structural characteristics of tumors, pathological examinations remain essential for establishing a definitive diagnosis. Methods: This study proposes a Vision Transformer (ViT)-based approach developed by fusing magnetic resonance imaging (MRI) and pathology images from the same patient in breast cancer diagnosis. In the study, models combined with different classifiers were trained using ViT-16 and ViT-32 architectures. Performance of the models was evaluated using accuracy, F1 score, sensitivity, precision, ROC, AUC, and Precision–Recall (PR) curves. Results: The findings show that models multimodal image fusion models outperform single-modality models in accuracy, precision, and sensitivity, demonstrating that the fusion approach is an effective method for breast cancer diagnosis. Specifically, the ViT-B/32 (Fusion) + SVM model proved to be the most successful, achieving 92.53% accuracy and a PR-AP value of 0.9708. Conclusions: These results demonstrate that evaluating radiological and pathological images improves diagnostic accuracy and reliability, and that multimodal image fusion is effective in distinguishing malignant lesions from benign ones. Full article

Vision-language foundation models have transformed medical image segmentation over the past three years. These models pair large image encoders with text prompts, so a single model can segment many anatomical structures, lesion types, and imaging modalities through natural language. This survey reviews vision-language foundation models designed for medical image segmentation. We describe the technical background from contrastive vision-language pretraining to the Segment Anything Model and its medical variants. We propose a three-part taxonomy that covers text-prompt-guided models, large-language-model-embedded architectures, and hybrid frameworks. We examine adaptation strategies such as full fine-tuning, Low-Rank Adaptation, adapters, and prompt engineering. We organize the literature by modality and cover computed tomography, magnetic resonance imaging, pathology, chest radiography, and ultrasound. We discuss clinical uses such as organ segmentation, tumor delineation, and radiotherapy planning. We summarize evaluation metrics and benchmark datasets. We identify four open challenges: prompt dependence, mask hallucination, slow volumetric inference, and limited annotated data. We close with a research roadmap for trustworthy deployment, multimodal pretraining, and clinical integration. Full article

Introduction: Posterior cervical fusion is commonly performed for cervical spine instability and fractures. However, dural injury may result in cerebrospinal fluid leakage, pseudomeningocele, and, rarely, hydrocephalus. These complications may lead to substantial neurological deterioration and functional decline. We report a rare case of severe cognitive impairment and dysphagia caused by postoperative CSF leakage-associated hydrocephalus after C1–2 fusion and highlight the role of comprehensive rehabilitation in functional recovery. Case presentation: A 67-year-old woman sustained a type III odontoid fracture and was initially managed with halo-vest immobilization. Because of fracture nonunion, posterior C1–2 fusion was performed. One month after surgery, she developed progressive mental status deterioration, confusion, and severe functional impairment. Brain computed tomography revealed progressive hydrocephalus, and cervical spine magnetic resonance imaging demonstrated a large posterior fluid collection consistent with pseudomeningocele. Revision surgery and ventriculoperitoneal shunt placement were performed. However, the patient remained bedridden with persistent vomiting, severe cognitive impairment, dysphagia requiring nasogastric tube feeding, and generalized deconditioning. Three months after revision surgery, her neurological condition stabilized and rehabilitation was initiated. Intensive and individualized rehabilitation, including cognitive rehabilitation, swallowing therapy was implemented. After three months of rehabilitation, the patient demonstrated gradual improvement in cognitive function, swallowing function, and mobility, ultimately achieving independent standing and ambulation using a walker. Conclusions: Postoperative CSF leakage-associated hydrocephalus and pseudomeningocele may lead to severe cognitive, swallowing, and functional impairments beyond structural complications alone. Comprehensive, individualized rehabilitation should be considered an essential component of care to maximize neurological and functional recovery. Full article

High-energy, ultrafast pulse generation from mid-infrared (MIR) fiber lasers is often limited by pulse splitting caused by excessive nonlinear phase accumulation, especially in anomalous-dispersion cavities. Dissipative soliton resonance (DSR) offers a route to energy scaling by accommodating additional gain through temporal pulse broadening under peak-power clamping. Here, we numerically demonstrate DSR operation in a net-normal-dispersion Er³⁺: ZBLAN mode-locked fiber laser at 2.8 µm, using an As₂S₃ fiber for dispersion and nonlinear management. Systematic parameter sweeps show that the gain saturation energy primarily governs pulse-energy scaling, whereas the output-coupling ratio controls peak-power extraction and the operation regime. The spectral filter bandwidth and saturable absorber parameters define the stability window and mediate transitions among dissipative solitons, DSR pulses, noise-like pulses, multi-pulse states, and unstable operation. After coordinated cavity optimization, a stable rectangular DSR pulse with a maximum energy of 408.52 nJ is obtained under a 55 nm filter bandwidth, relaxing the narrow-filtering requirement reported in previous MIR DSR designs. A high-peak-power DSR state with 3112.1 W peak power and 316.58 nJ energy is also achieved at a 95% output-coupling ratio. By tuning the As₂S₃ fiber length, DSR dynamics are also accessed near the zero-dispersion boundary and in the anomalous-dispersion regime, where spike-on-pedestal temporal profiles and dual-peak spectra emerge. This work advances the understanding of MIR DSR dynamics and offers design guidance for compact, high-energy ultrafast sources at 2.8 µm. Full article

Abdominal aortic aneurysm (AAA) is a critical condition with high rupture risk, and the maximum diameter alone is insufficient for prediction. Pulse wave velocity (PWV), a surrogate of aortic stiffness, can be estimated using 4D-Flow magnetic resonance imaging (MRI), but requires validation under dilated conditions. This in vitro study examined the relationship between PWV and stiffness by comparing healthy and aneurysmal compliant aortic models. Two latex phantoms were fabricated to represent normal and AAA geometries. A circulatory MRI-compatible system simulated physiological inlet flow, with flow rates measured across perpendicular planes using 4D- and 2D-Flow MRI. PWV was derived from transit times of the systolic upstroke and interplane distances. Complementary 1D numerical simulations and laboratory flowmeter measurements were performed. Although the wall elasticity and thickness were identical, PWV in the healthy model ranged from 6.2 to 7.7 m/s and in the aneurysmal model it ranged from 14.2 to 15 m/s. This increase was confirmed by temporal overlap of thoracic flow curves and reduced slope in the transit time–distance regression. Results were consistent across simulations, 2D-Flow, and flowmeter data. Findings highlight that indirect 4D-Flow assessment of thoracic stiffness in the presence of AAA must account for wave reflections introduced by dilation, which significantly alter PWV estimation. Full article

In the clinical management of prostate cancer, continuously refined scoring systems form the cornerstone of precise risk stratification. Pathological assessment systems, represented by the Gleason score and the International Society of Urological Pathology (ISUP) grade groups, have long been the cornerstone of prostate cancer risk stratification; however, they are subject to inherent limitations such as sampling bias and spatial heterogeneity. With advances in imaging technology, the PI-RADS scoring system based on multiparametric magnetic resonance imaging (mpMRI) has been widely adopted for the detection and localization of prostate cancer; however, inter-observer variability remains a significant issue in clinical practice. Concurrently, emerging functional imaging scoring systems based on PSMA-PET, such as PSMA-RADS and miTNM staging, have provided new tools for the precise staging of prostate cancer and restaging following biochemical recurrence. Currently, an increasing number of studies are attempting to integrate pathological and multimodal imaging information to construct comprehensive predictive models, thereby addressing the shortcomings of single-modality assessment methods, achieving more personalized and precise risk stratification, and ultimately optimizing treatment decisions and improving patient prognosis. Full article

Many models exist to describe the nature of sloshing, an intricate phenomena, including the linear mechanical model and the Duffing oscillator. This paper attempts to provide an alternative model that describes the maximum slosh wave height (MSWH) of different sloshing liquids, to more accurately predict the nuanced phenomena as well as to better understand the inherent nature of sloshing. We explore three different models, the classical linear mechanical model, the non-linear Duffing model and finally the novel fractional visco-elastic model. The latter illustrates promising results after being validated via experimentation. The paper leads to the conclusion that sloshing of liquids, particularly low-viscosity fluids, is better described to have a spectrum of fractional-order visco-elastic forces at near and post resonant excitation frequencies rather than independent viscous and elastic forces as assumed by the linear and non-linear mechanical models. Full article

Background/Objectives: Noninvasive determination of glioma molecular profiles is clinically crucial for assessing therapeutic efficacy and predicting disease outcomes. This study aimed to evaluate the potential of morphological magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), magnetic resonance spectroscopy (MRS), and dynamic contrast-enhanced perfusion-weighted imaging (DCE-PWI) in predicting TP53 gene status and X-linked alpha-thalassemia intellectual disability syndrome (ATRX) gene status in isocitrate dehydrogenase (IDH)-mutant gliomas. Methods: A retrospective analysis was performed on 106 IDH-mutant glioma patients using morphological MRI, DWI, MRS, and DCE-PWI data. Statistical comparisons of imaging parameters across molecular status groups were conducted, and logistic regression models were developed to predict molecular status, with diagnostic performance evaluated by receiver operating characteristic (ROC) curve analysis. Five-fold stratified cross-validation with 1000 bootstrap resamples was employed to assess model generalizability Results: Among 106 IDH-mutant gliomas, the TP53-mutant group showed a greater proportion of tumors with >33% enhancement (p = 0.018), higher Cho/Cr (p < 0.001), and higher Cho/NAA (p = 0.005) than the TP53-wildtype group. Multivariable analysis demonstrated that the Cho/Cr ratio was an independent predictor of TP53 mutation in IDH-mutant gliomas (odds ratio [OR] = 2.037, p = 0.021), with the model achieving an apparent AUC of 0.741. DCE-PWI parameters showed no significant differences across molecular subgroups. Ve was significantly elevated in ATRX-mutant tumors (median 57.16 vs. 30.63, p = 0.029). Ktrans, Kep, Vp, and iAUC showed no significant differences between groups (all p > 0.05). Furthermore, multivariable analysis showed that ADC values (OR = 1.005, p = 0.017) and the Cho/NAA ratio (OR = 3.073, p = 0.023) emerged as independent predictors of ATRX mutation, with the model achieving an apparent AUC of 0.863. Five-fold cross-validation demonstrated that the Cho/Cr model for TP53 prediction achieved a mean AUC of 0.717 ± 0.043 (Bootstrap 95% CI: 0.616–0.814), and the ADC + ChoNAA model for ATRX prediction achieved 0.865 ± 0.124 (95% CI: 0.780–0.953). All predictors remained significant across all five folds. Pooled confusion matrices yielded sensitivities of 0.623 and 0.757, specificities of 0.696 and 0.909, and accuracies of 0.654 and 0.840, respectively. Conclusions: Multimodal MRI techniques (morphological MRI, DWI, MRS, and DCE-PWI) can help predict TP53 and ATRX status without surgery. Higher Cho/Cr and Cho/NAA ratios were independently associated with TP53 mutation, whereas lower ADC and higher Cho/NAA independently predicted ATRX mutation. These findings suggest that a focused imaging protocol may be sufficient for preoperative molecular profiling in this tumor type. Full article

This study used black soldier fly protein (BSFP) as a base material and added 0%, 1%, 2%, 3%, 4%, and 5% of grape seed anthocyanidins (GSAs) to prepare composite gels. Through the combined use of low-field nuclear magnetic resonance, Fourier transform infrared spectroscopy, scanning electron microscopy, and rheometry, the relationships among GSA dosage (0–3%), gel structural properties (secondary protein conformation, water status, and microscopic morphology), and rheological printability were systematically evaluated. It was found that the better GSA content fell within 1–3%, and under this condition the extrusion-type 3D printing performance of the composite gels was significantly enhanced. At a 3% addition amount, the proportion of disordered conformations decreased (random coiling decreased from 15.93% to 15.46%), the ordered structure increased (β-sheet increased from 35.25% to 35.43%), and deformation resistance was enhanced. Low-field nuclear magnetic resonance showed an increase in the proportion of non-flowing water and an increase in physical constraints. Scanning electron microscopy showed a reduction in pore size and a thickening of pore walls, forming a denser 3D network. Rheologic analysis indicated that 3% GSA reached the maximum zero-shear viscosity (η₀) and that the storage modulus (G′) and loss modulus (G″) were higher in the experimental group than those in the control group. Printing fidelity increased from 45.73% in the control group to 60.08% in the 1% group, 62.14% in the 2% group, and 71.05% in the 3% group (p < 0.05). The 3–5% groups (fidelity: 71.05–75.66%) all achieved hollow cylindrical printing without collapse and had excellent self-supporting performance. However, excessive addition (4–5%) caused excess GSA to adsorb onto the protein skeleton surface, reducing the apparent viscosity and damaging the printing performance. Based on all the indicators, the composite gel with 3% GSA achieved the best balance between printability and structural integrity. Our research offers a new idea for using flavonoid compounds to improve the 3D printing performance of insect protein gels. The prepared composite gels can be used as food printing inks and applied to personalized nutrition customization, functional food development, and sustainable protein alternative product fields. Full article

Anthropomorphic breast phantoms are increasingly used for the development and evaluation of breast imaging technologies. The aim of this study is to evaluate the impacts of the material combination and stereolithography or Standard Tessellation Language (STL) export methodology on the multimodal imaging performance of patient-derived breast phantoms. A breast model derived from segmented magnetic resonance imaging (MRI) data was used to fabricate four multi-material phantom sections representing adipose- and glandular-equivalent regions. Two material combinations—acrylic styrene acrylonitrile and high-impact polystyrene (ASA-HIPS) and acrylic styrene acrylonitrile and acrylonitrile butadiene styrene (ASA-ABS)—and two STL export procedures were evaluated, including a conventional mesh-based workflow and an in-house voxel-preserving approach designed to eliminate interface gaps. The phantoms were imaged using clinical computed tomography (CT), mammography, and digital breast tomosynthesis systems. Quantitative evaluation included contrast-based image characteristics and region of interest-based intensity distribution analysis. The results showed that ASA-HIPS phantoms demonstrated higher inter-material contrast and greater attenuation separation than ASA-ABS across all imaging modalities. The voxel-preserving STL export procedure improved physical interface integrity and eliminated visible inter-material gaps, while producing only minor differences in global radiological metrics compared with the conventional workflow. CT imaging of the breast samples acquired at 70 kVp showed attenuation characteristics consistent with clinically reported Hounsfield unit ranges for low-density breast tissues observed in clinical CT examinations. Full article