Qian Wang

Multi-channel common-aperture optical systems, which excel at simultaneous multi-spectral information acquisition, are widely used for image fusion. However, complex systems for long-distance multi-band detection suffer from difficulties in assembly and adjustment and light vignetting. To resolve this, the paper proposes a modular design method that splits the optical path into independent modules: the common-aperture optical path adopts an off-axis reflective beam-shrinking structure to extend the focal length and ensure 100% light input, compared with coaxial multi-channel common-aperture systems. The relay optical path of each spectral channel uses a continuous zoom design for smooth detection–recognition switching. Based on the method, a three-channel common-aperture system is developed integrating visible light (VIS), short-wave infrared (SWIR), and mid-wave infrared (MWIR). The modulation transfer function (MTF) and wavefront distribution of the common-aperture optical path approach the diffraction limit. After integration with the relay optical paths, the system, without global optimization, can achieve the following performance: the root mean square (RMS) across the full field of view (FOV) at different focal lengths for each channel is smaller than the detector pixel size (3.45 μm for VIS, 15 μm for SWIR/MWIR); the MTF exceeds 0.2 at the cutoff frequency. Subsequently, the results of the tolerance analysis verify the feasibility of the design for each module and the advantage of the modular layout in the assembly and adjustment of the system. Finally, the paper discusses the influence of parallel plates on the wavefront distortion of the system and proposes optimization thinking using freeform surfaces. The design results of the study validate the feasibility of the modular layout in simplifying the design and assembly of multi-channel common-aperture optical systems.

The surface tension of a liquid droplet can be determined by fitting its actual profiles using the Young–Laplace equation, effectively reducing the measurement of surface tension to an accurate determination of the droplet’s profiles. Spectral confocal sensors are high-precision, interference-resistant, non-contact measurement systems for droplet surface profiling, employing a light source together with a dispersive objective lens and a spectrometer to acquire depth-dependent spectral information. The accuracy and stability of surface tension measurements can be effectively enhanced by spectral confocal sensors measuring the droplet surface profile. Although existing spectral confocal sensors have significantly improved measurement range and accuracy, their angular measurement performance remains limited, and deviations may arise at droplet edges with large inclinations or pronounced surface profile variations. This study presents the optical design of a large-angle spectral confocal sensor. By theoretically analyzing the conditions for generating linear axial dispersion in the dispersive objective lens, a front-end dispersive objective lens was designed by combining positive and negative lenses. Based on a Czerny–Turner (C-T) configuration, the back-end spectrometer was designed under the astigmatism-free condition, taking into account both central and edge wavelength effects. Zemax was employed for simulation optimization and tolerance analysis of each optical module. The results show that the designed system achieves an axial dispersion of 1.5 mm over the 430–700 nm wavelength range, with a maximum allowable object angle of ±40° and a theoretical resolution of 3 μm. The proposed spectral confocal sensor maintains high measurement accuracy over a wide angular range, facilitating precise measurement of droplet surface tension at large inclination angles.

Objective: To evaluate the clinical efficacy of a novel quantitative method using the Picture Archiving and Communication System (PACS) for multiplane assessment of supraspinatus muscle fatty infiltration (FI) and compare its reliability and accuracy with traditional single-plane visual evaluations (Under Direct Vision-FF) in preoperative planning for rotator cuff tear (RCT) patients.Methods: A retrospective analysis was conducted on patients undergoing arthroscopic rotator cuff repair (ARCR) between January and June 2023. Preoperative 3.0 T MRI scans were analyzed using PACS to measure FI in three sagittal planes (medial, Y-plane, lateral). Four orthopedic surgeons performed Goutallier classification and manual FI assessments under direct vision and via PACS. Intra- and interobserver reliability were evaluated using intraclass correlation coefficients (ICCs), while Bland-Altman analysis and paired t-tests compared measurement consistency and differences.Results: PACS-based measurements (PACS-FF) demonstrated superior reliability (intraobserver ICC: 0.973–0.996; interobserver ICC: 0.940–0.978) compared to direct vision assessments (intraobserver ICC: 0.538–0.967; interobserver ICC: 0.864–0.940). Significant discrepancies were observed between methods, with direct vision underestimating FI (p < 0.05–0.0001). Multiplane analysis revealed heterogeneous FI distribution, with lateral-plane FI significantly higher than medial and Y-plane values (p < 0.001). Bland-Altman analysis showed 60%–85% of direct vision measurements exceeded clinically acceptable limits of agreement (±10%).Conclusions: Quantitative multiplane PACS-based FI assessment improves accuracy and reliability over traditional single-plane visual evaluation, better reflecting heterogeneous fat distribution in the supraspinatus muscle. This method enhances preoperative risk stratification and surgical outcome prediction for RCT patients. Future integration of automated tools may further optimize clinical efficiency.

Talar fractures represent less than 1% of all fractures, and combined fractures involving the posteromedial and posterolateral talar processes along with a lateral process fracture are exceptionally rare. These fractures are considered severe injuries that may lead to prolonged disability and persistent pain. The intricate anatomical configuration and the proximity of nerves and blood vessels surrounding the talus present substantial challenges in the management of posterior talar process fractures. Surgical procedures in this area are rare, and inadequate treatment may lead to significant discomfort and limitations in daily functioning for patients. In this case report, we describe a 45-year-old male who experienced a fall from a 2-meter height, leading to persistent right ankle swelling for 6 days. Radiographs, CT scans, and 3D-CT reconstructions identified fractures involving the posteromedial and posterolateral talar processes, as well as an avulsion fracture at the calcaneofibular ligament attachment site. To the best of our knowledge, there are no previously documented reports of this combined injury. We conducted arthroscopically assisted reduction and internal fixation through a posterior approach utilizing Herbert screw. The patient underwent a 4-year postoperative follow-up, during which favorable fracture healing was observed. The objective of this report is to demonstrate that arthroscopy offers a well-defined surgical field, aids in reduction and internal fixation, and to suggest a novel treatment approach for this uncommon fracture pattern.

Colloidal quantum dots have been widely applied in various optoelectronic devices such as solar cells, photodetectors, and light emitting diodes. The measurement of carrier dynamics not only allows the study of the passivation quality of quantum dot surfaces but also contributes to analyze the performance of related devices. In this study, by measuring and comparing the photocarrier radiometry signals of PbS quantum dot films on different substrates from the same batch, we investigated the carrier transport and trap properties in the material. First, based on the differences in surface recombination velocities of colloidal quantum dot films on different substrates, we established a theoretical model of differential photocarrier radiometry technique applicable to colloidal quantum dot films. We simulated and analyzed the effects of the carrier transport parameters, such as carrier lifetime, carrier hopping diffusivity, and surface recombination velocities, on the differential photocarrier radiometry signals. Finally, the photocarrier radiometry signals of PbS quantum dot films on K9 glass substrate and transparent indium tin oxide film coated glass substrate were experimentally measured, and the carrier transport parameters of the quantum dot films were also obtained through multiparameter fitting. The simulation and experimental results demonstrate that the differential photocarrier radiometry technique can be used for non-destructive measurement of the carrier transport and trap properties of colloidal quantum dot films without the adverse effects of instrument frequency response.

Purpose: Osteosarcoma (OS) is the most common type of primary malignant bone tumor. Transducing a functional TP53 gene can effectively inhibit OS cell activity. Poly lactic acid-glycolic acid (PLGA) nanobubbles (NBs) mediated by focused ultrasound (US) can introduce exogenous genes into target cells in animal models, but this technique relies on the passive free diffusion of agents across the body. The inclusion of superparamagnetic iron oxide (SPIO) in microbubbles allows for magnetic-based tissue localization. A low-intensity-focused ultrasound (LIFU) instrument was developed at our institute, and different intensities of LIFU can either disrupt the NBs (RLI-LIFU) or exert cytocidal effects on the target tissues (RHI-LIFU). Based on these data, we performed US-magnetic-mediated TP53-NB destruction and investigated its ability to inhibit OS growth when combined with LIFU both in vitro and in vivo.Methods: Several SPIO/TP53/PLGA (STP) NB variants were prepared and characterized. For the in vitro experiments, HOS and MG63 cells were randomly assigned into five treatment groups. Cell proliferation and the expression of TP53 were detected by CCK8, qRT-PCR and Western blotting, respectively. In vivo, tumor-bearing nude mice were randomly assigned into seven treatment groups. The iron distribution of Perls’ Prussian blue-stained tissue sections was determined by optical microscopy. TUNEL-DAPI was performed to examine apoptosis. TP53 expression was detected by qRT-PCR and immunohistochemistry.Results: SPIO/TP53/PLGA NBs with a particle size of approximately 200 nm were prepared successfully. For in vitro experiments, ultrasound-targeted transfection of TP53 overexpression in OS cells and efficient inhibition of OS proliferation have been demonstrated. Furthermore, in a tumor-bearing nude mouse model, RLI-LIFU-magnetic-mediated SPIO/TP53/PLGA NBs increased the transfection efficiency of the TP53 plasmid, resulting in apoptosis. Adding RHI-LIFU to the treatment regimen significantly increased the apoptosis of OS cells in vivo.Conclusion: Combining LIFU and US-magnetic-mediated SPIO/TP53/PLGA NB destruction is potentially a novel noninvasive and targeted therapy for OS.

Understanding the surface recombination property of semiconductor materials is beneficial for improving the performance of optoelectronic devices. In this paper, differential photocarrier radiometry (PCR) is carried out to investigate the evolution of the surface recombination velocities of silicon wafers induced by laser irradiation. The PCR signal and the surface recombination velocities were found to be strongly dependent on the quality of the wafer surface and the duration of laser irradiation. The native oxide surface was more susceptible to laser irradiation than the Al2O3 passivated surface due to more surface defects being annealed. A surface-defect annealing model was used to explain the transient behavior of the PCR signal and the surface recombination velocity.

Based on the atmospheric molecular Doppler wind lidar system using dual-channel Mach–Zehnder interferometer (DMZI) double-edge detection, two important DMZI parameters, such as optical path difference and beam splitter transmittance, are analyzed. Furthermore, the changes in DMZI transmission response, wind speed sensitivity, and wind speed measurement errors of the lidar system caused by the errors of these two parameters are simulated. The ratio of the difference between the system measurement error caused by the non-optimal parameter and the optimal parameter to the system measurement error at the optimal parameter is defined as an error proportion factor, which can be used to quantitatively describe the variation of wind speed measurement error caused by the parameter errors. Numerical simulation shows that under the assumption that the horizontal wind speed is 20 m/s and the vertical detection height is 15 km, if this error proportion factor needs to be controlled to less than 1%, the difference δ_Δl₀ between the actual and the optimal optical path difference should be controlled in the range of 0 ≤ δ_Δl₀ < 3.16 mm. Similarly, if other parameters are optimal, the beam splitter transmittance of DMZI should be controlled in the range of 0.5 ± 0.0407, and the error proportion factor can be less than 1%. The results of this study not only provide theoretical guidance for the parameter selection of DMZI but also provide research ideas and methods for the error analysis of DMZI molecular Doppler lidar based on double-edge detection.