Multiplexing modulation design optimization and quality evaluation of BDS-3 PPP service signal

The Precise Point Positioning (PPP) service of BeiDou-3 Navigation Satellite System (BDS-3) is implemented on its Geostationary Earth Orbit (GEO) satellites. However, its signal design is limited by the actual power of satellite and other conditions. Furthermore, the design needs to fully consider the compatibility of different service phases. Starting from the actual state of the BDS-3 GEO satellite, this paper studies the multiplexing modulation of the BDS PPP service signal that is based on the Asymmetric Constant Envelope Binary Offset Carrier (ACE-BOC) technique and proposes several feasible schemes for this signal. Comparison and optimization of these techniques are made from the aspects of transmission efficiency, multiplexing efficiency, and service forward compatibility. Based on the Type-III ACE-BOC multiplexing modulation technique, phase rotation and intermodulation reconstruction techniques are proposed to suppress the intermodulation interference issue. Finally, a signal based on improved ACE-BOC multiplexing is designed. The quality of the proposed signal was continuously monitored and tested using large-diameter antennas. The evaluation results show that the power spectrum deviation of the signal is 0.228 dB, the correlation loss is 0.110 dB, the S-curve slope deviation is 1.558% on average, the average length difference between the positive/negative chip and the ideal chip is only 0.0006 ns, and the coherence between the carrier and the pseudo code is 0.082°. All quality indicators are satisfactory, indicating that the proposed signal multiplexing modulation technique is an ideal solution that meets all the requirements of the design constraints, and can achieve efficient information broadcasting and forward compatibility of the BDS PPP service.

Realization of Super-Large-Diameter Slurry Shield Passing through Settlement-Sensitive Area Based on Unreinforced Disturbance Control Technology

Due to the complex construction conditions of shield tunnels, ground disturbance is inevitable during the construction process, which leads to surface settlement and, in serious cases, damage to surrounding buildings (structures). Therefore, it is especially important to effectively control the constructive settlement of subway tunnels when crossing settlement-sensitive areas such as high-density shantytowns. Based on the project of Wuhan Metro Line 8 Phase I, the shield of Huangpu Road Station-Xujiapang Road Station interval crossing high-density shantytowns, we study the disturbance control technology of oversized diameter mud and water shield crossing unreinforced settlement-sensitive areas during the construction process. By optimizing the excavation parameters and evaluating the ground buildings, the excavation process can be monitored at the same time, and the water pressure, speed, and tool torque required during the excavation during the construction process can be finely adjusted; the control of tunneling process parameters can provide reference and basis for analyzing the construction control of large-diameter shield through old shantytowns.

Electrospun Scaffold Micro-Architecture Induces an Activated Transcriptional Phenotype within Tendon Fibroblasts

Biomaterial augmentation of surgically repaired rotator cuff tendon tears aims to improve the high failure rates (∼40%) of traditional repairs. Biomaterials that can alter cellular phenotypes through the provision of microscale topographical cues are now under development. We aimed to systematically evaluate the effect of topographic architecture on the cellular phenotype of fibroblasts from healthy and diseased tendons. Electrospun polydioxanone scaffolds with fiber diameters ranging from 300 to 4000 nm, in either a highly aligned or random configuration, were produced. Healthy tendon fibroblasts cultured for 7 days on scaffolds with highly aligned fibers demonstrated a distinctive elongated morphology, whilst those cultured on randomly configured fibers demonstrated a flattened and spread morphology. The effect of scaffold micro-architecture on the transcriptome of both healthy and diseased tendon fibroblasts was assessed with bulk RNA-seq. Both healthy (n = 3) and diseased tendon cells (n = 3) demonstrated a similar transcriptional response to architectural variants. Gene set enrichment analysis revealed that large diameter (≥2000 nm) aligned scaffolds induced an upregulation of genes involved in cellular replication and a downregulation of genes defining inflammatory responses and cell adhesion. Similarly, PDPN and CD248, markers of inflammatory or “activated” fibroblasts, were downregulated during culture of both healthy and diseased fibroblasts on aligned scaffolds with large (≥2000 nm) fiber diameters. In conclusion scaffold architectures resembling that of disordered type III collagen, typically present during the earlier phases of wound healing, resulted in tendon fibroblast activation. Conversely, scaffolds mimicking aligned diameter collagen I fibrils, present during tissue remodelling, did not activate tendon derived fibroblasts. This has implications for the design of scaffolds used during rotator cuff repair augmentation.

Comparison of the efficacies of 1.0mm and 1.5mm silicone tubes for the treatment of nasolacrimal duct obstruction

This study was designed to compare the postoperative outcomes of bicanalicular intubation using different diameters of silicone tubes to treat post-saccal nasolacrimal duct obstruction. A total of 130 patients diagnosed with post-saccal obstruction who underwent endoscopic-assisted silicone tube intubation were included in the study. The patients were divided into two groups; those intubated with a 1.5-mm large diameter tube (Group LD) and those with a 1.0-mm normal diameter tube (Group ND). The patency rates of the two groups at one year after tube removal were compared using the Kaplan–Meier's curve and Restricted mean survival time (RMST) method with τ = 365 days. Results showed that the recurrence rate after tube removal was significantly lower in the LD group compared to the ND group (p = 0.001). The patency rates at one year after removal in the LD and ND group were 0.857 (0.754-0.919) and 0.739 (0.617-0.828), respectively. When comparing the patency rates by the RMST method at τ = 365 days, the RMST difference, RMST ratio, and RMTL ratio were higher in the LD group at p = 0.045, 0.052, and 0.046, respectively.

Comparison of the efficacies of 1.0mm and 1.5mm silicone tubes for the treatment of nasolacrimal duct obstruction

This study was designed to compare the postoperative outcomes of bicanalicular intubation using different diameters of silicone tubes to treat post-saccal nasolacrimal duct obstruction. A total of 130 patients diagnosed with post-saccal obstruction who underwent endoscopic-assisted silicone tube intubation were included in the study. The patients were divided into two groups; those intubated with a 1.5-mm large diameter tube (Group LD) and those with a 1.0-mm normal diameter tube (Group ND). The patency rates of the two groups at one year after tube removal were compared using the Kaplan–Meier's curve and Restricted mean survival time (RMST) method with τ = 365 days. Results showed that the recurrence rate after tube removal was significantly lower in the LD group compared to the ND group (p = 0.001). The patency rates at one year after removal in the LD and ND group were 0.857 (0.754-0.919) and 0.739 (0.617-0.828), respectively. When comparing the patency rates by the RMST method at τ = 365 days, the RMST difference, RMST ratio, and RMTL ratio were higher in the LD group at p = 0.045, 0.052, and 0.046, respectively.

Bokeh Effect Rendering with Vision Transformers

Bokeh effect is growing to be an important feature in photography, essentially to choose an object of interest to be in focus with the rest of the background being blurred. While naturally rendering this effect requires a DSLR with large diameter of aperture, with the current advancements in Deep Learning, this effect can also be produced in mobile cameras. Most of the existing methods use Convolutional Neural Networks while some relying on the depth map to render this effect. In this paper, we propose an end-to-end Vision Transformer model for Bokeh rendering of images from monocular camera. This architecture uses vision transformers as backbone, thus learning from the entire image rather than just the parts from the filters in a CNN. This property of retaining global information coupled with initial training of the model for image restoration before training to render the blur effect for the background, allows our method to produce clearer images and outperform the current state-of-the-art models on the EBB! Data set. The code to our proposed method can be found at: https://github.com/Soester10/ Bokeh-Rendering-with-Vision-Transformers.

Research progress on preparation, mechanism, and clinical application of nanofat

Autologous adipose tissue is an ideal soft tissue filling material in theory, which has the advantages of easy access, comprehensive source, and high biocompatibility and is now widely used in clinical practice. Based on the above benefits of autologous fat, autologous fat grafting is an essential technique in plastic surgery. Conventional macrofat is used to improve structural changes after soft tissue damage or loss caused by various causes such as disease, trauma, or aging. Due to the large diameter of particles and to avoid serious complications such as fat embolism, blunt needles with larger diameters (2mm) are required, making the macrofat grafting difficult to the deep dermis and sub-dermis. Nanofat grafting is a relatively new technology that has gained popularity in cosmetic surgery in recent years. Nanofat is produced by mechanical shuffling and filtration of microfat, which is harvested by liposuction. The harvesting and processing of nanofat are cost-effective as it does not require additional equipment or culture time. Unlike microfat, nanofat particles are too small to provide a notable volumizing effect. Studies have shown that nanofat contains abundant stromal vascular fraction (SVF) cells and adipose-derived stem cells (ADSCs), which help reconstruct dermal support structures, such as collagen, and regenerate healthier, younger-looking skin. Moreover, the fluid consistency of nanofat allows application in tissue regeneration, such as scars, chronic wounds, and facial rejuvenation. This article reviews the current research progress on the preparation, mechanism, and clinical application of nanofat.