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Effective removal of noises from raw point clouds while preserving geometric features is the key challenge for point cloud denoising. To address this problem, we propose a novel method that jointly optimizes the point positions and normals. To preserve geometric features, our formulation uses a generalized robust error metric to enforce piecewise smoothness of the normal vector field as well as consistency between point positions and normals. By varying the parameter of the error metric, we gradually increase its non-convexity to guide the optimization towards a desirable solution. By combining alternating minimization with a majorization-minimization strategy, we develop a numerical solver for the optimization which guarantees convergence. The effectiveness of our method is demonstrated by extensive comparisons with previous works.

Abstract Deep learning has been successfully used for tasks in the 2D image domain. Research on 3D computer vision and deep geometry learning has also attracted attention. Considerable achievements have been made regarding feature extraction and discrimination of 3D shapes. Following recent advances in deep generative models such as generative adversarial networks, effective generation of 3D shapes has become an active research topic. Unlike 2D images with a regular grid structure, 3D shapes have various representations, such as voxels, point clouds, meshes, and implicit functions. For deep learning of 3D shapes, shape representation has to be taken into account as there is no unified representation that can cover all tasks well. Factors such as the representativeness of geometry and topology often largely affect the quality of the generated 3D shapes. In this survey, we comprehensively review works on deep-learning-based 3D shape generation by classifying and discussing them in terms of the underlying shape representation and the architecture of the shape generator. The advantages and disadvantages of each class are further analyzed. We also consider the 3D shape datasets commonly used for shape generation. Finally, we present several potential research directions that hopefully can inspire future works on this topic.

Immunogenic cell death (ICD), one of cell-death types through release of damage-associated molecular patterns from dying tumor cells, activates tumor-specific immune response and elicits anti-tumor immunity by traditional radiotherapy and chemotherapy. However, whether natural products could induce ICD in leukemia is not elucidated. Here, we report dietary γ-mangostin eradicates murine primary leukemic cells and prolongs the survival of leukemic mice. As well, it restrains primary leukemic cells and CD34+ leukemic progenitor cells from leukemia patients. Strikingly, γ-mangostin attenuates leukemic cells by inducing ICD as characterized by expression of HSP90B1, ANXA1 and IL1B. Additionally, γ-mangostin accelerates cytoplasmic chromatin fragments generation, promoting DNA damage response, and enhances cGAS activation, leading to up-regulation of chemokines. Meanwhile, it induces HDAC4 degradation and acetylated histone H3 accumulation, which promotes chemokines transcription. Ultimately, CD8+ T cell is activated and recruited by γ-mangostin-induced chemokines in the microenvironment. Our study identifies γ-mangostin triggers ICD and activates cGAS signaling through DNA damage response and epigenetic modification. Therefore, dietary γ-mangostin would act as a potential agent to provoke anti-tumor immunity in the prevention and treatment of leukemia.

Objective To describe the application of reversed contralateral distal femoral locking compression plate (DF‐LCP) inserted through a progressive and intermittent drilling procedure in the treatment of osteopetrotic subtrochanteric fracture (OSF). Methods Three patients (one male and two females with an average age of 45.33 ± 11.09 years) with OSF hospitalized between September 2015 and September 2020, were included in this present study. Lateral approach was applied in all patients who accepted open reduction and internal fixation (ORIF) with a reversed contralateral DF‐LCP inserted through a progressive and intermittent drilling procedure. The operation time and intraoperative blood loss were recorded to evaluate the efficiency of this surgical method. Physical examination and imaging examination of the fracture site were used to evaluate the fracture union status, the position and stability of the implant, and the alignment of the injured limb at 1, 3, 6, and 12 months after operation, then a subsequent visit was conducted at least once a year. Harris Hip Score (HHS) was used to evaluate the hip joint function at 6 and 12 months after operation. Results The average operation time was 140 ± 21.60 min (110, 160, and 150 min); The average intraoperative blood loss was about 333.33 ± 23.57 ml (300, 350, and 350 ml). The average follow‐up time was 22.33 ± 7.41 months (29, 26, and 12 months). All patients achieved bone union with an average time of 6.67 ± 0.94 months (6, 8, and 6 months). At the time of 6 months after operation, case 1 and 3 were almost pain‐free and could walk with full weight bearing while case 2 could walk only with partial weight bearing using a crutch. The HHS scores of cases 1, 2, and 3 were 84/100, 74/100, and 92/100, respectively. At the follow‐up at 12 months after operation, the HHS score improved to 91/100, 81/100, and 96/100, respectively. The contralateral incomplete old subtrochanteric fracture was deteriorated in case 1 at 26 months after operation. After 3 months of limited weight bearing using a crutch, bone union was verified in radiograph imaging. Fresh contralateral subtrochanteric fracture occurred in case 2 at 26 months after operation, which was treated using a similar surgical approach, and its clinical outcome is under follow‐up. Moreover, no perioperative complications including operation‐related death, vascular/nerve injury, deep venous thrombosis, pulmonary embolism, and incision infection, and long‐term complications involving malunion, nonunion, implant failure, ankylosis, heterotopic ossification, osteonecrosis, and osteomyelitis were identified. Conclusion The application of reversed contralateral DF‐LCP in OSF is practicable and reliable. Progressive and intermittent drilling is a safe and efficient method for implant insertion in this complicated situation.

The aerodynamic characteristics are vital for short cylindrical Terminal Sensitive Bullets (TSB) with low aspect ratio, especially in terminal trajectory. Currently, there is little research in terms of the TSB and short cylinder with two free ends, and particularly in this trajectory, where the scanning angle β and roll angle α vary over a broad range between 0° and 180°. In this work, wind tunnel experiments are first conducted to learn the effects of Reynolds number and scanning angle on aerodynamic parameters for short cylinder with aspect ratio L/D=1. Similar to infinite cylinder, for the short cylinder with two free ends, the drag crisis phenomenon still exists in the critical regime 1.7×105≤Re≤6.8×105. Then 3D simulations are performed to demonstrate the aerodynamic characteristics of short cylinder and TSB over a broad range of Re, L/D, α and β. The sensitivity analysis of time step and grid are presented as well. When β=0°, for short cylinder, the drag crisis phenomenon was also observed in the simulation, but not as obvious as in the wind tunnel test. In some attitudes, there is an obvious Kármán vortex in the wake of short cylinder and TSB. The correlation between time-averaged aerodynamic coefficients and L/D, Re, α&β is discussed. The vortex shedding frequency and shear layer behavior are obtained for quasi-steady and unsteady flow. Finally, the effect of end’s shape on drag reduction and vortex shedding frequency is analyzed.

Objective To investigate the clinical efficacy and outcomes of the coracoid osteotomy with or without Bristow–Latarjet procedures in the treatment of chronic anterior shoulder dislocation (CASD). Methods Between January 2013 and January 2019, 20 shoulders of 18 patients who were diagnosed with chronic anterior dislocation and underwent open reduction in our trauma center were retrospectively studied. Open coracoid osteotomy with Bristow–Latarjet procedures were performed on 16 shoulders and open coracoid osteotomy without Bristow–Latarjet procedures were performed on four shoulders. Open coracoid osteotomy with or without Bristow–Latarjet procedures were chosen on the basis of the stability of the shoulder after reduction. Outcomes were assessed preoperatively and postoperatively with the visual analog scale (VAS) for pain, the American Shoulder and Elbow Surgeons (ASES) score, the University of California Los Angeles (UCLA) shoulder rating scale, and the range of motion (ROM) for shoulder activity. Results There were three males and 15 females with an average age of 60.94 ± 2.69 years. The time between dislocation and treatment ranged from 21 to 240 days with an average of 73.3 ± 14.4 days. All patients were available for a mean follow‐up of 15.2 ± 4.3 months. No procedure‐related death or incision‐related superficial or deep tissue infection was identified in all cases. No iatrogenic neurovascular injuries or fractures were found in this study. At the time of 12 months follow‐up, the range of motion and the shoulder functional evaluation (VAS [P

Abstract Humans have the ability to perceive kinetic depth effects, i.e., to perceived 3D shapes from 2D projections of rotating 3D objects. This process is based on a variety of visual cues such as lighting and shading effects. However, when such cues are weak or missing, perception can become faulty, as demonstrated by the famous silhouette illusion example of the spinning dancer. Inspired by this, we establish objective and subjective evaluation models of rotated 3D objects by taking their projected 2D images as input. We investigate five different cues: ambient luminance, shading, rotation speed, perspective, and color difference between the objects and background. In the objective evaluation model, we first apply 3D reconstruction algorithms to obtain an objective reconstruction quality metric, and then use quadratic stepwise regression analysis to determine weights of depth cues to represent the reconstruction quality. In the subjective evaluation model, we use a comprehensive user study to reveal correlations with reaction time and accuracy, rotation speed, and perspective. The two evaluation models are generally consistent, and potentially of benefit to inter-disciplinary research into visual perception and 3D reconstruction.

Abstract Modeling the complete geometry of general shapes from a single image is an ill-posed problem. User hints are often incorporated to resolve ambiguities and provide guidance during the modeling process. In this work, we present a novel interactive approach for extracting high-quality freeform shapes from a single image. This is inspired by the popular lofting technique in many CAD systems, and only requires minimal user input. Given an input image, the user only needs to sketch several projected cross sections, provide a “main axis”, and specify some geometric relations. Our algorithm then automatically optimizes the common normal to the sections with respect to these constraints, and interpolates between the sections, resulting in a high-quality 3D model that conforms to both the original image and the user input. The entire modeling session is efficient and intuitive. We demonstrate the effectiveness of our approach based on qualitative tests on a variety of images, and quantitative comparisons with the ground truth using synthetic images.

To improve the damage efficiency of compact terminal sensitive projectile with EFP warhead, it is vital to understand how the embedded structure (ES) affects the EFP forming performance. In this paper, the corresponding numerical investigation is focused on, in which the fluid-structure interaction (FSI) method and the experimental verification are used. Based on the obtained quantitative relations between the forming performance and α (the ratio of height to maximum radius of ES), an optimal design is further provided. The results indicate that: when the embedded structural length and width range 0.1–0.3D and 0.1–0.2D (D: diameter of EFP warhead) at a fixed volume, respectively, EFP forming velocity nearly keeps as a constant, 1760 m/s; the height of ES has a dramatical effect on the propagating range of detonation wave, resulting in significant influence on the aerodynamic shape and length-to-diameter ratio of EFP; under the given constraints, the EFP length-diameter ratio can reach the optimal value 2.76, when the height of ES is 0.22D.