Local Reconstruction Research Articles

Local Oxygen Reconstruction Enables Dual‐Ion Active Sites in Carbon Cathode for High Energy Density Sodium‐Ion Capacitors

AbstractCarbon materials are the promising cathode material for sodium‐ion capacitors (SICs) with high energy/power density, however, clarifying the evolution processes of functional groups in carbon materials and revealing their energy storage mechanisms are full of challenges. Inspired by the ancient practice of alchemy, which sought to purify Dan medicine and remove impurities through precise control of the refining temperature, the local oxygen reconstruction strategy, to alter the functional groups species in SP3‐C, is pioneeringly utilized, achieving targeted regulation of carbonyl groups with increase from 27.9 to 43.3 at%, which efficiently change the electronic structure of the carbon framework and realize the dual‐ion adsorption of Na+ and ClO4−, according well with the theoretical calculations. As expected, the obtained carbon cathode delivers a specific capacity of 145 mAh g−1, higher than that of the parent carbon material (95 mAh g−1). Impressively, the ex situ X‐ray Photoelectron Spectroscopy and in situ Raman reveals that carbonyl can act as dual‐ion active sites for Na+ and ClO4− through pseudocapacitive behavior under different voltage states. Notably, the assembled SIC using the carbonyl‐rich carbon cathode exhibits an ultrahigh energy density of 162 Wh kg−1. This work opens a novel avenue for regulating the carbonyl content of carbon materials.

Real-Time LiDAR–Inertial Simultaneous Localization and Mesh Reconstruction

In this paper, a novel LiDAR–inertial-based Simultaneous Localization and Mesh Reconstruction (LI-SLAMesh) system is proposed, which can achieve fast and robust pose tracking and online mesh reconstruction in an outdoor environment. The LI-SLAMesh system consists of two components, including LiDAR–inertial odometry and a Truncated Signed Distance Field (TSDF) free online reconstruction module. Firstly, to reduce the odometry drift errors we use scan-to-map matching, and inter-frame inertial information is used to generate prior relative pose estimation for later LiDAR-dominated optimization. Then, based on the motivation that the unevenly distributed residual terms tend to degrade the nonlinear optimizer, a novel residual density-driven Gauss–Newton method is proposed to obtain the optimal pose estimation. Secondly, to achieve fast and accurate 3D reconstruction, compared with TSDF-based mapping mechanism, a more compact map representation is proposed, which only maintains the occupied voxels and computes the vertices’ SDF values of each occupied voxels using an iterative Implicit Moving Least Squares (IMLS) algorithm. Then, marching cube is performed on the voxels and a dense mesh map is generated online. Extensive experiments are conducted on public datasets. The experimental results demonstrate that our method can achieve significant localization and online reconstruction performance improvements. The source code will be made public for the benefit of the robotic community.

High order recovery of geometric interfaces from cell-average data

We consider the problem of recovering multivariate characteristic functions u := χΩ from cell-average data on a coarse grid, motivated in particular by the accurate treatment of interfaces in finite volume schemes. While linear recovery methods are known to perform poorly, nonlinear strategies based on local reconstructions of the jump interface Γ := ∂Ω by geometrically simpler interfaces may offer significant improvements. We study two main families of local reconstruction schemes the first one based on nonlinear least-squares fitting, the second one based on the explicit computation of a polynomial-shaped curve fitting the data, which yields simpler numerical computations and high order geometric fitting. For each of them, we derive a general theoretical framework which allows us to control the recovery error by the error of best approximation up to a fixed multiplicative constant. Numerical tests in 2d illustrate the expected approximation order of these strategies. Several extensions are discussed, in particular the treatment of piecewise smooth interfaces with corners.

Comparison of Patient-Reported Outcomes after Local Flap Coverage versus Amputation for Complex Lower Extremity Trauma

Abstract Background There is a paucity of patient-reported outcomes (PROs) data in lower extremity salvage. Limb salvage can often be achieved with the use of local muscle flaps or fasciocutaneous flaps. The purpose of this study was to compare PROs of patients who underwent lower extremity salvage using local fasciocutaneous flaps or muscle flaps to lower extremity amputation. Materials and Methods The outcomes of 61 patients that underwent lower extremity local flap reconstruction (n = 33) or amputation (n = 28) between 2014 and 2020 were recorded. Chart reviews were performed to collect perioperative data. Patients were contacted via telephone for participation in the survey portion of our study. PROs were recorded utilizing both the Lower Extremity Functional Scale (LEFS) and the 36-Item Short-Form Health Survey (SF-36). Results Surveys were completed by 61 patients (response rate 59.2%). The mean time of survey after flap reconstruction or amputation was 2.7 ± 1.4 years. Recent trauma (within 90 days) was the most common indication for local flap coverage (n = 23). LEFS score and SF-36 physical functioning scores were significantly lower in patients who underwent muscle flaps compared with fasciocutaneous flaps (p = 0.021 and p = 0.022). Muscle flap patients had similar LEFS and SF-36 scores to amputation patients, while fasciocutaneous flap patients had significantly higher LEFS (p = 0.01), SF-36 physical functioning (p = 0.031), physical role functioning (p = 0.031), and emotional role functioning (p = 0.047) scores than amputation patients. Conclusion Patients who underwent local fasciocutaneous flaps for limb salvage reported higher PRO scores than those undergoing amputation, while patients undergoing muscle flaps reported outcomes similar to those undergoing amputation. PROs for muscle flap patients were significantly lower than those of fasciocutaneous flap patients. These data suggest that while fasciocutaneous and muscle flaps are both useful limb salvage procedures, fasciocutaneous flaps may confer advantages that result in improved patient-perceived outcomes. Further study is needed to better characterize outcomes in limb salvage.

CPH-Fmnet: An Optimized Deep Learning Model for Multi-View Stereo and Parameter Extraction in Complex Forest Scenes

The three-dimensional reconstruction of forests is crucial in remote sensing technology, ecological monitoring, and forestry management, as it yields precise forest structure and tree parameters, providing essential data support for forest resource management, evaluation, and sustainable development. Nevertheless, forest 3D reconstruction now encounters obstacles including higher equipment costs, reduced data collection efficiency, and complex data processing. This work introduces a unique deep learning model, CPH-Fmnet, designed to enhance the accuracy and efficiency of 3D reconstruction in intricate forest environments. CPH-Fmnet enhances the FPN Encoder-Decoder Architecture by meticulously incorporating the Channel Attention Mechanism (CA), Path Aggregation Module (PA), and High-Level Feature Selection Module (HFS), alongside the integration of the pre-trained Vision Transformer (ViT), thereby significantly improving the model’s global feature extraction and local detail reconstruction abilities. We selected three representative sample plots in Haidian District, Beijing, China, as the study area and took forest stand sequence photos with an iPhone for the research. Comparative experiments with the conventional SfM + MVS and MVSFormer models, along with comprehensive parameter extraction and ablation studies, substantiated the enhanced efficacy of the proposed CPH-Fmnet model in addressing difficult circumstances such as intricate occlusions, poorly textured areas, and variations in lighting. The test results show that the model does better on a number of evaluation criteria. It has an RMSE of 1.353, an MAE of only 5.1%, an r value of 1.190, and a forest reconstruction rate of 100%, all of which are better than current methods. Furthermore, the model produced a more compact and precise 3D point cloud while accurately determining the properties of the forest trees. The findings indicate that CPH-Fmnet offers an innovative approach for forest resource management and ecological monitoring, characterized by cheap cost, high accuracy, and high efficiency.

National Trends in Laryngeal Laser Surgery: Comparison of Operative Versus Office-Based Procedures.

To analyze national trends in the prevalence of office-based laryngeal ablative procedures and compare those with traditional operative excisional procedures utilizing direct laryngoscopy. For years 2013-2022, the US Medicare Part B claims database was searched for Current Procedural Terminology (CPT) codes 31572 (flexible laryngoscopy with laser ablation of lesion), 31540 (operative direct laryngoscopy with excision of lesion), 31541 (operative direct microlaryngoscopy with excision of lesion), and 31545 (operative direct microlaryngoscopy with excision of lesion and local tissue flap reconstruction). For each CPT code, the total number of charges billed to the Medicare database in each calendar year was recorded and annual trends were analyzed. Biopsy procedures were not included. The annual number of office-based laser procedures (CPT 31572) remained relatively constant since the CPT code was introduced in 2017 (range: 18887-25241 procedures annually, trendline slope = +16, R2:0.02). Office-based laser procedures comprised a small portion of total laryngeal excisional procedures (range: 8.4%-12.1%). The total number of operative laryngeal excisions, billed by CPT 31540 and 31541, declined over the studied time frame (Trendline slope = -132, R2:0.93; Trendline slope = -950, R2: 0.93 respectively). Office-based laser procedures comprise a small fraction of procedures to remove laryngeal lesions. The number of office-based laser procedures has been relatively stable over the last 5 years. This finding contrasts with the prevailing health care trend toward office-based procedures. Further research is needed to understand the decrease in operative laryngeal lesion excision procedures observed over the last 10 years. 4 Laryngoscope, 2024.

Efficient pretraining model based on multi-scale local visual field feature reconstruction for PCB CT image element segmentation

Element segmentation is a key step in nondestructive testing of printed circuit boards (PCBs) based on computed tomography (CT) technology. In recent years, there has been rapid development of self-supervised pretraining technology that can obtain general image features without labeled samples and then uses a small amount of labeled samples to solve downstream tasks, which has good potential in PCB element segmentation. At present, a masked image modeling (MIM) pretraining model has been initially applied in PCB CT image element segmentation. However, due to the small and regular size of PCB elements such as vias, wires, and pads, the global visual field has redundancy for a single-element reconstruction, which may damage the performance of the model. Based on this issue, we propose an efficient pretraining model based on multi-scale local visual field feature reconstruction for PCB CT image element segmentation (EMLR-seg). In this model, the teacher-guided MIM pretraining model is introduced into PCB CT image element segmentation for the first time, to our knowledge, and a multi-scale local visual field extraction (MVE) module is proposed to reduce redundancy by focusing on local visual fields. At the same time, a simple four-Transformer-blocks decoder is used. Experiments show that EMLR-seg can achieve 88.6% mIoU on the PCB CT image dataset we proposed, which exceeds 1.2% by the baseline model, and the training time is reduced by 29.6 h, a reduction of 17.4% under the same experimental condition, which reflects the advantage of EMLR-seg in terms of performance and efficiency.

Pre-expanded Local Flaps: Optimal Choice for Repairing Defects Following Extensive Benign Tumor Resection in the Head and Face.

Treating extensive benign tumors of the head and face presents a longstanding challenge, necessitating efficacy at the lesion site, and postoperative esthetic considerations for the donor area. This study aims to explore the clinical outcomes of pre-expanded local flap reconstruction for extensive benign tumors of the head and face post resection. From March 2018 to March 2023, a total of 18 patients with extensive benign tumors of the head and face were admitted, including 13 cases of nevus, 2 cases of hemangioma, 2 cases of neurofibroma, and 1 case of verruca. Based on the location and size of the lesions, suitable local areas were selected for tissue expansion, and expanders were implanted for regular saline injections over 8 to 16 weeks. After reaching the desired expansion, resection of the head and facial tumors and local flap reconstruction were performed. Postoperatively, data on patients' information, tumor types, tumor area, expansion volume, postexpander complications, vascular condition after flap transfer, and donor site condition were collected. In this series of 18 patients, benign tumors of the head and face were completely repaired through 1 to 2 stages of tissue expansion surgeries. Postimplantation complications included hematoma in 1 case and infections in 2 cases, with one instance of expander infection leading to surgical failure. However, all other patients achieved adequate expansion, successful flap survival post-transfer, and experienced no other complications. Follow-up over 6 to 24 months showed no recurrence at the lesion sites, with flaps maintaining consistent color, texture, and thickness matching surrounding skin tissue. In addition, donor site healing was excellent, with no obvious surgical scars. Pre-expanded local flap reconstruction is an ideal method for repairing extensive benign tumors of the head and face postresection.

Adaptive infrared patterns for microscopic surface reconstructions.

Multi-zoom microscopic surface reconstructions of operating sites, especially in ENT surgeries, would allow multimodal image fusion for determining the amount of resected tissue, for recognizing critical structures, and novel tools for intraoperative quality assurance. State-of-the-art three-dimensional model creation of the surgical scene is challenged by the surgical environment, illumination, and the homogeneous structures of skin, muscle, bones, etc., that lack invariant features for stereo reconstruction. An adaptive near-infrared pattern projector illuminates the surgical scene with optimized patterns to yield accurate dense multi-zoom stereoscopic surface reconstructions. The approach does not impact the clinical workflow. The new method is compared to state-of-the-art approaches and is validated by determining its reconstruction errors relative to a high-resolution 3D-reconstruction of CT data. 200 surface reconstructions were generated for 5 zoom levels with 10 reconstructions for each object illumination method (standard operating room light, microscope light, random pattern and adaptive NIR pattern). For the adaptive pattern, the surface reconstruction errors ranged from 0.5 to 0.7 mm, as compared to 1-1.9 mm for the other approaches. The local reconstruction differences are visualized in heat maps. Adaptive near-infrared (NIR) pattern projection in microscopic surgery allows dense and accurate microscopic surface reconstructions for variable zoom levels of small and homogeneous surfaces. This could potentially aid in microscopic interventions at the lateral skull base and potentially open up new possibilities for combining quantitative intraoperative surface reconstructions with preoperative radiologic imagery.

Identifying Rare Events in Quantum Molecular Dynamics of Nanomaterials with Outlier Detection Indices.

Nanoscale and condensed matter systems evolve on multiple length- and time-scales, and rare events such as local phase transformation, ion segregation, defect migration, interface reconstruction, and grain boundary sliding can have a profound influence on material properties. We demonstrate how outlier detection indices can be used to identify rare events in machine-learning based, high-dimensional molecular dynamics (MD) simulations. Designed to order data-points from typical to untypical, the indices enable one to capture atomic events that are hard to detect otherwise. We demonstrate the approach with a nanosecond MD simulation of a grain boundary in a metal halide perovskite that is extensively studied for solar energy and optoelectronic applications. The method captures the initial grain boundary sliding and a spontaneous fluctuation half a nanosecond later, both events giving rise to persistent deep electronic trap states that impact charge carrier lifetime and transport and material performance. The approach offers a generalizable and simple method for identifying outlier events in complex condensed matter, molecular, and nanoscale systems.

FilterGNN: Image feature matching with cascaded outlier filters and linear attention

The cross-view matching of local image features is a fundamental task in visual localization and 3D reconstruction. This study proposes FilterGNN, a transformer-based graph neural network (GNN), aiming to improve the matching efficiency and accuracy of visual descriptors. Based on high matching sparseness and coarse-to-fine covisible area detection, FilterGNN utilizes cascaded optimal graph-matching filter modules to dynamically reject outlier matches. Moreover, we successfully adapted linear attention in FilterGNN with post-instance normalization support, which significantly reduces the complexity of complete graph learning from O(N2) to O(N). Experiments show that FilterGNN requires only 6% of the time cost and 33.3% of the memory cost compared with SuperGlue under a large-scale input size and achieves a competitive performance in various tasks, such as pose estimation, visual localization, and sparse 3D reconstruction.

Optimizing Lower Extremity Local Flap Reconstruction in Peripheral Vascular Disease.

Local flaps remain a valuable reconstructive tool as a means for limb salvage for patients with advanced arterial disease. Our single-center, retrospective cohort study aims to compare the outcomes of different patterns of blood flow affected by vascular disease to pedicles in local flap reconstruction of the foot and ankle. A retrospective review of 92 patients and 103 flaps was performed. On angiograms, pattern of blood flow to the flap pedicle was determined to be direct inline flow (DF) or indirect flow (IF). Patterns of IF were either by arterial-arterial connections (AC) or unnamed randomized collaterals (RC). Primary outcomes were immediate flap success and limb salvage. Comparative analyses were performed using the χ2 and Fisher tests for categorical variables. Among all flaps, 73.8% (n = 76/103) had DF and 26.2% (n = 27/103) had IF. Both groups experienced similar rates of immediate flap success (DF = 97.3% vs IF = 92.6%, P = 0.281) and limb salvage (DF = 75.% vs IF = 66.7%, P = 0.403). However, the rate of contralateral amputation was significantly higher in the IF group (26.9% vs 5.3%, P = 0.006). When comparing the 3 distinct patterns of blood flow (DF vs AC vs RC), pedicled flaps were more commonly supplied by DF and AC, while random pattern flaps were more commonly supplied by RC (P = 0.042). Alternative routes of revascularization can maintain local flap viability and achieve similar rates of limb salvage but risks contralateral amputation. We found that pedicled and local muscle flaps require inline blood flow or blood supply by ACs. Meanwhile, random pattern flap can be supported by random collaterals.

Management of Pediatric Type III Tibial Shaft Fractures: A Cohort Study Utilizing the Trauma Quality Improvement Program Database.

Pediatric open tibial fractures represent a challenging subset of injuries with limited literature to guide management. For children, the epidemiology, management, and outcomes of tibial-shaft fractures have not been fully described. A retrospective analysis of the Trauma Quality Improvement Program Data Bank from 2017-2020 was used to query demographics, injury patterns, and management strategies in pediatric open tibial fractures. Fractures were compared by age group (0-5, 6-12, 13-17 years) and type (I/II vs type III). A subgroup analysis was performed on patients with type III open fractures. A total of 3480 open tibial fractures were identified, 3049 were type I/II, and 431 were type III. Motor vehicle accidents (48%) were the most common mechanism of injury (P < 0.001). Subanalysis of 128 type IIIb/c tibial fractures revealed local flap reconstruction (25%) skin graft (25%), and free tissue transfer were the most common management strategies and soft-tissue coverage was achieved after 162 hours (interquartile range = 109-231). Negative pressure wound therapy was utilized in 63% of cases but used in isolation in only 23% of cases. Immediate fixation with intramedullary nailing was more frequently used in the 13-17 age group while plate fixation was more commonly used in younger age groups. Soft-tissue management patterns following open tibial shaft fractures mirror those seen in adult cohorts. The median time to achieve soft-tissue coverage exceeds the traditional 72-hour target advocated by Godina. Age-based variation is seen in orthopedic management of these fractures based on growth maintenance concerns.

A Breast Sharing Technique using the pedicled IMAP flap for Delayed Breast Reconstruction and Contralateral Symmetrising Mammaplasty: A case series and evolution of the surgical technique in selected patients.

IntroductionThe ‘breast-sharing’ procedure uses the disposable tissue as a flap to reconstruct the post-mastectomy defect. This enables simultaneous breast reconstruction and contralateral symmetrisation without additional donor site morbidity. However, controversies related to the oncological safety of this procedure have prevented its widespread uptake. We aim to present this technique based on a pedicled internal mammary artery perforator (IMAP) flap and discuss its technical feasibility and oncological safety. Patients and methodsBetween April 2013 and May 2022, a series of 10 consecutive patients underwent a breast-sharing procedure using the pedicled IMAP flap for breast reconstruction. Clinical and surgical aspects of the breast-sharing procedure were analysed. ResultsIn all cases, the breast-sharing technique allowed for simultaneous breast reconstruction and contralateral breast symmetrisation. Immediate complications included two total venous congestions and one hematoma. Three flaps had distal flap congestion. One flap required debridement and local flap reconstruction. All flaps required fat grafting during the secondary procedures to improve breast symmetry. With an average follow-up of 5,6 years, there was no evidence of recurrent disease. All patients were satisfied to very satisfied with the aesthetic outcome of this reconstructive option. ConclusionsThe breast-sharing technique based on the IMAP flap combines breast reconstruction and contralateral symmetrisation with good aesthetic outcomes in selected patients. The flap has a high complication rate related to venous drainage. Flap design modification and using ICG imaging may reduce venous congestion. A secondary venous micro-anastomosis at the axilla is highly recommended for persistent flap congestion. The reported incidence of contralateral breast cancer is low and thus the residual tissue obtained from the contralateral breast mammaplasty can be safely used for breast reconstruction. Level of EvidenceLevel IV

Integrative structural analysis of Pseudomonas phage DEV reveals a genome ejection motor

DEV is an obligatory lytic Pseudomonas phage of the N4-like genus, recently reclassified as Schitoviridae. The DEV genome encodes 91 ORFs, including a 3398 amino acid virion-associated RNA polymerase (vRNAP). Here, we describe the complete architecture of DEV, determined using a combination of cryo-electron microscopy localized reconstruction, biochemical methods, and genetic knockouts. We built de novo structures of all capsid factors and tail components involved in host attachment. We demonstrate that DEV long tail fibers are essential for infection of Pseudomonas aeruginosa but dispensable for infecting mutants with a truncated lipopolysaccharide devoid of the O-antigen. We determine that DEV vRNAP is part of a three-gene operon conserved in 191 Schitoviridae genomes. We propose these three proteins are ejected into the host to form a genome ejection motor spanning the cell envelope. We posit that the design principles of the DEV ejection apparatus are conserved in all Schitoviridae.

Efficacy and Functional Outcomes of Platysma Myocutaneous Flap in Oral and Maxillofacial Reconstruction.

Maxillofacial reconstruction strives to restore the form and function of the maxillofacial region in patientswith deformities caused by trauma, disease, cancer, or congenital malformations. An array of surgical procedures has been advised for restoring soft tissues in the oral cavity, with varied degrees of efficacy. This prospective study seeks to provide a thorough understanding of the success rate, complications, functional outcomes, and patient satisfaction associated with the utilization of platysma myocutaneous flap (PMF) in this specialized domain. This study aims to elaborate on the PMF surgical technique, along with the flap design, outcomes, and intricacies associated with age, gender, the recipient site, and defect size. The study included 30 patients with oral malignancies who intervened under general anesthesia with wide local excision and reconstruction with PMF at a single tertiary care center. The results showed that the PMF is an efficient flap in the context of its ease of harvest, minimal donor site morbidity, low complication rates (infection - 26.67%, flap dehiscence - 16.67%, and flap necrosis - 6.77%), and ability to rehabilitate both form and function. In conclusion, the PMF stands as a viable alternative in oral and maxillofacial reconstruction, offering a combination of versatility, reliable blood supply, and potential for functional restoration.

Control of Subband Energies via Interlayer Twisting in an Artificially Stacked WSe2 Bilayer.

Tuning the electronic structure of artificially stacked bilayer crystals using their twist angle has attracted a significant amount of interest. In this study, resonant tunneling spectroscopy was performed on trilayer WSe2/h-BN/twisted bilayer (tBL) WSe2 devices with a wide range of twist angles (θBL) of tBL WSe2, from 0° to 34°. We observed two resonant tunneling peaks, identified as the first and second lowest hole subbands at the valence band Γ point of tBL WSe2. The subband separation, which directly measured the interlayer coupling strength, was tuned by ∼0.1 eV as θBL increased toward 6° and remained nearly constant for larger θBL values. The θBL dependence was attributed to the emergence of a stable W/Se (Se/W) stacking domain in the small θBL region, owing to the atomic reconstruction of the moiré lattice in tBL WSe2. Our findings demonstrate that the twist-controlled subband energies in tBL WSe2 are predominantly determined by local atomic reconstruction.

A coupled local front reconstruction and immersed boundary method for simulating 3D multiphase flows with contact line dynamics in complex geometries

Multi-phase flows in the presence of complex solid geometries are encountered widely throughout industrial processes to intensify mass and heat transfer processes. The efficiency of these processes relies largely on the predominant fluid dynamics regime inside the reaction vessel (e.g. trickle bed, bubble column reactor). The prevailing flow structure is influenced by many factors including the nature of the fluid-solid interactions (i.e. wetting or non-wetting). Such flows are often studied using front-capturing techniques to capture the fluid-fluid interface in combination with an auxiliary model to account for fluid-solid interactions. However, these front-capturing methods have difficulties in accurately representing the interface. Therefore, we adopted a front-tracking method: the Local Front Reconstruction Method (LFRM). In this study, LFRM is coupled with the Immersed Boundary method to incorporate the no-slip boundary condition at the solid surface. The model performance is assessed using droplet spreading simulations, where the equilibrium droplet shape (i.e. radius, height, and outline), the interfacial pressure difference, and the surface tension force are compared to analytical solutions and literature data. The results show an excellent match with the analytical solutions, and additionally superior performance to state-of-the-art volume tracking models.

Object and spatial discrimination makes weakly supervised local feature better

Local feature extraction plays a crucial role in numerous critical visual tasks. However, there remains room for improvement in both descriptors and keypoints, particularly regarding the discriminative power of descriptors and the localization precision of keypoints. To address these challenges, this study introduces a novel local feature extraction pipeline named OSDFeat (Object and Spatial Discrimination Feature). OSDFeat employs a decoupling strategy, training descriptor and detection networks independently. Inspired by semantic correspondence, we propose an Object and Spatial Discrimination ResUNet (OSD-ResUNet). OSD-ResUNet captures features from the feature map that differentiate object appearance and spatial context, thus enhancing descriptor performance. To further improve the discriminative capability of descriptors, we propose a Discrimination Information Retained Normalization module (DIRN). DIRN complementarily integrates spatial-wise normalization and channel-wise normalization, yielding descriptors that are more distinguishable and informative. In the detection network, we propose a Cross Saliency Pooling module (CSP). CSP employs a cross-shaped kernel to aggregate long-range context in both vertical and horizontal dimensions. By enhancing the saliency of keypoints, CSP enables the detection network to effectively utilize descriptor information and achieve more precise localization of keypoints. Compared to the previous best local feature extraction methods, OSDFeat achieves Mean Matching Accuracy of 79.4% in local feature matching task, improving by 1.9% and achieving state-of-the-art results. Additionally, OSDFeat achieves competitive results in Visual Localization and 3D Reconstruction. The results of this study indicate that object and spatial discrimination can improve the accuracy and robustness of local feature, even in challenging environments. The code is available at https://github.com/pandaandyy/OSDFeat.

Dynamic anatomical study of the posterior brachial artery perforator flap: Aesthetic refinement and clinical results

BackgroundReconstruction of the axillary fossa represents a surgical challenge given the functional implications for mobility of the upper limb. The posterior brachial flap is a solution of choice for this indication, providing fine and functional local reconstruction, but little is known about its perforasome. This study aimed to identify the location of the perforator, analyze perfusion flow, and link vessel distribution, and propose an aesthetic refinement to the surgical technique by medializing the skin paddle to conceal aesthetic scarring at the donor site. MethodsFifteen fresh cadavers were harvested and dissected. Twenty-six arms were injected with methylene blue. Two arms were injected with radiopaque dye. A dynamic (4-dimensional) computed tomographic angiography was performed to complete the analysis. ResultsThe perforasome was centered on the posterior axis of the arm with a perfusion area ranging from 82.2 to 142.9 cm², with a median of 112.7 (96.7–125.6) cm². The median length of the pedicle was 83 mm on an average (65–91 mm). Its caliber at the emergence of the source vessel had a mean diameter of 1.43 mm (1.27–1.61 mm). The distal limit of the paddle was located on an average 10.7 cm from the olecranon (7.8–12.2 cm). The scans showed direct linking vessels toward the perforasomes on the medial side of the arm, suggesting that it is possible to medialize the cutaneous paddle. ConclusionThe posterior brachial flap presents with a constant perforasome. It can be harvested more medially than previously described to improve the aesthetic results, while maintaining reproducibility and satisfactory vascular reliability.