Local Reconstruction Research Articles

The Use of Flap Techniques to Preserve Limb Length in Patients with Transmetatarsal Amputations.

Chronic lower extremity wounds affect up to 13% of the US population. Transmetatarsal amputation (TMA) is frequently performed in patients with chronic forefoot wounds. TMA allows limb salvage and preserves functional gait, without need for prosthesis. Traditionally, when tension-free primary closure is not possible, a higher-level amputation is performed. This is the first series to evaluate the outcomes of local and free flap coverage of TMA stumps in patients with chronic foot wounds. A retrospective cohort of patients who underwent TMA with flap coverage from 2015 through 2021 was reviewed. Primary outcomes included flap success, early postoperative complications, and long-term outcomes (limb salvage and ambulatory status). Patient-reported outcome measures using the Lower Extremity Functional Scale (LEFS) were also collected. Fifty patients underwent 51 flap reconstructions (26 local, 25 free flap) after TMA. Average age and body mass index were 58.5 years and 29.8 kg/m 2 , respectively. Comorbidities included diabetes [ n = 43 (86%)] and peripheral vascular disease [ n = 37 (74%)]. Flap success rate was 100%. At a mean follow-up of 24.8 months (range, 0.7 to 95.7 months), the limb salvage rate was 86.3% ( n = 44). Forty-four patients (88%) were ambulatory. The LEFS survey was completed by 24 surviving patients (54.5%). Mean LEFS score was 46.6 ± 13.9, correlating with 58.2% ± 17.4% of maximal function. Local and free flap reconstruction after TMA are viable methods of soft-tissue coverage for limb salvage. Applying plastic surgery flap techniques for TMA stump coverage allows for preservation of increased foot length and ambulation without a prosthesis. Therapeutic, IV.

Synergistic electrocatalysis of crystal facet and O-vacancy for enhancive urea synthesis from nitrate and CO2

One-pot green urea electrosynthesis from CO2 and nitrogenous pollutants via the co-reductive C−N coupling route under ambient conditions is prospective to replace the traditional urea synthesis process. Here, a bifunctional indium hydroxide (Vo-S-IO-6) bearing oxygen vacancy (Vo) sites on {100} facets was developed to markedly enable urea synthesis (unprecedented faradaic efficiency of 60.6% with a high production rate of 910.4 μg h-1 mg-1cat.) from NO3− and CO2 by subtly integrating facet and defect engineering. ln-O-x-O-ln (x = C or N) configuration and Vo in Vo-S-IO-6 provided dual active sites for the adsorption and activation of NO3− and CO2 to exclusively form *NO2 and *CO2 species, respectively, which ensured highly selective C−N coupling. Moreover, theoretical calculations elaborated that Vo-induced local electron reconstruction accelerated the protonation rate-determining step, thus lowering overall energy barriers. This work offers a design strategy of synergistic electrocatalysts based on geometrical nature for efficient urea synthesis.

Super-resolution microscopy based on wide spectrum denoising and compressed sensing

WSD can effectively remove random noise of a raw image from very low density to ultra-high density fluorescent molecular distribution scenarios. The size of the raw image that WSD can denoise is subject to the used measurement matrix. A large raw image must be divided into blocks so that WSD denoises each block separately. Based on traditional single-molecule localization and super-resolution reconstruction scenarios, wide spectrum denoising (WSD) for blocks of different sizes was studied. The denoising ability is related to block sizes. The general trend is when the block gets larger, the denoising effect gets worse. When the block size is equal to 10, the denoising effect is the best. Using compressed sensing, only 20 raw images are needed for reconstruction. The temporal resolution is less than half a second. The spatial resolution is also greatly improved.

Adaptive Maximum Entropy Graph-Guided Fast Locality Discriminant Analysis.

Linear discriminant analysis (LDA) aims to find a low-dimensional space in which data points in the same class are to be close to each other while keeping data points from different classes apart. To improve the robustness of LDA to non-Gaussian distribution data, most existing discriminant analysis methods extend LDA by approximating the underlying manifold of data. However, these methods suffer from the following problems: 1) local affinity or reconstruction coefficients are learned on the basis of the relationships of all data pairs, which would lead to a sharp increase in the amount of computation and 2) they learn the manifold information in the original space, ignoring the interference of the noise and redundant features. Motivated by these challenges, this article represents a novel discriminant analysis model, called fast and adaptive locality discriminant analysis (FALDA), to improve the efficiency and robustness. First, with the anchor-based strategy, a bipartite graph of each class is constructed to characterize the local structure of data. Since the number of anchor points is far less than that of data points, learning of fuzzy membership relationships between data points and anchor points within each class can save training time. Second, a maximum entropy regularization is introduced to control the uniformity of the weights of graphs and avoid the trivial solution. Third, the above relationships are updated adaptively in the process of dimensionality reduction, which can suppress the interference of the noise and redundant features. Fourth, the whitening constraint is imposed on the projection matrix to remove the relevance between features and restrict the total scatter of data in the subspace. Last but not the least, data with complex distribution can be explicitly divided into sub-blocks according to the learned anchor points (or subclass center points). We test our proposed method on synthetic data, benchmark datasets, and imbalanced datasets. Promising experimental results demonstrate the success of this novel model.

The inherent strain rate method for thermo‐mechanical simulation of directed energy deposition additive manufacturing

AbstractTo reduce the computational time of thermo‐mechanical simulation of additive manufacturing by directed energy deposition, a new method is proposed, consisting in linearizing the transient standard thermomechanical simulation, by taking advantage of the strong concentration of strain rates around the deposition zone. In practice, a predictor/corrector algorithm is developed. The predictor step consists of a linearized mechanical resolution, which is obtained by considering the scalar generalized viscoplastic strain rate as an inherent strain rate, deduced from resolutions performed during previous time steps. The corrector step consists of a local (e.g., in each finite element) reconstruction of the effective stress field by solving a local nonlinear scalar equation. This predictor/corrector strategy is employed to deal with the dynamic evolution of strain rates and stress, during the distinct stages of the process: deposition, inter‐layer dwell time, and final cooling. With the proposed method, a time gain of around 5 is obtained for both a single wall and a curved turbine blade mock‐up, while the results (distortion and stress) of the full nonlinear thermomechanical resolution are replicated with an excellent accuracy. This makes the new inherent strain rate method a very promising tool for additive manufacturing simulation.

東日本大震災で被災した農村集落の共同空間管理の継続要因

In this study, we examined the form of common space management before and after the earthquake in rural villages in the local reconstruction area of the coastal area of Sendai City. And we clarified how collaborative space management is inherited by the local community. The results showed that common space management has been inherited, but that the local community responsible for management is weakening, and that common space management for the purpose of interaction is gaining ground.

In Situ Structures of the Ultra-Long Extended and Contracted Tail of Myoviridae Phage P1.

The Myoviridae phage tail is a common component of contractile injection systems (CISs), essential for exerting contractile function and facilitating membrane penetration of the inner tail tube. The near-atomic resolution structures of the Myoviridae tail have been extensively studied, but the dynamic conformational changes before and after contraction and the associated molecular mechanism are still unclear. Here, we present the extended and contracted intact tail-structures of Myoviridae phage P1 by cryo-EM. The ultra-long tail of P1, 2450 Å in length, consists of a neck, a tail terminator, 53 repeated tail sheath rings, 53 repeated tube rings, and a baseplate. The sheath of the contracted tail shrinks by approximately 55%, resulting in the separation of the inner rigid tail tube from the sheath. The extended and contracted tails were further resolved by local reconstruction at 3.3 Å and 3.9 Å resolutions, respectively, allowing us to build the atomic models of the tail terminator protein gp24, the tube protein BplB, and the sheath protein gp22 for the extended tail, and of the sheath protein gp22 for the contracted tail. Our atomic models reveal the complex interaction network in the ultra-long Myoviridae tail and the novel conformational changes of the tail sheath between extended and contracted states. Our structures provide insights into the contraction and stabilization mechanisms of the Myoviridae tail.

Cutaneous Radiation-Associated Angiosarcoma After Treatment of Carcinoma Penis: First Report from Tertiary Cancer Centre of North India.

Cutaneous radiation-associated angiosarcoma (cRAA) is a rare and aggressive secondary cutaneous angiosarcoma (cAS) with poor survival. cRAA has been mostly reported in breast carcinoma patients. Owing to its rarity, there is scanty literature available and no treatment guidelines. To the best of our knowledge, this is the first report of cRAA after multimodality treatment of carcinoma penis. A sixty-eight-year-old gentleman, a known case of carcinoma penis, underwent total penectomy with perineal urethrostomy and bilateral radical inguinopelvic lymph node dissection 6 years ago. He received adjuvant radiotherapy to the pelvis and bilateral groin. He presented with a bleeding plaque-like lesion with ulceration over the left lower abdomen (within previous radiation field) which rapidly progressed in size over the past 2 months. On examination, the lesion bled profusely on touch. Contrast MRI was suggestive of lobulated exophytic enhancing cutaneous lesion free from underlying muscle. Wedge biopsy was suggestive of cutaneous angiosarcoma. He underwent wide local excision with local perforator flap reconstruction from the right lower abdomen. Histopathology was suggestive of cutaneous angiosarcoma which showed immunoexpression of CD31, ERG1, cMYC suggestive of cRAA. cRAA is a very aggressive disease with 5-year survival of15-34%. To the best of our knowledge, this is the first ever reported case of cRAA of lower abdomen after multimodality management of carcinoma penis. It masquerades with other benign and less aggressive radiation-induced skin lesions. cMYC immunoexpression is specific for secondary cAS. Wide local resection with negative margin provides the best outcome.

FAmesh: Generating Frequency Adaptive Meshes from Single Images under 2D Hole Constraints

Reconstructing 3D models from a single image has numerous applications in fields such as VR/AR, medical imaging, and gaming. However, most mesh-based methods are limited by the use of 0-genus initial templates, which makes it difficult to reconstruct 3D meshes with complex topologies. Additionally, existing methods often prioritize reconstructing the overall shape and neglect to study local meshes with varying curvatures, resulting in a lack of correct and detailed local features in the generated meshes. This paper proposes a 3D reconstruction framework that transitions from global to local and incorporates MLP and GCN. The framework introduces a mesh pruning strategy under a 2D hole constraint to restore the correct mesh topology. Moreover, the framework fine-tunes local details by separately learning corresponding mapping functions on high-frequency and low-frequency local extended patches. The experiment with the proposed network on the ShapeNet dataset shows that the network has a CD value of 1.763 and an F-score of 85.40. The results from extensive experiments demonstrate that our proposed method outperforms existing methods in topology correction and local detail reconstruction.

Local Flap Reconstruction of Burn Contractures in Extremities and Neck: A Nine-Year Experience with Long-Term Outcome Evaluation in Southwestern Iran

Local Flap Reconstruction of Burn Contractures in Extremities and Neck: A Nine-Year Experience with Long-Term Outcome Evaluation in Southwestern Iran

Rehabilitation of Surgically Reconstructed Partially Edentulous Mandible with Iliac Crest Graft After Ameloblastoma Resection with an Implant-Supported “Toronto Prosthesis”

Ameloblastomas are locally invasive and benign odontogenic tumors with a high long-term recurrence rate. These lesions can cause serious anomalies in the facial area and alveolar bones, leading deformity and deterioration of functions. Wide local excision and reconstruction are required for the surgical treatment of these tumors. Aggressive resection effectively eliminates tumors; however, this approach may cause various problems that need reconstruction to restore the oral functions. In the present case report, the rehabilitation of surgically reconstructed partially edentulous mandible with iliac crest graft after ameloblastoma resection with an implant-supported “Toronto Prosthesis” is presented. In the surgical procedure, mandible was partially resected and simultaneous iliac bone graft was applied. Then, four dental implants were inserted into the reconstructed bone and implant-supported Toronto prosthesis was fabricated. The patient was satisfied with the final result of the treatment and recurrence was not observed during the 2-year clinical follow-up.

A Suture Tips Applied to Rotating Flaps in Reconstructing Facial Defects to Optimize Scarring: A Retrospective Study

Background: Local flap reconstruction is the most common method to repair facial defects. In this study, authors have explored and introduced a modified suture technique with rotation flap to repair facial defects that makes scarring more discreet and easier to perform. Methods: Patients with facial defects who underwent surgical treatment of the rotation flaps reconstructions and were admitted to our department between October 2014 and October 2019 were included in this retrospective study. The rotating flap is designed along the Relaxed Skin Tension Line (RSTLs) and contour lines, parts of patients received modified suture depending on the shape and size of the defect. Observe the flaps’ survival and complications. Assessments of the scars with Vancouver Scar Scale (VSS) regularly and follow-ups. Results: This five-year retrospective study evaluated a total of 56 patients; of these, 45 patients underwent modified suture surgery, the average defects were 19.7±4.5×25.5±5.2mm, and the average duration of follow-up was 13.8±5.0 months. Scar appearance was evaluated using the VSS score, range from 0-5, with an average of 1.6±1.1, and mainly reflected in pigmentation and vascularity. Postsurgical scar concealment is made afterward, and all flaps survive. No hemodynamic disorder or necrosis was found. Conclusion: The rotation flap was designed based on RSTLs/ contour lines to repair the facial defect and make the scarring well concealed. The modified suture method makes the flap line consistent with the RSTLs/ contour line of the facial skin to the maximum extent and leads to better facial aesthetics results.

D146. What Nipple Reconstruction Can Tell Us About the Latissimus Dorsi Flap Subdermal Plexus

PURPOSE: We previously presented our experience of local flap nipple reconstruction over various breast mound reconstructive modalities. Despite a conception that nipple reconstruction may be more reliable over flap beds than mastectomy skin, we preliminarily found that C-V flap designs on latissimus dorsi flap reconstructed breast mounds experience a 10-fold higher necrosis rate compared to implants or abdominally based flaps, leading the senior author to change his practice to exclusively base C-V flaps laterally over latissimus flaps. METHODS: A retrospective review was conducted from 2012 to 2022 of patients who underwent primary C-V subdermal pedicle flap nipple reconstruction by a single surgeon over implant-based, latissimus dorsi, and abdominally-based flap breast reconstruction. Demographics, C-V flap orientation, and nipple necrosis complications were recorded. RESULTS: Four hundred ninety-three nipple reconstructions in 312 patients were included, consisting of 41 latissimus dorsi, 45 deep inferior epigastric perforator, and 51 pedicled transverse rectus abdominis muscle flaps, 203 staged expander-to-implant, and 125 direct to implant reconstructions. In the latissimus cohort, 24.3% of patients experienced postoperative necrosis versus 1.6% to 5.9% among other reconstructive modalities. More interestingly, since the implementation of a laterally-based C-V flap on latissimus breast mounds, the complication rate fell to 10%. CONCLUSION: Our initial data, confirmed with the latest update, seem to highlight the unique subdermal plexus directionality in the latissimus dorsi flap compared to all other common reconstructed breast mounds. Extrapolated, these findings may imply a potential directional relationship between the subdermal vascular plexus and the axial pedicle of the underlying flap.

Atomic arrangement of Si adatom on the Silicene/Ag(111) surface

Silicene is a two-dimensional material with a honeycomb structure of silicon atoms that exhibits exotic electronic properties. Exploring Si adatom on monolayer silicene opens up new possibilities for studying tunable all-silicon-based devices at an atomic scale. Here we use non-contact atomic force microscopy and scanning tunneling microscopy to visualize and control the Si adatom on monolayer silicene at atomic resolution. We demonstrate that Si adatom forms a two-dimensional island on monolayer silicene. Si adatom can be manipulated on monolayer silicene, thereby delivering a tunable low-dimensional Si structure at an atomic scale. Local reconstruction of monolayer silicene with Si adatom has been confirmed by density functional theory calculations. Our results suggest that controlling the buckling structure of monolayer silicene by positioning Si adatom will locally tune the band structures and functionalities of monolayer silicene which is important for applications.

Modified Mustardé Flap for Lower Eyelid Reconstruction in Basal Cell Carcinoma: Revisited.

Full thickness defects of lower eyelid, following oncological resection, often pose a formidable challenge to the operating surgeon. Although a plethora of reconstructive options have been tried, the Mustardé flap has stood the test of time. Our patient, a 57-year old lady, diagnosed with basal cell carcinoma of the left lower eyelid underwent full-thickness wide local excision and reconstruction using modified Mustardé flap. The anterior part of defect was reconstructed using the flap. The posterior part was reconstructed using septal mucoperichondrial-cartilage composite graft, sutured to remnant palpebral conjunctiva. The patient had an uneventful post-operative period. On serial follow-up, the patient had an acceptable scar. At 6 months follow-up, the facial scar was barely perceptible with normal lower lid disposition. The modified Mustardé flap is a simple and reliable reconstructive option for full-thickness lower eyelid defects following oncological resection in carefully selected cases.

Increasing Gas Production of Continuous Freeze-Thaw Hydrate Deposits Based on Local Reservoir Reconstruction

The fracturing technology for increasing gas production based on hydrate reservoir reconstruction has been proven to have the application prospect of hydrate production. The main content of this work is to study the influence mechanism between multiple production wells after fracturing the reservoirs around horizontal wells. Simulation results indicated that the gas production rates and cumulative volume of released gas by using hydraulic fracturing were both higher than that by using the traditional depressurization method. The average gas-to-water ratio in this work has broken through the technical bottleneck of exploiting hydrate only by the traditional depressurization method. After the rock matrix around the horizontal well was fractured, the permeability of the reservoir in the fracturing area would be increased; thus, the propagation distance of pressure drop would be promoted. In addition, the penetration of the hydrate decomposition area between horizontal production wells was conducive to promoting the flow of decomposed gas and water to production wells. Besides, the hydraulic fracturing method to increase the permeability of the reservoir around the production well is very effective for the gas production of low-permeability natural hydrate deposits. The best distance between production wells was recommended to be 45~60 m, and it was recommended to provide appropriate heat in the area between the two wells to accelerate the decomposition of hydrate.

Computational spectrometer based on local feature-weighted spectral reconstruction.

The computational spectrometer enables the reconstruction of spectra from precalibrated information encoded. In the last decade, it has emerged as an integrated and low-cost paradigm with vast potential for applications, especially in portable or handheld spectral analysis devices. The conventional methods utilize a local-weighted strategy in feature spaces. These methods overlook the fact that the coefficients of important features could be too large to reflect differences in more detailed feature spaces during calculations. In this work, we report a local feature-weighted spectral reconstruction (LFWSR) method, and construct a high-accuracy computational spectrometer. Different from existing methods, the reported method learns a spectral dictionary via L 4-norm maximization for representing spectral curve features, and considers the statistical ranking of features. According to the ranking, weight features and update coefficients then calculate the similarity. What's more, the inverse distance weighted is utilized to pick samples and weight a local training set. Finally, the final spectrum is reconstructed utilizing the local training set and measurements. Experiments indicate that the reported method's two weighting processes produce state-of-the-art high accuracy.

Impact localization and force reconstruction for composite plates based on virtual time reversal processing with time-domain spectral finite element method

Composite structures are widely used in different industries as important load-carrying components due to their excellent performance. These structures are prone to be damaged under low-velocity impacts with invisible cracks. Hence, impact identification is a critical part of composite structural health monitoring. In this paper, an approach is developed, which is based on time-reversal (T-R) processing and time-domain spectral finite element method. The spatial and temporal focusing properties of T-R are utilized to locate the impact source and restore the impact force, respectively. Moreover, the impact energy is evaluated by establishing the function of impact force and kinetic energy at the impact moment. The proposed method is validated experimentally for different scenarios. The influences of the signal length and accuracy of the numerical model on the proposed method are discussed in detail. The results demonstrate that the proposed method can correctly locate the impact source in composite structures, and the identified impact force can reproduce the impact event efficiently. The impact localization is essentially independent of the effect of signal length while it is vulnerable to the mesh grid. Besides, the developed method has consistent results in the case of data perturbation of material properties in the numerical model, which shows its good robustness.

Checklist of the diatoms (Bacillariophyta) from Lake Naivasha, Kenya, with some historical notes.

Lake Naivasha is one of only two large freshwater lakes in the Eastern Rift Valley of Kenya, East Africa. Together with its satellite lakes Crescent Island Crater, Oloidien and Sonachi, it comprises a great variety of pelagic and benthic habitats for aquatic biota, and its sediment record represents a unique archive of past climate change and long-term ecosystem dynamics in equatorial East Africa. This is particularly so because local paleoenvironmental reconstructions can be checked against historical data on the composition of aquatic fauna and flora collected in Lake Naivasha since the early 20th century. Some of the most prominent biological proxies for reconstructing past changes in lakes are diatoms (Bacillariophyta), a group of unicellular autotrophic eukaryotes of which the siliceous skeletons (valves) preserve well in lake sediments and are good indicators for, among others, climate-driven changes in salinity. However, diatom taxonomy and species concepts have changed a lot in recent decades, making it sometimes difficult for non-taxonomists to know which species are concerned in different published studies. This paper provides the currently accepted taxonomic names of the 310 specific and infraspecific diatom taxa reported from Lake Naivasha and its satellite lakes to date, together with their synonyms used in literature concerning these lakes as well as other, commonly used synonyms. Further, a short overview is given of the history of diatom research conducted on materials from Lake Naivasha and its satellite lakes. The present checklist may facilitate the identification and interpretation aspects of future diatom studies on the wider Lake Naivasha ecosystem and on other East African lakes that are less well studied.

Effects of native and H related defects on magnetic properties of SrCoO2.5 and HSrCoO2.5

The tunable magnetism and reversible phase transformation between SrCoO2.5 (SCO) and HSrCoO2.5 (HSCO) have attracted vast research interest; however, the physical origin of the weakly ferromagnetism of the hydrogenated phase is still unclear. Various point defects, especially H related ones, may play important roles in the magnetic order of SCO and HSCO. In this study, we performed first-principles calculations combined with bond orbital model analysis to investigate the stabilities and magnetic effects of these defects and their complexes in both phases. We find that Hi, VO, CoSr, and Oi are relatively stable in SCO, while VH, CoSr, Hi, and Oi are relatively stable in HSCO. Additionally, these defects show significant differences of formation energy in these two phases because the charge transfer mechanisms from defects to nearby Co atoms are different. The different mechanisms also lead to different local reconstructions and crystal field splitting of the Co 3d states, affected by the interaction between Co–O bond orbital and surrounding bonding environment. Single defects of VH, Hi, and CoSr contribute significantly to the total magnetic moment of the system for HSCO or SCO. However, a ferromagnetic coupling is discovered in the two VH configurations only in HSCO, which may explain the experimental observation of the weakly ferromagnetism of HSCO.