Method Of Repair Research Articles

Mechanical properties and microscopic analysis of water-castable engineered cementitious composites (WECC)

To address the difficulties in repairing underwater concrete panels and the unsatisfactory results of existing repair methods and materials, water-castable engineered cementitious composites (WECC) are developed. The effects of flocculant dosage on anti-dispersibility, fluidity, tensile behaviors, flexural behaviors, and fracture behaviors were investigated. XRD, MIP, and SEM tests were conducted on the WECC. Excellent tensile properties, flexural energy absorption capacity, and crack resistance are exhibited by the WECC. The increase in flocculant dosage decreases the dispersion degree during the underwater casting process of WECC, reduces the early hydration reaction rate, increases the internal porosity, resulting in a decrease in various mechanical properties. By comparing the tensile properties of WECC and WECC(L), while integrating microscopic analysis results, the performance loss mechanism of WECC and the tensile constitutive model have been identified. Additionally, the effects of (washed sea sand) sand-colloid ratio on workability and mechanical properties were investigated. When the sand-colloid ratio is 0.25, a higher level of compatibility between the fibers and the matrix is observed, and good ductility is demonstrated. Considering various performance factors, two mixed proportions have been established. The time, resources, and labor required for the repair process can be significantly reduced by using WECC for repairing underwater components, and the hydraulic structures can operate normally. The externally generated complex stress can be effectively released by WECC. The tested results provide crucial references for the underwater reinforcement of WECC.

Characterization of corrosion mechanism and traditional soldering treatment of a composite bronze lamp from the Greco-Roman period of Egypt

This paper presents a study of treatment by soldering for a unique bronze oil lamp combined with Eros and dog figurines. In this object, there are two types of soldering; the first is ancient, used to join the three pieces together, and the other is used in conservation treatments to stop the degradation of the object. Soft solders have been a modern method of repair, with its historical use as the original joining technique demonstrating its general durability and effectiveness. Optical microscopy, portable X-ray fluorescence, and micro-Raman spectroscopy were used to identify the soldering treatment, the chemical composition of the alloy, and the corrosion products. Investigation techniques showed the use of a modern tin-lead alloy as soft soldering in past interventions to treat cracks and fill losses. Cracks propagated due to soil pressures and ongoing corrosion processes, as well as the combined action of tensile forces and the surface-active molten solder. The ancient solder used to attach the dog and Eros to the lamp was a hard solder. The three pieces were made of high-leaded tin bronze, with Pb contents ranging from 10.5 to 13 wt%. The chloride and sulfate corrosion products detected by µ-RS were more aggressive in the object structure. The corrosion products of the soft solder consisted mostly of lead and tin oxides, basic carbonates, and sulfates.

Clinical application of perforator-based propeller flaps in repair of hand wound

To investigate the effectiveness of the perforator-based propeller flaps (PPFs) based on digital artery (DA) and dorsal metacarpal artery (DMA) in repairing hand wounds. The clinical data of 45 patients with hand wounds between January 2018 and March 2023 were retrospectively analyzed. There were 27 males and 18 females with an average age of 41.2 years (range, 14-72 years). The causes of injury included twist injury in 15 cases, crush injury in 19 cases, and cut injury in 11 cases. The injured parts included 32 cases of digits, 10 cases of dorsal hand, and 3 cases of palmar hand, all of which had tendon, joint, and bone exposure. The time from injury to operation ranged from 2 to 8 hours (mean, 4.3 hours). The wound sizes after debridement ranged from 1.8 cm×1.0 cm to 5.0 cm×3.5 cm. Twenty-eight cases were repaired by the PPFs based on DA and 17 cases were repaired by the PPFs based on DMA. The flap size ranged from 2.5 cm×1.1 cm to 8.5 cm×4.0 cm. The defects of the donor sites in 14 patients were closed directly and the defects in the left 31 patients were resurfaced with free full-thickness skin graft from the proximal medial forearm. All the flaps survived after operation. Two cases of the PPF based on DA and 1 case of the PPF based on DMA underwent partially blisters at the distal end and healed after dressing change. The incisions in the donor site healed by first intention and the skin grafts survived. All patients were followed up 10-33 months, with a mean of 15.4 months. At last follow-up, the static two-point discrimination of the PPFs based on DA and DMA were 4-14 mm and 8-20 mm with the averages of 8.1 mm and 13.3 mm, respectively. According to the Michigan Hand Outcomes Questionnaire, 20 patients were very satisfied with the appearance of the PPF based on DA and 8 patients were satisfied; 8 patients were very satisfied with the appearance of the PPF based on DMA and 9 patients were satisfied. Based on the Vancouver Scar Scale (VSS), the appearance scores of the donor site of the PPFs based on DA and DMA were 2-7 and 4-9, with the averages of 4.2 and 6.1, respectively. The two kinds of PPFs are reliable in blood supply and easy to harvest, which provide a good method for emergency repair of small and medium area wounds in the hand.

A Scoping Review of Definitions of Success in Endovascular Aortic Arch Repair.

The present standard of care to treat aortic arch pathologies is open surgical repair with cardiopulmonary bypass and deep hypothermic arrest. With approaches for total endovascular and extra-anatomic cervical debranching hybrid arch repair becoming more diverse, understanding what is considered a successful operation is prerequisite for a rigorous comparison of techniques. This review describes the specific outcomes reported, the rates of success, and the definitions of technical and clinical success in total endovascular and extra-anatomic cervical debranching hybrid aortic arch repair. A comprehensive search of MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials was performed. Studies with patients undergoing total endovascular or hybrid extra-anatomic cervical debranching repair of the aortic arch were included. Any publications including only patients with Ishimaru zone 2 or distal repairs were excluded from this review. Studies with less than 5 patients were excluded. Data extraction was performed by one author. Data items included were study design, procedure type, procedural details, underlying pathology, type of cervical debranching, type of endograft repair, surgical outcomes, definition of cerebrovascular events, technical success, and the definition of technical success. Of 1754 studies screened for review, 85 studies with 5521 patients were included. By frequency, the included studies examined the following interventions: fenestrated devices, branched devices, parallel grafting. Most studies were retrospective single-institution studies. There were no randomized controlled trials. Short-term mortality and cerebrovascular events were nearly universally reported, present in 99% and 95% of studies reviewed, respectively. Only 27% of studies provided an explicit definition for cerebrovascular events. While 75% of studies reported a technical success rate, only 45% of those studies provided explicit criteria. Clinical success rates were infrequently reported, present in only 5.9% of studies reviewed. The definitions of technical success that were provided fell short of analogous defined reporting standards in nearly all studies, inflating technical success rates. Definitions of cerebrovascular events and technical success require stringent criteria to uniformly compare various methods of endovascular aortic arch repair. A societal consensus document for reporting standards of endovascular aortic arch repair would allow for higher-quality outcomes research. Total endovascular and extra-anatomic cervical debranching hybrid operations are being increasingly utilized for complex aortic arch repair. These techniques, however, can be associated with serious complications. Currently, there is no accepted metric to define technical or report clinical outcomes. Due to the paucity of high-quality data, use of these approaches may be limited in clinical practice. This study emphasizes the need for the development of standards for reporting outcomes in endovascular aortic arch repair. Future studies can then utilize these benchmarks, whcih will allow for improved efficacy and safety in these techniques.

Towards robust neural networks: Exploring counterfactual causality-based repair

Despite the widespread applications of neural networks, increasing concerns arise regarding their reliability and security. This paper introduces a novel repair approach integrating counterfactual causality with a multi-objective algorithm to mitigate critical security property issues, including backdoor attacks, safety violations, and unfairness. Firstly, we abstract the neural network into a counterfactual structure causal model, utilizing a causal trace to allocate contributions to each hidden layer neuron for output prediction. Secondly, ”faulty” neurons are identified through fault location, utilizing counterfactual causality between positive and negative example-guided attributes and neuronal contribution. Finally, an ablation study determines the number of neurons for repair. The multi-objective algorithm NSGA-III is then applied to optimize the faulty neurons, adjusting weight parameters to rectify erroneous behavior and eliminate vulnerabilities while maximizing the model’s accuracy. This method achieves notable Pareto optimization and effectively eliminates vulnerabilities in neural networks. In comparative experiments against CARE (CAusality-based REpair) techniques, our Counterfactual Causality-Based Repair (CCBR) method significantly reduces backdoor attack success rates and security violations to less than 1%, while maintaining model accuracy and ensuring security for normal inputs. In fairness repair tasks, CCBR improves fairness by 92.56%, a substantial 19.56% increase over CARE. These results affirm the robustness and practicality of CCBR, establishing it as a valuable tool for enhancing neural network safety and fairness.

A high bonding tensile strength of CFRP ultrafast laser surface texturing method for surface damage repair

Carbon fiber reinforced polymer composite (CFRP) has a wide range of applications in aerospace, but it can cause varying degrees of damage in harsh service environments. Seeking a high-performance repair method is an effective way to save costs and ensure the service performance of CFRP components. In this study, a high bonding tensile strength of CFRP surface ultrafast laser texturing method for damage repair was proposed, which achieved complete removal of surface resin while retaining intact exposed fiber filaments. The difference in groove processing under unidirectional scanning and cross-scanning modes at different angles was explored. When the groove spacing was 0.2 mm and 0.4 mm, the surface resin was completely removed, the carbon fiber remained intact, and no debris was inside the groove. The groove morphology has a significant impact on the contact zone of the surface, which in turn affects the mechanical properties of the bonded joint. Cross-scanning can effectively improve surface roughness to increase the contact surface area. However, there is more fiber breakage, manifested as a groove weakening effect, which limits the improvement of bonding strength. In the 0° unidirectional scanning mode, the tensile performance of the joint is the best, improved by 61.6 % compared to manual processing.

3D-Printed Silk Proteins for Bone Tissue Regeneration and Associated Immunomodulation.

Current bone repair methods have limitations, prompting the exploration of innovative approaches. Tissue engineering emerges as a promising solution, leveraging biomaterials to craft scaffolds replicating the natural bone environment, facilitating cell growth and differentiation. Among fabrication techniques, three-dimensional (3D) printing stands out for its ability to tailor intricate scaffolds. Silk proteins (SPs), known for their mechanical strength and biocompatibility, are an excellent choice for engineering 3D-printed bone tissue engineering (BTE) scaffolds. This article comprehensively reviews bone biology, 3D printing, and the unique attributes of SPs, specifically detailing criteria for scaffold fabrication such as composition, structure, mechanics, and cellular responses. It examines the structural, mechanical, and biological attributes of SPs, emphasizing their suitability for BTE. Recent studies on diverse 3D printing approaches using SPs-based for BTE are highlighted, alongside advancements in their 3D and four-dimensional (4D) printing and their role in osteo-immunomodulation. Future directions in the use of SPs for 3D printing in BTE are outlined.

Active and Passive Filling Stir Repairing of AISI 304 Alloy

This study investigates active filling friction stir repair (AF-FSR) and passive filling friction stir repair (PF-FSR) for repairing AISI 304 stainless steel sheets, focusing on addressing the challenges posed by high melting point metals. The research involved repairing overlapping 2 mm thick sheets with pre-drilled holes of 2, 4, and 6 mm diameters, simulating broken components. Various process parameters, including rotational speed, dwell time, and the use of metal fillers, were tested to evaluate their impact on repair quality. The results demonstrated that PF-FSR provided superior mechanical strength to AF-FSR, particularly for larger pre-hole diameters. PF-FSR achieved higher shear tension strength due to better defect filling and reduced void formation, with shear tension strengths exceeding 25 kN for larger pre-holes and lower variability in strength measurements. AF-FSR was less effective for larger pre-holes, resulting in significant voids and reduced strength. Microstructural analysis revealed that PF-FSR facilitated more efficient material mixing and filling, minimizing unrepaired regions. However, excessive rotational speeds and dwell times in PF-FSR led to deformation and flash formation, highlighting the need for optimal parameter selection. Although further studies are needed, this study confirms the feasibility of FSR techniques for repairing small defects in AISI 304 steels, offering valuable insights for sustainable manufacturing practices in industries such as automotive and aerospace, where efficient and reliable repair methods are critical.

Management and Outcomes of Delayed Cerebral Ischemia Associated with Vasospasm Post Nontraumatic Subarachnoid Hemorrhage: A Retrospective Cohort Study in the National Neurosurgical Center in Ireland

Abstract Background Delayed cerebral ischemia (DCI) is the leading cause of adverse outcome in patients who survive the initial phase of subarachnoid hemorrhage (SAH). While guidelines recommend induced hypertension as a first-line treatment for DCI, there is no high-level evidence confirming outcome benefit. Methods Patients admitted with nontraumatic SAH over 3 years period were identified. Demographics, clinical/radiological presentation, aneurysm repair method, and Glasgow outcome score (GOS) 3 months postdischarge were recorded. A subgroup of patients who suffered clinically significant vasospasm were identified, and their hypertensive therapy and outcomes were examined. Results A total of 532 patients were admitted with SAH; 68 developed vasospasm. The vasospasm subgroup was divided based on vasopressor treatment—norepinephrine alone (n = 27) versus norepinephrine plus vasopressin (n = 35). No correlation was found between percentage of days that mean arterial pressure (MAP) targets were met and GOS outcome. Patients treated with both agents had worse GOS outcomes at than those treated with norepinephrine alone. Conclusion In our study, 12.8% of patients SAH developed vasospasm. Twenty-seven patients were treated with norepinephrine alone and 35 were treated with norepinephrine plus vasopressin to achieve augmented MAP targets. There was no correlation between percentage of days that MAP targets were met and improved patient outcome. The 68 patients stayed a total of 783 days in ICU, with a mean length of stay of 11.5 days. Patients who required dual therapy to achieve MAP targets had significantly worse neurological outcomes.

Flexural performance of reinforced concrete beams repaired with BFRP grid-TSUHDC

Due to the influence of time, load, and external environmental factors, many reinforced concrete beams have been damaged and require repair. Tailings are waste generated during mineral production, resulting in substantial environmental pollution and economic losses due to the excessive generation of tailings and low comprehensive utilization. In the UHDC, tailings replaced quartz sand, while BFRP grids itself is an environmentally friendly material. Two repair methods were evaluated in this study, Tailings Sand Ultra-High Ductile Concrete (TSUHDC) and Basalt Fiber Reinforced Polymer (BFRP) grid-TSUHDC, grounded in the principles of green and sustainable development. Five reinforced concrete beam specimens were designed and fabricated for bending performance tests and finite element simulations. The effects of different repair methods and levels of damage on the flexural performance of reinforced concrete beams were investigated. The results reveal that, compared to untreated reinforced concrete beams, both TSUHDC and BFRP grid-TSUHDC repair methods enhanced bending load-bearing capacity. However, the stiffness of specimens repaired with TSUHDC decreased when subjected to 80 % of the pre-applied failure load. When the pre-applied failure load is less than 80 %, the recommended repair approach is the use of TSUHDC for repair. For cases where the pre-applied failure load exceeds 80 %, BFRP grid-TSUHDC is the preferable option. The flexural bearing capacity formula for this type of repair method was derived by improving existing formulas, yielding prediction results in close alignment with the experimental results.

Study on Bonding Characteristics of Polymer Grouted Concrete-Soil Interface.

The issue of interfacial shear damage has been a significant challenge in the field of geotechnical engineering, particularly in the context of diaphragm walls and surrounding soils. Polymer grouting is a more commonly used repair and reinforcement method but its application to interface repair and reinforcement in the field of geotechnical engineering is still relatively rare. Consequently, this paper presents a new polymer grouting material for use in grouting reinforcement at the interface between concrete and soils. The bonding characteristics and shear damage mode of the interface after grouting were investigated by the direct shear test, and the whole process of interface shear damage was investigated by digital image correlation (DIC) technology. Finally, the reinforcement mechanism was analyzed by microscopic analysis. The results demonstrate that the permeable polymer is capable of effectively filling the pores of soil particles and penetrating into the concrete-soil interface. Through a chemical reaction with water in the soil, the polymer cements the soil particles together, forming chemical adhesion at the interface and thereby achieving the desired reinforcement and repair effect. In the shear process, as the normal stress increased, the horizontal displacement and horizontal compressive strain at the distal end of the loading end decreased, while the maximum vertical displacement and maximum vertical strain of the cured soil also decreased. The results of scanning electron microscopy (SEM) demonstrated that the four groups of test polymers exhibited a reduction in soil porosity of 53.47%, 58.79%, 52.71%, and 54.12%, respectively. Additionally, the form of concrete-soil interfacial bonding was observed in the concrete-cohesive layer-cured soil mode. The findings of this study provide a foundation for further research on diaphragm wall repair and reinforcement.

Graft choice in pancreatectomy with vascular resection: equivalent safety in selected patients

BackgroundPancreatic cancer is the third leading cause of cancer-related death in the United States, with surgical resection being the only option for long-term survival. The ability to manage vascular involvement has expanded the pool of patients who are able to undergo resection with curative intent. However, not all vascular involvements can be detected preoperatively. This study aimed to investigate the patterns of vascular resection and methods of repair or reconstruction MethodsThis was a single-center retrospective review of adult patients undergoing pancreatectomy with vascular involvement at a tertiary care referral hospital between 2010 and 2022. The primary endpoint was graft thrombosis within 90 days. ResultsA total of 147 patients were included in the study. Of note, 21.8% of patients were not suspected of having vascular involvement preoperatively. Moreover, 68.0% of patients required vascular reconstruction, whereas the remaining 32.0% of patients underwent repair (either primary repair or patch angioplasty). Most patients who underwent reconstruction underwent primary end-to-end anastomosis (63.0%), with 19 patients requiring autologous interposition grafts and 16 patients requiring CryoVein interposition grafts. Univariate analysis found no clinical or technical predictors of early or 90-day thrombosis, including graft choice. In addition, 30- and 90-day mortalities occurred in 1 and 7 patients, respectively. ConclusionPancreatectomy with vascular resection can be performed with low mortality in carefully selected patients. Unsuspected vascular involvement is relatively common (1 in 5). If autologous graft is not readily available, CryoVein is a safe alternative with similar perioperative outcomes.

Oxidation failure behavior and repair of the damaged SiC-ZrB2/SiC coating of C/C composites

The impacts of damage on the thermal barrier performance of SiC-ZrB2/SiC coating of C/C composites were investigated. The microstructure, chemical components, and thermal protection performance of the damaged coating before and after repair were analyzed, and the failure behavior of the damaged coated C/C composites was studied. After oxidation at 1500 °C for 360 min, the weight loss of the undamaged sample was −0.38 %, while that of the damaged sample reached 21.16 %. A repair method using polysiloxane and SiC-ZrB2 powder as repair agent was employed to recover the oxidation resistance property of the damaged coating. The repair agent generated SiOC ceramics after high-temperature treatment, covering the damaged area and bonding well with the original coating. The weight loss of the repaired sample was 2.4 %, which was significantly improved compared to the damaged coating. This work offers a research foundation for the optimization of the repair of damaged silicon-based ceramic coatings.

The Relationship Between All-Suture and Solid Medial-Row Anchors and Patient-Reported Outcomes for Double-Row Suture Bridge Rotator Cuff Repair.

The use of all-suture anchors for rotator cuff repair is increasing. Potential benefits include decreased bone loss and decreased damage to the chondral surface. Minimal evidence exists comparing outcomes among medial-row anchor fixation methods in double-row suture bridge rotator cuff repair. To compare the clinical outcomes between all-suture and solid medial-row anchors in double-row suture bridge rotator cuff repair. Case series; Level of evidence, 4. A total of 352 patients (mean age at surgery, 60.3 years) underwent double-row suture bridge rotator cuff repair at our institution. Patients were separated into 2 groups based on whether they underwent all-suture (n = 280) or solid (n = 72) anchor fixation for the medial row. Outcomes data were collected via an ongoing longitudinal data repository or through telephone calls (minimum follow-up time, 2.0 years; mean follow-up time, 3.0 years). Outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) standardized shoulder assessment form and the visual analog scale (VAS). The same rehabilitation protocol was administered to all patients. The proportions of patients meeting previously published Patient Acceptable Symptom State (PASS) thresholds were calculated for the outcome measures, and outcome scores and the proportions of patients meeting PASS thresholds between groups were compared using linear and logistic regression, respectively. The groups did not differ in terms of age at surgery, sex distribution, rotator cuff tear size, or number of medial-row anchors used. The solid anchor group had a longer follow-up time compared with the all-suture anchor group (3.6 ± 0.7 vs 2.8 ± 0.8 years, respectively; P < .01). After controlling for follow-up time, the solid and all-suture anchor groups did not differ in ASES scores (89.6 ± 17.8 vs 88.8 ± 16.7, respectively; P = .44) or VAS scores (1.1 ± 2.1 vs 1.2 ± 2.1, respectively; P = .37). Similarly, after controlling for follow-up time, the solid and all-suture anchor groups did not differ in the proportions of patients meeting PASS cutoffs for the ASES (84.7% vs 80.7%, respectively; P = .44) or the VAS (80.6% vs 75.0%, respectively; P = .83). Double-row suture bridge rotator cuff repair using all-suture anchors for medial-row fixation demonstrated similar excellent clinical outcomes to rotator cuff repair using solid medial-row anchors.

Immunophenotyping of a population of cultured human umbilical cord cells from Wharton's jelly

BACKGROUND: Against the background of many existing methods of defect replacement in post-traumatic injuries the methods of repair of damaged tissues based on methods using products of tissue engineering and cultures of artificially cultured human cells are becoming more and more widespread in medical practice. The literature reports weak immunogenic activity of human umbilical cord tissues, which makes these cells promising components of regenerative medicine products. Due to possible errors in explant selection and cell transformation in the process of cultivation, it is necessary to reliably determine the phenotype of cells obtained as a result of tissue explantation and their further cultivation. Thus, the specificity of obtaining multipotent mesenchymal cells from human umbilical cord Warton's stool tissues requires reliable identification of the type of the obtained cells. AIM: To obtain reliable features of mesenchymal stem cells in the cell population obtained from human umbilical cord stool tissue. MATERIAL AND METHODS: Methods of cell cultivation, flow cytofluorimetry, immunocytochemistry for determination of surface and intracellular markers of mesenchymal stem cells were used in the study. RESULTS: In the course of work on the identification of cells of the population obtained by culturing explants from human umbilical cord Wharton stool, the heterogeneity of the type of cells constituting the cell population was established. Most of them are mesenchymal stem cells carrying fluorescent markers CD45, CD73, CD34, CD29, CD90, CD44, CD105, which agrees with the immunophenotype of mesenchymal stem cells defined by the International Society for Cell Therapy. The ratio of the applied markers allows us to refer the population of cells obtained by direct explantation of Varton's gelatin tissue fragments to mesenchymal stem cells. Visual control confirmed the localisation of labelled antibodies on the surface of cultured cells. And also, it was shown that there were no vascular muscle cells in the obtained culture. CONCLUSION: As a result of experiments on identification of the cells obtained during explantation of Wharton's jelly tissue fragments and their further cultivation, their belonging to mesenchymal stem cells was established by immunofluorescence cytophotometry.

Seismic Performance Analysis of PEC Structures

Partially-Encased Composite Steel and Concrete Members (PEC members for short) consists of H-shaped cross-section of the main steel and concrete filling between the flange and the web, compared with the pure steel structure, the PEC structure has the advantages of high stiffness, high bearing capacity, good fire resistance and so on. The arrival of an earthquake may cause damage to building structures. The use of PEC structures can effectively improve their bearing capacity and seismic performance, and the method of post earthquake repair is relatively easier and more economical. In recent years, PEC components have been gradually popularized and applied in building structures.

Intersection-union dual-stream cross-attention Lova-SwinUnet for skin cancer hair segmentation and image repair

Skin cancer images have hair occlusion problems, which greatly affects the accuracy of diagnosis and classification. Current dermoscopic hair removal methods use segmentation networks to locate hairs, and then uses repair networks to perform image repair. However, it is difficult to segment hair and capture the overall structure between hairs because of the hair being thin, unclear, and similar in color to the entire image. When conducting image restoration tasks, the only available images are those obstructed by hair, and there is no corresponding ground truth (supervised data) of the same scene without hair obstruction. In addition, the texture information and structural information used in existing repair methods are often insufficient, which leads to poor results in skin cancer image repair. To address these challenges, we propose the intersection-union dual-stream cross-attention Lova-SwinUnet (IUDC-LS). Firstly, we propose the Lova-SwinUnet module, which embeds Lovasz loss function into Swin-Unet, enabling the network to better capture features of various scales, thus obtaining better hair mask segmentation results. Secondly, we design the intersection-union (IU) module, which takes the mask results obtained in the previous step for pairwise intersection or union, and then overlays the results on the skin cancer image without hair to generate the labeled training data. This turns the unsupervised image repair task into the supervised one. Finally, we propose the dual-stream cross-attention (DC) module, which makes texture information and structure information interact with each other, and then uses cross-attention to make the network pay attention to the more important texture information and structure information in the fusion process of texture information and structure information, so as to improve the effect of image repair. The experimental results show that the PSNR index and SSIM index of the proposed method are increased by 5.4875 and 0.0401 compared with the other common methods. Experimental results unequivocally demonstrate the effectiveness of our approach, which serves as a potent tool for skin cancer detection, significantly surpassing the performance of comparable methods.

Data-driven models to predict the water-to-cement ratio and initial setting time of cement grouts

ABSTRACT As a common defect, the water–cement ratio of grout can currently be monitored only during the maintenance phase, which limits the repair methods and misses the optimal opportunity for repairs. To overcome this limitation, this study integrated ultrasonic parameters previously used to characterise cement-based materials and developed a new Initial Setting Time and Water–Cement Ratio (IST_WCR) risk model to predict the setting time and water–cement ratio grout using machine learning (ML) algorithms. Experiments on grout involved four different water–cement ratios, ranging from 0.11 to 0.18. A data-driven method based on ML was used to extract predictive factors from eight ultrasonic parameters, including the speed, energy, main frequency, and main frequency amplitude of P-waves and S-waves, and to evaluate multiple ML classifiers to establish the IST_WCR risk prediction model. This model underwent internal and external cross-validations and demonstrated very strong performance with a Brier score of under 0.01. The dataset for ML classifiers contained a total of 956 signals and 7648 features. Compared with traditional methods, this method can automatically characterise the setting process of grout and identify defective water–cement ratios at a very early stage of curing.

Bioelectret Materials and Their Bioelectric Effects for Tissue Repair: A Review.

Biophysical and clinical medical studies have confirmed that biological tissue lesions and trauma are related to the damage of an intrinsic electret (i.e., endogenous electric field), such as wound healing, embryonic development, the occurrence of various diseases, immune regulation, tissue regeneration, and cancer metastasis. As exogenous electrical signals, such as conductivity, piezoelectricity, ferroelectricity, and pyroelectricity, bioelectroactives can regulate the endogenous electric field, thus controlling the function of cells and promoting the repair and regeneration of tissues. Materials, once polarized, can harness their inherent polarized static electric fields to generate an electric field through direct stimulation or indirect interactions facilitated by physical signals, such as friction, ultrasound, or mechanical stimulation. The interaction with the biological microenvironment allows for the regulation and compensation of polarized electric signals in damaged tissue microenvironments, leading to tissue regeneration and repair. The technique shows great promise for applications in the field of tissue regeneration. In this paper, the generation and change of the endogenous electric field and the regulation of exogenous electroactive substances are expounded, and the latest research progress of the electret and its biological effects in the field of tissue repair include bone repair, nerve repair, drug penetration promotion, wound healing, etc. Finally, the opportunities and challenges of electret materials in tissue repair were summarized. Exploring the research and development of new polarized materials and the mechanism of regulating endogenous electric field changes may provide new insights and innovative methods for tissue repair and disease treatment in biological applications.

Experimental and analytical investigation of RC beams strengthened by ultra-high performance shotcrete

Currently, there is an increasing need for the repair of damaged structures, particularly those situated in confined and challenging locations. Historically, addressing such structures has been hampered by a lack of effective repair and rehabilitation methods. This study aims to investigate, both experimentally and analytically, the application of Ultra-High-Performance Shotcrete (UHPS) for strengthening and repairing reinforced concrete (RC) beams at the bottom. Five RC beams were cast, with one serving as a reference. The remaining four reinforced concrete beams were fabricated with grooved surfaces at the bottom. Subsequently, they underwent strengthening with UHPS at the soffit in two scenarios: one with reinforcements and one without reinforcements. The results indicate a significant enhancement in the load-carrying capacity of the composite beam, up to 126 %, when UHPS is combined with reinforcements. Additionally, the analytical method demonstrates good accuracy, with a maximum error of 16.62 % compared to the experimental results. These findings suggest that the utilization of UHPS effectively improves the structural behavior of RC beams, particularly in challenging locations. Furthermore, the proposed analytical method holds promise for practical application in the design field, offering a systematic approach for implementing UHPS and reinforcements in the repair and rehabilitation of reinforced concrete beams.