Repair Strategies Research Articles

Optimality criteria for the process of technical operation of locomotives

The efficiency of a locomotive fleet as a complex system depends significantly on the mode and conditions of its operation, which, in many cases, are determined both by its own condition and by the state of the maintenance system. In reality, changes in the state of the system, and its further behaviour in most cases can be described by the Markov process. It should be noted the excessive rigidity of the hypothesis about the Markov character of the behaviour in the process of technical operation of the locomotive fleet that makes the resulting model insufficiently adequate. The article proposes a methodology to assess the efficiency in the functioning of the locomotive fleet as a semi-Markov system. Relationships for calculating the main statistical characteristics of the efficiency indicators in the process of technical operation of locomotives have been obtained. The choice of optimality criteria for the process is justified. A procedure for constructing an ordered sequence of enhancing maintenance and repair strategies, considering the condition of a particular locomotive has been offered. Determining the optimality criteria for the technical operation process of the locomotive fleet based on the research of stochastic estimates in the efficiency of the semi-Markov model. Obtaining a sequence of maintenance and repair strategies. The efficiency of locomotive fleet operation significantly depends on the quality of service. The quality of service is determined by the effectiveness of diagnostic tools for technical conditions. The process of operating a locomotive fleet is described by a semi-Markov model. The semi-Markov model used makes it possible to more fully take into account, in the general case, the diagnostic support of the locomotive and the restoration process. The unit cost function the average unit cost, the average unit loss coefficient the coefficient of average, and operating factor was selected as target functions. A procedure has been proposed for constructing an ordered sequence of improving maintenance and repair strategies, considering the condition of a particular locomotive.

Repair Strategies in an English as a Foreign Language Online Educational Setting: A Case Study of Higher Education Studies

Repair Strategies in an English as a Foreign Language Online Educational Setting: A Case Study of Higher Education Studies

Wounding increases nuclear ploidy in wound-proximal epidermal cells of the Drosophila pupal notum.

After injury, tissues must replace cell mass and genome copy number. The mitotic cycle is one mechanism for replacement, but non-mitotic strategies have been observed in quiescent tissues to restore tissue ploidy after wounding. Here we report that nuclei of the mitotically capable Drosophila pupal notum enlarged following nearby laser ablation. Measuring DNA content, we determined that nuclei within 100 µm of a laser-wound increased their ploidy to ~8C, consistent with one extra S-phase. These data indicate non-mitotic repair strategies are not exclusively utilized by quiescent tissues and may be an underexplored wound repair strategy in mitotic tissues.

Chapter 3 - Autologous vs heterologous cell replacement strategies for Parkinson disease and other neurologic diseases

Successful cell replacement strategies for brain repair depend on graft integration into the neural network, which is affected by the immune response to the grafted cells. Using Parkinson disease as an example, in this chapter, we consider the immune system interaction and its role in autologous vs heterologous graft survival and integration, as well as past and emerging strategies to overcome the immunologic response. We also reflect on the role of nonhuman primate research to assess novel approaches and consider the role of different stakeholders on advancing the most promising new approaches into the clinic.

Electrical stimulation: a novel therapeutic strategy to heal biological wounds.

Electrical stimulation (ES) has emerged as a powerful therapeutic modality for enhancing biological wound healing. This non-invasive technique utilizes low-level electrical currents to promote tissue regeneration and expedite the wound healing process. ES has been shown to accelerate wound closure, reduce inflammation, enhance angiogenesis, and modulate cell migration and proliferation through various mechanisms. The principle goal of wound management is the rapid recovery of the anatomical continuity of the skin, to prevent infections from the external environment and maintain homeostasis conditions inside. ES at the wound site is a compelling strategy for skin wound repair. Several ES applications are described in medical literature like AC, DC, and PC to improve cutaneous perfusion and accelerate wound healing. This review aimed to evaluate the primary factors and provides an overview of the potential benefits and mechanisms of ES in wound healing, and its ability to stimulate cellular responses, promote tissue regeneration, and improve overall healing outcomes. We also shed light on the application of ES which holds excellent promise as an adjunct therapy for various types of wounds, including chronic wounds, diabetic ulcers, and surgical incisions.

A Promising Application of Injectable Hydrogels in Nerve Repair and Regeneration for Ischemic Stroke.

Ischemic stroke, a condition that often leads to severe nerve damage, induces complex pathological and physiological changes in nerve tissue. The mature central nervous system (CNS) lacks intrinsic regenerative capacity, resulting in a poor prognosis and long-term neurological impairments. There is no available therapy that can fully restore CNS functionality. However, the utilization of injectable hydrogels has emerged as a promising strategy for nerve repair and regeneration. Injectable hydrogels possess exceptional properties, such as biocompatibility, tunable mechanical properties, and the ability to provide a supportive environment for cell growth and tissue regeneration. Recently, various hydrogel-based tissue engineering approaches, including cell encapsulation, controlled release of therapeutic factors, and incorporation of bioactive molecules, have demonstrated great potential in the treatment of CNS injuries caused by ischemic stroke. This article aims to provide a comprehensive review of the application and development of injectable hydrogels for the treatment of ischemic stroke-induced CNS injuries, shedding light on their therapeutic prospects, challenges, recent advancements, and future directions. Additionally, it will discuss the underlying mechanisms involved in hydrogel-mediated nerve repair and regeneration, as well as the need for further preclinical and clinical studies to validate their efficacy and safety.

Analgesia strategy for inguinal hernia repair in children: a systematic review and network meta-analysis of randomized clinical trials based on regional blocks.

Despite its acknowledged benefits, the selection of an optimal regional block for analgesia pediatric hernia surgery remains a subject of debate. This study endeavored to conduct a network meta-analysis and systematic review of randomized clinical trials, aiming to amalgamate insights from both direct and indirect comparisons concerning the analgesic effectiveness and safety of various regional blocks post-inguinal hernia repair in children. A comprehensive literature search was performed across PubMed, EMBASE, Web of Science, and the Cochrane Library up to 12 November 2022 by two independent reviewers, employing a standardized protocol. The inclusion criteria encompassed randomized trials focusing on children undergoing inguinal hernia repair utilizing either local infiltration analgesia or regional analgesia. The primary outcomes assessed were pain scores at 2, 6, and 24 h post-operation. The initial search yielded 281 records relating to 1,137 patients. The analysis of ranking probability indicated that Paravertebral Block (PVB) holds the highest likelihood (88% and 48%) of being the most effective in alleviating pain at 2 h and 6 h post-surgery. Trans vs. Abdominis Plane Block (TAPB) emerged as the superior choice for mitigating pain (83%) and decreasing morphine consumption (93%) at 24 h following the operation. Local Anesthetic Infiltration (LAI) was identified as the most effective in shortening the hospital stay, with a 90% probability. Regional anesthesia significantly enhances postoperative pain management in pediatric inguinal hernia repair surgery. For short-term postoperative pain relief, PVB emerges as the most effective technique. Meanwhile, TAPB provides more prolonged analgesia. Although TAPB does not exhibit a pronounced advantage in short-term analgesia, its simplicity and the absence of a need for a special position render it a viable option. However, the interpretation of these results should be approached with caution due to the presence of limited data and heterogeneity. PROSPERO (CRD42022376435; www.crd.york.ac.uk/prospero).

Application of a calcium and phosphorus biomineralization strategy in tooth repair: a systematic review.

Biomineralization is a natural process in which organisms regulate the growth of inorganic minerals to form biominerals with unique layered structures, such as bones and teeth, primarily composed of calcium and phosphorus. Tooth decay significantly impacts our daily lives, and the key to tooth regeneration lies in restoring teeth through biomimetic approaches, utilizing mineralization strategies or materials that mimic natural processes. This review delves into the types, properties, and transformations of calcium and phosphorus minerals, followed by an exploration of the mechanisms behind physiological and pathological mineralization in living organisms. It summarizes the mechanisms and commonalities of biomineralization and discusses the advancements in dental biomineralization research, guided by insights into calcium and phosphorus mineral biomineralization. This review concludes by addressing the current challenges and future directions in the field of dental biomimetic mineralization.

Identification and validation of novel engineered AAV capsid variants targeting human glia.

Direct neural conversion of endogenous non-neuronal cells, such as resident glia, into therapeutic neurons has emerged as a promising strategy for brain repair, aiming to restore lost or damaged neurons. Proof-of-concept has been obtained from animal studies, yet these models do not efficiently recapitulate the complexity of the human brain, and further refinement is necessary before clinical translation becomes viable. One important aspect is the need to achieve efficient and precise targeting of human glial cells using non-integrating viral vectors that exhibit a high degree of cell type specificity. While various naturally occurring or engineered adeno-associated virus (AAV) serotypes have been utilized to transduce glia, efficient targeting of human glial cell types remains an unsolved challenge. In this study, we employ AAV capsid library engineering to find AAV capsids that selectively target human glia in vitro and in vivo. We have identified two families of AAV capsids that induce efficient targeting of human glia both in glial spheroids and after glial progenitor cell transplantation into the rat forebrain. Furthermore, we show the robustness of this targeting by transferring the capsid peptide from the parent AAV2 serotype onto the AAV9 serotype, which facilitates future scalability for the larger human brain.

Chapter 9 - Immunology of cell and gene therapy approaches for neurologic diseases

Repair and replacement strategies using cell replacement or viral gene transfer for neurologic diseases are becoming increasingly efficacious with clinically meaningful benefits in several conditions. An increased understanding of disease processes opens up opportunities for genetic therapies and precision medicine methods aiming at disease modification or repair of lesioned neurologic structures. However, such therapeutic effects may be limited or rendered ineffective by immune responses against gene products or cells used for the intended treatments. When introducing therapeutic agents into the nervous system, a set of biologic responses are inevitably triggered, which may lead to host responses that limit the intended therapeutic goals. Factors of importance include the type of vector used and origin of cells, the mode of introduction, the degree of host immunization, and any prior exposure to the agents used. It is possible to apply specific treatments that interfere with many of these steps and factors in order to limit host immunization and to reduce or eliminate host effector reactions against the therapeutic agents. This includes immune-evading design measures of the advanced therapeutic medicinal products and various immunosuppressive processes. Limited duration of specific immune modulations may be possible under carefully monitored programs.

Combining Electrical Stimulation and Conductive Nerve Guide Conduit: A Promising Strategy for Repair of Sciatic Nerve Gap in A Rat Model

Combining Electrical Stimulation and Conductive Nerve Guide Conduit: A Promising Strategy for Repair of Sciatic Nerve Gap in A Rat Model

Advanced approaches in skin wound healing - a review on the multifunctional properties of MXenes in therapy and sensing.

In recent years, the use of MXenes, a class of two-dimensional materials composed of transition metal carbides, nitrides, or carbonitrides, has shown significant promise in the field of skin wound healing. This review explores the multifunctional properties of MXenes, focusing on their electrical conductivity, photothermal effects, and biocompatibility in this field. MXenes have been utilized to develop advanced wound healing devices such as hydrogels, patches, and smart bandages for healing examination. These devices offer enhanced antibacterial activity, promote tissue regeneration, and provide real-time monitoring of parameters. The review highlights the synthesis methods, chemical features, and biological effects of MXenes, emphasizing their role in innovative skin repair strategies. Additionally, it discusses the potential of MXene-based sensors for humidity, pH, and temperature monitoring, which are crucial for preventing infections and complications in wound healing. The integration of MXenes into wearable devices represents a significant advancement in wound management, promising improved clinical outcomes and enhanced quality of life for patients.

P-doped spherical hard carbon with high initial coulombic efficiency and enhanced capacity for sodium ion batteries

We propose a repair strategy based on doping a trace amount of P to achieve a high capacity along with a high ICE, the obtained PHC-0.2 possesses a large interlayer space that facilitates Na+ storage and transportation.

Detection and monitoring of the fatigue crack growth on welds – Application-oriented use of NDT methods

Early detection of fatigue cracks and accurate measurements of the crack growth play an important role in the maintenance and repair strategies of steel structures exposed to cyclic loads during their service life. Observation of welded connections is especially of high relevance due to their higher susceptibility to fatigue damage. The aim of this contribution was to monitor fatigue crack growth in thick welded specimens during fatigue tests as holistically as possible, by implementing multiple NDT methods simultaneously in order to record the crack initiation and propagation until the final fracture. In addition to well-known methods such as strain gauges, thermography, and ultrasound, the crack luminescence method developed at the Bundesanstalt für Materialforschung und -prüfung (BAM), which makes cracks on the surface particularly visible, was also used. For data acquisition, a first data fusion concept was developed and applied in order to synchronize the data of the different methods and to evaluate them to a large extent automatically. The resulting database can ultimately also be used to access, view, and analyze the experimental data for various NDT methods. During the conducted fatigue tests, the simultaneous measurements of the same cracking process enabled a comprehensive comparison of the methods, highlighting their individual strengths and limitations. More importantly, they showed how a synergetic combination of different NDT methods can be beneficial for implementation in large-scale fatigue testing but also in monitoring and inspection programs of in-service structures - such as the support structures of offshore wind turbines.

Rapid On-orbit Repair Mission Planning for Multiple GEO Spacecraft Based on a Mixed Repair Strategy

Rapid On-orbit Repair Mission Planning for Multiple GEO Spacecraft Based on a Mixed Repair Strategy

Performance Analysis of a VM-PM Repair Strategy in MEC-Enabled Wireless Systems With Bursty Traffic

Performance Analysis of a VM-PM Repair Strategy in MEC-Enabled Wireless Systems With Bursty Traffic

A Fuzzy Synthesis Approach for Hierarchical Decision Analysis to Select Optimum Repair Technique

Selecting the best remanufacturing or repair strategy for engineering equipment/component is a complex task, partly due to the many factors affecting the decision as well as the high uncertainty associated with these factors. The challenge facing decision makers is to find an effective and reliable approach that supports their decisions regarding the best remanufacturing or repair technique that extends the service life of an equipment and keep it in operation from failures. This paper presents an innovative fuzzy-based approach for modelling the selection of optimum remanufacturing/repair technique for engineering equipment. The proposed fuzzy synthesis approach allows analysing hierarchical multi-criteria decision-making (MCDM) problems using a simplified and effective method for supporting the elicitation and processing of expert judgements. This approach is tested in a case study of selecting the optimum repair techniques for aero engine component and obtained good model performance in comparison with other alternative MCDM model, which shows the plausibility of applying the approach to domains that are based on human expertise.

A Study on the Influence of Users’ Privacy Literacy and Trust Repair Strategies on the Effectiveness of Trust Repair after Social Media Privacy Invasion

A Study on the Influence of Users’ Privacy Literacy and Trust Repair Strategies on the Effectiveness of Trust Repair after Social Media Privacy Invasion

An integrated design strategy coupling additive manufacturing and matrix-assisted pulsed laser evaporation (MAPLE) towards the development of a new concept 3D scaffold with improved properties for tissue regeneration.

Bioinspired strategies for scaffold design and optimization were improved by the introduction of Additive Manufacturing (AM), thus allowing for replicating and reproducing complex shapes and structures in a reliable manner, adopting different kinds of polymeric and nanocomposite materials properly combined according to the features of the natural host tissues. Benefiting from recent findings in AM, a Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique was employed for obtaining graphene-like material (GL) uniform coatings on 3D scaffolds for tissue repair strategies, towards the development of a new concept 3D scaffold with controlled morphological/architectural and surface features and mechanical and biological properties. The effect of the material-design combination through an integrated technological approach (i.e., MAPLE deposition of GL on 3D AM PCL scaffolds) was assessed through scanning electron microscopy, atomic force microscopy, contact angle measurements, mechanical measurements and biological analyses (cell viability assay and alkaline phosphatase activity) in conjunction with confocal laser scanning microscopy. The differentiation of hMSCs towards the osteoblast phenotype was also investigated analysing the gene expression profile. The obtained findings provided a further insight into the development of improved strategies for the functionalization or combination of GL with other materials and 3D structures in a hybrid fashion for ensuring a tighter adhesion onto the substrates, improving cell fate over time, without negatively altering the mechanical properties and behaviour of the neat constructs. In particular, the results provided interesting information, making 3D AM GL-coated scaffolds potential candidates for bone tissue engineering.

Rapid recovery strategy for seismic performance of seismic-damaged structures considering imperfect repair and seismic resilience

In the emergency repair process of seismic-damaged structures, it is necessary to determine the optimal repair strategy according to damage assessment results, available repair resources and repair time. In this study, the applicable conditions of various member-level and structure-level damage indexes or models are compared. Then, considering the actual conditions of limited available repair resources and repair time in the emergency repair process, the determination method of the optimal imperfect repair strategy is established. On this basis, the determination method of the optimal repair sequence is proposed by taking seismic resilience as the evaluation index. Finally, a seismic fragility analysis method that considers uniform collapse risk and residual service life of structures is introduced, which can be used to analyze the seismic performance of seismic-damaged structures and to compare the repair effectiveness of different repair strategies. Taken a 5-story reinforced concrete structure as an example for analysis. The analysis results show the optimal imperfect repair strategy and the optimal repair sequence determined by the proposed methods can effectively improve the seismic performance of seismic-damaged structures. The fragility analysis results further confirm that the repair based on the optimal imperfect repair strategy can effectively reduce the collapse risk of seismic-damaged structures.