Healing Performance Research Articles

Healing response of cold recycled asphalt mixtures with electric arc furnace slag under microwave heating and re-compaction

The objective of the present paper is the assessment of the healing efficiency of a thermomechanical treatment (microwave heating and re-compaction) on cold recycled asphalt mixtures. The asphalt mixture specimens were fabricated with different electric arc furnace slag (EAFS) contents to improve the mixtures' microwave susceptibility. The healing response was then assessed in terms of recovery of their initial indirect tensile strength. Furthermore, statistical analysis was conducted by means of a three-way analysis of variance to determine the influence of temperature, re-compaction energy, and EAFS content on the healing capability of the mixtures. Although re-compaction and heating in the ranges studied do not themselves cause healing, the combination of both produced excellent healing performance. The optimal content of EAFS was established at 5% of EAFS over the weight of the asphalt mixture.

Clavicle fracture and triathlon performance: a case report

BackgroundCollarbone fracture is a common injury, particularly among athletes involved in contact sports and participating in endurance activities. Conventional treatment requires surgery and postoperative immobilization, resulting in an average return-to-sport timeframe of approximately 13 weeks. This case challenges the established treatment protocols, aiming to expedite recovery and enable a quicker resumption of high-intensity athletic activities.Case presentationA 24-year-old Caucasian athlete completed a Half-Ironman Triathlon (70.3) merely three weeks post-collarbone fracture. Utilizing Extracorporeal Magneto-Transduction Therapy (EMTT) alongside surgical intervention, the patient achieved accelerated healing and remarkable performance outcomes without encountering any adverse effects.ConclusionsThe integration of EMTT into the treatment paradigm for bone fractures alters the traditional understanding of recovery timelines and rehabilitation strategies. This case highlights the potential benefits of electromagnetic wave therapy in expediting the healing process and enabling athletes to resume high-level sports activities at an earlier stage.

Self-healing flexible strain sensor fabricated through 3D printing template sacrifice for motion monitoring with enhanced healing and mechanical performance

With the advancements in flexible materials and information technology, flexible sensors are becoming increasingly pervasive in various aspects of life and production. They hold immense potential for further development in areas such as motion detection, electronic skin, soft robots, and wearable devices. Aminopropyl-terminated polydimethylsiloxane (PDMS) was used as the raw material, while a diisocyanate reagent served as the cross-linking agent for the polymerization reaction, which involved the introduction of ureido groups, containing N–H and C=O bonds, into the long siloxane chain. The dynamic hydrogen bonding between the clusters completes the self-healing of the material. Using 1-[3-(trimethoxysilyl)propyl]urea as a grafting agent, the urea groups are introduced into graphene oxide and carbon nanotubes (CNTs) as conductive fillers. Subsequently, a flexible polymer is used as the substrate to prepare conductive flexible self-healing composites. By controlling the amount of conductive fillers, flexible strain materials with varying sensitivities are obtained. Design the structure of the flexible strain sensor using three-dimensional (3D) modeling software with deposition printing method.

Antibacterial and wound healing performance of a novel electrospun nanofibers based on polymethyl-methacrylate/gelatin impregnated with different content of propolis

Wound management and care mainly relies on the production of new and effective wound dressing materials. Chronic wounds require protection against pathogens and bacterial infection. Therefore, it is very important to design wound dressings with antibacterial and restorative capabilities. In this research, polymethyl-methacrylate (PMMA) and gelatin (Gel) nanofibers (NFs) were produced in different ratios by electrospinning method. Propolis (Pro) as a wound healing drug was added to the optimal PMMA70/Gel30 parent scaffold at different concentrations (10, 30 and 50 %w/v). Physical and chemical characterization, porosity, degradation, water vapor transmission rate (WVTR), swelling, mechanical properties and contact angle of the mats were analyzed. The NFs presented a homogeneous and defect-free morphology. The PMMA70/Gel30 mats showed the lowest average diameter (362.1 ± 132.3 nm) among the scaffolds. In addition, the highest wettability (∼70°) and WVTR (∼250 g/m2 × 24h) are related to PMMA70/Gel30. The addition of Pro extract (up to 50%) increased the mean diameter of NF (571.1 ± 171.8 nm). None of the scaffolds showed toxicity in the environment. The optimal PMMA/Gel/Pro50% NF showed more adhesion and higher cell viability than other samples. The antioxidant activity of PMMA/Gel/Pro50% is more about 10 times compared to PMMA70/Gel30. Pro extract showed significant antibacterial activity in the scaffolds, so that the release of Pro (∼70% in 24hrs) in the PMMA/Gel/Pro50% caused the inhibition of S. aureus (9 mm) and E. coli (11 mm) bacteria in Mueller's culture medium. All these findings confirm that the produced NF mats, especially those loaded with Pro, have a high potential to be used as an effective wound dressing.

Effect of aggregate damage on self-healing characteristics of asphalt concrete: An image processing-based method

In the fracture-based healing test, asphalt specimens generally break into two halves and the aggregates in the crack path also break. In this study, the effect of aggregate damage on the self-healing performance of asphalt concrete was studied. To achieve this, semi-circle asphalt specimens were produced. Then, they were broken using the Semi-circle bending test (SCB) at different temperatures (i.e., −20, −10, 0, 10, and 20 °C) to create various aggregate damage situations. Next, the fracture surfaces of specimens were photographed and the percentages of damage types (i.e., adhesive, cohesive, and broken aggregates) were obtained by using image processing techniques. After the specimens were healed at a constant 55 °C, the SCB test was applied again to measure the strength of the specimens and to calculate healing performance. Finally, fracture surfaces were photographed again. According to findings, as breaking temperatures increase, broken aggregates and adhesive damage decrease. Cohesive damage, on the other hand, rose with the high breaking temperature. Healing performance was better at low breaking temperatures. A positive correlation was found between aggregate damage and healing levels, but it was explained as a spurious relationship. The real correlation was negative which was obtained from a second dataset.

Healing properties of residential balcony: Assessment of the characteristics of balcony space in Shanghai's collective housing

The balcony is open, connected with the outside, and close to nature, which can provide sunshine, air, vision, leisure, and social functions, bring a variety of health benefits, and gradually become a healing space in modern family life. However, current research lacks a systematic knowledge of the healing properties of balcony space features. The purpose of this paper is to determine the healing performance of balcony space characteristics of urban collective housing and its correlation with healing and to provide a theoretical basis for the design and optimization of residential balconies. Firstly, based on the literature review, the main spatial characteristics of a balcony and its healing index are determined. Then, based on the review results, a spatial assessment and analysis framework for a residential floor plan is developed. A combined qualitative and quantitative approach was used to assess the healing of balcony space characteristics of 1641 housing types in Shanghai. The results show that the healing of the balcony is at a low level, which has great potential for improvement. The spatial characteristics that affect the healing assessment mainly include structural type, connection mode, area, vision, and furniture. It was found that the spatial characteristics of balconies have interrelated and interacting role relationships that directly or indirectly affect the healing performance of balconies. This study provides a valuable reference for the renovation and design of residential balconies, helps to provide targeted design suggestions for real estate development departments and designers, and helps to improve the quality of living and the health and well-being of residents.

Development and characterization of plant derived wastes Nano-formulation loaded in thermo-reversible gel for burn healing: An effort towards Sustainable Development

The duty of research is to suggest solutions to ailments affecting humans. Recently, there has been a demand that these solutions should be environmentally responsible, eco-friendly and coincide with sustainable development goals. From this perspective, the objective of this study was to develop thermo-reversible and healing promoting gel formulations. The gel base incorporated Natural Plant derived Wastes’ ethanolic extracts of either Kiwi peels (KE) or Yucca seeds (YE) (antioxidant, vitamins and anti-inflammatory natural agent) loaded chitosan nanoparticles for enhancement of burn healing performance. Comparative evaluation was done to all formulations to find the best competitor to conventional marketed drug formulations. Both extracts were standardized using HPLC. The lipoid content of YE was investigated using GC-MS, showing a content of 32.78 and 15.7 %of linoleic and pamiticmethyl esters, respectively. The nanoparticles characterization and the in-vitro physicochemical characteristics of the final dosage form formulations were assessed, revealing86.65 and 76.6 % entrapment efficiency, 311.4 and 198.1 nm particle size for KE and YE nanoformulations, respectively. The efficacy of the formulations was investigated in vivo against the commercial burn healing drug Mebo®, biochemical parameters and histopathology were statistically investigated. Reduction in wound area reached 69.12 and 72.01 % on day 12 for KE and YE nanoformulations, respectively. The YE encapsulated within chitosan nanoparticles loaded gel showed a promising and a significant healing effect comparable to the most commonly used marketed drug product (Mebo®) and possible mechanisms involved in the phases of healing were illustrated. Eco-friendly waste herbal extracts-loaded chitosan nanoparticles in thermo-reversible gel have been successfully developed from the two extracts: Kiwi peels and yucca seeds for burn and wound healing. This confirms the possible use of traditional medicines in advanced formulations to satisfy the future market of pharmaceuticals.

A molecular dynamics analysis of the influence of iron corrosion products on the healing process of bitumen

Corrosion of iron materials in the asphalt concrete pavement occurs commonly when the bitumen film peels off, and the generation of corrosion products would affect the healing performance of bitumen. To identify the affection, this research focuses on the influence of iron corrosion products on the healing process of bitumen by molecular dynamics simulation. Firstly, bitumen model and iron corrosion products model were built. Then the healing systems of sandwich structure were constructed, and the simulated temperature were applied to reach equilibrium in the healing process with NVT ensemble (constant number of atoms, volume, and temperature). Dynamic movements of bitumen were characterized by appearance qualitatively. Healing rate of crack and healing rate of bitumen aggregation were held to evaluate the healing effect. Diffusion behaviors, internal force of motivation and interaction effect were also analyzed. The results indicate the duplicity of iron corrosion products in the healing process including the ease for bitumen climbing and the obstruction of bitumen movement. The comprehensive healing index demonstrated that iron corrosion products would reduce the healing degree, which was mainly caused by the obstruction effect and large internal stress generated by severe aggregation of bitumen in the limited space. From the perspective of crack closure and bitumen aggregation degree in the corrosion area, FeO healing systems were healed best, followed by Fe3O4, Fe2O3 and FeOOH. Furthermore, diffusion period of bitumen molecules on the surface of iron corrosion products during the healing process should be regarded as the important period affecting healing.

Bacteria-based crack healing of 3D printed PVA fiber reinforced geopolymer mortars

Geopolymers have been regarded as a promising environmentally friendly alternative to cementitious materials in 3D printing. In this study, 3D-printed fly ash based geopolymer mortars containing silica fume were produced with PVA fiber at 0%, 0.5%, 1%, and 1.5% ratios. Cracks were created in the specimens using flexural strength test after 28 days. Then, bacterial self-healing process was applied to the half of cracked samples and the remaining cracked samples were used as control samples. Sporosarcina pasteurii was used for healing. Lastly, the visual inspection, flexural strength, compressive strength, and water absorption analyzes were conducted mechanical properties to evaluate the healing performance of 3D-geopolymer samples containing PVA. In addition, the samples were subjected to microstructural examination using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) to determine the changes in the microstructural of bacterial based healing. As a result, CaCO3 precipitates, which are the bacterial healing output, filled the cracks and boosted the mechanical characteristics of 3D-geopolymer. The application in 3D-printed PVA fiber reinforced geopolymer mortars of bacterial healing resulted in a significant 36.23% improvement in flexural strength and an 11.57% reduction in the capillary water absorption coefficient compared to the non-healed samples.

Multifunctional On-Demand Removability Hydrogel Dressing Based on in Situ Formed AgNPs, Silk Microfibers and Hydrazide Hyaluronic Acid for Burn Wound Healing.

Elevated temperatures can deactivate tissues in the burn wound area, allowing pathogenic bacteria to multiply on the wound surface, ultimately leading to local or systemic infection. An ideal burn dressing should provide antibacterial properties and facilitate painless dressing changes. Silk microfibers coated with poly (2, 3, 4-trihydroxybenzaldehyde)(referred to as mSF@PTHB) to in situ reduce AgNO3 to silver nanoparticles (AgNPs) in a hydrazide hyaluronic acid-based hydrogel are utilized. The findings indicate a more homogeneous distribution of the silver elements compared to directly doped AgNPs, which also conferred antioxidant and antibacterial properties to the hydrogel. Moreover, hydrogels containing pH-responsive dynamic acylhydrazone bonds can undergo a gel-sol transition in a weak acid environment, leading to the painless removal of adhesive hydrogel dressings. Notably, the on-demand replaceable self-healing antioxidant hydrogel dressing exhibits antibacterial effects and cytocompatibility in vitro, and the wound-healing performance of the hydrogel is validated by treating a burn mouse model with full-thickness skin defects. It is demonstrated that hydrogel dressings offer a viable therapeutic approach to prevent infection and facilitate the healing of burn wounds.

Induction heating and induced healing evaluation of the asphalt concretes incorporating conductive aggregates exposed to microwave radiation

This study investigates the application of aggregate-based conductive additives, including steel slag, Iron slag, and ferrosilicon, in asphalt concretes for induction heating and induced healing purposes. The research focuses on evaluating the mechanical properties, induction heating capabilities, induced crack healing, environmental impacts, and cost of various conductive asphalt concretes. The Gray Relation Analysis (GRA) technique is then employed to determine the sustainability ranking of these mixtures based on the aforementioned criteria. The mechanical properties of the asphalt concretes were evaluated through the Indirect tensile strength at intermediate temperature and semi-circular bending tests at intermediate and low temperatures. The homogeneous induction heating rate of the mixtures was also examined. Additionally, the healing indices for the breaking-healing cycles were investigated. The environmental impacts and fabrication cost of conductive asphalt concretes were compared to identify the most sustainable conductive mixture with optimal performance and durability. The results demonstrate that the addition of aggregate-based conductive additives significantly improves the mechanical properties and homogeneous heating rates under microwave radiation. Furthermore, the conducted tests indicate that the introduced conductive asphalt concretes possess the ability to heal and restore their mechanical properties after damage or cracking. Moreover, the sustainability analysis reveals that the mixtures incorporating steel slag, especially asphalt concrete incorporating fine steel slag, are more sustainable and cost-effective compared to conventional asphalt mixtures. These findings provide valuable insights for road infrastructure and pavement design, aiming to incorporate innovative and environmentally friendly materials and methods to enhance the healing competencies and performance of flexible pavements.

Finite element model with realistic bone geometries for the optimal design of internal fixation during the fibula healing process.

A finite element model with realistic bone geometries is developed to design optimal internal fixation during the fibula healing process in this study. The effect of bone plate parameters on fibula fracture healing is studied. The relationship between differences in plate length, thickness and working length, and bone healing performance is focused. The optimal combination form of the bone plate parameters was selected by the orthogonal experimental design and fracture block strain to achieve bone healing maximize the performance. The model results show that the maximum equivalent force of the bone plate was below the material yield limit; the higher mean contact stresses in the bone fragments indicate that the bone plate is prone to higher contact stresses when they are long. The working length of the bone plate has a greater effect on callus healing than the thickness and length of the bone plate. The optimal internal fixation option for distal fibula fractures is achieved when it provides the stability required for internal fixation during bone healing. It ensures lower contact stresses in the fibula as well as maximum Young's modulus during callus healing process.

Staging and intertextualizing Franz Kafka’s “in the penal colony”

ABSTRACT In 2022, I adapted for the stage Franz Kafka’s 1914 short story “In the Penal Colony” and intertextualized the text with devised narratives about the body in pain. I theorize both the staged performance and this reflexive essay as a method of embodied intertextual resistance within literary performance practice to unearth the relationships between performance and writing, body and machine, and the page and the stage. I highlight three moments of intertextual vignettes within the production to highlight the role of literary performance in healing both ourselves and the world around us.

The flower of Abelmoschus manihot (L.) medik exerts antioxidant effects by regulating the Nrf2 signalling pathway in scald injury.

Scald is a common skin injury in daily life. It is well known that skin burns are associated with inflammation and oxidative stress. In our previous study, we found that Abelmoschus manihot (L.) medik had excellent therapeutic effects on scald-induced inflammation, but its effect on scald-induced oxidative stress was not reported. In this study, a deep second-degree scald model in mice was established, and the wound healing rate, healing time, malondialdehyde (MDA) and total superoxide dismutase (T-SOD) levels, and nuclear factor erythroid 2-related Factor 2 (Nrf2) expression in wound tissue were measured to evaluate the scald wound healing performance of extraction from A. manihot (L.) medik (EAM). Scalding activity in mice was examined in vivo by hot water-induced finger swelling. The treatment scald activities were also examined in vivo by subjecting mice to thermal water-induced digit swelling. Additionally, the antioxidant effect of EAM on fibroblasts was also used to determine the mechanism in vitro. The results showed that EAM not only decreased the wound healing time but also effectively regulated the levels of oxidising, MDA and T-SOD in wound tissue. Concurrently, EAM suppressed digit swelling and hyperalgesia. Furthermore, EAM had a significant protective effect on NIH-3T3 cells after H2 O2 injury by regulating the Nrf2 signalling pathway against oxidative injury. Therefore, EAM is a promising drug for the treatment of scald-induced inflammation.

Synthesis and characterization of new electrospun medical scaffold-based modified cellulose nanofiber and bioactive natural propolis for potential wound dressing applications.

Recently, the design of polymer nanofibers using the electrospinning process has attracted much interest. Particularly the use of natural polymers has promoted many advantages in their biomedical applications. However, the combination of multiple natural polymers remains a great challenge in terms of electrospun production and applied performance. From this perspective, the current investigation highlights the study of the preparation of electrospun nanomaterial scaffolds based on combined natural polymers for improved wound healing performance. First, we have synthesized a crosslinked polymer by reacting microcrystalline cellulose (MC) and chitosan (CS) biopolymer via the intermediate of citric acid as a crosslinking agent. Then a natural propolis biomolecule was incorporated into the polymer network. Different MC/CS blend ratios of 90/10 and 70/30 were then used and various machine parameters were optimized to obtain nanofiber scaffolds with excellent strength and structures. SEM, IR, physicochemical, mechanical, and morpho-logical characterization were then performed. SEM evaluation revealed homogeneous and bead-free nanofibrous structures, with well-defined morphology and a random deposition that could accurately mimic the extracellular matrix of native skin. The calculated average nanofiber diameters for the MC/CS blend ratios at 90/10 and 70/30 were 431.4 and 441.2 nm, respectively. The results showed that when the chitosan amount increased, larger nanofibers with narrow diameter distribution appeared. The prepared nanomaterials had a significant and close water vapor permeability of about 1735.12 and 1698.52 g per m per day for the two blend ratios of 90/10 and 70/30, respectively. The examination of swelling behavior revealed a noteworthy enhancement in hydrophilicity, a necessary attribute for improved healing efficacy. FT-IR analysis confirmed the success and the stability of the chemical crosslinking reaction between the two biopolymers before nanofiber conception. Excellent mechanical properties were acquired, based on the chitosan content. Both developed nanofiber scaffolds exhibited high tensile strength and Young's modulus values. The incorporation of 30% chitosan versus 10% results in an increase in tensile strength of 11% and 14% in Young's modulus. Therefore, we could adjust the different mechanical properties simply by varying the mixing rate of the electrospun polymers. Using epithelial HepG2 cells, viability and kinetic cell adhesion assays were assessed to obtain biological evaluation. No cytotoxicity was observed and good cytocompatibility was confirmed. Functionalized nanofiber biomaterials with different MC/CS ratios substantiated significant bactericidal effectiveness against Gram-positive and Gram-negative bacterial culture strains. The novel functional electrospun wound dressing scaffold demonstrated effective and promising biomedical performance, healing both acute and chronic wounds.

Green synthesis of polyurethane with reversible oxime-urethane bond to enhance the self-healing properties of asphalt binder at room temperature

The oxime-urethane group can undergo dynamic reversible reaction at room temperature, which can endow polyurethane (PU) with self-healing ability at ambient temperatures. This study prepared CO2-based PU containing oxime-urethane groups and introduced it into asphalt to enhance the self-healing performance of asphalt at room temperature. Firstly, the chemical structure, self-healing performance, and thermal stability of the prepared PU and ordinary PU were characterized. Then, the two types of PU were sheared in asphalt to prepare PU modified asphalts, the chemical characteristics and microstructure of the modified asphalts were characterized. Finally, the healing performance of different asphalts at room temperature was characterized. The results indicated that the prepared self-healing PU had good thermal stability and exhibited rapid self-healing performance at room temperature. After 6h of healing, the maximum tensile strength can recover to 88.78% of its initial value. Self-healing (S-PU) was successfully introduced into asphalt system without decomposition, but due to the role of intermolecular hydrogen bond and dynamic covalent bond of PU, its dispersion in asphalt was poor. The addition of S-PU can significantly enhance the self-healing capability of asphalt at room temperature. This study provides a new idea for the preparation of green PU modified asphalt containing dynamic covalent bond.

Study on self-healing mechanism of magnetic nano-powders functionalized fiber reinforced thermoplastic composites

At present, a variety of methods have been developed to realize the self-healing function of fiber-reinforced composites. However, the intrinsic mechanism of material damage recognition and self-healing initiation still lacks systematic research. In this paper, GF/(FeNip/PP) composites with multistage structures were prepared to study the self-healing properties and the mechanism of fiber-reinforced thermoplastic composites. The addition of a small amount of FeNip without affecting the melting peak temperature of the PP matrix (i.e., without reducing the use temperature of PP) can increase the electromagnetic loss (tanδ) of the composites by about 40% and the thermal conductivity by 36%. The cyclic stretching times of GF/(FeNip/PP) composites after microwave healing are doubled at 50% to 60%σmax load. It is indicated that FeNip endows the GF/PP composites with good microwave healing performance, and the purposeful repair can effectively extend the service life of the material. In addition, the self-healing mechanism of GF/(FeNip/PP) composites is discussed in detail from the aspects of microstructure change, multiphase interface effect, entropy enthalpy effect, starting and ending of self-healing procedures, etc. The magnetothermal effect, “entropy consumption” effect, and polymer chain diffusion are the fundamental reasons for the self-healing function of fiber reinforced thermoplastic composites.

Atividades biológicas e potencial de cicatrização de feridas de um polissacarídeo solúvel em água isolado de Glycyrrhiza glabra em rato Wistar

The present study aimed to evaluate the in vitro antibacterial and antioxidant activities and the in vivo wound healing performance of a polysaccharide isolated from Glycyrrhiza glabra named PSG. It was structurally characterized by Fourier transformed infrared (FT-IR) spectroscopy, which confirmed the presence of different polysaccharides functional bands. The antioxidant capacity of PSG was determined in vitro and evaluated in vivo through the examination of wound healing capacity. Thirty two rats were randomly divided into four groups: group I was treated with physiological serum (negative control); group II was treated with "CYTOL CENTELLA®"; group III was treated with glycerol and group IV was treated with polysaccharide. The response to treatments was assessed by macroscopic, histologic, and biochemical parameters. Data revealed that our sample exhibited potential antioxidant activities and accelerated significantly the wound healing process, after ten days of treatment, proved by the higher wound appearance scores and a higher content of collagen confirmed by histological examination, when compared with control and "CYTOL CENTELLA®". Overall, these findings proved that this polysaccharide isolated from Glycyrrhiza glabra could be considered as a natural bioactive polymer for therapeutic process in wound healing applications.

Evaluation of the Healing Performance of Hot-Mix Asphalt Containing Waste Steel Shavings under Different Microwave Induction Healing Cycles

Evaluation of the Healing Performance of Hot-Mix Asphalt Containing Waste Steel Shavings under Different Microwave Induction Healing Cycles

Effect of different composite plates on the healing of femoral fractures

In this paper, the effects of different composite plates on the healing of femoral fractures were studied by numerical simulation. The healing model of femoral fracture was established by ABAQUS display solver. Based on the fuzzy logic theory, the process of callus differentiation at femoral fracture was considered under the joint action of biological variables and mechanical stimulation, and the healing process of femur was simulated. Compare the stress on the screw, concentration of callus bone and cartilage, and callus healing performance of the carbon/epoxy composite (WSN3k) plate, glass/polypropylene composite (Twintex) plate, and stainless steel plate at various stages of bone healing, and investigate the impact of composite plates on the bone healing process. The results showed that the modulus of the plate had a notable impact on bone healing. Compared to stainless steel plate, the composite plate (due to its lower stiffness) exhibiting superior healing performance. Altering the sequence of composite laminates may modify the bone healing efficiency, and the wsn3k [0]18 composite plate exhibits superior healing performance.