Regenerative Activity Research Articles

Effect of gadolinium particle size on the performance of a magnetic refrigeration system

This study investigates the influence of gadolinium particle size on Magnetic Refrigeration (MR) system performance. Understanding how particle size of Magnetocaloric Materials (MCMs) within a fixed Active Magnetic Regenerator (AMR) volume affects cooling capacity and Coefficient of Performance (COP) is crucial for MR system design. However, research on this influence, especially using an experimental approach, has been surprisingly rare. This is despite the importance of considering various factors like total MCM mass, porosity, and pressure drop. The particles were categorized into five cases based on their sizes, which ranged from 0.50 to 2.00 mm opening sizes of the meshes. The magnetic field source produced the maximum 0.815 and 0.069 T for magnetization and demagnetization, respectively. A total four of AMRs were installed in the MR system for each case study. First, the porosity of the AMRs mostly increased as finer particles were filled up. This led to a tendency of lower mass of the MCMs in the same volume of the AMRs with smaller particles. Second, the temperature span showed the most outstanding value of 11.1 K in the 0.20 utilization factor using the finest particles (0.50–0.85 mm) in a no-load test. It also achieved a wider 8.3 K temperature span under 3.8 W of thermal load, outperforming the other sizes despite the least total mass of the MCMs. The major contribution to these results was the larger heat transfer area between the MCMs and heat transfer fluid inside the AMRs with the smaller particles. Nevertheless, the case with the second-finest particles (0.80–1.18 mm) exhibited the highest COP of 2.6, due to their favorable combination of moderately significant cooling capacity, reasonably small particle size, and elevated porosity that reduced pumping power demand and magnetic force.

Mussel shell-derived biogenic hydroxyapatite as reinforcement on chitosan-loaded gentamicin composite for antibacterial activity and bone regeneration

In this study, hydroxyapatite (HAp) was synthesized from natural biowaste materials, specifically mussel shells, and combined with chitosan (CS) and gentamicin sulfate antibiotic (GA) using an in-situ method. The resulting composite material, designated HAp/CS-GA, has its physicochemical and structural properties characterized by Fourier transform infrared spectroscopy (FTIR) analysis. The structure was confirmed by X-ray diffraction (XRD) analysis. Additionally, field emission scanning electron microscopy (FE-SEM) equipped with the energy dispersive X-ray spectroscopic (EDX) technique was used to determine the surface topography and main components. The composite of HAp/CS-GA was analyzed using a drug release profile by UV–visible spectroscopy (UV–Vis). The fabricated composites antimicrobial behavior was examined against bone infection-causing Gram-positive and Gram-negative bacteria, showing potential activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus compared to Escherichia coli, respectively. Simultaneously, the cytotoxicity of the composite was evaluated by MTT assay using an MG-63 osteoblast-like cell line that exhibited no toxicity in the prepared composite. After a 24 h incubation period, the MG-63 cells on the HAp/CS-GA composite showed good proliferation, according to Hoechst 33258 fluorescence staining results. The results suggested that the composite had excellent biocompatibility and antibacterial activity and enhanced the osteoblast cell proliferation. Therefore, the designed HAp/CS-GA composite would be a promising candidate for bone tissue engineering.

Extrusion-Based 3D Bioprinting of Bioactive and Piezoelectric Scaffolds as Potential Therapy for Treating Critical Soft Tissue Wounds.

Objective: This study focuses on developing bioactive piezoelectric scaffolds that could deliver bioelectrical cues to potentially treat injuries to soft tissues such as skeletal muscles and promote active regeneration. Approach: To address the underexplored aspect of bioelectrical cues in skeletal muscle tissue engineering (SMTE), we developed piezoelectric bioink based on natural bioactive materials such as sodium alginate, gelatin, and chitosan. Extrusion-based 3D bioprinting was utilized to develop scaffolds that mimic muscle stiffness and generate electrical stimulation (E-stim) when subjected to forces. The biocompatibility of these scaffolds was tested with the C2C12 muscle cell line. Results: The bioink demonstrated suitable rheological properties for 3D bioprinting, resulting in high-resolution composite sodium alginate-gelatin-chitosan scaffolds with good structural fidelity. The scaffolds exhibited a 42-60 kPa stiffness, similar to muscle. When a controlled force of 5N was applied to the scaffolds at a constant frequency of 4 Hz, they generated electrical fields and impulses (charge), indicating their suitability as a stand-alone scaffold to generate E-stim and instill bioelectrical cues in the wound region. The cell viability and proliferation test results confirm the scaffold's biocompatibility with C2C12s and the benefit of piezoelectricity in promoting muscle cell growth kinetics. Our study indicates that our piezoelectric bioink and scaffolds offer promise as autonomous E-stim-generating regenerative therapy for SMTE. Innovation: A novel approach for treating skeletal muscle wounds was introduced by developing a bioactive electroactive scaffold capable of autonomously generating E-stim without stimulators and electrodes. This scaffold offers a unique approach to enhancing skeletal muscle regeneration through bioelectric cues, addressing a major gap in the SMTE, that is, fibrotic tissue formation due to delayed muscle regeneration. Conclusion: A piezoelectric scaffold was developed, providing a promising solution for promoting skeletal muscle regeneration. This development can potentially address skeletal muscle injuries and offers a unique approach to facilitating skeletal muscle wound healing.

Spectroscopic Investigation of the Role of Water in Copper Zeolite Methane Oxidation.

Methane is one of the most potent greenhouse gases; developing technology for its abatement is essential for combating climate change. Copper zeolites can activate methane at low temperatures and pressures, demonstrating promise for this technology. However, a barrier to industrial implementation is the inability to recycle the Cu(II) active site. Anaerobic active site regeneration has been reported for copper-loaded mordenite, where it is proposed that water oxidizes Cu(I) formed from the methane reaction, producing H2 gas as a byproduct. However, this result has been met with skepticism given the overall reaction is thermodynamically unfavorable. In this study, we use X-ray absorption and electron paramagnetic resonance spectroscopies to study the role of water in copper zeolite methane oxidation. We find that water does not oxidize Cu(I) to Cu(II) in CH4-reacted Cu-MOR. Further, using isotope label mass spectrometry, we detail an alternate source of the hydrogen byproduct. We uncover that, although water does not oxidize Cu(I), it has the potential to facilitate low temperature methane abatement through promotion of product decomposition to carbon dioxide and H2.

Roles of SMAD and SMAD-Associated Signaling Pathways in Nerve Regeneration Following Peripheral Nerve Injury: A Narrative Literature Review.

Although several methods are being applied to treat peripheral nerve injury, a perfect treatment that leads to full functional recovery has not yet been developed. SMAD (Suppressor of Mothers Against Decapentaplegic Homolog) plays a crucial role in nerve regeneration by facilitating the survival and growth of nerve cells following peripheral nerve injury. We conducted a systematic literature review on the role of SMAD in this context. Following peripheral nerve injury, there was an increase in the expression of SMAD1, -2, -4, -5, and -8, while SMAD5, -6, and -7 showed no significant changes; SMAD8 expression was decreased. Specifically, SMAD1 and SMAD4 were found to promote nerve regeneration, whereas SMAD2 and SMAD6 inhibited it. SMAD exerts its effects by promoting neuronal survival and growth through BMP/SMAD1, BMP/SMAD4, and BMP/SMAD7 signaling pathways. Furthermore, it activates nerve regeneration programs via the PI3K/GSK3/SMAD1 pathway, facilitating active regeneration of nerve cells and subsequent functional recovery after peripheral nerve damage. By leveraging these mechanisms of SMAD, novel strategies for treating peripheral nerve damage could potentially be developed. We aim to further elucidate the precise mechanisms of nerve regeneration mediated by SMAD and explore the potential for developing targeted nerve treatments based on these findings.

Advancements in sustainable proton-conducting electrochemical cells: Direct recycling of sintered nickel oxide-doped barium zirconate half cells

The ongoing evolution in energy production and conversion technologies has brought solid oxide electrochemical cells (SOCs) to the forefront, recognized for their high efficiency and environmental benefits. However, establishing sustainable and scalable manufacturing processes for SOCs presents formidable challenges, including sourcing large-scale raw materials and implementing effective recycling methods for spent cells and manufacturing scraps. In response, we demonstrate closed-loop direct recycling of proton-conducting solid oxide electrochemical half cells, incorporating active comminution and cell regeneration using the recycled materials. This innovative approach achieves over 92 % material recovery and an impressive 100 % recovery in full cell performance, addressing a significant gap in current sustainable manufacturing practices while setting a new standard for the industry. This technology not only addresses a significant gap in current sustainable manufacturing practices but also sets a precedent for future advancements in the sustainable SOC field, potentially influencing broader practices in the recycling of multi-functional ceramics.

Real biofuel and fossil-fuel soot combustion activities in active and passive regeneration of diesel/gasoline particulate filters under different O2/NOx concentrations.

In this work, we aim to investigate and compare the combustion reactivities of real biofuel soot and fossil-fuel soot in the active and passive regeneration conditions of DPF and GPF through temperature-programmed oxidation (TPO). Higher reactivity of biofuel soot is achieved even under GPF conditions with extremely low oxygen concentration (~ 1%), which provides a great potential for low-temperature regeneration of GPF. Such a result is mainly attributed to the low graphitization and less surface C = C groups of biofuel soot. Unfortunately, the presence of high-content ashes (~ 47%) and P impurity in real biofuel soot hinder its combustion reactivity. TPO evidences that the O2/NOX-lacking conditions in GPF are key factors to impact the combustion of soot, especially fossil-fuel soot. This work provides some useful information for understanding real biofuel and fossil-fuel soot combustion in GPF and DPF regeneration and further improvement in filter regeneration process.

Retinal bipolar cells borrow excitability from electrically coupled inhibitory interneurons to amplify excitatory synaptic transmission.

Bipolar cells of the retina carry visual information from photoreceptors in the outer retina to retinal ganglion cells (RGCs) in the inner retina. Bipolar cells express L-type voltage-gated Ca2+ channels at the synaptic terminal, but generally lack other types of channels capable of regenerative activity. As a result, the flow of information from outer to inner retina along bipolar cell processes is generally passive in nature, with no opportunity for signal boost or amplification along the way. Here we report the surprising discovery that blocking voltage-gated Na+ channels profoundly reduces the synaptic output of one class of bipolar cell, the type 6 ON bipolar cell (CBC6), despite the fact that the CBC6 itself does not express voltage-gated Na+ channels. Instead, CBC6 borrows voltage-gated Na+ channels from its neighbor, the inhibitory AII amacrine cell, with whom it is connected via an electrical synapse. Thus, an inhibitory neuron aids in amplification of an excitatory signal as it moves through the retina, ensuring that small changes in the membrane potential of bipolar cells are reliably passed onto downstream RGCs.

Short-term cryoprotectant-free cryopreservation at -20°C does not affect the viability and regenerative capacity of nanofat.

Nanofat is an autologous fat derivative with high regenerative activity, which is usually administered immediately after its generation by mechanical emulsification of adipose tissue. For its potential repeated use over longer time, we herein tested whether cryopreservation of nanofat is feasible. For this purpose, the inguinal fat pads of donor mice were processed to nanofat, which was i) frozen and stored in a freezer at -20°C, ii) shock frozen in liquid nitrogen with subsequent storage at -80°C or iii) gradually frozen and stored at -80°C. After 7days, the cryopreserved nanofat samples were thawed and immunohistochemically compared with freshly generated nanofat (control). Nanofat frozen and stored at -20°C exhibited the lowest apoptotic rate and highest densities of blood and lymph vessels, which were comparable to those of control. Accordingly, nanofat cryopreserved at -20°C or control nanofat were subsequently fixed with platelet-rich plasma in full-thickness skin defects within dorsal skinfold chambers of recipient mice to assess vascularization, formation of granulation tissue and wound closure by means of stereomicroscopy, intravital fluorescence microscopy, histology and immunohistochemistry over 14days. These analyses revealed no marked differences between the healing capacity of wounds filled with cryopreserved or control nanofat. Therefore, it can be concluded that cryopreservation of nanofat is simply feasible without affecting its viability and regenerative potential. This may broaden the range of future nanofat applications, which would particularly benefit from repeated administration of this autologous biological product.

Mechanisms of biological effectiveness of ionic forms of metals of variable valence in respiratory medicine

Background: The task to develop new drugs containing metals of variable valence requires systematization of our knowledge, experimental and clinical studies. The aim of the study: To investigate the mechanisms of the effectiveness of the mineral complex containing metals of variable valence in the treatment of respiratory diseases, to conduct preclinical trials and clinical testing of a new inhalation mineral solution. Materials and methods: The ability of cerium (III) ions to exhibit reducing properties was demonstrated by carrying out chemical reactions of cerium (III) chloride and sulfate with potassium permanganate in the presence of sodium hydroxide or sulfuric acid (respectively). Preclinical studies of acute toxicity were carried out on laboratory mice and rats in accordance with the rules of bioethics and with generally accepted ethical standards for the treatment of animals, based on the standard operating procedures of the university, which comply with the rules adopted by the European Convention for the Protection of Vertebrate Animals used for research and other scientific purposes (Strasbourg, 1986). Clinical testing of two forms of the mineral complex for inhalation (1. Inhalation solution for nebulizer – Renerium; 2. intranasal spray) was carried out on 6 groups of volunteers in compliance with human rights and the principles of conducting medical research involving a person as a subject, declared on the 18th General Assembly of the World Medical Association (Helsinki, Finland), voluntary informed consent, approved by the local ethical committee. Results: Mineral preparation for inhalation therapy of patients with acute respiratory diseases does not show acute toxicity in preclinical studies on laboratory animals. The mechanism of action of the drug is most likely associated with the regulation of redox reactions at the level of the cell membrane, mitochondria and cell nucleus, which is manifested by anti-inflammatory and regenerative activity in the mucous membrane of the respiratory tract and alveolar apparatus. Both forms of the drug are well tolerated. A pronounced clinical efficacy of the drug Renerium in the form of inhalation through a compressor inhaler was noted in the case of a 5-day course of treatment, 5 ml once a day. Conclusion: Experimental and clinical data have demonstrated pronounced anti-inflammatory and regenerative properties of a new mineral complex based on cerium (III), the mechanism of which is due to the regulation of redox reactions.

Theoretical study of the mechanism of hydrogen production by catalytic methane decomposition on the carbon black catalyst

Catalytic methane decomposition (CMD) is a promising chemical process for hydrogen production from natural gas with zero CO2 emissions. In the present work we perform a systematic study of CMD on the graphene edge as a model of the carbon catalyst surface. Atomistic first-principles calculations (DFT level of theory) were performed to obtain the parameters of elementary reactions including the formation of active sites, interaction of methane molecules with these active sites and regeneration of the carbon catalyst surface. Our findings show that methane pyrolysis on the carbon catalyst is a unique heterogeneous radical chain process in which active sites are migrating over the catalyst surface via gas phase radical transport. Based on quantum-chemistry calculations, detailed kinetic mechanism of CMD on the carbon catalyst was developed and verified with respect to the latest experimental data. Calculated effective activation energies and methane conversions in CMD process are in reasonable agreement with experimental data. The present investigation of the mechanism of hydrogen production by CMD process on carbon catalyst can be useful for optimization of this process taking into account degradation of the carbon catalyst.

Aspergillus terreus mediated green synthesis of cerium oxide nanoparticles and its neuroprotective activity against rotenone-induced cytotoxicity in SH-SY5Y cells

Cerium oxide nanoparticles (CeO2 NPs) are being widely explored as therapeutic agents against neurodegenerative diseases due to their regenerative and strong antioxidant activity. The current study aims to investigate the protective effect of green synthesized CeO2 NPs using Aspergillus terreus (A. terreus) filtrate against rotenone-induced cytotoxicity in SH-SY5Y cells as an in-vitro Parkinson’s model. The CeO2 NPs were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, UV–visible (UV–vis) spectroscopy, Scanning electron microscopy (SEM), and High-resolution transmission electron microscopy (HR-TEM). PXRD data revealed the strain and the crystal grain size of the CeO2 NPs were 3.488 x 10-4 and ∼ 15 nm respectively. FTIR spectra exhibited the metal–oxygen bond (Ce–O) at 848 and 558 cm−1. The absorption peak at 352 nm obtained through UV–vis spectroscopy is because of the charge transfer from the valance band to the conduction band. SEM and HR-TEM analysis disclosed the formation of spherical-shaped CeO2 NPs within the size range of 8–12 nm. Our results revealed that CeO2 NPs dose-dependently attenuated the rotenone toxicity and reduced LDH release. Additionally, the flow cytometric studies revealed the concentration-dependent cellular uptake of CeO2 NPs. Further, the CeO2 NPs significantly attenuated the rotenone toxicity by suppressing ROS generation, and modulating apoptosis. Hence, our study suggests that the CeO2 NPs hold promising potential as nanotherapeutics against Parkinson’s disease.

Types of Short-Duration Electrical Stimulation-Induced Efficiency in the Axonal Regeneration and Recovery: Comparative in Vivo Study in Rat Model of Repaired Sciatic Nerve and its Tibial Branch after Transection Injury.

The restoration of adequate function and sensation in nerves following an injury is often insufficient. Electrical stimulation (ES) applied during nerve repair can promote axon regeneration, which may enhance the likelihood of successful functional recovery. However, increasing operation time and complexity are associated with limited clinical use of ES. This study aims to better assess whether short-duration ES types (voltage mode vs. current mode) are able to produce enhanced regenerative activity following peripheral nerve repair in rat models. Wistar rats were randomly divided into 3 groups: no ES (control), 30-minute ES with a current pulse, and 30-minute ES with a voltage pulse. All groups underwent sciatic nerve transection and repair using a silicone tube to bridge the 6-mm gap between the stumps. In the 2 groups other than the control, ES was applied after the surgical repair. Outcomes were evaluated using electrophysiology, histology, and serial walking track analysis. Biweekly walking tracks test over 12 weeks revealed that subjects that underwent ES experienced more rapid functional improvement than subjects that underwent repair alone. Electrophysiological analysis of the newly intratubular sciatic nerve at week 12 revealed strong motor function recovery in rats that underwent 30-minute ES. Histologic analysis of the sciatic nerve and its tibial branch at 12 weeks demonstrated robust axon regrowth in all groups. Both types of short-duration ES applied during nerve repair can promote axon regrowth and enhance the chances of successful functional recovery.

Secondary Succession in Fallow Agroforestry Systems Managed in Tropical Dry Forest in Western Mexico

Tropical dry forests (TDFs) are ecosystems of high biocultural value, in which agroforestry systems (AFSs) have been essential in their management and conservation. We aimed to characterize agroforestry practices and analyze their capacity to conserve perennial plant diversity. In addition, we sought to evaluate how the management of TDFs as AFSs, together with their regeneration, influences species diversity and vegetation structure in a landscape with AFSs and TDFs in different conservation states. We compared the species diversity and basal area (BA) of plants in active and fallow AFSs at different regeneration stages in Zacualpan, Colima, Mexico. We found that AFSs harbored 71% of species richness (0D), forming a mosaic that contributed to the gamma diversity (124 species) of TDFs in the area. AFSs supported 23 endemic and 12 protected species. TDFs, active and advanced regeneration AFSs, had the highest number of useful species and diversity. Species richness (0D) in management categories increased as succession progressed, but not the BA, possibly due to frequent browsing and wood and firewood extraction. However, BA may be related to the management of useful trees maintained through agroforestry practices. We suggest increasing the matrix quality through a mosaic of active and fallow AFSs to promote ecological connectivity and biodiversity conservation.

Theranostic aspects of palladium-based bimetallic nanoparticles in biomedical field: A state-of-the-art.

The exploration of newer antibacterial strategies is driven by antibiotic-resistant microbes that cause serious public health issues. In recent years, nanoscale materials have developed as an alternative method to fight infections. Despite the fact that many nanomaterials have been discovered to be harmful, numerous researchers have shown a keen interest in nanoparticles (NPs) made of noble metals like silver, gold and platinum. To make environmentally safe NPs from plants, green chemistry and nanotechnology have been combined to address the issue of toxicity. The study of bimetallic nanoparticles (BNPs) has increased tremendously in the past 10 years. The production of BNPs mediated by natural extracts is straightforward, low cost and environmentally friendly. Due to their low toxicity, safety and biological stability, noble BNPs with silver, gold, platinum and palladium have the potential to be used in biomedical applications. They have a significant impact on human health and are used in medicine and pharmacy due to their biological characteristics, which include catalytic, antioxidant, antibacterial, antidiabetic, anticancer, hepatoprotective and regenerative activity.

Study on the active regeneration characteristics of DPF in diesel-methanol dual-fuel engine under different exhaust oxygen concentrations

This study proposes a method to control exhaust oxygen (O2) concentration by adjusting the intake throttle valve, achieving intake throttling, and reducing intake airflow. The impact of exhaust O2 concentration at the inlet of the diesel oxidation catalyst (DOC) the diesel particulate filter (DPF) performance during active regeneration in diesel engines is investigated. Experiments are conducted under methanol substitution rates (MSR) of 0% and 20% to investigate how different exhaust O2 concentrations affect the performance of the DOC and DPF during active regeneration. A comparative analysis of fuel consumption and cumulative CO2 emissions during DPF active regeneration under different exhaust O2 concentrations is performed. Research results indicate that decreasing exhaust O2 concentration reduces exhaust flow, raising DOC inlet temperature. This enhancement improves catalytic conversion efficiency, accelerating the rise in DPF inlet temperature. The average conversion efficiency of DOC to unburned methanol exceeds 98.07%. After initiating DPF active regeneration, O2 concentration sharply drops, leading to elevated CO2 emissions. As soot combustion advances, the required O2 diminishes, resulting in a gradual rise and eventual stabilization of O2 emissions. Economically and environmentally, irrespective of MSR (20% or 0%), there exists an optimal exhaust O2 concentration that minimizes effective regeneration time during DPF active regeneration, achieving minimal fuel consumption and the lowest CO2 mass emissions. This study offers theoretical support for optimizing energy-saving and emission-reduction processes during DPF active regeneration.

Colloidal carbon soot templated TiO2/Ag surface functionalized 3D printed metal brushes as new generation surface enhanced Raman scattering substrates

This present work demonstrated the functional transformation of 3D printed metal substrates into a new family of Surface-enhanced Raman Scattering substrates, a promising approach in developing SERS-based Point-of-care (PoC) analytical platforms. l-Powder Bed Fusion (l-PBF, Additive manufacturing or 3D printing technique) printed metal substrates have rough surfaces, and exhibit high thermal stability and intrinsic chemical inertness, necessitating a suitable surface functionalization approach. This present work demonstrated a unique multi-stage approach to transform l-PBF printed metal structures as recyclable SERS substrates by colloidal carbon templating, chemical vapor deposition, and electroless plating methods sequentially. The surface of the printed metal structures was functionalized using the colloidal carbon soot particles, that were formed by the eucalyptus oil flame deposition method. These carbon particles were shown to interact with the metals present in the printed structures by forming metal carbides and function as an adlayer on the surface. Subsequent deposition of TiO2 onto these templates led to strong grafting of TiO2 and retaining the fractal structure of the soot template onto the metal surface. Electroless deposition of silver nanoparticles resulted in the formation of fractally structured TiO2/Ag nanostructures and these functionalized printed metal structures were shown as excellent SERS substrates in enhancing the vibrational spectral features of Rhodamine B (RhB). The presence of TiO2 photocatalyst on the surface was shown to remove the RhB analyte from the surface under photochemical conditions, which enables the regeneration of SERS activity, and the substrate can be recycled. The migration of metals from the printed metal structures into the fractally ordered TiO2/Ag nanostructures was found to enhance the photocatalytic activity and increase the recyclability of these substrates. This study demonstrates the potential of 3D-printed Inconel metal substrates as next-generation recyclable SERS platforms, offering a substantial advancement over traditional colloidal, thin-film, flexible, and hard SERS substrates.

A full solid-state conceptual magnetocaloric refrigerator based on hybrid regeneration

The environmental friendliness and high efficiency of magnetocaloric refrigeration make it a promising substitute for vapor compression refrigeration. However, the common use of heat transfer fluid in conventional passive magnetic regenerators (PMRs) and active magnetic regenerators (AMRs) makes only partial materials contribute to the regeneration process, which produces large regeneration loss and greatly limits the regeneration efficiency and refrigeration performance at high frequency. Herein, we propose a new conceptual hybrid magnetic regenerator (HMR) composed of multiple solid-state high thermal conductivity materials (HTCMs) and magnetocaloric materials (MCMs), in which both HTCM and MCM elements participate in the regeneration process. This novel working mode could greatly reduce regeneration losses caused by dead volume, pressure losses, and temperature nonuniformity in heat transfer substances to markedly improve regeneration efficiency at high working frequencies. Using the experimentally obtained adiabatic temperature change and magnetic work and with the help of finite element simulation, a maximum temperature of 26 K, a dramatically large cooling power of 8.3kW/kg, and a maximum ideal exergy efficiency of 54.2% are achieved at the working frequency of 10Hz for an ideal prototype device of a rotary HMR magnetocaloric refrigerator, which shows potential for achieving an integrative, advanced performance against current AMR/PMR systems.

Bio-inspired and biomimetic composites based on biodegradable polymers for sensing applications with emphasis on early diagnosis of cancer

With the increasing demand for tissue adhesive, soft self-healing, antifouling, biodegradable and biocompatible biosensors, the use of biomimetic polymers has paved the way for the development of these advanced sensing systems. Especially, biomimetic polymers have provided new opportunities and development directions for the soft implantable and wearable biosensors. In fact, the impressive development in the bio-inspired and biomimetic composites based on biodegradable polymers has led to the creation of tissue-adhesive implantable biosensors with the minimal immune response or biofouling. This review aims to cover the advances in the mimetic biodegradable polymers (natural or synthetic) with an emphasis on the state-of-the-art sensing devices based on these composites. It also highlights the unique properties of biomimetic polymers such as self-healing, self-adhesion, enzyme-like activity, antibacterial activity, regenerative activity, etc. Considering the high rate of cancer in the world, especially in developing countries, a separate section is dedicated to the use of mimetic biopolymers-based sensors for early diagnosis of cancer. Finally, an outlook on the current challenges and future developments of this field is presented.

Investigation of the impacts of regeneration temperature and methanol substitution rate on the active regeneration of diesel particulate filter in a diesel-methanol dual-fuel engine

Methanol (CH3OH), a sustainable fuel derived from many renewable resources, simultaneously reduces nitrogen oxides (NOx) and particulate matter (PM) in diesel-methanol dual-fuel engines. This study systematically investigated the effects of regeneration temperature and methanol substitution rate (MSR) on the performance of diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and the temperature characteristics of DPF substrate during active regeneration. The experimental results show that the DOC catalytic oxidation of unburned CH3OH has a conversion rate of more than 97.5 % across various MSR. DPF inlet temperature rose faster with higher MSR. Elevated regeneration temperature reduced effective regeneration times and diesel equivalent consumption. Within active regeneration conditions with MSR increases, both effective regeneration times and diesel equivalent consumption initially decreased and then increased as the MSR rose. At MSR = 30 %, the duration of effective regeneration times during DPF active regeneration was minimized, and diesel equivalent consumption at MSR = 30 % experienced an improvement of 22.52 % compared to MSR = 0 %. The highest DPF substrate temperatures across various MSR levels are consistently observed at T6 position within the DPF. This study can provide a theoretical basis for the active regeneration of DPF in methanol-diesel dual-fuel mode.