Regeneration Process Research Articles

Functionalized polyaniline nanofibrils on lamellar structured zirconium for effective bone mineralization

The surface physiology of certain implant material has the ability to promote implant–cell signalling process through which a stable environment is formed. The formation of this favourable environment hastens the process of biomineralization and regeneration. In this context, Zirconium (Zr) when treated with alkali undergoes a surface modification which results in the development of a lamellar structured Zirconium (ATZ). Further, encapsulation of polyaniline (PAni) on ATZ was achieved through the electropolymerization technique which results in an effective and homogeneous electrodeposition of PAni nanofibrils on ATZ surface. A high resolution scanning electron microscope analysis (HR-SEM), phase analysis and functional group analysis were carried out confirming the semi-crystalline PAni nanofibrils braided on the ATZ surface. Potentiodynamic polarization studies of the coated sample exhibited higher Ecorr (−0.060 V) and lower icorr (0.007 µA/cm2) values signifying its better corrosion resistance behaviour in higher potentials coupled with lower electrochemical activity in the SBF medium. The porosity of PAni/ATZ nanofibril was 0.007 % and it provides an effective platform for implant-tissue attachment. The In-vitro biomineralization studies proved the bioactivity of PAni/ATZ which forms well-matured HAp spherules over the surface. Further, hemocompatibility studies of PAni/ATZ expressed a hemolytic rate of ∼0.39 % which denotes it’s biocompatible and non-hemolytic behaviour with the blood cells. Further, the coated sample on gram-positive and gram-negative bacteria causes demise of bacterial cell wall and exhibits higher inhibition percentage. In addition, a standard MTT assay of PAni/ATZ provides an effective support in maintaining cell viability and aids in proliferation of MG-63 cells. Thus, the results demonstrate that the nanoscale surface architecture of PAni/ATZ could serve as a potential and conducive environment for bone-implant interaction on the implant material for better osseointegration.

TREATMENT OF TROPHIC COMPLICATIONS IN DECOMPENSATED FORMS OF IMPAIRED ARTERIAL BLOOD CIRCULATION OF THE LOWER EXTREMITIES

Summary. The aim of the study was to study the clinical effectiveness of using the developed method of cryopreservation on wound surfaces using a cryopreservation device. Materials and methods. 87 patients with ulcerative-necrotic defects of the lower legs and feet were selected for the study. The condition for inclusion in the study was Phase I of the wound process. Patients were divided into the main and comparison groups. The main group included 41 patients who had their wounds cleaned according to the proposed method, and the comparison group consisted of 46 patients who underwent surgical treatment. Results. The use of cryodestruction of the surface of trophic ulcers of arterial etiology led to rapid cleaning of necrotic masses, fibrin, a decrease in exudation and pain intensity, and the disappearance of unpleasant odors. The effectiveness of the methods lies in the fact that not only necrotic components of the wound surface, fibrin films, as well as the surface layers of ulcer surface cells are destroyed, that is, phenotypically altered cells of the wound edge and base are removed, leading to a violation of regeneration processes. Conclusions. Debridment methods based on the use of controlled cryodestruction of pathological tissues on the surface of trophic ulcers accelerate the transition of the wound process to phase II by 25% in patients with trophic ulcers with critical ischemia of the lower extremities.

Effects of Vegetable Cover on the Regeneration Process in Degraded Dry Forest in Brazil

ABSTRACTThe Brazilian Caatinga is among the most diverse dry forests in the world, yet half of its original coverage has been degraded. Natural regeneration is influenced by climatic and edaphic conditions, as well as the existing adult stratum. Despite its significance, this process remains poorly understood in the Caatinga. Thus, our study aimed to analyze how anthropogenic disturbance, vegetation cover, and soil properties affect the regenerating stratum under different levels of Caatinga vegetation cover. The research was conducted in the driest region of Brazil. The selected sites represent low (Area I) and high (Area II) normalized difference vegetation index. Six vegetable plots (50 × 20 m each) were delimited to study adult stratum, and four vegetable plots (10 × 10 m each) to regeneration stratum. Topsoil was sampled in all vegetable plots. Our results reveal interactions between soil characteristics and the adult and regenerating strata. Area II exhibited higher diversity and a greater number of exclusive species, while Area I was dominated by species more resistant to limiting conditions, such as Aspidosperma pyrifolium Mart. & Zucc. The C and N content in the soil showed a positive and significant correlation with the diversity of the regenerating stratum. The data suggest that the area with less vegetation cover, richness, and diversity shows signs of desertification.

Glial cell derived pathway directs regenerating optic nerve axons toward the CNS midline.

Several RGC intrinsic signaling pathways have been shown to enhance RGC survival and RGC axonal growth after optic nerve injury. Yet an unresolved challenge for regenerating RGC axons is to properly navigate the optic chiasm located at the Central Nervous System midline. Here, we use live-cell imaging in larval zebrafish to show that regrowing RGC axons initiate growth toward the midline and extend along a trajectory similar to their original projection. From a candidate genetic screen, we identify the glycosyltransferase Lh3 to be required during the process of regeneration to direct regrowing RGC axons toward the midline. Moreover, we find that mutants in collagen 18a1 (col18a1), a putative Lh3 substrate, display RGC axonal misguidance phenotypes similar to those we observe in lh3 mutants, suggesting that lh3 may act through col18a1 during regeneration. Finally, we show that transgenic lh3 expression in sox10+ presumptive olig2+ oligodendrocytes located near the optic chiasm restores directed axonal growth. Combined these data identify lh3 and col18a1 as part of a glial derived molecular pathway critical for guiding in vivo regenerating RGC axons towards and across the optic chiasm.

Investigation on CO2 capture performance of low-viscosity diamine non-aqueous absorbents with N-methyldiethanolamine regulation

In recent years, non-aqueous absorbents have attracted increasing attention due to their ability of significantly reducing sensible and latent heats in regeneration processes compared to conventional organic amine aqueous solution. But high viscosity of non-aqueous absorbents after CO2 absorption saturation became an obstacle to their industrial application. Here, a novel low-viscosity diamine non-aqueous absorbent for high-efficiency CO2 capture was proposed, in which N-methyldiethanolamine (MDEA) with steric hindrance effect was introduced as a regulator and dimethyl sulfoxide (DMSO) as a cosolvent. The effects of MDEA on CO2 capture performance of various non-aqueous absorbents and its regulation mechanism on CO2 absorbent viscosity were investigated systematically. Experimental results showed that when 25 wt% 2-(2-aminoethylamino)ethanol (AEEA) was screened as main CO2 absorption component, AEEA/MDEA/DMSO non-aqueous absorbent exhibited a high CO2 absorption capacity of 2.55 mol/kg and a fast CO2 absorption rate. Based on further mass fraction optimisation, it was found that the lowest viscosity of non-aqueous absorbents after CO2 absorption was 13.12 mPa s and the highest CO2 regeneration reached 93.5 % with AEEA and MDEA were 17.5 wt% and 12.5 wt%, respectively. 13C NMR tests showed that two characteristic peaks of carboxylated carbon appeared in CO2 products, which indicated that both amino groups on AEEA molecule were involved in CO2 absorption reaction. DFT calculations indicated that hydrogen bonding strength between MDEA and CO2 products was relatively lower than that of AEEA and CO2 products, which favored reducing absorbent saturation viscosity significantly. Thermodynamic analysis revealed that total regeneration energy consumption for 17.5 wt% AEEA/12.5 wt% MDEA/70 wt% DMSO non-aqueous absorbent was 1.72 GJ/t CO2, which was 53 % lower than that of MEA aqueous solution.

3D-BIOPRINTING OF BONE TISSUE IN VITRO И IN SITU

Advanced techniques in bone tissue regeneration include innovative achievements in the field of tissue engineering, among which 3D bioprinting technology holds a special place. This method demonstrates significant progress, driven by its numerous advantages, confirmed through extensive scientific research. 3D bioprinting offers the capability of precise printing of bone transplants with specified geometry, incorporating necessary biomaterials such as cells and growth factors, which facilitates effective osteoinduction, osteoconduction, and vascularization. This review article analyzes various modern methods of bone tissue restoration, including the use of autotransplants, allotransplants, and synthetic bone transplants. Particular attention is paid to the latest innovations in 3D bioprinting, opening prospects for creating individualized bone tissues characterized by a high degree of biocompatibility and minimizing the need for invasive procedures. Additionally, the article presents the concept of in situ bioprinting, developed by Weiss and his colleagues in 2007, as a method of direct printing of bio-inks directly in the area of damage in a living organism. This progressive approach provides high precision in the restoration of tissue defects, regardless of their complexity and geometric features. Over the last decade, several successful clinical cases of using printed structures have been registered, demonstrating the significance of 3D bioprinting in treating life-threatening diseases, as well as in accelerating the regeneration process and creating tissue transplants for subsequent implantation.

An increase in reactive oxygen species underlies neonatal cerebellum repair.

The neonatal mouse cerebellum shows remarkable regenerative potential upon injury at birth, wherein a subset of Nestin-expressing progenitors (NEPs) undergoes adaptive reprogramming to replenish granule cell progenitors that die. Here, we investigate how the microenvironment of the injured cerebellum changes upon injury and contributes to the regenerative potential of normally gliogenic-NEPs and their adaptive reprogramming. Single cell transcriptomic and bulk chromatin accessibility analyses of the NEPs from injured neonatal cerebella compared to controls show a temporary increase in cellular processes involved in responding to reactive oxygen species (ROS), a known damage-associated molecular pattern. Analysis of ROS levels in cerebellar tissue confirm a transient increased one day after injury at postanal day 1, overlapping with the peak cell death in the cerebellum. In a transgenic mouse line that ubiquitously overexpresses human mitochondrial catalase (mCAT), ROS is reduced 1 day after injury to the granule cell progenitors, and we demonstrate that several steps in the regenerative process of NEPs are curtailed leading to reduced cerebellar growth. We also provide evidence that microglia are involved in one step of adaptive reprogramming by regulating NEP replenishment of the granule cell precursors. Collectively, our results highlight that changes in the tissue microenvironment regulate multiple steps in adaptative reprogramming of NEPs upon death of cerebellar granule cell progenitors at birth, highlighting the instructive roles of microenvironmental signals during regeneration of the neonatal brain.

Programmed BRD9 Degradation and Hedgehog Signaling Activation via Silk-Based Core-Shell Microneedles Promote Diabetic Wound Healing.

Wound healing impairment in diabetes mellitus is associated with an excessive inflammatory response and defective regeneration capability with suppressed Hedgehog (Hh) signaling. The bromodomain protein BRD9, a subunit of the non-canonical BAF chromatin-remodeling complex, is critical for macrophage inflammatory response. However, whether the epigenetic drug BRD9 degrader can attenuate the sustained inflammatory state of wounds in diabetes remains unclear. Without a bona fide immune microenvironment, Hh signaling activation fails to effectively rescue the suppressed proliferative ability of dermal fibroblasts and the vascularization of endothelial cells. Therefore, a silk-based core-shell microneedle (MN) patch is proposed to dynamically modulate the wound immune microenvironment and the regeneration process. Specifically, the BRD9 degrader released from the shell of the MNs mitigated the excessive inflammatory response in the early phase. Subsequently, the positively charged Hh signaling agonist is released from the negatively charged core of the silk fibroin nanofibers and promotes the phase transition from inflammation to regeneration, including re-epithelialization, collagen deposition, and angiogenesis. These findings suggest that the programmed silk-based core-shell MN patch is an ideal therapeutic strategy for effective skin regeneration in diabetic wounds.

The terrestrial flatworm Microplana scharffi (Geoplanidae, Microplaninae): mitochondrial genome, phylogenetic proximity to the Bipaliinae and genes related to regeneration

A genome skimming approach of sequencing was undertaken on a subfamily of terrestrial flatworms that had been neglected in genomic studies until now, namely the Microplaninae as represented here by Microplana scharffi. A single run of short-read sequencing enabled retrieval of the complete mitogenome, the two paralogous versions of the 18S gene, the elongation factor gene EF1α, plus two genes involved in the regeneration process, namely those coding for ß-CATENIN-1 and adenomatous polyposis coli (APC). The 15,297 bp mitogenome lacks a functional tRNA-Ala and has a mandatory alternative TTG start codon in its cox1 gene. The multiprotein phylogeny, inferred from mitogenome proteins, positions M. scharffi as sister-group to the Bipaliinae with maximum support, although the organisation of the mitogenomes shows features previously never observed among Bipaliinae, such as the conserved 32 bp overlap between ND4 and ND4L. Similarly to what has been observed in recent publications on other species of Geoplanidae, the two types of 18S genes display strongly different coverages and are only 90.57% identical. Additionally, alien DNA was identified in the pool of contigs in the form of the complete mitochondrial genome of Lumbricus rubellus, confirming previous observations on the feeding habits of M. scharffi.

From two segments and beyond: Investigating the onset of regeneration in Syllis malaquini.

Annelids feature a diverse range of regenerative abilities, but complete whole-body regeneration is less common, particularly in the context of the head and anterior body regeneration. This study provides a detailed morphological description of Syllis malaquini regenerative abilities. By replicating previous experiments and performing diverse surgical procedures, we explored the capacity of this species for whole-body regeneration. We detailed the precise timing of regeneration of particular structures such as the eyes, proventricle, pharyngeal tooth, nuchal organs, and body pigmentation after amputation. Our high-resolution scanning electron microscopy and confocal laser-scanning microscopy images provide details of the blastema region, revealing that while anal opening remains in connection to the exterior environment, oral opening is formed "de novo" during blastema differentiation. Additionally, we performed amputations to isolate fragments consisting of one, two, and three segments from the intestinal trunk region. We found that S. malaquini requires at least two to three segments to successfully regenerate the whole body. In addition, we verified a variable capacity to regenerate depending upon the gut region, with structures of the foregut greatly impairing some steps of the regenerative process. Our work notably addresses the gap in knowledge concerning gut formation and its impact on regenerative capabilities. Ongoing research is crucial to unravel the role of gut tissue specificity and plasticity during regeneration in annelids, and particularly in syllids.

Utilization of thermoplastic resin as foamed asphalt modifier in cold recycled mixtures

The utilization of foamed virgin asphalt in cold recycled mixtures results in insufficient bonding strength between aggregates, leading to rapid deterioration to the recycled asphalt pavement. This ultimately causes inefficient clean production and increased carbon emissions. The foaming performance of thermoplastic resin modified asphalt (TRA) under different foaming conditions was analyzed. Micro-scale chemical and physical tests were utilized to discover the foaming mechanism of TRA. The road performance of cold recycled mixtures with foamed TRA was evaluated through splitting, rutting and fatigue tests. The results showed that the increase in the TRA polar functional group index led to an increase in its surface tension, thus limiting its expansion capacity. However, the increase in the specific heat capacity of TRA indicated that it preserves a low viscosity level essential for its foaming efficacy post-ejection from the foaming machine, thereby enhancing its half-life. Furthermore, the dynamic viscosity of the TRA with an 8% thermoplastic resin dosage exceeded 40000 Pa s at 60 °C, meeting the specification requirements for high viscosity asphalt, while exhibiting a notably lower viscosity of only 120 mPa s at the foaming temperature of 170 °C. The observed low viscosity of the asphalt is anticipated to favorably enhance the formation of a stable foam structure. The mechanical properties and overall road performance of the cold recycled mixture with foamed TRA were significantly enhanced, especially in terms of moisture damage resistance and low-temperature crack resistance. The purpose of this paper is to serve as a valuable reference for investigating the mechanism of modified asphalt foaming and to enhance the efficiency of cold recycled pavement regeneration processes.

Towards A City of Good Dwelling

One of the main issues in contemporary urban planning is the fragmentation of urban spaces (Batty 2009) due to the relentless processes of land transformation. This phenomenon can lead to the creation of isolated urban islands and a lack of high-quality public areas. Such weaknesses particularly affect the socio-economic conditions of marginal areas within the existing city, especially those on the outskirts near rural areas. Public spaces (Low et al 2006) are essential for social interaction, community building, and improving the overall quality of urban life. They are spaces where cultural, economic, and social activities converge, contributing to the city's vibrancy and inclusiveness. Are considered the key of the new processes of urban regeneration and it contributes significantly to the making of the city of "good dwelling" (Beauregard 2020). To obtain the conditions for a good dwelling, it is proposed to apply the seven principles contained in the "Manifesto della Città del Buon Abitare"(Colarossi et al 2023): the city of good dwelling must assume the general principles of hospitality, urbanity and beauty of its public spaces. The paper proposes as innovative approach, the use of an urban planning tool with which it is possible to apply the principles of the Manifesto of the city of good living and which is called "Plan-program of public space planning and public and private services" (P.A.S.S.i.). The effort of this research is to identify a general planning tool for the redevelopment to the existing city. The multi-scalar approach of the research tool simultaneously allows an overall vision of the program and a qualitative control of each individual project.

The role of the nervous system in liver diseases.

The nervous system significantly participates in maintaining homeostasis, and modulating repair and regeneration processes in the liver. Moreover, the nervous system also plays an important role in the processes associated with the development and progression of liver disease, and can either potentiate or inhibit these processes. The aim of this review is to describe the mechanisms and pathways through which the nervous system influences the development and progression of liver diseases, such as alcohol-associated liver disease, nonalcoholic fatty liver disease, cholestatic liver disease, hepatitis, cirrhosis, and hepatocellular carcinoma. Possible therapeutic implications based on modulation of signals transduction between the nervous system and the liver are also discussed.

Regeneration and Genetic Transformation in Eucalyptus Species, Current Research and Future Perspectives

Eucalyptus is an important plantation tree with a high economic value in China. The tree contributes significantly to China’s timber production. The stable and efficient Eucalyptus regeneration system and genetic transformation system are of great significance for exploring the regulatory function and possible genetic breeding capacity of important genes in the species. However, as a woody plant, Eucalyptus has problems, such as a long generation cycle, strong specificity of the regeneration system, and a low genetic conversion rate, which seriously limit the rapid development of Eucalyptus genetics and breeding programs. The present review summarizes the status of research on Eucalyptus regeneration and genetic transformation, with a focus on the effects of explants, media, plant growth regulators (PGRs), and concentrations in the Eucalyptus regeneration process. In addition, the effects of genotype, Agrobacterium, antibiotics, preculture, and co-culture on the genetic transformation efficiency of Eucalyptus are discussed. Furthermore, the study also summarizes the problems encountered in Eucalyptus regeneration and genetic transformation, with reference to previous studies, and it outlines future developments and prospects. The aim was to provide a reference for solving the problems of genetic instability and the low transformation efficiency of eucalyptus, and to establish an efficient and stable eucalyptus regeneration and transformation system to accelerate the process of its genetic improvement.

The regenerative effect of exosomes isolated from mouse embryonic fibroblasts in mice created as a sciatic nerve crush injury model.

Exosomes (Exos) are candidates for functional recovery and regeneration following sciatic nerve crushed (SNC) injury due to their composition which can accelerate tissue regeneration. Therefore, mouse embryonic fibroblast-derived exosomes were evaluated for their regenerative capacity in SNC injury. In the study, 40Balb/c males (20 ± 5g) and two pregnant mice (for embryonic fibroblast tissue) were used and crushed injury was induced in the left sciatic nerve with an aneurysm clamp. Sciatic nerve model mice were randomly divided into 5 groups (n = 8; control, n = 8; sham, n = 8; SNC, n = 8; Mouse embryonic fibroblast exosome (mExo), n = 8; SNC + Mouse embryonic fibroblast exosome (SNC + mExo). Rotarod tests for motor functions and hot plate and von Frey tests for sensory functions were analyzed in the groups. Expression changes of exosome genes (RARRES1, NAGS, HOXA13, and MEIS1) immunohistochemical analysis of these gene proteins, and structural exosome NF-200 and S100 proteins were evaluated by confocal microscopy. Behavioral analyses showed that the damage in SNC was significant between groups on day14 and day28 (P < 0.05). In behavioral analyses, it was determined that motor functions and mechanical sensitivity lost in SNC were regained after mExo treatment. While expression of all genes was detected in MEF-derived exosomes, the high expression was MESI1 and the low expression was HOXA13. NF200, an indicator of axon number and neurofilament density, was found to decrease in SNC (P < 0.001) and increase after treatment, but not significantly. The decreased S100 protein levels in SNC and the increase detected after treatment were not significant. The expression of four mRNAs in mExos indicates that these genes may have an effect on regenerative processes after SNC injury. The regenerative process supported by tissue protein expressions demonstrates the therapeutic potential of mExo treatment.

Techno-Economic Feasibility Analysis of Post-Combustion Carbon Capture in an NGCC Power Plant in Uzbekistan

As natural gas-fired combined cycle (NGCC) power plants continue to constitute a crucial part of the global energy landscape, their carbon dioxide (CO2) emissions pose a significant challenge to climate goals. This paper evaluates the feasibility of implementing post-combustion carbon capture, storage, and utilization (CCSU) technologies in NGCC power plants for end-of-pipe decarbonization in Uzbekistan. This study simulates and models a 450 MW NGCC power plant block, a first-generation, technically proven solvent—MEA-based CO2 absorption plant—and CO2 compression and pipeline transportation to nearby oil reservoirs to evaluate the technical, economic, and environmental aspects of CCSU integration. Parametric sensitivity analysis is employed to minimize energy consumption in the regeneration process. The economic analysis evaluates the levelized cost of electricity (LCOE) on the basis of capital expenses (CAPEX) and operational expenses (OPEX). The results indicate that CCSU integration can significantly reduce CO2 emissions by more than 1.05 million tonnes annually at a 90% capture rate, although it impacts plant efficiency, which decreases from 55.8% to 46.8% because of the significant amount of low-pressure steam extraction for solvent regeneration at 3.97 GJ/tonne CO2 and multi-stage CO2 compression for pipeline transportation and subsequent storage. Moreover, the CO2 capture, compression, and transportation costs are almost 61 USD per tonne, with an equivalent LCOE increase of approximately 45% from the base case. This paper concludes that while CCSU integration offers a promising path for the decarbonization of NGCC plants in Uzbekistan in the near- and mid-term, its implementation requires massive investments due to the large scale of these plants.

Regeneration of the caudal fin of the evolutionary ancient tropical gar Atractosteus tropicus

BackgroundThe tropical gar (Atractosteus tropicus), a member of the Lepisosteidae family, is native to regions extending from southeastern Mexico to southern Costa Rica. This species serves as a unique bridge between tetrapods and teleosts due to its phylogenetic position, slow evolutionary rate, dense genetic map, gene similarities with humans, and ease of laboratory cultivation. As a taxonomic sister group to teleosts like the zebrafish (Danio rerio), known for its high regenerative capacity, it remains unclear whether the tropical gar shares a similar ability for regeneration.ResultsThis study aims to elucidate the caudal fin regeneration process in tropical gar through skeletal and histological staining methods. Juvenile specimens were observed over a two-month period, during which they were fed brine shrimp, and anesthetized with 1% eugenol for caudal fin amputation. Samples were collected at various days post-amputation (dpa). Alcian blue and alizarin red staining were used to highlight skeletal regeneration, particularly the formation of new cartilage, while histological staining with hematoxylin and eosin was performed to observe tissue regeneration at the amputation site.ConclusionsThe findings reveal a remarkable ability for caudal fin regeneration in juvenile tropical gar. Given the Garfish evolutionary relationship with teleosts, this opens new avenues for research into tissue regeneration across different groups of Actinopterygii.

Tissue-Adaptive BSA Hydrogel with Dual Release of PTX and bFGF Promotes Spinal Cord Injury Repair via Glial Scar Inhibition and Axon Regeneration.

Spinal cord injury (SCI) is a severe clinical disease usually accompanied by activated glial scar, neuronal axon rupture, and disabled motor function. To mimic the microenvironment of the SCI injury site, a hydrogel system with a comparable mechanical property to the spinal cord is desirable. Therefore, a novel elastic bovine serum albumin (BSA) hydrogel is fabricated with excellent adhesive, injectable, and biocompatible properties. The hydrogel is used to deliver paclitaxel (PTX) together with basic fibroblast growth factor (bFGF) to inhibit glial scar formation as well as promote axon regeneration and motor function for SCI repair. Due to the specific interaction of BSA with both drugs, bFGF, and PTX can be controllably released from the hydrogel system to achieve an effective concentration at the wound site during the SCI regeneration process. Moreover, benefiting from the combination of PTX and bFGF, this bFGF/PTX@BSA system significantly aided axon repair by promoting the elongation of axons across the glial scar with reduced reactive astrocyte secretion. In addition, remarkable anti-apoptosis of nerve cells is evident with the bFGF/PTX@BSA system. Subsequently, this multi-functionalized drug system significantly improved the motor function of the rats after SCI. These results reveal that bFGF/PTX@BSA is an ideal functionalized material for nerve repair in SCI.

Urea solvothermal regeneration of spent LiNi0.5Co0.2Mn0.3O2: Performance and environmental benefits

With the large-scale application of power batteries, a large number of spent lithium-ion batteries (LIBs) will be formed in recent years. The improper disposal of spent LIBs will pose significant environmental pollution. LiNi0.5Co0.2Mn0.3O2 (NCM), as a typical type of LIBs cathodes material, are widely used and can be highly recycled. However, the existing hydrometallurgical and pyrometallurgical recycling processes consume large amounts of energy and introduce serious secondary pollution. This work presents a simple straightforward direct regeneration process that uses urea solvothermal treatment followed by calcination to obtain urea-regenerated spent NCM (UR-S-NCM). Surprisingly, the specific capacity of the regenerated NCM of UR-S-NCM recovers completely and reaches 166 mAh/g, higher than that of fresh NCM (F-NCM) at 156 mAh/g. After 100 charge/discharge cycles, the specific capacity of UR-S-NCM is 37 % higher than that of F-NCM at the same condition. Additionally, the CO2 emissions per kilogram of the regenerated UR-S-NCM are only 1.79 kg, about 31 % of pyrometallurgy and 48 % of hydrometallurgy, respectively. The surface smoothness, grain boundaries and layered structure of UR-S-NCM are recovered from S-NCM to the same situation of F-NCM. Smooth surface facilitates Li+ migration into and out of UR-S-NCM, grain boundaries reduction diminishes electrolyte corrosion, and the layered structure accommodates more Li+ compared to the spinel structure of S-NCM. This work provides an eco-friendly direct regeneration process and offers a new insight for LIBs regeneration.

Experimental investigation of CO2 capture at high pressure using energy-efficient amino acid salt solvents

The increase in energy consumption has led to greenhouse gas emissions, specifically CO2. This has caused many researchers to explore the possibility of capturing CO2 emissions. The utilization of typical water-based solvents, such as amine solutions, poses challenges in large-scale operations owing to the substantial energy consumption associated with their regeneration process. To decrease the energy required to regenerate the solvent, new types of phase change solvents, known as lean water amino acid-based phase change solvents, were invented. This study investigated the absorption capacity of an amino acid salt made up of glutamine and potassium hydroxide in a water-based solution including N,N-dimethylformamide (DMF) as a co-solvent. The measurement of absorption capacity was conducted under elevated pressures ranging from 5 to 30 bar. Additionally, an investigation was conducted to assess the impact of DMF volumetric concentration on absorption capacity. The findings of the study indicated that augmenting both the pressure and concentration of DMF increased the capacity for CO2 absorption. This enhancement was achieved by simultaneously raising the rates of physical and chemical absorption. The results obtained from the C NMR phase analysis revealed that the solid phase had carbon bonds that were related to the absorption of CO2, whilst the upper liquid phase did not contain any CO2. This phase might readily be recycled into the absorption process without the need for regeneration. The absorption capacity of this solvent was also assessed following three absorption-reduction cycles. The results indicated a decrease in absorption capacity by only 6.6 %.