Degradation In Environment Research Articles

Core-shell aerogel design for enhanced oral insulin delivery

Current protein-based therapies often rely on intravenous and subcutaneous injections leading to patient discomfort due to the need for frequent administration. Oral administration route presents a more patient-friendly alternative, but overcoming the challenge of low drug bioavailability remains paramount. This limitation is primarily attributed to protein degradation in the harsh gastric environment, enzymatic breakdown, and poor intestinal permeability. With their unique properties, such as high porosity and surface area, and easy scalability, aerogels offer a promising platform for oral delivery of therapeutic proteins. This study focused on the development and characterization of both conventional and core–shell aerogels derived from natural polysaccharides for the oral delivery of insulin, utilizing Humulin R® U-100 as the insulin source for the first time. Aerogels were produced via supercritical carbon dioxide (sc-CO2) drying of alginate gel beads. Scanning Electron Microscopy (SEM) images confirmed that the core–shell aerogels had higher uniformity in size and a more well-defined porous structure in comparison to conventional aerogels. Structural differences of two alginate sources were evaluated by Fourier Transform Infrared (FTIR) spectroscopy. A notable difference in encapsulation efficiencies was observed between conventional (12 %) and core–shell (53 %) aerogels, highlighting the superior carrier characteristics of the latter ones. In vitro insulin release profiles from the core–shell aerogels demonstrated their potential suitability for delivering regular/short-acting insulin therapeutics since only 30 % of insulin was released in Simulated Gastric Fluid (SGF) after 120 min, whereas 60 % of insulin was released in Simulated Intestinal Fluid (SIF) within the first hour followed by a sustained release stage.

Impact of niobium doping on photocatalytic degradation efficiency of iron oxide nanoparticles for methylene blue dye under UV and sunlight

Iron oxide (Fe2O3) nanoparticles were synthesized using lemon peel extract with niobium (Nb) doping (2, 4, and 6 mmol) via a hydrothermal method. Characterization techniques included FTIR, UV–Vis spectroscopy, XRD, PSA, and zeta potential measurement. FTIR confirmed Nb integration, with Fe-O and Nb-O bonds at 1.65 Å and 1.34 Å. Nb doping reduced particle size (93.74 nm to 56.01 nm) and enhanced stability (zeta potential −13.04 to −37.31 mV). XRD analysis confirmed phase purity and crystalline structure, while the Scherrer and Williamson-Hall methods revealed decreases in crystallite size and lattice strain with higher Nb concentration. Bandgap analysis showed a red shift (3.08 to 2.28 eV) due to Nb-doped energy levels. Nb-doped Fe2O3 (6 mmol) achieved 87 % degradation of methylene blue (10 ppm) under sunlight in 2 h. Enhanced photocatalysis resulted from prolonged electron-hole recombination, generating reactive radicals. These Nb-doped Fe2O3 nanostructures are promising for pollutant degradation in water environments.

Removal of tetracycline using an ultrastable Pt-decorated-BNCB photocatalyst under efficient solar-driven conditions

The pursuit of optimizing the photocatalytic performance of the novel perovskite-like Bi4NbO8X materials remains a vibrant area of research. In this paper, we report the successful synthesis of the Bi4Nb4O8Cl0.935Br0.065 (BNCB) composite photocatalyst, loaded with Pt nanoparticles, utilizing a combination of solid-state reaction and sodium borohydride reduction methods. Notably, the surface plasmon resonance (SPR) effect exhibited by Pt broadened the spectral response range, while the Schottky junction formed at the Pt/BNCB interface significantly accelerated the separation of photogenerated electron-hole pairs and facilitated the swift migration of photogenerated electrons towards Pt. Experimental outcomes underscore the superior photocatalytic degradation efficacy of the Pt/BNCB composite towards tetracycline (TC), achieving a degradation rate of up to 67%, significantly outperforming pure BNCB. Pt/BNCB exhibits excellent photocatalytic degradation and excellent stability in various pH and ionic environments. Collectively, this work presents a novel approach for designing highly efficient and stable perovskite-type photocatalytic materials, holding immense potential for applications in environmental remediation.

Neurotensin Conjugated Polymeric Porous Microparticles Suppress Inflammation and Improve Angiogenesis Aiding in Diabetic Wound Healing.

Neurotensin (NT), a bioactive tridecapeptide aids in diabetic wound healing by modulating inflammation and angiogenesis. However, its rapid degradation in peptidase-rich wound environment (plasma half-life <2 min) limits its efficacy. To address this, neurotensin-conjugated polymeric porous microparticles (NT-PMP) were developed and loaded in gelatin (hydrogel 15% w/v) for topical application, enabling sustained NT release to enhance therapeutic outcomes. NT-PMP exhibited a size range of 60 - 240 µm (mean: 120.63 ± 40.71 µm) and pore size of 5 - 16 µm (average: 10.68 ± 3.47 µm). In vitro studies demonstrated cytocompatibility of NT-PMP in fibroblasts and reduced TNF-α levels in inflammation-induced macrophages (1256 ± 167.02 pg/ml). Further NT-PMP scaffold depicted excellent cell adhesion and migration properties upon seeding of dermal fibroblasts on surface of PMPs. In vivo studies in diabetic wound rat model demonstrated effective wound management, characterized by notable regenerative and healing attributes in the presence of NT-PMP. This included complete re-epithelialization, reducing pro-inflammatory cytokine (TNF-α), and enhancing VEGF expression, ultimately leading to the development of a well-organized collagen matrix in diabetic wounds upon application of NT-PMP gel.Altogether, NT conjugated PMP loaded in hydrogel demonstrated significant regenerative and healing properties, suggesting its potential as an alternative treatment for diabetic wounds.

Microbial Diversity and Biodegradation Mechanism of Microorganisms in the Dingtao M2 Tomb.

The Dingtao M2 tomb, the largest and best-preserved imperial "Huangchangticou" tomb in China, holds great significance for its conservation. Currently, varying degrees of microbial degradation are occurring on the surfaces of the M2 tomb. This study aimed to determine the microbial diversity of the M2 tomb and its surrounding environment during July 2021 and August 2022. High-throughput metagenomic sequencing revealed that the dominant fungus on the surface of the tomb chamber was Dacrymyces stillatus (DTT1) in July 2021, which changed to Talaromyces pinophilus (DTT2) in August 2022. Enzymatic activities for cellulose and lignin degradation suggested that DTT1 has high levels of manganese peroxidase, lignin peroxidase, laccase, and cellulase. The wood of the tomb contained higher levels of Fe2+ and Ca2+, and experiments with different concentration gradients of these ions in the culture medium revealed that DTT1 exhibited greater activity of cellulose and lignin degradation in environments with higher concentrations of Fe2+ and Ca2+. DTT2 degraded both cellulose and lignin. Lastly, a laboratory plate inhibition experiment demonstrated that isothiazolinone fungicide had a significant fungicidal effect on these two dominant fungi. This study provides valuable data and a theoretical basis for the preservation of the M2 tomb and other wooden cultural relics.

Characteristics of deep-sea microbial cellulases: key determinants of the ultimate fate of plant biomass on Earth

Land plants, especially those with significant woody biomass, represent the largest source of biomass on Earth, making the biodegradation of lignocellulosic materials critical to understanding the global carbon cycle. Cellulose, a major component of lignocellulose, is notoriously resistant to degradation due to its highly crystalline structure. While the degradation of cellulose by terrestrial microbes has been extensively studied, the mechanisms of cellulose degradation in deep-sea environments remain largely unexplored. The deep-sea ecosystem depends on organic matter, such as cellulose, that is synthesized in terrestrial environments and surface waters and descends to the deep sea. Recent studies suggest that a significant amount of cellulose is likely to reach the deep sea. Here, we present an in-depth study of cellulases from a novel deep-sea γ-proteobacterial strain TOYAMA8, isolated from Toyama Bay, Japan, using Surface Pitting Observation Technology (SPOT), a highly sensitive assay for enzymatic cellulose hydrolysis. The cellulases of strain TOYAMA8 show similarities to those of a previously reported deep-sea cellulolytic microbe, Marinagarivorans cellulosilyticus strain GE09. Genomic and transcriptomic analyses of these strains reveal novel cellulase genes and mechanisms that differ from terrestrial counterparts, shedding light on the unique adaptations of deep-sea microbes to recalcitrant biomass. In particular, these strains produce high-molecular-weight cellulases with unique domain architectures, likely optimized for membrane anchoring, which prevents enzyme diffusion and ensures efficient localized activity. Our findings provide critical insights into the microbial cellulose degradation in the deep sea, highlighting its role in the fate of organic carbon and the potential for biotechnological applications in biorefineries.

Extraction, characterization, and evaluation of galactomannan from Barbatimão Verdadeiro as a potential additive for enhanced oil recovery fluids

Polymers play a crucial role in enhanced oil recovery (EOR) by increasing the viscosity of injection fluids and enhancing oil displacement. The widely used polymer, partially hydrolyzed polyacrylamide (HPAM), faces performance degradation in high-salinity and high-temperature environments. This study explores galactomannan from Stryphnodendron polyphyllum seeds as an alternative viscosifying agent for EOR fluids. An extraction process for galactomannan from Barbatimão Verdadeiro seeds was developed, yielding 23.3% m/m. The biopolymer was characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and size exclusion chromatography (SEC). Rheological behavior was tested in brines of different salinities, and injectivity/filterability tests were performed following API RP 63:1990 standards. The galactomannan obtained from Stryphnodendron polyphyllum exhibited a mannose-to-galactose ratio of 1.32. Rheological analysis showed pseudoplastic behavior, with viscosities of 38 cP in brine solutions at 7.37 s−1 and 60 °C. Filterability tests demonstrated satisfactory injectivity with factors of 1.09 (8 µm) and 0.67 (1.2 µm). Compared to HPAM, galactomannan exhibited superior viscosity retention in high-salinity conditions, where HPAM dropped to 6 cP. The galactomannan extracted from Stryphnodendron polyphyllum seeds is a promising biopolymer for EOR applications, offering superior performance under harsh conditions compared to traditional HPAM. Its resilience to high salinity and temperature makes it a viable alternative for pre-salt and offshore fields, contributing to more sustainable and efficient oil recovery.

Gear-fault monitoring and digital twin demonstration of aircraft engine based on piezoelectric vibration sensor for engine health management

Aircraft engine vibration signals carry crucial operational information, necessitating accurate monitoring and analysis to ensure flight safety. However, the detection accuracy of vibration sensors is significantly compromised in high-temperature environments, posing substantial challenges for traditional battery-powered models. Here, we present a self-powered piezoelectric vibration sensor based on a polyvinylidene fluoride-polyimide nanofiber membrane, which can effectively mitigate the performance degradation in high-temperature environments. The piezoelectric vibration sensor is capable of distinguishing the vibration signals generated by healthy gears, pitting gears, and broken gears, achieving a recognition accuracy of 96.3 % by using machine-learning algorithms. Finally, we develop a digital twin system to identify failure modes in aircraft engine gears, promising intelligent engine health management.

Restoration of soil multifunctional indicators requires more than thirty years in degraded shrubland of a semi-arid mountainous ecosystem

Vegetation degradation in natural environments leads to considerable fluctuations in soil function indicators, particularly in the sensitive and delicate habitats of semi-arid regions. In this study, the dynamic of both litter and soil properties was examined in northern Iran, in sites with Crataegus melanocarpa and Berberis integerrima dominance. The chosen sites have been degraded in 1993 due to exploitation for fuel production. Litter and soil (0–10, 10–20 and 20–30 cm depths) samples were collected in sites that have been degraded [i.e., 10-years post-degradation (2003), 20-years post-degradation (2013), and 30-years post-degradation (2023)]. A site not to exposed to degradation (year 2023) was also included as a control. In total, 48 litter samples (4 study sites × 12 samples) and 144 soil samples (4 study sites × 3 depths × 12 samples) were collected. Our findings showed a significant reduction of approximately 60–70% in the chemical characteristics of the litter, such as phosphorus (P) and magnesium (Mg) after 10-years post-degradation (2003) compared to the control site. Soil fertility indicators were also reduced 2–6 times as a result of habitat degradation. Aligned with this, the biota population in the 10-year post-degradation site showed a decrease of 70–90% with respect to the control. Moreover, the densities of fungi and bacteria decreased by approximately 30%–70% and 45–80% respectively compared to the 30-year post-degraded site. The peak activation of soil enzymes including urease, acid phosphatase, arylsulfatase, and invertase was found in the site that was not subjected to degradation, being 3.5, 5.8, 6.7 and 6.7- times higher in comparison to the 10-year post-degradation site. Overall, the results showed that in the non-degraded ecosystems, the input of plant-based organic matter was accompanied by an increase in soil fertility, organism population and soil function. This pinpoints the importance of protecting plant species in these areas, while in degraded areas planting native species adapted to the region's climate and fertilization could significantly contribute to restoring these areas.

Development of Fe-Cr-C alloys with high Mn content for bone implant

The object of this study is to combine the properties of Mn and the advantages of Fe-Cr-C to improve biomaterial compatible characteristics. Three alloys of Fe-Cr-C with compositions of 12 wt. % Mn, 16 wt. % Mn, and 20 wt. % Mn, were investigated. Microstructural analysis was carried out using a scanning electron microscope (SEM), and a Vickers hardness test kit was used to evaluate the hardness. The pin-on-disc method was used for the dry slide wear test, and the corrosion test was carried out using the three-electrode cell polarization method. The hardness value of Fe-Cr-C alloy increased by 28.7 % with the increase of Mn content from 12 wt. % (231.8 VHN) to 20 wt. % (298.4 VHN). The tensile strength value increased by 30.3 % with an increase in Mn content from 12 wt. % (522.69 MPa) to 20 wt. % (680.89 MPa), while the strain value decreased by 30.9 %. However, impact toughness did somewhat decline, from 0.213 J/mm2 at 12 wt. % Mn to 0.169 J/mm2 at 20 wt. % Mn. The wear rate results for Fe-Cr-C 20 wt. % Mn 0.000156 mm3/kg. show a reduction of more than 15 wt. % when compared to Fe-Cr-C 12 wt. % Mn because of an increase in the hard-intermetallic area. Additionally, corrosion resistance improved significantly, with the corrosion rate decreasing from 0.005814 mm/yr at 12 wt. % Mn to 0.001780 mm/yr at 20 wt. % Mn, demonstrating that higher Mn content reduces material degradation in corrosive environments. Based on the experimental results, Fe-Cr-C 20 wt % Mn alloy has the highest mechanical and corrosion resistance of the three types of alloys. Fe-Cr-C with high Mn alloys are promising candidates for application as biomaterials for bone implants by optimizing the Mn content and corrosion resistance

Advanced corrosion-resistant materials for enhanced nuclear fuel performance: A conceptual review of innovations in fuel cladding against molten salt degradation

The increasing demand for efficient and sustainable nuclear power has led to the development of advanced corrosion-resistant materials that can significantly enhance nuclear fuel performance. This conceptual review focuses on the innovations in fuel cladding materials designed to resist degradation in molten salt environments, which are crucial for advanced nuclear reactors like molten salt reactors (MSRs). Fuel cladding serves as a critical barrier between the nuclear fuel and the reactor environment, and its ability to withstand extreme temperatures and corrosive conditions is essential for safe and efficient reactor operation. Recent advancements in materials science have introduced novel alloys and coatings that demonstrate superior corrosion resistance in molten salts, which are used as both coolants and fuel solvents in MSRs. These innovations include high-temperature nickel-based alloys, refractory metals, and ceramic coatings, which are engineered to reduce the effects of molten salt corrosion, such as oxidation, pitting, and embrittlement. By enhancing the durability of fuel cladding, these materials contribute to improved fuel performance, longer reactor lifespans, and increased safety. This review explores key developments in corrosion-resistant materials, emphasizing the mechanisms by which these materials mitigate molten salt degradation. Additionally, it highlights the challenges associated with material selection, fabrication, and long-term performance in the highly corrosive environments of advanced nuclear reactors. Ongoing research into these materials offers promising avenues for the future of nuclear energy, particularly in addressing the limitations of current fuel cladding technologies. In conclusion, the use of advanced corrosion-resistant materials represents a significant step toward enhancing the performance and safety of nuclear fuel, ensuring the viability of MSRs and other advanced reactor designs. Continued innovation in this field is essential for the future of nuclear power.

Status and Enhancement Techniques of Plastic Waste Degradation in the Environment: A Review

Plastic waste has been gradually accumulating in the environment due to rapid population growth and increasing consumer demand, posing threats to both the environment and human health. In this overview, we provide a comprehensive understanding of the degradation of plastics in real environments, such as soil, aquatic environment, landfill, and compost. Both conventional and biodegradable plastics exhibit limited degradation in real environments, except for biodegradable plastics during industrial composting with high thermophilic temperatures. Meanwhile, we also review techniques for enhanced degradation of plastics such as physical technologies (e.g., photocatalysis, mechanical degradation, and pyrolysis), chemical technologies (e.g., hydrolysis, alcoholysis, ammonia, strong oxidation, and supercritical fluids), and biotechnologies (e.g., microorganisms, microfauna, and microalgae). The future research directions for the enhancement of plastic degradation are also discussed, such as the establishment of equivalency standards, adoption of internal control techniques, the control of precise recycling of plastic products, and the ecotoxicology of their degradation products. Therefore, this review comprehensively summarizes the state of plastic degradation in real environments and proposes methods to improve plastic degradation, providing a theoretical basis for the future control and disposal of plastics.

LIVS: a tightly coupled LiDAR, IMU, and camera-based SLAM system under scene degradation

In increasingly complex environments, single-sensor-based SLAM systems face scene degradation problems such as strong light, dynamic obstacle interference, and lack of structural features in the environment, which severely constrain the localization accuracy and mapping effectiveness of SLAM systems. To address this problem, this paper proposes a tightly coupled laser-IMU-visual SLAM system (LIVS) based on factor graph optimization. LIVS consists of two subsystems: the laser inertial system (LIS) and the visual inertial system (VIS). The pose estimation of the LIS can provide an initialization for the VIS; LiDAR suffers scene degradation in environments lacking structural features, while the VIS provides better constraints for Lidar in this environment. Firstly, a method of selecting keyframes based on ORB features and the relative motion of the mobile robot is proposed as a means of improving the positioning accuracy and tracking ability of the system in the case of strenuous motion, and a strategy of local sliding window optimization is adopted to effectively improve the real-time performance and robustness of the system. Meanwhile, in order to further improve the global map consistency and positioning accuracy, a hybrid closed-loop detection method based on laser and vision is proposed, which utilizes the geometrical features of laser and the image features of vision to accomplish the hybrid closed-loop detection. Secondly, the laser inertia factor, IMU pre-integration factor, vision inertia factor, and closed-loop factor are globally optimized in a factor map framework to achieve accurate estimation of the robot pose. Finally, this paper presents experimental evaluations on both public and homemade datasets and compares the performance of the proposed algorithm with that of other algorithms. Experimental results show that the algorithm in this paper exhibits better performance in both localization accuracy and mapping effectiveness.

A LiDAR SLAM Algorithm Considering Dynamic Extraction of Feature Points in Underground Coal Mine

Abstract. To address the absence of GNSS signals in underground coal mines and the susceptibility of mainstream LiDAR SLAM to degradation due to insufficient feature constraints, this paper proposes a tightly-coupled SLAM algorithm incorporating LiDAR and IMU for use in such environments. The paper initially introduces a dynamic feature point extraction strategy, where the number of corner feature points can be dynamically adjusted based on the occurrence of degradation in the underground coal mine environment. This approach constructs a constraint matrix with rich and robust feature information, enhancing pose estimation accuracy in environments with inadequate feature constraints, mitigating degradation effects, and reducing global cumulative error. Subsequently, the consistent building of the underground coal mine environment is achieved through back-end factor graph optimization. Finally, to validate the effectiveness of the method, experimental analysis is conducted in an underground coal mine. The results demonstrate that LeGO_LOAM exhibits poor robustness in underground coal mines and fails to construct a globally consistent pose estimation and map. Conversely, the pose estimation error of the proposed method in this paper is 50.93% lower in the plane direction and 42.13% lower in the elevation direction compared to LIO_SAM. This underscores the method's significance as crucial technical support for the intelligent perception and positioning of robots in underground coal mines.

Preparing efficient self-healing polyimide coating for enhancing stability of electromagnetic interference shielding film

Electromagnetic interference (EMI) shielding films were widely utilized in various electronic devices, but they were prone to damage and performance degradation in harsh environments. Therefore, it was urgent to maintain stable performance of EMI shielding films. In this work, we adopt the reactions between aldehyde-modified diamine monomers and dianhydride monomers with dynamic imine bond to successfully prepare a self-healing PI (SHPI) film. Benefit from dynamic imine and imide bond, the SHPI film possessed excellent thermal stability (T5 %=527.7°C), tensile strength (72 MPa) and self-healing efficiency (94.4 %). As protecting coating layer, the SHPI film was able to maintain the commercial aluminized polyimide (PI/Al) film with good EMI shielding performance in acid environment. The electromagnetic shielding film with self-healing coating still had average EMI shielding effectiveness value of 44.5 dB after exposed to 10 % concentration nitric acid solution for 30 min. It is noteworthy that when damaged by external forces, the electromagnetic shielding film with self-healing coating could achieve rapid healing, while the tensile strength was up to 87 MPa and the self-healing efficiency reached 92.5 %. This work provided an effective self-healing protective layer for EMI shielding material against corrosion in acidic environments and damage from external pressures.

Zinc-halide/phenylbutyrate co-passivation of CsPbX3 nanocrystals toward efficient and robust luminescence

Cesium lead halide perovskite nanocrystals (IPNCs) exhibit excellent optoelectronic properties but are susceptible to degradation in practical environments due to their ionic surface and unstable ligand capping. Here, we propose a post-synthesis surface passivation strategy for CsPbX3 (X = Br, I) IPNCs by employing combined zinc halide and zinc phenylbutyrate (Zn(PA)2) as surface ligands. ZnBr2 fills surface halide vacancies on IPNCs, resulting in high photoluminescence efficiency, whereas Zn(PA)2 stabilizes IPNCs by substituting surface ammonium ligands. Additionally, the −PA capping endows IPNCs with high solubility in polystyrene (PS), enabling the direct fabrication of highly efficient and uniform IPNCs-PS color conversion films through in situ polymerization of the IPNC-styrene solution. The resulting IPNCs-PS films displayed significantly enhanced stability, retaining excellent PL persistence after 1000 h of photoaging. This novel ligand and modification method presents a promising strategy for improving the efficiency and stability of IPNCs, facilitating their potential applications in display backlight and other optoelectronic applications.

Therapeutic effect of bloodletting on bone deterioration induced by hypobaric hypoxia in young rats

ObjectivesHigh-altitude regions, comprising hypoxic condition, are associated with different altitude-induced pathologies, including a reduction in bone density. Elucidating the mechanisms underlying bone degradation in such environments and developing targeted interventions and therapeutics is important. Bloodletting therapy has promising clinical applications, but its effects on the skeletal system and bone homeostasis are not well understood. The aim of this study was to investigate the effects of a hypobaric hypoxia environment on specific femoral morphological and structural properties, including the bone volume, cortical thickness, and trabecular microarchitecture, in juvenile Sprague–Dawley (SD) rats, and to explore the potential modulating effects of a bloodletting intervention on these parameters. MethodsMale SD rats, 6 weeks of age, were subjected to a simulated hypobaric hypoxia environment, replicating a 5000-m altitude, for 12 weeks. For the bloodletting intervention group, rats were subjected to a weekly 500 μL tail vein blood withdrawal. Micro-CT technology, hematoxylin and eosin staining, and tartrate-resistant acid phosphatase staining were employed to comprehensively assess the femoral microstructure, tissue architecture, and cellular morphology. Additionally, immunofluorescence analysis was conducted to quantify the expression of key proteins, and transcriptome analysis was performed to identify differentially expressed genes. ResultsExposing rats to hypobaric hypoxia led to a significant reduction in the bone mineral content, trabecular bone number, and cortical bone thickness, suggesting a deterioration of bone microstructure. Additionally, the hypoxic environment upregulated the expression of RANKL and HIF-1α, while downregulating RUNX2 expression. Notably, although bloodletting intervention did not significantly reverse these bone structural changes, transcriptome analysis revealed its regulatory influence on the expression of key genes, particularly Mmp2, Fosl2, and URS0000B2A65A, which are implicated in pathways governing the hypoxic response, osteoclast differentiation, and PI3K–Akt signaling. ConclusionThis study highlights the detrimental effect of hypobaric hypoxia on the bone microstructure of juvenile rats and underscores the therapeutic potential of bloodletting to ameliorate this condition. Additionally, our study on the regulatory mechanisms mediating the effects of bloodletting on gene expression offers new perspectives on bone alterations. It suggests promising avenues for the development of novel preventative measures and targeted therapies to address the challenges posed by related bone disorders.

Influence of Oxygen Exposure on Lignin Preservation during Sediment Lateral Transport in the Ocean: Insights from Molecular Dynamics Simulations.

Understanding the fate of terrestrial organic carbon (terrOC) preservation in the marine environments is critical for deciphering the biogeochemical processes associated with the global carbon cycle and the Earth's climate change. The mechanisms controlling terrOC preservation are not completely understood, while lateral oxygen exposure time (OET) is considered as a critical controlling factor. Here, we first utilized molecular dynamics simulations to investigate the structural properties of lignin under anoxic, suboxic, and oxic conditions for understanding the mechanisms of terrOC preservation during sediment lateral transport in the ocean. Our finding suggested that oxygen exposure was indispensable for terrOC degradation through influencing the structural stability and reactivity of lignin. Our simulated results showed that in suboxic environments, prolonged OET may enhance terrOC preservation. Our organic geochemical results suggested that terrOC preferably preserved in coarse silts (20-63 μm) than fine silts (<20 μm) in suboxic environments, largely due to hydrodynamics-driven prolonged OET in coarse sediments, which may efficiently reduce CO2 emissions. Overall, our study sheds new light on the mechanisms of lateral OETs on terrOC preservation in suboxic conditions and, from a unique molecular structural perspective, provides insights into the impact of prolonged OETs on terrOC oxidative degradation in the marine environment.

Multifunctional zinc oxide loaded stearic acid surfaces on biodegradable magnesium WE43 alloy with hydrophobic, self-cleaning and biocompatible attributes

Biodegradable Mg alloys are one of the most promising materials for implant applications, for which the widespread use is hampered by rapid degradation in physiological environment. The present study explores the development of a novel zinc-oxide (ZnO) loaded stearic acid (SA) coating on medical grade WE43 alloy using a facile, and environment-friendly technique for promising biomaterial surface applications. Morphology and chemical analyses reveal the development of a layered coating surface with uniformly dispersed ZnO nanoparticles in SA matrix. The developed coating exhibits hydrophobic performance (contact angle of 135°) along with the retainment of hydrophobicity under varying chemical (acidic pH of 1 and basic pH of 13) and mechanical (post scratch testing and peel-off studies) conditions. The observed surface water repellency facilitates self-cleaning performance pointing towards its efficacy against potential biofilm formation. The developed coating demonstrates superior resistance against surface degradation during immersion studies in phosphate buffer saline solution (pH = 7.4) and better cell viability with MG-63 (human osteosarcoma) cell line. The approach presented here sets a platform for the development of efficient coatings on biodegradable WE43 alloys surfaces for potential biomaterial technologies.

An Experimental Assessment Using Acoustic Emission Sensors to Effectively Detect Surface Deterioration on Steel Plates

Acoustic emission (AE) testing is used for the continuous evaluation of structural integrity and the monitoring of damage evolution in structural components and materials. During operation, the environmental and loading conditions of metal structures can result in corrosion and surface wear damage. The early detection of surface degradation flaws is crucial, as they can serve as local stress concentration points, leading to crack initiation and failure. In this work, the effectiveness of AE in monitoring corrosion and surface wear flaw formation was experimentally evaluated. AE sensors were installed on steel test plates during the artificial induction of corrosion and surface wear in order to detect and record the generated AE signals. Corrosion-related AE signals typically exhibit low amplitude, count, and energy values. The direct detection of active corrosion can be challenging in noisy environments, but it can be carried out under certain conditions using dedicated AE sensor groups. Surface-wear-related AE signals exhibit high amplitude, energy, and count values, with long duration values that are associated with wear and grinding conditions. It was found that AE sensors can be utilised to detect corrosion and surface degradation events. The effectiveness of the AE method in detecting surface degradation in noisy environments can be improved by implementing a filtering methodology. This will limit the recording of noise-related signals that can mask out actual surface degradation AE events.