Search Results (2,480)

(1) Background: This study evaluated the efficacy of magnesium nanoparticles (MgNPs) synthesized through a green method utilizing bacterial metabolites (BMs) produced by Escherichia coli. (2) Methods: BMs were tested for total phenolic content by high-performance liquid chromatography. MgNPs were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, photoluminescence, and ultraviolet–visible spectroscopy. MgNPs and BMs were tested for antibacterial and antibiofilm potentials against multidrug-resistant clinical isolates by agar well diffusion, minimum inhibitory and bactericidal concentration assays, time–kill test, and inhibition of biofilm formation and destruction of pre-formed biofilm assays. Furthermore, they were tested for antioxidant potential by 2,2-diphenyl-1-picryhydrazyl radical scavenging assay. (3) Results: BMs included carbohydrates, reducing sugars, and phenols (gallic acid and catechin) with a total phenolic content of 0.024 mg GAE/g. MgNPs showed a pure crystalline structure with a spherical shape, 17.8 nm in size, and a 4.19 eV energy gap. Bacteria included Streptococcus pneumonia, Enterococcus faecium, Klebsiella pneumonia, and Salmonella Typhimurium. The antibacterial results showed inhibition zones ranging between 7.2 and 10.4 mm, a bactericidal effect of MgNPs, a bacteriostatic effect of BMs, and growth inhibition after 3 h. The antibiofilm results demonstrated significant inhibition of biofilm formation (inhibition percentages of 64.931% for MgNPs and 71.407% for BMs). However, the assays revealed modest biofilm destruction (eradication percentages of 48.667% for MgNPs and 37.730% for BMs). Antioxidant capacity revealed notable scavenging activity of MgNPs (scavenging activity of 41.482%) and weak activity of BMs (scavenging activity of 16.460%). (4) Conclusions: These findings support the application of MgNPs in biomedical fields. Full article

In high-humidity environments, the epoxy resin solid insulation materials of high-frequency transformers are prone to aging, resulting in varying degrees of deterioration in the material’s dielectric properties and other aspects. To enhance the adaptability of epoxy resin in high humidity environments, this paper, based on the molecular dynamics simulation method, establishes epoxy resin-based nanocomposites with doped nanofillers: a pure epoxy resin model and three epoxy resin models, respectively, doped with carbon nanotubes, graphene(GR), and SiO₂. Based on the above models, using LAMMPS-17Apr2024, the thermal diffusion coefficients (thermal conductivity and specific heat capacity), glass transition temperatures, and dielectric constants under different moisture contents are calculated. The results show that the various properties of the epoxy resin nanocomposites doped with nanofillers have been improved to varying degrees. Among them, the GR/epoxy resin composite model shows the most significant improvements in thermal conductivity, thermal diffusivity, and glass transition temperature, and the SiO₂/epoxy resin composite model has the best dielectric properties. Considering the high-temperature operation conditions and heat dissipation requirements of the high-frequency transformer, the GR-enhanced epoxy resin becomes the optimal filler choice. Full article

Nanocolloids are nanoparticles suspended in fluids with the aim of improving fluid capability at heat transfer, with a focus on thermal conductivity. The major advantage is the increase in thermal conductivity, with a certain influence on isobaric heat capacity and viscosity. Nevertheless, PEGs are able to create steady suspensions due to their chemical composition and are used in a number of applications. This paper discusses both the advantages and the drawbacks of a suspension of PEG 400 and MWCNT nanoparticles in terms of its relevance for heat transfer applications. Our investigation is built on a complex experimental procedure, as well as an analysis of the state of the art and a discussion of the experimental results in the context of the Prandtl number and thermal diffusivity. This analysis also includes different performance evaluation criteria that are extensively employed both in the heat transfer literature and in practice. The addition of MWCNTs to polyethylene glycol decreases the thermal transport, being influenced by both temperature and the addition of NPs. The results for MWCNT nanocolloids indicate an intensification of the pumping power of up to 29.7%. Also, an interesting option is the use of PEG mixtures as base fluids in order to combine their properties. Full article

Background: Chronic lung allograft dysfunction (CLAD) occurs in up to 50% of patients within the first five years after lung transplantation (LuTX) and represents the main complication and cause of death regarding this surgery. Alveolar septal widening in transbronchial biopsies has shown an association with acute humoral allograft rejection. We aimed to explore histological markers that could predict the development of CLAD before its clinical manifestation. Methods: We retrospectively analyzed transbronchial biopsies taken at three time points from 57 patients who underwent LuTX between February 2010 and July 2019, 26 of whom developed CLAD up to November 2022. The biopsies were analyzed by microscopic morphometry and quantitative reverse transcription PCR to identify predictors of CLAD. Results: CLAD development was associated with increased alveolar septal width (ASW) as early as the first year post-LuTX (5.46 ± 0.76 µm versus 4.59 ± 0.44 µm; p < 0.001). The ASW in later biopsy timepoints predicted survival in multivariate models (last timepoint: hazard ratio 1.885, 95% confidence interval 1.086–3.269). Collagen (COL1A1 and COL3A1) expression was significantly increased in samples from patients who developed CLAD compared with those who did not. The increase in ASW was paralleled by interstitial deposition of COL1A1 and COL3A1 and a decrease in both the carbon monoxide (DLCO) diffusing capacity of the lung and the DLCO/alveolar volume. Conclusions: We report a new histologic approach for early assessment of risk of CLAD in patients who have undergone LuTX. The ASW represents a pre-symptomatic, continuous, and widely distributed change within the lung parenchyma that is accessible to transbronchial biopsy. Full article

Shale oil is a vital strategic resource in China. Developing shale oil using CO₂ not only enhances oil recovery but also contributes to achieving Chinese “dual carbon” goals. Given the challenges of insufficient number of fractures, inadequate vertical stimulation volume, and poor reservoir mobility associated with horizontal well fracturing, this study proposes a method for CO₂ flooding based on radial borehole fracturing in a single well to achieve long-term carbon sequestration. To this end, a multi-component numerical model is built to analyze the production capacity of radial borehole fracturing. This study analyzed the impacts of non-Darcy flow, diffusion, and adsorption mechanisms on CO₂ migration and sequestration. It also compared the applicability of continuous CO₂ flooding and CO₂ huff-and-puff under different matrix permeabilities. The results indicate that (1) CO₂ flooding using radial borehole fracturing can achieve long-term oil production and carbon sequestration. (2) Under low permeability conditions, the liquid non-Darcy effect retards the flow of oil and CO₂, while diffusion and adsorption facilitate CO₂ sequestration in the reservoir. The impact on carbon sequestration is ranked as follows: non-Darcy effect > adsorption > diffusion. (3) High-permeability reservoirs are more suitable for carbon sequestration and should utilize continuous CO₂ flooding. For low-permeability reservoirs (<0.001 mD), huff-and-puff should be employed to mobilize the reservoir around fractures and achieve carbon sequestration. The findings of this study are expected to provide new methods and a theoretical basis for efficient and economical carbon sequestration in shale oil reservoirs. Full article

Cadmium {Cd (II)} poses a high risk to ecological security and human health due to its high toxicity, easy migration and difficult degradation. Using waste rubber seed shell biochar (RSSB) as the carrier material of nZVI may inhibit the caking oxidation of zero-valent iron and improve the removal efficiency of Cd (II) from water. Through a series of batch experiments, the adsorption mechanism of modified biochar on Cd (II) clarified that the removal effect of nano-zero-valent iron-rubber seed shell biochar (nZVI-RSSB) on heavy metals in water was better than that of RSSB. The results showed that when the dosage of complex biochar was 80 mg, the initial concentration of Cd (II) was 50 mg/L, and the solution pH was 6, the maximum adsorption capacity of nZVI-RSSB for Cd (II) reached 30.42 mg/g, compared with the RSSB of 13.32 mg/g. The adsorption kinetics model showed that chemisorption and physical adsorption existed simultaneously. The results of the in-particle diffusion model show that the adsorption process may be divided into two stages. The Langmuir competitive adsorption model was followed. Electrostatic adsorption and precipitation/co-precipitation could be the main ways for the removal of Cd (II) by composite materials. Meanwhile, the synergistic adsorption of nZVI-RSSB composites with multiple metals in actual water showed its application potential in water pollution control. Hence, the nZVI-RSSB not only successfully inhibits the caking oxidation of zero-valent iron, but also effectively improves the removal efficiency of heavy metals from water. Full article

This study developed a novel adsorbent for Cr (VI) removal from wastewater by grafting N-[(dimethylamino)methylene]thiourea (TUFA) onto lignin. The resulting TUFA-functionalized lignin adsorbent AL was comprehensively characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS). Batch adsorption experiments systematically evaluated the influence of solution pH, contact time, temperature, initial Cr (VI) concentration, and adsorbent dosage. AL exhibited high adsorption capacity (593.9 mg g⁻¹ at 40 °C), attributed to its abundant nitrogen and sulfur-containing functional groups. Kinetic analysis revealed that the adsorption process followed pseudo-second-order kinetics. Equilibrium isotherm data were best described by the Langmuir model, indicating predominant monolayer chemisorption. Thermodynamic parameters demonstrated that Cr (VI) adsorption onto AL is spontaneous, endothermic, and entropy-driven. The adsorption mechanism involves membrane diffusion and intra-particle diffusion processes. This work successfully synthesized a stable, effective, and low-cost adsorbent (AL) using an amine agent incorporating both nitrogen and sulfur functional groups, offering a promising approach for treating Cr (VI)-contaminated wastewater. Full article

Phosphates pollution, primarily from agricultural runoff and wastewater discharge, is a major contributor to water eutrophication, adversely affecting aquatic ecosystems. This study reports the synthesis, characterization, and phosphates adsorption performance of a MgAlFe-layered double hydroxide (MgAlFe-LDH) with a 2:1:1 cationic ratio. The material was prepared via co-precipitation and characterized using digital microscopy, XRD, BET, XPS, and FTIR. Adsorption experiments were conducted at pH 3 and 9 to investigate equilibrium, kinetics, and reusability. The MgAlFe-LDH exhibited a high maximum adsorption capacity (q_max ≈ 215 mg/g) largely independent of pH, with adsorption well described by the Langmuir model. Kinetic studies revealed a pseudo-first-order mechanism, indicating that adsorption is dominated by surface diffusion and electrostatic interactions. Phosphate removal occurs through a dual mechanism involving rapid electrostatic attraction at protonated surface sites and slower ion exchange in the LDH interlayers. The material retained over 75% of its adsorption capacity after five consecutive adsorption–desorption cycles, highlighting its potential for sustainable phosphate recovery. Overall, the MgAlFe-LDH represents a promising, reusable adsorbent for phosphorus removal from wastewater, supporting circular economy strategies. Full article

This study discussed the influence of acetate and sodium chloride concentration on monitoring 2,4-dichlorophenol(2,4-DCP) by electroactive bacteria. The performance of the reactor was represented by power density, and the electrochemical activity was represented by redox capacity. At the same time, micro-electrodes were used to detect the redox potential between biofilms, and the changes in extracellular polymers and microbial community structure under different conditions were also explored. With acetate concentration of 1 g/L and sodium chloride concentration of 0.0125 g/L, the electroactive microorganisms were more sensitive to toxic substances and responded fast. The biofilm also evenly covered on the surface of the carrier, which aided in the diffusion of substances. Although the maximum power density monotonically increased with acetate concentration, high concentration of substrate may mask the inhibitory effect and affect the judgment of inhibitory results. The content of protein and polysaccharide increased monotonically with sodium chloride concentration. However, more polysaccharides would lead to high resistance to electron transfer. Compared to sodium chloride, the microbial content was more affected by acetate. The electroactive microorganisms had strong adaptability to salinity. In practical application, it is conducive to increase the sensitivity of MFCs to reasonably reduce the concentration of acetic acid and sodium chloride. Full article

During pregnancy, physiological adaptations occur in the respiratory and cardiovascular systems to support the increased metabolic needs of both mother and fetus. Key respiratory changes include mechanical adjustments of the chest wall and diaphragm to accommodate the growing uterus; decreases in functional residual capacity and its components—expiratory reserve volume and residual volume—with minimal or no change in total lung capacity; and an increase in minute ventilation. Major cardiovascular adaptations involve elevated cardiac output, stroke volume and heart rate, and decreased mean arterial pressure and systemic vascular resistance. During exercise in pregnancy, there is an increase in ventilation, alveolar diffusion, elevated oxygen consumption, greater carbon dioxide production and changes in respiratory volumes and capacities, as well as increases in cardiac output, stroke volume and heart rate. Understanding these normal physiological changes during pregnancy and exercise in pregnancy is essential for healthcare providers to develop and adapt exercise programs according to the gestational age and physical fitness level of the pregnant woman. Full article

Addressing the challenge of sulfonated lignite (SL) removal from oilfield wastewater, this study introduces a novel hierarchical MgFe-layered double hydroxide (LDH) adsorbent. The material was fabricated via in situ co-precipitation, utilizing a template formed by the NaCl-induced co-assembly of oleylaminopropyl betaine (OAPB) and sodium dodecyl sulfate (SLS) into zwitterionic, anionic, shear-responsive viscoelastic gels. This gel-templating approach yielded an LDH structure featuring a hierarchical pore network spanning 1–80 nm and a notably high specific surface area of 199.82 m²/g, as characterized by SEM and BET. The resulting MgFe-LDH demonstrated exceptional efficacy, achieving a SL removal efficiency exceeding 96% and a maximum adsorption capacity of 90.68 mg/g at neutral pH. Adsorption kinetics were best described by a pseudo-second-order model (R² > 0.99), with intra-particle diffusion identified as the rate-determining step. Equilibrium adsorption data conformed to the Langmuir isotherm, signifying monolayer uptake. Thermodynamic analysis confirmed the process was spontaneous (ΔG < 0) and exothermic (ΔH = −20.09 kJ/mol), driven primarily by electrostatic interactions and ion exchange. The adsorbent exhibited robust recyclability, maintaining over 79% of its initial capacity after three adsorption–desorption cycles. This gel-directed synthesis presents a sustainable pathway for developing high-performance adsorbents targeting complex contaminants in oilfield effluents. Full article

This study investigated the sorption properties of the biomass of larch (LaC), pine (PiC) and spruce cones (SpC) in relation to the anionic dye Reactive Black 5 (RB5) and cationic Basic Red 46 (BR46). The scope of the study included the properties of the sorbents (FTIR, SSA, fiber content, elemental analysis C, N, H, pH_PZC), the effect of pH on the sorption efficiency of the dyes, the sorption kinetics (pseudo-first-order model, second-order model, intraparticle diffusion model) and the maximum sorption capacity of the sorbents (Langmuir 1 and 2 models, Freundlich). The sorption efficiency of RB5 on the sorbents tested was highest at pH 2 and BR46 at pH 6. The pH_PZC values determined for LaC, PiC and SpC were 6.86, 7.02 and 7.19, respectively. The sorption equilibrium time depended mainly on the initial dye concentration and ranged from 150 to 180 min for RB5 and from 120 to 210 min for BR46. The sorption capacities (Q_max) of LaC, PiC and SpC for RB5 were 1.05 mg/g, 1.12 mg/g and 1.61 mg/g, respectively, and for BR46 were 70.53 mg/g, 76.60 mg/g and 96.44 mg/g, respectively. The most efficient sorbent for both dyes was SpC, which was partly related to the high lignin content of the material. Full article

Water pollution by organic dyes poses serious environmental and health challenges, demanding efficient and selective remediation methods. In this study, we engineered tailored organo-clay nanocomposites by modifying montmorillonite with hexadecyltrimethylammonium bromide (HTAB) and intercalating polyethylene glycol (PEG) chains of two distinct molecular weights (PEG200 and PEG4000). Comprehensive characterization techniques (XRD, FTIR, SEM, zeta potential, and TGA) confirmed the successful modification of the composites. Notably, PEG4000 promoted significant interlayer expansion, as evidenced by the shift of the (00l) reflection corresponding to the basal spacing d, indicating an increase in basal spacing. This expansion contributed to the formation of a well-ordered porous framework with uniformly distributed pores. In contrast, PEG200 produced smaller pores with a more uniform distribution but induced less pronounced interlayer expansion. Adsorption tests demonstrated rapid kinetics, achieving equilibrium in under 15 min, and impressive capacities: 420 mg/g of methylene blue (MB) adsorbed on PEG200/MMT@HTAB, and 385 mg/g of Congo red (CR) on PEG4000/MMT@HTAB. The crucial role of PEG chain length in adsorption selectivity was assessed, showing that shorter PEG chains favored methylene blue adsorption by producing narrower pores and faster kinetics, while longer PEG chains enhanced CR uptake via a stable, interconnected pore network that facilitates diffusion of larger dye molecules. Thermodynamic and Dubinin–Radushkevich analyses confirmed that the adsorption was spontaneous, exothermic, and predominantly driven by physical adsorption mechanisms involving weak van der Waals and dipole interactions. These findings highlight the potential of PEG-modified montmorillonite nanocomposites as cost-effective, efficient, and tunable adsorbents for rapid and selective removal of organic dyes in wastewater treatment. Full article

This study evaluates the sorption behavior of natural zeolite (NZ) and Fe(III)-modified natural zeolite (FeZ) for Ni(II) ions, with the objective of assessing their potential for application in the remediation of nickel-contaminated environments. Optimization of sorption parameters, including pH_o, solid/liquid ratio (S/L), contact time, and initial Ni(II) concentration was performed to maximize both the sorption capacity of the zeolites and the removal efficiency of Ni(II) from suspension. The results demonstrated that both pH_o and S/L ratio exert a significant influence on Ni(II) sorption onto both zeolites, with a particularly pronounced effect observed for FeZ. Experimental results confirmed that FeZ exhibits a four-to-five times higher sorption capacity for Ni(II) than NZ, which was additionally verified by elemental analysis, SEM-EDS, and elemental mapping of Ni(II)-saturated zeolites. Intraparticle diffusion was identified as the rate-limiting step in the transfer of Ni(II) ions to the active sorption sites. Ion exchange was identified as the main sorption mechanism accompanied by outer-sphere complexation and electrostatic attraction. Leaching tests of Ni(II)-saturated zeolites, conducted in accordance with the standard DIN 38414 S4 method, demonstrated that both zeolites effectively retained Ni(II) within their structures over a wide pH range, 4.11 ≤ pH_o ≤ 12.02. These findings indicate the potential applicability of zeolites for remediation of nickel-contaminated environments, with FeZ being particularly promising due to its enhanced sorption capacity for Ni(II) ions. Full article

Progressive pulmonary fibrosis (PPF) is a clinical syndrome associated with worsening quality of life and increased mortality among patients with various interstitial lung diseases. This review aims to update the concepts and criteria that adequately define PPF, aiming to facilitate earlier recognition and optimize clinical management. Fibrosing interstitial lung disease (ILD-f) can progress over time despite optimal management of the underlying conditions. Current criteria for defining PPF include worsening respiratory symptoms, decline in pulmonary function tests (particularly forced vital capacity and diffusing capacity), and radiographic progression over a 1-year follow-up period. However, implementation of these criteria in clinical practice poses challenges. This review discusses the limitations of current evaluation methods and proposes future directions, including the need for validated symptom assessment tools, standardization of pulmonary function testing, and improvements in quantitative radiological evaluation methods. Full article