ACS Omega最新文献

Drying shrinkage of the hardened cement mixture plays an important role in the durability of cementitious structures. However, the drying behavior of the cement paste remains unclear at the nanoscale. In this study, the effect of interlayer water on the drying deformation of C–S–H was investigated at the globule level (10^–10–10^–8m) via an artificial neural network-assisted molecular dynamics simulation approach. The present work revealed two drying deformation mechanisms of C–S–H from the perspective of the nanoscale and determined the transition threshold as RH ≈ 55%. Moreover, NaCl in the interlayer water was found to have a deleterious effect on the drying shrinkage at the nanoscale. Adding 25 wt % NaCl can increase the drying shrinkage to 54.3%. Overall, a prediction model with high accuracy was established to analyze the drying deformation of C–S–H under different moisture conditions, which explores the drying behavior at the nanoscale and paves the way for the multiscale application of drying shrinkage mitigations.

This study evaluates the ecological impacts of thermoelectrics (TEs) in stationary applications that periodically generate waste heat using life cycle assessment (LCA) methodology, a first of its kind. Six TE modules are analyzed for a periodic heat-emitting application: a natural gas-based power plant that meets only peak electricity demand. The analysis uses detailed inventories from an earlier study regarding the production and end-of-life stages of the TEs. The results show that while TEs are effective in conserving fossil fuels and lowering greenhouse gas emissions, they do not exhibit significant positive effects on other environmental impacts. These findings persist even when accounting for variations in TE conversion efficiency and lifetime and the implementation of a circular economy approach for recycling and repurposing TE modules. This suggests that the environmental suitability of TEs is predominantly influenced by the type of fossil energy source they replace, making current TEs unsuitable for stationary applications that periodically generate waste heat. The study also highlights the need for further research on the development of new, practical TEs that utilize nontoxic, abundant elements and are produced through less energy-intensive techniques.

Carbonate reservoirs, characterized by deep burial, high temperatures, strong heterogeneity, and extensive fracturing, pose challenges for effective acidizing stimulation. Gelled acid treatment offers a solution to issues such as severe acid fluid loss and limited penetration in high-temperature carbonate reservoirs. However, current gelled acids often lack sufficient temperature resistance, and the retardation effect of single gelled acids remains limited. In this study, a temperature-resistant gelled agent was synthesized using acrylamide (AM), methacryloyloxyethyl dimethyl octadecyl ammonium bromide (DM-18), dimethyl diallyl ammonium chloride (DMDAAC), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS), achieving the designed molecular structure. Additionally, the zwitterionic surfactant dodecyl betaine (BS-12) was selected as a retardation synergist, forming a retarded gelled acid with excellent stimulation performance and effective rock etching. Static retardation rate tests and high-temperature, high-pressure acid-rock reaction kinetic experiments were conducted to compare the retardation effects of gelled acid and retarded gelled acid. The kinetics equations and activation energies for hydrochloric acid, gelled acid, and retarded gelled acid under varying temperatures and concentrations were determined. Results demonstrated that the retarded gelled acid exhibited superior retardation efficiency compared to single gelled acid, achieving a retardation rate exceeding 80% within 1 h. Its kinetic reaction rate and activation energy at high temperatures were lower than those of single gelled acid, highlighting its stability and effectiveness in high-temperature environments. Scanning electron microscopy and infrared spectroscopy analyses revealed the retardation mechanism: the polymer network hindered hydrogen ion transfer, while the adsorption film prevented direct contact between hydrogen ions and the rock surface.

This study systematically evaluated the effects of media milling on the physicochemical properties, bioactive compound content, and functional applications of fresh jujube (Ziziphus jujuba Mill.) juice. Optimization experiments identified ideal conditions for nanoparticle production, including 5% solid content and a 180 min milling duration, resulting in significantly reduced particle sizes─volume-weighted average diameter (from 229.0 ± 1.0 to 25.0 ± 0.2 μm) and number-weighted average diameter (from 7.2 ± 0.0 to 0.1 ± 0.0 μm)─and improved dispersion stability. Media milling enhanced key physicochemical properties such as zeta potential, viscosity, and suspension stability, while also modifying color and pH. The process notably increased the content of bioactive compounds, including total flavonoids (from 2.9 ± 0.1 to 3.8 ± 0.0 mg catechin equivalent (CE)/g dry weight (DW)) and triterpenoids (from 15.4 ± 1.2 to 28.0 ± 4.9 mg oleanolic acid equivalent (OAE)/g DW). The antioxidant activity before and after media milling, assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, remained comparable. Fermentation with Lactiplantibacillus plantarum demonstrated that both blended and media-milled jujube juice can serve as effective substrates for substrate utilization and lactic acid production. Anti-inflammatory assays using RAW 264.7 macrophages revealed reduced nitric oxide production and lower levels of pro-inflammatory cytokines such as IL-1β, showcasing the juice’s potential to modulate inflammation. In a dextran sodium sulfate (DSS)-induced colitis mouse model, media-milled jujube juice demonstrated safety, though it did not show significant protective effects. These findings position media-milled jujube juice as a promising functional food ingredient with potential applications in health promotion and disease management.

Purpose: Targeting the programmed death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint blockade therapy plays a critical role in cancer therapy. However, not all patients benefit from this approach, with PD-L1 expression levels being a significant contributing factor. Positron emission tomography (PET) imaging of PD-L1 offers a noninvasive, whole-body, and dynamic assessment of its expression. This study aims to develop a novel peptide-based PD-L1 tracer, [⁶⁸Ga]HF12, to quantitatively evaluate PD-L1 expression in tumors, thereby offering clinical guidance. Methods: HF12 was successfully synthesized and radiolabeled with ⁶⁸Ga to yield [⁶⁸Ga]HF12. In vitro binding assays confirmed the specific binding affinity of HF12 for PD-L1 using CHO-hPD-L1 and CHO cell lines. Subsequent in vivo positron emission tomography (PET) imaging and biodistribution studies assessed [⁶⁸Ga]HF12 for monitoring PD-L1 expression levels in tumor-bearing mice, including those subjected to immunotherapy. Furthermore, PD-L1 expression in tumor tissues was evaluated by using autoradiography, Western blotting, and immunohistochemical (IHC) analysis. Results: The synthesis of [⁶⁸Ga]HF12 was successfully achieved with a radiochemical purity and yield exceeding 95%. Cellular uptake studies indicated that [⁶⁸Ga]HF12 demonstrated both high specificity and significant uptake in PD-L1-positive CHO-hPD-L1 cells. Micro-PET imaging and biodistribution studies revealed that [⁶⁸Ga]HF12 was preferentially accumulated in CHO-hPD-L1 tumors compared to PD-L1-negative CHO tumors. Treatment with Atezolizumab resulted in a significant reduction in [⁶⁸Ga]HF12 uptake in CHO-hPD-L1 tumors relative to pretreatment levels, whereas no significant changes were observed in the phosphate-buffered saline (PBS) control group. Subsequent biodistribution studies, along with Western blotting and immunohistochemical analyses, confirmed that PD-L1 expression levels in tumors were reduced following immunotherapy, consistent with the results obtained from PET imaging. Conclusions: [⁶⁸Ga]HF12 was successfully synthesized as a radiotracer for noninvasive quantitative PET imaging of PD-L1 expression levels. This radiotracer exhibited the potential to quantify PD-L1 expression across various tumors, thereby facilitating the prediction of patient response to anti-PD-1 and anti-PD-L1 immunotherapies and monitoring therapeutic efficacy.

This study presents the development and characterization of a novel catechol-conjugated alginate (C-Alg) hydrogel system that combines Ca²⁺-mediated ionic cross-linking with laccase-catalyzed enzymatic cross-linking. While traditional Ca²⁺-mediated alginate hydrogels are known for their rapid gelation, they suffer from poor long-term stability in physiological conditions, limiting their effectiveness in medical applications. In the system developed here, the hydrogel initially formed upon mixing C-Alg with Ca²⁺, followed by gradual chemical catechol cross-linking through enzyme catalysis. The C-Alg hydrogels exhibited markedly improved mechanical strength and enhanced stability compared to those cross-linked with Ca²⁺ alone. This dual cross-linking approach also effectively slowed the release rates of model molecules with molecular weights ranging from several hundred to ten thousand. These advantages highlight the potential of C-Alg hydrogels as effective platforms for injectable drug delivery systems.

The surge in antibiotic-resistant Staphylococcus aureus infections has been deemed a major public health concern. There is an urgent need for novel antimicrobial therapies, chemical and nonantibiotic. The basidiomycota-derived, secondary metabolite pleurotin has been shown to be effective against Gram-positive bacteria, while bacteriophages could be the ultimate nonantibiotic alternative. In this study, the combination of pleurotin and phage K targeting S. aureus was examined. Pleurotin was isolated from the basidiomycota fungus Hohenbuehelia grisea. The cytotoxicity of pleurotin was assessed in two human cell lines in comparison to pleuromutilin, vancomycin, and phage K. The antibiotics were then tested independently or in combination with phage K against two S. aureus strains. Cytotoxicity of pleurotin in human cells was comparable to vancomycin and pleuromutilin. Results suggest that adding phage K has a synergistic effect and can lower the MIC for pleurotin, pleuromutilin, and vancomycin. This demonstrates that pleurotin could be a viable antistaphylococcal drug.

Glycerol, often considered a waste byproduct of biodiesel production, holds the potential for conversion into chemicals of varying economic value, such as dihydroxyacetone (DHA) and formic acid (FA). Hence, accurate identification and quantification of glycerol oxidation reaction (GOR) products are crucial for glycerol valorization research and practical deployment. High-performance liquid chromatography (HPLC) is the preferred analytical method for these purposes due to its proficiency in separating and quantifying components in liquid mixtures, even in the presence of diluted solutes. On the other hand, peak overlap in chromatograms, especially among glycerol, DHA, and FA, poses a notable challenge in the analysis of GOR products. This study introduces a quantification method aimed at resolving peak overlaps in HPLC analysis of GOR products. Initially, we examine the optical properties of glycerol and GOR products to identify optimal wavelengths for spectrophotometric HPLC analysis and detection. Subsequently, we propose an algebraic approach to resolve the peak overlap of glycerol, DHA, and FA using various detectors, including the refractive index detector (RID) and the variable wavelength detector (VWD). This method is applied to analyze the GOR products of undoped, nonco-catalyzed nanoporous BiVO₄ photoanodes, which have shown an intrinsic catalytic activity toward GOR products in previous studies.

The efforts to utilize microflow liquid chromatography hyphenated to tandem mass spectrometry (μLC-MS/MS) for deep-scale proteomic analysis are still growing. In this work, two-dimensional LC separation and peptide derivatization by a tandem mass tag (TMT) were used to assess the capability of μLC-MS/MS to reveal protein changes associated with the severe chronic anthracycline cardiotoxicity phenotype in comparison with nanoflow liquid chromatography (nLC-MS/MS). The analysis of the control and anthracycline-treated rabbit myocardium by μLC-MS/MS and nLC-MS/MS allowed quantification of 3956 and 4549 proteins, respectively, with 84% of these proteins shared in both data sets. Both nLC-MS/MS and μLC-MS/MS revealed marked global proteome dysregulation in severe anthracycline cardiotoxicity, with a significant change in approximately 55% of all detected proteins. The μLC-MS/MS analysis allowed less compressed and more precise determination of the TMT channel ratio and correspondingly broader fold-change protein distribution than nLC-MS/MS. The total number of significantly changed proteins was higher in nLC-MS/MS (2498 vs 2183, 1900 proteins shared), whereas the opposite was true for a number of significantly changed proteins with a fold-change cutoff ≥ 2 (535 vs 820). The profound changes concerned mainly proteins of cardiomyocyte sarcomeres, costameres, intercalated discs, mitochondria, and extracellular matrix. In addition, distinct alterations in immune and defense response were found with a remarkable involvement of type I interferon signaling that has been recently hypothesized to be essential for anthracycline cardiotoxicity pathogenesis. Hence, μLC-MS/MS was found to be a sound alternative to nLC-MS/MS that can be useful for comprehensive mapping of global myocardial proteome alterations such as those associated with severe anthracycline cardiotoxicity.

Ternary metal oxides, known for their superior electrical and optical properties compared to binary or conventional oxides, hold significant promise for catalysis and energy storage applications. This study investigates the electrochemical performance of Ni_1–xMn_xCo₂O₄ nanoparticles for detecting acetaminophen in aqueous phosphate buffer solution. The cobaltite nanoparticles were obtained through a simple gel-combustion synthesis, and the sensors were characterized using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry. The anodic peak currents associated with acetaminophen oxidation were assessed by varying the scan rate of current–voltage cycles. Among the sensors tested, the one fabricated with Ni_0.5Mn_0.5Co₂O₄ nanoparticles as an active material exhibited the highest sensitivity of 38.2 μA cm^–2 mM^–1 and a detection limit of approximately 2 μM, demonstrating its potential for sensitive and efficient acetaminophen detection. Moreover, the sensors fabricated using these ternary oxide nanostructures demonstrate a rapid chronoamperometric response time of 35.4 s and a decay lifetime of 0.31 s, highlighting the fast detection capabilities of acetaminophen. The electrochemical oxidation mechanism of acetaminophen and the charge transfer characteristics at the electrode–electrolyte interface have been discussed.