ACS Omega最新文献

This study examines the conformation of soluble poly(vinyl alcohol) (PVA) in aqueous solution using small angle X-ray scattering (SAXS), dynamic light scattering (DLS), and atomic force microscopy (AFM). The focus is on PVA grades used in industrial water-soluble detergent films, comparing their behavior to nanometer-sized polystyrene (PS) beads. SAXS analysis indicates that soluble PVA chains adopt a single molecule random Gaussian coil conformation with a radius of gyration (R_g) of approximately 14 nm, consistent across various grades, dissolution temperatures, and water hardness. DLS corroborates this single-molecule behavior, and AFM imaging confirms separated PVA chains. SAXS, DLS, and AFM collectively enhance understanding of PVA’s behavior in solution. They provide distinguishing features (e.g., SAXS form factors, q^–4 decay, q^–2 decay; SAXS- and DLS-derived R_g/R_h ratio, AFM images) to aid in visualizing and differentiating between water-soluble polymers and micro- or nanoplastic polymers, which exhibit a hard interface. The study concludes that soluble PVA grades used in the detergent films maintain a stable single molecular chain conformation in water with a nonsolid interface, hence very different from known microplastics. This study also provides a basis for a methodology to differentiate the behavior of water-soluble polymers from microplastics.

Developing highly active catalysts for quinoline hydrogenation is crucial for efficient hydrogen carrier technologies and clean fossil fuel hydrodenitrogenation. In this work, we employed Tensor Algebra-based 3D-Geometrical Molecular Descriptors (QuBiLS-MIDAS) to develop Quantitative Structure–Property Relationship (QSPR) models predicting the initial rate of homogeneous quinoline hydrogenation catalyzed by transition metal complexes of Ru, Rh, Os, and Ir. A data set of 32 catalytic precursors was used: 25 for model training (training set) and 7 for external validation (testing set). Multiple linear regression analysis yielded a model with good predictive ability for the training set (R² = 0.90) and satisfactory external validation for the testing set (Q_EXT² = 0.86). The model’s descriptors highlighted the importance of hardness, softness, electrophilicity, and mass in predicting catalytic activity. The virtual screening revealed that Rh and Ir complexes with π-acidic ligands (e.g., olefins, diolefins, and η⁵-Cp) and nitrile ligands exhibited the highest predicted catalytic activity, suggesting potential for further improvement through ligand structural modification. Notably, iridium complexes, particularly those with tri(cyclopropyl)phosphine ligands, demonstrated significant potential for hydrogen storage, transport, and production, underscoring their relevance in sustainable energy systems. These findings demonstrate the potential of the QuBiLS-MIDAS approach for in silico design of efficient catalysts for quinoline hydrogenation processes.

Cirrhosis, characterized by liver fibrosis and structural remodeling, is a leading cause of liver cancer. The Fuzheng Huayu formula (FZHY) has been approved for treating liver fibrosis in China since 2002, but its effects and mechanisms on cirrhosis remain largely unknown. This study employed network pharmacology, molecular docking, and in vitro experiments to elucidate the specific mechanisms of FZHY against liver cirrhosis. First, intersecting genes between FZHY and cirrhosis were obtained from the Chinese Medicine System Pharmacology Database, the Swiss Target Prediction online platform, UniProt, GeneCards, DisGeNET, and OMIM. The STRING database was used to construct a protein–protein interaction network. Subsequently, Gene Ontology functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed, followed by molecular docking analysis to verify binding affinities between active ingredients and candidate targets. These analyses provided a theoretical basis for subsequent experimental research. Finally, we identified 117 FZHY target genes associated with cirrhosis and constructed a drug–component–target–cirrhosis-pathway network. Enrichment analysis revealed the AGE-RAGE signaling pathway in diabetic complications as a key pathway. Molecular docking showed that Isotanshinone II had the highest affinity for CHUK, IKBKB, and MAPK14. In vitro experiments demonstrated that Isotanshinone II dose-dependently reduced the mRNA expression of COL1A1 and α-SMA, as well as the protein levels of MAPK p38, IKKβ, and NF-κB p65 in LX-2 cells. These results revealed the underlying mechanism by which Isotanshinone II in FZHY inhibited LX-2 cell activation and collagen production through suppression of the MAPK/NF-κB signaling pathway. These findings support Isotanshinone II as a promising compound for cirrhosis targeting the MAPK/NF-κB pathway. Further research is warranted to explore the bioavailability of Isotanshinone II and to optimize its structure for clinical applications.

In the present work, poly(vinylidene fluoride) (PVDF) hollow fiber membranes were obtained using adipic acid as an additive in dope solution. The PVDF hollow fibers produced were used in the gas–liquid membrane contactor process, aiming at CO₂ capture. The morphology of PVDF hollow fibers was also characterized by scanning electron microscopy and helium ion microscopy (HIM). These techniques, mainly HIM, allowed us to clearly observe the presence of nanopores at the outer membrane surface, which may favor the process efficiency by preventing membrane wetting. The hollow fiber membranes were also characterized by helium picnometry, gas permeation, and the contactor membrane process. In the performance tests for CO₂ removal, the number of fibers and length of the PVDF hollow fibers were taken into account, since in-house modules were also compared to commercial ones. From these experiments, it could be seen that PVDF hollow fibers exhibited better performance of the CO₂ flux than commercial polypropylene hollow fibers.

Kinetic hydrate inhibitors (KHIs) are chemical substances that prevent gas hydrate plugging of oil and gas production flow lines. The main ingredient in a KHI formulation is one or more water-soluble amphiphilic polymers. We recently presented the first results on the KHI performance of a new class of amphiphilic polymers, namely, poly(2-dialkylamino-2-oxazoline)s, which showed good potential as KHIs. In this work, this class of novel KHIs has been investigated in more detail using both structure I and structure II hydrate-forming gases to optimize the polymer structure for best performance and with higher cloud point temperature for wider field applications. All polymers were tested in high-pressure rocking cells using the slow (1 °C/h) constant cooling test method. The best poly(2-dialkylamino-2-oxazoline)s tested at 2500 ppm contained 5-membered and 6-membered heterocyclic pendant groups and performed similarly to a commercial KHI polymer, poly(N-vinyl caprolactam) (PVCap), with both gases and with higher cloud point temperature (T_CP) than PVCap, thereby expanding the workability temperature range. The effect of salinity on KHI performance has also been studied, along with high flash point glycol solvents as synergists in combination with the best performing polymers. The onset temperature using the 2500–5000 ppm polymer could further be lowered by about 2–3 °C by the addition of 5000 ppm butylated glycol ethers. Hence, this work demonstrates the broader potential of poly(2-dialkylamino-2-oxazoline)s as KHIs.

Aqueous organic redox flow batteries (AORFBs), exploiting the reversible redox properties of aqueous soluble organic species to store energy, have been considered as a favorable large-scale and long-term energy storage technology for the deployment of renewable energy. Viologen-based species have been demonstrated as excellent negolyte candidates for AORFBs by virtue of their high water solubility, good electrochemical stability, and diverse molecular structure tunability. However, most viologen derivatives display one-electron redox during operation, limiting the output voltage, power, and energy density of AORFBs. Only a couple of reported viologen derivatives could take full advantage of two-electron reversible redox processes, which are mainly enabled by extending the conjugation skeleton of bipyridinium within viologen, demanding multistep synthesis that is detrimental to mass production. In this context, we proposed the 3-(triethylammonio) propyl viologen tetrachloride (BTMEP-Vi) as a negolyte for AORFBs, which could be acquired via a two-step synthesis from a cost-effective raw material with an acceptable yield. BTMEP-Vi demonstrates a water solubility of 2.56 M and possesses two electron-reversible redox processes at −0.34 and −0.70 V vs standard hydrogen electrode, respectively. A flow battery assembled with BTMEP-Vi displayed a high voltage of 1.50 V and a power density of 168.68 mW cm^–2. Additionally, we investigated the cycle stability and discussed the possible reasons causing capacity fade of the assembled AORFBs and proposed a possible degradation mechanism of BTMEP-Vi.

ESKAPE pathogens are responsible for complicated nosocomial infections worldwide and are usually resistant to commonly used antibiotics in clinical settings. Among these bacteria, vancomycin-resistant Enterococcus faecium and methicillin-resistant Staphylococcus aureus are the two most important Gram-positive pathogens for which alternative treatments and preventions are urgently needed. We previously designed a multipresenting antigen, embedding the main epitope displayed by the AdcA protein of E. faecium, that conferred protection against different Gram-positive pathogens both in passive and active immunization models. Here, we developed a new presentation strategy for this epitope, the EH-motif, based on a self-assembling peptide. Self-assembling peptides have been promising in the fields of material sciences, nanoscience, and medicine and have also potential in vaccine development, as they allow multiple presentations of the epitope and provide an ideal size for production and application. We show that this multipresenting peptide, here Q11-EH, forms stable fibers of nanometric size. We also demonstrate that antibodies raised against Q11-EH mediate the opsonic killing of a wide spectrum of Gram-positive pathogens, including E. faecium, S. aureus, and E. faecalis. Our data indicate that multiple presentation strategies are a potent tool for vaccine antigen improvement and point to Q11-EH as a promising antigen for the development of novel cross-protective vaccines.

Cancer is a major contributor to global morbidity and mortality. Among the different forms of cancer, colorectal cancer (CRC) is the third most frequently diagnosed cancer in men and the second most common cancer type in women globally. We aimed to explore the possible synergistic anticancer potential of curcumin (Cur) and plumbagin (PL) in the human colon cancer cell line (HCT-116). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)/cytotoxicity assay revealed IC₅₀ values of 7.7 and 7.5 μM for Cur and PL, respectively, as a separate entity. However, the combined treatment of Cur + PL significantly enhanced the cancer cell growth inhibitory potential compared with solitary treatments with an IC₅₀ value of 6.8 μM. The combined treatment also led to the induction of apoptosis by 41%, cell cycle arrest at the G2/M phase, while Bax and p53 genes were found to be upregulated and the Bcl-2 gene was downregulated compared to the untreated/solvent control. Furthermore, combined treatment elevated reactive oxygen species (ROS) production by 59% and resulted a decline in the mitochondrial membrane potential (MMP) compared to the control. Catalase and superoxide dismutase (SOD) activities were significantly reduced, leading to enhanced lipid peroxidation (LPO) and compromised membrane integrity, which were also confirmed by 4′,6-diamidino-2-phenylindole (DAPI) + propoidium iodide (PI) staining were also noted. Our in vitro data were further supported by molecular docking, which showed a higher binding energy of the proteins (Bax, Bcl-2, and p53) with Cur + PL. Overall, our findings highlight the potent synergistic effects of the Cur and PL combination, which can be exploited as a combination therapy for CRC.

Fungal infections remain a critical unmet medical need with millions of infections occurring annually. With only three classes of antifungal drugs available, drug resistance and modest activity toward some fungi represent threats to human health. To address this, optimization of the antifungal properties of approved drugs with appropriate pharmacokinetic properties represents an attractive strategy. Here, we have shown that the antifungal activity of phenothiazine-based CWHM-974 extends to include fluconazole-resistant Candida albicans, Candida auris, and Cryptococcus glabrata, filamentous molds such as Aspergillus fumigatus, Fusarium spp., and Rhizopus arrhizus, endemic human fungal pathogens Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides spp. Thus, phenothiazines (PTZs) have consistent antifungal activity toward a broad range of medically relevant fungi, including organisms that range from difficult to nearly impossible to treat with current drugs. Unfortunately, CWHM-974 did not exhibit in vivo efficacy in either Cryptococcus neoformans or C. albicans mouse infection models, necessitating an effort to optimize the scaffold further. Toward this end, synthesis and minimum inhibitory concentration (MIC) values are reported for 15 novel PTZ analogs to extend structure–activity relationships (SARs). Six analogs were identified as 2- to 4-fold more potent. Azaphenothiazines (aza-PTZs) were tolerated and resulted in potent antifungals with moderate reduction in lipophilicity and more facile chemical synthesis. One analog displayed modest selectivity improvement against the serotonin 5HT_2c receptor versus CWHM-974, but its overall selectivity profile versus a panel of other serotonin and dopamine receptors did not improve. Overall, the broad-spectrum antifungal activity and reduced neuroreceptor affinity of PTZ-based analogs encourages continued optimization to develop a novel antifungal therapeutic drug.

Recycling Mn compounds from spent alkaline batteries (SABs) not only follows the ongoing trend of circular economy but also conserves nature without disposal of hazardous battery wastes. Both pyrometallurgical and hydrometallurgical techniques were included to aim for a low-cost, environmental-contaminant-minimized, and mass-production process. The SAB-electrode powder mainly consisted of Mn(III) compounds by X-ray diffraction (XRD), together with ca. 6 wt % carbon by X-ray fluorescence (XRF). Heat treatment under N₂ gas was executed on the powder at a temperature from 650 to 950 °C for 2 h. At 950 °C, XRD revealed only crystalline MnO, yet other components were amorphous/nanocrystalline C- and Zn-based substances from XRF. Leaching the heated SAB powder was tried with stoichiometric volume +20 vol % excess of 2 M H₂SO₄ to receive MnSO₄ solution─the best leaching efficiency of 98%. The leachate was well-mixed with the stoichiometric KMnO₄ mass at 30, 60, or 90 °C for 1 h, giving the 99% yield SAB-MnO₂. SAB-MnO₂ was electrochemically tested (rate and long-cycling tests) as a Zn-ion battery (ZIB). Both tests show promising results: especially for the long cycling at 5 mA/g, good capacity retention of the ZIB using SAB-MnO₂ was recognized when the ZIB with commercial MnO₂ was a reference.