ACS Omega最新文献

Piezoresistive pressure sensors have been prepared by the electrospinning of poly(vinylidene fluoride) (PVDF) containing graphene nanoplatelets (GNP) functionalized using 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIM(OTf)) ionic liquid (IL). Optical microscopy demonstrated that the functionalized GNP powder presented particles with a smaller lateral size. The obtained mats were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, differential scanning calorimetry, electrical resistivity using two and four probes, and electromechanical testing with up to 32 load–unload cycles. Functionalization with BMIM(OTf) resulted in a higher PVDF electroactive phase. Electrospun mats obtained without the IL displayed a signal comparable to noise, while mats obtained with the BMIM(OTf) functionalized GNP displayed a clear signal, indicating that the IL helped with the dispersion of GNP on the PVDF matrix. Electrospun mats containing 1.0%m functionalized GNP presented the best performance among the evaluated samples, presenting low hysteresis and a lower distribution of the read values especially in the working range of 0 to 250 kPa. The piezoresistive behavior of the sample was tested under 32 load–unload cycles, remaining stable. Higher ranges of axial load resulted in the rupture of the fibers and swift degradation of the piezoresistive signal under a high number of cycles. A simple load cell was assembled to demonstrate the capacity of the membranes to act as piezoresistive compressive sensors capable of detecting the pressing of a human finger and differentiating between applied weights.

A binary dimensionally stable anode Ti/TiO₂–RuO₂ electrode was used to abate the antibiotic oxytetracycline (OTC) (C₂₂H₂₄N₂O₉) in chloride water. The anode was prepared using the Pechini method and subsequently characterized by X-ray diffraction, scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM–EDS), and cyclic voltammetry (CV). The optimum values of the operational parameters affecting removal efficiency were determined using a 2 × 3 factorial design by screening j (6.0, 10, and 20 A m^–2) and pH (3, 6.5, and 10). The textural analysis revealed the formation of active oxides (RuO₂ and TiO₂ coating rutile-type P4₂/mnm, space group 136), with a cracked surface and good dispersion of metal components. A contour graph verified that the most suitable condition for contaminant degradation was 20 A m^–2 at a circumneutral pH of 6.5, resulting in approximately 97% degradation after 20 min of electrolysis according to pseudo-first-order reaction kinetics and the loss of the antibiotic activity of OTC. In addition, the results of oxidant formation and CV indicate that the best electrochemical activation of the anode to form Cl₂-active mainly depended on pH. Liquid chromatography–mass spectrometry (LC–MS) and density functional theory were employed to propose a reaction pathway for OTC degradation. Three byproducts with m/z 426, 256, and 226 were identified corresponding to the removal of amide and amine groups, which are susceptible sites to electrophilic attack by active chlorine species. The findings from this work stand out for prospective applications of anodic electrochemical oxidation to efficiently eliminate antibiotics with similar chemical structures in wastewater containing chlorides.

Many important thermodynamic calculations for aqueous systems are profoundly limited because ion specific interactions have not been understood. Here an alternative modeling paradigm with compelling advantages is presented based on fundamental insights regarding ion–ion interactions at higher electrolyte concentrations. We also show how an intense ongoing controversy regarding single ion activity coefficients (SIACs) can be resolved and how SIACs can be quantified in full thermodynamic compliance using an overlooked convention. SIAC values can in fact be determined unequivocally and compatibly from two independent types of measurement at trace concentrations. These developments promise important advances, especially in defining pH and modeling multicomponent aqueous systems.

Recent advancements in materials synthesis and processing technology, coupled with a deeper understanding of bone nanoscale structure and biology, have provided new avenues for designing bioactive materials in bone tissue regenerative medicine. This Review focuses on the design and application of polydopamine-modified polycaprolactone scaffolds loading metal nanoparticles for bone tissue engineering. We explore their antibacterial properties and their ability to guide cell behavior. Specifically, we discuss the synthesis techniques, protein deposition, morphology variations, and interactions with the extracellular matrix of these scaffolds and biocompatibility and efficacy in promoting bone tissue regeneration in vitro and in vivo. Challenges and unmet needs are reviewed in the development of polymer- and metal-based materials for bone tissue engineering.

Nanodiamonds (NDs) are used more frequently as drug carriers through absorption or chemical modification. In this report, we describe the chemical binding of metal β-diketonato complexes onto the ND surface using an aminosilane linker. The metals used were iron(III) and copper(II), with β-diketones, acetylacetone, trifluoroacetylacetone, and the naturally occurring curcumin, which is known for its biological activity. Improved cytotoxicity was observed with metal complexes bound to the drug carrier compared to the free metal complexes as a result of increased stability when bound to a carrier. The curcumin-containing copper(II) conjugate demonstrated an IC₅₀ of 1.85 μM against the HeLa cell line and showed no toxicity in a larval zebrafish bioassay.

LC-HRMS/MS analysis facilitated the precise targeting, isolation, and identification of unusual dimeric diarylheptanoids from Alpinia officinarum (A. officinarum). The tandem MS data for (4E)-1,7-diphenyl-4-hepten-3-one (7) revealed fragment ions at m/z 91, 105, and 117, which are fragmentation patterns specific to diarylheptanoids. In the tandem MS data, peaks with m/z values ranging from 450 to 600 that exhibited these specific fragment ions were selected and isolated. Consequently, two previously undescribed dimeric diarylheptanoids (1 and 2) and four unusual diarylheptanoids (3–6) along with 10 monomeric diarylheptanoids (7–16) were isolated from the rhizomes of A. officinarum using various chromatographic techniques. The structures of the isolates were elucidated by an analysis of 1D/2D NMR and HRESIMS data, and a combination of DP4+ probability analysis and ECD calculations. To evaluate the anti-inflammatory effects of the isolated compounds, their inhibitory activity against nitric oxide production in LPS-induced RAW 264.7 cells was assessed. Compounds 1, 7, and 9 exhibited remarkable inhibitory effects with IC₅₀ values of 14.7, 6.6, and 5.0 μM, respectively.

The influence of the type of lamina and its combination on the reservoir quality in deep-sea shales of the Zigong Block in the southern Sichuan Basin was investigated. The shale reservoirs in the Wufeng and Longmaxi Formations were characterized in detail by employing a variety of advanced techniques such as full-scale thin section imaging, micro-X-ray fluorescence spectroscopy (Micro-XRF), field emission scanning electron microscopy, and a quantitative mineral evaluation system (QEMSCAN). This study systematically analyzed the structural characteristics of different types of lamina and their effects on the reservoir porosity, permeability, and gas content. The findings reveal that the type and combination of laminae significantly affect the reservoir quality of shale. Among the identified combinations, the “authigenic quartz–organic matter + carbonate + felsic–carbonate” lamina combination demonstrates the most favorable characteristics, with higher organic content, brittle mineral content, and porosity, making it the optimal “sweet spot” for shale gas development. This research provides crucial theoretical insights into the formation mechanisms of deep marine shale gas reservoirs and supports further advancements in shale gas exploration and development.

The previous step before the catalytic activity of MoS₂ nanoparticles for the hydrodesulfurization of dibenzothiophene (DBT), i.e., the DBT adsorption, is studied through dissipative-particle-dynamics (DPD) simulations. Density-functional-theory (DFT) calculations reveal that although DBT is chemisorbed, and, therefore, there is an intermolecular electronic exchange leading to the weakening of the DBT’s C–S bonds, the formed individual linking bonds among DBT and MoS₂ are noncovalent, fact that allows the application of DPD in order to at least qualitatively estimate the fraction of the content of DBT molecules within an oleic solvent that can be adsorbed by the MoS₂ nanoparticles. With the sake of getting realistic insights, we calculated the classical-DPD interaction parameters through the quantum-statistical approach conductor-like screening model for real solvents. A comparison between DFT calculations and the DPD simulations reveals that the quantum spontaneous attraction of DBT by MoS₂ nanoparticles begins at the distance where the DBT’s volumetric density in the neighborhood of a MoS₂ nanoparticle is maximum, as well as that the alkylic chain of the oleic solvent has an important influence on the performance of the catalyst since the chain length increases the probability that DBT will find MoS₂. These results suggest the combined DFT and DPD study can be useful for the design of HDS catalysts.

Nanoparticle-stabilized foams can overcome the problem that conventional foams are easy to defoam in complex reservoirs, thereby losing foam function and seriously affecting foam profile control and flooding effect. However, the oil displacement characteristics and effects of the nanoparticle-stabilized foam in cores with different permeabilities directly determine its application prospects. The nuclear magnetic resonance (NMR) visualization technology was combined with the traditional foam displacement method in this paper, with the nanoparticle-stabilized foam system and oil as the displacement medium and the displaced medium, respectively, and the core as the carrier to physically simulate the process of the nanoparticle-stabilized foam flooding oil. The oil displacement characteristics of the foam are visually observed by the NMR images, and the average size change of the pores where the fluid is located and the quality change of the fluid in the core are reflected by the T₂ spectrum to further study the visual profile control and displacement characteristics of the nanoparticle-stabilized foam in the core with different permeabilities.