RSC Advances最新文献

Replicating the intricate architecture of the extracellular matrix (ECM) is an actual challenge in the field of bone tissue engineering. In the present research study, calcium alginate/cellulose nanofibrils-based 3D printed scaffolds, double-reinforced with chitosan/polyethylene oxide electrospun nanofibers (NFs) and graphene oxide (GO) were prepared using the 3D printing technique. The porous matrix was provided by the calcium alginate, while the anisotropy degree and mechanical properties were ensured by the addition of fillers with different sizes and shapes (CNFs, NFs, GO), similar to the components naturally found in bone ECM. Surface morphology and 3D internal microstructure were analyzed using scanning electron microscopy (SEM) and micro-computed tomography (μ-CT), which evidenced a synergistic effect of the reinforcing and functional fibers addition, as well as of the GO sheets that seem to govern materials structuration. Also, the nanoindentation measurements showed significant differences in the elasticity and viscosity modulus, depending on the measurement point, this supported the anisotropic character of the scaffolds. In vitro assays performed on MG-63 osteoblast cells confirmed the biocompatibility of the calcium alginate-based scaffolds and highlighted the osteostimulatory and mineralization enhancement effect of GO. In virtue of their biocompatibility, structural complexity similar with the one of native bone ECM, and biomimetic mechanical characteristics (e.g. high mechanical strength, durotaxis), these novel materials were considered appropriate for specific functional needs, like guided support for bone tissue formation.

Fluorinated colorless transparent polyimide (CPI) films are crucial for flexible displays and wearable devices, but their development is limited by high costs and relatively low mechanical properties. In this study, a series of colorless transparent polyimide films was synthesized by incorporating the cost-effective ether-containing diamine, 4,4′-isopropylidenediphenoxy bis(phthalic anhydride) (BPADA), into commercially available 4,4′-(hexafluoroisopropyl)diphthalic anhydride (6FDA) and 2,2′-bis(trifluoromethyl)benzidine (TFMB). The comprehensive properties of the films were systematically investigated using a combination of experimental and numerical methods, including molecular dynamics (MD) simulations and density functional theory (DFT). This study focuses on exploring the influence of varying dianhydride ratios on the aforementioned properties. The incorporation of BPADA in the dianhydride significantly enhances the mechanical properties and flexibility of the film. When the ratio of ether anhydride to fluorine anhydride is 4 : 6 (CPI-4), the tensile strength is 135.3 MPa, and the elongation at break is 8.3%, which is 109.6% and 118.45% higher than that of the original film without ether anhydride. This research provides valuable insights for the future application of new polyimide materials in flexible display devices.

Integration of molecular photocatalysts into redox-inert polymers constitutes a path towards photocatalytically active, lightweight materials. In particular, electrospun polymer fibers hold potential due to their favorable surface-to-volume ratio and their straightforward fabrication. This study focuses on the polyacrylonitrile (PAN) fibers, into which the prototype photosensitizer (PS) ruthenium tris(bipyridine) [Ru(bpy)₃]²⁺, has been embedded by electrospinning. Studying the interaction between the optically excited [Ru(bpy)₃]²⁺ with a non-redox inert solvent within the nanofibers, we resolve a distribution of microenvironments, which differ by the extent to which the photosensitizer is exposed to the solvent. This results in a non-exponential decay of the complex's emission and pronounced differences in the transient absorption signals.

Organic fluorophores exhibit pressure-dependent behaviors that are often irregular and contingent upon the specific system. Elucidating how pressure influences these behaviors is essential for the accurate design of piezochromic materials. Here, we conducted an exhaustive theoretical analysis of the excited-state decay processes of crystalline 2,3,4,5-tetraphenylthiophene (TPT) at high pressure through a combined quantum mechanics and molecular mechanics (QM/MM) method. The study revealed that the fluorescence quantum yield experiences a pronounced initial increase owing to the decrease of nonradiative decay IC rate (k_ic). The suppression of low-frequency modes results in the decrease of λ_e, and then reduces the electron-vibration couplings, and finally slows down the non-radiative process. Our research provides detailed mechanism analyses on PIEE properties of solid state TPT, aiding the rational design of advanced PIEE materials.

Using a bio-guided isolation on the Vietnamese lichen Usnea baileyi based on alpha-glucosidase inhibition, eleven compounds were isolated and structurally elucidated, namely, protocetraric acid (1), 8′-methylstictic acid (2), stictic acid (3), 4,6-diformyl-8-hydroxy-3-methoxy-1,9-dimethyl-11-oxo-11H-dibenzo[b,e][1,4]dioxepine-7-carboxylic acid (4), vicanicin (5), norstictic acid (6), diffractaic acid (7), barbatic acid (8), atranol (9), 5-chlorohaematommic acid (10), and eumitrin A1 (11). Their chemical structures were identified by extensive 1D and 2D NMR analysis and high-resolution mass spectroscopy and compared with those reported in literature. Protocetraric acid (1) and norstictic acid (6) were selected for further modification to derive new compounds, namely, 1a–1e and 6a. Both isolated and synthesized compounds were assessed for their alpha-glucosidase inhibitory activity. Compounds 1–6, 1a–1e, 6a, and 11 showed significant alpha-glucosidase inhibition with IC₅₀ values ranging from 10.4 to 130 μM. Molecular docking was applied to the most active compounds 1–3, 6, 1a–1e, and 6a to clarify the inhibitory mechanism. Compound 1e was determined to be a mixed inhibitor through a kinetic study.

Convection and diffusion are key pathways for the migration of total petroleum hydrocarbons (TPH) and heavy metals (HMs) from soil to groundwater. However, the extent of their influence on pollutant migration, as well as the nonlinear relationships between these processes and pollutants, remains unclear. This study investigates the spatial distribution of TPH and HMs at a petrochemical site with complex hydrogeological conditions in southwestern China. In addition, machine learning (ML) was used to assess the effects of convection and diffusion on pollutant migration at the soil–groundwater interface. The analysis identifies and reveals TPH, Co, and Ni as the primary pollutants, with soil concentrations reaching 47.427, 7.024, and 4.766 times their respective screening values. Among various ML models, Random Forest (RF) was identified as the most effective, based on R², and RMSE performance metrics. The RF model demonstrates that the concentrations of TPH and As are closely related to soil depth. Furthermore, importance indices calculated by RF indicate that the significance of convection and diffusion varies across different soil–groundwater systems. Specifically, at the soil–perched water interface, convection plays a more significant role than diffusion in influencing the migration of TPH and As. However, at the soil–pore water interface, diffusion more significantly influences the migration of all pollutants compared to convection. Additionally, a threshold or saturation effect was observed for the impact of the convection factor on pollutant concentrations in groundwater. These findings highlight the distinct roles of convection and diffusion across various water interfaces, providing new insights into the mechanisms governing contaminant migration and fate.

Research on energy storage devices has focused on improving asymmetric supercapacitors (ASCs) by utilizing two different electrode materials. In this work, we have successfully prepared a unique material, ZnO/SnO₂ nanoflower, via the hydrothermal method. Graphene oxide (GO) was synthesized by applying the modified Hummers' technique. The ZnO/SnO₂ nanoflower was deposited on a polypyrrole (PPY) nanotube/graphene oxide composite (ZS/GP) in two steps: in situ chemical polymerization, followed by a hydrothermal method. Electrochemical properties of the prepared material nanocomposite were analyzed by applying cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. An asymmetric supercapacitor (ASC) was constructed using ZS/GP nanocomposite as the positive electrode and Caesalpinia pod-based carbonaceous material as the negative electrode material, and its performance was investigated. As a result, the fabricated ASCs were found to have an excellent specific capacitance of 165.88 F g⁻¹ at 1.4 V, with an energy density of 5.12 W h kg⁻¹ and a power density of 2672 W kg⁻¹. The prepared nanocomposite material for the ASC showed a cycle stability of 17k cycles at a current density of 5 A g⁻¹. This study revealed that the electrode material ZS/GP nanocomposite is highly suitable for supercapacitor applications. The ASC device's extended cycle life experiments for 17k cycles produced a coulombic efficiency of 97% and a capacitance retention of 73%, demonstrating the promising potential of the electrode materials for greener as well as efficient energy storage applications while converting abundant bio waste into effective energy.

Pollution from heavy metal ions has become a major issue worldwide. Water pollution, particularly with heavy metals like mercury, is a global problem. Developing environmentally friendly, low-cost, high-efficiency, sensitive, and selective sensors for the detection of mercury(II) ions in aqueous environments has attracted great interest in industry and academia. In this research paper, a bodipy-functionalized magnetic fluorescent MSp-TAB hybrid material was developed for detecting mercury(II) in aqueous media. The magnetic fluorescent MSp-TAB hybrid material was characterized using FT-IR, SEM, EDX, XRD, and TGA. We studied the influence of diverse factors such as contact time, temperature, and pH on the detection of Hg(II). The fluorometric study demonstrated that the developed magnetic-fluorescent hybrid material was sensitive/selective for Hg(II) ions in the absence and presence of interfering ions with a limit of detection (LOD) of 2.72 μM. In conclusion, the developed magnetic fluorescent MSp-TAB hybrid material has demonstrated its applicability and potential for accurate, sensitive, and practical detection of Hg(II) in tap water samples.

A new double perovskite phase, Sr₂(Sn_0.33Sb_0.33In_0.33)₂O₆, was successfully synthesized via a solid-state reaction and comprehensively characterized using both experimental and theoretical techniques. Powder X-ray diffraction was used to determine the crystal structure, while scanning electron microscopy (SEM) revealed a high degree of densification and uniform grain distribution across the ceramic. Raman and Fourier-transform infrared (FTIR) absorption spectra of the powder present broad bands predominantly due to different stretching modes of the various SnO₃²⁻, InO₃²⁻ and SbO₃²⁻ octahedra in the region ν = 400–800 cm⁻¹. An analysis of the UV-Vis diffuse reflectance spectrum shows excellent optical transparency and gives an estimation of an optical gap E_g ∼ 3.6 eV on bulk Sr₂(Sn_0.33Sb_0.33In_0.33)₂O₆, making this material a promising candidate for optoelectronic devices. Density Functional Theory calculations further validated the experimental findings, confirming the crystal structure and providing insight into the electronic and vibrational properties. Impedance spectroscopy revealed non-Debye dielectric relaxation and confirmed typical negative temperature coefficient of resistance (NTCR) behavior, underscoring the material's potential for temperature-sensing applications. The primary conduction mechanism, modeled as correlated barrier-hopping (CBH), was complemented by an Arrhenius-type process with activation energies of 0.33 eV and 0.9 eV across two distinct temperature ranges.

CRISPR/Cas has been explored as a powerful molecular scissor that uses a double-strand break mediated non-homologous end joining (NHEJ) or homology-directed repair (HDR) to achieve precise gene editing. Cas effectors come in several different forms, each with its own set of features and applications. SpCas9 was the first and most extensively studied CRISPR/Cas version, and it has been hailed as a biotechnology breakthrough that could potentially correct mutations to treat genetic diseases. Recently, the Cas12 and Cas13 effector variants of Class II, Type V and Type VI, have been explored for their specific collateral cleavage (trans-cleavage) activity on target recognition. This trans-cleavage activity helps in the recognition of target nucleic acids. CRISPR diagnostics technology utilized the binding of crRNA with Cas12/13 protein to form the Ribonucleoproteins (RNPs) complex, which further cleaves the target sequence in cis-cleavage, followed by the activation of trans-cleavage of a nonspecific fluorescent DNA/RNA probe, resulting in the production of a fluorescent signal that could be quantitatively recorded. Later, nanotechnology and mobile-based detection applications were incorporated into the system to develop advanced lateral flow-based strips and are also associated with the technology to make it more feasible. Overall, this review compiles the experimental evidence consolidating the application of CRISPR/Cas as next-generation biosensors for diagnostic applications.