Search Results (30,883)

The Al-Sb co-doped SnO₂ composite thin films were prepared by the sol–gel spin-coating method. The structure, morphology, optical and electrical properties of the samples were investigated using XRD, XPS, SEM, UV-Vis spectroscopy, and Hall effect tester, respectively. It was found that when the aluminum doping amount was 15 at%, the resistivity of the sample was the lowest, and the overall optoelectronic performance was the best. Moreover, the Al-SnO₂ composite thin film transformed from an n-type semiconductor to a p-type semiconductor. When Al and Sb were co-doped, the carrier concentration increased significantly from 4.234 × 10¹⁹ to 6.455 × 10²⁰. Finally, the conduction type of the Al-Sb-SnO₂ composite thin film changed from p-type to n-type. In terms of optical performance, the transmittance of the Al-Sb co-doped SnO₂ composite thin films in the visible light region was significantly improved, reaching up to 80% on average, which is favorable for applications in transparent optoelectronic devices. Additionally, the absorption edge of the thin films exhibited a blue-shift after co-doping, indicating an increase in the bandgap energy, which can be exploited to tune the light-absorption properties of the thin films for specific photonic applications. Full article

The detection of zinc ions plays an essential role in protecting public health and maintaining ecological balance. However, traditional fluorescent probes for Zn²⁺ are limited in their specificity, especially under complex environments, due to their single-mode optical signal and inadequate recognization capacities. Herein we report a dual-mode supramolecular sensing system constructed from a unique three-component assembly involving a terpyridine platinum (II) complex, oxalate, and Zn²⁺, enabling highly specific detection performance for Zn²⁺. The supramolecular sensing system exhibits excellent selectivity among various interfering substances, accompanied by ultra-low detection limit (0.199 μM) and fast response (<3 s). The high recognization capacity comes from tri-component-based supramolecular assembly, while the dual-mode response arises from the generation of intermelcular Pt-Pt and π-π interactions, which yields absorption and emission originating from low-energy metal–metal-to-ligand charge transfer (MMLCT) transitions. This work marks a pioneering demonstration for highly specific detection of Zn²⁺ and inspires an alternative strategy for designing cation probes. Full article

In 2022, the building sector accounted for 30% of global energy demand and 27% of CO₂ emissions, of which approximately 9% came from building material production. To mitigate this impact, it is critical to develop sustainable alternatives that reduce the environmental footprint of construction materials. This paper presents an original study where the effect of coconut fibre as a reinforcing material in gypsum composites is analysed. These plant-based fibres reduce the composite’s density, improve thermal behaviour, and integrate circular economy criteria in construction. In this way, a physico-mechanical characterisation of these novel gypsum-based composites is addressed, and their potential application for developing prefabricated slabs is innovatively explored. Composites were prepared with coconut fibre incorporation in volume up to 17.5%, and mechanical and thermal properties and their behaviour under water action were evaluated. The results indicate that the fibre addition reduced density by about 10.0%, improved flexural strength by 20.5% and compressive strength by 28.4%, and decreased thermal conductivity by 56.3%, which increased the energy efficiency of the building facade by 7.8%. In addition, hydrophobic properties improved, reducing capillary absorption by 15.9% and open porosity by 3.3%. These findings confirm the technical feasibility of coconut fibre-reinforced plaster for application in prefabricated wall and ceiling elements, promoting the efficient use of natural resources and driving the development of sustainable building materials. Full article

The mechanical properties, capillary water absorption, drying shrinkage, and morphology of high-volume fly ash mortar were investigated. The mortar contained 0~2.5 wt. % nano-silicon dioxide (nano-SiO₂, NS) and 0~1.5 vol.% polyvinyl alcohol (PVA) fiber, with fly ash (FA) replacing 50% of cement by weight. The experimental results demonstrated that the synergistic incorporation of NS and PVA fiber significantly improved the mortar’s mechanical performance. At 7 days of age, the flexural and compressive strength of mortar containing 1.5% NS and 1.0% PVA fiber increased by 105.8% and 25.1%, respectively, compared to the control mortar (without NS or PVA fiber). Moreover, NS and PVA fiber significantly reduced the capillary absorption rate and drying shrinkage. The composite addition of 2.0% NS and 1.0% PVA fiber led to a notable reduction in drying shrinkage: at 7, 14, 28, 90, and 180 days, the drying shrinkage decreased by 38.3%, 33.3%, 30.0%, 31.6%, and 31.4%, respectively, relative to the control mortar. The scanning electron microscopy and mercury intrusion porosimetry results indicated that NS and PVA fibers effectively improved the micropore structure of the mortar. Full article

In this study, we aimed to investigate the occurrence of rare earth elements (REEs) in commonly consumed foods and assess the dietary exposure risks among different age groups in Zhejiang Province. The results showed that tea and shrimp had the highest REE detection rates, reaching 100%. Of all the food categories examined, tea exhibited the highest REE concentrations, significantly exceeding those in other foods. This may be attributed to differences in moisture content, root absorption mechanisms, and processing methods. The concentration pattern of REEs in all samples occurred in the following order: cerium > lanthanum > yttrium > neodymium > neodymium > scandium > praseodymium > gadolinium > dysprosium. The light REEs/heavy REEs (HREEs) ratio was consistently > 2 but remained lower than the ratios observed in the soil and sediments, indicating a potential risk of HREE enrichment. Dietary exposure assessments revealed that the total REE intake among Zhejiang residents was below the established safety threshold (51.3 µg/kg BW/day), with children experiencing the highest exposure (3.71 µg/kg BW/day), primarily due to their lower body weight. In the assessment of individual rare earth elements, Ce exposure in children aged ≤6 years exceeded the toxicological reference value. However, this threshold was established based on studies in pregnant and lactating populations and might not be directly applicable to young children. Therefore, overall dietary exposure to individual REEs remains within safe limits. REE exposure from tea consumption did not pose a health risk, even for habitual tea drinkers. These findings underscore the importance of continuous monitoring of REE accumulation in food and additional research on the potential long-term health effects, even though the current exposure levels of REEs are below the established safety limit. This is especially important considering the bioaccumulative nature of REEs and the limited paucity of toxicological data, particularly in vulnerable populations. Full article

The co-incorporation of green manure and rice straw is commonly used to increase rice yield and improve soil fertility in paddy fields. However, the effects on nutrient uptake and utilization of rice under the synergistic interaction mechanism in the Taihu Plain of the Yangtze River Delta remain unclear. Based on field experiments, this study investigated the effects of green manure with rice straw return (GMS) under different nitrogen (N) fertilization rates on rice yield, nutrient use efficiency, and soil fertility. The results revealed that green manuring significantly increased rice yield while improving the uptakes and use efficiencies of N, phosphorus (P) and potassium (K). Green manure (GM) with 40% N fertilizer reduction (GM_N60) maintained the grain and straw yields and nutrient uptakes compared to winter fallow with 100% conventional N application (WF_N100). The N recovery efficiency in GM_N60 reached 45.52%, increasing by 41.26% compared to WF_N100. Rice yield and K uptake in the GMS with 40% N fertilizer reduction treatment (GMS_N60) was 10,058 and 15.41 kg/hm², increasing by 14.43% and 9.43% compared to winter fallow with rice straw return and 100% conventional N (WFS_N100). The N, P and K agronomic efficiencies in GMS_N60 increased by 77.04%, 50.22%, and 50.22% compared to WFS_N100, respectively. These findings indicate that rice straw return enhances the fertilizer-saving and yield-increasing effects of GM, promotes rice K uptake and improves P and K use efficiencies. The GM treatment increased the soil organic matter (SOM), total potassium (TK), ammonium nitrogen (NH₄⁺-N) and nitrate nitrogen (NO₃⁻-N) contents. Among the soil fertility indicators, TK and SOM were the most important factors influencing rice yield and N uptake. In conclusion, GMS can maintain or increase rice yield with 40% N fertilizer reduction, improve nutrient use efficiencies, and increase the reuse of rice straw, thereby supporting green and efficient rice production in the southern Jiangsu paddy area. Full article

This work presents a theoretical and numerical investigation of a switchable tri-functional terahertz metamaterial incorporating vanadium dioxide (VO₂) and photosensitive silicon. The selective absorption, broadband linear-to-linear polarization conversion, and dual-band asymmetric transmission (AT) can be realized by utilizing the phase transition characteristic of VO₂. When VO₂ behaves as a metal, the proposed metamaterial functions as a selective perfect absorber for x-polarized waves at 2.84 THz, while exhibiting near-zero absorption for y-polarized waves. When VO₂ is in its insulating state, the proposed metamaterial acts as a linear polarization converter, achieving a polarization conversion ratio exceeding 99% within the frequency range of 1.07 to 4.29 THz. Meanwhile, a dual-band AT effect can be simultaneously realized associated with the broadband near-perfect polarization conversion. Furthermore, the polarization conversion efficiency and AT can be actively modulated by adjusting the conductivity of the photosensitive silicon, offering a novel approach for realizing multifunctional terahertz devices. Full article

This study evaluates the impact of gadolinium-based contrast agents (Omniscan, Dotarem, and Gadovist) on the performance of PAGAT gel dosimeters using spectrophotometric analysis. Dosimeters were infused with gadolinium at concentrations ranging from 0 to 40 mg/mL and irradiated with a 6 MV photon beam over a dose range of 0–15 Gy. Regarding dosimeter behavior, Dotarem exhibited an enhancement in optical density prior to irradiation due to polymerization reactions between the dosimeter and the contrast agent starting at 10 mg/mL, which compromised optical readings above 20 mg/mL. Omniscan consistently showed 37.7% lower sensitivity than standard PAGAT across all concentrations and dose levels. Conversely, Gadovist enhanced sensitivity by up to 50% at 20 mg/mL, with additional gains at higher concentrations, although accompanied by saturation at lower dose levels. Radiological analysis showed that all tested concentrations maintained mass energy–absorption coefficient differences below 1% and water-equivalence in effective atomic number within 5% at 6 MV. These findings underscore the importance of selecting an appropriate contrast agent to enhance gel dosimeter sensitivity, particularly in low-dose regions where measurement uncertainty increases. Additionally, gadolinium-infused PAGAT gels show strong potential for assessing dose enhancement phenomena. Their sensitivity, threshold behavior, and radiological properties suggest they may be suitable for applications in dose enhancement dosimetry as well as conventional clinical settings. Full article

A detailed description of the components of the CRD technique is presented and applied to the detection of organic esters. These molecules typically have a pleasant smell resembling the aroma of flowers and fruits and are responsible for many distinct odors in plants. They are emitted into the atmosphere by natural sources and human production. The weak absorption spectrum of the fifth vibrational overtone of ethyl, ethyl trimethyl, and tert-butyl acetate are recorded to show the sensitivity of the CRD technique. A description of a compact instrument to be used in the near-IR and visible regions will be presented for measurements of ester detection in the field. Potential chemical reactions of esters induced by visible light absorption in the atmosphere are discussed. Full article

This investigation of hydroxyl and polysiloxane absorption peaks in elastic polymer composites reveals significant spectral shifts within the fingerprint region of FTIR spectra. Using poly(vinyl butyral) (PVB) as the base polymer and poly(vinyl acetate) (PVAc) and poly(vinyl alcohol) (PVA) as reference materials, solvent effects on polymer–solvent interactions were systematically analyzed. Among the tested alcohol solvents, PEG 400 induced the most pronounced spectral changes, with the C=O stretching band shifting from 1740 to 1732 cm⁻¹ and the O–H band significantly broadening and downshifting to around 3300 cm⁻¹, reflecting strong hydrogen-bonding interactions. Wavelet-based noise reduction effectively enhanced the signal-to-noise ratio, reducing the baseline standard deviation by over 90%. This study introduces a novel noise-enhanced FTIR recognition model that integrates baseline noise metrics to improve detection sensitivity. The model successfully uncovers subtle structural variations in polymer–solvent systems that are typically masked by conventional FTIR techniques, advancing materials analysis and providing a robust framework for future FTIR-based diagnostics and material characterization. Full article

Silver nanoparticles (AgNPs) are known for their antimicrobial properties, and can be synthesized through various routes. We used both chemical synthesis and green synthesis from the biomass of black soldier larvae (Hermetia illucens). To test the antimicrobial potential of these nanoparticles, we employed an in vitro test, with CFU counting, and also used the worm Caenorhabditis elegans as an in vivo model. C. elegans were infected with Pseudomonas aeruginosa and treated with AgNPs from both syntheses. These AgNPs exhibited absorption spectrum peaks around 400 nm and sizes of 8 ± 3.5 (chemical) and 11 ± 4.7 nm (green). P. aeruginosa-infected worms, without treatment with AgNPs, achieved 100% mortality within 3 days, while AgNPs-treated worms survived until the end of the experiment, with no statistical differences compared to the non-infected worms of the control group. The results demonstrate that nanoparticles produced from H. illucens biomass have antimicrobial capacity, reducing bacterial growth in vitro and being able to protect C. elegans from infection by P. aeruginosa, similar to those produced by chemical synthesis. However, AgNPs from green synthesis are less harmful to the environment while maintaining their antimicrobial potential. Full article

Formononetin is widely used in anti-tumor research, but its poor water solubility leads to low absorption and poor utilization efficiency in vivo, limiting further development. The triphenylphosphine cation was partially attached to the 7-position hydroxyl group of formononetin to specifically target it into the mitochondria of tumor cells to enhance the anti-tumor effect. Detailed structural characterization via ¹H-NMR and ¹³C-NMR analysis confirmed the physical properties and chemical structures of 21 newly synthesized derivatives. The effects of these derivatives on tumor cells were assessed by in vitro and computational methods. MTT results from four tumor cell lines showed that formononetin derivatives containing triphenylphosphine had stronger anti-tumor activity than formononetin and exhibited more cytotoxic effects in cancer cells than in normal cells. In particular, the final product 2c (IC₅₀ = 12.19 ± 1.52 μM) showed more potent anti-tumor activity against A549 cells. It was also superior to formononetin and 5-FU. To identify the potential biological targets, the core-expressed gene SHMT2 in lung cancer mitochondria was screened using network pharmacology technology, and molecular docking analysis confirmed the stable binding of the end products to the amino acid residues of the core genes through the formation of hydrogen bonds and via other interactions. In addition, molecular docking simulations further confirmed that the end product exhibited excellent stability when bound to SHMT2. These results suggest that triphenylphosphine-containing formononetin derivatives are worthy of further exploration in the search for novel drug candidates for the treatment of cancer. Full article

The functional properties of proteins are closely related to their structure and conformation. The effects of glycosylation and pH on the structural and conformational changes in whey protein isolate (WPI) were investigated using multispectral technology. More and higher-molecular-weight molecules of WPI–dextran conjugates (WDCs) with increased degrees of glycosylation (DGs) in SDS-PAGE occurred at the expense of band intensities of α-lactalbumin, β-lactoglobulin, and bovine serum albumin. The higher wavenumber shift in FTIR peaks of WPI after glycosylation in the Amide I, II, and III regions and the decrease in its intensity occurred. The maximum absorption wavelength (λ_max) of UV-Vis spectra of WPI before and after glycosylation in the range of 260–290 nm showed no significant difference in a pH range of 2.0–10.0. Moreover, the UV-Vis absorption intensities of WDCs at λ_max around 278 nm were highly and positively correlated with their DGs. The λ_max and intensities of total intrinsic fluorescence spectra of Tyr and Trp residues in WDCs with an increase in DGs had an obvious redshift and decrease, respectively. Although the intensities of synchronous fluorescence spectra of individual Tyr or Trp residues in WDCs with an increase in DGs also gradually decreased, the λ_max of the former and latter had a blueshift and redshift, respectively. UV-Vis absorption and fluorescence spectroscopies indicated that the changes in the λ_max and intensity of WPI were closely related to the protonation states of carbonyl groups and free amino groups and the degree of glycosylation. This work may be beneficial for understanding the structural and conformational changes in proteins by measuring the microenvironment around Tyr and/or Trp residues in proteins using UV-Vis absorption and synchronous fluorescence spectroscopies, providing a promising technique for quantitatively monitoring the degree of glycosylation (DG) in a rapid and practical way without any chemical reagents using UV-Vis absorption spectroscopy. Full article

Alkali-activated recycled concrete powder-foamed concrete (ARCP-FC) is a new type of insulation architectural material, which is prepared using recycled concrete powders (RCPs), slag powders, fly ash, and sodium silicate. In this study, the influence of the water-to-cement (W/C) ratio, the Na₂O content, and the mineral admixture content on the mechanical strength, physical properties, and thermal conductivity of ARCP-FC were investigated. The results showed that the compressive strength and dry apparent density of ARCP-FC decreased with the increase in the W/C ratio. In contrast, the water absorption rate increased as the W/C ratio increased. Fewer capillaries were formed due to the rapid setting property, and the optimal W/C ratio was 0.45. The compressive strength and dry apparent density first decreased and then increased with the increase in Na₂O content. Too high Na₂O addition was not conducive to the thermal insulation of ARCP-FC, and the optimal Na₂O content was 6%. The compressive strength and dry shrinkage gradually decreased, while the water absorption gradually increased as the fly ash content increased. Fly ash improved deformation, and the pore was closed to the sphere, reducing the shrinkage and thermal conductivity. The optimal mixture of ARCP-FC consisted of 60% recycled concrete powders, 20% slag, and 20% fly ash. The density, porosity, compressive strength, and thermal conductivity of ARCP-FC were 800 kg/m³, 59.1%, 4.1 MPa, and 0.1036 W/(m·K), respectively. ARCP-FC solved the contradiction between compressive strength and dry apparent density, making it a promising building material for external insulation boards and insulation layers. Full article

Type 2 diabetes mellitus remains a critical global health challenge, driving the pursuit of novel therapeutic strategies. This study investigated the anti-diabetic efficacy of the peptide 1CBR, derived from sodium caseinate hydrolysate, administered orally at 25 mg/kg/day to db/db mice over a 4-week period. Glucose tolerance was evaluated via oral glucose tolerance tests (OGTT), while plasma dipeptidyl peptidase-IV (DPP-IV) activity, glucagon-like peptide-1 (GLP-1), and insulin concentrations were quantified using enzyme-linked immunosorbent assays (ELISA). Two bioactive peptides, GPFPLPD and APDSGNFR, were isolated and characterized, exhibiting half-maximal inhibitory concentrations (IC₅₀) of 99.12 µM and 73.07 µM for DPP-IV inhibition, respectively, and both significantly stimulated GLP-1 secretion in enteroendocrine cells in vitro. Pharmacokinetic analysis in Sprague–Dawley rats demonstrated oral bioavailability of 11.28% and 19.12% for these peptides, surpassing typical expectations for peptide-based agents. Collectively, these results provide compelling evidence that 1CBR-derived peptides exert glucose-lowering effects through the dual mechanisms of DPP-IV inhibition and GLP-1 stimulation, combined with favorable oral absorption profiles. These findings underscore the potential of 1CBR peptides as promising candidates for development into nutraceuticals or pharmaceutical agents for diabetes management. Full article