Search Results (2,964)

Conventional and emerging extraction methods for recovering phenolic compounds (PCs) from Pinus radiata bark were investigated for their potential use in bio-composites and bio-based biomaterial applications. To optimize the recovery process, a Response Surface Methodology (RSM) based on a Box–Behnken design was used to evaluate the effects of extraction time (20–100 min), temperature (20–80 °C), and water or ethanol-water solvent concentrations with β-cyclodextrin (βCD) or NaOH (0.5–1.5% w/v CD/db). Polyphenolic profiles of the extracts were characterized using Fourier transform infrared spectroscopy (FTIR), LC-LTQ-Orbitrap-MS, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to evaluate the thermal stability and degradation behavior of the powdered extracts. Antioxidant capacity (DPPH, FRAP, ABTS) and antibacterial activity against Escherichia coli and Staphylococcus aureus were assessed by spectrophotometric assays and the agar diffusion method, respectively. Highest extraction yields were obtained using alkaline extraction (14.32%) and ultrasound-assisted extraction (UAE) (13.86%), followed by ethanol extraction (12.74%). Minimum inhibitory concentration (MIC) for P-βCD was 0.04 mg/mL, and the minimum bactericidal concentration (MBC) was 0.32 mg/mL against S. aureus. These results suggest a strong inhibitory capacity at low concentrations and the potential incorporation of these extracts into bio-based antimicrobial biomaterials. Full article

Solid-contact ion-selective electrodes (SC-ISEs) are typically constructed using ion-selective membrane (ISM)-based configurations. However, such structures often suffer from water-layer formation and the weak mechanical stability of the ISM. Herein, we report an ISM-free K⁺-SC-ISE based on a Prussian blue analogue transducer, KMnFe(CN)₆, eliminating the need for a conventional ionophore-based ISM layer. KMnFe(CN)₆ was synthesized via a one-step citrate-assisted co-precipitation method. The material functions as a bifunctional transducer, in which the open framework structure with ion-transport channels enables selective K⁺ recognition, while the redox-active Mn centers facilitate ion-to-electron transduction. The fabricated KMnFe(CN)₆-based K⁺ sensor exhibits a near-Nernstian response with a sensitivity of 52.3 ± 1.0 mV dec⁻¹ and a rapid response time of 25 s. The linear range and limit of detection were determined to 10⁻⁴ to 10⁻¹ M and 5.8 × 10⁻⁵ M, respectively. The sensor also demonstrates selectivity to representative interfering ions, with log K_ij of −2.39 ± 0.12 (Na⁺), −2.86 ± 0.09 (Li⁺), −3.06 ± 0.09 (Ca²⁺), −2.74 ± 0.12 (Mg²⁺) and −0.95 ± 0.08 (NH₄⁺). By eliminating the ISM layer, the water-layer effect is effectively avoided, resulting in excellent long-term stability with a potential drift of 57.2 ± 6.1 μV h⁻¹ over 7 days. The sensor was further applied to the analysis of K⁺ in real lake water samples, where the measured concentration showed good agreement with ion chromatography results. This work provides an ISM-free SC-ISE strategy for ion analysis in water environments. Full article

Saxitoxin (STX) is one of the most potent natural neurotoxins known and is the only marine toxin to be declared a chemical weapon. In both marine and freshwater systems filter feeding organisms can accumulate saxitoxin and human consumption of toxin-contaminated food can result in paralytic shellfish poisoning. Here we highlight for the first time a functional cell-based assay for the detection of STX on an automated patch clamp (APC) system. We demonstrate that a human embryonic kidney (HEK) cell line expressing human Nav1.6 can rapidly and sensitively detect the presence of a range of sodium ion channel blockers including STX. The use of neutralising monoclonal antibody GT13-A and/or saxiphilin was found to confer specificity to the assay by being able to dissociate between STX (along with closely related analogues) and tetrodotoxin. Finally, the application of the functional assay for the detection of STX in complex samples was evaluated during an international exercise led by the Organisation for the Prohibition of Chemical Weapons (OPCW). The neutralisation of STX activity in blinded samples enabled the indirect detection of the toxin in the relevant samples and provided an alternative orthogonal technique to corroborate the findings of liquid chromatography–mass spectrometry (LC-MS). Collectively this work demonstrates the significant potential for functional assays in the analysis of samples suspected of being contaminated with STX and related sodium ion channel targeting toxins; complementing traditional direct identification methods such as high-performance liquid chromatography with fluorescence detection (HPLC-FLD), LC-MS or enzyme-linked immunosorbent assay (ELISA). Full article

The increasing demand for high-purity lead sulfide (PbS) for optoelectronic applications necessitates efficient methods to remove residual antimony sulfide (Sb₂S₃) from complex ores—a challenge due to their chemical similarity and fine intergrowth. This study presents a hybrid purification strategy combining vacuum distillation pretreatment with oxygen-free alkaline selective leaching. Thermodynamic analysis using Eh-pH diagrams revealed significant differences in the behavior of trace Sb₂S₃ and bulk PbS under alkaline conditions (pH 9–11), identifying a suitable window for selective dissolution. The process begins with mechanical ball milling to break Sb₂S₃ inclusions and improve reaction kinetics, followed by anaerobic leaching in a sealed reactor under inert atmosphere using a NaOH solution at a controlled potential (Eh 0.1–0.35 V vs. SHE). Multiple characterization techniques confirmed that Sb₂S₃ undergoes dissolution and conversion while the PbS phase remains intact. Notably, zeta potential measurements (−12.3 mV) and high conductivity (204 mS/cm) indicated the formation of a stable colloidal dispersion system favorable for interfacial reactions. Under optimal conditions, antimony removal exceeded 99% with lead loss below 1%. Overall, the proposed strategy offers a technically viable route to produce ≥99.9% pure PbS from polymetallic sources, addressing a longstanding separation challenge. Full article

Textile wastewater contains recalcitrant dyes and organic matter, requiring efficient, scalable treatment technologies. This study optimized an aluminum-based electrocoagulation (EC) process to maximize color removal (Y₁) and chemical oxygen demand (COD) reduction (Y₂) using synthetic textile wastewater (SWW), and evaluated the practical transferability of the optimized conditions using real textile wastewater (RTW). A rotatable central composite design (CCD) coupled with response surface methodology (RSM) was used to assess the effects of treatment time, NaCl concentration, and applied voltage on both responses. From a modeling perspective, the results reveal the coexistence of symmetric and asymmetric response behaviors; quadratic effects define locally symmetric regions around the optimum, while interaction terms introduce asymmetry due to coupled electrochemical phenomena. Under the optimized conditions (16.5 min, 2.9 g·L⁻¹ NaCl, 18 V), removal efficiencies reached 99% for color and 97% for COD reduction, with a specific energy consumption of 6.6 kWh·m⁻³ and sludge moisture content of 92–94%. To assess applicability beyond bench scale, the optimized voltage, current, and electrolyte concentration were applied to a 50 L batch of RTW collected from the final rinsing stage of a denim dyeing process. Treatment time was extended to 84 min to compensate for the lower current density at the larger scale; under these conditions, 95% color removal and 80% COD reduction were achieved. Full article

We propose a terahertz (THz) antenna-coupled wire-channel field-effect transistor—modified EdgeFET (m-EdgeFET), formed by combining single-gate FinFET and dual-side-gate EdgeFET concepts, which is used for THz detection. The proposed hybrid design was implemented on AlGaN/GaN high-electron-mobility transistor (HEMT) structures, demonstrating distinct response characteristics under 150 GHz and 300 GHz radiation at room temperature. The responsivity dependence on the channel length was determined, revealing that the peak responsivity reached up to 6.5 V/W at a gate voltage of −3 V, i.e., at a gate bias that is an order lower in magnitude than that required for EdgeFET to reach the maximum response. Meanwhile, the gate leakage current decreased by an order of magnitude (to about 1 nA) compared to a FinFET with similar geometry. The proposed geometry was shown to operate in two regimes: source-drain coupling (SD) and gate coupling (GG) of THz radiation with the transistor wire channel. The results confirm that the m-EdgeFET design is suitable for electrically controlled and fast THz detection. Full article

Foodborne bacterial contamination creates significant public health and economic challenges. In the United States, the CDC estimates that foodborne illness causes approximately 48 million illnesses and 3000 deaths annually. Rapid screening is important because conventional confirmation methods are time- and labor-intensive. Microscopy-based analysis of early bacterial microcolonies can enable detection within hours rather than days, yet manual inspection is slow, subjective, and impractical at scale. Although deep learning object detectors such as YOLO offer a promising solution, the impact of architectural design choices on microscopy-based bacterial detection has not been systematically characterized under controlled conditions. In this work, we conducted a controlled architectural evaluation of YOLOv8 for detecting bacterial microcolonies in high-resolution microscopy images. We replaced the CSP-Darknet backbone with EfficientNetV2 variants and evaluated three feature fusion designs: no neck, the original PAN-FPN neck, and a NAS-FPN-inspired neck. All experiments were performed under identical conditions on a two-class dataset of Salmonella and E. coli. Our results show that EfficientNetV2 architectures consistently outperform the YOLOv8x baseline, which achieved 0.891 precision, 0.867 recall, and 0.898 mAP@50. The best overall performance was obtained with EfficientNetV2-S and the original YOLOv8 neck, reaching 0.976 precision, 0.968 recall, and 0.987 mAP@50, with comparable performance of 0.986 mAP@50 achieved by EfficientNetV2-S + NAS-FPN. The highest precision was obtained with EfficientNetV2-L + NAS-FPN, reaching 0.978. These findings demonstrate that effective bacterial detection depends on the interaction between backbone capacity and feature fusion design rather than backbone scaling alone. Full article

Surface water quality, serving as a key link between domestic water use and agricultural production, impacts both the drinking water safety of local residents and the sustainable use of irrigated soil. To better protect water resources and enhance their sustainable value, this study collected 50 water samples from the areas surrounding Nansi Lake. Using the Piper trilinear diagram, Gibbs model, and ion ratio analysis, the main hydrochemical types were identified. Based on this, the entropy-weighted water quality index (EWQI) was used to evaluate the water’s suitability for drinking, while irrigation water quality indicators were applied to assess its suitability for irrigation. The results indicate that during both dry and rainy seasons, Na⁺ and SO₄²⁻ dominate the water, with average total dissolved solids (TDS) of 1279 mg/L and 1163 mg/L, respectively, indicating moderately elevated salinity. The ion concentrations follow the order: SO₄²⁻ > HCO₃⁻ > Cl⁻ > NO₃⁻ > F⁻ and Na⁺ > Ca²⁺ > Mg²⁺ > K⁺. From a hydrochemical perspective, mixed-type and Cl-Na-type waters prevailed in both seasons. The chemical composition of surface water in the study area is largely governed by rock weathering, with ions primarily originating from the dissolution of silicate and evaporite minerals. Furthermore, cation exchange processes play a significant role in shaping the evolution of the water chemistry. The water quality evaluation indicates that surface water in the study area is generally Class II, representing good water quality. However, Class IV and Class V water exist in some areas, where the primary exceedance parameter is SO₄²⁻, which is a key factor influencing water quality. Irrigation suitability is generally good. Systematic investigation of surface water hydrochemistry and quality is of great practical significance for ensuring safe drinking and irrigation water and promoting sustainable socio-economic development. Full article

In this study, a polyethylene glycol (PEG)-based solid electrolyte composite (PEG)₁₀LiClO₄/NaAlOSiO suitable for anodic bonding packaging was successfully fabricated via a combined ball milling and hot pressing process. The micromorphology, ion transport characteristics, and mechanical packaging properties of the composite were systematically investigated using characterization techniques including electrochemical impedance spectroscopy, X-ray diffraction, scanning electron microscopy, and anodic bonding performance tests. The results demonstrate that doping with NaAlOSiO molecular sieve can effectively reduce the crystallinity of the polymer matrix, construct more efficient carrier transport pathways, and simultaneously enhance the ionic conductivity and mechanical properties of the material. When the mass fraction of NaAlOSiO doping is 8 wt.%, the composite exhibits a room temperature ionic conductivity of up to 1.31 × 10⁻⁵ S·cm⁻¹. Under room temperature and a bonding voltage of 800 V, the sample with this doping ratio achieves the optimal anodic bonding with metallic Al, and the tensile strength of the bonding interface reaches 5.93 MPa, showing excellent application prospects in micro–nano-packaging. Full article

Native cellulose I can be converted into crystalline polymorphs II and III_I, while cellulose II can be further converted into III_II through chemical treatments that induce significant structural, physical, and chemical changes. Accurate identification and differentiation of these polymorphs is essential for predicting fiber reactivity and processing behavior, but current methods are time-consuming. This study demonstrates the potential of near-infrared hyperspectral imaging (HSI-NIR) combined with linear discriminant analysis as a rapid, non-destructive tool for polymorph discrimination. Cellulose I, II, III_I, and III_II were produced from bleached kraft pulps of eucalyptus and pine and from cotton linters using NaOH (20% w/v) and ethylenediamine treatments. HSI-NIR successfully differentiated polymorphs based on spectral signatures in the 1480–1600 nm range, regardless of botanical source. Complementary characterization by XRD confirmed polymorph conversions, showing crystallinity reductions of 10–15% for cellulose I→II and I→III_I conversions, with crystallite size decreasing from 7.2 nm (cotton CI) to 3.2–3.4 nm in all CIII_II samples. XPS analysis revealed increased C-O surface accessibility in cellulose II and III, with complete disappearance of COOH groups in cellulose III samples. These results establish HSI as a promising screening tool for cellulose polymorph identification (>95% classification accuracy) and provide comprehensive baseline data on structural and chemical transformations that govern fiber reactivity in chemical and enzymatic processes. Full article

Sodium-ion batteries (SIBs) represent a compelling alternative to lithium-ion batteries for grid-scale energy storage, owing to the high natural abundance and low cost of sodium resources, as well as their strategic alignment with national energy security priorities. Nevertheless, the sluggish Na⁺ diffusion kinetics and limited specific capacity of anode materials continue to impede practical deployment. Herein, nitrogen-doped carbon-coated TiO₂ nanofibers (TiO₂/C-N) were rationally engineered through a facile electrospinning route integrated with synergistic defect and coating engineering. The in situ-formed N-doped carbon shell establishes a continuous, high-conductivity electron-transport network while simultaneously buffering volumetric strain during repeated (de)sodiation, thereby preserving long-term structural integrity. Electrochemical assessments demonstrate that the TiO₂/C-N electrode delivers a reversible specific capacity of 233.64 mAh g⁻¹ at 0.1 A g⁻¹ (initial Coulombic efficiency 54.13%). Quantitative kinetic analysis reveals a pronounced pseudocapacitive contribution of 41.4% at 1.2 mV s⁻¹, confirming a surface-controlled Na⁺ storage pathway that markedly enhances rate capability. Moreover, the electrode retains 245.5 mAh g⁻¹ after 150 cycles at 1 A g⁻¹, underscoring exceptional cycling stability. This work elucidates the synergistic regulation of N-doped carbon coating and pseudocapacitive kinetics in TiO₂-based anodes, offering a robust design strategy for high-rate, long-cycle-life SIB anodes. Full article

In marine service environments, material surfaces inevitably suffer from wear damage, which can compromise the integrity of protective coatings and further affect their corrosion resistance. Therefore, investigating the post-wear corrosion resistance of coatings is of great significance. In this work, single-layer CrN coatings, CrAlN coatings, and CrN/CrAlN multilayer coatings were deposited on stainless-steel substrates by arc ion plating, and the microstructure, tribological properties, and corrosion behavior before and after wear were systematically investigated. Wear tests were performed under applied loads of 2.5 N and 5 N. The corrosion behavior in the unworn condition and the post-wear corrosion resistance condition was evaluated in a 3.5 wt.% NaCl solution. The results showed that all coatings exhibited a face-centered cubic (FCC) structure, while the CrN/CrAlN multilayer coating possessed the smallest average grain size (13.47 nm). Under applied loads of 2.5 N and 5 N, the CrN/CrAlN multilayer coating exhibited the lowest wear rate, indicating the best wear resistance. In the unworn condition, the CrN/CrAlN multilayer coating showed the lowest corrosion current density (2.74 × 10⁻¹⁰ A/cm²) and the most positive corrosion potential (0.025 V), demonstrating the best corrosion resistance. After wear under a load of 5 N, the CrN/CrAlN multilayer coating retained a low corrosion current density (3.35 × 10⁻¹⁰ A/cm²), in contrast to the marked increases observed for the single-layer coatings. The enhanced performance is considered to be mainly associated with the periodic heterogeneous interfaces in the multilayer structure, which help suppress crack propagation and prolong the penetration path of corrosive media. Full article

Loop-mediated isothermal amplification (LAMP) is a widely used nucleic acid detection method, but its application is often limited by the suboptimal performance of wild-type Bacillus stearothermophilus (Bst) DNA polymerase. This study employed a combined deep learning and semi-rational design strategy to engineer Bst DNA polymerase. High-throughput screening identified the A0A150MFP3 sequence and the L105M mutation, which increased enzymatic activity by 32.92%. Fusion with the CL7 protein generated a CL7-Bst mutant with enhanced thermal stability and tolerance to common inhibitors, including 7% (v/v) ethanol, 0.18‰ (w/v) SDS, 80 mmol/L NaCl, and 0.8 mmol/L EDTA. Systematic optimization of the LAMP reaction system determined the optimal pH (9.0), enzyme concentration (0.20 U/μL), and temperature (64 °C). When applied to Escherichia coli O157:H7 detection, the CL7-Bst mutant achieved Tt values of 15.13 and 12.78 for crude and purified DNA, respectively, with a limit of detection of 1 × 10³ CFU/mL. In summary, integrating deep learning with semi-rational design and fusion protein engineering yielded a high-performance DNA polymerase that facilitates rapid, sensitive, and field-deployable LAMP-based pathogen detection. Full article

Wastewater surveillance emerged as a critical public health tool during the COVID-19 pandemic, enabling early detection of community-level pathogen circulation independent of clinical testing. Its ability to capture signals from both symptomatic and asymptomatic individuals highlighted the importance of optimizing sampling methodologies to improve sensitivity and reliability. A key question is whether the several-fold increase in SARS-CoV-2 detectability observed when using passive tampon swab sampling compared with paired grab samples also applies to other respiratory viruses, including influenza A (including its avian influenza H5N1 subtype), influenza B, and respiratory syncytial virus (RSV). We collected 24 h passive swab samples with same-day grab samples from Detroit sewersheds, concentrated and purified nucleic acids, and using RT-ddPCR, quantified respiratory syncytial virus, SARS-CoV-2, influenza A, influenza B, and H5N1 influenza A viruses using markers RSV, SC2, InfA, InfB, and H5, respectively. Samples testing positive for H5 (marker for H5N1 influenza A) were further analyzed by targeted PCR and amplicon sequencing. Across three sites, median 24 h swab:grab ratios of virus copies were 7.0 for RSV, 9.2 for SC2, 9.9 for InfA, and 3.6 for InfB. A 239 bp hemagglutinin sequence from a sample with a strong H5 signal (795 copies/10 mL) had 100% identity to avian influenza viruses from Canada geese. Twenty-four-hour swab sampling greatly improves viral detectability across diverse targets and enabled the first confirmed detection of H5 in Detroit wastewater. Combined with magnetic bead purification, the overall sensitivity gain over conventional PEG-NaCl-Qiagen methods is approximately 36-fold, enabling earlier warning of community pathogens than grab samples. By integrating 24 hour passive swab sampling with high-efficiency nucleic acid purification, we expand the sensitivity of wastewater surveillance to enable detection and confirmation of low-abundance pathogens like avian influenza (H5). Full article

This paper presents a nanowatt-scale operational transconductance amplifier (OTA) and an electronically tunable third-order low-pass filter (LPF) designed for energy-constrained biomedical signal conditioning. The circuits are implemented in a 65 nm CMOS process and verified through comprehensive schematic-level simulations. Biased in the deep subthreshold region at 1 nA, the OTA achieves a 50 dB low-frequency gain, a 225 Hz unity-gain bandwidth at 10 pF load capacitance and an input-referred noise floor of 1.55 μV/√Hz, with a total power consumption of only 1.75 nW. The integrated third-order LPF provides a wide tuning range (37–668 Hz) via bias current modulation, exhibiting excellent linearity with a THD of 0.059% and a 65.3 dB dynamic range. Monte Carlo and PVT corner analyses demonstrate the design’s theoretical robustness against process variations and environmental fluctuations. ECG signal simulations validate the circuit’s effectiveness in suppressing high-frequency artifacts while preserving morphological integrity, providing a proof-of-concept for ultra-low-power wearable healthcare architectures. Full article