Search Results (82)

To address the dilemma of ‘non-grain use of cultivated land’ and support China’s requisition–compensation balance policy, this study developed a multi-dimensional assessment framework integrating the production, ecological, and economic dimensions (3D evaluation model), using Shenyang City as a case study to demonstrate the framework’s operational application and policy relevance. Based on 34,704 Third National Land Survey (TNLS) parcels (27,408.39 ha), we applied the constraint factor assessment method and entropy-weighted composite index model. The results show that non-cultivated agricultural land (NCAL) is generally marginally suitable (citywide average score: 2.50/4), with highly suitable areas accounting for only 4.04% (1106.30 ha). These areas exhibit a triangular spatial pattern distributed across northeastern Faku County, central Sujiatun District, and southern Xinmin City. Sensitivity tests using equal weights and ±20% dimension-weight perturbations confirm that high-suitability area remains limited (3.37–5.63% under entropy-weight scenarios; 8.54% under equal weights). Primary limiting factors include severe organic matter deficiency (average 19 g/kg), shallow soil depth, unfavorable pH, land requiring engineering restoration (94%), and punctiform heavy metal contamination (7.53% of plots, 2065.05 ha as spatially excluded areas). Consequently, we propose a five-tier sequential restoration framework: (1) near-term priority recultivation of highly suitable areas; (2) mid-term topsoil reconstruction for moderately suitable areas; (3) medium-to-long-term topsoil stripping and thickening for low-suitability areas; (4) long-term soil amelioration and slope-to-terrace conversion for marginally suitable areas; and (5) strict prohibition of restoration in unsuitable areas. This study establishes a spatially explicit decision-making system integrating “evaluation–classification–sequencing”, and distinguishes technical suitability from economic, institutional, and policy feasibility, providing a decision-support framework for scientifically implementing the cultivated land requisition–compensation balance policy. Future empirical studies using post-restoration monitoring data are needed to test its predictive accuracy against observed restoration outcomes. Full article

Energy gels are widely used by athletes to maintain performance during endurance activities; however, their acidic composition may pose a risk to dental health. This study aimed to evaluate the pH of four commercial energy gels at different dilutions with artificial saliva and to assess the potential neutralizing effect of casein phosphopeptide–amorphous calcium phosphate (CPP–ACP). An in vitro experimental design was conducted using four commercial gels (FullGas Hydrogel, ENA Energy Gel, UltraTech Gel, and Maverick Race Gel). Serial dilutions with artificial saliva (1:2, 1:5, 1:7, and 1:10) were prepared, and pH was measured using indicator strips at 0, 15, and 30 min at 37 °C. The effect of CPP-ACP was evaluated in the 1:2 dilution. Undiluted gels showed highly acidic pH values ranging from 2.0 to 3.0. Dilutions of 1:2 and 1:5 remained significantly more acidic than artificial saliva (p < 0.001). From 1:7 dilution onward, pH values increased and approached salivary levels (approximately 7.0), with no significant differences compared with artificial saliva. The addition of CPP-ACP significantly increased pH in the 1:2 dilution (p < 0.05), although the effect was limited in more diluted conditions. These findings suggest that commercial energy gels may represent a source of acidic exposure under in vitro conditions, which could be relevant for dental health. Adequate dilution, particularly ≥1:7, was associated with a reduction in acidity under the experimental conditions tested, although its clinical relevance cannot be directly inferred, while CPP-ACP may provide a limited buffering effect under concentrated exposure conditions. Full article

Background/Objectives: The emergence of hypervirulent Pseudomonas aeruginosa strains resistant to β-lactamase inhibitor antibiotics is a critical health problem as they impede the treatment of infections. The objective of this study was to determine the different molecular arrangements of the virulence genotype related to β-lactamase genotype and the resistance phenotype to a combination of β-lactam antibiotics and β-lactamase inhibitors, and the phylogroups in P. aeruginosa strains isolated from patients with healthcare-associated infections and community-acquired infections. Methods: P. aeruginosa, virulence genes, β-lactamase genes and phylogroups were identified using polymerase chain reaction. Resistance to β-lactam antibiotics and β-lactamase inhibitors was determined using the disk diffusion method. The MIC determination of ticarcillin/clavulanic acid and piperacillin/tazobactam was performed using the MIC test strip for antimicrobial susceptibility testing. Results: In total, 124 P. aeruginosa strains from patients with healthcare-associated (67/124) and community-acquired infections (57/124) were analyzed. Most strains from patients with healthcare-associated infections and community-acquired infections harbored genes for proteases (aprA), phospholipases (pIcH and pIcN), elastases (lasA and lasB), rhamnolipids (rhLA), quorum-sensing system (lasI and rhII), and β-lactamase (bla_oxa-4, bla_oxa-1, and bla_GES). In total, 100% (124/124) and 99.1% (123/124) of the strains isolated from patients with healthcare-associated and community-acquired infections were resistant to the β-lactamase inhibitor antibiotics, amoxicillin/clavulanic acid and ampicillin/sulbactam, respectively, while 54% (67/124) of the strains were resistant to piperacillin/tazobactam. Phylogroup 1 (22/124) was detected more frequently among the strains in relation to phylogroup 2 (8/12). Conclusions: We demonstrated different association profiles of virulence genotype related to the β-lactamase genotype, the β-lactamase inhibitor resistome, phylogroups, and clinical origin of the strains. Therefore, medical treatment regimens against infections caused by P. aeruginosa should be improved. Full article

Natural dyes have emerged as a promising alternative to synthetic dyes for industrial applications due to their advantages, namely, easy availability, low cost, and environmental friendliness. In this sense, natural dyes, due to their potential to react over the pH range, could offer an alternative to conventional pH measuring techniques for industrial products, such as potentiometers, sensors, or indicator drops. Therefore, this project aims to evaluate the potential of several natural organic dyes in response to changes in pH and develop an indicator for determining pH grades. We extracted and analyzed the pigments of forty natural vegetable species using two extraction methods with a mixture of solvents, specifically 70% MeOH/30% H₂O. The results find that pigments of cabbage, hibiscus flower, radish, and turmeric in their dry state exhibit the best reaction over a broad pH range, and color can be easily distinguished according to its level. These findings demonstrate the potential of natural dyes as a novel approach for pH verification, providing a sustainable and cost-effective alternative to conventional techniques. Full article

Zearalenone (ZEN), a stable mycotoxin with estrogenic activity produced by various Fusarium species, poses a serious food safety risk. To facilitate the rapid, sensitive, on-site detection of ZEN in maize and ensure consumer dietary safety, a colloidal gold immunochromatographic assay (CG-ICA) based on a monoclonal antibody was established. ZEN was converted via oxime derivatization into hapten ZAN-O, which was conjugated to a carrier protein to prepare an immunogen for producing a highly specific and sensitive monoclonal antibody. Then, the antibody was conjugated into colloidal gold nanoparticles (AuNPs) and used as capture bioprobes of the CG-ICA test strip. The highly sensitive and specific detection platform was established through systematic optimization of pH value, coating antigen concentration, antibody-labeling dosage, incubation time, and strip assembly conditions. Under optimized conditions, the strip exhibited a detection limit of 11.79 pg/mL and an IC₅₀ of 99.06 pg/mL, with a linear detection range of 13.40–732.48 pg/mL. In addition, the anti-interference capability assay demonstrated that the developed test strip possessed excellent specificity. In spiked maize samples, the CG-ICA test strip demonstrated recoveries ranging from 85.36% to 98.86%, with relative standard deviations (RSDs) below 10%. Thus, the CG-ICA strip provides a rapid, sensitive, and robust on-site tool for ZEN screening in maize, and can be adapted to other hazards by simply switching the antibody. Full article

Rare-earth elements (REEs) are integral in a wide range of advanced technologies. Increasing demand for REEs, geopolitical tensions that threaten supply chains, and environmental strain due to extraction operations necessitate the development of new separation and purification methods. Novel selective adsorbents offer a promising alternative to traditional precipitation and solvent extraction due to high selectivity, surface area, and reusability. This research provides insight into the loading and stripping behavior of the 2-D Metal–Organic Framework (MOF) ‘NCU-1’ over multiple pH conditions and time domains in chloride media. NCU-1 structures were synthesized using standard methods, then evaluated for kinetics and equilibria via batch testing. Pseudo-first-order kinetics was used to model the adsorption behavior of all REEs tested. The kinetic trends between elements support a mechanism in which sorption affinity and rate correlate with REE ionic radius and surface interaction strength. The preliminary evaluation presented here suggests that such units are highly useful for both solution purification and the separation of light rare-earth (LREE) from heavy rare-earth elements (HREE). Full article

A novel fluorescent probe (PYB) for selective and sensitive detection of Cu²⁺ ions was rationally designed and synthesized via a multi-step organic reaction using pyrene as the fluorophore and salicylaldehyde-diethylenetriamine Schiff base as the recognition moiety. The structural characterization of PYB was confirmed by ¹H NMR, ¹³C NMR, and high-resolution mass spectrometry (HRMS). Photophysical properties investigation revealed that the probe exhibited strong fluorescence emission at 362 nm in DMF/HEPES-NaOH buffer solution (v:v = 1:1, pH 7.4), which underwent a significant fluorescence quenching response (quenching efficiency up to 77%) upon the addition of Cu²⁺, attributed to the formation of a 1:1 PYB-Cu²⁺ complex (binding constant K = 799.65 M⁻¹). The probe showed excellent selectivity for Cu²⁺ over other common metal ions (Ba²⁺, Na⁺, Mg²⁺, Zn²⁺, Cd²⁺, Ca²⁺, Mn²⁺, Pb²⁺, Hg²⁺, Fe³⁺, Co²⁺), with a low detection limit of 8.35 × 10⁻⁷ M, which is well below the maximum allowable concentration of Cu²⁺ in drinking water specified by the World Health Organization (WHO). Furthermore, a portable fluorescent test strip based on PYB was successfully fabricated, enabling rapid and visual detection of Cu²⁺ under UV light. Fluorescence imaging experiments in living HepG2 cells demonstrated that PYB could penetrate cell membranes efficiently and realize the intracellular detection of exogenous Cu²⁺. These results collectively indicate that PYB holds great potential as a practical tool for Cu²⁺ detection in environmental monitoring, food safety, and biological systems. Full article

A versatile voltammetric procedure for quantitative determination of Pb(II) directly in environmental water samples has been proposed. Differential pulse technique in the variant of anodic stripping voltammetry was applied to study Pb(II) at a solid bismuth microelectrode (SBiµE). The proposed procedure was tested using model solutions containing 0.1 mol L⁻¹ acetate buffer (pH = 3.4) and 5 × 10⁻⁹ mol L⁻¹ Pb(II). Under optimized measurement conditions, i.e., activation potential and time −2.5 V and 30 s, respectively, and accumulation potential and time −1.4 V and 30 s, respectively, a linearity range of 1 × 10⁻¹⁰–3 × 10⁻⁸ mol L⁻¹, a detection limit of 3.4 × 10⁻¹¹ mol L⁻¹ and a relative standard deviation of 3.1% were obtained. The applicability of the developed procedure was confirmed by direct analysis of environmental waters, such as water from the Bystrzyca River and water from the Baltic Sea. Full article

The article reports for the first time the application of a solid silver microelectrode array for the anodic stripping voltammetric determination of thallium(I) ions (Tl(I)). The microelectrode properties of the presented sensor were tested. The proposed solid metal microelectrode array is characterized by its eco-friendly nature due to the use of non-toxic electrode material. The advantage of this procedure is that no surface modification of the microelectrode was required. The optimization of the procedure for determining Tl(I) was performed. The experimental parameters (e.g., pH of supporting electrolyte, conditions of activation step, potential and time of deposition, effects of possible interferences) were investigated. The dependence of the thallium peak current on its concentration was linear in the range from 5 × 10⁻¹⁰ to 1 × 10⁻⁷ mol·L⁻¹ (deposition time of 120 s). The estimated detection limit was 1.35 × 10⁻¹⁰ mol·L⁻¹. The repeatability of the procedure expressed as RSD% for a Tl(I) concentration of 2 × 10⁻⁸ mol·L⁻¹ was 3.6% (n = 5). The proposed procedure was applied for determining Tl(I) in certified reference materials and for studying recovery in the environmental water sample. The obtained results indicated the possibility of an analytical application of the elaborated procedure in practice. Full article

Background: Acute cholecystitis (AC) is characterized by gallbladder inflammation and is commonly accompanied by disordered gallbladder motility. Although laparoscopic cholecystectomy is the standard treatment, it carries procedure-related risks. Low-intensity pulsed ultrasound (LIPUS), a safe and noninvasive modality widely applied for muscle repair, may offer therapeutic benefits for AC-associated motility dysfunction. Methods: In vivo, LIPUS (0.5 W/cm²) was applied for 15 min daily to acute cholecystitis guinea pigs over three consecutive days, starting 24 h after reversing common bile duct ligation (CBDL) surgery. In vitro, LIPUS (0.5 W/cm²) was delivered for 5 min to isolated gallbladder muscle strips and for 30 s to isolated interstitial cells of Cajal (ICCs). Gallbladder function and histology were assessed in vitro and in vivo using immunofluorescence, Western blotting, calcium imaging, muscle strip contractility testing, and related molecular methods. Results: LIPUS increased intracellular Ca²⁺ by activating the Ano1 channel in ICCs, thereby enhancing gallbladder smooth muscle contractility. At 72 h, the LIPUS 72 h (+) group showed a 71.3% increase in gallbladder muscle tone (p = 0.0001) and a 40.7% reduction in inflammation scores (p = 0.0001) compared with the LIPUS 72 h (−) group. Conclusions: LIPUS alleviates gallbladder contractile dysfunction in acute cholecystitis by acting on ICCs through mechanisms involving the promotion of ICC recovery and a reduction in inflammation. Full article

The ongoing COVID-19 pandemic has underscored the urgent need for rapid, sensitive, and versatile diagnostic tools. In this study, we developed a nanogold-based lateral flow immunoassay (LFIA) capable of detecting both SARS-CoV-2 nucleocapsid (N) protein antigens and anti-N IgG antibodies at the point of care. Following optimization of colloidal gold nanoparticle size, pH, and protein conjugation parameters, LFIA strips were assembled in two formats: a competitive assay for antigen detection and a sandwich assay for antibody detection. In the competitive format, gold nanoparticles (AuNPs)-conjugated N protein were used to detect varying concentrations of free N protein. The test line signal inversely correlated with antigen concentration, confirming the assay’s specificity and effectiveness. For antibody detection, the sandwich LFIA format employed immobilized anti-human IgG to capture anti-N antibodies in serum samples from COVID-19 patients. Strong test line signals were observed in samples collected ≥11 days post-symptom onset, indicating a time-dependent increase in IgG detectability. These results demonstrate that the AuNP-based LFIA platform provides a flexible, rapid, and low-cost diagnostic solution, suitable for both early antigen detection and serological monitoring during SARS-CoV-2 infection and recovery. Full article

Gyrification, the folding of the cerebral cortex, plays a crucial role in brain development and function. Perinatal hypoxia–ischemia (HI) is a leading cause of neonatal brain injury, affecting cortical folding that can be measured by the gyrification index (GI). Using a late-preterm ferret model, our objective was to explore the relationships between HI injury, GI changes, and behavior, as well as the potential moderating effects of sex and treatment. Animals received 3 mg/kg E. coli lipopolysaccharide and underwent bilateral carotid artery ligation followed by alternating hypoxia and hyperoxia (HIH) and were randomized to saline vehicle (n = 25), erythropoietin (n = 20), therapeutic hypothermia (6 h at 33.5 °C, n = 20), and uridine monophosphate (n = 6), with n = 20 unexposed littermates serving as controls. Early reflex testing, CatWalk gait analysis, open-field behavior, and an open-water swim test were performed. Average, peak, motor, and somatosensory strip GIs were then assessed using ex vivo MRI. In control animals, males had lower GI than females; however, HIH exposure resulted in male GI being more similar to females, where HIH animals had significantly higher average GI than controls (p = 0.02). Adjusting for brain volume and injury, GIs in motor and somatosensory areas were associated with faster reflex outcomes in males but not females. In female controls, motor and somatosensory GIs were associated with increased anxiety-like behaviors, such as spending less time in open water during the swim test. By comparison, in male controls, higher GI was associated with decreased anxiety-like behaviors, including higher exploration index in the swim test. These sex-specific relationships between GI and behavior were lost with HIH injury. Treatment did not meaningfully restore the relationship between GI and behavior after HIH, but targeting this outcome may be an important measure for use in future neuroprotection studies in the ferret. Full article

This paper reviews the apparent impact of how changes in nitrate, sulphate activities, and moisture affect the surface pH of rock art paintings at Cueva del Ratón, in the Sierra de San Francisco in Baja California Sur, Mexico. The data was collected after atypical weather events caused rain and mist in this normally arid area. The rock art paintings had been previously examined over several years and observed the unexpected formation of silica skins over some surfaces; such coatings are not often experienced in arid environments. The local geology of the cave and the availability of moisture can dramatically alter the microbiological activity on faecal material and development of surface acidity from such reactions which interacts with both the host rock and the pigments. Through a series of surface pH measurements and localised measurements on chloride, sulphate and nitrate it appears that both nitrate and sulphate concentrations have a significant impact on the surface pH, which is controlled by a diffusion-based movement of moisture from the closed to the open end of the shelter. The exfoliation of the rock surface and formation of the silica skins involves chemical reactions as contrasted with diffusion-controlled reactions which distribute the metabolites of the yeasts, moulds and bacteria, which are dominated by the availability of water through drip lines. The results are particularly relevant due to changing weather patterns in the last decade, caused by climate change, with an increase in hurricanes directly affecting the Baja California peninsula. The use of disposable test strips for semi-quantitative assessment of how these major anions impact on the decay mechanisms was a novel response to budget constraints and the remoteness of the location. Full article

The synergistic effect of using D2EHPA and TOPO together to enhance the extraction of samarium(III) from aqueous media via emulsion liquid membrane (ELM) technology was explored. D2EHPA in binary mixtures with TBP and in ternary mixtures with TOPO and TBP was also tested. Among the tested extractants, a binary mixture of 0.1% (w/w) D2EHPA and 0.025% (w/w) TOPO achieved 100% samarium(III) extraction at a low loading. This mixture outperformed D2EHPA-TBP and other systems because D2EHPA strongly binds to Sm(III) ions, while TOPO increases the solubility and transport efficiency of metal complexes. Additionally, process factors that optimize performance and minimize emulsion breakage were examined. Key insights for successfully implementing the process include the following: 5 min emulsification with 0.75% Span 80 in kerosene at pH 6.7 (natural), 250 rpm stirring, a 1:1 internal/membrane phase volume ratio, a 20:200 treatment ratio, and a 0.2 N HNO₃ stripping agent. These insights produced stable, fine droplets, enabling complete recovery and rapid carrier regeneration without emulsion breakdown. Extraction kinetics accelerate with temperature up to 35 °C but declined above this limit due to emulsion rupture. The activation energy was calculated to be 33.13 kJ/mol using pseudo-first-order rate constants. This suggests that the process is diffusion-controlled rather than chemically controlled. Performance decreases with Sm(III) feed concentrations greater than 200 mg/L and in high-salt matrices (Na₂SO₄ > NaCl > KNO₃). Integrating these parameters yields a scalable, low-loading ELM framework capable of achieving complete Sm(III) separation with minimal breakage. Full article

This study reports an investigation of the synergistic extraction of dysprosium (Dy(III)) from aqueous media using a low-concentration, binary carrier mixture of Cyanex 272 and D2EHPA within an emulsion liquid membrane (ELM). Within the tested formulations, the one containing 0.42% (w/w) Cyanex 272 and 0.28% (w/w) D2EHPA yielded the best results. The impact of process factors that maximize recovery efficiency and minimize emulsion breakdown was also examined. A Span 80 loading of 0.75% (w/w) achieved 97.5% extraction with minimal breakage (less than 2.1%). An external phase pH of 5.8 achieves an optimal balance of high-throughput Dy(III) recovery and membrane stability; 0.2 N HNO₃ as the stripping phase strikes the optimal balance, providing strong initial uptake with minimal emulsion degradation. As the initial Dy(III) loading increases, extraction efficiency decreases. Increasing the temperature from 15 to 45 °C accelerates mass transfer, achieving near-complete extraction in under 15 min. However, above 45 °C, emulsion breakage spikes, causing a collapse in efficiency. Similarly, increasing NaCl levels suppresses Dy(III) uptake and promotes coalescence. This reduces recovery from seawater to just over 70%. Nevertheless, the balanced mineral content of Zamzam water preserves emulsion integrity and enables 100% extraction. The activation energy was found to be 26.16 kJ/mol, suggesting that mass transfer, rather than the chemical reaction at the interface, controls the process. The results of this study highlight the synergistic efficiency advantage of the ELM system at lower carrier concentrations, even in complex water sources. Full article