Search Results (1,010)

Antigen detection provides rapid and convenient diagnosis of respiratory infections. This study develops an innovative dual-fluorescence aptasensing method based on polydopamine-functionalized MXene (PDA-MXene) for the simultaneous detection of spike protein and hemagglutinin protein. The method employs green- and red-emitting quantum dot (QD) probes as fluorescence reporters, and the PDA-MXene as an effective adsorption and separation substrate. Coupled with a centrifugation-assisted separation strategy, this design method reduces background interference and enhances detection reliability. The method demonstrates good analytical performance, with detection limits of 0.82 ng/mL for spike protein and 2.11 ng/mL for hemagglutinin protein in single-channel mode. The dual-channel mode enables reliable and simultaneous quantification of both target proteins with minimal spectral cross-talk. Furthermore, this method exhibits high specificity against interferents including ions, proteins, and toxins. Artificial saliva, chosen as real sample, is spiked with target proteins to investigate the practical applicability of the method, showing recovery rates for both target proteins between 100 and 114 sensing strategy is simple to operate and allows the detection of new targets by simply replacing the azide-modified aptamer lyophilized powder. It therefore holds promising application for the simultaneous detection of multiple proteins in point-of-care testing and health monitoring fields. Full article

This study aims to explore and evaluate the factors influencing Gen Z’s intention to choose green tourism destinations in Hanoi, Vietnam. The paper proposes a comprehensive analytical framework by integrating the Stimulus-Organism-Response (S-O-R) model and the Theory of Planned Behavior (TPB). A mixed-method approach was employed, in which quantitative data were collected from 269 Gen Z respondents in Hanoi and analyzed using the Partial Least Squares Structural Equation Modeling (PLS-SEM) technique through SmartPLS. The findings reveal that external environmental stimuli, including green destination image (GDI) and social media influence (SMI), positively affect individuals’ internal psychological states, namely environmental awareness (EA), attitude toward green tourism (ATT), and subjective norms (SM). These psychological states, in turn, exert positive effects and strongly promote Gen Z’s intention to choose green tourism destinations in Hanoi. This study not only contributes to filling the theoretical gap in sustainable tourism consumption behavior in the digital era but also provides practical managerial implications for policymakers and tourism businesses in developing communication strategies and tourism products that align with the preferences and expectations of younger generations. Full article

Amaranthin is a major red-violet betacyanin of Amaranthaceae and an increasingly relevant natural pigment for food, cosmetic, nutraceutical, and biotechnological applications. This review integrates knowledge from over 100 studies, addressing amaranthin as a chemically defined betalain, distinguishing it from other scientific uses of the term, and evaluates its natural sources, analytical methods, extraction strategies, in vitro production systems, biosynthetic regulation, and biological activity. Cultivated Amaranthus species are among the richest plant sources, with total betacyanins of 46.1–199 mg/100 g fresh weight and amaranthin constituting up to 80.9% of the pigment fraction. Reliable identification and quantification rely on high performance liquid chromatography coupled with a diode array detector (HPLC-DAD), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and ultraviolet–visible (UV–Vis) spectrophotometry, while microwave-, ultrasound-, and green solvent-assisted extraction markedly improve pigment recovery and stability. While plant in vitro cultures, including callus, suspension, and shoot systems, have clarified biosynthetic regulation and offer controlled production platforms, engineered Yarrowia lipolytica CcAmaSy1 currently provides the highest reported yield, reaching 2.97 ± 0.029 g L⁻¹ in fed-batch fermentation. Amaranthin-rich extracts and purified pigments demonstrate antioxidant, anti-inflammatory, antimicrobial, and antiviral potential; however, mechanistic, bioavailability, and in vivo evidence remain limited. Standardized analytical protocols, further investigation of stable high-yield sources, physicochemical stability assessment, and structure–activity studies are identified as priorities for advancing future application-oriented research on this multipotential pigment. Full article

Spectrophotometry offers the advantage of low cost and less time consumption, making it still attractive as a method of analysis, especially when coupled with multivariate calibration models. This enhancement solves the majority of the drawbacks of UV–VIS spectrophotometry, which have to do with the entangled spectra of complex mixtures. In this study, a multivariate model was developed and validated for the determination of perindopril erbumine, amlodipine besylate and indapamide, addressing previously unresolved challenges by systematically covering three fixed-dose combinations with differing component ratios and by achieving accuracy suitable for the assay determination. The experimental plan involved a Taguchi orthogonal array design with three factors at five levels. In order to create multivariate calibration models, principal component regression, partial least squares and concentration residual augmented least squares regression algorithms were tested. Principal component regression combined with a genetic algorithm for feature selection was chosen as the optimal model based on prediction performance estimated by nested cross-validation with cluster-based sample splitting. The developed method was also evaluated for its environmentally friendly potential while the analytical method validation procedure confirmed its applicability for the assay testing of the fixed-dose drug combination. Full article

Green Human Resource Management (GHRM) has emerged as an important managerial approach in response to the growing environmental, social, and economic challenges faced by contemporary organizations. While prior studies generally confirm a positive relationship between GHRM practices and environmental performance (EP), the existing body of literature remains fragmented. In particular, it tends to focus on selected levels of analysis—most often individual or organizational—and provides a limited explanation of the underlying mechanisms through which GHRM influences environmental outcomes. This paper presents a conceptualization of a research study and a structured research design aimed at addressing these limitations. Based on a review of the literature, key theoretical, empirical, and methodological gaps are identified, particularly regarding the lack of integrated, multilevel perspectives and insufficient attention to mediating mechanisms. In response, the paper develops an original, multilevel conceptual framework that explains how GHRM practices may affect environmental performance through mediators operating at individual, team, organizational, and interorganizational levels. Building on this framework, the study formulates a set of research hypotheses and proposes a two-stage mixed-method research design. The first stage involves qualitative multiple case studies to explore GHRM practices and identify context-specific mechanisms, while the second stage consists of a large-scale international survey aimed at testing the proposed relationships across organizations in selected European Union countries. The main contribution of the paper lies in designing a coherent and empirically testable research framework, rather than testing it directly. By integrating insights from prior literature and structuring a multilevel analytical approach, the study provides a foundation for future empirical research on the mechanisms linking GHRM and environmental performance and contributes to the further development of sustainable human resource management theory. Full article

MgCr₂O₄ nanospinel samples were synthesized using a modified Pechini method, followed by controlled calcination. The resulting materials were evaluated in terms of crystal structure, particle morphology, and optical and electronic properties. Their oxidative activity towards the degradation of organic dyes was investigated via photocatalysis, Fenton-like, and photon-Fenton-like processes. Various analytical techniques were employed to characterize the samples, including X-ray diffraction (XRD) with Rietveld refinements, infrared (IR) spectroscopy, UV–Vis spectroscopy, colorimetry, and transmission and high-resolution transmission electron microscopy (TEM/HRTEM). Structural characterization revealed that MgCr₂O₄ crystallized after calcination at 600 °C, and Rietveld refinements confirmed cubic Fd-3m symmetry. IR spectra confirmed the short-range order through the presence of vibrational modes assigned to CrO₆^2- octahedra. UV–Vis spectroscopy indicated mixed Cr valences (Cr³+/Cr⁶+) for samples calcined at temperatures below 900 °C, with Cr⁶+ eliminated at higher temperatures, confirmed by electron paramagnetic resonance (EPR) spectroscopy. This suggests that an oxidation reaction occurred due to oxygen vacancies in the lattice. Optical bandgap (Eg) increased with temperature. Samples calcined at low temperatures were dark green and became more saturated at temperatures above 900 °C, suggesting photoresponse to visible light, as indicated by the Eg values. The oxidative activity of the nanospinels in degrading the dyes methylene blue (MB) and rhodamine B (RhB) under visible light depended on the nature of the dye, the catalyst concentration, and the use of H₂O₂ in the process to improve the formation of hydroxyl radicals (•OH), as confirmed by photohydroxylation of terephthalic acid (TA). The highest degradation rate was observed in the photo-Fenton-like process, with 96% and 97% degradation of RhB and MB dyes in 60 min, reaching a kinetic rate constant (${\mathit{K}}_{app}$) of 0.055 min⁻¹ and 0.051 min⁻¹, respectively. This study highlights the importance of controlling various parameters to promote the formation of reactive oxygen species (ROS) required for oxidative degradation by nanospinels. Full article

The modern food industry faces increasing pressure to reduce environmental impacts, while at the same time preserving product safety, quality, nutritional value, and industrial relevance. This review synthesizes three related pillars of sustainable food processing: green extraction technologies, natural fermentation, and analytical quality validation. Green extraction methods can reduce dependence on conventional organic solvents, shorten processing time, and support the extraction of bioactive compounds from plant materials and by-products of the food industry. Natural fermentation is a low-impact biotechnological approach to improve sensory quality, shelf life, nutritional value, and valorization of low-cost raw materials or residues. However, sustainability cannot be judged only through lower consumption of resources or general “green” claims. It also requires analytical confirmation of the content of bioactive compounds, oxidative stability, contaminants, authenticity, traceability, standardization, and product safety. In response to reviewers’ recommendations, the review includes a transparent literature selection protocol, a clearer distinction of challenges, research gaps, and future perspectives, as well as additional quantitative comparative tables covering extraction technologies, fermentation applications, and analytical methods. The review shows that the future of sustainable food processing depends on integrating extraction, fermentation, by-product valorization, foodomics approaches, life cycle thinking, real-time monitoring, and industrial-scale validation within the circular economy. Full article

Catechol, a prevalent phenolic pollutant in food products, poses a significant threat to food safety, necessitating the development of rapid and sensitive detection methods. To overcome the limitations of conventional analytical techniques, such as expensive equipment and operational complexity, electrochemical sensors have gained considerable attention owing to their rapid response and facile miniaturization. However, the rational design of sensing materials that exhibit both high sensitivity and selectivity remains a significant challenge. Herein, a series of PdCu bimetallic nanoparticles supported on reduced graphene oxide (PdCu@rGO) composites with varying Pd/Cu molar ratios was synthesized via a one-step liquid-phase reduction method. Owing to the synergistic electronic effects between Pd and Cu and the high electrical conductivity of the rGO support, the resulting nanocomposites exhibited excellent electrocatalytic activity toward catechol oxidation. At the optimal Pd/Cu molar ratio of 1:2, the fabricated Pd₁Cu₂@rGO/SPE sensor demonstrated a broad linear range of 0.5–500 μM, a low limit of detection of 200 nM (S/N = 3), good repeatability (RSD = 4.9%), and robust anti-interference capability. Furthermore, the proposed sensor was successfully applied to the detection of catechol in spiked green tea and fruit juice samples without complex pretreatment, achieving satisfactory recoveries of 91.0–101.4% and 98.6–104.8%, respectively. This work provides a reliable platform for the rapid, on-site screening of catechol in food matrices and offers valuable experimental insights into the rational design of bimetallic alloy–graphene heterostructures. Full article

Rapid urbanization and increasing landscape fragmentation pose significant threats to ecological connectivity, creating a need for integrative decision support approaches in sustainable spatial planning. This study presents a systematic review of ecological network optimization studies published between 2005 and 2025, following the PRISMA protocol. A total of 78 peer-reviewed studies were analyzed to identify methodological trends, recurring limitations, and research gaps in the assessment of structural and functional connectivity. Based on the gaps identified through the systematic review, this study proposes a conceptual Sustainable Spatial Decision Support System (S-SDSS) framework that integrates Morphological Spatial Pattern Analysis (MSPA), Multi-Criteria Evaluation (MCE/AHP), Minimum Cumulative Resistance (MCR), Least-Cost Path (LCP), and Gravity Modeling (GM) within a unified analytical structure. The review findings reveal a clear shift from single-method applications toward integrated multi-model approaches that better represent ecological processes and improve corridor prioritization. The proposed framework synthesizes the complementary strengths of these established methods to support evidence-based ecological network planning. The framework operates as a hybrid structure that combines a sequential analytical workflow with a unified typological classification system, generating Hybrid Ecological Typologies (T1–T5) as planning-oriented outputs that cannot be produced by any individual method alone. The proposed S-SDSS offers a transferable and policy-relevant conceptual basis for ecological network optimization, supporting green infrastructure planning, biodiversity conservation, and long-term landscape resilience across multiple spatial scales. Full article

Over the past two decades, dispersive liquid–liquid microextraction (DLLME) has evolved from an emerging concept into a widely adopted approach within sustainable sample preparation. In parallel, a substantial body of review literature has accumulated, highlighting diverse applications and methodological developments. This umbrella review provides a structured synthesis of 59 review and systematic review articles published between 2006 and 2025, with the aim of examining how the review literature itself has shaped current understanding of DLLME. Methodological quality was appraised using the AMSTAR 2 framework, revealing considerable variability in review design and reporting practices. Key elements such as the transparent reporting of pre-defined review methods, fully reproducible search strategies, and structured assessments of bias were not routinely reported, and the majority of reviews were classified as critically low according to AMSTAR 2 criteria. To contextualize these findings, evidence redundancy was examined through structured overlap analysis, yielding a very low Corrected Covered Area (CCA = 0.0188), which indicates that existing reviews largely address complementary rather than repetitive aspects of DLLME. Thematic synthesis identified three dominant domains: methodological and mechanistic developments, green and sustainable extraction strategies, and application-driven advances in environmental and pharmaceutical analysis. Together, these findings provide a structured basis for improving future review design, evaluation, and editorial assessment in analytical chemistry, supporting more transparent, reproducible, and methodologically aligned evidence synthesis. Full article

Cities worldwide face persistent inequalities in access to urban green spaces, a condition associated with reduced physical activity and poorer mental wellbeing. In high-density metropolises, land scarcity further intensifies these disparities. Although recent studies have highlighted the potential of small-scale green spaces, limited attention has been paid to their system-level and spatially differentiated roles within urban green infrastructure. Consequently, the equality implications of micro-scale interventions such as pocket parks across urban–rural gradients remain insufficiently understood. This study addresses this gap by examining the accessibility impacts of 475 pocket parks in conjunction with 433 large parks in Shanghai, using a multidimensional, citywide analytical framework. The Gaussian two-step floating catchment area (G2SFCA) method was applied within the 15-min community life circle framework to assess service coverage, population served, and per capita accessible green space, as well as their urban–rural differentiation patterns. Results indicate that the inclusion of pocket parks modestly increases overall service coverage (+3.41%) but substantially improves population access (+7.83%), converting 143.79 km² of previously unserved areas into areas with basic green space provision. Spatial effects vary along the urban–rural gradient: pocket parks generate high marginal population-service benefits and improve spatial equality in urban cores, strengthen green space service networks in peri-urban areas, and produce incremental accessibility gains in outer suburbs. Taken together, these findings provide a novel system-level understanding of how pocket parks function within urban green infrastructure networks, offering policy-relevant evidence to guide equality-oriented planning in high-density cities. Full article

This study investigated the use of Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) as a cost-effective analytical approach for screening the bioactivity of green algal extracts. Samples of five Caulerpa species—C. ashmeadii, C. paspaloides, C. cupressoides, C. verticillata, and C. prolifera—were collected from Dzilam, Yucatán, Mexico, across seven seasonal campaigns. Sequential extraction was performed using solvents of increasing polarity: hexane, dichloromethane, acetone, and methanol. After solvent evaporation, extracts were analyzed via ATR-FTIR, and Total Phenolic Content (TPC) and Trolox Equivalent Antioxidant Capacity (TEAC) were quantified. Statistical analysis (PERMANOVA) revealed that the type of solvent accounted for most of the variance (61.6%), while species and collection date contributed minimally. Infrared (IR) band assignments highlighted functional groups associated with lipids, such as terpenes, and carbohydrates. K-means clustering enabled the subdivision of less polar extracts, notably grouping numerous samples from C. verticillata. Classification models comparing full-spectrum and IR band datasets showed that Partial Least Squares Discriminant Analysis (PLS-DA) with full-spectrum data achieved the best performance. TPC showed a positive correlation with absorption at 1730.8 cm⁻¹, which is associated with ester-containing metabolites. Although ATR-FTIR effectively distinguished extraction solvents, it was less sensitive to subtle biological variation among Caulerpa. However, the method remains a practical tool for rapid screening, with spectral data supporting solvent-based classification. Reduction of salt content prior to extraction may minimize interference in both FTIR measurements and biological assays. Full article

This research paper addresses the persistent problem of environmental opacity in sustainable debt markets, exposing a structural flaw that incremental regulation alone cannot remedy. This study advances a radical, physics-grounded solution that fundamentally transforms environmental reporting from voluntary self-disclosure to instrumentally verified, quantum-limited measurement. The method integrates three mutually reinforcing analytical frameworks: the design of Quantum-Verified Green Bonds (QVGBs), the application of cryptographic quantum key distribution (QKD), and the formal apparatus of financial contract theory. The principal conceptual innovation resides in a three-tiered architectural structure—physical, cyber–physical, and financial—that collectively shifts the epistemological foundation of sustainable finance from institutional norms and managerial discretion to the immutable constraints of physical laws. By deploying nitrogen-vacancy (NV) centers in diamond as primary sensing arrays at industrial emission points, this system achieves environmental parameter estimation bounded by the Cramér–Rao quantum limits, a precision ceiling governed by Quantum Fisher Information, not corporate policy. This architecture acquires high-fidelity, real-time data on CO₂ and CH₄ flux densities, transforming atmospheric pollutant concentrations into physically attested, contractually actionable financial variables. A QKD layer further leverages the no-cloning theorem to render any upstream data manipulation physically self-revealing through statistically detectable elevations in the Quantum Bit Error Rate (QBER). The central contribution of this work lies in the algorithmic coupling of bond coupon structures to these quantum-verified state variables, enforced via smart contracts, thereby converting “environmental misinformation” from a viable managerial strategy into a strictly dominated equilibrium outcome. These findings carry substantial implications for bridging the “trust gap” in green financial markets, a gap sustained by chronically undervalued transition risks and deficient accountability mechanisms in air quality and carbon reporting. The QVGB framework stabilizes green asset prices by subordinating capital allocation decisions to physical constraints rather than political or institutional ones, thereby establishing a new ontological baseline for the global sustainable debt market. Full article

Caffeine and chlorogenic acid are among the most extensively investigated bioactive compounds in coffee, tea, and other plant-derived products due to their noteworthy physical, nutritional, and industrial relevance. Caffeine is primarily acknowledged for its central nervous system stimulant activity, whereas chlorogenic acid, a phenolic ester, contributes antioxidant, anti-inflammatory, and metabolic health benefits. This review was conducted according to the PRISMA guidelines in order to systematically compile and summarize the extraction and analytical conditions reported for caffeine and CGAs in different matrices and to provide a structured comparison among the reported studies. All studies focusing on the extraction and/or quantification of caffeine and chlorogenic acids in several matrices were considered eligible. Three independent electronic searches were performed using PubMed, Science.gov, and BASE to identify relevant articles. Extraction of data was conducted independently by four authors based on consistent selection and extraction criteria. One hundred and twenty-five studies were identified. The results were summarized in tables including several parameters. Conventional extraction techniques, including aqueous and organic solvent-based methods, have formed the foundation for separating caffeine and chlorogenic acids. However, rising interest in green and sustainable technologies has shifted attention towards advanced approaches such as ultrasound-assisted extraction and microwave-assisted extraction. These methods not only enhance extraction yields and reduce processing times but also align with environmental and safety concerns in the modern food and pharmaceutical industries. For quantification, high-performance liquid chromatography equipped with ultraviolet or mass spectrometric detection remains the benchmark, offering precision and reproducibility in different matrices. This review sheds light on recent advances and ongoing research in the extraction and quantification of caffeine and chlorogenic acid in different types of matrices. Continued innovation in green extraction technologies and robust quantification methods is essential for supporting scientific research applications. Full article

Background: The invasive macroalga Rugulopteryx okamurae poses severe environmental challenges but presents an opportunity as a sustainable source of valuable carbohydrates. This study develops an eco-friendly method to extract monosaccharides from this biomass. Methods: Ultrasound-assisted extraction (with sonotrode) using water as the solvent was optimized with Design of Experiments, and the time, power and mass:solvent ratios were evaluated. The monosaccharide composition was evaluated by gas chromatography coupled to high-resolution mass spectrometry (GC-QTOF). Results: The analytical method was validated for accurate monosaccharide quantification using oximes and silylation, achieving a fast time of analysis (<20 min). The optimized UAE (1:15 mass:solvent ratio, 70% power, 30 min) yielded a total monosaccharide concentration of 210 mg mL⁻¹, significantly outperforming traditional acidic hydrolysis. Compared to the extraction of monosaccharides from the well-known seaweed Ulva ohnoi (31 mg mL⁻¹), it is far superior. Mannitol comprised 95% of the total extract. Conclusions: This scalable and green UAE methodology valorizes this seaweed by achieving high yields of simple sugars, offering a sustainable resource for industrial applications while mitigating the environmental impact of this invasive species. Full article