Search Results (260)

The topic of improving the strength and performance properties of secondary polyamide materials as part of their functional modification is a very relevant area of expanding the possibilities of secondary use of plastic waste. The article aims to conduct a systematic study of the combined modification of polyamide waste agglomerate by six different types of carbon materials to improve their technological and strength properties. PA6 waste agglomerate from polyamide clothing items, tights, socks, and various carbon materials were studied: masterbatch for polyamides MW-PA CB10, brown coal humic substances, coke residue from pyrolysis, a mixture of plastic waste, and finely dispersed coal enrichment waste. A sustainable polymer composite based on a modified agglomerate of PA6 waste was obtained by extruding pre-prepared raw materials in a single-screw extruder. The structural and morphological analysis of the studied carbon materials showed that, within the framework of the combined modification of polyamide-6 waste agglomerate, they should perform different functions related to their distinct morphology and chemical composition. Thus, humic substances can act as functional modifiers and compatibilizers due to their nanodispersity and a wide range of active chemical groups. In contrast, coke residue from pyrolysis and coal enrichment waste will act as a functional filler to improve the complex strength properties of sustainable polymer composites. As part of a study on the effect of modifying polyamide-6 waste agglomerate by carbon materials on its complex technological characteristics, it was demonstrated that humic substances enhance sustainable polymer composite’s technological properties by increasing the melting temperature and melt flow index while reducing density. The increase in the functional effect of humic substances is due to the growth of a wide range of active chemical groups (hydroxyl, carboxyl, peptide). During the initial oxidation of brown coal, the coke residue from pyrolysis and coal enrichment waste served as a filler, increasing the sustainable polymer composite’s density and melt flow index. As part of the study of the effect of modification by carbon materials on the complex strength characteristics of polyamide-6 waste agglomerate, it was shown that all carbon materials studied, except for coke residue, improve the strength characteristics of polyamide-6 waste agglomerate. The optimal content of different types of humic substances is 0.5% wt., while the sustainable polymer composite’s impact strength and breaking stress during bending increase with the increase in the functionalization of humic substances during the oxidation of brown coal. It has been shown that the combination of small amounts of oxidized humic substances at the level of 0.5% by weight, as a functional additive with a masterbatch MW-PACB10 in an amount of 2–3.5%wt., provides materials with increased impact strength from 23 to ~48 kJ/m² and bending fracture stress from 115 to ~135 MPa, which allows returning secondary PA6 waste to the “traditional areas of primary PA6” in the manufacture of general technical parts and products. Full article

Countercurrent electrophoresis (CCEP) is a technology that forms a steady focus in the separation channel through the coupling of electric field migration and reverse fluid flow, so as to realize the synchronous concentration and separation of substances. This paper reviews the evolution of CCEP from its theoretical origin, device design to microfluidic integration and optimization. Compared with traditional capillary electrophoresis, CCEP has higher processing flux, continuous operation ability and separation resolution, and has been successfully applied to isotope enrichment, protein recovery and complex matrix analysis. This paper further discusses the methods derived from it, such as isoelectric focusing (CACE), conductance gradient focusing (CGF) and electric field gradient focusing (EFGF), which expand the analysis ability and application scenarios of CCEP. Although the technology still faces challenges such as system stability, operation complexity and detection dependence, with the development of microfluidic, intelligent control and new material technology, CCEP shows broad development prospects in biomedicine, environmental monitoring and nuclide separation. Full article

The transport of carbonated slime pulps in pipelines is important for the acid lixiviation process that has developed in the nickel extraction industry in the eastern region of Cuba. This substance is a suspension of fine particles that behaves as a viscoplastic fluid. To address the lack of research conducted on carbonated slime pulps, we carried out an experimental investigation of the rheological properties of this substance over varied operational conditions. As the shear rates involved in the experiments covered more than two orders of magnitude, we fitted the flow curves to the Herschel–Bulkley model, which has been used in the past to model different suspensions. Through data analysis, we observed a transition in rheological behavior at a solid particle concentration of about 30%. Based on the trend of the flow curves, we built an empirical model to predict the rheological properties of slime pulps. In this model, the flow properties of the substance depend on the concentration of solid particles, the pH and the polydispersity index. Our empirical model exhibits high accuracy in predicting the flow properties of carbonated slime pulps. The results can be used to improve the efficiency of industrial processes involving these mineral suspensions. Full article

Coronaviruses are worldwide-distributed RNA viruses with zoonotic potential and the ability to jump from one host species to another, including humans. Even after the COVID-19 pandemic, the search for new, biologically active substances with anti-coronavirus activity continues to be a critical milestone for human health protection. In the framework of a complex engineering strategy, we cultivated the microalgal species Scenedesmus acutus in two different innovative types of flat-plate photobioreactors (PBR1 and K1) for CO₂ utilization and biomass production with special features. Isolated extracts from the microalgal biomass of each one were compared for their anti-coronavirus potential. The design of both PBRs allows a hydrodynamic regime to achieve best fluid flow distribution in their sections, therefore providing the optimal so-called flashing light effect. Of course, this is achieved under well-controlled operational conditions. A strain of beta coronavirus 1 (BCoV, bovine coronavirus) replicated in MDBK cells was used as an in vitro model for the evaluation of the antiviral activity of both extracts. The cell viability, number of survived BCoV particles, and cytopathic effect were evaluated after pre-incubation of the virus with the extracts or direct treatment. The extracts’ samples exhibited evident antiviral activity—extract 1 (from PBR1) in concentrations ≥ 200 µg/mL and extract 2 (from K1) in concentrations ≥150 µg/mL. The ddPCR result revealed significant diminishment of the BCoV particles in samples treated with higher concentrations of the extracts. The phytochemical analysis for certain main groups of compounds (flavonoids, polyphenols, carotenoids, and lipids) showed some differences for both extracts, which could be a possible reason for the observed difference in the antiviral activity. In conclusion, the innovative PBRs are a good platform for studying microalgal growth kinetics by applying different stress conditions from hydrodynamics and mass transfer subsystems. Both extracts showed promising potential for the isolation of metabolites with antiviral activity against BCoV and could be an object for future pharmacological investigations. Full article

Following the discovery of therapeutic molecules and the identification of specific biological targets, preparation of regulatory dossiers entails extensive product development and characterization to support their safety, efficacy, and stability. We have examined the drug development and relevant regulatory considerations related to inhaled biological proteins in the accompanying article. This review focuses on the characterization of locally acting inhaled biological proteins. Drug product characterization is a regulatory requirement, and it ensures drug product safety, efficacy, stability, and usability by the target populations. Together, these two articles provide a comprehensive discussion based on our review and analysis of the available open literature. We have attempted to fill gaps and simulate discussion of challenges following sound scientific pathways. This approach has the prospect of addressing regulatory expectations leading to rapid solutions to unmet medical needs. The robustness of characterization strategies and the development of analytical methods used in the in vitro testing for the evaluation of drug product attributes is assured through application of the Design-of-Experiment (DOE) and Quality-by-Design (QBD) approaches. Drug product characterization entails a variety of in vitro studies evaluating drug products for purity and contamination, and determination of drug delivery by the intended route of administration. Measurement of the proportion of the labeled amount per dose and the form suitable for delivery to the intended target sites is central to this assessment. For respiratory Drug–Device combination products, the testing may vary with the product designs. However, determination of the single-dose content, delivered-dose uniformity, aerodynamic particle size distribution, and device robustness when used by the target populations is common to all combination products. Characterization of aerosol plumes is limited to inhalation aerosols that produce specific aerosol clouds upon actuation. The flow rate dependency of devices is also examined. Product characterization also includes safety-related product attributes such as degradation products and leachables. For inhaled biological proteins, safety-related in vitro testing includes additional testing to assure maintenance of the three-dimensional structural integrity and the sustained biological activity of the drug substance in the formulation, during aerosolization and upon deposition. This article discusses various tests employed for regulatory-compliant product characterization. In addition, the stability testing and handling of possible changes during product development and post-approval are discussed. Full article

Few hydrogeological studies have focused on possible per- and poly-fluoroalkyl substance (PFAS) contamination in groundwater with particular attention to the role of hydraulic interconnections and to the interdigitations present between shallow and deep aquifer layers in heterogeneous alluvial systems. In general, deeper groundwater is considered chemically safer and less impacted by contamination, especially in multilayer aquifers characterized by low permeability apparently confining horizons. Therefore, this research analyzed PFAS in groundwater at depths ranging from 20 to 120 m below ground level, combining stratigraphic, hydrogeological, and chemical data with GIS mapping to identify industrial activities potentially contributing to PFAS contamination using the cross-checking methodology. During the second survey, the monitoring network was extended along a hydrogeological transect, including two springs located upstream and downstream of the deep wells, to assess PFAS concentration in shallow groundwater and the possible transfer along the groundwater flow path. The intra-site comparative analysis reveals, for the same sampling locations, a differentiation in the PFAS profiles detected across the two monitoring campaigns, indicating a temporal evolution in the chemical composition. Furthermore, chemical results show the presence of PFAS exclusively in deep monitoring wells, confirming a spatially heterogeneous distribution within the aquifer system. These results highlight both the temporal and spatial evolution of PFAS concentration, suggesting a complex contaminant migration pathway along preferential gravel and sand horizons in deeper aquifer layers. The conceptual hydrogeological model confirmed hydraulic interconnections among aquifer layers and identified zones of higher vulnerability to contamination. The analysis of possible PFAS migration pathways at the basin scale raised some questions about the influence of wells features and management practices on PFAS distribution in shallow and deep groundwater. The findings of this research contribute to environmental sustainability, providing initial insights for measuring and managing the presence and pathways of PFAS in deep alluvial aquifers. Full article

The presence of pathogens, toxic substances, and excess nutrients in rivers is due to the combination of industrial, agricultural, and livestock farming activities, as well as the absence of wastewater treatment plants and sewerage networks. River degradation is the result of these factors. The results from four monitoring campaigns of water quality, carried out between November 2023 and August 2024, in the rivers of northern Urabá, Colombia, are presented in this paper, and the relationships between physicochemical and microbiological parameters are assessed. Water samples from 16 sites, upstream, downstream, and within urban centers, as well as at the mouths of the Hobo, Zapata, and Damaquiel rivers, and two water bodies flowing into the coastal lagoon of Bahía El Uno are presented. Five water quality factors were analyzed at using Spearman’s correlation analysis (p = 0.005). The results revealed negative correlations between dissolved oxygen (DO) and coliforms (−0.49), and positive correlations between temperature and total dissolved solids (TDS) (0.365). The elevated content coliforms exceeding permissible Colombian standards to total coliforms (˂200 MPN/mL) and thermotolerance (1000 MPN/mL) reached 8,400,000 and 24,000,000 MPN/mL, respectively, indicating that urban discharges increase microbial loads and induce degradation of conditions in the study area. Full article

Background: The compaction of formulation blends is a critical stage in pharmaceutical tablet manufacturing, particularly when drug substances or functional excipients exhibit limited flowability and tabletability. Objectives: This study systematically examined the mechanical behaviour of viscoelastic microcrystalline cellulose (MCC) and brittle anhydrous dibasic calcium phosphate (DCPA), as well as their mixtures, to check how deformation mechanisms influence powder handling and tablet performance. Methods: A compaction simulator, mimicking a small rotary tablet press, was used to evaluate tablet weight variability, densification profiles, die-filling height, force–displacement behaviour, and in-die Heckel analysis. Additional assessments included compression times, breaking force, tensile strength, elastic recovery, as well as in-die and out-of-die tablet thickness across various compositions and compaction pressures. Results/Conclusions: Bulk density values from the simulator showed strong correlation with pharmacopeial measurements (R² ≥ 0.997). Measurable differences in true density and cohesiveness led to poor flowability for MCC and good flow for DCPA, with mixtures containing higher DCPA concentration displaying markedly improved flow characteristic. Compaction analyses confirmed extensive plastic deformation for MCC and fragmentation for DCPA. Increasing MCC content elevated die-fill height, compaction energy, and tablet weight variability, whereas higher DCPA fractions decreased apparent density of tablets and reduced energy demand. Tabletability and compressibility profiles reflected that MCC generated hard tablets but exhibited higher elastic recovery, while DCPA formed softer tablets with closer to linear strength–pressure relationships. Energy profiling demonstrated that MCC stored more elastic energy and required higher overall compression work, whereas DCPA reduced elastic accumulation. Overall, blending viscoelastic and brittle excipients offers a robust strategy for optimizing manufacturability, mechanical strength, and energy efficiency in tablet production. Full article

Pesticides are chemical substances widely used to control, prevent, or eliminate pests in agriculture, gardening, and other sectors. However, their use poses risks to human health, and recent regulatory efforts have focused on minimizing exposure and monitoring residue levels. In this study, the separation of seven pesticides was investigated using supercritical fluid chromatography coupled to diode-array detection (SFC-DAD). The influence of six different stationary phases and various organic modifiers, as well as additional parameters such as temperature, pressure, and the presence of additives, was systematically evaluated to optimize the chromatographic conditions. The best separation performance was achieved using a LiChrospher^® 100 DIOL column with methanol as the organic modifier under a gradient program. Analyses were carried out at a flow rate of 3 mL/min, a column temperature of 35 °C, and a system back pressure of 150 bar, resulting in a total analysis time of approximately 4 min. The optimized method allowed for a faster separation of the selected agricultural pesticides by SFC-DAD compared to conventional chromatographic techniques. Full article

Background: In Siberian folk medicine, Sagan-Dalya (Rhododendron adamsii Rehder) of the Ericaceae family is used as a tonic and restorative in the form of infusions and decoctions. Pharmacological studies have shown that alcoholic extracts of this plant enhance performance and have anti-inflammatory and immunomodulatory effects. Rhododendron adamsii shoots accumulate essential oil (up to 1.6%), flavonoids (1.8–3.0%), tannins (up to 6.9%), phenolic carbolic acids, β-sitosterin, oleanolic and ursolic acids, simple phenolic compounds, and coumarins. Methods: Supercritical carbon dioxide extraction (SC-CO₂) is the most preferred environmentally friendly and selective method for extracting these natural compounds from the plant matrix of Rh. adamsii due to their high thermolability. Tandem mass spectrometry was applied to detect chemical compounds. Mass-spectrometry (MS) analysis was performed on an ion trap equipped with an ESI source in negative and positive ion modes. The capture rate was one spectrum/s for MS and two spectrum/s for MS/MS. All experiments were repeated three times. A four-stage ion separation mode (MS/MS mode) was implemented. Results: The operative parameters and working conditions have been optimized by different pressure (100–400 bars) and temperature (31–70 °C) regimes, and CO₂ flow rate (10–25 mL/min) with 1 C₂H₅OH as a co-solvent. The extraction time varied from 60 to 90 min. The maximum global yield of biologically active substances (BAS) from R. adamsii leaves and stems was observed under the following extraction conditions: Pressure: 350 bar, extraction temperature: 65 °C, extraction time: 1 h; the global yield of BAS was 8.5 mg/g of plant sample; the share of the co-solvent (C₂H₅OH) was 2%. In total, forty-nine different BAS were identified in the Rh. adamsii SC-CO₂ extracts. Conclusions: The obtained results may shed new light on the scientific basis for the traditional medicinal use of Rh. adamsii leaf and stem extracts. The pharmacological contribution of the identified phytocannabinoids requires further detailed study. It is hypothesized that the excellent transdermal permeability of supercritical extracts may open new therapeutic approaches using transdermal formulations based on SC-CO₂ extracts of Rh. adamsii. Full article

This is the first report on the electrochemical simulation of phase I metabolism of 2-(4-bromo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25B-NBOMe), a relatively new psychoactive substance available on the illicit drug market. The electrochemical approach enables fast generation and characterization of potential in vivo metabolites, and thus, can assist in the preliminary assessment of xenobiotic activity and toxicity profiles in humans. Phase I oxidation reactions of 25B-NBOMe were simulated in a three-electrode thin-layer electrochemical flow cell. Electrochemically generated products were directly analyzed by high-resolution mass spectrometry. To verify relevance to human metabolism, they were compared with those detected in biological samples taken from individuals severely intoxicated with 25B-NBOMe. The electrochemical conversion of 25B-NBOMe yielded key phase I metabolites—hydroxylated and N-desalkylated—along with their corresponding dehydrogenated products. O-Desmethylated and bis-O,O-desmethylated drug derivatives were also formed electrochemically, though in lower amounts. The former was confirmed in gastric contents, blood, and urine samples. Furthermore, phase II metabolites, such as O-desmethyl-25B-NBOMe glucuronide and sulfonate, were detected exclusively in some biological specimens, highlighting the complementary role of in vivo analysis. Our findings demonstrate that the electrochemical method provides a promising platform for the rapid and straightforward evaluation of 25B-NBOMe phase I metabolism. The partial overlap with authentic human metabolites supports its relevance as a screening and hypothesis-generating tool. The electrochemical approach, although not fully consistent with data from biological samples, can complement conventional in vitro and in vivo models, aiding in the identification of potential biomarkers and the evaluation of toxicological risk associated with novel psychoactive substances. Full article

Objectives: The purpose of this study is to develop and verify a sandwich-type lateral flow immunoassay (LFA) integrated with a smartphone, enabling semi-quantitative 25-hydroxyvitamin D [25(OH)D] measurement including automated image analysis function, thereby establishing a reliable and accessible vitamin D evaluation system for point-of-care (POCT). Methods: A smartphone-based sandwich-type LFA was constructed, and 25(OH)D was measured semi-quantitatively. The system combined a customized test strip with an automatic image acquisition, calibration, and classification module integrated into an application dedicated to a smartphone. Analysis performance, reproducibility, and equivalence between sample types were comprehensively evaluated. Results: The developed analysis achieved a detection range of 5–100 ng/mL, and there were little interference and cross-reactivity for endogenous substances or structurally similar vitamin D derivatives. The image processing algorithm accurately classified the samples into three clinically important categories: deficiency (<20 ng/mL), insufficient (20–30 ng/mL), and sufficient (>30 ng/mL). Cross-platform testing between Android and iOS devices showed excellent reproducibility (r = 0.99, R² = 0.9967). Comparative analysis with the Atellica IM 1600 analyzer showed a high degree of agreement between 97.0% category consensus and κ = 0.951 (r = 0.99, R² ≥ 0.98). Comparative tests between serum and capillary samples also confirmed a 100% classification agreement rate and an overall diagnostic accuracy of 95.5%. Conclusions: This next-generation smartphone integration platform enables rapid, accurate, and semi-quantitative detection of 25(OH)D from fingerstick and serum specimens. By combining the sandwich-type LFA design with computational-based imaging analysis, the system effectively overcomes the major limitations of small-molecule immunoassay and has the potential to be applied to field diagnosis (POCT), decentralized diagnostics, and vitamin D screening in large populations. Full article

To investigate the influence of salt transport in water–steam mixtures on flow and heat transfer and to ensure the operational safety of steam injection boilers, this study simulated the behavior of high-dryness steam carrying salts in U-tubes. The analysis focused on three representative substances—silica, hematite, and calcium carbonate—to evaluate their effects on flow and heat transfer characteristics under varying conditions. The simulation results show that under specified operating conditions, vortices induced by rotational flow lead to complex flow behavior in U-tubes, with transitions from stratified flow to annular flow and back to stratified flow. The effects of salt precipitation on the temperature, velocity, and pressure fields of the boiling flow were also examined. The findings indicate that for pure water, large gradients and multiple vortices adversely affect flow stability, whereas the introduction of small amounts of salts provides localized stabilization in regions of the fluid away from the wall. Full article

The success and impact of biological invasions depend on adaptations to novel abiotic and biotic selective pressures. However, the genetic mechanisms underlying adaptations in invasive species are inadequately understood. Taenioides sp. is an invasive worm goby, originally endemic to brackish waters in the estuaries of Southeastern China, and now colonizes multiple inland freshwaters of North China within decades as a byproduct of the East Route of South-to-North Water Transfer (ESNT) project. However, the molecular mechanisms underlying their adaptations to the climate of North China, especially the temperature regime, are unknown. Here, we performed genomic resequencing analysis to assess genetic diversity and population genetic structure, and further investigated the genomic signatures of local adaptation in the invasive population of Taenioides sp. during their northward invasion. We revealed that all invasive populations exhibited no genetic differentiation but low gene flow and an obvious signal of population bottleneck. Yangtze River estuary may serve as the source population, while Gaoyou Lake serves as a potential bridgehead of the invasion. Selective sweep analyses revealed 117 genomic regions, containing 673 candidate genes, under positive selection in populations at the invasive front. Redundancy analysis suggested that local temperature variables, particularly the monthly minimum temperature, represent critical evolutionary forces in driving adaptive divergence. Functional enrichment analyses revealed that multiple biological processes, including metabolism and energy production, substance transmembrane transport, and neural development and synaptic transmission, may play important roles in adaptation to regional temperature conditions. Our findings revealed a scenario of adaptive evolution in teleost species that underpins their regional climate adaptation and successful establishment of invasive populations in a human-facilitated invasion context. Proper management strategies should be established to manage Taenioides sp invasion as soon as possible. Full article

Food contamination poses a significant global public health challenge, necessitating the accurate detection of hazardous substances within complex food matrices. Magnetic core–shell nanomaterials have emerged as critical materials for trace contaminant analysis due to their efficient magnetic separation capabilities, excellent adsorption performance, and tunable surface functionalities. By encapsulating magnetic cores with functional shells, these nanomaterials combine rapid magnetic responsiveness with advantageous shell properties, including target-specific recognition, enhanced dispersibility, colloidal stability, and high surface area. This enables a comprehensive detection approach encompassing target adsorption, rapid separation, and signal amplification. Magnetic core–shell nanomaterials have been effectively integrated with techniques including magnetic solid-phase extraction (MSPE), fluorescence (FL) assays, and lateral flow immunoassays (LFIAs), demonstrating broad applicability in food safety monitoring and detection. This review outlines synthesis strategies for magnetic core–shell nanomaterials, highlights their applications for food contaminant detection, and discusses future challenges and prospects in the field of food safety analysis. Full article