Search Results (2,689)

The continuous discharge of pharmaceutical residues into aquatic environments has raised significant environmental concerns due to their persistence and incomplete removal during wastewater treatment. Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently detected pharmaceutical contaminants in industrial effluents. In this study, a sensitive and selective analytical method was developed for the simultaneous determination of ketoprofen (KTP), meloxicam (MEL), and celecoxib (CEL) in pharmaceutical wastewater using micellar electrokinetic chromatography (MEKC) combined with off-line solid-phase extraction (SPE). A high-volume SPE procedure (1000 mL sample) followed by evaporation and reconstitution provided a theoretical enrichment factor of approximately 10,000. Under optimised conditions, complete separation was achieved in less than 10 min. The method exhibited excellent linearity over a range of 0.5–20 µg/mL (r² > 0.999), with limits of detection in wastewater ranging from 14 to 18 ng/L. Accuracy and precision complied with ICH Q2(B) guidelines, and recoveries from spiked wastewater samples ranged from approximately 99% to 101%, indicating efficient extraction and minimal analyte loss. The validated method was successfully applied to real pharmaceutical wastewater samples, demonstrating its suitability for the routine monitoring of trace-level NSAIDs in complex industrial matrices. Full article

In this study, thermogravimetric analysis was employed to investigate the non-isothermal combustion behavior and kinetic characteristics of poplar biomass under air and oxy-fuel (O₂/CO₂) atmospheres. The effects of heating rate and oxygen concentration on combustion performance, gaseous emissions, and kinetic parameters were systematically analyzed. Results show that poplar biomass combustion consists of four distinct stages: moisture evaporation, devolatilization with volatile oxidation, char and fixed carbon oxidation, and final burnout. Increasing the heating rate intensifies the combustion process, shifting characteristic temperatures to higher values and significantly enhancing the comprehensive combustion index. Compared with air combustion, oxy-fuel conditions reduce ignition temperature and the temperature corresponding to the maximum combustion rate, leading to an earlier ignition and a more concentrated reaction interval. Higher oxygen concentrations further improve overall combustion performance and promote more complete carbon conversion. Gas emission analysis indicates that oxy-fuel combustion effectively suppresses NO₂ and SO₂ formation, demonstrating notable emission-reduction potential. Kinetic analysis using the Kissinger–Akahira–Sunose and Flynn–Wall–Ozawa isoconversional methods shows that the activation energy varies with conversion degree and is generally higher under oxy-fuel atmospheres than in air. Overall, oxy-fuel combustion enhances biomass reactivity while achieving coordinated emission control through increased oxygen partial pressure and improved heat and mass transfer, supporting its practical application in biomass energy systems. Full article

In the current work, a novel heat pump drying system with precise control of temperature and humidity of drying medium was developed and the impacts of drying temperature and humidity on the drying characteristics of apple slices and energy consumption of drying system were investigated. Experimental results indicated that the temperature and relative humidity (RH) of drying medium have a significant impact on drying efficiency and operating performance. During the first hour of the drying process, the heat pump drying of apple slices exhibited the highest drying rate throughout the entire process at a temperature of 40~50 °C and a relative humidity of 30~60%. And then the apple slices drying was in a falling-rate drying stage. When the relative humidity of the drying medium exceeded 50%, the final moisture content of the material increased significantly and exceeded 20% (dry basis, d.b.). Increased air medium temperature and humidity enhance the dehumidification rate of the evaporator. When the drying temperature was maintained at 40–60 °C, the condensation rate at 60% RH was 3.5–10 times that at 30% RH. The increased dehumidification rate significantly promoted the energy efficiency. The specific moisture extraction rate (SMER) was 2.53 kg/(kW·h) at 60 °C and 60% RH, which is 3.4 times that at 30% RH. It was appropriate to adopt high-temperature and high-humidity conditions in the early drying stage to improve drying energy efficiency. Meanwhile, the relative humidity should be reduced to promote moisture removal from the material in the late drying stage. The obtained results provided theoretical methods for the energy-saving control of heat pump drying for fruits. Full article

Photovoltaic (PV) is the most promising clean energy, and water-surface PVs have been developing rapidly due to less land occupation. For south-facing fixed PV arrays, differences in the wind direction–angle will lead to variations in wind resistance. In this paper, surface wind speed and evaporation near the water surface of a PV-covered fish pond are observed. Results show the ratio of wind speed in the PV area to the reference site (denoted as α) is 0.2~0.3 in the south-biased wind direction, and 0.5~0.6 in the north-biased and east wind direction. A statistical formula for α with wind direction is proposed. The α values agree with previous conclusions from studies of single wind directions. Then the monthly average wind speed reduction ratio is calculated using the environmental wind rose diagram and α. The measured ratio of the monthly evaporation amount from the PV site to the reference site agrees well with that of the monthly wind speed. The method is applied to evaluate evaporation reduction at three PV sites of different latitudes. The results show the evaporation reduction by PVs is more than 50% at all three sites, and the maximum annual amount of 1236 mm occurred with a prevailing wind direction S. Full article

Background/Objectives: Current clinical evidence suggests that cannabidiol (CBD) demonstrates therapeutic potential in the management of chronic pain, particularly in conditions involving inflammation. However, its therapeutic potential is severely limited by poor oral bioavailability, extensive first-pass metabolism, and the need for frequent high-dose administration, which compromises patient adherence and tolerability. Long-acting injectable (LAI) delivery systems offer a strategy to overcome these limitations by providing sustained plasma concentrations and reducing dosing frequency. This study aimed to develop and optimise CBD-loaded poly (lactic-co-glycolic acid) (PLGA) microspheres for LAI delivery and to evaluate poly(2-ethyl-2-oxazoline) (POx) as a functional and biocompatible alternative to the conventionally used poly (ethylene glycol) (PEG). Methods: CBD-loaded microspheres were prepared using emulsion–solvent evaporation technique. The formulations were optimised based on entrapment efficiency (EE), drug loading (DL), particle size distribution, surface morphology, thermal behaviour, in vitro release kinetics, and cytocompatibility using NIH 3T3 fibroblasts. Multiple in vitro release methodologies, including dialysis bag, shaking-flask, and USP Apparatus IV, were evaluated to identify the most discriminative and practical approach for long-term release assessment. Results: The optimised POx-based microspheres demonstrated superior control over particle size, yielding significantly smaller and more uniform particles compared with PEG-based microspheres (124 ± 1.47 µm vs. 218 ± 13.5 µm, respectively). Differential scanning calorimetry (DSC) confirmed molecular dispersion of CBD within the polymer matrix. In vitro release studies demonstrated sustained drug release over 20 days. Conclusions: POx represents a promising alternative to PEG for the formulation of CBD-loaded PLGA microspheres, offering enhanced physicochemical stability and biological compatibility. This platform supports the development of safe and effective long-acting injectable CBD therapies and consideration of POx as an alternative to PEG. Full article

Introduction: Selective brain hypothermia has been investigated to improve neurological outcomes in patients with cardiac arrest; however, an optimal clinical method has not yet been established. This study aimed to evaluate the feasibility of a technique combining transnasal evaporative cooling with simultaneous endovascular temperature management to achieve selective brain hypothermia while preventing systemic hypothermia. Methods: Three adult male Göttingen swine were anesthetized and mechanically ventilated. Transnasal cooling was initiated at maximum output while endovascular warming preserved systemic temperature. Brain parenchymal and rectal temperatures, mean arterial pressure (MAP), heart rate (HR), and cardiac output (CO) were continuously monitored for 60 min. Temperature differences between brain and rectum at 60 min were analyzed. Results: A brain–rectal gradient ≥1.0 °C was achieved in all swine at 25, 40, and 30 min, respectively, and maintained at 1.0–1.5 °C thereafter. Brain temperature (34.5 ± 0.34 °C) was significantly lower than rectal temperature (35.8 ± 0.35 °C) at 60 min after initiation of the selective cooling procedure (p = 0.0048). MAP, HR, and CO showed no deviations from baseline. Conclusions: The combination of transnasal cooling and endovascular warming reliably induced selective brain hypothermia of 1–1.5 °C without adverse effects on hemodynamic parameters in swine. Full article

Background/Objectives: The formulation development of Isotretinoin (ISN) is limited by its solubility and stability issues. This study aimed to characterise the BCS class II drug ISN, particularly the possible different solid state and formulate amorphous solid dispersion aiming for a supersaturation state. Methods: ISN’s physical states are investigated in its raw form, quench-cooled form, physical mixture with the polymer and corresponding solid dispersion form. Quench-cooled ISN was prepared in situ using DSC. Carrier stabilisation of ISN was attempted using the solid dispersion technique. Hereby, the solid dispersion of drug-polymer PVPVA at a ratio of 1:3 was prepared using the solvent evaporation method. Solid dispersion, physical mixture and raw ISN were characterised for the saturated solubility. Physical characterisation of the samples was performed using DSC, ATR-FTIR and a light microscope. Results: Two polymorphs of ISN (forms I and II) were found in the raw ISN, with form II being thermodynamically more stable. ISN possesses strong crystallinity and resistance to amorphisation under the applied quench-cooling condition without the presence of a carrier system. The conjugated polyene structure in ISN contributes to the polymorphic transformation and isomerisation. The incorporation of PVPVA in the solid dispersion system successfully improved the water solubility (sixfold) of ISN despite a combination of crystalline and amorphous components being present in the system. Conclusions: ISN is a class II drug crystal molecule. Taking advantage of solubility and possibility in the polymorphic transformation of ISN in a binary system, we concluded that ISN could potentially be formulated into its corresponding crystalline solid dispersion form. Full article

Background: Accessory ostia (AOs) can notably alter maxillary sinus ventilation, yet configuration-specific effects remain unclear. This study quantified how AO location and orientation regulate sinus ventilation using in vitro measurements and numerical analyses. Methods: One patient-specific sinonasal geometry (control) was used to reconstruct five models with varying AO numbers, locations, and orientations (AO-F, AO-FC, AO-F30, AO-B, AO-FB). E-vapor was used as a visual tracer for sinus clearance under breath-hold and quiet breathing conditions. Complementary simulations characterized flow dynamics and sinus ventilation rates. Results: Both inhalation and AO presence accelerate e-vapor clearance for all conditions considered. The e-vapor clearance time in AO-FB decreases from 51 s under breath-hold to 29 s under quiet breathing (1 m/s). Configuration-wise, posterior AO ventilates the sinus faster than anterior AO, with dual anterior–posterior ostia (AO-FB) consistently performing the best. Among the three anterior AO, an uptilt AO ventilates the sinus faster than a parallel one, which is in turn faster than an AO located closer to the natural ostium (NO), i.e., AO-F30 > AO-F > AO-FC. CFD predictions provide a mechanistic understanding of the configuration-specific differences observed in vitro. Flow patterns in the ostium–sinus region, as well as the ventilation rate and driving pressure, show high sensitivities to AO location and orientation. At 1 m/s, the predicted AO-NO pressure drop ranges 2–18 mPa, with the lowest in AO-FC and highest in AO-B. Conclusions: The high sensitivity of sinus ventilation to AO configurations underscores the clinical importance of examining NO-adjacent openings in surgical planning and physiological interpretation. Full article

The integration of sustainable and natural waste-derived materials into lightweight metals presents a promising strategy with both environmental and performance-related benefits. In this study, a biobased magnesium composite reinforced with dried leaf powder (DLP) derived from fallen waste leaves was synthesized using a controlled powder metallurgy method incorporating energy efficient hybrid microwave sintering, followed by hot extrusion at varying temperatures (350 °C, 250 °C, 150 °C). Microstructural analysis revealed that the addition of DLP had minimal effect on the overall grain morphology, while lower extrusion temperatures promoted finer grains due to restricted grain growth. Mg–5DLP composites consistently exhibited higher porosity than pure Mg, primarily due to the evaporation of organic constituents during sintering. The damping performance of the biomass-containing materials was improved (54.5% increase), particularly at lower extrusion temperatures (250 °C), though mechanical performance showed a trade-off with reduced hardness and compressive strength. A slight increase in yield strength at lower extrusion temperatures was attributed to retained dislocation density and grain refinement. Thermal stability remained largely unaffected, while corrosion behavior was strongly dependent on both DLP addition and extrusion temperature, with Mg–5DLP samples corroding faster than pure Mg when extruded at higher temperatures; interestingly, however, at the lowest extrusion temperature (150 °C), improved corrosion resistance to pure Mg (1.3 mm/year for Mg-5DLP vs. 2.0 mm/year for pure Mg) was observed. Overall, this work demonstrates that extrusion temperature is a critical factor in controlling the microstructure, thermal response, damping response, mechanical behavior and corrosion of biobased composites. The study not only highlights the potential of using direct biomass reinforcement of magnesium to synthesize lightweight, ecofriendly materials, but also lays a strong foundation for future investigations into biobased composite design, processing optimization, and property tailoring. Full article

The depletion of natural resources remains an acute global problem, highlighting the importance of developing sustainable technologies that enable the simultaneous extraction of metals and recycling of waste. This paper describes a study of a technology for recycling aluminum slag from foundries to produce secondary aluminum alloy and regenerated flux. Research and processing methods include X-ray phase and spectral analysis of slag composition, multi-stage grinding in a jaw crusher and planetary mill, screening for fraction separation, and selective dissolution of the oxide–salt phase in water or hydrochloric acid followed by filtration and evaporation; obtaining regenerated flux based on phase diagrams of chloride systems; and briquetting and remelting of the extracted aluminum. The technology ensures the extraction of up to 85% of the metallic aluminum from slag and the production of regenerated flux based on the NaCl–KCl–MgCl₂ system with a low melting point. Full article

Terminal lakes in arid regions face severe degradation due to the dual pressures of climate change and anthropogenic water consumption. Traditional single-threshold methods for defining ecological water requirements often fail to balance ecosystem stability with water scarcity. To address this, this study constructs a comprehensive framework coupling “Morphometric Stability–Ecological Security Reliability–Resource Use Efficiency” to delineate the suitable ecological interval for Ebinur Lake, the largest saltwater lake in Xinjiang. Using multi-source remote sensing data (Landsat, Sentinel, ICESat, CryoSat), we reconstruct the long-term hydrological dynamics from 2001 to 2023. Results indicate a significant shrinking trend in the lake area, driven primarily by reduced inflow. We jointly consider the lake morphometric breakpoint, the ecological security baseline, and the lower bound of ecosystem service water use efficiency (ESWUE) to determine a minimum suitable ecological area of 500 km²; the regulation upper limit is set at 740 km² based on the marginal peak of ESWUE. However, monitoring data reveal that the lake falls below the minimum 500 km² baseline in approximately 40% of months, highlighting a severe ecological deficit risk. Furthermore, ESWUE analysis shows a peak in April (10 CNY/m³), suggesting that, under current climate conditions, a “Spring Surplus and Autumn Deficit” regulation strategy—advancing the replenishment window to the spring windy season—can maximize dust suppression benefits at a lower evaporative cost. This study provides a theoretical basis and methodological paradigm that will contribute to the sustainable management of shrinking terminal lakes globally. Full article

To address the limitations of traditional runoff prediction methods—namely, the oversimplification of meteorological factor selection, ambiguous interactions among core variables, and the disruptive influence of redundant inputs—this study focuses on the Zijiang River Basin as a representative case. A suite of machine learning models, including Long Short-Term Memory Neural Network (LSTM), Convolutional Neural Network (CNN)-LSTM, Temporal Convolutional Network (TCN), and Gradient Boosting Regression Tree (GBRT), was constructed and trained using 13 distinct combinations of meteorological variables. These configurations were systematically evaluated to assess their compatibility with each model in simulating daily runoff patterns. Additionally, the Shapley Additive Explanations (SHAP) algorithm was employed to quantitatively assess the contribution of each factor to predictive accuracy. Among the models tested, the TCN model consistently demonstrated superior performance, particularly in mitigating the effects of irrelevant or redundant features. The GBRT model showed distinctive strengths in accurately predicting peak flow timings. Of all input configurations, the combination of “runoff + precipitation + evaporation + temperature” emerged as the most effective. Findings indicate that the predictive value of individual meteorological variables hinges primarily on their direct correlation with runoff, while the effectiveness of multi-factor schemes depends on the degree of functional integration—specifically, the coupling of hydrological recharge, consumption, and regulatory processes. The presence of redundant variables was found to impair model performance unless they contributed to a meaningful synergistic relationship with core inputs. The SHAP analysis further reinforced these insights: precipitation-related variables proved to be the most critical to prediction accuracy, whereas temperature and evaporation served more complementary roles. Notably, the inclusion of relative humidity tended to suppress runoff responses and increased deviation in peak timing estimates. These findings shed light on the nuanced interplay between meteorological input design and model selection, offering a robust foundation for optimizing data-driven runoff prediction frameworks. Full article

The arid region of Northwest China (ARNWC) faces severe desertification, posing a major threat to ecological sustainability and socio-economic development. However, systematic evaluation of desertification across the entire northwestern arid zone remains limited. To address the uncertainty caused by mixed pixels in sparsely vegetated drylands, this study innovatively integrates vegetation and soil indices to develop a robust machine learning-based system for classifying desertification levels in the ARNWC over three decades. In addition, the geographical detector method is employed to quantify the driving factors influencing desertification. The key findings are as follows: (1) Desertification expansion predominantly occurred between 1990 and 1995, followed by a gradual improvement from 1995 to 2020. Transitions between severe and moderate desertification were the most frequent, with approximately 15 × 10⁴ km² shifting from severe to moderate desertification. (2) Physiographic factors were the primary drivers of changes in desertification level, followed by climatic factors. Fractional Vegetation Cover (FVC) had the strongest influence, with an average q-value of 0.72. (3) The explanatory power of the drivers increased significantly through interactions, with the combination of FVC and evaporation (EVA) showing the most pronounced effect. Overall, the methods and findings of this study provide critical insights for targeted desertification control and ecological restoration strategies in arid regions. Although this approach primarily captures desertification symptoms related to surface cover, it offers a valuable long-term perspective on surface cover dynamics. Full article

The solubilization of poorly water-soluble drugs remains a critical challenge in pharmaceutical research. The formulation of solid dispersions employing mesoporous silica nanoparticles (MSN) constitutes a key strategy for enhancing the hydrophilicity and oral bioavailability of Biopharmaceutics Classification System (BCS) Class II drugs. Although several commercial mesoporous silica excipients have been approved for pharmaceutical use, there remains room for improvement regarding drug loading capacity, stability, and controllability of drug release. Methods: for this purpose, dendritic mesoporous silica nanoparticles (DMSN) with a radial dendritic structure and pH-responsive degradation properties were designed and synthesized using celecoxib (CEL) as the model drug, featuring a pore size of 21.51 nm. CEL was loaded onto DMSN and seven commercial solid dispersion excipients using the solvent evaporation method. Results: owing to its high surface area, pore volume, and radial structure, DMSN achieved 39.72% drug loading in an amorphous state, markedly improving wettability, dissolution, and physical stability. Accelerated stability tests showed that DMSN inhibited recrystallization, outperforming traditional solid dispersions. Pharmacokinetic studies in rats demonstrated that the oral bioavailability of CEL-DMSN was 1.29-fold higher than that of commercial celecoxib capsules. Conclusions: in conclusion, these results confirmed the potential of DMSN in enhancing the stability, promoting oral absorption, and reducing gastrointestinal irritation of poorly soluble drugs. Full article

A series of nickel phyllosilicate catalysts (Ni-PS-T, where T represents the calcination temperature in °C) were synthesized via he ammonia-evaporation method and calcined at different temperatures to investigate their performance in the hydrogenation of 5-hydroxymethylfurfural (HMF). Characterization by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) revealed that increasing the calcination temperature (300–1100 °C) triggered a phase evolution from the 1:1-type (tetrahedral-octahedral) to the 2:1-type (tetrahedral-octahedral-tetrahedral) Ni-PS, eventually leading to phase separation into NiO and SiO₂. The content of the 2:1-type crystalline phase, H₂ adsorption capacity, and C=O hydrogenation activity of HMF all exhibited a volcano-shaped trend with calcination temperature. Under the conditions of 100 °C and 2.5 MPa H₂, Ni-PS-800 enabled HMF hydrogenation with a conversion of 90% and a selectivity of 84% to 2,5-dihydroxymethylfuran (DHMF), in which the catalyst exhibited good stability during five consecutive HMF hydrogenation cycles. The enhanced catalytic performance of Ni-PS-800 is attributed to its high 2:1-type phase fraction, which promotes a pronounced hydrogen-spillover effect and significantly enhances the intrinsic activity for C=O hydrogenation. Full article