A methodological framework for estimating ambient PM2.5 particulate matter concentrations in the UK.

Scientific evidence sustains PM2.5 particles' inhalation may generate harmful impacts on human beings' health; therefore, their monitoring in ambient air is of paramount relevance in terms of public health. Due to the limited number of fixed stations within the air quality monitoring networks, development of methodological frameworks to model ambient air PM2.5 particles is primordial to providing additional information on PM2.5 exposure and its trends. In this sense, this work aims to offer a global easily-applicable tool to estimate ambient air PM2.5 as a function of meteorological conditions using a multivariate analysis. Daily PM2.5 data measured by 84 fixed monitoring stations and meteorological data from ERA5 (ECMWF Reanalysis v5) reanalysis daily based data between 2000 and 2021 across the United Kingdom were attended to develop the suggested approach. Data from January 2017 to December 2020 were employed to build a mathematical expression that related the dependent variable (PM2.5) to predictor ones (sea-level pressure, planetary boundary layer height, temperature, precipitation, wind direction and speed), while 2021 data tested the model. Evaluation indicators evidenced a good performance of model (maximum values of RMSE, MAE and MAPE: 1.80 µg/m3, 3.24 µg/m3, and 20.63%, respectively), compiling the current legislation's requirements for modelling ambient air PM2.5 concentrations. A retrospective analysis of meteorological features allowed estimating ambient air PM2.5 concentrations from 2000 to 2021. The highest PM2.5 concentrations relapsed in the Mid- and Southlands, while Northlands sustained the lowest concentrations.

Modulating pro-fibrotic macrophages using yeast beta-glucan microparticles prepared by Pressurized Gas eXpanded liquid (PGX) Technology®.

Pro-fibrotic M2-like macrophages are widely implicated in the pathogenesis and progression of lung fibrosis due to their production of pro-fibrotic growth factors and cytokines. Yeast beta-glucan (YBG) microparticles have shown potential as immunomodulators that can convert macrophage polarization from a pro-fibrotic phenotype to an anti-fibrotic phenotype through the engagement of the Dectin-1 receptor. However, the processing conditions used to fabricate YBG microparticles can lead to unpredictable immunomodulatory effects. Herein, we report the use of Pressurized Gas eXpanded liquids (PGX) Technology® to fabricate YBG (PGX-YBG) microparticles with higher surface areas, lower densities, and smaller and more uniform size distributions compared to commercially available spray-dried YBGs. PGX-YBG is shown to activate Dectin-1 more efficiently in vitro while avoiding significant TLR 2/4 activation. Furthermore, PGX-YBG microparticles effectively modulate M2-like fibrosis-inducing murine and human macrophages into fibrosis-suppressing macrophages both in vitro as well as in ex vivo precision-cut murine lung slices, suggesting their potential utility as a therapeutic for addressing a broad spectrum of fibrotic end-point lung diseases.

Unraveling the impact of starch granule-associated proteins on the emulsifying ability of quinoa starch granules at multiple scales.

Total starch granule-associated proteins (tGAP), including granule-channel (GCP) and granule-surface proteins (GSP), alter the physicochemical properties of starches. Quinoa starch (QS) acts as an effective emulsifier in Pickering emulsion. However, the correlation between the tGAP and the emulsifying capacity of QS at different scales remains unclear. Herein, GCP and tGAP were selectively removed from QS, namely QS-C and QS-A. Results indicated that the loss of tGAP increased the water permeability and hydrophilicity of the starch particles. Mesoscopically, removing tGAP decreased the diffusion rate and interfacial viscous modulus. Particularly, GSP had a more profound impact on the interfacial modulus than GCP. Microscopically and macroscopically, the loss of tGAP endowed QS with weakened emulsifying ability in terms of emulsions with larger droplet size and diminished rheological properties. Collectively, this work demonstrated that tGAP played an important role in the structural and interfacial properties of QS molecules and the stability of QS-stabilized emulsions.

Adsorption of typical NDMA precursors by superfine powdered activated carbon: Critical role of particle size reduction.

Control of N-nitrosodimethylamine (NDMA) in drinking water could be achieved by removing its precursors as one practical way. Herein, superfine powdered activated carbons with a diameter of about 1 µm (SPACs) were successfully prepared by grinding powdered activated carbon (PAC, D50=24.3 µm) and applied to remove model NDMA precursors, i.e. ranitidine (RAN) and nizatidine (NIZ). Results from grain diameter experiments demonstrated that the absorption velocity increased dramatically with decreasing particle size, and the maximum increase in k2 was 26.8-folds for RAN and 33.4-folds for NIZ. Moreover, kinetic experiments explained that rapid absorption could be attributed to the acceleration of intraparticle diffusion due to the shortening of the diffusion path. Furthermore, performance comparison experiments suggested that the removal of RAN and NIZ (C0=0.5 mg/L) could reach 61.3% and 60%, respectively, within 5 min, when the dosage of SAPC-1.1 (D50=1.1 µm) was merely 5 mg/L, while PAC-24.3 could only eliminate 17.5% and 18.6%. The adsorption isotherm was well defined by Langmuir isotherm model, indicating that the adsorption of RAN/NIZ was a monolayer coverage process. The adsorption of RAN or NIZ by SAPC-1.1 and PAC-24.3 was strongly pH dependent, and high adsorption capacity could be observed under the condition of pH > pka+1. The coexistence of humic acid (HA) had no significant effect on the adsorption performance because RAN/NIZ may be coupled with HA and removed simultaneously. The coexistence of anions had little effect on the adsorption also. This study is expected to provide an alternative strategy for drinking water safety triggered by NDMA.

The effect of fine grits and fine debris concentrations on the MLVSS/MLSS ratio of an activated sludge system.

This study embarks on an explorative investigation into the effects of typical concentrations and varying particle sizes of fine grits (FG, the involatile portion of suspended solids) and fine debris (FD, the volatile yet unbiodegradable fraction of suspended solids) within the influent on the mixed liquor volatile suspended solids (MLVSS)/mixed liquor suspended solids (MLSS) ratio of an activated sludge system. Through meticulous experimentation, it was discerned that the addition of FG or FD, the particle size of FG, and the concentration of FD bore no substantial impact on the pollutant removal efficiency (denoted by the removal rate of COD and ammonia nitrogen) under constant operational conditions. However, a notable decrease in the MLVSS/MLSS ratio was observed with a typical FG concentration of 20 mg/L, with smaller FG particle sizes exacerbating this reduction. Additionally, variations in FD concentrations influenced both MLSS and MLVSS/MLSS ratios; a higher FD concentration led to an increased MLSS and a reduced MLVSS/MLSS ratio, indicating FD accumulation in the system. A predictive model for MLVSS/MLSS was constructed based on quality balance calculations, offering a tool for foreseeing the MLVSS/MLSS ratio under stable long-term influent conditions of FG and FD. This model, validated using data from the BXH wastewater treatment plant (WWTP), showcased remarkable accuracy.

On using an aerosol thermodynamic model to calculate aerosol acidity of coarse particles.

Thermodynamic modeling is still the most widely used method to characterize aerosol acidity, a critical physicochemical property of atmospheric aerosols. However, it remains unclear whether gas-aerosol partitioning should be incorporated when thermodynamic models are employed to estimate the acidity of coarse particles. In this work, field measurements were conducted at a coastal city in northern China across three seasons, and covered wide ranges of temperature, relative humidity and NH3 concentrations. We examined the performance of different modes of ISORROPIA-II (a widely used aerosol thermodynamic model) in estimating aerosol acidity of coarse and fine particles. The M0 mode, which incorporates gas-phase data and runs the model in the forward mode, provided reasonable estimation of aerosol acidity for coarse and fine particles. Compared to M0, the M1 mode, which runs the model in the forward mode but does not include gas-phase data, may capture the general trend of aerosol acidity but underestimates pH for both coarse and fine particles; M2, which runs the model in the reverse mode, results in large errors in estimated aerosol pH for both coarse and fine particles and should not be used for aerosol acidity calculations. However, M1 significantly underestimates liquid water contents for both fine and coarse particles, while M2 provides reliable estimation of liquid water contents. In summary, our work highlights the importance of incorporating gas-aerosol partitioning when estimating coarse particle acidity, and thus may help improve our understanding of acidity of coarse particles.

Combustion aerosols and suspended dust with controlled processes in Lhasa: Elemental analysis and size distribution characteristics.

To explore air contamination resulting from special biomass combustion and suspended dust in Lhasa, the present study focused on the size distribution and chemical characteristics of particulate matter (PM) emission resulting from 7 types of non-fossil pollution sources. We investigated the concentration and size distribution of trace elements from 7 pollution sources collected in Lhasa. Combining Lhasa's atmospheric particulate matter data, enrichment factors (EFs) have been calculated to examine the potential impact of those pollution sources on the atmosphere quality of Lhasa. The highest mass concentration of total elements of biomass combustion appeared at PM0.4, and the second highest concentration existed in the size fraction 0.4-1 µm; the higher proportion (12 %) of toxic metals was produced by biomass combustion. The elemental composition of suspended dust and atmospheric particulate matter was close (except for As and Cd); the highest concentration of elements was all noted in PM2.5-10 (PM3-10). Potassium was found to be one of the main biomass markers. The proportion of Cu in suspended dust is significantly lower than that of atmospheric particulate matter (0.53 % and 3.75 %), which indicates that there are other anthropogenic sources. The EFs analysis showed that the Cr, Cu, Zn, and Pb produced by biomass combustion were highly enriched (EFs > 100) in all particle sizes. The EFs of most trace elements increased with decreasing particle size, indicating the greater influence of humanfactors on smaller particles.

Physicochemical characteristics of airborne microplastics of a typical coastal city in the Yangtze River Delta Region, China.

Airborne microplastics (MPs) are important pollutants that have been present in the environment for many years and are characterized by their universality, persistence, and potential toxicity. This study investigated the effects of terrestrial and marine transport of MPs in the atmosphere of a coastal city and compared the difference between daytime and nighttime. Laser direct infrared imaging (LDIR) and polarized light microscopy were used to characterize the physical and chemical properties of MPs, including number concentration, chemical types, shape, and size. Backward trajectories were used to distinguish the air masses from marine and terrestrial transport. Twenty chemical types were detected by LDIR, with rubber (16.7%) and phenol-formaldehyde resin (PFR; 14.8%) being major components. Three main morphological types of MPs were identified, and fragments (78.1%) are the dominant type. MPs in the atmosphere were concentrated in the small particle size segment (20-50 µm). The concentration of MPs in the air mass from marine transport was 14.7 items/m3 - lower than that from terrestrial transport (32.0 items/m3). The number concentration of airborne MPs was negatively correlated with relative humidity. MPs from terrestrial transport were mainly rubber (20.2%), while those from marine transport were mainly PFR (18%). MPs in the marine transport air mass were more aged and had a lower number concentration than those in the terrestrial transport air mass. The number concentration of airborne MPs is higher during the day than at night. These findings could contribute to the development of targeted control measures and methods to reduce MP pollution.

Insights into the seasonal characteristics of single particle aerosols in Chengdu based on SPAMS.

To investigate the seasonal characteristics in air pollution in Chengdu, a single particle aerosol mass spectrometry was used to continuously observe atmospheric fine particulate matter during one-month periods in summer and winter, respectively. The results showed that, apart from O3, the concentrations of other pollutants (CO, NO2, SO2, PM2.5 and PM10) were significantly higher in winter than in summer. All single particle aerosols were divided into seven categories: biomass burning (BB), coal combustion (CC), Dust, vehicle emission (VE), K mixed with nitrate (K-NO3), K mixed with sulfate and nitrate (K-SN), and K mixed with sulfate (K-SO4) particles. The highest contributions in both seasons were VE particles (24%). The higher contributions of K-SO4 (16%) and K-NO3 (10%) particles occurred in summer and winter, respectively, as a result of their different formation mechanisms. S-containing (K-SO4 and K-SN), VE, and BB particles caused the evolution of pollution in both seasons, and they can be considered as targets for future pollution reduction. The mixing of primary sources particles (VE, Dust, CC, and BB) with secondary components was stronger in winter than in summer. In summer, as pollution worsens, the mixing of primary sources particles with 62 [NO3]- weakened, but the mixing with 97 [HSO4]- increased. However, in winter, the mixing state of particles did not exhibit an obvious evolution rules. The potential source areas in summer were mainly distributed in the southern region of Sichuan, while in winter, besides the southern region, the contribution of the western region cannot be ignored.

Effect of the addition of Chachafruto flour on the stability of oil-in-water emulsions and the physicochemical properties of spray-drying microcapsules.

This study aimed to assess the suitability of Chachafruto flour (CHF) as a stabilizing agent for an oil-in-water emulsion and its impact on the physicochemical properties of the emulsion after spray drying. Emulsions with varying CHF concentrations (2 %, 3 %, and 4 %) were prepared and compared to a control. The results from the creaming index and particle size (emulsion) analyses indicated that the highest emulsion stability was achieved with 4 %CHF, attributed to its protein content (20.5 %). The encapsulates exhibited spherical and rough surface morphologies but without holes on the surface. Low moisture content (MC < 5 %) and water activity (aw < 0.2) were associated with powder stability. The encapsulates added with CHF showed good reconstitution properties. FTIR confirmed the absence of chemical interactions during the encapsulation process, contributing to the stability. Furthermore, the addition of CHF improved the thermal stability of the encapsulates. This study represents the first investigation on the emulsifying potential of Chachafruto flour.

Highly ordered aggregation of soy protein isolate particles for enhanced gel-related properties through konjac glucomannan addition.

This study assessed the effect of konjac glucomannan (KGM) on the aggregation of soy protein isolate (SPI) and its gel-related structure and properties. Raman results showed that KGM promoted the rearrangement of SPI to form more ß-sheets, contributing to the formation of an ordered structure. Atomic force microscopy, confocal laser scanning microscopy, and small-angle X-ray scattering results indicated that KGM reduced the size of SPI particles, narrowed their size distribution, and loosened the large aggregates formed by the stacking of SPI particles, improving the uniformity of gel system. As the hydrogen bonding between the KGM and SPI molecules enhanced, a well-developed network structure was obtained, further reducing the immobilized water's content (T22) and increasing the water-holding capacity (WHC) of SPI gel. Furthermore, this gel structure showed improved gel hardness and resistance to both small and large deformations. These findings facilitate the design and production of SPI-based gels with desired performance.

Preparation and characterization of astaxanthin-loaded liposomes by phytosterol oleate instead of cholesterol.

Hydrophobic bioactive compounds like astaxanthin (AST) exhibit poor water solubility and low bioavailability. Liposomes, which serve as nanocarriers, are known for their excellent biocompatibility and minimal immunogenicity. Traditionally, liposomes have been primarily constructed using phospholipids and cholesterol. However, the intake of cholesterol may pose a risk to human health. Phytosterol ester was reported to reduce level of cholesterol and improve properties of liposomes. In this study, phytosterol oleate was used to prepare liposomes instead of cholesterol to deliver AST (AST-P-Lip). The size range of AST-P-Lip was 100-220 nm, and the morphology was complete and uniform. In vitro studies showed that AST-P-Lip significantly enhanced the antioxidant activity and oral bioavailability of AST. During simulated digestion, AST-P-Lip protected AST from damage by gastric and intestinal digestive fluid. Additionally, AST-P-Lip had a good storage stability and safety. These results provide references for the preparation of novel liposomes and the delivery of bioactive compounds.

Multivariate analysis of structural and functional properties of soluble dietary fiber from corn bran using different modification methods.

This study comprehensively investigated the effects of high-temperature cooking (HT), complex enzyme hydrolysis (CE), and high-temperature cooking combined enzymatic hydrolysis (HE) on the chemical composition, microstructure, and functional attributes of soluble dietary fiber (SDF) extracted from corn bran. The results demonstrated that HE-SDF yielded the highest output at 13.80 ± 0.20 g/100 g, with enhancements in thermal stability, viscosity, hydration properties, adsorption capacity, and antioxidant activity. Cluster analysis revealed three distinct categories of SDF's physicochemical properties. Principal component analysis (PCA) confirmed the superior functional properties of HE-SDF. Correlation analysis showed positive relationships between the monosaccharide composition, purity, and viscosity of SDF and most of its functional attributes, whereas particle size and zeta potential were inversely correlated. Furthermore, a highly significant positive correlation was observed between crystallinity and thermal properties. These findings suggest that the HE method constitutes a viable strategy for enhancing the quality of SDF sourced from corn bran.

Novel approaches of mycosynthesized zinc oxide nanoparticles (ZnONPs) using Pleurotus sajor-caju extract and their biological and environmental applications.

In this study, mycosynthesized zinc oxide nanoparticles (ZnONPs) are fabricated via Pleurotus sajor-caju mushroom extract, and their potential medical and environmental applications are demonstrated. The biosynthesized ZnONPs were assessed for their antibacterial, anticancer, and biodecolorization potential efficiency. They were also characterized and morphologically analyzed by UV-visible spectroscopy, XRD, FT-IR, FE-SEM, EDX, HR-TEM, Zeta potential, and GC-MS analysis. The UV visible spectrum analysis of synthesized ZnONPs analyzed outcome 354 nm was the SPR peak that the nanoparticles displayed. The characteristic Zn-O bond was indicated by a strong peak in the FT-IR study at 432.05 cm-1. Based on XRD analysis, P. sajor-caju mediated ZnONPs were crystalline nature, with an average nano particle size of 14.21 nm and a polydispersity directory of 0.29. The nanoparticles exhibit modest constancy, as shown by their zeta potential value of - 33.2 mV. The presence of oxygen and zinc was verified by EDX analysis. The ZnONPs were found to be spherical in shape and crystalline nature structure, with smooth surface morphology and a mean particle size of 10 nm using HR-TEM and SAED analysis. The significant antibacterial activity against S. aureus (6.2 ± 0.1), S. mutans (5.4 ± 0.4), and B. subtilis (5.2 ± 0.1 mm) was demonstrated by the synthesized ZnONPs made using mushroom extract. It was discovered that when the concentration of mushroom extract was increased together with synthesized ZnONPs, the bactericidal activity increased considerably. A higher concentration of ZnONPs demonstrated superior antibacterial activity across the ZnONPs ratio tests. The in vitro cytotoxicity assay showed that ZnONPs, even at low doses, had a substantial number of cytotoxic effects on liver cancer cells (LC50 values 47.42 µg/mL). The effectiveness test revealed that acid blue 129 was degraded. The best decolorization of acid blue 129 at 72.57% after 3 h of soaking serves as evidence for the theory that myco-synthesized ZnONPs by P. sajor-caju mushroom can function as catalysts in reducing the dye. The mycosynthesized ZnONPs from P. sajor-caju extract, and its potential for antibacterial, anticancer, and decolorization are in this investigation. The mycosynthesized ZnONPs suggest a novel use for nanoparticles in the creation of environmental and medicinal products.

[Preparation, characterization and antitumor effect of iron-based organic framework nano preparations loaded with piperlongumine].

The preparation processes of iron-based organic framework(FeMOF) MIL-100(Fe) and MIL-101(Fe) with two different ligands were optimized and screened, and the optimized FeMOF was loaded with piperlongumine(PL) to enhance the biocompatibility and antitumor efficacy of PL. The MIL-100(Fe) and MIL-101(Fe) were prepared by solvent thermal method using the optimized reaction solvent. With particle size, polymer dispersity index(PDI), and yield as indexes, the optimal preparation processes of the two were obtained by using the definitive screening design(DSD) experiment and establishing a mathematical model, combined with the Derringer expectation function. After characterization, the best FeMOF was selected to load PL by solvent diffusion method, and the process of loading PL was optimized by a single factor combined with an orthogonal experiment. The CCK-8 method was used to preliminarily evaluate the biological safety of blank FeMOF and the antitumor effect of the drug-loaded nano preparations. The experimental results showed that the optimal preparation process of MIL-100(Fe) was as follows: temperature at 127.8 ℃, reaction time of 14.796 h, total solvent volume of 11.157 mL, and feed ratio of 1.365. The particle size of obtained MIL-100(Fe) nanoparticles was(108.84±2.79)nm; PDI was 0.100±0.023, and yield was 36.93%±0.79%. The optimal preparation process of MIL-101(Fe) was as follows: temperature at 128.1 ℃, reaction time of 6 h, total solvent volume of 10.005 mL, and feed ratio of 0.500. The particle size of obtained MIL-101(Fe) nanoparticles was(254.04±22.03)nm; PDI was 0.289±0.052, and yield was 44.95%±0.45%. The optimal loading process of MIL-100(Fe) loaded with PL was as follows: the feed ratio of MIL-100(Fe) to PL was 1∶2; the concentration of PL solution was 7 mg·mL~(-1), and the ratio of DMF to water was 1∶5. The drug loading capacity of obtained MIL-100(Fe)/PL nanoparticles was 68.86%±1.82%; MIL-100(Fe) was nontoxic to HepG2 cells at a dose of 0-120 µg·mL~(-1), and the half-inhibitory concentration(IC_(50)) of free PL for 24 h treatment of HepG2 cells was 1.542 µg·mL~(-1). The IC_(50) value of MIL-100(Fe)/PL was 1.092 µg·mL~(-1)(measured by PL). In this study, the optimal synthesis process of MIL-100(Fe) and MIL-101(Fe) was optimized by innovatively using the DSD to construct a mathematical model combined with the Derringer expectation function. The optimized preparation process of MIL-100(Fe) nanoparticles and the PL loading process were stable and feasible. The size and shape of MIL-100(Fe) particles were uniform, and the crystal shape was good, with a high drug loading capacity, which could significantly enhance the antitumor effect of PL. This study provides a new method for the optimization of the nano preparation process and lays a foundation for the further development and research of antitumor nano preparations of PL.

The Cytoprotective Effect of C60 Derivatives in the Self-Microemulsifying Drug Delivery System against Triptolide-Induced Cytotoxicity In Vitro.

OBJECTIVE: The aim of this study was to optimize the formulation of a C60-modified self-microemulsifying drug delivery system loaded with triptolide (C60-SMEDDS/TP) and evaluate the cytoprotective effect of the C60-SMEDDS/TP on normal human cells. RESULTS: The C60-SMEDDS/TP exhibited rapid emulsification, an optimal particle size distribution of 50 ± 0.19 nm (PDI 0.211 ± 0.049), and a near-neutral zeta potential of -1.60 mV. The release kinetics of TP from the C60-SMEDDS/TP exhibited a sustained release profile and followed pseudo-first-order release kinetics. Cellular proliferation and apoptosis analysis indicated that the C60-SMEDDS/TP (with a mass ratio of TP: DSPE-PEG-C60 = 1:10) exhibited lower toxicity towards L02 and GES-1 cells. This was demonstrated by a higher IC50 (40.88 nM on L02 cells and 17.22 nM on GES-1 cells) compared to free TP (21.3 nM and 11.1 nM), and a lower apoptosis rate (20.8% on L02 cells and 26.3% on GES-1 cells, respectively) compared to free TP (50.5% and 47.0%) at a concentration of 50 nM. In comparison to the free TP group, L02 cells and GES-1 cells exposed to the C60-SMEDDS/TP exhibited a significant decrease in intracellular ROS and an increase in mitochondrial membrane potential (ΔψM). On the other hand, the C60-SMEDDS/TP demonstrated a similar inhibitory effect on BEL-7402 cells (IC50 = 28.9 nM) and HepG2 cells (IC50 = 107.6 nM), comparable to that of the free TP (27.2 nM and 90.4 nM). The C60-SMEDDS/TP group also exhibited a similar intracellular level of ROS and mitochondrial membrane potential compared to the SMEDDS/TP and free TP groups. METHOD: Fullerenol-Grafted Distearoyl Phosphatidylethanolamine-Polyethylene Glycol (DSPE-PEG-C60) was synthesized and applied in the self-microemulsifying drug delivery system. The C60-SMEDDS/TP was formulated using Cremophor EL, medium-chain triglycerides (MCT), PEG-400, and DSPE-PEG-C60, and loaded with triptolide (TP). The toxicity and bioactivity of the C60-SMEDDS/TP were assessed using normal human liver cell lines (L02 cells), normal human gastric mucosal epithelial cell lines (GES-1 cells), and liver cancer cell lines (BEL-7402 cells and HepG2 cells). The production of reactive oxygen species (ROS) after the C60-SMEDDS/TP treatment was assessed using 2',7'-dichlorofluorescein diacetate (DCFDA) staining. The alterations in mitochondrial membrane potential (ΔψM) were assessed by measuring JC-1 fluorescence. CONCLUSIONS: The cytoprotection provided by the C60-SMEDDS/TP favored normal cells (L02 and GES-1) over tumor cells (BEL-7402 and HepG2 cells) in vitro. This suggests a promising approach for the safe and effective treatment of TP.

Influence of Anions on the Antibacterial Activity and Physicochemical Properties of Different-Sized Silver Nanoparticles.

Silver nanoparticles (AgNPs) with different sizes have been extensively adopted in various commercial products, causing ecological concerns because of the inevitable release of AgNPs into the environment. Hence, understanding the interaction of different-sized AgNPs with environmental substances is important for assessing the environmental risk and fate of AgNPs. In this work, we investigated the impact of anions (NO3-, SO42-, HCO3-/CO32-, Cl-) in aquatic environments on the physicochemical properties and antibacterial activity of different-sized AgNPs (20, 40 and 57 nm). The results showed that the anions whose corresponding silver-based products had lower solubility were more likely to decrease the zeta potential (more negative) of particles, inhibit the dissolution of AgNPs and reduce their antibacterial activity. This should be attributed to the easier generation of coating layers on the surface of AgNPs during the incubation process with such anions. Additionally, the generation of coating layers was also found to be particle-size dependent. The anions were more prone to adsorbing onto larger-sized AgNPs, promoting the formation of coating layers, subsequently resulting in more pronounced variations in the physicochemical properties and antibacterial activity of the larger-sized AgNPs. Therefore, larger-sized AgNPs were more prone to experiencing specific effects from the anions.

Combined Chemo- and Photothermal Therapies of Non-Small Cell Lung Cancer Using Polydopamine/Au Hollow Nanospheres Loaded with Doxorubicin.

Purpose: The chemotherapeutic agent doxorubicin (DOX) is limited by its cardiotoxicity, posing challenges in its application for non-small cell lung cancer (NSCLC). This study aims to explore the efficacy of polydopamine/Au nanoparticles loaded with DOX for chemotherapy and photothermal therapy in NSCLC to achieve enhanced efficacy and reduced toxicity. Methods: Hollow polydopamine (HPDA)/Au@DOX was synthesized via polydopamine chemical binding sacrificial template method. Morphology was characterized using transmission electron microscopy, particle size and potential were determined using dynamic light scattering, and photothermal conversion efficiency was assessed using near-infrared (NIR) thermal imaging. Drug loading rate and in vitro drug release were investigated. In vitro, anti-tumor experiments were conducted using CCK-8 assay, flow cytometry, and live/dead cell staining to evaluate the cytotoxicity of HPDA/Au@DOX on A549 cells. Uptake of HPDA/Au@DOX by A549 cells was detected using the intrinsic fluorescence of DOX. The in vivo anti-metastasis and anti-tumor effects of HPDA/Au@DOX were explored in mouse lung metastasis and subcutaneous tumor models, respectively. Results: HPDA/Au@DOX with a particle size of (164.26±3.25) nm, a drug loading rate of 36.31%, and an encapsulation efficiency of 90.78% was successfully prepared. Under 808 nm laser irradiation, HPDA/Au@DOX accelerated DOX release and enhanced uptake by A549 cells. In vitro photothermal performance assessment showed excellent photothermal conversion capability and stability of HPDA/Au@DOX under NIR laser irradiation. Both in vitro and in vivo experiments demonstrated that the photothermal-chemotherapy combination group (HPDA/Au@DOX+NIR) exhibited stronger anti-metastatic and anti-tumor activities compared to the monotherapy group (DOX). Conclusion: HPDA/Au@DOX nanosystem demonstrated excellent photothermal effect, inhibiting the growth and metastasis of A549 cells. This nanosystem achieves the combined effect of chemotherapy and photothermal, making it promising for NSCLC treatment.

Analysis and calculation of scour critical velocity of suspended particles in a storm sewer.

The suspended particles in storm sewer can be easily washed away and migrated. However, few studies analyzed the scouring state of suspended particles in pipelines, and also, there was a lack of quantitative calculation. This study simulated the scouring process of suspended particles in a storm sewer with different pipe materials, and mathematical models were built for the scour critical velocity. The results showed that with the increase of particle size, density and the roughness of the pipe wall, the scour resistance of suspended particles increased, and the scouring rate decreased; therefore, the corresponding scour critical velocity increased. In accordance with the scouring rates of quartz sand and zeolite at different flow velocities in the storm sewer, the scouring state of the suspended particles could be divided into three types: no scouring, minor scouring, and massive scouring. The scour critical velocity ranges of quartz sand and zeolite with two densities in four kinds of pipes were determined, and mathematical models for the scour critical velocity of suspended particles were established. After verification, the difference rate between the calculated values and measured values was in the range of -10.56% to 6.63%, and the two values had good consistency. PRACTITIONER POINTS: Scour resistance of suspended particles increases with particle size or density. The smaller the roughness of the pipe wall, the higher the scouring rate. Higher flow velocity leads to a higher scouring rate. As scouring rate rises, no scouring, minor or massive scouring occur in sequence. Difference between the calculated and measured values is from -10.56% to 6.63%.

Fabrication of one-dimensional Zn-doped Bi2S3 nanorods for photodiode applications.

In this research, the impact of the different zinc (Zn) concentrations on the physical and optoelectronic properties of Bi2S3 nanorods as self-powered and photodiode applications was investigated. The performance of P-N junction photodiodes has been for decades since they are crucial in energy applications. The structure, degree of crystallinity, and shape of Zn-doped Bi2S3 nanorods of various doping percentages formed onto the indium tin oxide (ITO) substrates by the dip coating technique are investigated using X-ray powder diffraction (XRD) and SEM. With increasing illumination time, the current-voltage (I-V) graphs demonstrate a rise in photocurrent. The diode's idealist factor was estimated using the I-V technique under 30 min of light illumination.