Search Results (92)

Background/Objectives: This study aimed to evaluate the effects of lung injury induced by insoluble uranium oxide particles on gut microbiota and related metabolites in rats. Methods: The rats were randomly divided into six UO₂ dose groups. A rat lung injury model was established through UO₂ aerosol. The levels of uranium in lung tissues were detected by ICP-MS. The expression levels of the inflammatory factors and fibrosis indexes were measured by enzyme-linked immunosorbent assay. Paraffin embedding-based hematoxylin & eosin staining for the lung tissue was performed to observe the histopathological imaging features. Metagenomic sequencing technology and HM700-targeted metabolomics were conducted in lung tissues. Results: Uranium levels in the lung tissues increased with dose increase. The expression levels of Tumor Necrosis Factor-α (TNF-α), Interleukin-1β (IL-1β), Collagen I, and Hydroxyproline (Hyp) in rat lung homogenate increased with dose increase. Inflammatory cell infiltration and the deposition of extracellular matrix were observed in rat lung tissue post-exposure. Compared to the control group, the ratio of Firmicutes and Bacteroides in the gut microbiota decreased, the relative abundance of Akkermansia_mucinphila decreased, and the relative abundance of Bacteroides increased. The important differential metabolites mainly include αlpha-linolenic acid, gamma-linolenic acid, 2-Hydroxybutyric acid, Beta-Alanine, Maleic acid, Hyocholic acid, L-Lysine, L-Methionine, L-Leucine, which were mainly concentrated in unsaturated fatty acid biosynthesis, propionic acid metabolism, aminoacyl-tRNA biosynthesis, phenylalanine metabolism, and other pathways in the UO₂ group compared to the control group. Conclusions: These findings suggest that uranium-induced lung injury can cause the disturbance of gut microbiota and its metabolites in rats, and these changes are mainly caused by Akkermansia_mucinphila and Bacteroides, focusing on unsaturated fatty acid biosynthesis and the propionic acid metabolism pathway. Full article

Coal-fired power plants exacerbate hazy weather under low winter temperatures, while sulphate ions (SO₄²⁻) in condensable particulate matter (CPM) emitted from ultra-low emission coal-fired power plants accelerate sulphate formation. The transformation of gaseous precursors (SO₂, NOx, NH₃) is the main pathway for sulphate formation by homogeneous or non-homogeneous reactions. For the sustainability of the world, in this paper, the effects of condensation temperature, H₂O, NO_X and NH₃ on the SO₄²⁻ generation characteristics under low-temperature rapid condensation conditions are investigated. With lower temperatures, especially from 0 °C cooling to −20 °C, the concentration of SO₄²⁻ was as high as 26.79 mg/m³. With a greater proportion of H₂SO₄ in the aerosol state, and a faster rate of sulphate formation, H₂O vapour condensation can provide a reaction site for sulphuric acid aerosol generation. SO₄²⁻ in CPM is mainly derived from the non-homogeneous reaction of SO₂. SO₃ is an important component of CPM and provides a reaction site for the formation of SO₄²⁻. SO₂ and SO₃, in combination with Stefan flow, jointly play a synergistic role in the generation of SO₄²⁻. The content of SO₄²⁻ was as high as 36.18 mg/m³. While NO_X sometimes inhibits the formation of SO₄²⁻, NH₃ has a key role in the nucleation process of CPM. NH₃, SO₂ and NO_X have been found to rapidly form sulphate with particle sizes up to 5 µm at sub-zero temperatures and promote the formation of sulphuric acid aerosols. Full article

The characterization of airborne submicrometric composite structures’ debris is a challenge in the field of environmental monitoring and control. The work presented here aims to develop a new quantitative method to measure elemental mass concentrations via particle sampling and Transmission Electron Microscopy—Energy-Dispersive X-ray Spectroscopy (TEM-EDS). The principle is to collect airborne particles on a porous TEM grid, then add a certain mass of reference particles, and compare the relative mass percentages of elements from reference and sample particles via EDS. Diverse pairs of airborne particles (RbCl, CsCl, NaCl, SrCl₂, Ga(NO₃)₃, braking particles) were deposited on one TEM grid, and the experimental elemental mass ratios were measured by EDS and compared with the theoretical values. Results show that the quantitative and homogeneous collection of reference particles, such as RbCl, on the TEM grid could be suitable. For all the tested conditions, the absolute deviations between the theoretical elemental mass ratios and the experimental ratios remain lower than 8%. Thus, the mass concentration of Fe from the braking aerosol is calculated as 107 µg/m³. Compared to the cumbersome real-time instrument, this new method for mass characterization appears to be convenient, and requires a short time of aerosol sampling at the workplace. This approach ensures safety and practicability when assessing, e.g., the exposure risk of hazardous materials. Full article

Lidar has been used for many years to study the optical properties of aerosols, but estimating the boundary values requires solving the lidar elastic scattering equation, which remains a challenge. The boundary values are often determined by fitting to uniform regions of the atmosphere. This method typically excludes low signal-to-noise ratio (SNR) signals because it classifies them as non-uniform, reducing the effective detection range of the lidar. On the other hand, directly fitting low SNR signals to estimate the boundary values can introduce significant errors. The method is based on maximizing the lidar detection distance and determines the boundary value using a new estimation algorithm with the averaging of multiple fitted results in the low SNR region to reduce the impact of noise. Simulations demonstrate that the new method reduces the relative error in the boundary value estimation by approximately 5% and improves the accuracy of the extinction coefficient profile inversion compared with the method of directly fitting all-sample signals. Field comparison experiments with forward-scattering sensors further verify that the algorithm improves the retrieval accuracy by 17.3% under extremely low signal-to-noise ratio (SNR) conditions, while performing comparably to the traditional method in high SNR homogeneous atmospheres. Additionally, based on the scanned lidar signals, the algorithm can provide detailed information on the spatial distribution of sea fog and offer valuable insights for an in-depth understanding of the physical evolution of sea fog. Full article

Background/Objectives: This study aimed to fabricate, optimize, and characterize nanostructured lipid carriers (NLCs) loaded with trans-resveratrol (TRES) as an anti-cancer drug for pulmonary drug delivery using medical nebulizers. Methods: Novel TRES-NLC formulations (F1–F24) were prepared via hot, high-pressure homogenization. One solid lipid (Dynasan 116) was combined with four liquid lipids (Capryol 90, Lauroglycol 90, Miglyol 810, and Tributyrin) in three different ratios (10:90, 50:50, and 90:10 w/w), with a surfactant (Tween 80) in two different concentrations (0.5 and 1.5%), and a co-surfactant, soya phosphatidylcholine (SPC S-75; 50 mg). Results: Amongst the analyzed 24 TR-NLC formulations, F8, F14, and F22 were selected based on their physicochemical stability when freshly prepared and following storage (4 weeks 25 °C), as well as in terms of particle size (<145 nm), polydispersity index (PDI; <0.21) and entrapment efficiency (>96%). Furthermore, F14 showed greater stability at 4 and 25 °C for six months and exhibited enhanced aerosolization performance, demonstrating the greater deposition of TRES in the later stages of the next-generation impactor (NGI) when using an air-jet nebulizer than when using an ultrasonic nebulizer. The F14 formulation exhibited greater stability and release in acetate buffer (pH 5.4), with a cumulative release of 95%. Conclusions: Overall, formulation F14 in combination with an air-jet nebulizer was identified as a superior combination, demonstrating higher emitted dose (ED; 80%), fine particle dose (FPD; 1150 µg), fine particle fraction (FPF; 24%), and respirable fraction (RF; 94%). These findings are promising in the optimization and development of NLC formulations, highlighting their versatility and targeting the pulmonary system via nebulization. Full article

Background/Objectives: Electronic cigarettes (e-cigarettes) are commonly used by former smokers as an alternative product to conventional cigarettes and also by young adults and adolescents to deliver nicotine. E-cigarettes are thought to be a less harmful and more socially acceptable alternative to tobacco smoking; however, their long-term effects on health, including oral health, are currently unknown. Methods: A literature search for relevant papers indexed in the literature from 2016 to 2023 was conducted using the PubMed, Scopus, and Google Scholar databases. In our paper, we included clinical trials and both in vivo and in vitro research concerning the impact of e-cigarettes on oral health. Results: E-cigarettes impact the oral cavity, which is directly exposed to inhaled chemicals present in e-cigarette aerosols. The use of e-cigarettes has been linked to teeth discoloration and dental caries, promoting the development of periodontal diseases and causing oral mucosa lesions, including oral cancer. E-cigarette aerosols might also negatively affect the oral microbiome by suppressing the growth of commensal bacteria and increasing the population of bacteria responsible for developing numerous oral disorders. E-cigarettes also impact saliva composition and its properties, including reducing saliva’s antibacterial and antioxidant properties, which may subsequently lead to the promotion of oral diseases. Conclusions: The outcomes suggest that e-cigarette usage may cause the development of oral diseases, however further longitudinal studies of a larger and homogenous group of e-cigarette users are required. Full article

The population of Senegal faces health challenges related to desert dust and heat waves (HWs). This study aims to (a) update the documentation of HWs in Senegal, expanding on the work of Sambou et al. (2019); (b) investigate the modulation of dust indicators during HWs; and (c) assess the distinct impacts of dust content on night-time and daytime HWs. We use [i] the daily maximum air temperature (Tx), minimum air temperature (Tn), and apparent temperature (Ta) from 12 stations in the Global Surface Summary of the Day (GSOD) database and [ii] the Dust Aerosol Optical Depth (Dust AOD), particulate matter (PM) concentrations, 925 hPa wind, and Mean Sea Level Pressure (MSLP) from the Copernicus Atmosphere Monitoring Service (CAMS) reanalysis. HWs are defined for each station in spring as periods when Tx, Tn, or Ta exceeds the 95th percentile for at least three consecutive days. Three homogeneous zones from the Atlantic coast to inland Senegal are identified using hierarchical cluster analysis: Zone 1 (Saint-Louis, Dakar-Yoff, Ziguinchor, and Cap Skirring), Zone 2 (Podor, Linguère, Diourbel, and Kaolack), and Zone 3 (Matam, Tambacounda, Kédougou, and Kolda). Our results show that Zone 1 records the highest number of HWs for Tx, Tn, and Ta, while Zone 3 experiences more HWs in terms of Tn and Ta than Zone 2. The influence of dust is notably stronger for HWs linked to Tn and Ta than for those related to Tx. Analysis of the mechanisms shows that the presence of dust in Senegal and its surrounding regions is detected up to four days before the onset of HWs. These findings suggest that dust conditions associated with spring HWs in Senegal may be better distinguished and predicted. Full article

In this study, we analysed lithospheric, atmospheric, and top-side ionospheric magnetic field data six months before the three earthquake doublets occurred in the last ten years around the Arabian tectonic plate. They occurred in 2014, close to Dehloran (Iran), in 2018, offshore Kilmia (Yemen) and in 2022, close to Bandar-e Lengeh (Iran). For all the cases, we considered the equivalent event in terms of total released energy and mean epicentral coordinates. The lithosphere was investigated by calculating the cumulative Benioff strain with the USGS earthquake catalogue. Several atmospheric parameters (aerosol, SO₂, CO, surface air temperature, surface latent heat flux humidity, and dimethyl sulphide) have been monitored using the homogeneous data from the MERRA-2 climatological archive. We used the three-satellite Swarm constellation for magnetic data, analysing the residuals after removing a geomagnetic model. The analysis of the three geo-layers depicted an interesting chain of lithosphere, atmosphere, and ionosphere anomalies, suggesting a geophysical coupling before the Dehloran (Iran) 2014 earthquake. In addition, we identified interesting seismic accelerations that preceded the last 20 days, the Kilmia (Yemen) 2018 and Bandar-e Lengeh (Iran) 2022 earthquake doublets. Other possible interactions between the geolayers have been observed, and this underlines the importance of a multiparametric approach to properly understand a geophysical complex topic as the preparation phase of an earthquake. Full article

Background/Objectives: Live influenza vaccines are considered to stimulate better overall immune responses but are associated with safety concerns regarding shedding and the potential for transmission or reassortment with wild-type influenza viruses. Intranasal M2SR and BM2SR (M2- and BM2-deficient single replication), intranasal influenza viruses, have shown promise as broadly cross-reactive next-generation influenza vaccines. The replication deficiency, shedding, and transmissibility of M2SR/BM2SR viruses were evaluated in a ferret model. Methods: Wild-type influenza A and B control viruses replicated in upper respiratory organs and transmitted to both direct and aerosol contact ferrets, whereas M2SR and BM2SR influenza vaccine viruses were not detected in any tissues or in nasal washes after inoculation and were not recovered from any direct or aerosol contact ferrets. Mice were simultaneously infected with wild-type influenza A and M2SR viruses to assess reassortment potential. Sequence and PCR analyses of the genome recovered from individual virus plaques isolated from lung homogenates identified the origin of the segments as exclusively from the replicating wild-type virus. Results: These results indicate that M2SR and BM2SR influenza vaccine viruses are attenuated, do not shed or transmit, and have a low probability for reassortment after coinfection. Absence of shedding was further demonstrated in nasal swabs taken from subjects who were inoculated with H3N2 M2SR in a previously described Phase 1 clinical study. Conclusions: These results indicate that M2SR/BM2SR viruses have the potential to be used in a broader population range than current live influenza vaccines. Full article

Fungi are ubiquitous and metabolically versatile. Their dispersion has important scientific, environmental, health, and economic implications. They can be dispersed through the air by the aerosolization of near surfaces or transported from distant sources. Here, we tested the contribution of local (scale of meters) versus regional (kilometers) sources by analyzing an airborne fungal community by ITS sequencing around a copper mine in the North of Chile. The mine was the regional source, whereas the soil and vegetal detritus were the local sources at each point. The airborne community was highly homogeneous at ca. 2000 km², impeding the detection of regional or local contributions. Ascomycota was the dominant phylum in the three communities. Soil and vegetal detritus communities had lower alpha diversity, but some taxa had abundance patterns related to the distance from the mine and altitude. On the contrary, the air was compositionally even and unrelated to environmental or spatial factors, except for altitude. The presence of plant pathogens in the air suggests that other distant sources contribute to this region’s airborne fungal community and reinforces the complexity of tracking the sources of air microbial communities in a real world where several natural and human activities coexist. Full article

The aim of this study was to determine the drug loading capacity of phosphatidylcholine-based formulations for four poorly water-soluble drug substances (clofazimine, fenofibrate, artemether, cannabidiol). Two self-dispersing lipid formulations were investigated, which consisted of soybean phospholipids, medium-chain triglycerides and ethanol with a different phospholipid–oil ratio. The direct loading of the bulk formulation was conducted with dual centrifugation, which proved to be a suitable method for screening experiments with the highly viscous formulations. To estimate possible precipitation after dispersion in the gastrointestinal fluids, the solubility of the drugs was investigated in the dispersed formulations. For this purpose, nanodispersions were prepared from the bulk formulations via high pressure homogenization and subsequently subjected to passive loading. A newly developed HPLC method with Charged Aerosol Detection allowed a simultaneous evaluation of the content of soybean lecithin and medium-chain triglycerides in the nanodispersions. When comparing the two phosphatidylcholine-based formulations, a high content of oil was advantageous with regard to a high loading capacity. Drug substances with melting points below 150 °C exhibited a high solubility in the phospholipid-based formulations. A surprisingly high solubility was observed for artemether and cannabidiol with up to 13.0% and 33.3% drug loaded to the formulations, respectively. In the dispersions, a similar solubility as in the bulk formulations was obtained for fenofibrate and cannabidiol. Clofazimine yielded a higher loading result in the nanodispersions than in the bulk formulation. Full article

Aerosol optical properties retrieved using polarization Raman lidar observations play an increasingly vital role in meteorology and environmental protection. The quality of the data products directly affects the impact of relevant scientific applications. However, the quality of aerosol optical properties retrieved from polarization Raman lidar signals is difficult to assess. Various factors, such as hardware system performance, retrieval algorithm, and meteorological conditions at the observation site, influence data quality. In this study, we propose a method that allows for assessing the reliability of aerosol optical properties derived from polarization Raman lidar observations. We analyze the factors that affect the reliability of retrieved aerosol optical properties. We use scoring methods combined with a weight-assignment scheme to evaluate the quality of the retrieved aerosol optical properties. The scores and weights of each factor are arranged based on our analysis of a simulation study and the characteristics of each factor. We developed an automatic retrieval algorithm that allows for deriving homogeneous aerosol optical data sets. We also assess with this method the quality of retrieved aerosol optical properties obtained with different polarization Raman lidars under different measurement scenarios. Our results show that the proposed quality assurance method can distinguish the reliability of the retrieved aerosol optical properties. Full article

Electrostatic precipitators (ESP) are especially known for the efficient separation of micron and submicron particles from aerosols. Wet electrostatic precipitators are particularly suitable for highly resistive materials. Using these, particles can be directly transferred into a liquid for further processing or safer handling, which is advantageous for either hazardous or valuable materials. In this work, a wet ESP, which enables the separation of highly resistive particles into a heated liquid, was designed and investigated. To do this, spray-dried drug particles were embedded in a molten sugar alcohol to enhance the drug dissolution rate. After cooling, the solidified product showed advantageous properties such as a high drug dissolution rate and easy handling for further processing. For the design of the wet ESP, different discharge electrode configurations were tested. A wall film served as the collection electrode, which was generated by a specially designed distributer die. A laminar flow regime was achieved with a homogeneous film serving as the collection electrode, which is particularly important for a high separation efficiency. A prototype was designed and constructed in this respect. The particle separation into hot liquids or onto hot surfaces is challenging due to thermal effects in ESPs. The influence of thermophoresis and drag force on the particle transport was investigated, and optimum operation parameters were found for the present ESP. A broad field of applications can be covered with the presented device, where particles are embedded in even hot liquids to form liquid suspensions or, as it is presented here, solid dispersions. The dissolution of the drug-containing solid dispersion was studied in vitro. A remarkably faster drug dissolution was observed from the solid dispersion, as compared to a powder mixture of the drug and xylitol. Full article

For an efficient indoor air purification, it is important to know the detailed airflow distribution in the room. A series of numerical simulations are carried out for five heating regimes using an air–air heat pump, capillary mat on the ceiling, capillary mat on the walls, heated floor, and radiator. The most homogeneous temperature field is obtained for the case with the heated floor. The highest velocity is obtained for the air–air heat pump, while the lowest is obtained for the capillary mat on the ceiling. A portable air cleaner based on the prototype device is introduced into the model and its influence on the velocity and temperature distributions is calculated. Our simulations additionally consider is the transport of an infectious aerosol and its purification inside the air cleaner. The time dependency of the concentration is exponential, and the purification rate depends on the air cleaner’s orientation and heating regime. The efficiency is higher for a purifier with flow in the upwards direction compared to in a horizontal one. In the experimental part, an NaCl solution is dispersed into the air, and the efficiency of purification in the case of the air–air heat pump is evaluated by measuring the time-dependent particle concentrations. These experimental results corroborate the numerical model. Full article

A jet-based direct mixing process is used to effectively mix heterogeneous materials. In this work, its application in the structuring, coating and agglomeration of cathode materials for all-solid-state battery (ASSB) production is investigated, with the aim of increasing the homogeneity and conductivity of the composites and ultimately improving battery performance. In this process, different particle systems consisting of lithium iron phosphate (LFP), carbon black (CB) and sodium chloride (NaCl) are dispersed in the gas phase and brought together in a mixing zone as particle-laden aerosol jets. The cathode material’s structure is studied through scanning electron microscopy combined with a focussed ion beam (SEM–FIB). Electrical conductivity measurements of the resulting composites assess the degree of mixing and the changes in tortuosity, while a laser light diffractor and a cascade impactor analyse the particle size distribution (PSD). The jet-based process effectively produces hetero-agglomerates with the possibility of creating different composite structures by adjusting the process parameters. The mass concentration influences not only the structure, but also the PSD in the flow and the electrical conductivity of the composite. The results serve as a basis for future experiments with solid electrolytes to comprehensively evaluate the process and the resulting battery materials. Full article