Characterization Of Particles Research Articles

Nano-strategies for advancing oral drug delivery: Porous silicon particles and cyclodextrin encapsulation for enhanced dissolution of poorly soluble drugs

Development of novel active pharmaceutical ingredients (API) for oral use often face challenges due to low bioavailability. Nanoparticle-based drug delivery systems and cyclodextrin (CD) encapsulation offer promising solutions by enhancing API solubility or dissolution rates. Porous silicon nanoparticles have shown potential to encapsulate APIs in their amorphous form within pores, improving dissolution rates compared to crystalline counterparts. A novel synthesis approach, circumventing the expensive and tedious Si wafer material synthesis, has been developed using centrifugal Chemical Vapor Deposition (cCVD). Herein, various cCVD Si particles were evaluated for their ability to enhance the dissolution rate of the model drugs celecoxib (CEL), phenytoin (PHT), griseofulvin (GRI), diclofenac (DCF), and naproxen (NAP). Our findings demonstrate increased dissolution rates of all tested APIs when formulated with cCVD Si particles, compared to free API in pH 7.4 or pH 2.0. Particle characteristics were largely retained after loading, and the solid state of the loaded APIs were evaluated using Differential Scanning Calorimetry (DSC). Dissolution kinetics were influenced by the particle properties, mass loading and API characteristics. Loading of CD-CEL, −GRI and −DCF complexes into the cCVD Si particles showed a potential for further enhanced dissolution rates, representing the first reported investigation of this combination. In conclusion, the cCVD Si particles are promising for improving the dissolution rate of poorly soluble drugs, potentially due to precipitation of amorphous or metastable forms. Further enhancements were observed upon loading CD-drug complexes, thereby offering promising strategies for optimizing drug bioavailability

Migration and Deposition Characteristics of Sand Particles on Mesh Filter Surfaces in Water-Saving Irrigation Systems: Evidence from Simulation and Experimental Verification

Migration and Deposition Characteristics of Sand Particles on Mesh Filter Surfaces in Water-Saving Irrigation Systems: Evidence from Simulation and Experimental Verification

Pilot-scale study of turbid particle evolutional/removal characteristics during coagulation-sedimentation-filtration (CSF): Effects of coagulant dosage and secondary dosing after breakage

Considering the limitations of treated water turbidity, a thorough understanding of the changes in turbid particle size distribution during coagulation-sedimentation-filtration (CSF) is crucial for enhancing the removal efficiency of particulate and dissolved contaminants from raw water. In this study, a pilot-scale experimental system was utilized to track the evolution of turbid particles and assess how the characteristics of these turbid particles affected the quality of treated water in the CSF processes under varying cases of polyaluminum chloride (PAC) coagulant dosage and secondary coagulant dosage after breakage. It was found that differently from the role of PAC coagulant dosage (without high-shear breakage), different levels of secondary coagulant dosing after breakage had minimal influence on the aggregate structure produced by mechanical stirring flocculation. During the overall CSF processes, the changing trend in the total particle number for the filtered water appeared to be more consistent with the corresponding changing trend for the settled water, as the PAC coagulant dosage increased. In addition, the combined effects of shear-induced breakage and secondary dosing could not only improve the removal efficiency of organic matter after inclined-tube sedimentation following mechanical stirring flocculation, but also enhance the removal efficiencies of water turbidity and particulate matter through sand filtration. In order to reduce the frequency of backwashing and extend the service life of the filter media, greater emphasis should be placed on detecting and removing the number of smaller-sized particles existing in the sixth unit of the flocculation tank together with the effluent of the sedimentation tank.

Iron-doped diesel exhaust early-in-life inhalation-induced cardiopulmonary toxicity in chicken embryo: Roles of ferroptosis and Acyl hydrocarbon signaling

Diesel exhaust (DE) is a major contributor to air pollution. Iron-doping could improve diesel burning efficacy and decrease emission, however, it will also change the composition of DE, potentially enhancing the toxicities. This study is aimed to assess iron-doped DE-induced cardiopulmonary toxicity in an established in ovo early-in-life inhalation exposure chicken embryo model, and to explore potential mechanisms. Ferrocene (205, 410, 820 ,1640 mg/L, equivalent to 75, 150, 300, 600 ppm iron mass) was added to diesel fuel, DE was collected from a diesel generator, and then exposed to embryonic day 18-19 chicken embryo via in ovo inhalation. Hatched chickens were kept for 0, 1, or 3 months, and then sacrificed. Histopathology, electrocardiography along with biochemical methods were used to assess cardiopulmonary toxicities. For mechanistic investigation, inhibitor for ferroptosis (ferrostatin-1) or Acyl hydrocarbon receptor (PDM2) were administered before DE (with or without iron-doping), and the cardiopulmonary toxicities were compared. Characterization of DE particles indicated that addition of ferrocene significantly elevated iron content. Additionally, the contents of major toxic polycyclic aromatic hydrocarbons decreased following addition of 820 mg/L ferrocene, but increased at other doses. Remarkable cardiopulmonary toxicities, in the manifestation of elevated heart rates, cardiac remodeling and cardiac / pulmonary fibrosis were observed in animals exposed to iron-doped DEs, in which the addition of ferrocene significantly enhanced the toxicities. Both ferrostatin-1 and PDM2 pretreatment could effectively alleviate the observed effects in animals exposed to iron-doped DE. Inhibition of AhR signaling seems to be capable of alleviating changes to ferroptosis related molecules following exposure to iron-doped DE, while inhibition of ferroptosis does not seem to affect AhR signaling molecules. In summary, iron-doping with ferrocene to diesel enhanced DE-induced cardiopulmonary toxicities in chicken embryos. Ferroptosis and AhR signaling both seem to participate in this process, in which AhR signaling seems to affect ferroptosis.

LIBS as a fast and reliable alternative to µXRF and SEM–EDX for quantitative analysis of aluminium alloy particles in technical cleanliness analysis

The characterization of metal alloy (particle) characterization is a vital tool in today’s high–tech applications for quality and process control in industry, especially for applications in technical cleanliness analysis (TCA). Here, metal alloy fragments down to sizes of 200 µm need to be quantitatively characterized as accurate as possible. Laser-induced breakdown spectroscopy (LIBS) offers several advantages due to its easy use, short measurements times, and high sensitivity. To enable the application of LIBS in this context, the method must yield adequately accurate results. Therefore, in this study we assess the performance of LIBS by comparison with well–established methods – scanning electron microscopy coupled with energy-dispersive X‑ray spectroscopy (SEM-EDX) and µ‑X‑ray fluorescence (µXRF). We analyse particulate certified reference materials consecutively with non–destructive and destructive methods on the quantitative composition regarding the key elements necessary for distinguishing aluminium alloys: Si, Zn, Mn, Mg, Cu and Fe. Sample inhomogeneity and the effect of sampling location and area is shown via microstructure analysis and combined with an assessment of the analysis volume for each used method. By evaluating the data statistically and by comparing quantitative results achieved with different methods, we can postulate a high agreement between LIBS and the studied reference methods, providing a basis for the use of LIBS in industrial analysis of metal alloy particles.

The Role and Mechanism of Rice Husk Ash Particle Characteristics in Cement Hydration Process

The Role and Mechanism of Rice Husk Ash Particle Characteristics in Cement Hydration Process

Quantitative Particle Analysis of Neptunium-237 Oxides: Optimization of MAMA Analysis for Modified Direct Denitration Products.

The production of plutonium-238 through irradiation of neptunium-237 (237Np) target materials for the use in radioisotope thermoelectric generators is paramount for continued deep space exploration. This work employs scanning electron microscopy to analyze 237Np materials coupled with a well-developed image analysis framework (Morphological Analysis for Material Attribution, or MAMA) to determine the degree of micron-scale homogeneity in the materials. This work demonstrated how the quantification of particle characteristics can validate production materials and affirm the qualitative similarities observed in micrographs. The 237Np oxide particle analysis determined that the materials from five production runs were quantitatively homogenous (significant at α = 0.05) in particle area, circularity, equivalent circular diameter, and ellipse aspect ratio, with two of the sampling dates having statistically significant different means for one of the four characteristics. These metrics not only confirm general homogeneity of the material but also expand the application of MAMA workflows to 237Np materials, demonstrating the utility of MAMA analysis for a wider breadth of nuclear materials than previously reported. In the open literature, this study is the first time that these microanalytical techniques were applied to 237Np materials to this degree.

Characterization of soot and crystalline atmospheric ultrafine particles.

The extraction and characterization of atmospheric ultrafine particles (UFPs) is critical to understanding environmental health and climate dynamics. This study uses an aqueous extraction method to characterize the size distribution, shape, and composition of atmospheric UFPs. We propose a combined use of techniques rarely implemented in air quality analysis, such as atomic force microscopy (AFM), with more conventional methods, such as Transmission Electron microscopy (TEM) and Dynamic Light Scattering (DLS). DLS results indicate a hydrodynamic diameter range from 117 to 1069 nm and a polydispersity index of 0.3 to 0.79. The high polydispersity reflects the complexity of UFPs agglomeration processes. AFM identified NPs ranging from 10 to 25 nm; topographic images show soot and crystalline structures. High-resolution TEM analysis measured the interplanar distances of crystalline UFPs, showing the presence of calcium carbonates. TEM-EDS identified soot and crystalline particles with variable composition, from Si-enriched NPs to Ca-F-Cl-Na-Si, carbonates, chlorides, and Zn-Ti-enriched nanosilica. These findings provide valuable insights into the physicochemical properties of atmospheric dust, contributing to our knowledge and the potential implications for human health and the environment.

Enhanced electrorheological activity of rod-like Fe3O4@TiO2 particles in elastomers and their morphological effect

Abstract The properties of dielectric particles play the most important role in the electrorheological (ER) activity of elastomers, however, there is a lack of experimental research on the effect of particle morphology on the properties of electrorheological elastomers (EREs). In this study, spherical and rod-like Fe3O4@TiO2 core-shell particles were synthesized and used to prepare EREs. Particles characterization results showed that both spherical and rod-like Fe3O4@TiO2 exhibited an obvious core-shell structure and similar magnetic properties,with the aspect ratio of rod-like Fe3O4@TiO2 particles was approximately 7:1. Furthermore, the EREs filled with rod-like Fe3O4@TiO2 particles exhibit a higher dielectric constant and sharper dielectric loss peak than those filled with spherical particles, indicating that a larger aspect ratio enhances the dielectric performance. For EREs with the same volume fraction of particles or cured under the same external field, the storage modulus and relative ER effect of EREs filled with rod-like particles are both higher than those of EREs containing spherical particles. Additionally, it can be confirmed that the rod-like particle chain structures have a more significant strengthening effect on the ERE matrix, as evidenced by the rod-like Fe3O4@TiO2 particle filled elastomers exhibiting lower creep strain.

The proposed mechanism of glow of mesosphere clouds

The question of the physical mechanism of electromagnetic radiation scattering by mesospheric (noctilucent) clouds is considered. A hypothesis has been expressed about the special electromagnetic characteristics of nanometer-sized ice particles that make up mesospheric clouds. Particle ice consists of a recently discovered crystalline modification of water — ice 0, formed by the condensation of vapor on dust particles at temperatures of –140…–23°C. Ice 0 is a ferroelectric, and upon contact with a dielectric, a layer with high electrical conductivity is formed. Due to plasmon resonance in nanosized layers, strong scattering of electromagnetic radiation occurs over a wide frequency range. This mechanism causes the glow of noctilucent clouds when illuminated by the radiation of the Sun.

Synthesis, characterization and photo catalytic activity of silver nano particle derived from Arachis hypogaea L. seed peel extracts

Abstract The study focuses on the green synthesis of silver nanoparticles (AgNPs) using Arachis hypogaea L. seed peel extract (AHSPE) and evaluates their photocatalytic activity against Rhodamine B and Congo Red dyes. The synthesis involved reducing aqueous silver metal ions with AHSPE, characterized by various techniques including UV–visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and FT-Raman spectroscopy. UV–visible spectroscopy indicated characteristic absorption peaks at 428 and 439 nm, confirming the formation of AgNPs. XRD analysis revealed an average particle size of 4.77–5.6 nm. FT-IR spectra identified biomolecules such as amines, peptides, amides, lactones, and polyphenols in the extract, acting as reducing and capping agents, thereby stabilizing the AgNPs. SEM analysis showed pristine silver nanoparticles with diameters ranging from 1 to 10 µm. The biosynthesized AgNPs demonstrated strong photocatalytic activity in degrading Rhodamine B and Congo Red dyes. This method did not use any synthetic reagents, making it an environmentally safe and cost-effective alternative for synthesizing silver nanoparticles. The process aligns with green chemistry principles, offering potential applications in photocatalysis and environmental cleanup. The study underscores the importance of biosynthesized nanoparticles due to their unique biological properties and the role of plant secondary metabolites in facilitating green synthesis.

Activated charcoal application in gastric ulceration areas in horses: preliminary experimental study

Gastric ulceration is frequent in adult horses, bringing significant economic and welfare implications to these animals. Treatment may employ several drugs, but adsorbents, such as activated charcoal, are not mentioned. Activated charcoal may be a valuable therapeutic option mainly because of its few adverse effects, fecal elimination, and low cost. This study aimed to evaluate the use of activated charcoal in experimentally induced gastric ulceration in horses and perform the microscopic characterization of charcoal particles in the injured epithelium. Five adult, undefined breed horses underwent a gastric ulcer induction protocol based on alternating fasting and free food access periods. Next, we performed a gastroscopic examination and applied activated charcoal diluted in water at the ulcers through a probe passed through the working channel of the gastroscope. The gastric mucosa was washed with water after a contact period of 5 min until the complete lack of macroscopic product visualization. Then, we performed a biopsy of the aglandular mucosa in erosive to ulcerative injury sites and a microscopic assessment of the fragments. Macroscopically, all animals presented ulcerative lesions in the greater or lesser gastric curvature along the margo plicatus and hyperkeratosis in the aglandular portion. Microscopically, all animals had hyperplasia, hyperkeratosis, epithelial erosion, desquamated epithelial cells, inflammatory cells, and variable amounts of charcoal particles, either free or adhered to the epithelium. We concluded that activated charcoal remains adhered to aglandular gastric lesions in horses even after lavage with water and histological processing, allowing its microscopic visualization. Therefore, activated charcoal’s effectiveness as a therapy for equine gastric lesions warrants evaluation.

Microplastics and Trash Cleaning and Harmonization (MaTCH): Semantic Data Ingestion and Harmonization Using Artificial Intelligence.

With the rapid expansion of microplastic research and reliance on semantic descriptors, there is an increasing need for plastic pollution data harmonization. Data standards have been developed but are seldom implemented across research sectors, geographic regions, environmental media, or size classes of plastic pollution. Harmonization of existing data is currently hindered by increasingly large datasets using thousands of different categorical variable descriptors, as well as various metrics used to describe particle abundance and differing size ranges studied across groups. For this study, we used manually developed relational databases to build an algorithm utilizing artificial intelligence capable of automatically curating harmonized, more usable datasets describing micro to macro plastic pollution in the environment. The study algorithm MaTCH (microplastics and trash cleaning and harmonization) can harmonize datasets with different formats, nomenclature, methods, and measured particle characteristics with an accuracy of 71-94% when matching semantically. All other non-semantic corrections are reported within a 95% confidence interval and with model uncertainty. All steps of the algorithm are integrated in an open-source software tool for the benefit of the scientific community and ease of integration for all plastic pollution data.

Characterization of particles generated by non-catalytic methane pyrolysis in a tubular flow reactor

Characterization of particles generated by non-catalytic methane pyrolysis in a tubular flow reactor

Ultrasound-Responsive Lipid Nanoplatform with Nitric Oxide and Carbon Monoxide Release for Cancer Sono-Gaso-Therapy.

Local gas therapy is emerging as a potential cancer treatment approach due to its specificity as gas-containing molecules can be packed into a nanodelivery system to release the corresponding gaseous molecules around the tumor site upon a suitable stimulus. Single-gas therapy has been reported, while synergistic dual-gas therapy has rarely been reported. Herein, we report a dual-gas-containing nanoplatform for synergistic cancer gasotherapy upon ultrasound irradiation. First, a robust ultrasound-responsive lipid-coated nanosystem was prepared with suitable particle size and characteristics. A low-intensity ultrasound (1.25 W/cm2) was found to simultaneously modulate carbon monoxide (CO) and nitric oxide (NO) release from the nanosystem in media and CT26 colon cancer cells for efficient therapeutic effect. The intracellular release promoted the overgeneration of reactive oxygen species (ROS) and triggered cancer cell apoptosis synergistically. The in vivo test demonstrated that the optimal dual-gas-containing formulation efficiently inhibited tumor growth (by ∼87%) at relatively low doses upon ultrasound irradiation (1.25 W/cm2, 5 min). This therapeutic efficacy shows that the current responsive lipid-coated delivery system has potential for ultrasound-triggered dual-gas therapy of both superficially and deeply seated cancers.

Transpolar Arcs Are Not Always Cusp‐Aligned: Evidence of HiLDA‐Aligned Arcs

AbstractTranspolar arcs (TPAs) are often cusp‐aligned. Especially when multiple TPAs appear simultaneously, they join at the auroral signature of the cusp. Here we investigate the dayside connection point of TPAs using Defense Meteorological Satellite Program measurements and identify three cases where the tip of the TPA ends in a localized brightening. One is a typical cusp spot with a TPA attached. The cusp appears just poleward of the oval with a near circular shape. In the second case, multiple cusp spots are observed over a 3 MLT wide region, each connected to a TPA. In the third case, the brightening at the tip of a TPA is identified as high‐latitude dayside aurora (HiLDA). Cusp aurora appears between the HiLDA and the duskside oval. Plasma flows and particle characteristics indicate a lobe origin of the HiLDA. Our results indicate a more complicated connection between TPAs and dayside aurora than previously anticipated.

An analytical method for increasing the accuracy of the value of the Newtonian constant of gravitation

Despite hundreds of measurements of the Newtonian constant of gravitation, its accuracy remains very low. Over the past 55 years, it has improved by only one order of magnitude - from four to five digits after the decimal point. In this study, a new analytical method for improving the accuracy of estimating the value of the Newtonian constant of gravitation is proposed. Using the proposed method, its accuracy is increased by 7 orders of magnitude relative to the CODATA 2022 data. The method is based on the analytical estimate of the Planck mass, length, and time, with an accuracy of values ​​that is 5 orders of magnitude higher than their accuracy according to CODATA 2022. Such a significant increase in the accuracy of the Planck mass, length, and time values ​​was made possible by the integrated use of: 1) precision formulas for the Planck momentum; 2) representation of the speed of light in a vacuum through the Planck length and time; 3) the De Broglie principle: the moments of the Planck mass, leptons, and baryons are equal to each other; 4) high-precision characteristics of the proton. The method of analytical evaluation of Planck mass, length, and time allowed us to connect the main characteristics of the hypothetical virtual Planck particle with the main characteristics of the proton. Increasing the accuracy of the proton characteristics will entail increasing the accuracy of Planck mass, length, and time. Accordingly, the accuracy of the value of the Newtonian gravitational constant and all physical constants that can be represented through Planck mass, length, and time will be increased, which is especially important in light of the decisions of the 26th General Conference on Weights and Measures.

Multiyear high-temporal-resolution measurements of submicron aerosols at 13 French urban sites: data processing and chemical composition

Abstract. This paper presents a first comprehensive analysis of long-term measurements of atmospheric aerosol components from aerosol chemical speciation monitor (ACSM) and multiwavelength Aethalometer (AE33) instruments collected between 2015 and 2021 at 13 (sub)urban sites as part of the French CARA (Chemical Characterization of Particles) program. The datasets contain the mass concentrations of major chemical species within submicron aerosols (PM1), namely organic aerosols (OAs), nitrate (NO3-), ammonium (NH4+), sulfate (SO42-), non-sea-salt chloride (Cl−), and equivalent black carbon (eBC). Rigorous quality control, technical validation, and environmental evaluation processes were applied, adhering to both guidance from the French Reference Laboratory for Air Quality Monitoring (LCSQA) and the Aerosol, Clouds, and Trace Gases Research Infrastructure (ACTRIS) standard operating procedures. Key findings include geographical differences in the aerosol chemical composition, seasonal variations, and diel patterns, which are influenced by meteorological conditions, anthropogenic activities, and proximity to emission sources. Overall, OA dominates PM1 at each site (43 %–60 % of total mass), showing distinct seasonality with higher concentrations (i) in winter, due to enhanced residential heating emissions, and (ii) in summer, due to increased photochemistry favoring secondary aerosol formation. NO3 is the second most important contributor to PM1 (15 %–30 %), peaking in late winter and early spring, especially in northern France, and playing a significant role during pollution episodes. SO4 (8 %–14 %) and eBC (5 %–11 %) complement the major fine-aerosol species, with their relative contributions strongly influenced by the origin of air masses and the stability of meteorological conditions, respectively. A comparison with the 3D chemical transport model (CTM) CHIMERE shows high correlations between simulations and measurements, albeit with an OA concentration underestimation of 46 %–76 %. Regional discrepancies in NO3 concentration levels emphasize the importance of these datasets with respect to validating air quality models and tailoring air pollution mitigation strategies. The datasets can be found at https://doi.org/10.5281/zenodo.13318298 (Chebaicheb et al., 2024).

Heat transfer characteristics of petroleum coke particle packed bed: An experimental and CFD simulation study

AbstractDue to the complexity of the internal pore structure of petroleum coke loose particle‐packed beds, measuring their thermal conductivity has always been a challenging problem. This work independently developed an experimental apparatus for testing the thermal conductivity of petroleum coke particle‐packed beds and constructed a forward calculation model for the heat transfer process, which was based on one‐dimensional unsteady heat transfer. Using the Sparse Nonlinear OPTimizer (SNOPT) algorithm, a mathematical relationship between the thermal conductivity λ of the coke bed, temperature T, and equivalent particle diameter dp was established through inverse modeling. Concurrently, a digital model of the petroleum coke particle packed bed was derived utilizing three‐dimensional computed tomography (CT) scanning technology, and a pore‐scale gas–solid radiation heat transfer model was formulated based on CFD simulation technology, thereby further elucidating the heat transfer mechanism within the petroleum coke particle packed bed. The research results indicate that the temperature predicted by the established thermal conductivity model aligns well with experimental data. Further CFD simulation studies demonstrate that a smaller particle size leads to a larger temperature difference between the wall and the center of the packed bed, while a higher gas velocity results in a smaller temperature difference, with a linear correlation observed between these two factors. At high temperatures, thermal radiation between particles in the porous petroleum coke‐packed bed plays a dominant role. The research outcomes can offer significant theoretical support for a profound analysis of the heat transfer behavior of petroleum coke‐packed beds within a vertical shaft calciner.

Towards realism in hazard assessment of plastic and rubber leachates – Methodological considerations

While plastic chemicals are key drivers of observed effects to aquatic species, there remains a lack of standardized and fit-for-purpose approaches for experimentally deconvoluting the effects of plastic chemicals from particle effects. This study investigated differences in chemical composition determined using two different organic solvents for extractions (dichloromethane-ethyl acetate, methanol) and by thermal desorption applied to 51 thermoplastic and elastomer products. The composition of natural water leachates of four select elastomers was also investigated. The number of chemical features in each material varied according to the extraction method, with solvent extracts exhibiting the most chemicals, and only 19 compounds commonly identified by all three methods. The number of chemical features in leachates was generally similar to the corresponding chemical extracts, but strong differences in relative composition were detected. While turbulence had minimal impact on leachate composition, particle loading strongly influenced leachate composition, temperature and salinity influenced the leachate concentration for some chemicals, and leaching time depended upon chemical mobility. Leachate composition cannot be readily predicted from particle characterization and multiple parameters are drivers of compositional variance in aquatic leachates. Recommendations for performing leaching studies that are relevant for hazard characterization in a realistic aquatic environment risk assessment scenario are suggested, with a particular focus on particle loading.