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Molecules (Basel, Switzerland) Feb 2024Single-particle inductively coupled plasma mass spectrometry (spICP-MS) has been used for particle size measurement of diverse types of individual nanoparticles and...
Single-particle inductively coupled plasma mass spectrometry (spICP-MS) has been used for particle size measurement of diverse types of individual nanoparticles and micrometer-sized carbon-based particles such as microplastics. However, its applicability to the measurement of micrometer-sized non-carbon-based particles such as silica (SiO) particles is unclear. In this study, the applicability of spICP-MS to particle size measurement of non-porous/mesoporous SiO microspheres with a nominal diameter of 5.0 µm or smaller was investigated. Particle sizes of these microspheres were measured using both spICP-MS based on a conventional calibration approach using an ion standard solution and scanning electron microscopy as a reference technique, and the results were compared. The particle size distributions obtained using both techniques were in agreement within analytical uncertainty. The applicability of this technique to the detection of metal-containing protein-binding mesoporous SiO microspheres was also investigated. Bound iron (Fe)-containing proteins (i.e., lactoferrin and transferrin) of mesoporous SiO microspheres were detected using Fe as a presence marker for the proteins. Thus, spICP-MS is applicable to the particle size measurement of large-sized and non-porous/mesoporous SiO microspheres. It has considerable potential for element-based detection and qualification of bound proteins of mesoporous SiO microspheres in a variety of applications.
Topics: Silicon Dioxide; Particle Size; Microspheres; Plastics; Mass Spectrometry
PubMed: 38474598
DOI: 10.3390/molecules29051086 -
Journal of Breath Research Jul 2023Understanding particle deposition in the human lung is crucial for the assessment of environmental pollutants and the design of new drug delivery systems. Traditionally,...
Understanding particle deposition in the human lung is crucial for the assessment of environmental pollutants and the design of new drug delivery systems. Traditionally, research has been carried out by experimental analysis, but this generally requires expensive equipment and exposure of volunteers to radiation, resulting in limited data. To overcome these drawbacks, there is an emphasis on the development of numerical models capable of accurate predictive analysis. The most advanced of these computer simulations are based on three-dimensional computational fluid dynamics. Solving the flow equations in a complete, fully resolved lung airway model is currently not feasible due to the computational resources required. In the present work, a simplified lung model is presented and validated for accurate prediction of particle deposition. Simulations are performed for an 8-path approximation to a full lung airway model. A novel boundary condition method is used to ensure accurate results in truncated flow branches. Simulations are performed at a steady inhalation flow rate of 18 l min, corresponding to a low activity breathing rate, while the effects of particle size and density are investigated. Comparison of the simulation results with available experimental data shows that reasonably accurate results can be obtained at a small fraction of the cost of a full airway model. The simulations clearly evaluate the effect of both particle size and particle density. Most importantly, the results show an improvement over a previously documented single-path model, both in terms of accuracy and the ability to obtain regional deposition rates. The present model represents an improvement over previously used simplified models, including single-path models. The multi-path reduced airway approach described can be used by researchers for general and patient-specific analyses of particle deposition and for the design of effective drug delivery systems.
Topics: Humans; Models, Biological; Breath Tests; Lung; Administration, Inhalation; Computer Simulation; Particle Size; Aerosols
PubMed: 37437567
DOI: 10.1088/1752-7163/ace6c7 -
Journal of Pharmaceutical Sciences Aug 2023The specifications of excipients are important to pharmaceutical manufacturers to ensure that the final product can be manufactured robustly over the entire lifecycle of...
The specifications of excipients are important to pharmaceutical manufacturers to ensure that the final product can be manufactured robustly over the entire lifecycle of a drug product. Particle size specifications are key for dry powder inhalation excipients and they should be agreed between users and suppliers. The current paper evaluates two development strategies to set particle size specifications. It is shown that the application of quality-by-design principles to specification setting could result in broader specifications, while it guarantees that efficacy, safety and manufacturing of the medication is not affected. A multitude of reasons exist to keep specifications broader than the production capability range, including improved risk-mitigation and potentially reduced regulatory challenges during and after registration.
Topics: Powders; Excipients; Administration, Inhalation; Particle Size; Dry Powder Inhalers; Aerosols
PubMed: 36858177
DOI: 10.1016/j.xphs.2023.02.018 -
Environmental Science & Technology Apr 2024Stratospheric aerosol injection (SAI) is proposed as a means of reducing global warming and climate change impacts. Similar to aerosol enhancements produced by volcanic...
Stratospheric aerosol injection (SAI) is proposed as a means of reducing global warming and climate change impacts. Similar to aerosol enhancements produced by volcanic eruptions, introducing particles into the stratosphere would reflect sunlight and reduce the level of warming. However, uncertainties remain about the roles of nucleation mechanisms, ionized molecules, impurities (unevaporated residuals of injected precursors), and ambient conditions in the generation of SAI particles optimally sized to reflect sunlight. Here, we use a kinetic ion-mediated and homogeneous nucleation model to study the formation of HSO particles in aircraft exhaust plumes with direct injection of HSO vapor. We find that under the conditions that produce particles of desired sizes (diameter ∼200-300 nm), nucleation occurs in the nascent ( < 0.01 s), hot ( = 360-445 K), and dry (RH = 0.01-0.1%) plume and is predominantly unary. Nucleation on chemiions occurs first, followed by neutral new particle formation, which converts most of the injected HSO vapor to particles. Coagulation in the aging and diluting plumes governs the subsequent evolution to a narrow (σ = 1.3) particle size distribution. Scavenging by exhaust soot is negligible, but scavenging by acid impurities or incomplete HSO evaporation in the hot exhaust plume and enhanced background aerosols can matter. This research highlights the need to obtain laboratory and/or real-world experiment data to verify the model prediction.
Topics: Particle Size; Aerosols; Aircraft; Vehicle Emissions; Atmosphere; Air Pollutants
PubMed: 38651174
DOI: 10.1021/acs.est.3c08408 -
The Review of Scientific Instruments Oct 2023The synthesis of drug-loaded microparticles with precise control over size distribution and shape is crucial for achieving desired drug distribution in microparticles...
The synthesis of drug-loaded microparticles with precise control over size distribution and shape is crucial for achieving desired drug distribution in microparticles and tuning drug release profiles. Common large-scale production techniques produce microparticles with a broad particle size distribution and require challenging operating conditions. Recent methods employing microfluidics have enabled the production of microparticles with a uniform size distribution. Still, these methods are limited to low and moderate production rates and can handle fluids with a limited range of physicochemical properties. In this study, we couple the spinning disk atomization (SDA) technique for microdroplet production with a precipitation method to generate drug-loaded polymeric microparticles with a narrow size distribution. The design criteria and fabrication of equipment with a non-contact seal system that integrates spinning disk atomization and precipitation methods for conducting laboratory experiments involving volatile hydrocarbons while ensuring operational and personnel safety are discussed. The production of itraconazole drug-loaded microparticles using the SDA setup that considers the system's operation, maintenance, and safety aspects are discussed, and the system's efficiency is evaluated through material balance. This laboratory equipment is capable of producing drug-loaded microparticles with a narrow size distribution under moderate operating conditions and can be scaled up suitably to meet high production requirements. The applications of this equipment can be explored in various fields, such as the production of drug particles, conversion of waste polymers into microparticles, and microencapsulation of food ingredients.
Topics: Polymers; Particle Size
PubMed: 37874232
DOI: 10.1063/5.0139096 -
Environmental Science and Pollution... Nov 2023Cooking can emit high concentrations of particles and gaseous pollutants. Cooking has contributed to the major source of indoor air pollutants, especially for particle...
Cooking can emit high concentrations of particles and gaseous pollutants. Cooking has contributed to the major source of indoor air pollutants, especially for particle pollutants in residential buildings. Many studies already analyzed the emission characteristics of Chinese cooking-related UFPs and PM, while less for the fine particle size distributions. Currently, the fine particle emission characteristics of Chinese cooking need to be further investigated, since the mass size distribution of Chinese cooking is dominated by fine particles. This study determined the emission characteristics of PM and fine particles from three Chinese cooking methods. The capture efficiencies of particles were also measured by a modified indirect approach, including the impact of particle decay. The results showed that stir-fried vegetable and pan-fried meat dishes generated more fine particles at 0.542-1.5 μm. Besides, pan-fried and deep-fried meat dishes produce a higher generation of PM. The fine particles (0.542-10 μm) number-based and volume-based size distributions of six dishes both presented a monodisperse behavior. The cooking methods are not a sensitive factor to the volume frequency of fine particle ranging from 0.542 to 10 μm. The averaged volume median and mode diameter for six typical Chinese dishes are 2.5 μm and 3.3 μm, respectively. The Sauter and DeBroukere mean diameter is 4.7 μm and 5.6 μm, respectively. The decay of fine particles increases with the particle diameter. The impact of particle decay on capture efficiency for 2-3 μm particles is about 5%. The capture efficiencies of pan-fried and deep-fried meat dishes are lower than that of vegetable dishes. In contrast, the capture efficiency for stir-fried meat dishes is higher than that of vegetable dishes. The capture efficiency for PM and 0.542-5 μm particles from six typical Chinese dishes were 60-90% on the IEC recommended exhaust flowrate.
Topics: Air Pollutants; Air Pollution, Indoor; Cooking; Environmental Monitoring; Particle Size; Particulate Matter
PubMed: 37847366
DOI: 10.1007/s11356-023-30380-4 -
Frontiers in Public Health 2024Given the dense population on university campuses, indoor and outdoor airborne bacterial contamination may lead to the rapid spread of diseases in a university...
Given the dense population on university campuses, indoor and outdoor airborne bacterial contamination may lead to the rapid spread of diseases in a university environment. However, there are few studies of the characteristics of airborne and pathogenic bacterial communities in different sites on a university campus. In this study, we collected particulate matter samples from indoor and outdoor locations at a university in Bengbu City, Anhui Province, China, and analyzed the community characteristics of airborne and pathogenic bacteria using a high-throughput sequencing technique. The results showed that the composition of the dominant airborne and pathogenic bacterial communities was consistent among sites at the phylum and genus levels, with differences in their relative abundance. There were significant differences in the structure of the airborne and pathogenic bacterial communities between indoor and outdoor sites ( < 0.05). An analysis of similarities (ANOSIM) indicated that the structure of airborne bacterial communities in indoor sites was influenced by the room occupancy rate, ventilation conditions, and the extent of indoor furnishing ( < 0.05), while the structure of pathogenic bacterial communities was influenced by the number of individuals and spatial dimensions ( < 0.05). The impact of particle size on the structure of airborne and pathogenic bacterial communities was relatively minor. A total of 194 suspected pathogenic bacterial species were identified, accounting for 0.0001-1.3923% of the total airborne bacteria, all of which were conditional pathogens. Among them, , , and exhibited relatively high relative abundance, accounting for 24.40, 16.22, and 8.66% of the total pathogenic bacteria, respectively. Moreover, 18 emerging or re-emerging pathogenic bacterial species with significant implications for human health were identified, although their relative abundance was relatively low (0.5098%). The relative abundance of pathogenic bacteria in indoor environments was significantly higher than outdoors, with the laboratory and dormitory having the highest levels. The findings of this study provide valuable guidance for the prevention and control of airborne bacterial contamination and the associated health risks in both a campus environment and other public spaces with high occupancy rates.
Topics: Universities; Air Microbiology; China; Bacteria; Humans; Particle Size; Air Pollution, Indoor; Particulate Matter; Environmental Monitoring
PubMed: 38651126
DOI: 10.3389/fpubh.2024.1371656 -
Poultry Science Mar 2024The objective of this study was to evaluate combined effects of corn particle size and feed form on performance, carcass characteristics, nutrient digestibility, and...
Evaluation of particle size and feed form on performance, carcass characteristics, nutrient digestibility, and gastrointestinal tract development of broilers at 39 d of age.
The objective of this study was to evaluate combined effects of corn particle size and feed form on performance, carcass characteristics, nutrient digestibility, and gastrointestinal tract development of broilers from 1 to 39 d of age. A total of 1,800 days old, male Cobb 500 broilers were randomly assigned to 9 dietary treatments with 8 replicate pens (25 birds/pen). The experiment consisted of a factorial arrangement of 3 corn particle sizes (750, 1,150, and 1,550 μm) and 3 feed forms (mash, 3- and 4-mm pellets) provided from 1 to 39 d. Titanium dioxide (TiO) was added as an indigestible marker (0.5%) during the finisher phase (27-39 d) to determine nutrient digestibility. Feed intake (FI), body weight (BW), and feed conversion ratio (FCR) were determined at 17, 27, and 39 d of age, with FCR adjusted for mortality. On d 40, 10 birds/pen were randomly selected and processed for meat yield determination. Data were analyzed as a 3×3 factorial (particle size x feed form) arrangement of treatments. Broilers fed 3- and 4-mm pellets had increased (P < 0.05) BW, FI, and lower FCR than broilers fed mash diets at 39 d of age. At 39 d of age, broilers fed diets with 750 µm corn particle size had heavier (P < 0.05) BW and increased FI than broilers fed diets with corn particle sizes of 1,150 and 1,550 µm. At 39 d of age FCR was unaffected by corn particle size. Heavier (P < 0.05) carcass and breast weights were observed for broilers fed 3-mm pellets. Broilers fed diets with corn particle size of 750 µm had heavier (P < 0.05) carcass and breast weight than broilers fed diets with 1,550 µm. Digestibility of nutrients was higher (P < 0.05) in pelleted diets, particularly when corn particle size was increased from 750 to 1,550 µm. Breast myopathies such as wooden breast (WB) and spaghetti meat (SM), were greater (P < 0.05) in broilers fed 3-mm pellets compared to mash diets. In conclusion, broilers fed 3- and 4-mm pelleted diets had greater nutrient digestibility and improved broiler performance compared to broilers fed mash diets.
Topics: Animals; Male; Chickens; Particle Size; Nutrients; Eating; Zea mays; Gastrointestinal Tract
PubMed: 38290341
DOI: 10.1016/j.psj.2024.103437 -
Scientific Reports Jul 2023The purpose of this work was to establish the best particle size for recovering high yields of total phenolic compounds (TPC), total anthocyanin compounds(TAC) and total...
Influence of particle size in supercritical carbon dioxide extraction of roselle (Hibiscus sabdariffa) on bioactive compound recovery, extraction rate, diffusivity, and solubility.
The purpose of this work was to establish the best particle size for recovering high yields of total phenolic compounds (TPC), total anthocyanin compounds(TAC) and total flavonoid compounds (TFC) from roselle (Hibiscus sabdariffa) by applying supercritical carbon dioxide (ScCO). The extraction rate, diffusivity and solubility of yield in ScCO were also studied and calculated utilizing models. Pressure (10 and 30 MPa), temperature (40 and 60 °C), and particle size (250 µm < dp < 355 µm, 355 µm < dp < 425 µm and 425 µm < dp < 500 µm) were employed as variables in this experiment. The greatest recovery was 11.96% yield, 7.16 mg/100 g TAC, 42.93 mg/100 g TPC and 239.36 mg/100 g TFC under the conditions of 30 MPA, 40 °C and 250 µm < dp < 355 µm, respectively. The extraction rate of supercritical carbon dioxide in roselle extraction ranged from 5.19 E-03 to 1.35 E-03 mg/s fitted using the Esquivel model. The diffusivity coefficient of ScCO ranged from 2.17E-12 to 3.72E-11 mg/s, as fitted by a single sphere model. The greatest solubility of global yield, TAC, TPC and TFC in ScCO was 1.50 g/L, 0.3 mg/L, 1.69 mg/L and 9.97 mg/L, respectively, with a particle size of 250 µm < dp < 355 µm. The smaller particle size of roselle provides the maximum bioactive compound recovery and solubility. Furthermore, the diffusivity and extraction of ScCO are increased by decreasing the particle size. Therefore, a smaller particle size is appropriate for roselle extraction by ScCO based on the experimental and modelling data.
Topics: Hibiscus; Carbon Dioxide; Particle Size; Solubility; Phenols; Plant Extracts
PubMed: 37407592
DOI: 10.1038/s41598-023-32181-8 -
Food Chemistry Sep 2023This study employed solution crystallization in food engineering to prepare a high-purity vitamin intermediate, optimize its crystal morphology and regulate its particle...
This study employed solution crystallization in food engineering to prepare a high-purity vitamin intermediate, optimize its crystal morphology and regulate its particle size distribution. Model analysis was performed to investigate the quantitative correlations between the process variables and target parameters, indicating the substantial effect of temperature on separation performance. Under optimal conditions, the product purity exceeded 99.5%, which meets the requirement of the subsequent synthesis process. A high crystallization temperature reduced the agglomeration phenomenon and increased particle liquidity. Herein, we also proposed a temperature cycling strategy and a gassing crystallization routine to optimize the particle size. The results illustrated that the synergistic control of temperature and gassing crystallization could substantially improve the separation process. Overall, based on a high separation efficiency, this study combined model analysis and process intensification pathways to explore the process parameters on product properties such as purity, crystal morphology, and particle size distribution.
Topics: Crystallization; Particle Size; Temperature; Food
PubMed: 37030210
DOI: 10.1016/j.foodchem.2023.136051