Changes In Particle Size Research Articles

Development of biocompatible lipid-polymer hybrid nanoparticles for enhanced oral absorption of posaconazole: A mechanistic in vitro and in silico assessment

The current research focuses on the development of lipid-polymer hybrid nanoparticles (LPHNs) designed to enhance the solubility and bioavailability of posaconazole (PCZ). PCZ, an antifungal drug, faces challenges due to its poor water solubility, resulting in inconsistent absorption and limited bioavailability. LPHNs composed of stearic acid and poly-δ-decalactone (PDL) were successfully fabricated and characterized. The optimized formulation (P-LPHN4) exhibited a particle size of 104.0 nm, negative zeta potential (−38.9 mV), high drug loading (19.5 %), and efficient encapsulation (82.6 %). In vitro release studies demonstrated sustained drug release over 18 h, with P-LPHN4 displaying the highest drug release (92 %). Stability studies revealed good physical stability over 45 days with no significant changes in particle size, zeta potential, and PDI. In silico simulations using GastroPlus® predicted significantly improved intestinal absorption and systemic exposure for P-LPHN4 compared to the pure drug suspension in a simulated rat model. The model predicted a higher peak plasma concentration (Cmax) for P-LPHN4 (∼0.012 μg/mL) compared to the PCZ suspension (∼0.0058 μg/mL). The model identified the duodenum and jejunum as primary absorption sites for both formulations, with P-LPHNs showing significantly higher overall absorption (84.5 %) compared to the suspension (47.5 %). Simulation results revealed a dose-dependent increase in both Cmax and AUC with increasing oral P-LPHN4 dose, while Tmax remained unaffected. In conclusion, the developed posaconazole-loaded lipid-polymer hybrid nanoparticles (P-LPHN4) showed promising results in terms of enhanced drug release, stability, and bioavailability.

Ionic radius effect on structural and electrical properties of barium strontium titanate thin films

The effect of ion radius on the structural and electrical properties of the perovskite oxide Ba1-x SrxTiO3 thin film is investigated in this work. X-ray diffraction analysis confirmed the formation of phase perovskite structures. Investigations of ceramic microstructures and mechanical properties showed their dependence on the value of ratio x. X-ray diffraction (XRD) and Field emission scanning electron microscopy (FESEM) are used to study the crystallographic aspects of the materials. The XRD pattern changed from tetragonal to cubic as x rose. FESEM images revealed the particle size varied with the values of x increased. The results show that as the ion radius varies, the crystal structure undergoes distortions, affecting the symmetry and stability of the BaSrTiO3 thin films. Electrical properties change depending on the change in particle size.

(Digital Presentation) The Influence of Particle Size on Electrophotocatalytic Properties of Tungsten Trioxide Photoanodes

The need for advanced wastewater treatment technologies has been highlighted owing to the widespread contamination of water sources with toxic and persistent organic chemicals. Thin films of tungsten (VI) oxide (WO3) were prepared by spin-coating and meyer rod coating nanoparticulate dispersions following a top-down approach through ball milling. The morphological properties of the layers were investigated by profilometry. The results showed that the surface area increased with the increase in milling time and for 96 hours sample it showed a nine-fold increase compared to commercial tungsten (VI) oxide powder. The electron microscopic images provided insight into the change in particle size and layer texture which comply with the morphological changes observed by profilometry. The influence of the particle size on the charge generation efficiency was investigated using photoanodes prepared from the studied suspensions. Two distinct formulations of different particle sizes were mixed in variable ratios, and we showed that multimodal coatings exhibit larger photocurrents than monomodal coatings. The main contribution of this work can be found in the economically inexpensive method of preparing thin films WO3.

Toward Metallized Pellets for Steelmaking by Hydrogen Cooling Reduction: Effect of Gas Flow Rate.

This study proposed a strategy to prepare metalized pellets for direct steelmaking by hydrogen cooling reduction (HCR) of iron ore pellets with a focus on the effect of H2 flow rate on the process. It was demonstrated that increasing H2 flow rate could effectively enhance the reduction performance of iron ore pellets. However, due to the influence of the countercurrent diffusion resistance of gas molecules, too high H2 flow rate no longer promoted the reduction of the pellets when the maximum reduction rate was reached. The reduction swelling index (RSI) of the pellets initially increased and then decreased with increasing H2 flow rate. This change was associated with the decreased content of Fe2SiO4 in the metalized pellets and the changes in porosity and iron particle size. The compressive strength (CS) decreased continuously, showing a sharp decline when the H2 flow rate reached 0.6 L/min. It was attributed to the significant increases in porosity and average pore size of the metalized pellets, with the presence of surface cracks. When the H2 flow rate was 0.8 L/min, the metalized pellets had the optimal performance, namely, reduction degree of 91.45%, metallization degree of 84.07%, total iron content of 80.67 wt%, RSI of 4.66%, and CS of 1265 N/p. The findings demonstrated the importance of controlling the H2 flow rate in the preparation of metallized pellets by HCR.

Influence of Particle Size on Electrophotocatalytic Properties of Tungsten Trioxide Photoanodes

The need for advanced wastewater treatment technologies has been highlighted by the widespread contamination of water sources with toxic and persistent organic chemicals. In this work, thin films of tungsten (VI) oxide (WO3) were prepared by spin-coating and Meyer rod coating nanoparticulate dispersions following a top-down approach through ball milling. The morphological properties of the layers were investigated by profilometry. The results showed that the surface area increased with an increase in milling time for the milled mixture, and, for the sample milled for 96 h, it showed a nine-fold increase compared to the commercial tungsten (VI) oxide powder. The electron microscopic images provided insight into the change in particle size and layer texture which comply with the morphological changes observed by profilometry. The influence of the particle size on the charge generation efficiency was investigated using photoanodes prepared from the studied suspensions. Two distinct formulations of different particle sizes were mixed in variable ratios, and we showed that multimodal coatings exhibit larger photocurrents than monomodal coatings. The main contribution of this work can be found in the economically inexpensive method of preparing thin films WO3.

Exocomet Models in Transit: Light Curve Morphology in the Optical—Near Infrared Wavelength Range

Following the widespread practice of exoplanetary transit simulations, various presumed components of an extrasolar system can be examined in numerically simulated transits, including exomoons, rings around planets, and the deformation of exoplanets. Template signals can then be used to efficiently search for light curve features that mark specific phenomena in the data, and they also provide a basis for feasibility studies of instruments and search programs. In this paper, we present a method for exocomet transit light curve calculations using arbitrary dust distributions in transit. The calculations, spanning four distinct materials (carbon, graphite, pyroxene, and olivine), and multiple dust grain sizes (100–300 nm, 300–1000 nm, and 1000–3000 nm) encompass light curves in VRJHKL bands. We also investigated the behavior of scattering colors. We show that multicolor photometric observations are highly effective tools in the detection and characterization of exocomet transits. They provide information on the dust distribution of the comet (encoded in the light curve shape), while the color information itself can reveal the particle size change and material composition of the transiting material, in relation to the surrounding environment. We also show that the typical cometary tail can result in the wavelength dependence of the transit timing. We demonstrate that multi-wavelength observations can yield compelling evidence for the presence of exocomets in real observations.

Particle behaviors of Imipenem/Cilastatin in various liquids investigated by chemical structures and temporal microscope observations

Imipenem/Cilastatin (IPM/CS) is currently used as an embolic agent in transarterial embolization for chronic musculoskeletal pain due to its efficacy of short-term blood flow occlusion. However, due to its off-label use, the development of new materials to substitute IPM/CS is needed. Therefore, investigating the behavior of IPM/CS particles becomes crucial. In this paper, we observed the changes in particle size of IPM/CS when dissolved in phosphate-buffered saline, normal saline, iodinated contrast agent and water. The results indicated that the particle size of IPM/CS ranged from 16 to 57 µm and has fastest hydrolysis rate in iodinated contrast agent. And we analyzed the possible structure of hydrolyzed product of IPM/CS in water at room temperature and 37 ℃ using 1HNMR, HPLC. The results suggested Cilastatin is stable at both temperatures, while Imipenem hydrolyzed to produce slightly different products at different temperatures.

Calculation Method for Particle Self-Regulation Servo Based on Discrete Element Method

Particle Flow Code, as noncontinuous media calculation software, has found extensive applications in geotechnical engineering research. To simulate real physical processes, the commonly utilized servo-computing methods involve adjusting the boundaries to modify the model’s stress state. However, this approach alters the model’s initial boundaries, thereby compromising computational accuracy. Addressing this issue, this paper introduces a particle self-regulation servo-computing method. This method controls the internal particle self-adjustment and completes the servo through error analysis. On the basis of the error analysis of the average stress within the particle system and the servo stress during the iterative process, the method automatically calculates the change in particle size within the system, achieving rapid convergence to servo stress tolerance after finite number of iterations. Validation through uniaxial compression tests and complex slope cases indicates that this particle self-regulation servo method yields an error of less than 5% compared with conventional rigid servo methods. That is, it accurately achieves numerical simulation state control without altering the outer contours of the boundary model. The proposed computational method is applicable to servo calculations for irregular models in two or three dimensions, providing a viable approach for stress control in models under complex conditions.

Release of ions enhanced the antibacterial performance of laser-generated, uncoated Ag nanoparticles

Identifying the antibacterial mechanisms of elemental silver at the nanoscale remains a significant challenge due to the intertwining behaviors between the particles and their released ions. The open question is which of the above factor dominate the antibacterial behaviors when silver nanoparticles (Ag NPs) with different sizes. Considering the high reactivity of Ag NPs, prior research has primarily concentrated on coated particles, which inevitably hinder the release of Ag+ ions due to additional chemical agents. In this study, we synthesized various Ag NPs, both coated and uncoated, using the laser ablation in liquids (LAL) technique. By analyzing both the changes in particle size and Ag+ ions release, the impacts of various Ag NPs on the cellular activity and morphological changes of gram-negative (E. coil) and gram-positive (S. aureus) bacteria were evaluated. Our findings revealed that for uncoated Ag NPs, smaller particles exhibited greater ions release efficiency and enhanced antibacterial efficacy. Specifically, particles approximately 1.5 nm in size released up to 55 % of their Ag+ ions within 4 h, significantly inhibiting bacterial growth. Additionally, larger particles tended to aggregate on the bacterial cell membrane surface, whereas smaller particles were more likely to be internalized by the bacteria. Notably, treatment with smaller Ag NPs led to more pronounced bacterial morphological changes and elevated levels of intracellular reactive oxygen species (ROS). We proposed that the bactericidal activity of Ag NPs stems from the synergistic effect between particle-cell interaction and the ionic silver, which is dependent on the crucial parameter of particle size.

Study on Energy Transfer Mechanism of Grinding Balls in a Planetary Ball Milling System

Planetary ball milling systems (PBMSs) have become novel and high-energy milling equipment with wide applications. The present study explores the energy transfer mechanisms of grinding balls in these systems. A theoretical model has been developed by considering essential factors such as the diameter of the grinding balls and milling conditions, based on previous models and molecular dynamics simulations. To validate and improve the theoretical model, experimental data was collected by examining the impact of different grinding ball diameters on the change in copper powder particle size under controlled milling conditions. The mechanisms under particle size changes have been revealed, providing a deeper understanding of energy transfer in PBMSs and establishing a direct connection between the grinding ball diameter and the particle size of the resulting product. This research method makes it possible to predict the particle size and performance of the ball-milled product.

Protective Encapsulation of a Bioactive Compound in Starch-Polyethylene Glycol-Modified Microparticles: Degradation Analysis with Enzymes.

Starch is a promising polymer for creating novel microparticulate systems with superior biocompatibility and controlled drug delivery capabilities. In this study, we synthesized polyethylene glycol (PEG)-modified starch microparticles and encapsulated folic acid using a solvent-mediated acid-base precipitation method with magnetic stirring, which is a simple and effective method. To evaluate particle degradation, we simulated physiological conditions by employing an enzymatic degradation approach. Our results with FTIR and SEM confirmed the successful synthesis of starch-PEG microparticles encapsulating folic acid. The average size of starch microparticles encapsulating folic acid was 4.97 μm and increased to 6.01 μm upon modification with PEG. The microparticles were first exposed to amylase at pH 6.7 and pepsin at pH 1.5 at different incubation times at physiological temperature with shaking. Post-degradation analysis revealed changes in particle size and morphology, indicating effective enzymatic degradation. FTIR spectroscopy was used to assess the chemical composition before and after degradation. The initial FTIR spectra displayed characteristic peaks of starch, PEG, and folic acid, which showed decreased intensities after enzymatic degradation, suggesting alterations in chemical composition. These findings demonstrate the ongoing development of starch-PEG microparticles for controlled drug delivery and other biomedical applications and provide the basis for further exploration of PEG-starch as a versatile biomaterial for encapsulating bioactive compounds.

Probing the effect of protein corona on SERS signals: insights from melamine detection in milk matrix

Matrix effects limit the application of surface-enhanced Raman scattering (SERS) technology in the field of food safety. This study elucidated it from the perspective of protein corona by employing a model system for melamine SERS detection in milk. Compared with the melamine standard solution, higher detection limits (1 mg/L and 10 mg/L) are observed in milk matrix. The melamine signal exhibits an 80% reduction in whey protein solution, suggesting that protein has a significant impact on SERS signals. The changes in particle size, zeta potential and UV–vis spectra indicate the AuNPs interact with whey protein. Forming protein corona inhibits the melamine-induced AuNPs aggregation, reducing the number of ‘hot spot’ and the adsorption of melamine on AuNPs (from 0.28 mg/L to 0.07 mg/L), which may be responsible for signal loss. The found matrix effect from protein corona provides new insights for developing strategies about reducing matrix effect in SERS application.

Synthesis and study of the impact of calcination duration on the properties of Al4(ZnO)96 nanoparticles

Aluminium doped zinc oxide (Al4(ZnO)96) nanoparticles were synthesized using new sogel method at 40 °C, with zinc acetate dihydrate (Zn(CH3COO)2·2 H2O) and aluminium nitrate nonahydrate (Al(NO3)3·9 H2O) as precursors. The samples underwent analysis using various structural and optical techniques to investigate the effect of calcination duration on the properties. Prolonged calcination durations led to a significant reduction of oxygen at the grain boundaries, influencing particle size and crystallization. According to TEM-histogram analysis, the most probable size for 28.5 % of nanoparticles fell within the range of 15–20 nm, which aligns closely with the estimated particle size determined by XRD analysis. The material displayed a significant direct bandgap of approximately 3.283 eV, which increased with the duration of calcination. The band gap was affected by changes in phase, strain, and particle size, attributed to the presence of defect states and a substantial concentration of localized states. Additionally, the material exhibited excellent chemical stability and a significantly high binding energy. Moreover, the optical bandgap widened as the width of the Urbach tails in the localized states decreased with an increase in the duration of calcination.

TPGS nanoparticles co-loaded with ABT-737 and R848 for breast cancer therapy

The development of new effective drugs to treat breast cancer remains a huge challenge. ABT-737 can inhibit Bcl-2 proteins to promote apoptosis. Resiquimod (R848) is a TLR7/8 agonist that is effective in modulating the immunosuppressive microenvironment. In this study, a codelivery system (TPGS/ABT+R848 NPs) based on D-α-tocopheryl poly (ethylene glycol) 1000 succinate as a potential drug delivery vector to codelivery ABT-737 and R848 was investigated. The size of TPGS/ABT+R848 NPs was 102.5 nm, the drug loading of ABT-737 and R848 was 30.6 % and 12.5 %, and the entrapment efficiency was 84.2 % and 23.7 %, respectively. The nanoparticles showed no significant change in particle size over 14 days. R848 and ABT-737 were released in co-loaded nanoparticles in sequential order. In vitro anti-tumor experiments, the IC50 value of TPGS/ABT+R848 NPs was 0.30 μg·mL−1, 34 times lower than that of free ABT-737. Animal experiments also verified that TPGS/ABT+R848 NPs could enhance the anti-tumor activity, and the tumor weight inhibition rate was 75.3 %. This study demonstrated that TPGS NPs loaded with ABT-737 and R848 have superior combination tumor therapeutic effects, and the co-loaded preparation is conducive to anti-tumor efficacy. The TPGS/ABT+R848 NPs could be a promising platform against breast cancer.

Effect of temperature and particle size on dielectric property of vanadium-titanium magnetite

The current body of research on microwave-assisted grinding of vanadium-titanium magnetite (VTM) predominantly focuses on the analysis of changes in particle size and dissociation degree of the grinding products. Nonetheless, the microwave heating mechanism of the ore remains inadequately explored. In this study, the dielectric property of VTM with different particle sizes were measured at a frequency of 2.45 GHz and temperatures ranging from ambient to 800 °C. The results indicate that the dielectric constants (ε′) and dielectric loss factors (ε″) of VTM increase with temperature. The loss tangent coefficients (tan δ) initially increase and then decrease, reaching a maximum value of 0.44 at approximately 500 °C. The values of dielectric property parameters increase as the particle size decreases. By calculating the penetration depth equation, it can be determined that the optimal particle size for uniform heating in microwave of VTM is approximately 15 ∼ 30 mm. The heating rate of the ore in the microwave field is divided into two stages. Initially, the heating rate is very fast due to the ore being a strong magnetic mineral. However, when the ore temperature reaches 500 °C, the tan δ of the ore decreases, leading to a decrease in the heating rate.

Effect of temperature and sodium bicarbonate combined on aggregation, rheology and conformation of low-salt chicken myofibrillar protein

To study the impact of temperature (4–50 °C) and sodium bicarbonate (0.4%) on the solubility, protein aggregation and conformation of low-salt (1 mmol/L sodium chloride) chicken myofibrillar protein, the changes in turbidity, particle size, protein secondary and tertiary structures were investigated. There was no significant difference in pH when it did not exceed 30 °C, then a significant increase (p < 0.05) when it was above 30 °C. The solubility, total and reactive sulfhydryl groups, and apparent viscosity increased first and then decreased (p < 0.05), and reached the maximum values at 30 °C; whereas the turbidity, particle size, α-helix, and random coil contents showed opposite trends. Additionally, the fluorescence peak experienced a noticeable redshift with rising temperatures; β-turn content significantly increased but β-sheet content decreased significantly. Finally, combining sodium bicarbonate with a temperature of around 30 °C could enhance chicken myofibrillar protein solubility and change the protein structure under a low-salt condition.

Effect of heat transfer on the pressurization, extraction, and depressurization stages of a supercritical CO2 extraction process. 2. Simulation of a two-vessel industrial plant

In this work, we simulated the heat transfer in a two-vessel (1-m3, length-to-diameter ratio of 4) industrial plant to assess the effect of the temperature gradients formed during the reconditioning stage on the extraction curves. We simulated the extraction of 1-mm particles using 5 mm/s of CO2 at 48 MPa and 40 °C (case with an imposed temperature gradient) or 60 °C (case with temperature gradients from the reconditioning stage), with the service fluid at 60 °C. The results of these non-isothermal extractions were compared with those obtained in representative isothermal cases. The temperature gradients slightly affected the cumulative extraction curves in non-isothermal cases. We considered the presence of a basket containing the solid substrate. We also changed the superficial CO2 velocity to 3 or 10 mm/s and the particle size to 0.50 or 1.25 mm to compare the extraction curves. The effects of the basket and the changes in superficial CO2 velocity and particle size were minor. We simulated a limit case with higher temperature and pressure (80 °C and 70 MPa), where the extraction time was extremely short (10 min) and more significant temperature gradients were formed during the reconditioning stage. We observed more significant differences at this extreme extraction condition than when using an isothermal process at the required extraction temperature.

Study on the effect of sodium removal from citric acid pretreated red mud on the physical properties of red mud.

Red mud is a highly alkaline solid waste discharged from the alumina industry, and its high sodium content is the key factor limiting its wide utilization. Therefore, effective control of the "frosting" phenomenon during the application of red mud has received significant attention. In this study, the changes of particle size, phase, morphology, and pore size of red mud after sodium removal with different amounts of citric acid pretreatment were investigated. The single-factor experiment shows that the Na+ leaching rate is 86.33% under a citric acid dosage of 15%, liquid-to-solid ratio of 7mL/g, leaching temperature of 80°C, stirring speed of 300rpm, and leaching time of 10min. The leachate is characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The results reveal that Na+ mainly exists in a combined state in the form of cancrinite. With the increase of citric acid dosage, red mud agglomerates, calcite, and cancrinite are dissolved, and new phases such as calcium oxalate and magnesium aluminum hydroxide are formed. The specific surface area, pore volume, and pore diameter show irregular changes with the increase in the citric acid dosage. Citric acid pretreatment can effectively reduce the sodium content in red mud, the treatment cost of leaching solution is low, and the leaching residue is neutral, which is helpful to promote the practical application of red mud.

Effect of Heat Treatment on the Supramolecular Structure of Copolymers Based on Poly(propylene glycol fumarate phthalate) with Acrylic Acid

Previous studies investigating the thermal decomposition of p-PGFPh:AA copolymers in an inert atmosphere have provided only a general understanding of the changes that occur during thermolysis. Comprehensive studies are required to gain a better understanding of these processes [1]. The most comprehensive information on the influence of various factors on both the kinetics and the supramolecular structure of the resulting products can be obtained by combining the method of thermal analysis with IR, mass spectrometry, and scanning electron microscopy. The compounds studied have two different compositions, namely p‑PGFPh:AA 6.77:93.23 mol % and p-PGFPh:AA 86.67:13.33 mol %. These compounds were then subjected to a thermolysis process, which resulted in the emission of gases and a decrease in sample weight. The degradation process can be divided into three stages: 1) Depolymerization of the main chain; 2) Depolymerization of the side chain; 3) Final decomposition. These processes occur sequentially at different temperature ranges. According to TG- and DTG studies, complete decomposition of p-PGFPh:AA copolymers occurred at Tterm = 340–350 °C. In this temperature range, a slight loss of sample mass (less than 10 wt %) was observed along with a slight gas evolution. The main gaseous products from the transformation of the studied samples were CO and CO2. This was supported by IR-CO (2000–2200 cm−1) and CO2 (2310–2370 cm−1) as well as mass spectrometric observations. The final products resulting from the thermolysis of p-PGFPh:AA copolymers were examined under an electron microscope. The results showed a similar morphological pattern of mesostructures with sizes ranging from 0.3–1.5 μm, which were observed depending on the porous structure of the initial polymer material. Based on the experimental data, it can be concluded that the p-PGFPh:AA copolymers (in proportions of 6.77:93.23 mol % and 86.67:13.33 mol %) have a relatively high degree of resistance to heating and do not undergo any changes in chemical composition, particle size and shape. In conclusion, the results clearly indicate that the selection of conditions for pyrolysis plays a crucial role in increasing the thermal stability of polymeric materials. This method allows for purposeful changes in the structure and properties of polymers.

Online monitoring lignocellulosic particles by focus beam reflectance measurement for efficient bioprocessing

Lignocellulose presents a promising alternative to fossil fuels. Monitoring the mass and size changes of lignocellulosic particles without disrupting the process can assist in adjusting pretreatment and enzymatic hydrolysis, where conventional sieving methods fall short. A method utilizing focused beam reflectance measurement (FBRM) was developed to establish mathematical correlations between FBRM chord information (chord length and count) and particle characteristics (weight and size) quantified through sieving. Results indicate particle size exhibits a linear correlation with the square weighted median chord length (Lsqr) with R2 at 0.93. Further, real-time bulk particle mass can be predicted using Lsqr and chord count (R2 0.98). These correlations are applicable in range 53 μm to 358.5 μm. Real-time monitoring of enzymatic hydrolysis of corn stalks has demonstrated the practical applicability of FBRM. This study introduces a novel approach for online characterization of lignocellulosic particles, thereby enhancing lignocellulosic biorefineries.