Search Results (105)

The present study focuses on the effect of doping KH560-modified cellulose nanocrystals (CNCs) on the electro-optical characteristics of polymer-dispersed liquid crystals (PDLCs). PDLC films were fabricated through the polymerization-initiated phase separation (PIPS) process and doped with CNC nanoparticles at various concentrations. At low concentrations, the CNCs at the interface, by virtue of their unique chiral characteristics, induce an orderly arrangement of liquid crystal molecules. Meanwhile, the interaction between the film’s fiber structure and the liquid crystal droplets brings about an augmentation in the arrangement efficiency. The excellent dispersion of CNCs diminishes the random alignment of liquid crystal molecules and mitigates light scattering. Additionally, it aids in the deflection of the liquid crystal director, facilitating the lubrication of the liquid crystals’ movement. It is remarkable that within the range of relatively lower CNCs doping concentrations, specifically from 0.005 wt% to 0.05 wt%, the PDLC films exhibit lower threshold and saturation voltages, faster response, enhanced viewing angle performance and higher contrast. Full article

This study examines a Mei-Yu rainfall event using rain gauges (RG) and OTT Parsivel disdrometers to observe precipitation characteristics and raindrop size distributions (RSD), with comparisons made against Weather Research and Forecasting (WRF) model simulations. Results show that Parsivel-derived rain rates (RR) are slightly underestimated relative to RG measurements. Both observations and simulations identify 1–3 mm raindrops as the dominant precipitation contributors, though the model overestimates small and large drop contributions. At low RR, decreased small-drop and increased large-drop concentrations cause corresponding leftward and rightward RSD shifts with decreasing altitude—a pattern well captured by simulations. However, at elevated rainfall rates, the simulated concentration of large raindrops shows no significant increase, resulting in negligible rightward shifting of RSD in the model outputs. Autoconversion from cloud droplets to raindrops (ATcr), collision and breakup between raindrops (AGrr), ice melting (MLir), and evaporation of raindrops (VDrv) contribute more to the number density of raindrops. At 0.1 < RR < 1 mm·h⁻¹, ATcr dominates, while VDrv peaks in this intensity range before decreasing. At higher intensities (RR > 20 mm·h⁻¹), AGrr contributes most, followed by MLir. When the RR is high enough, the breakup of raindrops plays a more important role than collision, leading to a decrease in the number density of raindrops. The overestimation of raindrop breakup from the numerical parameterization may be one of the reasons why the RSD does not shift significantly to the right toward the surface under the heavy RR grade. The RSD near the surface varies with the RR and characterizes surface precipitation well. Toward the surface, ATcr and VDrv, but not AGrr, become similar when precipitation approaches. Full article

In this study, the heterogeneous reaction of oleic acid droplets with gas-phase ozone was studied by an ATR-FTIR flow reactor. The effects of droplet size, relative humidity, and ozone concentration on the reaction kinetics were carefully investigated. Specifically, the pseudo-first-order rate constant k_app and the uptake coefficient γ displayed a size dependence, with k_app decreasing from ~4.5 × 10⁻³ to ~3.2 × 10⁻³ and γ linearly increasing from ~4.4 × 10⁻⁵ to ~3.2 × 10⁻⁴ as the suspended droplet diameter increased from 0.1 to 1.0 μm. It is believed that the reaction kinetics were the major contributor to the reactive uptake in the reaction between the oleic acid droplets and gas-phase ozone observed in this study. In addition, RH showed no obvious influence on the heterogeneous reaction kinetics, in agreement with findings from previous studies. Furthermore, the k_app was found to display a Langmuir–Hinshelwood dependence on the gas-phase ozone concentration with K_O3 = (3.29 ± 0.46) × 10⁻¹⁵ molecules cm⁻³ and k[S] = 0.153 ± 0.007 s⁻¹, which is consistent with observations of the ozonolysis of unsaturated organic materials in the literature. Kinetics data related to the heterogeneous reaction of ozone and oleic acid under different conditions could be used in chemistry transport models and air quality models to better understand air pollutants’ adverse health impacts. Full article

Background/Objectives: Sodium acetate (NaA) has demonstrated potential in improving non-alcoholic fatty liver disease (NAFLD) by targeting hepatocytes and Kupffer cells. However, its clinical application is hindered by low oral bioavailability and insufficient liver concentrations. Liposomes, with their capacity to encapsulate water-soluble drugs and be surface-modified, offer a promising solution for targeted oral drug delivery. Methods: We designed NaA-loaded liposomes modified with sodium cholate (SC) and mannose (MAN) (NaA@SC/MAN-LPs) to target hepatocytes and Kupffer cells. Results: The NaA@SC/MAN-LPs had a mean diameter of approximately 100 nm with a positive surface charge. Compared to free NaA, NaA@SC/MAN-LPs significantly extended the serum half-life from 2.85 h to 15.58 h, substantially improving in vivo bioavailability. In vivo distribution studies revealed that NaA@SC/MAN-LPs extended the acetate peak time in the liver from 15 min to 60 min and increased hepatic acetate accumulation to 3.75 times that of free NaA. In in vitro cell experiments, NaA@SC/MAN-LPs significantly reduced the lipid droplet, triglycerides (TG), and total cholesterol (TC) in a fatty acid-induced hepatocyte steatosis model and suppressed proinflammation in a lipopolysaccharide (LPS)-activated Kupffer cell inflammation model. Free NaA effectively improved hepatic lipid deposition in NAFLD mice. Furthermore, NaA@SC/MAN-LPs decreased hepatic TG, TC, and the relative area of lipid droplets by 30.44%, 15.26%, and 55.83%, compared to free NaA. Furthermore, the liposomes reduced macrophage infiltration and pro-inflammatory response. Conclusions: The NaA@SC/MAN-LPs demonstrated effective dual targeting effects on hepatocytes and Kupffer cells, significantly improving the pathogenesis of NAFLD, compared to free NaA. This study provides a new strategy for developing effective and safe oral drugs for NAFLD. Full article

Thermally driven local-scale precipitation (LSP) is an important type of summer precipitation over China, but the prestorm environmental conditions remain unclear. In order to investigate the major factors controlling the LSP intensity, the meteorological parameters preceding the occurrence of light and heavy afternoon LSP over Eastern China during 2018–2022 are examined using rain gauge, radiosonde sounding, and satellite observations. The temperature differences between heavy and light LSP events are relatively small, but heavy LSP events exhibit larger water vapor mixing ratios (Q_v) below a 5 km altitude than light LSP. With an almost identical vertical temperature distribution, an increment in Q_v increases the relative humidity (RH) in the lower troposphere. Furthermore, large eddy simulations with spectral bin microphysics are performed to investigate the impacts of humidity and aerosols on the LSP intensity. Increased low-level RH leads to larger mass concentrations of rain and graupel at the expense of cloud droplets due to enhanced drop collisions and the riming of ice particles, respectively, thereby reinforcing the LSP. However, an increased aerosol concentration leads to more cloud water but reduced rain water content, resulting mainly from suppressed drop collisions. The graupel mixing ratio exhibits a non-monotonic trend with aerosols, mostly contributed by riming. As a result, the LSP intensity first increases and then decreases with an increment in the aerosol concentration in both dry and humid air. Moreover, more aerosols lead to the humidification of the surrounding air due to the enhanced evaporation of cloud droplets, particularly under lower-RH conditions. These findings provide an enhanced understanding of the effects of covariations in humidity and aerosol concentrations on the afternoon LSP intensity over Eastern China. Full article

Particulate matter (PM) is widely recognized as a major air pollutant with significant impacts on human health, highlighting the need for accurate monitoring. In developing countries, low-cost sensors are crucial for accessible PM monitoring, but their accuracy and reliability must first be assessed. This study benchmarked the Alphasense OPC-N3 and Next PM sensors through laboratory and field evaluations. Laboratory tests were performed in controlled conditions with HEPA-filtered air at low humidity and varying concentrations of water droplets from nebulized deionized water. A 27-day field study in Cienfuegos, Cuba, provided additional insights into real-world performance. The OPC-N3 showed susceptibility to perturbations and was more affected by outliers (especially PM₁₀), relative humidity, and interference from aqueous aerosols. In contrast, the Next PM sensor demonstrated superior stability, lower noise levels, and consistent performance across different environmental conditions. Despite a substantial price difference, both sensors provided valid measurements. Additionally, both sensors produced lognormal PM concentration distributions during field campaigns. This feature could aid in addressing the calibration stability challenges commonly associated with low-cost sensors through in situ calibration methods. While the PM measurements by affordable sensors are not perfect, they are sufficiently reliable for supporting air quality assessments in resource-limited settings. Full article

This study compared the use of cellulose nanofibrils (CNF) and lignocellulose nanofibrils (LCNF) in different concentrations to reinforce the poly(vinyl alcohol) (PVA) matrix. Both nanofillers significantly improved the elastic modulus and tensile strength of PVA biocomposite films. The optimum concentration of CNF and LCNF was 6% relative to PVA, which improved the tensile strength of the final PVA biocomposite with CNF and LCNF by 53% and 39%, respectively, compared to the neat PVA film. The addition of LCNF resulted in more elastic films than the addition of CNF to the PVA matrix. The elongation at break of the PVA biocomposite with 2% of LCNF was more than 100% higher than that of the neat PVA film. The integration of tannic acid (TA) into the PVA-LCNF system resulted in antioxidant-active and more water-resistant PVA biocomposites. The three-component biocomposite films with 2 and 6% LCNF and 10% TA exhibited a more than 20° higher contact angle of the water droplet on the surfaces of the biocomposite films and absorbed more than 50% less water than the neat PVA film. New formulations of biocomposite films have been developed with the addition of LCNF and TA in a polymeric PVA matrix. Full article

The objective of this study was to investigate the effects of retrograded resistant starch (RS3) (0, 2%, 4% and 6%; w/v) on the emulsion gel properties stabilized by myofibrillar proteins (MPs) and in vitro protein digestibility of the gels. The RS3 was prepared from corn or potato starch using the gelatinization–ultrasound–retrogradation method. The results showed that the addition of RS3 decreased the surface hydrophobicity (p < 0.05) and increased the fluorescence intensity of MPs, indicating enhanced protein–protein interactions. More stable emulsions stabilized by MP/RS3 mixtures were formed, along with higher electronegativity, a smaller droplet size and reduced creaming index. These changes promoted the formation of better gel networks with the oil droplets evenly dispersed, thus improving gel strength, water holding capacity (WHC) and texture, especially at the concentration of 6% RS3 added. The gel force results indicated that the addition of RS3 enhanced the hydrophobic interaction and disulfide bonds between MPs. LF-NMR and MRI data further confirmed that RS3 addition facilitated the migration of free water to immobilized water. Furthermore, the incorporation of RS3 caused a relatively lower pepsin digestibility but did not change the overall in vitro protein digestibility of the gels. This paper provides a method to produce high-quality low-GI meat products without degrading protein digestibility. Full article

The aim of the present study was the isolation of high exopolysaccharide (EPS) producers, Lactic Acid Bacteria (LAB) strains, from three types of milk: goat, sheep, and camel milk. Among 112 LAB isolates tested for their ability to produce EPS on MRS-sucrose agar, only 11 strains were able to produce EPS and only three higher producers’ strains were identified by 16S rRNA gene sequencing as two strains of Lactococcus lactis subsp. lactis (SP255, SP257) isolated from camel milk and one strain of Weissella cibaria (SP213) isolated from goat milk. The physicochemical characterization of the purified EPSs revealed a significant sugar yield, with concentrations ranging from 2.17 to 2.77 g/L, while the protein content remained relatively low (0.03 g/L). The UV-visible spectrum showed high Ultra Violet (UV) absorption at 240–280 nm and the Fourier-Transform Infrared (FTIR) spectra showed the presence of a large number of functional groups, including hydroxyl (-OH), carbonyl (-C=O), and methyl groups (-CH3). The EPS solubility indicated their hydrophilic properties and the investigation of interfacial properties indicated that these EPSs could be used as natural emulsifiers and stabilizers in both acidic and neutral emulsions. Moreover, a new type of emulsion system was developed by the utilization of EPSs in the formation of multilayer interfaces in oil-in-water (O/W) emulsions stabilized by sodium caseinate (CAS). Thus, the impact of an EPS addition on the particle size distribution and electrical charge has been studied. At pH 3, the studied EPSs adhered to the surfaces of caseinate-coated droplets and the stability of O/W emulsions was improved by adding certain concentrations of EPSs. The minimum concentration required to stabilize multilayer emulsions for EPSs SP255, EPS SP257, and EPS SP213 was 1.5, 1.5, and 1.7 g/L, respectively. These findings reveal a new EPS with significant potential for industrial use, particularly as an emulsion stabilizer. Full article

The challenge of producing polymer vesicles remains difficult, despite numerous attempts to modulate the kinetics of polymer vesicle budding and achieve precise control over the membrane characteristics. An innovative approach that incorporates the use of copolymer-loaded single-emulsion droplets is proposed to address this challenge. This method enables the precise manipulation of micelles and polymer vesicles’ composition, structures and dimensions. The emulsion contracts and forms microspheres when the copolymer concentrations exceed > 0.5 wt%, resulting in the formation of nano polymer vesicles. Conversely, the copolymer spontaneously forms micro polymer vesicles and micelles through vesicle budding at lower concentrations. The spontaneous production of vesicles and micelles can be induced by modifying the copolymer concentration in the emulsion. Our discoveries have a significant impact relative to the development of copolymer membranes and contribute to an enhanced comprehension of the mass manufacturing of polymer vesicles from single emulsions. Full article

Sedimentation is an undesirable phenomenon that complicates the design of microsystems that exploit dense microparticles as delivery tools, especially in biotechnological applications. It often informs the integration of continuous mixing modules, consequently impacting the system footprint, cost, and complexity. The impact of sedimentation is significantly worse in systems designed with the intent of particle metering or binary encapsulation in droplets. Circumventing this problem involves the unsatisfactory adoption of gel microparticles as an alternative. This paper presents two solutions—a hydrodynamic solution that changes the particle sedimentation trajectory relative to a flow-rate dependent resultant force, and induced hindered settling (i-HS), which exploits Richardson–Zaki (RZ) corrections of Stokes’ law. The hydrodynamic solution was validated using a multi-well fluidic multiplexing and particle metering manifold. Computational image analysis of multiplex metering efficiency using this method showed an average reduction in well-to-well variation in particle concentration from 45% (Q = 1 mL/min, n = 32 total wells) to 17% (Q = 10 mL/min, n = 48 total wells). By exploiting a physical property (cloud point) of surfactants in the bead suspension in vials, the i-HS achieved a 58% reduction in the sedimentation rate. This effect results from the surfactant phase change, which increases the turbidity (transient increase in particle concentration), thereby exploiting the RZ theories. Both methods can be used independently or synergistically to eliminate bead settling in microsystems or to minimize particle sedimentation Full article

Foliar fertilization, an effective agricultural practice, involves the application of nutrients directly through droplets on plant leaves. The mechanisms of mass transport and deposition that arise from the drying of a drop determine the distribution of mass on a surface. Understanding these processes is crucial for optimizing foliar fertilization, ensuring even nutrient distribution, and improving crop yields and quality. This study experimentally investigates deposit formation from the evaporation of fertilizer droplets in various configurations: sessile, vertical, and pendant. We explored the effects of initial droplet volume, vapor pressure, and sorbitol presence on the final deposit morphology. The results reveal distinctive morphological patterns. Sessile drops exhibit two types of deposits—central crystal accumulation with fibrous structures or entirely fibrous structures. In contrast, vertical drops display two zones—fibrous structures at the bottom and small aggregates at the top. On the other hand, pendant drops predominantly feature intertwined crystals with peripheral fibrous structures. We found that high vapor pressures (RH = 60%) inhibit deposit formation within 72 h. Furthermore, the study measures relative evaporation time, showing that sessile droplets exhibit the longest evaporation times, followed by vertical and pendant droplets. Texture analysis, based on GLCM entropy, reveals that deposits generated under low vapor pressure (RH = 20%) show no significant differences in their entropy values, regardless of the droplet configuration and its initial volume. However, at intermediate vapor pressure (RH = 40%), entropy values vary significantly with droplet volume and configuration, being higher in sessile drops and lower in vertical ones. Additionally, we investigated the impact of sorbitol on the coating of sessile fertilizer droplets. We find that configurational entropy decreases exponentially with sorbitol concentration, inducing a morphological transition from fibrous structures to dispersed small aggregates. These findings highlight the complexity of pattern formation in fertilizer deposits and their potential implications for optimizing surface coating processes. Full article

In this study, the whey protein isolate–high-methoxyl pectin (WPI-HMP) complex prepared by electrostatic interaction was utilized as an emulsifier in the preparation of docosahexaenoic acid (DHA) algal oils in order to improve their physicochemical properties and oxidation stability. The results showed that the emulsions stabilized using the WPI-HMP complex across varying oil-phase volume fractions (30–70%) exhibited consistent particle size and enhanced stability compared to emulsions stabilized solely using WPI or HMP at different ionic concentrations and heating temperatures. Furthermore, DHA algal oil emulsions stabilized using the WPI-HMP complex also showed superior storage stability, as they exhibited no discernible emulsification or oil droplet overflow and the particle size variation remained relatively minor throughout the storage at 25 °C for 30 days. The accelerated oxidation of the emulsions was assessed by measuring the rate of DHA loss, lipid hydroperoxide levels, and malondialdehyde levels. Emulsions stabilized using the WPI-HMP complex exhibited a lower rate of DHA loss and reduced levels of lipid hydroperoxides and malondialdehyde. This indicated that WPI-HMP-stabilized Pickering emulsions exhibit a greater rate of DHA retention. The excellent stability of these emulsions could prove valuable in food processing for DHA nutritional enhancement. Full article

The use of plant protection products (PPPs) has become fundamental to guarantee excellent field productivity. Nevertheless, their usage presents critical issues, such as the quantity of substances used, the relative toxicity, and the contamination of nearby fields caused by atmospheric drift. This study focuses on the characterization of aerosol droplets of PPPs produced by spraying a chemical marker, fluorescein, with an orchard airblast sprayer equipped with conventional hollow cone (HC) and anti-drift air inclusion (AI) nozzles, using a wind tunnel as a controlled environment. A particle/droplet image analysis was employed to study the droplet production of the nozzles, while a liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis allowed us to evaluate samples collected using a cascade impactor located at 5 m, 10 m, and 20 m from the emission point. Overall, HC nozzles are very accurate at producing specific drop size distributions (DSDs), while AI nozzles produce a much wider DSD, concentrating the largest part of the distributed volume into droplets of a larger size. The marker concentration was much lower for the AI nozzles compared to the HC nozzles; moreover, the two nozzles show a similar trend in the coarse droplet range, while significantly differing in the fine droplet spectrum. Full article

Using CloudSat/CALIPSO satellite data and ERA5 reanalysis data from 2006 to 2010, the effects of aerosols on ice- and mixed-phase, single-layer, non-precipitating clouds over the Tibetan Plateau during nighttime in the MAM (March to May), JJA (June to August), SON (September to November), and DJF (December to February) seasons were examined. The results indicated the following: (1) The macrophysical and microphysical characteristics of ice- and mixed-phase clouds exhibit a nonlinear trend with increasing aerosol optical depth (AOD). When the logarithm of AOD (lnAOD) was ≤−4.0, with increasing AOD during MAM and JJA nights, the cloud thickness and ice particle effective radius of ice-phase clouds and mixed-phase clouds, the ice water path and ice particle number concentration of ice-phase clouds, and the liquid water path and cloud fraction of mixed-phase clouds all decreased; during SON and DJF nights, the cloud thickness of ice-phase clouds, cloud top height, liquid droplet number concentration, and liquid water path of mixed-phase clouds all decreased. When the lnAOD was >−4.0, with increasing AOD during MAM and JJA nights, the cloud top height, cloud base height, cloud fraction, and ice particle number concentration of ice-phase clouds, and the ice water path of mixed-phase clouds all increased; during SON and DJF nights, the cloud fraction of mixed-phase clouds and the ice water path of ice-phase clouds all increased. (2) Under the condition of excluding meteorological factors, including the U-component of wind, V-component of wind, pressure vertical velocity, temperature, and relative humidity at the atmospheric pressure heights near the average cloud top height, within the cloud, and the average cloud base height, as well as precipitable water vapor, convective available potential energy, and surface pressure. During MAM and JJA nights. When the lnAOD was ≤−4.0, an increase in aerosols may have led to a decrease in the thickness of ice and mixed-phase cloud layers, as well as a reduction in cloud water path values. In contrast, when the lnAOD was >−4.0, an increase in aerosols may contribute to elevated cloud base and cloud top heights for ice-phase clouds. During SON and DJF nights, changes in various cloud characteristics may be influenced by both aerosols and meteorological factors. Full article