Limited accessibility measurements of park green spaces (PGSs) have given an account of multiple transportations when people enjoy the services. Considering the varying types and functions of PGSs, ...this study proposed a multi-mode method that is based on the traditional two-step floating catchment area method and relied on PGS classification to estimate spatial disparity between the supply of PGSs services and residents' demands in accessibility. Choosing the urban center of Wuhan as the study area, comparative analysis of space and statistics were conducted in accessibility between the traditional single-mode and the multi-mode methods. After a sensitive analysis of accessibility with varying travel time thresholds, underserved areas in the urban center were identified on a community level based on the PGS groups. Results indicated that the estimated accessibility average and standard deviation values by single-mode method were slimly higher than that of the multi-mode method. The average and standard deviation values of the accessibility among five time thresholds exhibited slight difference and an increasing trend. The further examination analysis of spatial accessibility in 25-min threshold demonstrated that accessibility presented spatial polarization and that most underserved areas distributed in the eastern and southwestern of the urban center in Wuhan. The findings may provide a more realistic estimation and further the knowledge of access to green spaces to help decision makers developing equal and effective planning policies and strategies.
•Spatial distribution comparisons suggested that the results of the multi-mode 2SFCA based on PGS classification method were closer to the single-mode in driving in travel time threshold 25-min.•Statistical comparisons indicated that accessibility average and standard deviation values by single-mode method were slimly higher than that of the multi-mode method and exhibited slight difference with an increasing trend among five time thresholds.•Spacial accessibility under varying time threshold consistently revealed the advantage of the urban center and the disadvantage of the southwest and northeast regions.•Further examination analysis demonstrated that spatial accessibility presented spatial polarization and that most underserved areas distributed in the eastern and southwestern of the urban center in Wuhan.
Salmon oil rich in omega-3 polyunsaturated fatty acids and astaxanthin was microencapsulated in polyethylene glycol-6000 using particles from gas saturated solutions process. The process conditions ...viz. temperature (45–55 °C), pressure (15–25 MPa), oil and polymer ratio (1:2.5–1:10), and nozzle size (300–500 μm) were optimized for maximizing encapsulation efficiency. The maximum encapsulation yield of 79.20% was obtained in the microparticle produced at a temperature of 50 °C, pressure of 25 MPa, oil and polymer ratio of 1:5, and nozzle diameter of 400 μm. Astaxanthin content of 40.60 μg/g oil in microparticle; bulk density of 0.26%; cohesiveness and flowability measured by the Carr index of 12.76, and wettability of 5.91 min of the microparticles were found. Scanning electron microscopic analysis showed microparticles of different morphologies, from spherical or elongated to amorphous-shaped, with the size of the microparticles between 0.37 μm and 449 μm. Fourier transform infra-red spectroscopy spectra and fatty acid compositions of salmon oil before and after microparticle formation suggested that there was no remarkable alteration due to the PGSS process. Microparticles showed significant thermogravimetric stability up to 350 °C, and in vitro release of oil in fluids stimulating gastric conditions was faster than in distilled water.
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•Microparticles of omega-3 PUFA-rich salmon oil in PEG-6000 were prepared by PGSS.•The EE was 79.20% at 50 °C, 25 MPa, oil: polymer 1:5, and 300 μm nozzle.•ω-3 PUFAs and astaxanthin were not affected by PGSS process conditions.•Characterizations proved good combination of salmon oil with PEG in PGSS process.•TGA and release profile showed applicability in food and pharmaceuticals.
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► The potential of lavandin essential oil formulations as antimicrobial agents against foodborne bacteria was demonstrated. ► Antibacterial effectiveness of the formulations depended ...mainly on the lavandin oil concentration and the encapsulating agent. Soybean lecithin resulted to be the most efficient carrier material due to its capacity to spontaneously form liposomes. ► E. coli (gram-negative bacteria) resulted to be the most sensitive strain, due to the differences in the cell membrane of bacterial groups. ► Encapsulation process is an important parameter, determining the load, size and morphology of the particles.
Lavandin (Lavandula hybrida) essential oil contains components with biocide and antiviral properties that can be used as substitutes of antibiotics. This application requires an appropriate formulation of the essential oil. In the present work, the antimicrobial activity of free and encapsulated lavandin essential oil against three pathogenic bacteria (Gram-negative: Escherichia coli; Gram-positive: Staphylococcus aureus and Bacillus cereus) was determined. The formulations were prepared using innovative high-pressure techniques (PGSS and PGSS-drying) as well as spray-drying. Carrier materials used for the encapsulation were soybean lecithin, n-octenyl succinic anhydride (OSA) modified starch and poly-caprolactone. Results demonstrated that lavandin oil antibacterial activity could be enhanced by encapsulation, due to the protection and control release of the oil. As well, encapsulation might present an interesting opportunity to facilitate the action of antimicrobials, improving essential oil penetration inside of the outer membrane.
Sequential-Dispersion Particles from Gas Saturated Solutions (SD-PGSS) process was applied to encapsulate lutein with biocompatible polymer excipients to elaborate drug-delivery particles for oral ...uptake at mild temperatures (38 and 45 °C) under 25 MPa. Polycaprolactone and a polycaprolactone/polyethyleneglycol mixture (1:1 w/w) were selected to modulate in-vitro release. An experimental setup was designed in-house to limit the challenging plugging issues often encountered with the PGSS process. In this study, process yields up to 94% were obtained. The drug precipitation yields varied from 43 to 61% and the homogeneity of lutein dispersion was demonstrated for all conditions. In-vitro release kinetics were performed in phosphate-buffered saline solutions for 8 h. A higher release of lutein was obtained from PCL/PEG blends (∼ 90% in 5 h), whereas only 56% were released from pure PCL formulations. This study highlights the potential of the SD-PGSS process in encapsulating thermosensitive compounds at moderate temperatures.
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•Sequential-dispersion PGSS (SD-PGSS) applied to polymer excipient processing.•Solvent-free SD-PGSS applied to the elaboration of controlled release drug delivery systems.•Lutein encapsulation with biocompatible polymers for oral uptake in AMD mitigation.•Process yields up to 94% under moderate temperatures (38 and 45 °C).•Modulation of lutein release profile from solid formulation.
Quercetin is an antioxidant compound with highly promising pharmacological properties against a wide variety of diseases. A major limitation for the clinical application of quercetin is its low ...bioavailability, due to its low solubility in water. In this work, quercetin is microencapsulated in a surfactant material with the objective of increasing its bioavailability. For this, quercetin is first treated using Supercritical Fluid Extraction of Emulsions in order to precipitate it in nanometric scale in an aqueous suspension, and then this suspension is further treated by Particles from Gas Saturated Solutions (PGSS)-drying technology, to obtain quercetin loaded dried particles in micrometric scale. Soy-bean lecithin and Pluronic L64® are used as surfactant and encapsulating materials. Mircoencapsulation of quercetin by lyophilisation of SFEE-produced aqueous suspensions is also studied in order to compare it with the results of PGSS-drying. Samples are characterized considering encapsulation efficiency, antioxidant activity and Franz-cell measurements of transdermal diffusion of encapsulated quercetin product as assessment of its bioavailability. It is observed that samples encapsulated by SFEE and PGSS-drying are more homogeneous and less crystalline than samples obtained by lyophilisation, which results in a higher transdermal diffusivity.
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•Quercetin was microencapsulated in lecithin by SFEE and PGSS techniques.•SFEE process was successfully scaled-up.•90% of quercetin was encapsulated, without formation of segregated crystals.•Formulated particles presented higher transdermal diffusivity.
The coefficient of determination (R2) is a well-established measure to indicate the predictive ability of polygenic scores (PGSs). However, the sampling variance of R2 is rarely considered so that ...95% confidence intervals (CI) are not usually reported. Moreover, when comparisons are made between PGSs based on different discovery samples, the sampling covariance of R2 is required to test the difference between them. Here, we show how to estimate the variance and covariance of R2 values to assess the 95% CI and p value of the R2 difference. We apply this approach to real data calculating PGSs in 28,880 European participants derived from UK Biobank (UKBB) and Biobank Japan (BBJ) GWAS summary statistics for cholesterol and BMI. We quantify the significantly higher predictive ability of UKBB PGSs compared to BBJ PGSs (p value 7.6e−31 for cholesterol and 1.4e−50 for BMI). A joint model of UKBB and BBJ PGSs significantly improves the predictive ability, compared to a model of UKBB PGS only (p value 3.5e−05 for cholesterol and 1.3e−28 for BMI). We also show that the predictive ability of regulatory SNPs is significantly enriched over non-regulatory SNPs for cholesterol (p value 8.9e−26 for UKBB and 3.8e−17 for BBJ). We suggest that the proposed approach (available in R package r2redux) should be used to test the statistical significance of difference between pairs of PGSs, which may help to draw a correct conclusion about the comparative predictive ability of PGSs.
R2 is a well-established measure for the reliability of polygenic score models although its significance test is rarely considered in this context. We release an R package r2redux that allows formal statistical comparison of two polygenic score models, providing the 95% confidence interval and significance of R2 difference.
The purpose of this investigation was to determine whether pyriproxyfen (PPF), a synthetic juvenile hormone analog (JHA), could be encapsulated in supercritical carbon dioxide (scCO2) using the ...process particles from the gas‐saturated solutions (PGSS) for a controlled‐release system. The PGSS process represents a promising two‐step production system especially suited for the encapsulation and controlled‐release system (CRS). In contrast to traditional encapsulation methods that often involve the use of harsh organic solvents or high temperatures, the PGSS process offers a gentler approach employing scCO2 as an alternative. The solubility of scCO2 in polymer (poly‐ϵ‐caprolactone PCL) allowed for the formation of PPF microparticles, and the particle size distribution could be controlled by adjustment of operating pressure and temperature. The obtained particles had a mean particle size of 73.6 ± 2 μm and encapsulation efficiency of 78.8 ± 9% at 60°C and 10 MPa. Furthermore, the in vitro dissolution profiles of PPF–PCL particles showed a low‐level release pattern (42.5 ± 5 ppb/d) in water, followed by zero‐order kinetics indicating a high‐performance CRS. Finally, the in vivo bioassay using microparticles treated water exhibited 95%–100% emergence inhibition of mosquitoes, suggesting the effectiveness of PPF–PCL particles as a mosquito control agent.
This study aimed to investigate the application of isothermal calorimetry as technique for monitoring microparticles oxidation produced by particles from gas saturation solution (PGSS) technique. ...Microparticles were obtained by mixing linseed oil (9.1 g/100 g) with glycerol stearate (90.9 g/100 g). The process was carried out at 10 MPa, 55 °C for 30 min. To enhance microparticles oxidative stability, β-carotene was also added to the formulation (0.4 up to 1.6 mg/g of oil). The results showed that the fatty acid profile of the oil did not change after the encapsulation process. From the isothermal calorimetry traces, it was possible to determine the induction time (τIC) and the rates of oxidation during the inhibited (Rinh) and uninhibited (Runi) period. The microencapsulation by PGSS significantly (p < 0.05) increased τIC values of microparticles compared to the bulk oil, which resulted equal to 32 ± 1 × 104 s and 10.2 ± 2 × 104 s, respectively. On the other side, Rinh significantly decreased confirming the higher microparticles oxidative stability. β-carotene addition enhanced the oxidative stability proportionally to the concentration of the added antioxidant. At the end of the oxidation, the 3-OH-beta-apo-11-carotenal and the 3-OH-beta-apo-carotenone compounds derived from β-carotene degradation were detected.
•Isothermal calorimetry monitored microcapsules rich in unsaturated fatty acids.•The kinetics parameters were evaluated from the calorimetric traces.•β-carotene addition improved microcapsules oxidative stability.
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•Production of liposomes by a supercritical and green process.•The quality by design strategy to find production conditions.•Different compositions of liposomes ...produced.•Physicochemical characteristics identical to liposomes produced by conventional method.
Liposomes were produced by an innovative method using supercritical carbon dioxide as a dispersing agent. A quality by design strategy was used to find optimal production conditions with specific parameters (lipid concentration, dispersion volume, agitation rate, temperature and pressure) allowing the production of liposomes with predicted physicochemical characteristics (particles size and PdI). Two conditions were determined with specific production parameters. It was shown that these two conditions allowed the production of liposomes of different compositions and that most of the liposome formulations had size and dispersity in accordance with the prediction values. The condition involving the higher lipid concentration showed a higher variability in terms of size and dispersity. However, this variability remained acceptable. This innovative supercritical method allowed the production of liposomes with physicochemical characteristics similar to those obtained by the conventional thin film hydration method. This new supercritical carbon dioxide method easily scalable in GMP conditions is a one-step production method contrarily to conventional methods which generally need an additional step as extrusion to homogenize the size of liposomes.
•In micronization via supercritical fluid methods, particles with narrow size distribution were produced.•The supercritical fluid has been used as solvents, antisolvents and solutes.•The product ...particle size distribution could be controlled by operating variables.
The solubility and bioavailability of pharmaceutical compounds are increased via size reduction. The conventional size reduction methods have some disadvantages. The pharmaceutical micronization with supercritical fluids (SCFs) techniques has been proposed. These methods overcome the disadvantages of conventional methods. Therefore, in this work, literature data analysis on the supercritical fluid micronization has been reviewed. The SC carbon dioxide is usually proposed. Micronization with supercritical fluids is classified based on the role of supercritical fluid in a process. Application of these methods for the pharmaceutical micronization has attracted interest in recent year because the micronized particles with narrow particle size distribution and no organic solvent are produced. These methods are rapid expansion of supercritical solutions (RESS) process, gas antisolvent (GAS) process, supercritical antisolvent (SAS) process, solution enhanced dispersion by supercritical (SEDS) process, aerosol solvent extraction system (ASES), supercritical fluid extraction of emulsions (SFEE), and particle from gas saturated solution (PGSS) process.
