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Environmental Microbiology Jan 2024Marine snow and other particles are abundant in estuaries, where they drive biogeochemical transformations and elemental transport. Particles range in size, thereby...
Marine snow and other particles are abundant in estuaries, where they drive biogeochemical transformations and elemental transport. Particles range in size, thereby providing a corresponding gradient of habitats for marine microorganisms. We used standard normalized amplicon sequencing, verified with microscopy, to characterize taxon-specific microbial abundances, (cells per litre of water and per milligrams of particles), across six particle size classes, ranging from 0.2 to 500 μm, along the main stem of the Chesapeake Bay estuary. Microbial communities varied in salinity, oxygen concentrations, and particle size. Many taxonomic groups were most densely packed on large particles (in cells/mg particles), yet were primarily associated with the smallest particle size class, because small particles made up a substantially larger portion of total particle mass. However, organisms potentially involved in methanotrophy, nitrite oxidation, and sulphate reduction were found primarily on intermediately sized (5-180 μm) particles, where species richness was also highest. All abundant ostensibly free-living organisms, including SAR11 and Synecococcus, appeared on particles, albeit at lower abundance than in the free-living fraction, suggesting that aggregation processes may incorporate them into particles. Our approach opens the door to a more quantitative understanding of the microscale and macroscale biogeography of marine microorganisms.
Topics: Bays; Particle Size; Salinity; Oxygen; Estuaries; Microbiota
PubMed: 38173306
DOI: 10.1111/1462-2920.16557 -
Arquivos Brasileiros de Cardiologia Nov 2023While Omega-3 and omega-6 polyunsaturated fatty acids (n-3 and n-6 PUFAs) have established effects on cardiovascular disease (CVD) risk factors, little is known about...
BACKGROUND
While Omega-3 and omega-6 polyunsaturated fatty acids (n-3 and n-6 PUFAs) have established effects on cardiovascular disease (CVD) risk factors, little is known about their impacts on LDL quality markers.
OBJECTIVE
To assess the associations of n-3 and n-6 PUFA within red blood cells (RBC) with LDL particle size, small dense LDL-c (sdLDL-c), and electronegative LDL [LDL(-)] in adults with CVD risk factors.
METHODS
Cross-sectional study involving 335 men and women aged 30 to 74 with at least one cardiovascular risk factor. Analyses were conducted on biochemical parameters, such as glucose, insulin, HbA1c, C-reactive protein (CRP), lipid profile, lipoprotein subfractions, electronegative LDL particle [LDL(-)] and its autoantibody, and RBC n-3 and n-6 PUFAs. Independent t-test/Mann-Whitney test, one-way ANOVA/Kruskal-Wallis test, and multiple linear regressions were applied. All tests were two-sided, and a p-value of less than 0.05 was considered statistically significant.
RESULTS
The RBC n-6/n-3 ratio was associated with increased LDL(-) (β = 4.064; 95% CI = 1.381 - 6.748) and sdLDL-c (β = 1.905; 95% CI = 0.863 - 2.947) levels, and reduced LDL particle size (β = -1.032; 95% CI = -1.585 - -0.478). Separately, n-6 and n-3 PUFAs had opposing associations with those parameters, reinforcing the protective effects of n-3 and showing the potential negative effects of n-6 on LDL particle quality.
CONCLUSION
RBC n-6 PUFA was associated with increased cardiometabolic risk and atherogenicity of LDL particles, while n-3 PUFA was associated with better cardiometabolic parameters and LDL particle quality.
Topics: Adult; Male; Humans; Female; Particle Size; Cross-Sectional Studies; Fatty Acids, Omega-3; Erythrocytes; Cardiovascular Diseases
PubMed: 37991120
DOI: 10.36660/abc.20230078 -
International Journal of Biological... Dec 2023The solubility of cyclodextrin metal-organic frameworks (CD-MOFs) in aqueous media making it not suitable as sustained-release drug carrier. Here, curcumin-loaded...
The solubility of cyclodextrin metal-organic frameworks (CD-MOFs) in aqueous media making it not suitable as sustained-release drug carrier. Here, curcumin-loaded CD-MOFs (CD-MOFs-Cur) was embedded in chitosan-graft-poly(lactic acid) (CS-LA) via a solid-in-oil-in-oil (s/o/o) emulsifying solvent evaporation method forming the sustained-release composite microspheres. At CS-LA concentration of 20 mg/mL, the composite microspheres showed good sphericity. The average particle size of CS-LA/CD-MOFs-Cur (2:1), CS-LA/CD-MOFs-Cur (4:1) and CS-LA/CD-MOFs-Cur (6:1) composite microspheres was about 9.3, 12.3 and 13.5 μm, respectively. The above composite microspheres exhibited various degradation rates and curcumin release rates. Treating in HCl solution (pH 1.2) for 120 min, the average particle size of above microspheres reduced 28.19 %, 24.34 % and 6.19 %, and curcumin released 86.23 %, 78.37 % and 52.57 %, respectively. Treating in PBS (pH 7.4) for 12 h, the average particle size of above microspheres reduced 30.56 %, 26.56 % and 10.66 %, and curcumin released 68.54 %, 54.32 % and 31.25 %, respectively. Moreover, the composite microspheres had a favorable cytocompatibility, with cell viability of higher than 90 %. These composite microspheres open novel opportunity for sustained drug release of CD-MOFs.
Topics: Curcumin; Delayed-Action Preparations; Metal-Organic Frameworks; Chitosan; Cyclodextrins; Microspheres; Drug Carriers; Particle Size
PubMed: 37866573
DOI: 10.1016/j.ijbiomac.2023.127519 -
Environmental Science and Pollution... Oct 2023The backfilling mining method that fills gobs with coal gangue can prevent water inrush hazards, protect groundwater resources, and protect the ecological environment of...
The backfilling mining method that fills gobs with coal gangue can prevent water inrush hazards, protect groundwater resources, and protect the ecological environment of the mining area. However, initial conditions including the particle size distribution of gangue and the stress environment may affect the seepage characteristics of gangue backfill and inrush prevention ability. Taking the particle size and stress as main controlling factors, the seepage tests were designed for gangue to evaluate influences of the particle size and stress on the void ratio, permeability, and non-Darcian flow factor of gangue. In the meantime, the four stages in dynamic changes of seepage channels were studied and the impervious envelope lines of gangue backfill materials were provided. The results show that the larger the particle sizes, the stronger the crushing resistance of particles; under high stress (> 6.67 MPa), seepage channels in small gangue particles (< 5 mm) change in a more complex manner, and the non-Darcian flow phenomena become more significant. The particle size and stress exert significant influences on the seepage characteristics. Therefore, when reducing water inrush hazards by gangue backfilling in gobs, the particle size distribution should be optimized by combining the stress and water pressure conditions. Seepage channels in gangue backfill materials vary with changes in the particle size and stress. Their variation can be divided into four stages: shrinkage of seepage channels, reconstruction of seepage channels, dynamic equilibrium between slight expansion and shrinkage, and persistence of the impervious effect. After the first and second stages have been fully developed, the preliminary impervious conditions are met; after full development of the fourth stage, the gangue backfill materials reach an impervious state.
Topics: Coal Mining; Particle Size; Coal; Environment; Water
PubMed: 37700127
DOI: 10.1007/s11356-023-29775-0 -
International Journal of Pharmaceutics Jul 2023Spray drying is a well-suited technique for producing fixed-dose drug combinations. There has been a growing interest in utilizing spray drying to engineer carrier-free...
Spray drying is a well-suited technique for producing fixed-dose drug combinations. There has been a growing interest in utilizing spray drying to engineer carrier-free inhalable drug particles. The aim of this study was to understand and optimise the spray drying process of a ciprofloxacin-quercetin fixed dose combination intended for pulmonary administration. A 2 fractional factorial design and multivariate data analysis was used to identify important process parameters and investigate correlations with particle characteristics. The independent variables were solute concentration along with the processing parameters: solution flow rate, atomizing air flow rate and inlet temperature. The dependent variables included particle size distribution, yield and residual moisture content (RMC). Correlations between dependent and independent variables were further investigated via principal component analysis. Overall, solution flow rate, atomizing air flow rate and inlet temperature were found to affect the particle size D and D while the solute concentration and the atomizing air flow rate mainly affected the span. The inlet temperature was the most important parameter affecting the RMC and the yield. The formulation with optimized independent variables had a D and span values of 2.42 µm and 1.81 with excellent process yield >70% and low RMC i.e. 3.4%. The optimized formulation was further investigated for its in vitro aerosolization performance using next generation impactor (NGI); it exhibited high emitted dose (ED > 80%) and fine particle fractions (FPF > 70%) for both drugs.
Topics: Ciprofloxacin; Quercetin; Spray Drying; Administration, Inhalation; Drug Combinations; Particle Size; Powders; Aerosols; Dry Powder Inhalers
PubMed: 37364778
DOI: 10.1016/j.ijpharm.2023.123151 -
Molecular Pharmaceutics Nov 2023Various approaches have been developed to enhance the solubility or dissolution rate for the delivery of poorly water-soluble molecules. In this work, guided by an...
Various approaches have been developed to enhance the solubility or dissolution rate for the delivery of poorly water-soluble molecules. In this work, guided by an solubility sensitivity analysis for oral absorption, a comparative assessment of the biopharmaceutical performance of a jet-milled free base, a tosylate salt, and a 50:50 (w/w) amorphous solid dispersion (ASD) with hydroxypropyl methylcellulose acetate succinate (HPMCAS) of a weak base drug candidate, GDC-3280, was conducted. Successful particle size reduction without amorphization or form change was confirmed for the jet-milled free base. The potential of solubility enhancement and desupersaturation risk were identified for tosylate salt and ASD formulation by measurements of tosylate salt solubility product constant () and amorphous solubility of GDC-3280. dissolution testing demonstrated dissolution rate improvement for the jet-milled free base when compared with the unmilled free base and confirmed solubility enhancement followed by desupersaturation for GDC-3280 tosylate salt and ASD formulation. A crystallization inhibitor, hydroxypropyl methylcellulose (HPMC), was found to slow down the desupersaturation of tosylate salt solution, providing general insights for the development of pharmaceutical salts with disproportionation risks. Finally, a pharmacokinetic study in dogs showed that the exposure increased by 1.7- to 2-fold for the tosylate salt and ASD formulation compared with the jet-milled free base, consistent with the solubility sensitivity analysis for the fraction of drug absorbed. Overall, this work provides insights into the evaluation of multiple formulation approaches for enhancing the biopharmaceutical performance of poorly water-soluble drugs.
Topics: Animals; Dogs; Pharmaceutical Preparations; Particle Size; Biological Products; Chemistry, Pharmaceutical; Solubility; Water; Drug Liberation
PubMed: 37792707
DOI: 10.1021/acs.molpharmaceut.3c00727 -
Colloids and Surfaces. B, Biointerfaces Aug 2023We investigated the distribution of intravenously administered thiol-organosilica particle (thiol-OS) in the spleen to evaluate their size effect in mice. A single...
We investigated the distribution of intravenously administered thiol-organosilica particle (thiol-OS) in the spleen to evaluate their size effect in mice. A single administration of particles of thiol-OS containing rhodamine B (Rh) (90, 280, 340, 450, 630, 1110, 1670, and 3030 nm in diameter) was performed. After 24 h, we conducted a combination analysis using histological studies by fluorescent microscopy and quantitative inductively coupled plasma optical emission spectrometry (ICP-OES), which revealed no clear correlation between the particle size and spleen uptake of particle weight and number per tissue weight, and the injection dose. Moreover, Rh with 450 nm diameter (Rh450) showed the highest uptake, and Rh with 340 nm diameter (Rh340) showed the lowest uptake. Histologically, large fluorescent areas in the marginal zone (MZ) and red pulp (RP) of the spleen were observed for all particle sizes, but less in the follicle of white pulp. Using combination analysis using the particle weights of ICP-OES and the fluorescent area, we compared the distributions of each particle in each region. Rh450 had the largest accumulated weight in the MZ and RP. Particles larger than Rh450 showed negative correlations between their sizes and accumulated weight in the MZ and RP. Simultaneous dual administration of particles using Rhs and thiol-OS containing fluorescein (90 nm in diameter) showed the size-dependent difference in cellular distribution and intracellular localization. Immunohistochemical staining against macrophage markers, CD169, and F4/80 showed various colocalization patterns with macrophages that uptook particles, indicating differences in particle uptake in each macrophage may have novel significance.
Topics: Mice; Animals; Nanoparticles; Spleen; Sulfhydryl Compounds; Microscopy, Fluorescence; Fluorescent Dyes; Particle Size
PubMed: 37348267
DOI: 10.1016/j.colsurfb.2023.113397 -
International Journal of Biological... Mar 2024Sesbania gum (SG), as an environmentally friendly and resourceful natural polymer, has attracted a lot of attention due to its favorable properties. The size...
Sesbania gum (SG), as an environmentally friendly and resourceful natural polymer, has attracted a lot of attention due to its favorable properties. The size distribution of SG powders was broadened owing to the growth. Therefore, it inevitably resulted in the differences in reaction activity, structure and properties of different SG particles. The results showed that small SG particles exhibited higher reaction activity in cross-linking, carboxymethylation and oxidation than its large counterparts. Compared with those of large SG particles, the sedimentation volume of small SG particles could be reduced by 1.1 mL, while their substitution degree of carboxymethyl groups and aldehyde content could be increased by 0.0824 and 18.11 %, respectively. The swelling capacity, freeze-thaw stability, acid and alkali resistance of small SG particles were greater than those of large SG particles, but their retrogradation was weaker than that of large counterparts. The crystalline degree of small SG particles consisting of more long molecular chains could be reduced by 9.8 % compared to large SG particles. The DSC curve of small SG particles was significantly different from that of large SG particles, while the difference in TGA curves between small particles and large particles was relatively small. The enthalpy change of small SG particle was reduced by 48.4 J/g compared to large SG particles. The peak viscosity, final viscosity, breakdown and setback of tapioca starch were obviously influenced by the addition of small SG particles. And their emulsification stability was also better than large SG particles.
Topics: Particle Size; Sesbania; Oxidation-Reduction; Viscosity; Thermodynamics; Starch
PubMed: 38280698
DOI: 10.1016/j.ijbiomac.2024.129719 -
Journal of the Science of Food and... Aug 2023The attraction of cappuccino-style beverages is attributed to the foam layer, as it greatly improves the texture, appearance, and taste of these products. Typical milk...
BACKGROUND
The attraction of cappuccino-style beverages is attributed to the foam layer, as it greatly improves the texture, appearance, and taste of these products. Typical milk has a low concentration of free fatty acids (FFAs), but their concentration can increase due to lipolysis during processing and storage, which is detrimental to the foamability and foam stability of milk. There are contradictory results in reported studies concerning the effects of FFAs on the foaming properties of milk due to differences in milk sources, methods inducing lipolysis, and methods of creating foam. In this study, the foaming properties and foam structure of milk samples whose lipolysis was induced by ultra-turraxing, homogenisation, and microfluidisation (1.5-3.5 μ-equiv. mL FFAs) were investigated.
RESULTS
Compared with others, microfluidised milk samples had the smallest particle size, lowest absolute zeta potential, and highest surface tension; thus exhibited high foamability and foam stability, and very small and homogeneous air bubbles in foam structure. For all shearing methods, increasing FFA content from 1.5 to 3.5 μ-equiv. mL markedly decreased the surface tension, foamability, and foam stability of milk samples. The FFA level that led to undesirable foam structure was 1.5 μ-equiv. mL for ultra-turraxed milk samples and 2.5 μ-equiv. mL for homogenised and microfluidised ones.
CONCLUSION
Shearing-induced lipolysis greatly affected the physical properties of milk samples and subsequently their foaming properties and foam structure. At the same FFA level, lipolysis induced by microfluidisation was much less detrimental to the foaming properties of milk than lipolysis induced by ultra-turraxing and homogenisation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Topics: Animals; Milk; Lipolysis; Fatty Acids, Nonesterified; Particle Size
PubMed: 37016733
DOI: 10.1002/jsfa.12604 -
Journal of Environmental Management Oct 2023Direct revegetation is a promising strategy for phytostabilization of metal smelting slag sites. Slag comes into direct contact with root exudates when slag sites...
Effect of simulated root exudates on the distribution, bioavailability, and fractionation of potentially toxic elements (PTEs) in various particle size fractions of zinc smelting slag: Implication of direct revegetation.
Direct revegetation is a promising strategy for phytostabilization of metal smelting slag sites. Slag comes into direct contact with root exudates when slag sites undergo direct revegetation. The slag particle size fractions are considered the key factor influencing the geochemical behaviour of potentially toxic elements (PTEs). However, the effects of root exudates on the geochemical behaviours of PTEs in various slag particle size fractions remain unclear. Here, the effects of simulated root exudates of perennial ryegrass (Lolium perenne) directly revegetated at a zinc smelting slag site on the distribution, bioavailability, and fractionation of PTEs (Cu, Pb, Zn, and Cd) in various slag particle size fractions were investigated. The results showed that PTEs mainly occurred in the <1 mm slag particles; the mass loads of PTEs in the <1 mm slag particles were higher than those in the >1 mm slag particles. The bioavailability of Cu, Zn, and Cd rather than Pb in the slag increased as the particle size decreased. There was a decrease in the <0.25 and 1-2 mm slag particles and an increase in the 0.25-0.5, 0.5-1, and >2 mm slag particles in the presence of root exudates. Root exudates enhanced the transformation of acid-soluble PTEs into other more stable fractions in various slag particle size fractions. Root exudates enhanced the aggregation of slag particles associated with the migration of PTEs, causing differences in the geochemical behaviour of PTEs in various slag particle size fractions. These findings are beneficial for understanding the geochemical behaviour of PTEs in metal smelting slags undergoing direct revegetation and provide an important basis for the guidance of environmental risk management of the revegetated metal smelting slag sites.
Topics: Biological Availability; Zinc; Cadmium; Lead; Particle Size; Exudates and Transudates; Lolium
PubMed: 37480634
DOI: 10.1016/j.jenvman.2023.118642