Self organization in oleic acid-coated CoFe2O4 colloids: a SAXS study

We report a structural study of magnetic colloids composed of CoFe₂O₄ nanoparticles (mean radii in the range 2–7 nm) synthesized by thermal decomposition of different high boiling temperature organic solvents in the presence of oleic acid and oleylamine, and subsequently re-suspended in hexane. Although the surfactant layer prevents permanent aggregation and precipitation of the disperse phase, competition between attractive interactions (i.e., dipolar and van der Waals) and repulsive steric interaction leads to self organization of the magnetic nanoparticles. Our small angle X-ray scattering results evidence the presence of distinctive self organized structures in the liquid colloid depending on the type of solvent used in the synthesis. A completely homogeneous dispersion is obtained for those colloids synthesized with benzyl-ether and octadecene. Bi-disperse systems, in which nanoclusters coexist with free nanoparticles, appear when phenyl-ether and trioctylamine are used. Chain-like structures are observed in a colloid containing the particles synthesized using phenyl-ether, while more compact 3D structures form in colloids prepared with particles synthesized with trioctylamine. The presented results have important implications in the design and selection of magnetic nanoparticles for those applications where the size dispersion determines the final efficiency of the material, such as magnetic fluid hyperthermia clinical therapy.Facultad de Ciencias ExactasInstituto de Física La Plat

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Reduced Cone Density Is Associated with Multiple Sclerosis

Purpose: Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system. Recent evidence suggests that degeneration of the inner layers of the retina occurs in MS. This study aimed to examine whether there are outer retinal changes in patients living with MS. Design: This was a single center, cross-sectional study. Participants: Sixteen patients with MS and 25 controls (volunteers without diagnosed MS) were recruited for the study. Methods: We acquired volumetric spectral domain-OCT scans of the macula and a circular scan around the optic nerve head (ONH). We also captured adaptive optics (AO) images at 0° (centered on the foveola), 2°, 4°, and 6° temporal to the fovea. Main Outcome Measures: We calculated the thickness of the different retinal layers in the macula and around the ONH using the inbuilt software of the OCT. We evaluated changes in cone photoreceptors by calculating cone density and spacing by the inbuilt AO automatic segmentation algorithm with manual correction. We compared patients with and without optic neuritis and controls. Results: We found significant thinning of the inner retina and a thickening of the outer retina in the eye with a history of optic neuritis (eyes of patients with MS with a history of optic neuritis; mean difference [MD]: −11.13 ± 3.61 μm, P = 0.002 and MD: 2.86 ± 0.89 μm, P = 0.001; respectively). We did not observe changes in retinal layers without optic neuritis in eyes of patients with MS without a history of optic neuritis. However, regional differences were detected in the peripapillary retinal nerve fiber layer. Analyzing AO images revealed a significantly lower cone outer-segment density at all eccentricities in all patients compared with control eyes (P < 0.05), independent of optic neuritis history. Conclusions: Our results showed that all MS cases were associated with decreased cone densities. Future longitudinal studies will help to elucidate whether this is a specific and sensitive method to detect and monitor the development and progression of MS. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references