Search results for "Pulmonary surfactant"
showing 8 items of 318 documents
Liquid Phase Micro-Extraction of Linear Alkylbenzene Sulfonate Anionic Surfactants in Aqueous Samples
2011
Hollow fiber liquid phase micro-extraction (LPME) of linear alkylbenzene sulfonates (LAS) from aqueous samples was studied. Ion pair extraction of C10, C11, C12 and C13 homologues was facilitated with trihexylamine as ion-pairing agent, using di-n-hexylether as solvent for the supported liquid membrane (SLM). Effects of extraction time, acceptor buffer concentration, stirring speed, sample volume, NaCl and humic acids were studied. At 10–50 µg L−1 linear R2-coefficients were 0.99 for C10 and C11 and 0.96 for C12. RSD was typically ~15%. Three observations were especially made. Firstly, LPME for these analytes was unusually slow with maximum enrichment observed after 15–24 h (depending on sa…
Effects of ultrasonically activated irrigants with or without surfactant on smear layer removal after post space preparation
2012
The aim of this study was to compare the effects of different NaOCl and EDTA formulations with/without ultrasonic use on smear layer removal and root canal surface characteristics after post space preparation. Study design: After post space preparations, forty-six teeth were subjected to different post space irrigation regimes; G1, 17% EDTA; G2, 17% EDTA+Ultrasonic activation; G3, EDTA-T; G4, EDTA-T+Ultrasonic activation; G5, NaOCl; G6, NaOCl+Ultrasonic activation. Specimens were examined under scanning electron microscope and scored for debris and smear layer removal and dentinal tubule opening and statistically analyzed with Kruskal Wallis and Dunn's test. Significance value was set at p<…
Supraglottic airway devices for surfactant treatment: systematic review and meta-analysis
2019
Objective: To compare surfactant administration via supraglottic airway device (SAD) vs. nasal CPAP alone or INSURE. Study design: A systematic search of PubMed, EMBASE, SCOPUS, Cochrane Central Register of Controlled Trials and Clinicaltrials.gov was performed. Articles meeting inclusion criteria (RCT, surfactant administration via SAD, laryngeal mask, I-gel) were assessed Results: Five RCTs were eligible. Surfactant administration via SAD reduced the need for intubation/mechanical ventilation (RR 0.57, 95%CI 0.38–0.85) and short-term oxygen requirements (MD −8.00, 95%CI −11.09 to −4.91) compared to nCPAP alone. Surfactant administration via SAD reduced the need for intubation/mechanical v…
Micelles in Mixtures of Sodium Dodecyl Sulfate and a Bolaform Surfactant
2006
Mixtures composed of water, sodium dodecyl sulfate (SDS), and a bolaform surfactant with two aza-crown ethers as polar headgroups (termed Bola C-16) were investigated by modulating the mole ratios between the components. The two surfactants have ionic and nonionic, but ionizable, headgroups, respectively. The ionization is due to the complexation of alkali ions by the aza-crown ether unit(s). Structural, thermodynamic, and transport properties of the above mixtures were investigated. Results from surface tension, translational self-diffusion, and small angle neutron scattering ( SANS) are reported and discussed. Interactions between the two surfactants to form mixed micelles result in a com…
Realization of polyaspartamide-based nanoparticles and in vivo lung biodistribution evaluation of a loaded gucocorticoid after aerosolization in mice
2016
Abstract In this study, novel polymeric nanoparticles (NPs) were developed and their potential as carriers for beclomethasone dipropionate (BDP) into the lung after aerosolization was demonstrated by in vivo studies in mice. In particular, these NPs were obtained starting from two polyaspartamide-based copolymers which were synthesized by chemical reaction of α,β-poly(N-2-hydroxyethyl)- dl -aspartamide (PHEA) and its pegylated derivative (PHEA-PEG2000) with poly(lactic acid) (PLA). To obtain nanosized particles, the high pressure homogenization (HPH)—solvent evaporation method was followed by using an organic phase containing both PHEA-PLA and PHEA-PEG2000-PLA (at a weight ratio equal to 1:…
Physicochemical investigation of surfactant-coated gold nanoparticles synthesized in the confined space of dry reversed micelles
2006
Abstract Gold nanoparticle/surfactant composites have been synthesized by a novel reduction reaction in the confined space of dry sodium bis(2- ethylhexyl)sulfosuccinate (AOT) or lecithin reversed micelles dispersed in n-heptane and cyclohexane, respectively. The reaction was carried out by adding an opportune amount of anhydrous hydrazine/tetrahydrofuran solution to a suspension of HAuCl4-containing dry reversed micelles dispersed in organic solvent. UV–vis investigation ascertained the formation of stable metal gold nanoparticles and the analysis of FT-IR spectra highlighted the formation of an oriented surfactant monolayer at the nanoparticle surface. Simple evaporation under vacuum of t…
A route to simple nonionic surfactants
2016
AbstractA method for the synthesis of nonionic surfactants – N-alkyl-O-(2-hydroxyethyl) carbamates is proposed by acylation of fatty amines with ethylene carbonate without any solvent or catalyst. The surface tension of the prepared surfactants was measured, toxicity and biodegradability were determined for the surfactant with n-dodecyl as a hydrophobic group and N-monosubstituted amide and hydroxyl groups for their hydrophilic part.
Clay/Non-Ionic Surfactant Hybrid Nanocomposites
2020
This chapter gives an overview of the structural and chemical physical properties of nanocomposites formed by clay minerals and surfactants, which represent a class of materials with promising features for applications in different industrial, biomedical, and environmental applications. Due to their non-toxicity and biocompatibility, a great deal of attention is nowadays devoted to the study of non-ionic surfactants. Among them, block copolymers represent a combination of the properties of common amphiphilic molecules and long polymer chains. These macromolecules can form a great variety of supra-molecular structures generated from self-organization phenomena in aqueous media. Nanostructure…