Acute otitis externa: Consensus definition, diagnostic criteria and core outcome set development.

OBJECTIVE: Evidence for the management of acute otitis externa (AOE) is limited, with unclear diagnostic criteria and variably reported outcome measures that may not reflect key stakeholder priorities. We aimed to develop 1) a definition, 2) diagnostic criteria and 3) a core outcome set (COS) for AOE. STUDY DESIGN: COS development according to Core Outcome Measures in Effectiveness Trials (COMET) methodology and parallel consensus selection of diagnostic criteria/definition. SETTING: Stakeholders from the United Kingdom. SUBJECTS AND METHODS: Comprehensive literature review identified candidate items for the COS, definition and diagnostic criteria. Nine individuals with past AOE generated further patient-centred candidate items. Candidate items were rated for importance by patient and professional (ENT doctors, general practitioners, microbiologists, nurses, audiologists) stakeholders in a three-round online Delphi exercise. Consensus items were grouped to form the COS, diagnostic criteria, and definition. RESULTS: Candidate COS items from patients (n = 28) and literature (n = 25) were deduplicated and amalgamated to a final candidate list (n = 46). Patients emphasised quality-of-life and the impact on daily activities/work. Via the Delphi process, stakeholders agreed on 31 candidate items. The final COS covered six outcomes: pain; disease severity; impact on quality-of-life and daily activities; patient satisfaction; treatment-related outcome; and microbiology. 14 candidate diagnostic criteria were identified, 8 reaching inclusion consensus. The final definition for AOE was 'diffuse inflammation of the ear canal skin of less than 6 weeks duration'. CONCLUSION: The development and adoption of a consensus definition, diagnostic criteria and a COS will help to standardise future research in AOE, facilitating meta-analysis. Consulting former patients throughout development highlighted deficiencies in the outcomes adopted previously, in particular concerning the impact of AOE on daily life

Interaction of DNA bases with silver nanoparticles: Assembly quantified through SPRS and SERS

Colloidal silver nanoparticles were prepared by reducing silver nitrate with sodium borohydride. The synthesized silver particles show an intense surface plasmon band in the visible region. The work reported here describes the interaction between nanoscale silver particles and various DNA bases (adenine, guanine, cytosine, and thymine), which are used as molecular linkers because of their biological significance. In colloidal solutions, the color of silver nanoparticles may range from red to purple to orange to blue, depending on the degree of aggregation as well as the orientation of the individual particles within the aggregates. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and absorption spectroscopy were used to characterize the assemblies. DNA base-induced differential silver nanoparticle aggregation was quantified from the peak separation (relates to color) of surface plasmon resonance spectroscopy (SPRS) and the signal intensity of surface-enhanced Raman scattering (SERS), which rationalize the extent of silver–nucleobase interactions. © 2008 Published by Elsevier Inc

Exploitation of electrostatic field force for immobilization and catalytic reduction of o-nitrobenzoic acid to anthranilic acid on resin-bound silver nanocomposites

A new solid-phase catalyst has been designed and reported here for the catalytic reduction of o-nitrobenzoic acid to anthranilic acid. Electrostatic field force helps immobilization, in turn deposition of silver nanoparticles onto solid resin surfaces and reduction of o-nitrobenzoic acid through effective catalysis. While characterization of catalyst particles has been performed by different physical methods (XRD, XPS, SEM, TEM, and EDX) in a worthwhile fashion, selective reduction of o-nitrobenzoic acid has also been achieved conveniently (95%). Different thermodynamic parameters for the reduction reaction have been presented from varied experimental conditions. Novelty of this work lies with the catalytic efficiency of nanometer size silver particles immobilized solid-phase matrix for one step synthesis of anthranilic acid over bulk silver

Comparative study of heat-affected zone with weld and base material after post-weld heat treatment of HSLA steel using ball indentation technique

Ball indentation technique (BIT) is employed to study the effect of post-weld heat treatment on the mechanical properties of a high strength low alloy (HSLA) steel and subsequently on the quality of the weldment. Well-defined load-deflection curves and corresponding true stress–strain curves for different zones (base, HAZ, weld) of sectioned sample (top and middle) and their validation with mechanical properties obtained by conventional method established the effectiveness of the present ball indentation (BI) set up. Investigations on microstructure of all the zones have been carried out to find out a correlation with the obtained mechanical properties. Evaluation of the mechanical properties of materials through BIT could characterize the heat-affected zone in weld HSLA steel

Synthesis and size-selective catalysis by supported gold nanoparticles: Study on heterogeneous and homogeneous catalytic process

Core−shell nanocomposites (R−Au) bearing well-defined gold nanoparticles as surface atoms of variable sizes (8−55 nm) have been synthesized exploiting polystyrene-based commercial anion exchangers. Immobilization of gold nanoparticles, prepared by the Frens method, onto the resin beads in the chloride form is possible by the ready exchange of the citrate-capped negatively charged gold particles. The difficulty of nanoparticle loading, avoiding aggregation, has been solved by stepwise operation. Analysis of the gold particles after immobilization and successive elution confirm the unaltered particle morphology while compared to those of the citrate-capped gold particles in colloidal dispersion. It was observed that the rate of the reaction increases with the increase in catalyst loading, which suggests the catalytic behavior of the gold nanoparticles for the reduction of the aromatic nitrocompounds. The rate constant, k, was found to be proportional to the total surface area of the nanoparticles in the system. Kinetic study for the reduction of a series of aromatic nitrocompounds reveals that the aromatic nitrocompound exclusively adsorbs to atop sites of gold particles and that the rate of the reduction reaction increases as the particle size decreases. Similar reaction kinetics was observed involving gold sol of variable size (homogeneous catalysis) as catalyst. The induction time and the activation energy of the reaction decreases with decrease in particle size indicating the decrease in activation energy for the smaller particles, which also speaks for the increase of surface roughness with decrease in particle size. The observed rate dependence, in relation to particle size, is attributed to a higher reactivity of the coordinatively unsaturated surface atoms in small particles compared to low-index surface atoms prevalent in larger particles

Stereodivergent C-C bond formation on arene-chromium template: endo-selective allylation by Hosomi-Sakurai reaction

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Cysteine functionalized copper organosol: synthesis, characterization and catalytic application

We herein report a facile one-pot synthesis, stabilization, redispersion and Cu–S interaction of L-cysteine and dodecanethiol (DDT) protected copper organosol in toluene from precursor copper stearate using sodium borohydride in toluene under a nitrogen atmosphere. Surface modification of the synthesized copper organosol with an amino acid L-cysteine and an alkanethiol (dodecanethiol, DDT) is accomplished by a thiolate bond between the used ligands and nanoparticle surface. The cysteine molecule binds the copper surface via a thiolate and amine linkage but not through electrostatic interaction with the carboxylate group due to the solvent polarity and dielectric medium. Fourier transform infrared (FTIR) analysis was performed to confirm the surface functionalization of the amino acid and DDT to the copper surface. Copper organosol has been characterized by optical spectroscopy (UV/vis), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD). The as-synthesized particles are spherical in shape and exhibit a Mie scattering profile with an absorption maxima in the visible range. Copper nanoparticles capped by cysteine and/or DDT in non-aqueous media are found to represent an interesting catalytic approach for the synthesis of octylphenyl ether

Synthesis of normal and inverted gold-silver core-shell architectures in ?-cyclodextrin and their applications in SERS

Beta-cyclodextrin (β-CD) in alkaline solution has been observed to produce mono- and bimetallic nanoparticles of silver and gold and to provide in-house stability to both types of particles. Thus, the weak reducing capability of the β-CD molecule (oxidation occurs at +1.33 V vs Ag/AgCl) and its unique kinetic control over the evolution of both normal and inverted core−shell bimetallic architectures have been established. The structure and composition of the bimetallic particles were characterized by UV−visible spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, electron dispersive spectroscopy, and X-ray photoelectron spectroscopy. Bimetallic core−shell particles containing silver shells have been shown to provide an elegant SERS-active substrate compared to the corresponding monometallic nanoparticles, and therefore, they highlight the importance of electronic ligand effects on the enhancement of the Raman signals of molecular probes on nanostructured metallic surfaces

Nonaqueous route for the synthesis of copper organosol from copper stearate: An effective catalyst for the synthesis of octylphenyl ether

Good quality highly stable copper organosol has been synthesized in a nonhydrolytic approach from the single phase reduction of the precursor Cu(II) stearate by sodium borohydride in toluene under nitrogen gas atmosphere. Surface modification of the synthesized copper organosol with an amino acid, l-cysteine and an alkanethiol (1-dodecanethiol, DDT) is accomplished by the thiolate bond formation between the ligands and the nanoparticle surface. Cysteine molecule binds the copper surface via a thiolate bond and amine linkage but not by the electrostatic interaction with the carboxylate group due to solvent polarity and dielectric medium of the solvent. The synthesized copper particles have been characterized by the optical spectroscopy (UV−vis), electron microscopy (transmission electron microscopy), X-ray photoelectron spectroscopy, and X-ray diffraction. Fourier transform infrared analysis was performed to confirm the surface functionalization of the copper particles either by the amino acid, l-cysteine, or DDT. The synthesized particles are stable for a couple of months without alteration of the spectral profile. After that, the copper particles lead to aggregation via hydrogen bond formation between the amino acid molecules located on the neighboring copper particles. It was found that only DDT (without the need of any reducing agent) could reduce copper stearate to Cu(0) but the synthesized particles remain stable for a week only. It was also observed that the chain length of the alkanethiols does not affect the particle morphology remarkably but has a bearing on the stability of the evolved particles. Furthermore, the synthesized copper particles have been found to serve as an effective catalyst for the synthesis of octlyphenyl ether under nitrogen gas atmosphere