Electrochemical determination of hydroquinone using hydrophobic ionic liquid-type carbon paste electrodes

Three types of carbon paste electrodes (CPEs) with different liquid binders were fabricated, and their electrochemical behavior was characterized via a potassium hexacyanoferrate(II) probe. 1-Octyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL) as a hydrophobic conductive pasting binder showed better electrochemical performance compared with the commonly employed binder. The IL-contained CPEs demonstrated excellent electroactivity for oxidation of hydroquinone. A diffusion control mechanism was confirmed and the diffusion coefficient (D) of 5.05 × 10-4 cm2 s-1 was obtained. The hydrophobic IL-CPE is promising for the determination of hydroquinone in terms of high sensitivity, easy operation, and good durability

Characterisation of biphasic electrodes based on the liquid N,N-didodecyl-N ' N '-diethylphenylenediamine redox system immobilised on porous hydrophobic silicates and immersed in aqueous media

Biphasic electrodes based on the water-insoluble redox liquid N,N-didodecyl-N,N'-diethylphenylene-diamine (DDPD) neat and dissolved in di-(2-ethyl-hexyl)phosphate (HDOP) deposited onto silicate matrices were prepared and studied in aqueous electrolyte media. As electrode substrates (i) bare gold, (ii) a gold surface covered with a hydrophobic silicate film, and (iii) a hydrophobic silicate carbon composite were employed. Both hydrophobic silicate based materials act as a host for the organic redox liquid and modify the electrochemical response in characteristic manner. The electrooxidation of DDPD occurs at the organic phase\aqueous phaselelectrode triple phase boundary and is accompanied by the transfer of the anion from the water into the organic phase. In the presence of an organic acid, HDOP, the oxidation process is accompanied by the expulsion of protons instead. This electrochemically driven proton exchange process results in a shift of redox potentials, which can be described by Nernst-type dependence with a slope strongly dependent on the electrode/host material and the deposition method. The formation of an DDPD-HDOP acid-base complex within microdroplets deposited deposited on gold surfaces is confirmed by IR reflectance spectra. (C) 2005 Elsevier B.V. All rights reserved

A meta‐analysis on allergen‐specific immunotherapy using MCT ®

BACKGROUND: The World Allergy Organization and the European Academy of Allergy and Clinical Immunology recommend to perform product‐specific meta‐analyses for allergen‐specific immunotherapies because of the high degree of heterogeneity between individual products. This meta‐analysis evaluates the efficacy and safety of Glutaraldehyde‐modified and MCT(®) (MicroCrystalline Tyrosine)‐adsorbed allergoids (MATA). METHODS: The databases MEDLINE, LILACS, embase, LIVIVO, Web of Science and Google (Scholar) were searched for publications on MATA up to June 2019. Primary endpoint was the combined symptom and medication score (CSMS). Secondary endpoints were single scores, immunogenicity and improvement of allergic condition. Secondary safety endpoints were the occurrence of side effects. A random effects model was applied with (standardized) mean differences ([S]MDs) including confidence intervals (CI). Heterogeneity was analyzed using the I(2) index and publication bias using Egger's test and Funnel plots. Subgroups were analyzed regarding age and asthma status. RESULTS: Eight randomized double‐blind placebo‐controlled trials were selected for efficacy and 43 publications for safety analysis. In total, 4531 patients were included in this analysis including eight studies containing data on children and adolescents. AIT with MATA significantly reduced allergic symptoms and medication use with a SMD for CSMS of −0.8 (CI: −1.24, −0.36) in comparison to placebo. Heterogeneity was moderate between the studies. The total symptom score (−1.2 [CI: −2.11, −0.29]) and the total medication score (−2.2 [CI: −3.65, −0.74]) were also significantly reduced after MATA treatment. Patient's condition improved significantly after treatment with MATA, with an odds ratio of 3.05 (CI: 1.90, 4.90) when compared to placebo. The proportion of patients, who developed side effects was 38% (CI: 19%, 57%). No serious side effects occurred. Safety in the subgroups of asthmatic patients, children and adolescents did not differ from the overall patient population. CONCLUSIONS: This meta‐analysis reveals a large body of evidence from publications investigating MATA. MATA significantly improved allergic symptoms and reduced the use of anti‐allergic medication in comparison to placebo, with an excellent safety profile. Especially for children and asthmatic patients, the use of MATAs can be considered as safe, because the safety profiles in these groups did not differ from the total patient population

Fast low-voltage electroactive actuators using nanostructured polymer electrolytes

Electroactive actuators have received enormous interest for a variety of biomimetic technologies ranging from robotics and microsensors to artificial muscles. Major challenges towards practically viable actuators are the achievement of large electromechanical deformation, fast switching response, low operating voltage and durable operation. Here we report a new electroactive actuator composed of self-assembled sulphonated block copolymers and ionic liquids. The new actuator demonstrated improvements in actuation properties over other polymer actuators reported earlier, large generated strain (up to 4%) without any signs of back relaxation. In particular, the millimetre-scale displacements obtained for the actuators, with rapid response (<1 s) at sub-1-V conditions over 13,500 cycles in air, have not been previously reported in the literature. The key to success stems from the evolution of the unique hexagonal structure of the polymer layer with domain size gradients beneath the cathode during actuation, which promotes the bending motion of the actuators