Treatment of acute otitis externa with ciprofloxacin otic 0.2% antibiotic ear solution

R Mösges, M Nematian-Samani, A EichelInstitute of Medical Statistics, Informatics and Epidemiology, Faculty of Medicine, University of Cologne, GermanyBackground/objective: An inflammation of the cutis and subcutis of the external auditory canal is a primary symptom in cases of acute otitis externa. It is usually treated locally, since this type of therapy ensures a high concentration of the drug and interacts at the site of inflammation with no systemic effects. This systematic review compares the efficacy of treatment using a ciprofloxacin 0.2% solution with other therapeutic options.Methods: After compiling a catalog of search terms, medical databases were searched systematically for randomized, controlled studies. This search initially yielded a total of 38 studies which were then evaluated by three independent reviewers. The number of studies was subsequently reduced to 14: six studies using a ciprofloxacin 0.2% solution, and eight studies using both 0.2% and 0.3% solutions.Results: The studies included in the review demonstrate the statistical equivalence between the ciprofloxacin solution (0.2%) and the reference products PNH (a combination of polymyxin B, neomycin sulfate and hydrocortisone), auriculum powder, and a ciprofloxacin foam with respect to the cure rate. The research groups consistently observed high in vitro activity of ciprofloxacin against Pseudomonas aeruginosa.Conclusion: This systematic review confirms the hypothesis of ciprofloxacin's noninferiority in the treatment of otitis externa, in terms of the cure rate and microbiological eradication.Keywords: otitis externa, ciprofloxacin, antibiotic, ear solution, efficac

Experimental evidence for the relaxation coupling of all longitudinal 7Li magnetization orders in the superionic conductor Li10GeP2S12

This contribution addresses the experimental proof of the relaxation coupling of the 7Li (I = 3/2) longitudinal magnetization orders in the solid-state electrolyte Li10GeP2S12 (LGPS). This effect was theoretically described by Korb and Petit in 1988 but has not yet been shown experimentally. In a 2D-T1/spin-alignment echo (SAE) experiment, the inverse Laplace transformation of the spectral component over two time dimensions revealed the asymmetric course of the spin-lattice relaxation following from the coupling of all longitudinal orders. These observations were supported by Multi-quantum-filter experiments and by simulations of the 2D-T1/SAE experiment with a lithium spin system. Since the asymmetric relaxation effects are directly dependent on the velocities and degrees of freedom of ion motion they could be used especially in fast Li-ion conductors as a separation tool for environments with different mobility processes

The nature of iron-oxygen vacancy defect centers in PbTiO3

The iron(III) center in ferroelectric PbTiO3 together with an oxygen vacancy forms a charged defect associate, oriented along the crystallographic c-axis. Its microscopic structure has been analyzed in detail comparing results from a semi-empirical Newman superposition model analysis based on finestructure data and from calculations using density functional theory. Both methods give evidence for a substitution of Fe3+ for Ti4+ as an acceptor center. The position of the iron ion in the ferroelectric phase is found to be similar to the B-site in the paraelectric phase. Partial charge compensation is locally provided by a directly coordinated oxygen vacancy. Using high-resolution synchrotron powder diffraction, it was verified that lead titanate remains tetragonal down to 12 K, exhibiting a c/a-ratio of 1.0721.Comment: 11 pages, 5 figures, accepted in Phys. Rev.

Sr Surface Enrichment in Solid Oxide Cells – Approaching the Limits of EDX Analysis by Multivariate Statistical Analysis and Simulations

In solid oxide cells, Sr segregation has been correlated with degradation. Yet, the atomistic mechanism remains unknown. Here we begin to localize the origin of Sr surface nucleation by combining force field based simulations, energy dispersive X-ray spectroscopy (EDX), and multi-variate statistical analysis. We find increased ion mobility in the complexion between yttria-stabilized zirconia and strontium-doped lanthanum manganite. Furthermore, we developed a robust and automated routine to detect localized nucleation seeds of Sr at the complexion surface. This hints at a mechanism originating at the complexion and requires in-depth studies at the atomistic level, where the developed routine can be beneficial for analyzing large hyperspectral EDX datasets

Enhanced sulfur utilization in lithium-sulfur batteries by hybrid modified separators

The extraordinary energy density and low cost enable lithium-sulfur (Li-S) batteries to be a promising alternative to traditional energy storage systems. The principal hurdle facing Li-S batteries is the unsatisfactory utilization of sulfur cathodes. The detrimental shuttle issue of polysulfides and the sluggish charge transfer kinetics result in quick capacity degradation of Li-S batteries. An MFLC hybrid material composed of manganese-iron layered double hydroxides (Mn-Fe LDH) and carbon nanotubes (CNT) has been developed. Such heterostructure combines the advantages of effective chemical bonding of Mn-Fe LDH towards polysulfides with the high conductivity of CNT. When modified on a polypropylene (PP) separator, the hybrid material is proven to significantly inhibit the shuttle issue of polysulfides and accelerate their redox reaction kinetics. Li-S batteries with MFLC-modified separators revealed considerably improved electrochemical performance. A high initial capacity of 1138 mA h g−1 and 70 % capacity retention after 200 cycles were achieved at 0.2 C. The enhanced sulfur utilization can be directly evaluated from the discharge voltage plateaus. The results indicate a new solution for the practical application of Li-S batteries and provide a simple approach to determine the efficiency of sulfur utilization

Variations in TcdB Activity and the Hypervirulence of Emerging Strains of Clostridium difficile

Hypervirulent strains of Clostridium difficile have emerged over the past decade, increasing the morbidity and mortality of patients infected by this opportunistic pathogen. Recent work suggested the major C. difficile virulence factor, TcdB, from hypervirulent strains (TcdBHV) was more cytotoxic in vitro than TcdB from historical strains (TcdBHIST). The current study investigated the in vivo impact of altered TcdB tropism, and the underlying mechanism responsible for the differences in activity between the two forms of this toxin. A combination of protein sequence analyses, in vivo studies using a Danio rerio model system, and cell entry combined with fluorescence assays were used to define the critical differences between TcdBHV and TcdBHIST. Sequence analysis found that TcdB was the most variable protein expressed from the pathogenicity locus of C. difficile. In line with these sequence differences, the in vivo effects of TcdBHV were found to be substantially broader and more pronounced than those caused by TcdBHIST. The increased toxicity of TcdBHV was related to the toxin's ability to enter cells more rapidly and at an earlier stage in endocytosis than TcdBHIST. The underlying biochemical mechanism for more rapid cell entry was identified in experiments demonstrating that TcdBHV undergoes acid-induced conformational changes at a pH much higher than that of TcdBHIST. Such pH-related conformational changes are known to be the inciting step in membrane insertion and translocation for TcdB. These data provide insight into a critical change in TcdB activity that contributes to the emerging hypervirulence of C. difficile

Overpotential analysis of graphite-based Li-ion batteries seen from a porous electrode modeling perspective

The overpotential of Li-ion batteries is one of the most relevant characteristics influencing the power and energy densities of these battery systems. However, the intrinsic complexity and multi-influencing factors make it challenging to analyze the overpotential precisely. To decompose the total overpotential of a battery into various individual components, a pseudo-two-dimensional (P2D) model has been adopted and used for electrochemical simulations of a graphite-based porous electrode/Li battery. Analytical expressions for the total overpotential have been mathematically derived and split up into four terms, associated with the electrolyte concentration overpotential, the Li concentration overpotential in the solid, the kinetic overpotential, and the ohmic overpotential. All these four terms have been separately analyzed and are found to be strongly dependent on the physical/chemical battery parameters and the reaction-rate distribution inside the porous electrode. The reaction-rate distribution of the porous electrode is generally non-uniform and shows dynamic changes during (dis)charging, resulting in fluctuations in the four overpotential components. In addition, the disappearance of the phase-change information in the voltage curve of the graphite-based porous electrode/Li battery under moderate and high C-rates is ascribed to the Li concentration overpotential among solid particles, resulting from the non-uniform reaction-rate distribution