263 research outputs found

    Strukturelle Charakterisierung eines unbekannten Metaboliten von Ciprofloxacin [Structural characterization of an unknown metabolite of ciprofloxacin]

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    The chemical structure of an unknown metabolite of ciprofloxacin (CAS 85721-33-1) is characterized by means of reversed phase ion pair liquid chromatography, absorption and fluorescence spectroscopy, partition coefficients as well as chemical and enzymatic hydrolytic degradation. A chemical structure of the unknown metabolite is proposed: N-formyl-desethylen-ciprofloxacin. It can be formed as an intermediate in the oxidative degradation of ciprofloxacin via oxociprofloxacin to desethylen-ciprofloxacin, or it may be formed by conjugation of desethylen-ciprofloxacin with formic acid. The amounts found in plasma and urine of patients were in the range of desethylen-ciprofloxacin, i.e. about 1% of the parent compound

    Beyond convergence rates: Exact recovery with Tikhonov regularization with sparsity constraints

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    The Tikhonov regularization of linear ill-posed problems with an â„“1\ell^1 penalty is considered. We recall results for linear convergence rates and results on exact recovery of the support. Moreover, we derive conditions for exact support recovery which are especially applicable in the case of ill-posed problems, where other conditions, e.g. based on the so-called coherence or the restricted isometry property are usually not applicable. The obtained results also show that the regularized solutions do not only converge in the â„“1\ell^1-norm but also in the vector space â„“0\ell^0 (when considered as the strict inductive limit of the spaces Rn\R^n as nn tends to infinity). Additionally, the relations between different conditions for exact support recovery and linear convergence rates are investigated. With an imaging example from digital holography the applicability of the obtained results is illustrated, i.e. that one may check a priori if the experimental setup guarantees exact recovery with Tikhonov regularization with sparsity constraints

    Open Design: Contributions, Solutions, Processes and Projects

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    Open design is a catchall term for various on- and offline design and making activities. It can be used to describe a type of design process that allows for (is open to) the participation of anybody (novice or professional) in the collaborative development of something. As well as this, it can mean the distribution and unrestricted use of design blueprints and documentation for the use by others. In this paper, the authors highlight various aspects of open and collaborative design and argue for the use of new terms that address what is open and when. A range of design projects and online platforms that have open attributes are then explored, whereby these terms are applied. In terms of design, the focus is specifically on the design of physical things rather than graphical, software or system design

    Interferon-Îł Activates Nuclear Factor-Îş B in Oligodendrocytes through a Process Mediated by the Unfolded Protein Response

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    Our previous studies have demonstrated that the effects of the immune cytokine interferon-Îł (IFN-Îł) in immune-mediated demyelinating diseases are mediated, at least in part, by the unfolded protein response (UPR) in oligodendrocytes. Data indicate that some biological effects of IFN-Îł are elicited through activation of the transcription factor nuclear factor-ÎşB (NF-ÎşB). Interestingly, it has been shown that activation of the pancreatic endoplasmic reticulum kinase (PERK) branch of the UPR triggers NF-ÎşB activation. In this study, we showed that IFN-Îł-induced NF-ÎşB activation was associated with activation of PERK signaling in the oligodendroglial cell line Oli-neu. We further demonstrated that blockage of PERK signaling diminished IFN-Îł-induced NF-ÎşB activation in Oli-neu cells. Importantly, we showed that NF-ÎşB activation in oligodendrocytes correlated with activation of PERK signaling in transgenic mice that ectopically express IFN-Îł in the central nervous system (CNS), and that enhancing IFN-Îł-induced activation of PERK signaling further increased NF-ÎşB activation in oligodendrocytes. Additionally, we showed that suppression of the NF-ÎşB pathway rendered Oli-neu cells susceptible to the cytotoxicity of IFN-Îł, reactive oxygen species, and reactive nitrogen species. Our results indicate that the UPR is involved in IFN-Îł-induced NF-ÎşB activation in oligodendrocytes and suggest that NF-ÎşB activation by IFN-Îł represents one mechanism by which IFN-Îł exerts its effects on oligodendrocytes in immune-mediated demyelinating diseases

    Overview of the PALM model system 6.0

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    In this paper, we describe the PALM model system 6.0. PALM (formerly an abbreviation for Parallelized Largeeddy Simulation Model and now an independent name) is a Fortran-based code and has been applied for studying a variety of atmospheric and oceanic boundary layers for about 20 years. The model is optimized for use on massively parallel computer architectures. This is a follow-up paper to the PALM 4.0 model description in Maronga et al. (2015). During the last years, PALM has been significantly improved and now offers a variety of new components. In particular, much effort was made to enhance the model with components needed for applications in urban environments, like fully interactive land surface and radiation schemes, chemistry, and an indoor model. This paper serves as an overview paper of the PALM 6.0 model system and we describe its current model core. The individual components for urban applications, case studies, validation runs, and issues with suitable input data are presented and discussed in a series of companion papers in this special issue
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