2,216 research outputs found

    Circadian rhythms in obsessive-compulsive disorder

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    The etiopathology and neurobiology of obsessive-compulsive disorder (OCD) are not fully understood. As for altered circadian rhythms associated with OCD, hormonal dysregulation and a delayed sleep phase have come into the focus of research. The novel antidepressant agomelatine is able to resynchronize circadian rhythms and the augmentative administration of this compound has been shown to be of benefit in some OCD patients who are refractory to common forms of pharmacotherapy. Adjunctive chronotherapy might also enhance the outcome in treatment-refractory OCD. The present review summarises the findings regarding circadian abnormalities in OCD

    Observation of Long-Lived Muonic Hydrogen in the 2S State

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    The kinetic energy distribution of ground state muonic hydrogen atoms mu-p(1S) is determined from time-of-flight spectra measured at 4, 16, and 64 hPa H2 room-temperature gas. A 0.9 keV-component is discovered and attributed to radiationless deexcitation of long-lived mu-p(2S) atoms in collisions with H2 molecules. The analysis reveals a relative population of about 1%, and a pressure-dependent lifetime (e.g. (30.4 +21.4 -9.7) ns at 64 hPa) of the long-lived mu-p(2S) population, equivalent to a 2S-quench rate in mu-p(2S) + H2 collisions of (4.4 +2.1 -1.8) 10^11 s^-1 at liquid hydrogen density.Comment: 4 pages, 2 figures, accepted for publication in Physical Review Letter

    Feeding-induced changes in allatostatin-A and short neuropeptide F in the antennal lobes affect odor-mediated host seeking in the yellow fever mosquito, <i>Aedes aegypti</i>

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    Aedes aegypti is a model species in which the endogenous regulation of odor-mediated host seeking behavior has received some attention. Sugar feeding and host seeking in female A. aegypti are transiently inhibited following a blood meal. This inhibition is partially mediated by short neuropeptide F (sNPF). The paired antennal lobes (ALs), as the first processing centers for olfactory information, has been shown to play a significant role in the neuropeptidergic regulation of odor-mediated behaviors in insects. The expression of sNPF, along with other peptides in the ALs of A. aegypti, indicate parallel neuromodulatory systems that may affect olfactory processing. To identify neuropeptides involved in regulating the odor-mediated host seeking behavior in A. aegypti, we use a semi-quantitative neuropeptidomic analysis of single ALs to analyze changes in the levels of five individual neuropeptides in response to different feeding regimes. Our results show that the level of sNPF-2, allatostatin-A-5 (AstA-5) and neuropeptide-like precursor-1-5 (NPLP-1-5), but not of tachykinin-related-peptides and SIFamide (SIFa), in the AL of female mosquitoes, changes 24 h and 48 h post-blood meal, and are dependent on prior access to sugar. To assess the role of these neuropeptides in modulating host seeking behavior, when systemically injected individually, sNPF-2 and AstA-5 significantly reduced host seeking behavior. However, only the injection of the binary mixture of the two neuropeptides lead to a host seeking inhibition similar to that observed in blood fed females. We conclude that modulation of the odor mediated host seeking behavior of A. aegypti is likely regulated by a dual neuropeptidergic pathway acting in concert in the ALs

    Near-optimal experimental design for model selection in systems biology

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    Motivation: Biological systems are understood through iterations of modeling and experimentation. Not all experiments, however, are equally valuable for predictive modeling. This study introduces an efficient method for experimental design aimed at selecting dynamical models from data. Motivated by biological applications, the method enables the design of crucial experiments: it determines a highly informative selection of measurement readouts and time points. Results: We demonstrate formal guarantees of design efficiency on the basis of previous results. By reducing our task to the setting of graphical models, we prove that the method finds a near-optimal design selection with a polynomial number of evaluations. Moreover, the method exhibits the best polynomial-complexity constant approximation factor, unless P = NP. We measure the performance of the method in comparison with established alternatives, such as ensemble non-centrality, on example models of different complexity. Efficient design accelerates the loop between modeling and experimentation: it enables the inference of complex mechanisms, such as those controlling central metabolic operation. Availability: Toolbox ‘NearOED' available with source code under GPL on the Machine Learning Open Source Software Web site (mloss.org). Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics onlin

    Synthesis of Thiophene‐fused Helicenes

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    The synthesis of three penta- and three hexahelicenes containing two terminal thiophene units is described. The syntheses of pentahelicenes consist of 1,4-bisalkynylation of a benzene precursor and double Suzuki coupling in 2,3-position to introduce thiophene units. The ortho,ortho’ fusion yielding the final products was achieved with Fürstner\u27s protocol using platinum(II) chloride or JohnPhos-complexed gold(I) as catalysts. A similar approach to hexahelicenes started with a naphthalene derivative, where 2,7-bisalkynylation and subsequent double Suzuki coupling with thiophene-2-boronic acid at 1,8-position furnished precursors, in which ortho,ortho’ fusion to the respective hexahelicenes was achieved with platinum(II) chloride or, favourably, with indium(III) chloride. UV/Vis spectra and cyclic voltammograms were recorded for all helicenes and HOMO/LUMO gaps were calculated with DFT methods

    Oscillating Combustion - Primary Measure to Reduce Nitrogen Oxide in a Grate Furnace - Experiments and Simulations

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    The emission from industries and the mobility sector is under strong legal regulations in many countries worldwide. In Germany, the amendment to the 17th BlmSchV (Federal pollution control ordinance), which has been in force for waste incineration plants since 2013, has given rise to a new limit for nitrogen oxides of 150 mg/m3 as the daily mean level from 2019 on. A similar focus is on biomass-fired plants. According to the MCP (medium combustion plant) guideline of the EU, as a consequence, existing plants are required to either increase their consumption of ammonia water for nitrogen oxide reduction (SNCR process) or back fit SCR catalysts as secondary measures, which is a costly procedure. This paper presents a novel two-stage process in which an oscillating supply of secondary air allows nitrogen oxides to be reduced by approx. 50% at a good burnout level, which may obviate the need for secondary measures. Besides experimental investigations in a fixed bed reactor, CFD simulations confirm a high potential for reduction of nitrogen oxides. Together with the company POLZENITH, this process is under development for scale-up in a biomass incineration plant as a next step
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