47 research outputs found

    Fatty acid synthesis in the developing brain.

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    The study of biochemical aspects of brain metabolism is very complex because brain tissue is composed of different cell types. The two major cell types are neurones and oligodendroglia. These two cell types have differing roles but are very closely associated with normal brain development and function. Oligodendroglia are responsible for the synthesis and maintenance of the myelin membrane. In the developing brain, the myelin membrane is formed during a very short period of time. The aims of this study are (i) to investigate age-dependent changes in the activity of the lipogenic enzymes, fatty acid synthetase and palmitoyl-CoA synthetase which are intimately involved in the synthesis and activation of fatty acids for the formation of phospholipids for incorporation into the myelin membrane;(ii) to determine the sub-cellular location of these enzymes;(iii) to investigate the effect of thyroid hormone on the activity of these enzymes and (iv) to determine the route of fatty acid incorporation into myelin lipids. The results presented indicate (i) that the activities of fatty acid synthetase and palmitoyl-CoA synthetase increase during the period of myelination; (ii) fatty acid synthetase is found predoninantly in the cytoplasmic fraction from brain homogenates, whereas palmitoyi-CoA synthetase activity is present in all menribrane fractions, although activity measured in myelin may be due to contamination; (iii) the administration of thyroid hormone has no effect on palmitoyl-CoA, synthetase, whereas its specific antagonist, propylthiouracil, causes a decrease in enzyme activity in the mitochondria enriched fraction; (iv) the accumulation of radioactivity in the myelin fraction from labelled fatty.: acid involves all subcellular organelles including the cytoplasm and no precursor-product relationship is apparent. The results will be considered in the light of data available for lipo- genic and other enzymes involved in lipid synthesis

    Reconstructing time of flight detector values of angular streaking using machine learning

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    Angular streaking experiments enable for experimentation in the attosecond regions. However, the deployed time of flight TOF detectors are susceptible to noise and failure. These shortcomings make the outputs of the TOF detectors hard to understand for humans and further processing, such as, for example, the extraction of beam properties. In this article, we present an approach to remove high noise levels and reconstruct up to three failed TOF detectors from an arrangement of 16 TOF detectors. Due to its fast evaluation time, the presented method is applicable online during a running experiment. It is trained with simulation data, and we show the results of denoising and reconstruction of our method on real world experiment dat

    Site-specific interrogation of an ionic chiral fragment during photolysis using an X-ray free-electron laser

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    Ultrashort circularly polarised light pulses from free-electron lasers offer a route for exploring chiral molecules and their dynamics, but remain challenging to harness. Here, X-ray pump-probe experiments enable a site-specific photoelectron circular dichroism measurement on a dissociating chiral molecule
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