219 research outputs found
An Evaluation of Four Experimental Methods for Measuring Mean Properties of a Supersonic Turbulent Boundary Layer
Surveys were made through a turbulent boundary layer on a flat plate by means of a pitot probe, an x-ray densitometer, and hot-wire and cold-wire probes. Results from these surveys were analyzed to determine (a) the reliability of the basic data and hence the methods by which they were obtained, and (b) how well the actual distributions of properties in the boundary layer compare with those commonly assumed in semiempirical and theoretical analyses. All surveys were made at the same longitudinal station on the flat plate. The tests were conducted in a an 8- by 8-inch supersonic nozzle. The free-stream Mach number was 3.03 and the Reynolds number was approximately 210,000 based on boundary-layer thickness
Staurosporine and NEM mainly impair WNK-SPAK/OSR1 mediated phosphorylation of KCC2 and NKCC1
This is the final version. Available from the publisher via the DOI in this record.The pivotal role of KCC2 and NKCC1 in development and maintenance of fast inhibitory
neurotransmission and their implication in severe human diseases arouse interest in posttranscriptional regulatory mechanisms such as (de)phosphorylation. Staurosporine (broad
kinase inhibitor) and N-ethylmalemide (NEM) that modulate kinase and phosphatase activities enhance KCC2 and decrease NKCC1 activity. Here, we investigated the regulatory
mechanism for this reciprocal regulation by mass spectrometry and immunoblot analyses
using phospho-specific antibodies. Our analyses revealed that application of staurosporine
or NEM dephosphorylates Thr1007 of KCC2, and Thr203, Thr207 and Thr212 of NKCC1.
Dephosphorylation of Thr1007 of KCC2, and Thr207 and Thr212 of NKCC1 were previously
demonstrated to activate KCC2 and to inactivate NKCC1. In addition, application of the two
agents resulted in dephosphorylation of the T-loop and S-loop phosphorylation sites Thr233
and Ser373 of SPAK, a critical kinase in the WNK-SPAK/OSR1 signaling module mediating
phosphorylation of KCC2 and NKCC1. Taken together, these results suggest that reciprocal
regulation of KCC2 and NKCC1 via staurosporine and NEM is based on WNK-SPAK/OSR1
signaling. The key regulatory phospho-site Ser940 of KCC2 is not critically involved in the
enhanced activation of KCC2 upon staurosporine and NEM treatment, as both agents have
opposite effects on its phosphorylation status. Finally, NEM acts in a tissue-specific manner
on Ser940, as shown by comparative analysis in HEK293 cells and immature cultured hippocampal neurons. In summary, our analyses identified phospho-sites that are responsive to
staurosporine or NEM application. This provides important information towards a better
understanding of the cooperative interactions of different phospho-sitesNational Natural Science Foundation of Chin
Scanning laser optical tomography for in toto imaging of the murine cochlea
The mammalian cochlea is a complex macroscopic structure due to its helical shape and the microscopic arrangements of the individual layers of cells. To improve the outcomes of hearing restoration in deaf patients, it is important to understand the anatomic structure and composition of the cochlea ex vivo. Hitherto, only one histological technique based on confocal laser scanning microscopy and optical clearing has been developed for in toto optical imaging of the murine cochlea. However, with a growing size of the specimen, e.g., human cochlea, this technique reaches its limitations. Here, we demonstrate scanning laser optical tomography (SLOT) as a valuable imaging technique to visualize the murine cochlea in toto without any physical slicing. This technique can also be applied in larger specimens up to cm3 such as the human cochlea. Furthermore, immunolabeling allows visualization of inner hair cells (otoferlin) or spiral ganglion cells (neurofilament) within the whole cochlea. After image reconstruction, the 3D dataset was used for digital segmentation of the labeled region. As a result, quantitative analysis of position, length and curvature of the labeled region was possible. This is of high interest in order to understand the interaction of cochlear implants (CI) and cells in more detail. © 2017 Nolte et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.DFG/EXC/1077/1Ministry of Lower SaxonyVolkswagenStiftun
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