167 research outputs found
Muscarine and t-LHRH suppress M-current by activating an IAP- insensitive G-protein
No full textThe control of M-current by muscarinic ACh receptors and luteinizing hormone releasing hormone (LHRH) receptors was studied in dialyzed frog sympathetic ganglion neurons. M-current was recorded in dialyzed cells without run-down or changes in its biophysical properties and could be reversibly suppressed by muscarine and teleost LHRH (t-LHRH). However, dialysis with internal solutions lacking ATP or substituting with APP(NH)P caused the loss of M-current, suggesting that dephosphorylation suppresses the activity of M-channels. M-current over- recovers after agonist addition and removal to a size 30% larger than control, as if latent channels are activated during the recovery. Dialysis of cells with the G-protein activators GTP gamma S, fluoride, and aluminum fluoride causes loss of M-current. G-protein activation by receptors was confirmed by dialysis with low concentrations of GTP gamma S in competition with GTP. This prevents the rapid loss of M- current, but addition of muscarine or t-LHRH caused irreversible loss of M-current, suggesting that both transmitter receptors do suppress M- current by activating a G-protein. Suppression of M-current was not affected by treatment with 0.1 microgram/ml pertussis toxin (IAP) for 24–48 hr. In addition, based on the lack of IAP-specific labeling of frog sympathetic neuron membrane proteins, no IAP-sensitive G-proteins are present in these cells. These results indicate that an IAP- insensitive G-protein couples muscarinic and LHRH receptors to the suppression of M-current.</jats:p
Pfaffinger, William (Death, 1893-10-03)
No full textAddress: Powers St. & C. H. & D. R. R.Age at death: 6-10-2021/Pg.95/1893/M W S/Cinti, Ohio/Dr. C. B. Van Meter/Spaeth/St. Marys Cem.Original record filed in drawer labeled 'PETRI-PFLUNG'
Pfaffinger, William T. (Birth, 1903-06-04)
No full textAddress: 312 E. 7th2684/Pg 225/1903/M W/O/O/Dr. W. E. DeCourcyOriginal record filed in drawer labeled 'PETRI-PFLUNG'
Implementierung einer Geometrieschnittstelle zur Unterstützung von FluidStrukturKopplung mit PowerFLOW und ANSYS
No full textIm Ingenieurwesen treten haufig Problemstellungen auf, bei denen sich Strömungsvorgänge und Strukturdynamik gegenseitig beeinflussen. Um diese Phänomene mit Hilfe numerischer Simulation zu untersuchen, muss einerseits die Strömung und das Verhalten der Struktur abgebildet, andererseits deren Interaktion berücksichtigt werden. Dabei unterscheiden sich die jeweiligen Modelle typischerweise grundlegend hinsichtlich der Diskretisierung, der Lösungsdomäne (Struktur bzw. die Struktur umgebendes Fluid) sowie der Art der Ergebnisse. Diese Diplomarbeit beschäftigt sich mit der Implementierung einer benutzerfreundlichen Geometrieschnittstelle für die Kopplung des Finite-Element- Programms ANSYS und des auf der Gitter-Boltzmann-Methode basierenden CFD-Programms PowerFLOW. Die Schnittstelle soll den Austausch relevanter Daten zwischen Strömungs- und Strukturmodell unter Berücksichtigung der unterschiedlichen Netz- bzw. Gittergeometrien ermöglichen. Ergänzend wurde die Schnittstelle mit Hilfe von Vergleichsrechnungen getestet. Hieraus ergeben sich auch Richtlinien für die Netzgestaltung in ANSYS
Development and optimization of photopolymerizable slurries for the Lithography-based Ceramic Manufacturing process
No full textDie vorliegende Arbeit beschäftigt sich mit den, für den Lithography-based Ceramic Manufacturing (LCM) Prozess als Ausgangsmaterial dienenden, photopolymerisierbaren keramischen Schlickersystemen. Diese stellen kolloidale Suspensionen dar. Keramische Partikel sind mithilfe eines Dispergieradditivs in einem organischen Gemisch aus Lösungsmittel und Monomeren fein dispergiert. Ein Photoinitiator ermöglicht durch selektive Belichtung des Schlickers das schichtweise Aushärten und schlussendliche Strukturieren dreidimensionaler Formkörper. In einer abschließenden thermischen Behandlung wird die organische Matrix der Bauteile ausgebrannt und die Keramikpartikel zu einer dichten Keramik ( 99 % theor. Dichte) gesintert. Bauteile hergestellt im LCM Prozess zeichnen sich durch hohe Auflösung ( 99 % theor. density). Parts manufactured in the LCM process excel in high resolution (< 25 µm) as well as high surface quality. Slurry systems are covered for the dental ceramics zirconia, an oxide ceramic with good mechanical properties used for restorations in the posterior tooth region and lithium disilicate, a glass ceramic with tooth-like optical properties (translucency, color) used for highly aesthetic restorations in the anterior region. Furthermore, suspensions for the bioceramic tricalcium phosphate are examined. There are three main requirements to ceramic-filled slurries in the LCM process, long-time stability against sedimentation, stability against separation due to occuring shear forces, and an easy, time efficient debinding of the manufactured green bodies. For this purpose different approaches are pursued to enable a stable, flawless and reproducible production of parts out of high-performance ceramics. Through applying a thermoplastic component in existing slurry formulations instead of the diluent or by using fumed silica, an inorganic rheology additive, the ceramic slurries could be stabilized against sedimentation. However, during the layer-wise manufacturing of parts difficulties arose due to separation processes or deficient flow properties. Stereolithography as an optical forming process for the production of high quality parts requires specific optical properties of the raw material. On this account slurry systems with improved optical properties (matching of the refractive index of organic components and ceramic powder) are developed which allow the manufacturing of parts with the highest possible resolution and surface quality (minimal wall thickness of 100 µm). Due to the modified organic fraction the slurries show thixotropic flow behavior. Thereby long-time stability against sedimentation is achieved. Besides the slurry development an adaptation of the overall process chain, including additive manufacturing of parts, thermal debinding of green bodies and final sintering was necessary. Additionally, with this slurry system the author could establish a time efficient debinding process (dental crown in < 3 h)
Towards Interactive Indoor Thermal Comfort Simulation
No full textThe paper addresses the current state of the development of a computational steering environment (CSE) for interactive indoor thermal comfort simulation by utilizing high-performance supercomputing facilities. The CSE consists of a parallel CFD kernel, a fast spacetree-based 3D mesh generator and an integrated virtual reality-based visualization engine. The numerical method is based on a hybrid thermal lattice Boltzmann (LB) method with extensions for large eddy simulations of turbulent convective flows. We use a multiple-relaxation-time LB scheme for solving the mass and momentum equations numerically and a finite difference scheme for the heat equation. The CSE allows for modifying both the geometric model and the boundary conditions during runtime with immediate visualization of changes in the results. The application is demonstrated by two industrial applications with complex geometries, turbulent natural convection in the separator room of a ferry boat and turbulent convection in a trains passenger carriage. We currently enhance our model using a radiosity method with a fast spacetree-based visibility check and integrate a new local thermal comfort model developed by our partners
A new TASK for Dipeptidyl Peptidase-like Protein 6.
No full textDipeptidyl Peptidase-like Protein 6 (DPP6) is widely expressed in the brain where it co-assembles with Kv4 channels and KChIP auxiliary subunits to regulate the amplitude and functional properties of the somatodendritic A-current, ISA. Here we show that in cerebellar granule (CG) cells DPP6 also regulates resting membrane potential and input resistance by increasing the amplitude of the IK(SO) resting membrane current. Pharmacological analysis shows that DPP6 acts through the control of a channel with properties matching the K2P channel TASK-3. Heterologous expression and co-immunoprecipitation shows that DPP6 co-expression with TASK-3 results in the formation of a protein complex that enhances resting membrane potassium conductance. The co-regulation of resting and voltage-gated channels by DPP6 produces coordinate shifts in resting membrane potential and A-current gating that optimize the sensitivity of ISA inactivation gating to subthreshold fluctuations in resting membrane potential
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