Search results for " GaN"
showing 10 items of 417 documents
Nerves projecting from the intrinsic cardiac ganglia of the pulmonary veins modulate sinoatrial node pacemaker function
2013
Rationale: Autonomic nerves from sinoatrial node (SAN) ganglia are known to regulate SAN function. However, it is unclear whether remote pulmonary vein ganglia (PVG) also modulate SAN pacemaker rhythm. Objective: To investigate whether in the mouse heart PVG modulate SAN function. Methods and Results: In hearts from 45 C57BL and 7 Connexin40+/GFP mice, we used tyrosine-hydroxylase (TH) and choline-acetyltransferase (ChAT) immunofluorescence labeling to characterize adrenergic and cholinergic elements, repectively, within the PVG and SAN. PVG project postganglionic nerves to the SAN. TH and ChAT stained nerves, enter the SAN as an extensive, dense mesh-like neural network. Neurons in PVG are…
Central retinal artery occlusion-A new, provisional treatment approach.
2019
The retinal ganglion cells infarcted in central retinal artery occlusion (CRAO) are the somata of the optic nerve axons, part of the central nervous system. Consequently, CRAO with inner retinal infarction is a small vessel stroke, usually with the devastating consequence of severe visual loss in the affected eye. At present, there is no generally accepted, evidence-based therapy of nonarteritic CRAO in contrast to ischemic cerebral stroke that has well-accepted treatment protocols. Widely divergent and controversial therapeutic options for CRAO reflect the desperation of treating physicians and disparate conflicting studies. We examine reasons why treatment of nonarteritic CRAO remains pro…
Modification of the sheet resistance under Ti/Al/Ni/Au Ohmic contacts on AlGaN/GaN heterostructures
2018
This paper reports on the modification of the sheet resistance under Ti/Al/Ni/Au Ohmic contacts on AlGaN/GaN heterostructures, studied by means of Transmission Line Model (TLM) structures, morphological and structural analyses, as well as computer simulations. In particular, the contacts exhibited an Ohmic behaviour after annealing at 800 degrees C, with a specific contact resistance rho(c) = (2.4 +/- 0.2) x 10(-5) Omega cm(2), which was associated to morphological and structural changes of both the metal layer and the interface. Interestingly, TLM analyses gave a value of the sheet resistance under the contact (R-SK = 26.1 +/- 5.0 Omega/rectangle) significantly lower than that measured out…
Suppression of leakage currents in GaN-based LEDs induced by reactive-ion etching damages
2008
Forward and reverse leakage currents in GaN/InGaN multi-quantum well light-emitting diodes (LEDs) are caused by reactive-ion etching (RIE) damages during device patterning. A method to recover the damaged surfaces, based on a chemical etch in KOH: ethylene-glycol is described. Leakage currents decrease of more than a factor of 10 and are completely suppressed in most of devices.
Chronoendokinologia — Quo vadis?
2002
The present review deals with important new chronobiological results especially in the field of chronoendocrinology, shedding new light on the circadian organisation of mammals including man. In vitro studies have shown that the concept of the existence of a single circadian oscillator located in the suprachiasmatic nucleus has to be extended. Circadian oscillators have also been found to exist in the retina, islets of Langerhans, liver, lung, and fibroblasts. Another major result is the detection of a new photopigment, melanopsin, present in a subpopulation of retinal ganglion cells which are lightsensitive and project to the suprachiasmatic nucleus, acting as zeitgeber for the photic entr…
La senyalització dels recursos turístics del Centre històric d'Oliva: Diversificació i complementarietat en els productes turístics
2012
Des del punt de vista del cicle de vida del producte (Butler, 1990), Oliva es troba en la fase de maduresa i des dels poders públics se'n pren consciència, per a dur a terme polítiques de rejoveniment de la destinació. Oliva és una destinació de sol i platja consolidada a la costa valenciana, però l'estratègia de complementar l'oferta amb nous productes ha dut els go· vernants, des dels anys 90, a accions de valoració del centre històric. L'objectiu del nostre paper és mostrar ferramentes als investigadors en turisme i als policy makers locals i regionals, per a dur a terme polítiques de revaloració de centres històrics des d'un prisma turístic, mostrant una meto· dologia aplicable a altres…
In Vivo Microdialysis in Parkinson’s Research
2009
Parkinson’s disease (PD) is a progressive neurodegenerative disorder that is primarily characterized by the degeneration of dopamine (DA) neurons in the nigrostriatal system, which in turn produces profound neurochemical changes within the basal ganglia, representing the neural substrate for parkinsonian motor symptoms. The pathogenesis of the disease is still not completely understood, but environmental and genetic factors are thought to play important roles. Research into the pathogenesis and the development of new therapeutic intervention strategies that will slow or stop the progression of the disease in human has rapidly advanced by the use of neurotoxins that specifically target DA ne…
Picomolar inhibition of cholera toxin by a pentavalent ganglioside GM1os-calix[5]arene
2013
Cholera toxin (CT), the causative agent of cholera, displays a pentavalent binding domain that targets the oligosaccharide of ganglioside GM1 (GM1os) on the periphery of human abdominal epithelial cells. Here, we report the first GM1os-based CT inhibitor that matches the valency of the CT binding domain (CTB). This pentavalent inhibitor contains five GM1os moieties linked to a calix[5]arene scaffold. When evaluated by an inhibition assay, it achieved a picomolar inhibition potency (IC50 = 450 pM) for CTB. This represents a significant multivalency effect, with a relative inhibitory potency of 100000 compared to a monovalent GM1os derivative, making GM1os-calix[5]arene one of the most potent…
Characterization of the land snail Ganula lanuginosa (Boissy, 1835) (Mollusca: Hygromiidae): new invader of the Iberian Peninsula.
2021
Recently, a well-established population of the hygromiid Ganula lanuginosa has been discovered in the Iberian Peninsula, specifically in Xàtiva (Province of Valencia, Spain), corresponding to the first record for the Iberian Peninsula and the Continental Europe. It is a land snail native to North Africa and also known from the European Mediterranean islands, namely the Balearic Islands (Spain), Sardinia (Italy) and Corsica (France). Morpho-anatomical studies of the shell and the reproductive system have been carried out, and these features have been compared with those of the most similar hygromiids, which has allowed us to correctly identify them. In addition, parasitological and ec…