Direct experimental evidence for the role of oxygen in the luminescent properties of GaN

1999 ◽  
Vol 59 (3) ◽  
pp. 1575-1578 ◽  
Author(s):  
M. Toth ◽  
K. Fleischer ◽  
M. R. Phillips
Keyword(s):  
Experimental Evidence ◽  
Luminescent Properties ◽  
Direct Experimental Evidence

The role of Schottky barrier in the resistive switching of SrTiO3: direct experimental evidence

2015 ◽  
Vol 17 (1) ◽  
pp. 134-137 ◽  
Author(s):  
Xue-Bing Yin ◽  
Zheng-Hua Tan ◽  
Xin Guo
Keyword(s):  
Experimental Evidence ◽  
Schottky Barrier ◽  
Resistive Switching ◽  
Metallic Electrode ◽  
Barrier Heights ◽  
Direct Experimental Evidence

Different Schottky barrier heights are responsible for the different resistance states in the metallic electrode/donor-doped SrTiO3 stack.

TESTING GOAL-DRIVEN CAPTURE BY THREAT

2019 ◽  
Author(s):  
Chris Robert Harrison Brown
Keyword(s):  
Experimental Evidence ◽  
Attentional Capture ◽  
Critical Role ◽  
Experimental Manipulation ◽  
Contingent Capture ◽  
Top Down ◽  
Affective Stimuli ◽  
Clinical Disorders ◽  
Positive Stimuli

Attention has long been characterised within prominent models as reflecting a competition between goal-driven and stimulus-driven processes. It remains unclear, however, how involuntary attentional capture by affective stimuli, such as threat-laden content, fits into such models. While such effects were traditionally held to reflect stimulus-driven processes, recent research has increasingly implicated a critical role of goal-driven processes. Here we test an alternative goal-driven account of involuntary attentional capture by threat, using an experimental manipulation of goal-driven attention. To this end we combined the classic ‘contingent capture’ and ‘emotion-induced blink’ (EIB) paradigms in an RSVP task with both positive or threatening target search goals. Across six experiments, positive and threat distractors were presented in peripheral, parafoveal, and central locations. Across all distractor locations, we found that involuntary attentional capture by irrelevant threatening distractors could be induced via the adoption of a search goal for a threatening category; adopting a goal for a positive category conversely led to capture only by positive stimuli. Our findings provide direct experimental evidence for a causal role of voluntary goals in involuntary capture by irrelevant threat stimuli, and hence demonstrate the plausibility of a top-down account of this phenomenon. We discuss the implications of these findings in relation to current cognitive models of attention and clinical disorders.

scholarly journals Experimental evidence of pathogenic role of IgG autoantibodies in IgA nephropathy

2021 ◽  
Vol 118 ◽  
pp. 102593
Author(s):  
Zina Moldoveanu ◽  
Hitoshi Suzuki ◽  
Colin Reily ◽  
Kenji Satake ◽  
Lea Novak ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Iga Nephropathy ◽  
Pathogenic Role

scholarly journals O-GlcNAcylation protein disruption by Thiamet G promotes changes on the GBM U87-MG cells secretome molecular signature

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Maria Cecilia Oliveira-Nunes ◽  
Glaucia Julião ◽  
Aline Menezes ◽  
Fernanda Mariath ◽  
John A. Hanover ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Critical Role ◽  
Molecular Signature ◽  
Label Free ◽  
Intercellular Signaling ◽  
Tumor Aggressiveness ◽  
Signaling Axis ◽  
Literature Evidence ◽  
Therapeutic Tools

AbstractGlioblastoma (GBM) is a grade IV glioma highly aggressive and refractory to the therapeutic approaches currently in use. O-GlcNAcylation plays a key role for tumor aggressiveness and progression in different types of cancer; however, experimental evidence of its involvement in GBM are still lacking. Here, we show that O-GlcNAcylation plays a critical role in maintaining the composition of the GBM secretome, whereas inhibition of OGA activity disrupts the intercellular signaling via microvesicles. Using a label-free quantitative proteomics methodology, we identified 51 proteins in the GBM secretome whose abundance was significantly altered by activity inhibition of O-GlcNAcase (iOGA). Among these proteins, we observed that proteins related to proteasome activity and to regulation of immune response in the tumor microenvironment were consistently downregulated in GBM cells upon iOGA. While the proteins IGFBP3, IL-6 and HSPA5 were downregulated in GBM iOGA cells, the protein SQSTM1/p62 was exclusively found in GBM cells under iOGA. These findings were in line with literature evidence on the role of p62/IL-6 signaling axis in suppressing tumor aggressiveness and our experimental evidence showing a decrease in radioresistance potential of these cells. Taken together, our findings provide evidence that OGA activity may regulate the p62 and IL-6 abundance in the GBM secretome. We propose that the assessment of tumor status from the main proteins present in its secretome may contribute to the advancement of diagnostic, prognostic and even therapeutic tools to approach this relevant malignancy.

Cytoplasmic streaming in characean cells: role of subcortical fibrils

1980 ◽  
Vol 58 (7) ◽  
pp. 760-765 ◽  
Author(s):  
Eiji Kamitsubo
Keyword(s):  
Electrical Stimulation ◽  
Experimental Evidence ◽  
Cytoplasmic Streaming ◽  
Motive Force ◽  
Microbeam Irradiation ◽  
Subcortical Fibrils

Three or four parallel fibrils of ca. 0.1 μm in width attached to each file of chloroplasts in intact internodal cells generate the motive force for cytoplasmic streaming. Experimental evidence for this conclusion is drawn from experiments in which fibrillar motion and streaming are interrupted by centrifugation, microbeam irradiation, and electrical stimulation. The role of Pb2+ in preventing cessation of cytoplasmic streaming after electrical stimulation is interpreted in terms of localized changes in viscosity of the cytoplasm.

Overexpression of cysteine dioxygenase reduces intracellular cysteine and glutathione pools in HepG2/C3A cells

2007 ◽  
Vol 293 (1) ◽  
pp. E62-E69 ◽  
Author(s):  
John E. Dominy ◽  
Jesse Hwang ◽  
Martha H. Stipanuk
Keyword(s):  
Steady State ◽  
Experimental Evidence ◽  
Cysteine Dioxygenase ◽  
Wild Type ◽  
Hepatic Expression ◽  
Direct Experimental Evidence ◽  
Homeostatic Response ◽  
Catabolic Enzyme ◽  
In Cells

Cysteine levels are carefully regulated in mammals to balance metabolic needs against the potential for cytotoxicity. It has been postulated that one of the major regulators of intracellular cysteine levels in mammals is cysteine dioxygenase (CDO). Hepatic expression of this catabolic enzyme increases dramatically in response to increased cysteine availability and may therefore be part of a homeostatic response to shunt excess toxic cysteine to more benign metabolites such as sulfate or taurine. Direct experimental evidence, however, is lacking to support the hypothesis that CDO is capable of altering steady-state intracellular cysteine levels. In this study, we expressed either the wild-type (WT) or a catalytically inactivated mutant (H86A) isoform of CDO in HepG2/C3A cells (which do not express endogenous CDO protein) and cultured them in different concentrations of extracellular cysteine. WT CDO, but not H86A CDO, was capable of reducing intracellular cysteine levels in cells incubated in physiologically relevant concentrations of cysteine. WT CDO also decreased the glutathione pool and potentiated the toxicity of CdCl2. These results demonstrate that CDO is capable of altering intracellular cysteine levels as well as glutathione levels.

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