49,795 research outputs found
Human fibroblasts in culture metabolize differently exogenous G(M3) ganglioside species containing C18 and C20 sphingosine
No full textPreparation of radioactive G(M3) Species containing isotopically labeled C18 sphingosine or C20 sphingosine is reported and their use for studying some aspects of the sphingolipid biosynthesis in cells is discussed. Human fibroblasts in culture that have only C18 sphingolipids and G(M3) as the major gangliosides, were fed with the two radioactive G(M3) Species. The radioactive gangliosides were taken up by the cells and metabolized. The analyses of the radioactivity metabolic fate, in this model provides the following information. i - About 70-80% of the total catabolic sphingosine is re-cycled for biosynthesis of complex sphingolipids. ii - A small amount of the catabolic C20 sphingosine was re-cycled for biosynthesis of C20 sphingolipids, thus yielding complex lipids that are not naturally present in fibroblast cells. iii - A regulatory step in the biosynthesis of sphingolipid species differring long chain base content, C18 or C20 sphingosine, is in some way involved in the first steps of sphingolipid biosynthesis, and thus plays a decisive role in the availability of the long chain bases
Powder bed irregularity and hot-spot detection in electron beam melting by means of in-situ video imaging
No full textThe electron beam melting process has been successfully applied in various sectors to produce high-value-added products. Being a hot process operating in vacuum environment with x-rays and material vaporization among by-products, in-situ sensing and monitoring presents more challenges than in laser powder bed fusion. However, an automated and robust detection of unstable process conditions represents a key capability to meet challenging qualification requirements imposed by industry. This study presents novel in-situ monitoring methods based on high spatial resolution imaging for powder bed homogeneity monitoring and high temporal resolution video-imaging for hot-spot detection, i.e., the detection of anomalous local heat accumulations
Sialidase in Cerebellar Granule Cells Differentiating in Culture
No full textAbstract: The optimal conditions for the assay of sialidase in cerebellar granule cells cultivated in vitro, established using f3H]GDla and 2′‐(4‐methylumbelliferyl)‐α‐D‐N‐acetyl‐neuraminic acid (MUB‐NeuNAc) as substrates, were the following: pH optimum for both substrates, 3.9; optimal molarity of sodium acetate/acetic acid buffer, 0.05 M with [3HJGDla and 0.1 M for MUB‐NeuNAc; substrate concentration for apparent maximal activity, 0.5 mM for MUB‐NeuNAc and 0.1 mM for [3H]GDla; enzyme activity linear with time up to 30 min with MUB‐NeuNAc and up to 90 min with f3HJGDla; and enzyme activity linear with enzyme protein content up to 80 μg with MUB‐NeuNAc and up to 20 μg with f3H]GDla. The assay with [3H]GDla required the presence of Triton X‐100 in a molar ratio to GDla of 15:1. Poly‐L‐lysine, which was used for plating the cells, was capable of decreasing sialidase activity against [3H]GDla/ Triton X‐100 when added to the incubation mixture. However, it had no effect on the enzyme working on MUB‐NeuNAc. Using no more than 20 μg of cellular protein, the contamination, if any, by poly‐L‐lysine released from the dish was below the concentration limit exhibiting inhibition. Using the above optimal conditions, sialidase activity was measured during cerebellar granule cell differentiation in culture. From day 0 to day 7–8 in culture, the enzyme activity rose from 20 to 130 nmol of product released/h/mg of protein with MUB‐NeuNAc and from 1 to 100 nmol of product released/ h/mg of protein with [3H]GDla. The values of enzyme activity in differentiated granule cells are the highest ever reported for mammalian sialidases in isolated cells or tissue homogenates. In fully differentiated cells, the sialidase activity against endogenous substrates was 4.2 nmol of liberated N‐acetylneuraminic acid/h/mg of protein. The marked increase of sialidase activity in cerebellar granule cells during the process of differentiation with formation of functional synapses suggests that sialidase enrichment is a marker for the same process
Correction to: Outcomes on safety and efficacy of left atrial appendage occlusion in end stage renal disease patients undergoing dialysis (Journal of Nephrology, (2021), 34, 1, (63-73), 10.1007/s40620-020-00774-5)
No full textThe article Outcomes on safety and efficacy of left atrial appendage occlusion in end stage renal disease patients undergoing dialysis, written by Simonetta Genovesi, Luca Porcu, Giorgio Slaviero, Gavino Casu, Silvio Bertoli, Antonio Sagone, Monique Buskermolen, Federico Pieruzzi, Giovanni Rovaris, Alberto Montoli, Jacopo Oreglia, Emanuela Piccaluga, Giulio Molon, Mario Gaggiotti, Federica Ettori, Achille Gaspardone, Roberto Palumbo, Francesca Viazzi, Marco Breschi, Maurizio Gallieni, Gina Contaldo, Giuseppe D’Angelo, Pierluigi Merella, Fabio Galli, Paola Rebora, Mariagrazia Valsecchi, and Patrizio Mazzone, was originally published electronically on the publisher’s internet portal on 6 June 2020 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 10 July 2020 to © The Author(s) 2020 and this article is licensed under a Creative Commons Attribution 4.0 International License (http://creat iveco mmons .org/licen ses/ by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The original article has been updated
On nilpotent Moufang loops with central associators
No full textn this paper, we investigate Moufang p-loops of nilpotency class at least three for p>3. The smallest examples have order p5 and satisfy the following properties: (1) They are of maximal nilpotency class, (2) their associators lie in the center, and (3) they can be constructed using a general form of the semidirect product of a cyclic group and a group of maximal class. We present some results concerning loops with these properties. As an application, we classify proper Moufang loops of order p^5, p>3, and collect information on their multiplication groups
Su un caso di morte naturale da leucemia acuta in sospetto di omicidio preterintenzionale
No full textDiscrimination of Autism/PDDNOS versus Other Developmental Disorders in Preschool Children
No full textIs mind wandering reflected in microsaccade dynamics?
No full textMind wandering is a state in which our mental processes are directed towards task-unrelated thoughts. This phenomenon has been shown to underlie attentional lapses and represents a common experience in everyday life. Previous studies have found an association between mind wandering and eye-related indices. In the present study, we addressed for the first time whether the rate of microsaccades-miniaturised saccades that we spontaneously produce during prolonged fixation-is sensitive to the occurrence of mind wandering. Participants performed the Sustained Attention to Response Task, a go/no-go task highly vulnerable to mind wandering. The analyses focused on possible differences in microsaccade rate emerging from the comparison of time intervals preceding commission errors and time intervals preceding correct target withholds, under the assumption that a commission error would reflect a mind wandering episode. The results showed that microsaccadic rate was consistently reduced in time windows preceding a target trial in which participants produced a commission error as compared to when they correctly inhibited the tendency to manually respond. Cluster-based analyses established that this pattern was robust. Because microsaccades are known to occur involuntarily and a reduction in their frequency has been associated with higher mental effort, the present findings provide new insights as regards the relevance of mind wandering and lend support to the idea that during mind wandering our mind is far from being idle and is absorbed and committed to effortful activities instead
SPECIFIC GANGLIOSIDE CELL PROTEIN INTERACTIONS - A STUDY PERFORMED WITH GM1 GANGLIOSIDE DERIVATIVE CONTAINING PHOTOACTIVABLE AZIDE AND RAT CEREBELLAR GRANULE CELLS IN CULTURE
No full textThe incubation of cultured rat cerebellar granule cells with a photoreactive derivative of radiolabeled GM1 ganglioside, [H-3]GM1(N3), followed by illumination, led to the specific association of ganglioside to cell proteins. After 30 min of incubation only a few out of the cell proteins became radiolabeled. Two of these, at apparent molecular weights of 95 and 112 kDa, are interacting with the portion of associated ganglioside that is released by trypsin treatment; others, in the region between 31 and 44 kDa, are probably bound to molecules of ganglioside inserted into the outer membrane layer, thus showing that the ganglioside association to the cell surface is a selective phenomenon, involving specific proteins. Increasing the incubation time up to 24 h resulted in a larger number of radiolabeled proteins, probably as a consequence of the internalization and metabolic processing of administered [H-3]GM1(N3). In fact, photoreactive and radioactive metabolic derivatives of [H-3]GM1(N3) can also interact with a number of proteins. After 24 h incubation, some radioactivity was also associated to cytosolic proteins. Again in this case the interaction with proteins seems to be a specific process involving only a few out of the total cytosolic proteins
Head movements modulate visual responsiveness in the absence of gaze shifts
No full textVisuospatial attention is strongly associated with saccades. Given that gaze shifts are often accomplished by combined eye-head movements, attention may also be coupled to head movements. We showed that simply turning the head without shifting the gaze is sufficient to cause a transient unbalance in responding to a visual stimulus. Manual responses to a stimulus flashed shortly before the onset of a horizontal head movement were faster in congruent trials, when the head moved towards the stimulus, than in incongruent trials, when the head moved away from the stimulus. These effects are similar to those observed for saccades. We take this as evidence for a tight link between visuospatial attention and head movements, even when the gaze does not shift. © 2008 Lippincott Williams & Wilkins, Inc
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