927 research outputs found

    Fast Timing for High-Rate Environments with Micromegas

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    The current state of the art in fast timing resolution for existing experiments is of the order of 100 ps on the time of arrival of both charged particles and electromagnetic showers. Current R&D on charged particle timing is approaching the level of 10 ps but is not primarily directed at sustained performance at high rates and under high radiation (as would be needed for HL-LHC pileup mitigation). We demonstrate a Micromegas based solution to reach this level of performance. The Micromegas acts as a photomultiplier coupled to a Cerenkov-radiator front window, which produces sufficient UV photons to convert the ~100 ps single-photoelectron jitter into a timing response of the order of 10-20 ps per incident charged particle. A prototype has been built in order to demonstrate this performance. The first laboratory tests with a pico-second laser have shown a time resolution of the order of 27 ps for ~50 primary photoelectrons, using a bulk Micromegas readout.Comment: MPGD2015 (4th Conference on Micro-Pattern Gaseous Detectors, Trieste, Italy, 12 - 15 October, 2015). 5 pages, 8 figure

    Effects of hyperoxia exposure on metabolic markers and gene expression in 3T3- L1 adipocytes

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    Adipose tissue often becomes poorly oxygenated in obese subjects. This feature may provide cellular mechanisms involving chronic inflammation processes such as the release of proinflammatory cytokines and macrophage infiltration. In this context, the purpose of the present study was to determine whether a hyperoxia exposure on mature adipocytes may influence the expression of some adipokines and involve favorable changes in specific metabolic variables. 3T3-L1 adipocytes (14 days differentiated) were treated with 95% oxygen for 24 h. Cell viability, intra and extracellular reactive oxygen especies (ROS) content, glucose uptake and lactate and glycerol concentrations were measured in the culture media. Also, mRNA levels of HIF-1[alfa], leptin, IL-6, MCP-1, PPAR-[gamma], adiponectin, and ANGPTL-4 were analyzed. Hyperoxia treatment increased intra and extracellular ROS content, reduced glucose uptake and lactate release and increased glucose release. It also led to an upregulation of the expression of IL-6, MCP-1 and PPAR-[gamma], while ANGPTL4 was downregulated in the hyperoxia group with respect to control. The present data shows that hyperoxia treatment seems to provoke an inflammatory response due to the release of ROS and the upregulation of pro-inflammatory adipokines, such as IL-6 and MCP-1. On the other hand, hyperoxia may have an indirect effect on the improvement of insulin sensitivity, due to the upregulation of PPAR-[gamma] gene expression as well as a possible modulation of both glucose and lipid metabolic markers. To our knownledge, this is the first study analyzing the effect of hyperoxia in 3T3-L1 adipocytes

    Urinary cyclophilin A as marker of tubular cell death and kidney injury

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    Background: Despite the term acute kidney injury (AKI), clinical biomarkers for AKI re-flect function rather than injury and independent markers of injury are needed. Tubular cell death, including necroptotic cell death, is a key feature of AKI. Cyclophilin A (CypA) is an intracellular protein that has been reported to be released during necroptosis. We have now explored CypA as a potential marker for kidney injury in cultured tubular cells and in clinical settings of ischemia-reperfusion injury (IRI), characterized by limitations of current diagnostic criteria for AKI. Meth-ods: CypA was analyzed in cultured human and murine proximal tubular epithelial cells exposed to chemical hypoxia, hypoxia/reoxygenation (H/R) or other cell death (apoptosis, necroptosis, fer-roptosis) inducers. Urinary levels of CypA (uCypA) were analyzed in patients after nephron sparing surgery (NSS) in which the contralateral kidney is not disturbed and kidney grafts with initial function. Results: Intracellular CypA remained unchanged while supernatant CypA increased in parallel to cell death induction. uCypA levels were higher in NSS patients with renal artery clamping (that is, with NSS-IRI) than in no clamping (NSS-no IRI), and in kidney transplantation (KT) recipients (KT-IRI) even in the presence of preserved or improving kidney function, while this was not the case for urinary Neutrophil gelatinase-associated lipocalin (NGAL). Furthermore, higher uCypA levels in NSS patients were associated with longer surgery duration and the incidence of AKI increased from 10% when using serum creatinine (sCr) or urinary output criteria to 36% when using high uCypA levels in NNS clamping patients. Conclusions: CypA is released by kidney tubular cells during different forms of cell death, and uCypA increased during IRI-induced clinical kidney injury independently from kidney function parameters. Thus, uCypA is a potential bi-omarker of kidney injury, which is independent from decreased kidney functionResearch by the authors was funded by FIS/ FEDER funds (PI17/00257, PI18/01386, PI19/00588, PI19/00815, DTS18/00032, ERA-PerMed-JTC2018 (KIDNEY ATTACK AC18/00064 and PERSTIGAN AC18/00071, ISCIII-RETIC REDinREN RD016/0009), Sociedad Espa√Īola de Nefrolog√≠a, FRIAT, Comunidad de Madrid en Biomedicina B2017/BMD-3686 CIFRA2-CM. Salary support: ISCIII Miguel Servet to A.B.S., MICIN Ramon y Cajal to M.D.S.-N., REDinREN RD016/0009 to M.F.-B.,SENEFRO to D.M.-S. and Consejer√≠a de Educaci√≥n, Juventud y Deporte (Comunidad de Madrid/FSE) to A.M.L.-

    Signal coupling and signal integrity in multi-strip Resistive Plate Chambers used for timing applications

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    We have systematically studied the transmission of electrical signals along several 2-strip Resistive Plate Chambers (RPCs) in the frequency range f=0.1‚ąí3.5f=0.1-3.5GHz. Such a range was chosen to fully cover the bandwidth associated to the very short rise-times of signals originated in RPCs used for sub-100ps timing applications. This work conveys experimental evidence of the dominant role of modal dispersion in counters built at the 1 meter scale, a fact that results in large cross-talk levels and strong signal shaping. It is shown that modal dispersion appears in RPCs due to the intrinsic unbalance between the capacitive and the inductive coupling Cm/Co‚ȆLm/LoC_m/C_o \neq L_m/L_o. A practical way to restore this symmetry has been introduced (hereafter `electrostatic compensation'), allowing for a cross-talk suppression factor of around √ó12\times 12 and a rise-time reduction by 200ps. Under conditions of compensation the signal transmission is only limited by dielectric losses, yielding a length-dependent cutoff frequency of around 1GHz per 2 meter for typical float glass -based RPCs (tan‚Ā°őī‚ą£glass=0.025¬Ī0.005\tan \delta|_{glass} = 0.025\pm0.005). It is further shown that `electrostatic compensation' can be achieved for an arbitrary number of strips as long as the nature of the coupling is `short-range', that is an almost exact assumption for typical strip-line RPCs. Evidence for deviations from the dominant TEM propagation mode has been observed, although they seem to have negligible influence in practical signal observables. This work extends the bandwidth of previous studies by a factor of almost √ó20\times 20.Comment: submitted to NI

    Corrigendum: Suitability of potyviral recombinant virus-like particles bearing a complete food allergen for immunotherapy vaccines(Front. Immunol., (2023), 13, (986823), 10.3389/fimmu.2022.986823)

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    In the published article, there was an error in the author list, and author Marina Amores-Borge was erroneously excluded. The corrected author list appears below. ‚ÄúDiego Pazos-Castro, Cl√©mence Margain, Zulema Gonzalez-Klein, Marina Amores- Borge, Carmen Yuste-Calvo, Maria Garrido-Arandia, Lucia Zurita, Vanesa Esteban, Jaime Tome-Amat, Araceli Diaz-Perales, Fernando Ponz‚ÄĚIn the published article, there was an error. The missing author was not included in the Author Contributions section. A correction has been made to Author contributions. This sentence previously stated: ‚ÄúDP-C: Conceptualization, investigation, writing original draft. CM: Investigation. ZG-K: Conceptualization, investigation, writing review. CY-C: Investigation. MG-A: Investigation, writing review. LZ: Investigation. VE: Writing review, resources, funding acquisition. JT-A: Conceptualization, investigation, writing original draft. AD-P: Conceptualization, writing original draft, resources, funding acquisition. FP: Conceptualization, writing review,resources, funding acquisition. All authors contributed to the article and approved the submitted version.‚ÄĚ The corrected sentence appears below: ‚ÄúDP-C: Conceptualization, investigation, writing original draft. CM: Investigation. ZG-K: Conceptualization, investigation, writing review. MA-B: Investigation. CY-C: Investigation. MG-A: Investigation, writing review. LZ: Investigation. VE: Writing review, resources, funding acquisition. JT-A: Conceptualization, investigation, writing original draft. AD-P: Conceptualization, writing original draft, resources, funding acquisition. FP: Conceptualization, writing review, resources, funding acquisition. All authors contributed to the article and approved the submitted version.‚ÄĚ The authors apologize for these errors and state that they do not change the scientific conclusions of the article in any way. The original article has been updated.Peer reviewe
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