274 research outputs found

    Einfluss der Holzfeuchte und ausgewählter technologischer Parameter auf die Verklebung mit 1K-PUR Klebstoffen unter extremen klimatischen Bedingungen

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    Zusammenfassung: 1K-PUR Klebstoffe benötigen eine Mindestmenge an Wasser für das vollständige Aushärten. Insbesondere im Winter bei sehr niedrigen relativen Luftfeuchten können teilweise Probleme bei der Verklebung auftreten. Mit der vorliegenden Arbeit wurde der Einfluss der geringen Holzfeuchte bzw. Holzoberflächenfeuchte, der Luftfeuchte, der offenen Wartezeit sowie der aufgesprühten Zusatzwassermenge auf das Abbindeverhalten von 1K-PUR Klebstoffen experimentell untersucht. Dazu wurden 3 Klebstoffe mit unterschiedlicher Reaktivität der Fa. Purbond AG/Schweiz eingesetzt. Es konnten dabei deutliche Unterschiede im Verhalten der Klebstoffe nachgewiesen werden. Die Ergebnisse zeigen, dass die in den Verarbeitungsrichtlinien vorgegebenen Parameter unbedingt eingehalten werden müssen. Damit wird eine hohe Prozesssicherheit gewährleistet und ein qualitativ hochstehendes, verleimtes Bauteil ist das Ergebni

    Robustness assessment of the ‘cooperation under resource pressure’ (CURP) model: Insights on resource availability and sharing practices among hunter-gatherers

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    A well-known challenge in archaeological research is the exploration of the social mechanisms that hunter-gatherers may have implemented throughout history to deal with changes in resource availability. The agent-based model (ABM) ‘cooperation under resource pressure’ (CURP) was conceived to explore food stress episodes in societies lacking a food preservation technology. It was particularly aimed at understanding how cooperative behaviours in the form of food sharing practices emerge, increase and may become the prevailing strategy in relation to changes in resource availability and expectancy of reciprocity. CURP’s main outcome is the identification of three regimes of behaviour depending on the stress level. In this work, the model’s robustness to the original selection mechanism (random tournament) is assessed, as different dynamics can lead to different persistent regimes. For that purpose, three other selection mechanisms are implemented and evaluated, to identify the prevailing states of the system. Results show that the three regimes are robust irrespective of the analysed dynamics. We consequently examine in more detail the long-term archaeological implications that these results may have.Spanish Ministry of Economy and Competitiveness (former Ministry of Science and Innovation): SimulPast Project (CSD2010- 00034 CONSOLIDER-INGENIO 2010), HAR2009-06996 and CULM Project (HAR2016- 77672-P); from the Argentine National Scientific and Technical Research Council (CONICET): Project PIP-0706; from the Wenner-Gren Foundation for Anthropological Research: Project GR7846; from the project H2020 FET OPEN RIA IBSEN/662725 and from the European Social Fund as one of the authors is the recipient of a predoctoral grant from the Department of Education of Junta de Castilla y León (Spain)

    Serum S-100B adds incremental value for the prediction of symptomatic intracranial hemorrhage and brain edema after acute ischemic stroke

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    Background: Early identification of patients developing symptomatic intracranial hemorrhage and symptomatic brain edema after acute ischemic stroke is essential for clinical decision-making. Astroglial protein S-100B is a marker of blood-brain barrier disruption, which plays an important role in the formation of intracranial hemorrhage and brain edema. In this study, we assessed the prognostic value of serum S-100B for the development of these complications. Methods: Serum S-100B levels were measured within 24 h from symptom onset in 1749 consecutive acute ischemic stroke patients from the prospective, observational, multicenter BIOSIGNAL cohort study (mean age 72.0 years, 58.3% male). To determine symptomatic intracranial hemorrhage or symptomatic brain edema, follow-up neuroimaging was performed in all patients receiving reperfusion therapy or experiencing clinical worsening with an NIHSS increase of ⩾4. Results: Forty six patients (2.6%) developed symptomatic intracranial hemorrhage and 90 patients (5.2%) developed symptomatic brain edema. After adjustment for established risk factors, log10_{10}S-100B levels remained independently associated with both symptomatic intracranial hemorrhage (OR 3.41, 95% CI 1.7–6.9, p = 0.001) and symptomatic brain edema (OR 4.08, 95% CI 2.3–7.1, p < 0.001) in multivariable logistic regression models. Adding S-100B to the clinical prediction model increased the AUC from 0.72 to 0.75 ( p = 0.001) for symptomatic intracranial hemorrhage and from 0.78 to 0.81 ( p < 0.0001) for symptomatic brain edema. Conclusions: Serum S-100B levels measured within 24 h after symptom onset are independently associated with the development of symptomatic intracranial hemorrhage and symptomatic brain edema in acute ischemic stroke patients. Thus, S-100B may be useful for early risk-stratification regarding stroke complications

    Serum S-100B adds incremental value for the prediction of symptomatic intracranial hemorrhage and brain edema after acute ischemic stroke

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    Early identification of patients developing symptomatic intracranial hemorrhage and symptomatic brain edema after acute ischemic stroke is essential for clinical decision-making. Astroglial protein S-100B is a marker of blood-brain barrier disruption, which plays an important role in the formation of intracranial hemorrhage and brain edema. In this study, we assessed the prognostic value of serum S-100B for the development of these complications. Serum S-100B levels were measured within 24 h from symptom onset in 1749 consecutive acute ischemic stroke patients from the prospective, observational, multicenter BIOSIGNAL cohort study (mean age 72.0 years, 58.3% male). To determine symptomatic intracranial hemorrhage or symptomatic brain edema, follow-up neuroimaging was performed in all patients receiving reperfusion therapy or experiencing clinical worsening with an NIHSS increase of ⩾4. Forty six patients (2.6%) developed symptomatic intracranial hemorrhage and 90 patients (5.2%) developed symptomatic brain edema. After adjustment for established risk factors, logS-100B levels remained independently associated with both symptomatic intracranial hemorrhage (OR 3.41, 95% CI 1.7-6.9, p = 0.001) and symptomatic brain edema (OR 4.08, 95% CI 2.3-7.1, p < 0.001) in multivariable logistic regression models. Adding S-100B to the clinical prediction model increased the AUC from 0.72 to 0.75 (p = 0.001) for symptomatic intracranial hemorrhage and from 0.78 to 0.81 (p < 0.0001) for symptomatic brain edema. Serum S-100B levels measured within 24 h after symptom onset are independently associated with the development of symptomatic intracranial hemorrhage and symptomatic brain edema in acute ischemic stroke patients. Thus, S-100B may be useful for early risk-stratification regarding stroke complications

    The Native Copper- and Zinc- Binding Protein Metallothionein Blocks Copper-Mediated Aβ Aggregation and Toxicity in Rat Cortical Neurons

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    Background: A major pathological hallmark of AD is the deposition of insoluble extracellular b-amyloid (Ab) plaques. There are compelling data suggesting that Ab aggregation is catalysed by reaction with the metals zinc and copper. Methodology/Principal Findings: We now report that the major human-expressed metallothionein (MT) subtype, MT-2A, is capable of preventing the in vitro copper-mediated aggregation of Ab1–40 and Ab1–42. This action of MT-2A appears to involve a metal-swap between Zn 7MT-2A and Cu(II)-Ab, since neither Cu 10MT-2A or carboxymethylated MT-2A blocked Cu(II)-Ab aggregation. Furthermore, Zn7MT-2A blocked Cu(II)-Ab induced changes in ionic homeostasis and subsequent neurotoxicity of cultured cortical neurons. Conclusions/Significance: These results indicate that MTs of the type represented by MT-2A are capable of protecting against Ab aggregation and toxicity. Given the recent interest in metal-chelation therapies for AD that remove metal from Ab leaving a metal-free Ab that can readily bind metals again, we believe that MT-2A might represent a different therapeuti
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