1,631 research outputs found
Rate effect in inclined fibre pull-out for smooth and hooked-end fibres: a numerical study
Based on a numerical model to simulate the static behaviour of a smooth fibre extracted from a cementitious matrix, a rate dependent friction law, widely used in earthquake engineering for steady-state slip phenomena, is proposed to capture the rate effect observed in dynamic pull-out tests for both smooth and hooked-end fibres. After calibrating the friction coefficients with the experimental results of smooth fibres, the model is subsequently applied to predict the pullout behaviour of both smooth and hooked-end fibres at different inclination angles (0â, 30â and 60â) loaded at three different velocities (0.01, 0.1 and 1 mm/s). The global tendency of all the pull-out curves was captured, fibreâs cross sectional deformations were also reproduced remarkably well. Moreover, the developed model helps to cast light on the different mechanisms related to the pull-out process.Ministerio de Ciencia, InnovaciĂłn y Universidades, Spain, through the projects BIA2015-68678-C2-1-R and RTC-2017-6736-3, is acknowledged. Elisa Poveda appreciates the funding from the International Campus of Excellence CYTEMA, as well as, the University of Castilla-La Mancha, throughout Ayudas para estancias en universidades en el extranjero en 2019 en el ĂĄmbito del plan propio de investigaciĂłn susceptibles de co-financiaciĂłn por el Fondo FEDER, Programa 010100021 to fund her stay in the University of Minho during 2018 and 2019, respectively. Manuel Tarifa acknowledges the financial support from the Department of Applied Mechanics and Project Engineering, UCLM (2018), and from the Programa propio de I+D+i de la Universidad PolitĂ©cnica de Madrid para realizar estancias de investigaciĂłn internacional igual o superior a un mes (2019), with the same purpose. The last two authors acknowledge the support provided by the project ICoSyTec (POCI-01-0145-FEDER-027990) financed by FCT and co-funded by FEDER through the Operational Competitiveness and Internationalization Programme (POCI). The authors thank BEKAERT for the supply of fibre
Potentiation of amyloid beta phagocytosis and amelioration of synaptic dysfunction upon FAAH deletion in a mouse model of Alzheimerâs disease.
Background: The complex pathophysiology of Alzheimerâs disease (AD) hampers the development of effective treatments.
Attempts to prevent neurodegeneration in AD have failed so far, highlighting the need for further clarification
of the underlying cellular and molecular mechanisms. Neuroinflammation seems to play a crucial role in disease
progression, although its specific contribution to AD pathogenesis remains elusive. We have previously shown that
the modulation of the endocannabinoid system (ECS) renders beneficial effects in a context of amyloidosis, which
triggers neuroinflammation. In the 5xFAD model, the genetic inactivation of the enzyme that degrades anandamide
(AEA), the fatty acid amide hydrolase (FAAH), was associated with a significant amelioration of the memory deficit.
Methods: In this work, we use electrophysiology, flow cytometry and molecular analysis to evaluate the cellular and
molecular mechanisms underlying the improvement associated to the increased endocannabinoid tone in the 5xFAD
mouseâ
model.
Results: We demonstrate that the chronic enhancement of the endocannabinoid tone rescues hippocampal
synaptic plasticity in the 5xFAD mouse model. At the CA3âCA1 synapse, both basal synaptic transmission and longterm
potentiation (LTP) of synaptic transmission are normalized upon FAAH genetic inactivation, in a CB1 receptor
(CB1R)- and TRPV1 receptor-independent manner. Dendritic spine density in CA1 pyramidal neurons, which is notably
decreased in 6-month-old 5xFAD animals, is also restored. Importantly, we reveal that the expression of microglial
factors linked to phagocytic activity, such as TREM2 and CTSD, and other factors related to amyloid beta clearance and
involved in neuronâglia crosstalk, such as complement component C3 and complement receptor C3AR, are specifically
upregulated in 5xFAD/FAAHâ/â animals.
Conclusion: In summary, our findings support the therapeutic potential of modulating, rather than suppressing,
neuroinflammation in Alzheimerâs disease. In our model, the long-term enhancement of the endocannabinoid tone
triggered augmented microglial activation and amyloid beta phagocytosis, and a consequent reversal in the neuronal
phenotype associated to the diseasepost-print4206 K
Mortality and Advanced Support Requirement for Patients With Cancer With COVID-19 : A Mathematical Dynamic Model for Latin America
PURPOSE: In the midst of a global pandemic, evidence suggests that similar to other severe respiratory viral infections, patients with cancer are at higher risk of becoming infected by COVID-19 and have a poorer prognosis. METHODS: We have modeled the mortality and the intensive care unit (ICU) requirement for the care of patients with cancer infected with COVID-19 in Latin America. A dynamic multistate Markov model was constructed. Transition probabilities were estimated on the basis of published reports for cumulative probability of complications. Basic reproductive number (R0) values were modeled with R using the EpiEstim package. Estimations of days of ICU requirement and absolute mortality were calculated by imputing number of cumulative cases in the Markov model. RESULTS: Estimated median time of ICU requirement was 12.7 days, median time to mortality was 16.3 days after infection, and median time to severe event was 8.1 days. Peak ICU occupancy for patients with cancer was calculated at 16 days after infection. Deterministic sensitivity analysis revealed an interval for mortality between 18.5% and 30.4%. With the actual incidence tendency, Latin America would be expected to lose approximately 111,725 patients with cancer to SARS-CoV-2 (range, 87,116-143,154 patients) by the 60th day since the start of the outbreak. Losses calculated vary between < 1% to 17.6% of all patients with cancer in the region. CONCLUSION: Cancer-related cases and deaths attributable to SARS-CoV-2 will put a great strain on health care systems in Latin America. Early implementation of interventions on the basis of data given by disease modeling could mitigate both infections and deaths among patients with cancer
Hexagonal Hybrid Bismuthene by Molecular Interface Engineering
High-quality devices based on layered heterostructures are typically built from materials obtained by complex solid-state physical approaches or laborious mechanical exfoliation and transfer. Meanwhile, wet-chemically synthesized materials commonly suffer from surface residuals and intrinsic defects. Here, we synthesize using an unprecedented colloidal photocatalyzed, one-pot redox reaction a few-layers bismuth hybrid of âelectronic gradeâ structural quality. Intriguingly, the material presents a sulfur-alkyl-functionalized reconstructed surface that prevents it from oxidation and leads to a tuned electronic structure that results from the altered arrangement of the surface. The metallic behavior of the hybrid is supported by ab initio predictions and room temperature transport measurements of individual nanoflakes. Our findings indicate how surface reconstructions in two-dimensional (2D) systems can promote unexpected properties that can pave the way to new functionalities and devices. Moreover, this scalable synthetic process opens new avenues for applications in plasmonics or electronic (and spintronic) device fabrication. Beyond electronics, this 2D hybrid material may be of interest in organic catalysis, biomedicine, or energy storage and conversion.This work has been supported by the European Union (ERC-2018-StG 804110-2D-PnictoChem & and ERC Proof of Concept Grant 101101079-2D4H2 to G.A.; ERC-2021-StG 101042680 2D-SMARTiES awarded to J.J.B.), the Spanish MICINN (PID2019-111742GA-I00, PID2020â115100GBâI00, MRR/PDC2022-133997-I00, TED2021-131347B-I00, and Excellence Unit MarĂa de Maeztu CEX2019-000919-M), and the Generalitat Valenciana (CIDEGENT/2018/001, CIDEGENT/2018/005, and CDEIGENT/2019/022). Financial support by Severo Ochoa centre of excellence program (CEX2021â001230âS) is gratefully acknowledged. M.K. and H.B.W. acknowledge support by the Deutsche Forschungsgemeinschaft (DFG), under Projektnummer 182849149 (SFB 953, projects B08 and B13). Electron microscopy work carried out at UCM (M.V., G.S.S.) sponsored by MICINN PID2021-122980OB-C51 and Comunidad de Madrid MAD2D-CM-UCM3. G.S.S. acknowledges financial support from Spanish MCI Grant Nos. RTI2018-099054-J-I00 (MCI/AEI/FEDER, UE) and IJC2018-038164-I. C.D. and Y.M.E. thank the cluster of excellence 3DMM2O funded by DFG under Germanyâs Excellence Strategy â 2082/1 â 390761711 for financial support. The authors thank Lukas GrĂŒnwald and Erich MĂŒller for helpful discussions. A.M.R. thanks the Spanish MIU (Grant No FPU21/04195). A.S.-D. thanks the Universidad de Valencia, for an âAtracciĂłn del talentoâ predoctoral grant. F.G.-P. thanks ITQ, UPVâCSIC for concession of a contract (PAID 01-18)
CSA06 Computing, Software and Analysis challenge at the Spanish Tier-1 and Tier-2 sites
This note describes the participation of the Spanish centres PIC, CIEMAT and IFCA as Tier-1 and Tier-2 sites in the CMS CSA06 Computing, Software and Analysis challenge. A number of the facilities, services and workflows have been demonstrated at the 2008 25% scale. Very valuable experience has been gained running the complex computing system under realistic conditions at a significant scale. The focus of this note is on presenting achieved results, operational experience and lessons learnt during the challenge
Case report: Challenges and implications of conduction system pacing in pediatrics: Case series
Cardiac electrical stimulation in children usually is needed in the setting of complete congenital atrioventricular block, atrioventricular block after heart surgery, and bradycardia associated with some specific channelopathies. In cases of atrioventricular block, the high percentage of ventricular stimulation raises concern on the deleterious effects of chronic stimulation of the right ventricle. In recent years, physiologic stimulation has developed as a valid approach for adult patients and a great interest has risen in offering conduction system pacing also to the pediatric population. We present three pediatric cases of stimulation of the conduction system (His bundle or left bundle branch), in order to show the intrinsic particularities and challenges implied in these new techniques
Bose-Einstein correlations of same-sign charged pions in the forward region in pp collisions at âs=7 TeV
Bose-Einstein correlations of same-sign charged pions, produced in protonproton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected
by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the
form of an enhancement of pairs of like-sign charged pions with small four-momentum
difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source
is investigated, determining both the correlation radius and the chaoticity parameter. The
measured correlation radius is found to increase as a function of increasing charged-particle
multiplicity, while the chaoticity parameter is seen to decreas
- âŠ