A
bstract
We study the four-top (
t
t
¯
t
t
¯
) final state at the LHC as a probe for New Physics (NP) effects due to new particles that couple predominantly to the top quark and whose masses are ...below the top-quark-pair production threshold. We consider simple NP models containing a new particle with either spin 0, spin 1, or spin 2, and find benchmark points compatible with current experimental results. We find that interference effects between NP and QED amplitudes can be large, pointing out the necessity of NLO contributions to be explicitly computed and taken into account when NP is present. We examine kinematic differences between these models and the Standard Model (SM) at the parton level and the reconstructed level. In the latter case, we focus on events selected requiring two same-sign leptons and multiple jets. We investigate how the different Lorentz structure of the light NP affects the kinematic hardness, the polarization, the spin correlations, and the angular distributions of the parton-level and/or final-state particles. We find that spin-2 light NP would be identified by harder kinematics than the SM. We also show that the angular sepa- ration between the same-sign leptons is a sensitive observable for spin-0 NP. The spin-0 and spin-2 NP cases would also yield a signal in
t
t
¯
γγ
with the invariant mass of the photons in- dicating the mass of the new particle. The spin-1 NP would be identified through an excess in four-top signal and slight or not modification in other observables, as for instance the lack of signal in
t
t
¯
γγ
due to the Landau-Yang theorem. We comment on the opportunities that would open from the kinematic reconstruction of some of the top quarks in the
t
t
¯
t
t
¯
state. Our results provide new handles to probe for light top-philic NP as part of the ongoing experimental program of searches for four-top production at the LHC Run 2 and beyond.
A
bstract
We propose a new search strategy for directly-produced sbottoms at the LHC with a small mass splitting between the sbottom and its decayed stable neutralino. Our search strategy is based on ...boosting sbottoms through an energetic initial state radiation jet. In the final state, we require a large missing transverse energy and one or two
b
-jets besides the initial state radiation jet. We also define a few kinematic variables to further increase the discovery reach. For the case that the sbottom mainly decays into the bottom quark and the stable neutralino, we have found that even for a mass splitting as small as 10 GeV sbottoms with masses up to around 400 GeV can be excluded at the 95 % confidence level with 20 inverse femtobarn data at the 8 TeV LHC.
We perform a joint analysis of the prediction of composite Higgs models for the discrepancies of the forward-backward asymmetries of top and bottom quarks at Tevatron and LEP + SLC, respectively. We ...build a two sector model which can be thought as an effective low energy description of 5D warped models and choose the quantum numbers of the fermionic resonances to protect the Z-couplings of the partially composite Standard Model light quarks. We analyze the cross section, forward-backward asymmetry and invariant mass distribution of the top anti-top production at Tevatron, as well as the bottom forward-backward asymmetry and the Z-branching fraction into b-quarks at LEP and SLC, for the two sector model. In the region of the parameter space that naturally leads to the Standard Model spectrum and solves the bottom anomaly, the model improves the top forward-backward asymmetry, giving a prediction of up to 10%, and predicts a small decrease of the
cross section. It also predicts non-universal corrections of the Z-couplings to the light quarks of order 0.001.
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We aimed to study the effects of the new oral anticoagulant edoxaban, a factor X activated (FXa) inhibitor, on key endothelial functions that could contribute to cardiovascular ...benefit.
Human umbilical endothelial cells (HUVEC) were obtained from donated umbilical cords and used to analyse 1) structural functions like cell proliferation, migration, and angiogenesis in appropriate assays; 2) anti-inflammatory reactions as mononuclear cell (PBMC) or platelet adhesion to HUVEC monolayers; and 3) haemostasis control by fibrin formation or plasminogen activator modulation. Key molecular effectors and signalling pathways on each function were explored by profiled protein arrays, mRNA, or protein expression analyses.
Edoxaban promoted viability and growth in HUVEC cultures, as well as counteracted the promigratory and antiangiogenic effects of FXa, through action on the PI3K/AKT pathway. Edoxaban inhibited the adhesion to endothelial cells and the transmigration through endothelial monolayers of PBMC, and even counteracted the action of pro-inflammatory stimuli such as FXa by blocking the FXa-induced expression of cell adhesion molecules via the PAR 1-2/PI3K/NF-kB pathway. Haemostatic control of edoxaban could be exerted from the endothelium by the reduction of platelets’ adhesion to endothelial cells and the possible acute activation of urokinase plasminogen activator.
Edoxaban is a safe and structural stabilizing factor for endothelial cells and also has remarkable anti-inflammatory action, preventing PBMC adhesion and transmigration through the endothelium. It may also contribute to haemostasis control by reducing platelet adhesion. Its main molecular mechanism seems to be the control of the PI3K/NF-κB pathways.
During the current data era, data analysis across multiple disciplines has become a critical task for researchers to obtain meaningful insights and solve complex problems that are immeasurable using ...traditional technologies. Big Data has led to the development of state-of-the-art technologies that have revolutionized the process of experimentation. These innovations span from automating the setup of the infrastructure required for data analysis to providing user-friendly interfaces that simplify coding and result visualization. However, managing and scaling these resources for large-scale data processing remains a challenge. In this work, we introduce a novel framework called Datalab as a Service which integrates cutting-edge and open-source technologies to offer an online platform designed for both resource providers and researchers. The platform enables users to easily and automatically deploy interactive environments tailored for data analysis, thereby streamlining the process of managing computational resources. Through DLaaS, users gain access to cloud-based infrastructures and distributed computing resources, which are essential for performing compute-intensive tasks on massive datasets. The framework ensures scalability, resource management and optimization, and high availability, all within an accessible and user-friendly platform. Furthermore, this paper presents several use cases where researchers have successfully utilized DLaaS resources, demonstrating its practical applications in real-world scenarios.
Coronavirus disease (COVID-19) causes various vascular and blood-related reactions, including exacerbated responses. The role of endothelial cells in this acute response is remarkable and may remain ...important beyond the acute phase. As we move into a post-COVID-19 era (where most people have been or will be infected by the SARS-CoV-2 virus), it is crucial to define the vascular consequences of COVID-19, including the long-term effects on the cardiovascular system. Research is needed to determine whether chronic endothelial dysfunction following COVID-19 could lead to an increased risk of cardiovascular and thrombotic events. Endothelial dysfunction could also serve as a diagnostic and therapeutic target for post-COVID-19. This review covers these topics and examines the potential of emerging vessel-on-a-chip technology to address these needs. Vessel-on-a-chip would allow for the study of COVID-19 pathophysiology in endothelial cells, including the analysis of SARS-CoV-2 interactions with endothelial function, leukocyte recruitment, and platelet activation. “Personalization” could be implemented in the models through induced pluripotent stem cells, patient-specific characteristics, or genetic modified cells. Adaptation for massive testing under standardized protocols is now possible, so the chips could be incorporated for the personalized follow-up of the disease or its sequalae (long COVID) and for the research of new drugs against COVID-19.
trans-Resveratrol (t-RESV; 1-10 microM), a phenolic component of wines, had no effect on phenylephrine-(PE; 1 microM) and high KCl-(60 mM) induced contractions in endothelium-denuded rat aortic ...rings. However, it relaxed the contractile response produced by these vasoconstrictor agents in intact rat aorta. The vasorelaxing effects of t-RESV were completely inhibited by N(G)-nitro-L-arginine (L-NOARG; 0.1 mM) and methylene blue (10 microM), but they were unaffected by atropine (10 microM) and yohimbine (1 microM). The reversal effect produced by L-NOARG was antagonized by L-arginine but not by D-arginine (0.1 mM). t-RESV (1-10 microM) did not significantly modify rat aorta constitutive nitric-oxide synthase activity. However, this natural compound decreased NADH/NADPH oxidase activity in rat aortic homogenates. In addition, t-RESV (1-10 microM) was ineffective in scavenging superoxide anions (O(2)*) generated enzymatically by a hypoxanthine/xanthine oxidase (HX/XO) system and/or to inhibit XO. The above data demonstrate that the characteristic endothelium-dependent vasorelaxant effect of t-RESV in rat aorta seems to be caused by the inhibition of vascular NADH/NADPH oxidase and the subsequent decrease of basal cellular O(2)* generation and, therefore, of NO biotransformation. Under the assumption that t-RESV exhibits a similar behavior in human blood vessels and bearing in mind that an overactivity of NADH/NADPH oxidase has been found in a number of cardiovascular pathologies, the results obtained in this work suggest that t-RESV could play an important role in the cardioprotective effects induced by the long-term moderate wine consumption.
Although the natural polyphenol resveratrol posses a direct vasorelaxant effect, its effects on cytoplasmic Ca(2+) concentration (Ca(2+)(i)) in vascular cells remain still unclear. Here, we have ...investigated the effects of the isomers trans- and cis-resveratrol on agonist- and high-K(+)-induced Ca(2+)(i) increases and on voltage-activated transmembrane Ca(2+) fluxes using imaging and patch-clamp techniques in vascular A7r5 myocytes. Arginine vasopressin (AVP) or angiotensin II caused a biphasic increase in Ca(2+)(i) that was reduced by preincubation with trans-resveratrol and cis-resveratrol. Both isomers also reduced the agonist-induced increase in Ca(2+)(i) in absence of extracellular Ca(2+). In high-K(+) Ca(2+)-free solution, reintroduction of Ca(2+) caused a sustained rise in Ca(2+)(i) that was reduced by preincubation with trans-resveratrol or cis-resveratrol. When the isomers were applied during the plateau phase of the agonist- or the high-K(+)-induced response, a biphasic change in Ca(2+)(i) was observed: a transient reduction of the plateau (<5 min) followed by an increase (>10 min). Finally, trans-resveratrol and cis-resveratrol inhibited voltage-dependent L-type Ca(2+) currents (I(Ca(L))). In conclusion, resveratrol isomers exert a dual effect on Ca(2+)(i) handling in A7r5 myocytes: 1) a blockade of I(Ca(L)) and 2) an increase in Ca(2+)(i) by depletion of intracellular Ca(2+) stores (which interferes with the agonist-induced release of intracellular Ca(2+)) and influx of Ca(2+), mainly due to activation of capacitative Ca(2+) entry, although other Ca(2+)-permeable channels are also involved. Taken together, these effects may explain, in part, the endothelium-independent vasorelaxant effects of resveratrol in rat aorta.
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