3,970 research outputs found
Paracrine osteoprotegerin and β-catenin stabilization support synovial sarcomagenesis in periosteal cells
Recent developments for the calculation of elastic and non-elastic breakup of weakly-bound nuclei
In this contribution, we review some recent theoretical advances for the calculation of breakup cross sections in reactions induced by weakly-bound nuclei.Ministerio de Economía y Competitividad FIS2013-41994-P, CSD2007-00042Junta de Andalucía FQM160, P07-FQM-02894European Commission 60037
Introducing a new multi-particle collision method for the evolution of dense stellar systems II. Core collapse
In a previous paper we introduced a new method for simulating collisional
gravitational -body systems with linear time scaling on , based on the
Multi-Particle Collision (MPC) approach. This allows us to simulate globular
clusters with a realistic number of stellar particles in a matter of hours on a
typical workstation. We evolve star clusters containing up to stars to
core collapse and beyond. We quantify several aspects of core collapse over
multiple realizations and different parameters, while always resolving the
cluster core with a realistic number of particles. We run a large set of N-body
simulations with our new code. The cluster mass function is a power-law with no
stellar evolution, allowing us to clearly measure the effects of the mass
spectrum. Leading up to core collapse, we find a power-law relation between the
size of the core and the time left to core collapse. Our simulations thus
confirm the theoretical self-similar contraction picture but with a dependence
on the slope of the mass function. The time of core collapse has a
non-monotonic dependence on the slope, which is well fit by a parabola. This
holds also for the depth of core collapse and for the dynamical friction
timescale of heavy particles. Cluster density profiles at core collapse show a
broken power law structure, suggesting that central cusps are a genuine feature
of collapsed cores. The core bounces back after collapse, and the inner density
slope evolves to an asymptotic value. The presence of an intermediate-mass
black hole inhibits core collapse. We confirm and expand on several predictions
of star cluster evolution before, during, and after core collapse. Such
predictions were based on theoretical calculations or small-size direct
-body simulations. Here we put them to the test on MPC simulations with a
much larger number of particles, allowing us to resolve the collapsing core.Comment: 8 pages, 9 figs., 1 tab. Version accepted for publication in A&
Causa prima: cosmology meets causal discovery for the first time
In astrophysics, experiments are impossible. We thus must rely exclusively on
observational data. Other observational sciences increasingly leverage causal
inference methods, but this is not yet the case in astrophysics. Here we
attempt causal discovery for the first time to address an important open
problem in astrophysics: the (co)evolution of supermassive black holes (SMBHs)
and their host galaxies. We apply the Peter-Clark (PC) algorithm to a
comprehensive catalog of galaxy properties to obtain a completed partially
directed acyclic graph (CPDAG), representing a Markov equivalence class over
directed acyclic graphs (DAGs). Central density and velocity dispersion are
found to cause SMBH mass. We test the robustness of our analysis by random
sub-sampling, recovering similar results. We also apply the Fast Causal
Inference (FCI) algorithm to our dataset to relax the hypothesis of causal
sufficiency, admitting unobserved confounds. Hierarchical SMBH assembly may
provide a physical explanation for our findings.Comment: ML4PS NeurIPS workshop 2023 accepte
Reaction Theory and Advanced CDCC
The Continuum-Discretized Coupled-Channels (CDCC) has been successfully employed to describe elastic and breakup of nuclear reactions induced by weakly bound projectiles. In this contribution, we review some other, less widespread applications of the CDCC wavefunction, some of them in combination with other reaction formalisms, which are being currently employed in the analysis of reactions involving three or more fragments in the initial or final state.National Science Foundation NSF-PHY-1520972Ministerio de Ciencia, Innovación y Universidades FIS2017-88410-PEuropean Union's Horizon 2020 65400
Expanded CURB-65: A new score system predicts severity of community-acquired pneumonia with superior efficiency
Aim of this study was to develop a new simpler and more effective severity score for communityacquired pneumonia (CAP) patients. A total of 1640 consecutive hospitalized CAP patients in Second
Affiliated Hospital of Zhejiang University were included. The effectiveness of different pneumonia
severity scores to predict mortality was compared, and the performance of the new score was validated
on an external cohort of 1164 patients with pneumonia admitted to a teaching hospital in Italy.
Using age≥ 65 years, LDH>230u/L, albumin<3.5g/dL, platelet count<100×109/L, confusion,
urea>7mmol/L, respiratory rate≥30/min, low blood pressure, we assembled a new severity score
named as expanded-CURB-65. The 30-day mortality and length of stay were increased along with
increased risk score. The AUCs in the prediction of 30-day mortality in the main cohort were 0.826
(95%CI, 0.807–0.844), 0.801 (95%CI, 0.781–0.820), 0.756 (95%CI, 0.735–0.777), 0.793 (95%CI,
0.773–0.813) and 0.759 (95%CI, 0.737–0.779) for the expanded-CURB-65, PSI, CURB-65, SMART-COP
and A-DROP, respectively. The performance of this bedside score was confirmed in CAP patients of
the validation cohort although calibration was not successful in patients with health care-associated
pneumonia (HCAP). The expanded CURB-65 is objective, simpler and more accurate scoring system for
evaluation of CAP severity, and the predictive efficiency was better than other score systems
Age related changes in the elastic fiber system of the interfoveolar ligament
Com o objetivo de avaliar as alterações do sistema de fibras elásticas relacionadas ao envelhecimento do ligamento interfoveolar estudou-se o anel inguinal profundo em 33 cadáveres do sexo masculino com idade variando de recém-nascido a 76 anos. Métodos de coloração seletiva para as fibras elásticas foram empregados para diferenciar fibras oxitalânicas, fibras elaunínicas e fibras elásticas maduras. Verificaram-se alterações quantitativas significantes no sistema de fibras elásticas do ligamento interfoveolar com o envelhecimento: uma redução progressiva de fibras oxitalânicas, responsáveis pela resistência do tecido conjuntivo, e um aumento de fibras elásticas maduras e elaunínicas, responsáveis pela elasticidade tecidual. Demonstraram-se alterações estruturais, como espessamento, encurtamento e encurvamento das fibras elásticas maduras e elaunínicas. Estas alterações induzem a perda de função das fibras elásticas, o que certamente levará a perda de complacência do ligamento interfoveolar, predispondo à hérnia inguinal indireta, que freqüentemente aparece em homens adultos ou idosos, especialmente acima de 50 anos de idade.In order to evaluate age related changes of the elastic fiber system in the interfoveolar ligament, we studied the deep inguinal ring from 33 male cadavers aged from stillborn to 76 years. Selective and alternated staining methods for elastic fibers were performed to differentiate oxytalan, elaunin, and mature elastic fibers. We confirmed quantitative changes of the elastic fiber system with aging. There was a significant and progressive reduction of the oxytalan fibers (responsible for tissue resistance) and a significant increment in the mature elastic and elaunin fibers (responsible for tissue elasticity). Furthermore, there were structural changes in the thickness, shortness and curling of these mature elastic fibers. These changes induced loss of the elastic fiber function and loss of the interfoveolar ligament compliance. These factors predispose individuals to the development of indirect inguinal hernias that frequently emerge in adults and aged individuals, especially above the fifth decade
Apoptotic Killing of HIV-1–Infected Macrophages Is Subverted by the Viral Envelope Glycoprotein
Viruses have evolved strategies to protect infected cells from apoptotic clearance. We present evidence that HIV-1 possesses a mechanism to protect infected macrophages from the apoptotic effects of the death ligand TRAIL (tumor necrosis factor–related apoptosis-inducing ligand). In HIV-1–infected macrophages, the viral envelope protein induced macrophage colony-stimulating factor (M-CSF). This pro-survival cytokine downregulated the TRAIL receptor TRAIL-R1/DR4 and upregulated the anti-apoptotic genes Bfl-1 and Mcl-1. Inhibition of M-CSF activity or silencing of Bfl-1 and Mcl-1 rendered infected macrophages highly susceptible to TRAIL. The anti-cancer agent Imatinib inhibited M-CSF receptor activation and restored the apoptotic sensitivity of HIV-1–infected macrophages, suggesting a novel strategy to curtail viral persistence in the macrophage reservoir
Guest entrapment in metal-organic nanosheets for quantifiably tuneable luminescence
Luminescent metal-organic frameworks (LMOFs) are promising materials for nanophotonic applications due to their tuneable structure and programmability. Yet, the 3D nature of LMOFs creates challenges for stability, optical transparency, and device integration. Metal-organic nanosheets (MONs) potentially overcome these limitations by combining the benefits of metal-organic frameworks (MOFs) with an atomically thin morphology of large planar dimensions. Herein, the bottom-up synthesis of few-layer thin ZIF-7-III MONs via facile low-energy salt-templating is reported. Employing guest@MOF design, the fluorophores Rhodamine B and Fluorescein are intercalated into ZIF-7 nanosheets (Z7-NS) to form light emissive systems exhibiting intense and highly photostable fluorescence. Aggregation and Förster resonance energy transfer, enabled by the MON framework, are revealed as the mechanisms behind fluorescence. By varying guest concentration, these mechanisms provide predictable quantified control over emission chromaticity of a dual-guest Z7-NS material and the definition of an “emission chromaticity fingerprint” – a unique subset of the visible spectrum that a material can emit by fluorescence
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