307 research outputs found
Dynamical and photometric imprints of feedback processes on the early evolution of E/S0 galaxies
We show that the observed Velocity Dispersion Function of E/S0 galaxies
matches strikingly well the distribution function of virial velocities of
massive halos virializing at z > 1.5, as predicted by the standard hierarchical
clustering scenario in a \LambdaCDM cosmology, for a constant ratio sigma/V_vir
= 0.55 \pm 0.05, close to the value expected at virialization if it typically
occurred at z > 3. This strongly suggests that dissipative processes and later
merging events had little impact on the matter density profile. Adopting the
above sigma/V_vir ratio, the observed relationships between photometric and
dynamical properties which define the fundamental plane of elliptical galaxies,
such as the luminosity-sigma (Faber-Jackson) and the luminosity-effective
radius relations, as well as the M_BH-sigma relation, are nicely reproduced.
Their shapes turn out to be determined by the mutual feedback of star-formation
(and supernova explosions)and nuclear activity, along the lines discussed by
Granato et al. (2004). To our knowledge, this is the first semi-analytic model
for which simultaneous fits of the fundamental plane relations and of the
epoch-dependent luminosity function of spheroidal galaxies have been presented.Comment: 14 pages, 6 figures, submitted to Ap
Treatment with a Urokinase Receptor-derived Cyclized Peptide Improves Experimental Colitis by Preventing Monocyte Recruitment and Macrophage Polarization
Leukocyte migration across the blood barrier and into tissues represents a key process in the pathogenesis of inflammatory bowel diseases. The urokinase receptor (urokinase-type plasminogen activator receptor) is a master regulator of leukocyte recruitment. We recently found that cyclization of the urokinase-type plasminogen activator receptor-derived peptide Ser-Arg-Ser-Arg-Tyr [SRSRY] inhibits transendothelial migration of monocytes. Now, we have explored the effects of [SRSRY] administration during experimental colitis
Dark Matter in Fractional Gravity I: Astrophysical Tests on Galactic Scales
[abridged] We explore the possibility that the dark matter (DM) component in
galaxies may originate fractional gravity. In such a framework, the standard
law of inertia continues to hold, but the gravitational potential associated to
a given DM density distribution is determined by a modified Poisson equation
including fractional derivatives (i.e., derivatives of non-integer type), that
are meant to describe non-local effects. We derive analytically the expression
of the potential that in fractional gravity corresponds to various spherically
symmetric density profiles, including the Navarro-Frenk-White (NFW)
distribution that is usually exploited to describe virialized halos of
collisionless DM as extracted from body cosmological simulations. We show
that in fractional gravity the dynamics of a test particle moving in a cuspy
NFW density distribution is substantially altered with respect to the Newtonian
case (i.e., basing on the standard Poisson equation), mirroring what in
Newtonian gravity would instead be sourced by a density profile with an inner
core. We test the fractional gravity framework on galactic scales, showing
that: (i) it can provide accurate fits to the stacked rotation curves of
galaxies with different properties; (ii) it can reproduce to reasonable
accuracy the observed shape and scatter of the radial acceleration relation
(RAR); (iii) it can properly account for the universal surface density and the
core radius vs. disk scale-length scaling relations. Finally, we discuss the
possible origin of the fractional gravity behavior as a fundamental or emerging
property of the elusive DM component.Comment: 30 pages, 11 figures, Accepted by Ap
Upadacitinib in refractory cutaneous pseudolymphoma: A case report
Cutaneous pseudolymphoma is a benign condition characterized by a reactive B-cell, T-cell or mixed lymphoproliferative
process. Different causative agents (e.g. injected substances, tattoo, drugs and insect bites) have been described, but in many
cases no cause can be identified; hence, the term idiopathic cutaneous pseudolymphoma. There are no specific guidelines for the
treatment of cutaneous pseudolymphoma, and sometimes a few cases are refractory to conventional treatments. We describe
a case of a 41-year-old African woman with refractory facial IgG4 pseudolymphoma successfully treated with upadacitinib
Nutritional aspects in neuroendocrine neoplasms. bridging the gap between dietary interventions and cancer care strategies: a scoping review
Purpose: Neuroendocrine neoplasms (NENs) represent heterogeneous tumors arising from neuroendocrine cells in different organs. Despite growing interest in the nutritional aspects of NEN management, research in this area is limited. Aim of this review is to summarize the current state of knowledge, highlight research gaps, and underscore the significance of nutrition in the comprehensive care of NEN patients.
Methods: We conducted an extensive bibliographic search focusing on studies (including retrospective and prospective studies, systematic reviews, case series, and guidelines) exploring the relationship between nutritional assessments, dietary interventions, micronutrient deficiencies, and their impact on NEN outcomes.
Results: Significant gaps exist in current research, particularly in understanding the specific nutritional needs of NEN patients and how tailored nutritional interventions can improve clinical outcomes. Evidence suggests that a high-fat Western diet may promote the growth of NEN, while a Mediterranean diet may help lower insulin levels and strengthen the immune system, potentially preventing tumor development. The ketogenic diet and intermittent fasting may also have positive impacts. Addressing common micronutrient deficiencies, such as vitamin D and niacin, is crucial to mitigate disease progression. There's a crucial need for future studies to include a comprehensive nutritional assessment incorporating patient-reported outcomes, to fully capture the impact of nutritional strategies.
Conclusion: Nutritional management, an important but under-researched facet of NEN treatment, significantly improves patients' quality of life and survival. Integrating nutrition into personalized cancer care is essential, highlighting the role of nutritional strategies in optimizing patient outcomes
Reduced cortical thickness in patients with acute-on-chronic liver failure due to non-alcoholic etiology
Background:
Acute-on-chronic liver failure (ACLF) is a form of liver disease with high short-term mortality. ACLF offers considerable potential to affect the cortical areas by significant tissue injury due to loss of neurons and other supporting cells. We measured changes in cortical thickness and metabolites profile in ACLF patients following treatment, and compared it with those of age matched healthy volunteers.
Methods:
For the cortical thickness analysis we performed whole brain high resolution T1-weighted magnetic resonance imaging (MRI) on 15 ACLF and 10 healthy volunteers at 3T clinical MR scanner. Proton MR Spectroscopy (1H MRS) was also performed to measure level of altered metabolites. Out of 15 ACLF patients 10 survived and underwent
follow-up study after clinical recovery at 3 weeks. FreeSurfer program was used to quantify cortical thickness and LC- Model software was used to quantify absolute metabolites concentrations. Neuropsychological (NP) test was performed to assess the cognitive performance in follow-up ACLF patients compared to controls.
Results:
Significantly reduced cortical thicknesses in multiple brain sites, and significantly decreased N-acetyl
aspartate (NAA), myo-inositol (mI) and significantly increased glutamate/glutamine (glx) metabolites were observed in ACLF compared to those of controls at baseline study. Follow-up patients showed significant recovery in cortical thickness and Glx level, while NAA and mI were partially recovered compared to baseline study. When compared to controls, follow-up patients still showed reduced cortical thickness and altered metabolites level. Follow-up patients had abnormal neuropsychological (NP) scores compared to controls.
Conclusions:
Neuronal loss as suggested by the reduced NAA, decreased cellular density due to increased cerebral hyperammonemia as supported by the increased glx level, and increased proinflammatory cytokines and free radicals may account for the reduced cortical thickness in ACLF patients. Presence of reduced cortical thickness, altered
metabolites and abnormal NP test scores in post recovery subjects as compared to those of controls is associated
with incomplete clinical recovery. The current imaging protocol can be easily implemented in clinical settings to evaluate and monitor brain tissue changes in patients with ACLF during the course of treatment
Planck intermediate results XIV : Dust emission at millimetre wavelengths in the Galactic plane
Peer reviewe
Planck Intermediate Results. XXXVI. Optical identification and redshifts of Planck SZ sources with telescopes at the Canary Islands Observatories
We present the results of approximately three years of observations of Planck
Sunyaev-Zeldovich (SZ) sources with telescopes at the Canary Islands
observatories as part of the general optical follow-up programme undertaken by
the Planck collaboration. In total, 78 SZ sources are discussed. Deep-imaging
observations were obtained for most of these sources; spectroscopic
observations in either in long-slit or multi-object modes were obtained for
many. We effectively used 37.5 clear nights. We found optical counterparts for
73 of the 78 candidates. This sample includes 53 spectroscopic redshift
determinations, 20 of them obtained with a multi-object spectroscopic mode. The
sample contains new redshifts for 27 Planck clusters that were not included in
the first Planck SZ source catalogue (PSZ1).Comment: 15 pages, 14 figures, accepted for publication in A&
The Black Hole Mass Function across Cosmic Time. II. Heavy Seeds and (Super)Massive Black Holes
This is the second paper in a series aimed at modeling the black hole (BH) mass function from the stellar to the (super)massive regime. In the present work, we focus on (super)massive BHs and provide an ab initio computation of their mass function across cosmic time. We consider two main mechanisms to grow the central BH that are expected to cooperate in the high-redshift star-forming progenitors of local massive galaxies. The first is the gaseous dynamical friction process, which can cause the migration toward the nuclear regions of stellar mass BHs originated during the intense bursts of star formation in the gas-rich host progenitor galaxy and the buildup of a central heavy BH seed, M• ∼ 103−5 M⊙, within short timescales of ≲some 107 yr. The second mechanism is the standard Eddington-type gas disk accretion onto the heavy BH seed through which the central BH can become (super)massive, M• ∼ 106−10 M⊙, within the typical star formation duration, ≲1 Gyr, of the host. We validate our semiempirical approach by reproducing the observed redshift-dependent bolometric AGN luminosity functions and Eddington ratio distributions and the relationship between the star formation and the bolometric luminosity of the accreting central BH. We then derive the relic (super)massive BH mass function at different redshifts via a generalized continuity equation approach and compare it with present observational estimates. Finally, we reconstruct the overall BH mass function from the stellar to the (super)massive regime over more than 10 orders of magnitudes in BH mass
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