Nature is characterized by a number of physical laws and fundamental dimensionless couplings. These determine the properties of our physical universe, from the size of atoms, cells and mountains to ...the ultimate fate of the universe as a whole. Yet it is rather remarkable how little we know about them. The constancy of physical laws is one of the cornerstones of the scientific research method, but for fundamental couplings this is an assumption with no other justification than a historical assumption. There is no 'theory of constants' describing their role in the underlying theories and how they relate to one another or how many of them are truly fundamental. Studying the behaviour of these quantities throughout the history of the universe is an effective way to probe fundamental physics. This explains why the ESA and ESO include varying fundamental constants among their key science drivers for the next generation of facilities. This symposium discussed the state-of-the-art in the field, as well as the key developments anticipated for the coming years.
Biosimilars are new and more affordable similar versions of previously approved reference biological drugs. Following the approval of the first monoclonal antibody biosimilar in 2013, the Portuguese ...Society of Rheumatology issued a position paper on the use of biosimilars in rheumatic conditions covering efficacy, safety, extrapolation, interchangeability, substitution and pharmacovigilance. However, as this is a rapidly evolving field, it was felt that the knowledge and evidence gathered since then justified an update of these statements. Literature searches on these issues were performed and the search results were presented and discussed in a national meeting. Portuguese rheumatologists considered that affordability should be taken into consideration when initiating a biological drug, but other factors were equally important. In patients already on reference biological treatment, switch to a more affordable biosimilar is desirable, provided a set of conditions is rigorously met. Automatic substitution is not acceptable and current evidence is insufficient to support interchangeability. Extrapolation of clinical indications is endorsed by Portuguese rheumatologists, and the statements on safety, pharmacovigilance and traceability are in accordance with the previous position paper.
Objectives To evaluate the histological alterations of extracellular matrix in long-term alloxan-induced diabetes and aging urethras of male rats with descriptions of total connective tissue, muscle ...layer and collagen types I and III relative amounts. Methods Histologic evaluations were performed in 3 animal groups: group 1, 8 weeks old; group 2, 44 weeks old; and group 3, 44 weeks old with alloxan-induced diabetes. The muscle layer thickness, extracellular matrix fibrosis, and collagen were quantified on digital images of the urethral samples. Results A higher total thickness and muscle layer thickness and higher connective tissue and collagen content were observed in the urethras of group 3. No changes in the collagen type III/I ratio were found in the urethra of groups 2 and 3. Conclusions Our results suggest that the morphologic alterations of the urethra should also be considered in long-term studies of diabetic lower urinary tract dysfunction. These morphologic alterations due to diabetes differ from the changes induced by aging itself and could represent a final stage in decompensate urethras. Further studies are necessary to establish the real influence of the urethral morphologic changes on lower urinary tract diabetes dysfunction.
The Universe's assumed homogeneity and isotropy is known as the cosmological principle. It is one of the assumptions that lead to the Friedmann-Lema\^ıtre-Robertson-Walker (FLRW) metric and it is a ...cornerstone of modern cosmology, because the metric plays a crucial role into the determination of the cosmological observables. Thus, it is of paramount importance to question this principle and perform observational tests that may falsify this hypothesis. Here we explore the use of galaxy cluster counts as a probe of a large-scale inhomogeneity, which is a novel approach for the study of inhomogeneous models, and to determine the precision with which future galaxy cluster surveys will be able to test the cosmological principle. We present forecast constraints on the inhomogeneous Lema\^ıtre-Tolman-Bondi (LTB) model with a cosmological constant and cold dark matter, from a combination of simulated data according to a compilation of `Stage-IV' galaxy surveys following a methodology that involves the use of a mass function correction from numerical \(N\)-body simulations of an LTB cosmology. When considering the \lcdm fiducial model as a baseline for constructing our mock catalogs, we find that our combination of the forthcoming cluster surveys, will improve the constraints on the cosmological principle parameters as well on the FLRW parameters by about \(50\%\) with respect to previous similar forecasts performed using geometrical and linear growth of structure probes, with \(\pm20\%\) variations depending on the level of knowledge of systematic effects.These results indicate that galaxy cluster abundances are sensitive probes of inhomogeneity, and that next-generation galaxy cluster surveys, will thoroughly test homogeneity at cosmological scales, tightening the constraints on possible violations of the cosmological principle in the framework of \(\Lambda\)LTB scenarios. (Abridged)
Chemical evolution models predict a gradual build-up of \(^{13}\)C in the universe, based on empirical nuclear reaction rates and assumptions on the properties of stellar populations. However, old ...metal-poor stars within the Galaxy contain more \(^{13}\)C than is predicted, suggesting that further refinements to the models are necessary. Gas at high redshift provides important supplementary information at metallicities \(-2\lesssim\) Fe/H \(\lesssim-1\), for which there are only a few measurements in the Galaxy. We obtained new, high-quality, VLT/ESPRESSO observations of the QSO B1331+170 and used them to measure \(^{12}\)C/\(^{13}\)C in the damped Lyman-\(\alpha\) system (DLA) at \(z_{abs}=1.776\), with Fe/H=-1.27. AI-VPFIT, an Artificial Intelligence tool based on genetic algorithms and guided by a spectroscopic information criterion, was used to explore different possible kinematic structures of the carbon gas. Three hundred independent AI-VPFIT models of the absorption system were produced using pre-set \(^{12}\)C/\(^{13}\)C values, ranging from 4 to 500. Our results show that \(^{12}\)C/\(^{13}\)C\(=28.5^{+51.5}_{-10.4}\), suggesting a possibility of \(^{13}\)C production at low metallicity.
The QUBRICS (QUasars as BRIght beacons for Cosmology in the Southern hemisphere) survey aims at constructing a sample of the brightest quasars with z>~2.5, observable with facilities in the Southern ...Hemisphere. QUBRICS makes use of the available optical and IR wide-field surveys in the South and of Machine Learning techniques to produce thousands of bright quasar candidates of which only a few hundred have been confirmed with follow-up spectroscopy. Taking advantage of the recent Gaia Data Release 3, which contains 220 million low-resolution spectra, and of a newly developed spectral energy distribution fitting technique, designed to combine the photometric information with the Gaia spectroscopy, it has been possible to measure 1672 new secure redshifts of QUBRICS candidates, with a typical uncertainty \(\sigma_z = 0.02\). This significant progress of QUBRICS brings it closer to (one of) its primary goals: providing a sample of bright quasars at redshift 2.5 < z < 5 to perform the Sandage test of the cosmological redshift drift. A Golden Sample of seven quasars is presented that makes it possible to carry out this experiment in about 1500 hours of observation in 25 years, using the ANDES spectrograph at the 39m ELT, a significant improvement with respect to previous estimates.
Photocatalytic processes based on titanium dioxide (TiO
2
) nanoparticles have attracted increasing attention in the last decades. However, approaches based on nanoparticles show some drawbacks, in ...particular due to the need for expensive and time consuming post-treatment of nanoparticles filtration/separation. This hindrance demands the development of immobilized configurations with tailored properties, as an alternative to allow simple recovery of the photocatalytic particles. Thus, this work reports on the development of photocatalytic membranes based on TiO
2
nanoparticles immobilized into a poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) membrane and the comparative study of their performance with dispersed TiO
2
nanoparticles. Photocatalytic nanocomposite membranes with a highly porous structure (∼75%) and controlled wettability by NaY addition were successfully produced. These properties were paramount to achieve a methylene blue degradation efficiency of 96% in 40 min under ultraviolet (UV) irradiation, corresponding to an efficiency loss of just 3% regarding the TiO
2
nanoparticle assays.
Optimized photocatalytic membranes based on TiO
2
and NaY immobilized into P(VDF-TrFE) have been developed showing a degradation efficiency of 96%.
This paper presents a quantitative metric for memory effects in power amplifiers (PAs) and applies it to various active device technologies and wireless system contexts. The proposed metric is ...mathematically founded in the dynamic two-tone distortion response, has a clear physical meaning in the important field of PA linearization and can be easily evaluated from either harmonic balance simulations or measurement data gathered in a microwave laboratory. In addition, a memoryless PA linearizer, optimum for reducing the integrated intermodulation distortion (IMD) power in the operation bandwidth for a two-tone excitation, is derived, providing a rigorous figure-of-merit of PA linearizability under static IMD compensation. The application of this figure-of-merit is then illustrated for three different PA prototypes based on Si LDMOS, InGaP/GaAs heterojunction bipolar transistors, and GaN high electron-mobility transistors, designed for 900-MHz (global system for mobile communications), 2.1-GHz (wideband code division multiple access), and 3.5-GHz (WiMax) wireless systems, respectively
The gravitationally lensed quasar J014516.6-094517 at z=2.719 has been observed with the ESPRESSO instrument at the ESO VLT to obtain high-fidelity spectra of the two images A and B with a resolving ...power R=70000. At the redshifts under investigation (2.1 < z < 2.7), the Lyman forests along the two sightlines are separated by sub-kiloparsec physical distances and exhibit a strong correlation. We find that the two forests are indistinguishable at the present level of signal-to-noise ratio and do not show any global velocity shift, with the cross-correlation peaking at \(\Delta v = 12 \pm 48\) m/s. The distribution of the difference in velocity of individual Lyman-\(\alpha\) features is compatible with a null average and a mean absolute deviation of 930 m/s. Significant differences in NHI column density are not detected, putting a limit to the RMS fluctuation in the baryon density on \(\leq 1\) proper kpc scales of \(\Delta \rho / \rho < 3\)%. On the other hand, metal lines show significant differences both in velocity structure and in column density. A toy model shows that the difference in velocity of the metal features between the two sightlines is compatible with the the motions of the baryonic component associated to dark matter halos of typical mass \(M\simeq 2\times 10^{10} M_\odot\), also compatible with the observed incidence of the metal systems. The present observations confirm the feasibility of the Sandage test of the cosmic redshift drift with high-fidelity spectroscopy of the Lyman forest of distant, bright quasars, but also provide an element of caution about the intrinsic noise associated to the usage of metal features for the same purpose.
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