239700 research outputs found
Sort by
Cytokines, chemokines and antibodies against histone-3/4 citrullinated peptides in rheumatoid arthritis patients with pulmonary fibrosis
No full textFEAST: JWST/NIRCam View of the Resolved Stellar Populations of the Interacting Dwarf Galaxies NGC 4485 and NGC 4490
No full textWe present new JWST/NIRCam observations of the interacting dwarf galaxy system NGC 4485-NGC 4490 (aka Arp 269), obtained as part of the Cycle 1 Feedback in Emerging Extragalactic Star Clusters (FEAST) program. NGC 4485 and NGC 4490 form the closest known pair of interacting late-type dwarf galaxies (at ∼7.4 Mpc), excluding the Magellanic Clouds. Near-infrared color-magnitude diagrams (CMDs) reveal a wide range of stellar populations in both galaxies, including young (≲200 Myr) upper main-sequence stars, core helium-burning stars, and oxygen-rich asymptotic giant branch (AGB) stars. We also identify intermediate-age (∼200 Myr-1 Gyr) carbon-rich AGB stars and a well-populated old (≳1 Gyr) red giant branch. The CMDs show two distinct bursts of star formation beginning ∼30 and ∼200 Myr ago, the latter consistent with the most recent pericenter passage predicted by N-body simulations. The spatial distribution of stars reveals a tidal bridge extending from NGC 4485 and connecting to the disk of NGC 4490. Compact star-forming regions are seen along NGC 4490’s spiral arms, possibly originating from its infrared nucleus. A significant metallicity gradient is observed in the young stellar populations forming the bridge. These findings suggest that during the last pericenter passage, gas was stripped from NGC 4485 via tidal forces or ram pressure, accreted by NGC 4490, and mixed with in situ material, fueling ongoing star formation. This system provides a unique nearby laboratory for studying how tidal interactions shape the star formation and chemical enrichment history of dwarf galaxies
Rails of Progress? Exploring the nexus between railroad access and innovation in Italy (19th-20th centuries)
No full textSelective Hydrogenation of 5-Hydroxymethylfurfural to 5-hydroxymethyltetrahydrofuran: Study of the reaction with commercial Pd-based catalysts
No full textThe transition from fossil resources to renewable ones is highly required to develop bio-based routes for
fuels and chemicals synthesis. Among the available renewable molecules, 5-hydroxymethylfurfural
(HMF) is a really promising platform compound, because of its multifunctional structure, which enables
the production of diverse value-added intermediates. In particular, 5-hydroxymethyltetrahydrofuran
(HMTHF) is an attractive intermediate for the synthesis of pharmaceuticals, polymers, and fine
chemicals. It can be obtained by the selective hydrogenation of the HMF furanic ring, while
preserving the aldehyde group. However, its selective production remains challenging, due to the
competitive hydrogenation of furanic ring to 2,5-bis(hydroxymethyl)furan (BHMF), as well as the full
reduction to 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF). In the field of heterogeneous
catalysis, Pd supported systems are attractive for improving the HMTHF selectivity. On this basis,
in this work, the influence of key reaction parameters, including catalyst loading, Pd loading, type of
catalyst support and hydrogen pressure, was studied, to achieve the selective hydrogenation of HMF to
HMTHF, adopting EtOAc as the solvent. Noteworthy, commercial Pd-based catalysts have been
preferred over the ad-hoc synthesized ones, being easily scalable at industrial scale. The preliminary
results highlighted that an excessive catalyst activity led to the predominant formation of BHMTHF,
rather than HMTHF. Therefore, lower catalyst amount, lower Pd dispersion and lower hydrogen pressure
enhanced the selectivity towards the desired product. In the perspective of working at low hydrogen
pressure, the reaction was also successfully performed at atmospheric pressure, under continuous
hydrogen flow, and the role of the solvent was specifically considered. Our findings indicated that
primary alcohols (MeOH, EtOH, 1-PrOH and 1-BuOH) led to higher HMF conversion than EtOAc but
unfortunately also to lower HMTHF selectivity, thus promoting the carbonyl hydrogenation. However,
branched alcohol, such as 2-PrOH, enabled the complete HMF conversion, at the same time keeping
high the BHMTHF selectivity. To get more insight into possible synergistic effects of base–metal
interactions on this reaction, solid basic co-catalyst (CaO, MgO or ZrO2) was also included in the
reaction mixture, as physical mixture with 5% Pd/C (in different ratios), employing also a
mechanochemical approach to improve the interactions between the two catalysts. In conclusion, this
work shows that it is possible to improve the HMTHF synthesis, preferring sustainable reaction
conditions, and properly tuning the solvent-catalyst characteristics
Direct dark matter searches with metal halide perovskites
No full textPolar materials with optical phonons in the meV range are excellent candidates for both dark matter direct detection via dark photon-mediated scattering and light dark matter absorption. In this study, we propose, for the first time, the metal halide perovskites MAPbI3, MAPbCl3, and CsPbI3 for these purposes. Our findings reveal that CsPbI3 is the best material, significantly improving exclusion limits compared to other polar materials. For scattering, CsPbI3 can probe dark matter masses down to the keV range. For absorption, it enhances sensitivity to detect dark photon masses below ~10 meV. The only material that has so far been investigated and that could provide competitive bounds is CsI, which, however, demonstrates lower stability as device platform compared to CsPbI3. Moreover, CsI is isotropic while the anisotropic structure of CsPbI3 enables daily modulation analysis, showing that a significant percentage of daily modulation exceeding 1% is achievable for dark matter masses below 40 keV
Ancora in tema di pregiudizialità, costituzionale ed eurounitaria: le sentt. nn. 210 del 2024 e 1 del 2025, e l'emergere di una nuova "dottrina" della Corte.
No full textLa nota si focalizza sulle sentt. nn. 2010 del 2024 e 1 del 2025, entrambe di rilievo per il tema della cosiddetta doppia pregiudizialità, costituzionale ed eurounitaria, provando a inquadrarle nel contesto della giurisprudenza recente. L’ipotesi è quella che stia emergendo un orientamento ulteriormente innovativo, non indenne da elementi critici, che riguarda la sottoponibilità immediata alla Corte costituzionale del sospetto contrasto tra la legge italiana (in queste vicende, due leggi provinciali) e atti di diritto europeo dotati di effetti diretti; tale orientamento sembra legarsi alla particolare prospettiva assunta, anche in sede dottrinale, dal medesimo giudice redattore delle pronunce, Giovanni Pitruzzella
Explosive discovery, surprising future: The extraordinary journey of nitroglycerin, nitroderivatives and nitric oxide
No full textFor over 150 years, nitrates have been a cornerstone in the treatment of cardiovascular disease. Nitroglycerin — synthesized by Italian chemist Ascanio Sobrero in 1847 — was initially used in explosives, as the main component of dynamite, by Alfred Nobel. The Scottish physician Lauder Brunton first used amyl nitrite for angina in 1867, and in 1879 the English physician William Murrell described the benefits of nitroglycerin for angina pectoris. Organic nitrates, including nitroglycerin, act as nitric oxide donors, sharing the mechanism of NO release, which induces vasodilation. This paper reviews the fascinating history of nitroglycerin and nitroderivatives, the related discovery of nitric oxide as a cardiovascular signaling molecule, and the 1998 Nobel Prize awarded for this discovery. The paper also succinctly explores current and future roles of nitric oxide donors in cardiovascular treatment
Getting to know False Friends: A case study from the perspective of Italian learners of EFL
No full textFalse friends (FF) pose a significant challenge in foreign language learning due to their potential for interlinguistic interference, also supporting the non-selective language access hypothesis in bilinguals. Note that in this context, bilingualism is broadly understood as a continuum that encompasses both L2 speakers and those who have complete mastery of two distinct language systems. The said hypothesis is bolstered by neuroimaging evidence showing that the mental representations of bilinguals’ two languages are integrated and exhibit a non-selective, parallel language activation. While a lack of the inhibitory control over one language is acknowledged as a potential source of errors for learners, these lexical items are not usually systematically covered in the classroom or in textbooks. Despite the difficulties posed by FF and their neglect in teaching materials, research on their most effective pedagogical approaches is limited, especially, to our knowledge at least, from the perspective of English as a Foreign Language (EFL) for Italians.
The present study on FF is part of a broader project on the informalisation of English language learning through the media (Prin 2020NNJTW3), which ultimately seeks to ascertain the correlation between extramural contact with L2 English and language input, learning outcomes and sociolinguistic attitudes from an Italian perspective. In fact, the goal of our research is to explore the possible impact of different types of contact with English on the learning of FF, starting with a focus on the formal one, to pave the way for the investigation of the possible effect of informal encounters. In the present contribution, we attempted to answer several questions: To what extent are English FF actually known by Italian learners? To what degree does the learners’ proficiency level reflect the knowledge of FF? And do learners perform better depending on the schools they attended?
The study is based on data collected through several tests and a questionnaire exploring learners’ backgrounds and their habits of contact with English. Participants were undergraduate students in the humanities. This stage of the research focuses on correlations derived from the interplay of the following aspects: 1) verification of informants’ English proficiency level using the Oxford Placement Test (OPT), 2) assessment of their knowledge of a sample of FF via a specifically devised test called False Friends Vocabulary Test (FFVT), 3) collection of selected information from the questionnaire regarding participants’ formal education. Initial findings indicate a positive moderate non-linear correlation between the proficiency level obtained through the OPT and scores on the FFVT. This suggests that higher proficiency levels generally correspond to better knowledge of FF. However, this correlation cannot be interpreted as predictive of superior performance in this lexical area. Conversely, correlations between FF knowledge and formal language courses show a positive but extremely weak correlation. These results can therefore be understood as non-linear and non-significant suggesting that FF might need targeted teaching approaches to contrast the automatic non-selective mechanisms of bilingual language processing. Actually, informal contact may also play a significant role, a matter we will investigate in the next stage of our research