484 research outputs found

    Nonlinear phononic crystals based on chains of disks alternating with toroidal structures

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    We study experimentally the acoustic response of a load-bearing, phononic crystal composed of alternating steel disks, and polytetrafluoroethylene o-rings under precompression. The crystal allows for axial, rocking, and shear-polarized wavemodes when excited by a broad-band signal applied off-axis. Finite element analysis is employed to determine the system’s wave modes. The nonlinear interaction between disks and o-rings supports a dynamic response that is tunable with variations in static precompression, leading to controllable frequency shifts in a large band gap. A modal analysis reveals that four of the six principal wave modes are susceptible to external precompression while two modes are not

    Poesia in posa

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    Catalogo della mostra, a cura di C. Gian Ferrari, M. Scolaro, C. Spadoni. Rilettura dell'opera di Felice Casorati con particolare attenzione al contesto di riferimento culturale e alle fonti, all'ambiente torinese che rappresent\uf2 il primo destinatario della sua opera. Analisi approfondite dei rapporti con gli intellettuali piemontesi, con Piero Gobetti, primo esegeta dell'arte di Casorati, e con i coniugi Gualino, importanti figure di committenti/mecenati

    Adiponectin levels are reduced in children born small for gestational age and are inversely related to postnatal catch-up growth

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    Adiponectin is an adipocytokine with insulin-sensitizing and antiatherogenic properties. Reduced concentrations of adiponectin precede the onset of type 2 diabetes and the development of atherosclerosis. Our aim was to quantify adiponectin concentrations in small for gestational age (SGA) children. Fifty-one SGA children, 24 obese, and 17 short-normal children with birth weight appropriate for gestational age (short-AGA) were studied. The statures of the SGA children were corrected for their midparental height and subdivided into two groups according to their corrected height: catch-up growth group, children with corrected height of 0 z-score or greater (n = 17); and noncatch-up growth group, subjects with corrected height less than 0 z-score (n = 34). SGA children showed adiponectin levels significantly lower than short-normal children (35.2 +/- 3.5 vs. 80.4 +/- 26.6 mug/ml; P < 0.0001) and obese children (77.5 +/- 39.4 ÎĽg/ml; P < 0.0001). Catch-up growth children showed adiponectin levels significantly lower than noncatch-up growth subjects (29.4 +/- 10.3 vs. 38.1 +/- 11.5 mug/ml; P = 0.01). Adiponectin concentrations were inversely related to height z-score, corrected stature, weight, and body mass index and were positively related to birth weight. Our results suggest that adiponectin levels are reduced in SGA children and are even lower in those with postnatal catch-up growth. Whether this finding implies a higher risk of developing type 2 diabetes and atherosclerosis remains to be established

    40. The gas-phase ammoxidation of n-hexane to unsaturated C6 dinitriles, intermediates for hexamethylenediamine synthesis

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    This paper reports about an investigation on the catalytic gas-phase ammoxidation of n-hexane aimed at the production of 1,6-C6 dinitriles, precursors for the synthesis of hexamethylenediamine. Catalysts tested were those also active and selective in the ammoxidation of propane to acrylonitrile: rutile-type V/Sb and Sn/V/Nb/Sb mixed oxides. Several N-containing compounds formed; however, the selectivity to cyano-containing aliphatic linear C6 compounds was low, due to the relevant contribution of side reactions such as combustion, cracking and formation of heavy compounds.INGLES

    The digital whomanities project. Best practices for digital pedagogy in the pandemic era

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    This paper aims to enter the ongoing debate about the critical issues of digital pedagogy through the presentation of Digital WHOmanities, a series of online conferences and workshops held at the University of Bologna. Distance learning has become one of the most discussed topics in educational institutions during the spread of Covid-19, revealing a discrepancy between the rapid development of technology and the ability of learning environments to adapt to this turn. In view of this ongoing debate, Digital WHOmanities tried to define the complex and multifaceted figure of the digital humanist and to provide a methodological framework that could foster further online academic initiatives. Specifically, the accurate organization of timing and contents and the adoption of synchronous and asynchronous approaches have highlighted the effectiveness of flexible digital didactics

    Smith-Magenis sindrome and growth hormone deficiency

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    Smith-Magenis syndrome (SMS) is a multiple congenital anomaly/mental retardation syndrome including physical and neurobehavioural features. The disease is commonly associated with a ca. 3.7 Mb interstitial deletion of chromosome 17p11.2, while a 1.1 Mb critical region has been identified, containing about 20 genes expressed in multiple tissues. Haploinsufficiency of one of them, RAI1, seems to be responsible for the neurobehavioural, craniofacial and otolaryngological features of the syndrome, but not for short stature, commonly seen in SMS patients with chromosome deletion, implying the role of other genes in the 17p11.2 region. Growth failure is a final result of several different mechanisms involving decreased growth hormone (GH) production, reduced tissue response to GH, or impaired activity of epistatic factors. To our knowledge, the association of GH deficiency with SMS has never been reported and rarely investigated, despite the very short stature of SMS patients. We describe a girl with a full SMS phenotype and a typical 3.7 Mb deletion of 17p11.2 who also has GH deficiency. After starting replacement therapy, growth has significantly improved, her stature being now above both the 10th percentile and her genetic target. CONCLUSION: we suggest that an investigation of both growth hormone secretion and function is carried out in patients with Smith-Magenis syndrome and 17p11.2 deletion

    NAAA-regulated lipid signaling governs the transition from acute to chronic pain

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    Chronic pain affects 1.5 billion people worldwide but remains woefully undertreated. Understanding the molecular events leading to its emergence is necessary to discover disease-modifying therapies. Here we show that N-acylethanolamine acid amidase (NAAA) is a critical control point in the progression to pain chronicity, which can be effectively targeted by small-molecule therapeutics that inhibit this enzyme. NAAA catalyzes the deactivating hydrolysis of palmitoylethanolamide, a lipid-derived agonist of the transcriptional regulator of cellular metabolism, peroxisome proliferator-activated receptor-α (PPAR-α). Our results show that disabling NAAA in spinal cord during a 72-h time window following peripheral tissue injury halts chronic pain development in male and female mice by triggering a PPAR-α-dependent reprogramming of local core metabolism from aerobic glycolysis, which is transiently enhanced after end-organ damage, to mitochondrial respiration. The results identify NAAA as a crucial control node in the transition to chronic pain and a molecular target for disease-modifying medicines
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