Publications UniTS
URI permanente per questa collezione
Sfogliare
Immissioni recenti
1 - 5 di 97832
-
-
PubblicazioneCucurbituril–Gold Nanoparticle Assemblies for Aqueous Oxime Formation Catalysis( 2025)Efficient substrate binding and spatial organization are critical for enzyme-like catalysis. This study examines a nanoparticle-based catalytic platform in which cucurbit[7]uril macrocycles are integrated into negatively charged gold nanoparticle monolayers. The resulting supramolecular constructs, referred to as “suprazymes,” catalyze the formation of oximes from aldehydes and hydroxylamine in water. By systematically varying substrate charge, size, and structure, as well as nanoparticle curvature and monolayer composition, we identify key structural features that influence catalysis. A suprazyme with phosphonate-terminated ligands achieves an over 2400-fold rate acceleration relative to the uncatalyzed reaction. These findings reveal design principles for engineering advanced nanoparticle-based enzyme mimics and provide a framework for their development.
-
PubblicazioneExpression of Properdin, the positive regulator of the Complement Alternative Pathway, at the fetal-maternal interface in Preeclampsia( 2026)Introduction: Aberrant complement activation can cause damage to newly formed fetal-derived structures and excessive inflammatory response at the feto-maternal interface, contributing to pregnancy-related complications, including preeclampsia (PE), which is one of the most severe pathologies in new-borns. Properdin is the only known positive regulator of the complement alternative pathway, as it stabilizes the inherently labile C3bBb complex and amplifies its activity. This study describes the presence of properdin in PE and investigates its role in the pathogenesis. Methods: We examined the distribution and expression of properdin at both the transcript and protein levels in term placental tissue, serum, placental syncytiotrophoblast microvesicles (STBMs), and circulating placental exosomes from PE women compared to healthy mothers, using RT-qPCR, western blot, immunohistochemistry, transmission electron microscopy (TEM), and immunofluorescence. To link properdin levels with alternative pathway complement factors, we also assessed the expression of C3 and C5. Results: PE placentae showed significantly higher properdin, C3 and C5 at transcript as well as protein levels compared to healthy placentae. Conversely, properdin levels in serum, STBMs, and circulating placental exosomes were lower in PE compared to healthy pregnancies. Immunohistochemical analysis revealed properdin distribution throughout the PE placentae, with higher concentrations at the syncytial knots containing pyknotic nuclei were observed via TEM, along with elevated levels of cleaved caspase 3. Discussion: Thus, properdin was significantly upregulated in the PE placentae, along with C3 and C5, and might be associated with the apoptotic nuclei inside syncytial knots. This evidence suggests that properdin may trigger complement-mediated damage to the placental barrier, exacerbating the development of PE placentae.
-
PubblicazioneAnalyzing fatigue in dynamic exercise through electromyography signals and similarity metrics( 2025)Electromyography (EMG) is a technique that registers the electrical activity from the muscle; one application for this kind of signal is muscle fatigue analysis, which can be defined as the clue of losing muscle strength during physical activities. These activities can involve isometric or dynamic contractions, whereas, for the last one, there is no consensus about the more precise technique for muscle fatigue analysis. This work aims to compare three different analysis techniques to study muscle fatigue using EMG signals recorded during a pedaling exercise named Wingate test (dynamic contractions): median frequency (MDF), correlation coefficient (CC), and mutual information (MI). The techniques were applied in the frequency domain and, for CC and MI, were observed the similarity between the end and beginning of the signal using two kinds of references: fixed and variable. If the difference between these parts is identified using the references, it successfully identifies muscle fatigue. Comparing the results, CC and MI got better results than MDF, which reached 70.2% of the expected result, which we consider as indicative of fatigue. The results with CC and MI were more satisfactory: for fixed reference, CC got 77.2% of indicative of fatigue and 94.7% with MI. Variable reference got the best results: CC got approximately 98.2% and MI 96.5%, respectively.
-
PubblicazioneHold or hurry? Speed of imitation of rivals' innovations in changing technological landscapes( 2026)Firms seeking fast-mover advantages often confront a critical challenge: not only whether to imitate rivals' innovations but also how quickly to do so. Fast imitation, however, entails risks, particularly in highly uncertain environments. By bridging information-based and rivalry-based theories of imitation with the technological change literature, we investigate how firms adjust their speed of imitation of rivals' technological innovations during periods of technological transition and technological stability. Using a database of 9060 mobile phones and 156 mobile-phone-related technological innovations introduced from 1992 to 2019, we find that a firm's speed of imitation is lower during periods of technological transition following a technological discontinuity compared to periods of technological stability where a dominant design is established. Furthermore, we find that the relationship between technological transitions and a firm's speed of imitation is shaped by three moderating factors: the firm's pioneering orientation, the relative market share position of the technology pioneer, and the visibility of the technological innovation. Our study contributes to the imitation and technological change literature by providing a nuanced understanding of the trade-offs associated with speed of imitation in the context of industry-wide technological shifts.