2,339 research outputs found
Development of independent walking and gait stability in infants using inertial sensors
No full textDespite the number of studies that analyzed the development of independent walking in literature, the number of infants included was always small and only few studies performed longitudinal observations. The aim of the present study was to collect longitudinally data from a large group of infants (>20) using inertial sensors over a 6-months period after the onset of independent walking. This database will allow evaluating the changes in gait temporal parameters, stability and coordination at the beginning of independent walking. Moreover, it will permit to observe when and how the development of pendulum mechanism occurs. Since there is not a commonly accepted way to define or quantify locomotor stability, the collected data will permit also to apply and evaluate the stability indexes proposed in literature, looking for the index that better describes infant locomotor stability and its relation to infant risk of falls
Tetrazolati come leganti per complessi luminescenti di Ru(II) e Ir(III)
No full textLo studio della chimica di coordinazione dei composti tetrazolici (R-CN4H) rappresenta uno degli obbiettivi primari dell’attività scientifica svolta nel nostro gruppo negli ultimi anni. Le fasi iniziali di questa ricerca sono state incentrate sulla preparazione di alcuni dei primi esempi di complessi organometallici di Fe(II) recanti derivati di tipo 5-aril tetrazolico nella sfera di coordinazione.1 In seguito, le peculiari caratteristiche strutturali ed elettroniche mostrate dai leganti tetrazolici coordinati hanno costituito la spinta fondamentale per la loro coordinazione a diversi frammenti metallici redox e fotoattivi, quali complessi polipiridinici di Ru(II) e derivati ciclometallati di Ir(III). I risultanti complessi mono e dinucleari hanno rivelato interessanti proprietà elettrochimiche e buone performances emittive, sia di natura foto che elettroindotta.2,3 In generale, i buoni risultati ottenuti dallo studio dei complessi tetrazolici di Ru(II) e di Ir(III) costituiscono la premessa per il più recente sviluppo della nostra linea di ricerca, che è rappresentata dalla sintesi e dallo studio di nuovi complessi eterodinucleari misti Ru(II)-Ir(III) in cui i centri metallici sono connessi da leganti tetrazolici a ponte.
Verranno discusse la sintesi, le caratteristiche elettrochimiche e le proprietà fotoemittive dei complessi in questione.
Bibliografia
[1] Palazzi, A.; Stagni, S.; J. Organomet. Chem. 2005, 690, 2052 e riferimenti ivi citati;
[2] Stagni, S.; Palazzi, A.; Zacchini, S.; Ballarin, B.; Marcaccio, M.; Paolucci F.; Bruno C.; Monari M.; Carano M.; Bard, A.J. Inorg. Chem. 2006, 45, 695;
[3] Zanarini, S.; Bard, A.J.; Marcaccio, M.; Palazzi, A;. Paolucci, F.; Stagni, S. J. Phys. Chem. B, 2006, 110, 22551
Objective assessment of movement competence in children using wearable sensors: An instrumented version of the TGMD-2 locomotor subtest
No full textMovement competence (MC) is defined as the development of sufficient skill to assure successful performance in different physical activities. Monitoring children MC during maturation is fundamental to detect early minor delays and define effective intervention. To this purpose, several MC assessment batteries are available. When evaluating movement strategies, with the aim of identifying specific skill components that may need improving, widespread MC assessment is limited by high time consumption for scoring and the need for trained operators to ensure reliability. This work aims to facilitate and support the assessment by designing, implementing and validating an instrumented version of the TGMD-2 locomotor subtest based on Inertial Measurement Units (IMUs) to quantify MC in children rapidly and objectively. 45 typically developing children, aged 6–10, performed the TGMD-2 locomotor subtest (six skills). During the tests, children wore five IMUs mounted on lower back, on ankles and on wrists. Sensor and video recordings of the tests were collected. Three expert evaluators performed the standard assessment of TGMD-2. Using theoretical and modelling approaches, algorithms were implemented to automatically score children tests based on IMUs’ data. The automatic assessment, compared to the standard one, showed an agreement higher than 87% on average on the entire group for each skill and a reduction of time for scoring from 15 to 2 min per participant. Results support the use of IMUs for MC assessment: this approach will allow improving the usability of MC assessment, supporting objectively evaluator decisions and reducing time requirement for the evaluation of large groups
Epigallocatechin-3-gallate: Linking the neurogenesis, hippocampus, and Down syndrome
No full textEpigallocatechin-3-gallate (EGCG) is thought to largely mediate the beneficial effects of green tea on the brain. In addition to its antioxidant and metal chelator actions, EGCG is an inhibitor of DYRK1A, one of the triplicated genes in Down syndrome (DS), a genetic condition caused by triplication of chromosome 21. Based on the key role of DYRK1A in the neurodevelopmental alterations that characterize DS, a few preclinical and two clinical studies have sought to establish whether EGCG may be a suitable therapy for DS. Some studies in the Ts65Dn model of DS show that EGCG improves hippocampal development and hippocampus-dependent cognitive performance, although other studies failed to find any behavioral improvement. The clinical trials show that EGCG ameliorates, albeit transiently, some aspects of cognition. These results give hope that EGCG may be of benefit for DS, although critical issues such as optimization of dose, route, and timing of administration need to be further investigated in thorough preclinical studies
Edge dislocation inside a lamellar inhomogeneity.
No full textThe elastic field induced by an edge dislocation inside a lamellar inhomogeneity is evaluated, the resulting formulas applying as well to an internal stress source within a lamella in generalized plane stress or plane strain, and the Peach-Koehler force on the dislocation derived. The fatures of the interaction are determined by the mismatch in both the shear moduli and the Poisson's ratios of lamella and matrix. The differences from the case of an edge dislocation in either a free or a clamped strip turn out to be mainly of a quantitative nature and to become relevant when the lamella is up to one order of magnitude harder or softer than the matrix
Interaction between an edge dislocation and a lamellar inhomogeneity with a slipping interface
No full textThe plane elasticity problem of an internal stress source located near a lamellar inhomogeneity is considered. It is assumed that the lamella matrix interface does not transmit tangential displacements or shear tractions (slipping interface). The elastic field is given in terms of the source bulk field and one parameter formed from the elastic constants. The image force on an edge dislocation near the lamella is calculated and discussed. A dislocation stable equilibrium position exists in a do¬main of elastic constants and Burgers vector directions. This result is characteristic of the interaction with a slipping lamellar inhomogeneity having finite thickness
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