118,960 research outputs found
Molecular Dynamics simulation of sucrose coated and trehalose coated carboxy-myoglobin
No full textWe performed a room temperature
molecular dynamics (MD) simulation on a system
containing 1 carboxy-myoglobin (MbCO) molecule
in a sucrose–water matrix of identical composition
(89% [sucrose/(sucrose water)] w/w) as for a previous
trehalose–water–MbCO simulation (Cottone et
al., Biophys J 2001;80:931–938). Results show that, as
for trehalose, the amplitude of protein atomic meansquare
fluctuations, on the nanosecond timescale, is
reduced with respect to aqueous solutions also in
sucrose. A detailed comparison as a function of
residue number evidences mobility differences along
the protein backbone, which can be related to a
different efficacy in bioprotection. Different heme
pocket structures are observed in the 2 systems. The
joint distribution of the magnitude of the electric
field at the CO oxygen atom and of the angle between
the field and the CO unit vector shows a
secondary maximum in sucrose, absent in trehalose.
This can explain the CO stretching band profile (A
substates distribution) differences evidenced by infrared
spectroscopy in sucrose- and trehalose-coated
MbCO(Giuffrida et al., J Phys ChemB2004;108:15415–
15421), and in particular the appearance of a further
substate in sucrose. Analysis of hydrogen bonds at the
protein–solvent interface shows that the fraction of
water molecules shared between the protein and the
sugar is lower in sucrose than in trehalose, in spite of
a larger number of water molecules bound to the
protein in the former system, thus indicating a lower
protein–matrix coupling, as recently observed by Fourier
transform infrared (FTIR) experiments (Giuffrida
et al., J Phys Chem B 2004;108:15415–15421)
Memorie d’un Educatore, par Santi Giuffrida ; Catane, chez Nicolò Giannotta, libraire-éditeur, 1885
No full textL. B. H. Memorie d’un Educatore, par Santi Giuffrida ; Catane, chez Nicolò Giannotta, libraire-éditeur, 1885. In: La revue pédagogique, tome 8, Janvier-Juin 1886. pp. 181-182
Action of L-acetylcarnitine on age-dependent modifications of mitochondrial membrane proteins from rat cerebellum
No full textProtein patterns of mitochondrial outer membrane, inner membrane, and matrix from non-synaptic (free) mitochondria from rat cerebellum at different ages (4, 8, 12, 16, 20, and 24 months) were analyzed by gel electrophoresis. Acute L-acetylcarnitine treatment was performed by a single i.p. injection (100 mg/kg body weight) of the substance 60 min before the sacrifice of the animals. Different age-dependent changes were obtained for the proteins of the three fractions. The amount of some protein subunits increased and/or decreased after drug treatment. In particular, protein composition of the inner mitochondrial membrane showed significant age-related modifications. This result probably indicates differences in protein synthesis and/or turnover rates in the various mitochondrial compartments during aging. Acute L-acetylcarnitine treatment caused: a high increase in the amount of one inner membrane protein with Mw 16 kDa, at all the ages studied; a decrease in the amount of many other inner membrane proteins; modifications of some matrix proteins. Our results show that in vivo administration of L-acetylcarnitine affects mainly the inner membrane protein composition of cerebellar mitochondri
Light-induced protein-matrix uncoupling and protein relaxation in dry samples of trehalose coated MbCO at room temperature
No full textIn humid samples of trehalose-coated carboxy-myoglobin (MbCO), thermally driven conformational relaxation takes place after photodissociation of the carbon monoxide (CO) molecule at room temperature. In such samples, because of the extreme viscosity of the external matrix, photodissociated CO cannot diffuse out of the protein and explores the whole (proximal and distal side) heme pocket, experiencing averaged protein heme pocket structures, as a results of the presence of Brownian motions. At variance, in very dry samples, a lower portion of the photodissociated CO diffuses from the distal to the proximal heme pocket side probing in nonaveraged structures. We revisit here the flash photolysis data by Librizzi et al. (2002) and report on new, room temperature experiments in MbCO-trehalose samples, shortly illuminated prior the laser pulse. In dry samples, pre-illumination increased the diffusion of CO from the distal to the proximal heme pocket side, which resulted in less structure than in non-pre-illuminated samples. Such an effect, which is absent in humid samples, stems from a decoupling of the protein internal degrees of freedom from those of the external water-sugar matrix. We suggest that such a decoupling can be brought about by the continuous attempts performed by the protein during pre-illumination to undergo relaxation toward the photodissociated deoxy state. This, in turn, causes a collapse in the hydrogen bond network, which connects the protein surface to the water-sugar matrix, as reported by Cottone et al. (2002) and Giuffrida et al. (2003). In the conclusion section, we discuss the possible involvement of the processes invoked to rationalize the present data, in the function of macromolecules and interactions in living cells
Pasquale Giuffrida. Principídi Sintassi latina. Concetto e funzione del modo. (R. Università di Torino. Pubblicazioni della facoltà di Magistero, I, 3)
No full textRochus L. Pasquale Giuffrida. Principídi Sintassi latina. Concetto e funzione del modo. (R. Università di Torino. Pubblicazioni della facoltà di Magistero, I, 3). In: L'antiquité classique, Tome 9, fasc. 1, 1940. pp. 170-171
Decreto “Semplifica Italia” e spending review: la razionalizzazione delle misure di sostegno finanziario per gli interventi conservativi sui beni culturali
No full textL’Autore illustra il contenuto di alcune disposizioni relative alla materia dei beni culturali incluse nel decreto c.d. “Semplifica Italia” (d.l. 9 febbraio 2012, n. 5, conv. nella l. 4 aprile 2012, n. 35). L’Autore si sofferma, in particolare, sull’art. 42 di detto decreto, evidenziando le criticità che tale disposizione pone per gli interventi conservativi volontari sui beni culturali, anche alla luce del decreto sulla Spending review (d.l. 6 luglio 2012 n. 95, conv. nella l. 7 agosto 2012, n. 135) e del c.d. “d.d.l. Semplificazioni bis”
Decreto «Semplifica Italia» e spending review: la razionalizzazione delle misure di sostegno finanziario per gli interventi conservativi sui beni culturali
No full textL’Autore illustra il contenuto di alcune disposizioni relative alla materia dei beni culturali incluse nel decreto c.d. “Semplifica Italia” (d.l. 9 febbraio 2012, n. 5, conv. nella l. 4 aprile 2012, n. 35). L’Autore si sofferma, in particolare, sull’art. 42 di detto decreto, evidenziando le criticità che tale disposizione pone per gli interventi conservativi volontari sui beni culturali, anche alla luce del decreto sulla Spending review (d.l. 6 luglio 2012 n. 95, conv. nella l. 7 agosto 2012, n. 135) e del c.d. “d.d.l. Semplificazioni bis”
A YOLOv2 convolutional neural network-based Human-Machine Interface for the control of assistive robotic manipulators
No full textDuring the last years, the mobility of people with upper limb disabilities and constrained on power wheelchairs is empowered by robotic arms. Nowadays, even though modern manipulators offer a high number of functionalities, some users cannot exploit all those potentialities due to their reduced manual skills, even if capable of driving the wheelchair by means of proper Human-Machine Interface (HMI). Owing to that, this work proposes a low-cost manipulator realizing only simple tasks and controllable by three different graphical HMI. The latter are empowered using a You Only Look Once (YOLO) v2 Convolutional Neural Network that analyzes the video stream generated by a camera placed on the robotic arm end-effector and recognizes the objects with which the user can interact. Such objects are shown to the user in the HMI surrounded by a bounding box. When the user selects one of the recognized objects, the target position information is exploited by an automatic close-feedback algorithm which leads the manipulator to automatically perform the desired task. A test procedure showed that the accuracy in reaching the desired target is 78%. The produced HMIs were appreciated by different user categories, obtaining a mean score of 8.13/10
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