Search results for "slip"
showing 10 items of 471 documents
Estudio de la variación a largo plazo de los parámetros bioquímicos metabólicos en pacientes con obesidad mórbida e intervenidos mediante bypass gást…
2015
INTRODUCCIÓN La Obesidad es ya uno de los mayores problemas de salud pública en los países occidentales y se prevé que en un futuro cercano sea una verdadera epidemia. La naturaleza de este problema no es estética, como es habitual que se valore en nuestro entorno social. Tiene un sinfín de repercusiones. Empezando por las comorbilidades metabólicas que la acompañan, las complicaciones osteoarticulares que desencadena o simplemente el rechazo social que muchas veces genera. Todo ello sumado, da lugar a una pérdida importante de esperanza de vida y de la calidad de la misma. La consecuencia fundamental de la Obesidad y que provoca el mayor riesgo de morbilidad y, sobre todo de mortalidad, es…
Oxidative stress and small, dense low-density lipoproteins: current and future perspectives
2019
Small, dense low-density lipoproteins (LDLs) are more susceptible to oxidation than their larger, more buoyant counterparts and therefore the biological modification of these LDL particles may, in part, be responsible for their atherogenic properties. Kotani et al. found that at multiple regression analysis there was an independent and significant inverse correlation between the mean LDL particle size and the oxidative stress status; notably, the authors adjusted not only for the traditional cardiovascular risk factors, but also for drug treatments. Higher levels of small, dense LDL concentrations significantly contribute to atherosclerosis, and lipoprotein size and subfractions may refine …
X-ray topographic study of solid-state polymerized poly-[1,2-bis-(p tolylsulphonyloxymethylene)-1-butene-3-inylene]
1976
Local extinction contrast effects have been observed in macroscopic polymer crystals, using Berg-Barrett X-ray topography. Results from as-polymerized crystals indicate that the crystals are perfect enough for defect regions to be imaged. As-polymerized crystals exhibited apparent defects lying along [021]. [010] slip traces in the (100) surface of a crystal were imaged; the slip system here appears to be consistent with (h01) [¯10h], forh, l ≠ 0 and [010] the chain direction.
Confinement-induced screening of hydrodynamic interactions and spinodal decomposition: Multiscale simulations of colloid-polymer mixtures
2012
Phase separation kinetics of a colloid-polymer mixture confined between two planar repulsive walls is studied by a multiscale simulation approach. Colloids and polymers are described by particles interacting with continuous potentials suitable for molecular-dynamics simulation, while hydrodynamic interactions mediated by solvent particles are accounted for by the multiparticle collision dynamics method. Varying the distance D between the walls and the character of the boundary conditions, the interplay of structure formation parallel and perpendicular to the walls is studied, and the effect of hydrodynamics on the growth of domain size ld(t) with time t is elucidated. Only for slip boundary…
Anisotropic Stick-slip friction of highly oriented thin films of poly(tetrafluoroethylene) at the molecular level
1996
Lateral force microscopy (LFM) studies of poly(tetrafluoroethylene) (PTFE) films with molecular resolution are reported. Thin PTFE layers with a high degree of orientation were obtained by pressing and sliding a block of polymer on a clean, heated muscovite mica substrate. LFM nanographs obtained on these films by scanning at directions between ca. 40 and 90° with respect to the film orientation direction, i.e. with respect to the direction of the polymer chains, showed a “stick-slip” type frictional motion of the LFM probe tip at the molecular level. The friction force observed at constant load decreased with decreasing scan angles. Chain-chain packing distances obtained by LFM and contact…
Hydrodynamic mechanisms of spinodal decomposition in confined colloid-polymer mixtures: A multiparticle collision dynamics study
2013
A multiscale model for a colloid-polymer mixture is developed. The colloids are described as point particles interacting with each other and with the polymers with strongly repulsive potentials, while polymers interact with each other with a softer potential. The fluid in the suspension is taken into account by the multiparticle collision dynamics method (MPC). Considering a slit geometry where the suspension is confined between parallel repulsive walls, different possibilities for the hydrodynamic boundary conditions (b.c.) at the walls (slip versus stick) are treated. Quenching experiments are considered, where the system volume is suddenly reduced (keeping the density of the solvent flui…
Analysis of the metabolic switch induced by the spirulina peptide SP6 in high fat diet ApoE-/-mice model: A direct infusion FT-ICR-MS based approach
2021
Atherosclerosis, dyslipidemia and hypertension are comorbid diseases often found in combination. Among different pharmacological approaches the employment of natural multifunctional peptides is an attractive option as side therapy. Mass spectrometry-based metabolomics provide valuable information on metabolic changes and can be useful to elucidate peptide pharmacodynamics. In this this work we performed a preliminary investigation on the potential effect of a recently characterized Spirulina platensis peptide named SP6 (GIVAGDVTPI) on the modulation of metabolism in a high fat diet ApoE-/- mice atherosclerotic model. A direct infusion Fourier transform ion cyclotron resonance mass spectrome…
3.9.1. Villagrazia di Carini (PA), [Sito 86]
2016
The materials found in the catacomb of Villagrazia di Carini consist essentially of African Red Slip Ware, coarse ware of probable African production and oil lamps, both Tripolitan and types Atlante VIII and X. Almost all the materials have been regularly published in the reports of the excavations carried out by the Pontificia Commissione di Archeologia Sacra and the Department of Cultural Heritage of the University of Palermo, from 2000 to date: a first catalogue have been published in the Proceedings of the IX National Congress of Christian Archeology (2007), followed by updates in Rivista di Archeologia Cristiana (2009) and in a recent study by E. Vitale about the territory of the Early…
Materiali ceramici di importazione africana dalla catacomba di Villagrazia di Carini. Un aggiornamento sulla circolazione nel territorio della eccles…
2012
Primo volume della Collana "Quaderni Digitali di Archeologia Postclassica". La catacomba di Villagrazia di Carini è uno dei principali monumenti del primo Cristianesimo siciliano, cimitero di una comunità agiata e aperta alle relazioni con l'area mediterranea. Lo studio proposto in questo volume, partendo dai dati relativi ai materiali ceramici restituiti dalla stratigrafia archeologica dei settori indagati dal 2000 al 2012, testimonia i rapporti commerciali intercorsi fra il territorio servito dalla presenza del complesso catacombale, coincidente con quello dell'ecclesia carinensis citata da Gregorio Magno, e l'Africa romana e protobizantina.
Interazione tra processi geomorfologici che coinvolgono il suolo e condizioni di rischio geoambientale
2010
Lo studio dei fenomeni di instabilità superficiale risulta di particolare interesse in quanto molto spesso tale tipologia di dissesto produce gravi danni alle strutture antropiche e, talvolta, anche perdite di vite umane. Nonostante la modesta massa di terreno mobilizzata, queste frane possiedono una elevata pericolosità dovuta principalmente alla loro forza d’urto; i danni più frequenti riguardano le strade ed i relativi muri in calcestruzzo o in pietra che subiscono forti spinte laterali che ne provocano il ribaltamento. In alcuni casi possono causare anche gravi lesioni agli edifici, sfondando i muri posti sulla traiettoria della massa in movimento, provocando anche delle vittime; esempi…