Search results for "Static"

Protein diffusion through charged nanopores with different radii at low ionic strength

2014

[EN] The diffusion of two similar molecular weight proteins, bovine serum albumin (BSA) and bovine haemoglobin (BHb), through nanoporous charged membranes with a wide range of pore radii is studied at low ionic strength. The effects of the solution pH and the membrane pore diameter on the pore permeability allow quantifying the electrostatic interaction between the chargedpore and the protein. Because of the large screening Debye length, both surface and bulk diffusion occur simultaneously. By increasing the pore diameter, the permeability tends to the bulk self-diffusion coefficient for each protein. By decreasing the pore diameter, the charges on the pore surface electrostatically hinder …

Heterogeneity at the Glass Transition:  Translational and Rotational Self-Diffusion

1997

Self-diffusion coefficients, D, have been measured in the glass forming liquids salol, glycerol, phenolphthaleine dimethyl ether (PDE), cresolphthaleine dimethyl ether (CDE), and ααβ-trinaphthylbenzene (TNB) in the supercooled regime. The NMR static magnetic field gradient technique was applied where D >10-14 m2 s-1 can be attained. The results are similar to previous diffusion experiments where an enhancement of translational diffusion was found in comparison with rotational diffusion and shear viscosity. Various models of spatial heterogeneity are related to a phenomenological environmental fluctuation model in view of recent diffusion and relaxation data close to the glass transition.

A New Metaheuristic for the Vehicle Routing Problem with Split Demands

2007

In this paper we present a metaheuristic procedure constructed for the special case of the Vehicle Routing Problem in which the demands of the clients can be split, i.e., any client can be serviced by more than one vehicle. The proposed algorithm, based on the scatter search methodology, produces a feasible solution using the minimum number of vehicles. The results obtained compare with the best results known up to date on a set of instances previously published in the literature.

Single intense prenatal stress reduce behavioural suppression in an operant conflict paradigm in the adult progeny. Influence of Metyrapone administr…

2008

Stressors presented during late prenatal period can have long-term effects on offspring behaviour (1). Indeed we showed that in the rat progeny a single immobilization procedure at gestational day 16 enhances spatial learning in a non-aversive, rewarded-facilitated learning task, the Can Test, and decreases anxiety-like behaviour in the elevated plus maze (2). In this study, we wanted to investigate: (i) the effects of a single prenatal immobilization-stress on the operant conflict task (OCT), an anxiety-related procedure, in which positively reinforced responses are suppressed by contingent punishment (3); (ii) the expression of mineralcorticoid and glucocorticoid receptors (MRs, GRs) in t…

Benign Prostatic Hyperplasia: Correlations between Receptor Density and Binding Affinity of 1-Adrenoceptors and Several Clinical Parameters

2002

The aim of the study was to determine whether relations do exist between the concentration and activity of 1-adrenoceptors, both inside the prostatic adenoma and the periurethral zone corresponding to the bladder neck, and clinical and biological parameters such as symptoms, evaluated by the American Urological Association (AUA) score, age, weight of the prostate, PSA, and the flow rate. Twenty patients with symptomatic benign prostatic hyperplasia were selected for an open prostatectomy. One gram of tissue was dissected from inside the adenoma and 1 g from the periurethral zone corresponding to the bladder neck. The 1-adrenoceptors were evaluated for the apparent dissociation constant (Kd)…

Analysis of UGT1A1*28 and DPYD*2A polymorphisms in Sicilians patients with metastatic colorectal cancer treated with Irinotecan and 5-fluorouracil.

2013

Structural and Dynamic Disturbances Revealed by Molecular Dynamics Simulations Predict the Impact on Function of CCT5 Chaperonin Mutations Associated…

2023

Mutations in genes encoding molecular chaperones, for instance the genes encoding the subunits of the chaperonin CCT (chaperonin containing TCP-1, also known as TRiC), are associated with rare neurodegenerative disorders. Using a classical molecular dynamics approach, we investigated the occurrence of conformational changes and differences in physicochemical properties of the CCT5 mutations His147Arg and Leu224Val associated with a sensory and a motor distal neuropathy, respectively. The apical domain of both variants was substantially but differently affected by the mutations, although these were in other domains. The distribution of hydrogen bonds and electrostatic potentials on the surfa…

Organic Salts as Tectons for Self-assembly Processes in Solution

2022

The literature, covering the last decade, about the self-assembly processes of organic salts in conventional solvents was analyzed. In particular, data reported about imidazolium and ammonium salts have been considered. The analysis shows that these processes are highly determined by structural features of the salts. Indeed, besides the nature of the cationic head, features of the alkyl chain borne on the cation structure and its possible functionalization, as well as the nature of the anion play a pivotal role. These factors determine not only the nature of the solvent in which the process occurs but also the nature of the self-assembly mechanism. Consequently, the structure tunability of …

Static Light Scattering as a tool to control extruded liposomes concentration: A novel physicist-friendly approach

Temperature and density structure of hot and cool loops derived from the analysis of TRACE data

2002

We address the plasma structuring both across and along the magnetic field in two sets of solar coronal loops, observed with TRACE in the 17lÅ and 195Å passbands. We derive, after proper background removal, the density stratification and the thermal structure of the plasma in the fibrils forming the loops with two techniques: a) filter ratio diagnostic (195 Å/171 Å) and b) modeling intensity profiles along the fibrils with hydrostatic models. We find evidence of a hot fibril (T ∼ 5·106 K), with temperature and density stratification well-described with a typical non-isothermal hydrostatic loop model, and evidence of rather cold fibrils (T ∼ 2 · 105 K), isothermal and probably in dynamic con…