Search results for " Gradient"
showing 10 items of 575 documents
Comparative lipidomics and proteomics analysis of platelet lipid rafts using different detergents
2016
Lipid rafts play a pivotal role in physiological functions of platelets. Their isolation using nonionic mild detergents is considered as the gold standard method, but there is no consensual detergent for lipid raft studies. We aimed to investigate which detergent is the most suitable for lipid raft isolation from platelet membrane, based on lipidomics and proteomics analysis. Platelets were obtained from healthy donors. Twelve sucrose fractions were extracted by three different detergents, namely Brij 35, Lubrol WX, and Triton X100, at 0.05% and 1%. After lipidomics analysis and determination of fractions enriched in cholesterol (Ch) and sphingomyelin (SM), proteomics analysis was performed…
Stress gradient versus strain gradient constitutive models within elasticity
2014
Abstract A stress gradient elasticity theory is developed which is based on the Eringen method to address nonlocal elasticity by means of differential equations. By suitable thermodynamics arguments (involving the free enthalpy instead of the free internal energy), the restrictions on the related constitutive equations are determined, which include the well-known Eringen stress gradient constitutive equations, as well as the associated (so far uncertain) boundary conditions. The proposed theory exhibits complementary characters with respect to the analogous strain gradient elasticity theory. The associated boundary-value problem is shown to admit a unique solution characterized by a Helling…
Bounded and unbounded solutions for a class of quasi-linear elliptic problems with a quadratic gradient term
2001
Abstract Our aim in this article is to study the following nonlinear elliptic Dirichlet problem: − div [a(x,u)·∇u]+b(x,u,∇u)=f, in Ω; u=0, on ∂Ω; where Ω is a bounded open subset of RN, with N>2, f∈L m (Ω) . Under wide conditions on functions a and b, we prove that there exists a type of solution for this problem; this is a bounded weak solution for m>N/2, and an unbounded entropy solution for N/2>m⩾2N/(N+2). Moreover, we show when this entropy solution is a weak one and when can be taken as test function in the weak formulation. We also study the summability of the solutions.
GREEN ENERGY HARVESTING FROM CONCENTRATED SALTWORKS BITTERNS BY REVERSE ELECTRODIALYSIS
2022
Concentrated bitterns discharged from saltworks have extremely high salinity, often up to 300 g/L, thus their direct disposal not only can have harmful effect on the environment, but also generates a depletion of a potential resource of renewable energy. Here, reverse electrodialysis (RED), an emerging electrochemical membrane process, is introduced to capture the salinity gradient power (SGP) intrinsically conveyed by these bitterns also aiming at the reduction of concentrated salty water disposal. A RED unit at the laboratory scale has been adopted to study the SGP potential with different ion exchange membrane and different operating conditions. In particular, membranes supplied by Fujif…
Influence of the Richardson number on EM force driven flow structures in square-shaped crucible
2014
Abstract This study is devoted to the experimental investigation of the turbulent melt motion in a square crucible where the flow is created by Lorentz forces generated by an external AC magnetic field. As a strong vertical thermal gradient is present in melt during a directional solidification process, a stratification effect takes place and motion in the vertical direction is damped by buoyancy forces. Such a situation arises if density of fluid layers decreases with height. Experimental velocity and temperature measurements are conducted. Transient effects, like collapse of stratification, are observed experimentally. The significance of stratification in the directional solidification m…
Degassing at the Volcanic/Geothermal System of Kos (Greece): Geochemical Characterization of the Released Gases and CO2 Output Estimation
2019
Forty-five gas samples have been collected from natural gas manifestations at the island of Kos—the majority of which are found underwater along the southern coast of the island. On land, two anomalous degassing areas have been recognized. These areas are mainly characterized by the lack of vegetation and after long dry periods by the presence of sulfate salt efflorescence. Carbon dioxide is the prevailing gas species (ranging from 88 to 99%), while minor amounts of N2 (up to 7.5%) and CH4 (up to 2.1%) are also present. Significant contents of H2 (up to 0.2%) and H2S (up to 0.3%) are found in the on-land manifestations. Only one of the underwater manifestations is generally rich in N2 (up t…
The geological CO2degassing history of a long-lived caldera
2015
The majority of the ~100 Holocene calderas on Earth host vigorously active hydrothermal systems, the heat and volatile budgets of which are sustained by degassing of deeply stored magma. Calderas may thus contribute a nontrivial, although poorly quantified, fraction of the global budget of magmatic volatiles such as CO2. Here we use original isotopic a d petrological results from Campi Flegrei volcano, Italy, to propose that hydrothermal calcites are natural mineral archives for the magmatic CO2 that reacted with reservoir rocks during the geological history of a caldera. We show that Campi Flegrei calcites, identified in core samples extracted from 3-km-deep geothermal wells, formed at iso…
Fluid geochemistry in a low-enthalpy geothermal field along a sector of southern Apennines chain (Italy)
2020
Abstract The chemical and isotopic features of the fluids (water and gases) in the Lucane thermal area (southern Italy) have been investigated in order to verify their origin, water temperature in the geothermal reservoir, and to recognize the main natural processes concerning the water composition during ascent towards the surface. The Lucane geothermal system is placed in the southern sector of the Apennines chains, a seismically active area, close to the southern base of the Mt. Alpi carbonate massif. Along the study area, two main sets of high-angle faults form an almost orthogonal fault system that, as suggested by local structural geology, acts as a preferential pathway for uprising d…
P11.09 Pan-RTK inhibition of sLRIG1 mediates AXL downregulation in Glioblastoma
2019
Abstract INTRODUCTION Aberrant regulation of receptor tyrosine kinase (RTK) activity is characteristic of Glioblastoma (GBM). However, RTK-based targeted therapies have been largely unsuccessful in GBM patients, partially due to the complexity and redundance of RTK signaling. LRIG1 (Leucine-rich Repeats and ImmunoGlobulindomains protein 1) is known as an endogenous inhibitor of epidermal growth factor receptor (EGFR) during health and disease, however its mechanism of action is poorly understood. We previously showed that the soluble form of LRIG1 potently inhibits of GBM growth in vivo, irrespective of EGFR expression level and status, suggesting the involvement of other RTKs. Here, we aim…
Socioeconomic Environment and Survival in Patients with Digestive Cancers: A French Population-Based Study
2021
Simple Summary Studies investigating the social gradient in digestive cancer survival are scarce, and the statistical methods used do not always consider important assumptions in survival analysis for adequate assessment. Using an ecological index (European Deprivation Index), we found a negative impact of social environment in digestive cancers net survival (especially for esophagus, stomach, bile ducts among females; colon and rectum for both sexes) and provided insight into how this social gradient in cancer survival builds up, and at what time of follow-up it appears. These results can guide clinical practice/public health actions to address social inequalities in survival by targeting …