3,873 research outputs found
Regularity of solutions of elliptic equations in divergence form in modified local generalized Morrey spaces
AbstractAim of this paper is to prove regularity results, in some Modified Local Generalized Morrey Spaces, for the first derivatives of the solutions of a divergence elliptic second order equation of the formLu:=âi,j=1naij(x)uxixj=â·f,for almost allxâΩwhere the coefficientsaijbelong to the Central (that is, Local) Sarason class CVMO andfis assumed to be in some Modified Local Generalized Morrey SpacesLM~{x0}p,Ï. Heart of the paper is to use an explicit representation formula for the first derivatives of the solutions of the elliptic equation in divergence form, in terms of singular integral operators and commutators with CalderĂłnâZygmund kernels. Combining the representation formula with some Morrey-type estimates for each operator that appears in it, we derive several regularity results
Investigation on the composition of agaroseâcollagen i blended hydrogels as matrices for the growth of spheroids from breast cancer cell lines
Three-dimensional (3D) cell culture systems mimic the structural complexity of the tissue microenvironment and are gaining increasing importance as they resemble the extracellular matrix (ECM)âcell and cellâcell physical interactions occurring in vivo. Several scaffold-based culture systems have been already proposed as valuable tools for large-scale production of spheroids, but they often suffer of poor reproducibility or high costs of production. In this work, we present a reliable 3D culture system based on collagen I-blended agarose hydrogels and show how the variation in the agarose percentage affects the physical and mechanical properties of the resulting hydrogel. The influence of the different physical and mechanical properties of the blended hydrogels on the growth, size, morphology, and cell motility of the spheroids obtained by culturing three different breast cancer cell lines (MCF-7, MDA-MB-361, and MDA-MB-231) was also evaluated. As proof of concept, the cisplatin penetration and its cytotoxic effect on the tumor spheroids as function of the hydrogel stiffness were also investigated. Noteworthily, the possibility to recover the spheroids from the hydrogels for further processing and other biological studies has been considered. This feature, in addition to the ease of preparation, the lack of cross-linking chemistry and the high re-producibility, makes this hydrogel a reliable biomimetic matrix for the growth of 3D cell structures
One-loop calculations of hyperon polarizabilities under the large N_c consistency condition
The spin-averaged electromagnetic polarizabilities of the hyperons
and are calculated within the one-loop approximation by use of the
dispersion theory. The photon and meson couplings to hyperons are determined so
as to satisfy the large N_c consistency condition. It is shown that in order
for the large N_c consistency condition to hold exotic hyperon states such as
with I=2 and J=3/2 are required in the calculation of the
magnetic polarizability of the state.Comment: 17 pages, REVTeX, no figure
Cytotoxic, antioxidant, and enzyme inhibitory properties of the traditional medicinal plant matthiola incana (L.) R. Br.
Matthiola incana (L.) R. Br. (Brassicaceae) is widely cultivated for ornamental purposes and utilized as a medicinal plant. In the present work, the hydroalcoholic extract from the aerial parts of this species has been evaluated in different bioassays in order to detect potential pharmacological applications. The cytotoxic capacity against the human colorectal adenocarcinoma (CaCo-2) and breast cancer (MCF-7) cell lines was tested using the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. The extract was investigated as a neuroprotective inhibitor of central nervous system (CNS) enzymes such as monoamine oxidase A, tyrosinase, acetylcholinesterase, and as a natural enzyme inhibitor of a-glucosidase and lipase involved in some metabolic disorders such as obesity or type 2 diabetes. The antioxidant ability was also evaluated in an enzymatic system (xanthine/xanthine oxidase assay). Results showed that the M. incana extract displayed moderate to low cytotoxicity vs. CaCo-2 cells. The extract acted as a superoxide radical scavenger and enzymatic inhibitor of monoamine oxidase A, tyrosinase, a-glucosidase, and lipase. The best results were found in the a-glucosidase assay, as M. incana hydroalcoholic extract was able to inhibit the enzyme a-glucosidase up to 100% without significant differences, compared to the antidiabetic drug acarbose. Matthiola incana has been demonstrated to exert different biological properties. These are important in order to consider this species as a source of bioactive compounds
Compton Scattering and the Spin Structure of the Nucleon at Low Energies
We analyze polarized Compton scattering which provides information on the
spin-structure of the nucleon. For scattering processes with photon energies up
to 100 MeV the spin-structure dependence can be encoded into four independent
parameters-the so-called spin-polarizabilities of the
nucleon, which we calculate within the framework of the "small scale expansion"
in SU(2) baryon chiral perturbation theory. Specific application is made to
"forward" and "backward" spin- polarizabilities.Comment: 8 pages revtex file, separation between pion-pole and regular
contributions detailed + minor wording changes, results and conclusions
unchange
Assessing cognitive function in neuromuscular diseases: A pilot study in a sample of children and adolescents
Central nervous system (CNS) involvement has been variously studied in pediatric neuromuscular disorders (NMDs). The primary goal of this study was to assess cognitive functioning in NMDs, and secondary aims were to investigate possible associations of cognitive impairment with motor impairment, neurodevelopmental delay, and genotype. This was a cross-sectional study of 43 pediatric patients, affected by six NMDs. Myotonic dystrophy type 1 (DM1) and glycogen storage disease type 2 (GSD2) patients had a delay on the Bayley-III scales. On Wechsler scales, DMD and DM1 patients showed lower FSIQ scores, with an intellectual disability (ID) in 27% and 50%, respectively. FSIQ was normal in Becker muscular dystrophy (BMD), GSD2, and hereditary motor sensory neuropathy (HMSN) patients, while higher individual scores were found in the spinal muscular atrophy (SMA) group. In the DM1 cohort, lower FSIQ correlated with worse motor performance (Ï = 0.84, p < 0.05), and delayed speech acquisition was associated with ID (p = 0.048), with worse cognitive impairment in the congenital than in the infantile form (p = 0.04). This study provides further evidence of CNS in some NMDs and reinforces the need to include cognitive assessment in protocols of care of selected pediatric NMDs
Determination of commercial animal and vegetable milksâ lipid profile and its correlation with cell viability and antioxidant activity on human intestinal caco-2 cells
Lipids from milk are important nutritional components, although their health effects, especially for animal milks, are still questioned. Four types of commercial milks, two semi-skimmed animal milks (bovine and goat) and two vegetable ones (soy and rice), along with their total and free lipid fractions recovered by sequential centrifugation or by ethyl acetate extraction, respectively, have been analyzed. A higher antioxidant ability, reported as Trolox equivalent antioxidant capacity, was found for all raw milks compared to that of rice. This trend was confirmed, except for soy milk, as ROS reduction in Caco-2 cells. The free lipid fraction was shown to have the highest antioxidant potential in both chemical and biological tests. Moreover, goat and soy raw milks positively regulated Caco-2 cell viability after an inflammatory stimulus. This effect was lost when their total lipid fraction was tested. Finally, only the free lipid fraction from rice milk preserved the Caco-2 viability after LPS stimulation. Our data demonstrated that the lipid profile of each milk, characterized by GC-MS analysis, could contribute to dictate its biological effects, and, although additional in vitro and in vivo studies are needed, they could support the literature re-evaluating the health effects of animal-based versus plant-based milks in the intestinal cellular model
A limit model for thermoelectric equations
We analyze the asymptotic behavior corresponding to the arbitrary high
conductivity of the heat in the thermoelectric devices. This work deals with a
steady-state multidimensional thermistor problem, considering the Joule effect
and both spatial and temperature dependent transport coefficients under some
real boundary conditions in accordance with the Seebeck-Peltier-Thomson
cross-effects. Our first purpose is that the existence of a weak solution holds
true under minimal assumptions on the data, as in particular nonsmooth domains.
Two existence results are studied under different assumptions on the electrical
conductivity. Their proofs are based on a fixed point argument, compactness
methods, and existence and regularity theory for elliptic scalar equations. The
second purpose is to show the existence of a limit model illustrating the
asymptotic situation.Comment: 20 page
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