55 research outputs found
Analyticity and criticality results for the eigenvalues of the biharmonic operator
We consider the eigenvalues of the biharmonic operator subject to several
homogeneous boundary conditions (Dirichlet, Neumann, Navier, Steklov). We show
that simple eigenvalues and elementary symmetric functions of multiple
eigenvalues are real analytic, and provide Hadamard-type formulas for the
corresponding shape derivatives. After recalling the known results in shape
optimization, we prove that balls are always critical domains under volume
constraint.Comment: To appear on the proceedings of the conference "Geometric Properties
for Parabolic and Elliptic PDE's - 4th Italian-Japanese Workshop" held in
Palinuro (Italy), May 25-29, 201
On a classical spectral optimization problem in linear elasticity
We consider a classical shape optimization problem for the eigenvalues of
elliptic operators with homogeneous boundary conditions on domains in the
-dimensional Euclidean space. We survey recent results concerning the
analytic dependence of the elementary symmetric functions of the eigenvalues
upon domain perturbation and the role of balls as critical points of such
functions subject to volume constraint. Our discussion concerns Dirichlet and
buckling-type problems for polyharmonic operators, the Neumann and the
intermediate problems for the biharmonic operator, the Lam\'{e} and the
Reissner-Mindlin systems.Comment: To appear in the proceedings of the workshop `New Trends in Shape
Optimization', Friedrich-Alexander Universit\"{a}t Erlangen-Nuremberg, 23-27
September 201
Conformational altered p53 affects neuronal function: relevance for the response to toxic insult and growth-associated protein 43 expression
The role of p53 in neurodegenerative diseases is essentially associated with neuronal death. Recently an alternative point of view is emerging, as altered p53 conformation and impaired protein function have been found in fibroblasts and blood cells derived from Alzheimer's disease patients. Here, using stable transfected SH-SY5Y cells overexpressing APP751wt (SY5Y-APP) we demonstrated that the expression of an unfolded p53 conformation compromised neuronal functionality. In particular, these cells showed (i) augmented expression of amyloid precursor protein (APP) and its metabolites, including the C-terminal fragments C99 and C83 and β-amyloid peptide (ii) high levels of oxidative markers, such as 4-hydroxy-2-nonenal Michael-adducts and 3-nitro-tyrosine and (iii) altered p53 conformation, mainly due to nitration of its tyrosine residues. The consequences of high-unfolded p53 expression resulted in loss of p53 pro-apoptotic activity, and reduction of growth-associated protein 43 (GAP-43) mRNA and protein levels. The role of unfolded p53 in cell death resistance and lack of GAP-43 transcription was demonstrated by ZnCl(2) treatment. Zinc supplementation reverted p53 wild-type tertiary structure, increased cells sensitivity to acute cytotoxic injury and GAP-43 levels in SY5Y-APP clone
Increased susceptibility to Chrysanthemum Yellows phytoplasma infection in Atcals7ko plants is accompanied by enhanced expression of carbohydrate transporters
Main conclusion: Loss of CALS7 appears to confer increased susceptibility to phytoplasma infection in Arabidopsis, altering expression of genes involved in sugar metabolism and membrane transport. Abstract: Callose deposition around sieve pores, under control of callose synthase 7 (CALS7), has been interpreted as a mechanical response to limit pathogen spread in phytoplasma-infected plants. Wild-type and Atcals7ko mutants were, therefore, employed to unveil the mode of involvement of CALS7 in the plant’s response to phytoplasma infection. The fresh weights of healthy and CY-(Chrysanthemum Yellows) phytoplasma-infected Arabidopsis wild type and mutant plants indicated two superimposed effects of the absence of CALS7: a partial impairment of photo-assimilate transport and a stimulated phytoplasma proliferation as illustrated by a significantly increased phytoplasma titre in Atcal7ko mutants. Further studies solely dealt with the effects of CALS7 absence on phytoplasma growth. Phytoplasma infection affected sieve-element substructure to a larger extent in mutants than in wild-type plants, which was also true for the levels of some free carbohydrates. Moreover, infection induced a similar upregulation of gene expression of enzymes involved in sucrose cleavage (AtSUS5, AtSUS6) and transmembrane transport (AtSWEET11) in mutants and wild-type plants, but an increased gene expression of carbohydrate transmembrane transporters (AtSWEET12, AtSTP13, AtSUC3) in infected mutants only. It remains still unclear how the absence of AtCALS7 leads to gene upregulation and how an increased intercellular mobility of carbohydrates and possibly effectors contributes to a higher susceptibility. It is also unclear if modified sieve-pore structures in mutants allow a better spread of phytoplasmas giving rise to higher titre
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SMART-1 Impact Ground-based campaign
Based on predictions of impact magnitude and cloud ejecta dynamics, we organized a SMART-1 ground-based observation campaign to perform coordinated measurements of the impact. Results from the coordinated multi-site campaign will be discussed
Evaluation of a large set of patients with Autoimmune Polyglandular Syndrome from a single reference centre in context of different classifications
Purpose: To characterize patients with APS and to propose a new approach for their follow-up. Query ID="Q1" Text="Please check the given names and familynames." Methods: Monocentric observational retrospective study enrolling patients referred to the Outpatients clinic of the Units of Endocrinology, Diabetology, Gastroenterology, Rheumatology and Clinical Immunology of our Hospital for Autoimmune diseases. Results: Among 9852 patients, 1174 (11.9%) [869 (73.9%) female] were diagnosed with APS. In 254 subjects, the diagnosis was made at first clinical evaluation (Group 1), all the other patients were diagnosed with a mean latency of 11.3 ± 10.6 years (Group 2). Group 1 and 2 were comparable for age at diagnosis (35.7 ± 16.3 vs. 40.4 ± 16.6 yrs, p =.698), but different in male/female ratio (81/173 vs 226/696, p =.019). In Group 2, 50% of patients developed the syndrome within 8 years of follow-up. A significant difference was found after subdividing the first clinical manifestation into the different outpatient clinic to which they referred (8.7 ± 8.0 vs. 13.4 ± 11.6 vs. 19.8 ± 8.7 vs. 7.4 ± 8.1 for endocrine, diabetic, rheumatologic, and gastroenterological diseases, respectively, p <.001). Conclusions: We described a large series of patients affected by APS according to splitters and lumpers. We propose a flowchart tailored for each specialist outpatient clinic taking care of the patients. Finally, we recommend regular reproductive system assessment due to the non-negligible risk of developing premature ovarian failure
Role of androgens in dhea-induced rack1 expression and cytokine modulation in monocytes
Conformational Altered p53 as an Early Marker of Oxidative Stress in Alzheimer's Disease
In order to study oxidative stress in peripheral cells of Alzheimer's disease (AD) patients, immortalized lymphocytes derived from two peculiar cohorts of patients, referring to early onset AD (EOSAD) and subjects harboured AD related mutation (ADmut), were used. Oxidative stress was evaluated measuring i) the typical oxidative markers, such as HNE Michel adducts, 3 Nitro-Tyrosine residues and protein carbonyl on protein extracts, ii) and the antioxidant capacity, following the enzymatic kinetic of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRD). We found that the signs of oxidative stress, measured as oxidative marker levels, were evident only in ADmut but not in EOSAD patients. However, oxidative imbalance in EOSAD as well as ADmut lymphocytes was underlined by a reduced SOD activity and GRD activity in both pathological groups in comparison with cells derived from healthy subjects. Furthermore, a redox modulated p53 protein was found conformational altered in both EOSAD and ADmut B lymphocytes in comparison with control cells. This conformational altered p53 isoform, named “unfolded p53”, was recognized by the use of two specific conformational anti-p53 antibodies. Immunoprecipitation experiments, performed with the monoclonal antibodies PAb1620 (that recognizes p53wt) and PAb240 (that is direct towards unfolded p53), and followed by the immunoblotting with anti-4-hydroxynonenal (HNE) and anti- 3-nitrotyrosine (3NT) antibodies, showed a preferential increase of nitrated tyrosine residues in unfolded p53 isoform comparing to p53 wt protein, in both ADmut and EOSAD. In addition, a correlation between unfolded p53 and SOD activity was further found. Thus this study suggests that ROS/RNS contributed to change of p53 tertiary structure and that unfolded p53 can be considered as an early marker of oxidative imbalance in these patients
Sicurezza sociale I aggiornamento
La voce enciclopedica tratteggia le linee evolutive del sistema di sicurezza sociale, alla luce dei testi normativi dell'ultimo decennio e della letteratura giuridica
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