Mathematical and Asymptotic Analysis of Thermoelastic Shells in Normal Damped Response Contact

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] The purpose of this paper is twofold. We first provide the mathematical analysis of a dynamic contact problem in thermoelasticity, when the contact is governed by a normal damped response function and the constitutive thermoelastic law is given by the Duhamel-Neumann relation. Under suitable hypotheses on data and using a Faedo-Galerkin strategy, we show the existence and uniqueness of solution for this problem. Then, we study the particular case when the deformable body is, in fact, a shell and use asymptotic analysis to study the convergence to a 2D limit problem when the thickness tends to zero.This project has received funding from the European Union Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No 823731 CONMECH and grant MTM2016-78718-P by Ministerio de Economía Industria y Competitividad of Spain with the participation of FEDE

Asymptotic Analysis of a Problem for Dynamic Thermoelastic Shells in Normal Damped Response Contact

[Abstract] The purpose of this paper is twofold. We first provide the mathematical analysis of a dynamic contact problem in thermoelasticity, when the contact is governed by a normal damped response function and the constitutive thermoelastic law is given by the Duhamel-Neumann relation. Under suitable hypotheses on data and using a Faedo-Galerkin strategy, we show the existence and uniqueness of solution for this problem. We then study the particular case when the deformable body is, in fact, a shell and use asymptotic analysis to study the convergence to a 2D limit problem when the thickness tends to zero.[Resumo] En termoelasticidade, dado un problema de contacto entre una lámina tipo membrana elíptica e un obstáculo, estudamos a existencia de problema bidimensional límite cando o espesor tende a cero. Preséntase un teorema de converxencia para xustificar a bondade da aproximación.This project has received funding from the European Unions Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement Nº 823731 CONMECH and grant MTM2016-78718-P by Ministerio de Economía Industria y Competitividad of Spain with the participation of FEDE

The Effects of the Mediterranean Diet on Biomarkers of Vascular Wall Inflammation and Plaque Vulnerability in Subjects with High Risk for Cardiovascular Disease. A Randomized Trial

Adherence to the Mediterranean diet (MD) is associated with reduced morbidity and mortality due to cardiovascular disease. However, how the MD exerts its effects is not fully known. Aim: To assess the 12-month effects of two enhanced MDs compared to a low-fat diet on inflammatory biomarkers related to atherosclerosis and plaque vulnerability in a subcohort of the PREDIMED (Prevencion con Dieta Mediterranea) study. Methods: A total of 164 participants at high risk for cardiovascular disease were randomized into three diet groups: MD supplemented with 50 mL/d of extra virgin olive oil (MD+EVOO) or 30 g/d of nuts (MD+Nuts) and a low-fat diet. Changes in classical cardiovascular risk factors, inflammatory biomarkers of atherosclerosis and plaque vulnerability were measured after 12 months of intervention. Results: Compared to participants in the low-fat diet group, those receiving MD+EVOO and MD+Nuts showed a higher decrease in systolic (6 mmHg)and diastolic (3 mmHg) blood pressure (P = 0.02; both), as well as a reduction of 10% and 8% in LDL-cholesterol (P = 0.04), respectively. Patients in the MD+Nuts group showed a significant reduction of 34% in CD40 expression on monocyte surface compared to low-fat diet patients (P = 0.03). In addition, inflammatory biomarkers related to plaque instability such as C-reactive protein and interleukin-6 were reduced by 45% and 35% and 95% and 90% in the MD+EVOO and MD+Nuts groups, respectively (P<0.05; all) compared to the low-fat diet group. Likewise, sICAM and Pselectin were also reduced by 50% and 27%, respectively in the MD+ EVOO group (P = 0.04) and P-selectin by 19% in MD+Nuts group (P = 0.04) compared to the low-fat diet group. Conclusions: Adherence to the MD is associated with an increase in serum markers of atheroma plaque stability which may explain, at least in part, the protective role of MD against ischemic heart disease

Mediterranean Diet and Atherothrombosis Biomarkers: A Randomized Controlled Trial

Scope: To assess whether following a Mediterranean diet (MedDiet) improves atherothrombosis biomarkers in high cardiovascular risk individuals. Methods and results: In 358 random volunteers from the PREvención con DIeta MEDiterránea trial, the 1-year effects on atherothrombosis markers of an intervention with MedDiet, enriched with virgin olive oil (MedDiet-VOO; n = 120) or nuts (MedDiet-Nuts; n = 119) versus a low-fat control diet (n = 119), and whether large increments in MedDiet adherence (≥3 score points, versus compliance decreases) and intake changes in key food items are associated with 1-year differences in biomarkers. Differences are observed between 1-year changes in the MedDiet-VOO intervention and control diet on the activity of platelet activating factor acetylhydrolase in high-density lipoproteins (HDLs) (+7.5% [95% confidence interval: 0.17; 14.8]) and HDL-bound 1-antitrypsin levels (−6.1% [−11.8; −0.29]), and between the MedDiet-Nuts intervention and the control arm on non-esterified fatty acid concentrations (−9.3% [−18.1; −0.53]). Large MedDiet adherence increments are associated with less fibrinogen (−9.5% [−18.3; −0.60]) and non-esterified fatty acid concentrations (−16.7% [−31.7; −1.74]). Increases in nut, fruit, vegetable, and fatty fish consumption, and decreases in processed meat intake are linked to enhancements in biomarkers. Conclusion: MedDiet improves atherothrombosis biomarkers in high cardiovascular risk individuals

Oxidative stress is associated with an increased antioxidant defense in elderly subjects: a multilevel approach.

BACKGROUND: Studies of associations between plasma GSH-Px activity and cardiovascular risk factors have been done in humans, and contradictory results have been reported. The aim of our study was to assess the association between the scavenger antioxidant enzyme glutathione peroxidase (GSH-Px) activity in plasma and the presence of novel and classical cardiovascular risk factors in elderly patients. METHODS: We performed a cross-sectional study with baseline data from a subsample of the PREDIMED (PREvención con DIeta MEDiterránea) study in Spain. Participants were 1,060 asymptomatic subjects at high risk for cardiovascular disease (CVD), aged 55 to 80, selected from 8 primary health care centers (PHCCs). We assessed classical CVD risk factors, plasma oxidized low-density lipoproteins (ox-LDL), and glutathione peroxidase (GSH-Px) using multilevel statistical procedures. RESULTS: Mean GSH-Px value was 612 U/L (SE: 12 U/L), with variation between PHCCs ranging from 549 to 674 U/L (Variance =  013.5; P<0.001). Between-participants variability within a PHCC accounted for 89% of the total variation. Both glucose and oxidized LDL were positively associated with GSH-Px activity after adjustment for possible confounder variables (P = 0.03 and P = 0.01, respectively). CONCLUSION: In a population at high cardiovascular risk, a positive linear association was observed between plasma GSH-Px activity and both glucose and ox-LDL levels. The high GSH-Px activity observed when an oxidative stress situation occurred, such as hyperglycemia and lipid oxidative damage, could be interpreted as a healthy defensive response against oxidative injury in our cardiovascular risk population