205 results on '"S Madeira"'
Search Results
2. QSR-Dissipativity-Based Stabilization of Non-Passive Nonlinear Discrete-Time Systems by Linear Static Output Feedback.
- Author
-
Thiago Alves Lima, Diego de S. Madeira, and Marc Jungers
- Published
- 2024
- Full Text
- View/download PDF
3. A convex approach for the robust static output feedback stabilization of LTI systems based on dissipativity theory.
- Author
-
Valessa V. Viana, Diego de S. Madeira, and Thiago Alves Lima
- Published
- 2023
- Full Text
- View/download PDF
4. Dissipativity-based ℒ2 gain-scheduled static output feedback design for rational LPV systems.
- Author
-
Valessa V. Viana, Diego de S. Madeira, and Thiago Alves Lima
- Published
- 2022
- Full Text
- View/download PDF
5. Global Stabilization of Polynomial Systems Using Equilibrium-Independent Dissipativity.
- Author
-
Diego de S. Madeira and Thiago Alves Lima
- Published
- 2022
- Full Text
- View/download PDF
6. On Saturated Linear State Feedback and Anti-Windup Design Using Sector-Based Conditions and Convex Hull Representations.
- Author
-
Diego de S. Madeira
- Published
- 2022
- Full Text
- View/download PDF
7. Necessary and Sufficient Dissipativity-Based Conditions for Feedback Stabilization.
- Author
-
Diego de S. Madeira
- Published
- 2022
- Full Text
- View/download PDF
8. Dissipativity-based conditions for the feedback stabilization of systems with time-varying input delays.
- Author
-
Thiago Alves Lima, Diego de S. Madeira, and Marc Jungers
- Published
- 2023
- Full Text
- View/download PDF
9. Enhanced prediction for discrete-time input-delayed systems with unknown disturbances.
- Author
-
Thiago Alves Lima, Valessa V. Viana, Bismark C. Torrico, Fabricio Gonzalez Nogueira, and Diego de S. Madeira
- Published
- 2021
10. Static output feedback stabilization of uncertain rational nonlinear systems with input saturation.
- Author
-
Thiago Alves Lima, Diego de S. Madeira, and Valessa V. Viana
- Published
- 2021
11. Dissipativity-based L2 gain-scheduled static output feedback design for rational LPV systems.
- Author
-
Valessa V. Viana, Diego de S. Madeira, and Thiago Alves Lima
- Published
- 2021
12. Dissipativity-based static output feedback design for discrete-time LTI systems with time-varying input delays.
- Author
-
Thiago Alves Lima and Diego de S. Madeira
- Published
- 2021
13. Corrigendum to 'Development of a method to produce FGMs by controlling the reinforcement distribution' [Materials and Design 92 (2016) 233–239].
- Author
-
O. Carvalho, M. Buciumeanu, G. Miranda, S. Madeira, and F.S. Silva
- Subjects
Materials of engineering and construction. Mechanics of materials ,TA401-492 - Published
- 2020
- Full Text
- View/download PDF
14. Newton-series-based observer-predictor control for disturbed input-delayed discrete-time systems.
- Author
-
Thiago Alves Lima, Valessa V. Viana, Bismark C. Torrico, Fabricio Gonzalez Nogueira, and Diego de S. Madeira
- Published
- 2022
- Full Text
- View/download PDF
15. Static output feedback stabilization of uncertain rational nonlinear systems with input saturation.
- Author
-
Thiago Alves Lima, Diego de S. Madeira, Valessa V. Viana, and Ricardo C. L. F. Oliveira
- Published
- 2022
- Full Text
- View/download PDF
16. Asymptotic stabilization of nonlinear systems using passivity indices.
- Author
-
Diego de S. Madeira and Jürgen Adamy
- Published
- 2016
- Full Text
- View/download PDF
17. Static output feedback: An LMI condition for stabilizability based on passivity indices.
- Author
-
Diego de S. Madeira and Jürgen Adamy
- Published
- 2016
- Full Text
- View/download PDF
18. Output feedback control of rational nonlinear systems: A new approach based on passivity indices.
- Author
-
Diego de S. Madeira and Jürgen Adamy
- Published
- 2016
- Full Text
- View/download PDF
19. Hybrid capture as a tool for cervical lesions screening in HIV-infected women: insights from a Brazilian cohort
- Author
-
Emilia Moreira Jalil, Paula M. Luz, Marcel Quintana, Ruth Khalili Friedman, Rosa M. Domingues S. Madeira, Angela Cristina Andrade, Janice Chicarino, Ronaldo Ismerio Moreira, Monica Derrico, José Eduardo Levi, Fabio Russomano, Valdilea Gonçalves Veloso, and Beatriz Grinsztejn
- Subjects
Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
Introduction: Cervical cancer remains an important burden for HIV-infected women in the era of combination antiretroviral therapy. Recommendations for cervical screening in these women diverge and may include high-risk HPV (HRHPV) testing. We aimed to evaluate the clinical usefulness of a single HRHPV testing for cervical screening of HIV-infected women. Methods: 723 HIV-infected women from a Brazilian prospective cohort were included between 1996 and 2012. Inclusion criteria were: normal cervical cytology at baseline and having a HRHPV-test at baseline. We calculated incidence rates of any squamous intraepithelial lesion (SIL) and high grade SIL+ (HSIL+) and negative predictive values (NPV) within 12 and 36 months. Hazard Ratios were obtained using Cox proportional hazards regression models. Results: Incidence rate for both outcomes was low (9.9 cases per 100 PY [95% CI 8.8–11.0] for any SIL and 1.3 cases per 100 PY [95% IC 0.9–1.8] for HSIL+). Women with a HRHPV positive status at baseline had 1.7-fold (95% CI 1.3–2.2) and 3.2-fold (95% CI 1.5–7.1) increased risk of presenting any SIL and HSIL+, respectively, during follow-up. Negative-HRHPV test presented high NPV for both periods and outcomes (any SIL: 92.4% [95% CI 89.7–94.6] for 12 months and 80.9% [95% CI 77.2–84.3] for 36 months; and HSIL+: 99.8% [95% CI 98.9–100.0] for 12 months and 99.0 [95% CI 97.6–99.7] for 36 months). Conclusions: Incidence of any and high grade cytological abnormality was significantly higher among HIV-infected women with positive-HRHPV test. A single negative-HRHPV test helped reassure follow-up free of cytological abnormalities through three years of follow-up in HIV-infected women with negative cytology. Keywords: HPV, HIV, Women, Cohort, Incidence
- Published
- 2018
- Full Text
- View/download PDF
20. Markers of neuroprotection of combined EPA and DHA provided by fish oil are higher than those of EPA (Nannochloropsis) and DHA (Schizochytrium) from microalgae oils in Wistar rats
- Author
-
Paula A. Lopes, Narcisa M. Bandarra, Susana V. Martins, Joana Martinho, Cristina M. Alfaia, Marta S. Madeira, Carlos Cardoso, Cláudia Afonso, Maria C. Paulo, Rui M. A. Pinto, José L. Guil-Guerrero, and José A. M. Prates
- Subjects
Fish oil ,Microalgae ,Fatty acid composition ,Forced swimming test ,Transcriptional profile ,Nutrition. Foods and food supply ,TX341-641 ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
Abstract Background To overcome the current overexploitation of fish rich in n-3 long chain polyunsaturated fatty acids (LCPUFA), microalgae have become a promising marine lipid source. The purpose of this study was to assess eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), isolated or combined from distinct marine origins, on the promotion of neuroprotective effects. Methods The experiment lasted for 10 weeks and involved 32 Wistar rats, divided into 4 diets (n = 8): a diet rich in milk fat was taken as control (Milk Fat) and compared to n-3 LCPUFA enriched diets, either in EPA + DHA form through fish oil (Fish Oil), or EPA through Nannochloropsis oil (Nanno), or DHA through Schizochytrium oil (Schyzo), while maintaining Milk Fat incorporation. Results Plasma lipid profile and dopamine levels were more beneficial in Fish Oil diet. In addition, n-3 LCPUFA incorporation was found increased in liver and erythrocytes from Fish Oil fed rats, suggesting that fish oil is a better dietary source for fatty acids deposition in the organism than microalgae. The Forced Swimming Test revealed a positive behavioural action of EPA + DHA, in opposition to Milk Fat and Nanno diets, which had higher immobile times. mRNA levels of serotonin receptors, HT1A and HT2A along with CREB, the transmission factor for learning and memory, were higher in the hippocampus of rats fed n-3 LCPUFA diets comparative to Milk Fat. Conclusion Taken together, the combination of EPA and DHA from fish oil can counteract the undesirable health effects of saturated fat based diets and benefit, in the long run, neurological function.
- Published
- 2017
- Full Text
- View/download PDF
21. De toda maneira tem que andar junto: ações intersetoriais entre saúde e educação para crianças vivendo com a síndrome congênita do vírus Zika
- Author
-
Miriam Ribeiro Calheiros de Sá, Ana Carolina Dias Vieira, Barbara S. Madeira Castro, Olivia Agostini, Tracey Smythe, Hannah Kuper, Maria Elisabeth Lopes Moreira, and Martha Cristina Nunes Moreira
- Subjects
Criança ,Zika Vírus ,Pessoas com Deficiência ,Colaboração Intersetorial ,Medicine ,Public aspects of medicine ,RA1-1270 - Abstract
Resumo: Com base na experiência de um programa de intervenção para famílias de crianças com a síndrome congênita do vírus Zika, que inclui múltiplas deficiências, em uma instituição de educação, foram observados os desafios e conquistas encontrados com a entrada dessas famílias no sistema escolar. O objetivo deste artigo foi explorar os achados de pesquisa realizada após a conclusão de um programa de intervenção mediante entrevistas semiabertas com profissionais da instituição, e as possíveis contribuições para a construção das relações intersetoriais visando à inclusão escolar de crianças com deficiência. É possível constatar uma mudança provocada pelo programa na relação entre as famílias e os profissionais da instituição de educação; as famílias tiveram espaço para elaborar seus receios e discutir o papel da escola na vida de crianças com deficiência. Dessa forma, os profissionais passaram a vê-las em uma posição mais ativa. Acredita-se que esta experiência possa favorecer outros serviços e municípios que busquem a inclusão escolar de crianças e adolescentes com deficiência assim como sua inclusão social e de suas famílias.
- Published
- 2019
- Full Text
- View/download PDF
22. On the Equivalence Between Strict Positive Realness and Strict Passivity of Linear Systems.
- Author
-
Diego de S. Madeira and Jürgen Adamy
- Published
- 2016
- Full Text
- View/download PDF
23. Correlation of transforming growth factor-β1 and tumour necrosis factor levels with left ventricular function in Chagas disease
- Author
-
Eduardo OV Curvo, Roberto R Ferreira, Fabiana S Madeira, Gabriel F Alves, Mayara C Chambela, Veronica G Mendes, Luiz Henrique C Sangenis, Mariana C Waghabi, and Roberto M Saraiva
- Subjects
Chagas disease ,tumour necrosis factor ,transforming growth factor beta 1 ,brain natriuretic peptide ,echocardiography ,Microbiology ,QR1-502 ,Infectious and parasitic diseases ,RC109-216 - Abstract
BACKGROUND Transforming growth factor β1 (TGF-β1) and tumour necrosis factor (TNF) have been implicated in Chagas disease pathophysiology and may correlate with left ventricular (LV) function. OBJECTIVES We determined whether TGF-β1 and TNF serum levels correlate with LV systolic and diastolic functions and brain natriuretic peptide (BNP) serum levels in chronic Chagas disease. METHODS This cross-sectional study included 152 patients with Chagas disease (43% men; 57 ± 12 years old), classified as 53 patients with indeterminate form and 99 patients with cardiac form (stage A: 24, stage B: 25, stage C: 44, stage D: 6). TGF-β1, TNF, and BNP were determined by enzyme-linked immunosorbent assay ELISA. Echocardiogram was used to determine left atrial and LV diameters, as well as LV ejection fraction and diastolic function. FINDINGS TGF-b1 serum levels were lower in stages B, C, and D, while TNF serum levels were higher in stages C and D of the cardiac form. TGF-β1 presented a weak correlation with LV diastolic function and LV ejection fraction. TNF presented a weak correlation with left atrial and LV diameters and LV ejection fraction. CONCLUSIONS TNF is increased, while TGF-β1 is decreased in the cardiac form of chronic Chagas disease. TNF and TGF-β1 serum levels present a weak correlation with LV systolic and diastolic function in Chagas disease patients.
- Published
- 2018
- Full Text
- View/download PDF
24. Coronary sinus reducer device for the treatment of refractory angina therapy. A multicentric initial experience
- Author
-
J P Dias Ferreira Reis, C Brizido, S Madeira, R Ramos, M Almeida, and D Cacela
- Subjects
Cardiology and Cardiovascular Medicine - Abstract
Introduction The coronary sinus Reducer device (CSRD) emerged as a complementary therapy in patients with severe angina refractory to optimal medical therapy and not amenable to revascularization. Our aim was to assess the safety and efficacy of the CSRD in a real-world setting. Methods Twenty-six patients with refractory angina (RA), evidence of myocardial ischemia attributable to the left coronary artery unsuitable for revascularization were treated with the CSRD at two centres between May 2017 and July 2019. Safety endpoints were procedural success and complications. Efficacy endpoints, assessed at 6-month follow-up, were a reduction in CCS class, improvement in quality of life (QoL) assessed using the short version of the Seattle Angina Questionnaire (SAQ-7) and reduction in anti-anginal therapy. Results Twenty-three patients had end-stage CAD without revascularization targets and 3 patients had microvascular disease without epicardial stenosis. Procedural success was achieved 23 patients, with 2 device/procedural-related complications and one anatomically-related failure to deliver the device. Ultimately 25 patients implanted the device and entered the efficacy analysis. Eighteen patients (75.0%) had at least 1 reduction in CCS class, 41.7% had at least 2 class reductions, and 16.7% became asymptomatic, with a mean reduction of CCS class of 1.3±0.2 (p=0.001) at 6-month follow-up. All SAQ-7 domains improved, namely physical limitation (p=0.001), angina frequency (p=0.005) and QoL (p=0.006). There was a mean reduction of anti-ischemic drugs from 3.4±1.1 to 2.9±1.2 (p=0.010). Conclusion In this real-world, multicentric experience, implantation of the CSRD was associated with improvement of angina and QoL in patients with RA. Funding Acknowledgement Type of funding sources: None.
- Published
- 2022
- Full Text
- View/download PDF
25. Correlation between NSTE-ACS risk scores with Syntax: can we predict coronary lesion complexity before angiography?
- Author
-
S Maltes, M S Paiva, S Madeira, R C Teles, M S Almeida, and M Mendes
- Subjects
Cardiology and Cardiovascular Medicine - Abstract
Background and aim Standard single antiplatelet regimen (SAPT) is currently recommended before invasive risk stratification in non-ST elevation acute coronary syndromes (NSTE-ACS). However, there are subsets in whom dual antiplatelet therapy (DAPT) may be more protective according to the coronary anatomy and revascularization strategy. We aimed to identify pre-procedural predictors of coronary artery complexity that may be helpful in selecting an individualized antiplatelet regimen. Methodology Retrospective single-center study including patients with NSTE-ACS performing coronary angiography between January 2020 and July 2021. Clinical variables and classical NSTE-ACS risk scores (TIMI, GRACE and HEART) were captured and SYNTAX 1 score was calculated. Patients were divided into low (0–22), moderate (23–32) and high (≥33) SYNTAX score. Multivariate logistic regression analysis was performed to determine predictors of anatomical complexity (defined as significant left main disease [stenosis ≥50%] or SYNTAX ≥33). Results A total of 448 patients were included (mean age 67±13 years; 74% males; 85% with NSTE-myocardial infarction). Overall, 350 (78%), 63 (14%) and 35 (8%) patients had a low, moderate or high-SYNTAX score, respectively. Thirty-one (7%) patients had significant left main disease. At multivariate analysis (adjusted for age, diabetes, renal function, GRACE and TIMI scores), the HEART score (hazard ratio 2.3, 95% confidence interval 1.5–3.3, p7 showed a sensitivity of 76% and specificity of 75% in identifying such patients. Conclusion In this cohort of NSTE-ACS patients, the HEART score was an independent predictors of complex coronary anatomies. These results suggest that those with high (>7) HEART score may merit from SAPT as opposed to DAPT, given the high probability of complex lesions amenable to CABG. Funding Acknowledgement Type of funding sources: None.
- Published
- 2022
- Full Text
- View/download PDF
26. Cardiopulmonary exercise testing in Fontan patients: unmasking the secret of Super-Fontans
- Author
-
M Paiva, J Rato, R Santos, G Cunha, D Gomes, S Cordeiro, S Madeira, S Guerreiro, L Moreno, A Durazzo, and M Mendes
- Subjects
Cardiology and Cardiovascular Medicine - Abstract
Background Exercise capacity is usually reduced in Fontan patients, however there is a subset of patients who have normal exercise capacity and better outcomes, the “Super-Fontans”. The aim of this study was to characterize a cohort of Fontan patients undergoing cardiopulmonary exercise testing (CPET) and identify predictors of better functional capacity. Methods Single center retrospective analysis of consecutive Fontan patients aged >10 years old who underwent CPET, between March 2018 and May 2021. Peak respiratory exchange ratio1.05 defined maximal CPET. Peak VO2 (pVO2) as a percentage of its predicted value was used as reference value to stratify patients in tertiles. Patients in 3rd tertile, with a percentage predicted pVO2 superior to 75%, were considered good-performers. Blood tests and transthoracic echocardiogram (TTE) were performed on the same day. Additional data were collected from electronic charts. Results In total, 49 patients were included (mean age 19±7 years old, 67% male) with intra or extracardiac conduit implanted in mean 12±7 years prior to the CPET. The most common primary diagnoses were tricuspid/pulmonary atresia (43%), followed by unbalanced complete AV septal defect (14%) and double inlet left ventricle (14%). 12 patients had a systemic right ventricle. All, except 5 patients, had preserved systolic ventricular function and 37% had moderate to severe AV regurgitation. The majority had normal hemoglobin levels (median 15.6 g/dL), hepatic enzymes (median total bilirubin 0.8 mg/dL), renal function (median creatinine 0.8 mg/dL) and low NT-proBNP (median 122 pg/mL). All patients had maximal CPET, median %VO2 at VT1 was 57% of peak and mean pVO2 was 66±14% of the predicted. Most patients (69%) showed exercise limitation due to cardiovascular cause, followed by O2 desaturation, present in 22% of CPETs. The age of Fontan completion was not associated with functional capacity (p=0.6). The good-performer group comprised 13 patients (27%), all in sinus rhythm, of which 10 were physically active. Compared with the remainder, this group had higher VO2 at VT1 (18.7 vs. 14.6, p=0.01) and VO2 at VT2 (25.9 vs. 22.1, p=0.02), both in mL/kg/min. Also, peak heart rate (% predicted) (90 vs. 81, p=0.03) was higher in this subgroup – fig.1. Conversely, differences on TTE parameters (GLS and AV valve regurgitation) and blood biomarkers were not statistically significant. On multivariable analysis, no single variable predicted better functional capacity. Conclusion In our Fontan cohort, most patients had reduced exercise capacity, largely due to cardiovascular dysfunction. However, “Super-Fontans” stood out as they had a higher anaerobic threshold illustrating their better physical condition. These findings highlight the role of regular physical activity in Fontan patients as a cornerstone for better functional capacity. Funding Acknowledgement Type of funding sources: None.
- Published
- 2022
- Full Text
- View/download PDF
27. NOAC in adult congenital heart disease patients: a single-center experience
- Author
-
B Rocha, S Maltes, G Cunha, M Paiva, C Brizido, C Aguiar, S Madeira, and M Mendes
- Subjects
Cardiology and Cardiovascular Medicine - Abstract
Background Adult Congenital Heart Disease (ACHD) patients at increased risk for thromboembolic events are often treated with oral anticoagulation. While vitamin-K antagonists have been the agent of choice for decades, the use of non-vitamin K oral anticoagulants (NOAC) is increasing. We aimed to assess the safety and effectiveness of NOAC in ACHD patients at our centre. Methods This is a single-centre study enrolling all patients with ACHD treated with a NOAC from inception to November 2021. Data was collected using a standardized questionnaire applied to all patients by means of a telephone visit, in parallel with a detailed retrospective chart review. The endpoints of interest included thromboembolic and haemorrhagic events, defined as per the standardized International Society on Thrombosis and Haemostasis (ISTH) scale. Results Overall, 36 ACHD patients were enrolled [mean age 53±15 years; female sex – 66.7%; previous stroke – 33.3%; median HAS-BLED and CHA2DS2-VASc score – 1 (1–2) and 3 (2–5), respectively], predominantly with moderate or complex congenital defects (52.7%), of whom 14, 8, 8 and 4 were treated with rivaroxaban, apixaban, edoxaban and dabigatran, respectively. Two-thirds had their first NOAC prescription in the latest 3 years (Figure 1). The most common indication for anticoagulation was atrial fibrillation or flutter (77.8%). Over a median time of 36 (18–63) months on NOAC treatment, there were no patients with thromboembolic events, whilst 13 (36.1%) had a haemorrhagic event – annualized event rate of 12.0 (6.9–24.1%). All bleeding events were minor, most often self-limited gingival haemorrhage or epistaxis (n=7) or menorrhagia (n=3). Nasal cautery was needed to treat recurrent epistaxis in 3 patients, whilst 3 other required oral iron supplementation. The strongest predictor of any haemorrhage was a prior cardiovascular hospitalization (HR 3.88; p=0.027). Conclusions The use of NOAC in ACHD patients has been increasing in our centre, with encouraging results. The present findings suggest that NOAC are safe and may be effective for thromboembolic event prevention in heterogeneous forms of ACHD. Funding Acknowledgement Type of funding sources: None.
- Published
- 2022
- Full Text
- View/download PDF
28. Optimization of machining parameters using response surface methodology with desirability function in turning duplex stainless steel UNS S32760
- Author
-
Luiz G. Cardoso, Emerson José de Paiva, Rubén A. Miranda, Thulio E. P. A. Ricomini, Tarcisio Gonçalves Brito, and Deise S. Madeira
- Subjects
Materials science ,Central composite design ,Mechanical Engineering ,Process (computing) ,Mechanical engineering ,Duplex (telecommunications) ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Corrosion ,Desirability function ,Machining ,Control and Systems Engineering ,Surface roughness ,Response surface methodology ,Software - Abstract
The turning process of the duplex stainless steel (DSS) has received special attention in recent years due to its attractive combination of mechanical and corrosion properties, which are suitable for many marine and petrochemical applications, particularly where chlorides are present. Thus, a better understanding of the machining parameters is critical in attaining high quality in the turning process of the DSS. This paper presents a predictive and optimization model based on integrated response surface methodology (RSM) and desirability function to predict the surface roughness, the material removal rate, and the corresponding machining parameters during the turning of the UNS S32760 with a chemical vapor deposition (CVD) tool. The experimental design was a central composite design (CCD) with three center points and an axial distance of 1.68 from the center. The statistical significance of the developed model has been tested by the analysis of variance and the influence of the factors analyzed. The optimization results are presented considering three aims: (1) minimizing surface roughness; (2) maximizing the material removal rate; and (3) minimizing the surface roughness and maximizing the material removal rate.
- Published
- 2021
- Full Text
- View/download PDF
29. Development of a novel hybrid Ti6Al4V-ZrO
- Author
-
S, Madeira, M, Buciumeanu, D, Nobre, O, Carvalho, and F S, Silva
- Abstract
The development of implant metal-free surfaces has gained attention since non-benefic results have been reported related to the metallic ions released from metal implants to the human body. Ceramic coatings have been proposed as a possible solution however, the detachment of these coatings, during implantation or even in function, can compromise its function. In order to overcome this problem, this work proposes a novel hybrid Ti6Al4V-ZrO
- Published
- 2022
30. On Saturated Linear State Feedback and Anti-Windup Design Using Sector-Based Conditions and Convex Hull Representations
- Author
-
de S. Madeira, Diego, primary
- Published
- 2022
- Full Text
- View/download PDF
31. Micro-grooved surface laser texturing of zirconia: Surface characterization and artificial soft tissue adhesion evaluation
- Author
-
Óscar Carvalho, S. Madeira, A. Barbosa, and Filipe Samuel Silva
- Subjects
010302 applied physics ,Materials science ,Process Chemistry and Technology ,Soft tissue ,02 engineering and technology ,Adhesion ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,Seal (mechanical) ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Characterization (materials science) ,law.invention ,Laser technology ,law ,0103 physical sciences ,Ultimate tensile strength ,Materials Chemistry ,Ceramics and Composites ,Cubic zirconia ,0210 nano-technology ,Biomedical engineering - Abstract
Despite the reported high success of dental implants, problems related to biofilm formation and peri-implantitis due to the entrance and proliferation of bacteria on the peri-implant zone have increasing attention. In this sense, this work proposes a new zirconia surface with micro-grooves aiming to develop an effective tight seal between artificial soft tissue and implant surface and thus, to protect from bacterial invasion. In this study, different laser and design parameters were tested to produce successive micro-grooves with different and variated depth, width and wall. The micro-grooves were produced by a Nd:YAG laser and were morphologically characterized by SEM. Higher marked depths were obtained for a high number of laser passages under low scan speed as a result of a high amount of laser energy density. The most adequate conditions were mechanically tested regarding their capacity to retain artificial soft tissue (mimicking natural gingiva) by mechanical tensile strength test. The strength of adhesion between soft tissue and the micro-grooved surface revealed to be strongly dependent on the depth and width. The obtained results showed that the production of successive micro-grooves on the zirconia surface increased the adhesion of artificial soft tissue to its surface, proving that laser technology is a promising approach for the manufacturing of implants with micro-grooves sites that can protect from bacterial invasion.
- Published
- 2020
- Full Text
- View/download PDF
32. Aunps and Agμps-functionalized zirconia surfaces by hybrid laser technology for dental implants
- Author
-
Óscar Carvalho, A. Barbosa, Mihaela Buciumeanu, Filipe Samuel Silva, C.G. Moura, and S. Madeira
- Subjects
010302 applied physics ,Laser ablation ,Materials science ,Process Chemistry and Technology ,Nanoparticle ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Selective laser sintering ,law ,Colloidal gold ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Cubic zirconia ,Particle size ,Laser power scaling ,Composite material ,0210 nano-technology - Abstract
This work presents innovative zirconia surfaces functionalized with gold nanoparticles (Aunps) and silver microparticles (Agμps) through versatile laser technology where laser parameters and subtractive/additive strategies were combined to apply in dental implant surfaces regarding antibacterial potentialities. Aunps-functionalized zirconia surfaces were produced by a hybrid process starting with nanoparticles production by Nd:YAG laser ablation, followed by its deposition through spray system and its adhesion to the zirconia surface by the laser CO2 action, varying laser power and scan speed parameters. Agμps-functionalized zirconia surfaces were obtained through a hybrid laser process starting by laser texturing of the compacted zirconia surface, followed by allocation of Ag powder into the texture and its subsequent laser sintering, varying laser power. The functionalized zirconia surfaces were analyzed through SEM/EDS. In order to mimic the implant screwing effect, the samples were subjected to reciprocating friction tests against bone. It allows to evaluate the adhesion of the zirconia surface to the bone and the resistance to surface detachment. A purple colloidal solution of spherical gold nanoparticles with an average size of 5 ± 3 nm was successfully produced by laser. The friction tests revealed a good behavior of both functionalized zirconia surfaces indicating that their integrity is not affected during implant screwing insertion. A good dispersion of nanoparticles on the zirconia surface was observed indicating that the spray system is an effective way to deposit nanoparticles on the surface. A high amount of agglomerates was found for samples where low laser power (P = 11W) and scan speed (v = 1000 mm/s) were applied, probably due to the high density of energy (E). A decrease of defects on the sintered Ag layer with increasing laser power from 3 to 6 W was found, mainly related with the amount of laser energy density. The ion release showed to be strongly dependent on particle size.
- Published
- 2020
- Full Text
- View/download PDF
33. Central and South America
- Author
-
Castellanos, Edwin J., Lemos, Maria Fernanda, Astigarraga, Laura, Chacón, Noemí, Cuvi, Nicolás, Huggel, Christian, Miranda, Liliana, Vale, Mariana Moncassin, Ometto, Jean Pierre Henry Balbaud, Peri, Pablo L., Postigo, Julio C., Ramajo, Laura, Rocco, Lisandro, Rusticucci, Matilde, Menezes, Júlia Alves, Borges, Pedro, Bueno, Jhonattan, Cuesta, Francisco, Drenkhan, Fabian, Guerra, Alex, Guinder, Valeria, Hagen, Isabel, Hardoy, Jorgelina, Hartinger, Stella, Herrera, Gioconda, Herzog, Cecilia, Jacob, Bárbara, Kasecker, Thais, Lampis, Andrea, Lentino, Izabella, Domingues, Luis C. S. Madeira, Marengo, José, Lapola, David Montenegro, Moreno, Ana Rosa, Caldas, Julia de Niemeyer, Pacay, Eduardo, Pasten, Roberto, Piaggio, Matias, Rezende, Osvaldo, Rodriguez-Morales, Alfonso J., Romanello, Marina, Ryan, Sadie J., Stewart-Ibarra, Anna, Valladares, María, Castellanos, Edwin J., Lemos, Maria Fernanda, Astigarraga, Laura, Chacón, Noemí, Cuvi, Nicolás, Huggel, Christian, Miranda, Liliana, Vale, Mariana Moncassin, Ometto, Jean Pierre Henry Balbaud, Peri, Pablo L., Postigo, Julio C., Ramajo, Laura, Rocco, Lisandro, Rusticucci, Matilde, Menezes, Júlia Alves, Borges, Pedro, Bueno, Jhonattan, Cuesta, Francisco, Drenkhan, Fabian, Guerra, Alex, Guinder, Valeria, Hagen, Isabel, Hardoy, Jorgelina, Hartinger, Stella, Herrera, Gioconda, Herzog, Cecilia, Jacob, Bárbara, Kasecker, Thais, Lampis, Andrea, Lentino, Izabella, Domingues, Luis C. S. Madeira, Marengo, José, Lapola, David Montenegro, Moreno, Ana Rosa, Caldas, Julia de Niemeyer, Pacay, Eduardo, Pasten, Roberto, Piaggio, Matias, Rezende, Osvaldo, Rodriguez-Morales, Alfonso J., Romanello, Marina, Ryan, Sadie J., Stewart-Ibarra, Anna, and Valladares, María
- Abstract
Pages: 12-1 - 12-181
- Published
- 2022
34. Necessary and Sufficient Dissipativity-Based Conditions for Feedback Stabilization
- Author
-
de S. Madeira, Diego, primary
- Published
- 2022
- Full Text
- View/download PDF
35. Bacteria co-culture adhesion on different texturized zirconia surfaces
- Author
-
Paula Vaz, Mariana Rodrigues da Silva, Jorge Padrão, T.A. Dantas, Andrea Zille, Filipe Samuel Silva, S. Madeira, Paulo Daniel Araújo Pinto, and Universidade do Minho
- Subjects
Staphylococcus aureus ,Surface Properties ,medicine.medical_treatment ,Biomedical Engineering ,chemistry.chemical_element ,Bacterial adhesion ,02 engineering and technology ,medicine.disease_cause ,Osseointegration ,Microbiology ,Biomaterials ,03 medical and health sciences ,0302 clinical medicine ,Escherichia coli ,medicine ,Engenharia dos Materiais [Engenharia e Tecnologia] ,Cubic zirconia ,Dental implant ,Dental Implants ,Titanium ,Science & Technology ,biology ,Pseudomonas aeruginosa ,Dental implants ,030206 dentistry ,Adhesion ,021001 nanoscience & nanotechnology ,biology.organism_classification ,Coculture Techniques ,Engenharia e Tecnologia::Engenharia dos Materiais ,chemistry ,Mechanics of Materials ,Zirconia ,Surface characteristics ,Zirconium ,0210 nano-technology ,Bacteria - Abstract
Zirconia is becoming reckoned as a promising solution for different applications, in particular those within the dental implant investigation field. It has been proved to successfully overcome important limitations of the commonly used titanium implants. The adhesion of microorganisms to the implants, in particular of bacteria, may govern the success or the failure of a dental implant, as the accumulation of bacteria on the peri-implant bone may rapidly evolve into periodontitis. However, bacterial adhesion on different zirconia architectures is still considerably unknown. Therefore, the adhesion of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa to zirconia surfaces with different finishings was evaluated and compared to a titanium surface. The adhesion interaction between S. aureus and P. aeruginosa was also evaluated using a co-culture since these bacteria are infamous due to their common presence in chronic wound infections. Results showed that different bacterium species possess different properties which influence their propensity to adhere to different roughness levels and architectures. E. coli revealed a higher propensity to adhere to zirconia channelled surfaces (7.15 × 106 CFU/mL), whereas S. aureus and P. aeruginosa adhered more to the titanium control group (1.07 × 105 CFU/ mL and 8.43 × 106 CFU/mL, respectively). Moreover, the co-culture denoted significant differences on the adhesion behaviour of bacteria. Despite not having shown an especially better behaviour regarding bacterial adhesion, zirconia surfaces with micro-channels are expected to improve the vascularization around the implants and ultimately enhance osseointegration, thus being a promising solution for dental implants., This work was supported by FCT-Portugal through the grant PD/BD/140202/2018, and the projects POCI-01-0145-FEDER-030498, POCI-01-0247-FEDER-017828, UIDB/04436/2020 and UIDP/04436/2020. This work was also funded by FEDER funds through the Operational Competitiveness Program-COMPETE and by National Funds through FCT-under the projects PTDC/CTM-TEX/28295/2017 and UID/CTM/00264/2019.
- Published
- 2021
36. TAVI via alternative access routes: patient selection and 10-year center experience
- Author
-
B Rocha, T Nolasco, R Teles, S Madeira, N Vale, M Madeira, J Brito, L Raposo, P Goncalves, H M Gabriel, M Sousa-Uva, M Abecasis, M Almeida, J P Neves, and M Mendes
- Subjects
Cardiology and Cardiovascular Medicine - Abstract
Background Femoral access is considered the gold standard for transcatheter aortic valve implantation (TAVI). However, this route might be precluded due to the presence of tortuosity, small vessel diameter and/or peripheral artery disease. We aimed to investigate TAVI through an alternative access (AA), focusing on the selection criteria and clinical outcomes compared to the femoral route (TF). Methods We conducted an all-comers longitudinal single-centre prospective registry in whom a TAVI was performed. The feasibility, safety and efficacy of TAVI by means of an access route other than standard TF was assessed, according to the VARC-2 criteria. The prospective surgical criteria used at our institution to accept an AA route were: a) TF deemed inappropriate; b) acceptable haemorrhagic risk; c) acceptable general anaesthesia risk; and d) adequate anatomy and diameter within acceptable range (subclavian, axillar, transaortic) or e) age Results From 2008 to 2018, there were 548 patients submitted to TAVI [median age 84 (79–87) years, males 45.4%]. An AA route was used in 100 patients (79 trans-apical, 9 trans-aortic, and 12 trans-subclavian), with a decreasing rate over follow-up (−11% per year). Compared to TF, these patients were younger [80 (77–84) vs. 85 (80–87) years; p Conclusion In the first 10 years of experience, 1 in every 6 patients was treated with a TAVI by means of an AA, most often trans-apically initially and, nowadays, via a trans-subclavian approach. The use of meticulous prospective selection criteria seems to explain the one-year similar results, regardless of the access route. Funding Acknowledgement Type of funding sources: None.
- Published
- 2021
- Full Text
- View/download PDF
37. Prognostic impact of the presence and management of coronary artery disease in patients undergoing TAVI
- Author
-
P Custodio, S Madeira, R Teles, M Almeida, and M Mendes
- Subjects
cardiovascular diseases ,Cardiology and Cardiovascular Medicine - Abstract
Introduction Approximately half of transcatheter aortic valve implantaton (TAVI) candidates have coronary artery disease (CAD). Controversial results have been reported regarding the effect of the presence/severity of CAD and its management on clinical outcomes post-TAVI. Aim To describe the presence, extension, severityand management of CAD pre-TAVIand to evaluate its impact on 2-yearmortality in areal world all comers population. Methods and population Single centre retrospective analysis from a prospectively collected institutional registry (VCROSS) including 517 patients that underwent TAVI for severe aortic stenosis between January 2009 and December 2018. Patients who underwent pre TAVI CA in the context of ACS or at other institution were excluded n=138. Ultimately 380 entered the analysis. Obstructive CAD was defined as stenosis >50% in in major epicardial vessels (>2.5 mm). The total number of major epicardial with obstructive CAD was reported as was assessed the number of those left untreated. Univariate analysis was performed to assess 1) differences between patients with or without CAD and between those with significant CAD who have or have not undergone PCI, 2) variables associated with 2-year mortality. Binary logistic regression was performed to identify independent predictors of 2-year mortality including the presence of significant CAD and the type of management. Results A total of 380 patients were included, 55.3% male with an average age of 83YO (±6.3), mean Euroscore II of 4.35. 76 had previous coronary artery bypassgrafting (CABG) and 136 had previous PCI (43 had both). 55 patients (14.4%) presented with normal coronary arteries, 120 (31.6%) with non-obstructive CAD and 205 (54%) with obstructive CAD. Out of the latter, 112 (29.5%) underwent PCI. Statistically significant differences were found between obstructive CAD vs non-obstructive patients in terms of age, previous history of ICP and CABG. In the subgroup population with obstructive CAD, no statistically significant differences was found in the PCI vs non PCI group, apart from previous history of ICP and CABG – Figure 1. Diabetes mellitus, previous history of percutaneous coronary intervention (PCI) and reduced ejection fraction (rEF – defined has Conclusion The presence and type of management of obstructive CAD in this real world all comers registry did not impact the prognosis at 2 years. Funding Acknowledgement Type of funding sources: None.
- Published
- 2021
- Full Text
- View/download PDF
38. Pork Byproducts
- Author
-
Cristina Mateus Alfaia, Marta S. Madeira, José Pestana, Diogo Coelho, Paula A. Lopes, Fidel Toldrá, and José A.M. Prates
- Published
- 2019
- Full Text
- View/download PDF
39. Influence of sintering pressure on the microstructure and tribological properties of low temperature fast sintered hot-pressed Y-TZP
- Author
-
Óscar Carvalho, S. Madeira, Filipe Samuel Silva, and Mihaela Buciumeanu
- Subjects
010302 applied physics ,Materials science ,Process Chemistry and Technology ,Sintering ,02 engineering and technology ,Tribology ,021001 nanoscience & nanotechnology ,Microstructure ,Hot pressing ,01 natural sciences ,Grain size ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,visual_art ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Cubic zirconia ,Crystallite ,Ceramic ,Composite material ,0210 nano-technology - Abstract
Contrarily to conventional sintering (CS) method where longer cycles and high temperature (1400–1500 °C) are applied to sinter yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics, this work presents a faster and low temperature (1175 °C) way through hot pressing (HP) to produce full densified zirconia with good mechanical and tribological properties. This work is concerned with the influence of sintering pressure on the microstructure and tribological properties of hot-pressed Y-TZP. For this purpose, four sintering pressures 5, 20, 60 and 100 MPa were tested. The wear tests were carried out by reciprocating ball-on-plate as a simplified test for tooth-to-restorative material contact under 37 °C using artificial saliva to mimic oral conditions. The results demonstrated that density, hardness and tribological properties are strongly influenced by the sintering pressure, namely an improvement with pressure increase was achieved. The highest density, hardness values and wear resistance were achieved for Y-TZP samples produced at P = 100 MPa. Furthermore, it was revealed that a smaller grain size for Z100 samples (full densification condition) was achieved comparatively to conventional-sintered Y-TZP. This work proves that it is possible to produce dense Y-TZP materials under low sintering temperature and faster cycles with reduced grain size without compromise mechanical and tribological properties.
- Published
- 2019
- Full Text
- View/download PDF
40. Comparative toothbrush abrasion resistance and surface analysis of different dental restorative materials
- Author
-
P. Pinto, A. Carvalho, F.S. Silva, J.R. Gomes, O. Carvalho, and S. Madeira
- Subjects
Mechanics of Materials ,Mechanical Engineering ,Surfaces and Interfaces ,Surfaces, Coatings and Films - Published
- 2022
- Full Text
- View/download PDF
41. Laser surface treatment on Yttria-stabilized zirconia dental implants: Influence on cell behavior
- Author
-
Filipe Samuel Silva, S. Madeira, Joana Marques, António Mata, Óscar Carvalho, Paulo Daniel Araújo Pinto, Beatriz Fernandes, João Caramês, and Mariana Cruz
- Subjects
Materials science ,Biocompatibility ,Surface Properties ,medicine.medical_treatment ,Biomedical Engineering ,chemistry.chemical_element ,02 engineering and technology ,Biomaterials ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Cubic zirconia ,Yttrium ,Viability assay ,Osteopontin ,Cell adhesion ,Dental implant ,Yttria-stabilized zirconia ,Dental Implants ,Titanium ,Osteoblasts ,biology ,030206 dentistry ,021001 nanoscience & nanotechnology ,chemistry ,biology.protein ,Zirconium ,0210 nano-technology ,Biomedical engineering - Abstract
Yttria-stabilized zirconia (YSZ) is being proposed as an alternative material to Titanium for dental implants due to its aesthetic and biocompatibility properties. However, is it yet to define the optimal surface treatment to improve YSZ bioactivy. Texturization is a promising approach, but the biological role of patterned YSZ surfaces in cell cultures is yet to be determined. Thus, cellular behavior of osteoblasts and fibroblasts in contact with groove-texturized YSZ surfaces was investigated. YSZ discs were groove-textured by conventional milling and Nd:YAG laser. All samples including control were sandblasted and acid-etched. Human osteoblasts and fibroblasts were cultured on discs for 14 days. Morphology and cellular adhesion were observed. Cell viability, interleukin-1β, osteopontin, collagen type I prodution, alkaline phosphatase activity, and interleukin-8 were measured. YSZ texturization by conventional milling improved osteoblasts viability and differentiation when compared to laser texturization. Fibroblasts behavior did not seem to be influenced by the texturing technique. Compared to sandblasting and acid etching currently used as gold standard for zirconia dental implants no superiority of macrotexturization was found.
- Published
- 2021
42. Robust Static Output Feedback Stabilization of Linear Systems Using Dissipativity Theory
- Author
-
null Valessa V. Viana and null Diego de S. Madeira
- Published
- 2021
- Full Text
- View/download PDF
43. Dietary Arthrospira platensis improves systemic antioxidant potential and changes plasma lipids without affecting related hepatic metabolic pathways in post-weaned piglets
- Author
-
Paula Lopes, Cátia Falcão Martins, José A. M. Prates, Rui Pinto, Marta S. Madeira, José Miguel Pestana Assunção, and Cristina M. Alfaia
- Subjects
Male ,030309 nutrition & dietetics ,Veterinary medicine ,Soybean meal ,Sus scrofa ,Arthrospira platensis ,enzymes ,piglets ,hepatic lipid metabolism ,Antioxidants ,03 medical and health sciences ,Basal (phylogenetics) ,chemistry.chemical_compound ,Multienzyme Complexes ,SF600-1100 ,Spirulina ,Animals ,Food science ,Carotenoid ,chemistry.chemical_classification ,0303 health sciences ,General Veterinary ,Chemistry ,0402 animal and dairy science ,Fatty acid ,04 agricultural and veterinary sciences ,General Medicine ,Metabolism ,Lipid Metabolism ,040201 dairy & animal science ,Animal Feed ,Enzymes ,Diet ,Antioxidant potential ,Metabolic pathway ,Enzyme ,Hepatic lipid metabolism ,Piglets ,Liver ,antioxidant potential ,Animal Nutritional Physiological Phenomena ,Muramidase ,Lysozyme ,Research Article - Abstract
Background The ability of a high level of dietary Arthrospira platensis, individually or in combination with two exogenous carbohydrate-degrading enzymes (lysozyme and Rovabio®), to improve systemic antioxidant potential and hepatic lipid metabolism was tested in piglets. Forty male post-weaned piglets, sons of Large White × Landrace sows crossed with Pietrain boars, were allocated into 4 groups (n = 10) and fed during 28 days one of the following diets: 1) a control basal diet (cereal and soybean meal); 2) a basal diet with 10% of A. platensis (AP); 3) the AP diet supplemented with 0.005% of Rovabio® (AP + R); 4) the AP diet supplemented with 0.01% of lysozyme (AP + L). Results Arthrospira platensis decreased BW gain of piglets, regardless the addition of feed enzymes. The majority of plasma metabolites were affected by diets. A. platensis increased total lipids, total cholesterol and LDL-cholesterol, without changing hepatic fatty acid content or modulating, in an expressive manner, the transcriptional profile of lipid sensitive mediators. The antioxidant potential in general, and total carotenoids in particular, were improved by the microalga, regardless lysozyme or Rovabio®. Conclusions Summing up, A. platensis, individually and combined with feed enzymes, impacts negatively on piglets’ growth but improves the systemic antioxidant potential and changes plasma lipids with a minor modulation on related hepatic metabolic pathways.
- Published
- 2021
44. Additional file 2 of Genetic diversity of vector-borne pathogens in spotted and brown hyenas from Namibia and Tanzania relates to ecological conditions rather than host taxonomy
- Author
-
Kr��cken, J��rgen, Czirj��k, G��bor ��., Ram��nke, Sabrina, Serocki, Maria, Heinrich, Sonja K., Melzheimer, J��rg, Costa, M. Carolina, Hofer, Heribert, Aschenborn, Ortwin H. K., Barker, Nancy A., Capodanno, Stefano, de Carvalho, Lu��s Madeira, von Samson-Himmelstjerna, Georg, East, Marion L., and Wachter, Bettina
- Abstract
Additional file 2: Table S2. Primer sequences and PCR conditions.
- Published
- 2021
- Full Text
- View/download PDF
45. An Application of QSR-Dissipativity to the Problem of Static Output Feedback Robust Stabilization of Nonlinear Systems
- Author
-
Diego de S. Madeira and Valessa V. Viana
- Subjects
Lemma (mathematics) ,Polynomial ,Nonlinear system ,Computer science ,Simple (abstract algebra) ,Control theory ,Polytope ,Robust control ,Parametric statistics ,Domain (software engineering) - Abstract
In this work we deal with the asymptotic stabilization problem of polynomial (and rational) input-affine systems subject to parametric uncertainties. The problem of linear static output feedback (SOF) control synthesis is handled, having as a prerequisite a differential algebraic representation (DAR) of the plant. Using the property of strict QSR-dissipativity, theFinsler's Lemma and the notion of linear annihilators we introduce a new dissipativity-based strategy for robust stabilization which determines a static feedback gain by solving a simple linear semidenite program on a polytope. At the same time, an estimate of the closed-loop domain of attraction is given in terms of an ellipsoidal set. The novelty of the proposed approach consists in this combination of dissipativity theory and powerful semidenite programming(SDP) tools allowing for a simple solution of the challenging problem of static output feedback design for nonlinear systems. A numerical example allows the reader to verify the applicability of the proposed technique.
- Published
- 2020
- Full Text
- View/download PDF
46. Corrigendum to 'Development of a method to produce FGMs by controlling the reinforcement distribution' [Materials and Design 92 (2016) 233–239]
- Author
-
Filipe Samuel Silva, S. Madeira, Óscar Carvalho, Mihaela Buciumeanu, and Georgina Miranda
- Subjects
Materials science ,Distribution (number theory) ,Mechanical Engineering ,Mechanical engineering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Mechanics of Materials ,lcsh:TA401-492 ,General Materials Science ,lcsh:Materials of engineering and construction. Mechanics of materials ,0210 nano-technology ,Reinforcement - Published
- 2020
47. Damping and mechanical behavior of metal-ceramic composites applied to novel dental restorative systems
- Author
-
Filipe Samuel Silva, S. Madeira, Michael Gasik, Bruno Henriques, and Júlio C.M. Souza
- Subjects
Materials science ,medicine.medical_treatment ,Biomedical Engineering ,Modulus ,02 engineering and technology ,Ceramic matrix composite ,CoCrMo alloy ,Dental restorations ,Damper ,Biomaterials ,Damping capacity ,Stress (mechanics) ,03 medical and health sciences ,0302 clinical medicine ,Dental porcelain ,stomatognathic system ,Hardness ,Elastic Modulus ,Metals, Heavy ,Materials Testing ,medicine ,ta318 ,Ceramic ,Dynamic Young's modulus ,Composite material ,Mechanical Phenomena ,Temperature ,030206 dentistry ,021001 nanoscience & nanotechnology ,Dental Porcelain ,Mechanics of Materials ,Metals ,visual_art ,Porcelain ,visual_art.visual_art_medium ,Veneer ,0210 nano-technology - Abstract
Conversely to natural teeth, where periodontal ligament (PDL) and pulp works as a damper reducing the effect of the stress on surrounding structures, when natural teeth is lost and replaced or restored the biting forces are directly transmitted to the bone or affect the integrity of the adjacent bottom layers. In this study, damping capacity and dynamic Young's modulus of CoCrMo-porcelain composites for dental restorations were evaluated. Dynamic Young's modulus and damping capacity of materials were assessed by dynamic mechanical analyzes (DMA) at 1 and 10 Hz frequencies, over a temperature ranging (18–60 °C). Results show that by reinforcing dental porcelain with metallic particles, producing ceramic matrix composites (CMCs) with 20 vol% and 40 vol% of metallic particles, the damping capacity and dynamic Young's modulus are improved. A decrease on both properties of the metal matrix composites (MMCs) with increasing ceramic particles content (from 20 vol% to 40 vol% of ceramic phase) was observed for all the studied frequencies and temperatures. While damping capacity is strongly dependent on frequency, no significant difference in dynamic Young's modulus was found. Results show that besides the yet reported advantages of the bio-inspired functionally graded restorations over traditional bilaminate ones, traduced by improved veneer to substrate adhesion and by the enhanced thermal and mechanical stress distribution, these restorations can also display improved behavior as regard to a damping capacity, which may have a positive impact in the long-term performance of implant – supported prosthesis.
- Published
- 2019
- Full Text
- View/download PDF
48. Can Psychologic Stress Elevate Intraocular Pressure in Healthy Individuals?
- Author
-
Ricardo Y. Abe, Sebastião X. Curado, Luciene Barbosa de Sousa, Mariana S. Madeira, Izabella Dantas, Thairis Cássia Santana Silva, and Vital Paulino Costa
- Subjects
Male ,endocrine system ,Intraocular pressure ,Psychologic stress ,Health Status ,Glaucoma ,01 natural sciences ,03 medical and health sciences ,Tonometry, Ocular ,0302 clinical medicine ,Heart Rate ,Surveys and Questionnaires ,Heart rate ,Trier social stress test ,Medicine ,Humans ,Prospective Studies ,0101 mathematics ,Intraocular Pressure ,business.industry ,010102 general mathematics ,General Medicine ,Middle Aged ,medicine.disease ,Healthy Volunteers ,Anesthesia ,Healthy individuals ,Case-Control Studies ,030221 ophthalmology & optometry ,Anxiety ,Female ,medicine.symptom ,business ,State-Trait Anxiety Inventory ,Stress, Psychological ,Follow-Up Studies - Abstract
To investigate if a stress event can influence intraocular pressure (IOP) in a group of healthy individuals.Case-control study.A total of 28 healthy subjects were included: 17 in the stress group and 11 in the control group.The Trier Social Stress Test (TSST) is a tool to evaluate cortisol response to psychologic stimulation based on the stress induced by public speaking. All participants underwent a modified diurnal tension curve (DTC) 1 week before the TSST, with 3 IOP measurements performed between 8:00 am and 2:00 pm. We evaluated the response to the TSST measuring the levels of salivary cortisol, IOP, and heart rate before, immediately after, and 40 minutes after TSST. The State Trait Anxiety Inventory (STAI) was applied to evaluate the levels of anxiety at the same time intervals.Changes in IOP (mmHg), salivary cortisol, heart rate, and STAI scores.At baseline, there were no significant differences between case and controls regarding age (52.2 ± 6.26 vs. 53.8 ± 8.4 years, P = 0.661), gender (52.94% male vs. 45.45% female, P = 0.669), and ethnicity. Salivary cortisol (6.8 nmol/l, P0.001) and heart rate (7.2 beats/min, P = 0.035) increased significantly after the TSST. We observed a mean IOP increase of 1.0 mmHg (right eye, P = 0.003) and 1.1 mmHg (left eye, P = 0.004) when comparing IOP measurements obtained during the DTC and immediately after TSST. In addition, 35% (6/17) of the subjects in the TSST group showed an IOP increase higher than 2 mmHg after the test compared with 18% (2/11) in the control group. The STAI state score significantly increased after the stress event compared with baseline (P = 0.026) and decreased from poststress to the recovery period (P = 0.006) in the TSST group. The control group did not show significant changes in IOP, heart rate, salivary cortisol levels, and STAI scores.Significant elevations of IOP, salivary cortisol, STAI scores, and heart rate occurred after inducing psychologic stress with TSST in a group of healthy individuals.
- Published
- 2020
49. Effect of dietary inclusion of Spirulina on production performance, nutrient digestibility and meat quality traits in post-weaning piglets
- Author
-
José Miguel Pestana Assunção, Diogo Coelho, J. P. C. Lemos, André M. Almeida, Cátia Falcão Martins, David M. Ribeiro Santos, Joao P.B. Freire, Paula Lopes, José A. M. Prates, Cristina M. Alfaia, and Marta S. Madeira
- Subjects
Male ,Meat ,040301 veterinary sciences ,Swine ,Weaning ,piglets ,0403 veterinary science ,meat ,chemistry.chemical_compound ,Food Animals ,Lipid oxidation ,Spirulina ,Animals ,Food science ,lysozyme ,Spirulina (genus) ,chemistry.chemical_classification ,Meal ,Nutrient digestibility ,biology ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,Nutrients ,biology.organism_classification ,040201 dairy & animal science ,Animal Feed ,Diet ,Enzyme ,chemistry ,digestibility ,Dietary Supplements ,Post weaning ,Animal Science and Zoology ,Animal Nutritional Physiological Phenomena ,Digestion ,Lysozyme - Abstract
The effect of Spirulina (Arthrospira platensis), individually or in combination with two commercial carbohydrases, in piglet diets was assessed on growth performance, nutrient digestibility and meat quality traits. Forty post-weaned male piglets from Large White × Landrace sows crossed with Pietrain boars with an initial live weight of 12.0 ± 0.89 kg were used. Piglets were assigned to one of four dietary treatments (n = 10): cereal and soya bean meal base diet (control), base diet with 10% Spirulina (SP), SP diet supplemented with 0.005% Rovabio® Excel AP (SP + R) and SP diet supplemented with 0.01% lysozyme (SP + L). Animals were slaughtered after a 4-week experimental period. Growth performance was negatively affected by the incorporation of Spirulina in the diets, with an average decrease of 9.1% on final weight, in comparison with control animals. Total tract apparent digestibility (TTAD) of crude protein was higher (p < .05) in the control group than in other groups. In addition, lysozyme increased TTAD of crude fat and acid detergent fibre, relative to the SP and control groups, respectively. In addition, the incorporation of Spirulina, individually and supplemented with enzymes, did not impair meat quality traits. Surprisingly, no protective effect against lipid oxidation was observed with the inclusion of Spirulina in pork after 7 days of storage. This study indicates that growth performance of post-weaning piglets was impaired by the incorporation of 10% Spirulina in the diets, which is mediated by an increase in digesta viscosity and a lower protein digestibility, as a consequence of the resistance of microalga proteins to the action of endogenous peptidases. In addition, it also indicates that lysozyme, in contrast to Rovabio® Excel AP, is efficient in the degradation of Spirulina cell wall in piglet's intestine. However, the digestion of proteins liberated by Spirulina cell wall disruption is still a challenge info:eu-repo/semantics/publishedVersion
- Published
- 2020
50. HAp-functionalized zirconia surfaces via hybrid laser process for dental applications
- Author
-
Óscar Carvalho, F. Sousa, S. Madeira, Georgina Miranda, and Filipe Samuel Silva
- Subjects
Materials science ,Scanning electron microscope ,030206 dentistry ,02 engineering and technology ,Adhesion ,021001 nanoscience & nanotechnology ,Laser ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,03 medical and health sciences ,Selective laser sintering ,0302 clinical medicine ,Machining ,law ,Surface modification ,Cubic zirconia ,Laser power scaling ,Electrical and Electronic Engineering ,Composite material ,0210 nano-technology - Abstract
The development of new approaches to improve the implant integration and subsequently its long-term maintenance is an actual challenge. In this way and trying to mimic natural bone composition, HAp-functionalized zirconia surfaces were produced by means of hybrid laser technique combining additive (laser sintering) and subtractive (laser machining) processes. Nd:YAG laser-generated textures were created to improve mechanical interlocking of hydroxyapatite (HAp) powder and consequently enhance its adhesion to zirconia surface. Different laser parameters and also different approaches were tested to optimize the textured line-patterning of zirconia surface. The created microtextures were characterized by Scanning Electron Microscopy (SEM). Furthermore, textured zirconia surfaces were functionalized with HAp by means of CO2 laser. Different power and scan speed laser parameters were tested to promote HAp retention inside of line-patterning. The results showed that it is possible to design the textured surface by changing energy density and atmosphere. Furthermore, high amount of retained and sintered bioactive material was found when high laser power and low scan speed were performed.
- Published
- 2018
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.