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Your search keyword '"Freitas, João P."' showing total 33 results
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33 results on '"Freitas, João P."'

1. Regression models for binary data with scale mixtures of centered skew-normal link functions

Author

de Freitas, João Victor B. and Azevedo, Caio L. N.

Subjects
Statistics - Methodology
Abstract

For the binary regression, the use of symmetrical link functions are not appropriate when we have evidence that the probability of success increases at a different rate than decreases. In these cases, the use of link functions based on the cumulative distribution function of a skewed and heavy tailed distribution can be useful. The most popular choice is some scale mixtures of skew-normal distribution. This family of distributions can have some identifiability problems, caused by the so-called direct parameterization. Also, in the binary modeling with skewed link functions, we can have another identifiability problem caused by the presence of the intercept and the skewness parameter. To circumvent these issues, in this work we proposed link functions based on the scale mixtures of skew-normal distributions under the centered parameterization. Furthermore, we proposed to fix the sign of the skewness parameter, which is a new perspective in the literature to deal with the identifiability problem in skewed link functions. Bayesian inference using MCMC algorithms and residual analysis are developed. Simulation studies are performed to evaluate the performance of the model. Also, the methodology is applied in a heart disease data.

Published
2024

2. Bayesian inference for scale mixtures of skew-normal linear models under the centered parameterization

Author

de Freitas, João Victor B. and Azevedo, Caio L. N.

Subjects
Statistics - Methodology
Abstract

In many situations we are interested in modeling real data where the response distribution, even conditionally on the covariates, presents asymmetry and/or heavy/light tails. In these situations, it is more suitable to consider models based on the skewed and/or heavy/light tailed distributions, such as the class of scale mixtures of skew-normal distributions. The classical parameterization of this distributions may not be good due to the some inferential issues when the skewness parameter is in a neighborhood of 0, then, the centered parameterization becomes more appropriate. In this paper, we developed a class of scale mixtures of skew-normal distributions under the centered parameterization, also a linear regression model based on them was proposed. We explore a hierarchical representation and set up a MCMC scheme for parameter estimation. Furthermore, we developed residuals and influence analysis tools. A Monte Carlo experiment is conducted to evaluate the performance of the MCMC algorithm and the behavior of the residual distribution. The methodology is illustrated with the analysis of a real data set.

Published
2024

3. Massive graviton from diffeomorphism invariance

Author

de Freitas, João M. L. and Kuntz, Iberê

Subjects
High Energy Physics - Theory, General Relativity and Quantum Cosmology
Abstract

We describe a mechanism in which the graviton acquires a mass from the functional measure without violating the diffeomorphism symmetry nor including St\"uckelberg fields. Since gauge invariance is not violated, the number of degrees of freedom goes as in general relativity. For the same reason, Boulware-Deser ghosts and the vDVZ disconinuity do not show up. The graviton thus becomes massive at the quantum level while avoiding the usual issues of massive gravity.

Published
2023

5. FUNCK: Information Funnels and Bottlenecks for Invariant Representation Learning

Author

de Freitas, João Machado and Geiger, Bernhard C.

Subjects
Computer Science - Machine Learning
Abstract

Learning invariant representations that remain useful for a downstream task is still a key challenge in machine learning. We investigate a set of related information funnels and bottleneck problems that claim to learn invariant representations from the data. We also propose a new element to this family of information-theoretic objectives: The Conditional Privacy Funnel with Side Information, which we investigate in fully and semi-supervised settings. Given the generally intractable objectives, we derive tractable approximations using amortized variational inference parameterized by neural networks and study the intrinsic trade-offs of these objectives. We describe empirically the proposed approach and show that with a few labels it is possible to learn fair classifiers and generate useful representations approximately invariant to unwanted sources of variation. Furthermore, we provide insights about the applicability of these methods in real-world scenarios with ordinary tabular datasets when the data is scarce., Comment: 28 pages

Published
2022

6. Compressed Hierarchical Representations for Multi-Task Learning and Task Clustering

Author

de Freitas, João Machado, Berg, Sebastian, Geiger, Bernhard C., and Mücke, Manfred

Subjects
Computer Science - Machine Learning
Abstract

In this paper, we frame homogeneous-feature multi-task learning (MTL) as a hierarchical representation learning problem, with one task-agnostic and multiple task-specific latent representations. Drawing inspiration from the information bottleneck principle and assuming an additive independent noise model between the task-agnostic and task-specific latent representations, we limit the information contained in each task-specific representation. It is shown that our resulting representations yield competitive performance for several MTL benchmarks. Furthermore, for certain setups, we show that the trained parameters of the additive noise model are closely related to the similarity of different tasks. This indicates that our approach yields a task-agnostic representation that is disentangled in the sense that its individual dimensions may be interpretable from a task-specific perspective., Comment: Accepted by the 2022 International Joint Conference on Neural Networks (IJCNN 2022)

Published
2022
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13. Interconnected marine habitats form a single continental-scale reef system in South America

Author

Carneiro, Pedro B. M., Ximenes Neto, Antônio R., Jucá-Queiroz, Bruno, Teixeira, Carlos E. P., Feitosa, Caroline V., Barroso, Cristiane X., Matthews-Cascon, Helena, de Morais, Jader O., Freitas, João E. P., Santander-Neto, Jones, de Araújo, Jorge T., Monteiro, Leonardo H. U., Pinheiro, Lidriana S., Braga, Marcus D. A., Cordeiro, Ralf T. S., Rossi, Sergio, Bejarano, Sonia, Salani, Sula, Garcia, Tatiane M., Lotufo, Tito M. C., Smith, Tyler B., Faria, Vicente V., and Soares, Marcelo O.

Published
2022
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15. Effect of Asymptomatic and Symptomatic COVID-19 on Acute Ischemic Stroke Revascularization Outcomes

Author

Strambo, Davide, Marto, João Pedro, Ntaios, George, Nguyen, Thanh N., Michel, Patrik, Herzig, Roman, Członkowksa, Anna, Demeestere, Jelle, Yassin Mansour, Ossama, Georgiopoulos, Georgios, Nogueira, Raul G., Salerno, Alexander, Wegener, Susanne, Baumgartner, Philipp, Cereda, Carlo W., Bianco, Giovanni, Beyeler, Morin, Arnold, Marcel, Carrera, Emmanuel, Machi, Paolo, Altersberger, Valerian, Bonati, Leo, Gensicke, Henrik, Bolognese, Manuel, Peters, Nils, Wetzel, Stephan, Magriço, Marta, Nuno Ramos, João, Sargento-Freitas, João, Machado, Rita, Maia, Carolina, Machado, Egídio, Paiva-Nunes, Ana, Ferreira, Patrícia, Pinho-e-Melo, Teresa, Carvalho-Dias, Mariana, Paula, André, Alberto Correia, Manuel, Castro, Pedro, Azevedo, Elsa, Albuquerque, Luís, Nuno-Alves, José, Ferreira-Pinto, Joana, Meira, Torcato, Pereira, Liliana, Rodrigues, Miguel, Araújo, André, Rodrigues, Marta, Rocha, Mariana, Pereira-Fonseca, Ângelo, Ribeiro, Luís, Varela, Ricardo, Cappellari, Manuel, Zivelonghi, Cecilia, Sajeva, Giulia, Zini, Andrea, Gentile, Mauro, Forlivesi, Stefano, Migliaccio, Ludovica, Sessa, Maria, Pezzini, Alessandro, Sangalli, Davide, Zedde, Marialuisa, Pascarella, Rosario, Diamanti, Susanna, Beretta, Simone, Schwarz, Ghil, Frisullo, Giovanni, Marcheselli, Simona, Seners, Pierre, Sabben, Candice, Escalard, Simon, Piotin, Michel, Maier, Benjamin, Charbonnier, Guillaume, Vuillier, Fabrice, Legris, Loic, Cuisenier, Pauline, Vodret, Francesca R., Marnat, Gaultier, Liegey, Jean-Sebastien, Sibon, Igor, Flottmann, Fabian, Broocks, Gabriel, Gloyer, Nils-Ole, Bohmann, Ferdinand O., Hendrik Schaefer, Jan, Nolte, Christian H., Audebert, Heinrich, Siebert, Eberhard, Sykora, Marek, Lang, Wilfried, Ferrari, Julia, Mayer-Suess, Lukas, Knoflach, Michael, Gizewski, Elke-Ruth, Stolp, Jeffrey, Stolze, Lotte J., Coutinho, Jonathan M., Nederkoorn, Paul J., van-den-Wijngaard, Ido, de Meris, Joke, Lemmens, Robin, De Raedt, Sylvie, Vandervorst, Fenne, Pierre Rutgers, Matthieu, Guilmot, Antoine, Dusart, Anne, Bellante, Flavio, Calleja-Castaño, Patricia, Ostos, Fernando, Gonzalez-Ortega, Guillermo, Martín-Jiménez, Paloma, García-Madrona, Sebastian, Cruz-Culebras, Antonio, Vera, Rocio, Matute, Maria-Consuelo, Fuentes, Blanca, Alonso-de-Leciñana, María, Rigual, Ricardo, Díez-Tejedor, Exuperio, Pérez-Sánchez, Soledad, Montaner, Joan, Díaz-Otero, Fernando, Perez de la Ossa, Natalia, Flores-Pina, Belén, Muñoz-Narbona, Lucia, Chamorro, Angel, Rodríguez-Vázquez, Alejandro, Renú, Arturo, Ayo-Martin, Oscar, Hernandez-Fernandez, Francisco, Segura, Tomas, Tejada-Meza, Herbert, Hlaing, Thant, See, Isaiah, Simister, Robert, Werring, David J., Saxhaug Kristoffersen, Espen, Nordanstig, Annika, Jood, Katarina, Rentzos, Alexandros, Šimůnek, Libor, Krajíčková, Dagmar, Krajina, Antonín, Mikulík, Robert, Cviková, Martina, Vinklárek, Jan, Školoudík, David, Roubec, Martin, Hurtikova, Eva, Hrubý, Rostislav, Ostry, Svatopluk, Skoda, Ondrej, Pernicka, Marek, Kočí, Lubomír, Eichlová, Zuzana, Jíra, Martin, Kovář, Martin, Panský, Michal, Mencl, Pavel, Paloušková, Hana, Tomek, Aleš, Janský, Petr, Olšerová, Anna, Šrámek, Martin, Havlíček, Roman, Malý, Petr, Trakal, Lukáš, Fiksa, Jan, Slovák, Matěj, Karliński, Michał, Nowak, Maciej, Sienkiewicz-Jarosz, Halina, Bochynska, Anna, Wrona, Pawel, Homa, Tomasz, Sawczynska, Katarzyna, Slowik, Agnieszka, Wlodarczyk, Ewa, Wiącek, Marcin, Tomaszewska-Lampart, Izabella, Sieczkowski, Bartosz, Bartosik-Psujek, Halina, Bilik, Marta, Bandzarewicz, Anna, Dorobek, Malgorzata, Zielińska-Turek, Justyna, Nowakowska-Kotas, Marta, Obara, Krystian, Urbanowski, Paweł, Budrewicz, Sławomir, Guziński, Maciej, Świtońska, Milena, Rutkowska, Iwona, Sobieszak-Skura, Paulina, Łabuz-Roszak, Beata, Dębiec, Aleksander, Staszewski, Jacek, Stępień, Adam, Zwiernik, Jacek, Wasilewski, Grzegorz, Tiu, Cristina, Terecoasă, Elena-Oana, Radu, Razvan-Alexandru, Negrila, Anca, Dorobat, Bogdan, Panea, Cristina, Tiu, Vlad, Petrescu, Simona, Özcan-Özdemir, Atilla, Mahmoud, Mostafa, El-Samahy, Hussam, Abdelkhalek, Hazem, Al-Hashel, Jasem, Ibrahim Ismail, Ismail, Salmeen, Athari, Ghoreishi, Abdoreza, Sabetay, Sergiu, Gross, Hana, Klein, Piers, Abdalkader, Mohamad, Jabbour, Pascal, El Naamani, Kareem, Tjoumakaris, Stavropoula, Abbas, Rawad, Mohamed, Ghada-A., Chebl, Alex, Min, Jiangyong, Hovingh, Majesta, Tsai, Jenny, Khan, Muhib-A., Nalleballe, Krishna, Onteddu, Sanjeeva, Masoud, Hesham E., Michael, Mina, Kaur, Navreet, Maali, Laith, Abraham, Michael, Khandelwal, Priyank, Bach, Ivo, Ong, Melody, Babici, Denis, Khawaja, Ayaz-M., Hakemi, Maryam, Rajamani, Kumar, Cano-Nigenda, Vanessa, Arauz, Antonio, Amaya, Pablo, Llanos, Natalia, Arango, Akemi, Vences, Miguel A., Barrientos, José-Domingo, Caetano, Rayllene, Targa, Rodrigo, Scollo, Sergio, Yalung, Patrick, Nagendra, Shashank, Gaikwad, Abhijit, and Seo, Kwon-Duk

Published
2024
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16. Effects of twelve weeks of dance Exergames on the quality-of-life variables of elderly Brazilian women enrolled in a community program.

Author

dos Santos, Rafaela G., de Freitas, João V.R., Alcantara, Lara M., Lopes, Giovanna G.C., Galvão, Lucas L., de Queiroz, Bruno M., Santos, Douglas A.T., de Lira, Claudio A.B., Andrade, Marilia S., Knechtle, Beat, Nikolaidis, Pantelis T., and Vancini, Rodrigo L.

Abstract

Exercise-based interventions can be a safe alternative to improve and maintain physical and mental health during the aging process. The aim of the present study was to evaluate the effects of a 12-week training program with Dance Exergames on the mood and functional fitness profile of elderly women. The sample (n = 22) was divided into Exergames (EG, n = 9, 70.6 ± 1.6 years) and Control Groups (CG, n = 13, 73.6 ± 2.2 years). Evaluations were carried out before and after the interventions. Each participant played, in pairs, the electronic game Dance Central 3, with the XBOX 360 Kinect console (Slim, Microsoft, USA). The EG trained for 12 weeks (24 sessions), with two weekly sessions of 50 min and the CG performed manual activities workshops. In functional fitness, both exercise training with exergame (EG) and the intervention model for the CG did not produce significant effects regarding interaction (group*time). Mood state presented significant effect of time intervention regarding tension (p = <0.001), depression (p = 0.001), anger (p = 0.030), fatigue (p = 0.001), and mental confusion (p = 0.004). Twelve weeks of training with a dance exergame (for, EG) and manual activities (for, CG) is enough to promote improvements in the mood state of healthy elderly women. This is an interesting result, as it shows that social interaction is as important a component as improving functional capacity. [ABSTRACT FROM AUTHOR]

Published
2023
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18. Fatigue life estimation of dental implants using a combination of the finite element method and traditional fatigue criteria

Author

Hernandez, Bruno A, Freitas, João PO, and Capello Sousa, Edson A

Abstract

Failure by fatigue can be sudden and catastrophic. Therefore, ensuring that dental implants, which are under constant cyclic loading, do not fail to fatigue is imperative. The majority of the studies about the topic only performed in vitro tests, which are expensive and time-consuming. The Finite Element (FE) method is less costly and it allows the simulation of several different loading scenarios. Nonetheless, there are only a few studies analysing fatigue in dental prostheses using FE models, and the few available did not include all the relevant parameters, such as geometry effect, surface finishing, etc. Therefore, this study aimed to analyse the fatigue behaviour of a single-unit dental implant with two screws using a combination of the numerical results and the traditional fatigue criteria – a combination that was not yet fully and correctly explored. A finite element model comprising a single implant, one abutment, one abutment screw, one fixation screw and one prosthetic crown was developed. Material properties were assigned based on literature data. A 100 Nload was applied to mimic the mastication forces and fatigue analysis was conducted using the Gerber, Goodman and Soderberg fatigue criteria. The fatigue analysis demonstrated that the abutment screw could fail in less than 1 year, depending on the criteria, while the fixation screw exhibits an infinite life. The results illustrated the importance of analysing the fatigue behaviour of dental implants and highlighted the potential of finite element models to simulate the biomechanical behaviour of dental implants.

Published
2023
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19. Acute total occlusion of the unprotected left main coronary artery: Patient characteristics and outcomes

Author

Calvão, João, Braga, Marta, Brandão, Mariana, Campinas, Andreia, Alexandre, André, Amador, Ana, Costa, Catarina, Silva, João C., Silva, Marisa, Brochado, Bruno, Freitas, João, and Macedo, Filipe

Abstract

Acute total occlusion of the unprotected left main coronary artery (LMCA) is a dramatic event. There are limited data regarding this population. We aimed to describe the clinical presentation and outcomes of patients and to determine predictors of in-hospital mortality.

Published
2023
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20. Safety and Outcome of Revascularization Treatment in Patients With Acute Ischemic Stroke and COVID-19

Author

Marto, João Pedro, Strambo, Davide, Ntaios, George, Nguyen, Thanh N., Herzig, Roman, Czlonkowska, Anna, Demeestere, Jelle, Mansour, Ossama Yassin, Salerno, Alexander, Wegener, Susanne, Baumgartner, Philipp, Cereda, Carlo W., Bianco, Giovanni, Beyeler, Morin, Arnold, Marcel, Carrera, Emmanuel, Machi, Paolo, Altersberger, Valerian, Bonati, Leo, Gensicke, Henrik, Bolognese, Manuel, Peters, Nils, Wetzel, Stephan, Magriço, Marta, Ramos, João Nuno, Sargento-Freitas, João, Machado, Rita, Maia, Carolina, Machado, Egídio, Nunes, Ana Paiva, Ferreira, Patricia, Pinho e Melo, Teresa, Dias, Mariana Carvalho, Paula, André, Correia, Manuel Alberto, Castro, Pedro, Azevedo, Elsa, Albuquerque, Luís, Alves, José Nuno, Ferreira-Pinto, Joana, Meira, Torcato, Pereira, Liliana, Rodrigues, Miguel, Araujo, Andre Pinho, Rodrigues, Marta, Rocha, Mariana, Pereira-Fonseca, Ângelo, Ribeiro, Luís, Varela, Ricardo, Malheiro, Sofia, Cappellari, Manuel, Zivelonghi, Cecilia, Sajeva, Giulia, Zini, Andrea, Gentile, Mauro, Forlivesi, Stefano, Migliaccio, Ludovica, Sessa, Maria, La Gioia, Sara, Pezzini, Alessandro, Sangalli, Davide, Zedde, Marialuisa, Pascarella, Rosario, Ferrarese, Carlo, Beretta, Simone, Diamanti, Susanna, Schwarz, Ghil, Frisullo, Giovanni, Marcheselli, Simona, Seners, Pierre, Sabben, Candice, Escalard, Simon, Piotin, Michel, Maïer, Benjamin, Charbonnier, Guillaume, Vuillier, Fabrice, Legris, Loïc, Cuisenier, Pauline, Vodret, Francesca R., Marnat, Gaultier, Liegey, Jean-Sebastien, Sibon, Igor, Flottmann, Fabian, Broocks, Gabriel, Gloyer, Nils-Ole, Bohmann, Ferdinand O., Schaefer, Jan Hendrik, Nolte, Christian, Audebert, Heinrich J., Siebert, Eberhard, Sykora, Marek, Lang, Wilfried, Ferrari, Julia, Mayer-Suess, Lukas, Knoflach, Michael, Gizewski, Elke Ruth, Stolp, Jeffrey, Stolze, Lotte J., Coutinho, Jonathan M., Nederkoorn, Paul, van den Wijngaard, Ido, De Meris, Joke, Lemmens, Robin, De Raedt, Sylvie, Vandervorst, Fenne, Rutgers, Matthieu Pierre, Guilmot, Antoine, Dusart, Anne, Bellante, Flavio, Calleja-Castaño, Patricia, Ostos, Fernando, González-Ortega, Guillermo, Martín-Jiménez, Paloma, García-Madrona, Sebastian, Cruz-Culebras, Antonio, Vera, Rocio, Matute, Maria Consuelo, Fuentes, Blanca, Alonso-de-Leciñana, María, Rigual, Ricardo, Díez-Tejedor, Exuperio, Perez-Sanchez, Soledad, Montaner, Joan, Díaz-Otero, Fernando, Pérez-de-la-Ossa, Natalia, Flores-Pina, Belén, Muñoz-Narbona, Lucia, Chamorro, Angel, Rodríguez-Vázquez, Alejandro, Renú, Arturo, Ayo-Martin, Oscar, Hernández-Fernández, Francisco, Segura, Tomas, Tejada-Meza, Herbert, Sagarra-Mur, Daniel, Serrano-Ponz, Marta, Hlaing, Thant, See, Isaiah, Simister, Robert, Werring, David, Kristoffersen, Espen Saxhaug, Nordanstig, Annika, Jood, Katarina, Rentzos, Alexandros, Šimůnek, Libor, Krajíčková, Dagmar, Krajina, Antonín, Mikulik, Robert, Cviková, Martina, Vinklárek, Jan, Školoudík, David, Roubec, Martin, Hurtikova, Eva, Hrubý, Rostislav, Ostry, Svatopluk, Skoda, Ondrej, Pernicka, Marek, Jurak, Lubomir, Eichlová, Zuzana, Jíra, Martin, Kovar, Martin, Panský, Michal, Mencl, Pavel, Palouskova, Hana, Tomek, Aleš, Janský, Petr, Olšerová, Anna, Sramek, Martin, Havlicek, Roman, Malý, Petr, Trakal, Lukáš, Fiksa, Jan, Slovák, Matěj, Karlinski, Michal Adam, Nowak, Maciej, Sienkiewicz-Jarosz, Halina, Bochynska, Anna, Wrona, Pawel, Homa, Tomasz, Sawczynska, Katarzyna, Slowik, Agnieszka, Wlodarczyk, Ewa, Wiacek, Marcin, Tomaszewska-Lampart, Izabella, Sieczkowski, Bartosz, Bartosik-Psujek, Halina, Bilik, Marta, Bandzarewicz, Anna, Dorobek, Malgorzata, Zielinska-Turek, Justyna, Nowakowska-Kotas, Marta, Obara, Krystian, Urbanowski, Paweł, Budrewicz, Slawomir, Guziński, Maciej, Świtońska, Milena, Rutkowska, Iwona, Sobieszak-Skura, Paulina, Labuz-Roszak, Beata M., Debiec, Aleksander, Staszewski, Jacek, Stępień, Adam, Zwiernik, Jacek, Wasilewski, Grzegorz, Tiu, Cristina, Terecoasă, Elena Oana, Radu, Razvan Alexandru, Negrila, Anca, Dorobat, Bogdan, Panea, Cristina, Tiu, Vlad, Petrescu, Simona, Ozdemir, Atilla, Mahmoud, Mostafa, El-Samahy, Hussam, Abdelkhalek, Hazem, Al-Hashel, Jasem, Ismail, Ismail Ibrahim, Salmeen, Athari, Ghoreishi, Abdoreza, Sabetay, Sergiu Ionut, Gross, Hana, Klein, Piers, Abdalkader, Mohamad, Jabbour, Pascal, El Naamani, Kareem, Tjoumakaris, Stavropoula, Abbas, Rawad, Mohamed, Ghada A., Chebl, Alex, Min, Jiangyong, Hovingh, Majesta, Tsai, Jenney P., Khan, Muhib, Nalleballe, Krishna, Onteddu, Sanjeeva, Masoud, Hesham, Michael, Mina, Kaur, Navreet, Maali, Laith, Abraham, Michael G., Khandelwal, Priyank, Bach, Ivo, Ong, Melody, Babici, Denis, Khawaja, Ayaz M., Hakemi, Maryam, Rajamani, Kumar, Cano-Nigenda, Vanessa, Arauz, Antonio, Amaya, Pablo, Llanos, Natalia, Arango, Akemi, Vences, Miguel Ángel, Barrientos Guerra, Jose Dominguo, Caetano, Rayllene, Martins, Rodrigo Targa, Scollo, Sergio Daniel, Yalung, Patrick Matic, Nagendra, Shashank, Gaikwad, Abhijit, Seo, Kwon-Duk, Georgiopoulos, Georgios, Nogueira, Raul G., and Michel, Patrik

Published
2023
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21. Electrospun composite fibers of PLA/PLGA blends and mesoporous silica nanoparticles for the controlled release of gentamicin sulfate.

Author

Batista, Henrique, Freitas, João P., Abrunheiro, Alexandra, Gonçalves, Teresa, Gil, Maria H., Figueiredo, Margarida, and Coimbra, Patrícia

Subjects
*MESOPOROUS silica, *SILICA nanoparticles, *FIBROUS composites, *GENTAMICIN, *POLYMERIC composites, *POLYMER solutions, *SULFATES, *POLYMER blends
Abstract

With the objective of developing a localized gentamicin sulfate (GS) delivery system with a controlled release kinetics for the prevention/management of osteomyelitis, composite electrospun fibers composed of poly(lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA) blends and GS loaded mesoporous silica nanoparticles (npSiGS) were prepared (PLA/PLGA: 1:3, 1:1, 3:1 w/w). GS was loaded into silica nanoparticles by adsorption, using a concentrated GS solution, and npSiGS were dispersed in the polymer solutions and immobilized in the polymeric matrix by occlusion, during fibers formations. For comparison, non-composite fibers with the same blend compositions containing GS simply dispersed in the polymeric phase were also produced. GS loaded nanoparticles were characterized by nitrogen adsorption/desorption isotherms and GS loading was quantified by thermogravimetric analysis. The morphology of the electrospun fibers, assessed by SEM, revealed that npSiGS were embedded along the composite fibers, some in the form of small aggregates. In vitro release studies showed that composite fibers exhibited lower initial burst releases and slower release kinetics, dependent on blend composition. Composite fibers with PLGA as the major component (25PLA-npSiGS) had the fastest release kinetics, while fibers with equal amounts of both polymers (50PLA-npSiGS) or with PLGA as the minor component (75PLA-npSiGS) had slower release kinetics, with constant GS release rates after the first day. These results suggest that PLA/PLGA blend composition can be manipulated to obtain composite fibers with a controlled and tailored GS release for at least three weeks. Finally, the antibacterial effect against Staphylococcus aureus of all produced fibers containing GS was confirmed by a disk diffusion method. [ABSTRACT FROM AUTHOR]

Published
2022
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22. Comparison of bone mineral density between female amateur triathletes and nonathletes: A cross-sectional study

Author

Cruz Correa Netto Soares, Guilherme, Barbosa Junior, José Geraldo Gomes, Seffrin, Aldo, Vivan, Lavínia, Rosa de Freitas, João Victor, Costa, Gustavo De Conti Teixeita, de Lira, Claudio André Barbosa B, Vancini, Rodrigo Luiz, Weiss, Katja, Knechtle, Beat, and Andrade, Marilia Santos

Abstract

Purpose: Physical inactivity is considered an important risk factor for osteoporosis, however, some athletes performing extremely high training volumes can also develop bone mass loss. Moreover, the effect of total body mass or body surface area on bone mineral density remains controversial. Therefore, the aim of this study was to compare the absolute bone mineral density and bone mineral density adjusted to body surface area between amateur triathletes and nonactive women.Methods: Forty-two healthy women (23 amateur triathletes and 19 nonactive individuals) were evaluated for body composition using a dual-energy X-ray absorptiometry system.Results: Compared to nonactive women, amateur triathletes exhibited lower body mass index (p < 0.001), lower bone mineral density (p < 0.001), and body surface area (p < 0.001). However, bone mineral density adjusted by body surface area in the triathletes was higher than in the nonactive women (p = 0.03).Conclusion: These findings showed that amateur triathles presented lower absolute bone mineral density, but higher bone mineral density adjusted to body surface area. Future studies are recommended to identify if the higher bone mineral density adjusted to body surface area are associated with a lower bone fragility.

Published
2024
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25. Acute management of cerebral venous thrombosis: Indications, technique, and outcome of endovascular treatment in two high-volume centers

Author

Sousa, João André, Achutegui, Maider Iza, Juega-Mariño, Jesus, Requena, Manuel, Bernardo-Castro, Sara, Rodrigo-Gisbert, Marc, Rizzo, Federica, Olivé, Marta, Garcia-Tornel, Álvaro, Chaves, Ana Carolina, Rodriguez-Villatoro, Noelia, Muchada, Marian, Pagola, Jorge, Rodriguez-Luna, David, Rubiera, Marta, Martins, Ana Inês, Silva, Fernando, Veiga, Ricardo, Nunes, Cesar, Machado, Egídio, Diana, Francesco, de Dios, Marta, Hernández, David, Ribo, Marc, Molina, Carlos, Sargento-Freitas, João, and Tomasello, Alejandro

Abstract

Introduction After several uncontrolled studies and one randomized clinical trial, there is still uncertainty regarding the role of endovascular treatment (EVT) in cerebral venous thrombosis (CVT). This study aims to describe and assess different acute management strategies in the treatment of CVT.Methods We performed a retrospective analysis of an international two-center registry of CVT patients admitted since 2019. Good outcome was defined as a return to baseline modified Rankin scale at three months. We described and compared EVT versus no-EVT patients.Results We included 61 patients. Only one did not receive systemic anticoagulation. EVT was performed in 13/61 (20%) of the cases, with a median time from diagnosis to puncture of 4.5 h (1.25–28.5). EVT patients had a higher median baseline NIHSS [6 (IQR 2–17) vs 0 (0–2.7), p= 0.002)] and a higher incidence of intracerebral hemorrhage (53.8% vs 20.3%, p= 0.03). Recanalization was achieved in 10/13 (77%) patients. Thrombectomy was performed in every case with angioplasty in 7 out of 12 patients and stenting in 3 cases. No postprocedural complication was reported. An improvement of the median NIHSS from baseline to discharge [6 (2–17) vs 1(0–3.75); p< 0.001] was observed in EVT group. A total of 31/60 patients (50.8%) had good outcomes. Adjusting to NIHSS and ICH, EVT had a non-significant increase in the odds of a good outcome [aOR 1.42 (95%CI 0.73–2.8, p= 0.307)].Conclusions EVT in combination with anticoagulation was safe in acute treatment of CVT as suggested by NIHSS improvement. Selected patients may benefit from this treatment.

Published
2024
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27. Tratamento de fraturas patológicas tumorais diafisárias do úmero com haste intramedular rígida bloqueada estática – Experiência de 22 anos

Author

Moura, Diogo Lino, Alves, Filipe, Fonseca, Rúben, Freitas, João, and Casanova, José

Abstract

Estudo retrospetivo observacional em pacientes submetidos à fixação com haste intramedular de fratura patológica tumoral consumada ou iminente da diáfise do úmero em contexto de doença tumoral disseminada ao longo de 22 anos na mesma instituição.

Published
2024
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28. SÍNDROME DE TURCOT: RELATO DE CASO

Author

Freitas, João Victor Maia, Silva, Felipe Teixeira da, Reis, Vanessa Siqueira, Testi, Isabela Augusta de Carvalho, Filho, Oswaldo de Moraes, Santos, Antônio Carlos Nóbrega dos, Martins, Bruno Augusto Alves, and de Sousa, João Batista

Published
2023
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30. LINFOMA PLASMABÁSTICO PERIANAL: RELATO DE CASO

Author

Sprogis, Rafaela de Melo, Freitas, João Victor Maia, Reis, Vanessa Siqueira, Testi, Isabela Augusta Carvalho, Santos, Antonio Carlos Nobrega dos, Barbosa, Camila Oliveira, Berford, Flavia, and de Sousa, João Batista

Published
2023
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31. EP111 ELECTRONIC WOUND RECORDS: IMPLICATIONS AND CONTRIBUTIONS TO THE CONTINUITY OF CARE.

Author

Vieira, Sofia, Sousa, Cláudia, Freitas, João, and Frade, Samuel

Subjects
WOUND care, MEDICAL quality control, KEY performance indicators (Management), CONFERENCES & conventions, CONTINUUM of care, CLINICAL medicine, ELECTRONIC health records
Abstract

Aim: To determine whether the wound records on electronic recording platforms guarantee the continuity of care, providing health indicators in the treatment of wounds and in the quality of care provided. Method: A systematic review was conducted in accordance with the Joanna Briggs Institute (JBI) recommendations. The search was conducted in September 2022 on 6 electronic databases: B-On, BVS, EBSCO/CINAHL, MEDLINE/PubMed, Scielo, Cochrane, using the descriptors "Wound healing", "Electronic health records", "Outcome assessment", "Pressure ulcer", "Wounds", having been selected 6 articles. Results / Discussion: It was found that electronic records in the assessment and treatment of wounds are fundamental regarding internal regulations, continuity of care, reducing the level of documentation error, reducing running costs and increasing wound care capacity. When comparing the use of paper and electronic registers, there was a wide preference of patients and health professionals in the electronic version of the records. The use of electronic health records, although at an early stage, is extremely useful in nursing care, although it is necessary to ensure that they are intuitive and user-friendly, so as to not further increase the complexity of the records and workload of health professionals. Conclusion: The use of electronic records benefits the continuity, quality and safety of the care provided and encourages communication between health professionals. As future projects, we intend to make our contribution to professional practice, incorporating the results of this study into clinical practice, through the implementation of a project aimed at creating a platform for recording wounds. [ABSTRACT FROM AUTHOR]

Published
2023

32. Single-phase CT angiography predicts ASPECTS decay and may help determine when to repeat CT before thrombectomy.

Author

Sousa, João André, Machado, Ana Rita, Rito-Cruz, Luís, Paiva-Simões, Joana, Santos-Martins, Leonor, Bernardo-Castro, Sara, Martins, Ana Inês, Brás, Ana, Almendra, Luciano, Cecília, Carla, Machado, Cristina, Rodrigues, Bruno, Galego, Orlando, Nunes, César, Veiga, Ricardo, Santo, Gustavo, Silva, Fernando, Machado, Egídio, and Sargento-Freitas, João

Abstract

Objetives: Time is relative in large-vessel occlusion acute ischemic stroke (LVO-AIS). We aimed to evaluate the rate of inter-hospital ASPECTS decay in patients transferred from a primary (PSC) to a comprehensive stroke center (CSC); and to identify patients that should repeat computed tomography (CT) before thrombectomy.Materials and Methods: This was a retrospective cohort study of consecutive anterior circulation LVO-AIS transferred patients. The rate of ASPECTS decay was defined as (PSC-ASPECTS - CSC-ASPECTS)/hours elapsed between scans. Single-phase CT angiography (CTA) at the PSC was used to classify the collateral score. We compared patients with futile versus useful CT scan re-evaluation.Results: We included 663 patients, of whom 245 (37.0%) repeated CT at a CSC. The median rate of ASPECTS decay was 0.4/h (0.0-0.9). Patients excluded from thrombectomy after a CT scan repeat (n=64) had a median ASPECTS decay rate of 1.18/h (0.83-1.61). Patients with absent collateral circulation had a median rate of 1.51(0.65-2.19). The collateral score was an independent predictor of the ASPECTS decay rate (aβ = -0.35; 95%CI -0.45 - -0.19, p<0.001). Age (aOR: 1.04 95% CI 1.02-1.07, p<0.001), NIHSS (aOR: 1.11 95% CI 1.06-1.15, p<0.001), PSC ASPECTS (aOR: 0.74 95% CI 0.60-0.91, p=0.006) and the CTA collateral score (aOR: 0.14 95% CI 0.08-0.22, p<0.001) were independent predictors of the usefulness of a CT scan repeat.Conclusions: The rate of ASPECTS decay can be predicted by the CTA collateral score, helping in the selection of patients that would benefit from repeating a CT assessment on arrival at the CSC. [ABSTRACT FROM AUTHOR]

Published
2022
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33. Acute Myocardial Infarction after Intravenous Thrombolysis for Acute Ischemic Stroke: Case Series and Systematic Review.

Author

Marto, João Pedro, Kauppila, Linda Azevedo, Jorge, Cláudia, Faustino, Pedro, Sargento-Freitas, João, Pereira, Liliana, Galego, Sofia, Dias, Rafael, Castro, Pedro, Pinho-e-Melo, Teresa, and Fonseca, Ana Catarina

Abstract

Background and Objectives: Intravenous thrombolysis (IV-rtPA) has been suggested as a potential cause of myocardial infarction (MI) after acute ischemic stroke (AIS), with randomized clinical trials showing a higher number of cardiac events within the thrombolysis group. We assessed the prevalence and MI mechanisms after IV-rtPA for AIS.Methods: Retrospective review of consecutive AIS patients admitted to six stroke units and systematic literature review searching for AIS patients who suffered a MI less than 24 h after IV-rtPA. In those with available coronary angiography, MI etiology was defined as atherosclerotic or embolic. Patients' characteristics were compared between groups.Results: Fifty-two patients were included. Thirty-two patients (61.5%) derived from hospital cases, after reviewing 6958 patients treated with IV-rtPA [0.5% (95% CI 0.38-0.54) of total hospital cases]. After coronary angiography (n = 25, 48.1%), 14 (54%) patients were considered to have an atherosclerotic MI, and 11 (46%) due to coronary embolism. Patients with an embolic MI more frequently had a cardioembolic AIS (72.7% vs 28.6%; p-value = 0.047) and an intracardiac thrombus (27.3% vs 0.0%; p-value = 0.044). Although not statistically significant, patients with an embolic MI had apparent lower time intervals between starting IV-rtPA infusion and MI occurrence [2 h (0.2-3.0) vs 3 h (1.0-15.0); p-value = 0.134].Conclusions: MI within the first 24 h after IV-rtPA for AIS is an infrequent event, and more frequently non-embolic. However, the prevalence of embolic MI was superior to what is found in the general population with MI. There was an association between the pathophysiology of AIS and MI. The low number of events and publication bias may have limited our conclusions. [ABSTRACT FROM AUTHOR]

Published
2022
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