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SSRN 2025年

作者： Coelho, Nathalia B.M. Alves, Arthur de Souza Borges Zuchet Santos, Carla J. Neves, Lúcio P. Perini, Ana P. Belinato, Walmir Ferreira, José Rafael S. Santos, William S. Postgraduate Program in Biomedical Engineering Faculty of Electrical Engineering Federal University of Uberlândia Uberlândia Brazil Institute of Physics Federal University of Uberlândia Uberlândia Brazil Federal Institute of Bahia - IFBA BA Vitória da Conquista Brazil Department of Physics Federal University of Sergipe São Cristóvão Brazil Universidade Federal da Bahia Brazil

The use of radionuclides for therapeutic and diagnostic purposes is the primary function of nuclear medicine. Among these radionuclides, the iodine family stands out as isotopes that can serve various purposes, including brachytherapy, scintigraphy, and research. The internal dosimetry of these nuclides becomes even more important when considering high-risk groups such as pregnant patients, as it involves concerns for both the mother and the fetus. This study aims to use Monte Carlo simulations to calculate S-values for a set of target organs in both the pregnant woman and the fetus, considering different source organs in the mother and three iodine isotopes: 131I, 125I, and 123I. The results indicated that 131I, with the highest emission energy, presented a high dose deposition pattern in target organs farther from the source organs, while 125I, with the lowest energy, showed a localized dose absorption pattern in adjacent organs. The highest S-values (all in mGy/MBq.s) were obtained for the pregnant woman, with values of 5.8E-05 in the thyroid using 123I and 125I, and 3.7E-04 in the bladder using 131I. For fetal organs, the most irradiated were the brain and skull using 131I, with values of 6.3E-06 and 5.6E-06, respectively, while the lowest values were associated with the use of 125I in source organs distant from the target organ, with contributions as low as 1E-12 for the thyroid as a source. This work presents a qualitative and quantitative study of the internal dosimetry of a pregnant patient and her fetus, addressing variables such as radioactive isotope and source and target organs, serving as a reference for dosimetric calculations deemed necessary in clinical practices to minimize the dose received by this critical group. © 2025, The Authors. All rights reserved.

关键词： Nuclear medicine

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Multilocus sequence typing of Treponema pallidum in male patients with genital ulcers in a public sexually transmitted infections clinic: a new allele and almost complete macrolide resistance

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Anais Brasileiros de Dermatologia 2025年第3期100卷 569-573页

作者： Esteves, Leonardo Souza Grassi, Vera Mileide Trivellato Grassi, Liliane Trivellato Nicola, Maria Rita Castilhos Silva, Marcia Susana Nunes Rossetti, Maria Lucia Rosa Ramos, Mauro Cunha Laboratory of Molecular Biology Applied to Microbacteria Fundação Oswaldo Cruz RJ Rio de Janeiro Brazil Program in Cellular and Molecular Biology Applied to Health Sciences Universidade Luterana do Brasil RS Canoas Brazil Biomedical Engineering Universidade Luterana do Brasil RS Canoas Brazil Sanitary Dermatology Outpatient Unit Secretaria Estadual de Saúde RS Porto Alegre Brazil DNTech - Development of New Technologies LTDA Agência Estadual de Pesquisa Desenvolvimento e Inovação do Rio Grande do Sul / Financiadora de Estudos e Projetos RS Porto Alegre Brazil Postgraduate Program Faculdade de Biologia Celular e Molecular Aplicada à Saúde Universidade Luterana do Brasil RS Canoas Brazil

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A Two-stage Reconfiguration in Network Function Virtualization: Toward Service Function Chain Optimization

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IEEE Transactions on Network and Service Management 2025年

作者： Assis, Karcius D. R. Almeida, Raul C. Baghban, Hojjat Santos, Alex F. Boutaba, Raouf Electrical and Computer Engineering Department Salvador Brazil University of Waterloo David R. Cheriton School of Computer Science Canada Department of Electronics and Systems Recife Brazil Chang Gung University Department of Artificial Intelligence Taiwan Chang Gung University College of Intelligent Computing Taiwan Center of Science and Technology in Energy and Sustainability Brazil Postgraduate Program in Computer Science Bahia Brazil

Network Function Virtualization (NFV), as a promising paradigm, speeds up the service deployment by separating network functions from proprietary devices and deploying them on common servers in the form of software. Any service in NFV-enabled networks is achieved as a Service Function Chain (SFC) which consists of a series of ordered Virtual Network Functions (VNFs). However, migration of VNFs for more flexible services within a dynamic NFV-enabled network is a key challenge to be addressed. Current VNF migration studies mainly focus on single VNF migration decisions without considering the sharing and concurrent migration of VNF instances. In this paper, we assume that each deployed VNF is used by multiple SFCs and deal with the optimal placement for the contemporaneous migration of VNFs based on the actual network situation. We formalize the VNF migration and SFC reconfiguration problem as a mathematical model, which aims to minimize the VNF migration between nodes or the total number of core changes per node. The approach is a two-stage MILP based on optimal order to solve the reconfiguration. Extensive evaluation shows that the proposed approach can reduce the change in terms of location or number of cores per node in a 6-node and 14-node networks while ensuring network latency compared with the model without reconfiguration. © 2004-2012 IEEE.

关键词： Network function virtualization

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The effect of smart mirror environment on proprioception factors of children with Down syndrome

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Research on Biomedical engineering 2020年第2期36卷 187-195页

作者： Valencia-Jimenez, Nicolas da Luz, Sheila Santos, Dayse Souza, Mariane Bastos, Teodiano Frizera, Anselmo Postgraduate Program in Electrical Engineering Federal University of Espirito Santo Vitoria Brazil Postgraduate Program in Biotechnology Federal University of Espirito Santo Vitoria Brazil Postgraduate Program in Psychology Federal University of Espirito Santo Vitoria Brazil

Purpose: Down syndrome (DS) is the most common cause of intellectual disability worldwide and the most common genetic disorder, which generates problems regarding the functionality and independence to perform activities of daily living (ADLs). This study aims at developing a smart mirror environment (SME) to assist in the evaluation of proprioception skills in children with Down syndrome (CwDS) through an automated analysis of corporal movements with RGB-D camera. Methods: The SME is implemented following a clinical protocol to objectively elicit cognitive and proprioceptive skills, in addition to practical needs and requirements raised by psychologists and physical therapists. The system is proposed as a complement to conventional assessments and motor development evaluation, providing support to professionals in generating objective parameters for analysis during physical training and therapy. Results: The results demonstrate the significance of the parameters obtained in the assessment protocol with the virtual immersion generated by the SME, where the proprioception was evaluated and the kinesthetic sense was improved in 29.9%. In the same way, we found an important influence of the intervention with visual feedback, which can help CwDS to develop their skills more efficiently, such as in the body drawings made after using the SME, presenting human body design improvement compared with the drawings made before the interaction. Conclusion: This work enhances the importance of our quantitative assessment, which provides objective parameters of the proprioception progress in CwDS, indicating that they need more stimulation to satisfactorily develop certain body skills. © 2020, Sociedade Brasileira de Engenharia Biomedica.

关键词： Mirrors

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PRECIPITATION AND RECRYSTALLIZATION DURING PROCESSING OF A SUPERPLASTIC AL-10MG-0.1ZR ALLOY

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MATERIALS SCIENCE AND engineering A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 1993年第1-2期166卷 135-143页

作者： MCNELLEY, TR CROOKS, R KALU, PN ROGERS, SA Materials Engineering Program Department of Mechanical Engineering Naval Postgraduate School Monterey CA 93943 USA

Microstructural evolution during thermomechanical processing (TMP) of a superplastic Al-10Mg-0.1Zr (weight per cent) alloy was studied. The TMP was carried out at 300-degrees-C and consisted of 12 rolling passes corresponding to a total strain of 2.5. Superplastic elongations at 300-degrees-C exceeded 1 000% for an optimum processing schedule involving a 30 min interpass anneal (IPA) time. Precipitation of the intermetallic beta-phase (Al8Mg5) was complete at an accumulated strain of 1.5 and the precipitate particle size and size distribution were found to be nearly constant for the remainder of the TMP. Particle stimulated nucleation (PSN) of recrystallization associated with prolonged IPA times accounted for the grain refinement necessary to support superplastic deformation. A model for PSN is applied to the data.

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Understanding the effect of preparation technique and compaction pressure on the microstructure, sinterability and mechanical properties of the Cu-20 wt% WC composite prepared with recycled WC

Journal of Alloys and Compounds Communications

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Journal of Alloys and Compounds Communications 2025年 6卷

作者： Rafael A. Raimundo Franciné A. Costa Marco A. Morales Daniel A. Macedo Angelus G.P. Silva Uílame U. Gomes Federal University of Paraíba Department of Materials Science and Engineering João Pessoa PB 58051-900 Brazil TEMA – Centre for Mechanical Technology and Automation Department of Mechanical Engineering University of Aveiro Aveiro 3810-193 Portugal Mechanical Engineering Postgraduate Program UFRN Natal 59078-970 Brazil Department of Theoretical and Experimental Physics UFRN Natal 59078-970 Brazil Materials Science and Engineering Postgraduate Program UENF Campos dos Goytacazes 28015-620 Brazil Materials Science and Engineering Postgraduate Program UFRN Natal 59078-970 Brazil

The study investigated the impact of different preparation techniques (Mechanical Mixing - MM and High Energy Milling - HEM) and compaction pressures on the microstructure, sinterability and mechanical properties of the Cu-20 %WC composite using recycled WC. The results indicated that HEM promotes greater homogeneity, dispersion and refinement of the WC phase in copper, resulting in denser and more uniform microstructures after sintering. Although higher pressures increased the density of green compacts, they reduced densification during sintering, especially for powders prepared by MM, due to the segregation of the Cu and WC phases. On the other hand, compacts sintered with HEM powders prsented higher Vickers microhardness and better magnetic properties, attributed to the uniform distribution of WC particles and the increase in the interaction between the phases. Furthermore, the study highlights the influence of metallic impurities (Fe, Co and Ni) on the magnetic properties of the composite materials.

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Cost-saving electrical energy consumption in underground ventilation by the use of ventilation on demand

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Mining Technology: Transactions of the Institute of Mining and Metallurgy 2020年第1期129卷 1-8页

作者： de Vilhena Costa, Leandro Margarida da Silva, José Postgraduate Program in Mineral Engineering– PPGEM UFOP Ouro Preto Brazil

Electricity is one of the biggest expenses associated with underground mining and ventilation often accounts for 50% of the total electricity use. Ventilation on demand is not widely used in Brazil, but the Ipueira, Cuiaba, and Corrego do Sitio I mines reported savings of 26%, 30%, and 21%, respectively, following its application. Frequency inverters are used to control the rotation of the main fans during shift changes. The Cuiaba mine has a control room and fans are monitored online using wireless scattered sensors. Data from field studies were compared to other foreign mines. The results showed that the application of this technique, even in an experimental way, can reduce electricity consumption significantly. Despite the energy savings that can be achieved by providing air only when/where it is needed, the costs of automation, software, and infrastructure mean that it is not practical to apply this technique at a more advanced level. © 2019, © 2019 Institute of Materials, Minerals and Mining and The AusIMM Published by Taylor & Francis on behalf of the Institute and The AusIMM.

关键词： Energy utilization

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Production of cobalt- and manganese-based oxide nanofibers via solution blow spinning: Structural properties and high-performance oxygen evolution reaction

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Applied Surface Science 2025年 703卷

作者： Pereira, Thiago O. Raimundo, Rafael A. Alves, Ricardo F. Morales, Marco A. Simões, Thiago A. Medeiros, Eliton S. Macedo, Daniel A. Dutra, Ricardo P.S. Materials Science and Engineering Postgraduate Program Federal University of Paraíba PB João Pessoa58051-900 Brazil TEMA – Centre for Mechanical Technology and Automation Department of Mechanical Engineering University of Aveiro Aveiro3810-193 Portugal Department of Mechanical Engineering Federal University of Paraíba PB João Pessoa58051-900 Brazil Department of Theoretical and Experimental Physics Federal University of Rio Grande do Norte Natal59078-970 Brazil Cabo de Santo Agostinho PE 54518-430 Brazil Department of Materials Engineering Federal University of Paraíba PB João Pessoa58051-900 Brazil

Cobalt- and manganese-based oxides (Co3O4, MnCo2O4, and CoMn2O4) with nanofiber-like morphology were successfully synthesized via solution blow spinning (SBS) and evaluated as electrocatalysts for the oxygen evolution reaction (OER). The structural, morphological, and surface properties of the prepared materials were investigated through x-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Fourier-transform infrared (FTIR), Raman spectroscopy, x-ray photoelectron spectra (XPS), and magnetic measurements. The magnetic characterization of MnCo2O4, CoMn2O4, and Co3O4 confirmed their phase purity and expected magnetic behavior. MnCo2O4 exhibited ferromagnetic ordering (θ = +145 K) with Hc = 8200 Oe and Ms = 11.9 emu/g at 5 K. CoMn2O4 showed multiple transitions at 178 K, 169 K, and 81 K, suggesting ferrimagnetic ordering. Co3O4 displayed antiferromagnetic behavior with a Néel temperature of 37 K. These results corroborate with the literature, validating the synthesis and characterization. X-ray photoelectron spectroscopy (XPS) analysis confirmed the oxidation states of Co and Mn and the presence of oxygen vacancies in CoMn2O4, MnCo2O4, and Co3O4. The Oads/Olats ratio indicated a higher concentration of oxygen vacancies in CoMn2O4 (1.21), while MnCo2O4 exhibited the highest Mn4+ content (Mn4+/Mn3+ = 0.76). The Co3+/Co2+ ratio was higher in MnCo2O4 (1.94), suggesting enhanced oxidation stability. The electrochemical characterization for OER in 1 M KOH electrolyte of the CoMn2O4, MnCo2O4, and Co3O4 samples displayed overpotentials of 330, 348, and 375 mV, respectively, to achieve a current density of 10 mA cm−2. Cyclic voltammetry and electrochemical impedance spectroscopy further corroborate these findings. The electrodes exhibited great stability maintaining their performance for 20 h. A detailed surface chemistry analysis showed that oxygen vacancy-rich samples exhibited enhanced charge transfer and generated Mn catalytic sites that facilitated

关键词： Fourier transform infrared spectroscopy

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Evaluation of fluoride concentration in toothpastes with antimicrobial molecules commercialized in Brazil

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Research on Biomedical engineering 2021年第1期37卷 9-14页

作者： Medeiros, Maria da Conceição de Araújo Valadas, Lídia Audrey Rocha Lotif, Mara Assef Leitão Bottenberg, Peter Marciano, Fernanda Roberta Biomedical Engineering Postgraduate Program Brazil University São Paulo Brazil Development and Technological Innovation in Medicines Postgraduate Program Federal University of Ceara Fortaleza Brazil Brussels Belgium

Purpose: This study aimed to analyze the fluoride concentrations in different dentifrices with antimicrobial and natural molecules marketed in Brazil. Thus, 12 dentifrices were selected to be analyzed for the concentration of total fluoride (TF), total soluble fluoride (TSF) and ionizable fluoride (IF). Methods: Two tubes of each brand were purchased at different locations. The samples were analyzed in duplicates using an ion-specific electrode and the concentrations were determined in μg F/g. Results: The TF of all calcium carbonate dentifrices showed averages below 1500 ppm F. Regarding TSF, only one toothpaste had an average above 1000 ppm F−, while the IF values were almost 500 ppm F. In the analysis of fluoride in dentifrices which present silica as abrasive, the TF presented averages below 1500 ppm F, while the TSF all presented averages close to 1000 ppm F−, and the IF values varied from close to 500 ppm to more than 1000 ppm F. In dentifrices whose formulation contained calcium carbonate associated with silica or other formulations such as sodium bicarbonate, the TF, TSF, and IF values were all above 1000 ppm F. Conclusion: The evaluated dentifrices generally showed TF concentrations lower than those declared on the packaging;however, the TSF content remained close to 1000 ppm F. It can be concluded that the analyzed dentifrices with antimicrobial molecules showed values close to those suggested regarding anti-caries effect. © 2020, Sociedade Brasileira de Engenharia Biomedica.

关键词： Calcium carbonate

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Study of doxorubicin release carried out by pH-responsive chitosan-alginate hydrogels

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Journal of Molecular Liquids 2025年 429卷

作者： Oliveira, Thayane Portela da Silva, Jhaemely Gabrielly Vieira Costa, Paloma Maia de Oliveira, Maykol Christian Damasceno Coelho, Ronaldo Cunha Santos Nascimento, Ariane Maria Silva Silva-Filho, Edson Cavalcanti dos Santos, Francisco Eroni Paz Muniz, Edvani Curti Postgraduate Program in Engineering and Materials Science Federal University of Piauí PI Teresina64049550 Brazil Physics Department Federal University of Piauí PI Teresina64049550 Brazil Department of Teacher Training Instituto Federal do Piauí PI Teresina64053-390 Brazil Chemistry Department Federal University of Piauí PI Teresina64049550 Brazil Chemistry Department State University of Maringá PR Maringá87020-900 Brazil

The use of polysaccharides in drug delivery systems has attracted increasing interest due to their functional properties. Among these, alginate (ALG) and chitosan (CH) are promising candidates for sustained drug delivery as they respond to pH, ensuring that the compound is released in a desired area. In this research physical hydrogels based on alginate and chitosan (ALG/CH) were prepared by varying the synthesis parameters (ALG at ALG/CH ratio, pH and speed stirring) and the effects of such parameters on hydrogels’ chemical and physical structure were accessed through several techniques. Also, the effects synthesis parameters on fractional release (Fmax), half time (t1/2) and percentage encapsulation efficiency (EE%), as the evaluated responses, were statically measured using a factorial design. Analysis through Raman and FTIR spectroscopies revealed the modes and bands corresponding to the precursors, confirming the formation of physically cross-linked hydrogels. The porous structure of the materials was confirmed by scanning electron microscopy (SEM). The swelling capacities of the hydrogels were analyzed at different pHs (5.4 and 7.4) and demonstrated that absorption increases in slightly acidic media. TG/DTG and Micro-CT analyzes of the sample with the greatest swelling showed that the degradation of the hydrogel occurs in two endothermic events and that the material possesses several sized and interconnected pores. The doxorubicin (DOX) release study showed that the release rate is higher as the higher proportion of CH relative to ALG. The factorial design analysis indicated the statistically significant factors in the DOX release tests. Thus, the results suggest that ALG/CH hydrogels can be tuned during their preparation to achieve optimal structure for pH-responsive to be applied for DOX releasing system. © 2025 Elsevier B.V.

关键词： Microgels

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