The Synergistic Effect of Polymer Composition, Solvent Volatility, and Collector Distance on Pullulan and PVA Fiber Production by Rotary Jet Spinning

Leonardo de Souza,Alex Carvalho Alavarse,Marco Aurélio da Vinci,Jean-Jacques Bonvent 한국섬유공학회 2021 Fibers and polymers Vol.22 No.4

Rotary jet spinning (RJS) method is showing a growing interest as one of the most efficient techniques for micro/nanofibers production. This paper reports the investigation on the influence of the pullulan/PVA blend solution composition,the solvent volatility and spinneret-collector distance on the fiber’s diameters produced by RJS technique. To optimize thenumber of required experiments for a complete evaluation, a central composite rotatable design (CCRD) and responsesurface methodology (RSM) were applied by means of Design Expert software. The fibrous mats morphology and thermalstability were analyzed as a function of the different parameters investigated. It was found a strong dependence of the fiberdiameter on the blend composition and DMSO content, which could be explained mainly by the rheological properties of thepolymer solution. The Response Surface Methodology analysis shows that the complex influence of the independentvariables on the fiber’s diameter could be fitted by an empirical model.

Dynamic analysis of buildings considering the effect of masonry infills in the global structural stiffness

de Souza Bastos, Leonardo,Guerrero, Carolina Andrea Sanchez,Barile, Alan,da Silva, Jose Guilherme Santos Techno-Press 2019 Coupled systems mechanics Vol.8 No.2

This research work presents a study that aims to assess the dynamic structural behaviour and also investigate the human comfort levels of a reinforced concrete building, when subjected to nondeterministic wind dynamic loadings, considering the effect of masonry infills on the global stiffness of the structural model. In general, the masonry fills most of the empty areas within the structural frames of the buildings. Although these masonry infills present structural stiffness, the common practice of engineers is to adopt them as static loads, disregarding the effect of the masonry infills on the global stiffness of the structural system. This way, in this study a numerical model based on sixteen-storey reinforced concrete building with 48 m high and dimensions of $14.20m{\times}15m$ was analysed. This way, static, modal and dynamic analyses were carried out in order to simulate the structural model based on two different strategies: no masonry infills and masonry infills simulated by shell finite elements. In this investigation, the wind action is considered as a nondeterministic process with unstable properties and also random characteristics. The fluctuating parcel of the wind is decomposed into a finite number of harmonic functions proportional to the structure resonant frequency with phase angles randomly determined. The nondeterministic dynamic analysis clearly demonstrates the relevance of a more realistic numerical modelling of the masonry infills, due to the modifications on the global structural stiffness of the building. The maximum displacements and peak accelerations values were reduced when the effect of the masonry infills (structural stiffness) were considered in the dynamic analysis. Finally, it can be concluded that the human comfort evaluation of the sixteen-storey reinforced concrete building can be altered in a favourable way to design.

Brain Neuroplasticity after Treatment with Antiseizure: A Review

Débora Lopes Silva de Souza,Hosana Mirelle Goes e Silva Costa,Francisca Idalina Neta,Paulo Leonardo Araujo de Gois Morais,Luís Marcos de Medeiros Guerra,Fausto Pierdoná Guzen,Lucídio Clebeson de Olive 대한정신약물학회 2023 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.21 No.4

Epilepsy is a disease characterized by the periodic occurrence of seizures. Seizures can be controlled by antiseizure medications, which can improve the lives of individuals with epilepsy when given proper treatment. Therefore, this study aimed to review the scientific literature on brain neuroplasticity after treatment with antiseizure drugs in different regions of the brain. According to the findings, that several antiseizure, such as lamotrigine, diazepam, levetiracetam, and valproic acid, in addition to controlling seizures, can also act on neuroplasticity in different brain regions. The study of this topic becomes important, as it will help to understand the neuroplastic mechanisms of these drugs, in addition to helping to improve the effectiveness of these drugs in controlling the disease.

Partial denture metal framework may harbor potentially pathogenic bacteria

Cristiane Machado Mengatto,Leonardo Marchini,Luciano Angelo de Souza Bernardes,Sabrina Carvalho Gomes,Alecsandro Moura Silva,Célia Marisa Rizzatti-Barbosa 대한치과보철학회 2015 The Journal of Advanced Prosthodontics Vol.7 No.6

PURPOSE. The aim of this study was to characterize and compare bacterial diversity on the removable partial denture (RPD) framework over time. MATERIALS AND METHODS. This descriptive pilot study included five women who were rehabilitated with free-end mandibular RPD. The biofilm on T-bar clasps were collected 1 week (t1) and 4 months (t2) after the RPD was inserted (t0). Bacterial 16S rDNA was extracted and PCR amplified. Amplicons were cloned; clones were submitted to cycle sequencing, and sequences were compared with GenBank (98% similarity). RESULTS. A total of 180 sequences with more than 499 bp were obtained. Two phylogenetic trees with 84 (t1) and 96 (t2) clones represented the bacteria biofilm at the RPD. About 93% of the obtained phylotypes fell into 25 known species for t1 and 17 for t2, which were grouped in 5 phyla: Firmicutes (t1=82%; t2=60%), Actinobacteria (t1=5%; t2=10%), Bacteroidetes (t1=2%; t2=6%), Proteobacteria (t1=10%; t2=15%) and Fusobacteria (t1=1%; t2=8%). The libraries also include 3 novel phylotypes for t1 and 11 for t2. Library t2 differs from t1 (P=.004); t1 is a subset of the t2 (P=.052). Periodontal pathogens, such as F. nucleatum, were more prevalent in t2. CONCLUSION. The biofilm composition of the RPD metal clasps changed along time after RPD wearing. The RPD framework may act as a reservoir for potentially pathogenic bacteria and the RPD wearers may benefit from regular follow-up visits and strategies on prosthesis-related oral health instructions.

Innovative Analysis for Parameter Estimation Quality

Marina B. A. Souza,Leonardo de Mello Honório,Edimar José de Oliveira 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.1

This paper performs an analysis of the solution space influence of a nonlinear dynamic system on theparameter estimation quality. For parameters estimation, the proposed approach uses an Optimal Input Design(OID) as the Suboptimal Excitation Signal Generation and Optimal Parameter Estimation (SOESGOPE). Basedon the studies of a small mobile robot that is represented by a parametric mathematical model indicate that themodel reliability level maximizes using the shortest set of parameters. Applications, qualities, and limitations of themethod are analyzed considering the solution space. Through an in-depth analysis of the identification process ofa differential mobile robot, the paper becomes a reference for a review of a nonlinear dynamic system, aiming toselect the most suitable model for the identification process.

Recursive Approach of Sub-Optimal Excitation Signal Generation and Optimal Parameter Estimation

Marina B. A. Souza,Leonardo de Melo Honório,Edimar José de Oliveira,António Paulo G. M. Moreira 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.8

Optimal Input Design (OID) methodologies are developed to find a signal that could best estimate a set of parameters of a given model. Their application in constrained nonlinear systems, especially when the search space limits or the initial conditions are unknown, may present several difficulties due to the numerical instability related to the optimization processes. A good choice over the parameters possible ranges is a trade-off among numerical stability, search space size, and effectiveness, and it is hardly found. To deal with this problem, this paper proposes a series of changes in the Sub-Optimal Excitation Signal Generation and Optimal Parameter Estimation (SOESGOPE) methodology. First, the limits over the parameters are tightly adjusted according to their confidence. A recursive approach runs the optimization methodology, analyzes the solution’s feasibility and marginal costs given by the Lagrange Multipliers, and selects a direction that could improve the system’s response. This approach improves the convergence and the assertiveness of the estimation process. To validate this approach, some cases, including a parameters estimation of a mobile robot nonlinear system, are tested.

Antimicrobial activity of tea tree oil nanoparticles against American and European foulbrood diseases agents

Roberto Christ Vianna Santos,Leonardo Quintana Soares Lopes,Camilla Filippi dos Santos Alves,Viviane Pedroso Fausto,Kauana Pizzutti,Victor Barboza,Marcia Ebling de Souza,Renata Platchek Raffin,Patrici 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3

Paenibacillus larvae and Melissococcus plutonius are the primary bacterial pathogens of honeybees and the causativeagents of American and European foulbrood disease (AFB and EFB) respectively. Such diseases have beengaining importance since there are few therapeutic options beyond the reporting of microorganisms resistantto conventional antibiotics. Due to the inefficiency and/or lowefficacy of some antibiotics, researches with nanotechnologyrepresent, possibly, new therapeutic strategies. Nanostructured drugs have presented some advantagesover the conventional medicines, such as slow, gradual and controlled release, increased bioavailability,and reduced side-effects, among others. In this study, in vitro antimicrobial activity of tea tree oil (TTO) nanoparticlesagainst Paenibacillus species, including P. larvae and M. plutonius strains was evaluated. Minimal inhibitoryconcentration (MIC) in Mueller–Hinton or KSBHI broth by the microdilution method was assessed. TTO registeredMIC values of 0.18–6.25%, while the MIC values obtained for the TTO nanoparticle were of 0.01–0.93%. The possible toxic effect of TTO and TTO nanoparticle has been assessed by the spraying application method inthe concentrations higher than the MICs. Bee mortality was evident only in treatment with TTO and the TTOnanoparticles show no toxic effects after 7 days of observation. Our results showed for the first time that TTOnanoencapsulation presented a high activity against Paenibacillus species and M. plutonius strains showing thatthe use of nanotechnology may represent one alternative way for the treatment or prevention of AFB and EFB.

Partial denture metal framework may harbor potentially pathogenic bacteria

Mengatto, Cristiane Machado,Marchini, Leonardo,de Souza Bernardes, Luciano Angelo,Gomes, Sabrina Carvalho,Silva, Alecsandro Moura,Rizzatti-Barbosa, Celia Marisa The Korean Academy of Prosthodonitics 2015 The Journal of Advanced Prosthodontics Vol.7 No.6

PURPOSE. The aim of this study was to characterize and compare bacterial diversity on the removable partial denture (RPD) framework over time. MATERIALS AND METHODS. This descriptive pilot study included five women who were rehabilitated with free-end mandibular RPD. The biofilm on T-bar clasps were collected 1 week ($t_1$) and 4 months ($t_2$) after the RPD was inserted ($t_0$). Bacterial 16S rDNA was extracted and PCR amplified. Amplicons were cloned; clones were submitted to cycle sequencing, and sequences were compared with GenBank (98% similarity). RESULTS. A total of 180 sequences with more than 499 bp were obtained. Two phylogenetic trees with 84 ($t_1$) and 96 ($t_2$) clones represented the bacteria biofilm at the RPD. About 93% of the obtained phylotypes fell into 25 known species for $t_1$ and 17 for $t_2$, which were grouped in 5 phyla: Firmicutes ($t_1=82%$; $t_2=60%$), Actinobacteria ($t_1=5%$; $t_2=10%$), Bacteroidetes ($t_1=2%$; $t_2=6%$), Proteobacteria ($t_1=10%$; $t_2=15%$) and Fusobacteria ($t_1=1%$; $t_2=8%$). The libraries also include 3 novel phylotypes for $t_1$ and 11 for $t_2$. Library $t_2$ differs from $t_1$ (P=.004); $t_1$ is a subset of the $t_2$ (P=.052). Periodontal pathogens, such as F. nucleatum, were more prevalent in $t_2$. CONCLUSION. The biofilm composition of the RPD metal clasps changed along time after RPD wearing. The RPD framework may act as a reservoir for potentially pathogenic bacteria and the RPD wearers may benefit from regular follow-up visits and strategies on prosthesis-related oral health instructions.

Control and Reorganization of Heterogeneous Vehicle Platoons after Vehicle Exits and Entrances

Daniel Almeida Godinho,Armando Alves Neto,Leonardo Amaral Mozelli,Fernando de Oliveira Souza 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8

Platoons are efficient solutions to improve road transportation, traffic throughput, and other demands. But problems such as environmental disturbances, network imperfections, and unaware surrounding vehicles increase the necessity for resilient methods that ensure stability and connectivity among the platoon members. Hence, in this paper, we study the problem of decentralized control for platoons of heterogeneous vehicles under a limited communication range with a constant spacing policy. The goals are to guarantee inter-vehicle distances in steady-state, and resourcefulness to overcome entrances and exits of vehicles. Our main result is a resilient strategy, composed of a reconfiguration protocol and some simple rules for tuning the control law, based on local information about the relative connectivity to neighbors. It guarantees, in a decentralized manner, the automatic reorganization of the platoon under the entry and exit of agents. We conclude by illustrating our approach with simulated experiments on platoons with different numbers of vehicles, and by comparing it with the current state-of-the-art.

Quercetin: Further Investigation of its Antinociceptive Properties and Mechanisms of Action

Arnaldo Willain Filho,Valdir Cechinel Filho,Leonardo Olinger,Marcia Maria de Souza 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.6

The antinociceptive action of quercetin, a common bioactive flavonoid present in many medicinal plants, was assessed in different models of chemical and thermal nociception in mice. Quercetin (10-60 mg/kg, i.p. or 100-500 mg/kg, p.o.) dose-dependently inhibited nociceptive behavior in the acetic acid-induced pain test. Moreover, quercetin (10-60 mg/kg, i.p.) inhibited both phases of formalin-induced pain, with ID50 values of 374.1 (68.0-402.0) mmol/kg and 103.0 (45.0-201.0) mmol/kg, for the neurogenic and inflammatory phases, respectively. Quercetin (10-60 mg/kg) also inhibited the nociception induced by glutamate and capsaicin by 68.2% and 75.5%, respectively. Its analgesic action was significantly reversed by p-chlorophenylalanine methyl ester, katanserin, methysergide, a GABAA antagonist (bicuculline), or a GABAB antagonists (baclofen). Its action was also modulated by tachykinins, but was not affected by adrenal-gland hormones. Furthermore, the antinociceptive effects did not result from muscle-relaxant or sedative action. Together, these results indicate that quercetin produces dose-related anti-nociception in several models of chemical pain, through mechanisms that involve interaction with L-arginine-nitric oxide, serotonin, and GABAergic systems. These results confirm and extend other investigations on the analgesic effect of quercetin and its mechanisms of action.