Universidade Federal de Uberlândia (UFU)
  • Uberlândia, Minas Gerais, Brazil
Recent publications
The dispersion of SARS-CoV-2 in aquatic environments via the discharge of domestic and hospital sewage has been confirmed in different locations. Thus, we aimed to evaluate the possible impacts of zebrafish (Danio rerio) exposure to SARS-CoV-2 peptide fragments (PSPD-2001, 2002, and 2003) alone and combined with a mix of emerging pollutants. Our data did not reveal the induction of behavioral, biometric, or mutagenic changes. But we noticed an organ-dependent biochemical response. While nitric oxide and malondialdehyde production in the brain, gills, and muscle did not differ between groups, superoxide dismutase activity was reduced in the “PSPD”, “Mix”, and “Mix+PSPD” groups. An increase in catalase activity and a reduction in DPPH radical scavenging activity were observed in the brains of animals exposed to the treatments. However, the “Mix+PSPD” group had a higher IBRv2 value, with NO levels (brain), the reduction of acetylcholinesterase activity (muscles), and the DPPH radical scavenging activity (brain and muscles), the most discriminant factors for this group. The principal component analysis (PCA) and hierarchical clustering analysis indicated a clear separation of the “Mix+PSPD” group from the others. Thus, we conclude that exposure to viral fragments, associated with the mix of pollutants, induced more significant toxicity in zebrafish adults than in others.
The present observational study was designed to characterize the integrative profile of serum soluble mediators to describe the immunological networks associated with clinical findings and identify putative biomarkers for diagnosis and prognosis of active tuberculosis. The study population comprises 163 volunteers, including 84 patients with active pulmonary tuberculosis/(TB), and 79 controls/(C). Soluble mediators were measured by multiplexed assay. Data analysis demonstrated that the levels of CCL3, CCL5, CXCL10, IL-1β, IL-6, IFN-γ, IL-1Ra, IL-4, IL-10, PDGF, VEGF, G-CSF, IL-7 were increased in TB as compared to C. Patients with bilateral pulmonary involvement/(TB-BI) exhibited higher levels of CXCL8, IL-6 and TNF with distinct biomarker signatures (CCL11, CCL2, TNF and IL-10) as compared to patients with unilateral infiltrates/(TB-UNI). Analysis of biomarker networks based in correlation power graph demonstrated small number of strong connections in TB and TB-BI. The search for biomarkers with relevant implications to understand the pathogenetic mechanisms and useful as complementary diagnosis tool of active TB pointed out the excellent performance of single analysis of IL-6 or CXCL10 and the stepwise combination of IL-6 → CXCL10 (Accuracy = 84 %; 80 % and 88 %, respectively). Together, our finding demonstrated that immunological networks of serum soluble biomarkers in TB patients differ according to the unilateral or bilateral pulmonary involvement and may have relevant implications to understand the pathogenetic mechanisms involved in the clinical outcome of Mtb infection.
Compacted clays are being considered to build engineered barrier systems (EBS) intended for the safe isolation of high-level nuclear waste (HLW) and spent nuclear fuel (SNF). The corrosion of the metallic canister containing the HLW/SNF will lead to the generation and buildup of the gas pressure in the more internal part of the clay buffer. This phenomenon would eventually trigger the formation and propagation of fractures in the clay barrier, jeopardizing its safety functions. In this work we propose to use the fragmentation technique (MFT) to model evolving fractures in clays triggered by gas pressurization. The MFT has been successfully used to model the formation of fractures in concrete, drying cracks in soil, hydraulic and thermo-fractures in rocks. In this work, we extend the MFT to deal with multiphase fluid flow in deformable porous media, and we upgraded a fully coupled computer finite element code using the extended technique. The proposed approach is first verified against analytical solutions and is then applied to model gas breakthrough experiments in clays. A very satisfactory performance of the method is observed in all the analyses, showing the potential of the MFT to tackle multiphase flow problems in deformable porous media with evolving discontinuities.
The COVID-19 era has profoundly affected everyday human life, the environment, and freshwater ecosystems worldwide. Despite the numerous influences, a strict COVID-19 lockdown might improve the surface water quality and thus provide an unprecedented opportunity to restore the degraded freshwater resource. Therefore, we intend to investigate the spatiotemporal water quality, sources, and preliminary health risks of heavy metal(loid)s in the Karatoya River basin (KRB), a tropical urban river in Bangladesh. Seventy water samples were collected from 35 stations in KRB in 2019 and 2022 during the dry season. The results showed that the concentrations of Ni, Cu, Zn, Pb, Cd, and Cr were significantly reduced by 89.3–99.7% during the post-lockdown period (p<0.05). However, pH, Fe, Mn, and As concentrations increased due to the rise of urban waste and the usage of disinfectants during the post-lockdown phase. In the post-lockdown phase, the heavy metal pollution index, heavy metal evaluation index, and Nemerow’s pollution index values lessened by 8.58%, 42.86%, and 22.86%, respectively. Besides, the irrigation water quality indices also improved by 59%–62%. The total hazard index values increased by 24% (children) and 22% (adults) due to the rise in Mn and As concentrations during the lockdown. In comparison, total carcinogenic risk values were reduced by 54% (children) and 53% (adults) in the post-lockdown. We found no significant changes in river flow, rainfall, or land cover near the river from the pre to post-lockdown phase. The results of semivariogram models have demonstrated that most attributes have weak spatial dependence, indicating restricted industrial and agricultural effluents during the lockdown, significantly improving river water quality. Our study confirms that the lockdown provides a unique opportunity for the remarkable improvement of degraded freshwater resources. Long-term management policies and regular monitoring should reduce river pollution and clean surface water.
Although the in vivo toxicity of nanoplastics(NPs) has already been reported in different model systems, their effects on mammalian behavior are poorly understood. Thus, we aimed to evaluate whether exposure to polystyrene (PS) NPs (diameter: 23.03±0.266 nm) alters the behavior (locomotor, anxiety-like and antipredator) of male Swiss mice, induces brain antioxidant activity, and erythrocyte DNA damage. For this, the animals were exposed to NPs for 20 days at different doses (6.5 ng/kg and 6500 ng/kg). Initially, we did not observe any effect of pollutants on the locomotor activity of the animals (inferred via open field test and Basso mouse scale for locomotion). However, we noticed an anxiolytic-like behavior (in the open field test) and alterations in the antipredatory defensive response of mice exposed to PS NPs, when confronted with their predator potential (snake, Pantherophis guttatus). Furthermore, such changes were associated with suppressing brain antioxidant activity, inferred by lower DPPH radical scavenging activity, reduced total glutathione content, as well as the translocation and accumulation of NPs in the brain of the animals. In addition, we noted that the treatments induced DNA damage, evaluated via a single-cell gel electrophoresis assay (comet assay) applied to circulating erythrocytes of the animals. However, we did not observe a dose-response effect for all biomarkers evaluated and the estimated accumulation of PS NPs in the brain. The values of the integrated biomarker response index and the results of the principal component analysis (PCA) and the hierarchical clustering analysis confirmed the similarity between the responses of animals exposed to different doses of PS NPs. Therefore, our study sheds light on how PS NPs can impact mammals and reinforce the ecotoxicological risk associated with the dispersion of these pollutants in natural environments and their uptake by mammals.
A numerical-experimental methodology is presented in this study to estimate the absorption efficiency in a laser welding process by estimating the rate of energy transferred to a metal plate. The iterative Function Specification Method was modified to account for moving temperature sensor thermal sensitivity as a function of time and position relative to the welding bead. Thus, highly nonlinear problems can be solved by using a high-temperature gradient in the measurement sensor region. Three experiments on an AISI 1020 steel sheet were carried out using a 3 kW fiber laser and a 3 m/min welding speed. A thermo-fluid model was used with solid–liquid phase changes, buoyancy forces, and the Marangoni effect in the welding pool to model the physical phenomena. A code in Matlab was developed to solve the inverse problem. The direct problem was solved using COMSOL Multiphysics through the Livelink for Matlab feature. The average absorption efficiency was 79.5% for the welding process. A comparison was made between the geometry of the welding bead obtained in experiments with the numerically calculated welding bead to validate the model. The results obtained in this article are intended to assist simulations in laser welding processes and are in agreement with the literature data.
It is common to define the secular state in terms of public reason. According to one of its leading proponents, John Rawls, public reason does not allow religious reasons to be used as the sole source of justification for using state power. It is often assumed that excluding religious reasons from the justificatory universe of state power implies that secularism should be understood as an institutional arrangement that excludes religious content from state institutions. This article reviews this thesis. It argues that the pluralist project of Rawls’ political liberalism implies accepting the possibility of institutional arrangements of secularism that do not call for this kind of exclusion. Thus, political liberalism, including the idea of public reason, is not specific regarding the institutional arrangement of secularism implemented in a constitutional democracy. Contextual factors will be crucial in determining which secularism regime to adopt. Rawls; liberalism; religion; laicity; secularism
Recent advances in the production of perforated steel profiles have given rise to the emergence of new opening patterns, among which the sinusoidal pattern stands out. Profiles manufactured with this type of opening are usually used to overcome large free spans and they have a cross-section height considerably higher in relation to the plain-webbed profile that originates them. Due to this, profiles of this nature are more susceptible to failure by lateral-torsional buckling. However, not enough research is found on this type of profile, especially in relation to global instability. In addition, the existing lack of consensus in determining the critical moment in alveolar beams is amplified when considering the openings in a sinusoidal pattern. Therefore, the present work consisted of a numerical evaluation of the elastic stability behavior of these elements through ABAQUS software, in which an extensive parametric study was developed with 15205 finite element models. Through the parametric study, it was possible to evaluate the influence of several geometric parameters of these beams in the critical moment, as well as to propose an analytical calculation method suitable for beams with sinusoidal openings, considering different loading conditions, which showed excellent compliance with the numerical results.
In this work, a strategy was proposed aiming to describe an efficient kraft lignin (KL) fractionation method to extract large amounts of low molar mass lignin to partially replace non-renewable phenol with the KL fractions in the synthesis of phenolic resins. KL from Eucalyptus urograndis wood was refined by a fractionation process in ethyl acetate (EtAc). The lignin-phenol-formaldehyde (LPF) resins were formulated by replacing 25% and 50% of phenol with the fractionated lignin. The lignin employed were KL, fraction of KL insoluble in EtAc (LFIns) and fraction of KL soluble in EtAc (LFSol). The LFSol and LFIns fractions were analyzed for composition, functional group content, and thermal properties. Gel Permeation Chromatography (GPC) results indicated that the lower molar mass lignin fractions (LFSol) showed higher solubility in EtAc. The total hydroxyl groups content (by ³¹P NMR) of the soluble EtAc fraction increased to 4.73 mmol.g⁻¹ after fractionation. The phenolic resin based on monomers derived from LFSol showed adhesion strength, glass transition temperature and thermal stability with values close to commercial phenolic resins. The better homogeneity of the LPF resin produced from LFSol at 25% phenol substitution resulted in adhesion properties similar to the control resin. On the other hand, LFSol could successfully directly replace 15% of the commercial PF resin (corresponding to > 30% phenol replacement) showing the performance similar to the commercial PF control and significantly higher than the LFIns and non-fractionated KL.
Understanding workshops as one of the main forms of therapeutic intervention in Psychosocial Care Centers, the aim of this article was to reflect on their planning, development and evaluation process based on the experience of dramatic games about sexuality. Ten workshops were held, with 43 users. They were audio-recorded and transcribed. The thematic analysis produced two categories: “Challenges in facilitating the workshops” and “Assessments of participation.” The workshops were based on coconstruction and reflection on everyday life, responding to the ideas of deinstitutionalization. They produced new perceptions of the self and the other in the debate on sexuality, going beyond biomedical and essentialist views. This experience illustrates the feasibility and importance of dramatic games about sexuality at Psychosocial Care Centers. KEYWORDS Group Therapy; Psychodrama; Mental health; Sexuality
Temporal graphs represent interactions between entities over the time. These interactions may be direct (a contact between two nodes at some time instant), or indirect, through sequences of contacts called temporal paths (journeys). Deciding whether an entity can reach another through a journey is useful for various applications in communication networks and epidemiology, among other fields. In this paper, we present a data structure that maintains temporal reachability information under the addition of new contacts. In contrast to previous works, the contacts can be inserted in an arbitrary order—in particular, non-chronologically—which corresponds to systems where the information is collected a posteriori (e.g., when trying to reconstruct contamination chains among people). The main component of our data structure is a generalization of transitive closure called timed transitive closure (TTC), which allows us to maintain reachability information relative to all nested time intervals, without storing all these intervals, nor the journeys themselves. Let n be the number of nodes and \(\tau\) be the number of timestamps in the lifetime of the temporal graph. Our data structure answers reachability queries regarding the existence of a journey from a given node to another within a given time interval in time \(O(\log \tau )\); it has a worst-case insertion time of \(O(n^2\log \tau )\); and it can reconstruct a valid journey that witnesses reachability in time \(O(k\log \tau )\), where \(k<n\) is the maximum number of contacts of this journey. Finally, the space complexity of our reachability data structure is \(O(n^2\tau )\), which remains within the worst-case size of the temporal graph itself.
Background This study aimed to assess the distribution of non-carious cervical lesions (NCCLs) by tooth type, investigate the prevalence of NCCLs in patients undergoing orthodontic treatment, and identify the possible associated factors. Material and methods A total of 160 patients were enrolled in this retrospective study. Data on the following variables were collected from pre-and post-orthodontic treatment records: age, sex, Angle’s malocclusion, facial pattern, number of activation sessions, compensatory treatment, and retreatment. Frontal, right and left lateral intraoral photographs of each patient were evaluated to identify the presence or absence of NCCLs in each tooth and assess the distribution of NCCLs in the 3840 teeth from the enrolled patients. Furthermore, patients were classified as NCCLs present, irrespective of the number of NCCLs on the teeth or NCCL absent. Bivariate and multivariate Poisson regression analyses with robust variance were used to assess the association between the NCCLs and each independent variable. Prevalence ratio and 95% confidence intervals were calculated and p < 0.05 was considered statistically significant. Results The prevalence of NCCLs before and after orthodontic treatment was 22.71% and 30.91%, respectively. Premolars were the most affected teeth, followed by the first molars, canines, and incisors. After statistical analysis, age was found to be the variable factor that influenced the prevalence ratio, with NCCL being the most prevalent when orthodontic treatment was performed in adulthood. Conclusions Premolars were most commonly affected by NCCLs. Furthermore, age seemed to contribute to the increased prevalence of NCCLs in adults undergoing orthodontic treatment.
Resumo: A tradução apresenta ao público de língua portuguesa o texto “A história da dialética”, de Herbert Marcuse. Publicado como parte do verbete “Dialética”, na enciclopédia Marxism, Communism, and Western Societies: A Comparative Encyclopaedia (New York: Herder and Herder, 1972), este trabalho fornece uma análise acadêmica relativamente detalhada do “Significado da dialética na Filosofia Antiga”, iniciando em Zenão, nos sofistas e Sócrates, passando por Platão e Aristóteles e concluindo com uma abordagem sobre os estoicos e Plotino; na sequência, volta-se para o horizonte da Filosofia Moderna, a que Marcuse dedica a seção “Significado da dialética em Kant, Fichte e Hegel”; o texto é finalizado com uma análise sobre o “Significado e o alcance da dialética em Marx”, único filósofo privilegiado com uma seção própria. De modo geral, esta publicação revela Marcuse como um estudioso de primeira classe do conceito de dialética e oferece ao leitor uma análise abrangente e extremamente qualificada da história da dialética, no plano filosófico.
Abstract A hemispherical dielectric lens antenna is proposed to provide beam-steering for communication networks operating in X-band. Two different printed antennas are simultaneously used to guarantee high performance and diversity of applications, one a wideband linear polarized antenna, and the other a narrowband circular polarized antenna. To ensure this, the design relies on adding printed angled feeders correctly positioned in relation to the center of a homogeneous dielectric lens. A prototype was simulated, fabricated and tested. The measured results show that the antenna is capable of operating from 8.0 GHz to 12 GHz (gain of 14.2 dBi) or 9.5 GHz to 10 GHz (gain of 17.52 dBi).
This paper proposes the combined use of two promising techniques in the design of 5G systems: fractal antennas and smart antennas. This new arrangement is capable to operating efficiently in multiband while directing the beam to the region of interest, promoting a better use of the spectrum and therefore allowing multiplesbeamforming to share resources in the time and frequency domain, an essential requirement for the fifth generation. In addition, the proposed array can be availed in projects that still use the previous generation technology, 4G, which would allow a more economically viable transition to 5G, especially for Latin American countries.A new type of smart fractal antenna is simulatedfor a wide range of frequencies.The parameters chosen for measuring the performance of the structure are the return loss, the radiation diagram and the 3D polar diagram, the most used in the literature. The proposed antenna achieved a return loss of -36 dB for 20.6 GHz and a notable gain of 15 dB, operating in multiband. These values are compared with other works already carried out by other researchers, which allows us to conclude that the proposed antenna is suitable for modern 5G communications.
The emergence and rapid spread outside of monkeypox virus (MPXV) to nonendemic areas has led to another global health emergency in the midst of the COVID-19 pandemic. The scientific community has sought to rapidly develop in vitro and in vivo models that could be applied in research with MPXV. In vitro models include two-dimensional (2D) cultures of immortalized cell lines or primary cells and three-dimensional (3D) cultures. In vitro models are considered cost-effective and can done in highly controlled conditions, however, they do not always resemble physiological conditions. In this way, several in vivo models are being characterized to meet the growing demand for new studies related to MPXV. In this review, we summarize the main MPXV models that have already been developed and discuss how they can contribute to the advance the understanding of its pathogenesis, replication, and transmission, as well as identifying antivirals to treat infected patients.
Nanotechnology is a multidisciplinary area of study that has grown significantly in serving many functions and impacting human society. New fields of science have been facilitated by the clean, non-toxic, and biocompatible nature of plant-derived nanoparticles. The present study deals with the first green synthesis of silver nanoparticles (Ag-NPs) using Endostemon viscosus, and their synthesized Ag NPs were characterized by different spectral methods (UV–vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction Spectroscopy (XRD), Transmission Electron Microscopy (TEM) and Energy dispersive X-ray Spectroscopy (EDAX). The change initially observed the production of Ag-NPs in color from green to ash and then confirmed by SPR band at 435 nm in UV–vis spectral analysis. The FTIR findings indicate that many functional groups belong to the pharmaceutically useful phytochemicals, which interact as reducing, capping, and stabilizing agents in synthesizing silver nanoparticles. The predominant peaks in the XRD pattern belong to the planes 210°, 111°, 200°, 241°, and 311° and thus demonstrated the Ag-NPs FCC crystal structure. TEM analysis exhibited spherical-shaped particles with an average size of 13 nm, and the EDAX band showed a distinctive metallic silver peak at 3.0 keV. The antibacterial activity of Ag-NPs tested to show a maximum zone of inhibition of 19 mm for Staphylococcus aureus and 15 mm for Escherichia coli at 100 μg/mL, respectively. Bio-fabricated Ag-NPs were assessed for antioxidant activity (DPPH with % inhibition 57.54% and FRAP with % inhibition 70.89%). The biosynthesized Ag-NPs demonstrated potential larvicidal efficacy against Aedes aegypti with more than 90% at 250 μg/mL. Histological profiles were altered while treating with Ag-NPs at 250 μg/mL. The photocatalytic activity of synthesized E. viscosus Ag-NPs was tested against methylene blue (MB) and crystal violet (CV), and the maximum degradation efficiency was found as 90 and 94%, respectively. Furthermore, the toxicity test on zebrafish embryos demonstrated that aberrations have only been induced at concentrations higher than 500 μg/mL. We conclude that the greenly produced Ag-NPs may find use in biomedical applications based on bacteria and cost-effective industrial wastewater treatment.
The purpose of this study was to evaluate the effect of a surface modified by blasting and acid attack and maintained in an isotonic solution compared to a machined surface on osseointegration in normo- and hyperglycaemic animals. Sixty-four animals were allocated into 4 groups with 16 animals each, and they were subdivided into two experimental periods (15 and 45 days), with 8 animals in each group. The groups were divided according to the type of implant that was installed in the animals' tibia and the animals’ systemic condition: CM - Machined implants placed in Healthy animals; CH - Hydrophilic implants placed in Healthy animals, HM - Machined implants placed in animals with hyperglycaemia; HH- Hydrophilic implants installed in animals with hyperglycaemia. The following analyses were performed: biomechanical (removal torque), microtomographic (evaluation of the bone volume around the implants- BV/TV), and histomorphometric (evaluation of bone-implant contact BIC% and of the bone formation area between the threads BBT%). It was found that the implants with hydrophilic surfaces presented higher removal torques and quantities of BV/TV% and higher BIC% and BBT% values in normo- and hyperglycaemic animals. The results of this study indicated that the hydrophilic surface accelerates the osseointegration process (~ 15% BIC/BBT at 15-day period), especially in animals with hyperglycaemia. The hydrophilic surface equaled the osseointegration between normo- and hyperglycaemic animals, reversing the negative potential of hyperglycaemia on the osseointegration process.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
6,407 members
Samuel Lima
  • Instituto de Geografia/Laboratório de Geografia Médica
Reginaldo Dos Santos Pedroso
  • Technical School of Health
Milla Alves Baffi
  • Institute of Agricultural Sciences (ICIAG)
Nicolás Pelegrin
  • Institute of Biology (IB)
Odilon Jose de Oliveira Neto
  • Faculdade de Administração, Ciências Contábeis, Engenharia de Produção e Serviço Social (FACES)
Information
Address
Av. João Naves de Ávila 2121, Campus Santa Mônica, 38408100, Uberlândia, Minas Gerais, Brazil
Head of institution
Prof. Valder Steffen Jr
Website
www.ufu.br
Phone
+55 34 3239-4411