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BACKGROUND: SARS-CoV2 virus, responsible for the COVID-19 pandemic, has four structural proteins and 16 nonstructural proteins. S-protein is one of the structural proteins exposed on the virus surface and is the main target for producing neutralizing antibodies and vaccines. The S-protein forms a trimer that can bind the angiotensin-converting enzyme 2 (ACE2) through its receptor binding domain (RBD) for cell entry. AIMS: The goal of this study was to express in HEK293 cells a new RBD recombinant protein in a constitutive and stable manner in order to use it as an alternative immunogen and diagnostic tool for COVID-19. MATERIALS & METHODS: The protein was designed to contain an immunoglobulin signal sequence, an explanded C-terminal section of the RBD, a region responsible for the bacteriophage T4 trimerization inducer, and six histidines in the pCDNA-3.1 plasmid. Following transformation, the cells were selected with geneticin-G418 and purified from serum-fre culture supernatants using Ni2+-agarand size exclusion chromatography. The protein was structurally identified by cross-linking and circular dichroism experiments, and utilized to immunize mice in conjuction with AS03 or alum adjuvants. The mice sera were examined for antibody recognition, receptor-binding inhibition, and virus neutralization, while spleens were evaluated for γ-interferon production in the presence of RBD. RESULTS: The protein released in the culture supernatant of cells, and exhibited a molecular mass of 135 kDa with a secondary structure like the monomeric and trimeric RBD. After purification, it formed a multimeric structure comprising trimers and hexamers, which were able to bind the ACE2 receptor. It generated high antibody titers in mice when combined with AS03 adjuvant (up to 1:50,000). The sera were capable of inhibiting binding of biotin-labeled ACE2 to the virus S1 subunit and could neutralize the entry of the Wuhan virus strain into cells at dilutions up to 1:2000. It produced specific IFN-γ producing cells in immunized mouse splenocytes. DISCUSSION: Our data describe a new RBD containing protein, forming trimers and hexamers, which are able to induce a protective humoral and cellular response against SARS-CoV2. CONCLUSION: These results add a new arsenal to combat COVID-19, as an alternative immunogen or antigen for diagnosis.
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Enzima de Conversão de Angiotensina 2 , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19 , Proteínas Recombinantes , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Animais , Humanos , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/química , Camundongos , Anticorpos Neutralizantes/imunologia , SARS-CoV-2/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Células HEK293 , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , Camundongos Endogâmicos BALB C , Feminino , Multimerização Proteica , Domínios Proteicos/imunologia , Ligação ProteicaRESUMO
Water is used as the main solvent in model systems containing bioorganic molecules. Choosing the right water model is an important step in the study of the biophysical and biochemical processes that occur in cells. In the present work, we perform molecular dynamics simulations using two distinct force fields for water: the rigid model TIP4P/2005, where only intermolecular interactions are considered, and the flexible model SPC/Fw, where intramolecular interactions are also taken into account. The simulations aim to determine the effect of the inclusion of intramolecular interactions on the accuracy of calculated properties of bulk water (density and thermal expansion coefficient, self-diffusion coefficients, shear viscosity, radial distribution functions, and dielectric constant), as compared to experimental results, over a temperature range between 250 and 370 K. We find that the results of the rigid model present the smallest deviations relative to experiments for most of the calculated quantities, except for the shear viscosity of supercooled water and the water dielectric constant, where the flexible model presents better agreement with experiments.
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In this study, using nonequilibrium molecular dynamics simulation, the flow of water in deformed carbon nanotubes is studied for two water models TIP4P/2005 and simple point charge/FH (SPC/FH). The results demonstrated a nonuniform dependence of the flow on the tube deformation and the flexibility imposed on the water molecules, leading to an unexpected increase in the flow in some cases. The effects of the tube diameter and pressure gradient are investigated to explain the abnormal flow behavior with different degrees of structural deformation.
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OBJECTIVE: The objective of this study was to estimate the seroprevalence of severe acute respiratory syndrome coronavirus 2 antibodies in patients with tuberculosis. METHODS: This cross-sectional study was conducted at an outpatient tuberculosis clinic in Alvorada, RS, Brazil, with data collection between October and December 2020. Outpatients aged>18 years with active pulmonary tuberculosis, no prior history of coronavirus disease 2019, and no suspected coronavirus disease 2019 were included in the study. Whole blood samples were collected to perform the severe acute respiratory syndrome coronavirus 2 antibodies test. RESULTS: During the study period, 52 patients met the inclusion and were included in the analysis. Severe acute respiratory syndrome coronavirus 2 antibodies were positive in 16 (30.8%) patients. Male sex was more frequent among patients with negative severe acute respiratory syndrome coronavirus 2 antibodies than in patients with positive severe acute respiratory syndrome coronavirus 2 antibodies (86.1 vs. 56.3%, p=0.031). Contact with coronavirus disease 2019 case was more common in patients with positive severe acute respiratory syndrome coronavirus 2 antibodies compared with patients with negative severe acute respiratory syndrome coronavirus 2 antibodies (87.5 vs. 8.3%, p<0.0001). In a multivariate analysis, in a model including the variables such as male sex and contact with coronavirus disease 2019 case, only contact with coronavirus disease 2019 was independently associated with positive severe acute respiratory syndrome coronavirus 2 antibodies (OR 77.0, 95%CI 11.5-512.4, p<0.0001). CONCLUSION: This study revealed a seroprevalence of 30.8% severe acute respiratory syndrome coronavirus 2 among patients with tuberculosis.
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COVID-19 , Tuberculose Pulmonar , Humanos , Masculino , SARS-CoV-2 , Estudos Transversais , Estudos Soroepidemiológicos , COVID-19/epidemiologia , Tuberculose Pulmonar/epidemiologia , Pacientes AmbulatoriaisRESUMO
SUMMARY OBJECTIVE: The objective of this study was to estimate the seroprevalence of severe acute respiratory syndrome coronavirus 2 antibodies in patients with tuberculosis. METHODS: This cross-sectional study was conducted at an outpatient tuberculosis clinic in Alvorada, RS, Brazil, with data collection between October and December 2020. Outpatients aged>18 years with active pulmonary tuberculosis, no prior history of coronavirus disease 2019, and no suspected coronavirus disease 2019 were included in the study. Whole blood samples were collected to perform the severe acute respiratory syndrome coronavirus 2 antibodies test. RESULTS: During the study period, 52 patients met the inclusion and were included in the analysis. Severe acute respiratory syndrome coronavirus 2 antibodies were positive in 16 (30.8%) patients. Male sex was more frequent among patients with negative severe acute respiratory syndrome coronavirus 2 antibodies than in patients with positive severe acute respiratory syndrome coronavirus 2 antibodies (86.1 vs. 56.3%, p=0.031). Contact with coronavirus disease 2019 case was more common in patients with positive severe acute respiratory syndrome coronavirus 2 antibodies compared with patients with negative severe acute respiratory syndrome coronavirus 2 antibodies (87.5 vs. 8.3%, p<0.0001). In a multivariate analysis, in a model including the variables such as male sex and contact with coronavirus disease 2019 case, only contact with coronavirus disease 2019 was independently associated with positive severe acute respiratory syndrome coronavirus 2 antibodies (OR 77.0, 95%CI 11.5-512.4, p<0.0001). CONCLUSION: This study revealed a seroprevalence of 30.8% severe acute respiratory syndrome coronavirus 2 among patients with tuberculosis.
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In this work we have compared the self-perceived competences of future chemistry teachers who are pursuing teacher training courses in all the regions of Brazil taking the following factors into account: sex, age and Brazilian region origin. A quantitative exploration was adopted and the data were collected using the Self-Perceived Competences of Teachers in Initial Chemistry Training (SPCTICT) instrument, composed of 21 items. An exploratory factor analysis enabled grouping the items into three factors: (a) self-perception of technical competences (knowledge), (b) Self-perception of competences linked to specific aspects (know-how) and, finally, (c) self-perception of generic competences (knowing how to act or how to behave). The results demonstrate statistically significant differences among men and women on the self-perception of their own competences regarding knowledge construction in chemistry.
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Conhecimento , Masculino , Humanos , Feminino , BrasilRESUMO
The Zika virus (ZIKV) epidemic brought new discoveries regarding arboviruses, especially flaviviruses, as ZIKV was described as sexually and vertically transmitted. The latter shows severe consequences for the embryo/fetus, such as congenital microcephaly and deficiency of the neural system, currently known as Congenital ZIKV Syndrome (CZS). To better understand ZIKV dynamics in trophoblastic cells present in the first trimester of pregnancy (BeWo, HTR-8, and control cell HuH-7), an experiment of viral kinetics was performed for African MR766 low passage and Asian-Brazilian IEC ZIKV lineages. The results were described independently and demonstrated that the three placental cells lines are permissive and susceptible to ZIKV. We noticed cytopathic effects that are typical in in vitro viral infection in BeWo and HTR-8. Regarding kinetics, MR766lp showed peaks of viral loads in 24 and 48 hpi for all cell types tested, as well as marked cells death after peak production. On the other hand, the HTR-8 lineage inoculated with ZIKV-IEC exhibited increased viral production in 144 hpi, with a peak between 24 and 96 hpi. Furthermore, IEC had peak variations of viral production for BeWo in 144 hpi. Considering such in vitro results, the hypothesis that maternal fetal transmission is probably a way of virus transmission between the mother and the embryo/fetus is maintained.
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Infecção por Zika virus , Zika virus , Humanos , Gravidez , Feminino , Placenta , Brasil , Cinética , Linhagem CelularRESUMO
Chagas disease (ChD) represents a significant health burden in endemic regions of Latin America and is increasingly being recognized as a global health issue. The cardiac involvement in ChD, known as Chagas cardiomyopathy (ChCM), is the most severe manifestation and a leading cause of heart failure and mortality in affected individuals. Echocardiography, a non-invasive imaging modality, plays a crucial role in the diagnosis, monitoring, and risk stratification of ChCM. This consensus recommendation aims to provide guidance on the appropriate use of echocardiography in ChD. An international panel of experts, including cardiologists, infectious disease specialists, and echocardiography specialists, convened to review the available evidence and provide practical recommendations based on their collective expertise. The consensus addresses key aspects related to echocardiography in ChD, including its role in the initial evaluation, serial monitoring, and risk assessment of patients. It emphasizes the importance of standardized echocardiographic protocols, including the assessment of left ventricular function, chamber dimensions, wall motion abnormalities, valvular involvement, and the presence of ventricular aneurysm. Additionally, the consensus discusses the utility of advanced echocardiographic techniques, such as strain imaging and 3D echocardiography, in assessing myocardial mechanics and ventricular remodeling.
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Cardiomiopatia Chagásica , Doença de Chagas , Insuficiência Cardíaca , Humanos , Doença de Chagas/diagnóstico por imagem , Ecocardiografia , Cardiomiopatia Chagásica/diagnóstico por imagem , ConsensoRESUMO
CONTEXT: In this paper, we have addressed two issues that are relevant to the interaction of water in pristine and vacant graphene through first-principles calculations based on the Density Functional Theory (DFT). The results showed that for the interaction of pristine graphene with water, the DOWN configuration (with the hydrogen atoms facing downwards) was the most stable, presenting binding energies in the order of -13.62 kJ/mol at a distance of 2.375 Å in the TOP position. We also evaluated the interaction of water with two vacancy models, removing one carbon atom (Vac-1C) and four atoms (Vac-4C). In the Vac-1C system, the most favourable system was the DOWN configuration, with binding energies ranging from -20.60 kJ/mol to -18.41 kJ/mol in the TOP and UP positions, respectively. A different behaviour was observed for the interaction of water with Vac-4C; regardless of the configuration of the water, it is always more favourable for the interaction to occur through the vacancy centre, with binding energies ââbetween -13.28 kJ/mol and -20.49 kJ/mol. Thus, the results presented open perspectives for the technological development of nanomembranes as well as providing a better understanding of the wettability effects of graphene sheets, whether pristine or with defects. METHOD: We evaluated the interaction of pristine and vacant graphene with the water molecule, through calculations based on Density Functional Theory (DFT); implemented by the SIESTA program. The electronic, energetic, and structural properties were analyzed by solving self-consistent Kohn-Sham equations. In all calculations, a double ζ plus a polarized function (DZP) was used for the numerical baise set. Local Density Approximation (LDA) with the Perdew and Zunger (PZ) parameterisation along with a basis set superposition error (BSSE) correction were used to describe the exchange and correlation potential (Vxc). The water and isolated graphene structures were relaxed until the residual forces were less than 0.05 eV/Å-1 in all atomic coordinates.
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In this work, we investigate the water capture process for functionalized carbon nanocones (CNCs) through molecular dynamic simulations in the following three scenarios: a single CNC in contact with a reservoir containing liquid water, a single CNC in contact with a water vapor reservoir, and a combination of more than one CNC in contact with vapor. We found that water flows through the nanocones when in contact with the liquid reservoir if the nanocone tip presents hydrophilic functionalization. In contact with steam, we observed the formation of droplets at the base of the nanocone only when hydrophilic functionalization is present. Then, water flows through in a linear manner, a process that is more efficient than that in the liquid reservoir regime. The scalability of the process is tested by analyzing the water flow through more than one nanocone. The results suggest that the distance between the nanocones is a fundamental ingredient for the efficiency of water harvesting.
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This article performs an analysis of female participation in science, in the Brazilian system of graduate studies and scientific research as a case study. This is relevant because science is a central supporting structure for modern societies and, therefore, a detailed analysis of the scientific power structure behind academic policy creation can reveal aspects of androcentrism in scientific activity. The main goal of this work is to identify the process of misogyny in science by describing its reproductive pattern. Our results show that women are around 50% of the undergraduate and graduate students when all fields are taken into consideration, but only 37% of the researchers in the CNPq system. We also observe a significant increase in female percentage within scientific activities at the initial and intermediary levels, except for the most prestigious areas as hard science. However, a scissor effect is identified between the initial level and the more prominent positions. This unbalanced participation reveals that female occupations in science are mostly as lower workforce since women are quite far from the social decision-making circles in this career.
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Educação de Pós-Graduação , Tecnologia , Humanos , Feminino , Brasil , Reprodução , PesquisadoresRESUMO
We modeled the change in the temperature of maximum density (TMD) of a waterlike solvent when small amounts of solute are added to the mixture. The solvent is modeled as a two length scales potential, which is known to exhibit waterlike characteristic anomalies, while the solute is chosen to have an attractive interaction with the solvent which is tuned from small to large attractive potential. We show that if the solute exhibits high attraction with the solvent it behaves as a structure maker and the TMD increases with the addition of solute, while if the solute shows a low attraction with the solvent the TMD decreases, with the solute behaving as a structure breaker.
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We aimed to evaluate the reasons for disagreement between screening echocardiography (echo), acquired by nonexperts, and standard echo in the Brazilian primary care (PC). Over 20 months, 22 PC workers were trained on simplified handheld (GE VSCAN) echo protocols. Screening groups, consisting of patients aged 17-20, 35-40 and 60-65 years, and patients referred for clinical indications underwent focused echo. Studies were remotelyinterpreted in US and Brazil, and those diagnosed with major or severe HD were referred for standard echoperformed by an expert. Major HD was defined as moderate to severe valve disease, ventriculardysfunction/hypertrophy, pericardial effusion or wall-motion abnormalities. A random sample of exams wasselected for evaluation of variables accounting for disagreement. A sample of 768 patients was analyzed, 651(85%) in the referred group. Quality issues were reported in 5.8%, and the random Kappa for major HD between screening and standard echo was 0.51. The most frequent reasons for disagreement were: overestimation of mitral regurgitation (MR) (17.9%, N=138), left ventricular (LV) dysfunction (15.7%, N=121), aortic regurgitation (AR) (15.2%, N=117), LV hypertrophy (13.5%, N=104) and tricuspid regurgitation (12.7%, N=98). Misdiagnosis of mitral and aortic morphological abnormalities was observed in 12.4% and 3.0%, and underestimation of AR and MR occurred in 4.6% and 11.1%. Among 257 patients with suspected mild/moderate MR, 129 were reclassified to normal. In conclusion, although screening echo with task-shifting in PC is a promising tool in low-income areas, estimation of valve regurgitation and LV function and size account for considerable disagreement with standard exams.
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Insuficiência da Valva Aórtica , Insuficiência da Valva Mitral , Disfunção Ventricular Esquerda , Humanos , Ecocardiografia/métodos , Valor Preditivo dos Testes , Insuficiência da Valva Mitral/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/diagnóstico por imagem , Atenção Primária à SaúdeRESUMO
In this work, we propose a method to harvest liquid water from water vapor using carbon nanocones. The condensation occurs due to the presence of hydrophilic sites at the nanocone entrance. The functionalization, together with the high mobility of water inside nanostructures, leads to a fast water flow through the nanostructure. We show using molecular dynamics simulations that this device is able to collect water if the surface functionalization is properly selected.
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Cada vez mais, observamos em nossa clínica analisandos que apresentam um discurso vazio, que evoca nossas sensações, dando origem a uma experiência que vai além do uso e da apreensão da própria palavra. Por meio da apresentação de fragmentos de um caso clínico e tendo como pano de fundo a teoria psicanalítica, procuro demonstrar como o sujeito corpo pode dar voz ao sofrimento psíquico não passível de elaboração. Experimentando na relação analítica um ambiente flexível e acolhedor (FERENCZI, 1934), mesmo no cenário virtual, o sujeito pode conseguir promover a integração do seu eu(AU)
More and more in our clinic, we observe analysands who present an empty speech, which evokes our sensations, giving rise to an experience that goes beyond the use and apprehension of the word itself. Through the presentation of fragments of a clinical case, against the backdrop of psychoanalytic theory, I try to demonstrate how the body subject can give voice to psychic suffering that cannot be elaborated. Experiencing a flexible and welcoming environment (Ferenczi, 1934), even in the virtual setting, the subject may be able to promote the integration of his self(AU)
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Objetivo:Descrever as atividades implementadas pelo enfermeiro no processo de captação de coração e pulmão em um centro transplantador brasileiro e sua implicação no aumento do número de transplantes realizados. Métodos: Estudo descritivo e observacional, com foco no organograma instituído sobre as atividades do enfermeiro para avaliação e o aceite do doador. Resultados:Com a formação da unidade, exclusivamente dedicada ao processo captação/transplante, houve entre os meses de agosto de 2013 e dezembro de 2021, um aumento de 138,18% na realização de transplantes cardíacos adultos, 76,54% nos transplantes pediátricos e/ou cardiopatias congênitas e 63,22% nos procedimentos de pulmão,quando comparado ao mesmo período dos anos anteriores.Conclusão: O estudo descreve pela primeira vez a importância da atuação do enfermeiro na implementação de um programa de transplantes de sucesso e como suas ações contribuíram para o aumento do número de procedimentos realizados e podem servir de modelo para outros centros.(AU)
Objective: To describe the activities performed by nurses in the heart and lung harvesting process in a Brazilian transplant center and their implication in the increase in the number of transplants performed. Methods: Descriptive and observational study, focusing on the organizational chart established on the activities of nurses for the evaluation and acceptance of the donor. Results: With the formation of the unit, exclusively dedicated to the capture/transplantation process, between August 2013 and December 2021, there was an increase of 138.18% in adult heart transplants, 76.54% in pediatric transplants and/ or congenital heart disease and 63.22% in lung procedures, when compared to the same period in previous years. Conclusion: The study describes for the first time the importance of nurses' performance in the implementation of a successful transplant program and how their actions contributed to the increase in the number of procedures performed and can serve as a model for other centers.(AU)
Objetivo: Describir las actividades realizadas por enfermeros en el proceso de extracción de corazón y pulmón en un centro de trasplante brasileño y su implicación en el aumento de trasplantes realizados. Métodos: Estudio descriptivo y observacional, con foco en el organigrama establecido sobre las actividades de los enfermeros para la evaluación y aceptación del donante. Resultados: Con la formación de la unidad, dedicada exclusivamente al proceso de captación/trasplante, entre agosto de 2013 y diciembre de 2021, hubo un aumento del 138,18% en trasplantes cardíacos adultos, 76,54% en trasplantes pediátricos y/o cardiopatías congénitas y 63,22% % en procedimientos pulmonares, en comparación con años anteriores. Conclusión: El estudio describe por primera vez la importancia de la actuación de los enfermeros en la implementación de un programa de trasplante exitoso y cómo sus acciones contribuyeron para el aumento del número de procedimientos realizados y pueden servir de modelo para otros centros.(AU)