Publications by authors named "Rafael Freitas"

Article Synopsis
  • - Malaria, caused by the Plasmodium parasite, faces challenges due to drug resistance, prompting the need for new treatments targeting both symptomatic and asymptomatic liver stages; a cost-effective luciferase detection method for liver stage screening has been developed using common lab reagents.
  • - The study optimized a protocol for testing liver stage parasites, validating it with 28 existing anti-malarials to ensure reliable signal data, enabling the screening of the Global Health Priority Box (GHPB) for potential drug candidates.
  • - Results showed that the optimized screening method produced a more stable luciferase signal with lower cell density, identifying 9 promising hits with selective activity against the P. berghei liver stages.
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  • The State University of North Fluminense has been running a breeding program for 15 years to create new cultivars of elephant grass, aimed specifically at meeting the needs of local producers in Rio de Janeiro due to a lack of available cultivars.
  • The study analyzed 11 inbred families of elephant grass by estimating genetic diversity and variances, and utilized mixed models to identify the best genotypes based on traits like dry matter production and plant height.
  • Results indicated that certain families were highly productive and genetically diverse, with selection indices suggesting that certain approaches could yield greater gains in genotypic quality.
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Common bean provides diet rich in vitamins, fiber, minerals, and protein, which could contribute into food security of needy populations in many countries. Developing genotypes that associate favorable agronomic and grain quality traits in the common bean crop could increase the chances of adopting new cultivars black bean. In this context, the present study aimed at selection of superior black bean lines using multi-variate indexes, Smith-Hazel-index, and genotype by yield*trait biplot analysis.

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Leptospirosis is a zoonosis of great importance for One Health. In this context, the Amazonian biome may harbor numerous hosts for spp. that contribute to the maintenance of the pathogen in the environment.

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Ingestion of an additional blood meal(s) by a hematophagic insect can accelerate development of several vector-borne parasites and pathogens. Most studies, however, offer blood from the same vertebrate host species as the original challenge (for e.g.

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Background: A new generation of modified surface flow diverters (FDs) and monotherapy using new antiplatelets may reduce both ischemic and hemorrhagic complications during the treatment of intracranial aneurysms. Previous preliminary safety analysis of distal unruptured intracranial aneurysms treated with the FD p48 MW HPC (phenox-Wallaby, Bochum, Germany) under antiplatelet monotherapy with prasugrel showed promising results. However, the long term outcomes of distal intracranial aneurysms treated with FDs under antiplatelet monotherapy are not known.

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This study evaluated the possible association between the diurnal variations of climatic factors during the rainy (RS) or less rainy (LS) seasons on the testicular hemodynamics and thermoregulatory responses of hair sheep rams raised in a humid tropical climate. Santa Inês rams (n = 6) underwent evaluation of general and testicular physiological parameters (heart and respiratory rates, internal and scrotal temperatures, internal-scrotal temperature gradient, scrotal distention, and color Doppler ultrasound evaluation of the spermatic cords and spectral analyses of testicular arteries) over six consecutive weeks per season at three separate times daily (morning = 8:00 a.m.

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Urease is an enzyme containing a dinuclear nickel active center responsible for the hydrolysis of urea into carbon dioxide and ammonia. Interestingly, inorganic models of urease are unable to mimic its mechanism despite their similarities to the enzyme active site. The reason behind the discrepancy in urea decomposition mechanisms between inorganic models and urease is still unknown.

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Arbovirus epidemiology lacks efficient and timely surveillance systems with accurate outbreak alert signals. We devised a citywide integrated surveillance system combining entomologic, epidemiologic, and entomo-virologic data gathered during 2017-2020 in Foz do Iguaçu, Brazil. We installed 3,476 adult mosquito traps across the city and inspected traps every 2 months.

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We herein report a comprehensive investigation on the magnetic, structural, and electric properties of CoO nanoparticles with different sizes by local inspection through hyperfine interactions measured in a wide range of temperatures (10-670 K) by using radioactive [Formula: see text]In([Formula: see text]Cd) tracers with the perturbed angular correlations technique. Small cobalt oxide nanoparticles with the characteristic size of 6.5 nm have been prepared by the wet chemical route that turned out to be essential to incorporate radioactivity tracers during nucleation and growth of the particles.

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Quantum spin liquids are exotic states of matter that form when strongly frustrated magnetic interactions induce a highly entangled quantum paramagnet far below the energy scale of the magnetic interactions. Three-dimensional cases are especially challenging due to the significant reduction of the influence of quantum fluctuations. Here, we report the magnetic characterization of K_{2}Ni_{2}(SO_{4})_{3} forming a three-dimensional network of Ni^{2+} spins.

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Article Synopsis
  • The study investigates the safety and effectiveness of endovascular selective embolization using N-butyl cyanoacrylate glue (NBCA) for treating active abdominal pelvic bleeding (APB) in polytraumatized patients.
  • Conducted as a retrospective analysis of 47 patients treated between January 2013 and June 2019, the study found a 100% efficacy rate and no procedural complications, although the overall mortality rate was 14.8% mainly due to neurological issues.
  • The findings suggest that endovascular embolization is a highly safe and effective alternative to emergency exploratory surgeries for traumatic abdominopelvic bleeding.
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Background: Flow diverters (FDs) are effective in the treatment of carotid aneurysms. Compared with carotid aneurysms, the treatment of distal intracranial aneurysms with FDs has been associated with a relatively high incidence of complications. Low thrombogenic modified-surface FDs may reduce ischemic complications and allow for the use of a single antiplatelet medication.

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Background: Flow diverters (FDs) result in high occlusion rates of aneurysms located distally to the carotid artery. However, the complications reported are not negligible. New modified surface FDs have low thrombogenic properties that may reduce ischemic complications related to the treatment.

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The intermolecular dynamics in the THz frequency range of the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N1114][NTf2], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N1444][NTf2], were investigated by a combined usage of inelastic neutron scattering (INS), Raman, and far-infrared (FIR) spectroscopies and the power spectrum calculated by molecular dynamics (MD) simulations. The collective dynamics of the simulated systems is also discussed by the calculation of time correlation functions of charge and mass currents that are projected onto acoustic- and optic-like motions. The INS and Raman measurements have been performed as a function of temperature in the glassy, crystalline, and liquid phases.

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Background: Venous pulsatile tinnitus (PT) can be caused by the perception of blood flow through the mastoid emissary vein (MEV). However, the causal relationship of this anomaly has not been established as selective occlusion of this vein has never been performed. The aim of this study was to report on a small series of patients suspected of having PT caused by an MEV, who underwent MEV embolization as treatment for PT, and to identify the correct indications for this procedure.

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Background: Intracranial arteriovenous malformations (AVMs) have been considered congenital. We present and discuss a case of a child who had no evidence of an AVM at 6 years of age when presenting with parenchymatous hemorrhage due to cavernous angioma and who developed the lesion during 10 years of follow-up.

Case Description: A 6-year-old female presented with parenchymatous hemorrhage and was diagnosed with cavernous angioma of the right occipital lobe.

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Objectives: Women with invasive placentation (IP) are at high risk of life-threatening hemorrhage. In the last two decades, less invasive surgical approaches combined with endovascular procedures have proven to be safe. Most case series describe the use of temporary balloon occlusion and embolization, either combined or not.

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Background: Several mutations in voltage gated sodium channel (Na) have been identified in populations worldwide. However, only few are related to knockdown resistance to pyrethroids, most of which with variations in the 1016 and 1534 Na sites. In Brazil, at least two alleles are known: NaR1, with a substitution in the 1534 (1016 Val + 1534 Ile ) and NaR2, with substitutions in both 1016 and sites (1016Ile + 1534Cys ).

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In the investigation reported in this paper a modified thermal decomposition method was developed to produce very small ErO nanoparticles (NPs). Particles structure, shape and size were characterized by x-ray diffraction and transmission electron microscopy which showed that the synthesis by thermal decomposition under O atmosphere produced very small and monodisperse NPs, allowing the investigation of finite-size and surface effects. Results of magnetization measurements showed that the smallest particles present the highest values of susceptibility that decrease as particle size increases.

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A local order-disorder transition has been disclosed in the thermophysical behavior of the ionic liquid 1-benzyl-3-methylimidazolium dicyanamide, [Bzmim][N(CN)], and its microscopic nature revealed by spectroscopic techniques. Differential scanning calorimetry and specific heat measurements show a thermal event of small enthalpy variation taking place in the range 250-260 K, which is not due to crystallization or melting. Molecular dynamic simulations and X-ray diffraction measurements have been used to discuss the segregation of domains in the liquid structure of [Bzmim][N(CN)].

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Alcohol dehydrogenase (ADH) from Saccharomyces cerevisiae was covalently attached, via glutaraldehyde, to magnetite nanoparticles (MagNP) previously coated with aminopropyltriethoxysilane (MagNP/APTS), or with a silica shell followed by the APTS coating (MagNP@SiO2/APTS). In both cases, a great improvement of enzymatic activity has been observed for the ethanol-acetaldehyde conversion. The MagNP@SiO2/APTS-ADH system exhibited the best stability with respect to pH and temperature.

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In bone tissue engineering (TE) endothelial cell-osteoblast cocultures are known to induce synergies of cell differentiation and activity. Bone marrow mononucleated cells (BMCs) are a rich source of mesenchymal stem cells (MSCs) able to develop an osteogenic phenotype. Endothelial progenitor cells (EPCs) are also present within BMC.

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