Publications by authors named "Rafael Gomes"

Article Synopsis
  • This study focuses on the presence of human polyomaviruses (HPyV) in head and neck squamous cell carcinoma (SCC) samples, particularly examining the role of these viruses alongside traditional risk factors like smoking and alcohol.
  • Researchers analyzed 60 samples from different mouth and throat areas for four types of HPyV, finding a 60% positivity rate for JCPyV and low rates for MCPyV (5%) with no instances of BKPyV or TSPyV.
  • The study concluded that while JCPyV is commonly present in oral cavity and oropharyngeal SCC, no strong links to patient demographics or clinical characteristics were found, except for a notable association between JCP
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  • This systematic review investigated the connection between oncoviruses and head and neck cancers (HNC).
  • Researchers analyzed studies from five databases and assessed their reliability using established guidelines.
  • The findings revealed a significant relationship between certain oncoviruses, particularly HPV-16, HPV-18, and Epstein-Barr virus, and the development of HNC, while further research is needed on other viruses like human cytomegalovirus and Merkel Cell Polyomavirus.
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Introduction: Atrial fibrillation is responsible for a considerable number of cases of cardioembolism, accounting for 17% to 30% of the etiologies of all strokes. The software known as Stroke Risk Analysis (SRA) detects patients at high risk of paroxysmal atrial fibrillation by analyzing a continuous electrocardiogram recorded over different periods of time.

Objectives: This article aims to carry out a systematic review investigating the effectiveness of the SRA method in predicting the risk of stroke patients having paroxysmal atrial fibrillation as the cause of the event.

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Two 1-day-old full-term female calves from different farms located in the Brazilian state of Rio Grande do Sul were unable to stand due to paresis of the pelvic limbs. Both calves had spina bifida on the spinal lumbar segment and were submitted to euthanasia due to poor prognosis. Postmortem examination revealed cerebellar herniation, caudal displacement of the brainstem, rostral deviation of the cranial nerves, caudal extension of occipital lobes, absence of dorsal lamina of lumbar vertebrae with exposed spinal cord, myelodysplasia, kyphosis, segmental spinal agenesis, renal fusion, muscular atrophy, and arthrogryposis.

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Objective: Stress distribution assessment by finite elements analysis in poly(etheretherketone) (PEEK) implant and abutment as retainers of single crowns in the anterior region.

Materials And Methods: Five 3D models were created, varying implant/abutment manufacturing materials: titanium (Ti), zirconia (Zr), pure PEEK (PEEKp), carbon fiber-reinforced PEEK (PEEKc), glass fiber-reinforced PEEK (PEEKg). A 50 N load was applied 30 off-axis at the incisal edge of the upper central incisor.

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Article Synopsis
  • Secondary electron-poor anilines are difficult to use in Lewis acid-catalyzed transformations with furfural, contrasting with secondary alkyl amines and electron-rich anilines.
  • This study presents a method to synthesize -4,5-diamino cyclopentenones (DCP) through a high-pressure Nazarov-like electrocyclization of Stenhouse salts, produced from the Sc(III)-catalyzed condensation of furfural with these anilines.
  • The reaction shows increased yields (2- to 18-fold) for electron-poor anilines and is compatible with various secondary amines, facilitating the synthesis of pharmacologically active compounds.
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This article aimed to map therapeutic itineraries in health care within rural Quilombola communities in the north of Minas Gerais, Brazil. This is a section of a qualitative research conducted in six visited communities. The data was collected through 18 individual interviews, analyzed using the theoretical-methodological framework of Therapeutic Itineraries, and organized into three empirical themes.

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An environmental toxicological assessment of fourteen furanic compounds serving as valuable building blocks produced from biomass was performed. The molecules selected included well studied compounds serving as control examples to compare the toxicity exerted against a variety of highly novel furans which have been additionally targeted as potential or current alternatives to biofuels, building blocks and polymer monomers. The impact of the furan platform chemicals targeted on widely applied ecotoxicity model organisms was determined employing the marine bioluminescent bacterium and the freshwater green microalgae , while their ecotoxicity effects on plants were assessed using dicotyledonous plants and .

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A laboratory experiment was developed for the continuous flow preparation of an aminal derived from the condensation of furfural with morpholine. The experiment introduces the students to concepts of green chemistry, heterogeneous catalysis, and continuous flow. A cheap and easy setup allows the heterogeneous catalyst reactor to be built in class.

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Copper(II) complexes are interesting for cancer treatment due to their unique properties, including their redox potential, possible coordination structures with different ligands, the most diverse geometries, and different biomolecule reactivity. The present work synthesized new copper(II) complexes with Schiff-base (imine) type ligands using natural aldehydes such as cinnamaldehyde, vanillin, or ethyl vanillin. The ligands were obtained through the reaction of these aldehydes with the amines 1,3-diaminopropane, 2,2-dimethyl-1,3-propanediamine, or 1,3-diamino-2-propanol and characterized by H and C NMR, FTIR and ESI-HRMS.

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  • This study assessed the effects of adding hydroxyapatite nanoparticles (HAp) or 58S bioactive glass (BAG) with diphenyliodonium hexafluorophosphate (DPI) on experimental infiltrants' physicochemical properties.
  • Results showed that HAp enhanced polymerization and conversion rates compared to Icon and BAG, while DPI improved these rates in the BAG group but overall didn't enhance the physicochemical properties.
  • Caution is advised when adding bioactive particles to infiltrants due to increased viscosity and limited clinical benefits, with DPI being useful only when compensating for added components.
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Natural products containing aminocyclopentanes are common secondary metabolites, often biologically active. This work aims at the preparation of a useful synthon for total synthesis containing orthogonally protected amines. To this end, furfural and two amines were employed to form mixed -4,5-diaminocyclopentenones promoted by Cu(OTf).

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The demand for new biomass-derived fine and commodity chemicals propels the discovery of new methodologies and synthons. Whereas furfural and 5-hydroxymethylfurfural are cornerstones of sustainable chemistry, 3-acetamido-5-acetyl furan (3A5AF), an N-rich furan obtained from chitin biomass, remains unexplored, due to the poor reactivity of the acetyl group relative to previous furanic aldehydes. Here we developed a reactive 3-acetamido-5-furfuryl aldehyde (3A5F) and demonstrated the utility of this synthon as a source of bio-derived nitrogen-rich heteroaromatics, carbocycles, and as a bioconjugation reagent.

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In this study were synthesized non-Michael acceptor cyclopentenones (CP) from biomass derivative furfural as anticancer agents. Cyclic enones, both from natural sources and synthetic analogues, have been described as cytotoxic agents. Most of these agents were unsuccessful in becoming valuable therapeutic agents due to toxicity problems derived from unselective critical biomacromolecule alkylation.

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Statement Of Problem: Rehabilitation with wide-diameter reduced-length implants has become popular for patients with minimal vertical bone. However, a consensus on the benefits of this approach is lacking.

Purpose: The purpose of this systematic review with meta-analysis was to evaluate the influence of wide compared with regular diameter on the clinical performance of short (<10 mm) and extrashort (≤6 mm) dental implants used for rehabilitations with single crowns, fixed partial dentures, or both, in the posterior region.

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The cellular prion protein (PrP), in its native conformation, performs numerous cellular and cognitive functions in brain tissue. However, despite the cellular prion research in recent years, there are still questions about its participation in oxidative and neurodegenerative processes. This study aims to elucidate the involvement of PrP in the neuroprotection cascade in the presence of oxidative stressors.

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The incorporation of both nitric oxide (NO) donor (S-nitrosoglutathione, GSNO) and silica nanoparticles loaded with cisplatin (SiO@CisPt NPs) into a polymeric matrix represents a suitable approach to creating a drug-delivery system with sustained and localized drug release against tumor cells. Herein, we report the synthesis, characterization, and cytotoxicity evaluation of Pluronic F-127/hyaluronic acid hydrogel containing GSNO and SiO@CisPt NPs against breast cancer cells. SiO@CisPt NPs were successfully synthesized, revealing a spherical morphology with an average size of 158 ± 20 nm.

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Background: Coronary artery disease is an important cause of morbidity and mortality. The impact of ventricular arrhythmias with impaired cardiac vagal activity is one of the most recently studied prognostic factors. However, there are no studies evaluating the phenomenon of heart rate turbulence (HRT) during physical exertion.

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Statement Of Problem: Implant-supported single crowns are more prone to screw loosening than splinted prostheses. Therefore, the locking taper system, which has a screwless abutment, may perform better when associated with this type of rehabilitation. However, systematic reviews on this system are lacking.

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This work describes the first formal cycloaddition reaction of photogenerated nucleophilic carbenes derived from acylsilanes with electrophilic dienes. The resulting transient donor-acceptor cyclopropane rearranges to its stable and highly functionalized cyclopentene isomer in an unprecedented metal-free process. The cyclopropanation-vinyl cyclopropane rearrangement sequence was corroborated by computational calculations.

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Coronary artery disease remains an important cause of morbidity and mortality worldwide. The impact of ventricular arrhythmias and impaired cardiac vagal activity on coronary events is one of the most relevant prognostic factors, despite little research being conducted in clinical practice. A simple and cost-effective way to analyze cardiac autonomic regulation is through the heart rate turbulence (HRT) method.

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The presence of sulfur-carbon bonds is transversal to several areas of chemistry, e.g., drug discovery, materials, and chemical biology.

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ARHGAP21 is a member of the RhoGAP family of proteins involved in cell growth, differentiation, and adhesion. We have previously shown that the heterozygous Arhgap21 knockout mouse model (Arhgap21) presents several alterations in the hematopoietic compartment, including increased frequency of hematopoietic stem and progenitor cells (HSPC) with impaired adhesion , increased mobilization to peripheral blood, and decreased engraftment after bone marrow transplantation. Although these HSPC functions strongly depend on their interactions with the components of the bone marrow (BM) niche, the role of ARHGAP21 in the marrow microenvironment has not yet been explored.

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This study evaluated the probability of survival, failure mode, and stress distribution of narrow diameter implants (NDIs) with internal implant-abutment conical connection comprised of different taper angles and thread designs. Sixty-three NDIs (Ø 3.5 × 8.

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