O MÚLTIPLO E O DIVERSO EM "VÍCIOS E VIRTUDES"

The Helder Macedo's narrative presents us the writer who meets a friend, also writer, and listens from him the story of his loves. The text inside the text leads us, in a spiral movement, from the author to the character, from the present to the past, from the contingent to the history. The present work aims to reflect on the games of masks formulated by Macedo from the overlapping of registers and narrative plans that is presented in his novel.A narrativa de Helder Macedo conta-nos do escritor que encontra o amigo, também escritor, e ouve desse a história de seus amores. O texto dentro do texto vai nos levando, em espiral, do autor à personagem, do presente ao passado, do contingente ao  histórico.  Este  trabalho  pretende  refletir  sobre  os  jogos  de  máscaras  e  fingimentos formulados por Macedo a partir da sobreposição de registros e de planos narrativos que este seu livro apresenta

Behaviour of a biocompatible titanium alloy during orthogonal micro-cutting employing green machining techniques

The sustainability of a process is the objective of modern industries aiming to reduce waste in production, since consumers require high quality and efficiency with fair price. Thus, a good understanding of the process should be its starting point. The manufacture of dental implants is an example in which waste reduction is important for the reduction of prices due to the demand for great quality and accuracy. This study observed the behaviour of sustainable micro-cutting applied to the Ti-6Al-7Nb titanium alloy, considering the ploughing effect on minimum quantity lubrication (MQL) and high-speed machining (HSM) conditions. When compared with dry condition and low-speed cutting in orthogonal micro-cutting, the use of HSM in dry cutting was more efficient than using MQL. The dry condition presented lower surface roughness, whilst the cooled/lubricated condition presented lower burr formation.publishe

Orthobiologics in delayed union and non-union of adult long bones fractures: A systematic review

Background: Fracture healing poses a significant challenge in orthopedics. Successful regeneration of bone is provided by mechanical stability and a favorable biological microenvironment. This systematic review aims to explore the clinical application of orthobiologics in treating aseptic delayed union and non-union of long bones in adults. Methods: A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Three databases were explored, with no date restrictions, using keywords related to orthobiologics and delayed union and non-union. Eligible studies included human clinical studies in English, with available full texts, examining orthobiologics such as platelet-rich plasma (PRP), mesenchymal stem cells (MSCs), and bone morphogenetic protein (BMPs) for treating aseptic delayed unions and non-unions in adults. Animal studies, in vitro research, and studies on non-unions due to congenital defects, tumors or infections were excluded. Results: The initial search identified 9417 studies, with 20 ultimately included in the review. These studies involved 493 patients affected by non-union and 256 patients affected by delayed union, with an average age respectively of 40.62 years and 41.7 years. The mean follow-up period was 15.55 months for non-unions and 8.07 months for delayed unions. PRP was the most used orthobiologic, and outcomes were evaluated through time to union, functional scores, and clinical examinations. The results indicated that orthobiologics, especially PRP, tended to yield better outcomes compared to surgical procedures without biological factors. Conclusion: This systematic review suggests that orthobiologics, such as PRP, BMPs, and MSCs, can be effective and safe in the management of delayed union and non-union fractures. These biological treatments have the potential to improve union rates, reduce healing times, and enhance functional outcomes in patients with non-union fractures. Further research is essential to refine treatment protocols and determine the most suitable orthobiologic for specific patient populations and fracture types

The influence of electrical high-speed rotation on mandibular third molar surgeries: a prospective, randomized, split-mouth clinical and radiographic study

Abstract The aim of this split-mouth randomized clinical trial was to evaluate the clinical outcomes (operative time, edema, trismus, and pain), the immediate histological effects, the alveolar repair (2 and 4 months), and the quality of life after the extraction of impacted third molars using high-speed pneumatic and electrical rotation. Sixteen patients underwent extraction of the two mandibular third molars with a minimum interval of 15 days. On one side of the participant’s mouth, high-speed pneumatic rotation was used (Control Group—CG) while for the other side, high-speed electrical rotation was used (Study Group—SG). Statistical analysis included ANOVA repeated measures and Pearson correlations. SG group showed: shorter operative time (p = 0.019), less pain (p = 0.034), swelling (p < 0.001) and trismus (p = 0.025) on the 1st postoperative day; less pain (p = 0.034) and trismus (p = 0.010) on the 3rd postoperative day; less trismus (p = 0.032) on the 7th postoperative day; and better quality of life (p = 0.007). No differences were observed for peripheral bone damage or bone density of alveolar repair at 2 and 4 months between groups. Electric high-speed rotation provided better postoperative clinical parameters of pain, edema and trismus when compared with pneumatic high-speed rotation for mandibular third molar surgery. Trial registration: Brazilian Registry of Clinical Trials registration number RBR-4xyqhqm ( https://ensaiosclinicos.gov.br/rg/RBR-4xyqhqm )

The effect of a very high overheating on the microstructural degradation of superalloy 718

Under the harsh conditions imposed by the processing or due to an “overheating event”, the superalloy 718 may be exposed to very high temperatures, which can result in degradation of the microstructure. The time under such high temperatures can be short, as during the welding process, or long, as during reheating or homogenization of billets. Operational events or accidents that induce very high temperatures can also be a source of microstructural degradation. The present work aims to study the effect of a very high temperature on the degradation of the microstructure of the nickel base superalloy 718. Samples were heated up to 1300 °C under air at different time intervals from 1 to 480 min. The microstructural changes were evaluated by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction and compared with thermodynamic calculations. It was evidenced that even for a very short time as 1 min, Nb segregation at grain boundaries induces constitutional liquation and oxidation at those regions, as well as the formation of Laves phase and Nb-rich MC carbides with “Chinese script” morphology. With the continuous grain growth, a more intense liquation of the grain boundaries is induced, up to circa 60 min. After this threshold value, the intergranular liquation is “channeled out” via the interconnected grain boundary network, resulting in the disruption of grain boundaries and accelerated structural collapse of the material. Keywords: Superalloy 718, Grain boundary liquation, Oxidatio

Effect of yttrium addition on phase transformations in alloy 718

The nickel-base alloy 718 is widely used due to its superior performance at high temperatures, combining properties such as high strength, high corrosion and oxidation resistances and good formability and weldability. Its properties can be further improved by controlled additions of alloying elements such as Ce, W, Mo, P, B and Y. The present work aims to evaluate the effect of the yttrium alloying on the phase transformation in alloy 718. Thermodynamic calculation, scanning electron microscopy, electron backscattered diffraction, hardness measurements and differential scanning calorimetry tests were conducted. The Ni17Y2 phase was observed in two situations: associated with the Nb-rich particles or as single particles. The addition of yttrium has a remarkable effect on grain size control. The differential scanning calorimetry tests indicated that the alloy with the high Y content showed earlier precipitation of the γ"phase (Ni3Nb), which is the main hardening contributor, resulting in an increase in hardness.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Evaluation of Osteoconduction of Biphasic Calcium Phosphate Ceramic in the Calvaria of Rats: Microscopic and Histometric Analysis

(1) Background: Evaluate the osteoconduction capability of a biphasic calcium phosphate (BCP) ceramic composed of hydroxyapatite and &beta;-tricalcium phosphate 60%/40% in a rat model. (2) Methods: In the calvarial bone of 54 adult male rats, 7-mm diameter critical size defects were performed. The animals were randomly allocated to three experimental groups according to the type of material: blood clot (BCG), blood clot covered with a bovine-derived collagen membrane (MBCG), and BCP ceramic covered with a bovine-derived collagen membrane (BCPG). In each group, 6 animals were euthanatized at post-operative days 7, 30, and 60 for histological and histometric analysis. (3) Results: The qualitative analysis revealed the persistence of the collagen membrane at seven days, with no relevant newly bone formation in all groups. At 30 days, centripetal bone formation was observed residual particles of the biomaterial surrounded by fibroblasts noted in the BCPG. At 60 days, while BCG and MBCG showed a partial maturation with the central part of the defect populated by a fibrous connective tissue, in the BCPG the critical area was entirely occupied by newly formed bone. In the intra groups analysis was noted a significant increase in new bone formation during the experimental period (p &lt; 0.05). At 60 days, BCPG showed a higher percentage area of new bone formation (p &lt; 0.05). (4) Conclusion: BCP promoted a new bone formation by osteoconduction and might be considered a valid alternative in bone regeneration procedures

Aspiration of the dental crown in an elderly patient

The aspiration of objects and foreign bodies requires quick and systematic care. During emergent orotracheal intubation, accidental dental crown release can cause a threat to the patient's life. This paper aimed to report a case of foreign body (dental prosthetic crown) aspiration and its management and discuss alternative approaches. An 81-year-old male patient, who was admitted to the hospital's intensive care unit (ICU) for meningitis, presented with altered consciousness, and decreased oxygen saturation. He underwent emergent orotracheal intubation. After intubation, chest radiography was performed to check for proper orotracheal tube positioning and lung expansion. The resultant images revealed the presence of a foreign body within the right lower lobe bronchus in the shape of a dental crown. The foreign body, intubation cannula and basket clamp were successfully removed, followed by reintubation of the patient. The foreign body was a prosthetic upper premolar dental crown (24). While care should be taken to avoid complications, if a foreign body is aspirated during emergent orotracheal intubation, endoscopic removal appears safe and effective. Careful creation, placement, maintenance, and preservation of prosthetic crowns are critically important in elderly patients

Early Peri-Implant Bone Healing on Laser-Modified Surfaces with and without Hydroxyapatite Coating: An In Vivo Study

(1) Objective: The aim of this study was to assess the biological behavior of bone tissue on a machined surface (MS) and modifications made by a laser beam (LS) and by a laser beam incorporated with hydroxyapatite (HA) using a biomimetic method without thermic treatment (LHS). (2) Methods: Scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM/EDX) was performed before and after installation in the rabbit tibiae. A total of 20 Albinus rabbits randomly received 30 implants of 3.75 × 10 mm in the right and left tibias, with two implants on each surface in each tibia. In the animals belonging to the 4-week euthanasia period group, intramuscular application of the fluorochromes calcein and alizarin was performed. In implants placed mesially in the tibiofemoral joint, biomechanical analysis was performed by means of a removal torque (N/cm). The tibias with the implants located distally to the joint were submitted for analysis by confocal laser microscopy (mineral apposition rate) and for histometric analysis by bone contact implant (%BIC) and newly formed bone area (%NBA). (3) Results: The SEM showed differences between the surfaces. The biomechanical analysis revealed significant differences in removal torque values between the MSs and LHSs over a 2-week period. Over a 4-week period, both the LSs and LHSs demonstrated removal torque values statistically higher than the MSs. BIC of the LHS implants were statistically superior to MS at the 2-week period and LHS and LS surfaces were statistically superior to MS at the 4-week period. Statistical analysis of the NBA of the implants showed difference between the LHS and MS in the period of 2 weeks. (4) Conclusions: The modifications of the LSs and LHSs provided important physicochemical modifications that favored the deposition of bone tissue on the surface of the implants

CD77 levels over enzyme replacement treatment in Fabry Disease Family (V269M)

<div><p>ABSTRACT Introduction: Fabry disease (FD) is a disorder caused by mutations in the gene encoding for lysosomal enzyme α-galactosidase A (α-GAL). Reduced α-GAL activity leads to progressive accumulation of globotriaosylceramide (Gb3), also known as CD77. The recent report of increased expression of CD77 in blood cells of patients with FD indicated that this molecule can be used as a potential marker for monitoring enzyme replacement therapy (ERT). Objective: The purpose of this study was to evaluate the CD77 levels throughout ERT in FD patients (V269M mutation). Methods: We evaluated the fluctuations in PBMC (peripheral blood mononuclear cell) membrane CD77 expression in FD patients undergoing ERT and correlated these levels with those observed in different cell types. Results: A greater CD77 expression was found in phagocytes of patients compared to controls at baseline. Interestingly, the variability in CD77 levels is larger in patients at baseline (340 - 1619 MIF) and after 12 months of ERT (240 - 530 MIF) compared with the control group (131 - 331 MFI). Furthermore, by analyzing the levels of CD77 in phagocytes from patients throughout ERT, we found a constant decrease in CD77 levels. Conclusion: The increased CD77 levels in the phagocytes of Fabry carriers together with the decrease in CD77 levels throughout ERT suggest that measuring CD77 levels in phagocytes is a promising tool for monitoring the response to ERT in FD.</p></div