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A sociedade está cada vez mais exigente e em busca de excelência quando o assunto é estética facial. O sorriso tem grande impacto na harmonia da face e, atualmente, os pacientes estão mais conscientes sobre a influência da gengiva na beleza do sorriso. A exposição da gengiva em excesso, conhecida como sorriso gengival, afeta a estética, podendo interferir na autoestima e nas relações sociais dos pacientes. Existem diversos procedimentos descritos para solucionar o problema e, para o planejamento do caso e escolha do método, é preciso determinar a etiologia e levar em consideração o desejo do paciente. A injeção da proteína botulínica é uma alternativa minimamente invasiva que está sedo cada vez mais utilizada para a correção do sorriso gengival. Com isso, o objetivo do presente trabalho monográfico foi realizar uma revisão de literatura sobre o uso da toxina botulínica na correção do sorriso gengival, analisando técnicas de injeção, identificando o efeito imediato e a longo prazo da toxina nos músculos elevadores do lábio superior, além de avaliar a relevância desse método na correção do sorriso gengival, sozinho ou em conjunto com outros procedimentos. Foi realizada uma revisão de literatura nas bases de dados PubMed e Scielo, buscando artigos dos anos de 2013 até 2022, utilizando os descritores "botulinum toxin", "botox", "gummy smile", "gingival display" e "gingival exposure". Essa revisão analisa 15 artigos que discorrem sobre o método, durabilidade e eficácia da aplicação de proteína botulínica para correção do sorriso gengival. Algumas variantes diferenciam as técnicas de aplicação, como a marca do produto e recomendações do fabricante, classificação do sorriso e extensão da exposição gengival. Com base na revisão de literatura, pôde-se concluir que, apesar de ser transitório, esse procedimento se mostrou eficaz, tanto ao ser realizado como método principal, quanto como coadjuvante no tratamento. Além de ser comprovadamente seguro, rápido, minimamente invasivo e ser o tratamento de preferência entre os pacientes, com alto índice de satisfação, são raras as complicações relacionadas a aplicação da proteína botulínica para esse fim.
Society is becoming increasingly demanding, seeking excellence in facial aesthetics. The smile greatly impacts facial harmony, and nowadays, patients are more aware of the influence of the gums on smile beauty. Excessive gum exposure, known as gummy smile, affects aesthetics and can interfere with patients' self-esteem and social relationships. There are various procedures described to address this issue, and for case planning and method selection, it is necessary to determine the etiology and take into account the patient's desires. The injection of botulinum protein is a minimally invasive alternative that is increasingly being used for gummy smile correction. Thus, the aim of this monographic work was to conduct a literature review on the use of botulinum toxin in gummy smile correction, analyzing injection techniques, identifying the immediate and long-term effects of the toxin on the upper lip elevator muscles, and evaluating the relevance of this method in gummy smile correction, either alone or in conjunction with other procedures. A literature review was conducted in the PubMed and Scielo databases, seeking articles from 2013 to 2022, using the descriptors "botulinum toxin", "botox", "gummy smile", "gingival display", and "gingival exposure". This review analyzes 15 articles that discuss the method, durability, and effectiveness of botulinum toxin application for gummy smile correction. Some variations differentiate the application techniques, such as the product brand and manufacturer's recommendations, smile classification, and extent of gum exposure. Based on the literature review, it was possible to conclude that, despite being temporary, this procedure proved to be effective, both when performed as the main method and as an adjunct in treatment. In addition to being proven safe, fast, minimally invasive, and the preferred treatment among patients, with a high satisfaction rate, complications related to botulinum toxin application for this purpose are rare.
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Sorriso , Toxinas Botulínicas , Resultado do Tratamento , Toxinas Botulínicas Tipo A , GengivaRESUMO
Escalating global surface temperatures are highlighting the urgent need for energy-saving solutions. Phase-change materials (PCMs) have emerged as a promising avenue for enhancing thermal comfort in the construction sector. This study assessed the impact of incorporating PCMs ranging from 1% to 10% by mass into composite Portland cement partially replaced by fly ash (FA) and nanosilica particles (NS). Mechanical and electrochemical techniques were utilized to evaluate composite cements. The results indicate that the presence of PCMs delayed cement hydration, acting as a filler without chemically interacting within the composite. The combination of FA and PCMs reduced compressive strength at early ages, while thermal conductivity decreased after 90 days due to the melting point and the latent heat of PCMs. Samples with FA and NS showed a significant reduction in the CO2 penetration, attributed to their pozzolanic and microfiller effects, as well as reduced water absorption due to the non-absorptive nature of PCMs. Nitrogen physisorption confirmed structural changes in the cement matrix. Additionally, electrical resistivity and thermal behavior assessments revealed that PCM-containing samples could reduce temperatures by an average of 4 °C. This suggested that PCMs could be a viable alternative for materials with thermal insulation capacity, thereby contributing to energy efficiency in the construction sector.
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A new, sustainable polypropylene terephthalate (PPT) coating was synthesized from recycled polyethylene terephthalate (PET) and applied onto a hydraulic concrete substrate to improve its durability. For the first step, PET bottle wastes were ground and depolymerized by glycolysis using propylene glycol (PG) in a vessel-type reactor (20-180 °C) to synthesize bis(2-hydroxypropyl)-terephthalate (BHPT), which was applied as a coating to one to three layers of hydraulic concrete substrate using the brushing technique and polymerized (150 °C for 15 h) to obtain PPT. PET, BHPT, and PPT were characterized by FT-IR, PET, and PPT using TGA, and the PPT coatings by SEM (thickness), ASTM-D3359-17 (adhesion), and water contact angle (wettability). The durability of hydraulic concrete coated with PPT was studied using resist chloride ion penetration (ASTM-C1202-17), carbonation depth at 28 days (RILEM-CPC-18), and the absorption water ratio (ASTM-C1585-20). The results demonstrated that the BHPT and PPT were synthetized (FT-IR), and PPT had a similar thermal behavior to PET (TGA); the PPT coatings had good adhesion to the substrate, with thicknesses of micrometric units. PPT coatings presented hydrophilic hydrophilic behavior like PET coatings, and the durability of hydraulic concrete coated with PPT (2-3 layers) improved (migration of chloride ions decreased, carbonation depth was negligible, and the absorption water ratio decreased).
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RESUMEN Introducción: la anatomía arterial es la principal limitante para el abordaje aórtico endovascular estándar. Presentamos nuestra experiencia para la reparación endovascular de aneurismas aórticos complejos. Material y métodos: estudio observacional retrospectivo en pacientes con aneurismas complejos (yuxta/pararrenales y toracoabdominales) tratados en forma consecutiva mediante: endoprótesis fenestradas (FEVAR), ramificadas (BEVAR), con EndoAnchors (ESAR), o en chimenea (ChEVAR). La decisión de la técnica fue determinada con base en la anatomía arterial. Resultados: se evaluaron los últimos 50 procedimientos (6 mujeres; edad promedio 71,3 años; diámetro 69,6mm; 3 pacientes con aneurismas complicados), de los cuales 22 recibieron FEVAR (2,8 fenestraciones / paciente), 11 BEVAR, 11 ESAR y 6 ChEVAR (1,8 chimeneas /paciente). La tasa de éxito técnico fue del 100% (ausencia de endoleak I o III con permeabilidad adecuada de los vasos viscerales). A 30 días 3 pacientes fallecieron (6%). Durante el seguimiento, 5 pacientes presentaron oclusión de la arteria renal, repermeabilizada en 4. Cuatro pacientes desarrollaron un endoleak tipo IA (3 ESAR secundarios y un ChEVAR), un paciente un endoleak IC y un cuarto uno IIIB (22%, 3 de los 11 ESAR, ninguno de los FEVAR industriales). En el análisis de supervivencia, la supervivencia global fue del 88,6% al año, y libre de reoperación del 86,5%. Conclusiones: se trata de la primera publicación en nuestro medio que muestra un enfoque global del paciente con un aneurisma de aorta complejo, de acuerdo con sus características anatómicas. Estas tecnologías ya desempeñan un papel primario en el tratamiento de estos pacientes.
ABSTRACT Background: Arterial anatomy is the main limiting factor for standard endovascular aortic (EVAR) approach. We present our experience for endovascular repair of complex aortic aneurysms. Material and Methods: This is a retrospective observational study in patients with complex aneurysms (juxta/pararenal and thoracoabdominal) treated consecutively with: fenestrated (FEVAR), branched (BEVAR), EndoAnchors (ESAR), or chimney (ChEVAR) stents. The decision of the technique was determined based on the arterial anatomy. Results: The last 50 procedures were evaluated (6 women; mean age 71.3 years; diameter 69.6 mm; and 3 patients with complicated aneurysms), among whom 22 received FEVAR (2.8 fenestrated stents/patient), 11 BEVAR, 11 ESAR and 6 ChEVAR (1.8 chimney stents/patient). Technical success rate was 100% (absence of type I or III endoleak with adequate patency of the visceral vessels). Three patients died within the first 30 days (6%). During follow-up, 5 patients presented with renal artery occlusion, treated successfully in 4 cases. Four patients developed type IA endoleak (3 secondary ESAR and one ChEVAR), one patient IC endoleak and almost a quarter of cases type IIIB endoleak (22%, 3 out of 11 patients receiving ESAR, none of the industrial FEVAR group). In survival analysis, overall survival analysis was 88.6% at one year, and 86.5% of cases were free from reoperation. Conclusions: This is the first publication in our setting that shows a global approach to the patient with complex aortic aneurysm, according to the anatomical characteristics. These technologies already play a primary role in the treatment of these patients.
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This article evaluated the effect of using mining waste on the mechanical, physical, thermal, and microstructural properties of cement-wood panels. The percentages of 10, 20, 30, and 40% were evaluated as replacing cement with mining waste. The wood particles of Pinus oocarpa were evaluated for their chemical, anatomical, and physical characteristics, and the mining waste was evaluated for its granulometry, chemical composition, and inhibition index. The composites were evaluated for their physical-mechanical properties, X-ray diffraction and infrared spectroscopy analysis, microstructural, thermal, and durability. All evaluated treatments met the requirements of the Bison standard for MOR and MOE for static bending and internal bonding, even after accelerated aging. It was possible to conclude that it is feasible to replace 40% of cement with mining waste for the production of cement-wood panels in industrial scale.
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Pinus , Madeira , Indústrias , Mineração , Ferro/químicaRESUMO
The initial weight and volume relationships are crucial factors in determining the strength, stiffness, and durability of cement-stabilized soils. The porosity/binder ratio has been widely used as a control parameter for stabilized soil mixtures. However, this approach does not take into consideration the water content used during the stabilization process, which can impact the strength and durability of the final product. To address this issue, this paper introduces the porosity-water/binder relationship as a new parameter to predict the strength, stiffness (Go), and durability against wetting-drying cycles of artificially cemented soils. The strengths, Go, and accumulated losses of mass (ALM) of different stabilized soils were compared based on this new parameter, and the comprehensive results were analyzed to demonstrate its effectiveness. The findings indicate that the new parameter is a suitable design parameter for soil-lime, soil-cement, and geopolymerized soil mixtures. Furthermore, it was determined that the water content has no effect on the splitting tensile strength to compressive strength ratio. The results of this study offer valuable insights into the optimization of stabilized soils and the development of improved soil stabilization processes.
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The decision of premature culling cows directly impacts the profitability of dairy farms. A comprehensive characterization of the primary causes of culling reasons would greatly improve both management and selection objectives in dairy cattle breeding programs. Therefore, this study aimed to analyze the temporal frequencies of 34 culling reasons in Canadian Holstein cows. After data editing and quality control, records from 3,096,872 cows culled from 9,683 herds spread across Canada were used for the analyses covering the periods from 1996 to 2020. Reproductive issues were the main culling reason accounting for 23.02%, followed by milk production (20.82%), health (20.39%), conformation problems (13.69%), economic factors (13.10%), accidents (5.67%), age-related causes (1.67%), and workability (1.63%). Nearly fifty-eight percent of cows were culled after 47 months of age. The observed frequencies of culling due to economic factors were lower than expected from 1996 to 2014 and higher than expected between 2015 and 2020. Reproduction issues had the highest culling frequencies during fall (24.54%), winter (24.02%), and spring (22.51%), while health issues were the most frequent (22.51%) culling reason in the summer season. Health issues (25.50%) and milk production (27.71%) were the most frequent culling reasons in the provinces of Quebec and Ontario, respectively. Reproductive issues showed the highest frequency across climates based on the Köppen climate classification, except for Csb (Dry-summer subtropical or Mediterranean climate) and Bsk (Middle latitude steppe climate), which correspond to small regions in Canada, where production was the most frequent culling reason (29.42% and 21.56%, respectively). Reproductive and milk performance issues were the two main culling reasons in most ecozones, except in Boreal Shield and Atlantic Marine, where health issues had the highest frequencies (25.12 and 23.75%, respectively). These results will contribute to improving management practices and selective decisions to reduce involuntary culling of Holstein cows.
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Bio-based materials, such as wood bio-concrete (WBC), hold promise in reducing energy consumption and carbon footprint of the construction industry. However, the durability of these materials is not well understood and can be negatively affected by the high water absorption capacity of wood bio-aggregates. In the field of cement composites, for example, silane-siloxane-based water repellent has been used to protect such materials from natural environmental attack. Nevertheless, there is still a limited understanding of various aspects related to this type of treatment, including its performance when applied to the bio-concrete substrate. This research aimed to investigate the influence of silane-siloxane on the rheology and hydration of cementitious paste through isothermal calorimetry and thermogravimetric analysis. Additionally, the impact of silane-siloxane on the physical and mechanical properties of WBCs was examined by conducting tests at fresh state (flow table and entrained air content) and hardened state (compressive strength and capillary water absorption). The composites were produced with a volumetric fraction of 45% of wood shavings while the cement matrix consisted of a combination of cement, rice husk ash, and fly ash. Silane-siloxane was applied in three ways: as coating, incorporated as an admixture, and in a combination of both methods. The results indicated that by incorporating silane in the cementitious pastethe viscosity increased by 40% and the hydration was delayed by approximately 6 h when compared to the reference. In addition, silane improved the compressive strength of WBCs by 24% when incorporated into the mixture, expressively reduced the water sorptivity of WBCs (93%), and was more effective if used as coating.
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Portland cement (PC) is a material that is indispensable for satisfying recent urban requirements, which demands infrastructure with adequate mechanical and durable properties. In this context, building construction has employed nanomaterials (e.g., oxide metals, carbon, and industrial/agro-industrial waste) as partial replacements for PC to obtain construction materials with better performance than those manufactured using only PC. Therefore, in this study, the properties of fresh and hardened states of nanomaterial-reinforced PC-based materials are reviewed and analyzed in detail. The partial replacement of PC by nanomaterials increases their mechanical properties at early ages and significantly improves their durability against several adverse agents and conditions. Owing to the advantages of nanomaterials as a partial replacement for PC, studies on the mechanical and durability properties for a long-term period are highly necessary.
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BACKGROUND: Guaranteeing durability, provenance, accessibility, and trust in open data sets can be challenging for researchers and organizations that rely on public repositories of data critical for epidemiology and other health analytics. The required data repositories are often difficult to locate and may require conversion to a standard data format. Data-hosting websites may also change or become unavailable without warning. A single change to the rules in one repository can hinder updating a public dashboard reliant on data pulled from external sources. These concerns are particularly challenging at the international level, because policies on systems aimed at harmonizing health and related data are typically dictated by national governments to serve their individual needs. OBJECTIVE: In this paper, we introduce a comprehensive public health data platform, EpiGraphHub, that aims to provide a single interoperable repository for open health and related data. METHODS: The platform, curated by the international research community, allows secure local integration of sensitive data while facilitating the development of data-driven applications and reports for decision-makers. Its main components include centrally managed databases with fine-grained access control to data, fully automated and documented data collection and transformation, and a powerful web-based data exploration and visualization tool. RESULTS: EpiGraphHub is already being used for hosting a growing collection of open data sets and for automating epidemiological analyses based on them. The project has also released an open-source software library with the analytical methods used in the platform. CONCLUSIONS: The platform is fully open source and open to external users. It is in active development with the goal of maximizing its value for large-scale public health studies.
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Análise de Dados , Saúde Pública , Humanos , Coleta de Dados , Bases de Dados Factuais , Governo FederalRESUMO
Introduction: Wood is a natural resource used for construction and the manufacture of many products. This material is exposed to damage due to biotic and abiotic factors. An important biotic factor is wood-degrading fungi that generate large economic losses. The objectives of this study were to determine the effect of xylophagous fungi (Coniophora puteana and Trametes versicolor) on the natural durability of six timber species in southern Durango, Mexico, and to establish differences between fungal effects on each tree species. Materials and Methods: Samples of Pinus durangensis, P. cooperi, P. strobiformis, Juniperus deppeana, Quercus sideroxyla, and Alnus acuminata were exposed to fungi for 4 months under laboratory conditions according to European Standard EN350-1. Samples of Fagus sylvatica were used as control. Durability was determined as the percentage of wood mass loss for each species. Welch ANOVA tests were performed to establish differences among tree species. Welch t-tests were used to prove loss mass differences between fungi for each tree species. Results: The most resistant species to C. puteana were P. durangensis, J. deppeana, P. cooperi and P. strobiformis, showing mean mass losses lower than 8.08%. The most resistant species to T. versicolor were J. deppeana, P. strobiformis and P. durangensis (mean mass losses lower than 7.39%). Pinus strobiformis and Q. sideroxyla were more susceptible to C. puteana effect; in contrast, P. durangensis and P. cooperi showed more damage due to T. versicolor degradation. Conclusions: Woods of P. durangensis, P. cooperi, P. strobiformis and Juniperus deppeana are well adapted to infection by these xylophagous fungi and are therefore highly recommended for commercial use in southern Durango, Mexico.
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Fagus , Pinus , Trametes/metabolismo , México , Madeira/metabolismo , Pinus/metabolismo , Fagus/microbiologiaRESUMO
This research aims to improve the quality of recycled concrete fine aggregates (RFA) by using diammonium hydrogen phosphate (DAP). We aimed to understand the effect of DAP treatment on durability performance due to the carbonation action of mortars with the partial and total substitution of treated RFA. The results showed a maximum reduction in the RFA water absorption of up to 33% using a minimum DAP concentration due to a pore refinement as a consequence of the formation of calcium phosphates such as hydroxyapatite (HAP). The carbonation phenomenon did not have a significant effect on the durability of mortars with DAP-treated RFA, as we did not find a decrease in the compressive strength; the carbonation depth of the mortars with 100% treated RFA decreased up to 90% and 63% for a w/c of 0.45 and 0.50, in comparison with mortars with 0% treated RFA. An inversely proportional relationship was found between the accelerate carbonation and the compressive strength, showing that higher percentages of treated RFAs in the mortar promoted an increase in compressive strength and a decrease in the carbonation rate, which is behavior associated with a lower permeability of the cement matrix as one of the consequences of the microstructural densification by DAP treatment.
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Glass fiber reinforced polymer (GFRP) bars have been increasingly used as reinforcement in concrete structures. However, when the bars are exposed to high temperatures, there is a change in the internal structure of the polymer which affects the tensile strength of the matrix and its adhesion with the fibers, reducing the mechanical strength of the bar. In addition, with increasing temperature, the bar-concrete interface is also damaged by the decomposition of hydration products from the cement paste and the loss of surface adhesion. The intensity of these changes is associated with the type of resin used as a matrix since each polymer has its own molecular structure that provides a greater or lesser ability to resist the changes imposed by temperature. The present study evaluates the mechanical behavior of reinforced concrete containing different types of GFRP bars and subjected to temperatures of 150 °C, 300 °C, and 350 °C. The GFRP bars with three types of matrices (polyester, vinyl ester, or epoxy) were mechanically evaluated under tension in two conditions: isolated and inserted into reinforced concrete specimens with a thickness of 20 mm, using two types of concrete (with and without silica fume). Degradation mechanisms at the bar/concrete interface were evaluated using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), differential thermal analysis (DTA), and bond techniques. The results showed that the type of matrix has a significant influence on the tensile behavior of GFRP bars, with the epoxy matrix showing the best performance, followed by bars with vinyl ester and polyester matrix resins. The use of silica fume improved the performance of the concrete coating and, consequently, improved the protection of GFRP bars, hindering the diffusion of oxygen and heat; bar/concrete adhesion was compromised by thermal degradation of GFRP bar ribs.
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Background: Endoscopically visualized spine surgery has become an essential tool that aids in identifying and treating anatomical spine pathologies that are not well demonstrated by traditional advanced imaging, including MRI. These pathologies may be visualized during endoscopic lumbar decompression (ELD) and categorized into primary pain generators (PPG). Identifying these PPGs provides crucial information for a successful outcome with ELD and forms the basis for our proposed personalized spine care protocol (SpineScreen). Methods: a prospective study of 412 patients from 7 endoscopic practices consisting of 207 (50.2%) males and 205 (49.8%) females with an average age of 63.67 years and an average follow-up of 69.27 months was performed to compare the durability of targeted ELD based on validated primary pain generators versus image-based open lumbar laminectomy, and minimally invasive lumbar transforaminal interbody fusion (TLIF) using Kaplan-Meier median survival calculations. The serial time was determined as the interval between index surgery and when patients were censored for additional interventional and surgical treatments for low back-related symptoms. A control group was recruited from patients referred for a surgical consultation but declined interventional and surgical treatment and continued on medical care. Control group patients were censored when they crossed over into any surgical or interventional treatment group. Results: of the 412 study patients, 206 underwent ELD (50.0%), 61 laminectomy (14.8%), and 78 (18.9%) TLIF. There were 67 patients in the control group (16.3% of 412 patients). The most common surgical levels were L4/5 (41.3%), L5/S1 (25.0%), and L4-S1 (16.3%). At two-year f/u, excellent and good Macnab outcomes were reported by 346 of the 412 study patients (84.0%). The VAS leg pain score reduction was 4.250 ± 1.691 (p < 0.001). No other treatment during the available follow-up was required in 60.7% (125/206) of the ELD, 39.9% (31/78) of the TLIF, and 19.7% (12/61 of the laminectomy patients. In control patients, only 15 of the 67 (22.4%) control patients continued with conservative care until final follow-up, all of which had fair and poor functional Macnab outcomes. In patients with Excellent Macnab outcomes, the median durability was 62 months in ELD, 43 in TLIF, and 31 months in laminectomy patients (p < 0.001). The overall survival time in control patients was eight months with a standard error of 0.942, a lower boundary of 6.154, and an upper boundary of 9.846 months. In patients with excellent Macnab outcomes, the median durability was 62 months in ELD, 43 in TLIF, and 31 months in laminectomy patients versus control patients at seven months (p < 0.001). The most common new-onset symptom for censoring was dysesthesia ELD (9.4%; 20/206), axial back pain in TLIF (25.6%;20/78), and recurrent pain in laminectomy (65.6%; 40/61) patients (p < 0.001). Transforaminal epidural steroid injections were tried in 11.7% (24/206) of ELD, 23.1% (18/78) of TLIF, and 36.1% (22/61) of the laminectomy patients. The secondary fusion rate among ELD patients was 8.8% (18/206). Among TLIF patients, the most common additional treatments were revision fusion (19.2%; 15/78) and multilevel rhizotomy (10.3%; 8/78). Common follow-up procedures in laminectomy patients included revision laminectomy (16.4%; 10/61), revision ELD (11.5%; 7/61), and multilevel rhizotomy (11.5%; 7/61). Control patients crossed over into ELD (13.4%), TLIF (13.4%), laminectomy (10.4%) and interventional treatment (40.3%) arms at high rates. Most control patients treated with spinal injections (55.5%) had excellent and good functional outcomes versus 40.7% with fair and poor (3.7%), respectively. The control patients (93.3%) who remained in medical management without surgery or interventional care (14/67) had the worst functional outcomes and were rated as fair and poor. Conclusions: clinical outcomes were more favorable with lumbar surgeries than with non-surgical control groups. Of the control patients, the crossover rate into interventional and surgical care was 40.3% and 37.2%, respectively. There are longer symptom-free intervals after targeted ELD than with TLIF or laminectomy. Additional intervention and surgical treatments are more often needed to manage new-onset postoperative symptoms in TLIF- and laminectomy compared to ELD patients. Few ELD patients will require fusion in the future. Considering the rising cost of surgical spine care, we offer SpineScreen as a simplified and less costly alternative to traditional image-based care models by focusing on primary pain generators rather than image-based criteria derived from the preoperative lumbar MRI scan.
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INTRODUCTION: The XEN Gel Stent (AbbVie Pharmaceuticals) is a device made from Gelatin; a well-known material in the medical field that is firm enough to hold its shape and soft enough to conform to tissues and reduce the risk of erosion. The Gel Stent creates a permanent outflow connection between the anterior chamber and subconjunctival space. AREAS COVERED: Validation testing done on the Gel Stent to evaluate biocompatibility and durability of the material as well as real-world experience are included and discussed in this paper. EXPERT OPINION: Correlating the results of the preclinical testing, study outcomes available in the published literature, and the surgeons' experiences, the device and materials have shown to have an acceptable biocompatibility and durability profile, with a stable, nondegradable, and permanent implant.
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Implantes para Drenagem de Glaucoma , Glaucoma de Ângulo Aberto , Câmara Anterior , Humanos , Pressão Intraocular , StentsRESUMO
Disposal of mine tailings can cause negative environmental effects by releasing contaminants to surface and underground water. Alkali activation is a promising technique for immobilizing metals in stabilization/solidification of these wastes. This study evaluates the leaching behavior of cemented bauxite tailings (BT) submitted to weathering conditions. The alkali-activated binder was composed of sugar cane bagasse ash, carbide lime, and sodium hydroxide solution. Comparisons of the durability and leaching behavior of BT stabilized with alkali-activated binder and high initial strength Portland cement were performed. The durability results for alkali-activated were similar to the Portland cement, showing an average difference of 16%. Portland cement showed favorable results in the encapsulation of heavy metals like Cd and Hg, while the alkali-activated cement on Al, Cr, and Se. For Ba, Fe, Mn, and Zn immobilization, both types of cement presented an equal performance. The durability and leaching behavior of stabilized bauxite tailings is governed by the cement content and porosity of the blends, as well as their pH.
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Materiais de Construção , Metais Pesados , Álcalis , Óxido de Alumínio , Metais Pesados/químicaRESUMO
This study aimed to evaluate the effect of using expanded vermiculite and its impact on the production of concrete roof tiles. The control treatment and replacement of 12.5, 25, 37.5, and 50% sand by vermiculite were evaluated. The concrete roof tiles were moulded by the simultaneous pressing and extrusion mechanical process. The control trace was comprised by 21.95% CPV-ARI cement, 65.85% sand, and 12.20% limestone. After production, the concrete roof tiles were cured for 28 days. The physical (roof tiles classification, samples dry weight, water absorption, and porosity), mechanical (splitting tensile strength), and microstructural properties were evaluated. All treatments were assessed before and after accelerated ageing. The thermal properties of the modification in the concrete roof tiles' composition were also analysed. The evaluated amounts of vermiculite significantly affected the physical, mechanical, and thermal properties of concrete roof tiles. The use of vermiculite in concrete roof tiles reduced their dry weight and thermal conductivity, not impairing their durability. The use of 31.0% vermiculite in concrete roof tiles was suggested for better thermal insulation optimization (20.29% reduction) and weight reduction (7.92% and 7.94% at 28 days of curing and after accelerated ageing, respectively), along with adequate physical, mechanical, and durability properties.
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Materiais de Construção , Areia , Silicatos de Alumínio , Materiais de Construção/análise , Condutividade TérmicaRESUMO
OBJECTIVE: The durability of root repair for acute type A aortic dissection is not well studied in the context of aortic insufficiency and stability of the sinuses of Valsalva. We compared clinical and functional outcomes in patients undergoing root repair and replacement for acute type A aortic dissection. METHODS: Of 716 patients undergoing surgery for acute type A aortic dissection, 585 (81.7%) underwent root repair and 131 (18.3%) underwent root replacement. Survival, cumulative incidence of reoperation, aortic insufficiency, and sinuses of Valsalva dilation were compared between the 2 groups. RESULTS: Survival at 1, 5, and 10 years was 84.1% versus 77.3%, 70.8% versus 69.2%, 57.6% versus 58.0% in the root repair and replacement groups, respectively (P = .69). Cumulative incidence of reoperation at 1, 5, and 10 years was 0.0% versus 0.8%, 1.4% versus 3.8%, and 3.4% versus 8.6% in the root repair and root replacement groups, respectively (P = .011). Multivariable Cox regression identified sinuses of Valsalva diameter 45 mm or more as a risk factor for proximal aortic reoperation (hazard ratio, 9.06; 95% confidence interval, 1.26-65.24). In a repeated-measures, linear, mixed-effects model, root replacement was associated with smaller follow-up of sinuses of Valsalva dimensions (ß = -0.66, P < .001). In an ordinal longitudinal mixed model, root replacement was associated with lower severity of postoperative aortic insufficiency (ß = -3.10, P < .001). CONCLUSIONS: Survival is similar, but the incidence of aortic insufficiency and root dilation may be greater after root repair compared with root replacement for acute type A aortic dissection.
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Aneurisma Aórtico/cirurgia , Dissecção Aórtica/cirurgia , Insuficiência da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Implante de Prótese Vascular , Procedimentos Cirúrgicos Cardíacos , Seio Aórtico/cirurgia , Doença Aguda , Adulto , Idoso , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/mortalidade , Aneurisma Aórtico/diagnóstico por imagem , Aneurisma Aórtico/mortalidade , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Insuficiência da Valva Aórtica/diagnóstico por imagem , Insuficiência da Valva Aórtica/fisiopatologia , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/mortalidade , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/cirurgia , Recidiva , Reoperação , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Seio Aórtico/diagnóstico por imagem , Seio Aórtico/fisiopatologia , Fatores de Tempo , Resultado do TratamentoRESUMO
The need for environmental preservation requires civil engineering to reach new concepts and technical solutions aiming at the sustainability of its activities and products. In this context, this study aimed to evaluate the effect of using different types and percentages of vegetable particles on the physical, mechanical, and thermal properties of soil-cement bricks. Bamboo, rice husk, and coffee husk particles at 1.5 and 3% percentages and a control treatment not using the particle were evaluated. The chemical properties, shrinkage, compaction, consistency limits, and grain size were characterized for the soil; and the anatomical, chemical, and physical properties for the lignocellulosic particles. The bricks were produced using an automatic press and characterized after the curing process for density, water absorption, porosity, loss of mass by immersion, compressive strength, durability, and thermal conductivity. The increase in the lignocellulosic waste percentage caused a mechanical strength decrease and bricks' porosity and water absorption increase. However, it caused a decrease in density and an enhancement in loss of mass and thermal insulation properties. The bricks produced with rice husk obtained the best results in terms of mechanical and thermal properties, and were still among the best treatments for physical properties, standing out among the lignocellulosic waste as an alternative raw material source for soil-cement brick production.
Assuntos
Materiais de Construção , Solo , Força Compressiva , Lignina , Condutividade TérmicaRESUMO
The present research work shows the effect on the carbonation of Portland cement-based mortars (PC) with the addition of green materials, specifically residues from two groups: agricultural and industrial wastes, and minerals and fibres. These materials have the purpose of helping with the waste disposal, recycling, and improving the durability of concrete structures. The specimens used for the research were elaborated with CPC 30R RS, according to the Mexican standard NMX-C-414, which is equivalent to the international ASTM C150. The aggregates were taken from the rivers Lerma and Huajumbaro, in the State of Michoacan, Mexico, and the water/cement relation was 1:1 in weight. The carbonation analyses were performed with cylinder specimens in an accelerated carbonation test chamber with conditions of 65 +/- 5% of humidity and 25 +/- 2 °C temperature. The results showed that depending on the PC substitutions, the carbonation front advance of the specimens can increase or decrease. It is highlighted that the charcoal ashes, blast-furnace slags, and natural perlite helped to reduce the carbonation advance compared to the control samples, consequently, they contributed to the durability of concrete structures. Conversely, the sugarcane bagasse ash, brick manufacturing ash, bottom ash, coal, expanded perlite, metakaolin, and opuntia ficus-indica dehydrated fibres additions increased the velocity of carbonation front, helping with the sequestration of greenhouse gases, such as CO2, and reducing environmental pollution.