27 research outputs found
Electrochemical and mechanical behavior of UV curing paint on hybrid films modified with polyethyleneglycol plasticizer applied on tinplate
The objective of this work is to coat tinplate with a hybrid film obtained from a sol-gel process constituted by the alkoxide precursor tetraethoxysilane (TEOS) and 3-trimethoxysilylpropyl methacrylate (TMSM), with the addition of cerium nitrate (0.01 M) and polyethyleneglycol plasticizer (20 g.L-1) to the sol formulation. The films were obtained by dip-coating, applying one and two layers and curing them at different temperatures (60°C and 90°C) for 20 minutes, and adhering UV curing paint to each film respectively. The results showed that the double layered hybrid film obtained at 60°C had a higher layer of thickness and the best performance in the electrochemical assays, in other words, higher resistance to corrosion. Furthermore, in studies following the application of UV coating, the hybrid-film monolayer cured at 60°C wich had an organic coating of cured UV applied to it, achieved a performance similar to that of the pretreated alkyd greenhouse currently used in the metal packaging industry
Regimes terapĂȘuticos para a Ășlcera pĂ©ptica e erradicação de helicobacter pylori nos utentes da rede mĂ©dicos-sentinela
Introdução: A relação entre Helicobacter pylori (H.pylori) e a doença ulcerosa pĂ©ptica (DUP) estĂĄ hoje perfeitamente estabelecida, bem como o benefĂcio do uso de terapĂȘuticas que, alĂ©m de cicatrizarem a Ășlcera, erradicam a bactĂ©ria.
Objectivo: Caracterizar as opçÔes terapĂȘuticas seguidas na prĂĄtica clĂnica diĂĄria em doentes com Ășlcera pĂ©ptica(UP) confirmada ou sujeitos a uma terapĂȘutica de erradicação de H.pylori, mesmo sem Ășlcera confirmada.
Metodologia: Adoptou-se um modelo de estudo descritivo, com a duração de 1 ano no qual participaram 36 clĂnicos gerais pertencentes Ă rede MĂ©dicos-Sentinela. A população alvo foi de 36.408 utentes. A amostra foi constituĂda por 120 casos, sendo 75 de Ășlcera pĂ©ptica confirmada por endoscopia e 45 sem Ășlcera pĂ©ptica confirmada, aos quais o clĂnico instituiu terapĂȘutica de erradicação de H.pylori.
Resultados: Os 75 casos de Ășlcera confirmada foram de localização duodenal, em 46,7% dos casos (31,4% das quais eram recidivas), e de localização gĂĄstrica em 41,4% (25,8% eram recidivas). Foi possĂvel identificar o H. pylori como etiologia provĂĄvel, em 24% do total de casos. SĂł em 52% dos doentes com Ășlcera confirmada foi prescrita uma terapĂȘutica de erradicação para o agente, mas essa proporção atingiu os 94,4% quando a infecção foi confirmada.
ConclusĂ”es: As terapĂȘuticas instituĂdas revelaram, de forma geral, uma prĂĄtica clĂnica consistente com as recomendaçÔes publicadas para o tratamento da Ășlcera pĂ©ptica, embora se tenha encontrado alguma variabilidade no tempo de duração da terapĂȘutica com os inibidores da bomba de protĂ”es
RelatĂłrio Anual 2013 - A Situação do PaĂs em MatĂ©ria de Drogas e ToxicodependĂȘncias
Ă responsabilidade do SICAD a elaboração deste RelatĂłrio, a apresentar anualmente Ă Assembleia da RepĂșblica e ao Governo PortuguĂȘs, fornecendo elementos de apoio Ă decisĂŁo polĂtica e ao planeamento da intervenção. Anexo: O volume anexo ao RelatĂłrio integra informação mais pormenorizada relativa Ă componente do RelatĂłrio: Parte A - Caracterização e Evolução da Situação.info:eu-repo/semantics/publishedVersio
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Comparison of the Electrochemical Response of Carbon-Fiber-Reinforced Plastic (CFRP), Glassy Carbon, and Highly Ordered Pyrolytic Graphite (HOPG) in Near-Neutral Aqueous Chloride Media
Carbon-fiber-reinforced polymers (CFRP), being conductive, are capable of supporting cathodic oxygen reduction reactions (ORR) and thus promote galvanic corrosion when coupled to many metallic materials. Hence, understanding cathodic processes at carbon surfaces is critical to developing new strategies for the corrosion protection of multi-material assemblies. In the present work, the electrochemical responses of CFRP, glassy carbon, and HOPG (Highly Ordered Pyrolytic Graphite) have been evaluated in a quiescent 50 mM NaCl solution, and their respective activities towards ORR have been ranked. Employing the averages of the specific charges (CFRP, 129.52 mC cm−2; glassy carbon, 89.95 mC cm−2; HOPG, 60.77 mC cm−2) passed during 1 h polarization of each of the 3 carbon surfaces at −1000 mVSCE in the test media as a ranking criterion, the propensities of the 3 carbon surfaces (CFRP, GC, and HOPG) to support cathodic activities that can lead to anodic metal dissolution on galvanic coupling to metallic materials are ranked thusly; CFRP > GC > HOPG. This ranking is consistent with the trend of capacitance values obtained in this work: CFRP (19.5 to 34.5 μF cm−2), glassy carbon (13.6 to 85.5 μF cm−2), and HOPG (1.4 to 1.8 μF cm−2). A comparison of electrochemical data at potentials relevant to galvanic coupling to metals indicated that at these cathodic potential(s) the CFRP surface is the most electrochemically active of the studied carbon surfaces. On the basis of the values and trends of the electrochemical parameters evaluated, it is postulated that the observed differences in the electrochemical responses of these 3 carbon-rich surfaces to ORR are significantly due to differences in the proportions of edge sites present on each carbon surface. These results could provide valuable insights on plausible strategies for designing carbon surfaces and carbon fiber composites with reduced activity toward ORR for corrosion protection applications or enhanced activity towards ORR for energy applications
Filling of simulated lateral canals with gutta-percha or thermoplastic polymer by warm vertical compaction
The aim of this study was to evaluate the ability of gutta-percha and a thermoplastic synthetic polymer (Resilon) to fill simulated lateral canals, using warm vertical compaction. Forty-five single-rooted human teeth were prepared using the rotary crown-down technique. Artificial lateral canals were made at 2, 5, and 8 mm from the working length (WL) in each root. The specimens were divided into three groups (n = 15), according to the filling material: Dentsply gutta-percha (GD), Odous gutta-percha (GO), and Resilon cones (RE). The root canals were obturated using warm vertical compaction, without endodontic sealer. The specimens were subjected to a tooth decalcification and clearing procedure. Filling of the lateral canals was analyzed by digital radiography and digital photographs, using the Image Tool software. The data were subjected to the Kruskal-Wallis and Dunn tests at 5% significance. RE had the best filling ability in all root thirds (p 0.05). Resilon may be used as an alternative to gutta-percha as a solid core filling material for use with the warm vertical compaction technique. The study findings point to the potential benefit of the warm vertical compaction technique for filling lateral canals, and the study provides further information about using Resilon and gutta-percha as materials for the warm vertical compaction technique.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Solvent capacity of different substances on gutta-percha and resilon
The aim of this study was to evaluate the effectiveness of 3 solvents (eucalyptol, orange oil, and xylol) on 2 types of gutta-percha (conventional and thermoplastic) and Resilon. Specimens (10 mm diameter à 1 mm thick; n=7 per condition) were prepared and maintained at 37°C for 48 h. Each specimen was weighed on a precision scale every 24 h until its mass was stable, at which time the initial mass was determined. Specimens (n=7) were then immersed in the solvent solutions and, after 48 h at 37°C, they were reweighed at 24- h intervals, until stabilization (final mass). The difference between the final and the initial mass determined the solvent capacity of each solvent. Data were subjected to analysis of variance and Tukey's test at 5% significance level. The results demonstrated that xylol was the most effective, especially on conventional gutta-percha and Resilon (p<0.05). Eucalyptol and orange oil were more effective on thermoplastic gutta-percha than the other materials (p<0.05). It was concluded that all evaluated substances presented solvent action, but xylol was the most effective on both gutta-percha or Resilon
Biocompatibility, bioactivity, porosity, and sealer/dentin interface of bioceramic ready-to-use sealers using a dentin-tube model
Abstract This study evaluated the biocompatibility, bioactivity, porosity, and sealer/dentin interface of Sealer Plus BC (SP), Bio-C Sealer (BIOC), TotalFill BC Sealer (TF), and AH Plus (AHP). Dentin tubes filled with the sealers and empty tubes (control group) were implanted in the subcutaneous tissue of rats for different periods (nâ=â6 per group/period). Number of inflammatory cells (ICs), capsule thickness, von Kossa reaction, interleukin-6 (IL-6) and osteocalcin (OCN) were evaluated. Porosity and voids in the interface dentin/sealers were assessed by micro-computed tomography. The data were submitted to ANOVA/Tukeyâs tests (αâ=â0.05). Greater capsule thickness, ICs and IL-6 immunolabeling cells were observed in AHP. No significant difference in thickness of capsule, ICs, and IL-6- immunolabeling cells was detected between SP and TF, in all periods, and after 30 and 60 days between all groups. At 60 days all groups had reduction in capsule thickness, ICs and IL-6 immunolabeling cells. Von Kossa-positive and birefringent structures were observed in the capsules around the sealers. BIOC, SP, and TF exhibited OCN-immunolabeling cells. All sealers had porosity values below 5%, besides low and similar interface voids. BIOC, SP and TF are biocompatible, bioactive, and have low porosity and voids. The dentin-tube model used is an alternative for evaluating bioceramic materials