Effect of repeated disinfections by microwave energy on the physical and mechanical properties of denture base acrylic resins

The present study evaluated the effect of repeated simulated microwave disinfection on physical and mechanical properties of Clássico, Onda-Cryl and QC-20 denture base acrylic resins. Aluminum patterns were included in metallic or plastic flasks with dental stone following the traditional packing method. The powder/liquid mixing ratio was established according to the manufacturer's instructions. After water-bath polymerization at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling and finished. Each specimen was immersed in 150 mL of distilled water and underwent 5 disinfection cycles in a microwave oven set at 650 W for 3 min. Non-disinfected and disinfected specimens were subjected to the following tets: Knoop hardness test was performed with 25 g load for 10 s, impact strength test was done using the Charpy system with 40 kpcm, and 3-point bending test (flexural strength) was performed at a crosshead speed of 0.5 mm/min until fracture. Data were analyzed statistically by ANOVA and Tukey's test (α= 0.05%). Repeated simulated microwave disinfections decreased the Knoop hardness of Clássico and Onda-Cryl resins and had no effect on the impact strength of QC-20. The flexural strength was similar for all tested resins.Este estudo verificou o efeito de repetidas desinfecções por microondas sobre a dureza, impacto e resistência à flexão das resinas acrílicas Clássico, Onda-Cryl e QC-20. Matrizes de alumínio foram incluídas em muflas metálica ou plástica com gesso pedra tipo III, de acordo com a técnica de inclusão tradicional. A proporção polímero/monômero usada foi de acordo com as recomendações dos fabricantes. Depois da polimerização em água à temperatura de 74ºC por 9 h, água em ebulição por 20 min ou por energia de microondas a 900 W por 3 min, os corpos-de-prova foram demuflados após esfriamento da mufla em temperatura ambiente e submetidos ao polimento convencional. Testes de dureza, impacto e resistência à flexão foram feitos nos corpos-de-prova controle e experimentais. Cada corpo-de-prova foi submetido individualmente a 5 desinfecções por microondas em forno doméstico com 900 W de energia por 3 min, imersos em 150 mL de água destilada. O teste de dureza Knoop foi realizado com carga de 25 g por 10 s, de resistência ao impacto pelo sistema Charpy com 40 kpcm e de resistência à flexão por três pontos com velocidade de 0,5 mm/min até fratura. Os dados obtidos foram submetidos à análise de variância e ao teste de Tukey (α=0,05%). Repetidas desinfecções por microondas diminuíram a dureza das resinas Clássico e Onda-Cryl, não promoveram nenhum efeito sobre a resistência ao impacto da resina QC-20. A resistência à flexão foi similar para todas as resinas.CNP

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Tendências Promissoras: O Papel dos Inibidores do SGLT2 no Tratamento da Diabetes Tipo 2 e seus Impactos Cardiovasculares

This study reviewed the role of sodium-glucose cotransporter 2 (SGLT2) inhibitors in the treatment of type 2 diabetes and their cardiovascular impacts. Through the analysis of clinical studies, including those conducted with empagliflozin, canagliflozin, dapagliflozin, and ertugliflozin, a significant reduction in the risk of adverse cardiovascular events was observed in patients treated with these medications. Additionally, SGLT2 inhibitors were associated with additional benefits, such as reducing the progression of renal disease and hospitalization for heart failure. However, further research is needed to fully understand the mechanisms of action of these medications and their potential long-term adverse effects. In summary, SGLT2 inhibitors represent an important therapeutic option in the management of type 2 diabetes, offering additional cardiovascular and renal benefits beyond glycemic control.Este trabalho revisou o papel dos inibidores do cotransportador de sódio-glicose 2 (SGLT2) no tratamento da diabetes tipo 2 e seus impactos cardiovasculares. A partir da análise de estudos clínicos, incluindo aqueles conduzidos com empagliflozina, canagliflozina, dapagliflozina e ertugliflozina, observou-se uma redução significativa do risco de eventos cardiovasculares adversos em pacientes tratados com esses medicamentos. Além disso, os inibidores do SGLT2 foram associados a benefícios adicionais, como a redução da progressão da doença renal e da hospitalização por insuficiência cardíaca. No entanto, são necessárias mais pesquisas para compreender completamente os mecanismos de ação desses medicamentos e seus potenciais efeitos adversos a longo prazo. Em resumo, os inibidores do SGLT2 representam uma importante opção terapêutica no manejo da diabetes tipo 2, oferecendo benefícios cardiovasculares e renais adicionais além do controle glicêmico