A novel method to produce a ceramic paver recycling waste glass

The present work studies the incorporation of the waste glass in ceramic paver, containing clay, one plentiful raw material in the earth’s crust. Ceramic paver has a huge capacity of use and, consequently too, of recycling of the waste glass. A more sustainable process is presented here, since there is the use of waste which give more energy efficiency during ceramic firing, because of the fluxing protagonism of the waste glass. Formulations using clay up to 60% by weight of the waste glass were evaluated. The pressing method is used to produce pavers for its firing in temperatures between 900 and 1000 ​°C. As a main result, the waste glass acts as fluxing in formulations, improving pavers properties. Pavers produced at 900 ​°C present properties for application in industrial floors, light vehicular and pedestrian traffic, and when fired at 950 ​°C, are suitable for use in heavy vehicle traffic. The waste glass makes it possible to produce novelty ceramic pavers with high properties from lower firing temperatures when compared to formulations without waste glass

Gene expression of bovine cumulus oophorus cells after vitrification

Um dos desafios da criobiologia continua sendo o desenvolvimento de um método que proporcione a manutenção da viabilidade após a criopreservação de oócitos imaturos na espécie bovina. A vitrificação tem sido a metodologia que proporciona resultados de sobrevivência após a criopreservação mais promissores para complexos cumulus-oócito (CCOs) imaturos bovinos. Entretanto, a ação dos crioprotetores sobre as células do cumulus oophorus, no que diz respeito à regulação da expressão de genes importantes nesta fase, ainda é pouco compreendida. O objetivo do trabalho foi avaliar a expressão gênica das proteínas ácido hialurônico sintase 2 (HAS2), link protein (HAPLN1), conexina 43 (GJA1) e proteína de choque térmico HSP70-1 (HSP70-1) em células do cumulus oophorus de oócitos imaturos bovinos submetidos a exposição e/ou vitrificação na solução crioprotetora (SV) composta por 20% de etileno glicol (EG) + 20% dimetil sulfóxido (DMSO) + 0,5M de sacarose. Os CCOs foram selecionados e distribuídos em 4 grupos experimentais: G1, CCOs não submetidos a maturação in vitro (MIV); G2, CCOs submetidos à MIV; G3, CCOs maturados após a exposição à SV; e G4, CCOs maturados após a vitrificação com a SV. A MIV foi realizada em TCM 199, suplementado com soro de égua em estro, à 39oC, 5% de CO2 e máxima umidade relativa, por 22 a 24 horas. A extração do RNA das amostras de células do cumulus foi realizada pelo método do fenol-clorofórmio seguido por uma etapa de captação específica do mRNA. Após a utilização da técnica de RT-PCR para a obtenção do cDNA e amplificação dos quatro fragmentos específicos, a análise dos resultados não mostrou diferença significativa entre os grupos para a abundância relativa dos transcritos de link protein (p=0,486), HAS2 (p=0,394), conexina 43 (p=0,116) e HSP70-1 (p=0,248).A challenge of cryobiology remains in to develop a method that provides adequate results of viability after cryopreservation of immature bovine oocytes. Vitrification has been the methodology that provides most promising survival results after cryopreservation for immature bovine cumulus-oocyte complexes (COCs). However, the action of cryoprotectants on the gene expression regulation of cumulus oophorus cells is still poorly understood. The aim of this study was to evaluate, through the RT-PCR technique, the gene expression of hyaluronic acid synthase protein 2 (HAS2), link protein, connexin 43 and heat shock protein 70 (HSP70-1) in cumulus oophorus cells of immature bovine oocytes exposed and/or vitrified in cryoprotectant solution (VS) containing 20% ethylene glycol (EG) + 20% dimethilsulfoxide (DMSO) + 0.5 M sucrose before in vitro maturation (IVM). The immature COCs were sellected, and allocated into four experimental groups: G1, COCs no submitted to IVM; G2, COCs submitted to IVM; G3, COCs exposed to VS and submitted to IVM; and G4, COCs vitrified with VS and submitted to IVM. The IVM was performed in TCM 199 supplemented with oestrus mare serum, at 39°C, under 5% of CO2 and maximum relative humidity, for 22 to 24 hours. The RNA extraction from cumulus cells samples was performed by using the phenol-chloroform followed by the specific capture of the mRNA. The mRNAs were transcribed into cDNA using RT-PCR to evaluate patterns of gene expression. The results showed no significant difference between the groups tested for the relative abundance of link protein (p=0.486), HAS2 (p=0.394), connexin 43 (p = 0.116) and HSP70-1 (p = 0.248) transcripts

Microwave-assisted solid sampling analysis coupled to flame furnace atomic absorption spectrometry for cd and pb determination in food-contact polymers

Microwave-assisted solid sampling analysis coupled to flame furnace atomic absorption spectrometry (MW-SS-FF-AAS) was used for Cd and Pb determination in food-contact polymer samples, with the aim of minimizing reagents and laboratory waste. Operational parameters, such as the FF tube design, the oxygen flow rate, the flame stoichiometry, the sample mass, among others, were evaluated and optimized. Calibration was performed using only reference solutions, and the limits of quantification were 1.7 and 4.6 µg g−1 for Cd and Pb, respectively. Accuracy was assessed by the analysis of certified reference materials (CRMs), and by comparison with the results obtained by inductively coupled plasma mass spectrometry after microwave-assisted wet digestion. The MW-SS-FF-AAS results for the CRMs showed no statistical difference with the certified values, and good agreement was observed with the results of the digestion method. The MW-SS-FF-AAS method was considered suitable for Cd and Pb determination in food-contact polymers. The concentrations of Cd and Pb in the analyzed samples varied from <1.7 to 628 µg g−1, and from <4.6 to 614 µg g−1, respectively. As sample digestion is not necessary, the use of concentrated acids can be avoided by using the proposed MW-SS-FF-AAS method, greatly reducing waste generation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland