Navegando por Palavras-chave "recycling"

Agora exibindo 1 - 3 de 3
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Desenvolvimento de uma rota alternativa via processamento no estágio sólido para a reciclagem da liga de alumínio contendo lítio, aa2050
    (Universidade Federal de São Paulo (UNIFESP), 2016-01-04) Guido, Vanessa [UNIFESP]; Cardoso, Kátia Regina Cardoso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    This study aimed the development of an alternative route for the recycling of aluminum alloy AA2050 machining chips. The route is based on powder metallurgy technique: high energy ball milling and compaction by direct hot extrusion. The route takes place
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Receptor-mediated endocytosis of angiotensin II in rat myometrial cells
    (Elsevier B.V., 1997-08-01) Lazari, Maria de Fatima Magalhaes [UNIFESP]; Porto, Catarina Segreti [UNIFESP]; Freymüller-Haapalainen, Edna [UNIFESP]; Abreu, Lygia C.; Picarelli, Zuleika P.; Universidade Federal de São Paulo (UNIFESP); INST BUTANTAN; CTR ELECTRON MICROSCOPY
    The events involved in the processing of the angiotensin II (Ang II)-receptor complex were studied in primary cultures of rat myometrial cells. Ang II bound to rat myometrial cells in aspecific, time-and temperature-dependent fashion. Pretreatment with cycloheximide did not interfere with binding up to 3 ha, but inhibited increases in binding observed over longer periods. The [H-3]Ang II binding to intact cells was inhibited by dithiothreitol (DTT), and the rank order of potency of Ang II and nonpeptide antagonists to inhibit the [H-3]Ang II binding was Ang II > Losartan much greater than PD 123319 or CGP 42112B, indicating the presence of the AT(1) receptor type. Whereas most of the [H-3]Ang II binding at 4 degrees was susceptible to acid or pronase treatment, binding at 35 degrees was resistant to both treatments, suggesting an internalization of the Ang II-receptor complex. Phenylarsine oxide (PAO) and N ethylmaleimide (NEM) caused a concentration-dependent inhibition when the binding assay was performed at 35 degrees, but no effect was observed at 4 degrees, indicating that these agents did not alter cell-surface binding but actually prevented the internalization process. Simultaneous treatment with 1 mM DTT or beta-mercaptoethanol prevented the inhibitory effect of NEM, but only DTT could prevent the inhibition caused by PAO, indicating that two closely located sulfhydryl groups must be involved in the internalization process. Chloroquine (100 mu M) inhibited the [H-3]Ang II dissociation from cells, and monensin (25 mu M) induced a 30% inhibition of [H-3]Ang II binding (35 degrees, 3 hr), suggesting endosomal processing of the Ang II-receptor complex with receptor recycling to the cell surface. These results indicate that Ang II binding to AT(1) receptors in rat myometrial cells is followed by internalization of the Ang II-receptor complex and recycling of the receptor to the cell surface. (C) 1997 Elsevier Science Inc.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Reprocessability of PHB in extrusion: ATR-FTIR, tensile tests and thermal studies
    (Assoc Brasil Polimeros, 2017) Rivas, Leonardo Fabio; Casarin, Suzan Aline; Nepomuceno, Neymara Cavalcante; Alencar, Marie Isabele; Marcondes Agnelli, Jose Augusto; de Medeiros, Eliton Souto; Wanderley Neto, Alcides de Oliveira; de Oliveira, Mauricio Pinheiro [UNIFESP]; de Medeiros, Antonio Marcos; Ferreira e Santos, Amelia Severino
    Mechanical recycling of biodegradable plastics has to be encouraged, since the consumption of energy and raw materials can be reduced towards a sustainable development in plastics materials. In this study, the evolution of thermal and mechanical properties, as well as structural changes of poly(hydroxybutyrate) (PHB) up to three extrusion cycles were investigated. Results indicated a significant reduction in mechanical properties already at the second extrusion cycle, with a reduction above 50% in the third cycle. An increase in the crystallinity index was observed due to chemicrystallization process during degradation by chain scission. On the other hand, significant changes in the chemical structure or in thermal stability of PHB cannot be detected by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA), respectively.