2-Hydroxylethyl methacrylate (HEMA), a tooth restoration component, exerts its genotoxic effects in human gingival fibroblasts trough methacrylic acid, an immediate product of its degradation

HEMA (2-hydroxyethyl methacrylate), a methacrylate commonly used in dentistry, was reported to induce genotoxic effects, but their mechanism is not fully understood. HEMA may be degraded by the oral cavity esterases or through mechanical stress following the chewing process. Methacrylic acid (MAA) is the primary product of HEMA degradation. In the present work we compared cytotoxic and genotoxic effects induced by HEMA and MAA in human gingival fibroblasts (HGFs). A 6-h exposure to HEMA or MAA induced a weak decrease in the viability of HGFs. Neither HEMA nor MAA induced strand breaks in the isolated plasmid DNA, but both compounds evoked DNA damage in HGFs, as evaluated by the alkaline comet assay. Oxidative modifications to the DNA bases were monitored by the DNA repair enzymes Endo III and Fpg. DNA damage induced by HEMA and MAA was not persistent and was removed during a 120 min repair incubation. Results from the neutral comet assay indicated that both compounds induced DNA double strand breaks (DSBs) and they were confirmed by the γ-H2AX assay. Both compounds induced apoptosis and perturbed the cell cycle. Therefore, methacrylic acid, a product of HEMA degradation, may be involved in its cytotoxic and genotoxic action

Perspectives on utilization of edible coatings and nano-laminate coatings for extension of postharvest storage of fruits and vegetables

It is known that in developing countries, a large quantity of fruit and vegetable losses results at postharvest and processing stages due to poor or scarce storage technology and mishandling during harvest. The use of new and innovative technologies for reducing postharvest losses is a requirement that has not been fully covered. The use of edible coatings (mainly based on biopolymers) as a postharvest technique for agricultural commodities has offered biodegradable alternatives in order to solve problems (e.g., microbiological growth) during produce storage. However, biopolymer-based coatings can present some disadvantages such as: poor mechanical properties (e.g., lipids) or poor water vapor barrier properties (e.g., polysaccharides), thus requiring the development of new alternatives to solve these drawbacks. Recently, nanotechnology has emerged as a promising tool in the food processing industry, providing new insights about postharvest technologies on produce storage. Nanotechnological approaches can contribute through the design of functional packing materials with lower amounts of bioactive ingredients, better gas and mechanical properties and with reduced impact on the sensorial qualities of the fruits and vegetables. This work reviews some of the main factors involved in postharvest losses and new technologies for extension of postharvest storage of fruits and vegetables, focused on perspective uses of edible coatings and nano-laminate coatings.María L. Flores-López thanks Mexican Science and Technology Council (CONACYT, Mexico) for PhD fellowship support (CONACYT Grant Number: 215499/310847). Miguel A. Cerqueira (SFRH/BPD/72753/2010) is recipient of a fellowship from the Fundação para a Ciência e Tecnologia (FCT, POPH-QREN and FSE Portugal). The authors also thank the FCT Strategic Project of UID/ BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project ‘‘BioInd Biotechnology and Bioengineering for improved Industrial and AgroFood processes,’’ REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico – FUNCAP, CE Brazil (CI10080-00055.01.00/13)

Prace nad konstrukcjami pomp zatapialnych z silnikiem chłodzonym płaszczem wodnym

W artykule opisano typową konstrukcję zatapialnego agregatu pompowego z silnikiem chłodzonym płaszczem wodnym. Przytoczono kryteria oceny układu przepływowego pompy wirowej. Przedstawiono nową konstrukcję pompy i jej elementów. Przedstawiono wyniki badań numerycznych i empirycznych przepływów przez pompę oraz opracowane jej charakterystyki. Opisano badania dopuszczające do pracy w strefie zagrożonej wybuchem gazu. Porównano charakterystyki, nominalne parametry pracy i wskaźniki ruchowe nowej pompy i pomp innych producentów.The article describes a typical construction of submersible pump unit with the engine cooled by water jacket. The criteria for assessing of the flow of the pump impeller are quoted. It presents a new design of the pump and its components. It also presents the results of numerical and empirical researches of flows through the pump and its characteristics developed. The article describes studies allowing for operation in area endangered by gas explosion. We compared the characteristics, nominal operating parameters and ratios of a new motor pumps and pumps from other manufacturers