Additional research in these and other areas is critical if we ar

Additional research in these and other areas is critical if we are

to make headway towards ameliorating the effects of this devastating condition.”
“In this article, a new type of strongly dimerizing 2-ureido-4-[1H]-pyrimidinone (UPy) with amine group is synthesized and then used as end-group to prepare a novel series of supramolecular polyurethanes (PUs). The effects of strong and well-defined hydrogen bonding on material properties of PUs are studied. In these PUs, the UPy groups consequently serve as thermoreversible associations or the “”hard blocks” and the bi-functional PU chains act as the “”monomers.” This theoretical hypothesis is proved by the results of dynamic mechanical thermal analy-sis (DMTA) and rheological test. Thermal 17-AAG mouse Prexasertib molecular weight analysis shows that the strong hydrogen bonds from end groups restrict the formation of their microcrystalline domains. The supramolecular PUs exhibit good mechanical performance and their self-assemble mechanism is discussed. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 1755-1763, 2012″
“Recent studies have suggested that aluminium (Al) induces programmed cell death (PCD) in plants. To investigate possible mechanisms, fluorescence techniques were used to monitor the behaviour of mitochondria in vivo,

as well as the activation of caspase-3-like activity during protoplast PCD induced by Al. A quick burst of mitochondrial reactive oxygen species (ROS) was detected in Al-treated protoplasts. The mitochondrial swelling and mitochondrial transmembrane potential (MTP) loss occurred prior to cell death. Pre-incubation with ascorbic acid (AsA, antioxidant molecule) retarded mitochondrial swelling and MTP loss. The real-time detection of caspase-3-like activation was achieved by measuring the GW4869 inhibitor degree of fluorescence resonance energy transfer (FRET). At 30 min after exposure to Al, caspase-3-like protease activation, indicated by the decrease in the FRET ratio, occurred, taking about 1 h to reach completion in single living protoplasts. The mitochondrial permeability transition pore

(MPTP) inhibitor, cyclosporine (CsA) gave significant protection against MTP loss and subsequent caspase-3-like activation. Our data also showed that Al-induced mitochondrial ROS possibly originated from complex I and III damage in the respiratory chain through the interaction between Al and iron-sulphur (Fe-S) protein. Alternative oxidase (AOX), the unique respiratory terminal oxidase in plants, was demonstrated to play protective roles in Al-induced protoplast death. Our results showed that mitochondrial swelling and MTP loss, as well as the generation of mitochondrial ROS play important roles in Al-induced caspase-3-like activation and PCD, which provided new insight into the signalling cascades that modulate Al phytotoxicity mechanism.

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