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Cementitious binders are often used to immobilize industrial wastes such as residues of coal combustion. Such immobilization stabilizes wastes that contain contaminants by chemical containment, i.e., by uptake of contaminants into the cementitious reaction products. Expectedly, the release ("leachability") of contaminants is linked to: (i) the stability of the matrix (i.e., its resistance to decomposition on exposure to water), and, (ii) its porosity, which offers a pathway for the intrusion of water and egress of contaminant species. To examine the effects of the matrix chemistry on its suitability for immobilization, an equilibrium thermodynamics-based approach is demonstrated for cementitious formulations based on: ordinary portland cement (OPC), calcium aluminate cement (CAC) and alkali activated fly ash (AFA) binding agents. First, special focus is placed on computing the equilibrium phase assemblages using the bulk reactant compositions as an input. Second, the matrix's stability is assessed by simulating leaching that is controlled by progressive dissolution and precipitation of solids across a range of liquid (leachant)-to-(reaction product) solid (l/s) ratios and leachant pH's; e.g., following the LEAF 1313 and 1316 protocols. The performance of each binding formulation is evaluated based on the: (i) relative ability of the reaction products to chemically bind the contaminant(s), (ii) porosity of the matrix which correlates to its hydraulic conductivity, and, (iii) the extent of matrix degradation that follows leaching and which impact the rate and extent of release of potential contaminants. In this manner, the approach enables rapid, parametric assessment of a wide-range of stabilization solutions with due consideration of the matrix's mineralogy, porosity, and the leaching (exposure) conditions., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background and Aims: Debridement therapy with sterile bred larvae in non-healing wounds is a widely accepted safe and efficient treatment modality. However, during application in the contaminated wound bed microbial contamination with potential microbial pathogen spread after escape from the wound or after unreliable disposal procedure may happen, particularly in the case of not using bio-bags. The aims of this work were first to investigate the release of ingested bacteria into the environment by maggots and second to examine the common practice of freezing the maggots after use and/or disposal in trash-bags. Potential methods for hygienic safe disposal of used maggots should be deduced., Methods: First, Maggots were contaminated with S. aureus by allowing them to crawl over an agar surface completely covered with bacterial growth over 24 h at 37°C. After external disinfection maggots were transferred onto sterile Columbia agar plates and shedding of S. aureus was visualized. Second, maggots were frozen at -20°C for 1, 2, 5, 10, 30, and 60 min. After exposure, the larvae were transferred onto Columbia blood agar with consecutive incubation at 37°C over 48 h. The larvae were analyzed visually for mobility and eating activities. The frozen bodies of dead larvae were examined for viable bacteria., Results: We could demonstrate that maggots release formerly ingested pathogens (S. aureus). Freezing at -20°C for at least 60 min was able to kill all maggots, however the contaminant bacteria inside could survive., Conclusion: Since freezing is apparently able to kill maggots but not to reliabely inactivate the ingested bacterial pathogens, we recommend the disposal of free-range larvae in screw cap vials after use to achieve full hygienic control.

Lipases are involved in the generation of jasmonates, which regulate responses to biotic and abiotic stresses. Two sn-1-specific acyl hydrolases, DEFECTIVE IN ANTHER DEHISCENCE1 (DAD1) and DONGLE (DGL), have been reported to be localized in plastids and to be essential and sufficient for jasmonate biosynthesis in Arabidopsis (Arabidopsis thaliana) leaves. Here, we show that levels of 12-oxo-phytodienoic acid (OPDA) and jasmonic acid in three different DGL RNA interference lines and the dad1 mutant were similar to wild-type levels during the early wound response as well as after Pseudomonas infection. Due to the lack of sn-2 substrate specificity, synthesis of dinor OPDA was not expected and also not found to be affected in DGL knockdown and DGL-overexpressing lines. As reported, DAD1 participates in jasmonate formation only in the late wound response. In addition, DGL protein was found to be localized in lipid bodies and not in plastids. Furthermore, jasmonate levels in 16 additional mutants defective in the expression of lipases with predicted chloroplast localization did not show strong differences from wild-type levels after wounding, except for a phospholipase A (PLA) PLA-Igamma1 (At1g06800) mutant line that displayed diminished wound-induced dinor OPDA, OPDA, and jasmonic acid levels. A quadruple mutant defective in four DAD1-like lipases displayed similar jasmonate levels as the mutant line of PLA-Igamma1 after wounding. Hence, we identify PLA-Igamma1 as a novel target gene to manipulate jasmonate biosynthesis. Our results suggest that, in addition to DAD1 and PLA-Igamma1, still unidentified enzymes with sn-1 and sn-2 hydrolase activity are involved in wound- and pathogen-induced jasmonate formation, indicating functional redundancy within the lipase family.

The phloem is the major route for the transport of solutes and nutrients from source to sink organs in plants. The functional transport phloem consists of parenchymal tissue, enucleate sieve elements, and the intimately connected companion cells. The general absence of a nucleus and functional ribosomes in sieve tubes poses problems especially for damage avoidance and repair of sieve element components. To examine how sieve tubes can remain functional during oxidative stress, we analysed phloem sap of cucumber and pumpkin plants with respect to the presence of antioxidant defence enzymes, their enzymatic activity, and activity changes after exposure to drought stress. Using 1D SDS-PAGE and nano ESI MS/MS, the presence of proteins such as cytosolic Cu/Zn superoxide dismutase, monodehydroascorbate reductase, and peroxidase could be shown. Moreover, activities for several antioxidant enzymes (superoxide dismutase, dehydroascorbate reductase, peroxidase) in phloem exudate could be demonstrated. The activity of these enzymes in phloem sap from cucumber and pumpkin plants increased in response to drought stress. The presented results together with earlier findings provide evidence supporting the presence of a complete machinery of antioxidant defence enzymes and detoxifying metabolites important for avoiding damage to essential components of the sieve elements due to oxidative stress.