N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone, also known as 6PPD quinone, was recently identified as a toxic chemical that causes acute mortality in coho salmon following exposure to ...urban runoff. Despite its potential occurrence in receiving waters worldwide, there is no information about the toxicity of 6PPD quinone to other aquatic species. In this study, to assess the aquatic toxicity of 6PPD quinone to freshwater fish and crustacean species, we performed standardized 48–96 h acute toxicity tests of 6PPD quinone with four species (Danio rerio, Oryzias latipes, Daphnia magna, and Hyalella azteca). In contrast to the high toxicity observed in coho salmon in a previous study (24 h LC50 of 0.79 μg/L), 6PPD quinone did not exhibit acute lethal toxicity to any species at its maximum water solubility. The absence of acute lethality of 6PPD quinone to tested species indicates that the urban runoff toxicity observed for the species can be attributed to other chemicals. The observed large discrepancy in toxicity (by a factor of ∼100) might be due to the specific toxicity of 6PPD quinone to coho salmon. Further research is needed to reveal the underlying mechanisms of the observed difference, which will be useful for both urban runoff management and aquatic toxicology.
•LBO and Al2O3 solution-derived sintering additives were used to sinter LLZT.•Liquid-phase sintering is enhanced by LLZT containing lanthanum oxide.•1.2 vol% LBO and 1.5 vol% Al2O3 as sintering ...additives of LLZT achieves an ionic conductivity of 0.8 mS cm−1 at 25 °C.
The sintering and processing of garnet-type solid ceramic electrolytes (e.g., Li7La3Zr2O12 (LLZ)) are challenging because the material composition and microstructure at high temperatures must be carefully controlled to obtain the stabilization of highly conductive cubic phase and dense ceramic. Liquid-phase sintering using sintering aids is typically used for densifying ceramic materials, as it is a faster and/or lower-temperature process. In this study, we used solution-process-derived sintering additives to sinter garnet-type solid electrolytes highly effective in terms of relative density and properties at 1000 °C (10 h). The liquid phase formation during the sintering was rationalized to establish the optimal sintering conditions. The use of 1.2-vol% 75Li2O∙25B2O3 and 1.5-vol% Al2O3 as sintering additives was highly effective in densifying a Ta-doped LLZ, achieving a high ionic conductivity of 0.8 mS cm−1 (25 °C) with low activation energy (9 kJ mol−1) and almost negligible contribution of the grain boundary resistance (10 %).
Aquatic heavy metal pollution is a growing concern. To facilitate heavy metal monitoring in water, we developed transgenic Daphnia that are highly sensitive to heavy metals and respond to them ...rapidly. Metallothionein A, which was a metal response gene, and its promoter region was obtained from Daphnia magna. A chimeric gene fusing the promoter region with a green fluorescent protein (GFP) gene was integrated into D. magna using the TALEN technique and transgenic Daphnia named D. magna MetalloG were produced. When D. magna MetalloG was exposed to heavy metal solutions for 1 h, GFP expression was induced only in their midgut and hepatopancreas. The lowest concentrations of heavy metals that activated GFP expression were 1.2 µM Zn
, 130 nM Cu
, and 70 nM Cd
. Heavy metal exposure for 24 h could lower the thresholds even further. D. magna MetalloG facilitates aqueous heavy metal detection and might enhance water quality monitoring.
To develop a method for predicting chronic toxicity of pharmaceuticals in Daphnia, we investigated the feasibility of combining the presence of drug-target orthologs in Daphnia magna, classification ...based on pharmacological effects, and ecotoxicity quantitative structure-activity relationship (QSAR) prediction. We established datasets on the chronic toxicity of pharmaceuticals in Daphnia, including information on therapeutic categories, target proteins, and the presence or absence of drug-target orthologs in D. magna, using literature and databases. Chronic toxicity was predicted using ecotoxicity prediction QSAR (Ecological Structure Activity Relationship and Kashinhou Tool for Ecotoxicity), and the differences between the predicted and measured values and the presence or absence of drug-target orthologs were examined. For pharmaceuticals without drug-target orthologs in D. magna or without expected specific actions, the ecotoxicity prediction QSAR analysis yielded acceptable predictions of the chronic toxicity of pharmaceuticals. In addition, a workflow model to assess the chronic toxicity of pharmaceuticals in Daphnia was proposed based on these evaluations and verified using an additional dataset. The addition of biological aspects such as drug-target orthologs and pharmacological effects would support the use of QSARs for predicting the chronic toxicity of pharmaceuticals in Daphnia.
•Datasets on chronic toxicity of pharmaceuticals in Daphnia were constructed.•Quantitative structure-activity relationships gave acceptable predictions.•A classification workflow for predicting chronic toxicity in Daphnia was proposed.
Feline noroviruses (FNoVs) are potential clinical pathogens in cats. To perform an epidemiological study of FNoV infection, it is necessary to develop a simple and effective method for virus ...detection. We investigated whether a commercial human NoV quantitative RT-PCR kit for the detection of human NoVs used in medical practice can be applied for FNoV detection. This kit was capable of detecting the FNoV gene regardless of the genogroup (GIV and GVI) in experimental and field samples. Based on the above findings, it is possible to detect FNoVs using human NoV tests. The relationship between FNoV infection and gastroenteritis in cats may be clarified by applying these methods to an epidemiological survey of FNoVs.
•Weight of evidence (WoE) method to evaluate key events in adverse outcome pathways.•Biological plausibility, empirical evidence and essentiality are WoE determinants.•Application to human health and ...ecological AOPs is illustrated with six examples.•A prototype quantitative decision analysis (MCDA) WoE model for AOPs is described.
Systematic consideration of scientific support is a critical element in developing and, ultimately, using adverse outcome pathways (AOPs) for various regulatory applications. Though weight of evidence (WoE) analysis has been proposed as a basis for assessment of the maturity and level of confidence in an AOP, methodologies and tools are still being formalized. The Organization for Economic Co-operation and Development (OECD) Users’ Handbook Supplement to the Guidance Document for Developing and Assessing AOPs (OECD 2014a; hereafter referred to as the OECD AOP Handbook) provides tailored Bradford-Hill (BH) considerations for systematic assessment of confidence in a given AOP. These considerations include (1) biological plausibility and (2) empirical support (dose-response, temporality, and incidence) for Key Event Relationships (KERs), and (3) essentiality of key events (KEs). Here, we test the application of these tailored BH considerations and the guidance outlined in the OECD AOP Handbook using a number of case examples to increase experience in more transparently documenting rationales for assigned levels of confidence to KEs and KERs, and to promote consistency in evaluation within and across AOPs. The major lessons learned from experience are documented, and taken together with the case examples, should contribute to better common understanding of the nature and form of documentation required to increase confidence in the application of AOPs for specific uses. Based on the tailored BH considerations and defining questions, a prototype quantitative model for assessing the WoE of an AOP using tools of multi-criteria decision analysis (MCDA) is described. The applicability of the approach is also demonstrated using the case example aromatase inhibition leading to reproductive dysfunction in fish. Following the acquisition of additional experience in the development and assessment of AOPs, further refinement of parameterization of the model through expert elicitation is recommended. Overall, the application of quantitative WoE approaches hold promise to enhance the rigor, transparency and reproducibility for AOP WoE determinations and may play an important role in delineating areas where research would have the greatest impact on improving the overall confidence in the AOP.
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