Dose-response metabolomics and pathway sensitivity to map molecular cartography of bisphenol A exposure.

In the toxicological regime, the toxicological endpoint and its dose-response relationship are two of the most prominent characters in conducting a risk assessment for chemical exposure. Systems biological methods have been used to comprehensively characterize the impact of toxicants on the biochemical pathways. However, the majority of the current studies are only based on single-dose, and limited information can be extrapolated to other doses from these experiments, regardless of the sensitivity of each endpoint. This study aims to understand the dose-response metabolite dysregulation pattern and metabolite sensitivity at the system-biological level. Here, we applied bisphenol A (BPA), an endocrine-disrupting chemical (EDC), as the model chemical. We first employed the global metabolomics method to characterize the metabolome of breast cancer cells (MCF-7) upon exposure to different doses (0, 20, 50, and 100 µM) of BPA. The dysregulated features with a clear dose-response relationship were also effectively picked up with an R-package named TOXcms. Overall, most metabolites were dysregulated by showing a significant dose-dependent behaviour. The results suggested that BPA exposure greatly perturbed purine metabolism and pyrimidine metabolism. Interestingly, most metabolites within the purine metabolism were described as a biphasic dose-response relationship. With the established dose-response relationship, we were able to fully map the metabolite cartography of BPA exposure within a wide range of concentrations and observe some unique patterns. Furthermore, an effective concentration of certain fold changes (e.g., EC+10 means the dose at which metabolite is 10% upregulated) and metabolite sensitivity were defined and introduced to this dose-response omics information. The result showed that the purine metabolism pathway is the most venerable target of BPA, which can be a potential endogenous biomarker for its exposure. Overall, this study applied the dose-response metabolomics method to fully understand the biochemical pathway disruption of BPA treatment at different doses. Both dose-response omics strategy and metabolite sensitivity analysis can be further considered and emphasized in future chemical risk assessments.

Designed Construction of a Graphene and Iron Oxide Freestanding Electrode with Enhanced Flexible Energy-Storage Performance.

In this work, a bendable graphene@iron oxide hybrid film (GFeF) electrode was fabricated through a filtration-assisted self-assembly method. Morphological characterization of GFeF revealed a uniform distribution of iron oxide nanoparticles between graphene nanosheets. Surface chemical characterization confirmed that graphene oxide in the as-prepared hybrid film was effectively reduced after thermal reduction. The electrochemical performance of a GFeF half-cell versus Li/Li(+) exhibited high gravimetric capacity (855.2 mAh g(-1) at 0.02 A g(-1)), high volumetric capacity (1949.9 mAh cm(-3) at 0.02 A g(-1)), and superior cycling stability (93% capacitance retention after 500 cycles). On the basis of such a bendable electrode, a hybrid Li-ion supercapacitor that offers an operation voltage of 3.5 V and delivers a high energy density (129.6 Wh kg(-1)) like a Li-ion battery combined with a high power density (1870 W kg(-1)) like a supercapacitor was fabricated. In addition to the superior energy-storage capability, the as-fabricated prototype pouch cell also exhibited excellent mechanical flexibility and stable electrochemical performances under dynamic bending. The viability of such an energy-storage device provides a possible design pathway for future wearable electronics.