Large-scale energy storage is becoming increasingly critical to balance the intermittency between renewable energy production and consumption 1. Organic redox flow batteries (RFBs), based on inexpensive and sustainable redox-active materials, are promising storage technologies that are cheaper and have fewer environmental hazards than the more mature vanadium-based batteries (typically < 15 Wh/dm 3 , vs. 20-35 Wh/dm 3 , respectively) 2,3. Unfortunately, they have shorter calendar lifetimes and lower energy-densities and fundamental insight at the molecular level is thus required to improve performance 4,5. Here we report two in situ NMR methods to study flow batteries, which are applied on two separate anthraquinones, 2,6-dihydroxyanthraquinone, DHAQ and 4,4'-((9,10-anthraquinone-2,6diyl)dioxy) dibutyrate, DBEAQ as redox-active electrolytes. In one method we follow the changes of the liquids as they flow out of the electrochemical cell, while in the second, we observe the changes that occur in both the positive and negative electrodes in the full electrochemical cell. Making use of the bulk magnetisation changes, observed via the 1 H NMR shift of the water resonance, and the linebroadening of the 1 H shifts of the quinone resonances as a function of state of charge, we determine the potential differences of the two one-electron couples, identify and quantify the rate of electron transfer between reduced and oxidised species and the extent of electron delocalization of the unpaired spins over the radical anions. The method allows electrolyte decomposition and battery self-discharge to be explored in real time, showing that DHAQ is decomposed electrochemically via a reaction which can be minimized by limiting the voltage used on charging. Applications of the new NMR metrologies to understand a wide range of redox processes in flow and other battery systems are readily foreseen. The two in situ NMR setups Ex situ characterization of RFBs can be challenging due to the high reactivity, sensitivity to sample preparation and short lifetimes of some of the oxidised and/or reduced redox-active molecules and ions within the electrolytes. However, one of the distinct features of RFBs is the decoupling of energy storage and power generation, providing different opportunities for in situ monitoring. To date, methods such as in situ optical spectrophotometry 6 and Electron Paramagnetic Resonance (EPR) 7 have been used to study, for example, crossover of quinones and vanadyl ions, but considerable opportunities remain to improve characterization methods to address limitations inherent to each method and to probe different phenomena. Nuclear Magnetic Resonance (NMR) spectroscopy was used to study benzoquinone and polyoxometalate redox reactions in an in situ

Despite recent progress in our understanding of the association between the gut microbiome and colorectal cancer (CRC), multi-kingdom gut microbiome dysbiosis in CRC across cohorts is unexplored. We investigated four-kingdom microbiota alterations using CRC metagenomic datasets of 1,368 samples from 8 distinct geographical cohorts. Integrated analysis identified 20 archaeal, 27 bacterial, 20 fungal and 21 viral species for each single-kingdom diagnostic model. However, our data revealed superior diagnostic accuracy for models constructed with multi-kingdom markers, in particular the addition of fungal species. Specifically, 16 multi-kingdom markers including 11 bacterial, 4 fungal and 1 archaeal feature, achieved good performance in diagnosing patients with CRC (area under the receiver operating characteristic curve (AUROC) = 0.83) and maintained accuracy across 3 independent cohorts. Coabundance analysis of the ecological network revealed associations between bacterial and fungal species, such as Talaromyces islandicus and Clostridium saccharobutylicum. Using metagenome shotgun sequencing data, the predictive power of the microbial functional potential was explored and elevated D-amino acid metabolism and butanoate metabolism were observed in CRC. Interestingly, the diagnostic model based on functional EggNOG genes achieved high accuracy (AUROC = 0.86). Collectively, our findings uncovered CRC-associated microbiota common across cohorts and demonstrate the applicability of multi-kingdom and functional markers as CRC diagnostic tools and, potentially, as therapeutic targets for the treatment of CRC.

Associations between gut microbiota and colorectal cancer (CRC) have been widely investigated. However, the replicable markers for early-stage adenoma diagnosis across multiple populations remain elusive. Here, we perform an integrated analysis on 1056 public fecal samples, to identify adenoma-associated microbial markers for early detection of CRC. After adjusting for potential confounders, Random Forest classifiers are constructed with 11 markers to discriminate adenoma from control (area under the ROC curve (AUC) = 0.80), and 26 markers to discriminate adenoma from CRC (AUC = 0.89), respectively. Moreover, we validate the classifiers in two independent cohorts achieving AUCs of 0.78 and 0.84, respectively. Functional analysis reveals that the altered microbiome is characterized with increased ADP-l-glycero-beta-d-manno-heptose biosynthesis in adenoma and elevated menaquinone-10 biosynthesis in CRC. These findings are validated in a newly-collected cohort of 43 samples using quantitative real-time PCR. This work proves the validity of adenoma-specific markers across multi-populations, which would contribute to the early diagnosis and treatment of CRC.