Rechargeable lithium ion batteries (RLBs) have great potential for applications in electric and hybrid vehicles due to their high energy density, high voltage, and long lifespan. However, their rate performance, one of the most important factors decisive for the above applications, urgently needs to be improved. [1][2][3] In general, electrodes in lithium ion batteries are based on insertion reactions, in which lithium ions are accommodated into an open host structure with electron addition and followed by an extraction with electron removal during the cycling processes. Thus, the rate performance of RLBs is limited by the diffusion rate of lithium ions and the electron transport in electrode materials. [4,5]

Recently, electrochemically active metals and metal oxides, such as Sn, [1] Si, [2] Co 3 O 4 , [3,4] and Fe 2 O 3 , [5] have attracted much attention as anode materials for lithium ion batteries due to their high theoretical capacities and promising potential. However, a large specific volume change commonly occurs in the host matrix of these metals and metal oxides during the cycling process. The resulting partial pulverization of the electrodes leads to a decrease in electrical conductivity and reversible capacity. [1,6] To circumvent these problems, graphitic carbons with high electrical conductivity have been widely used as matrices for metals and metal oxides to improve their cycle performances. [7,8] Although remarkable progress has been made, the metals and metal oxides unavoidably aggregate after long cycles since they are mainly located on the surface of the graphitic carbon. [7] Graphene, an integral part of graphite, is a 2D aromatic monolayer of carbon atoms not only exhibiting superior electrical conductivity and high surface area, [3,9] but also possessing structural flexibility, chemical tolerance, and reassembly properties.[10-13] Such merits suggest that graphene sheets hold promise as matrices for metals and metal oxides to improve their electrochemical performance. Graphene can generally be produced by the chemical reduction of readily available exfoliated graphite oxide with reducing agents, such as hydrazine or dimethylhydrazine. [14][15][16][17] Recently, SnO 2 /graphene, [11] carbon nanotube/graphene, and fullerene/graphene [10] composites were fabricated by the assembly of graphene sheets in the presence of inorganic precursors. Highly reversible capacities and good cycle performances were achieved when using these as anode materials for lithium ion batteries. Nevertheless, these inorganic precursors are still prone to strong aggregation and thus preclude a homogenous dispersion in graphenebased composites.In this Communication, we describe a new strategy by choosing planar metallo-organic molecules, such as cobalt phthalocyanine (CoPc), for the purpose of fabricating organic metal/graphene composites. Due to their pronounced p-interactions with graphene sheets, [18] they enable a homogenous dispersion of cobalt and cobalt oxide into/onto the graphene sheets by a simple pyrolysis and oxidation process. As a consequence, the graphene sheets (GS) in composites can not only efficiently buffer the volume change of cobalt oxide during charging and discharging processes but also preserve the high electrical conductivity of the overall electrode. One thus expects highly reversible capacity, good cycle performance, and good rate capability of the cobalt oxide/graphene composite as anode materials for lithium ion batteries.As illustrated in Scheme 1, graphite oxide was suspended in a solution of ultrapure water and ammonia (25 wt % in water) to create a brown dispersion with a concentration of 0.05 wt %. The dispersion was then homogeneously mixed with CoPc molecules by ultrasonication, in which th...

New types of modifications of histones keep emerging. Recently, histone H4K8 2-hydroxyisobutyrylation (H4K8) was identified as an evolutionarily conserved modification. However, how this modification is regulated within a cell is still elusive, and the enzymes adding and removing 2-hydroxyisobutyrylation have not been found. Here, we report that the amount of H4K8 fluctuates in response to the availability of carbon source in and that low-glucose conditions lead to diminished modification. The removal of the 2-hydroxyisobutyryl group from H4K8 is mediated by the histone lysine deacetylase Rpd3p and Hos3p in vivo. In addition, eliminating modifications at this site by alanine substitution alters transcription in carbon transport/metabolism genes and results in a reduced chronological life span (CLS). Furthermore, consistent with the glucose-responsive H4K8 regulation, proteomic analysis revealed that a large set of proteins involved in glycolysis/gluconeogenesis are modified by lysine 2-hydroxyisobutyrylation. Cumulatively, these results established a functional and regulatory network among K, glucose metabolism, and CLS.

Core fucosylation (CF) is a special glycosylation pattern of proteins that has a strong relationship with cancer. The Food and Drug Administration (FDA) has approved the core fucosylated α-fetoprotein as a biomarker for the early diagnosis of hepatocellular carcinoma (HCC). The technology for identifying core fucosylated proteins has significant practical value. The major method for core fucosylated glycoprotein/glycopeptide analysis is neutral loss-based MS(3) scanning under collision-induced dissociation (CID) by ion trap mass spectrometry. However, due to the limited speed and low resolution of the MS(3) scan mode, it is difficult to achieve high-throughput, with only dozens of core fucosylated proteins identified in a single run. In this work, we developed a novel strategy for the identification of CF glycopeptides at a large scale, integrating the stepped fragmentation function, one novel feature of quadrupole-orbitrap mass spectrometry, with "glycan diagnostic ion"-based spectrum optimization. By using stepped fragmentation, we were able to obtain both highly accurate glycan and peptide information of a simplified CF glycopeptide in one spectrum. Moreover, the spectrum could be recorded with the same high speed as the conventional MS(2) scan. By using the "glycan diagnostic ion"-based spectrum refinement method, the efficiency of the CF glycopeptide discovery was significantly improved. We demonstrated the feasibility and reproducibility of our method by analyzing CF glycoproteomes of mouse liver tissue and HeLa cell samples spiked with standard CF glycoprotein. In total, 1364 and 856 CF glycopeptides belonging to 702 and 449 CF glycoproteins were identified, respectively, within a 78-min gradient analysis, which was approximately a 7-fold increase in the identification efficiency of CF glycopeptides compared to the currently used method. In this work, we took core fucosylated glycopeptides as a practical example to demonstrate the great potential of our novel method for use in glycoproteome analysis, and we also anticipate using the flexible novel method in other research fields.

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Quantification of targeted metabolites, especially trace metabolites and structural isomers, in complex biological materials is an ongoing challenge for metabolomics. Initially developed for proteomic analysis, the parallel reaction monitoring (PRM) technique exploiting high-resolution MS2 fragment ion data has shown high promise for targeted metabolite quantification. Notably, MS1 ion intensity data acquired independently as part of each PRM scan cycle are often underutilized in the PRM assay. In this study, we developed an MS1/MS2-combined PRM workflow for quantification of central carbon metabolism intermediates, amino acids and shikimate pathway-related metabolites on an orthogonal QqTOF system. Concentration curve assessment revealed that exploiting both MS1 and MS2 scans in PRM analysis afforded higher sensitivity, wider dynamic range and better reproducibility than relying on either scan mode for quantification. Furthermore, Skyline was incorporated into our workflow to process the MS1/MS2 ion intensity data, and eliminate noisy signals and transitions with interferences. This integrated MS1/MS2 PRM approach was applied to targeted metabolite quantification in engineered E. coli strains for understanding of metabolic pathway modulation. In addition, this new approach, when first implemented in a dynamic C-labeling experiment, showed its unique advantage in capturing and correcting isotopomer labeling curves to facilitate nonstationaryC-labeling metabolism analysis.