No abstract

Metabolites, lipids, and other small molecules are key constituents of tissues supporting cellular programs in health and disease. Here, we present METASPACE, a community-populated knowledge base of spatial metabolomes from imaging mass spectrometry data. METASPACE is enabled by a high-performance engine for metabolite annotation in a confidence-controlled way that makes results comparable between experiments and laboratories. By sharing their results publicly, engine users continuously populate a knowledge base of annotated spatial metabolomes in tissues currently including over 3000 datasets from human cancer cohorts, whole-body sections of animal models, and various organs. The spatial metabolomes can be visualized, explored and shared using a web app as well as accessed programmatically for large-scale analysis. By using novel computational methods inspired by natural language processing, we illustrate that METASPACE provides molecular coverage beyond the capacity of any individual laboratory and opens avenues towards comprehensive metabolite atlases on the levels of tissues and organs.

the energy density of LIBs because Si has ten times higher theoretical capacity (3579 mAh g −1 ) comparing with those of conventional graphite (372 mAh g −1 ). [9][10][11] However, large-scale applications of Si anodes still face several significant challenges, including pulverization of Si particles, continuous growth of a solid electrolyte interface (SEI) layer during the charge/discharge processes, and large swelling of the Si-based anode. [12,13] Without successfully overcoming those challenges, Si can be used only as a limited additive in graphite-based anodes to incrementally increase the energy density of LIBs.Several approaches have been developed in recent years to address those challenges. [14][15][16][17] In this regard, Si nanocomposites stabilized by heterogeneous elements has been used as one of most effective approaches to accommodate large volume changes and prevent side reactions between the electrolyte and Si. [15,16,[18][19][20] Moreover, practical issues associated with the use of nanoengineered Si anodes [21] (e.g., high surface area, low density, and high interparticle resistance) have been addressed by building the nanostructure in a local scale within micrometersized particles. [14,[22][23][24] Representative design of nanostructured Si includes the pomegranate-inspired Si/C anode [23] and Si nanolayer embedded graphite. [24] These nanostructure materials form micrometer (µm) size particles that can be used in practical applications and that are compatible with conventional battery manufacturing process. However, as the primary particle size decreases to nanometer-scale, it is increasingly difficult to assemble nanostructured Si into micrometer-sized material. [25][26][27][28] In this work, we demonstrate a facile method for preparing a Si/C composite containing micrometer-sized nanoporous Si (denoted Np-Si) that is protected by pitch-derived carbon (denoted PC). The resulting PC/Np-Si not only successfully retains its single nanometer-sized Si primary particle without sintering in micrometer-scale, but also exhibits favorable powder properties for conventional battery manufacturing process such as narrow particle size distribution, high density, strong mechanical strength, and small surface area. It also exhibits low swelling upon lithiation at both particle-and Porous silicon (Si)/carbon nanocomposites have been extensively explored as a promising anode material for high-energy lithium (Li)-ion batteries (LIBs). However, shrinking of the pores and sintering of Si in the nanoporous structure during fabrication often diminishes the full benefits of nanoporous Si. Herein, a scalable method is reported to preserve the porous Si nano structure by impregnating petroleum pitch inside of porous Si before high-temperature treatment. The resulting micrometer-sized Si/C composite maintains a desired porosity to accommodate large volume change and high conductivity to facilitate charge transfer. It also forms a stable surface coating that limits the penetration of electrolyte into nanoporous Si and ...