Microglia play vital roles in the health and diseases of the central nervous system. Loss of microglia homeostatic state is a key feature of brain aging and neurodegeneration. However, the mechanisms ...underlying the maintenance of distinct microglia cellular states are largely unclear. Here, we show that NG2 glia, also known as oligodendrocyte precursor cells, are essential for maintaining the homeostatic microglia state. We developed a highly efficient and selective NG2 glia depletion method using small‐molecule inhibitors of platelet‐derived growth factor (PDGF) signaling in cultured brain slices. We found that loss of NG2 glia abolished the homeostatic microglia signature without affecting the disease‐associated microglia profiles. Similar findings were also observed in vivo by genetically depleting NG2 glia or conditionally inhibiting NG2 glia PDGF signaling in the adult mouse brain. These data suggest that NG2 glia exert a crucial influence onto microglia cellular states that are relevant to brain aging and neurodegenerative diseases. In addition, our results provide a powerful, convenient, and selective tool for the investigation of NG2 glia function.
Main points
Postnatal NG2 glia maintenance obligatorily depends on continuous PDGF signaling.
A highly efficient, selective and versatile NG2 glia depletion method is established.
Loss of NG2 glia abolishes the homeostatic microglia signature both ex vivo and in vivo.
Covalent cross-linking of rubbers is essential for obtaining high resilience and environmental resistance but prevents healing and recycling. Integrating dynamic covalent bonds into cross-linked ...rubbers can resolve the trade-off between permanent cross-linking and plasticity. The state-of-the-art elastomer-based dynamic covalent networks require either intricate molecular makeup or present poor mechanical properties. In this work, we demonstrate a simple way to prepare mechanically robust yet healable and recyclable elastomeric vitrimers by engineering dynamic dual cross-links of boronic esters and coordination bonds into a commercial rubber. Specifically, epoxidized natural rubber is covalently cross-linked with a boronic ester cross-linker carrying dithiol through chemical reaction between epoxy and thiol groups. The covalently cross-linked networks are able to alter the topologies through boronic ester transesterifications, thereby conferring them with healing ability and reprocessability. In particular, the mechanical properties can be remarkably enhanced by introducing sacrificial metal–ligand coordination bonds into the networks without compromising the healing ability or reprocessability.
Reinforcement, recycling, and functional applications are three important issues in elastomer science and engineering. It is of great importance, but rarely achievable, to integrate these properties ...into elastomers. Herein, we report a simple way to prepare covalently cross-linked yet recyclable, robust, and macroscopically responsive elastomer vitrimers by engineering exchangeable bonds into rubber–carbon nanodot (CD) interphase using CD as high-functionality cross-linker. The cross-linked rubbers can rearrange the network topology through transesterification reactions in the interphase, conferring the materials the ability to be recycled, reshaped, and welded. The relatively short chains bridging adjacent CD are highly stretched and preferentially rupture to dissipate energy under external force, resulting in remarkable improvements on the mechanical properties. Moreover, the malleable and welding properties allow the samples to access reconfigurable/multiple shape memory effects.
Parkinson's disease (PD), the second most common age-associated neurodegenerative disorder, is characterized by the loss of dopaminergic (DA) neurons and the presence of α-synuclein-containing ...aggregates in the substantia nigra pars compacta (SNpc). Chronic neuroinflammation is one of the hallmarks of PD pathophysiology. Post-mortem analyses of human PD patients and experimental animal studies indicate that activation of glial cells and increases in pro-inflammatory factor levels are common features of the PD brain. Chronic release of pro-inflammatory cytokines by activated astrocytes and microglia leads to the exacerbation of DA neuron degeneration in the SNpc. Besides, peripheral immune system is also implicated in the pathogenesis of PD. Infiltration and accumulation of immune cells from the periphery are detected in and around the affected brain regions of PD patients. Moreover, inflammatory processes have been suggested as promising interventional targets for PD and even other neurodegenerative diseases. A better understanding of the role of inflammation in PD will provide new insights into the pathological processes and help to establish effective therapeutic strategies. In this review, we will summarize recent progresses in the neuroimmune aspects of PD and highlight the potential therapeutic interventions targeting neuroinflammation.
Carbon-based fibres hold promise for preparing multifunctional fabrics with electrical conductivity, thermal conductivity, permeability, flexibility and lightweight. However, these fabrics are of ...limited performance mainly because of the weak interaction between fibres. Here we report non-woven graphene fibre fabrics composed of randomly oriented and interfused graphene fibres with strong interfibre bonding. The all-graphene fabrics obtained through a wet-fusing assembly approach are porous and lightweight, showing high in-plane electrical conductivity up to ∼2.8 × 10
S m
and prominent thermal conductivity of ∼301.5 W m
K
. Given the low density (0.22 g cm
), their specific electrical and thermal conductivities set new records for carbon-based papers/fabrics and even surpass those of individual graphene fibres. The as-prepared fabrics are further used as ultrafast responding electrothermal heaters and durable oil-adsorbing felts, demonstrating their great potential as high-performance and multifunctional fabrics in real-world applications.
Due to an ever‐increasing demand for electronic devices, rechargeable batteries are attractive for energy storage systems. A novel rechargeable aluminum‐ion battery based on Al3+ intercalation and ...deintercalation is fabricated with Ni3S2/graphene microflakes composite as cathode material and high‐purity Al foil as anode. This kind of aluminum‐ion battery comprises of an electrolyte containing AlCl3 in an ionic liquid of 1‐ethyl‐3‐methylimidazolium chloride (EMImCl). Galvanostatic charge/discharge measurements have been performed in a voltage range of 0.1–2.0 V versus Al/AlCl4
−. An initial discharge specific capacity of 350 mA h g−1 at a current density of 100 mA g−1 is achieved, and the discharge capacity remains over 60 mA h g−1 and coulombic efficiency of 99% after 100 cycles. Typically, for the current density at 200 mA g−1, the initial charge and discharge capacities are 300 and 235 mA h g−1, respectively. More importantly, it should be emphasized that the battery has a high discharge voltage plateau (≈1.0 V vs Al/AlCl4
−). These meaningful results represent a significant step forward in the development of aluminum‐ion batteries.
A novel rechargeable aluminium‐ion battery based on Al3+ intercalation and deintercalation is fabricated with Ni3S2/graphene micro‐flakes composite as cathode materials and high‐purity Al foil as anode. It is clear that two batteries in series can light the red light‐emitting diode (LED) lamp, and the discharge capacity remains over 60 mA h g−1 and coulombic efficiency of 99% after 100 cycles.
Two‐dimensional colloidal nanomaterials are running into renaissance after the enlightening researches of graphene. Macroscopic one‐dimensional fiber is an optimal ordered structural form to express ...the in‐plane merits of 2D nanomaterials, and the formation of liquid crystals (LCs) allows the creation of continuous fibers. In the correlated system from LCs to fibers, understanding their macroscopic organizing behavior and transforming them into new solid fibers is greatly significant for applications. Herein, we retrospect the history of 2D colloids and discuss about the concept of 2D nanomaterial fibers in the context of LCs, elaborating the motivation, principle and possible strategies of fabrication. Then we highlight the creation, development and typical applications of graphene fibers. Additionally, the latest advances of other 2D nanomaterial fibers are also summarized. Finally, conclusions, challenges and perspectives are provided to show great expectations of better and more fibrous materials of 2D nanomaterials. This review gives a comprehensive retrospect of the past century‐long effort about the whole development of 2D colloids, and plots a clear roadmap — “lamellar solid — LCs — macroscopic fibers — flexible devices”, which will certainly open a new era of structural‐multifunctional application for the conventional 2D colloids.
2D colloidal nanomaterials are experiencing a full‐scale renaissance after the enlightening research of graphene. The history of 2D colloidal liquid crystals is comprehensively reviewed from the first V2O5 colloid to the recently discovered graphene (oxide) and other graphenelike 2D nanomaterials. Their attractive solution‐processible properties facilitate the construction of macroscopic fibers with versatile functionalities.
Graphene aerogel microlattices (GAMs) hold great prospects for many multifunctional applications due to their low density, high porosity, designed lattice structures, good elasticity, and tunable ...electrical conductivity. Previous 3D printing approaches to fabricate GAMs require either high content of additives or complex processes, limiting their wide applications. Here, a facile ion‐induced gelation method is demonstrated to directly print GAMs from graphene oxide (GO) based ink. With trace addition of Ca2+ ions as gelators, aqueous GO sol converts to printable gel ink. Self‐standing 3D structures with programmable microlattices are directly printed just in air at room temperature. The rich hierarchical pores and high electrical conductivity of GAMs bring admirable capacitive performance for supercapacitors. The gravimetric capacitance (Cs) of GAMs is 213 F g−1 at 0.5 A g−1 and 183 F g−1 at 100 A g−1, and retains over 90% after 50 000 cycles. The facile, direct 3D printing of neat graphene oxide can promote wide applications of GAMs from energy storage to tissue engineering scaffolds.
Ultralight neat graphene aerogel microlattices (GAMs) with 3D geometric structure are fabricated via an ion‐induced gelation 3D printing method. The printed GAMs display rich hierarchical pores and high electrical conductivity, affording GAMs outstanding capacitive performance as supercapacitors. The facile, direct 3D printing strategy opens an avenue to wide applications of GAMs.
A conceptually new defect‐free principle is proposed for designing graphene cathode of aluminum‐ion battery: the fewer the defects, the better the performances. Developed through scalable approach, ...defect‐free graphene aerogel cathode affords high capacity of 100 mAh g−1 under an ultrahigh rate of 500 C, exceeding defective graphene and previous reports. This defect‐free principle can guide us to fabricate better graphene‐based electrodes.
Macro-assembled carbon-based films (GF) have demonstrated tremendous functional applications as high electrical/thermal conductors, and electromagnetic interference (EMI) shielding materials. Here, ...we report the synergistic effect of graphene and carbon nanotubes (CNT), that electrical conductivity significant improves from 1.78 × 105 to 2.74 × 105 S m−1, and thermal conductivity improves from 510 to 1154 W m−1 K−1 simply by adding 20 wt% CNTs into the graphene films. Moreover, the EMI shielding performance of the macro-assembled graphene-CNT composite films improves from ∼50 dB for pure GF to ∼60 dB for GF with 20 wt% CNT load. Our finding of the synergistic effect opens an avenue to design materials with higher electrical conductivity, thermal conductivity and EMI shielding performance.
We find the synergistic effect of carbon nanotubes and graphene, and design the graphene-carbon nanotube composite films with enhanced electrical conductivity (2.74 × 105 S m−1), thermal conductivity (1154 W m−1 K−1) and electromagnetic interference shielding performance (∼60 dB at 15 μm thickness). Display omitted
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