Conserved and divergent gene regulatory programs of the mammalian neocortex.

Divergence of cis-regulatory elements drives species-specific traits1, but how this manifests in the evolution of the neocortex at the molecular and cellular level remains unclear. Here we investigated the gene regulatory programs in the primary motor cortex of human, macaque, marmoset and mouse using single-cell multiomics assays, generating gene expression, chromatin accessibility, DNA methylome and chromosomal conformation profiles from a total of over 200,000 cells. From these data, we show evidence that divergence of transcription factor expression corresponds to species-specific epigenome landscapes. We find that conserved and divergent gene regulatory features are reflected in the evolution of the three-dimensional genome. Transposable elements contribute to nearly 80% of the human-specific candidate cis-regulatory elements in cortical cells. Through machine learning, we develop sequence-based predictors of candidate cis-regulatory elements in different species and demonstrate that the genomic regulatory syntax is highly preserved from rodents to primates. Finally, we show that epigenetic conservation combined with sequence similarity helps to uncover functional cis-regulatory elements and enhances our ability to interpret genetic variants contributing to neurological disease and traits.

Ultrafast self-assembly of supramolecular hydrogels toward novel flame-retardant separator for safe lithium ion battery.

Traditional polyolefin separators for lithium-ion batteries (LIBs) often experience limited thermal stability and intrinsic flammability, resulting in great safety risks during their usage. Therefore, it is highly important to develop novel flame-retardant separators for safe LIBs with high performance. In this work, we report a flame-retardant separator derived from boron nitride (BN) aerogel with a high BET surface area of 1127.3 m2 g-1. The aerogel was pyrolyzed from a melamine-boric acid (MBA) supramolecular hydrogel, which was self-assembled at an ultrafast speed. The in-situ evolution details of the nucleation-growth process of the supramolecules could be observed in real-time using a polarizing microscope under ambient conditions. The BN aerogel was further composited with bacterial cellulose (BC) to form a BN/BC composite aerogel with excellent flame-retardant performance, electrolyte-wetting ability and high mechanical property. By using the BN/BC composite aerogel as the separator, the developed LIBs exhibited high specific discharge capacity of 146.5 mAh g-1 and excellent cyclic performance, maintaining 500 cycles with a capacity degradation of only 0.012% per cycle. The high-performance flame-retardant BN/BC composite aerogel represents a promising candidate for separators not only in LIBs but also in other flexible electronics.

A novel bilayer heterogeneous poly(ionic liquid) electrolyte for high-performance flexible supercapacitors with ultraslow self-discharge.

Flexible supercapacitors with high power density and long cyclic stability represent a promising candidate to be used as power supplies for portable electronics, but often suffer from the disadvantages of a limited working voltage and rapid self-discharge (spontaneous drop of open-circuit voltage). Here, we design a bilayer heterogeneous poly(ionic liquid) electrolyte (BHPE) consisting of a polycation complex and a polyanion complex with different zeta potentials to suppress the self-discharge of flexible symmetric supercapacitors. The resultant BHPE-based supercapacitors using active carbon/carbon nanotube composite electrodes exhibit a high working potential of 3.0 V and an energy density of 33 W h kg-1, which are comparable with those of devices obtained by using a homogeneous poly(ionic liquid) electrolyte (HPE). More significantly, the developed BHPE-based supercapacitor charged under forward bias exhibits a self-discharge time of 23.2 h, which is at least twice that of the device charged under reverse bias and is also much superior to those of HPE-based supercapacitors. The BHPE-based supercapacitors also possess excellent mechanical flexibility and stability, due to the stabilized interface contact between two layers of poly(ionic liquid)s.

Natural wood-derived free-standing films as efficient and stable separators for high-performance lithium ion batteries.

A sustainable and low-cost separator is highly required for electrochemical energy storage systems. Herein, a type of modified natural wood film with excellent mechanical properties, ion conductivity and thermal stability is fabricated for high-performance lithium ion batteries. Using the modified natural wood film as a separator, the fabricated symmetric cell exhibits a more stable and lower plating/stripping voltage for Li than that of the cell with a commercialized polypropylene (PP) separator. The LiFePO4/Li half-cell with the modified wood film separator shows a small polarization voltage and high discharge capacity because of the multi-level nanostructure and abundant functional groups of the modified wood films. The results suggest that the modified wood films are a promising candidate for use as separators in lithium ion batteries. As desired, the LiFePO4/Li half-cells with the modified wood film separator deliver much higher discharge capacities and more stable Coulomb efficiency over two hundred charge/discharge cycles than the cell based on the PP separator. The present work systematically investigate the feasibility of abundant and cheap natural wood-derived materials for use as efficient separators instead of synthetic polymers for high-performance lithium ion batteries with long cycle life.

Regulating the Self-Discharge of Flexible All-Solid-State Supercapacitors by a Heterogeneous Polymer Electrolyte.

Supercapacitors with high power density and an ultralong cyclic lifetime have been intensively investigated. However, the crucial challenge of their rapid self-discharge process is often neglected in most cases. A heterogeneous interface formed between two layers of polymer electrolytes is designed, in which a polyanion and a polycation are added into a common matrix of polymer electrolyte, respectively. By using the heterogeneous polymer electrolyte (HPE) as the separator simultaneously, the resultant supercapacitors exhibit comparable electrochemical performance to that of devices based on traditional polymer electrolytes. The HPE-based supercapacitors using both electric double-layer capacitive and pseudocapacitive electrodes show at least one time longer self-discharge time than that of devices based on homogenous polymer electrolyte, especially for the electrode in an electrolyte containing polyanion served as a positive pole during the charging process. Because of the same polymer matrix used, the heterojunction structure of the HPE exhibits excellent stability without obvious phase separation during thousands of charge/discharge and repeated bending cycles. This novel strategy by interface engineering of electrolyte to suppress the self-discharge behavior of supercapacitors is very meaningful to promote their practical applications.

Lateral hypothalamus orexinergic inputs to lateral habenula modulate maladaptation after social defeat stress.

Social stress, a common stressor, causes multiple forms of physical and mental dysfunction. Prolonged exposure to social stress is associated with a higher risk of psychological disorders, including anxiety disorders and major depressive disorder (MDD). The orexinergic system is involved in the regulation of multiple motivated behaviors. The current study examined the regulatory effect of orexinergic projections from the lateral hypothalamic area (LHA) to the lateral habenula (LHb) in depression- and anxiety-like behaviors after chronic social defeat stress. When mice were defeated during social interaction, both orexinergic neurons in the LHA and glutamatergic neurons in the LHb were strongly activated, as indicated by the FosTRAP strategy. Infusion of orexin in the LHb significantly alleviated social avoidance and depression-like behaviors induced by chronic social defeat stress. Administration of an orexin receptor 2 antagonist in the LHb further aggravated the depressive phenotype. Photoactivation of orexinergic cell bodies in the LHA or terminals in the LHb relieved anxiety-like behaviors induced by chronic social defeat stress. Collectively, we identified the antidepressant and anxiolytic effects of the circuit from LHA orexinergic neurons to the LHb in response to chronic social stress, providing new evidence of the antidepressant properties of LHA orexin circuits.

Amphiphobic triboelectric nanogenerators based on silica enhanced thermoplastic polymeric nanofiber membranes.

It is necessary to construct an amphiphobic triboelectric nanogenerator (TENG) since water, oil and other antistatic agents will have a great impact on its electrical output performance during practical applications. Herein, we put forward a high-performance TENG based on silica enhanced thermoplastic polymeric nanofiber membranes that possess outstanding droplet-repellency after being modified with fluorine-containing polymers. With in situ polycondensation of SiO2 nanoparticles on the surface of the raw materials of garment-thermoplastic nanofiber membranes fabricated by the melt-blending extrusion method, the electrical output performance of the prepared TENGs enhanced a lot, corresponding to an excellent peak power density of 2.14 W m-2 that was enough to supply several green LEDs. For improving its ability to resist moisture and antistatic agents existing in daily life, FAS/PTFE was dip-coated on the above modified membranes to achieve remarkable amphiphobicity that gave it another ability for self-cleaning. Considering the good stability of amphiphobicity and the excellent compatibility between the thermoplastic polymeric nanofiber membranes and garment, the developed TENG is believed to be the most suitable candidate for powering wearable electronics in the near future.