Facile design of low‐cost and highly active catalysts from earth‐abundant elements is favorable for the industrial application of water splitting. Here, a simple strategy to synthesize an ultrathin ...molybdenum disulfide/nitrogen‐doped reduced graphene oxide (MoS2/N‐RGO‐180) nanocomposite with the enlarged interlayer spacing of 9.5 Å by a one‐step hydrothermal method is reported. The synergistic effects between the layered MoS2 nanosheets and N‐doped RGO films contribute to the high activity for hydrogen evolution reaction (HER). MoS2/N‐RGO‐180 exhibits the excellent catalytic activity with a low onset potential of −5 mV versus reversible hydrogen elelctrode (RHE), a small Tafel slope of 41.3 mV dec−1, a high exchange current density of 7.4 × 10−4 A cm−2, and good stability over 5 000 cycles under acidic conditions. The HER performance of MoS2/N‐RGO‐180 nanocomposite is superior to the most reported MoS2‐based catalysts, especially its onset potential and exchange current density. In this work, a novel and simple method to the preparation of low‐cost MoS2‐based electrocatalysts with the extraordinary HER performance is presented.
A simple strategy to synthesize an ultrathin molybdenum disulfide/nitrogen‐doped reduced graphene oxide (MoS2/N‐RGO‐180) nanocomposite with the enlarged interlayer spacing of 9.5 Å is reported. MoS2/N‐RGO‐180 exhibits excellent hydrogen evolution reaction (HER) catalytic activity with a low onset potential of −5 mV versus RHE, a small Tafel slope of 41.3 mV dec−1 and good stability over 5000 cycles.
Stretchable self‐healing supercapacitors (SCs) can operate under extreme deformation and restore their initial properties after damage with considerably improved durability and reliability, expanding ...their opportunities in numerous applications, including smart wearable electronics, bioinspired devices, human–machine interactions, etc. It is challenging, however, to achieve mechanical stretchability and self‐healability in energy storage technologies, wherein the key issue lies in the exploitation of ideal electrode and electrolyte materials with exceptional mechanical stretchability and self‐healing ability besides conductivity. Conductive hydrogels (CHs) possess unique hierarchical porous structure, high electrical/ionic conductivity, broadly tunable physical and chemical properties through molecular design and structure regulation, holding tremendous promise for stretchable self‐healing SCs. Hence, this review is innovatively constructed with a focus on stretchable and self‐healing CH based electrodes and electrolytes for SCs. First, the common synthetic approaches of CHs are introduced; then the stretching and self‐healing strategies involved in CHs are systematically elaborated; followed by an explanation of the conductive mechanism of CHs; then focusing on CH‐based electrodes and electrolytes for stretchable self‐healing SCs; subsequently, application of stretchable and self‐healing SCs in wearable electronics are discussed; finally, a conclusion is drawn along with views on the challenges and future research directions regarding the field of CHs for SCs.
Conductive hydrogels (CHs) are a new class of soft functional materials that have recently found application in flexible energy storage devices such as batteries and supercapacitors (SCs). Herein, the promise of CHs in this emerging field is demonstrated through summarizing their roles as ideal electrode and electrolyte materials for stretchable and self‐healing SCs.
In high‐temperature proton exchange membrane fuel cells (HT‐PEMFCs), the poisoning of Pt by phosphoric species severely affects the kinetics of the oxygen reduction reaction, which restricts their ...commercialized application. Herein, for the first time, the phosphate tolerance of PtFe ordered intermetallic alloys is enhanced by a doping‐modulated strain strategy via employing a low amount of Cu as a dopant to boost HT‐PEMFCs. This Cu doping facilitates the formation of compressive strain in PtFe crystals, consequently altering the electronic structure of electrocatalysts and then benefiting for weakening the adsorption energy between phosphoric acid and Pt surfaces. In addition, the high temperature phosphate adsorption tests also reveal that the dopant of Cu in Pt based electrocatalysts can improve the tolerance of phosphoric acid. The HT‐PEMFCs assembled by those cathodic electrocatalysts with the low‐Pt loading of 0.5 mgPt cm−2 achieve a preeminent peak power of 793.5 and 432.6 mW cm−2 under the condition of H2–O2 and H2–air atmosphere, respectively, or nearly 1.53 and 1.34 times higher as compared with commercial Pt/C electrocatalysts. Moreover, those electrocatalysts also exhibit robust stability under harsh condition in H2–O2 atmosphere with negligible activity loss for at least 100 h, exceeding most of other reported ORR electrocatalysts.
This Cu doping in PtFe crystals facilitates the formation of compressive strain, consequently altering the electronic structure and then enhancing the phosphate tolerance. The maximum output power of Cu‐PtFe/NC in HT‐PEMFC reaches as high as 793.5 and 432.6 mW cm−2 under the condition of H2–O2 and H2–air atmosphere, respectively, exceeding that of most reported ORR electrocatalysts.
Colorectal cancer is one of the most common cancers in the world. Although genomic mutations and single nucleotide polymorphisms have been extensively studied, the epigenomic status in colorectal ...cancer patient tissues remains elusive. Here, together with genomic and transcriptomic analysis, we use ChIP-Seq to profile active enhancers at the genome wide level in colorectal cancer paired patient tissues (tumor and adjacent tissues from the same patients). In total, we sequence 73 pairs of colorectal cancer tissues and generate 147 H3K27ac ChIP-Seq, 144 RNA-Seq, 147 whole genome sequencing and 86 H3K4me3 ChIP-Seq samples. Our analysis identifies 5590 gain and 1100 lost variant enhancer loci in colorectal cancer, and 334 gain and 121 lost variant super enhancer loci. Multiple key transcription factors in colorectal cancer are predicted with motif analysis and core regulatory circuitry analysis. Further experiments verify the function of the super enhancers governing PHF19 and TBC1D16 in regulating colorectal cancer tumorigenesis, and KLF3 is identified as an oncogenic transcription factor in colorectal cancer. Taken together, our work provides an important epigenomic resource and functional factors for epigenetic studies in colorectal cancer.
Adult hippocampal neurogenesis plays a critical role in memory and emotion processing, and this process is dynamically regulated by neural circuit activity. However, it remains unknown whether ...manipulation of neural circuit activity can achieve sufficient neurogenic effects to modulate behavior. Here we report that chronic patterned optogenetic stimulation of supramammillary nucleus (SuM) neurons in the mouse hypothalamus robustly promotes neurogenesis at multiple stages, leading to increased production of neural stem cells and behaviorally relevant adult-born neurons (ABNs) with enhanced maturity. Functionally, selective manipulation of the activity of these SuM-promoted ABNs modulates memory retrieval and anxiety-like behaviors. Furthermore, we show that SuM neurons are highly responsive to environmental novelty (EN) and are required for EN-induced enhancement of neurogenesis. Moreover, SuM is required for ABN activity-dependent behavioral modulation under a novel environment. Our study identifies a key hypothalamic circuit that couples novelty signals to the production and maturation of ABNs, and highlights the activity-dependent contribution of circuit-modified ABNs in behavioral regulation.
Nucleus accumbens (NAc) is involved in behaviors that depend on heightened wakefulness, but its impact on arousal remains unclear. Here, we demonstrate that NAc dopamine D1 receptor (D1R)-expressing ...neurons are essential for behavioral arousal. Using in vivo fiber photometry in mice, we find arousal-dependent increases in population activity of NAc D1R neurons. Optogenetic activation of NAc D1R neurons induces immediate transitions from non-rapid eye movement sleep to wakefulness, and chemogenetic stimulation prolongs arousal, with decreased food intake. Patch-clamp, tracing, immunohistochemistry, and electron microscopy reveal that NAc D1R neurons project to the midbrain and lateral hypothalamus, and might disinhibit midbrain dopamine neurons and lateral hypothalamus orexin neurons. Photoactivation of terminals in the midbrain and lateral hypothalamus is sufficient to induce wakefulness. Silencing of NAc D1R neurons suppresses arousal, with increased nest-building behaviors. Collectively, our data indicate that NAc D1R neuron circuits are essential for the induction and maintenance of wakefulness.
Are children less susceptible to COVID-19? Lee, Ping-Ing; Hu, Ya-Li; Chen, Po-Yen ...
Journal of microbiology, immunology and infection,
06/2020, Letnik:
53, Številka:
3
Journal Article
Grain size is an important component trait of grain yield, which is frequently threatened by abiotic stress. However, little is known about how grain yield and abiotic stress tolerance are regulated. ...Here, we characterize GSA1, a quantitative trait locus (QTL) regulating grain size and abiotic stress tolerance associated with metabolic flux redirection. GSA1 encodes a UDP-glucosyltransferase, which exhibits glucosyltransferase activity toward flavonoids and monolignols. GSA1 regulates grain size by modulating cell proliferation and expansion, which are regulated by flavonoid-mediated auxin levels and related gene expression. GSA1 is required for the redirection of metabolic flux from lignin biosynthesis to flavonoid biosynthesis under abiotic stress and the accumulation of flavonoid glycosides, which protect rice against abiotic stress. GSA1 overexpression results in larger grains and enhanced abiotic stress tolerance. Our findings provide insights into the regulation of grain size and abiotic stress tolerance associated with metabolic flux redirection and a potential means to improve crops.
Health-protective behaviors, such as receiving a vaccine, wearing a face mask, and washing hands frequently, can reduce the risk of contracting influenza. However, little is known about how social ...capital may influence health-protective behavior in the general population. This study examined whether each of the social capital dimensions (bonding, bridging, and linking) contributed to the intention to adopt any of the health-protective behaviors in an influenza pandemic. The data of this study were from the 2014 Taiwan Social Change Survey. A stratified, three-stage probability proportional-to-size sampling from across the nation, was conducted to select adults aged 20 years and older (N = 1,745). Bonding social capital was measured by the frequency of neighborly contact and support. Bridging social capital was measured based on association membership. Linking social capital was measured according to general government trust and trust in the government's capacity to counter an influenza pandemic. Binary logistic regressions were used to assess the multivariate associations between social capital and behavioral intention. The study results indicate that social capital may influence the response to influenza pandemic. Specifically, the intention to receive a vaccine and to wash hands more frequently were associated with the linking dimension and the bonding dimension of social capital, while the intention to wear a face mask was associated with all forms of social capital. The findings of this study suggest that government credibility and interpersonal networks may play a crucial role in health-protective behavior. This study provides new insights into how to improve the effectiveness of influenza prevention campaigns.
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