The electrochemical hydrogen evolution reaction (HER) is an attractive technology for the mass production of hydrogen. Ru‐based materials are promising electrocatalysts owing to the similar bonding ...strength with hydrogen but much lower cost than Pt catalysts. Herein, an ordered macroporous superstructure of N‐doped nanoporous carbon anchored with the ultrafine Ru nanoclusters as electrocatalytic micro/nanoreactors is developed via the thermal pyrolysis of ordered macroporous single crystals of ZIF‐8 accommodating Ru(III) ions. Benefiting from the highly interconnected reticular macro–nanospaces, this superstrucure affords unparalleled performance for pH‐universal HER, with order of magnitude higher mass activity compared to the benchmark Pt/C. Notably, an exceptionally low overpotential of only 13 mV@10 mA cm−2 is required for HER in alkaline solution, with a low Tafel slope of 40.41 mV dec−1 and an ultrahigh turnover frequency value of 1.6 H2 s−1 at 25 mV, greatly outperforming Pt/C. Furthermore, the hydrogen generation rates are almost twice those of Pt/C during practical overall alkaline water splitting. A solar‐to‐hydrogen system is also demonstrated to further promote the application. This research may open a new avenue for the development of advanced electrocatalytic micro/nanoreactors with controlled morphology and excellent performance for future energy applications.
An ordered macroporous superstructure of nitrogen‐doped nanoporous carbon implanted with ultrafine Ru nanoclusters is developed via thermal pyrolysis of the ordered macroporous single crystals of ZIF‐8 accommodating Ru(III) ions, which affords unparalleled performance for the pH‐universal hydrogen evolution reaction, with order of magnitude higher mass activity compared to the benchmark Pt/C.
The immunosuppressive microenvironment that is shaped by hepatic metastatic pancreatic ductal adenocarcinoma (PDAC) is essential for tumor cell evasion of immune destruction. Neutrophils are ...important components of the metastatic tumor microenvironment and exhibit heterogeneity. However, the specific phenotypes, functions and regulatory mechanisms of neutrophils in PDAC liver metastases remain unknown. Here, we show that a subset of P2RX1-negative neutrophils accumulate in clinical and murine PDAC liver metastases. RNA sequencing of murine PDAC liver metastasis-infiltrated neutrophils show that P2RX1-deficient neutrophils express increased levels of immunosuppressive molecules, including PD-L1, and have enhanced mitochondrial metabolism. Mechanistically, the transcription factor Nrf2 is upregulated in P2RX1-deficient neutrophils and associated with PD-L1 expression and metabolic reprogramming. An anti-PD-1 neutralizing antibody is sufficient to compromise the immunosuppressive effects of P2RX1-deficient neutrophils on OVA-activated OT1 CD8+ T cells. Therefore, our study uncovers a mechanism by which metastatic PDAC tumors evade antitumor immunity by accumulating a subset of immunosuppressive P2RX1-negative neutrophils.
The development of infrared photodetectors is mainly limited by the choice of available materials and the intricate crystal growth process. Moreover, thermally activated carriers in traditional III-V ...and II-VI semiconductors enforce low operating temperatures in the infrared photodetectors. Here we demonstrate infrared photodetection enabled by interlayer excitons (ILEs) generated between tungsten and hafnium disulfide, WS
/HfS
. The photodetector operates at room temperature and shows an even higher performance at higher temperatures owing to the large exciton binding energy and phonon-assisted optical transition. The unique band alignment in the WS
/HfS
heterostructure allows interlayer bandgap tuning from the mid- to long-wave infrared spectrum. We postulate that the sizeable charge delocalization and ILE accumulation at the interface result in a greatly enhanced oscillator strength of the ILEs and a high responsivity of the photodetector. The sensitivity of ILEs to the thickness of two-dimensional materials and the external field provides an excellent platform to realize robust tunable room temperature infrared photodetectors.
Neuromorphic computing, which emulates the biological neural systems could overcome the high‐power consumption issue of conventional von‐Neumann computing. State‐of‐the‐art artificial synapses made ...of two‐terminal memristors, however, show variability in filament formation and limited capacity due to their inherent single presynaptic input design. Here, a memtransistor‐based artificial synapse is realized by integrating a memristor and selector transistor into a multiterminal device using monolayer polycrys‐talline‐MoS2 grown by a scalable chemical vapor deposition (CVD) process. Notably, the memtransistor offers both drain‐ and gate‐tunable nonvolatile memory functions, which efficiently emulates the long‐term potentiation/depression, spike‐amplitude, and spike‐timing‐dependent plasticity of biological synapses. Moreover, the gate tunability function that is not achievable in two‐terminal memristors, enables significant bipolar resistive states switching up to four orders‐of‐magnitude and high cycling endurance. First‐principles calculations reveal a new resistive switching mechanism driven by the diffusion of double sulfur vacancy perpendicular to the MoS2 grain boundary, leading to a conducting switching path without the need for a filament forming process. The seamless integration of multiterminal memtransistors may offer another degree‐of‐freedom to tune the synaptic plasticity by a third gate terminal for enabling complex neuromorphic learning.
Multiterminal memtransistor‐based artificial synapses are realized using monolayer polycrystalline MoS2 grown by a scalable chemical vapor deposition process. The device shows a robust nonvolatile resistive switching behavior, which efficiently emulates the long‐term synaptic plasticity of biological synapses. Moreover, the memtransistor offers another degree‐of‐freedom to tune the synaptic plasticity by a third gate terminal, making it promising for enabling complex neuromorphic learning.
•This review focuses on metal cluster-based porous coordination polymers (PCPs).•Cluster-based PCPs have various important and modifiable functionalities.•Post-synthetic modification can improve the ...functionality of cluster-based PCPs.
This review focuses on a particular class of porous coordination polymers (PCPs) called metal cluster-based PCPs, which are constructed by linking versatile polynuclear clusters as secondary building units via organic linkers. These types of PCPs provide a unique platform for systematically studying the correlations among structure–property relationships and for developing new functional PCP materials with improved properties due to their various advantages, such as their diverse components, stable frameworks, highly predictable topologies, controllable structural flexibility, and various modifiable functionalities. In this review, we highlight and discuss selected examples of cluster-based PCPs, the functionalities of which benefit from either the clusters themselves or their cooperation with linkers, such as gas adsorption, heterogeneous catalysis, magnetism, flexibility, and luminescent sensing, as well as modulations of these functionalities via post-synthetic modifications of the cluster building units.
Strain sensors with superb stretchability are highly desirable for applications in wearable devices. Here we report a simple method via immersion-swelling followed by in situ reduction to fabricate a ...highly stretchable strain sensor with a graphene/AgNPs synergic conductive network and a sandwich structure ( i.e. , one insulating layer sandwiched between two conductive layers). In the strain sensor, AgNPs were in situ formed without adding any other organic stabilizer, and graphene nanosheets acted as a conductive bridge between them, ensuring the wearable sensor excellent initial electrical conductivity ( σ ≈ 1.4 × 10 5 S m −1 ). During stretching, the pure graphene/TPU insulating layer of the sandwich structure maintained the high stretchability, and the graphene located between the cracks of AgNPs resulted in the connection of conductivity networks under high strain (1000% maximum strain). What is more, the low detection limit (0.5%), high gauge factor (7 at 50% strain, 476 at 500% strain) and high working stability (more than 1000 cycles at 50% strain) of the strain sensor enable it to meet the needs for numerous applications in wearable devices.
Alzheimer's disease (AD) is a neurodegenerative disorder causing 70% of dementia cases. However, the mechanism of disease development is still elusive. Despite the availability of a wide range of ...biological data, a comprehensive understanding of AD's mechanism from machine learning (ML) is so far unrealized, majorly due to the lack of needed data density. To harness the AD mechanism's knowledge from the expression profiles of postmortem prefrontal cortex samples of 310 AD and 157 controls, we used seven predictive operators or combinations of RapidMiner Studio operators to establish predictive models from the input matrix and to assign a weight to each attribute. Besides, conventional fold-change methods were also applied as controls. The identified genes were further submitted to enrichment analysis for KEGG pathways. The average accuracy of ML models ranges from 86.30% to 91.22%. The overlap ratio of the identified genes between ML and conventional methods ranges from 19.7% to 21.3%. ML exclusively identified oxidative phosphorylation genes in the AD pathway. Our results highlighted the deficiency of oxidative phosphorylation in AD and suggest that ML should be considered as complementary to the conventional fold-change methods in transcriptome studies.
LRRK2 mutations are the leading cause of familial Parkinson’s disease (PD) and are a significant risk factor for idiopathic PD cases. However, the molecular mechanisms underlying the degeneration of ...dopaminergic (DA) neurons in LRRK2 PD patients remain unclear. To determine the translatomic impact of LRRK2 expression in DA neurons, we employed gene set enrichment analysis (GSEA) to analyze a translating ribosome affinity purification (TRAP) RNA-seq dataset from a DA-neuron-specific-expressing Drosophila model. We found that the tyrosine metabolism pathway, including tyrosine hydroxylase (TH), is downregulated in DA neurons with LRRK2 overexpression; in contrast, the Hippo signaling pathway is downregulated in the G2019S mutant compared to wild-type LRRK2 in the DA neurons. These results imply that the downregulation of tyrosine metabolism occurs before pronounced DA neuron loss and that LRRK2 may downregulate the tyrosine metabolism in a DA-neuron-loss-independent way.
A novel viologen-based multifunctional Eu-MOF was obtained by integrating a luminescent component Eu(NO
3
)
3
·6H
2
O and a viologen-functionalized ligand. The Eu-MOF not only exhibited reversible ...photochromic and electrochromic properties, but also displayed photoluminescent and electroluminochromic properties.
A novel viologen-based multifunctional Eu-MOF integrating photochromism, photomodulated fluorescence, and electrochromic and electroluminochromic properties was investigated.
Recent studies have identified a class of small non‐coding RNA molecules, named microRNA (miRNA), that is dysregulated in malignant brain glioblastoma. Substantial data have indicated that miRNA‐16 ...(miR‐16) plays a significant role in tumors of various origins. This miRNA has been linked to various aspects of carcinogenesis, including cell apoptosis and migration. However, the molecular functions of miR‐16 in gliomagenesis are largely unknown. We have shown that the expression of miR‐16 in human brain glioma tissues was lower than in non‐cancerous brain tissues, and that the expression of miR‐16 decreased with increasing degrees of malignancy. Our data suggest that the expression of miR‐16 and nuclear factor (NF)‐κB1 was negatively correlated with glioma levels. MicroRNA‐16 decreased glioma malignancy by downregulating NF‐κB1 and MMP9, and led to suppressed invasiveness of human glioma cell lines SHG44, U87, and U373. Our results also indicated that upregulation of miR‐16 promoted apoptosis by suppressing BCL2 expression. Finally, the upregulation of miR‐16 in a nude mice model of human glioma resulted in significant suppression of glioma growth and invasiveness. Taken together, our experiments have validated the important role of miR‐16 as a tumor suppressor gene in glioma growth and invasiveness, and revealed a novel mechanism of miR‐16‐mediated regulation in glioma growth and invasiveness through inhibition of BCL2 and the NF‐κB1/MMP‐9 signaling pathway. Therefore, our experiments suggest the possible future use of miR‐16 as a therapeutic target in gliomas.
We first report that miR‐16 and NF‐κB1expression were inversely correlated to glioma levels in the same patient samples. We further identified the miR‐16 as a negative regulator of tumor growth and invasion, both in vitro and in vivo. Mechanistically the tumor‐suppressive role of miR‐16 can be attributed to inhibition of BCL‐2 and NF‐kappaB1/MMP9 signaling pathways.
PDF
