The lithium metal anode has attracted soaring attention as an ideal battery anode. Unfortunately, nonuniform Li nucleation results in uncontrollable growth of dendritic Li, which incurs serious ...safety issues and poor electrochemical performance, hindering its practical applications. Herein, this study shows that uniform Li nucleation/growth can be induced by an ultralight 3D current collector consisting of in situ nitrogen‐doped graphitic carbon foams (NGCFs) to realize suppressing dendritic Li growth at the nucleating stage. The N‐containing functional groups guide homogenous growth of Li nucleus nanoparticles and the initial Li nucleus seed layer regulates the following well‐distributed Li growth. Benefiting from such favorable Li growth behavior, superior electrochemical performance can be achieved as evidenced by the high Coulombic efficiency (≈99.6% for 300 cycles), large capacity (10 mA h cm−2, 3140 mA h g−1NGCF‐Li), and ultralong lifespan (>1200 h) together with low overpotential (<25 mV at 3 mA cm−2); even under a high current density up to 10 mA cm−2, it still displays low overpotential of 62 mV.
Uniform Li nucleation/growth can be induced by an ultralight 3D current collector consisting of in situ nitrogen‐doped graphitic carbon foams for high‐performance lithium‐metal anodes. The N‐containing functional groups guide initial homogeneous formation of Li nanoparticles and the initial nucleus seed layer regulates the even Li growth that follows. Significantly improved electrochemical performance can be achieved.
The prognostic role of inflammation index like neutrophil‐to‐lymphocyte ratio (NLR) in colorectal cancer (CRC) remains controversial. We conduct a meta‐analysis to determine the predictable value of ...NLR in the clinical outcome of CRC patients. The analysis was carried out based on the data from 16 studies (19 cohorts) to evaluate the association between NLR and overall survival (OS) and progression‐free survival (PFS) in patients with CRC. In addition, the relationship between NLR and clinicopathological parameters was assessed. Hazard ratio (HR) or odds ratio (OR) with its 95% confidence interval (CI) was used as the effect size estimate. Our analysis results indicated that elevated pretreatment NLR predicted poorer OS (HR: 1.813, 95% CI: 1.499–2.193) and PFS (HR: 2.102, 95% CI: 1.554–2.843) in patients with CRC. Increased NLR is also significantly associated with the poorer differentiation of the tumor (OR: 1.574, 95% CI: 1.226–2.022) and higher carcino‐embryonie antigen (CEA) level (OR: 1.493, 95% CI: 1.308–1.705). By these results, we conclude that NLR gains a prognostic value for patients with CRC. NLR should be monitored in CRC patients for rational stratification of the patients and adjusting the treatment strategy.
What's new?
Although correlated with the severity of disease course, the impact of neutrophil‐to‐lymphocyte ratio (NLR) on survival and tumor characteristics in cancer patients remains unclear. In the meta‐analysis presented here, elevated pre‐treatment NLR was found to predict poor overall survival in patients with colorectal cancer. NLR was also associated with unfavorable biologic behavior in colorectal cancer. The findings suggest that NLR, as an inexpensive and widely available index, should be routinely monitored in colorectal cancer patients.
Although single-atomically dispersed metal-N
on carbon support (M-NC) has great potential in heterogeneous catalysis, the scalable synthesis of such single-atom catalysts (SACs) with high-loading ...metal-N
is greatly challenging since the loading and single-atomic dispersion have to be balanced at high temperature for forming metal-N
. Herein, we develop a general cascade anchoring strategy for the mass production of a series of M-NC SACs with a metal loading up to 12.1 wt%. Systematic investigation reveals that the chelation of metal ions, physical isolation of chelate complex upon high loading, and the binding with N-species at elevated temperature are essential to achieving high-loading M-NC SACs. As a demonstration, high-loading Fe-NC SAC shows superior electrocatalytic performance for O
reduction and Ni-NC SAC exhibits high electrocatalytic activity for CO
reduction. The strategy paves a universal way to produce stable M-NC SAC with high-density metal-N
sites for diverse high-performance applications.
The exploration of new efficient OER electrocatalysts based on nonprecious metals and the understanding of the relationship between activity and structure of electrocatalysts are important to advance ...electrochemical water oxidation. Herein, we developed an efficient OER electrocatalyst with nickel boride (Ni3B) nanoparticles as cores and nickel(II) borate (Ni‐Bi) as shells (Ni‐Bi@NB) via a very simple and facile aqueous reaction. This electrocatalyst exhibited a small overpotential of 302 mV at 10 mA cm−2 and Tafel slope of 52 mV dec−1. More interestingly, it was found that the OER activity of Ni‐Bi@NB was closely dependent on the crystallinity of the Ni‐Bi shells. The partially crystalline Ni‐Bi catalyst exhibited much higher activity than the amorphous or crystalline analogues; this higher activity originated from the enhanced intrinsic activity of the catalytic sites. These findings open up opportunities to explore nickel(II) borates as a new class of efficient nonprecious metal OER electrocatalysts, and to improve the electrocatalyst performance by modulating their crystallinity.
A new winner! Crystallinity‐dependent activity was demonstrated on a new efficient electrocatalyst for the oxygen evolution reaction (OER) which consists of a nickel(II) borate thin layer on nickel boride (NB) nanoparticles (Ni‐Bi@NB) (see figure). The partially crystalline Ni‐Bi catalyst exhibits excellent OER performance.
Two‐dimensional (2D) nanomaterials, such as graphene and transition metal chalcogenides, show many interesting dimension‐related materials properties. Inspired by the development of 2D inorganic ...nanomaterials, single‐layered covalent organic frameworks (sCOFs), featuring atom‐thick sheets and crystalline extended organic structures with covalently bonded building blocks, have attracted great attention in recent years. With their unique graphene‐like topological structure and the merit of structural diversity, sCOFs promise to possess novel and designable properties. However, the synthesis of sCOFs with well‐defined structures remains a great challenge. Herein, the recent development of the bottom‐up synthesis methods of 2D sCOFs, such as thermodynamic equilibrium control methods, growth‐kinetics control methods, and surface‐assisted covalent polymerization methods, are reviewed. Finally, some of the critical properties and application prospects of these materials are outlined.
Single‐layered covalent organic frameworks (sCOFs), mimicking the topology of graphene, but incorporating chemical functionality into their backbones, are pursued as potential candidates in nanoelectronics. Several representative synthesis strategies for the synthesis of high‐quality graphene‐like sCOFs with extended order are reviewed and the application prospects of sCOFs are outlined.
Aims
An ongoing outbreak of 2019 novel coronavirus (CoV) disease (COVID‐19), caused by severe acute respiratory syndrome (SARS) CoV‐2, has been spreading in multiple countries. One of the reasons for ...the rapid spread is that the virus can be transmitted from infected individuals without symptoms. Revealing the pathological features of early‐phase COVID‐19 pneumonia is important for understanding of its pathogenesis. The aim of this study was to explore the pulmonary pathology of early‐phase COVID‐19 pneumonia in a patient with a benign lung lesion.
Methods and results
We analysed the pathological changes in lung tissue from a 55‐year‐old female patient with early‐phase SARS‐CoV‐2 infection. In this case, right lower lobectomy was performed for a benign pulmonary nodule. Detailed clinical, laboratory and radiological data were also examined. This patient was confirmed to have preoperative SARS‐CoV‐2 infection by the use of real‐time reverse transcription polymerase chain reaction and RNA in‐situ hybridisation on surgically removed lung tissues. Histologically, COVID‐19 pneumonia was characterised by exudative inflammation. The closer to the visceral pleura, the more severe the exudation of monocytes and lymphocytes. Perivascular inflammatory infiltration, intra‐alveolar multinucleated giant cells, pneumocyte hyperplasia and intracytoplasmic viral‐like inclusion bodies were seen. However, fibrinous exudate and hyaline membrane formation, which were typical pulmonary features of SARS pneumonia, were not evident in this case. Immunohistochemical staining results showed an abnormal accumulation of CD4+ helper T lymphocytes and CD163+ M2 macrophages in the lung tissue.
Conclusion
The results highlighted the pulmonary pathological changes of early‐phase SARS‐CoV‐2 infection, and suggested a role of immune dysfunction in the pathogenesis of COVID‐19 pneumonia.
The confined synthesis of two-dimensional covalent organic framework (2D COF) thin films was developed by using thin superspreading water on the hydrogel immersed under oil as reactor. Through ...loading two monomers into oil and hydrogel, respectively, COF thin films are synthesized at the oil/water/hydrogel interface. This strategy provides a new way for synthesis of freestanding 2D COF thin films. Detailed characterizations of the COF thin films reveal homogeneous topography, large area, controllable thickness from 4 to 150 nm, and crystallinity with certain orientation. Young’s modulus of COF film is measured by AFM indentation as 25.9 ± 0.6 GPa, showing good mechanical properties. On the basis of the freestanding COF films, a nanofilter membrane and photoelectrochemical sensors for Ru3+ were successfully developed. Moreover, the strategy was extended to the synthesis of crystalline zeolitic imidazolate framework-8 thin film, which exhibited high application potential.
•Thermal sensitive flexible PCMs broaden the use of energy storage technology.•Flexible PCMs present thermal sensitive flexibility with Tparaffin,m as stimulus.•Transformation from rigid to ...flexibility is reversible for flexible PCMs.•Thermal contact resistance and poor installation are overcame by using flexible PCMs.•Thermal conductivity of flexible PCMs was improved to a breakthrough level.
Application of thermal energy storage technology in practical engineering has been inhibited due to the constant strong rigidity of phase change materials (PCMs) at any given temperature. To solve this problem, a novel kind of thermal sensitive flexible PCMs was developed by using difunctional olefin blockcopolymer (OBC) replacing conventional supporting materials. Due to phase separation morphology, OBC presents physical crosslinked network and elasticity which is essential for macroscopical elastic deformation of composite. The developed PCMs based on OBC not only exhibit the same high latent capacity and stable shape as shape-stabilized PCMs, but also present thermal sensitive flexibility with the melting point of paraffin Tparaffin,m as the stimulus. Below the melting point of OBC-TOBC,m, the transformation from rigid to flexibility is reversible. The above excellent flexibility of the developed PCMs contributes to reducing thermal contact resistance and improving poor installation for conventional PCMs in energy storage field, such as in energy-storage air-conditioning and compact electron device thermal control, especially in spacecraft thermal control system. Furthermore, thermal conductivity was improved to a breakthrough level (479% of original rate) by adding 3wt.% of the maximum size of expanded graphite, which is based on the guidance of the novel calculation model on account of thermal conductivity for thermal sensitive flexible PCMs.
Abstract
Background
Plants live with diverse microbial communities which profoundly affect multiple facets of host performance, but if and how host development impacts the assembly, functions and ...microbial interactions of crop microbiomes are poorly understood. Here we examined both bacterial and fungal communities across soils, epiphytic and endophytic niches of leaf and root, and plastic leaf of fake plant (representing environment-originating microbes) at three developmental stages of maize at two contrasting sites, and further explored the potential function of phylloplane microbiomes based on metagenomics.
Results
Our results suggested that plant developmental stage had a much stronger influence on the microbial diversity, composition and interkingdom networks in plant compartments than in soils, with the strongest effect in the phylloplane. Phylloplane microbiomes were co-shaped by both plant growth and seasonal environmental factors, with the air (represented by fake plants) as its important source. Further, we found that bacterial communities in plant compartments were more strongly driven by deterministic processes at the early stage but a similar pattern was for fungal communities at the late stage. Moreover, bacterial taxa played a more important role in microbial interkingdom network and crop yield prediction at the early stage, while fungal taxa did so at the late stage. Metagenomic analyses further indicated that phylloplane microbiomes possessed higher functional diversity at the early stage than the late stage, with functional genes related to nutrient provision enriched at the early stage and N assimilation and C degradation enriched at the late stage. Coincidently, more abundant beneficial bacterial taxa like Actinobacteria,
Burkholderiaceae
and
Rhizobiaceae
in plant microbiomes were observed at the early stage, but more saprophytic fungi at the late stage.
Conclusions
Our results suggest that host developmental stage profoundly influences plant microbiome assembly and functions, and the bacterial and fungal microbiomes take a differentiated ecological role at different stages of plant development. This study provides empirical evidence for host exerting strong effect on plant microbiomes by deterministic selection during plant growth and development. These findings have implications for the development of future tools to manipulate microbiome for sustainable increase in primary productivity.
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