A high Li-ion diffusion kinetics in multidimensional and compact-structured electrodes via vacuum filtration casting

Manufacturing process,diffusion co-efficient and areal capacity are the three main criteria for regulating thick electrodes for lithium-ion batteries(LIBs).However,simultaneously regulating these criteria for LIBs is desirable but remains a significant challenge.In this work,niobium pentoxide(Nb_(2)O_(5))anode and lithium iron phosphate(LiFePO_(4))cathode materials were chosen as the model materials and demonstrate that these three parameters can be simultaneously modulated by incorporation of micro-carbon fibers(MCF)and carbon nanotubes(CNT)with both Nb_(2)O_(5) and LFP via vacuum filtration approach.Both as-prepared MNC-20 anode and MLC-20 cathode achieves high reversible areal capacity of≈5.4 m A h cm^(-2)@0.1 C and outstanding Li-ion diffusion coefficients of≈10~(-8)cm~2 s~(-1)in the half-cell configuration.The assembled MNC-20‖MLC-20 full cell LIB delivers maximum energy and power densities of244.04 W h kg^(-1)and 108.86 W kg^(-1),respectively.The excellent electrochemical properties of the asprepared thick electrodes can be attributed to the highly conductive,mechanical compactness and multidimensional mutual effects of the MCF,CNT and active materials that facilitates rapid Li-ion diffusion kinetics.Furthermore,electrochemical impedance spectroscopy(EIS),symmetric cells analysis,and insitu Raman techniques clearly validates the enhanced Li-ion diffusion kinetics in the present architecture.

Atomic modulation of Fe‐Co pentlandite coupled with nitrogen‐doped carbon sphere for boosting oxygen catalysis

Reversible oxygen reaction plays a crucial role in rechargeable battery systems,but it is limited by the slow reaction kinetics.Herein,the ionic modulation of cobalt pentlandite coupled with nitrogen‐doped bowl‐like hollow carbon sphere is well designed on octahedral and tetrahedral sites.The robust FexCo9−xS8‐NHCS‐V with iron replacing at the octahedron possesses prolonged metal sulfur bond and exhibits excellent bifunctional electrocatalytic performance towards oxygen reduction reaction(ORR,E_(1/2)=0.80 V vs.RHE)and excellent oxygen evolution reaction(OER,E_(j=10)=1.53 V vs.RHE)in 0.1 mol/L KOH.Accordingly,a rechargeable Zn‐air battery of Fe_(x)Co_(9−x)S_(8)‐NHCS‐V cathode endows high energy efficiency(102 mW cm^(−2)),and a microbial fuel cell achieves a high‐power density(791±42 mW m^(−2)),outperforming the benchmark Pt/C catalyst.

Nuclear magnetic resonance-based metabolomics and metabolic pathway networks from patient-matched esophageal carcinoma,adjacent noncancerous tissues and urine

BACKGROUND Several studies have demonstrated a correlation between esophageal cancer(EC)and perturbed urinary metabolomic profiles,but none has described the correlation between urine metabolite profiles and those of the tumor and adjacent esophageal mucosa in the same patient.AIM To investigate how urinary metabolic phenotypes were linked to the changes in the biochemical landscape of esophageal tumors.METHODS Nuclear magnetic resonance-based metabolomics were applied to esophageal tumor tissues and adjacent normal mucosal tissues alongside patient-matched urine samples.RESULTS Analysis revealed that specific metabolite changes overlapped across both metrics,including glucose,glutamate,citrate,glycine,creatinine and taurine,indicating that the networks for metabolic pathway perturbations in EC,potentially involved in but not limited to disruption of fatty acid metabolism,glucose and glycolytic metabolism,tricarboxylic acid cycle and glutaminolysis.Additionally,changes in most urinary biomarkers correlated with changes in biomarker candidates in EC tissues,implying enhanced energy production for rapid cell proliferation.CONCLUSION Overall,these associations provide evidence for distinct metabolic signatures and pathway disturbances between the tumor tissues and urine of EC patients,and changes in urinary metabolic signature could reflect reprogramming of the aforementioned metabolic pathways in EC tissues.Further investigation is needed to validate these initial findings using larger samples and to establish the underlying mechanism of EC progression.

Hetero-interfacial nickel nitride/vanadium oxynitride porous nanosheets as trifunctional electrodes for HER,OER and sodium ion batteries

The development of single electrode with multifunctional purposes for electrochemical devices remains a symbolic challenge in recent technology.This work explores interfacially-rich transition metal nitride hybrid that consist of nickel nitride and vanadium oxynitride(VO_(0.26)N_(0.52))on robust carbon fiber(denoted CF/Ni_(3)N/VON)as trifunctional electrode for hydrogen evolution reaction(HER),oxygen evolution reaction(OER),and sodium ion batteries(SIBs).The as-prepared CF/Ni_(3)N/VON exhibits low HER overpotential of 48 m V@10 m A cm^(-2),OER overpotential of 287 m V@10 m A cm^(-2),and sodium-ion anode storage reversible capacity of 555 m A h g^(-1)@0.2 C.Theoretical analyses reveal that the Ni_(3)N effectively facilitates hydrogen desorption for HER,increases the electrical conductivity for OER,and promotes the Na-ion storage intercalation process,while the VON substantially elevates the water dissociation kinetics for HER,accelerates the adsorption of OH*intermediate for OER and enhances the Na-ion surface adsorption storage process.Owing to the excellent HER and OER performances of the CF/Ni_(3)N/VON electrode,an overall water splitting device denoted as CF/Ni_(3)N/VON//CF/Ni_(3)N/VON was not only assembled showing an operating voltage of 1.63 V at current density of 10 m A cm^(-2)but was also successfully self-powered by the assembled CF/Ni_(3)N/VON//CF/Na_(3)V_(2)(PO_(4))_(3) flexible sodium ion battery.This work will contribute to the development of efficient and cost-effective flexible integrated electrochemical energy devices.

Subculturing cells have no effect on CRISPR/Cas9-mediated cleavage of UL30 gene in pseudorabies virus

CRISPR/Cas9-mediated genome editing can inhibit virus infection by targeting the conserved regions of the viral genomic DNA. Unexpectedly, we found previously that pseudorabies virus(PRV) could escape from CRISPR/Cas9-mediated inhibition.In order to elucidate whether the escape of PRV from Cas9-mediated inhibition was due to cell deficiencies, such as genetic instability of sgRNA or Cas9 protein, the positive cells were passaged ten times, and PRV infection in the sgRNA-expressing cells was evaluated in the present study. The results showed that subculturing cells has no effect on Cas9-mediated cleavage of PRV. Different passages of PX459-PRV cells can stably express sgRNA to facilitate Cas9/sgRNA cleavage on the UL30 gene of PRV, resulting in a pronounced inhibition of PRV infection. Studies to elucidate the mechanism of PRV escape are currently in progress.

Boosted Storage Kinetics in Thick Hierarchical Micro-Nano Carbon Architectures for High Areal Capacity Li-Ion Batteries

A practical and effective approach to increase the energy storage capacity of lithium ion batteries(LIBs)is to boost their areal capacity.Developing thick electrodes is one of the most crucial ways to achieve high areal capacity but limited by sluggish ion/electron transport,poor mechanical stability,and high-cost manufacturing strategies.Here we address these constraints by engineering a unique hierarchical-networked 10 mm thick all-carbon electrode,providing a scalable strategy to produce high areal capacity LIB electrodes.The hierarchical-networked structure utilizes micrometer-sized carbon fibers(MCFs)as building blocks,nano-sized carbon nanotubes(CNTs)as good continuous network with excellent electrical conductivity,and pyrolytic carbon as the binder and active material with excellent storage capacity.The combination of the above features endows our HNT-MCF/CNT/PC electrode with excellent performance including high reversible capacity of 15.44 mAh cm^(-2) at 2.0 mA cm^(-2) and exhibits excellent rate capability of 2.50 mAh cm^(-2) under 10.0 mA cm^(-2) current density.The Li-ion storage mechanism in HNT-MCF/CNT/PC involves dual-storage mechanism including intercalation and surface adsorption(pseudocapacitance)confirmed by the cyclic voltammetry and symmetric cell analysis.This work provides insights into the construction of high mechanical stability thick electrode for the next generation high areal capacity LIBs and beyond.

Mouse models of porcine circovirus 2 infection

PCV2 is considered the main pathogen of porcine circovirus diseases and porcine circovirus-associated diseases(PCVD/PCVAD). However, the exact mechanism underlying PCVD/PCVAD is currently unknown. Mouse models of PCV2 are valuable experimental tools that can shed light on the pathogenesis of infection and will enable the evaluation of antiviral agents and vaccine candidates. In this review, we discuss the current state of knowledge of mouse models used in PCV2 research that has been performed to date, highlighting their strengths and limitations, as well as prospects for future PCV2 studies.

S, N co-doped carbon nanotube-encapsulated core-shelled CoS2@Co nanoparticles： efficient and stable bifunctional catalysts for overall water splitting

Hydrogen, serving as a clean, sustainable energy source, may be mainly produced from electrolysis water. Herein, we report cobalt disulphide encapsulated in self-catalyzed carbon nanotubes （S, N-CNTs/ CoS2@Co） serving as a bifunctional catalyst, which exhibits excellent hydrogen evolution reaction perfor-mance （10.0 mAcm^-2 at 0.112 V, and low Tafel slope for 104.9 mV dec^-1 ） and oxygen evolution reaction performance （10.0 mAcm^-2 at 1.57 V, and low Tafel slope for 76.1 mV dec^-1）, meanwbile with a strong stability at various current densities. In-depth study reveals that the excellent catalytic properties can be mainly attributed to the increased catalytic sites induced by S, N co-doping, the improved electronic con-ductivity derived from the carbon nanotubes, and Mott-Schottky effect between the metal cobalt and semiconductive cobalt disulfide. Notably, when the bifunctional catalysts are applied to overall water splitting, a low potential of 1.633 V at the current density of 10.0 mAcm^-2 is achieved, which can com-pete with the precious metal catalyst benchmarks in alkaline media, demonstrating its promising prac-ticability in the realistic water splitting application. This work elucidates a practicable way to the design of transition metal and nano-carbon composite catalysts for a broad application in the fields of energy chemistry.

Transition metal-based electrocatalysts for overall water splitting

Electrochemical overall water splitting is attracting a broad focus as a promising strategy for converting the electrical output of renewable resources into chemical fuels,specifically oxygen and hydrogen.However,the urgent challenge in water electrolysis is to search for low-cost,high-efficiency catalysts based on earth-abundant elements as an alternative to the high-cost but effective noble metal-based catalysts.The transition metal-based catalysts are more appealing than the noble metal catalysts because of its low cost,high performance and long stability.Some recent advances for the development in overall water splitting are reviewed in terms of transition metal-based oxides,carbides,phosphides,sulfides,and hybrids of their mixtures as hybrid bifunctional electrocatalysts.Concentrating on different catalytic mechanisms,recent advances in their structural design,controllable synthesis,mechanistic insight,and performance-enhancing strategies are proposed.The challenges and prospects for the future development of transition metal-based bifunctional electrocatalysts are also addressed.©2021 Chinese Chemical Society and Institute of Materia Medica,Chinese Academy of Medical Sciences.

Heterostructures of NiFe LDH hierarchically assembled on MoS_(2) nanosheets as high-efficiency electrocatalysts for overall water splitting

Typically,rational interfacial engineering can effectively modify the adsorption energy of active hydrogen molecules to improve water splitting efficiency.NiFe layered double hydroxide(NiFe LDH)composite,an efficient oxygen evolution reaction(OER)catalyst,suffers from slow hydrogen evolution reaction(HER)kinetics,restricting its application for overall water splitting.Herein,we construct the hierarchical MoS_(2)/NiFe LDH nanosheets with a heterogeneous interface used for HER and OER.Benefiting the hierarchical heterogeneous interface optimized hydrogen Gibbs free energy,tens of exposed active sites,rapid mass-and charge-transfer processes,the MoS_(2)/NiFe LDH displays a highly efficient synergistic electrocatalytic effect.The MoS_(2)/NiFe LDH electrode in 1 mol/L KOH exhibits excellent HER activity,only 98 mV overpotential at 10 mA/cm^(2).Significantly,when it assembled as anode and cathode for overall water splitting,only 1.61 V cell voltage was required to achieve 10 mA/cm^(2)with excellent durability(50 h).

Tuning the selectivity of CO_(2)conversion to CO on partially reduced Cu_(2)O/ZnO heterogeneous interface

The development of stable and efficient low-cost electrocatalysts is conducive to the industrialization of CO_(2).The synergy effect between the heterogeneous interface of metal/oxide can promote the conversion of CO_(2).In this work,Cu_(2)O/ZnO heterostructures with partially reduced metal/oxide heterointerfaces in Zn plates(CZZ)have been synthesized for CO_(2)electroreduction in different cationic solutions(K^(+)and Cs^(+)).Physical characterizations were used to demonstrate the heterojunction of Cu_(2)O/ZnO and the heterointerfaces of metal/oxide,electrochemical tests were used to illustrate the enhancement of the selectivity of CO_(2)to CO in different cationic solutions.Faraday efficiency for CO with CZZ as catalyst reaches 70.9%in K+solution(current density for CO−3.77 mA cm^(−2)and stability 24 h),and the Faraday efficiency for CO is 55.2%in Cs^(+)solution(−2.47 mA cm^(−2)and 21 h).In addition,in situ techniques are used to elucidate possible reaction mechanisms for the conversion of CO_(2)to CO in K^(+)and Cs^(+)solutions.

我国老年教育政策变迁的影响因素、路径依赖与价值取向

我国老年教育开展了将近四十年,在老龄化程度持续加深的情况下,政府以不同效力的文本形式出台了各种法规和政策。研究透过历史制度主义视角对我国老年教育政策进行文本内容分析发现:就制度动因而言,政治、经济、文化和人口四个方面成为老年教育政策制定的逻辑起点;就制度变迁而言,体现出以下的趋势,政策属性由以社会本位价值为主转向以人为本价值为主,实施方式由政府主导与部门开展转向政府投入和市场投资,政策对象由特定老年群体转向全体城乡老年群体,考评路径由政策单向实施转向政策评价监督,反映了老年教育政策的路径依赖和关键节点特性。最后,从制度创新角度提出老年教育的价值取向,包括完善个体生命价值取向、持续开发人力资源取向、构建协同整合机制取向、跨代共施生命教育取向和彰显信息技术人文关怀取向。

Vertically-interlaced NiFeP/MXene electrocatalyst with tunable electronic structure for high-efficiency oxygen evolution reaction

Layered double hydroxides(LDHs)with decent oxygen evolution reaction(OER)activity have been extensively studied in the fields of energy storage and conversion.However,their poor conductivity,ease of agglomeration,and low intrinsic activity limit their practical application.To date,improvement of the intrinsic activity and stability of NiFe-LDHs through the introduction of heteroatoms or its combination with other conductive substrates to enhance their water-splitting performance has drawn increasing attention.In this study,vertically interlaced ternary phosphatised nickel/iron hybrids grown on the surface of titanium carbide flakes(NiFe P/MXene)were successfully synthesised through a hydrothermal reaction and phosphating calcination process.The optimised NiFe P/MXene exhibited a low overpotential of 286 m V at 10 m A cm^(-2) and a Tafel slope of 35 m V dec^(-1) for the OER,which exceeded the performance of several existing NiFe-based catalysts.NiFe P/MXene was further used as a water-splitting anode in an alkaline electrolyte,exhibiting a cell voltage of only 1.61 V to achieve a current density of 10 m A cm^(-2).Density functional theory(DFT)calculations revealed that the combination of MXene acting as a conductive substrate and the phosphating process can effectively tune the electronic structure and density of the electrocatalyst surface to promote the energy level of the d-band centre,resulting in an enhanced OER performance.This study provides a valuable guideline for designing high-performance MXenesupported NiFe-based OER catalysts.