Study on Antioxidant Enzyme Activity and Physiology and Biochemistry of Solanum nigrum L. under Glyphosate Stress

[Objectives] This study was conducted to investigate the scientific prevention and control of Solanum nigrum L. [Methods] Through experiments on S. nigrum from different sources, it was found that glyphosate stress had significant effects on antioxidant enzyme activity and oxidative damage of sensitive S. nigrum plants. [Results] Sensitive S. nigrum showed oxidative damage under glyphosate stress, while resistant S. nigrum responded to adversity damage by improving its antioxidant enzyme activity. The experimental results showed that the antioxidant enzymes and reduced glutathione of S. nigrum had certain metabolic detoxification effects under glyphosate stress. [Conclusions] This study provides a theoretical basis for scientific prevention and control of S. nigrum , and has a certain reference value for revealing the glyphosate resistance mechanism of S. nigrum .

Anti-Corrosion and Reconstruction of Surface Crystal Plane for Zn Anodes by an Advanced Metal Passivation Technique

For the aqueous Zn-ion battery,dendrite formation,corrosion,and interfacial parasitic reactions are major issues,which greatly inhibits their practical application.How to develop a method of Zn construction or treatment to solve these issues for Zn anodes are still great challenges.Herein,a simple and cheap metal passivation technique is proposed for Zn anodes from a corrosion science perspective.Similar to the metal anticorrosion engineering,the formed interfacial protective layer in a chemical way can sufficiently solve the corrosion issues.Furthermore,the proposed passivity approach can reconstruct Zn surface-preferred crystal planes,exposing more(002)planes and improving surface hydrophilicity,which inhibits the formation of Zn dendrites and hydrogen evolution effectively.As expected,the passivated Zn achieves outstanding cycling life(1914 h)with low voltage polarization(<40 mV).Even at 6 mA cm^(−2) and 3 mA h cm^(−2),it can achieve stable Zn deposition over 460 h.The treated Zn anode coupled with MnO_(2) cathode shows prominently reinforced full batteries service life,making it a potential Zn anode candidate for excellent performance aqueous Zn-ion batteries.The proposed passivation approach provides a guideline for other metal electrodes preparation in various batteries and establishes the connections between corrosion science and batteries.

A machine-learning-based electron density (MLED) model in the inner magnetosphere

Plasma density is an important factor in determining wave-particle interactions in the magnetosphere.We develop a machine-learning-based electron density(MLED)model in the inner magnetosphere using electron density data from Van Allen Probes between September 25,2012 and August 30,2019.This MLED model is a physics-based nonlinear network that employs fundamental physical principles to describe variations of electron density.It predicts the plasmapause location under different geomagnetic conditions,and models separately the electron densities of the plasmasphere and of the trough.We train the model using gradient descent and backpropagation algorithms,which are widely used to deal effectively with nonlinear relationships among physical quantities in space plasma environments.The model gives explicit expressions with few parameters and describes the associations of electron density with geomagnetic activity,solar cycle,and seasonal effects.Under various geomagnetic conditions,the electron densities calculated by this model agree well with empirical observations and provide a good description of plasmapause movement.This MLED model,which can be easily incorporated into previously developed radiation belt models,promises to be very helpful in modeling and improving forecasting of radiation belt electron dynamics.

Design and motion control analysis of double helix wall climbing robot

For the detection environment of complex walls such as high-rise buildings,a double helix wall climbing robot(DHWCR)with strong adsorption force and good stability is designed and developed,which uses symmetrical propellers to provide adsorption force.The symmetrical driving structure can provide smooth thrust for the DHWCR,so that the robot can be absorbed to the wall surface with different roughness.A left and right control frame with multiple degrees of freedom is designed,which can adjust the fixed position of the brushless propeller motor in the front and back directions,realize the continuous adjustable thrust direction of the robot,and improve the flexibility of the robot movement.Using the front wheel steering mechanism with universal joint,the steering control of the DHWCR is realized by differential control.In the vertical to ground transition,the front and rear brushless motors can provide the pull up and oblique thrust,so that the DHWCR can smoothly transition to the vertical wall.The motion performance and adaptability of the DHWCR in the horizontal ground and vertical wall environment are tested.The results show that the DHWCR can switch motion between the horizontal ground and vertical wall,and can stably adsorb on the vertical wall with flexible attitude control.The DHWCR can move at a fast speed.The speed on the horizontal ground is higher than that on the vertical wall,which verifies the feasibility and reliability of the DHWCR moving stably on the vertical wall.

基于正交质谱的N-糖组谱揭示哈夫病潜在病原学

食用煮熟的小龙虾可能导致哈夫病(HD),该病被认为是由不明毒素引起的,而病因尚不清楚。N-糖组的剖析将促进破译疾病的分子机制,而HD相关的糖基化从未被探索过。2019-2020年期间,本研究团队招募了来自武汉市疾病预防控制中心的90份HD患者和对照组血清样本。本文中,采用基于高通量的正交质谱对HD中血清和血清衍生的IgG的N-糖组谱进行了表征。数据显示,HD与总血清糖蛋白的核心岩藻糖基化和单半乳糖醇化升高有关。血清IgG水平是HD患者的良好指标。此外,IgG的差异半乳糖基化和唾液酸化与HD密切相关。值得注意的是,IgG1和IgG2的半乳糖基化和唾液酸化的变化具有亚类特异性。有意义的是,IgG2或IgG3/4的唾液酸化和半乳糖基化改变与HD的临床标志物密切相关。本研究表明差异化IgG N-糖基化与HD的关联,为这种罕见疾病的病因提供了新的见解。

Direct evidence for efficient scattering of suprathermal electrons by whistler mode waves in the Martian magnetosphere

Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which enhanced whistler mode waves(~10^(−11) V^(2)/m^(2)/Hz)with frequency of 0.1 f_(ce)-0.5 f_(ce) occurred,based on MAVEN data,exactly corresponding to a significant decrease of suprathermal electron fluxes.The diffusion coefficients are calculated by using the observed electric field wave spectra.The pitch angle diffusion coefficient can approach 10^(−2) s^(−1),which is much larger,by~100 times,than the momentum diffusion coefficient,indicating that pitch angle scattering dominates the whistler-electron resonance process.The current results can successfully explain the dropout of the suprathermal electrons in this event.This study provides direct evidence for whistler-driven electron losses in the Martian magnetosphere.

Boron nitride nanofibers enhanced composite PEO-based solid-state polymer electrolytes for lithium metal batteries

Polyethylene oxide(PEO)-based solid-state polymer electrolytes(SPEs)are limited by their poor cyclic stability and inferior ionic conductivity for applicating in high-safety,long-cycling and high-energy-density lithium metal batteries.Herein,porous boron nitride nanofibers(BNNFs)are filled into PEO-based SPE,which significantly suppresses Li dendrites growth and enhances the electrochemical performance of Li metal battery.BNNFs with high porosity have more active sites to connect with PEO,which can effectively reduce the crystallinity of the PEO matrix and enhance its ionic conductivity.Moreover,owing to the hardness and good stability of BNNFs,BNNFs/PEO/Li TFSI electrolyte exhibits a wider electrochemical window,better mechanical property and higher thermal stability compared with PEO/Li TFSI electrolyte.Consequently,the Li symmetric cell composed of 1%BNNFs/PEO/Li TFSI performs good cyclic stability(>1800 h),and the Li||1%BNNFs/PEO/Li TFSI||LFP full battery shows obviously improved performances in charge-discharge polarization voltage,discharge specific capacity,rate performance and cyclic stability than the Li||PEO/Li TFSI||LFP battery.

进展期胃癌术后腹腔热灌注化疗的研究进展

胃癌为临床常见恶性肿瘤之一,外科手术是其重要治疗方案,进展期胃癌患者术后5年生存率较低,而术后癌灶复发成为影响患者预后的重要因素。随着国内医学水平不断发展,腹腔热灌注化疗技术得以不断改进,其在进展期胃癌患者术后辅助治疗中的应用日益广泛,长期临床实践表明预防性运用腹腔热灌注化疗可明显降低进展期胃癌术后复发率并提高其5年生存率,在改善患者生存质量及总体临床疗效方面的作用明确。本文旨在对中国进展期胃癌术后腹腔热灌注化疗的临床应用进展进行综述。

Artificial interphases enable dendrite-free Li-metal anodes

Li-metal is an ideal anode that can provide rechargeable batteries with high energy density,but its application in large scale is restricted by its high activity that leads to the severe decomposition of electrolyte components(solvents and salts) and the growth of Li dendrites.These parasitic reactions are responsible for the cycle life deterioration and the safety accidents of rechargeable Li-metal batteries.Correspondingly,much effort has been made to regulate Li/electrolyte interface chemistry.In this review,we summarize some strategies that have been developed recently to stabilize Li/electrolyte interface by constructing protective interphases on Li-metal anodes.Firstly,the currently available understandings on the instability of Li/electrolyte interface are outlined.Then,artificial interphases recently constructed exsitu and in-situ are illustrated in detail.Finally,possible approaches to acquire more efficiently protective interphases are prospected.

Data-driven Reliability Assessment of an Electric Vehicle Penetrated Grid Utilizing the Diffusion Estimator and Slice Sampling

Due to the stochasticity of charging behaviors of electric vehicles(EVs),it is difficult to anticipate when charging load demand will be densely concentrated.If massive charging loads and the system peak profile appear at the same time,it may pose a risk to the reliable operation of power grids.For a system integrated with renewable energies,this risk can be much higher because of their unsteady power output.With load measurements more widely collected,this paper presents a data-driven framework to assess the reliability of a power grid considering charging EVs.Specifically,the diffusion estimator is firstly applied to estimate the probability density function of EV charging loads,which possesses both regional adaptivity and good boundary estimation performance.Then,charging load samples are produced through slice sampling.It is capable of sampling from irregularly-shaped distributions with high accuracy.The proposed approach is verified by the numerical results from the simulations on a modified IEEE 30-bus test system based on real measurement data.

Operation Strategy of EV Battery Charging and Swapping Station

An operation strategy of the electric vehicle （EV） battery charging and swapping station is proposed in the paper. The strategy is established based on comprehensively consideration of the EV charging behaviors and the possible mutual actions between battery charging and swapping. Three energy management strategies can be used in the station： charging period shifting, energy exchange between EVs, and energy supporting from surplus swapping batteries. Then an optimization model which minimizes the total energy management costs of the station is built. The Monte Carlo simulation is applied to analyze the characteristics of the EV battery charging load, and a heuristic algorithm is used to solve the strategy providing the relevant information of EVs and the battery charging and swapping station. The operation strategy can efficiently reduce battery charging during the high electricity price periods and make more reasonable use of the resources. Simulations prove the feasibility and rationality of the strategy.

Negatively charged insulated boron nitride nanofibers directing subsurface zinc deposition for dendrite-free zinc anodes

The practical application of aqueous zinc-ion batteries(ZIBs)is limited by the growth of dendrite during cycling.How to rationally design and construct an efficient artificial interface layer by selecting suitable building units to control the dendrite growth is still a challenge.Herein,a porous boron nitride nanofibers(BNNFs)artificial interface layer was constructed,and its working mechanisms were revealed by both experiments(electrochemical characterization and in-situ optical microscope)and theoretical calculations(density functional theory(DFT)and finite element simulation).The insulated BNNFs layer leads to position-selected electroplating between BNNFs layer and Zn foil.The unique negatively charged surface and porosity of BNNFs contribute to the self-concentrating and pumping features of Zn ions,thus suppressing the concentration polarization on the Zn surface.Additionally,densely arranged porous BNNFs have a shunt effect on Zn ions diffusion,resulting in uniform distributions of Zn ions and electric field.The introduced BNNFs layer not only makes Zn deposition uniform but also restrains the dendrite growth,therefore the Zn+BNNFs symmetric cells perform ultralong stable cycling for 1,600 h at 1 mA·cm–2 and more than 500 h at 10 mA·cm–2.Moreover,Zn+BNNFs||CNT/MnO2 battery presents a high initial capacity of 293.6 mAh·g–1 and an excellent retention rate of 97.6%at 1 A·g–1 after 400 cycles,while Zn||CNT/MnO2 battery only maintains 37.1%discharge capacity.This artificial interface layer with negatively charged BNNFs exhibits excellent dendrite-inhibit and may have enormous prospects in other metal batteries.

Facile synthesis and functionalization of fluoranthenes via intramolecular[4+2]annulations between thiophenes and alkynes

Fluoranthenes have attracted tremendous attention due to their unique optoelectronic properties and extensive applications.Although several synthetic methodologies have been developed for the preparation of fluoranthene derivatives,it is still unfavorable to functionalize the fluoranthene framework at different positions due to the relatively low selectivity and reactivity.Herein,a catalyst-free intramolecular[4+2]annulation between thiophenes and alkynes is developed towards the synthesis of fluoranthenes.Altogether 20 examples have been demonstrated using this method.Various functional groups can be precisely introduced into the fluoranthene skeleton at different positions by simply tuning the substituents on the thiophenes and alkynes.The conjugation of the fluoranthene can be facilely extended through different directions.Furthermore,the feasibility of this[4+2]annulation reaction is also investigated by density functional theory calculations.Therefore,this protocol provides not only a synthetic methodology towards fluoranthenes with substituents functionalized at different positions,but also an effective pathway to construct large polycyclic aromatic hydrocarbons containing fluoranthene moieties.

Facile Synthesis of S-Fused Multi-Membered Polycyclic Heterocycles:A Construction Strategy towards Thermally Stable Thiepine Derivatives

S-fused heterocycles have become popular building blocks to construct functional polycyclic compounds.In contrast to the abundant synthetic methodologies for thiophene-fused aromatics,the synthesis of S-heterocycles containing six-membered thiopyran and seven-membered thiepine rings is much less reported owing to their unfavorable synthetic protocols and the thermal instabilities.Herein,a series of thiepine-containing polycyclic S-heterocycles have been successfully synthesized via different synthetic routes which involve initial construction of sulfur bridges and final ring-closure reactions.Therefore,the dilithium intermediates are ex-cluded,which facilitates the fusion on the thiepine ring with different S-heterocycles,including thiophene and thiopyran derivatives.Typically,a S-fused multi-membered polycyclic compound simultaneously involving thiophen,thiopyran,and thiepine rings has been successfully prepared.Interestingly,nucleus-independent chemical shift calculations reveal that the incorporated thiopyran and thiepine rings demonstrate aromatic and nonaromatic characteristics,respectively.Moreover,the thermal stabilities of the thiepine derivatives have been tremendously improved after the fusion on the three vinyl groups in the thiepine unit,which is attributed to the enhancements of the activation energies for the S-extrusion reactions,as revealed by density functional theory calculations.Therefore,our findings not only provide a facile synthetic methodology for S-fused multi-membered polycyclic heterocycles,but also furnish a novel construction strategy towards thermally stable thiepine derivatives.

Non-alcoholic fatty liver degree and long-term risk of incident inflammatory bowel disease:A large-scale prospective cohort study

Background:Non-alcoholic fatty liver disease(NAFLD)and inflammatory bowel disease(IBD)have shown similar worsening epidemic patterns globally and shared various overlapping pathophysiological mechanisms.However,evidence on the relationship between NAFLD and IBD risk is lacking.We aimed to investigate the associations between long-term risk of incident IBD and NAFLD in a large prospective cohort.Methods:Participants from the United Kingdom Biobank cohort(https://biobank.ndph.ox.ac.uk/)who were free of IBD and alcoholic liver disease at baseline were enrolled.Baseline non-alcoholic fatty liver degree was measured by the well-established fatty liver index(FLI).The outcomes of interest included incident IBD,ulcerative colitis(UC),and Crohn’s disease(CD).Multivariable Cox proportional hazard regression was used to calculate hazard ratios(HRs)and 95%confidence intervals(CIs).Results:Among 418,721 participants(mean FLI:48.11±30.11),160,807(38.40%)participants were diagnosed as NAFLD at baseline.During a median of 12.4 years’follow-up,2346 incident IBD cases(1545 UC,653 CD,and 148 IBD-unclassified)were identified.Due to limited events,those IBD-unclassified were combined in UC or CD when examining the associated risk of UC or CD,separately.Compared with the lowest quartile of FLI,the highest quartile showed a separately 36.00%,25.00%,and 58.00%higher risk of incident IBD(HR_(Q4 vs.Q1)=1.36,95%CI:1.19-1.55,P_(trend)<0.001),UC(HR_(Q4 vs.Q1)=1.25,95%CI:1.07-1.46,P_(trend)=0.047),and CD(HR_(Q4 vs.Q1)=1.58,95%CI:1.26-1.97,P_(trend)<0.001)after multivariable adjustment.Compared with non-NAFLD,NAFLD participants had a significantly higher risk of incident IBD(HR=1.13,95%CI:1.04-1.24)and CD(HR=1.36,95%CI:1.17-1.58).Conclusions:Higher degree of non-alcoholic fatty liver is associated with increased risk of incident IBD.Interventions aimed at improving NAFLD may be a potential targeted strategy for the detection and treatment of IBD.

揭示下一代高通量测序在传染病诊断中的潜力:挑战与前景

Pathogen identification for infectious disease diagnosis is crucial and can be achieved through direct isolation of microbes or indirect detection based on the host immune system. Clinical metagenomic next-generation sequencing(mNGS) is an emerging technology that comprehensively analyzes genetic material(DNA and RNA) from both microbes and the host. It does not rely on prior knowledge of a pathogen's genome. This article reviews the clinical utility of mNGS in diagnosing infectious diseases and current technical difficulties.

Development and validation of an improved probabilistic quotient normalization method for LC/MS-and NMR-based metabonomic analysis

Robust normalization is a prerequisite for reliable metabonomic analysis especially when intervention treatments cause drastic metabolomic changes or when spot urinary samples are employed without knowing the drinking water quantity.With the simulated and real datasets,here,we report a probabilistic quotient normalization method based on the mode-of-quotients(mPQN)which is suitable for metabonomic analysis of both NMR and LC-MS data with little and/or drastic metabolite changes.When applied to metabonomic analysis of both animal plasma samples and human urinary samples,this newly proposed method has clearly shown better robustness than all classical normalization methods especially when drastic changes of some metabolites occur.

An H-phosphonate strategy for the synthesis of 2',3'-dideoxynucleoside triphosphates and homodinucleotides

The triphosphates and homodinucleotides of AZT and d4T have been efficiently synthesized from the corresponding nucleoside 5-H-phosphonate monoesters via the reactive pyridinium phosphoramidate intermediates.

Objectness Region Enhancement Networks for Scene Parsing

Semantic segmentation has recently witnessed rapid progress, but existing methods only focus on identifying objects or instances. In this work, we aim to address the task of semantic understanding of scenes with deep learning. Different from many existing methods, our method focuses on putting forward some techniques to improve the existing algorithms, rather than to propose a whole new framework. Objectness enhancement is the first effective technique. It exploits the detection module to produce object region proposals with category probability, and these regions are used to weight the parsing feature map directly. 'Extra background' category, as a specific category, is often attached to the category space for improving parsing result in semantic and instance segmentation tasks. In scene parsing tasks, extra background category is still beneficial to improve the model in training. However, some pixels may be assigned into this nonexistent category in inference. Black-hole filling technique is proposed to avoid the incorrect classification. For verifying these two techniques, we integrate them into a parsing framework for generating parsing result. We call this unified framework as Objectness Enhancement Network (OENet). Compared with previous work, our proposed OENet system effectively improves the performance over the original model on SceneParse150 scene parsing dataset, reaching 38.4 mIoU (mean intersection-over-union) and 77.9% accuracy in the validation set without assembling multiple models. Its effectiveness is also verified on the Cityscapes dataset.