Fe-N-C core-shell catalysts with single low-spin Fe(Ⅱ)-N_(4)species for oxygen reduction reaction and high-performance proton exchange membrane fuel cells

Fe-N-doped carbon materials(Fe-N-C)are promising candidates for oxygen reduction reaction(ORR)relative to Pt-based catalysts in proton exchange membrane fuel cells(PEMFCs).However,the intrinsic contributions of Fe-N_(4)moiety with different chemical/spin states(e.g.D1,D2,D3)to ORR are unclear since various states coexist inevitably.In the present work,Fe-N-C core-shell nanocatalyst with single lowspin Fe(Ⅱ)-N_(4)species(D1)is synthesized and identified with ex-situ ultralow temperature Mossbauer spectroscopy(T=1.6 K)that could essentially differentiate various Fe-N_(4)states and invisible Fe-O species.By quantifying with CO-pulse chemisorption,site density and turnover frequency of Fe-N-C catalysts reach 2.4×10^(-9)site g^(-1)and 23 e site~(-1)s^(-1)during the ORR,respectively.Half-wave potential(0.915V_(RHE))of the Fe-N-C catalyst is more positive(approximately 54 mV)than that of Pt/C.Moreover,we observe that the performance of PEMFCs on Fe-N-C almost achieves the 2025 target of the US Department of Energy by demonstrating a current density of 1.037 A cm^(-2)combined with the peak power density of 0,685 W cm^(-2),suggesting the critical role of Fe(Ⅱ)-N_(4)site(D1).After 500 h of running,PEMFCs still deliver a power density of 1.26 W cm^(-2)at 1.0 bar H_(2)-O_(2),An unexpected rate-determining step is figured out by isotopic labelling experiment and theoretical calculation.This work not only offers valuable insights regarding the intrinsic contribution of Fe-N_(4)with a single spin state to alkaline/acidic ORR,but also provides great opportunities for developing high-performance stable PEMFCs.

Recent Advances in Mechanistic Understanding of Metal-Free Carbon Thermocatalysis and Electrocatalysis with Model Molecules

Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and sustainability.Over the past decade,well-designed carbon catalysts with tunable structures and heteroatom groups coupled with various characterization techniques have proposed numerous reaction mechanisms.However,active sites,key intermediate species,precise structure-activity relationships and dynamic evolution processes of carbon catalysts are still rife with controversies due to the monotony and limitation of used experimental methods.In this Review,we sum-marize the extensive efforts on model catalysts since the 2000s,particularly in the past decade,to overcome the influences of material and structure limitations in metal-free carbon catalysis.Using both nanomolecule model and bulk model,the real contribution of each alien species,defect and edge configuration to a series of fundamentally important reactions,such as thermocatalytic reactions,electrocatalytic reactions,were systematically studied.Combined with in situ techniques,isotope labeling and size control,the detailed reaction mechanisms,the precise 2D structure-activity relationships and the rate-determining steps were revealed at a molecular level.Furthermore,the outlook of model carbon catalysis has also been proposed in this work.

Plasmon Induced Heat Funneling from Au to Cu in the Bimetallic Au@Cu Core-Shell Nanoparticles

The bimetallic nanostructures that mix a plasmonic metal with a transition metal in the form of the core-shell nanoparticles are promising to promote catalytic performance.But it is still unclear how the heat(hot electrons and phonons)transfers on the interface between two metals.We have designed and synthesized Au@Cu bimetallic nanoparticles with Au as core and Cu as shell.By using transient absorption spectroscopy,we find that there are two plasmon induced heat funneling processes from Au core to Cu shell.One is the electron temperature equilibrium(electron heat transfer)with equilibration time of~560 fs.The other is the lattice temperature equilibrium(lattice heat transfer)with equilibration time of~13 ps.This plasmon induced heat funneling may be universal in similar bimetallic nanostructures,so our finding could contribute to further understanding the catalytic mechanism of bimetallic plasmonic photothermal catalysis.

Silicon Mitigates Aluminum Toxicity of Tartary Buckwheat by Regulating Antioxidant Systems

Aluminum (Al) toxicity is a considerable factor limiting crop yield and biomass in acidic soil. Tartary buckwheatgrowing in acidic soil may suffer from Al poisoning. Here, we investigated the influence of Al stress on the growthof tartary buckwheat seedling roots, and the alleviation of Al stress by silicon (Si), as has been demonstrated inmany crops. Under Al stress, root growth (total root length, primary root length, root tips, root surface area, androot volume) was significantly inhibited, and Al and malondialdehyde (MDA) accumulated in the root tips. At thesame time, catalase (CAT) and ascorbate peroxidase activities, polyphenols, flavonoids, and 1,1-diphenyl-2-picrylhydrazyl(DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free-radical scavenging abilitywere significantly decreased. After the application of Si, root growth, Al accumulation, and oxidative damage wereimproved. Compared to Al-treated seedlings, the contents of ·O2− and MDA decreased by 29.39% and 25.22%,respectively. This was associated with Si-induced increases in peroxidase and CAT enzyme activity, flavonoidcompounds, and free-radical scavenging (DPPH and ABTS). The application of Si therefore has positive effectson Al toxicity in tartary buckwheat roots by reducing Al accumulation in the roots and maintaining oxidationhomeostasis.

Research Progress on Modern Biological Mechanism of Chinese Medicine in Prevention and Treatment of Gouty Nephropathy

Chinese medicine prevention and treatment of gouty nephropathy often uses single drugs and compound formulae to regulate uric acid,which has the effect of lowering uric acid,protecting the kidneys and improving clinical symptoms.In conclusion,the mechanism of action of Chinese medicine against gouty nephropathy mainly involves oxidative stress,inflammatory response,etc.,with a view to providing new ideas and methods for the prevention and treatment of gouty nephropathy by Chinese medicine.

Research Progress of Dai and Western Medicine in the Treatment of Gouty Arthritis

This paper reviews the pathogenesis,diagnostic criteria,and treatment means of gouty arthritis from the perspectives of Western medicine and Dai medicine in order to provide a reference for clinical medication.

Risk Factors for Acute Kidney Injury in Patients Receiving Antibiotic Therapy:A Systematic Review and Meta-Analysis

[Objectives]To systematically analyze the risk factors for acute kidney injury(AKI)in patients treated with antibiotics and to conduct a meta-analysis of published clinical studies.[Methods]PubMed,Web of Science,and Embase were searched for relevant cohort and case-control studies from January 1,2001,to October 31,2022.Meta-analysis was performed using RevMan5.4 and StataMP15.[Results]A total of 22 studies were included.Regarding patient factors,serum creatinine(SCr;MD=1.03,95%CI of-0.07 to-0.02)was associated with increased antibiotic-associated AKI.Regarding the comorbidities and clinical factors,diabetes(OR=1.34,95%CI of 1.06 to 1.69,tumor(OR=2.07,95%CI of 1.13 to 3.79),pneumonia(OR=1.83,95%CI of 1.24 to 2.71),mechanical ventilation(OR=3.44,95%CI of 1.93 to 6.12),and ICU admission(OR=2.83,95%CI of 2.13 to 3.75)increased the risk of AKI in patients receiving antibiotic therapy.Regarding drug factors,diuretics(OR=2.76,95%CI of 2.16 to 3.52)increased the risk of antibiotic-associated AKI.[Conclusions]This paper may assist clinicians in predicting the risk factors for AKI in patients receiving antibiotic therapy.

Exploring the Mechanism of Action of Gastrodin in Parkinson's Disease Based on Network Pharmacology

[Objectives]To explore the mechanism of action of gastrodin in the treatment of Parkinson's disease(PD)by employing network pharmacology technology,and to provide a scientific theoretical basis for the rational clinical application of gastrodin.[Methods]The target of gastrodin was identified through a search of the SwissTargetPrediction database.The keyword"Parkinson Disease"was employed to identify the pertinent targets of PD in the GeneCards and OMIM databases.The relationship between gastrodin and PD was elucidated,and a Veen map was constructed to identify the genes that were common to both.A total of 52 common drug targets associated with PD as identified in the Wayne chart were imported into the String database(https://string-db.org/)for protein-protein interaction prediction.Subsequently,Cytoscape 3.9.1 software was employed to construct a"drug-target"network.The potential targets of gastrodin in the treatment of PD were then imported into the DAVID database,where GO analysis and KEGG enrichment results were obtained.[Results]A total of 22 core targets and 53 related pathways of gastrodin were identified as potentially beneficial for the treatment of PD.[Conclusions]Gastrodin may be a potential therapeutic agent for the treatment of PD by modulating the biological process of apoptosis,affecting the relevant pathways such as the IL-17 signaling pathway and the TNF signaling pathway,and acting on GAPDH,EGFR,CASP3,MMP9 and other targets.

Advances in Research of Chinese Medicine Tianma in the Treatment of Parkinson's Disease

In this study,a systematic review was conducted on the experimental study as well as the clinical application of Tianma(Gastrodia elata Blume),a traditional Chinese medicine,in the prevention and treatment of Parkinson's disease(PD).On this basis,a summary and outlook were made,so as to provide ideas and theoretical basis for the study,development and utilization of Tianma PD field.

全生命周期锂离子电池安全特性测试方法

以热失控为特征的安全性问题是制约锂离子电池规模应用的重要因素,从电池安全的重要性以及安全失效的机理出发,提出了一种进行电池单体安全特性探索的方法和思路,通过DOE试验设计来进行电池安全边界开发,并基于某款电池单体进行了试验数据和现象的分析总结。电池在使用过程中因不断老化使其安全性能随之发生变化,进一步对不同老化程度后的电池进行了安全滥用试验,量化分析了老化后电池的安全特性,支持全生命周期的电池安全设计与管理。对电池系统的结构集成设计、电池管理系统开发及防热扩散保护方案设计都有较强的指导意义和重要参考价值。

Growth,ROS Markers,Antioxidant Enzymes,Osmotic Regulators and Metabolic Changes in Tartary Buckwheat Subjected to Short Drought

Tartary buckwheat(Fagopyrum tataricum)is an important pseudocereal feed crop with medicinal and nutritional value.Drought is one of the main causes of reduced growth and yield in these plants.We investigated the growth,physiological,and metabolic responses of the widely promoted Tartary buckwheat variety Chuan Qiao No.1 to polyethylene glycol(PEG)-mediated drought stress.Drought significantly decreased shoot length,shoot biomass and relative water content.Root length,malondialdehyde content,electrolyte leakage,activities of superoxide dismutase,peroxidase,catalase and amylase,and contents of soluble sugar,soluble protein and proline were increased by PEG-mediated drought.Untargeted metabolomics analysis identified 32 core metabolites in seedlings subjected to PEG-mediated drought,16 of which increased—including quercetin,isovitexin,cyanidin 3-O-beta-D-glucoside,L-arginine,and glycerophosphocholine,while the other 16 decreased—including 3-methoxytyramine,2,6-diaminopimelic acid,citric acid,UDP-alpha-D-glucose,adenosine,keto-D-fructose.The 32 core metabolites were enriched in 29 metabolic pathways,including lysine biosynthesis,citrate(TCA)cycle,anthocyanin biosynthesis,and aminoacyl-tRNA biosynthesis.Among them,taurine and hypotaurine metabolism,flavor and flavor biosynthesis,indole alkaline biosynthesis,and alanine,aspartate and glutamate metabolism were the four main metabolic pathways affected by drought.Our findings provide new insights into the physiological and metabolic response mechanisms of Tartary buckwheat to drought stress.

Evaluation of Pre-Harvest Sprouting(PHS)Resistance and Screening of High-Quality Varieties from Thirty-Seven Quinoa(Chenopodium quinoa Willd.)Resources in Chengdu Plain

Pre-harvest sprouting(PHS)will have a serious effect both on the yield and quality of quinoa(Chenopodium quinoaWilld.).It is crucial to select and breed quinoa varieties with PHS resistance and excellent agronomic traits for guidance production and utilization of quinoa.A comprehensive evaluation of the PHS resistance and agronomic traits of 37 species of quinoa resources was conducted in Chengdu Plain.The evaluation used various methods,including grain germination rate(GR),grain germination index(GI),total spike germination rate(SR),total grain germination index(SI),grey correlation analysis(GCA),cluster analysis and correlation analysis.Results showed significant differences in PHS resistance and agronomic traits amongst the 37 quinoa resources.CDU-23 was most resistant to PHS within 24 h,with a germination rate of 2.67%and 0%according to the GR and SR results,respectively.However,in the same time,CDU-31 showed the maximum susceptibility to PHS based on the SR of 31.07%,while CDU-34 was the most sensitive to PHS according to the GR of 100%.The comprehensive evaluation identified one and nine kinds of high resistance species for grain and whole spike germination,respectively.In both cases,the coefficients of variation(CV)for these parameters were 34.78%and 82.13%,respectively.GCA results showed that the magnitude of the association between each trait and yield in the thirty-seven quinoa resources was in the following order:thousand grain weight>seed length>seed area>seed width.Although the seed weight of CDU-18 reached 3.7010 g,the seed weight of CDU-5 was only 1.6030 g.However,the size of the seeds,their width and area did not correlate with their 1000-grain weight.There was a complex correlation between PHS resistance index and agronomic traits.Based on clustering analysis,thirty-seven quinoa resources were classified into three taxa.It was found that various taxa differed in PHS resistance and agronomic traits.Several comparisons of the aggregated data led to the selection of five varieties of quinoa,of which CDU-2 presented excellent agronomic qualities and strong PHS resistance.This study has provided a reference for breeding excellent quinoa varieties with PHS resistance.

Discussion on Construction and Mechanism of Practice Bases for Professional Degree Postgraduates Based on the Integration of Production and Education in Local Universities

Under the background of emerging agricultural education,practice bases are an important place to train profession talented person that match social needs,so it is very important to build stable and long-term practice bases.At present,the main problems in the construction of practice bases for postgraduates in local colleges and universities are mainly focusing on construction and neglecting management,imperfect cooperation mechanism and lack of teaching management effectively.It is of great significance to build a long-term management mechanism to ensure the education quality of practice bases.Therefore,constructing the mode of"double integration and double promotion of production and education"with practice bases as the carrier and realizing the organic combination of industrial needs and postgraduate projects is an important idea for local colleges and universities to train professional degree postgraduates to"know agriculture,love agriculture,strengthen agriculture and promote agriculture",and it also provides a reference for the mechanism construction of postgraduate bases.

Oxidative esterification of acetol with methanol to methyl pyruvate over hydroxyapatite supported gold catalyst: Essential roles of acid-base properties

Acetol is a major light oxygenate and readily produced from staged or fast pyrolysis of lignocellulose biomass. Herein we report that acetol can be selectively converted to methyl pyruvate, an important fine chemical, through oxidative esterification over Au-based catalysts. Detailed experimental studies showed that Au on amphoteric supports with appropriate strength and balanced ratio of acid and base sites can facilitate the desired oxidative-esterification pathway without accelerating undesired aldol-condensation or Cannizzaro reactions. In particular, hydroxyapatite (with a Ca/P ratio of 1.62) supported Au achieved 87% selectivity to methyl pyruvate at an acetol conversion of 62%.

一种快速筛查电池模组内电芯绝缘问题的测试方法

针对动力电池试验后可能会漏电发生绝缘故障的问题,研究了一种可以排查绝缘电压以及问题点位置的测量方法。本方案利用低成本且有效的方法进行绝缘测试排查,方法的原理清晰且操作步骤简单,为动力电池组开发验证过程中出现绝缘失效问题的排查锁定提供了快速高效的分析方法,同时也为将来电动汽车售后绝缘安全问题的排查降低了成本并提供了极大的便利性。

数字化协同设计对智能油气田建设的支持

油气田生产信息化建设在进入智能化阶段后,对工程信息的采集、整合与分析应用提出了更高的要求。以工程建设的数字化协同设计平台建设与应用角度从前端数据管理系统、工艺系统设计、厂(站)三维设计、线路数字化设计系统、材料管理平台、数字化移交六个方面,总结了数字化协同设计模式下的工程建设对智能油气田建设的支持,提出了工程建设面向工程全生命周期、实现工程建设与运维一体化的目标。从而促进数字化协同设计在油气田建设领域的应用与发展。

Potential of Arbidol for Post-exposure Prophylaxis of COVID-19 Transmission:A Preliminary Report of a Retrospective Cohort Study

The efficient transmission of severe acute respiratory syndrome-2 coronavirus(SARS-CoV-2)from patients to health care workers or family members has been a worrisome and prominent feature of the ongoing outbreak.On the basis of clinical practice and in-vitro studies,we postulated that post-exposure prophylaxis(PEP)using Arbidol is associated with decreased infection among individuals exposed to confirmed cases of COVID-19 infection.We conducted a retrospective cohort study on family members and health care workers who were exposed to patients confirmed to have SARS-CoV-2 infection by real-time RT-PCR and chest computed tomography(CT)from January 1 to January 16,2020.The last follow-up date was Feb.26,2020.The emergence of fever and/or respiratory symptoms after exposure to the primary case was collected.The correlations between post-exposure prophylaxis and infection in household contacts and health care workers were respectively analyzed.A total of 66 members in 27 families and 124 health care workers had evidence of close exposure to patients with confirmed COVID-19.The Cox regression based on the data of the family members and health care workers with Arbidol or not showed that Arbidol PEP was a protective factor against the development of COVID-19(HR 0.025,95%CI 0.003-0.209,P=0.0006 for family members and HR 0.056,95%CI 0.005-0.662,P=0.0221 for health care workers).Our findings suggest Arbidol could reduce the infection risk of the novel coronavirus in hospital and family settings.This treatment should be promoted for PEP use and should be the subject of further investigation.

Seed Setting and Its Spatial Characteristics in Tartary Buckwheat(Fagopyrum tataricum)

A low seed-setting rate is the main limiting factor influencing Tartary buckwheat production under high-yield cultivation conditions.To investigate the seed setting and its spatial characteristics,two Tartary buckwheat cultivars(high seed-setting rate cultivar Qianku 3;low seed-setting rate cultivar Liuku 3)were compared by a two-year field trial in 2017 and 2018.The results showed that the Tartary buckwheat underwent simultaneous flowering and fruiting.Flowers,generated from branch,were still blooming during the mature stage of grains on stem,which resulting in a greater number of flowers and grains on the branch than those on the stem at the low part of plant.The seed-setting characteristics significantly differed between two cultivars.The high seed-setting rate of Qianku 3 was 26.6%and 33.2%higher than Liuku 3 in 2017 and 2018,respectively.Meanwhile,Qianku 3 showed a higher filled grain number(157.8%)and seed-setting rate(66.4%)on branch than Liuku 3.A network analysis showed that the whole-plant seed-setting rate was positively correlated with grain number,which was closely correlated with flower number at the same position of plant.The path-coefficient analysis revealed that grains number on branches was the most dominant component(Path coefficient(P)=2.19)of the seed-setting rate,followed by grains number on stem(P=0.60).The grains number on branches showed the greatest positive direct effect with significant correlation(r=0.76 and P<0.01)on the seed-setting rate.Overall,the present study indicated that the grain number of branches may play a vital role in improving the seed-setting rate in Tartary buckwheat.

微信公众号信息数据归档初探

“互联网+”浪潮下,微博、微信、微电影、微视频等新媒体已成为企业宣传文化、推介产品、展示服务的重要呈现方式,在其广泛运用中形成的文章、图片、视频等信息数据具有很高的留档价值。如何将这些数据信息规范化存档?本文以常州公交微信公众号为例,对新媒体时代下信息数据的收集、整理和归档进行探讨。

Polysaccharide Elicitor from the Endophyte Bionectria sp.Fat6 Improves Growth of Tartary Buckwheat under Drought Stress

Drought can limit the growth and reduce the yield of crops,but the safe and effective bio-approach to improve the drought resistance of crops is very little.We conducted an experiment in which we monitored the effects of polysaccharide from the endophyte Bionectria sp.Fat6 on the growth of Tartary buckwheat(Fagopyrum tataricum(L.)Gaertn)seedlings under control and drought-stressed conditions by determining gas exchange,photosynthesis parameters,photosynthetic pigment contents,and metabolite accumulation.Results indicated that the polysaccharide from endophyte stimulated plant growth and increased the aboveground biomass,root mass,and root/shoot ratio of Tartary buckwheat.Application of the polysaccharide to drought-stressed plants resulted in a significant increase in the net photosynthetic rate,stomatal conductance,and transpiration rate of Tartary buckwheat and decreased the intercellular CO_(2) concentration.The contents of chlorophyll a,chlorophyll b,chlorophyll a+b,and carotenoids in leaves were higher in polysaccharide-treated seedlings than that in control.Polysaccharide notably increased the soluble protein and proline content and decreased the malondialdehyde content in Tartary buckwheat leaves.The endophytic polysaccharide may protect Tartary buckwheat against drought by improving leaf gas exchange and photosynthetic capacity,and altering concentrations of protective metabolites.Together,these changes may compensate for the negative impacts of drought stress on the growth of Tartary buckwheat.Thus,the polysaccharide from the endophyte Bionectria sp.Fat6 may be an effective biotic elicitor and a promising bio-approach to improve Tartary buckwheat production worldwide.