Influence of deformation on the corrosion behavior of LZ91 Mg-Li alloy

The effect of rolling and forging on the microstructure and corrosion behavior of LZ91 alloy was investigated using an electron probe micro-analyzer,immersion and electrochemical tests.Results showed that the area fraction of theβ-Li phase remained unchanged,and the grain size of theβ-Li phase decreased after forging.The as-rolled forged alloy(FR-LZ91)exhibited the highest area fraction of theβ-Li phase and the longest grains.The corrosion resistance of the forged LZ91 alloy increased due to grain refinement that prevented further corrosion during the immersion test.Among the experimental alloys,FR-LZ91 showed the highest resistance of corrosion film and charge transfer resistance values due to its protective film caused by the high area fraction of theβ-Li phase.

Photothermal‐boosted polaron transport in Fe_(2)O_(3)photoanodes for efficient photoelectrochemical water splitting

Introduction of the photothermal effect into transition-metal oxide photoanodes has been proven to be an effective method to improve the photoelectrochemical(PEC)water-splitting performance.However,the precise role of the photothermal effect on the PEC performance of photoanodes is still not well understood.Herein,spinel-structured ZnFe_(2)O_(4)nanoparticles are deposited on the surface of hematite(Fe_(2)O_(3)),and the ZnFe_(2)O_(4)/Fe_(2)O_(3)photoanode achieves a high photocurrent density of 3.17 mA cm^(-2)at 1.23 V versus a reversible hydrogen electrode(VRHE)due to the photothermal effect of ZnFe_(2)O_(4).Considering that the hopping of electron small polarons induced by oxygen vacancies is thermally activated,we clarify that the main reason for the enhanced PEC performance via the photothermal effect is the promoted mobility of electron small polarons that are bound to positively charged oxygen vacancies.Under the synergistic effect of oxygen vacancies and the photothermal effect,the electron conductivity and PEC performance are significantly improved,which provide fundamental insights into the impact of the photothermal effect on the PEC performance of small polaron-type semiconductor photoanodes.

BnbHLH92a negatively regulates anthocyanin and proanthocyanidin biosynthesis in Brassica napus

Yellow seed trait is a desirable characteristic with potential for increasing seed quality and commercial value in rapeseed,and anthocyanin and proanthocyanidins(PAs)are major seed-coat pigments.Few transcription factors involved in the regulation of anthocyanin and PAs biosynthesis have been characterized in rapeseed.In this study,we identified a transcription factor gene BnbHLH92a(BnaA06T0441000ZS)in rapeseed.Overexpressing BnbHLH92a both in Arabidopsis and in rapeseed reduced levels of anthocyanin and PAs.Correspondingly,the expression profiles of anthocyanin and PA biosynthesis genes(TT3,BAN,TT8,TT18,and TTG1)were shown by quantitative real-time PCR to be inhibited in BnbHLH92a-overexpressing Arabidopsis seeds,indicating that BnbHLH92a represses the anthocyanin and PA biosynthesis pathway in Arabidopsis.BnbHLH92a physically interacts with the BnTTG1 protein and represses the biosynthesis of anthocyanins and PAs in rapeseed.BnbHLH92a also binds directly to the BnTT18 promoter and represses its expression.These results suggest that BnbHLH92a is a novel upstream regulator of flavonoid biosynthesis in B.napus.

关于短期及超短期风电功率预测的评述

讨论风电功率预测及其误差对电力系统的影响,从信息流观点解读风电功率预测过程,归纳影响风电功率预测精度的因素,并对风电功率预测的研究现状加以归类与梳理。在此基础上,讨论对风电功率预测结果评价指标的要求,提出误差评估指标应该反映整个时间窗口内的预报质量,并展望风电功率预测可能的突破。

Inversion of Seawater Physical Properties Based on Allied Elastic Impedance

Inversion of seawater physical parameters (temperature, salinity and density) from seismic data is an important part of Seismic Oceanography, which was raised recent years to study physical oceanography. However present methods have problems that inversion accuracy is not high or inverted parameters are incomprehensive. To overcome these problems, this paper derives Allied Elastic Impedance (AEI), from which we can extract acoustic velocity and density of seawater directly. Furthermore this paper proposes a method to fit temperature and salinity with acoustic velocity and density respectively, breaking through the limitation that temperature and salinity can only be extracted from acoustic velocity. After applying it to model and real data, we find that this method not only solves the problem that ocean density is hard to extract, but also increases accuracy of other parameters, with the temperature and salinity resolution of 0.06°C and 0.02 psu respectively. All results show that AEI is promising in inversion of seawater physical parameters.

lncRNA调控畜禽抗病力性状研究进展

长链非编码RNA(long non-coding RNA,lncRNA)是一类长度大于200个核苷酸的非编码RNA分子。lncRNA虽然不具备蛋白编码能力,但可通过转录调控、转录后调控及表观遗传修饰调控等方式影响基因的表达,进而影响性状的表型。在现代畜牧业生产中,除提高生长发育和产量性状外,研究免疫因子、细胞因子等抗病力相关指标及性状的调控机制,对提高和改善畜禽的健康、福利及公共卫生尤为重要。近年来,利用lncRNA研究鸡(Gallus gallus)、猪(Sus scrofa)、牛(Bos taurus)等重要畜禽的抗病力性状的调控机制取得了一定进展,为将表观遗传标记应用于动物抗病遗传育种打下了一定的基础。本文介绍了lncRNA的生物学功能和产生机制,着重阐述了lncRNA对畜禽抗病力性状的调控作用及研究进展,以期为lncRNA在畜禽抗病遗传育种方面的研究及应用提供科学依据。

Transcriptome sequencing analysis for the identification of stable lncRNAs associated with bovine Staphylococcus aureus mastitis

Background:Staphylococcus aureus(S.aureus)mastitis is one of the most difficult diseases to treat in lactating dairy cows worldwide.S.aureus with different lineages leads to different host immune responses.Long non-coding RNAs(lncRNAs)are reported to be widely involved in the progress of inflammation.However,no research has identified stable lncRNAs among different S.aureus strain infections.In addition,folic acid(FA)can effectively reduce inflammation,and whether the inflammatory response caused by S.aureus can be reduced by FA remains to be explored.Methods:lncRNA transcripts were identified from Holstein mammary gland tissues infected with different concentrations of S.aureus(in vivo)and mammary alveolar cells(Mac-T cells,in vitro)challenged with different S.aureus strains.Differentially expressed(DE)lncRNAs were evaluated,and stable DE lncRNAs were identified in vivo and in vitro.On the basis of the gene sequence conservation and function conservation across species,key lncRNAs with the function of potentially immune regulation were retained for further analysis.The function of FA on inflammation induced by S.aureus challenge was also investigated.Then,the association analysis between these keys lncRNA transcripts and hematological parameters(HPs)was carried out.Lastly,the knockdown and overexpression of the important lncRNA were performed to validate the gene function on the regulation of cell immune response.Results:Linear regression analysis showed a significant correlation between the expression levels of lncRNA shared by mammary tissue and Mac-T cells(P<0.001,R^(2)=0.3517).lncRNAs PRANCR and TNK2-AS1 could be regarded as stable markers associated with bovine S.aureus mastitis.Several HPs could be influenced by SNPs around lncRNAs PRANCR and TNK2-AS1.The results of gene function validation showed PRANCR regulates the mRNA expression of SELPLG and ITGB2 within the S.aureus infection pathway and the Mac-T cells apoptosis.In addition,FA regulated the expression change of DE lncRNA involved in toxin metabolism and inflammation to fight against S.aureus infection.Conclusions:The remarkable association between SNPs around these two lncRNAs and partial HP indicates the potentially important role of PRANCR and TNK2-AS1 in immune regulation.Stable DE lncRNAs PRANCR and TNK2-AS1 can be regarded as potential targets for the prevention of bovine S.aureus mastitis.FA supplementation can reduce the negative effect of S.aureus challenge by regulating the expression of lncRNAs.

Classification Criteria of Narrow/Wide Ice-ResistantConical Structures Based on Direct Measurements

Ice-induced structural vibration generally decreases with an increase in structural width at the waterline. Definitions of wide/narrow ice-resistant conical structures, according to ice-induced vibration, are directly related to structure width, sea ice parameters, and clearing modes of broken ice. This paper proposes three clearing modes for broken ice acting on conical structures: complete clearing, temporary ice pile up, and ice pile up. In this paper, sea ice clearing modes and the formation requirements of dynamic ice force are analyzed to explore criteria determining wide/narrow ice-resistant conical structures. According to the direct measurement data of typical prototype structures, quantitative criteria of the ratio of a cone width at waterline(D) to sea ice thickness(h) is proposed. If the ratio is less than 30(narrow conical structure), broken ice is completely cleared and a dynamic ice force is produced; however, if the ratio is larger than 50(wide conical structure), the front stacking of broken ice or dynamic ice force will not occur.

Geographic differentiation and phylogeographic relationships among world soybean populations

A fast-growing protein and oil crop,soybean was domesticated in ancient China and disseminated early in Asia and afterwards to other continents,in particular the Americas in recent centuries.After adaptation,locally developed landraces and cultivars formed a diversity of geographic-populations.In an investigation of their phylogeographic features,marker-derived traits were combined with geography-related photo-and temperaturesensitive traits to study 13 geographic-populations comprising 371 accessions.Extreme differentiation among geographic-populations was observed for flowering date(33–94 days),maturity date(79–181 days),and main stem node number(6–25 nodes).Restriction-site associated DNA sequencing revealed strong genetic differentiation among these geographic-populations,including genetic richness(alleles,35,242–44,986)and specific-present alleles(SPAs,0–67).More SPAs(28–67)emerged in some secondary and tertiary centers than in centers of origin(8–11).Phenotypic and genotypic clustering divided 11 of the 13 geographic-populations into the same five sets of sensitivity-similar geographic-populations and grouped the populations of northeast China and northern North America rather than center-of-origin populations as secondary centers,indicating the importance of geography-related traits in determining genetic differences among geographic-populations.A model of four soybean dissemination paths is presented:from the center of origin to the north,east,and south in Asia and from northeast China to Europe and the Americas.These findings provide a detailed phylogeographic understanding of worldwide soybeans.

Immunization with recombinant baculovirus expressing the VP6 protein of grass carp reovirus induces immunity in grass carp

Dear Editor,Grass carp reovirus(GCRV),a member of the genus Aquareovirus in the family Reoviridae(Attoui H,et al,2002),is one of the most virulent aquareoviruses iden-tified so far,leading to high fatality rates(up to 85%)of fingerlings and yearlings of grass carp(Fang Q,et al,2007).No commercial vaccines against GCRV infection have been developed as yet.

Trim28 citrullination maintains mouse embryonic stem cell pluripotency via regulating Nanog and Klf4 transcription

Protein citrullination,including histone H1 and H3 citrullination,is important for transcriptional regulation,DNA damage response,and pluripotency of embryonic stem cells(ESCs).Tripartite motif containing 28(Trim28),an embryonic development regulator involved in ESC self-renewal,has recently been identified as a novel substrate for citrullination by Padi4.However,the physiological functions of Trim28 citrullination and its role in regulating the chromatin structure and gene transcription of ESCs remain unknown.In this paper,we show that Trim28 is specifically citrullinated in mouse ESCs(m ESCs),and that the loss of Trim28 citrullination induces loss of pluripotency.Mechanistically,Trim28 citrullination enhances the interaction of Trim28with Smarcad1 and prevents chromatin condensation.Additionally,Trim28 citrullination regulates m ESC pluripotency by promoting transcription of Nanog and Klf4 which it does by increasing the enrichment of H3K27ac and H3K4me3 and decreasing the enrichment of H3K9me3 in the transcriptional regulatory region.Thus,our findings suggest that Trim28citrullination is the key for the epigenetic activation of pluripotency genes and pluripotency maintenance of ESCs.Together,these results uncover a role Trim28 citrullination plays in pluripotency regulation and provide novel insight into how citrullination of proteins other than histones regulates chromatin compaction.

宁夏六盘山国家级自然保护区眼蝶群落多样性

蝴蝶是地球生物多样性的重要指示物种之一,其种群动态及群落结构变化能够揭示环境改变对生态系统的影响。六盘山国家级自然保护区生境优越,植物区系多样,孕育了丰富的蝶类资源。为了有效利用环境和保护蝶类资源,2016–2018年,作者采用样线调查法,对宁夏六盘山国家级自然保护区人工植被、针阔混交林、阔叶林、灌木林4种生境中眼蝶亚科昆虫进行了调查,分析了眼蝶在空间及时间上的动态变化。共记录眼蝶亚科13属19种4,363只,其中阿芬眼蝶(Aphantopushyperanthus,961只)、亚洲白眼蝶(Melanargiaasiatica,637只)、爱珍眼蝶(Coenonymphaoedippus,594只)分别占总数的22%、15%和13%,为保护区优势种;蟾眼蝶(Triphysaphryne,17只)仅占总数的0.39%,为保护区的稀有种。在空间分布上,4类生境中针阔混交林眼蝶物种丰富度和优势度低,多样性指数最高,不同生境眼蝶群落物种丰富度指数、多样性指数、均匀度指数存在明显差异(P<0.05),优势度指数差异不显著。在时间动态上,2016–2018年眼蝶个体数量呈下降趋势,物种个体数量高峰期主要发生在8月,优势种变化明显。因此,保护宁夏六盘山国家级自然保护区蝴蝶种类多样性刻不容缓。

Morphological responses to water-level fluctuations of two submerged macrophytes, Myriophyllum spicatum and Hydrilla verticillata

Aims Myriophyllum spicatum and Hydrilla verticillata are common submerged macrophytes in the Yangtze River basin.To investigate their tolerances and adaptations to water-level fluctuations,an experiment was conducted in a pond.Methods We designed five different amplitudes of water-level fluctuations as static,615,630,660 and 690 cm during the 74 days of the experiment.In each amplitude treatment,two cultivation methods were examined as monoculture and mixed culture.Important Findings The results showed that M.spicatum had greater morphological responses to water-level fluctuations than H.verticillata.Fluctuating amplitude had significant effects on branch number,shoot length and root dry weight(DW)of M.spicatum,whereas it only had significant effect on branch number of H.verticillata.Both fluctuating amplitude and cultivation method had significant effects on total DW of M.spicatum,which was higher in monoculture than mixed culture.The total DW of H.verticillata was affected by fluctuating amplitude only,and the largest biomass was in the amplitude of 630 cm.Fruit DW of M.spicatum was largest in the amplitude of 630 cm,high amplitude of water-level fluctuations would inhibit flowering and seed production.Root DW proportion was significantly affected by fluctuating amplitude and cultivation method in both species,and the root DW proportion of M.spicatum was significantly higher in the amplitude-of 690 cm.We conclude that moderate amplitude of water-level fluctuations can promote the distribution and growth of both species,and in order to accelerate the restoration of both species in natural habitats,the optimum amplitude should be keep at 615 to 630 cm.

Comments on 2018 CPCS guideline for diagnosis and treatment of syncopein children and adolescents

Syncope is one kind of transient loss of consciousness,due to transient global cerebral hypoperfusion.It is sometimes misunderstood with other causes of transient loss of consciousness,like epilepsy,metabolic disorders,head trauma,psychological factors,and so on.Syncope in children and adolescents is common and seriously impacts the quality of their lives.However,its pathogenesis,etiologies,diagnosis and management are complex.The studies on syncope attract great interest of pediatricians and great progress has been made in this interesting field.Based on the improvement achieved so far,Chinese Pediatric Cardiology Society(CPCS)successfully developed a guideline for the diagnosis and treatment of syncope in children and adolescents,which would greatly improve the level of clinical management of syncope.

Seismic Low-Frequency Shadow beneath Gas Hydrate in the Shenhu Area Based on the Stereoscopic Observation System

Spectral analysis shows a low-frequency shadow under the BSR interface. Traditional low-frequency shadow analysis is based on stacked data. In order to understand the BSR low-frequency shadow more clearly, a frequency division analysis on stereoscopic observation seismic data based on the adaptive optimal-kernel （AOK） frequency analysis method is presented. It includes ocean-bottom seismometer （OBS） data （common receiver point data including vertical and horizontal components）, vertical cable data （common receiver point data） and horizontal cable data （stacked section of different offsets）. The OBS data frequency analysis gets a conclusion that vertical component has a significant effect on the low-frequency shadow, but the horizontal component did not. The vertical cable data shows that the low frequency band of vertical cable is wider than OBS. And then the horizontal cable data frequency analysis points out that the bigger the angle of incidence is, the more obvious the low-frequency shadow will be. The low-frequency shadow feature is shown in the stereoscopic observation field and the visual effect on com- mon reception point data is better. The lateral reservoir distribution characteristics are predicted from low-frequency shadow feature analysis of the hydrate BSR based on stereoscopic observation.

Molecular Characterization and Expression Analysis of ftr01, ftr42,and ftr58 in Zebrafish(Danio rerio)

Tripartite motif(TRIM)proteins were shown to play an important role in innate antiviral immunity.FinTRIM(ftr)is a new subset of TRIM genes that do not possess obvious orthologs in higher vertebrates.However,little is known about its function.In this study,we used bioinformatic analysis to examine the phylogenetic relationships and conserved domains of zebrafish(Danio rerio)fir01,fir42,and fir58.as well as qualitative real-time PCR to examine their expression patterns in zebrafish embryonic fibroblast(ZF4)cells and zebrafish tissues.Sequence analysis showed that the three finTRIMs are highly conserved,and all contain a RING domain.B-box domain,and SPRY-PRY domain.In addition,fr42 and fir58 had one coiled-coil domain(CCD),whereas ftrol had two CCDs.Tissue expression analysis revealed that the mRNA level of ftr01 was the highest in the liver,whereas those of ftr42 and ftr58 were the highest in the gill;the expression of thesefinTRIMs was clearly upregulated not in the eyes,but in the liver,spleen,kidney,gill,and brain of zebrafish following spring viremia of carp virus(SVCV)infection.Similarly,the expression of these three finTRIM genes also increased in ZF4 cells after SVCV infection.Our study revealed that fir01,fr42,and fir58 may play an important role in antiviralimmune responses,and these findings validate the need for more in-depth research on the finTRIM family in the future.

Screening of novel synthetic derivatives of dehydroepiandrosterone for antivirals against flaviviruses infections

Flaviviruses are important arthropod-borne pathogens that represent an immense global health problem.Their unprecedented epidemic rate and unpredictable clinical features underscore an urgent need for antiviral interventions.Dehydroepiandrosterone(DHEA)is a natural occurring adrenal-derived steroid in the human body that has been associated in protection against various infections.In the present study,the plaque assay based primary screening was conducted on 32 synthetic derivatives of DHEA against Japanese encephalitis virus(JEV)to identify potent anti-flaviviral compounds.Based on primary screening,HAAS-AV3026 and HAAS-AV3027 were selected as hits from DHEA derivatives that exhibited strong antiviral activity against JEV(IC_(50)=2.13 and 1.98μmol/L,respectively)and Zika virus(ZIKV)(IC_(50)=3.73 and 3.42μmol/L,respectively).Mechanism study indicates that HAAS-AV3026 and HAAS-AV3027 do not exhibit inhibitory effect on flavivirus binding and entry process,while significantly inhibit flavivirus infection at the replication stage.Moreover,indirect immunofluorescence assay,Western blot analyses,and quantitative reverse transcription-PCR(qRT-PCR)revealed a potent antiviral activity of DHEA derivatives hits against JEV and ZIKV in terms of inhibition of viral infection,protein production,and viral RNA synthesis in Vero cells.Taken together,our results may provide a basis for the development of new antivirals against flaviviruses.

Maternally inherited H4K16 acetylation primes zygotic gene activation in Drosophila

In a recent study published in Cell, Samata et al. demonstrated a novel mechanism that guided the genomic reprogramming. They showed that the acetylation of histone H4 at Lysine 16(H4K16ac) was intergenerationally maintained from the mother’s oocyte to the young embryo and primed zygotic gene activation in Drosophila(Samata et al., 2020).Embryonic development is initially directed by maternal gene products. Then gradually, developmental control is handed to the zygotic genome during the maternal-to-zygotic transition(MZT).