Characterization of the sphingolipid profiling of Emiliania huxleyi against virus infection

Lipidomics approach by UPLC-Q-Exactive-MS was used for the identification,quantification,comparison,and characterization of sphingolipids in virus infected marine Emiliania huxleyi BOF92 cells.The results show that 16 significantly changed sphingolipids(including Cer,CerG1,and SPHm)were identified during viral infection.Our data confirmed previously recognized facts that viral infection led to a shift toward virus-specific sphingolipids,which is consistent with the down-regulation of genes involved in the host de novo sphingolipid biosynthesis.Moreover,we revealed the upregulation of virusencoded homologous genes participating in de novo sphingolipids biosynthesis and virus-specific hydroxylated long chain bases(LCBs)as phytoCer,suggesting the competitive inhibition of host sphingolipid synthesis to produce the required building blocks for viral production,replication,and assembly.Additionally,Cer 40꞉1;2,Cer 40꞉2;2 isomer,and CerG139꞉0;2,Cer 39꞉0;2 as novel metabolite markers might indicate the general dysfunctions in E.huxleyi in response to viral infection.Our results show that viral infection led to a profound remodeling of host sphingolipidome,by which viruses depend on the hijacking of host sphingolipid metabolism to support the viral life cycle.

Effects of soil drought on photosynthetic traits and antioxidant enzyme activities in Hippophae rhamnoides seedlings

Water deficit is one of the major limiting factors in vegetation recovery and reconstruction in the semi-arid area of loess hilly regions. Leaf photosynthesis in Hippophae rhamnoides Linn., a common tree grown in this region, decreases under water stress, but the mechanism responsible is not clear. The objective of this study was to investigate the effects of drought stress on photosynthesis and the relationship between photosynthetic variables and soil water contents to help us better understand the photophysiological characteristics of H. rhamnoides under water stress and guide cultivation in the loess hilly region. Here,gas exchange, chlorophyll fluorescence and antioxidant enzyme activity in leaves of 3-year-old saplings of H.rhamnoides grown in pots were tested under eight soil water conditions. When soil water content（RWC） was between 38.9 and 70.5 %, stomatal limitation was responsible for the reduced net photosynthetic rate（PN）.When RWC was lower than 38.9 %, nonstomatal limitation was the main factor restricting PN. Moderate water stress improved the water use efficiency（WUE） of the leaf.Water stress significantly influenced fluorescence variables and the antioxidant enzyme system. When RWC was between 38.9 and 70.5 %, nonphotochemical quenching（NPQ） increased and then decreased, indicating that thermal energy dissipation was a significant photoprotection mechanism. Antioxidant enzymes were activated when RWC ranged from 48.3 to 70.5 %; under severe water stress（RWC ／ 38.9 %）, the antioxidant enzyme system was damaged, the activity of the antioxidant enzymes declined, and membranes were damaged. In the semiarid loess hilly region, RWC between 58.6 and 70.5 % was the economic water threshold value that maintained higher WUE and PN, and the maximum soil water deficit level that could sustain H. rhamnoides was RWC of 38.9 %.

Geochronological and geochemical comparison of Precambrian meta-mafic volcanics in Zhongtiaoshan and Lüliangshan Regions in Shanxi, North China Craton

To unravel the geochemical heterogeneity and its origin in different terranes of North China,we conducted geochronological and geochemical analyses of the meta-mafic rocks from the Lüliang–Zhongtiao rift zone(Shanxi Province).LA-ICP-MS zircon U–Pb dating yielded mostly End-Neoarchean to Proterozoic ages for the basement rocks(Sushui Complex:2516±26 Ma;Metamafic rocks:2494±31 Ma),Jiangxian Group(~2213 Ma),Zhongtiao Group(2077±29 Ma),Jiehekou Group(1998±23 Ma),and Lüliang Group(2152±52 Ma).Petrographic characteristics show that the meta-mafic rocks from the Neoarchean–Paleoproterozoic Zhongtiaoshan(Sushui Complex)have similar geochemical characteristics to the overlying Jiangxian and Zhongtiao Groups.The Paleoproterozoic Lüliang andYejishan Group meta-mafic rocks from Lüliangshan also have similar geochemical characteristics but are geochemically different from similar-age rocks from Zhongtiaoshan.This shows that the late-stage rocks have a geochemical inheritance from the early-stage rocks in the same region and that the geochemical heterogeneity of rocks from different areas was originated from the inherited heterogeneity of the magma source.

Transformation of coccolithophorid Emiliania huxleyi harboring a marine virus(Coccolithoviruses)serine palmitoyltransferase(SPT)gene by electroporation

Emiliania huxleyi is the most prominent modern coccolithophore,a group of marine unicellular eukaryotes that play a critical role in ocean biogeochemistry.Coccolithoviruses are large double stranded DNA viruses,which is responsible for the demise of large oceanic blooms formed by E.huxleyi.E.huxleyi virus(EhVs)acquired a series of enzyme-coding genes predicted to be involved in the sphingolipid biosynthesis by horizontal gene transfer between virus-host.Currently,there is limited experimental validation identifying the functions of these genes in EhV.Genetic transformation of eukaryotic cells is a powerful tool to get an insight into gene functions of the studied organisms.Serine palmitoyltransferase(SPT)catalyzes the first committed step in de novo sphingolipid biosynthetic pathway.Here,a novel vector system for the transformation of E.huxleyi was designed.It contained fragments of promoter and terminator sequences of E.huxleyi endogenic fucoxanthin chlorophyll a/c-binding protein gene“fcp”and harbored EhV-99B1 spt gene.The resultant recombinant transformation vectors pEhux-I-spt and pEhux-II were co-transferred into E.huxleyi BOF92 by electroporation.Transformants were obtained upon glufosinate-ammonium selection,and confirmed by Southern hybridization,genome PCR,qRT-PCR and Western blot screening of spt gene,which indicated that spt gene was integrated into the nuclear genome and was expressed at the mRNA and protein levels.The expression of the viral spt gene led to differences in lipid compositions analyzed using thin-layer chromatography(TLC).The results present the genetic transformation system for E.huxleyi,providing additional genetic resource with potential for exploring basic biological questions such as the virus-host interactions.

Collusion detector based on G-N algorithm for trust model

In the open network environment, malicious attacks to the trust model have become increasingly serious. Compared with single node attacks, collusion attacks do more harm to the trust model. To solve this problem, a collusion detector based on the GN algorithm for the trust evaluation model is proposed in the open Internet environment. By analyzing the behavioral characteristics of collusion groups, the concept of flatting is defined and the G-N community mining algorithm is used to divide suspicious communities. On this basis, a collusion community detector method is proposed based on the breaking strength of suspicious communities. Simulation results show that the model has high recognition accuracy in identifying collusion nodes, so as to effectively defend against malicious attacks of collusion nodes.

Blockade of the deubiquitinating enzyme USP48 degrades oncogenic HMGA2 and inhibits colorectal cancer invasion and metastasis

HMGA2,a pivotal transcription factor,functions as a versatile regulator implicated in the progression of diverse aggressive malignancies.In this study,mass spectrometry was employed to identify ubiquitin-specific proteases that potentially interact with HMGA2,and USP48 was identified as a deubiquitinating enzyme of HMGA2.The enforced expression of USP48 significantly increased HMGA2 protein levels by inhibiting its degradation,while the deprivation of USP48 promoted HMGA2 degradation,thereby suppressing tumor invasion and metastasis.We discovered that USP48 undergoes SUMOylation at lysine 258,which enhances its binding affinity to HMGA2.Through subsequent phenotypic screening of small molecules,we identified DUB-IN-2 as a remarkably potent pharmacological inhibitor of USP48.Interestingly,the small-molecule inhibitor targeting USP48 induces destabilization of HMGA2.Clinically,upregulation of USP48 or HMGA2 in cancerous tissues is indicative of poor prognosis for patients with colorectal cancer(CRC).Collectively,our study not only elucidates the regulatory mechanism of DUBs involved in HMGA2 stability and validates USP48 as a potential therapeutic target for CRC,but also identifies DUB-IN-2 as a potent inhibitor of USP48 and a promising candidate for CRC treatment.

Simultaneous detection of enterovirus-D68 and vaccine-related poliovirus 3 in the stool samples of a 5-month hospitalized child with acute respiratory disease:A case report

Human enterovirus(EV)infections can lead to various manifestations,with variable correlations between genotypes and symptoms.Human enterovirus D68(EV-D68)was considered to be associated with acute respiratory disease and acute flaccid myelitis.In this short report,both EV-D68 and poliovirus 3 were detected in the stool of a hospitalized 5-month child who presented with acute respiratory symptoms and who was recently vaccinated with oral polio vaccine(OPV),using a metatranscriptomic high-throughput sequencing method.The nearly full-length genome sequences with complete open reading frames of EV-D68 and poliovirus 3 were assembled.One previously-reported neurovirulence-related amino acid substitution(T860N)in the EV-D68 VP1 region was observed,but the patient showed no neurological symptoms.More attention should be paid to EV-D68,and continuous multiple syndrome-based surveillance on non-polio enterovirus is called for.

Robust Alcohol Soluble Polyurethane/Chitosan/Silk Sericin(APU/CS/SS)Nanofiber Scaffolds Toward Artificial Skin Extracellular Matrices via Microfluidic Blow‑Spinning

Skin regeneration is a matter of high concern since many individuals suffer from skin damage.To date,the concept of protein-based artificial skin scaffolds have been successfully applied and proven in skin regeneration.However,realizing a skin tissue scaffold with a skin-like extracellular matrix(ECM)that combines low price,good biocompatibility,excellent antibacterial properties,good cell adhesion,and strong mechanical properties is still a major challenge.In this study,inexpensive silk sericin(SS)protein-based artificial skin nanofiber scaffolds(NFSs)with excellent biological activity,no immune rejection,and high mechanical strength were fabricated via microfluidic blow-spinning(MBS).In particular,the as-prepared NFS was transformed from a random coil structure to aβ-sheet structure by using the MBS in high-speed shear chips to improve its stability and mechanical strength.Additionally,through in vitro and in vivo studies,it was shown that SS protein-based artificial skin NFSs possessed excellent antibacterial effects and degradability properties,as well as accelerated tissue granu-lation growth,effectively promoting full skin wound healing and skin regeneration for medical problems worldwide.Thus,this skin ECM-inspired NFS offers new perspectives for accelerating wound healing and tissue regeneration and provides potential applications for clinical medicine.

Practical N-alkylation via homogeneous iridium-catalyzed direct reductive amination

Direct reductive amination(DRA)is one of the most efficient methods for amine synthesis.Herein we report a practical homogeneous DRA procedure utilizing iridium catalysis.Applying simple,readily available and inexpensive PPh_(3)and alike ligands along with iridium at a low loading,aldehydes and ketones reductively coupled with primary and secondary amines to efficiently form structurally and functionally diverse amine products,including a set of drugs and compounds from late-stage manipulation.The reaction conditions were exceptionally mild and additive-free,in which oxygen,moisture,polar protic groups and multiple other functional groups were tolerated.For targeted products,this methodology is especially versatile for offering multiple possible synthetic options.The 10 gram-scale synthesis further demonstrated the potential and promise of this procedure in practical amine synthesis.DFT studies reveal an“outer-sphere”H-addition pathway,in whichπ-πinteractions and H-bonding play important roles.

Visualization of in vivo cell-cell contact in the present and in the past

Cells are specialized to perform diverse functions to support the development and homeostasis of a multicellular organism.Cell-cell contact can mediate important communications between cells to coordinate cellular activities,which are essential in multiple biological processes to maintain tissue structure and function(Armingol et al.,2021).In vivo cell-cell contact remains largely unexplored.Recently,Zhang et al.(2022)report a comprehensive toolbox to label ongoing cell-cell contact or to trace the historical cell-cell contact in vivo.

Evaluating the efficacy and cardiotoxicity of EGFR-TKI AC0010 with a novel multifunctional biosensor

Non-small cell lung cancer(NSCLC)is a leading cause of cancer mortality worldwide.Although epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs)have dramatically improved the life expectancy of patients with NSCLC,concerns about TKI-induced cardiotoxicities have increased.AC0010,a novel third-generation TKI,was developed to overcome drug resistance induced by EGFR-T790M mutation.However,the cardiotoxicity of AC0010 remains unclear.To evaluate the efficacy and cardiotoxicity of AC0010,we designed a novel multifunctional biosensor by integrating microelectrodes(MEs)and interdigital electrodes(IDEs)to comprehensively evaluate cell viability,electrophysiological activity,and morphological changes(beating of cardiomyocytes).The multifunctional biosensor can monitor AC0010-induced NSCLC inhibition and cardiotoxicity in a quantitative,label-free,noninvasive,and real-time manner.AC0010 was found to significantly inhibit NCI-H1975(EGFR-L858R/T790M mutation),while weak inhibition was found for A549(wild-type EGFR).Negligible inhibition was found in the viabilities of HFF-1(normal fibroblasts)and cardiomyocytes.With the multifunctional biosensor,we found that 10μM AC0010 significantly affected the extracellular field potential(EFP)and mechanical beating of cardiomyocytes.The amplitude of EFP continuously decreased after AC0010 treatment,while the interval decreased first and then increased.We analyzed the change in the systole time(ST)and diastole time(DT)within a beating interval and found that the DT and DT/beating interval rate decreased within 1 h after AC0010 treatment.This result probably indicated that the relaxation of cardiomyocytes was insufficient,which may further aggravate the dysfunction.Here,we found that AC0010 significantly inhibited EGFR-mutant NSCLC cells and impaired cardiomyocyte function at low concentrations(10μM).This is the first study in which the risk of AC0010-induced cardiotoxicity was evaluated.In addition,novel multifunctional biosensors can comprehensively evaluate the antitumor efficacy and cardiotoxicity of drugs and candidate compounds.

1:250万月球全月地质图

月球地质图系统表达了月壳表面地层、构造、岩性和年代学等地质方面的信息,反映了月球岩浆作用、撞击作用和火山活动等地质过程的演化.20世纪90年代以来,人类对月球的探索取得了巨大成就,深刻地拓展了我们对月球的认识.基于月球动力学演化历史,充分利用国内外探月数据和研究结果,世界第一幅全月1:250万地质图编制完成.在新的月球地质图中,基于月球动力学演化的认识更新了月球地质年表,表达了不同时代的撞击坑物质和盆地建造,以及17种岩石类型和14类构造要素.此图可为月球科学研究、探测规划和着陆点选址等提供重要的基础资料,为其他行星地质图的编制提供参考.

Anti-rutting performance evaluation of modified asphalt binders: A review

Asphalt pavement inevitably suffers rutting distress induced by repeated loads under high temperatures, which can be effectively alleviated by the modification of asphalt binders.This paper summarized the asphalt modifiers for enhancing the performance of asphalt pavement at high temperatures in terms of the modifier type, additive amount and improving effect. Then, the anti-rutting performance evaluation methods of asphalt binder were introduced with details, including the ring and ball(R&B) test, the dynamic viscosity test, the zero/low shear viscosity(ZSV/LSV) test, the dynamic shear rheometer(DSR) test,the repeated creep and recovery(RCR) test, and the multiple stress creep and recovery(MSCR) test. Furthermore, the sensitivity of the evaluation method to asphalt modifier was analyzed using the normalization method. It was found that the indicators from the MSCR test could clearly reveal the influence of asphalt modifiers on high temperature performance of asphalt binder. But it still had some limitations affecting the accuracy of evaluation results, such as the number of creep-recovery cycles, the stress level and the recovery time. In addition, according to the rutting resistance improvement ratio(RRIR),the styrene-butadiene-styrene(SBS) modifier performed better in improving the rutting resistance of asphalt binder, compared with other modifiers when added within the usual dosage range.

1:250万月球岩石类型图

人类对月表物质成分的科学认识始于20世纪60~70年代.大量的无人和载人月球探测获得了珍贵的历史数据.利用这些数据资料,美国地质勘探局编制了最早的一批月球地质图,但由于当时缺乏全面的月表物质成分探测数据,早期的月表地质单元划分多以形貌特征为依据而缺少成分约束. 20世纪90年代以来,新一轮的月球探测任务获取了全月球表面的物质成分探测数据,为开展月表物质成分编图提供了第一手资料.通过对月表物质成分分布信息的研究,本研究建立了月球内动力地质作用形成的岩石类型分类体系.基于GIS平台编制完成的1:250万月球岩石类型分布图及建立的月球物质成分数据库,为开展月球数字地质图编研和月球地质综合研究以及未来其他天体的编图工作奠定了基础.

H3K27me3 shapes DNA methylome by inhibiting UHRF1-mediated H3 ubiquitination

DNA methylation and histone lysine tri-methylation at H3K27(H3K27me3)are two chromatin modifications for transcriptional gene silencing,which play important roles in diverse biological processes,including cell fate determination and cell lineage commitment.These two marks are largely mutually exclusive and target distinct sets of genes in the mammalian genome.However,how H3K27me3 shapes the DNA methylome remains elusive.Here,we report that the loss of H3K27me3 modification leads to increased DNA methylation at previously marked H3K27me3 sites,indicating that H3K27me3 negatively regulates DNA methylation.Genome-wide analysis of H3 ubiquitination,essential for recruitment and activation of DNA methyltransferase DNMT1,reveals the absence of H3 ubiquitination at H3K27me3 marked nucleosomes.Moreover,loss of H3K27me3 modification induces an increase in H3K18 ubiquitination at the corresponding hyper-methylated loci.Importantly,we show that H3K27me3 directly inhibits UHRF1-mediated H3 ubiquitination toward nucleosomes in a defined biochemical assay.Taken together,our findings reveal a general mechanism for H3K27me3-mediated shaping of the mammalian DNA methylome via modulation of H3 ubiquitination.

A convenient immunochromatographic test strip for rapid detection of Scylla serrata reovirus

Scylla serrata reovirus （SsRV）, first discovered in Chinain 2004, is now known to be widespread in the mud crab（Scylla serrata） farming pond of China. （Chen et al.,2008）. Since there are no effective treatments currentlyavailable for this viral pathogen, early diagnosis is theonly way to prevent disease progression.

CRISPR/Cas9-mediated pou4f3 knockout induces defects in the development of the zebrafish inner ear

Objective:The zebrafish is an excellent model for studying gene function in auditory system development.Pou4f3 plays an important role in mouse hair cell formation.Here,we constructed apou4f3-knockoutTg(Brn3c:GFP)zebrafish to provide an efficient fluorescence-visualized model for studying the molecular mechanisms of ear development.Methods:Cas9/single guide RNAs targeting exon 2 ofpou4f3 were designed and injected into one-cell stage zebrafish embryos(G0 generation).The G0 generation were crossed withTg(Brn3c:GFP)zebrafish to obtainpou4f3-mutantTg(Brn3c:GFP)zebrafish.The targeting efficiency was detected by polymerase chain reaction amplification and Sanger sequencing.Zebrafish hair cells were observed by laser scanning confocal microscopyin vivo.The morphology of the otoliths and semicircular canals were analyzed.All animal experiments were approved by the Animal Care and Use Committee of Shandong Provincial Hospital,Cheeloo College of Medicine,Shandong University(approval No.2016-KY-040)on March 3,2016.Results:Thepou4f3-mutantTg(Brn3c:GFP)zebrafish line was successfully established.Fluorescence observation suggested that hair cell development was delayed inpou4f3-knockout zebrafish.Knockout ofpou4f3 also induced defects in the otoliths and semicircular canals and impaired ear function in zebrafish.Conclusion:A CRISPR/Cas9-mediatedpou4f3 mutantTg(Brn3c:GFP)zebrafish model was established for the first time to demonstrate the essential role ofpou4f3 in zebrafish ear development.Our study provides a highly efficient method for the establishment of a visualized model of gene knockout zebrafish and has the potential to allow high-throughput drug screening to explore therapeutics for related diseases.