We discovered two distinctive features in the mechanical properties of extruded Mg alloys containing a long-period stacking ordered(LPSO)phase,which are highly desirable for a new class of high-strength,lightweight ma...We discovered two distinctive features in the mechanical properties of extruded Mg alloys containing a long-period stacking ordered(LPSO)phase,which are highly desirable for a new class of high-strength,lightweight materials.First,the Mg/LPSO-extruded alloy shows greater elongation compared to other Mg solid-solution-extruded alloys when a certain high strength is required.Second,the simultaneous achievement of high strength and large elongation in the Mg/LPSO-extruded alloy enhances with a reduction in extrusion speed.In this study,the physical origins of these features were examined,focusing on how changes in the microstructure affect the mechanical properties of the extruded alloys.Our findings clarify that the LPSO phase contributes not only to increased strength but also to enhanced elongation through an increase in the work-hardening rate,a mechanism we termed aanisotropic mechanical property-induced ductilizationo(AMID).Until now,most efforts to improve the ductility of Mg materials have focused on achieving aisotropic mechanical propertieso via grain refinement.Based on our results,we propose an entirely opposite approach:increasing the elongation of Mg alloy by locally enhancing theiraanisotropic mechanical propertieso through the AMID mechanism.Computational analysis further suggests that reducing the diameter of Mg-worked grains should effectively improving elongation in Mg/LPSO alloys with a high volume fraction of Mg-worked grains.展开更多
Microbial consortia that catalyze chain elongation processes have been enriched using different selection strategies,for which the electron donor is an essential one.Propanol is an extraordinarily promising electron d...Microbial consortia that catalyze chain elongation processes have been enriched using different selection strategies,for which the electron donor is an essential one.Propanol is an extraordinarily promising electron donor because it can be generated from renewable resources,including lignocellulosic biomass and protein wastes.Here,propanol was proven in detail to be an efficient electron donor,enhancing the production of odd medium-chain carboxylates during chain elongation.By exploring various electron acceptors,reactor conditions,and electron donor/electron acceptor mol ratios,our study highlights that acetate is the most suitable electron acceptor for the production of both odd-and even-chain carboxylates.The optimal conditions for propanol-based chain elongation were 30℃ and pH 6,achieving 82.8%selectivity for odd-chain carboxylates.Another critical insight from our work is that a propanol/acetate mol ratio of 1:1 can minimize the inhibitory effect of propanol and maximize the yield of medium-chain carboxylates,with the highest concentration of n-heptanoate reaching 124.5 mmol C/L.This was further illustrated by 16S rRNA amplicon sequencing,which elucidated that the community composition and keystone species in a propanol-based reactor closely resembled that of the ethanol one.The dominant phylum of the propanol-based reactor,Firmicutes showed a significant positive correlation with the concentrations of n-caproate and n-valerate.Additionally,the co-occurrence of Clostridium sensu stricto 12 and Oscillibacter,known as typical chain elongators,was identified within the propanol-based reactor.These findings enhance our understanding of propanolbased chain elongation,offer guiding principles for reactor microbiota assembly,and support efficient odd medium-chain carboxylate production.展开更多
Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a...Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a comparative observation on the early hypocotyl development between two cultivars,‘SZQ’belonging to pak-choi(B.campestris ssp.chinensis var.communis)with longer hypocotyls,and‘WTC’belonging to Tacai(B.campestris L.ssp.chinensis var.rosularis)with shortter hypocotyls,and found that the difference in auxin biosynthesis might contribute to the varied hypocotyl phenotype between these two cultivars.By applying GWAS analysis using a total of 226 B.campestris accessions,we identified that the AT-Hook motif nuclear localized(AHL)gene BcAHL24-MF1 contributed to the natural variation in hypocotyl length.Functional variation of BcAHL24-MF1 was attributed to four haplotypes featuring four SNPs within the promoter region,of which Hap I accumulated more transcripts with shorter hypocotyls.Constitutive overexpression of BcAHL24-MF1 in B.campestris caused decreased hypocotyl length under light circumstances and even constant darkness,as BcAHL24-MF1 repressed the PIFmediated transcriptional activation of auxin biosynthesis genes BcYUC6-MF2 and BcYUC8-LF.Our research uncovered the important role of BcAHL24-MF1 in regulating light-triggered inhibition of hypocotyl elongation,therefore presenting a valuable genetic target for crop breeding.展开更多
Microbial chain elongation(CE),utilizing anaerobic fermentation for the synthesis of high-value medium chain fatty acids(MCFAs),merges as a promising strategy in resource sustainability.Recently,it has pivoted that th...Microbial chain elongation(CE),utilizing anaerobic fermentation for the synthesis of high-value medium chain fatty acids(MCFAs),merges as a promising strategy in resource sustainability.Recently,it has pivoted that the use of different types of additives or accelerantstowards enhancing the products yield and fermentation quality has got much attention,with carbon-based materials emerging as vital facilitators.Based on bibliometrics insights,this paper firstly commences with a comprehensive review of the past two decades’progress in applying carbon-based materials within anaerobic fermentation contexts.Subsequently,the recent advancements made by different research groups in order to enhance the performance of CE systemperformance are reviewed,with particular focus on the application,impact,and underlying mechanisms of carbon-based materials in expediting MCFAs biosynthesis via CE.Finally,the future research direction is prospected,aiming to inform innovative material design and sophisticated technological applications,as well as provide a reference for improving the efficiency of anaerobic fermentation of MCFAs using carbon-based material,thereby contributing to the broader discourse on enhancing sustainability and efficiency in bio-based processes.展开更多
Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and foun...Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.展开更多
Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes ...Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.展开更多
This study demonstrates the feasibility and effectiveness of utilizing native soils as a resource for inocula to produce n-caproate through the chain elongation(CE)platform,offering new insights into anaerobic soil pr...This study demonstrates the feasibility and effectiveness of utilizing native soils as a resource for inocula to produce n-caproate through the chain elongation(CE)platform,offering new insights into anaerobic soil processes.The results reveal that all five of the tested soil types exhibit CE activity when supplied with high concentrations of ethanol and acetate,highlighting the suitability of soil as an ideal source for n-caproate production.Compared with anaerobic sludge and pit mud,the native soil CE system exhibited higher selectivity(60.53%),specificity(82.32%),carbon distribution(60.00%),electron transfer efficiency(165.00%),and conductivity(0.59 ms∙cm^(-1)).Kinetic analysis further confirmed the superiority of soil in terms of a shorter lag time and higher yield.A microbial community analysis indicated a positive correlation between the relative abundances of Pseudomonas,Azotobacter,and Clostridium and n-caproate production.Moreover,metagenomics analysis revealed a higher abundance of functional genes in key microbial species,providing direct insights into the pathways involved in n-caproate formation,including in situ CO_(2)utilization,ethanol oxidation,fatty acid biosynthesis(FAB),and reverse beta-oxidation(RBO).The numerous functions in FAB and RBO are primarily associated with Pseudomonas,Clostridium,Rhodococcus,Stenotrophomonas,and Geobacter,suggesting that these genera may play roles that are involved or associated with the CE process.Overall,this innovative inoculation strategy offers an efficient microbial source for n-caproate production,underscoring the importance of considering CE activity in anaerobic soil microbial ecology and holding potential for significant economic and environmental benefits through soil consortia exploration.展开更多
The rapid elongation of rice(Oryza sativa)coleoptile is pivotal for the plant plumule to evade hypoxia stress induced by submergence,a condition often arising from overirrigation,ponding,rainstorms,or flooding.While b...The rapid elongation of rice(Oryza sativa)coleoptile is pivotal for the plant plumule to evade hypoxia stress induced by submergence,a condition often arising from overirrigation,ponding,rainstorms,or flooding.While brassinosteroids(BRs)are recognized for their diverse roles in plant growth and development,their influence on coleoptile elongation under hypoxic conditions remains largely unexplored.In this study,we demonstrate the significant requirement of BRs for coleoptile elongation in deep water.During coleoptile development,Glycogen Synthase Kinase3-Like Kinase2(GSK2),the central inhibitor of BR signaling in rice,undergoes substantial suppression in deep water but induction in air.In contrast,the dephosphorylated form of BRASSINAZOLE RESISTANT1(OsBZR1),representing the active form of the key BR signaling transcription factor,is induced in water but suppressed in air.Remarkably,the knockout of GSK3-like kinase genes significantly enhances coleoptile elongation in deep water,strongly indicating a vital contribution of BR response to hypoxia-stimulated coleoptile elongation.Transcriptome analysis uncovers both BR-associated and BR-independent hypoxia responses,implicating substance metabolism,redox reactions,abiotic stress responses,and crosstalk with other hormones in the regulation of BR-induced hypoxia responses.In summary,our findings suggest that rice plumules rapidly elongate coleoptiles through the activation of BR response in deep water,enabling them to escape from submergence-induced hypoxia stress.展开更多
High temperature-induced hypocotyl elongation is a typical thermomorphogenesis trait that may significantly affect early seedling growth and subsequent crop yield.The ambient temperature and endogenous auxin are two c...High temperature-induced hypocotyl elongation is a typical thermomorphogenesis trait that may significantly affect early seedling growth and subsequent crop yield.The ambient temperature and endogenous auxin are two critical factors that regulate hypocotyl growth.However,the mechanism of temperature and auxin integration in horticultural plants remains poorly understood.In this study,the roles of the basic helix-loop-helix transcription factor CsPIF4 in regulating auxin biosynthesis genes and the auxin content in the hypocotyl of cucumber(Cucumis sativus L.)seedlings under high temperature were investigated.qRT-PCR and in situ hybridization analysis revealed that expression of CsPIF4 was enhanced in the epidermis and vascular bundles in the hypocotyl of cucumber seedlings in response to high temperature.qRT-PCR and HPLC analysis showed that CsPIF4 positively regulated transcription of the auxin biosynthesis gene CsYUC8 and the auxin content in the hypocotyl under high temperature(35℃).The CRISPR/Cas9-mediated knockout of CsPIF4 resulted in a shorter hypocotyl compared with that of the wild type,together with decreased expression of CsYUC8 and lower auxin content in response to high temperature.Furthermore,biochemical assays showed that CsPIF4 could bind directly to the G-box motif of the CsYUC8 promoter and thereby activate CsYUC8 expression.These findings provide insight into the molecular mechanism of high temperature-mediated hypocotyl elongation in cucumber.展开更多
A mixed nitrate (NO_(3)^(–)) and ammonium (NH_(4)^(+)) supply can promote root growth in maize (Zea mays),however,the changes in root morphology and the related physiological mechanism under different N forms are sti...A mixed nitrate (NO_(3)^(–)) and ammonium (NH_(4)^(+)) supply can promote root growth in maize (Zea mays),however,the changes in root morphology and the related physiological mechanism under different N forms are still unclear.Here,maize seedlings were grown hydroponically with three N supplied in three different forms (NO_(3)^(–)only,75/25 NO_(3)^(–)/NH_(4)^(+)and NH_(4)^(+)only).Compared with sole NO_(3)^(–)or NH_(4)^(+),the mixed N supply increased the total root length of maize but did not affect the number of axial roots.The main reason was the increased total lateral root length,while the average lateral root (LR) length in each axle was only slightly increased.In addition,the average LR density of 2nd whorl crown root under mixed N was also increased.Compared with sole nitrate,mixed N could improve the N metabolism of roots (such as the N influx rate,nitrate reductase (NR) and glutamine synthase (GS)enzyme activities and total amino content of the roots).Experiments with exogenously added NR and GS inhibitors suggested that the increase in the average LR length under mixed N was related to the process of N assimilation,and whether the NR mediated NO synthesis participates in this process needs further exploration.Meanwhile,an investigation of the changes in root-shoot ratio and carbon (C) concentration showed that C transportation from shoots to roots may not be the key factor in mediating lateral root elongation,and the changes in the sugar concentration in roots further proved this conclusion.Furthermore,the synthesis and transportation of auxin in axial roots may play a key role in lateral root elongation,in which the expression of ZmPIN1B and ZmPIN9 may be involved in this pathway.This study preliminarily clarified the changes in root morphology and explored the possible physiological mechanism under a mixed N supply in maize,which may provide some theoretical basis for the cultivation of crop varieties with high N efficiency.展开更多
Using molecular dynamics(MD)simulations,this study explores the fluid properties of three polymer melts with the same number of entanglements,Z,achieved by adjusting the entanglement length Ne,while investigating the ...Using molecular dynamics(MD)simulations,this study explores the fluid properties of three polymer melts with the same number of entanglements,Z,achieved by adjusting the entanglement length Ne,while investigating the evolution of polymer melt conformation and entanglement under high-rate elongational flow.The identification of a master curve indicates consistent normalized linear viscoelastic behavior.Surprising findings regarding the steady-state viscosity at various elongational rates(Wi_(R)>4.7)for polymer melts with the same Z have been uncovered,challenging existing tube models.Nevertheless,the study demonstrates the potential for normalizing the steady-state elongational viscosity at high rates(Wi_(R)>4.7)by scaling with the square of the chain contour length.Additionally,the observed independence of viscosity on the elongational rate at high rates suggests that higher rates lead to a more significant alignment of polymer chains,a decrease in entanglement,and a stretching in contour length of polymer chains.Molecular-level tracking of tagged chains further supports the assumption of no entanglement under rapid elongation,emphasizing the need for further research on disentanglement in polymer melts subjected to high-rate elongational flow.These results carry significant implications for understanding and predicting the behavior of polymer melts under high-rate elongational flow conditions.展开更多
[Objective] The aim of this study was to prepare the recombination protein of rubber elongation factor and its polyclonal antibodies.[Method] The encoding gene of rubber elongation factor(REF)was amplified by RT-PCR,a...[Objective] The aim of this study was to prepare the recombination protein of rubber elongation factor and its polyclonal antibodies.[Method] The encoding gene of rubber elongation factor(REF)was amplified by RT-PCR,and cloned into the prokaryotic expression vector pDEST17 to transform into Escherichia coil BI2I-AI.The recombinant protein induced by L-Arabinose was purified by the affinity chromatography.As the immunogen,the recombination protein was used to immunize mice for preparing polyclonal antibodies,while ELISA and Western blot hybridization were used to detect the titers and specificity.[Result] The purified recombination protein of REF with high expression was used to immunize house mice for preparing polyclonal antibodies with high titer and specificity.The western blot hybridization showed that the antibody could recognize the natural REF from latex.[Conclusion] The recombination protein of REF was successfully obtained and the mouse anti REF antibody with high titer and specificity was prepared,which lays a basis for further studies on biological functions of rubber elongation factor and other membrane proteins in rubber particles.展开更多
Differences of gene expression between salinity_stressed and control rice ( Oryza sativa L. ssp. indica ) cultivar “Zhaiyeqing 8' were compared using differential display PCR (DD_PCR) technique. Sequence an...Differences of gene expression between salinity_stressed and control rice ( Oryza sativa L. ssp. indica ) cultivar “Zhaiyeqing 8' were compared using differential display PCR (DD_PCR) technique. Sequence analysis of one salt_inducible cDNA clone revealed that this clone represented a new member of rice translation elongation factor 1A (eEF1A) gene family and was tentatively named REF1A. Northern blot hybridization using REF1A fragment as a probe was performed to investigate the expression of rice translation elongation factor 1A gene in response to various environmental factors. It was observed that expression of the eEF1A gene in rice shoots was dramatically induced by salinity stress or exogenous application of abscisic acid (ABA). The induction of this gene by ABA stress occurred more quickly than that by salinity stress. In addition, expression of rice translation elongation factor 1A gene was also induced by drought (15% PEG6000), cold (4 ℃) or heat_shock (37 ℃) stresses. The results suggested that the induction of translation elongation factor 1A gene expression by environmental stresses might reflect the general adaptive response of rice plants to the adverse circumstances.展开更多
[Objective]The research aimed to discuss the tolerance of Salix matsudana to single or compound heavy metals and provide theoretical basis for renovating polluted soil by heavy metals with woody plants.[Method]Using r...[Objective]The research aimed to discuss the tolerance of Salix matsudana to single or compound heavy metals and provide theoretical basis for renovating polluted soil by heavy metals with woody plants.[Method]Using root elongation method,the effects of heavy metal Cu^2＋,Pb^2＋,Zn^2＋ and their mixed solution on the adventitious roots growth of S.matsudana cuttings were studied.[Result]The adventitious roots growth of S.matsudana cuttings was obviously affected by different concentrations of heavy metals solution.Adventitious roots of S.matsudana cuttings could not grow while the concentration of Cu^2＋ was higher than 15 mg/L,the mixture solution concentration was higher than 20 mg/L and Zn^2＋ concentration was higher than 30 mg/L.When the solution concentration reached 40 mg/L,adventitious roots of S.matsudana cuttings could grow only in Pb^2＋ treatment group.With the increasing of the solution concentration,the number of adventitious roots of S.matsudana cuttings gradually decreased.In 5 mg/L Zn^2＋ treatment group,the number of adventitious roots of S.matsudana cuttings was the most,the longest root length and average root length were the longest and the rooting rate was the highest.[Conclusion]The tolerance of S.matsudana to Pb^2＋ was strongest and its tolerance to Cu^2＋ was the weakest.The tolerance order of S.matsudana to three kinds of heavy metals and their mixed solution was as following：Pb^2＋〉Zn^2＋〉Cu^2＋＋Pb^2＋＋Zn^2＋〉Cu^2＋.展开更多
The main goal of this research was to increase the strength of Polylactic acid (PLA), an entirely biodegradable thermoplastic polyester, and an increase in elongation at the breaking point compared to neat PLA. To thi...The main goal of this research was to increase the strength of Polylactic acid (PLA), an entirely biodegradable thermoplastic polyester, and an increase in elongation at the breaking point compared to neat PLA. To this end, S1, S2, and S3 were melt blended with various percentages of Zeolite, Glycerol, White vinegar, green camphor, Eucalyptus, and Carom seed oils. Here, the addition of glycerol, eucalyptus, and carom seed oils demonstrated an average improvement in impact and tensile strength of 13.44% and 14.55% respectively. Zeolite and glycerol work together as binding agents to improve stress transfer in the matrix, which increases tensile and flexural modulus as well as toughness elongation (>10%). The addition of the aforementioned materials led to an increase in the glass transition temperature and melting temperature, according to further DSC investigation. The thermal stability increased gradually, according to TGA data.展开更多
According to LN?,theoretical&true elongation of tensile,and by adopting the increasing function of formulas with the derivation and analogy methods,the elongation formula of 0<(1+ε)^1/ε<e&0<ε^1/ε&...According to LN?,theoretical&true elongation of tensile,and by adopting the increasing function of formulas with the derivation and analogy methods,the elongation formula of 0<(1+ε)^1/ε<e&0<ε^1/ε<1&four convergences are deduced too whenε>1 and 0<ε<1.The inequalities of LNε<εand LN(1+ε)<εand LN(1+ε)>LNεare deduced ifε>1 and 0<ε<1 in material dynamics.Finally the conclusions of LNε<εand LNε<LN(1+ε)<εare deduced together ifε>1 and 0<ε<1.展开更多
Cotton fibers elongate rapidly after initiation of elongation, eventually leading to the deposit of a large amount of cellulose. To reveal features of cotton fiber cells at the fast elongation and the secondary cell w...Cotton fibers elongate rapidly after initiation of elongation, eventually leading to the deposit of a large amount of cellulose. To reveal features of cotton fiber cells at the fast elongation and the secondary cell wall synthesis stages, we compared the respective transcriptomes and metabolite profiles. Comparative analysis of transcriptomes by cDNA array identified 633 genes that were differentially regulated during fiber development. Principal component analysis （PCA） using expressed genes as variables divided fiber samples into four groups, which are diagnostic of developmental stages. Similar grouping results are also found if we use non-polar or polar metabolites as variables for PCA of developing fibers. Auxin signaling, wall-loosening and lipid metabolism are highly active during fiber elongation, whereas cellulose biosynthesis is predominant and many other metabolic pathways are downregulated at the secondary cell wall synthesis stage. Transcript and metabolite profiles and enzyme activities are consistent in demonstrating a specialization process of cotton fiber development toward cellulose synthesis. These data demonstrate that cotton fiber cell at a certain stage has its own unique feature, and developmental stages of cotton fiber cells can be distinguished by their transcript and metabolite profiles. During the secondary cell wall synthesis stage, metabolic pathways are streamed into cellulose synthesis.展开更多
A simplified model was proposed targeting at the isotropic high porosity metal materials with well distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for th...A simplified model was proposed targeting at the isotropic high porosity metal materials with well distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition. A simplified model was proposed targeting at the isotropic high porosity metal materials with well distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition.展开更多
The tumor selective over-expression of the human Hsp70 gene has been well documented in human tumors,linked to the poor prognosis,being refractory to chemo-and radio-therapies as well as the advanced stage of tumorous...The tumor selective over-expression of the human Hsp70 gene has been well documented in human tumors,linked to the poor prognosis,being refractory to chemo-and radio-therapies as well as the advanced stage of tumorous lesions in particular.However,both the nature and details of aberrations in the control of the Hsp70 expression in tumor remain enigmatic.By comparing various upstream segments of the Hsp70 gene for each''s ability to drive the luciferase reporter genes in the context of the tumor cell lines varying in their p53 status and an immortal normal liver cell line,we demonstrated in a great detail the defects in the control mechanisms at the both initiation and elongation levels of transcription being instrumental to the tumor selective profile of its expression.Our data should not only offer new insights into our understanding of the tumor specific over-expression of the human Hsp70 gene,but also paved the way for the rational utilization of the tumor selective mechanism with the Hsp70 at the central stage fortargeting the therapeutic gene expression to human tumors.展开更多
AIM: To assess the impact of eukaryotic elongation factor 1 alpha 2 (eEF1A2) on hepatocellular carcinoma (HCC) cell proliferation, apoptosis, migration and invasion, and determine the underlying mechanisms.METHODS: eE...AIM: To assess the impact of eukaryotic elongation factor 1 alpha 2 (eEF1A2) on hepatocellular carcinoma (HCC) cell proliferation, apoptosis, migration and invasion, and determine the underlying mechanisms.METHODS: eEF1A2 levels were detected in 62 HCC tissue samples and paired pericarcinomatous specimens, and the human HCC cell lines SK-HEP-1, HepG2 and BEF-7402, by real-time PCR and immunohistochemistry. Experimental groups included eEF1A2 silencing in BEL-7402 cells with lentivirus eEF1A2-shRNA (KD group) and eEF1A2 overexpression in SK-HEP-1 cells with eEF1A2 plasmid (OE group). Non-transfected cells (control group) and lentivirus-based empty vector transfected cells (NC group) were considered control groups. Cell proliferation (MTT and colony formation assays), apoptosis (Annexin V-APC assay), cell cycle (DNA ploidy assay), and migration and invasion (Transwell assays) were assessed. Protein levels of PI3K/Akt/NF-κB signaling effectors were evaluated by Western blot.RESULTS: eEF1A2 mRNA and protein levels were significantly higher in HCC cancer tissue samples than in paired pericarcinomatous and normal specimens. SK-HEP-1 cells showed lower eEF1A2 mRNA levels; HepG2 and BEL-7402 cells showed higher eEF1A2 mRNA levels, with BEL-7402 cells displaying the highest amount. Efficient eEF1A2 silencing resulted in reduced cell proliferation, migration and invasion, increased apoptosis, and induced cell cycle arrest. The PI3K/Akt/NF-κB signaling pathway was notably inhibited. Inversely, eEF1A2 overexpression resulted in promoted cell proliferation, migration and invasion.CONCLUSION: eEF1A2, highly expressed in HCC, is a potential oncogene. Its silencing significantly decreases HCC tumorigenesis, likely by inhibiting PI3K/Akt/NF-κB signaling.展开更多
基金supported by the Japan Science and Technology Agency(JST),CREST(grant number JPMJCR2094)。
文摘We discovered two distinctive features in the mechanical properties of extruded Mg alloys containing a long-period stacking ordered(LPSO)phase,which are highly desirable for a new class of high-strength,lightweight materials.First,the Mg/LPSO-extruded alloy shows greater elongation compared to other Mg solid-solution-extruded alloys when a certain high strength is required.Second,the simultaneous achievement of high strength and large elongation in the Mg/LPSO-extruded alloy enhances with a reduction in extrusion speed.In this study,the physical origins of these features were examined,focusing on how changes in the microstructure affect the mechanical properties of the extruded alloys.Our findings clarify that the LPSO phase contributes not only to increased strength but also to enhanced elongation through an increase in the work-hardening rate,a mechanism we termed aanisotropic mechanical property-induced ductilizationo(AMID).Until now,most efforts to improve the ductility of Mg materials have focused on achieving aisotropic mechanical propertieso via grain refinement.Based on our results,we propose an entirely opposite approach:increasing the elongation of Mg alloy by locally enhancing theiraanisotropic mechanical propertieso through the AMID mechanism.Computational analysis further suggests that reducing the diameter of Mg-worked grains should effectively improving elongation in Mg/LPSO alloys with a high volume fraction of Mg-worked grains.
基金supported by the National Key R&D Program of China(No.2022YFC2105301)the National Natural Science Foundation of China(No.52270096).
文摘Microbial consortia that catalyze chain elongation processes have been enriched using different selection strategies,for which the electron donor is an essential one.Propanol is an extraordinarily promising electron donor because it can be generated from renewable resources,including lignocellulosic biomass and protein wastes.Here,propanol was proven in detail to be an efficient electron donor,enhancing the production of odd medium-chain carboxylates during chain elongation.By exploring various electron acceptors,reactor conditions,and electron donor/electron acceptor mol ratios,our study highlights that acetate is the most suitable electron acceptor for the production of both odd-and even-chain carboxylates.The optimal conditions for propanol-based chain elongation were 30℃ and pH 6,achieving 82.8%selectivity for odd-chain carboxylates.Another critical insight from our work is that a propanol/acetate mol ratio of 1:1 can minimize the inhibitory effect of propanol and maximize the yield of medium-chain carboxylates,with the highest concentration of n-heptanoate reaching 124.5 mmol C/L.This was further illustrated by 16S rRNA amplicon sequencing,which elucidated that the community composition and keystone species in a propanol-based reactor closely resembled that of the ethanol one.The dominant phylum of the propanol-based reactor,Firmicutes showed a significant positive correlation with the concentrations of n-caproate and n-valerate.Additionally,the co-occurrence of Clostridium sensu stricto 12 and Oscillibacter,known as typical chain elongators,was identified within the propanol-based reactor.These findings enhance our understanding of propanolbased chain elongation,offer guiding principles for reactor microbiota assembly,and support efficient odd medium-chain carboxylate production.
基金supported by grants from the Key R and D Program of Zhejiang(Grant Nos.2022C02032 and 2022C02030)the SanNong JiuFang Science and Technology Cooperation Project of Zhejiang Province(Grant No.2023SNJF008)+1 种基金the Grand Science and Technology Special Project of Zhejiang Province(Grant No.2021C02065)the Science and Technology Plan Project of Jiaxing(Grant No.2023AZ11002).
文摘Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a comparative observation on the early hypocotyl development between two cultivars,‘SZQ’belonging to pak-choi(B.campestris ssp.chinensis var.communis)with longer hypocotyls,and‘WTC’belonging to Tacai(B.campestris L.ssp.chinensis var.rosularis)with shortter hypocotyls,and found that the difference in auxin biosynthesis might contribute to the varied hypocotyl phenotype between these two cultivars.By applying GWAS analysis using a total of 226 B.campestris accessions,we identified that the AT-Hook motif nuclear localized(AHL)gene BcAHL24-MF1 contributed to the natural variation in hypocotyl length.Functional variation of BcAHL24-MF1 was attributed to four haplotypes featuring four SNPs within the promoter region,of which Hap I accumulated more transcripts with shorter hypocotyls.Constitutive overexpression of BcAHL24-MF1 in B.campestris caused decreased hypocotyl length under light circumstances and even constant darkness,as BcAHL24-MF1 repressed the PIFmediated transcriptional activation of auxin biosynthesis genes BcYUC6-MF2 and BcYUC8-LF.Our research uncovered the important role of BcAHL24-MF1 in regulating light-triggered inhibition of hypocotyl elongation,therefore presenting a valuable genetic target for crop breeding.
基金financially supported by the National Key R&D Program of China(No.2019YFC1906600)the National Natural Science Foundation of China(No.52000132).
文摘Microbial chain elongation(CE),utilizing anaerobic fermentation for the synthesis of high-value medium chain fatty acids(MCFAs),merges as a promising strategy in resource sustainability.Recently,it has pivoted that the use of different types of additives or accelerantstowards enhancing the products yield and fermentation quality has got much attention,with carbon-based materials emerging as vital facilitators.Based on bibliometrics insights,this paper firstly commences with a comprehensive review of the past two decades’progress in applying carbon-based materials within anaerobic fermentation contexts.Subsequently,the recent advancements made by different research groups in order to enhance the performance of CE systemperformance are reviewed,with particular focus on the application,impact,and underlying mechanisms of carbon-based materials in expediting MCFAs biosynthesis via CE.Finally,the future research direction is prospected,aiming to inform innovative material design and sophisticated technological applications,as well as provide a reference for improving the efficiency of anaerobic fermentation of MCFAs using carbon-based material,thereby contributing to the broader discourse on enhancing sustainability and efficiency in bio-based processes.
基金supported by the National Natural Science Foundation of China,Nos.31730031,32130060the National Natural Science Foundation of China,No.31971276(to JH)+1 种基金the Natural Science Foundation of Jiangsu Province,No.BK20202013(to XG)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Major Program),No.19KJA320005(to JH)。
文摘Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.
基金supported by the National Natural Science Foundation of China (32170367 and 32000146)the Fundamental Research Funds for the Central Universities, China (2021TS066 and GK202103063)the Excellent Graduate Training Program of Shaanxi Normal University, China (LHRCCX23181).
文摘Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.
基金supported by the National Natural Science Foundation of China(52000132 and 51978201)Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(HC202241)the Fundamental Research Funds for the Central Universities.
文摘This study demonstrates the feasibility and effectiveness of utilizing native soils as a resource for inocula to produce n-caproate through the chain elongation(CE)platform,offering new insights into anaerobic soil processes.The results reveal that all five of the tested soil types exhibit CE activity when supplied with high concentrations of ethanol and acetate,highlighting the suitability of soil as an ideal source for n-caproate production.Compared with anaerobic sludge and pit mud,the native soil CE system exhibited higher selectivity(60.53%),specificity(82.32%),carbon distribution(60.00%),electron transfer efficiency(165.00%),and conductivity(0.59 ms∙cm^(-1)).Kinetic analysis further confirmed the superiority of soil in terms of a shorter lag time and higher yield.A microbial community analysis indicated a positive correlation between the relative abundances of Pseudomonas,Azotobacter,and Clostridium and n-caproate production.Moreover,metagenomics analysis revealed a higher abundance of functional genes in key microbial species,providing direct insights into the pathways involved in n-caproate formation,including in situ CO_(2)utilization,ethanol oxidation,fatty acid biosynthesis(FAB),and reverse beta-oxidation(RBO).The numerous functions in FAB and RBO are primarily associated with Pseudomonas,Clostridium,Rhodococcus,Stenotrophomonas,and Geobacter,suggesting that these genera may play roles that are involved or associated with the CE process.Overall,this innovative inoculation strategy offers an efficient microbial source for n-caproate production,underscoring the importance of considering CE activity in anaerobic soil microbial ecology and holding potential for significant economic and environmental benefits through soil consortia exploration.
基金supported by STI 2030–Major Projects (2023ZD0407101)National Key Research and Development Program of China (2022YFD1201700)+1 种基金National Natural Science Foundation (U21A20208,32201704)Innovation Program of CAAS。
文摘The rapid elongation of rice(Oryza sativa)coleoptile is pivotal for the plant plumule to evade hypoxia stress induced by submergence,a condition often arising from overirrigation,ponding,rainstorms,or flooding.While brassinosteroids(BRs)are recognized for their diverse roles in plant growth and development,their influence on coleoptile elongation under hypoxic conditions remains largely unexplored.In this study,we demonstrate the significant requirement of BRs for coleoptile elongation in deep water.During coleoptile development,Glycogen Synthase Kinase3-Like Kinase2(GSK2),the central inhibitor of BR signaling in rice,undergoes substantial suppression in deep water but induction in air.In contrast,the dephosphorylated form of BRASSINAZOLE RESISTANT1(OsBZR1),representing the active form of the key BR signaling transcription factor,is induced in water but suppressed in air.Remarkably,the knockout of GSK3-like kinase genes significantly enhances coleoptile elongation in deep water,strongly indicating a vital contribution of BR response to hypoxia-stimulated coleoptile elongation.Transcriptome analysis uncovers both BR-associated and BR-independent hypoxia responses,implicating substance metabolism,redox reactions,abiotic stress responses,and crosstalk with other hormones in the regulation of BR-induced hypoxia responses.In summary,our findings suggest that rice plumules rapidly elongate coleoptiles through the activation of BR response in deep water,enabling them to escape from submergence-induced hypoxia stress.
基金the China Postdoctoral Science Foundation(Grant No.2021M703530)the National Natural Science Foundation of China(Grant No.31972398).
文摘High temperature-induced hypocotyl elongation is a typical thermomorphogenesis trait that may significantly affect early seedling growth and subsequent crop yield.The ambient temperature and endogenous auxin are two critical factors that regulate hypocotyl growth.However,the mechanism of temperature and auxin integration in horticultural plants remains poorly understood.In this study,the roles of the basic helix-loop-helix transcription factor CsPIF4 in regulating auxin biosynthesis genes and the auxin content in the hypocotyl of cucumber(Cucumis sativus L.)seedlings under high temperature were investigated.qRT-PCR and in situ hybridization analysis revealed that expression of CsPIF4 was enhanced in the epidermis and vascular bundles in the hypocotyl of cucumber seedlings in response to high temperature.qRT-PCR and HPLC analysis showed that CsPIF4 positively regulated transcription of the auxin biosynthesis gene CsYUC8 and the auxin content in the hypocotyl under high temperature(35℃).The CRISPR/Cas9-mediated knockout of CsPIF4 resulted in a shorter hypocotyl compared with that of the wild type,together with decreased expression of CsYUC8 and lower auxin content in response to high temperature.Furthermore,biochemical assays showed that CsPIF4 could bind directly to the G-box motif of the CsYUC8 promoter and thereby activate CsYUC8 expression.These findings provide insight into the molecular mechanism of high temperature-mediated hypocotyl elongation in cucumber.
基金supported by the National Natural Science Foundation of China(31421092)the Central Publicinterest Scientific Institution Basal Research Fund,China(1610232023023)。
文摘A mixed nitrate (NO_(3)^(–)) and ammonium (NH_(4)^(+)) supply can promote root growth in maize (Zea mays),however,the changes in root morphology and the related physiological mechanism under different N forms are still unclear.Here,maize seedlings were grown hydroponically with three N supplied in three different forms (NO_(3)^(–)only,75/25 NO_(3)^(–)/NH_(4)^(+)and NH_(4)^(+)only).Compared with sole NO_(3)^(–)or NH_(4)^(+),the mixed N supply increased the total root length of maize but did not affect the number of axial roots.The main reason was the increased total lateral root length,while the average lateral root (LR) length in each axle was only slightly increased.In addition,the average LR density of 2nd whorl crown root under mixed N was also increased.Compared with sole nitrate,mixed N could improve the N metabolism of roots (such as the N influx rate,nitrate reductase (NR) and glutamine synthase (GS)enzyme activities and total amino content of the roots).Experiments with exogenously added NR and GS inhibitors suggested that the increase in the average LR length under mixed N was related to the process of N assimilation,and whether the NR mediated NO synthesis participates in this process needs further exploration.Meanwhile,an investigation of the changes in root-shoot ratio and carbon (C) concentration showed that C transportation from shoots to roots may not be the key factor in mediating lateral root elongation,and the changes in the sugar concentration in roots further proved this conclusion.Furthermore,the synthesis and transportation of auxin in axial roots may play a key role in lateral root elongation,in which the expression of ZmPIN1B and ZmPIN9 may be involved in this pathway.This study preliminarily clarified the changes in root morphology and explored the possible physiological mechanism under a mixed N supply in maize,which may provide some theoretical basis for the cultivation of crop varieties with high N efficiency.
基金supported by the National Key R&D Program of China(Nos.2020YFA0713601 and 2023YFA1008800)the National Natural Science Foundation of China(Nos.22341304,22341303,22103079 and 22073092)the Cooperation Project between Jilin Province and CAS(No.2023SYHZ0003).
文摘Using molecular dynamics(MD)simulations,this study explores the fluid properties of three polymer melts with the same number of entanglements,Z,achieved by adjusting the entanglement length Ne,while investigating the evolution of polymer melt conformation and entanglement under high-rate elongational flow.The identification of a master curve indicates consistent normalized linear viscoelastic behavior.Surprising findings regarding the steady-state viscosity at various elongational rates(Wi_(R)>4.7)for polymer melts with the same Z have been uncovered,challenging existing tube models.Nevertheless,the study demonstrates the potential for normalizing the steady-state elongational viscosity at high rates(Wi_(R)>4.7)by scaling with the square of the chain contour length.Additionally,the observed independence of viscosity on the elongational rate at high rates suggests that higher rates lead to a more significant alignment of polymer chains,a decrease in entanglement,and a stretching in contour length of polymer chains.Molecular-level tracking of tagged chains further supports the assumption of no entanglement under rapid elongation,emphasizing the need for further research on disentanglement in polymer melts subjected to high-rate elongational flow.These results carry significant implications for understanding and predicting the behavior of polymer melts under high-rate elongational flow conditions.
基金Supported by the National Natural Science Foundation(30460021)the National Nonprofit Institute Research Grant of CATAS-ITBB(ITB-BZD0717)~~
文摘[Objective] The aim of this study was to prepare the recombination protein of rubber elongation factor and its polyclonal antibodies.[Method] The encoding gene of rubber elongation factor(REF)was amplified by RT-PCR,and cloned into the prokaryotic expression vector pDEST17 to transform into Escherichia coil BI2I-AI.The recombinant protein induced by L-Arabinose was purified by the affinity chromatography.As the immunogen,the recombination protein was used to immunize mice for preparing polyclonal antibodies,while ELISA and Western blot hybridization were used to detect the titers and specificity.[Result] The purified recombination protein of REF with high expression was used to immunize house mice for preparing polyclonal antibodies with high titer and specificity.The western blot hybridization showed that the antibody could recognize the natural REF from latex.[Conclusion] The recombination protein of REF was successfully obtained and the mouse anti REF antibody with high titer and specificity was prepared,which lays a basis for further studies on biological functions of rubber elongation factor and other membrane proteins in rubber particles.
文摘Differences of gene expression between salinity_stressed and control rice ( Oryza sativa L. ssp. indica ) cultivar “Zhaiyeqing 8' were compared using differential display PCR (DD_PCR) technique. Sequence analysis of one salt_inducible cDNA clone revealed that this clone represented a new member of rice translation elongation factor 1A (eEF1A) gene family and was tentatively named REF1A. Northern blot hybridization using REF1A fragment as a probe was performed to investigate the expression of rice translation elongation factor 1A gene in response to various environmental factors. It was observed that expression of the eEF1A gene in rice shoots was dramatically induced by salinity stress or exogenous application of abscisic acid (ABA). The induction of this gene by ABA stress occurred more quickly than that by salinity stress. In addition, expression of rice translation elongation factor 1A gene was also induced by drought (15% PEG6000), cold (4 ℃) or heat_shock (37 ℃) stresses. The results suggested that the induction of translation elongation factor 1A gene expression by environmental stresses might reflect the general adaptive response of rice plants to the adverse circumstances.
基金Supported by Natural Science Foundation of Anhui University(KJ2007B120)Doctor Foundation Projects of Anhui Agricultural University (WD2006-12)~~
文摘[Objective]The research aimed to discuss the tolerance of Salix matsudana to single or compound heavy metals and provide theoretical basis for renovating polluted soil by heavy metals with woody plants.[Method]Using root elongation method,the effects of heavy metal Cu^2＋,Pb^2＋,Zn^2＋ and their mixed solution on the adventitious roots growth of S.matsudana cuttings were studied.[Result]The adventitious roots growth of S.matsudana cuttings was obviously affected by different concentrations of heavy metals solution.Adventitious roots of S.matsudana cuttings could not grow while the concentration of Cu^2＋ was higher than 15 mg/L,the mixture solution concentration was higher than 20 mg/L and Zn^2＋ concentration was higher than 30 mg/L.When the solution concentration reached 40 mg/L,adventitious roots of S.matsudana cuttings could grow only in Pb^2＋ treatment group.With the increasing of the solution concentration,the number of adventitious roots of S.matsudana cuttings gradually decreased.In 5 mg/L Zn^2＋ treatment group,the number of adventitious roots of S.matsudana cuttings was the most,the longest root length and average root length were the longest and the rooting rate was the highest.[Conclusion]The tolerance of S.matsudana to Pb^2＋ was strongest and its tolerance to Cu^2＋ was the weakest.The tolerance order of S.matsudana to three kinds of heavy metals and their mixed solution was as following：Pb^2＋〉Zn^2＋〉Cu^2＋＋Pb^2＋＋Zn^2＋〉Cu^2＋.
文摘The main goal of this research was to increase the strength of Polylactic acid (PLA), an entirely biodegradable thermoplastic polyester, and an increase in elongation at the breaking point compared to neat PLA. To this end, S1, S2, and S3 were melt blended with various percentages of Zeolite, Glycerol, White vinegar, green camphor, Eucalyptus, and Carom seed oils. Here, the addition of glycerol, eucalyptus, and carom seed oils demonstrated an average improvement in impact and tensile strength of 13.44% and 14.55% respectively. Zeolite and glycerol work together as binding agents to improve stress transfer in the matrix, which increases tensile and flexural modulus as well as toughness elongation (>10%). The addition of the aforementioned materials led to an increase in the glass transition temperature and melting temperature, according to further DSC investigation. The thermal stability increased gradually, according to TGA data.
基金KNRF(the Korea of National Research Foundation)under the Specified base program 96-0300-11-01-3.
文摘According to LN?,theoretical&true elongation of tensile,and by adopting the increasing function of formulas with the derivation and analogy methods,the elongation formula of 0<(1+ε)^1/ε<e&0<ε^1/ε<1&four convergences are deduced too whenε>1 and 0<ε<1.The inequalities of LNε<εand LN(1+ε)<εand LN(1+ε)>LNεare deduced ifε>1 and 0<ε<1 in material dynamics.Finally the conclusions of LNε<εand LNε<LN(1+ε)<εare deduced together ifε>1 and 0<ε<1.
文摘Cotton fibers elongate rapidly after initiation of elongation, eventually leading to the deposit of a large amount of cellulose. To reveal features of cotton fiber cells at the fast elongation and the secondary cell wall synthesis stages, we compared the respective transcriptomes and metabolite profiles. Comparative analysis of transcriptomes by cDNA array identified 633 genes that were differentially regulated during fiber development. Principal component analysis （PCA） using expressed genes as variables divided fiber samples into four groups, which are diagnostic of developmental stages. Similar grouping results are also found if we use non-polar or polar metabolites as variables for PCA of developing fibers. Auxin signaling, wall-loosening and lipid metabolism are highly active during fiber elongation, whereas cellulose biosynthesis is predominant and many other metabolic pathways are downregulated at the secondary cell wall synthesis stage. Transcript and metabolite profiles and enzyme activities are consistent in demonstrating a specialization process of cotton fiber development toward cellulose synthesis. These data demonstrate that cotton fiber cell at a certain stage has its own unique feature, and developmental stages of cotton fiber cells can be distinguished by their transcript and metabolite profiles. During the secondary cell wall synthesis stage, metabolic pathways are streamed into cellulose synthesis.
文摘A simplified model was proposed targeting at the isotropic high porosity metal materials with well distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition. A simplified model was proposed targeting at the isotropic high porosity metal materials with well distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition.
文摘The tumor selective over-expression of the human Hsp70 gene has been well documented in human tumors,linked to the poor prognosis,being refractory to chemo-and radio-therapies as well as the advanced stage of tumorous lesions in particular.However,both the nature and details of aberrations in the control of the Hsp70 expression in tumor remain enigmatic.By comparing various upstream segments of the Hsp70 gene for each''s ability to drive the luciferase reporter genes in the context of the tumor cell lines varying in their p53 status and an immortal normal liver cell line,we demonstrated in a great detail the defects in the control mechanisms at the both initiation and elongation levels of transcription being instrumental to the tumor selective profile of its expression.Our data should not only offer new insights into our understanding of the tumor specific over-expression of the human Hsp70 gene,but also paved the way for the rational utilization of the tumor selective mechanism with the Hsp70 at the central stage fortargeting the therapeutic gene expression to human tumors.
基金Supported by the Middle-Young Age Backbone Talent Cultivation Program of Fujian Health System,No.2013-ZQNJC-2Key Projects of Science and Technology Plan of Fujian Province,No.2014Y0009
文摘AIM: To assess the impact of eukaryotic elongation factor 1 alpha 2 (eEF1A2) on hepatocellular carcinoma (HCC) cell proliferation, apoptosis, migration and invasion, and determine the underlying mechanisms.METHODS: eEF1A2 levels were detected in 62 HCC tissue samples and paired pericarcinomatous specimens, and the human HCC cell lines SK-HEP-1, HepG2 and BEF-7402, by real-time PCR and immunohistochemistry. Experimental groups included eEF1A2 silencing in BEL-7402 cells with lentivirus eEF1A2-shRNA (KD group) and eEF1A2 overexpression in SK-HEP-1 cells with eEF1A2 plasmid (OE group). Non-transfected cells (control group) and lentivirus-based empty vector transfected cells (NC group) were considered control groups. Cell proliferation (MTT and colony formation assays), apoptosis (Annexin V-APC assay), cell cycle (DNA ploidy assay), and migration and invasion (Transwell assays) were assessed. Protein levels of PI3K/Akt/NF-κB signaling effectors were evaluated by Western blot.RESULTS: eEF1A2 mRNA and protein levels were significantly higher in HCC cancer tissue samples than in paired pericarcinomatous and normal specimens. SK-HEP-1 cells showed lower eEF1A2 mRNA levels; HepG2 and BEL-7402 cells showed higher eEF1A2 mRNA levels, with BEL-7402 cells displaying the highest amount. Efficient eEF1A2 silencing resulted in reduced cell proliferation, migration and invasion, increased apoptosis, and induced cell cycle arrest. The PI3K/Akt/NF-κB signaling pathway was notably inhibited. Inversely, eEF1A2 overexpression resulted in promoted cell proliferation, migration and invasion.CONCLUSION: eEF1A2, highly expressed in HCC, is a potential oncogene. Its silencing significantly decreases HCC tumorigenesis, likely by inhibiting PI3K/Akt/NF-κB signaling.
