The evolutionarily conserved mitogen-activated protein kinase(MAPK)cascades relay extracellular signals into cells,triggering a variety of cellular responses.We previously revealed NtMPK4 as a positive regulator of ni...The evolutionarily conserved mitogen-activated protein kinase(MAPK)cascades relay extracellular signals into cells,triggering a variety of cellular responses.We previously revealed NtMPK4 as a positive regulator of nicotine biosynthesis;however,its upstream regulation remains unclear.Here,we characterized a MAPK cascade,comprising NtMEKK1b,NtMPKK2a,and NtMPK4,that promotes nicotine biosynthesis.This signaling module transduces external cues,including jasmonate and pathogen elicitors such as flg22,into post-translational modifications that enhance transcriptional activity and pathway gene expression.NtMPKK2a physically interacts with and phosphorylates NtMPK4 in vivo,confirming its role as an upstream kinase.RNAi-mediated silencing of NtMPKK2a significantly reduced the expression of nicotine pathway genes and decreased nicotine accumulation,whereas induced-overexpression of NtMPKK2a upregulated nicotine pathway genes and increased nicotine contents in tobacco hairy roots.Overexpression of NtMPKK2a in tobacco cells enhanced the transactivation activity of a NIC2-locus Ethylene Response Factor NtERF221 on Putrescine N-methyltransferase(NtPMT)promotor,further supporting its role in promoting nicotine biosynthesis.Furthermore,we identified NtMEKK1b,a tobacco MEKK that interacts with NtMAPKK2a in yeast cells.Knock-down of NtMEKK1b in transgenic tobacco plants attenuated the expression of nicotine pathway genes and reduced nicotine contents,whereas induced-overexpression of NtMEKK1b upregulated gene expression and nicotine accumulation.Our findings uncover a previously uncharacterized MAPK cascade module,NtMEKK1b-NtMPKK2a-NtMPK4,that regulates nicotine biosynthesis,highlighting the importance of posttranslational regulation in nicotine biosynthesis.展开更多
The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tub...The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tubers is regulated remains poorly understood.In this study,we identified and functionally validated key transcription factors that regulate anthocyanin biosynthesis based on a comparative transcriptome and metabolome analysis of three D.alata cultivars with different colored tubers(dark purple,light purple,and white).The anthocyanin glycoside cyanidin-3-O-(2′′-O-glucosyl)glucoside was abundant during early tuber development,and we determined that its accumulation is regulated in opposite manners by two R2R3-MYB transcription factors:DaMYB75 and DaMYB56.Yeast two-hybrid and bimolecular fluorescence complementation assays in Nicotiana benthamiana and co-expression assays in D.alata demonstrated that DaMYB75 promotes anthocyanin biosynthesis by specifically activating the promoter of the late anthocyanin biosynthesis gene DaANS and enhancing its expression through an interaction with DabHLH72.By contrast,DaMYB56 is a negative regulator of anthocyanin biosynthesis that binds to the DaANS promoter together with DabHLH72.Furthermore,the methylation levels of the DaMYB75 promoter were significantly lower in purple tubers than in white tubers.These findings shed light on the regulation of anthocyanin biosynthesis by MYBs and provide the basis for genetically improving anthocyanin content in D.alata.展开更多
Iris domestica,a perennial herb of the Iridaceae family,is widely recognized for its rich isoflavone content and broad therapeutic properties.To elucidate the biosynthetic pathway of these medicinally significant comp...Iris domestica,a perennial herb of the Iridaceae family,is widely recognized for its rich isoflavone content and broad therapeutic properties.To elucidate the biosynthetic pathway of these medicinally significant compounds,we constructed a haplotype-resolved genome assembly of this species.Transcriptomic and metabolomic analyses revealed tissue-specific accumulation of isoflavone,particularly in rhizomes and roots.Functional characterization identified two candidate isoflavone synthase genes,among which IdIFS was confirmed to promote the biosynthesis of key compounds tectorigenin and irisflorentin.The high-quality genome assembly presented here provides a foundational resource for further research into the evolution,secondary metabolite,and environmental adaptation of I.domestica.展开更多
Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the bi...Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the biosynthetic pathway of saikosaponins,we identified two cytochrome P450 monooxygenases,CYP716A41 and CYP716Y4,in Bupleurum chinense.These enzymes catalyze the C-28 oxidation and C-16 hydroxylation of oleanane-type triterpene skeletons,respectively.The catalytic efficiency of CYP716A41 from a southern B.chinense variety was significantly higher than that from a northern variety.Molecular docking and mutagenesis experiments revealed that amino acid residues at sites 9 and 35 may contribute to this difference in catalytic efficiency.Additionally,under cold stress,the expression levels of both CYP450 genes and the saikosaponin contents in the leaves of southern varieties were significantly higher compared to those in northern varieties.The variation in the catalytic efficiency of CYP716A41 and the differential expression of the two CYP450 genes under cold stress during winter are associated with the differences in saikosaponin biosynthesis in the leaves of southern and northern B.chinense varieties.This is consistent with the distinct medicinal usage practices observed between southern and northern China.展开更多
Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent f...Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.展开更多
Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon ...Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.展开更多
It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,...It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).展开更多
Lignin is a significant secondary metabolite produced through the phenylpropanoid pathway.As a vital component of the plant cell wall,lignin affects various fruit characteristics,including size,seed quantity,and firmn...Lignin is a significant secondary metabolite produced through the phenylpropanoid pathway.As a vital component of the plant cell wall,lignin affects various fruit characteristics,including size,seed quantity,and firmness.In this study,we conducted comprehensive identification and phylogenetic analysis of 265 Caffeic acid O-methyltransferase(COMT)genes across ten different plant species,including Vaccinium corymbosum and four other Vaccinium species.The results reveal that VcCOMT38 is a promising structural gene for the biosynthesis of lignin in blueberry.An in vitro enzymatic assay of VcCOMT38 demonstrated that it is a special enzyme in the lignin biosynthesis pathway and prefers to use caffeic acid as a substrate over 5-hydroxyferulic acid.Transient overexpression and silencing of VcCOMT38 in Vaccinium corymbosum‘Northland’fruits demonstrated that VcCOMT38 participates in lignin biosynthesis and contributes to both an increased number of immature seeds and enhanced fruit firmness.The heterologous overexpression of VcCOMT38 in Nicotiana benthamiana revealed that this gene could increase the lignin content and the syringyl/guaiacyl(S/G)ratio,which determines the maximum monomer yield during lignin depolymerization.These results highlight VcCOMT38 as a crucial gene in lignin biosynthesis and its potential for improving lignin production in industry through genetically modified woody plants.展开更多
Flavonoids are crucial secondary metabolites widely distributed in plants,playing vital roles in diverse biological processes.Although the flavonoid biosynthesis pathway has been extensively characterized,the transcri...Flavonoids are crucial secondary metabolites widely distributed in plants,playing vital roles in diverse biological processes.Although the flavonoid biosynthesis pathway has been extensively characterized,the transcriptional regulatory mechanisms remain poorly understood.In this study,we identify the miR166–ATHB14-LIKE module comprising the miR166 and its target gene ATHB14-LIKE as a key regulator of flavonoid biosynthesis in soybean(Glycine max).Knockdown of miR166 or overexpression of ATHB14-LIKE upregulated multiple flavonoid biosynthesis genes,leading to increased flavonoid accumulation.Conversely,miR166 overexpression suppressed these genes and reduced flavonoid levels.We further show that ATHB14-LIKE directly activates specific flavonoid biosynthesis genes by binding to their promoters.Additionally,ATHB14-LIKE forms homodimers and heterodimers with homologous proteins to regulate downstream flavonoid biosynthesis genes.Together,our findings demonstrate that the miR166–ATHB14-LIKE module controls soybean flavonoid content by coordinating the expression of key biosynthetic genes.展开更多
Locust plagues result in significant agricultural and ecological damage,and the current dependence on broadspectrum chemical pesticides raises serious concerns regarding environmental sustainability and public health....Locust plagues result in significant agricultural and ecological damage,and the current dependence on broadspectrum chemical pesticides raises serious concerns regarding environmental sustainability and public health.In this study,we elucidated the biosynthetic pathway of the locust aggregation pheromone 4-vinylanisole(4VA).Through analysis of the crystal structure of the 4VPMT2-4VA-SAM complex,it was determined that 4-nitrophenol acts as a substrate analogue,effectively inhibiting 4VPMT enzyme activity and thereby preventing the formation of 4VA.This study revealed key enzymatic targets and lead inhibitors for intervention,establishing a molecular foundation for pheromone-based,environmentally sustainable locust control strategies and offering a viable alternative to reduce reliance on conventional chemical pesticides.展开更多
Proanthocyanidins(PAs)are a group of oligomeric flavonoids also known as condensed tannins.PAs in human diet have antioxidant and health-promoting effects.BSISTER(BS)promotes the accumulation of PAs,but its direct tar...Proanthocyanidins(PAs)are a group of oligomeric flavonoids also known as condensed tannins.PAs in human diet have antioxidant and health-promoting effects.BSISTER(BS)promotes the accumulation of PAs,but its direct target gene and regulation mechanism in PAs biosynthesis are not clear.Here,we reported VviBS1 and VviBS2 genes,which bind directly to the promoter of PA synthesis key genes VviANR(ANTHOCYANIDIN REDUCTASE)and VviLAR(LEUCOANTHOCYANIDIN REDUCTASE)and up-regulate their expression to promote the PAs biosynthesis in grapevine.VviBS1 and VviBS2 partially rescued the transparent testa phenotype of an Arabidopsis tt16 mutant.Overexpression of BS1 and BS2 in grapevine callus increased the content of PAs,as well as the expression of specific genes related to PA synthesis.VviBS1 and VviBS2 proteins bound directly to the promoter regions of the key PA synthesis genes VviANR1,VviANR2,and VviLAR1.Overexpression of VviBS1 and VviBS2 promotes VviANR1,VviANR2 and VviLAR1 expression and PAs biosynthesis.Some BS1-and BS2-interacting MADS-box proteins have an effect on PAs biosynthesis.This study provides insight into the regulatory mechanisms of PAs biosynthesis in grapevine,which could be effectively employed for metabolic engineering to increase PA content.展开更多
Flavonoids,abundant in the fruits,are pivotal to their growth,development,and storage.In addition,they have significant beneficial effects on human health.Consequently,research is increasingly concentrating on the reg...Flavonoids,abundant in the fruits,are pivotal to their growth,development,and storage.In addition,they have significant beneficial effects on human health.Consequently,research is increasingly concentrating on the regulatory mechanisms governing flavonoid biosynthesis in fruits.Phytohormones are involved in the regulation of flavonoid biosynthesis.The abscisic acid,ethylene,jasmonic acid,cytokinins,and brassinosteroids promote flavonoid biosynthesis,while auxin negatively regulates flavonoid biosynthesis.Subsequently,transcription factors from the MYB,bHLH,WRKY,NAC,and bZIP families are pivotal in regulating flavonoid biosynthesis.In addition,non-coding RNAs(microRNA and lncRNA)also participate in the regulation of flavonoids biosynthesis.MicroRNAs are generally believed to negatively regulate flavonoid metabolism in fruits,while lncRNAs have the opposite effect.Furthermore,the interactions between plant hormones,transcription factors,and non-coding RNAs in fruit flavonoid biosynthesis were analyzed.Ultimately,a foundational regulatory network for fruit flavonoid biosynthesis was hereby established.展开更多
Coating-free press-hardened steel(CF-PHS)had effectively tackled the challenge of high-temperature oxidation during processing through Cr-Si alloying strategy.However,it is equally essential to investigate its corrosi...Coating-free press-hardened steel(CF-PHS)had effectively tackled the challenge of high-temperature oxidation during processing through Cr-Si alloying strategy.However,it is equally essential to investigate its corrosion resistance and the role of the oxide scale in corrosion environments.The corrosion resistance of CF-PHS with and without oxide scale was comprehensively evaluated by analyzing electrochemical processes and corrosion products,as well as characterizing the corroded oxide scale features,while comparing it with commercial 22MnB5 steel.The results indicate that CF-PHS exhibits superior corrosion resistance compared to 22MnB5 steel and the presence of oxide scale may have a negative influence on short-time corrosion resistance.The ultra-thin oxide scale is unable to effectively and timely mitigate pit propagation during the rapid electrochemical tests.Conversely,during the prolonged corrosion process,the oxide scale can still function as the physical barrier to provide protective effects,making the corrosion process develop more slowly and evenly.展开更多
Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassi...Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassium fertilization interactively influence lignin biosynthesis in oil flax stems require further investigation.Therefore,this study aimed to enhance lodging resistance and increase grain yield in oil flax.We examined the interactive effects of different nitrogen (75,150,and 225 kg N ha^(–1)) and potassium (60 and 90 kg K_(2)O ha^(–1)) fertilizer rates on lignin metabolism,lodging resistance,and grain yield during the 2022 and 2023 growing seasons.Results indicated that nitrogen and potassium fertilizer levels and their interactions promoted lignin accumulation,improved lodging resistance,and increased grain yield.Compared to the control (CK),the75–150 kg N ha^(–1) combined with 60 kg K_(2)O ha^(–1) treatments significantly enhanced the activities of key lignin-synthesizing enzymes (tyrosine ammonia-lyase (TAL),phenylalanine ammonia-lyase (PAL),cinnamyl alcohol dehydrogenase (CAD),and peroxidase (POD)) and upregulated the expression of 4CL1 and F5H3 genes,leading to a 29.63–43.30%increase in lignin content,improved stem bending strength and lodging resistance index,and a 23.27–32.34%increase in grain yield.Correlation analysis revealed that nitrogen and potassium fertilizers positively regulated enzyme activities and gene expression related to lignin biosynthesis,thereby facilitating lignin accumulation and enhancing stem mechanical strength and lodging resistance.Positive correlations were observed among lignin-related enzyme activities,gene expression,lodging resistance traits,and grain yield.In summary,the application of 75–150 kg N ha^(–1) in conjunction with 60 kg K_(2)O ha^(–1)promoted lignin biosynthesis and accumulation,enhanced lodging resistance,and increased grain yield in oil flax grown in the dryland farming region of central Gansu,China.Furthermore,this treatment provides a technical basis for cultivating stress-tolerant and high-yield oil flax in arid regions.展开更多
Flower color is an essential trait in ornamental plant breeding. Lycoris longituba is a popular ornamental plant native to central eastern China. The decrease in anthocyanin accumulation causes L. longituba petal colo...Flower color is an essential trait in ornamental plant breeding. Lycoris longituba is a popular ornamental plant native to central eastern China. The decrease in anthocyanin accumulation causes L. longituba petal color fading during flower development, which considerably affects the ornamental value of L. longituba. However, mechanisms underlying anthocyanin biosynthesis inhibition during L. longituba petal development remain unclear. In this study, three LlDFR genes were confirmed to be involved in anthocyanin biosynthesis and LlDFRc exerted the strongest promoting effect on anthocyanin accumulation. According to the correlation analysis results, LlbHLH12 exhibited the strongest negative correlation with LlDFRc. Quantitative real-time PCR analysis showed that LlbHLH12 was highly expressed during the medium bud and full bloom stages of flower development. LlbHLH12 was identified as a member of subgroup XII of bHLH transcription factor family. Subcellular localization and transcriptional activation ability assay revealed that LlbHLH12 was located in the nucleus without transcriptional activation activity. Overexpression of LlbHLH12 in Nicotiana tabacum and L. longituba inhibited anthocyanin accumulation by suppressing the expression of anthocyanin biosynthetic pathway genes. Furthermore, yeast one-hybrid, dual-luciferase, and β-glucuronidase activity assays showed that LlbHLH12 directly bound to the promoters of LlPAL and LlDFRc and suppressed their expression to inhibit anthocyanin biosynthesis. Overall, our study identified a novel bHLH repressor negatively regulating anthocyanin biosynthesis and provided new insights into the molecular mechanisms underlying color fading in L. longituba petals.展开更多
Nitric oxide(NO)is a key vasodilator that regulates vascular pressure and blood flow.Tibetans have developed a"blunted"mechanism for regulating NO levels at high altitude,with GTP cyclohydrolase 1(GCH1)ident...Nitric oxide(NO)is a key vasodilator that regulates vascular pressure and blood flow.Tibetans have developed a"blunted"mechanism for regulating NO levels at high altitude,with GTP cyclohydrolase 1(GCH1)identified as a key candidate gene.Here,we present comprehensive genetic and functional analyses of GCH1,which exhibits strong Darwinian positive selection in Tibetans.We show that Tibetan-enriched GCH1 variants down-regulate its expression in the blood of Tibetans.Based on this observation,we generate the heterozygous Gch1 knockout(Gch1^(+/-))mouse model to simulate its downregulation in Tibetans.We find that under prolonged hypoxia,the Gch1^(+/-)mice have relatively higher blood NO and blood oxygen saturation levels compared with the wild-type(WT)controls,providing better oxygen supplies to the cardiovascular and pulmonary systems.Markedly,hypoxia-induced cardiac hypertrophy and pulmonary remodeling are significantly attenuated in the Gch1^(^(+/-))mice compared with the WT controls,likely due to the adaptive changes in molecular regulations related to metabolism,inflammation,circadian rhythm,extracellular matrix,and oxidative stress.This study sheds light on the role of GCH1 in regulating blood NO,contributing to the physiological adaptation of the cardiovascular and pulmonary systems in Tibetans at high altitude.展开更多
High-entropy oxides(HEOs)have emerged as a promising class of memristive materials,characterized by entropy-stabilized crystal structures,multivalent cation coordination,and tunable defect landscapes.These intrinsic f...High-entropy oxides(HEOs)have emerged as a promising class of memristive materials,characterized by entropy-stabilized crystal structures,multivalent cation coordination,and tunable defect landscapes.These intrinsic features enable forming-free resistive switching,multilevel conductance modulation,and synaptic plasticity,making HEOs attractive for neuromorphic computing.This review outlines recent progress in HEO-based memristors across materials engineering,switching mechanisms,and synaptic emulation.Particular attention is given to vacancy migration,phase transitions,and valence-state dynamics—mechanisms that underlie the switching behaviors observed in both amorphous and crystalline systems.Their relevance to neuromorphic functions such as short-term plasticity and spike-timing-dependent learning is also examined.While encouraging results have been achieved at the device level,challenges remain in conductance precision,variability control,and scalable integration.Addressing these demands a concerted effort across materials design,interface optimization,and task-aware modeling.With such integration,HEO memristors offer a compelling pathway toward energy-efficient and adaptable brain-inspired electronics.展开更多
Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic struct...Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.展开更多
Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its...Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.展开更多
Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity an...Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.展开更多
基金supported partially by the Kentucky Tobacco Research and Development Center(KTRDC),University of Kentucky.
文摘The evolutionarily conserved mitogen-activated protein kinase(MAPK)cascades relay extracellular signals into cells,triggering a variety of cellular responses.We previously revealed NtMPK4 as a positive regulator of nicotine biosynthesis;however,its upstream regulation remains unclear.Here,we characterized a MAPK cascade,comprising NtMEKK1b,NtMPKK2a,and NtMPK4,that promotes nicotine biosynthesis.This signaling module transduces external cues,including jasmonate and pathogen elicitors such as flg22,into post-translational modifications that enhance transcriptional activity and pathway gene expression.NtMPKK2a physically interacts with and phosphorylates NtMPK4 in vivo,confirming its role as an upstream kinase.RNAi-mediated silencing of NtMPKK2a significantly reduced the expression of nicotine pathway genes and decreased nicotine accumulation,whereas induced-overexpression of NtMPKK2a upregulated nicotine pathway genes and increased nicotine contents in tobacco hairy roots.Overexpression of NtMPKK2a in tobacco cells enhanced the transactivation activity of a NIC2-locus Ethylene Response Factor NtERF221 on Putrescine N-methyltransferase(NtPMT)promotor,further supporting its role in promoting nicotine biosynthesis.Furthermore,we identified NtMEKK1b,a tobacco MEKK that interacts with NtMAPKK2a in yeast cells.Knock-down of NtMEKK1b in transgenic tobacco plants attenuated the expression of nicotine pathway genes and reduced nicotine contents,whereas induced-overexpression of NtMEKK1b upregulated gene expression and nicotine accumulation.Our findings uncover a previously uncharacterized MAPK cascade module,NtMEKK1b-NtMPKK2a-NtMPK4,that regulates nicotine biosynthesis,highlighting the importance of posttranslational regulation in nicotine biosynthesis.
基金supported by the National Natural Science Foundation of China(32460767)Jiangxi Provincial Key Research and Development Program(20232BBF60007)Jiangxi Provincial Natural Science Foundation(20224BAB205024).
文摘The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tubers is regulated remains poorly understood.In this study,we identified and functionally validated key transcription factors that regulate anthocyanin biosynthesis based on a comparative transcriptome and metabolome analysis of three D.alata cultivars with different colored tubers(dark purple,light purple,and white).The anthocyanin glycoside cyanidin-3-O-(2′′-O-glucosyl)glucoside was abundant during early tuber development,and we determined that its accumulation is regulated in opposite manners by two R2R3-MYB transcription factors:DaMYB75 and DaMYB56.Yeast two-hybrid and bimolecular fluorescence complementation assays in Nicotiana benthamiana and co-expression assays in D.alata demonstrated that DaMYB75 promotes anthocyanin biosynthesis by specifically activating the promoter of the late anthocyanin biosynthesis gene DaANS and enhancing its expression through an interaction with DabHLH72.By contrast,DaMYB56 is a negative regulator of anthocyanin biosynthesis that binds to the DaANS promoter together with DabHLH72.Furthermore,the methylation levels of the DaMYB75 promoter were significantly lower in purple tubers than in white tubers.These findings shed light on the regulation of anthocyanin biosynthesis by MYBs and provide the basis for genetically improving anthocyanin content in D.alata.
文摘Iris domestica,a perennial herb of the Iridaceae family,is widely recognized for its rich isoflavone content and broad therapeutic properties.To elucidate the biosynthetic pathway of these medicinally significant compounds,we constructed a haplotype-resolved genome assembly of this species.Transcriptomic and metabolomic analyses revealed tissue-specific accumulation of isoflavone,particularly in rhizomes and roots.Functional characterization identified two candidate isoflavone synthase genes,among which IdIFS was confirmed to promote the biosynthesis of key compounds tectorigenin and irisflorentin.The high-quality genome assembly presented here provides a foundational resource for further research into the evolution,secondary metabolite,and environmental adaptation of I.domestica.
基金supported by CARS(CARS-21),the CAMS Innovation Fund for Medical Sciences(2021-I2M-1-032)the Science and Technology Department of Xizang(XZ202401ZY0020)+2 种基金the Science and Technology Department of Sichuan Province(2023YFH0044,2023YFH0018)the Sichuan Province Science Foundation for Distinguished Young Scholars(2022JDJQ0006)the Doctoral Fund of Southwest University of Science and Technology(19ZX7117,21ZX7116).
文摘Saikosaponins are the major pharmacologically active components in Bupleurum genus and exhibit significant application potential in multiple fields such as immune regulation and anti-tumor activity.To elucidate the biosynthetic pathway of saikosaponins,we identified two cytochrome P450 monooxygenases,CYP716A41 and CYP716Y4,in Bupleurum chinense.These enzymes catalyze the C-28 oxidation and C-16 hydroxylation of oleanane-type triterpene skeletons,respectively.The catalytic efficiency of CYP716A41 from a southern B.chinense variety was significantly higher than that from a northern variety.Molecular docking and mutagenesis experiments revealed that amino acid residues at sites 9 and 35 may contribute to this difference in catalytic efficiency.Additionally,under cold stress,the expression levels of both CYP450 genes and the saikosaponin contents in the leaves of southern varieties were significantly higher compared to those in northern varieties.The variation in the catalytic efficiency of CYP716A41 and the differential expression of the two CYP450 genes under cold stress during winter are associated with the differences in saikosaponin biosynthesis in the leaves of southern and northern B.chinense varieties.This is consistent with the distinct medicinal usage practices observed between southern and northern China.
基金Supported by the Natural Science Foundation of Shanxi Province(202203021221303)the Science and Technology Major Project of Shanxi Province(202005D121002)the Science and Technology Cooperation and Communication Project of Shanxi Province(202304041101016)。
文摘Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.
文摘Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.
文摘It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).
文摘Lignin is a significant secondary metabolite produced through the phenylpropanoid pathway.As a vital component of the plant cell wall,lignin affects various fruit characteristics,including size,seed quantity,and firmness.In this study,we conducted comprehensive identification and phylogenetic analysis of 265 Caffeic acid O-methyltransferase(COMT)genes across ten different plant species,including Vaccinium corymbosum and four other Vaccinium species.The results reveal that VcCOMT38 is a promising structural gene for the biosynthesis of lignin in blueberry.An in vitro enzymatic assay of VcCOMT38 demonstrated that it is a special enzyme in the lignin biosynthesis pathway and prefers to use caffeic acid as a substrate over 5-hydroxyferulic acid.Transient overexpression and silencing of VcCOMT38 in Vaccinium corymbosum‘Northland’fruits demonstrated that VcCOMT38 participates in lignin biosynthesis and contributes to both an increased number of immature seeds and enhanced fruit firmness.The heterologous overexpression of VcCOMT38 in Nicotiana benthamiana revealed that this gene could increase the lignin content and the syringyl/guaiacyl(S/G)ratio,which determines the maximum monomer yield during lignin depolymerization.These results highlight VcCOMT38 as a crucial gene in lignin biosynthesis and its potential for improving lignin production in industry through genetically modified woody plants.
基金the Projects of Science and Technology of Shanghai(22N11900400)Key Projects of Beijing Institute of Life Science and Technology(2024400CB0050)+1 种基金National Natural Science Foundation of China(32488102)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24030303)。
文摘Flavonoids are crucial secondary metabolites widely distributed in plants,playing vital roles in diverse biological processes.Although the flavonoid biosynthesis pathway has been extensively characterized,the transcriptional regulatory mechanisms remain poorly understood.In this study,we identify the miR166–ATHB14-LIKE module comprising the miR166 and its target gene ATHB14-LIKE as a key regulator of flavonoid biosynthesis in soybean(Glycine max).Knockdown of miR166 or overexpression of ATHB14-LIKE upregulated multiple flavonoid biosynthesis genes,leading to increased flavonoid accumulation.Conversely,miR166 overexpression suppressed these genes and reduced flavonoid levels.We further show that ATHB14-LIKE directly activates specific flavonoid biosynthesis genes by binding to their promoters.Additionally,ATHB14-LIKE forms homodimers and heterodimers with homologous proteins to regulate downstream flavonoid biosynthesis genes.Together,our findings demonstrate that the miR166–ATHB14-LIKE module controls soybean flavonoid content by coordinating the expression of key biosynthetic genes.
基金support of the National Natural Science Foundation of China(32472594).
文摘Locust plagues result in significant agricultural and ecological damage,and the current dependence on broadspectrum chemical pesticides raises serious concerns regarding environmental sustainability and public health.In this study,we elucidated the biosynthetic pathway of the locust aggregation pheromone 4-vinylanisole(4VA).Through analysis of the crystal structure of the 4VPMT2-4VA-SAM complex,it was determined that 4-nitrophenol acts as a substrate analogue,effectively inhibiting 4VPMT enzyme activity and thereby preventing the formation of 4VA.This study revealed key enzymatic targets and lead inhibitors for intervention,establishing a molecular foundation for pheromone-based,environmentally sustainable locust control strategies and offering a viable alternative to reduce reliance on conventional chemical pesticides.
基金funded by the Key R&D Program of Shaanxi province(Grant Nos.2023-ZDLNY-23 and 2023XCZX2-18)the National Key R&D Program of China(Grant No.2019YFD1001405).
文摘Proanthocyanidins(PAs)are a group of oligomeric flavonoids also known as condensed tannins.PAs in human diet have antioxidant and health-promoting effects.BSISTER(BS)promotes the accumulation of PAs,but its direct target gene and regulation mechanism in PAs biosynthesis are not clear.Here,we reported VviBS1 and VviBS2 genes,which bind directly to the promoter of PA synthesis key genes VviANR(ANTHOCYANIDIN REDUCTASE)and VviLAR(LEUCOANTHOCYANIDIN REDUCTASE)and up-regulate their expression to promote the PAs biosynthesis in grapevine.VviBS1 and VviBS2 partially rescued the transparent testa phenotype of an Arabidopsis tt16 mutant.Overexpression of BS1 and BS2 in grapevine callus increased the content of PAs,as well as the expression of specific genes related to PA synthesis.VviBS1 and VviBS2 proteins bound directly to the promoter regions of the key PA synthesis genes VviANR1,VviANR2,and VviLAR1.Overexpression of VviBS1 and VviBS2 promotes VviANR1,VviANR2 and VviLAR1 expression and PAs biosynthesis.Some BS1-and BS2-interacting MADS-box proteins have an effect on PAs biosynthesis.This study provides insight into the regulatory mechanisms of PAs biosynthesis in grapevine,which could be effectively employed for metabolic engineering to increase PA content.
基金supported by the China Agricultural Research System(Grant No.CARS-09)the Central Government Guiding Local Science and Technology Development Project(Grant No.YDZX2023029)the Gansu Planning Projects on Science and Technology(Grant No.23CXNJ0013).
文摘Flavonoids,abundant in the fruits,are pivotal to their growth,development,and storage.In addition,they have significant beneficial effects on human health.Consequently,research is increasingly concentrating on the regulatory mechanisms governing flavonoid biosynthesis in fruits.Phytohormones are involved in the regulation of flavonoid biosynthesis.The abscisic acid,ethylene,jasmonic acid,cytokinins,and brassinosteroids promote flavonoid biosynthesis,while auxin negatively regulates flavonoid biosynthesis.Subsequently,transcription factors from the MYB,bHLH,WRKY,NAC,and bZIP families are pivotal in regulating flavonoid biosynthesis.In addition,non-coding RNAs(microRNA and lncRNA)also participate in the regulation of flavonoids biosynthesis.MicroRNAs are generally believed to negatively regulate flavonoid metabolism in fruits,while lncRNAs have the opposite effect.Furthermore,the interactions between plant hormones,transcription factors,and non-coding RNAs in fruit flavonoid biosynthesis were analyzed.Ultimately,a foundational regulatory network for fruit flavonoid biosynthesis was hereby established.
基金supported by the National Natural Science Foundation of China(Grant Nos.U22A20106,52201112,and U22A20173)Fundamental Research Funds for the Central Universities(N25LJ002).
文摘Coating-free press-hardened steel(CF-PHS)had effectively tackled the challenge of high-temperature oxidation during processing through Cr-Si alloying strategy.However,it is equally essential to investigate its corrosion resistance and the role of the oxide scale in corrosion environments.The corrosion resistance of CF-PHS with and without oxide scale was comprehensively evaluated by analyzing electrochemical processes and corrosion products,as well as characterizing the corroded oxide scale features,while comparing it with commercial 22MnB5 steel.The results indicate that CF-PHS exhibits superior corrosion resistance compared to 22MnB5 steel and the presence of oxide scale may have a negative influence on short-time corrosion resistance.The ultra-thin oxide scale is unable to effectively and timely mitigate pit propagation during the rapid electrochemical tests.Conversely,during the prolonged corrosion process,the oxide scale can still function as the physical barrier to provide protective effects,making the corrosion process develop more slowly and evenly.
基金funded by the National Natural Science Foundation of China (31760363)the Earmarked Fund for CARS (CARS-14-1-16)+1 种基金the Gansu Education Science and Technology Innovation Industry Support Program,China (2021CYZC-38)the Gansu Provincial Key Laboratory of Arid Land Crop Science,Gansu Agricultural University,China (GSCS-2020-Z6)。
文摘Lodging is a major constraint limiting oil flax production efficiency in northern China.Crop lodging susceptibility is closely related to stem lignin content,and the regulatory mechanisms by which nitrogen and potassium fertilization interactively influence lignin biosynthesis in oil flax stems require further investigation.Therefore,this study aimed to enhance lodging resistance and increase grain yield in oil flax.We examined the interactive effects of different nitrogen (75,150,and 225 kg N ha^(–1)) and potassium (60 and 90 kg K_(2)O ha^(–1)) fertilizer rates on lignin metabolism,lodging resistance,and grain yield during the 2022 and 2023 growing seasons.Results indicated that nitrogen and potassium fertilizer levels and their interactions promoted lignin accumulation,improved lodging resistance,and increased grain yield.Compared to the control (CK),the75–150 kg N ha^(–1) combined with 60 kg K_(2)O ha^(–1) treatments significantly enhanced the activities of key lignin-synthesizing enzymes (tyrosine ammonia-lyase (TAL),phenylalanine ammonia-lyase (PAL),cinnamyl alcohol dehydrogenase (CAD),and peroxidase (POD)) and upregulated the expression of 4CL1 and F5H3 genes,leading to a 29.63–43.30%increase in lignin content,improved stem bending strength and lodging resistance index,and a 23.27–32.34%increase in grain yield.Correlation analysis revealed that nitrogen and potassium fertilizers positively regulated enzyme activities and gene expression related to lignin biosynthesis,thereby facilitating lignin accumulation and enhancing stem mechanical strength and lodging resistance.Positive correlations were observed among lignin-related enzyme activities,gene expression,lodging resistance traits,and grain yield.In summary,the application of 75–150 kg N ha^(–1) in conjunction with 60 kg K_(2)O ha^(–1)promoted lignin biosynthesis and accumulation,enhanced lodging resistance,and increased grain yield in oil flax grown in the dryland farming region of central Gansu,China.Furthermore,this treatment provides a technical basis for cultivating stress-tolerant and high-yield oil flax in arid regions.
基金supported by the National Natural Science Foundation of China(Grant Nos.31870695,32071828)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Flower color is an essential trait in ornamental plant breeding. Lycoris longituba is a popular ornamental plant native to central eastern China. The decrease in anthocyanin accumulation causes L. longituba petal color fading during flower development, which considerably affects the ornamental value of L. longituba. However, mechanisms underlying anthocyanin biosynthesis inhibition during L. longituba petal development remain unclear. In this study, three LlDFR genes were confirmed to be involved in anthocyanin biosynthesis and LlDFRc exerted the strongest promoting effect on anthocyanin accumulation. According to the correlation analysis results, LlbHLH12 exhibited the strongest negative correlation with LlDFRc. Quantitative real-time PCR analysis showed that LlbHLH12 was highly expressed during the medium bud and full bloom stages of flower development. LlbHLH12 was identified as a member of subgroup XII of bHLH transcription factor family. Subcellular localization and transcriptional activation ability assay revealed that LlbHLH12 was located in the nucleus without transcriptional activation activity. Overexpression of LlbHLH12 in Nicotiana tabacum and L. longituba inhibited anthocyanin accumulation by suppressing the expression of anthocyanin biosynthetic pathway genes. Furthermore, yeast one-hybrid, dual-luciferase, and β-glucuronidase activity assays showed that LlbHLH12 directly bound to the promoters of LlPAL and LlDFRc and suppressed their expression to inhibit anthocyanin biosynthesis. Overall, our study identified a novel bHLH repressor negatively regulating anthocyanin biosynthesis and provided new insights into the molecular mechanisms underlying color fading in L. longituba petals.
基金funded by grants from the National Natural Science Foundation of China(32288101 and 91631306 to B.S32170632 and 32000390 to Y.H.32400503 to Y.G.)Major Scientific Project of Yunnan Province(202305AH340007 to B.S.)+4 种基金Yunnan Revitalization Talent Support Program Science&Technology Champion Project(202005AB160004 to B.S.)Yunnan Revitalization Talent Support Program Innovation Team(202405AS350008)Yunnan Scientist Workshops(to B.S.)the Youth Innovation Promotion Association of CAS(to Y.H.),the Science and Technology General Program of Yunnan Province(202301AW070010 and 202001AT070110 to Y.H.)and the Provincial Key Research,Development,and Translational Program(XZ202101ZY0009G to Baima.).
文摘Nitric oxide(NO)is a key vasodilator that regulates vascular pressure and blood flow.Tibetans have developed a"blunted"mechanism for regulating NO levels at high altitude,with GTP cyclohydrolase 1(GCH1)identified as a key candidate gene.Here,we present comprehensive genetic and functional analyses of GCH1,which exhibits strong Darwinian positive selection in Tibetans.We show that Tibetan-enriched GCH1 variants down-regulate its expression in the blood of Tibetans.Based on this observation,we generate the heterozygous Gch1 knockout(Gch1^(+/-))mouse model to simulate its downregulation in Tibetans.We find that under prolonged hypoxia,the Gch1^(+/-)mice have relatively higher blood NO and blood oxygen saturation levels compared with the wild-type(WT)controls,providing better oxygen supplies to the cardiovascular and pulmonary systems.Markedly,hypoxia-induced cardiac hypertrophy and pulmonary remodeling are significantly attenuated in the Gch1^(^(+/-))mice compared with the WT controls,likely due to the adaptive changes in molecular regulations related to metabolism,inflammation,circadian rhythm,extracellular matrix,and oxidative stress.This study sheds light on the role of GCH1 in regulating blood NO,contributing to the physiological adaptation of the cardiovascular and pulmonary systems in Tibetans at high altitude.
基金financially supported by the National Natural Science Foundation of China(Grant No.12172093)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515012607)。
文摘High-entropy oxides(HEOs)have emerged as a promising class of memristive materials,characterized by entropy-stabilized crystal structures,multivalent cation coordination,and tunable defect landscapes.These intrinsic features enable forming-free resistive switching,multilevel conductance modulation,and synaptic plasticity,making HEOs attractive for neuromorphic computing.This review outlines recent progress in HEO-based memristors across materials engineering,switching mechanisms,and synaptic emulation.Particular attention is given to vacancy migration,phase transitions,and valence-state dynamics—mechanisms that underlie the switching behaviors observed in both amorphous and crystalline systems.Their relevance to neuromorphic functions such as short-term plasticity and spike-timing-dependent learning is also examined.While encouraging results have been achieved at the device level,challenges remain in conductance precision,variability control,and scalable integration.Addressing these demands a concerted effort across materials design,interface optimization,and task-aware modeling.With such integration,HEO memristors offer a compelling pathway toward energy-efficient and adaptable brain-inspired electronics.
基金supported by Korea Evaluation Institute of Industrial Technology(KEIT)grant funded by the Korea Government(MOTIE)(RS-2022-00154720,Technology Innovation Program Development of next-generation power semiconductor based on Si-on-SiC structure)the National Research Foundation of Korea(NRF)by the Korea government(RS-2023-NR076826)Global-Learning&Academic Research Institution for Master's·PhD students,and Postdocs(LAMP)Program of the National Research Foundation of Korea(NRF)by the Ministry of Education(No.RS-2024-00443714).
文摘Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.
基金the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C01072)the Institute of Zhejiang University-Quzhou for their financial support。
文摘Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.
基金financially supported by the International Cooperation Program from the Ministry of Science and Technology of Hubei Province(No.2023EHA069)Shenzhen Science and Technology Program(No.JCYJ20230807143702005)National Foreign Experts Program(No.G2022027015L)。
文摘Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.
