Objective:Erianin has potential anticancer activities,especially against lung cancer.The specific mechanisms underlying the anticancer effects,including the molecular targets and signaling pathways in lung cancer,rema...Objective:Erianin has potential anticancer activities,especially against lung cancer.The specific mechanisms underlying the anticancer effects,including the molecular targets and signaling pathways in lung cancer,remain poorly understood and necessitate further investigation.Methods:Lung cancer cell viability was evaluated using the CCK-8 assay.Flow cytometry was used to examine the effects of erianin on apoptosis and cell cycle progression.m RNA sequencing and metabolomics analysis were utilized to explore erianin-induced biological changes.Potential targets were identified and validated through molecular docking and Western blot analysis.The roles of mammalian target of rapamycin(m TOR)and carbamoyl-phosphate synthetase/aspartate transcarbamylase/dihydroorotase(CAD)in erianin-induced growth inhibition were studied using gene overexpression/knockdown techniques with uridine and aspartate supplementation confirming pyrimidine metabolism involvement.Additionally,lung cancer-bearing nude mouse models were established to evaluate the anti-lung cancer effects of erianin in vivo.Results:Erianin significantly inhibits the proliferation of lung cancer cells,induces apoptosis,and causes G2/M phase cell cycle arrest.Integrative analysis of m RNA sequencing and metabolomics data demonstrated that erianin disrupts pyrimidine metabolism in lung cancer cells.Notably,uridine supplementation mitigated the inhibitory effects of erianin,establishing a connection between pyrimidine metabolism and anticancer activity.Network pharmacology analyses identified m TOR as a key target of erianin.Erianin inhibited m TOR phosphorylation,thereby blocking downstream effectors(S6K and CAD),which are essential regulators of pyrimidine metabolism.Conclusions:Erianin is a promising therapeutic candidate for lung cancer.Erianin likely inhibits lung cancer cell growth by disrupting pyrimidine metabolism by suppressing m TOR activation.展开更多
Heat stress is a major threat to maize(Zea mays L.)production worldwide.Heat shock transcription factors(HSFs)play vital roles in plant responses to heat stress.However,the molecular and genetic mechanisms underlying ...Heat stress is a major threat to maize(Zea mays L.)production worldwide.Heat shock transcription factors(HSFs)play vital roles in plant responses to heat stress.However,the molecular and genetic mechanisms underlying HSF-meditated thermotolerance in maize remain largely unexplored.In this study,we demonstrate that the alternative splicing of ZmHsf23 modulates heat stress tolerance in maize.Hsf23 produced two functional transcripts,Hsf23L and Hsf23S,which differ by the presence of a cryptic mini-exon in Hsf23L that is spliced out in Hsf23S.Both transcripts were strongly induced by heat stress.Mutants lacking Hsf23L alone(hsf23l)or both Hsf23L and Hsf23S(hsf23l23s)exhibited increased susceptibility to heat stress,whereas overexpression of Hsf23S enhanced heat stress tolerance in maize.Subsequently,we found that Hsf23S positively regulates heat stress tolerance by directly activating the transcription of three sHSP genes(Hsp16.9,Hsp17.2,and Hsp18a)and TIL1 gene.In addition,Hsf23L physically interacted with Hsf23S and enhanced the transcriptional activation of Hsf23S on the sHSPs and TIL1 promoters.Notably,genetic analysis suggested that co-overexpression of Hsf23L and Hsf23S further improves heat tolerance of the transgenic plants.Taken together,these results reveal two splicing variants of ZmHsf23 cooperatively regulate maize heat tolerance,thus highlighting potential value of ZmHsf23 in breeding heat-tolerant maize varieties.展开更多
As main part of underground rock mass,the three-dimensional(3D)morphology of natural fractures plays an important role in rock mass stability.Based on previous studies on 3D morphology,this study probes into the law a...As main part of underground rock mass,the three-dimensional(3D)morphology of natural fractures plays an important role in rock mass stability.Based on previous studies on 3D morphology,this study probes into the law and mechanism regarding the influence of the confining pressure constraints on 3D morphological features of natural fractures.First,fracture surfaces were obtained by true triaxial compression test and 3D laser scanning.Then 3D morphological parameters of fractures were calculated by using Grasselli’s model.The results show that the failure mode of granites developed by true triaxial stress can be categorized into tension failure and shear failure.Based on the spatial position of fractures,they can be divided into tension fracture surface,S-1 shear fracture surface,and S-2 shear fracture surface.Micro-failure of the tension fracture surface is dominated by mainly intergranular fracture;the maximum height of asperities on the fracture surface and the 3D roughness of fracture surfaces are influenced by σ_(3) only and they are greater than those of shear fracture surfaces,a lower overall uniformity than tension fracture surface.S-1 shear fracture surface and S-2 shear fracture surface are dominated by intragranular and intergranular coupling fracture.The maximum height of asperities on the fracture surface and 3D roughness of fracture surface are affected by σ_(1),σ_(2),and σ_(3).With the increase of σ_(2) or σ_(3),the cutting off of asperities on the fracture surface becomes more common,the maximum height of asperities and 3D roughness of fracture surface further decrease,and the overall uniformity gets further improved.The experimental results are favorable for selecting technical parameters of enhanced geothermal development and the safety of underground mine engineering.展开更多
The influence of surface roughness on the interfacial dynamic recrystallization kinetics and mechanical properties of Ti-6 Al-3 Nb-2 Zr-1 Mo hot-compression bonding joints was systematically investigated.It is found t...The influence of surface roughness on the interfacial dynamic recrystallization kinetics and mechanical properties of Ti-6 Al-3 Nb-2 Zr-1 Mo hot-compression bonding joints was systematically investigated.It is found that for the bonding interface of rough surfaces,elongated fine grains are formed at the bonding interface due to shear deformation of the interfacial area.As the surface roughness increases,the proportion of elongated grains drastically decreases as they further reorient to form equiaxed grains along the bonding interface of rougher surfaces resulting from severe incompatible deformation of the interface area.Meanwhile,high-density geometrically necessary dislocations accumulate around the interfacial recrystallization area to accommodate the incompatible strain and lattice rotation.A rotational dynamic recrystallization mechanism is thereby proposed to rationalize the formation of fine interfacial recrystallization grains during bonding of rough surfaces.In contrast to that of rough surfaces,bonding interface of polished surfaces exists in the form of straight interface grain boundaries without fine grains under the same deformation conditions.While with the increase of deformation strain,small grain nuclei form along the bonding interface,which is associated with discontinuous dynamic recrystallization assisted by strain-induced boundary migration of interface grain boundaries.Moreover,the bonding joints of rough surfaces show lower elongation compared with that of polished surfaces.This is because the formation of heterogeneous fine grains with low Schmid factor along the bonding interface of rough surfaces,leading to worse compatible deformation capability and thereby poor ductility of bonding joints.展开更多
The shear failure of intact rock under thermo-mechanical(TM)coupling conditions is common,such as in enhanced geothermal mining and deep mine construction.Under the effect of a continuous engineering disturbance,shear...The shear failure of intact rock under thermo-mechanical(TM)coupling conditions is common,such as in enhanced geothermal mining and deep mine construction.Under the effect of a continuous engineering disturbance,shear-formed fractures are prone to secondary instability,posing a severe threat to deep engineering.Although numerous studies regarding three-dimensional(3D)morphologies of fracture surfaces have been conducted,the understanding of shear-formed fractures under TM coupling conditions is limited.In this study,direct shear tests of intact granite under various TM coupling conditions were conducted,followed by 3D laser scanning tests of shear-formed fractures.Test results demonstrated that the peak shear strength of intact granite is positively correlated with the normal stress,whereas it is negatively correlated with the temperature.The internal friction angle and cohesion of intact granite significantly decrease with an increase in the temperature.The anisotropy,roughness value,and height of the asperities on the fracture surfaces are reduced as the normal stress increases,whereas their variation trends are the opposite as the temperature increases.The macroscopic failure mode of intact granite under TM coupling conditions is dominated by mixed tensileeshear and shear failures.As the normal stress increases,intragranular fractures are developed ranging from a local to a global distribution,and the macroscopic failure mode of intact granite changes from mixed tensileeshear to shear failure.Finally,3D morphological characteristics of the asperities on the shear-formed fracture surfaces were analyzed,and a quadrangular pyramid conceptual model representing these asperities was proposed and sufficiently verified.展开更多
Waxy maize is a specialty maize that produces mainly amylopectin starch with special food or industrial values. The objective of this study was to overcome the limitations of wx mutant allele acquisition and breeding ...Waxy maize is a specialty maize that produces mainly amylopectin starch with special food or industrial values. The objective of this study was to overcome the limitations of wx mutant allele acquisition and breeding efficiency by conversion of parental lines from normal to waxy maize. The intended mutation activity was achieved by in vivo CRISPR/Cas9 machinery involving desired-target mutation of the Wx locus in the ZC01 background,abbreviated as ZC01-DTM^(wx). Triple selection was applied to segregants to obtain high genome background recovery with transgene-free wx mutations. The targeted mutation was identified, yielding six types of mutations among progeny crossed with ZC01-DTM^(wx).The amylopectin contents of the endosperm starch in mutant lines and hybrids averaged94.9%, while those of the wild-type controls were significantly(P < 0.01) lower, with an average of 76.9%. Double selection in transgene-free lines was applied using the Bar strip test and Cas9 PCR screening. The genome background recovery ratios of the lines were determined using genome-wide SNP data. That of lines used as male parents was as high as98.19% and that of lines used as female parents was as high as 86.78%. Conversion hybrids and both parental lines showed agronomic performance similar to that of their wild-type counterparts. This study provides a practical example of the efficient extension of CRISPR/Cas9 targeted mutation to industrial hybrids for transformation of a recalcitrant species.展开更多
GTs(Glycosyltransferases)are important in plant growth and abiotic stresses.However,its role in maize heat response is far from clear.Here,we describe the constitutively expressed UDP-glycosyltransferase ZmUGT92A1,whi...GTs(Glycosyltransferases)are important in plant growth and abiotic stresses.However,its role in maize heat response is far from clear.Here,we describe the constitutively expressed UDP-glycosyltransferase ZmUGT92A1,which has a highly conserved PSPG box and is localized in chloroplasts,is induced under heat stress.Functional disruption of ZmUGT92A1 leads to heat sensitivity and reactive oxygen species accumulation in maize.Metabolomics analysis revealed that ZmUGT92A1 affected multiple metabolic pathways and altered the metabolic homeostasis of flavonoids under heat stress.In vitro assay showed ZmUGT92A1 exhibits glycosyltransferase activity on flavonoids and hormones.Additionally,we identified a rapidly heat-induced transcription factor,ZmHSF08,which can directly bind and repress the promoter region of ZmUGT92A1.The ZmHSF08 overexpression line exhibits heat sensitivity and reactive oxygen species accumulation.These findings reveal that the ZmHSF08-ZmUGT92A1 module plays a role in heat tolerance in maize and provide candidate strategies for the development of heat-tolerant varieties.展开更多
With Yunyan 87 as an experimental material, the effects of different transplanting dates on the growth and development of tobacco plants and the yield and quality of cured tobacco leaves were studied in Lingbao City, ...With Yunyan 87 as an experimental material, the effects of different transplanting dates on the growth and development of tobacco plants and the yield and quality of cured tobacco leaves were studied in Lingbao City, Sanmenxia City. With the postponement of transplanting date, the growth period in field was prolonged, and the plant height and leaf area both increased at first and decreased then. TMV, weather fleck and brown spot all showed an incidence and a disease index decreased with the postponement of transplanting date. The total sugar and reducing sugar contents of the cured tobacco leaves from the upper and middle part increased at first and decreased then with the postponement of transplanting date. The main nitrogenous compounds decreased at first and increased then. The economic traits and leaf class were on the decrease.展开更多
Germinating seeds undergo elaborate de-etiolation developmental transitions upon initial soil emergence.As central transcription factors promoting cotyledon greening,the abundance of ETHYLENE-INSENSITIVE 3(EIN3)and PH...Germinating seeds undergo elaborate de-etiolation developmental transitions upon initial soil emergence.As central transcription factors promoting cotyledon greening,the abundance of ETHYLENE-INSENSITIVE 3(EIN3)and PHYTOCHROME-INTERACTING FACTOR 3(PIF3)are strictly controlled by physically associating themselves with the EIN3-BINDING F BOX PROTEINS 1 and 2(EBF1/2)for ubiquitination.Here,we report that the B-box zinc-finger protein BBX32,as a positive regulator during seedling de-etiolation.BBX32 is robustly elevated during the dark-to-light transitions.Constitutively expressing BBX32 ultimately protects against severe photobleaching damage by synchronizing the accumulation of protochlorophyllide(Pchlide)and the differentiation of etioplast–chloroplast apparatus in buried seedlings.Specifically,BBX32 directly interacts with EIN3,PIF3 and EBF1/2.These associations disrupt the assembly of the SCF^(EBF1/2)-EIN3/PIF3 E3 ligation protein complexes,thus dampening E3 ligase activity and robustly controlling EIN3/PIF3 stability.Under soil conditions,BBX32-ox largely rescues the greening deficiency of EBF1ox,and all EIN3ox/bbx32 seedlings override the bbx32 mutant defect and successfully turn green.Both biochemical findings and genetic evidence reveal a novel regulatory paradigm by which the B-box protein dampens the E3 ligase binding activity to achieve green seedlings upon changes in light or soil environmental conditions.展开更多
Adequacy is a key concern of power system planning,which refers to the availability of sufficient facilities to meet demand.The capacity value(CV)of variable renewable energy(VRE)generation represents its equivalent c...Adequacy is a key concern of power system planning,which refers to the availability of sufficient facilities to meet demand.The capacity value(CV)of variable renewable energy(VRE)generation represents its equivalent contribution to system adequacy,in comparison to conventional generators.While VRE continues to grow and increasingly dominates the generation portfolio,its CV is becoming non-negligible,with the corresponding impact mechanisms becoming more complicated and nuanced.In this paper,the concept of CV is revisited by analyzing how VRE contributes to power system balancing at a high renewable energy penetration level.A generalized loss function is incorporated into the CV evaluation framework considering the adequacy of the power system.An analytical method for the CV evaluation of VRE is then derived using the statistical properties of both hourly load and VRE generation.Through the explicit CV expression,several critical impact factors,including the VRE generation variance,source-load correlation,and system adequacy level,are identified and discussed.Case studies demonstrate the accuracy and effectiveness of the proposed method in comparison to the traditional capacity factor-based methods and convolution-based methods.In the IEEERTS79 test system,the CV of a 2500 MW wind farm(with40%renewable energy penetration level)is found to be 6.8%of its nameplate capacity.Additionally,the sensitivity of CV to various impact factors in power systems with high renewable energy penetration is analyzed.展开更多
Summary H3K4me3 plays important roles in development, transcription, and environmental responses. Here, we report that SDG721 （SET-domain group protein 721） and SDG705 are involved in regulating rice development. SD...Summary H3K4me3 plays important roles in development, transcription, and environmental responses. Here, we report that SDG721 （SET-domain group protein 721） and SDG705 are involved in regulating rice development. SDG721 and SDG705 encode TRITHORAX-Iike proteins, which appear to modulate H3K4 methylation levels. Loss of SDG721 and SDG705 function resulted in GA-deficient phenotypes, including semi-dwarfism, reduced cell length, and reduced panicle branching.展开更多
As one of the most important food and feed crops worldwide,maize suffers much more tremendous damages under heat stress compared to other plants,which seriously inhibits plant growth and reduces productivity.To mitiga...As one of the most important food and feed crops worldwide,maize suffers much more tremendous damages under heat stress compared to other plants,which seriously inhibits plant growth and reduces productivity.To mitigate the heat-induced damages and adapt to high temperature environment,plants have evolved a series of molecular mechanisms to sense,respond and adapt high temperatures and heat stress.In this review,we summarized recent advances in molecular regulations underlying high temperature sensing,heat stress response and memory in maize,especially focusing on several important pathways and signals in high temperature sensing,and the complex transcriptional regulation of ZmHSFs(Heat Shock Factors)in heat stress response.In addition,we highlighted interactions between ZmHSFs and several epigenetic regulation factors in coordinately regulating heat stress response and memory.Finally,we laid out strategies to systematically elucidate the regulatory network of maize heat stress response,and discussed approaches for breeding future heat-tolerance maize.展开更多
Tropane alkaloids(TAs)are a kind of plant secondary metabolite that mainly originate from Solanaceae.They have potent anticholinergic activity,and are well-known anticholinergic drugs,but have also been reported as pl...Tropane alkaloids(TAs)are a kind of plant secondary metabolite that mainly originate from Solanaceae.They have potent anticholinergic activity,and are well-known anticholinergic drugs,but have also been reported as plant toxins.Many studies have been conducted on TAs,but no scientometric research has been performed.This study aimed to expound the knowledge network and development of the feld of TAs and predict the emerging development topics based on bibliometrics.In particular,this research combined VOSviewer and CiteSpace for visualization and covered 1,298 related scientifc publications(1953–2022).The research on TAs is rapidly developing,with the participation of 86 countries,1,129 research institutions,and 4,087 researchers.China,the University of Geneva,and P.Christen are the most productive country,institution,and researcher,respectively.Currently,the main research topics on TAs include biosynthesis,in vitro synthesis,chemical synthesis,and determination methods.Since 2018,the monitoring of TAs in food related to human health has shown citation burst characteristics,which is considered an emerging development trend in the future.The fndings of this study will enable researchers to quickly tap into the knowledge background/structure of TAs from massive data to provide a reference for further research.展开更多
The excellent adsorption and rapid separation capabilities of magnetic MOFs make them desirable pretreatment materials for solid substrates.In this study,magnetic ZIF-8(mZIF-8)was synthesized in situ by a one-step met...The excellent adsorption and rapid separation capabilities of magnetic MOFs make them desirable pretreatment materials for solid substrates.In this study,magnetic ZIF-8(mZIF-8)was synthesized in situ by a one-step method in the aqueous solution of magnetic beads.Isothermal adsorption verified that the maximum adsorption capacity of(011)crystal-exposed rhombic dodecahedral ZIF-8 for chloramphenicol was up to 128.31 mg/g(mZIF-8=67.18 mg/g).Kinetic adsorption revealed that the type of ZIF-8/mZIF-8 adsorption on chloramphenicol belongs to the pseudo-secondary adsorption kinetics of chemical monomolecular layers.Characterization by FTIR,XPS,and XRD revealed that mZIF-8 interacts with chloramphenicol mainly byπ-πelectron stacking,electrostatic attraction,and hydrogen bonding interaction.ELISA confirmed that chloramphenicol remained antigenically active after adsorption by mZIF-8.The adsorption and separation of chloramphenicol residues in chicken and egg were completed by mZIF-8 within 20 min.mZIF-8 can be used directly for elution-free ELISA after the adsorption of chloramphenicol.The limits of detection(IC10)of the mZIF-8+ELISA in chicken and eggs were 1.18 ng/mL and 0.64 ng/mL,respectively.mZIF-8 is expected to be used as a magnetic solid-phase extraction material for the rapid pretreatment of antibiotic residues in other complex solid matrices.展开更多
基金supported by the National Natural Science Foundation of China(82104207)Natural Science Foundation of Zhejiang Province(LQ22H280001)。
文摘Objective:Erianin has potential anticancer activities,especially against lung cancer.The specific mechanisms underlying the anticancer effects,including the molecular targets and signaling pathways in lung cancer,remain poorly understood and necessitate further investigation.Methods:Lung cancer cell viability was evaluated using the CCK-8 assay.Flow cytometry was used to examine the effects of erianin on apoptosis and cell cycle progression.m RNA sequencing and metabolomics analysis were utilized to explore erianin-induced biological changes.Potential targets were identified and validated through molecular docking and Western blot analysis.The roles of mammalian target of rapamycin(m TOR)and carbamoyl-phosphate synthetase/aspartate transcarbamylase/dihydroorotase(CAD)in erianin-induced growth inhibition were studied using gene overexpression/knockdown techniques with uridine and aspartate supplementation confirming pyrimidine metabolism involvement.Additionally,lung cancer-bearing nude mouse models were established to evaluate the anti-lung cancer effects of erianin in vivo.Results:Erianin significantly inhibits the proliferation of lung cancer cells,induces apoptosis,and causes G2/M phase cell cycle arrest.Integrative analysis of m RNA sequencing and metabolomics data demonstrated that erianin disrupts pyrimidine metabolism in lung cancer cells.Notably,uridine supplementation mitigated the inhibitory effects of erianin,establishing a connection between pyrimidine metabolism and anticancer activity.Network pharmacology analyses identified m TOR as a key target of erianin.Erianin inhibited m TOR phosphorylation,thereby blocking downstream effectors(S6K and CAD),which are essential regulators of pyrimidine metabolism.Conclusions:Erianin is a promising therapeutic candidate for lung cancer.Erianin likely inhibits lung cancer cell growth by disrupting pyrimidine metabolism by suppressing m TOR activation.
基金supported by the National Key Research and Development Program of China(2021YFF1000301)the National Natural Science Foundation of China(31771805)。
文摘Heat stress is a major threat to maize(Zea mays L.)production worldwide.Heat shock transcription factors(HSFs)play vital roles in plant responses to heat stress.However,the molecular and genetic mechanisms underlying HSF-meditated thermotolerance in maize remain largely unexplored.In this study,we demonstrate that the alternative splicing of ZmHsf23 modulates heat stress tolerance in maize.Hsf23 produced two functional transcripts,Hsf23L and Hsf23S,which differ by the presence of a cryptic mini-exon in Hsf23L that is spliced out in Hsf23S.Both transcripts were strongly induced by heat stress.Mutants lacking Hsf23L alone(hsf23l)or both Hsf23L and Hsf23S(hsf23l23s)exhibited increased susceptibility to heat stress,whereas overexpression of Hsf23S enhanced heat stress tolerance in maize.Subsequently,we found that Hsf23S positively regulates heat stress tolerance by directly activating the transcription of three sHSP genes(Hsp16.9,Hsp17.2,and Hsp18a)and TIL1 gene.In addition,Hsf23L physically interacted with Hsf23S and enhanced the transcriptional activation of Hsf23S on the sHSPs and TIL1 promoters.Notably,genetic analysis suggested that co-overexpression of Hsf23L and Hsf23S further improves heat tolerance of the transgenic plants.Taken together,these results reveal two splicing variants of ZmHsf23 cooperatively regulate maize heat tolerance,thus highlighting potential value of ZmHsf23 in breeding heat-tolerant maize varieties.
基金support from the National Natural Science Foundation of China(Nos.51974173 and 52004147)the Natural Science Foundation of Shandong Province(Nos.ZR2020QD122 and ZR2020QE129).
文摘As main part of underground rock mass,the three-dimensional(3D)morphology of natural fractures plays an important role in rock mass stability.Based on previous studies on 3D morphology,this study probes into the law and mechanism regarding the influence of the confining pressure constraints on 3D morphological features of natural fractures.First,fracture surfaces were obtained by true triaxial compression test and 3D laser scanning.Then 3D morphological parameters of fractures were calculated by using Grasselli’s model.The results show that the failure mode of granites developed by true triaxial stress can be categorized into tension failure and shear failure.Based on the spatial position of fractures,they can be divided into tension fracture surface,S-1 shear fracture surface,and S-2 shear fracture surface.Micro-failure of the tension fracture surface is dominated by mainly intergranular fracture;the maximum height of asperities on the fracture surface and the 3D roughness of fracture surfaces are influenced by σ_(3) only and they are greater than those of shear fracture surfaces,a lower overall uniformity than tension fracture surface.S-1 shear fracture surface and S-2 shear fracture surface are dominated by intragranular and intergranular coupling fracture.The maximum height of asperities on the fracture surface and 3D roughness of fracture surface are affected by σ_(1),σ_(2),and σ_(3).With the increase of σ_(2) or σ_(3),the cutting off of asperities on the fracture surface becomes more common,the maximum height of asperities and 3D roughness of fracture surface further decrease,and the overall uniformity gets further improved.The experimental results are favorable for selecting technical parameters of enhanced geothermal development and the safety of underground mine engineering.
基金financially supported by the National Key Research and Development Program(No.2018YFA0702900)the Postdoctoral Science Foundation of China(No.2020M681004)+2 种基金the National Natural Science Foundation of China(No.51774265)the National Science and Technology Major Project of China(No.2019ZX06004010)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC04000000)。
文摘The influence of surface roughness on the interfacial dynamic recrystallization kinetics and mechanical properties of Ti-6 Al-3 Nb-2 Zr-1 Mo hot-compression bonding joints was systematically investigated.It is found that for the bonding interface of rough surfaces,elongated fine grains are formed at the bonding interface due to shear deformation of the interfacial area.As the surface roughness increases,the proportion of elongated grains drastically decreases as they further reorient to form equiaxed grains along the bonding interface of rougher surfaces resulting from severe incompatible deformation of the interface area.Meanwhile,high-density geometrically necessary dislocations accumulate around the interfacial recrystallization area to accommodate the incompatible strain and lattice rotation.A rotational dynamic recrystallization mechanism is thereby proposed to rationalize the formation of fine interfacial recrystallization grains during bonding of rough surfaces.In contrast to that of rough surfaces,bonding interface of polished surfaces exists in the form of straight interface grain boundaries without fine grains under the same deformation conditions.While with the increase of deformation strain,small grain nuclei form along the bonding interface,which is associated with discontinuous dynamic recrystallization assisted by strain-induced boundary migration of interface grain boundaries.Moreover,the bonding joints of rough surfaces show lower elongation compared with that of polished surfaces.This is because the formation of heterogeneous fine grains with low Schmid factor along the bonding interface of rough surfaces,leading to worse compatible deformation capability and thereby poor ductility of bonding joints.
基金supported by the National Natural Science Foundation of China(Grant No.51974173)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2020QD122).
文摘The shear failure of intact rock under thermo-mechanical(TM)coupling conditions is common,such as in enhanced geothermal mining and deep mine construction.Under the effect of a continuous engineering disturbance,shear-formed fractures are prone to secondary instability,posing a severe threat to deep engineering.Although numerous studies regarding three-dimensional(3D)morphologies of fracture surfaces have been conducted,the understanding of shear-formed fractures under TM coupling conditions is limited.In this study,direct shear tests of intact granite under various TM coupling conditions were conducted,followed by 3D laser scanning tests of shear-formed fractures.Test results demonstrated that the peak shear strength of intact granite is positively correlated with the normal stress,whereas it is negatively correlated with the temperature.The internal friction angle and cohesion of intact granite significantly decrease with an increase in the temperature.The anisotropy,roughness value,and height of the asperities on the fracture surfaces are reduced as the normal stress increases,whereas their variation trends are the opposite as the temperature increases.The macroscopic failure mode of intact granite under TM coupling conditions is dominated by mixed tensileeshear and shear failures.As the normal stress increases,intragranular fractures are developed ranging from a local to a global distribution,and the macroscopic failure mode of intact granite changes from mixed tensileeshear to shear failure.Finally,3D morphological characteristics of the asperities on the shear-formed fracture surfaces were analyzed,and a quadrangular pyramid conceptual model representing these asperities was proposed and sufficiently verified.
基金supported the National Transgenic Science and Technology Program(2019ZX08010-003)the National Natural Science Foundation of China(31771808)+3 种基金the National Key Research and Development Program of China(2016YFD0101803)the Key Area Research and Development Program of Guangdong Province(2018B020202008)Beijing Municipal Science and Technology Commission(D171100007717001)National Engineering Laboratory for Crop Molecular Breeding。
文摘Waxy maize is a specialty maize that produces mainly amylopectin starch with special food or industrial values. The objective of this study was to overcome the limitations of wx mutant allele acquisition and breeding efficiency by conversion of parental lines from normal to waxy maize. The intended mutation activity was achieved by in vivo CRISPR/Cas9 machinery involving desired-target mutation of the Wx locus in the ZC01 background,abbreviated as ZC01-DTM^(wx). Triple selection was applied to segregants to obtain high genome background recovery with transgene-free wx mutations. The targeted mutation was identified, yielding six types of mutations among progeny crossed with ZC01-DTM^(wx).The amylopectin contents of the endosperm starch in mutant lines and hybrids averaged94.9%, while those of the wild-type controls were significantly(P < 0.01) lower, with an average of 76.9%. Double selection in transgene-free lines was applied using the Bar strip test and Cas9 PCR screening. The genome background recovery ratios of the lines were determined using genome-wide SNP data. That of lines used as male parents was as high as98.19% and that of lines used as female parents was as high as 86.78%. Conversion hybrids and both parental lines showed agronomic performance similar to that of their wild-type counterparts. This study provides a practical example of the efficient extension of CRISPR/Cas9 targeted mutation to industrial hybrids for transformation of a recalcitrant species.
基金supported by the National Key Research and Development Program of China (2021YFF1000301)the National Natural Science Foundation of China (31771805)。
文摘GTs(Glycosyltransferases)are important in plant growth and abiotic stresses.However,its role in maize heat response is far from clear.Here,we describe the constitutively expressed UDP-glycosyltransferase ZmUGT92A1,which has a highly conserved PSPG box and is localized in chloroplasts,is induced under heat stress.Functional disruption of ZmUGT92A1 leads to heat sensitivity and reactive oxygen species accumulation in maize.Metabolomics analysis revealed that ZmUGT92A1 affected multiple metabolic pathways and altered the metabolic homeostasis of flavonoids under heat stress.In vitro assay showed ZmUGT92A1 exhibits glycosyltransferase activity on flavonoids and hormones.Additionally,we identified a rapidly heat-induced transcription factor,ZmHSF08,which can directly bind and repress the promoter region of ZmUGT92A1.The ZmHSF08 overexpression line exhibits heat sensitivity and reactive oxygen species accumulation.These findings reveal that the ZmHSF08-ZmUGT92A1 module plays a role in heat tolerance in maize and provide candidate strategies for the development of heat-tolerant varieties.
文摘With Yunyan 87 as an experimental material, the effects of different transplanting dates on the growth and development of tobacco plants and the yield and quality of cured tobacco leaves were studied in Lingbao City, Sanmenxia City. With the postponement of transplanting date, the growth period in field was prolonged, and the plant height and leaf area both increased at first and decreased then. TMV, weather fleck and brown spot all showed an incidence and a disease index decreased with the postponement of transplanting date. The total sugar and reducing sugar contents of the cured tobacco leaves from the upper and middle part increased at first and decreased then with the postponement of transplanting date. The main nitrogenous compounds decreased at first and increased then. The economic traits and leaf class were on the decrease.
基金supported by grants from the National Natural Science Foundation of China(3210040280)Natural Science Research Project of University in Anhui Province(2022AH020062)Anhui Agricultural University Startup Fund(rc422104)to Qingqing Wu.
文摘Germinating seeds undergo elaborate de-etiolation developmental transitions upon initial soil emergence.As central transcription factors promoting cotyledon greening,the abundance of ETHYLENE-INSENSITIVE 3(EIN3)and PHYTOCHROME-INTERACTING FACTOR 3(PIF3)are strictly controlled by physically associating themselves with the EIN3-BINDING F BOX PROTEINS 1 and 2(EBF1/2)for ubiquitination.Here,we report that the B-box zinc-finger protein BBX32,as a positive regulator during seedling de-etiolation.BBX32 is robustly elevated during the dark-to-light transitions.Constitutively expressing BBX32 ultimately protects against severe photobleaching damage by synchronizing the accumulation of protochlorophyllide(Pchlide)and the differentiation of etioplast–chloroplast apparatus in buried seedlings.Specifically,BBX32 directly interacts with EIN3,PIF3 and EBF1/2.These associations disrupt the assembly of the SCF^(EBF1/2)-EIN3/PIF3 E3 ligation protein complexes,thus dampening E3 ligase activity and robustly controlling EIN3/PIF3 stability.Under soil conditions,BBX32-ox largely rescues the greening deficiency of EBF1ox,and all EIN3ox/bbx32 seedlings override the bbx32 mutant defect and successfully turn green.Both biochemical findings and genetic evidence reveal a novel regulatory paradigm by which the B-box protein dampens the E3 ligase binding activity to achieve green seedlings upon changes in light or soil environmental conditions.
基金supported in part by the National Key R&D Program of China(No.2022YFB2403300)in part by the Scientific&Technical Project of State Grid Shanghai Electric Power Company(No.SGSHDK00DWJS2310470)in part by the Scientific&Technical Project of China Electric Power Planning&Engineering Institute(No.K202316)。
文摘Adequacy is a key concern of power system planning,which refers to the availability of sufficient facilities to meet demand.The capacity value(CV)of variable renewable energy(VRE)generation represents its equivalent contribution to system adequacy,in comparison to conventional generators.While VRE continues to grow and increasingly dominates the generation portfolio,its CV is becoming non-negligible,with the corresponding impact mechanisms becoming more complicated and nuanced.In this paper,the concept of CV is revisited by analyzing how VRE contributes to power system balancing at a high renewable energy penetration level.A generalized loss function is incorporated into the CV evaluation framework considering the adequacy of the power system.An analytical method for the CV evaluation of VRE is then derived using the statistical properties of both hourly load and VRE generation.Through the explicit CV expression,several critical impact factors,including the VRE generation variance,source-load correlation,and system adequacy level,are identified and discussed.Case studies demonstrate the accuracy and effectiveness of the proposed method in comparison to the traditional capacity factor-based methods and convolution-based methods.In the IEEERTS79 test system,the CV of a 2500 MW wind farm(with40%renewable energy penetration level)is found to be 6.8%of its nameplate capacity.Additionally,the sensitivity of CV to various impact factors in power systems with high renewable energy penetration is analyzed.
文摘Summary H3K4me3 plays important roles in development, transcription, and environmental responses. Here, we report that SDG721 （SET-domain group protein 721） and SDG705 are involved in regulating rice development. SDG721 and SDG705 encode TRITHORAX-Iike proteins, which appear to modulate H3K4 methylation levels. Loss of SDG721 and SDG705 function resulted in GA-deficient phenotypes, including semi-dwarfism, reduced cell length, and reduced panicle branching.
基金supported by grants from Program for High-level Talents Recruitment of Anhui Agricultural University(rc422208)Anhui Agricultural University fund(rc312212).
文摘As one of the most important food and feed crops worldwide,maize suffers much more tremendous damages under heat stress compared to other plants,which seriously inhibits plant growth and reduces productivity.To mitigate the heat-induced damages and adapt to high temperature environment,plants have evolved a series of molecular mechanisms to sense,respond and adapt high temperatures and heat stress.In this review,we summarized recent advances in molecular regulations underlying high temperature sensing,heat stress response and memory in maize,especially focusing on several important pathways and signals in high temperature sensing,and the complex transcriptional regulation of ZmHSFs(Heat Shock Factors)in heat stress response.In addition,we highlighted interactions between ZmHSFs and several epigenetic regulation factors in coordinately regulating heat stress response and memory.Finally,we laid out strategies to systematically elucidate the regulatory network of maize heat stress response,and discussed approaches for breeding future heat-tolerance maize.
基金the Ministry of Science and Technology of the People’s Republic of China(No.2020YFF01014605).
文摘Tropane alkaloids(TAs)are a kind of plant secondary metabolite that mainly originate from Solanaceae.They have potent anticholinergic activity,and are well-known anticholinergic drugs,but have also been reported as plant toxins.Many studies have been conducted on TAs,but no scientometric research has been performed.This study aimed to expound the knowledge network and development of the feld of TAs and predict the emerging development topics based on bibliometrics.In particular,this research combined VOSviewer and CiteSpace for visualization and covered 1,298 related scientifc publications(1953–2022).The research on TAs is rapidly developing,with the participation of 86 countries,1,129 research institutions,and 4,087 researchers.China,the University of Geneva,and P.Christen are the most productive country,institution,and researcher,respectively.Currently,the main research topics on TAs include biosynthesis,in vitro synthesis,chemical synthesis,and determination methods.Since 2018,the monitoring of TAs in food related to human health has shown citation burst characteristics,which is considered an emerging development trend in the future.The fndings of this study will enable researchers to quickly tap into the knowledge background/structure of TAs from massive data to provide a reference for further research.
基金supported by the National Key Research and Development Program of China(No.2020YFF01014605).
文摘The excellent adsorption and rapid separation capabilities of magnetic MOFs make them desirable pretreatment materials for solid substrates.In this study,magnetic ZIF-8(mZIF-8)was synthesized in situ by a one-step method in the aqueous solution of magnetic beads.Isothermal adsorption verified that the maximum adsorption capacity of(011)crystal-exposed rhombic dodecahedral ZIF-8 for chloramphenicol was up to 128.31 mg/g(mZIF-8=67.18 mg/g).Kinetic adsorption revealed that the type of ZIF-8/mZIF-8 adsorption on chloramphenicol belongs to the pseudo-secondary adsorption kinetics of chemical monomolecular layers.Characterization by FTIR,XPS,and XRD revealed that mZIF-8 interacts with chloramphenicol mainly byπ-πelectron stacking,electrostatic attraction,and hydrogen bonding interaction.ELISA confirmed that chloramphenicol remained antigenically active after adsorption by mZIF-8.The adsorption and separation of chloramphenicol residues in chicken and egg were completed by mZIF-8 within 20 min.mZIF-8 can be used directly for elution-free ELISA after the adsorption of chloramphenicol.The limits of detection(IC10)of the mZIF-8+ELISA in chicken and eggs were 1.18 ng/mL and 0.64 ng/mL,respectively.mZIF-8 is expected to be used as a magnetic solid-phase extraction material for the rapid pretreatment of antibiotic residues in other complex solid matrices.
