Nitrogen(N)serves both as a vital macronutrient and a signaling molecule for plants.Unveiling key regulators involved in N metabolism helps dissect the mechanisms underlying N metabolism,which is essential for develop...Nitrogen(N)serves both as a vital macronutrient and a signaling molecule for plants.Unveiling key regulators involved in N metabolism helps dissect the mechanisms underlying N metabolism,which is essential for developing maize with high N use efficiency.Two maize lines,B73 and Ki11,show differential chlorate and low-N tolerance.Time-course transcriptomic analysis reveals that the expression of N utilization genes(NUGs)in B73 and Ki11 have distinct responsive patterns to nitrate variation.By the coexpression networks,significant differences in the number of N response modules and regulatory networks of transcription factors(TFs)are revealed between B73 and Ki11.There are 23 unique TFs in B73 and 41 unique TFs in Ki11.MADS26 is a unique TF in the B73 N response network,with different expression levels and N response patterns in B73 and Ki11.Overexpression of MADS26 enhances the sensitivity to chlorate and the utilization of nitrate in maize,at least partially explaining the differential chlorate tolerance and low-N sensitivity between B73 and Ki11.The findings in this work provide unique insights and promising candidates for maize breeding to reduce unnecessary N overuse.展开更多
Objective To compare the therapeutic efficacy of portal and tail vein transplantation of bone marrowderived mesenchymal stem cells(BMSCs) against cholestatic liver fibrosis in mice.Methods BMSCs were isolated and co-c...Objective To compare the therapeutic efficacy of portal and tail vein transplantation of bone marrowderived mesenchymal stem cells(BMSCs) against cholestatic liver fibrosis in mice.Methods BMSCs were isolated and co-cultured with starvation-activated hepatic stellate cells(HSCs).HSC activation markers were identified using immunofluorescence and qRT-PCR. BMSCs were injected into the liver tissues of bile duct ligation(BDL) mice via the tail and portal veins. Histomorphology, liver function, inflammatory cytokines, and the expression of key proteins were all determined in the liver tissues.Results BMSCs inhibited HSC activation by reducing α-SMA and collagen I expression. Compared to tail vein injection, DIL-labeled BMSCs injected through the portal vein maintained a high homing rate in the liver. Moreover, BMSCs transplanted through the portal vein resulted in greater improvement in liver color, hardness, and gallbladder size than did those transplanted through the tail vein. Furthermore,BMSCs injected by portal vein, but not tail vein, markedly ameliorated liver function, reduced the secretion of inflammatory cytokines, including TNF-α, IL-6, and IL-1β, and decreased α-SMA + hepatic stellate cell(HSC) activation and collagen fiber formation.Conclusion The therapeutic effect of BMSCs on cholestatic liver fibrosis in mice via portal vein transplantation was superior to that of tail vein transplantation. This comparative study provides reference information for further BMSC studies focused on clinical cholestatic liver diseases.展开更多
Non-stoiehiometry effect on the extreme magnetoresistanee is systematically investigated for the Weyl semimetal WTe2. Magnetoresistance and Hall resistivity are measured for the as-grown samples with a slight differen...Non-stoiehiometry effect on the extreme magnetoresistanee is systematically investigated for the Weyl semimetal WTe2. Magnetoresistance and Hall resistivity are measured for the as-grown samples with a slight difference in Te vacancies and the annealed samples with increased Te vacancies. The fits to a two-band model show that the magnetoresistanee is strongly dependent on the residual resistivity ratio （i.e., the degree of non-stoichiometry）, which is eventually understood in terms of electron doping that not only breaks the balance between electron-type and hole-type carrier densities, but also reduces the average carrier mobility. Thus the compensation effect and ultrahigh mobility are probably the main driving force of the extreme magnetoresistance in WTe2.展开更多
The East African Rift System(EARS)is located in East Africa,separating into two main branches,the eastern branch and the western branch.It is considered as an intracontinental ridge system,which meets the Red Sea and
To the Editor:Kinase cell division cycle 7(CDC7),a cell division cycle protein,takes a vital role in mediating DNA replication1.CDC7 complexes in the nucleus can phosphorylate the minichromosome maintenance complex(MC...To the Editor:Kinase cell division cycle 7(CDC7),a cell division cycle protein,takes a vital role in mediating DNA replication1.CDC7 complexes in the nucleus can phosphorylate the minichromosome maintenance complex(MCM)family members that bind to chromosomes.In addition,CDC7 kinase,as a molecular switch regulating DNA replication,can mediate DNA damage signaling pathways to stimulate cell cycle termination as well as DNA replication2.Studies have shown that CDC7 is overexpressed in many types of cancer cells,and its overexpression was related to poor patient survival,tumor grade,genetic instability,aneuploidy and so on3.Therefore,CDC7 is a promising target for antitumor therapy.展开更多
Fe_(3)GaTe_(2)has attracted significant interest due to its intrinsic room-temperature ferromagnetism,yet its magnetic interactions remain debated.We thoroughly investigate the magnetism of Fe_(3)GaTe_(2)using critica...Fe_(3)GaTe_(2)has attracted significant interest due to its intrinsic room-temperature ferromagnetism,yet its magnetic interactions remain debated.We thoroughly investigate the magnetism of Fe_(3)GaTe_(2)using critical analysis,nitrogen–vacancy(NV)center magnetometry,and Density Function Theory(DFT).Our critical phenomenon analysis with exponents[β=0.3706(9),=1.32(6),σ=4.7(2)]and DFT calculations reveal competition between itinerant and localized spins driven by anisotropic coupling,which can be attributed to a net charge transfer of approximately 0.22 electrons from Fe^(3+)to surrounding Ge/Te atoms.As confirmed by NV center magnetometry,the ferromagnetism in Fe_(3)GaTe_(2)remains robust even in thin-layered sheet of 16 nm(corresponding to approximately 20 layers).The out-of-plane ferromagnetism in thin Fe_(3)GaTe_(2)sheets is stabilized due to the distinct spin interaction energies between intralayers(J_(1)~66.74 meV andJ_(2)~17.33 meV)and interlayers(J_(z)~3.78 meV).In addition,the constant energy contour profiles near the Fermi surface of Fe_(3)GaTe_(2)suggest the presence of both hole and electron pockets with a distorted contour around the K/K′point,indicating hexagonal trigonal warping effects.Furthermore,the layer-resolved electronic band structure uncovers a layer–valley coupling near the Fermi surface,with bands at valleys K and K′associated with different layers.These findings pave way for advanced electronic applications operating above-room-temperature.展开更多
Background:Intensive phototherapy(IPT)and exchange transfusion(ET)are the main treatments for extreme hyperbilirubinemia.However,there is no reliable evidence on determining the thresholds for these treatments.This mu...Background:Intensive phototherapy(IPT)and exchange transfusion(ET)are the main treatments for extreme hyperbilirubinemia.However,there is no reliable evidence on determining the thresholds for these treatments.This multicenter study compared the effectiveness and complications of IPT and ET in the treatment of extreme hyperbilirubinemia.Methods:This retrospective cohort study was conducted in seven centers from January 2015 to January 2018.Patients with extreme hyperbilirubinemia that met the criteria of ET were included.Patients were divided into three subgroups(low-,medium-,and high-risk)according to gestational week and risk factors.Propensity score matching(PSM)was performed to balance the data before treatment.Study outcomes included the development of bilirubin encephalopathy,duration of hospitalization,expenses,and complications.Mortality,auditory complications,seizures,enamel dysplasia,ocular motility disorders,athetosis,motor,and language development were evaluated during follow-up at age of 3 years.Results:A total of 1164 patients were included in this study.After PSM,296 patients in the IPT only group and 296 patients in the IPT plus ET group were further divided into the low-,medium-,and high-risk subgroups with 188,364,and 40 matched patients,respectively.No significant differences were found between the IPT only and IPT plus ET groups in terms of morbidity,complications,and sequelae.Hospitalization duration and expenses were lower in the low-and medium-risk subgroups in the IPT only group.Conclusions:In this study,our results suggest that IPT is a safe and effective treatment for extreme hyperbilirubinemia.The indication of ET for patients with hyperbilirubinemia could be stricter.However,it is necessary to have a contingency plan for emergency ET as soon as IPT is commenced especially for infants with risk factors.If IPT can be guaranteed and proved to be therapeutic,ET should be avoided as much as possible.展开更多
The interaction between complex magnetic structures and non-trivial band structures in ternary rare-earth GdCr_(6)Ge_(6) induces exotic and abundant electro-magnetic phenomena.In this work,we perform a systematical in...The interaction between complex magnetic structures and non-trivial band structures in ternary rare-earth GdCr_(6)Ge_(6) induces exotic and abundant electro-magnetic phenomena.In this work,we perform a systematical investigation on critical behaviors and magnetic properties of the single-crystal GdCr_(6)Ge_(6).The temperature,field,and angle dependence of magnetization unveils strong magnetic anisotropy along the c-axis and isotropic characteristic in the ab-plane.Critical exponentsβ=0.252(1),γ=0.905(9),δ=4.606(3)for H//ab,andβ=0.281(3),γ=0.991(8),δ=4.541(5)for H//c are obtained by the modified Arrott plot method(MAP)and critical isotherm(CI)analysis.The determined exponents for both directions are consistent with the theoretical prediction of a tricritical mean-field model.Based on detailed magnetization measurements and universality scaling,comprehensive magnetic phase diagrams of GdCr6Ge6for H//ab and H//c are constructed,which reveal that the external field induces a ferromagnetic(FM)transition for H//ab while a ferrimagnetic(FIM)one for H//c.Two tricritical points are determined for H//ab(11.2 K,266.3 Oe)and H//c(11.3 K,3.3 kOe)on the phase diagrams,respectively.The field-induced anisotropic magnetic configurations and multiple phases are clarified,where the moments of Gd and Cr form FM coupling for H//ab while FIM one for H//c via the interaction between Gd and Cr sublattices.展开更多
Infectious diseases caused by pathogenic bacteria are a serious threat to global public health.Nowadays,antibiotics and other clinical drugs suffer from some fundamental disadvantages such as narrow-spectrum antibacte...Infectious diseases caused by pathogenic bacteria are a serious threat to global public health.Nowadays,antibiotics and other clinical drugs suffer from some fundamental disadvantages such as narrow-spectrum antibacterial effect and the risk to induce drug resistance,while inorganic functional nanomaterials with biological catalytic activities have been developed as novel antibacterial agents.In this study,we prepared two-dimensional ultrathin vanadium oxide nanosheets(VO_(x)NSs)with mixed valence states from the oxidised layer of vanadium powder(bulk V)by ultrasonically assisted liquid exfoliation.By conveniently switching between V^(IV)and V^(V),VO_(x)NSs can efficiently catalyse H_(2)O_(2)enriched in bacterially infected areas to generate hydroxyl radicals(·OH),which induce bacterial oxidative stress and apoptosis.This process can occur in both weakly alkaline and acidic environments,thus being independent of the pH value in infection areas.In addition,contributed by the intrinsic characteristics of vanadium,two-dimensional morphology and reasonable valence state ratios,VO_(x)NSs exhibit the advantages of broad antibacterial spectrum,high catalytic activity and non-toxic by-products.This novel nanosheet offers a new strategy to heal infected wounds and extends the application of nanocatalytic medicine towards anti-infection.展开更多
Ferroptosis and autophagy, playing significant roles in tumor treatment, are two typical forms of the programmed cell death. However, the rational combination of ferroptosis and autophagy for synergistic tumor therapy...Ferroptosis and autophagy, playing significant roles in tumor treatment, are two typical forms of the programmed cell death. However, the rational combination of ferroptosis and autophagy for synergistic tumor therapy is still highly challenging. Herein, we report on an intriguing nanomedicine strategy for achieving autophagy-enhanced ferroptosis on efficiently combating cancer, which was based on the construction of trehalose-loaded mSiO_(2)@MnO_(x)-mPEG(Tre MMM) nanoparticles with satisfactory biocompatibility. The nanoparticles are endowed with high glutathione(GSH) consumption efficiency, thereby inducing cancer-cell ferroptosis via inactivating glutathione peroxidases 4(GPX4). Subsequently, the Tre MMM degradation due to the GSH depletion and p H sensitivity contributed to the trehalose release for inducing autophagy, promoting/enhancing ferroptosis by NCOA4-mediated degradation of ferritin.A substantial in vitro and in vivo antitumor effect was achieved by such an intriguing autophagyenhanced ferroptosis. Therefore, the rational combination of GSH-consumption-induced ferroptosis and trehalose-induced autophagy by nanomedicine design provides an alternative but effective strategy for tumor treatment.展开更多
A novel braking material,C/C-ZrB_(2)-ZrC-SiC carbon fibre-reinforced hybrid ceramic matrix composite,was prepared by chemical vapour infiltration and polymeric precursor infiltration and pyrolysis.Investigation of the...A novel braking material,C/C-ZrB_(2)-ZrC-SiC carbon fibre-reinforced hybrid ceramic matrix composite,was prepared by chemical vapour infiltration and polymeric precursor infiltration and pyrolysis.Investigation of the microstructure of C/C-ZrB_(2)-ZrC-SiC composite showed the homogenous dispersion of three-phase ceramic as the matrix.The frictional properties of the hybrid C/C-ZrB_(2)-ZrC-SiC ceramic matrix composite were measured by a disk-on-disk type dynamometer under dry and wet conditions to simulate the normal landing state of aircraft brake disk friction pairs.C/C-ZrB_(2)-ZrC-SiC ceramic matrix composite has a higher and more stable friction coefficient under wet condition than under dry condition,indicating that the composite has better performance compared with C/C or C/C-SiC braking materials.展开更多
High-temperature stretching plays a crucial role in enhancing the performance of fibres,while a quantitative investigation into the impacts of tension and stretching duration on the microstructure and performance of h...High-temperature stretching plays a crucial role in enhancing the performance of fibres,while a quantitative investigation into the impacts of tension and stretching duration on the microstructure and performance of hexagonal boron nitride(h-BN)fibres remains absent.In this study,to elucidate the microstructural evolution of the h-BN fibres under thermal stretching,amorphous BN fibres were heated at 2000℃under tension of 30,50,and 70 N for 1,3,and 5 h in a nitrogen atmosphere.Subsequently,the grain size,pore structure,orientation degree,microscopic morphology,and mechanical properties were analysed at room temperature.The results show that high-temperature stretching enhances the orientation degree of the BN fibres,consequently elevating Young’s modulus.The maximum orientation degree of the BN fibres was 86%,aligning with a corresponding Young’s modulus of 206 GPa.Additionally,high-temperature stretching enlarged the sizes of grains and pores,a fact substantiated by the radial cracking of the fibres upon extending thermal stretching time.Owing to the expanded pore structure of the BN fibres and the inability to form a sufficiently strong“card structure”between shorter microfibre bundles,the tensile strength of the BN fibres did not increase continually,reaching a maximum of 1.0 GPa.Microstructural observations revealed that the BN fibres,composed of highly oriented lamellar h-BN grains,tend to form radial textures under high-tensile thermal stretching and onion-skin textures under prolonged thermal stretching.These findings offer a theoretical foundation for the preparation of high-performance h-BN fibres.展开更多
基金supported by the National Natural Science Foundation of China(32272133)the“JBGS”Project of Seed Industry Revitalization in Jiangsu Province(JBGS(2021)012)+2 种基金Jiangsu Agriculture Science and Technology Innovation Fund(CX(21)1003)Anhui Provincial Major Science and Technology Project(202003a06020004)Jiangsu Funding Program for Excellent Postdoctoral Talent(JB23058,2023ZB422).
文摘Nitrogen(N)serves both as a vital macronutrient and a signaling molecule for plants.Unveiling key regulators involved in N metabolism helps dissect the mechanisms underlying N metabolism,which is essential for developing maize with high N use efficiency.Two maize lines,B73 and Ki11,show differential chlorate and low-N tolerance.Time-course transcriptomic analysis reveals that the expression of N utilization genes(NUGs)in B73 and Ki11 have distinct responsive patterns to nitrate variation.By the coexpression networks,significant differences in the number of N response modules and regulatory networks of transcription factors(TFs)are revealed between B73 and Ki11.There are 23 unique TFs in B73 and 41 unique TFs in Ki11.MADS26 is a unique TF in the B73 N response network,with different expression levels and N response patterns in B73 and Ki11.Overexpression of MADS26 enhances the sensitivity to chlorate and the utilization of nitrate in maize,at least partially explaining the differential chlorate tolerance and low-N sensitivity between B73 and Ki11.The findings in this work provide unique insights and promising candidates for maize breeding to reduce unnecessary N overuse.
基金supported by grants from the Natural Science Research Project of Shanxi Basic Research Program [20210302123246]the Scientific Research Project of Shanxi Provincial Health Commission [2020079]+1 种基金the Natural Science Foundation Youth Fund of Hebei Province[C2022402032]the Shanxi Province Higher Education “Billion Project” Science and Technology Guidance Project [BYJL036]。
文摘Objective To compare the therapeutic efficacy of portal and tail vein transplantation of bone marrowderived mesenchymal stem cells(BMSCs) against cholestatic liver fibrosis in mice.Methods BMSCs were isolated and co-cultured with starvation-activated hepatic stellate cells(HSCs).HSC activation markers were identified using immunofluorescence and qRT-PCR. BMSCs were injected into the liver tissues of bile duct ligation(BDL) mice via the tail and portal veins. Histomorphology, liver function, inflammatory cytokines, and the expression of key proteins were all determined in the liver tissues.Results BMSCs inhibited HSC activation by reducing α-SMA and collagen I expression. Compared to tail vein injection, DIL-labeled BMSCs injected through the portal vein maintained a high homing rate in the liver. Moreover, BMSCs transplanted through the portal vein resulted in greater improvement in liver color, hardness, and gallbladder size than did those transplanted through the tail vein. Furthermore,BMSCs injected by portal vein, but not tail vein, markedly ameliorated liver function, reduced the secretion of inflammatory cytokines, including TNF-α, IL-6, and IL-1β, and decreased α-SMA + hepatic stellate cell(HSC) activation and collagen fiber formation.Conclusion The therapeutic effect of BMSCs on cholestatic liver fibrosis in mice via portal vein transplantation was superior to that of tail vein transplantation. This comparative study provides reference information for further BMSC studies focused on clinical cholestatic liver diseases.
基金Supported by the National Key R&D Program of China under Grant Nos 2016YFA0300404 and 2017YFA0403600the National Natural Science Foundation of China under Grant Nos 51603207,U1532267,11574288 and 11674327the Natural Science Foundation of Anhui Province under Grant No 1708085MA08
文摘Non-stoiehiometry effect on the extreme magnetoresistanee is systematically investigated for the Weyl semimetal WTe2. Magnetoresistance and Hall resistivity are measured for the as-grown samples with a slight difference in Te vacancies and the annealed samples with increased Te vacancies. The fits to a two-band model show that the magnetoresistanee is strongly dependent on the residual resistivity ratio （i.e., the degree of non-stoichiometry）, which is eventually understood in terms of electron doping that not only breaks the balance between electron-type and hole-type carrier densities, but also reduces the average carrier mobility. Thus the compensation effect and ultrahigh mobility are probably the main driving force of the extreme magnetoresistance in WTe2.
文摘The East African Rift System(EARS)is located in East Africa,separating into two main branches,the eastern branch and the western branch.It is considered as an intracontinental ridge system,which meets the Red Sea and
基金Zenji Research Laboratories for financial aid to this work
文摘To the Editor:Kinase cell division cycle 7(CDC7),a cell division cycle protein,takes a vital role in mediating DNA replication1.CDC7 complexes in the nucleus can phosphorylate the minichromosome maintenance complex(MCM)family members that bind to chromosomes.In addition,CDC7 kinase,as a molecular switch regulating DNA replication,can mediate DNA damage signaling pathways to stimulate cell cycle termination as well as DNA replication2.Studies have shown that CDC7 is overexpressed in many types of cancer cells,and its overexpression was related to poor patient survival,tumor grade,genetic instability,aneuploidy and so on3.Therefore,CDC7 is a promising target for antitumor therapy.
基金supported by the National Key R&D Program of China(Grant No.2024YFA1611103)the National Natural Science Foundation of China(Grant Nos.12350410367,12074360,12374128,12074386,12250410238,and 62150410438)+3 种基金the Alliance of International Science Organizations(Grant Nos.ANSO-VF-2022-03 and ANSO-VF-2024-03)Anhui Provincial Major S&T Project(Grant No.s202305a12020005)A portion of this work was supported by the Basic Research Program of the Chinese Academy of Sciences Based on Major Scientific Infrastructures(Grant No.JZHKYPT-2021-08)the High Magnetic Field Laboratory of Anhui Province under Contract No.AHHM-FX-2020-02.
文摘Fe_(3)GaTe_(2)has attracted significant interest due to its intrinsic room-temperature ferromagnetism,yet its magnetic interactions remain debated.We thoroughly investigate the magnetism of Fe_(3)GaTe_(2)using critical analysis,nitrogen–vacancy(NV)center magnetometry,and Density Function Theory(DFT).Our critical phenomenon analysis with exponents[β=0.3706(9),=1.32(6),σ=4.7(2)]and DFT calculations reveal competition between itinerant and localized spins driven by anisotropic coupling,which can be attributed to a net charge transfer of approximately 0.22 electrons from Fe^(3+)to surrounding Ge/Te atoms.As confirmed by NV center magnetometry,the ferromagnetism in Fe_(3)GaTe_(2)remains robust even in thin-layered sheet of 16 nm(corresponding to approximately 20 layers).The out-of-plane ferromagnetism in thin Fe_(3)GaTe_(2)sheets is stabilized due to the distinct spin interaction energies between intralayers(J_(1)~66.74 meV andJ_(2)~17.33 meV)and interlayers(J_(z)~3.78 meV).In addition,the constant energy contour profiles near the Fermi surface of Fe_(3)GaTe_(2)suggest the presence of both hole and electron pockets with a distorted contour around the K/K′point,indicating hexagonal trigonal warping effects.Furthermore,the layer-resolved electronic band structure uncovers a layer–valley coupling near the Fermi surface,with bands at valleys K and K′associated with different layers.These findings pave way for advanced electronic applications operating above-room-temperature.
基金This work was supported by the National Science Foundation of China(Nos.81630038,81971433,81971428)the grants from the Science and Technology Bureau of Sichuan Province(Nos.2020YJ0236,2020YFS0041)+1 种基金the grant from the Ministry of Education of China(No.IRT0935)the grant of clinical discipline program(Neonatology)from the Ministry of Health of China(No.1311200003303).
文摘Background:Intensive phototherapy(IPT)and exchange transfusion(ET)are the main treatments for extreme hyperbilirubinemia.However,there is no reliable evidence on determining the thresholds for these treatments.This multicenter study compared the effectiveness and complications of IPT and ET in the treatment of extreme hyperbilirubinemia.Methods:This retrospective cohort study was conducted in seven centers from January 2015 to January 2018.Patients with extreme hyperbilirubinemia that met the criteria of ET were included.Patients were divided into three subgroups(low-,medium-,and high-risk)according to gestational week and risk factors.Propensity score matching(PSM)was performed to balance the data before treatment.Study outcomes included the development of bilirubin encephalopathy,duration of hospitalization,expenses,and complications.Mortality,auditory complications,seizures,enamel dysplasia,ocular motility disorders,athetosis,motor,and language development were evaluated during follow-up at age of 3 years.Results:A total of 1164 patients were included in this study.After PSM,296 patients in the IPT only group and 296 patients in the IPT plus ET group were further divided into the low-,medium-,and high-risk subgroups with 188,364,and 40 matched patients,respectively.No significant differences were found between the IPT only and IPT plus ET groups in terms of morbidity,complications,and sequelae.Hospitalization duration and expenses were lower in the low-and medium-risk subgroups in the IPT only group.Conclusions:In this study,our results suggest that IPT is a safe and effective treatment for extreme hyperbilirubinemia.The indication of ET for patients with hyperbilirubinemia could be stricter.However,it is necessary to have a contingency plan for emergency ET as soon as IPT is commenced especially for infants with risk factors.If IPT can be guaranteed and proved to be therapeutic,ET should be avoided as much as possible.
基金supported by the National Natural Science Foundation of China(Grant Nos.12074386,11874358,U1432138,11974181,12204006,and 12250410238)the Collaborative Innovation Program of Hefei Science Center,CAS(Grant No.2021HSC-CIP006)+3 种基金the Alliance of International Science Organizations(Grant No.ANSO-VF-2022-03)the Key Project of Natural Scientific Research of Universities in Anhui Province(Grant No.K120462009)the Anhui Provincial Natural Science Foundation(Grant No.2108085QA21)supported by the High Magnetic Field Laboratory of Anhui Province。
文摘The interaction between complex magnetic structures and non-trivial band structures in ternary rare-earth GdCr_(6)Ge_(6) induces exotic and abundant electro-magnetic phenomena.In this work,we perform a systematical investigation on critical behaviors and magnetic properties of the single-crystal GdCr_(6)Ge_(6).The temperature,field,and angle dependence of magnetization unveils strong magnetic anisotropy along the c-axis and isotropic characteristic in the ab-plane.Critical exponentsβ=0.252(1),γ=0.905(9),δ=4.606(3)for H//ab,andβ=0.281(3),γ=0.991(8),δ=4.541(5)for H//c are obtained by the modified Arrott plot method(MAP)and critical isotherm(CI)analysis.The determined exponents for both directions are consistent with the theoretical prediction of a tricritical mean-field model.Based on detailed magnetization measurements and universality scaling,comprehensive magnetic phase diagrams of GdCr6Ge6for H//ab and H//c are constructed,which reveal that the external field induces a ferromagnetic(FM)transition for H//ab while a ferrimagnetic(FIM)one for H//c.Two tricritical points are determined for H//ab(11.2 K,266.3 Oe)and H//c(11.3 K,3.3 kOe)on the phase diagrams,respectively.The field-induced anisotropic magnetic configurations and multiple phases are clarified,where the moments of Gd and Cr form FM coupling for H//ab while FIM one for H//c via the interaction between Gd and Cr sublattices.
基金financial support from the National Key R&D Program of China(Grant No.2022YFB3804500)Shanghai Pilot Program for Basic Research-Chinese Academy of Science,Shanghai Branch(Grant No.JCYJ-SHFY-2022-003)+7 种基金National Natural Science Foundation of China(Grant No.52372276,52002391 and 22335006)Basic Research Program of Shanghai Municipal Government(Grant No.21JC1406000)Youth Innovation Promotion Association CAS(Grant No.2023262)Young Elite Scientists Sponsorship Program by CAST(Grant No.YESS20210149)Shanghai Science and Technology Committee Rising-Star Program(Grant No.22QA1410200)Academic Leaders Training Program of Pudong Health Bureau of Shanghai(Grant No.PWRd2022-03),Academic Leaders Training Program of Pudong Health Bureau of Shanghai(Grant No.2022-3)shanghai Science and Technology Innovation Action Plan(Grant No.21Y11900800)Shanghai Municipal Health and Planning Commission(No.202150010)。
文摘Infectious diseases caused by pathogenic bacteria are a serious threat to global public health.Nowadays,antibiotics and other clinical drugs suffer from some fundamental disadvantages such as narrow-spectrum antibacterial effect and the risk to induce drug resistance,while inorganic functional nanomaterials with biological catalytic activities have been developed as novel antibacterial agents.In this study,we prepared two-dimensional ultrathin vanadium oxide nanosheets(VO_(x)NSs)with mixed valence states from the oxidised layer of vanadium powder(bulk V)by ultrasonically assisted liquid exfoliation.By conveniently switching between V^(IV)and V^(V),VO_(x)NSs can efficiently catalyse H_(2)O_(2)enriched in bacterially infected areas to generate hydroxyl radicals(·OH),which induce bacterial oxidative stress and apoptosis.This process can occur in both weakly alkaline and acidic environments,thus being independent of the pH value in infection areas.In addition,contributed by the intrinsic characteristics of vanadium,two-dimensional morphology and reasonable valence state ratios,VO_(x)NSs exhibit the advantages of broad antibacterial spectrum,high catalytic activity and non-toxic by-products.This novel nanosheet offers a new strategy to heal infected wounds and extends the application of nanocatalytic medicine towards anti-infection.
基金This work was supported by the National Key R&D Program of China(2016YFA0203700)the National Natural Science Foundation of China(51722211,51672303,and 51902334)+1 种基金Program of Shanghai Academic Research Leader(18XD1404300)the National Science Foundation for Young Scientists of China(81903178)。
文摘Ferroptosis and autophagy, playing significant roles in tumor treatment, are two typical forms of the programmed cell death. However, the rational combination of ferroptosis and autophagy for synergistic tumor therapy is still highly challenging. Herein, we report on an intriguing nanomedicine strategy for achieving autophagy-enhanced ferroptosis on efficiently combating cancer, which was based on the construction of trehalose-loaded mSiO_(2)@MnO_(x)-mPEG(Tre MMM) nanoparticles with satisfactory biocompatibility. The nanoparticles are endowed with high glutathione(GSH) consumption efficiency, thereby inducing cancer-cell ferroptosis via inactivating glutathione peroxidases 4(GPX4). Subsequently, the Tre MMM degradation due to the GSH depletion and p H sensitivity contributed to the trehalose release for inducing autophagy, promoting/enhancing ferroptosis by NCOA4-mediated degradation of ferritin.A substantial in vitro and in vivo antitumor effect was achieved by such an intriguing autophagyenhanced ferroptosis. Therefore, the rational combination of GSH-consumption-induced ferroptosis and trehalose-induced autophagy by nanomedicine design provides an alternative but effective strategy for tumor treatment.
基金This work was funded by the National Natural Science Foundation of China(Grant No.51102236).
文摘A novel braking material,C/C-ZrB_(2)-ZrC-SiC carbon fibre-reinforced hybrid ceramic matrix composite,was prepared by chemical vapour infiltration and polymeric precursor infiltration and pyrolysis.Investigation of the microstructure of C/C-ZrB_(2)-ZrC-SiC composite showed the homogenous dispersion of three-phase ceramic as the matrix.The frictional properties of the hybrid C/C-ZrB_(2)-ZrC-SiC ceramic matrix composite were measured by a disk-on-disk type dynamometer under dry and wet conditions to simulate the normal landing state of aircraft brake disk friction pairs.C/C-ZrB_(2)-ZrC-SiC ceramic matrix composite has a higher and more stable friction coefficient under wet condition than under dry condition,indicating that the composite has better performance compared with C/C or C/C-SiC braking materials.
基金supported by the Key Laboratory of Science and Technology on Particle Materials(Grant No.CXJJ-21S043)the Key Laboratory of Multiphase Complex Systems(Grant No.MPCS-2021-a-02)+2 种基金the Key Research Program of the Chinese Academy of Sciences(Grant Nos.ZDRW-CN-2021-2,ZDRW-CN-2021-3)Projects of Ganjiang Innovation Academy CAS(Grant Nos.E155D001,E055A002)and the Double Thousand Plan of Jiangxi Province(Grant No.JXSQ2020105012)。
文摘High-temperature stretching plays a crucial role in enhancing the performance of fibres,while a quantitative investigation into the impacts of tension and stretching duration on the microstructure and performance of hexagonal boron nitride(h-BN)fibres remains absent.In this study,to elucidate the microstructural evolution of the h-BN fibres under thermal stretching,amorphous BN fibres were heated at 2000℃under tension of 30,50,and 70 N for 1,3,and 5 h in a nitrogen atmosphere.Subsequently,the grain size,pore structure,orientation degree,microscopic morphology,and mechanical properties were analysed at room temperature.The results show that high-temperature stretching enhances the orientation degree of the BN fibres,consequently elevating Young’s modulus.The maximum orientation degree of the BN fibres was 86%,aligning with a corresponding Young’s modulus of 206 GPa.Additionally,high-temperature stretching enlarged the sizes of grains and pores,a fact substantiated by the radial cracking of the fibres upon extending thermal stretching time.Owing to the expanded pore structure of the BN fibres and the inability to form a sufficiently strong“card structure”between shorter microfibre bundles,the tensile strength of the BN fibres did not increase continually,reaching a maximum of 1.0 GPa.Microstructural observations revealed that the BN fibres,composed of highly oriented lamellar h-BN grains,tend to form radial textures under high-tensile thermal stretching and onion-skin textures under prolonged thermal stretching.These findings offer a theoretical foundation for the preparation of high-performance h-BN fibres.
