Breast cancer is the most common malignant tumor in Chinese women.Early screening is the best way to improve the rates of early diagnosis and survival of breast cancer patients.The peak onset age for breast cancer in ...Breast cancer is the most common malignant tumor in Chinese women.Early screening is the best way to improve the rates of early diagnosis and survival of breast cancer patients.The peak onset age for breast cancer in Chinese women is considerably younger than those in European and American women.It is imperative to develop breast cancer screening guideline that is suitable for Chinese women.By summarizing the current evidence on breast cancer screening in Chinese women,and referring to the latest guidelines and consensus on breast cancer screening in Europe,the United States,and East Asia,the China Anti-Cancer Association and National Clinical Research Center for Cancer(Tianjin Medical University Cancer Institute and Hospital)have formulated population-based guideline for breast cancer screening in Chinese women.The guideline provides recommendations on breast cancer screening for Chinese women at average or high risk of breast cancer according to the following three aspects:age of screening,screening methods,and screening interval.This article provides more detailed information to support the recommendations in this guideline and to provide more direction for current breast cancer screening practices in China.展开更多
Despite of suitable band structures for harvesting solar light and driving water redox reactions,polymeric carbon nitride(PCN)has suffered from poor charge transfer ability and sluggish surface reaction kinetics,which...Despite of suitable band structures for harvesting solar light and driving water redox reactions,polymeric carbon nitride(PCN)has suffered from poor charge transfer ability and sluggish surface reaction kinetics,which limit its photocatalytic activity for water splitting.Herein,atomically dispersed Zn-coordinated three-dimensional(3D)sponge-like PCN(Zn-PCN)is synthesized through a novel intermediate coordination strategy.Advanced characterizations and theoretical calculations well evidence that Zn single atoms are coordinated and stabilized on PCN in the form of Zn-N_(6) configura-tion featured with an electron-deficient state.Such an electronic configuration has been demonstrated contributive to promoted electron excitation,accelerated charge separation and transfer as well as reduced water redox barriers.Further benefited from the abundant surface active sites derived from the 3D porous structure,Zn-PCN realizes visible-light photocatalysis for overall water splitting with H_(2) and O_(2) simultaneously evolved at a stoichiometric ratio of 2:1.This work brings new insights into the design of novel single-atom photocatalysts by deepening the understanding of electronic configurations and reactive sites favorable to excellent photocatalysis for water splitting and related solar energy conversion reactions.展开更多
LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)layered oxides have been regarded as promising alternative cathodes for the next generation of high-energy lithium ion batteries(LIBs)due to high discharge capacities and energy ...LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)layered oxides have been regarded as promising alternative cathodes for the next generation of high-energy lithium ion batteries(LIBs)due to high discharge capacities and energy densities at high operation voltage.However,the capacity fading under high operation voltage still restricts the practical application.Herein,the capacity degradation mechanism of NCM811 at atomic-scale is studied in detail under various cut-off voltages using aberration-corrected scanning transmission electron microscopy(STEM).It is observed that the crystal structure of NCM811 evolution from a layered structure to a rock-salt phase is directly accompanied by serious intergranular cracks under 4.9 V,which is distinguished from the generally accepted structure evolution of layered,disordered layered,defect rock salt and rock salt phases,also observed under 4.3 and 4.7 V.The electron energy loss spectroscopy analysis also confirms the reduction of Ni and Co from the surface to the bulk,not the previously reported only Li/Ni interlayer mixing.The degradation mechanism of NCM811 at a high cut-off voltage of4.9 V is attributed to the formation of intergranular cracks induced by defects,the direct formation of the rock salt phase,and the accompanied reduction of Ni^(2+)and Co^(2+)phases from the surface to the bulk.展开更多
The notorious growth of zinc dendrite and the water-induced corrosion of zinc metal anodes(ZMAs)restrict the practical development of aqueous zinc ion batteries(AZIBs).In this work,a zinc metallized,imide-pillared cov...The notorious growth of zinc dendrite and the water-induced corrosion of zinc metal anodes(ZMAs)restrict the practical development of aqueous zinc ion batteries(AZIBs).In this work,a zinc metallized,imide-pillared covalent organic framework(ZPC)protective film has been engineered as a stable Zn^(2+)ion-conducting interphase to modulate interfacial kinetics and suppress side reactions for ZMAs.Compared to bare Zn,ZPC@Zn exhibits a higher Zn^(2+)ionic conductivity,a larger Zn^(2+)transference number,a lower electronic conductivity,a smaller desolvation activation energy and correspondingly a significant suppression of corrosion,hydrogen evolution and Zn dendrites.Impressively,the ZPC@Zn||ZPC@Zn symmetric cell obtains a cycling lifespan over 3000 h under 5 mA cm^(-2)for 1 mA h cm^(-2).The ZPC@Zn||NH_(4)V_(4)O_(10)coin-type full battery delivers a specific capacity of 195.8 mA h g^(-1)with a retention rate of78.5%at 2 A g^(-1)after 1100 cycles,and the ZPC@Zn||NH_(4)V_(4)O_(10) pouch full cell shows a retention of70.1%in reversible capacity at 3 A g^(-1)after 1100 cycles.The present incorporation of imide-linked covalent organic frameworks in the surface modification of ZMAs will offer fresh perspectives in the search for ideal protective films for the practicality of AZIBs.展开更多
Understanding the structural origin of the competition between oxygen 2p and transition-metal 3d orbitals in oxygen-redox(OR)layered oxides is eminently desirable for exploring reversible and high-energy-density Li/Na...Understanding the structural origin of the competition between oxygen 2p and transition-metal 3d orbitals in oxygen-redox(OR)layered oxides is eminently desirable for exploring reversible and high-energy-density Li/Na-ion cathodes.Here,we reveal the correlation between cationic ordering transition and OR degradation in ribbon-ordered P3-Na_(0.6)Li_(0.2)Mn_(0.8)O_(2) via in situ structural analysis.Comparing two different voltage windows,the OR capacity can be improved approximately twofold when suppressing the in-plane cationic ordering transition.We find that the intralayer cationic migration is promoted by electrochemical reduction from Mn^(4+)to Jahn–Teller Mn^(3+)and the concomitant NaO_(6) stacking transformation from triangular prisms to octahedra,resulting in the loss of ribbon ordering and electrochemical decay.First-principles calculations reveal that Mn^(4+)/Mn^(3+)charge ordering and alignment of the degenerate eg orbital induce lattice-level collective Jahn–Teller distortion,which favors intralayer Mn-ion migration and thereby accelerates OR degradation.These findings unravel the relationship between in-plane cationic ordering and OR reversibility and highlight the importance of superstructure protection for the rational design of reversible OR-active layered oxide cathodes.展开更多
Leukoaraiosis(LA)results from ischemic injury in small cerebral vessels,which may be attributable to decreased vascular density,reduced cerebrovascular angiogenesis,decreased cerebral blood flow,or microcirculatory dy...Leukoaraiosis(LA)results from ischemic injury in small cerebral vessels,which may be attributable to decreased vascular density,reduced cerebrovascular angiogenesis,decreased cerebral blood flow,or microcirculatory dysfunction in the brain.In this study,we enrolled 357 patients with mild intracerebral hemorrhage(ICH)from five hospitals in China and analyzed the relationships between LA and clinical symptom severity at admission,neurological function prognosis at 3 months,and 1-year stroke recurrence.Patients were divided into groups based on Fazekas scale scores:no LA(n=83),mild LA(n=64),moderate LA(n=98)and severe LA(n=112).More severe LA,larger hematoma volume,and higher blood glucose level at admission were associated with more severe neurological deficit.More severe LA,older age and larger hematoma volume were associated with worse neurological function prognosis at 3 months.In addition,moderate-to-severe LA,admission glucose and symptom-free cerebral infarction were associated with 1-year stroke recurrence.These findings suggest that LA severity may be a potential marker of individual ICH vulnerability,which can be characterized by poor tolerance to intracerebral attack or poor recovery ability after ICH.Evaluating LA severity in patients with mild ICH may help neurologists to optimize treatment protocols.This study was approved by the Ethics Committee of Ruijin Hospital Affiliated to Shanghai Jiao Tong University(approval No.12)on March 10,2011.展开更多
Objective:This post-approval safety study assessed the efficacy and safety of exemestane after 2-3 years of tamoxifen treatment among postmenopausal women with estrogen receptor-positive(ER+)early breast cancer in Chi...Objective:This post-approval safety study assessed the efficacy and safety of exemestane after 2-3 years of tamoxifen treatment among postmenopausal women with estrogen receptor-positive(ER+)early breast cancer in China.Methods:Enrolled patients had received 2-3 years of tamoxifen and were then switched to exemestane for completion of 5 consecutive years of adjuvant endocrine therapy.The primary endpoint was the time from enrollment to the first occurrence of locoregional/distant recurrence of the primary breast cancer,appearance of a second primary or contralateral breast cancer,or death due to any cause.Other endpoints included the proportion of patients experiencing each event,incidence rate per annum,relationships between human epidermal growth factor receptor 2 status and time to event,and relationship between disease history variables and time to event.Results:Overall,558 patients were included in the full analysis set:397(71.1%)completed the study,20experienced an event,and 141 discontinued[47 owing to an adverse event(AE);37 no longer willing to participate].Median duration of treatment was 29.5(range,0.1-57.7)months.Median time to event was not reached.Eventfree survival probability at 36 months was 91.4%(95%CI,87.7%-95.1%).The event incidence over the total exposure time of exemestane therapy was 3.5 events/100 person-years(20/565).Multivariate analysis showed an association between tumor,lymph node,and metastasis stage at initial diagnosis and time to event[hazard ratio:1.532(95%CI,1.129-2.080);P=0.006].Most AEs were grade 1 or 2 in severity,with arthralgia(7.7%)being the most common treatment-related AE.Conclusions:This study supports the efficacy and safety of exemestane in postmenopausal Chinese women with ER+breast cancer previously treated with adjuvant tamoxifen for 2-3 years.No new safety signals were identified in the Chinese population.展开更多
通过电解水制备氢气是实现“碳中和”目标的理想途径之一.因此,可在全p H条件下使用的氢析出(HER)催化剂的研发是近年来电催化领域的研究热点.原子级分散的催化剂,能够在保留铂族金属(PGM)固有活性的同时,降低催化剂中PGM的用量.虽然可...通过电解水制备氢气是实现“碳中和”目标的理想途径之一.因此,可在全p H条件下使用的氢析出(HER)催化剂的研发是近年来电催化领域的研究热点.原子级分散的催化剂,能够在保留铂族金属(PGM)固有活性的同时,降低催化剂中PGM的用量.虽然可以通过X射线吸收光谱(XAS)来表征原子分散的PGM电催化剂的配位环境,但目前对原子空间分布的控制仍然具有挑战.本文制备了钒掺杂钨青铜内通道氨配位的钌单原子催化剂(Ru/V-NHWO),用于全p H范围内的HER反应.采用X射线衍射(XRD)、高角环形暗场扫描透射电镜(HAADF-STEM)、X射线光电子能谱(XPS)和原位X射线吸收光谱(XAS)等进行表征,研究了钌单原子与V-NHWO载体的结合方式以及构效关系,并采用密度泛函理论(DFT)计算探索了催化剂中诸多位点的活性贡献.在1 mol/LKOH, 0.5 mol/L H_(2)SO_(4)和1 mol/L磷酸盐缓冲溶液中,其在10 m Acm^(-2)下的过电位分别为28.0, 29.6和40.6 m V.同时,在过电位100 m V时,质量活性分别达到3930, 1941和602.8 m Amg^(-1)Ru,数倍于同等条件下的商业铂碳.XRD结果表明,钌的引入可以确保催化剂在氩气条件下热解后仍保持六方钨铵青铜晶相,证明钌与钨铵青铜六方晶体通道内氨物种,即“通道氨”的结合.HAADF-STEM结果表明,钌原子与NHWO间存在强烈相互作用,有助于提升HER性能.XPS和XAS结果表明, W5+信号出现在引入钌后,峰位置的结合能增加且峰面积降低,说明钌与通道氨之间存在相互作用.N的XPS结果表明,钌的引入导致了金属氨键的形成.XAS结果表明, Ru/V-NHWO/CC中钌单原子和钌团簇共存,钌单原子与通道氨配位,并且钒的引入会诱发V-NHWO中金属键长缩短,这表明催化剂的金属性得到了提升,有利于改善其导电性.采用DFT计算进一步研究了HER活性的来源.相比于V-NHWO载体和钌团簇修饰的V-NHWO,以单原子形式结合的钌具有更低的水解离能垒,该能垒在氨桥接的钌双原子垂直插入、钒掺杂和多通道插入等多种因素作用下进一步降低.同时,氢中间体结合能得到了相应的优化而趋近于0 e V.此外,差分电荷密度模拟结果表明,氢中间体结合后, V-NHWO对于钌单原子存在明显的供电子行为,有利于HER动力学过程.综上,本工作报道了金属载体对于高分散金属原子空间分布调控的重要作用,可为设计和构筑可应用于诸多能源转换过程的新型原子级分散催化剂提供参考.展开更多
Intercalation provides to the host materials a means for controlled variation of many physical/chemical properties and dominates the reactions in metal‐ion batteries.Of particular interest is the graphite intercalati...Intercalation provides to the host materials a means for controlled variation of many physical/chemical properties and dominates the reactions in metal‐ion batteries.Of particular interest is the graphite intercalation compounds with intriguing staging structures,which however are still unclear,especially in their nanostructure and dynamic transition mechanism.Herein,the nature of the staging structure and evolution of the lithium(Li)‐intercalated graphite was revealed by cryogenic‐transmission electron microscopy and other methods at the nanoscale.The intercalated Li‐ions distribute unevenly,generating local stress and dislocations in the graphitic structure.Each staging compound is found macroscopically ordered but microscopically inhomogeneous,exhibiting a localized‐domains structural model.Our findings uncover the correlation between the long‐range ordered structure and short‐range domains,refresh the insights on the staging structure and transition of Li‐intercalated/deintercalated graphite,and provide effective ways to enhance the reaction kinetic in rechargeable batteries by defect engineering.展开更多
Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries.To make doping effective,it is important ...Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries.To make doping effective,it is important to understand the mechanism of how the dopants regulate the electronic band,lattice parameter adjusting,or hetero-phase formation to achieve high stability.In this study,we investigate LiNi_(0.9)Mn_(0.1)O_(2)cathodes doped with IVB grouping elements via multiple characterization techniques.By utilizing in situ XRD and TEM methods,we found that the stronger Ti-O bond effectively improves the cathode stability via a dual protection mechanism.Specifically,the bulk lattice of cathode is wellpreserved during cycling as a result of the suppressed H_(2)-H_(3)phase transition,while a in situ formed Ti-rich surface layer can prevent continuous surface degradation.As a result,the 5%Ti doped LiNi_(0.9)Mn_(0.1)O_(2)cathode exhibits a high capacity retention of 96%after 100 cycles.Whereas,despite IVB group elements Zr and Hf have stronger bonding energy with oxygen,their larger ionic radii actually impede their diffusion into the cathode,thereby they can not improve the cycling stability.Our findings uncover the functional origin of doped elements with their dynamic modification on cathode structure,providing mechanistic insights into the design of nickel-rich cobalt-free cathodes.展开更多
Aim:Gastric cancer(GC)is one of the most common malignant tumors.Chrysophanol has been reported to possess antitumor effects on a variety of cancers;however,its role in GC remains unclear.This study aimed to investiga...Aim:Gastric cancer(GC)is one of the most common malignant tumors.Chrysophanol has been reported to possess antitumor effects on a variety of cancers;however,its role in GC remains unclear.This study aimed to investigate the effects of chrysophanol on the proliferation,pyroptosis,migration,and invasion of GC cells.Methods:Human GC cell lines MKN 28 and AGS cells were treated with different concentrations of chrysophanol,then cell proliferation,migration,invasion and pyroptosis were determined by CCK-8,colony-forming assay,wound healing assay,Transwell assay,and flow cytometry.Cell migration and invasion were reassessed in these transfected cells following the transfection of nod-like receptor protein-3(NLRP3)siRNA in MKN 28 and AGS cells.To examine the downstream signaling pathway of the NLRP3 signaling pathway,NLRP3,caspase-1,gasdermin-D,interleukin(IL)-1β,and IL-18 were detected by quantitative real-time-polymerase chain reaction or western blotting.Results:Chrysophanol inhibited the proliferation of GC cells,caused pyroptosis,inhibited cell migration and invasion,and increased the expression of NLRP3 inflammasomes in GC cells.Knockdown of NLRP3 inhibited the effects of chrysophanol on proliferation,pyroptosis,migration,and invasion of GC cells.Chrysophanol plays an anticancer role by enhancing NLRP3.Conclusions:Chrysophanol exerts anti-neoplastic effects in vitro in GC cells by modulating NLRP3,thus highlighting its therapeutic potential in GC.展开更多
The oxygen octahedral rotation(OOR)forms fundamental atomic distortions and symmetries in perovskite oxides and definitely determines their properties and functionalities.Therefore,epitaxial strain and interfacial str...The oxygen octahedral rotation(OOR)forms fundamental atomic distortions and symmetries in perovskite oxides and definitely determines their properties and functionalities.Therefore,epitaxial strain and interfacial structural coupling engineering have been developed to modulate the OOR patterns and explore novel properties,but it is difficult to distinguish the 2 mechanisms.Here,different symmetries are induced in Na_(0.5)Bi_(0.5)TiO_(3)(NBT)epitaxial films by interfacial oxygen octahedral coupling rather than epitaxial strain.The NBT film grown on the Nb:SrTiO_(3)substrate exhibits a paraelectric tetragonal phase,while with La_(0.5)Sr_(0.5)MnO_(3)as a buffer layer,a monoclinic phase and robust ferroelectricity are obtained,with a remanent polarization of 42μC cm^(-2)and a breakdown strength of 7.89 MV cm^(-1),which are the highest record among NBT-based films.Moreover,the interfacial oxygen octahedral coupling effect is demonstrated to propagate to the entire thickness of the film,suggesting an intriguing long-range effect.This work provides a deep insight into understanding the structure modulation in perovskite heterostructures and an important avenue for achieving unique functionalities.展开更多
A compact dual-band quasi-elliptic filter with high selectivity is developed and investigated in this communication.It employs two hybrid-structure substrate integrated waveguide(SIW)triplets,which show completely inv...A compact dual-band quasi-elliptic filter with high selectivity is developed and investigated in this communication.It employs two hybrid-structure substrate integrated waveguide(SIW)triplets,which show completely inverse transfer responses under the same conditions of inductive cross coupling.The first meander-line-based triplet is able to produce a transmission zero(TZ)above the passband.Whereas the second SIW triplet,which is composed by a composite right/left-handed(CRLH)resonator,creates a TZ below the passband.By utilizing these features,a dual-band quasi-elliptic filter based on SIW dual-mode resonances(TE101 and TE201),whose operating frequencies are allocated at 8 GHz and 10 GHz,is designed for demonstration.The design process,principles,and experiments are carefully described in this communication.The measured and simulated results are in good agreement,indicating excellent electrical performance with low loss,compact device size and high selectivity.The most notable point is that a dual-band quasi-elliptic filter on SIW platforms is obtained with all inductive couplings for the first time,which shows a unique benefit in eliminating negative-coupling structures while permitting miniaturization for SIW dual-band filter design.展开更多
An intrinsic magnetic topological insulator(TI) is a stoichiometric magnetic compound possessing both inherent magnetic order and topological electronic states. Such a material can provide a shortcut to various novel ...An intrinsic magnetic topological insulator(TI) is a stoichiometric magnetic compound possessing both inherent magnetic order and topological electronic states. Such a material can provide a shortcut to various novel topological quantum effects but remained elusive experimentally for a long time. Here we report the experimental realization of thin films of an intrinsic magnetic TI, MnBi2Te4, by alternate growth of a Bi2Te3 quintuple layer and a MnTe bilayer with molecular beam epitaxy. The material shows the archetypical Dirac surface states in angle-resolved photoemission spectroscopy and is demonstrated to be an antiferromagnetic topological insulator with ferromagnetic surfaces by magnetic and transport measurements as well as first-principles calculations. The unique magnetic and topological electronic structures and their interplays enable the material to embody rich quantum phases such as quantum anomalous Hall insulators and axion insulators at higher temperature and in a well-controlled way.展开更多
基金supported by National Key Technology Support Program (Grant No. 2015BAI12B15)
文摘Breast cancer is the most common malignant tumor in Chinese women.Early screening is the best way to improve the rates of early diagnosis and survival of breast cancer patients.The peak onset age for breast cancer in Chinese women is considerably younger than those in European and American women.It is imperative to develop breast cancer screening guideline that is suitable for Chinese women.By summarizing the current evidence on breast cancer screening in Chinese women,and referring to the latest guidelines and consensus on breast cancer screening in Europe,the United States,and East Asia,the China Anti-Cancer Association and National Clinical Research Center for Cancer(Tianjin Medical University Cancer Institute and Hospital)have formulated population-based guideline for breast cancer screening in Chinese women.The guideline provides recommendations on breast cancer screening for Chinese women at average or high risk of breast cancer according to the following three aspects:age of screening,screening methods,and screening interval.This article provides more detailed information to support the recommendations in this guideline and to provide more direction for current breast cancer screening practices in China.
基金This work was supported by the National Key Research and Development Program of China(2018YFB1502003)the National Natural Science Foundation of China(52225606,21875183,52172248)+2 种基金the“Fundamental Research Funds for the Central Universities”the Natural Science Basic Research Program of Shaanxi Province(2019JCW-10)“The Youth Innovation Team of Shaanxi Universities”.
文摘Despite of suitable band structures for harvesting solar light and driving water redox reactions,polymeric carbon nitride(PCN)has suffered from poor charge transfer ability and sluggish surface reaction kinetics,which limit its photocatalytic activity for water splitting.Herein,atomically dispersed Zn-coordinated three-dimensional(3D)sponge-like PCN(Zn-PCN)is synthesized through a novel intermediate coordination strategy.Advanced characterizations and theoretical calculations well evidence that Zn single atoms are coordinated and stabilized on PCN in the form of Zn-N_(6) configura-tion featured with an electron-deficient state.Such an electronic configuration has been demonstrated contributive to promoted electron excitation,accelerated charge separation and transfer as well as reduced water redox barriers.Further benefited from the abundant surface active sites derived from the 3D porous structure,Zn-PCN realizes visible-light photocatalysis for overall water splitting with H_(2) and O_(2) simultaneously evolved at a stoichiometric ratio of 2:1.This work brings new insights into the design of novel single-atom photocatalysts by deepening the understanding of electronic configurations and reactive sites favorable to excellent photocatalysis for water splitting and related solar energy conversion reactions.
基金supported by the National Natural Science Foundation of China(U2032131)the Key R&D Program of Shaanxi Province(2021GY-118)the Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2022SX-TD012 and 2021SXTD012)。
文摘LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)layered oxides have been regarded as promising alternative cathodes for the next generation of high-energy lithium ion batteries(LIBs)due to high discharge capacities and energy densities at high operation voltage.However,the capacity fading under high operation voltage still restricts the practical application.Herein,the capacity degradation mechanism of NCM811 at atomic-scale is studied in detail under various cut-off voltages using aberration-corrected scanning transmission electron microscopy(STEM).It is observed that the crystal structure of NCM811 evolution from a layered structure to a rock-salt phase is directly accompanied by serious intergranular cracks under 4.9 V,which is distinguished from the generally accepted structure evolution of layered,disordered layered,defect rock salt and rock salt phases,also observed under 4.3 and 4.7 V.The electron energy loss spectroscopy analysis also confirms the reduction of Ni and Co from the surface to the bulk,not the previously reported only Li/Ni interlayer mixing.The degradation mechanism of NCM811 at a high cut-off voltage of4.9 V is attributed to the formation of intergranular cracks induced by defects,the direct formation of the rock salt phase,and the accompanied reduction of Ni^(2+)and Co^(2+)phases from the surface to the bulk.
基金supported by the National Natural Science Foundation of China (52373065)the Joint Fund of Ministry of Education for Equipment Pre-research (8091B032206)+1 种基金the Guang Dong Basic and Applied Basic Research Foundation (2021A1515111067,2023A1515010735)the start-up funding of“Hundred Talent Program”from Sun Yat-sen University。
文摘The notorious growth of zinc dendrite and the water-induced corrosion of zinc metal anodes(ZMAs)restrict the practical development of aqueous zinc ion batteries(AZIBs).In this work,a zinc metallized,imide-pillared covalent organic framework(ZPC)protective film has been engineered as a stable Zn^(2+)ion-conducting interphase to modulate interfacial kinetics and suppress side reactions for ZMAs.Compared to bare Zn,ZPC@Zn exhibits a higher Zn^(2+)ionic conductivity,a larger Zn^(2+)transference number,a lower electronic conductivity,a smaller desolvation activation energy and correspondingly a significant suppression of corrosion,hydrogen evolution and Zn dendrites.Impressively,the ZPC@Zn||ZPC@Zn symmetric cell obtains a cycling lifespan over 3000 h under 5 mA cm^(-2)for 1 mA h cm^(-2).The ZPC@Zn||NH_(4)V_(4)O_(10)coin-type full battery delivers a specific capacity of 195.8 mA h g^(-1)with a retention rate of78.5%at 2 A g^(-1)after 1100 cycles,and the ZPC@Zn||NH_(4)V_(4)O_(10) pouch full cell shows a retention of70.1%in reversible capacity at 3 A g^(-1)after 1100 cycles.The present incorporation of imide-linked covalent organic frameworks in the surface modification of ZMAs will offer fresh perspectives in the search for ideal protective films for the practicality of AZIBs.
基金funding supports from the National Key R&D Program of China(Grant Nos.2022YFB2404400 and 2019YFA0308500)Beijing Natural Science Foundation(Z190010)National Natural Science Foundation of China(Grant Nos.51991344,52025025,52072400,and 52002394)。
文摘Understanding the structural origin of the competition between oxygen 2p and transition-metal 3d orbitals in oxygen-redox(OR)layered oxides is eminently desirable for exploring reversible and high-energy-density Li/Na-ion cathodes.Here,we reveal the correlation between cationic ordering transition and OR degradation in ribbon-ordered P3-Na_(0.6)Li_(0.2)Mn_(0.8)O_(2) via in situ structural analysis.Comparing two different voltage windows,the OR capacity can be improved approximately twofold when suppressing the in-plane cationic ordering transition.We find that the intralayer cationic migration is promoted by electrochemical reduction from Mn^(4+)to Jahn–Teller Mn^(3+)and the concomitant NaO_(6) stacking transformation from triangular prisms to octahedra,resulting in the loss of ribbon ordering and electrochemical decay.First-principles calculations reveal that Mn^(4+)/Mn^(3+)charge ordering and alignment of the degenerate eg orbital induce lattice-level collective Jahn–Teller distortion,which favors intralayer Mn-ion migration and thereby accelerates OR degradation.These findings unravel the relationship between in-plane cationic ordering and OR reversibility and highlight the importance of superstructure protection for the rational design of reversible OR-active layered oxide cathodes.
基金supported by the National Natural Science Foundation of China,Nos.81771281(to FXS),81471177(to FXS)the Natural Science Foundation of Shanghai of China,No.20ZR1434200(to YF)。
文摘Leukoaraiosis(LA)results from ischemic injury in small cerebral vessels,which may be attributable to decreased vascular density,reduced cerebrovascular angiogenesis,decreased cerebral blood flow,or microcirculatory dysfunction in the brain.In this study,we enrolled 357 patients with mild intracerebral hemorrhage(ICH)from five hospitals in China and analyzed the relationships between LA and clinical symptom severity at admission,neurological function prognosis at 3 months,and 1-year stroke recurrence.Patients were divided into groups based on Fazekas scale scores:no LA(n=83),mild LA(n=64),moderate LA(n=98)and severe LA(n=112).More severe LA,larger hematoma volume,and higher blood glucose level at admission were associated with more severe neurological deficit.More severe LA,older age and larger hematoma volume were associated with worse neurological function prognosis at 3 months.In addition,moderate-to-severe LA,admission glucose and symptom-free cerebral infarction were associated with 1-year stroke recurrence.These findings suggest that LA severity may be a potential marker of individual ICH vulnerability,which can be characterized by poor tolerance to intracerebral attack or poor recovery ability after ICH.Evaluating LA severity in patients with mild ICH may help neurologists to optimize treatment protocols.This study was approved by the Ethics Committee of Ruijin Hospital Affiliated to Shanghai Jiao Tong University(approval No.12)on March 10,2011.
文摘Objective:This post-approval safety study assessed the efficacy and safety of exemestane after 2-3 years of tamoxifen treatment among postmenopausal women with estrogen receptor-positive(ER+)early breast cancer in China.Methods:Enrolled patients had received 2-3 years of tamoxifen and were then switched to exemestane for completion of 5 consecutive years of adjuvant endocrine therapy.The primary endpoint was the time from enrollment to the first occurrence of locoregional/distant recurrence of the primary breast cancer,appearance of a second primary or contralateral breast cancer,or death due to any cause.Other endpoints included the proportion of patients experiencing each event,incidence rate per annum,relationships between human epidermal growth factor receptor 2 status and time to event,and relationship between disease history variables and time to event.Results:Overall,558 patients were included in the full analysis set:397(71.1%)completed the study,20experienced an event,and 141 discontinued[47 owing to an adverse event(AE);37 no longer willing to participate].Median duration of treatment was 29.5(range,0.1-57.7)months.Median time to event was not reached.Eventfree survival probability at 36 months was 91.4%(95%CI,87.7%-95.1%).The event incidence over the total exposure time of exemestane therapy was 3.5 events/100 person-years(20/565).Multivariate analysis showed an association between tumor,lymph node,and metastasis stage at initial diagnosis and time to event[hazard ratio:1.532(95%CI,1.129-2.080);P=0.006].Most AEs were grade 1 or 2 in severity,with arthralgia(7.7%)being the most common treatment-related AE.Conclusions:This study supports the efficacy and safety of exemestane in postmenopausal Chinese women with ER+breast cancer previously treated with adjuvant tamoxifen for 2-3 years.No new safety signals were identified in the Chinese population.
文摘通过电解水制备氢气是实现“碳中和”目标的理想途径之一.因此,可在全p H条件下使用的氢析出(HER)催化剂的研发是近年来电催化领域的研究热点.原子级分散的催化剂,能够在保留铂族金属(PGM)固有活性的同时,降低催化剂中PGM的用量.虽然可以通过X射线吸收光谱(XAS)来表征原子分散的PGM电催化剂的配位环境,但目前对原子空间分布的控制仍然具有挑战.本文制备了钒掺杂钨青铜内通道氨配位的钌单原子催化剂(Ru/V-NHWO),用于全p H范围内的HER反应.采用X射线衍射(XRD)、高角环形暗场扫描透射电镜(HAADF-STEM)、X射线光电子能谱(XPS)和原位X射线吸收光谱(XAS)等进行表征,研究了钌单原子与V-NHWO载体的结合方式以及构效关系,并采用密度泛函理论(DFT)计算探索了催化剂中诸多位点的活性贡献.在1 mol/LKOH, 0.5 mol/L H_(2)SO_(4)和1 mol/L磷酸盐缓冲溶液中,其在10 m Acm^(-2)下的过电位分别为28.0, 29.6和40.6 m V.同时,在过电位100 m V时,质量活性分别达到3930, 1941和602.8 m Amg^(-1)Ru,数倍于同等条件下的商业铂碳.XRD结果表明,钌的引入可以确保催化剂在氩气条件下热解后仍保持六方钨铵青铜晶相,证明钌与钨铵青铜六方晶体通道内氨物种,即“通道氨”的结合.HAADF-STEM结果表明,钌原子与NHWO间存在强烈相互作用,有助于提升HER性能.XPS和XAS结果表明, W5+信号出现在引入钌后,峰位置的结合能增加且峰面积降低,说明钌与通道氨之间存在相互作用.N的XPS结果表明,钌的引入导致了金属氨键的形成.XAS结果表明, Ru/V-NHWO/CC中钌单原子和钌团簇共存,钌单原子与通道氨配位,并且钒的引入会诱发V-NHWO中金属键长缩短,这表明催化剂的金属性得到了提升,有利于改善其导电性.采用DFT计算进一步研究了HER活性的来源.相比于V-NHWO载体和钌团簇修饰的V-NHWO,以单原子形式结合的钌具有更低的水解离能垒,该能垒在氨桥接的钌双原子垂直插入、钒掺杂和多通道插入等多种因素作用下进一步降低.同时,氢中间体结合能得到了相应的优化而趋近于0 e V.此外,差分电荷密度模拟结果表明,氢中间体结合后, V-NHWO对于钌单原子存在明显的供电子行为,有利于HER动力学过程.综上,本工作报道了金属载体对于高分散金属原子空间分布调控的重要作用,可为设计和构筑可应用于诸多能源转换过程的新型原子级分散催化剂提供参考.
基金support from the National Natural Science Foundation of China(NSFC nos.52172257,22005334,21773301 and 52022106)the Natural Science Foundation of Beijing(grant no.Z200013).
文摘Intercalation provides to the host materials a means for controlled variation of many physical/chemical properties and dominates the reactions in metal‐ion batteries.Of particular interest is the graphite intercalation compounds with intriguing staging structures,which however are still unclear,especially in their nanostructure and dynamic transition mechanism.Herein,the nature of the staging structure and evolution of the lithium(Li)‐intercalated graphite was revealed by cryogenic‐transmission electron microscopy and other methods at the nanoscale.The intercalated Li‐ions distribute unevenly,generating local stress and dislocations in the graphitic structure.Each staging compound is found macroscopically ordered but microscopically inhomogeneous,exhibiting a localized‐domains structural model.Our findings uncover the correlation between the long‐range ordered structure and short‐range domains,refresh the insights on the staging structure and transition of Li‐intercalated/deintercalated graphite,and provide effective ways to enhance the reaction kinetic in rechargeable batteries by defect engineering.
基金the funding support from the National Key Research and Development Program of China(2020YFB2007400)the National Natural Science Foundation of China(22209202,22075317)the Strategic Priority Research Program(B)(XDB33030200)of Chinese Academy of Sciences。
文摘Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries.To make doping effective,it is important to understand the mechanism of how the dopants regulate the electronic band,lattice parameter adjusting,or hetero-phase formation to achieve high stability.In this study,we investigate LiNi_(0.9)Mn_(0.1)O_(2)cathodes doped with IVB grouping elements via multiple characterization techniques.By utilizing in situ XRD and TEM methods,we found that the stronger Ti-O bond effectively improves the cathode stability via a dual protection mechanism.Specifically,the bulk lattice of cathode is wellpreserved during cycling as a result of the suppressed H_(2)-H_(3)phase transition,while a in situ formed Ti-rich surface layer can prevent continuous surface degradation.As a result,the 5%Ti doped LiNi_(0.9)Mn_(0.1)O_(2)cathode exhibits a high capacity retention of 96%after 100 cycles.Whereas,despite IVB group elements Zr and Hf have stronger bonding energy with oxygen,their larger ionic radii actually impede their diffusion into the cathode,thereby they can not improve the cycling stability.Our findings uncover the functional origin of doped elements with their dynamic modification on cathode structure,providing mechanistic insights into the design of nickel-rich cobalt-free cathodes.
基金This study was supported by the Natural Science Research Project of Anhui Province,Grant/Award No.[2008085MH282]Graduate Research Innovation Project of Bengbu Medical College,Grant/Award No.[Byycx20022]+1 种基金Key Science and Technology Project of Anhui Province Fund,Grant/Award No.[201904a07020022]2020 Outstanding University Talents Support Project,Grant/Award No.[gxyq2020023].
文摘Aim:Gastric cancer(GC)is one of the most common malignant tumors.Chrysophanol has been reported to possess antitumor effects on a variety of cancers;however,its role in GC remains unclear.This study aimed to investigate the effects of chrysophanol on the proliferation,pyroptosis,migration,and invasion of GC cells.Methods:Human GC cell lines MKN 28 and AGS cells were treated with different concentrations of chrysophanol,then cell proliferation,migration,invasion and pyroptosis were determined by CCK-8,colony-forming assay,wound healing assay,Transwell assay,and flow cytometry.Cell migration and invasion were reassessed in these transfected cells following the transfection of nod-like receptor protein-3(NLRP3)siRNA in MKN 28 and AGS cells.To examine the downstream signaling pathway of the NLRP3 signaling pathway,NLRP3,caspase-1,gasdermin-D,interleukin(IL)-1β,and IL-18 were detected by quantitative real-time-polymerase chain reaction or western blotting.Results:Chrysophanol inhibited the proliferation of GC cells,caused pyroptosis,inhibited cell migration and invasion,and increased the expression of NLRP3 inflammasomes in GC cells.Knockdown of NLRP3 inhibited the effects of chrysophanol on proliferation,pyroptosis,migration,and invasion of GC cells.Chrysophanol plays an anticancer role by enhancing NLRP3.Conclusions:Chrysophanol exerts anti-neoplastic effects in vitro in GC cells by modulating NLRP3,thus highlighting its therapeutic potential in GC.
基金supported by the National Key Research Program of China(Grant No.2022YFB3807604)the National Natural Science Foundation of China(Grant Nos.52027817,52072400,52025025,and 52150092).
文摘The oxygen octahedral rotation(OOR)forms fundamental atomic distortions and symmetries in perovskite oxides and definitely determines their properties and functionalities.Therefore,epitaxial strain and interfacial structural coupling engineering have been developed to modulate the OOR patterns and explore novel properties,but it is difficult to distinguish the 2 mechanisms.Here,different symmetries are induced in Na_(0.5)Bi_(0.5)TiO_(3)(NBT)epitaxial films by interfacial oxygen octahedral coupling rather than epitaxial strain.The NBT film grown on the Nb:SrTiO_(3)substrate exhibits a paraelectric tetragonal phase,while with La_(0.5)Sr_(0.5)MnO_(3)as a buffer layer,a monoclinic phase and robust ferroelectricity are obtained,with a remanent polarization of 42μC cm^(-2)and a breakdown strength of 7.89 MV cm^(-1),which are the highest record among NBT-based films.Moreover,the interfacial oxygen octahedral coupling effect is demonstrated to propagate to the entire thickness of the film,suggesting an intriguing long-range effect.This work provides a deep insight into understanding the structure modulation in perovskite heterostructures and an important avenue for achieving unique functionalities.
基金supported in part by the Natural Sciences and Engineering Research Council(NSERC)of Canadain part by the China Scholarship Council(Grant No.202006070154).
文摘A compact dual-band quasi-elliptic filter with high selectivity is developed and investigated in this communication.It employs two hybrid-structure substrate integrated waveguide(SIW)triplets,which show completely inverse transfer responses under the same conditions of inductive cross coupling.The first meander-line-based triplet is able to produce a transmission zero(TZ)above the passband.Whereas the second SIW triplet,which is composed by a composite right/left-handed(CRLH)resonator,creates a TZ below the passband.By utilizing these features,a dual-band quasi-elliptic filter based on SIW dual-mode resonances(TE101 and TE201),whose operating frequencies are allocated at 8 GHz and 10 GHz,is designed for demonstration.The design process,principles,and experiments are carefully described in this communication.The measured and simulated results are in good agreement,indicating excellent electrical performance with low loss,compact device size and high selectivity.The most notable point is that a dual-band quasi-elliptic filter on SIW platforms is obtained with all inductive couplings for the first time,which shows a unique benefit in eliminating negative-coupling structures while permitting miniaturization for SIW dual-band filter design.
基金Supported by the Ministry of Science and Technology of Chinathe National Science Foundation of Chinathe Beijing Advanced Innovation Center for Future Chip(ICFC)
文摘An intrinsic magnetic topological insulator(TI) is a stoichiometric magnetic compound possessing both inherent magnetic order and topological electronic states. Such a material can provide a shortcut to various novel topological quantum effects but remained elusive experimentally for a long time. Here we report the experimental realization of thin films of an intrinsic magnetic TI, MnBi2Te4, by alternate growth of a Bi2Te3 quintuple layer and a MnTe bilayer with molecular beam epitaxy. The material shows the archetypical Dirac surface states in angle-resolved photoemission spectroscopy and is demonstrated to be an antiferromagnetic topological insulator with ferromagnetic surfaces by magnetic and transport measurements as well as first-principles calculations. The unique magnetic and topological electronic structures and their interplays enable the material to embody rich quantum phases such as quantum anomalous Hall insulators and axion insulators at higher temperature and in a well-controlled way.