Although many emerging new phenomena have been unraveled in two dimensional(2D)materials with long-range spin orderings,the usually low critical temperature in van der Waals(vdW)magnetic material has thus far hindered...Although many emerging new phenomena have been unraveled in two dimensional(2D)materials with long-range spin orderings,the usually low critical temperature in van der Waals(vdW)magnetic material has thus far hindered the related practical applications.Here,we show that ferromagnetism can hold above 300 K in a metallic phase of 1T-CrTe2 down to the ultra-thin limit.It thus makes CrTe2 so far the only known exfoliated ultra-thin vdW magnets with intrinsic long-range magnetic ordering above room temperature.An in-plane room-temperature negative anisotropic magnetoresistance(AMR)was obtained in ultra-thin CrTe2 devices,with a sign change in the AMR at lower temperature,with−0.6%and+5%at 300 and 10 K,respectively.Our findings provide insights into magnetism in ultra-thin CrTe2,expanding the vdW crystals toolbox for future room-temperature spintronic applications.展开更多
目的探讨股骨假体套筒翻修术治疗旋转铰链膝关节股骨假体聚乙烯套筒磨损的临床疗效。方法回顾性分析2008年8月至2023年4月在中国人民解放军总医院第四医学中心骨科医学部治疗的旋转铰链型膝关节股骨假体聚乙烯套筒磨损患者21例,男8例、...目的探讨股骨假体套筒翻修术治疗旋转铰链膝关节股骨假体聚乙烯套筒磨损的临床疗效。方法回顾性分析2008年8月至2023年4月在中国人民解放军总医院第四医学中心骨科医学部治疗的旋转铰链型膝关节股骨假体聚乙烯套筒磨损患者21例,男8例、女13例,年龄63(38,76)岁,左侧11例、右侧10例,体质指数为25.0(22.5,31.0)kg/m^(2),均为单侧膝关节翻修。接受铰链型膝关节假体至翻修的时间间隔为10.5(6.0,17.0)年,其中18例为初次翻修、3例为再次翻修。所有患者均因股骨假体聚乙烯套筒磨损而接受股骨假体套筒翻修术治疗。收集并记录患者视觉模拟评分(visual analogue scale,VAS)、膝关节活动范围(range of motion,ROM)、髋膝踝角(hip-knee-ankle angle,HKA)变化程度和美国膝关节协会评分(Knee Society score,KSS)评估手术效果。结果所有患者均获得随访,随访时间为12.5(11.7,13.4)个月。术前VAS评分为5(3,7分),末次随访时减小至0(0,1)分,差异有统计学意义(Z=5.721,P<0.001)。末次随访时,KSS评分由术前的(41.19±13.65)分降至(79.81±7.80)分,差异有统计学意义(t=12.560,P<0.001);HKA由术前的174.65°±5.20°提高至178.71°±2.79°,差异有统计学意义(t=5.533,P<0.001);膝关节ROM由术前的69.05°±34.37°增加至110.00°±10.12°,差异有统计学意义(t=5.960,P<0.001);患者膝关节稳定,无被动屈伸松弛。结论股骨假体套筒翻修术治疗旋转铰链膝关节股骨假体聚乙烯套筒磨损可避免整体翻修造成的大量骨与软组织丢失,术后早期临床疗效满意。展开更多
Mesoporous carbons have been widely utilized as the sulfur host for lithium-sulfur （Li-S） batteries. The ability to engineer the porosity, wall thickness, and graphitization degree of the carbon host is essential fo...Mesoporous carbons have been widely utilized as the sulfur host for lithium-sulfur （Li-S） batteries. The ability to engineer the porosity, wall thickness, and graphitization degree of the carbon host is essential for addressing issues that hamper commercialization of Li-S batteries, such as fast capacity decay and poor high-rate performance. In this work, highly ordered, ultrathin mesoporous graphitic-carbon frameworks （MGFs） having unique cage-like mesoporosity, derived from self-assembled Fe304 nanoparticle superlattices, are demonstrated to be an excellent host for encapsulating sulfur. The resulting S@MGFs exhibit high specific capacity （1,446 mAh.g-1 at 0.15 C）, good rate capability （430 mAh.g-1 at 6 C）, and exceptional cycling stability （-0.049% capacity decay per cycle at 1 C） when used as Li-S cathodes. The superior electrochemical performance of the S@MGFs is attributed to the many unique and advantageous structural features of MGFs. In addition to the interconnected, ultrathin graphitic-carbon framework that ensures rapid electron and lithium-ion transport, the microporous openings between adjacent mesopores efficiently suppress the diffusion of polysulfides, leading to improved capacity retention even at high current densities.展开更多
Ni-rich layered cathodes have become the promising candidates for the next-generation high-energy Liion batteries due to their high energy density and competitive cost.However,they suffer from rapidcapacity fading due...Ni-rich layered cathodes have become the promising candidates for the next-generation high-energy Liion batteries due to their high energy density and competitive cost.However,they suffer from rapidcapacity fading due to the structural and interfacial instability upon long-term operation.Herein,the Tidoped and LiYO2-coated Ni-rich layered cathode has been synthesized via a facile one-step sinteringstrategy,which significantly restrains the interfacial parasitic side reactions and enhances the structuralstability.Specifically,the trace Ti^(4+)doping greatly stabilizes the lattice oxygen and alleviates the Li/Nidisorder while the LiYO_(2) coating layer can prevent the erosion of the cathode by the electrolyte duringcycles.As a result,the Ti-NCM83@LYO delivers a high specific capacity of 135 mAh g^(-1) even at 10C andthere is almost no capacity loss at 1C for 100 cycles.This work provides a simple one-step dual-modification strategy to meet the commercial requirements of Ni-rich cathodes.展开更多
In recirculating aquaculture systems,nitrification is usually accelerated by inoculating nitrifier or mature biocarriers.In this study,the performance of the establishment of nitrification in the MBBR according to thr...In recirculating aquaculture systems,nitrification is usually accelerated by inoculating nitrifier or mature biocarriers.In this study,the performance of the establishment of nitrification in the MBBR according to three different strategies:conventional method(Control group A),inoculation with biofloc recovered from a tilapia biofloc culture system(Group B),and addition with extra nitrite(Group C)in the Moving bed biofilm reactor(MBBR)was compared.Among them,the biofloc-inoculated group considerably accelerated the nitrification process in the MBBR(38 d),which is roughly 18 d faster than the control group(A)(56 d)and 21 d faster than group C(59 d).Less ammonia(8 mg/L NH_(4)^(+)-N,10 mg/L in other groups)and external nitrite(2 mg/L NO_(2)^(-)N)in the influent caused effluent ammonia to drop more slowly(5 d slower than the control group,8 d slower than the B group),which is detrimental to the nitrification process’development.Notably,the influent’s hydraulic retention time(HRT)was reduced from 12 h to 6 h following the successful establishment of nitrification.During the adaptation to reduced HRT,the MBBR inoculated with biofloc experienced short-term changes in the water quality index of the effluent water,whereas the other groups did not.The biofilm seeded with biofloc had the highest mean gray value ratio(1.42)of live/dead cell fluorescence,which grew better and could cover the entire groove under multiple microscope observations.However,the other groups did not demonstrate a similar trend.In summary,the research found that seeding biofloc use as nitrification bioaugmentation into the MBBR of the recirculating aquaculture system(RAS)to greatly speed up the nitrification process.展开更多
SARS-CoV-2 causes the pandemic of COVID-19 and no effective drugs for this disease are available thus far.Due to the high infectivity and pathogenicity of this virus,all studies on the live virus are strictly confined...SARS-CoV-2 causes the pandemic of COVID-19 and no effective drugs for this disease are available thus far.Due to the high infectivity and pathogenicity of this virus,all studies on the live virus are strictly confined in the biosafety level 3(BSL3)laboratory but this would hinder the basic research and antiviral drug development of SARS-CoV-2 because the BSL3 facility is not commonly available and the work in the containment is costly and laborious.In this study,we constructed a reverse genetics system of SARS-CoV-2 by assembling the viral cDNA in a bacterial artificial chromosome(BAC)vector with deletion of the spike(S)gene.Transfection of the cDNA into cells results in the production of an RNA replicon that keeps the capability of genome or subgenome replication but is deficient in virion assembly and infection due to the absence of S protein.Therefore,such a replicon system is not infectious and can be used in ordinary biological laboratories.We confirmed the efficient replication of the replicon by demonstrating the expression of the subgenomic RNAs which have similar profiles to the wild-type virus.By mutational analysis of nsp12 and nsp14,we showed that the RNA polymerase,exonuclease,and cap N7 methyltransferase play essential roles in genome replication and sgRNA production.We also created a SARS-CoV-2 replicon carrying a luciferase reporter gene and this system was validated by the inhibition assays with known anti-SARS-CoV-2 inhibitors.Thus,such a one-plasmid system is biosafe and convenient to use,which will benefit both fundamental research and development of antiviral drugs.展开更多
The nano-opto-electro-mechanical systems(NOEMS)are a class of hybrid solid devices that hold promises in both classical and quantum manipulations of the interplay between one or more degrees of freedom in optical,elec...The nano-opto-electro-mechanical systems(NOEMS)are a class of hybrid solid devices that hold promises in both classical and quantum manipulations of the interplay between one or more degrees of freedom in optical,electrical and mechanical modes.To date,studies of NOEMS using van der Waals(vdW)heterostructures are very limited,although vdW materials are known for emerging phenomena such as spin,valley,and topological physics.Here,we devise a universal method to easily and robustly fabricate vdW heterostructures into an architecture that hosts opto-electro-mechanical couplings in one single device.We demonstrated several functionalities,including nano-mechanical resonator,vacuum channel diodes,and ultrafast thermo-radiator,using monolithically sculpted graphene NOEMS as a platform.Optical readout of electric and magnetic field tuning of mechanical resonance in a CrOCl/graphene vdW NOEMS is further demonstrated.Our results suggest that the introduction of the vdW heterostructure into the NOEMS family will be of particular potential for the development of novel lab-on-a-chip systems.展开更多
基金This work is supported by the National Key R&D Program of China(Nos.2019YFA0307800,2017YFA0206302,and 2017YFA0206200)the National Natural Science Foundation of China(NSFC)(Nos.11974357,U1932151,and 51627801)+4 种基金G.Y.and X.H.thank the financial supports from the National Natural Science Foundation of China(NSFC)(No.11874409)This work is supported by the National Natural Science Foundation of China(NSFC)(Nos.61574060,and 8206300210)T.Y.acknowledges supports from the Major Program of Aerospace Advanced Manufacturing Technology Research Foundation NSFC and CASC,China(No.U1537204)Z.H.acknowledges the support from the Program of State Key Laboratory of Quantum Optics and Quantum Optics Devices(No.KF201816)The authors appreciate the help of Dr.Binbin Jiang in obtaining the HAADF-STEM images.
文摘Although many emerging new phenomena have been unraveled in two dimensional(2D)materials with long-range spin orderings,the usually low critical temperature in van der Waals(vdW)magnetic material has thus far hindered the related practical applications.Here,we show that ferromagnetism can hold above 300 K in a metallic phase of 1T-CrTe2 down to the ultra-thin limit.It thus makes CrTe2 so far the only known exfoliated ultra-thin vdW magnets with intrinsic long-range magnetic ordering above room temperature.An in-plane room-temperature negative anisotropic magnetoresistance(AMR)was obtained in ultra-thin CrTe2 devices,with a sign change in the AMR at lower temperature,with−0.6%and+5%at 300 and 10 K,respectively.Our findings provide insights into magnetism in ultra-thin CrTe2,expanding the vdW crystals toolbox for future room-temperature spintronic applications.
文摘目的探讨股骨假体套筒翻修术治疗旋转铰链膝关节股骨假体聚乙烯套筒磨损的临床疗效。方法回顾性分析2008年8月至2023年4月在中国人民解放军总医院第四医学中心骨科医学部治疗的旋转铰链型膝关节股骨假体聚乙烯套筒磨损患者21例,男8例、女13例,年龄63(38,76)岁,左侧11例、右侧10例,体质指数为25.0(22.5,31.0)kg/m^(2),均为单侧膝关节翻修。接受铰链型膝关节假体至翻修的时间间隔为10.5(6.0,17.0)年,其中18例为初次翻修、3例为再次翻修。所有患者均因股骨假体聚乙烯套筒磨损而接受股骨假体套筒翻修术治疗。收集并记录患者视觉模拟评分(visual analogue scale,VAS)、膝关节活动范围(range of motion,ROM)、髋膝踝角(hip-knee-ankle angle,HKA)变化程度和美国膝关节协会评分(Knee Society score,KSS)评估手术效果。结果所有患者均获得随访,随访时间为12.5(11.7,13.4)个月。术前VAS评分为5(3,7分),末次随访时减小至0(0,1)分,差异有统计学意义(Z=5.721,P<0.001)。末次随访时,KSS评分由术前的(41.19±13.65)分降至(79.81±7.80)分,差异有统计学意义(t=12.560,P<0.001);HKA由术前的174.65°±5.20°提高至178.71°±2.79°,差异有统计学意义(t=5.533,P<0.001);膝关节ROM由术前的69.05°±34.37°增加至110.00°±10.12°,差异有统计学意义(t=5.960,P<0.001);患者膝关节稳定,无被动屈伸松弛。结论股骨假体套筒翻修术治疗旋转铰链膝关节股骨假体聚乙烯套筒磨损可避免整体翻修造成的大量骨与软组织丢失,术后早期临床疗效满意。
基金A. G. D. acknowledges the financial support from the National Basic Research Program of China （No. 2014CB845602）, Natural National Science Foundation of China （No. 21373052）, and Shanghai International Science and Technology Cooperation Project （No. 15520720100）. D. Y. is grateful for financial support from Natural National Science Foundation of China （Nos. 51373035, 51373040, 51573030, and 51573028）, and International Science and Technology Cooperation Program of China （No. 2014DFE40130）.
文摘Mesoporous carbons have been widely utilized as the sulfur host for lithium-sulfur （Li-S） batteries. The ability to engineer the porosity, wall thickness, and graphitization degree of the carbon host is essential for addressing issues that hamper commercialization of Li-S batteries, such as fast capacity decay and poor high-rate performance. In this work, highly ordered, ultrathin mesoporous graphitic-carbon frameworks （MGFs） having unique cage-like mesoporosity, derived from self-assembled Fe304 nanoparticle superlattices, are demonstrated to be an excellent host for encapsulating sulfur. The resulting S@MGFs exhibit high specific capacity （1,446 mAh.g-1 at 0.15 C）, good rate capability （430 mAh.g-1 at 6 C）, and exceptional cycling stability （-0.049% capacity decay per cycle at 1 C） when used as Li-S cathodes. The superior electrochemical performance of the S@MGFs is attributed to the many unique and advantageous structural features of MGFs. In addition to the interconnected, ultrathin graphitic-carbon framework that ensures rapid electron and lithium-ion transport, the microporous openings between adjacent mesopores efficiently suppress the diffusion of polysulfides, leading to improved capacity retention even at high current densities.
基金This work was supported by the National Natural ScienceFoundation of China(grant No.21975074)the Innovation Programof Shanghai Municipal Education Commission,and the Fundamental Research Funds for the Central Universities.
文摘Ni-rich layered cathodes have become the promising candidates for the next-generation high-energy Liion batteries due to their high energy density and competitive cost.However,they suffer from rapidcapacity fading due to the structural and interfacial instability upon long-term operation.Herein,the Tidoped and LiYO2-coated Ni-rich layered cathode has been synthesized via a facile one-step sinteringstrategy,which significantly restrains the interfacial parasitic side reactions and enhances the structuralstability.Specifically,the trace Ti^(4+)doping greatly stabilizes the lattice oxygen and alleviates the Li/Nidisorder while the LiYO_(2) coating layer can prevent the erosion of the cathode by the electrolyte duringcycles.As a result,the Ti-NCM83@LYO delivers a high specific capacity of 135 mAh g^(-1) even at 10C andthere is almost no capacity loss at 1C for 100 cycles.This work provides a simple one-step dual-modification strategy to meet the commercial requirements of Ni-rich cathodes.
基金the Shanghai Municipal Science and Technology Commission Project(19DZ2284300).
文摘In recirculating aquaculture systems,nitrification is usually accelerated by inoculating nitrifier or mature biocarriers.In this study,the performance of the establishment of nitrification in the MBBR according to three different strategies:conventional method(Control group A),inoculation with biofloc recovered from a tilapia biofloc culture system(Group B),and addition with extra nitrite(Group C)in the Moving bed biofilm reactor(MBBR)was compared.Among them,the biofloc-inoculated group considerably accelerated the nitrification process in the MBBR(38 d),which is roughly 18 d faster than the control group(A)(56 d)and 21 d faster than group C(59 d).Less ammonia(8 mg/L NH_(4)^(+)-N,10 mg/L in other groups)and external nitrite(2 mg/L NO_(2)^(-)N)in the influent caused effluent ammonia to drop more slowly(5 d slower than the control group,8 d slower than the B group),which is detrimental to the nitrification process’development.Notably,the influent’s hydraulic retention time(HRT)was reduced from 12 h to 6 h following the successful establishment of nitrification.During the adaptation to reduced HRT,the MBBR inoculated with biofloc experienced short-term changes in the water quality index of the effluent water,whereas the other groups did not.The biofilm seeded with biofloc had the highest mean gray value ratio(1.42)of live/dead cell fluorescence,which grew better and could cover the entire groove under multiple microscope observations.However,the other groups did not demonstrate a similar trend.In summary,the research found that seeding biofloc use as nitrification bioaugmentation into the MBBR of the recirculating aquaculture system(RAS)to greatly speed up the nitrification process.
基金supported by Grants(the National Natural Science Foundation of China#32041002,#31971161,#31900546 and#81620108020)the Guangdong Science and Technology Department(#2019A1515011332)+1 种基金the Shenzhen Science and Technology Innovation Program(JSGG20200225150431472,JCYJ20190807160615255,JCYJ20190807153203560,and KQTD20180411143323605)supported by the Guangdong Zhujiang Leading Talents Programme and the National Tenthousand Talents Program。
文摘SARS-CoV-2 causes the pandemic of COVID-19 and no effective drugs for this disease are available thus far.Due to the high infectivity and pathogenicity of this virus,all studies on the live virus are strictly confined in the biosafety level 3(BSL3)laboratory but this would hinder the basic research and antiviral drug development of SARS-CoV-2 because the BSL3 facility is not commonly available and the work in the containment is costly and laborious.In this study,we constructed a reverse genetics system of SARS-CoV-2 by assembling the viral cDNA in a bacterial artificial chromosome(BAC)vector with deletion of the spike(S)gene.Transfection of the cDNA into cells results in the production of an RNA replicon that keeps the capability of genome or subgenome replication but is deficient in virion assembly and infection due to the absence of S protein.Therefore,such a replicon system is not infectious and can be used in ordinary biological laboratories.We confirmed the efficient replication of the replicon by demonstrating the expression of the subgenomic RNAs which have similar profiles to the wild-type virus.By mutational analysis of nsp12 and nsp14,we showed that the RNA polymerase,exonuclease,and cap N7 methyltransferase play essential roles in genome replication and sgRNA production.We also created a SARS-CoV-2 replicon carrying a luciferase reporter gene and this system was validated by the inhibition assays with known anti-SARS-CoV-2 inhibitors.Thus,such a one-plasmid system is biosafe and convenient to use,which will benefit both fundamental research and development of antiviral drugs.
基金This work is supported by the National Key R&D Program of China(2019YFA0307800,2017YFA0304203,and 2018YFA0306900)the National Natural Science Foundation of China(NSFC)(Grants 12004389,11974357,U1932151,and 12174444)+4 种基金L.W.acknowledges support from the Key Research Program of Frontier Sciences,CAS(Grant ZDBS-LY-JSC015)X.Li acknowledges support from the Joint Research Fund of Liaoning-Shenyang National Laboratory for Materials Science with Grant No.2019JH3/30100031D.S.acknowledges the Strategic Priority Research Program of Chinese Academy of Sciences(XDB30000000)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(ZDBS-LY-JSC027,QYZDB-SSW-SLH031)Liaoning Revitalization Talents Program(XLYC1807109)。
文摘The nano-opto-electro-mechanical systems(NOEMS)are a class of hybrid solid devices that hold promises in both classical and quantum manipulations of the interplay between one or more degrees of freedom in optical,electrical and mechanical modes.To date,studies of NOEMS using van der Waals(vdW)heterostructures are very limited,although vdW materials are known for emerging phenomena such as spin,valley,and topological physics.Here,we devise a universal method to easily and robustly fabricate vdW heterostructures into an architecture that hosts opto-electro-mechanical couplings in one single device.We demonstrated several functionalities,including nano-mechanical resonator,vacuum channel diodes,and ultrafast thermo-radiator,using monolithically sculpted graphene NOEMS as a platform.Optical readout of electric and magnetic field tuning of mechanical resonance in a CrOCl/graphene vdW NOEMS is further demonstrated.Our results suggest that the introduction of the vdW heterostructure into the NOEMS family will be of particular potential for the development of novel lab-on-a-chip systems.
