Due to the high theoretical capacity and energy density,conversion-type metal fluorides have captured plenty of attentions but still suffer from the inferior kinetic behaviors and serious capacity fading.For addressin...Due to the high theoretical capacity and energy density,conversion-type metal fluorides have captured plenty of attentions but still suffer from the inferior kinetic behaviors and serious capacity fading.For addressing the issues above,the strategies of surface/interface engineering are utilized for the preparation of sphere-like porous FeF3@C materials,where the as-resulted sample displays the uniform particle size(~150 nm in radii)and the ultrathin carbon layers(thickness of~10 nm).Significantly,benefitting from the rich oxygen of precursor,the interfacial chemical bonds Fe-O-C are successfully constructed between carbon matrix and FeF3 materials,accompanying by the enhancements of ions/electrons(e-)conductivity and stability.When used as Li-storage cathodes,the initial lithium-ions storage capacity could reach up to~400mAh·g^(-1) at 0.1 A·g^(-1).Even at 1.0 A·g^(-1),the capacity could be still remained at about 210 mAh·g^(-1),with the retention of 85%after 400 cycles.Assisted by the detailed kinetic behaviors,the considerable electrochemical properties come from the enhanced diffusion-controlled contributions,whilst the segregation of Fe with LiF is effectively alleviated by unique architecture.Moreover,during cycling,solid electrolyte interface film is reversibly formed/decomposed.Thus,this work is expected to offer rational exterior/interfacial designing strategies for metalbased samples.展开更多
Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)are two typical titanate-based sodium-storage materials,featuring the high theoretical capacity and favorable structure stability,respectively.Regulating the ratio of them in the...Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)are two typical titanate-based sodium-storage materials,featuring the high theoretical capacity and favorable structure stability,respectively.Regulating the ratio of them in the composite material is the key to strengthen its electrochemical characteristics.Herein,based on the high specific surface area and abundant surface functional groups of carbon dots(CDs),sodium titanate precursors containing CDs were in situ prepared by one-step hydrothermal method.After the thermal conversion of the precursors,a composite material(NNTO/C)of Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)was obtained,containing conductive carbon derived from CDs.The introduc⁃tion of conductive carbon not only adjusts the composition ratio of the mixed phases,but also provides a small charge transfer impedance(Rct,7.48Ω)and a big specific surface area(100.8 m^(2)/g).As a result,NNTO/C composites exhibit better sodium storage behavior while playing the synergistic interaction of mixed phases.When employed as the anode,after 200 cycles at 0.05 A/g,NNTO/C still maintains a specific capacity of 143.8 mA‧h/g.After 400 cycles at 1.00 A/g,the specific capacity remains as high as 108 mA‧h/g.This study suggests an innovative thinking for designing two-phase structures of electrode materials and the greater use of CDs in electrochemical energy storage.展开更多
Single-crystalline Ni-rich cathodes can provide high energy density and capacity retention rates for lithium-ion batteries(LIBs).However,single-crystalline Ni-rich cathodes experience severe transition metal dissoluti...Single-crystalline Ni-rich cathodes can provide high energy density and capacity retention rates for lithium-ion batteries(LIBs).However,single-crystalline Ni-rich cathodes experience severe transition metal dissolution,irreversible phase transitions,and reduced structural stability during prolonged cycling at high voltage,which will significantly hinder their practical application.Herein,a Li4TeO5surface coating along with bulk Te-gradient doping strategy is proposed and developed to solve these issues for single-crystalline Ni-rich LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2)cathode(LTeO-1.0).It has been found that the bulk Te^(6+)gradient doping can lead to the formation of robust Te-O bonds that effectively inhibit H_(2)-H3 phase transformations and reinforce the lattice framework,and the in-situ Li4TeO5coating layer can act as a protective layer that suppresses the parasitic reactions and grain fragmentation.Besides,the modified material exhibits a higher Young's modulus,which will be conducive to maintaining significant structural and electrochemical stability under high-voltage conditions,Especially,the LTeO-1.0 electrode shows the improved Li^(+)diffusion kinetics and thermodynamic stability as well as high capacity retention of 95.83%and 82.12%after 200 cycles at the cut-off voltage of 4.3 and 4,5 V.Therefore,the efficacious dualmodification strategy will definitely contribute to enhancing the structural and electrochemical stability of single-crystalline Ni-rich cathodes and developing their application in LIBs.展开更多
The polysulfide shuttle effect critically hinders lithium-sulfur(Li-S)battery development,therefore,the design of heterogeneous interface engineering with“adsorption-catalysis”functions for polysulfide conversion ha...The polysulfide shuttle effect critically hinders lithium-sulfur(Li-S)battery development,therefore,the design of heterogeneous interface engineering with“adsorption-catalysis”functions for polysulfide conversion has garnered considerable attention.However,the exploration of the intricate relationship between key electronic properties and catalytic activity at such interfaces remains a challenge.Additionally,a comprehensive understanding of the thermodynamic growth mechanisms for heterostructure materials is lacking.Herein,a Ni-based homologous structure was precisely constructed via thermodynamic control,with a specific focus on optimizing the interface design.The theoretical results show that the heterostructures with adjustable composition realize the appropriate upward shift to the D-band,improving the affinity towards polysulfide,and further reducing the reaction energy barrier.On this basis,the relationship between interface design and the D-band center,as well as catalytic performance,was established.Specifically,M-Ni_(3)Fe/Ni_(3)ZnC_(0.7)accomplishes the electron enrichment at the interface,supporting the further diffusion of polysulfides,and lowering the Li-S bond energy,performing the bidirectional catalytic transformation of polysulfides.As a result,the Li-S batteries with the cathode of M-Ni_(3)Fe/Ni_(3)ZnC_(0.7)/S deliver rate performances of discharge capacity of 514 mA h g^(−1)at 5.0 C.This understanding of the D-band and interfacial design provides a framework for Li-S catalyst optimization.展开更多
Stroke is a main cause of death and disability worldwide.The ability of the brain to selfrepair in the acute and chronic phases after stroke is minimal;however,promising stem cell-based interventions are emerging that...Stroke is a main cause of death and disability worldwide.The ability of the brain to selfrepair in the acute and chronic phases after stroke is minimal;however,promising stem cell-based interventions are emerging that may give substantial and possibly complete recovery of brain function after stroke.Many animal models and clinical trials have demonstrated that neural stem cells(NSCs)in the central nervous system can orchestrate neurological repair through nerve regeneration,neuron polarization,axon pruning,neurite outgrowth,repair of myelin,and remodeling of the microenvironment and brain networks.Compared with other types of stem cells,NSCs have unique advantages in cell replacement,paracrine action,inflammatory regulation and neuroprotection.Our review summarizes NSC origins,characteristics,therapeutic mechanisms and repair processes,then highlights current research findings and clinical evidence for NSC therapy.These results may be helpful to inform the direction of future stroke research and to guide clinical decision-making.展开更多
Cerebral palsy is the most common disease in children associated with lifelong disability in many countries.Clinical research has demonstrated that traditional physiotherapy and rehabilitation therapies cannot alone c...Cerebral palsy is the most common disease in children associated with lifelong disability in many countries.Clinical research has demonstrated that traditional physiotherapy and rehabilitation therapies cannot alone cure cerebral palsy.Stem cell transplantation is an emerging therapy that has been applied in clinical trials for a variety of neurological diseases because of the regenerative and unlimited proliferative capacity of stem cells.In this review, we summarize the design schemes and results of these clinical trials.Our findings reveal great differences in population characteristics, stem cell types and doses, administration methods, and evaluation methods among the included clinical trials.Furthermore, we also assess the safety and efficacy of these clinical trials.We anticipate that our findings will advance the rational development of clinical trials of stem cell therapy for cerebral palsy and contribute to the clinical application of stem cells.展开更多
Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends a...Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically.In this study,we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word.Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies.Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder.We identified 78 high-frequency Medical Subject Heading(MeSH)terms.A visual matrix was built with the repeated bisection method in gCLUTO software.A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software.The analyses demonstrated that in the 6-year period,hot topics were clustered into five categories.As suggested by the constructed strategic diagram,studies related to cytology and physiology were well-developed,whereas those related to neural stem cell applications,tissue engineering,metabolism and cell signaling,and neural stem cell pathology and virology remained immature.Neural stem cell therapy for stroke and Parkinson’s disease,the genetics of microRNAs and brain neoplasms,as well as neuroprotective agents,Zika virus,Notch receptor,neural crest and embryonic stem cells were identified as emerging hot spots.These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells.展开更多
Administration of human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)is believed to be an effective method for treating neurodevelopmental disorde rs.In this study,we investigated the possibility of hUC-MSCs...Administration of human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)is believed to be an effective method for treating neurodevelopmental disorde rs.In this study,we investigated the possibility of hUC-MSCs treatment of neonatal hypoxic/ischemic brain injury associated with maternal immune activation and the underlying mechanism.We established neonatal rat models of hypoxic/ischemic brain injury by exposing pregnant rats to lipopolysaccharide on day 16 or 17 of pregnancy.Rat offspring were intranasally administe red hUC-MSCs on postnatal day 14.We found that polypyrimidine tract-binding protein-1(PTBP-1)participated in the regulation of lipopolysaccharide-induced maternal immune activation,which led to neonatal hypoxic/ischemic brain injury.Intranasal delive ry of hUC-MSCs inhibited PTBP-1 expression,alleviated neonatal brain injury-related inflammation,and regulated the number and function of glial fibrillary acidic protein-positive astrocytes,there by promoting plastic regeneration of neurons and im p roving brain function.These findings suggest that hUC-MSCs can effectively promote the repair of neonatal hypoxic/ischemic brain injury related to maternal immune activation through inhibition of PTBP-1 expression and astrocyte activation.展开更多
Duplex-structured TC21 alloy samples were first solution-treated at a higher temperature in theα+βregion(940°C)with furnace cooling(FC),air cooling(AC),and water cooling(WC),followed by a second-stage solution ...Duplex-structured TC21 alloy samples were first solution-treated at a higher temperature in theα+βregion(940°C)with furnace cooling(FC),air cooling(AC),and water cooling(WC),followed by a second-stage solution treatment at a lower temperature in theα+βregion(900°C),and then finally aged at 590°C.The effects of the morphology and quantity ofαphases on the structure and properties of the TC21 alloy after the different heat treatments were analyzed.The in-situ tensile deformation process and crack propagation behavior were observed using scanning electron microscopy(SEM).The quantity of equiaxedαphases as well as the thickness of lamellarαphases reduced,the tensile strength increased firstly and then decreased,the elongation decreased with the increasing cooling rate after the first-stage solution treatment.The amount and size of lamellarαphases increased after the second-stage solution treatment because of sufficient diffusion of the alloying elements,thereby leading to increased tensile strength.The amount of dispersedαphases increased after the third-stage aging treatment owing to the increase in the nucleation rate,resulting in a noteworthy strengthening effect.After the third-stage aging treatment,the first-stage FC sample exhibited better mechanical properties because it contained more equiaxedαandβtrans phases than the first-stage AC and WC samples.展开更多
Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated ...Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated by X-ray diffraction, focused-ion beam-scanning electron microscopy dual-beam system, and transmission electron microscopy. When used as the anode material for lithium-ion batteries, Sb_2S_3 hollow microspheres manifest excellent rate property and enhanced lithium-storage capability and can deliver a discharge capacity of 674 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. Even at a high currentdensity of 5000 m A g^(-1), a discharge capacity of541 m Ah g^(-1) is achieved. Sb_2S_3 hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture, and the outstanding stability property is attributed to the sufficient interior void space,which can buffer the volume expansion.展开更多
Previous studies have shown that caveolin-1 is involved in regulating the differentiation of mesenchymal stem cells.However,its role in the differentiation of human adipose mesenchymal stem cells into dopaminergic neu...Previous studies have shown that caveolin-1 is involved in regulating the differentiation of mesenchymal stem cells.However,its role in the differentiation of human adipose mesenchymal stem cells into dopaminergic neurons remains unclear.The aim of this study was to investigate whether caveolin-1 regulates the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons.We also examined whether the expression of caveolin-1 could be modulated by RNA interference technology to promote the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons.The differentiation of human adipose mesenchymal stem cells into dopaminergic neurons was evaluated morphologically and by examining expression of the markers tyrosine hydroxylase,Lmx1a and Nurr1.The analyses revealed that during the differentiation of human adipose mesenchymal stem cells into dopaminergic neurons,the expression of caveolin-1 is decreased.Notably,the downregulation of caveolin-1 promoted the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons,and it increased the expression of tyrosine hydroxylase,Lmx1a and Nurr1.Together,our findings suggest that caveolin-1 plays a negative regulatory role in the differentiation of dopaminergic-like neurons from stem cells,and it may therefore be a potential molecular target for strategies for regulating the differentiation of these cells.This study was approved by the Medical Ethics Committee of the First Affiliated Hospital of Dalian Medical University of China(approval No.PJ-KS-KY-2020-54)on March 7,2017.展开更多
To study the effect ofαphase morphology(equiaxedα(αE)/lamellarα(αL))on the in situ tensile behavior of TC21 alloy,the slip band,dislocation,crack initiation,and propagation were analyzed by scanning electron micr...To study the effect ofαphase morphology(equiaxedα(αE)/lamellarα(αL))on the in situ tensile behavior of TC21 alloy,the slip band,dislocation,crack initiation,and propagation were analyzed by scanning electron microscopy(SEM)with in situ tensile stage and transmission electron microscopy(TEM).The results show that the slip bands first concentrate in theαE phases and easily truncate at theα/βphase boundaries,whereas the slip bands move across theαlamellae in theαL phase.Microcracks are easily generated inαE orα/βphase boundaries with large plastic deformation.When the quantity ofαL is more thanαE,the crack tip is more easily deflected atαphases orαclusters with different orientations,making the main crack propagation path more zigzag.When the volume fraction ratio ofαE toαL is~3:4,i.e.,the volume fraction ofαE is close to that ofαL,TC21 alloy exhibits better strength and slower crack propagation rate.展开更多
Nowadays, asphalt road has dominated highways around the world. Among various defects of asphalt road, crackshave been paid more attention, since cracks often cause major engineering and personnel safety incidents. Cu...Nowadays, asphalt road has dominated highways around the world. Among various defects of asphalt road, crackshave been paid more attention, since cracks often cause major engineering and personnel safety incidents. Currentmanual crack inspection methods are time-consuming and labor-intensive, and most segmentation methods cannot detect cracks at the pixel level. This paper proposes an intelligent segmentation and measurement model basedon the modified Mask R-CNN algorithm to automatically and accurately detect asphalt road cracks. The modelproposed in this paper mainly includes a convolutional neural network (CNN), an optimized region proposalnetwork (RPN), a region of interest (RoI) Align layer, a candidate area classification network and a Mask branch offully convolutional network (FCN). The ratio and size of anchors in the RPN are adjusted to improve the accuracyand efficiency of segmentation. Soft non-maximum suppression (Soft-NMS) algorithm is developed to improvethe segmentation accuracy. A dataset including 8,689 images (512× 512 pixels) of asphalt cracks is established andthe road crack is manually marked. Transfer learning is used to initialize the model parameters in the trainingprocess. To optimize the model training parameters, multiple comparison experiments are performed, and the testresults show that the mean average precision (mAP) value and F1-score of the optimal trained model are 0.952 and0.949. Subsequently, the robustness verification test and comparative test of the trained model are conducted andthe topological features of the crack are extracted. Then, the damage area, length and average width of the crackare measured automatically and accurately at pixel level. More importantly, this paper develops an automatic crackdetection platform for asphalt roads to automatically extract the number, area, length and average width of cracks,which can significantly improve the crack detection efficiency for the road maintenance industry.展开更多
Using low-cost FePO4·2H2O as iron source,Na2FePO4F/C composite is prepared by alcohol-assisted ball milling and solid-state reaction method.The XRD pattern of Na2FePO4F/C composite demonstrates sharp peaks,indica...Using low-cost FePO4·2H2O as iron source,Na2FePO4F/C composite is prepared by alcohol-assisted ball milling and solid-state reaction method.The XRD pattern of Na2FePO4F/C composite demonstrates sharp peaks,indicating high crystalline and phase purity.The SEM and TEM images reveal that diameter of the spherical-like Na2FePO4F/C particles ranges from 50 to 300 nm,and HRTEM image shows that the surface of Na2FePO4F/C composite is uniformly coated by carbon layer with a average thickness of about 3.6 nm.The carbon coating constrains the growth of the particles and effectively reduces the agglomeration of nanoparticles.Using lithium metal as anode,the composite delivers a discharge capacities of 102.8,96.4 and 90.3 mA·h/g at rates of 0.5C,1C and 2C,respectively.After 100 cycles at 0.5C,a discharge capacity of 98.9 mA·h/g is maintained with capacity retention of 96.2%.The Li+diffusion coefficient(D)of Na2FePO4F/C composite is calculated as 1.71×10^–9 cm^2/s.This study reveals that the simple solid state reaction could be a practical and effective synthetic route for the industrial production of Na2FePO4F/C material.展开更多
As a promising energy-storage device,the hybrid lithium-ion capacitor coupling with both a large energy density battery-type anode and a high power density capacitor-type cathode is attracting great attention.For the ...As a promising energy-storage device,the hybrid lithium-ion capacitor coupling with both a large energy density battery-type anode and a high power density capacitor-type cathode is attracting great attention.For the sake of improving the energy density of hybrid lithium-ion capacitor,the free-standing anodes with good electrochemical performance are essential.Herein,we design an effective electrospinning strategy to prepare free-standing MnS/Co4S3/Ni3S2/Ni/C-nanofibers(TMSs/Ni/C-NFs)film and firstly use it as a binder-free anode for hybrid lithium-ion capacitor.We find that the carbon nanofibers can availably prevent MnS/Co4S3/Ni3S2/Ni nanoparticles from aggregation as well as significantly improve the electrochemical performance.Therefore,the binder-free TMSs/Ni/C-NFs membrane displays an ultrahigh reversible capacity of 1246.9 m Ah g-1at 100 m A g-1,excellent rate capability(398 mAh g-1 at2000 mA g-1),and long-term cyclic endurance.Besides,we further assemble the hybrid lithium-ion capacitor,which exhibits a high energy density of 182.0 Wh kg-1at 121.1 W kg-1(19.0 Wh kg-1 at 3512.5 W kg-1)and remarkable cycle life.展开更多
Non-alcoholic fatty liver disease(NAFLD)has emerged as a significant health challenge,characterized by its widespread prevalence,intricate natural progression and multifaceted pathogenesis.Although NAFLD initially pre...Non-alcoholic fatty liver disease(NAFLD)has emerged as a significant health challenge,characterized by its widespread prevalence,intricate natural progression and multifaceted pathogenesis.Although NAFLD initially presents as benign fat accumulation,it may progress to steatosis,non-alcoholic steatohepatitis,cirrhosis,and hepatocellular carcinoma.Mesenchymal stem cells(MSCs)are recognized for their intrinsic self-renewal,superior biocompatibility,and minimal immunogenicity,positioning them as a therapeutic innovation for liver diseases.Therefore,this review aims to elucidate the potential roles of MSCs in alleviating the progression of NAFLD by alteration of underlying molecular pathways,including glycolipid metabolism,inflammation,oxidative stress,endoplasmic reticulum stress,and fibrosis.The insights are expected to provide further understanding of the potential of MSCs in NAFLD therapeutics,and support the development of MSC-based therapy in the treatment of NAFLD.展开更多
In this work,a high-efficiency photocatalytic BiOCl material with a visible light absorption range was successfully prepared by one-pot molecular self-assembly and particle recrystallization method at room temperature...In this work,a high-efficiency photocatalytic BiOCl material with a visible light absorption range was successfully prepared by one-pot molecular self-assembly and particle recrystallization method at room temperature.In the process of crystal growth,tartaric acid,as a structure control agent,gradually transforms the stacked two-dimensional nano-sheet-like BiOCl into a hierarchical structure composed of petallike nano-sheets through hydrogen bonding.Besides,the acid etching of organic carboxylic acid on the crystal surface increases the number of micropores and mesopores,thereby the reaction interface.The thiourea(TU)molecules adsorbed on the BiOCl surface with a strong electronic effect introduce oxygen vacancies(OVs)under the condition of low oxygen content.The synergistic effect of hierarchical structure and OVs reduces the recombination of photogenerated carriers,but absorbs more O_(2)and OH−to generate a large number of superoxide radicals(·O_(2)−)and hydroxyl radicals(·OH)effectively.The photocatalytic performance of the synthesized BiOCl material has been significantly improved,and it can effectively degrade 94.15%of rhodamine B(RhB)within 20 min.Furthermore,90.95%of tetracycline(TC),93.76%of ciprofloxacin(CIP),and 85.53%of methyl orange(MO)can be removed in 80 min.Therefore,our work provides an effective method for preparing BiOCl with visible light catalytic activity,which,of course,can be used to treat and repair actual environmental problems under mild conditions.展开更多
Extracellular vesicles(EVs)-based cell-free therapy,particularly stem cell-derived extracellular vesicles(SC-EVs),offers new insights into treating a series of neurological disorders and becomes a promising candidate ...Extracellular vesicles(EVs)-based cell-free therapy,particularly stem cell-derived extracellular vesicles(SC-EVs),offers new insights into treating a series of neurological disorders and becomes a promising candidate for alternative stem cell regenerative therapy.Currently,SC-EVs are considered direct therapeutic agents by themselves and/or dynamic delivery systems as they have a similar regenerative capacity of stem cells to promote neurogenesis and can easily load many functional small molecules to recipient cells in the central nervous system.Meanwhile,as non-living entities,SC-EVs avoid the uncontrollability and manufacturability limitations of live stem cell products in vivo(e.g.,low survival rate,immune response,and tumorigenicity)and in vitro(e.g.,restricted sources,complex preparation processes,poor quality control,low storage,shipping instability,and ethical controversy)by strict quality control system.Moreover,SC-EVs can be engineered or designed to enhance further overall yield,increase bioactivity,improve targeting,and extend their half-life.Here,this review provides an overview on the biological properties of SC-EVs,and the current progress in the strategies of native or bioengineered SC-EVs for nerve injury repairing is presented.Then we further summarize the challenges of recent research and perspectives for successful clinical application to advance SC-EVs from bench to bedside in neurological diseases.展开更多
Na0.44MnO2 nanorods have been prepared by a hydrothermal method.The experimental parameters have been systematically investigated and optimized.The results show that Na0.44MnO2 nanorods obtained via the hydrothermal t...Na0.44MnO2 nanorods have been prepared by a hydrothermal method.The experimental parameters have been systematically investigated and optimized.The results show that Na0.44MnO2 nanorods obtained via the hydrothermal treatment at 200℃for 16 h show the best electrochemical properties,which deliver the high initial discharge capacity of 110.7 mA·h/g at 50 mA/g in potential window 2.0-4.0 V.To further improve their electrochemical properties,a ball milling process with graphene has been carried out to obtain Na0.44MnO2/graphene composite.The initial discharge capacity of Na0.44MnO2/graphene composite is 106.9 mA·h/g at a current density of 50 mA/g.After 100 cycles,the residual discharge capacity is 91.8 mA·h/g and the capacity retention rate is 85.9%,which is much higher than that of pristine Na0.44MnO2 nanorods(74.7%)at the same condition.What is more,when the current density reaches 500 and 1000 mA/g,the corresponding discharge capacities of Na0.44MnO2/graphene composite are about 89 and 78 mA·h/g,respectively,indicating outstanding rate capability.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52004334,52003230,91962223 and 21473258)the Science and TechnologyInnovation Program of Hunan Province(No.2021RC2091)+3 种基金the China Postdoctoral Science Foundation(No.2021M692703)Natural Science Foundation of Hunan Province(No.2021JJ20073)National Key Research and Development Program of China(Nos.2018YFC1901601 and 2019YFC1907801)Collaborative Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2017-13)。
文摘Due to the high theoretical capacity and energy density,conversion-type metal fluorides have captured plenty of attentions but still suffer from the inferior kinetic behaviors and serious capacity fading.For addressing the issues above,the strategies of surface/interface engineering are utilized for the preparation of sphere-like porous FeF3@C materials,where the as-resulted sample displays the uniform particle size(~150 nm in radii)and the ultrathin carbon layers(thickness of~10 nm).Significantly,benefitting from the rich oxygen of precursor,the interfacial chemical bonds Fe-O-C are successfully constructed between carbon matrix and FeF3 materials,accompanying by the enhancements of ions/electrons(e-)conductivity and stability.When used as Li-storage cathodes,the initial lithium-ions storage capacity could reach up to~400mAh·g^(-1) at 0.1 A·g^(-1).Even at 1.0 A·g^(-1),the capacity could be still remained at about 210 mAh·g^(-1),with the retention of 85%after 400 cycles.Assisted by the detailed kinetic behaviors,the considerable electrochemical properties come from the enhanced diffusion-controlled contributions,whilst the segregation of Fe with LiF is effectively alleviated by unique architecture.Moreover,during cycling,solid electrolyte interface film is reversibly formed/decomposed.Thus,this work is expected to offer rational exterior/interfacial designing strategies for metalbased samples.
文摘Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)are two typical titanate-based sodium-storage materials,featuring the high theoretical capacity and favorable structure stability,respectively.Regulating the ratio of them in the composite material is the key to strengthen its electrochemical characteristics.Herein,based on the high specific surface area and abundant surface functional groups of carbon dots(CDs),sodium titanate precursors containing CDs were in situ prepared by one-step hydrothermal method.After the thermal conversion of the precursors,a composite material(NNTO/C)of Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)was obtained,containing conductive carbon derived from CDs.The introduc⁃tion of conductive carbon not only adjusts the composition ratio of the mixed phases,but also provides a small charge transfer impedance(Rct,7.48Ω)and a big specific surface area(100.8 m^(2)/g).As a result,NNTO/C composites exhibit better sodium storage behavior while playing the synergistic interaction of mixed phases.When employed as the anode,after 200 cycles at 0.05 A/g,NNTO/C still maintains a specific capacity of 143.8 mA‧h/g.After 400 cycles at 1.00 A/g,the specific capacity remains as high as 108 mA‧h/g.This study suggests an innovative thinking for designing two-phase structures of electrode materials and the greater use of CDs in electrochemical energy storage.
基金supported by the National Natural Science Foundation of China(U19A2018)the Natural Science Foundation of Hunan Province(2021JJ30651)the Postgraduate Scientific Research Innovation Project of Hunan Province(CX20230643).
文摘Single-crystalline Ni-rich cathodes can provide high energy density and capacity retention rates for lithium-ion batteries(LIBs).However,single-crystalline Ni-rich cathodes experience severe transition metal dissolution,irreversible phase transitions,and reduced structural stability during prolonged cycling at high voltage,which will significantly hinder their practical application.Herein,a Li4TeO5surface coating along with bulk Te-gradient doping strategy is proposed and developed to solve these issues for single-crystalline Ni-rich LiNi_(0.90)Co_(0.05)Mn_(0.05)O_(2)cathode(LTeO-1.0).It has been found that the bulk Te^(6+)gradient doping can lead to the formation of robust Te-O bonds that effectively inhibit H_(2)-H3 phase transformations and reinforce the lattice framework,and the in-situ Li4TeO5coating layer can act as a protective layer that suppresses the parasitic reactions and grain fragmentation.Besides,the modified material exhibits a higher Young's modulus,which will be conducive to maintaining significant structural and electrochemical stability under high-voltage conditions,Especially,the LTeO-1.0 electrode shows the improved Li^(+)diffusion kinetics and thermodynamic stability as well as high capacity retention of 95.83%and 82.12%after 200 cycles at the cut-off voltage of 4.3 and 4,5 V.Therefore,the efficacious dualmodification strategy will definitely contribute to enhancing the structural and electrochemical stability of single-crystalline Ni-rich cathodes and developing their application in LIBs.
基金supported financially by the National Natural Science Foundation of China(52172242,22109135,52371237)the Science&Technology Talents Lifting Project of Hunan Province(2023TJ-Z32)+2 种基金the Hunan Provincial Education Office Foundation of China(20B570,23B0126)the Natural Science Foundation of Hunan Province(2021JJ30659,2022JJ40423)the Postgraduate Scientific Research Innovation Project of Hunan Province(QL20230146).
文摘The polysulfide shuttle effect critically hinders lithium-sulfur(Li-S)battery development,therefore,the design of heterogeneous interface engineering with“adsorption-catalysis”functions for polysulfide conversion has garnered considerable attention.However,the exploration of the intricate relationship between key electronic properties and catalytic activity at such interfaces remains a challenge.Additionally,a comprehensive understanding of the thermodynamic growth mechanisms for heterostructure materials is lacking.Herein,a Ni-based homologous structure was precisely constructed via thermodynamic control,with a specific focus on optimizing the interface design.The theoretical results show that the heterostructures with adjustable composition realize the appropriate upward shift to the D-band,improving the affinity towards polysulfide,and further reducing the reaction energy barrier.On this basis,the relationship between interface design and the D-band center,as well as catalytic performance,was established.Specifically,M-Ni_(3)Fe/Ni_(3)ZnC_(0.7)accomplishes the electron enrichment at the interface,supporting the further diffusion of polysulfides,and lowering the Li-S bond energy,performing the bidirectional catalytic transformation of polysulfides.As a result,the Li-S batteries with the cathode of M-Ni_(3)Fe/Ni_(3)ZnC_(0.7)/S deliver rate performances of discharge capacity of 514 mA h g^(−1)at 5.0 C.This understanding of the D-band and interfacial design provides a framework for Li-S catalyst optimization.
基金This work was supported by the National Natural Science Foundation of China,No.81471308(to JL)Program of China National Health Commission and National Medical Products Administration(NMPA),No.CMR-20161129-1003(to JL)+1 种基金Liaoning Province Excellent Talent Program Project,No.XLYC1902031(to JL)Dalian Innovation Fund,No.2018J11CY025(to JL).
文摘Stroke is a main cause of death and disability worldwide.The ability of the brain to selfrepair in the acute and chronic phases after stroke is minimal;however,promising stem cell-based interventions are emerging that may give substantial and possibly complete recovery of brain function after stroke.Many animal models and clinical trials have demonstrated that neural stem cells(NSCs)in the central nervous system can orchestrate neurological repair through nerve regeneration,neuron polarization,axon pruning,neurite outgrowth,repair of myelin,and remodeling of the microenvironment and brain networks.Compared with other types of stem cells,NSCs have unique advantages in cell replacement,paracrine action,inflammatory regulation and neuroprotection.Our review summarizes NSC origins,characteristics,therapeutic mechanisms and repair processes,then highlights current research findings and clinical evidence for NSC therapy.These results may be helpful to inform the direction of future stroke research and to guide clinical decision-making.
基金supported by the National Natural Science Foundation of China, No.81471308(to JL)the Stem Cell Clinical Research Project of China, No.CMR-20161129-1003(to JL)the Dalian Innovation Technology Funding of China, No.2018 J11 CY025(to JL)。
文摘Cerebral palsy is the most common disease in children associated with lifelong disability in many countries.Clinical research has demonstrated that traditional physiotherapy and rehabilitation therapies cannot alone cure cerebral palsy.Stem cell transplantation is an emerging therapy that has been applied in clinical trials for a variety of neurological diseases because of the regenerative and unlimited proliferative capacity of stem cells.In this review, we summarize the design schemes and results of these clinical trials.Our findings reveal great differences in population characteristics, stem cell types and doses, administration methods, and evaluation methods among the included clinical trials.Furthermore, we also assess the safety and efficacy of these clinical trials.We anticipate that our findings will advance the rational development of clinical trials of stem cell therapy for cerebral palsy and contribute to the clinical application of stem cells.
基金supported by the National Natural Science Foundation of China,No.81471308(to JL)the Stem Cell Clinical Research Project in China,No.CMR-20161129-1003(to JL)the Innovation Technology Funding of Dalian in China,No.2018J11CY025(to JL)
文摘Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically.In this study,we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word.Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies.Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder.We identified 78 high-frequency Medical Subject Heading(MeSH)terms.A visual matrix was built with the repeated bisection method in gCLUTO software.A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software.The analyses demonstrated that in the 6-year period,hot topics were clustered into five categories.As suggested by the constructed strategic diagram,studies related to cytology and physiology were well-developed,whereas those related to neural stem cell applications,tissue engineering,metabolism and cell signaling,and neural stem cell pathology and virology remained immature.Neural stem cell therapy for stroke and Parkinson’s disease,the genetics of microRNAs and brain neoplasms,as well as neuroprotective agents,Zika virus,Notch receptor,neural crest and embryonic stem cells were identified as emerging hot spots.These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells.
基金the National Natural Science Foundation of China,No.81471308(to JL)Stem cell Clinical Research Registry Program,No.CMR-20161129-1003(to JL)+2 种基金Liaoning Province Excellent Talent Program Project of China,No.XLYC1902031(to JL)Dalian Innovation Fund of China,No.2018J11CY025(to JL)National Defense Science and Technology New Special Zone Contract,No.19-163-00-kx-003-001-01(to JL)。
文摘Administration of human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)is believed to be an effective method for treating neurodevelopmental disorde rs.In this study,we investigated the possibility of hUC-MSCs treatment of neonatal hypoxic/ischemic brain injury associated with maternal immune activation and the underlying mechanism.We established neonatal rat models of hypoxic/ischemic brain injury by exposing pregnant rats to lipopolysaccharide on day 16 or 17 of pregnancy.Rat offspring were intranasally administe red hUC-MSCs on postnatal day 14.We found that polypyrimidine tract-binding protein-1(PTBP-1)participated in the regulation of lipopolysaccharide-induced maternal immune activation,which led to neonatal hypoxic/ischemic brain injury.Intranasal delive ry of hUC-MSCs inhibited PTBP-1 expression,alleviated neonatal brain injury-related inflammation,and regulated the number and function of glial fibrillary acidic protein-positive astrocytes,there by promoting plastic regeneration of neurons and im p roving brain function.These findings suggest that hUC-MSCs can effectively promote the repair of neonatal hypoxic/ischemic brain injury related to maternal immune activation through inhibition of PTBP-1 expression and astrocyte activation.
基金This work was financially supported by the Guizhou Science and Technology Fund Project(Nos.[2018]1027,[2019]2165,and[2014]6013)the Engineering Research Center Project from Guizhou Provincial Education Department,China(No.[2017]016).
文摘Duplex-structured TC21 alloy samples were first solution-treated at a higher temperature in theα+βregion(940°C)with furnace cooling(FC),air cooling(AC),and water cooling(WC),followed by a second-stage solution treatment at a lower temperature in theα+βregion(900°C),and then finally aged at 590°C.The effects of the morphology and quantity ofαphases on the structure and properties of the TC21 alloy after the different heat treatments were analyzed.The in-situ tensile deformation process and crack propagation behavior were observed using scanning electron microscopy(SEM).The quantity of equiaxedαphases as well as the thickness of lamellarαphases reduced,the tensile strength increased firstly and then decreased,the elongation decreased with the increasing cooling rate after the first-stage solution treatment.The amount and size of lamellarαphases increased after the second-stage solution treatment because of sufficient diffusion of the alloying elements,thereby leading to increased tensile strength.The amount of dispersedαphases increased after the third-stage aging treatment owing to the increase in the nucleation rate,resulting in a noteworthy strengthening effect.After the third-stage aging treatment,the first-stage FC sample exhibited better mechanical properties because it contained more equiaxedαandβtrans phases than the first-stage AC and WC samples.
基金supported financially by the National Natural Foundation of China(Grant No.51672234)the Research Foundation for Hunan Youth Outstanding People from Hunan Provincial Science and Technology Department(2015RS4030)+1 种基金Hunan 2011 Collaborative Innovation Center of Chemical Engineering&Technology with Environmental Benignity and Effective Resource UtilizationProgram for Innovative Research Cultivation Team in University of Ministry of Education of China(1337304)
文摘Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated by X-ray diffraction, focused-ion beam-scanning electron microscopy dual-beam system, and transmission electron microscopy. When used as the anode material for lithium-ion batteries, Sb_2S_3 hollow microspheres manifest excellent rate property and enhanced lithium-storage capability and can deliver a discharge capacity of 674 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. Even at a high currentdensity of 5000 m A g^(-1), a discharge capacity of541 m Ah g^(-1) is achieved. Sb_2S_3 hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture, and the outstanding stability property is attributed to the sufficient interior void space,which can buffer the volume expansion.
基金This work was supported by National Stem Cell Clinical Research Registered Project,No.CMR-20161129-1003(to JL)Dalian Science and Technology Innovation Fund,No.2018J11CY025(to JL).
文摘Previous studies have shown that caveolin-1 is involved in regulating the differentiation of mesenchymal stem cells.However,its role in the differentiation of human adipose mesenchymal stem cells into dopaminergic neurons remains unclear.The aim of this study was to investigate whether caveolin-1 regulates the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons.We also examined whether the expression of caveolin-1 could be modulated by RNA interference technology to promote the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons.The differentiation of human adipose mesenchymal stem cells into dopaminergic neurons was evaluated morphologically and by examining expression of the markers tyrosine hydroxylase,Lmx1a and Nurr1.The analyses revealed that during the differentiation of human adipose mesenchymal stem cells into dopaminergic neurons,the expression of caveolin-1 is decreased.Notably,the downregulation of caveolin-1 promoted the differentiation of human adipose mesenchymal stem cells into dopaminergic-like neurons,and it increased the expression of tyrosine hydroxylase,Lmx1a and Nurr1.Together,our findings suggest that caveolin-1 plays a negative regulatory role in the differentiation of dopaminergic-like neurons from stem cells,and it may therefore be a potential molecular target for strategies for regulating the differentiation of these cells.This study was approved by the Medical Ethics Committee of the First Affiliated Hospital of Dalian Medical University of China(approval No.PJ-KS-KY-2020-54)on March 7,2017.
基金financially supported by Guizhou Science and Technology Project(Nos.(2018)1027 and(2019)2165)the Engineering Research Center Project from Guizhou Provincial Education Department(No.(2017)016)。
文摘To study the effect ofαphase morphology(equiaxedα(αE)/lamellarα(αL))on the in situ tensile behavior of TC21 alloy,the slip band,dislocation,crack initiation,and propagation were analyzed by scanning electron microscopy(SEM)with in situ tensile stage and transmission electron microscopy(TEM).The results show that the slip bands first concentrate in theαE phases and easily truncate at theα/βphase boundaries,whereas the slip bands move across theαlamellae in theαL phase.Microcracks are easily generated inαE orα/βphase boundaries with large plastic deformation.When the quantity ofαL is more thanαE,the crack tip is more easily deflected atαphases orαclusters with different orientations,making the main crack propagation path more zigzag.When the volume fraction ratio ofαE toαL is~3:4,i.e.,the volume fraction ofαE is close to that ofαL,TC21 alloy exhibits better strength and slower crack propagation rate.
基金This research was funded by the National Key Research and Development Program of China(No.2017YFC1501204)the National Natural Science Foundation of China(No.51678536)+4 种基金the Guangdong Innovative and Entrepreneurial Research Team Program(2016ZT06N340)the Program for Science and Technology Innovation Talents in Universities of Henan Province(Grant No.19HASTIT043)the Outstanding Young Talent Research Fund of Zhengzhou University(1621323001)the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(18IRTSTHN007)the Research on NonDestructive Testing(NDT)and Rapid Evaluation Technology for Grouting Quality of Prestressed Ducts(Contract No.HG-GCKY-01-002).The authors would like to thank for these financial supports.
文摘Nowadays, asphalt road has dominated highways around the world. Among various defects of asphalt road, crackshave been paid more attention, since cracks often cause major engineering and personnel safety incidents. Currentmanual crack inspection methods are time-consuming and labor-intensive, and most segmentation methods cannot detect cracks at the pixel level. This paper proposes an intelligent segmentation and measurement model basedon the modified Mask R-CNN algorithm to automatically and accurately detect asphalt road cracks. The modelproposed in this paper mainly includes a convolutional neural network (CNN), an optimized region proposalnetwork (RPN), a region of interest (RoI) Align layer, a candidate area classification network and a Mask branch offully convolutional network (FCN). The ratio and size of anchors in the RPN are adjusted to improve the accuracyand efficiency of segmentation. Soft non-maximum suppression (Soft-NMS) algorithm is developed to improvethe segmentation accuracy. A dataset including 8,689 images (512× 512 pixels) of asphalt cracks is established andthe road crack is manually marked. Transfer learning is used to initialize the model parameters in the trainingprocess. To optimize the model training parameters, multiple comparison experiments are performed, and the testresults show that the mean average precision (mAP) value and F1-score of the optimal trained model are 0.952 and0.949. Subsequently, the robustness verification test and comparative test of the trained model are conducted andthe topological features of the crack are extracted. Then, the damage area, length and average width of the crackare measured automatically and accurately at pixel level. More importantly, this paper develops an automatic crackdetection platform for asphalt roads to automatically extract the number, area, length and average width of cracks,which can significantly improve the crack detection efficiency for the road maintenance industry.
基金Projects(51472211,51502256)supported by the National Natural Science Foundation of ChinaProjects(2016GK4005,2016GK4030)supported by the Strategic New Industry of Hunan Province,ChinaProject(13C925)supported by the Research Foundation of Education Bureau of Hunan Province,China
文摘Using low-cost FePO4·2H2O as iron source,Na2FePO4F/C composite is prepared by alcohol-assisted ball milling and solid-state reaction method.The XRD pattern of Na2FePO4F/C composite demonstrates sharp peaks,indicating high crystalline and phase purity.The SEM and TEM images reveal that diameter of the spherical-like Na2FePO4F/C particles ranges from 50 to 300 nm,and HRTEM image shows that the surface of Na2FePO4F/C composite is uniformly coated by carbon layer with a average thickness of about 3.6 nm.The carbon coating constrains the growth of the particles and effectively reduces the agglomeration of nanoparticles.Using lithium metal as anode,the composite delivers a discharge capacities of 102.8,96.4 and 90.3 mA·h/g at rates of 0.5C,1C and 2C,respectively.After 100 cycles at 0.5C,a discharge capacity of 98.9 mA·h/g is maintained with capacity retention of 96.2%.The Li+diffusion coefficient(D)of Na2FePO4F/C composite is calculated as 1.71×10^–9 cm^2/s.This study reveals that the simple solid state reaction could be a practical and effective synthetic route for the industrial production of Na2FePO4F/C material.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51072173, 51272221 and 51302239)Specialized Research Fund for the Doctoral Program of Higher Education (Grant Nos. 20134301130001)the Natural Science Foundation of Hunan Province, China (Grant Nos. 13JJ4051).
文摘As a promising energy-storage device,the hybrid lithium-ion capacitor coupling with both a large energy density battery-type anode and a high power density capacitor-type cathode is attracting great attention.For the sake of improving the energy density of hybrid lithium-ion capacitor,the free-standing anodes with good electrochemical performance are essential.Herein,we design an effective electrospinning strategy to prepare free-standing MnS/Co4S3/Ni3S2/Ni/C-nanofibers(TMSs/Ni/C-NFs)film and firstly use it as a binder-free anode for hybrid lithium-ion capacitor.We find that the carbon nanofibers can availably prevent MnS/Co4S3/Ni3S2/Ni nanoparticles from aggregation as well as significantly improve the electrochemical performance.Therefore,the binder-free TMSs/Ni/C-NFs membrane displays an ultrahigh reversible capacity of 1246.9 m Ah g-1at 100 m A g-1,excellent rate capability(398 mAh g-1 at2000 mA g-1),and long-term cyclic endurance.Besides,we further assemble the hybrid lithium-ion capacitor,which exhibits a high energy density of 182.0 Wh kg-1at 121.1 W kg-1(19.0 Wh kg-1 at 3512.5 W kg-1)and remarkable cycle life.
文摘Non-alcoholic fatty liver disease(NAFLD)has emerged as a significant health challenge,characterized by its widespread prevalence,intricate natural progression and multifaceted pathogenesis.Although NAFLD initially presents as benign fat accumulation,it may progress to steatosis,non-alcoholic steatohepatitis,cirrhosis,and hepatocellular carcinoma.Mesenchymal stem cells(MSCs)are recognized for their intrinsic self-renewal,superior biocompatibility,and minimal immunogenicity,positioning them as a therapeutic innovation for liver diseases.Therefore,this review aims to elucidate the potential roles of MSCs in alleviating the progression of NAFLD by alteration of underlying molecular pathways,including glycolipid metabolism,inflammation,oxidative stress,endoplasmic reticulum stress,and fibrosis.The insights are expected to provide further understanding of the potential of MSCs in NAFLD therapeutics,and support the development of MSC-based therapy in the treatment of NAFLD.
基金Project(52072325)supported by the National Natural Science Foundation of ChinaProject(20A486)supported by the Key Research Foundation of Education Bureau of Hunan Province,ChinaProject(1337304)supported by Hunan 2011 Collaborative Innovation Center of Chemical Engineering and Technology with Environmental Benignity and Effective Resource Utilization,China。
基金financially supported by the National Natural Science Foundation of China (No. 51602281)the China Postdoctoral Science Foundation (No. 2017M621832)+3 种基金the Science and Technology Innovation Cultivation Fund project of Yangzhou University (No. 2019CXJ092)the project of national local joint engineering laboratory to functional adsorption material technology for the environmental protection, Soochow University (No. SDGC2124)Yangzhou University High-end Talent Support Programthe “Qinglan Project” of Jiangsu Universities
文摘In this work,a high-efficiency photocatalytic BiOCl material with a visible light absorption range was successfully prepared by one-pot molecular self-assembly and particle recrystallization method at room temperature.In the process of crystal growth,tartaric acid,as a structure control agent,gradually transforms the stacked two-dimensional nano-sheet-like BiOCl into a hierarchical structure composed of petallike nano-sheets through hydrogen bonding.Besides,the acid etching of organic carboxylic acid on the crystal surface increases the number of micropores and mesopores,thereby the reaction interface.The thiourea(TU)molecules adsorbed on the BiOCl surface with a strong electronic effect introduce oxygen vacancies(OVs)under the condition of low oxygen content.The synergistic effect of hierarchical structure and OVs reduces the recombination of photogenerated carriers,but absorbs more O_(2)and OH−to generate a large number of superoxide radicals(·O_(2)−)and hydroxyl radicals(·OH)effectively.The photocatalytic performance of the synthesized BiOCl material has been significantly improved,and it can effectively degrade 94.15%of rhodamine B(RhB)within 20 min.Furthermore,90.95%of tetracycline(TC),93.76%of ciprofloxacin(CIP),and 85.53%of methyl orange(MO)can be removed in 80 min.Therefore,our work provides an effective method for preparing BiOCl with visible light catalytic activity,which,of course,can be used to treat and repair actual environmental problems under mild conditions.
基金financial support received from the Program of the China National Health Commission and National Medical Products Administration(NMPA)under Grant No.CMR-20161129-1003(to JL)The National Nature Science Foundation of China under Grant No.82072953(to LW)+2 种基金The Liaoning Province Excellent Talent Program Project under Grant No.XLYC1902031(to JL)Top young talents of Liaoning Provincial Government under Grant No.XLYC1907009(to LW)Dalian Outstanding Young Talents Project under Grant No.2021RJ12(to LW)。
文摘Extracellular vesicles(EVs)-based cell-free therapy,particularly stem cell-derived extracellular vesicles(SC-EVs),offers new insights into treating a series of neurological disorders and becomes a promising candidate for alternative stem cell regenerative therapy.Currently,SC-EVs are considered direct therapeutic agents by themselves and/or dynamic delivery systems as they have a similar regenerative capacity of stem cells to promote neurogenesis and can easily load many functional small molecules to recipient cells in the central nervous system.Meanwhile,as non-living entities,SC-EVs avoid the uncontrollability and manufacturability limitations of live stem cell products in vivo(e.g.,low survival rate,immune response,and tumorigenicity)and in vitro(e.g.,restricted sources,complex preparation processes,poor quality control,low storage,shipping instability,and ethical controversy)by strict quality control system.Moreover,SC-EVs can be engineered or designed to enhance further overall yield,increase bioactivity,improve targeting,and extend their half-life.Here,this review provides an overview on the biological properties of SC-EVs,and the current progress in the strategies of native or bioengineered SC-EVs for nerve injury repairing is presented.Then we further summarize the challenges of recent research and perspectives for successful clinical application to advance SC-EVs from bench to bedside in neurological diseases.
基金Project(51672234)supported by the National Natural Science Foundation of ChinaProject(1337304)supported by the Program for Innovative Research Cultivation Team in University,Ministry of Education,China
文摘Na0.44MnO2 nanorods have been prepared by a hydrothermal method.The experimental parameters have been systematically investigated and optimized.The results show that Na0.44MnO2 nanorods obtained via the hydrothermal treatment at 200℃for 16 h show the best electrochemical properties,which deliver the high initial discharge capacity of 110.7 mA·h/g at 50 mA/g in potential window 2.0-4.0 V.To further improve their electrochemical properties,a ball milling process with graphene has been carried out to obtain Na0.44MnO2/graphene composite.The initial discharge capacity of Na0.44MnO2/graphene composite is 106.9 mA·h/g at a current density of 50 mA/g.After 100 cycles,the residual discharge capacity is 91.8 mA·h/g and the capacity retention rate is 85.9%,which is much higher than that of pristine Na0.44MnO2 nanorods(74.7%)at the same condition.What is more,when the current density reaches 500 and 1000 mA/g,the corresponding discharge capacities of Na0.44MnO2/graphene composite are about 89 and 78 mA·h/g,respectively,indicating outstanding rate capability.
