Current perspectives on mesenchymal stem cells as a potential therapeutic strategy for non-alcoholic fatty liver disease

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.

Solid-state synthesis and ion transport characteristics of the β-KSbF_(4) for all-solid-state fluoride-ion batteries

All-solid-state fluoride ion batteries(FIBs)have been recently considered as a post-lithium-ion battery system due to their high safety and high energy density.Just like all solid-state lithium batteries,the key to the development of FIBs lies in room-temperature electrolytes with high ionic conductivity.β-KSbF_(4) is a kind of promising solid-state electrolyte for FIBs owing to its rational ionic conductivity and relatively wide electrochemical stability window at room temperature.However,the previous synthesis routes ofβ-KSbF_(4) required the use of highly toxic hydrofluoric acid and the ionic conductivity of as-prepared product needs to be further improved.Herein,the β-KSbF_(4) sample with an ionic conductivity of 1.04×10^(-4)s cm^(-1)(30°C)is synthesized through the simple solid-state route.In order to account for the high ionic conductivity of the as-synthesizedβ-KSbF_(4),X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive X-ray spectroscopy(EDS)are used to characterize the physic-ochemical properties.The results show that the as-synthesizedβ-KSbF_(4) exhibits higher carrier concentra-tion of 1.0×10^(-6)S cm-Hz^(-1)K and hopping frequency of 1.31×10^(6)Hz at 30°C due to the formation of the fluorine vacancies.Meanwhile,the hopping frequency shows the same trend as the changes of ionic conductivity with the changes of temperature,while the carrier concentration is found to be almost con-stant.The two different trends indicate the hopping frequency is mainly responsible for the ionic conduc-tion behavior withinβ-KSbF_(4).Furthermore,the all-solid-state FIBs,in which Ag and Pb+PbF_(2) are adopted as cathode and anode,andβ-KSbF_(4) as fluoride ion conductor,are capable of reversible charge and discharge.The assembled FIBs show a discharge capacity of 108.4 mA h g^(-1) at 1st cycle and 74.2 mA h g^(-1) at 50th cycle.Based on an examination of the capacity decay mechanism,it has been found that deterioration of the electrolyte/electrode interface is an important reason for hindering the commer-cial application of FIBs.Hence,the in-depth comprehension of the ion transport characteristics inβ-KSbF_(4) and the interpretation of the capacity fading mechanism will be conducive to promoting development of high-performanceFIBs.

多孔氮掺杂FeP/C纳米纤维作为钾离子电池负极

由于自然界中钾储量巨大且K+/K电位低,钾离子电池(PIBs)被认为是锂离子电池的替代品之一。因此,在这项工作中,我们合成了多孔氮掺杂FeP/C纳米纤维(P-FeP/C-N NFs),一种用于PIB的新型电极材料。通过简单的静电纺丝和随后的煅烧处理,将聚丙烯腈(PAN)和聚甲基丙烯酸甲酯(PMMA)分别用作氮源和造孔剂,引入氮提高了材料的导电性,多孔结构的形成增加了比表面积。将P-FeP/CN NFs用作钾离子电池的电极,表现出优异的电化学性能。P-FeP/C-N NFs电极在100 mA/g循环250次后放电容量为274.2 mA·h/g,在1000 mA/g循环300次后放电容量为171.3 mA·h/g。即使在5000 mA/g下,也显示出150.1 mA·h/g的高放电容量。结果表明P-FeP/C-N NFs有望成为钾离子电池负极材料的候选材料。

Restraining migration and dissolution of transition-metal-ions via functionalized separator for Li-rich Mn-based cathode with high-energy-density

Lithium-rich manganese-based materials(LRMs) are promising cathode for high-energy-density lithiumion batteries due to their high capacity,low toxicity,and low cost.However,LRMs suffer from serious voltage decay and capacity fade due to continual migration and dissolution of transition metal ions(TMs) during cycling process.Herein,a novel strategy is proposed to inhibit the TMs migration of LRMs through a modified separator by means of functionalized carbon coating layer,which depends on the chemical constraint of the abundant functional groups in the modified super P.In addition,it has been found that the dissolution of TMs can be restrained based on the Le Chatelier's principle.Moreover,the modified separator owns good wettability toward the electrolyte.As a result,the LRMs cathode with the modified separator delivers a high discharge capacity of 329.93 mA h g-1 at 0.1 C,and achieves good cyclic performance,the enhanced reaction kinetics and low voltage decay.Therefore,this work provides a new idea to promote the comprehensive electrochemical performances of Li-ion batteries with LRMs cathode through a strategy of separator modification.

Study on Evaluation Method of Failure Pressure for Pipeline with Axially Adjacent Defects

The interaction between axially adjacent defects is more significant than that between circumferentially aligned defects.However,the existing failure pressure assessment methods cannot accurately predict the failure pressure of axial adjacent defects.In the paper,the finite element model is adopted to analyze the influence of defect size,distribution mode and spacing between adjacent defects on failure pressure.A new failure pressure evaluation method is proposed by establishing the effective depth calculation model of corrosion colony with different distribution model.The burst test of X52 pipeline is carried out to verify the applicability of the method.It shows that the results of new method are consistent with the test results of pipeline with various defects and steel grades.

Neuroregeneration and functional recovery after stroke: advancing neural stem cell therapy toward clinical application

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.

Mapping theme trends and knowledge structures for human neural stem cells:a quantitative and co-word biclustering analysis for the 2013-2018 period

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.

Progress in clinical trials of stem cell therapy for cerebral palsy

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.

Human umbilical cord-derived mesenchymal stem cells promote repair of neonatal brain injury caused by hypoxia/ischemia in rats

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.

Influence of multi-stage heat treatment on the microstructure and mechanical properties of TC21 titanium alloy

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.

Template-Free Synthesis of Sb_2S_3 Hollow Microspheres as Anode Materials for Lithium-Ion and Sodium-Ion Batteries

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.

Caveolin-1 downregulation promotes the dopaminergic neuron-like differentiation of human adipose-derived mesenchymal stem cells

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.

Intelligent Segmentation and Measurement Model for Asphalt Road Cracks Based on Modified Mask R-CNN Algorithm

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.

Synthesis and characterization of Na0.44MnO2 nanorods/graphene composite as cathode materials for sodium-ion batteries

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.

Na2FePO4F/C composite synthesized via a simple solid state route for lithium-ion batteries

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.

Nitrogen-Doped TiO_2–C Composite Nanofibers with High-Capacity and Long-Cycle Life as Anode Materials for Sodium-Ion Batteries

Nitrogen-doped TiO_2–C composite nanofibers(TiO_2/N–C NFs) were manufactured by a convenient and green electrospinning technique in which urea acted as both the nitrogen source and a pore-forming agent. The TiO_2/N–C NFs exhibit a large specific surface area(213.04 m^2 g^(-1)) and a suitable nitrogen content(5.37 wt%). The large specific surface area can increase the contribution of the extrinsic pseudocapacitance, which greatly enhances the rate capability. Further, the diffusion coefficient of sodium ions(DNa_+) could be greatly improved by the incorporation of nitrogen atoms. Thus, the TiO_2/N–C NFs display excellent electrochemical properties in Na-ion batteries. A TiO_2/N–C NF anode delivers a high reversible discharge capacity of 265.8 mAh g^(-1) at 0.05 A g^(-1) and an outstanding long cycling performance even at a high current density(118.1 m Ah g^(-1)) with almost no capacity decay at 5 A g^(-1) over 2000 cycles. Therefore, this work sheds light on the application of TiO_2-based materials in sodium-ion batteries.

Free-standing ternary metallic sulphides/Ni/C-nanofiber anodes for high-performance lithium-ion capacitors

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.

Dielectric Characterization and Microwave Roasting of Molybdenite Concentrates at 915 MHz Frequency

The magnetic hysteresis loop was measured to know the magnetic property of molybdenite concentrate.In order to evaluate its microwave absorption capacity, the dielectric properties of molybdenite concentrate was investigated using cavity perturbation method at 915 MHz dependent on densities and temperatures.The parameter data were fitted using regression fit and a model related to the same density and temperature ranges was developed.A nonlinear surface fitting was used to present visually the effect of dielectric parameters on the microwave penetrate depth of molybdnite concentrate.The crystal products of MoO 3 obtained from microwave roasting at different temperatures were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD).The results show both the dielectric constants and loss factors increase in the increase of apparent densities and temperatures with different growth rates in the experimental range.Due to the distinguished trend of dielectric performance dependent on temperatures, two parts in the heating scenario for the molybdenite concentrate samples were divided.The microwave penetration depth is inversely proportional to both apparent densities and temperatures.The nonlinear fitting surfaces indicate the increase of dielectric loss provides an enough decrease in microwave penetration depth.In contrast, the dielectric constant has a positive effect for it.Pure MoO 3 was produced at 800 ℃ by using microwave energy.This work can be helpful to design and simulate microwave system for efficient beneficiation of molybdenite concentrate and to prepare molybdenum products from this concentrate.

Next generation of neurological therapeutics:Native and bioengineered extracellular vesicles derived from stem cells

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.

Acoustic pressure simulation and experiment design in seafloor mining environment

Since the suspended sediments have severe influence on acoustic radiated field of transducer, it is significant for sonar system to analyze the influence of suspended sediments on acoustic pressure in the seafloor mining environment. Based on the KZK （Khokhlov-Zabolotkaya-Kuznetsov） equation, the method of sound field analysis in turbid water is proposed. Firstly, based on the analysis of absorption in clean water and viscous absorption of suspended sediments, the sound attenuation coefficient as a function of frequency in the mining environment is calculated. Then, based on the solution of KZK equation in frequency domain, the axial sound pressure of transducer in clear water as well as turbid water is simulated using MATLAB. Simulation results show that the influence of the suspended sediments on the pressure of near field is negligible. With the increase of distance, the axial sound pressures of transducer decay rapidly. Suspended sediments seriously affect the pressure in far-field. To verify the validity of this numerical method, experiment is designed and the axial sound pressure of transducer with a frequency of 200 kHz and a beam width of 7.5~ is measured in simulated mining experiment. The results show that the simulation results agree well with the experiments, and the KZK equation can be used to calculate the sound field in turbid water.