Direct Regeneration of Spent Lithium-Ion Battery Cathodes:From Theoretical Study to Production Practice

Direct regeneration method has been widely concerned by researchers in the field of battery recycling because of its advantages of in situ regeneration,short process and less pollutant emission.In this review,we firstly analyze the primary causes for the failure of three representative battery cathodes(lithium iron phosphate,layered lithium transition metal oxide and lithium cobalt oxide),targeting at illustrating their underlying regeneration mecha-nism and applicability.Efficient stripping of material from the collector to obtain pure cathode material has become a first challenge in recycling,for which we report several pretreatment methods currently available for subsequent regeneration processes.We review and discuss emphatically the research progress of five direct regeneration methods,including solid-state sintering,hydrothermal,eutectic molten salt,electrochemical and chemical lithiation methods.Finally,the application of direct regeneration technology in production practice is introduced,the problems exposed at the early stage of the industrialization of direct regeneration technol-ogy are revealed,and the prospect of future large-scale commercial production is proposed.It is hoped that this review will give readers a comprehensive and basic understanding of direct regeneration methods for used lithium-ion batteries and promote the industrial application of direct regeneration technology.

Investigations on High-Speed Flash Boiling Atomization of Fuel Based on Numerical Simulations

Flash boiling atomization(FBA)is a promising approach for enhancing spray atomization,which can generate a fine and more evenly distributed spray by increasing the fuel injection temperature or reducing the ambient pressure.However,when the outlet speed of the nozzle exceeds 400 m/s,investigating high-speed flash boiling atomization(HFBA)becomes quite challenging.This difficulty arises fromthe involvement ofmany complex physical processes and the requirement for a very fine mesh in numerical simulations.In this study,an HFBA model for gasoline direct injection(GDI)is established.This model incorporates primary and secondary atomization,as well as vaporization and boilingmodels,to describe the development process of the flash boiling spray.Compared to lowspeed FBA,these physical processes significantly impact HFBA.In this model,the Eulerian description is utilized for modeling the gas,and the Lagrangian description is applied to model the droplets,which effectively captures the movement of the droplets and avoids excessive mesh in the Eulerian coordinates.Under various conditions,numerical solutions of the Sauter mean diameter(SMD)for GDI show good agreement with experimental data,validating the proposed model’s performance.Simulations based on this HFBA model investigate the influences of fuel injection temperature and ambient pressure on the atomization process.Numerical analyses of the velocity field,temperature field,vapor mass fraction distribution,particle size distribution,and spray penetration length under different superheat degrees reveal that high injection temperature or low ambient pressure significantly affects the formation of small and dispersed droplet distribution.This effect is conducive to the refinement of spray particles and enhances atomization.

Correction:Direct Regeneration of Spent Lithium‑Ion Battery Cathodes:From Theoretical Study to Production Practice

The Highlights session of the article unfortunately was taken falsely from another manuscript.The correct Highlights session is now in place.The correct is:Analyze the primary causes of cathode failure in three representative batteries,illustrating their underlying regeneration mechanism.

Factors influencing ruminative thinking behaviours in nurses:a cross-sectional study of 858 subjects in a tertiary care hospital

To the editor:Nurses play a vital role in healthcare by providing direct medical care to patients,and their mental well-being significantly impacts the quality of service and patient satisfaction.^(1)Ruminative thinking involves repetitive thoughts about negative feelings,their causes and consequences.This common psychological behaviour innurses can significantly impact their self-evaluation and result in feelings of worthlessness.

Study of the inflammatory activating process in the early stage of Fusobacterium nucleatum infected PDLSCs

Fusobacterium nucleatum(F.nucleatum)is an early pathogenic colonizer in periodontitis,but the host response to infection with this pathogen remains unclear.In this study,we built an F.nucleatum infectious model with human periodontal ligament stem cells(PDLSCs)and showed that F.nucleatum could inhibit proliferation,and facilitate apoptosis,ferroptosis,and inflammatory cytokine production in a dose-dependent manner.The F.nucleatum adhesin Fad A acted as a proinflammatory virulence factor and increased the expression of interleukin(IL)-1β,IL-6 and IL-8.Further study showed that Fad A could bind with PEBP1 to activate the Raf1-MAPK and IKK-NF-κB signaling pathways.Time-course RNA-sequencing analyses showed the cascade of gene activation process in PDLSCs with increasing durations of F.nucleatum infection.NFκB1 and NFκB2 upregulated after 3 h of F.nucleatum-infection,and the inflammatory-related genes in the NF-κB signaling pathway were serially elevated with time.Using computational drug repositioning analysis,we predicted and validated that two potential drugs(piperlongumine and fisetin)could attenuate the negative effects of F.nucleatum-infection.Collectively,this study unveils the potential pathogenic mechanisms of F.nucleatum and the host inflammatory response at the early stage of F.nucleatum infection.

高校研究生试题库系统建设的探索与实践

在借鉴国内外同类学科硕士研究生教学研究、培养模式、改革实践的基础上,针对地球探测科学与技术学院的5个二级学科,开展了6个专业学术型硕士研究生专业试题库建设和研究生培养模式改革的尝试,以达到“以考促教、以考促学”的目的.该试题库包括16门课程：电法勘探、重磁场理论、应用地球化学理论基础、重磁勘探方法、测井信息处理与解释、工程与环境地球物理、地图数据处理、高等应用测量、数字摄影测量学、空间大地测量学、地理信息系统导论、遥感信息科学概论、地震波理论、地球物理信号检测理论、地球物理信号分析、重磁学;包含3种题型：单选题、多选题和判断题;每门课程的试题数量平均为400题.该试题库通过地探学院2013级的67名硕士研究生的测试和后期考试平台的调整、试题库的补充,效果良好.说明该试题库对进一步加强研究生专业考试工作的科学性、客观性、规范性,提高研究生教学和培养质量,具有重要意义.

高风险垂体腺瘤的临床病理特征

目的:探讨高风险垂体腺瘤的临床病理特征及诊断要点。方法:选取2017年6月至2020年9月北京大学国际医院收治的24例高风险垂体腺瘤患者,进行形态学观察、免疫组织化学染色及基因检测,同时收集患者的临床资料并进行随访,综合分析病理特点与临床特征的相互关系。结果:24例高风险垂体腺瘤中男性14例,女性10例,发病年龄28~68岁,平均年龄45.4岁,临床表现为鞍区占位或激素分泌异常的症状。肿瘤最大径0.7~4.8 cm,影像学提示侵袭性腺瘤12例。根据固有激素、转录因子和低分子量角蛋白的免疫组织化学染色特点,结合临床症状及血清激素水平进行诊断,其中稀疏颗粒型生长激素细胞腺瘤4例,沉默性促肾上腺皮质激素细胞腺瘤12例,男性泌乳激素细胞大腺瘤6例,多激素PIT-1阳性腺瘤2例。基因检测1例存在GNAS基因突变。14例获得随访资料,2例复发(其中1例因肿瘤复发死亡)。结论:高风险垂体腺瘤的诊断应该结合免疫组织化学、血清激素水平及临床症状综合分析,并且需要提示临床复发和进展的风险。

Effects of polygonatum sibiricum polysaccharide on learning and memory in a scopolamine-induced mouse model of dementia

BACKGROUND： Learning and memory processes are accompanied by complex neuropathological and biochemical changes. Free radicals play an important role in learning and memory damage. OBJECTIVE： To observe the effects of polygonatum sibiricum polysaccharide （PSP） in comparison with vitamin 12 on inhibiting free radical damage, as well as improving the degree of cerebral ischemia and learning and memory in a scopolamine-induced mouse model of dementia. DESIGN： Randomized controlled animal study. SETTINGS： Department of Pharmacology, Taishan Medical College; Shandong Jewim Pharmaceutical Co., Ltd. MATERIALS： A total of 105 healthy Kunming mice, comprising 90 males and 15 females that were clean grade, were provided by the Animal Center of Taishan Medical College. PSP （extracted and purified by Huangjing, Taishan） was provided by the Department of Traditional Chinese Medicine, Taishan Medical College （purity of 79.6% by using a phenol-concentrated sulphate acid method）, and hydrogen bromine acid scopolamine injection solution （SCO） by Shanghai Hefeng Pharmaceutical Co., Ltd. METHODS： This study was performed at the Pharmacological Laboratory of Taishan Medical College from March to June 2007. （1） A total of 75 healthy Kunming male mice of clean grade were randomly divided into a normal control group, positive control group, and low-dosage and high-dosage PSP groups, with 15 mice in each group. Mice in both the low-dosage and high-dosage PSP groups were intragastrically administered 0.5 g/kg and 2.0 g/kg PSP, respectively. Mice in the positive control group were intragastrically administered 0.5 g/kg vitamin 12. In addition, mice in both the normal control group and model group were intragastrically administered the same volume of saline, respectively, once a day for 7 consecutive days. One hour after the final administration on day 6, mice in the positive control group, model group, low-dosage and high-dosage PSP groups were subcutaneously injected with 3.0 mg/kg SCO, while mice in the normal control group were subcutaneously injected with the same volume of distilled water. Ten minutes later, the step test was employed to measure memory. The training was performed 5 times, with 30-minute intervals between 2 sets. If the mice remained on the platform （latent period） for 30 minutes, they were determined to have learned the task. An eligible percentage was then recorded. Twenty-four hours later, the number of error responses from each mouse was recorded in a 5-minute period, based on the above-mentioned parameters. Mice were sacrificed under anesthesia. The activities of glutathione hyperoxide enzyme （GSH-Px）, superoxide dismutase （SOD）, and the content of malondialdehyde （MDA） were assayed using an UV spectrophotometer. （2） The remaining 30 healthy Kunming mice of both genders were randomly divided into 3 groups, including control group, low-dosage PSP group, and high-dosage PSP group, with 10 mice in each group. Mice in both the low-dosage and high-dosage PSP groups were intragastrically administered 0.5 g/kg and 2.0 g/kg PSP, respectively, while the mice in the control group were perfused with the same volume of saline. Forty minutes later, the mice under superficial anesthesia were decapitated, and the number and duration of mouth-opening breaths of the isolated mouse head were immediately recorded. MAIN OUTCOME MEASURE： （1） Numbers of error responses within 5 minutes on the platform. （2） GSH-Px and SOD activity, as well as MDA content in mouse brain tissue. （3） Numbers and duration of mouth-opening breaths of the isolated mouse head. RESULTS： Of the 105 Kunming experimental mice, two mice died due to electric shock during the step-down test, therefore, a total of 103 mice were involved in the final analysis. （1） Effects of PSP on learning in mice： The eligible percentage in the high-dosage PSP group was higher than the control group at the 3rd and 5th training sessions （P 〈 0.05）. （2） Effects of PSP on memory in mice： The number of errors in the step-down test in the model group was higher than in the normal control group （P 〈 0.01）. Compared to the model group, the number of errors in the step-down test was lower in both the low-dosage and high-dosage PSP groups （P 〈 0.01）. （3） Effects of PSP on amount of GSH-Px, SOD, and MDA in mouse brain tissue： SOD and GSH-Px activity was higher in both the low-dosage and high-dosage PSP groups than in the model group. MDA content was lower in the high-dosage PSP group, compared to the model group. GSH-Px activity in the brain tissue of the high-dosage PSP group was similar to the positive control group （P 〉 0.05）. （4） Effects of PSP on acute cerebral ischemia in mice： The low-dosage PSP, and in particular the high-dosage PSP, prolonged the number and duration of mouth-opening breaths of the isolated mouse head （P 〈 0.05, 0.01）. CONCLUSION： PSP can improve learning and memory in a scopolamine-induced mouse model of dementia by reducing the damaging effects of cerebral ischemia and anti-oxidation. In addition, the effects are dose-dependent and are similar to those provided by vitamin E.

Tree-ring response of Larix chinensis on regional climate and sea-surface temperature variations in alpine timberline in the Qinling Mountains

Tree-ring width chronologies of Larix chinensis were developed from the northern and southern slopes of the Qinling Mountains in Shaanxi Province,and climatic factors affecting the tree-ring widths of L.chinensis were examined.Correlation analysis showed that similar correlations between tree-ring width chronologies and climatic factors demonstrated that radial growth responded to climate change on both slopes.The radial growth of L.chinensis was mainly limited by temperature,especially the growing season.In contrast,both chronologies were negatively correlated with precipitation in May of the previous year and April of the current year.Spatial climate-correlation analyses with gridded land-surface climate data revealed that our tree-ring width chronologies contained a strong regional temperature signal over much of northcentral and eastern China.Spatial correlation with seasurface temperature fields highlights the influence of the Pacific Ocean,Indian Ocean,and North Atlantic Ocean.Wavelet coherence analysis indicated the existence of some decadal and interannual cycles in the two tree-ring width chronologies.This may suggest the influences of El Nin˜o-Southern Oscillation and solar activity on tree growth in the Qinling Mountains.These findings will help us understand the growth response of L.chinensis to climate change in the Qinling region,and they provide critical information for future climate reconstructions based on this species in semi-humid regions.

Fault Diagnosis of Motor in Frequency Domain Signal by Stacked De-noising Auto-encoder

With the rapid development of mechanical equipment,mechanical health monitoring field has entered the era of big data.Deep learning has made a great achievement in the processing of large data of image and speech due to the powerful modeling capabilities,this also brings influence to the mechanical fault diagnosis field.Therefore,according to the characteristics of motor vibration signals(nonstationary and difficult to deal with)and mechanical‘big data’,combined with deep learning,a motor fault diagnosis method based on stacked de-noising auto-encoder is proposed.The frequency domain signals obtained by the Fourier transform are used as input to the network.This method can extract features adaptively and unsupervised,and get rid of the dependence of traditional machine learning methods on human extraction features.A supervised fine tuning of the model is then carried out by backpropagation.The Asynchronous motor in Drivetrain Dynamics Simulator system was taken as the research object,the effectiveness of the proposed method was verified by a large number of data,and research on visualization of network output,the results shown that the SDAE method is more efficient and more intelligent.

Research on the Signal Reconstruction of the Phased Array Structural Health Monitoring Based Using the Basis Pursuit Algorithm

The signal processing problem has become increasingly complex and demand high acquisition system,this paper proposes a new method to reconstruct the structure phased array structural health monitoring signal.The method is derived from the compressive sensing theory and the signal is reconstructed by using the basis pursuit algorithm to process the ultrasonic phased array signals.According to the principles of the compressive sensing and signal processing method,non-sparse ultrasonic signals are converted to sparse signals by using sparse transform.The sparse coefficients are obtained by sparse decomposition of the original signal,and then the observation matrix is constructed according to the corresponding sparse coefficients.Finally,the original signal is reconstructed by using basis pursuit algorithm,and error analysis is carried on.Experimental research analysis shows that the signal reconstruction method can reduce the signal complexity and required the space efficiently.

Surface contact behavior of functionally graded thermoelectric materials indented by a conducting punch

The contact problem for thermoelectric materials with functionally graded properties is considered.The material properties,such as the electric conductivity,the thermal conductivity,the shear modulus,and the thermal expansion coefficient,vary in an exponential function.Using the Fourier transform technique,the electro-thermoelastic problems are transformed into three sets of singular integral equations which are solved numerically in terms of the unknown normal electric current density,the normal energy flux,and the contact pressure.Meanwhile,the complex homogeneous solutions of the displacement fields caused by the gradient parameters are simplified with the help of Euler’s formula.After addressing the non-linearity excited by thermoelectric effects,the particular solutions of the displacement fields can be assessed.The effects of various combinations of material gradient parameters and thermoelectric loads on the contact behaviors of thermoelectric materials are presented.The results give a deep insight into the contact damage mechanism of functionally graded thermoelectric materials(FGTEMs).

IgG4-related Autoimmune Pancreatitis Mimicking Acute Pancreatitis:A Case Report

IGG4-RELATED autoimmune pancreatitis (AIP) is themost common type of IgG4-related diseases. Theobservation of a diffused and localized enlargementof the pancreas and strictures in the main pancreaticduct on radiological imaging is essential fordiagnosing AIP. The clinical features of AIP which presentas a localized pancreatic mass greatly mimic pancreaticcancer. Cases with AIP mimicking pancreatic cancer arereported numerously. However, cases of IgG4-related AIPmanifesting acute pancreatitis symptoms and extensiveperipancreatic effusion are rarely observed. Meanwhile,acute pancreatitis is a common disease. If misdiagnosed asacute pancreatitis, IgG4-related AIP may progressseriously. Here, we report a rare case of IgG4-related AIPsuspected of acute pancreatitis because of epigastric painand extensive peripancreatic effusion on computed tomography(CT) images.

Association of microRNA polymorphisms with the risk of head and neck squamous cell carcinoma in a Chinese population:a case-control study

Background:MicroRNA(miRNA) polymorphisms may alter miRNA-related processes,and they likely contribute to cancer susceptibility.Various studies have investigated the associations between genetic variants in several key miRNAs and the risk of human cancers;however,few studies have focused on head and neck squamous cell carcinoma(HNSCC) risk.This study aimed to evaluate the associations between several key miRNA polymorphisms and HNSCC risk in a Chinese population.Methods:In this study,we genotyped five common single-nucleotide polymorphisms(SNPs) in several key miRNAs(miR-149 rs2292832,miR-146 a rs2910164,miR-605 rs2043556,miR-608 rs4919510,and miR-196a2 rs11614913) and evaluated the associations between these SNPs and HNSCC risk according to cancer site with a case-control study including 576 cases and 1552 controls,which were matched by age and sex in a Chinese population.Results:The results revealed that miR-605 rs2043556[dominant model:adjusted odds ratio(OR) 0.71,95%confidence interval(CI) 0.58-0.88;additive model:adjusted OR 0.74,95%CI 0.62-0.89]and miR-196a2 rs11614913(dominant model:adjusted OR 1.36,95%C11.08-1.72;additive model:adjusted OR 1.28,95%C11.10-1.48) were significantly associated with the risk of oral squamous cell carcinoma(OSCC).Furthermore,when these two loci were evaluated together based on the number of putative risk alleles(rs2043556 A and rs11614913 G),a significant locus-dosage effect was noted on the risk of OSCC(P_(trend) < 0.001).However,no significant association was detected between the other three SNPs(miR-149 rs2292832,miR- 146 a rs2910164,and miR-608 rs4919510) and HNSCC risk.Conclusion:Our study provided the evidence that miR-605 rs2043556 and miR-196a2 rs11614913 may have an impact on genetic susceptibility to OSCC in Chinese population.

Layer-element analysis of multilayered saturated soils subject to axisymmetric vertical time-harmonic excitation

The analytical layer-elements for a single poroelastic soil layer and the underlying half-space are established using an algebraic manipulation and Hankel trans- form. According to the boundary conditions and adjacent continuity conditions of general stresses and displacements, a global matrix equation in the transform domain for multi- layered saturated soil media is assembled and solved. Solutions in the frequency domain can be further obtained with an inverse Hankel transform. Numerical examples are used to examine accuracy of the present method and demonstrate effects of soil parameters and load conditions on dynamic responses of the multilayered poroelastic saturated soils.

Dynamics Modeling and Stability Analysis of Tilt Wing Unmanned Aerial Vehicle During Transition

In the transition mode of quad tilt wing-unmanned aerial vehicle(QTW-UAV),the system stability of UAV will change with the tilt angle changes,which will cause serious head drop down.Meanwhile,with the complex air flow and other disturbances,the system is prone to side bias,frying,stall and other kinetic stability problems,hence the system stability analysis has become an urgent problem to be solved.To solve the stability problem,we need the quantitative criteria of system stability and effective tool of stability analysis,and can improve the stability of the motion control by optimizing the structural parameters of the aircraft.Therefore,based on the design of the mechanical structure,the quantitative relationship between the structure parameters of the aerial vehicle and kinetic stability of the system transition mode is established by the Lyapunov exponent method.In this paper,the dynamic modeling of the position and attitude angle is carried out and the stability of the system is analyzed by Lyapunov exponent,the results show that changing the mechanical structure of the system can improve the flight stability for the system transition mode and lay a theoretical foundation for the system stability analysis.Compared with the Lyapunov direct method,this method can be construct easily,has a simple calculation process and so on.We improve the flight stability by optimizing the structure and the experiment confirms that expanding area can enhance flight stability within limits.

Detection of Precipitation Cloud over the Tibet Based on the Improved U-Net

Aiming at the problem of radar base and ground observation stations on the Tibet is sparsely distributed and cannot achieve large-scale precipitation monitoring.U-Net,an advanced machine learning(ML)method,is used to develop a robust and rapid algorithm for precipitating cloud detection based on the new-generation geostationary satellite of FengYun-4A(FY-4A).First,in this algorithm,the real-time multi-band infrared brightness temperature from FY-4A combined with the data of Digital Elevation Model(DEM)has been used as predictor variables for our model.Second,the efficiency of the feature was improved by changing the traditional convolution layer serial connection method of U-Net to residual mapping.Then,in order to solve the problem of the network that would produce semantic differences when directly concentrated with low-level and high-level features,we use dense skip pathways to reuse feature maps of different layers as inputs for concatenate neural networks feature layers from different depths.Finally,according to the characteristics of precipitation clouds,the pooling layer of U-Net was replaced by a convolution operation to realize the detection of small precipitation clouds.It was experimentally concluded that the Pixel Accuracy(PA)and Mean Intersection over Union(MIoU)of the improved U-Net on the test set could reach 0.916 and 0.928,the detection of precipitation clouds over Tibet were well actualized.

Advances in regenerative medicine applications of tetrahedral framework nucleic acid-based nanomaterials: an expert consensus recommendation

With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versatile functions. Especially promising nanostructures are tetrahedral framework nucleic acids(t FNAs), first proposed by Turberfield with the use of a one-step annealing approach. Benefiting from their various merits, such as simple synthesis, high reproducibility, structural stability, cellular internalization, tissue permeability, and editable functionality, t FNAs have been widely applied in the biomedical field as threedimensional DNA nanomaterials. Surprisingly, t FNAs exhibit positive effects on cellular biological behaviors and tissue regeneration,which may be used to treat inflammatory and degenerative diseases. According to their intended application and carrying capacity,t FNAs could carry functional nucleic acids or therapeutic molecules through extended sequences, sticky-end hybridization,intercalation, and encapsulation based on the Watson and Crick principle. Additionally, dynamic t FNAs also have potential applications in controlled and targeted therapies. This review summarized the latest progress in pure/modified/dynamic t FNAs and demonstrated their regenerative medicine applications. These applications include promoting the regeneration of the bone,cartilage, nerve, skin, vasculature, or muscle and treating diseases such as bone defects, neurological disorders, joint-related inflammatory diseases, periodontitis, and immune diseases.

Migration of Resovist-labeled neural stem cells towards focal rat cerebral ischemic regions as determined by in vivo tracking and magnetic resonance imaging

BACKGROUND： Resovist, a superparamagnetic iron oxide, can be used to label neural stem cells （NSCs）. Magnetic resonance tracking of superparamagnetic iron oxide-labeled NSCs is a non-invasive technique to track transplanted NSCs following focal cerebral ischemia. OBJECTIVE： To observe survival and migration of transplanted NSCs in a rat model of focal ischemia/repeffusion using magnetic resonance imaging （MRI）. DESIGN, TIME AND SETTING： An in vitro, in vivo, tracking study was performed at the Basic Laboratory of Harbin Medical University and the Room of MRI, Second Affiliated Hospital of Harbin Medical University, China from December 2006 to December 2009. MATERIALS： Resovist （Schering, Germany） and Achieva 1.5TMR imaging system （Philips, Amsterdam, the Netherlands） were utilized in the present study. METHODS： NSCs were harvested from brain tissues of neonatal Sprague Dawley rats and were labeled with Resovist （11.2μg/mL and 5 ×10^5 cells/mL）. A total of 15 adult, Sprague Dawley rats were randomly assigned to model （n = 9） and control （n = 6） groups. All rats were utilized to establish models of middle cerebral artery occlusion. Rats in the model group were subjected to Resovist-labeled NSCs transplantation by injection of cell suspension into both ventricles （5μL/ ventricle）. Rats in the control group were treated with an equal volume of physiological saline. MAIN OUTCOME MEASURES： Immunocytochemistry, transmission electron microscopy, and Prussian blue staining were employed to observe whether cells phagocytized iron particles. In addition, 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide assay was used to measure viability and differentiation of NSCs labeled by various concentrations of Resovist. MRI was used to trace survival and migration of Resovist-labeled NSCs. RESULTS： Following Resovist and NSCs co-incubation, Prussian blue staining revealed iron particles in cells. In addition, staining was observed in daughter cells following cell division under transmission electron microscopy. A significant difference in viability and differentiation of NSCs in vitro labeled by various Resovist concentrations （2.8-11.2 μg/mL） was not detected （P 〉 0.05）. Resovist （〉 22.4 μg/mL） decreased cell viability and differentiation （P 〈 0.05）./n vivo MRI of Resovist-labeled NSCs （11.2 μg/mL） revealed low signals. However, cells migrated towards the ischemic focus over time. CONCLUSION： Resovist, a magnetic probe, successfully labeled NSCs. MRI was successfully used to trace magnetic-labeled NSCs in vivo and allowed observation of cell survival and migration following transplantation.

Impact Dynamics of a Dragonfly Wing

The lift force was reported not to be high enough to support the dragonfly’s weight during flight in some conventional investigations,and higher lift force is required for its takeoff.In this study,by employing a thin plate model,impact effect is investigated for the wing deformation in dragonfly flapping during takeoff.The static displacement is formulated to compare with the dynamical displacement caused by impact.The governing equation of motion for the impact dynamics of a dragonfly wing is derived based on Newton’s second law.Separation of variables technique and assumed modes method are introduced to solve the resulting equations.Further,lift force is presented for the cases of considering and without considering the impact on the wing flapping which indicates that the impact has prominent effects for the dragonfly’s aerodynamic performance.Numerical simulations demonstrate that considering the impact effect on the wing flapping can increase the wing deformation,which results in the rise of the lift force.The enhanced lift force is of critical importance for the dragonfly’s takeoff.