Neural stem cell-derived exosomes promote mitochondrial biogenesis and restore abnormal protein distribution in a mouse model of Alzheimer's disease

Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.

Pressure generation under deformation in a large-volume press

Deformation can change the transition pathway of materials under high pressure,thus significantly affects physical and chemical properties of matters.However,accurate pressure calibration under deformation is challenging and thereby causes relatively large pressure uncertainties in deformation experiments,resulting in the synthesis of complex multiphase materials.Here,pressure generations of three types of deformation assemblies were well calibrated in a Walker-type largevolume press(LVP)by electrical resistance measurements combined with finite element simulations(FESs).Hard Al_(2)O_(3) or diamond pistons in shear and uniaxial deformation assemblies significantly increase the efficiency of pressure generation compared with the conventional quasi-hydrostatic assembly.The uniaxial deformation assembly using flat diamond pistons possesses the highest efficiency in these deformation assemblies.This finding is further confirmed by stress distribution analysis based on FESs.With this deformation assembly,we found shear can effectively promote the transformation of C60 into diamond under high pressure and realized the synthesis of phase-pure diamond at relatively moderate pressure and temperature conditions.The present developed techniques will help improve pressure efficiencies in LVP and explore the new physical and chemical properties of materials under deformation in both science and technology.

Grapevine-like high entropy oxide composites boost high-performance lithium sulfur batteries as bifunctional interlayers

Lithium-sulfur batteries(LSBs)with high energy densities have been demonstrated the potential for energy-intensive demand applications.However,their commercial applicability is hampered by hysteretic electrode reaction kinetics and the shuttle effect of lithium polysulfides(LiPSs).In this work,an interlayer consisting of high-entropy metal oxide(Cu_(0.7)Fe_(0.6)Mn_(0.4)Ni_(0.6)Sn_(0.5))O_(4) grown on carbon nanofibers(HEO/CNFs)is designed for LSBs.The CNFs with highly porous networks provide transport pathways for Li^(+) and e^(-),as well as a physical sieve effect to limit LiPSs crossover.In particular,the grapevine-like HEO nanoparticles generate metal-sulfur bonds with LiPSs,efficiently anchoring active materials.The unique structure and function of the interlayer enable the LSBs with superior electrochemical performance,i.e.,the high specific capacity of 1381 mAh g^(-1) at 0.1 C and 561 mAh g^(-1) at 6 C.This work presents a facile strategy for exploiting high-performance LSBs.

Investigations of the mechanical response of dummy HTPB propellant grain under ultrahigh acceleration overload conditions using onboard flight-test measurements

In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were performed.Two projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 g.The onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and analysed.Uniaxial compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching process.During the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant grain.The calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were observed.The dynamic mechanical response process of the dummy propellant grain was analysed in detail.The results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.

An Efficient and Secure Privacy-Preserving Federated Learning Framework Based on Multiplicative Double Privacy Masking

With the increasing awareness of privacy protection and the improvement of relevant laws,federal learning has gradually become a new choice for cross-agency and cross-device machine learning.In order to solve the problems of privacy leakage,high computational overhead and high traffic in some federated learning schemes,this paper proposes amultiplicative double privacymask algorithm which is convenient for homomorphic addition aggregation.The combination of homomorphic encryption and secret sharing ensures that the server cannot compromise user privacy from the private gradient uploaded by the participants.At the same time,the proposed TQRR(Top-Q-Random-R)gradient selection algorithm is used to filter the gradient of encryption and upload efficiently,which reduces the computing overhead of 51.78%and the traffic of 64.87%on the premise of ensuring the accuracy of themodel,whichmakes the framework of privacy protection federated learning lighter to adapt to more miniaturized federated learning terminals.

Numerical Analysis of Perforation during Hydraulic Fracture Initiation Based on Continuous-Discontinuous Element Method

Perforation is a pivotal technique employed to establish main flow channels within the reservoir formation at the outset of hydraulic fracturing operations.Optimizing perforation designs is critical for augmenting the efficacy of hydraulic fracturing and boosting oil or gas production.In this study,we employ a hybrid finite-discrete element method,known as the continuous–discontinuous element method(CDEM),to simulate the initiation of post-perforation hydraulic fractures and to derive enhanced design parameters.The model incorporates the four most prevalent perforation geometries,as delineated in an engineering technical report.Real-world perforations deviate from the ideal cylindrical shape,exhibiting variable cross-sectional profiles that typically manifest as an initial constriction followed by an expansion,a feature consistent across all four perforation types.Our simulations take into account variations in perforation hole geometries,cross-sectional diameters,and perforation lengths.The findings show that perforations generated by the 39g DP3 HMX perforating bullet yield the lowest breakdown pressure,which inversely correlates with increases in sectional diameter and perforation length.Moreover,this study reveals the relationship between breakdown pressure and fracture degree,providing valuable insights for engineers and designers to refine perforation strategies.

Hydrogen-bonded organic framework modified separator for simultaneously enhancing the safety and electrochemical performance of Ni-rich lithium-ion battery

Nickel-rich layered oxide cathode(LiNi_(x)Co_(y)Mn_(1−x−y)O_(2),x>0.5,NCM)shows substantial potential for applications in longer-range electrical vehicles.However,the rapid capacity decay and serious safety concerns impede its practical viability.This work provides a hydrogen-bonded organic framework(HOF)modification strategy to simultaneously improve the electrochemical performance,thermal stability and incombustibility of separator.Melamine cyanurate(MCA),as a low-cost and reliable flame-retardant HOF,was implemented in the separator modification layer,which can prevent the battery short circuit even at a high temperature.In addition,the supermolecule properties of MCA provide unique physical and chemical microenvironment for regulating ion-transport behavior in electrolyte.The MCA coating layer enabled the nickel-rich layered oxide cathode with a high-capacity retention of 90.3%after 300 cycles at 1.0 C.Collectively,the usage of MCA in lithium-ion batteries(LIBs)affords a simple,low-cost and efficient strategy to improve the security and service life of nickel-rich layered cathodes.

Prediction of the Pore-Pressure Built-Up and Temperature of Fire-Loaded Concrete with Pix2Pix

Concrete subjected to fire loads is susceptible to explosive spalling, which can lead to the exposure of reinforcingsteel bars to the fire, substantially jeopardizing the structural safety and stability. The spalling of fire-loaded concreteis closely related to the evolution of pore pressure and temperature. Conventional analytical methods involve theresolution of complex, strongly coupled multifield equations, necessitating significant computational efforts. Torapidly and accurately obtain the distributions of pore-pressure and temperature, the Pix2Pix model is adoptedin this work, which is celebrated for its capabilities in image generation. The open-source dataset used hereinfeatures RGB images we generated using a sophisticated coupled model, while the grayscale images encapsulate the15 principal variables influencing spalling. After conducting a series of tests with different layers configurations,activation functions and loss functions, the Pix2Pix model suitable for assessing the spalling risk of fire-loadedconcrete has been meticulously designed and trained. The applicability and reliability of the Pix2Pix model inconcrete parameter prediction are verified by comparing its outcomes with those derived fromthe strong couplingTHC model. Notably, for the practical engineering applications, our findings indicate that utilizing monochromeimages as the initial target for analysis yields more dependable results. This work not only offers valuable insightsfor civil engineers specializing in concrete structures but also establishes a robust methodological approach forresearchers seeking to create similar predictive models.

Multi-field Split Curvature Wavefront Sensing and its Application in the Large Field Survey Telescope

The image quality of a large field survey telescope with a fast focal ratio of the primary mirror is high sensitivity to the optical elements’misalignments and the primary mirror’s deformations.To maintain good optical performance,the perturbations need to be aligned,and the tomographic reconstruction of these perturbations can be derived from wavefront sensing with multi-field points for alignment.This work undertakes a comprehensive examination related to the implementation and optimization of a multi-field split curvature wavefront sensing system,including defocus distance,signal pre-processing,deblending of overlapped doughnuts,field-dependent correction,and distorted coordinate correction.We also conduct experiments to demonstrate the application and performance of a multi-field split curvature wavefront sensing system in Mephisto.In the context of the decentering of the secondary mirror,the coefficient of determination(R)attains a high value of 0.993,indicating a robust linearity between the coma coefficients and the decentering of the secondary mirror.A comparative analysis of the simulated and experimental results shows that the difference between them is less than 0.1λ.

S-型异质结CeO_(2)/Zn_(x)Cd_(1-x)In_(2)S_(4)空心结构的构建及其可见光分解水制氢性能

层状结构材料ZnIn_(2)S_(4)(ZIS)具有强的可见光吸收、合适的能带结构、高的化学稳定性和低毒性,是优良的光催化材料。然而,ZIS的低载流子分离效率造成其光催化产氢效率较低。为了解决这一难题,本文提出了一种整合固溶体形成和异质结构建的能带结构调控策略。通过在CeO_(2)空心球表面原位生长ZnxCd1-xIn_(2)S_(4)(ZCIS)纳米片,成功制备了具有分级中空结构的CeO_(2)/ZCIS复合光催化剂。制备的1:6-CeO_(2)/Zn_(0.9)Cd_(0.1)In_(2)S_(4)样品在可见光下表现出了4.09 mmol·g^(-1)·h^(-1)的最佳产氢速率,分别是ZIS、ZCIS和CeO_(2)/ZIS的6.8、3.0和2.2倍。其光催化活性的显著增强主要归功于CeO_(2)/ZCIS的能带结构改变产生S-型异质结电荷传输通道。同时,引入Cd阳离子使得ZIS的导带和价带同时上移,为水裂解提供强还原性光电子。相比于CeO_(2)/ZIS异质结,ZCIS和CeO_(2)之间存在更大的费米能级差,可促进更多的自由电子从ZCIS转移到CeO_(2),在CeO_(2)/ZCIS界面形成强内建电场,促进载流子有效分离,提高光催化产氢效率。本研究将为S-型异质结光催化材料设计和构筑提供一种有效策略。

Continuous-discontinuous element method for three-dimensional thermal cracking of rocks

Thermal cracking of rocks can significantly affect the durability of underground structures in engineering practices such as geothermal energy extraction,storage of nuclear waste and tunnelling in freezeethaw cycle induced areas.It is a scenario of strong coupled thermomechanical process involving discontinuity behaviours of rocks.In this context,a numerical model was proposed to investigate the thermal cracking of rocks,in a framework of the continuous-discontinuous element method(CDEM)for efficiently capturing the initiation and propagation of multiple cracks.A simplex integration strategy was adopted to account for the influences of temperature-dependent material properties.Several benchmark tests were considered and the obtained results were compared with analytical solutions and numerical results from the literature.The results show that the fracture degree of the cases when considering temperature-dependent material parameters had 10%differences approximately compared with the cases with constant parameters.

Image Representations of Numerical Simulations for Training Neural Networks

A large amount of data can partly assure good fitting quality for the trained neural networks.When the quantity of experimental or on-site monitoring data is commonly insufficient and the quality is difficult to control in engineering practice,numerical simulations can provide a large amount of controlled high quality data.Once the neural networks are trained by such data,they can be used for predicting the properties/responses of the engineering objects instantly,saving the further computing efforts of simulation tools.Correspondingly,a strategy for efficiently transferring the input and output data used and obtained in numerical simulations to neural networks is desirable for engineers and programmers.In this work,we proposed a simple image representation strategy of numerical simulations,where the input and output data are all represented by images.The temporal and spatial information is kept and the data are greatly compressed.In addition,the results are readable for not only computers but also human resources.Some examples are given,indicating the effectiveness of the proposed strategy.

A facile finger-paint physical modification for bilateral electrode/electrolyte interface towards a stable aqueous Zn battery

Since the electrode/electrolyte interface(EEI)is the main redox center of electrochemical processes,proper manipulation of the EEI microenvironment is crucial to stabilize interfacial behaviors.Here,a finger-paint method is proposed to enable quick physical modification of glass-fiber separator without complicated chemical technology to modulate EEI of bilateral electrodes for aqueous zinc-ion batteries(ZIBs).An elaborate biochar derived from Aspergillus Niger is exploited as the modification agent of EEI,in which the multi-functional groups assist to accelerate Zn^(2+)desolvation and create a hydrophobic environment to homogenize the deposition behavior of Zn anode.Importantly,the finger-paint interface on separator can effectively protect cathodes from abnormal capacity fluctuation and/or rapid attenuation induced by H_(2)O molecular on the interface,which is demonstrated in modified MnO_(2),V_(2)O_(5),and KMn HCF-based cells.The as-proposed finger-paint method opens a new idea of bilateral interface engineering to facilitate the access to the practical application of the stable zinc electrochemistry.

Dark Forest Algorithm:A Novel Metaheuristic Algorithm for Global Optimization Problems

Metaheuristic algorithms,as effective methods for solving optimization problems,have recently attracted considerable attention in science and engineering fields.They are popular and have broad applications owing to their high efficiency and low complexity.These algorithms are generally based on the behaviors observed in nature,physical sciences,or humans.This study proposes a novel metaheuristic algorithm called dark forest algorithm(DFA),which can yield improved optimization results for global optimization problems.In DFA,the population is divided into four groups:highest civilization,advanced civilization,normal civilization,and low civilization.Each civilization has a unique way of iteration.To verify DFA’s capability,the performance of DFA on 35 well-known benchmark functions is compared with that of six other metaheuristic algorithms,including artificial bee colony algorithm,firefly algorithm,grey wolf optimizer,harmony search algorithm,grasshopper optimization algorithm,and whale optimization algorithm.The results show that DFA provides solutions with improved efficiency for problems with low dimensions and outperforms most other algorithms when solving high dimensional problems.DFAis applied to five engineering projects to demonstrate its applicability.The results show that the performance of DFA is competitive to that of current well-known metaheuristic algorithms.Finally,potential upgrading routes for DFA are proposed as possible future developments.

Division and Correlation of Lacustrine Gravity Flow Reservoirs Based on High-Resolution Sequence Stratigraphic Analysis—Taking Oil Formation I of Lower Es3 in Wuhaozhuang Oilfield as an Example

The phase change of lacustrine gravity flow deposition is fast and complex. In its reservoir division and correlation, the isochronous problem is very important. Taking the oil formation I of Es3 in Wuhaozhuang oilfield as an example, through the analysis of stratigraphic drilling and logging data in the study area, according to the genetic types of different levels of base level cycle interfaces and the characteristics of high-resolution sequence stratigraphy, this paper subdivides the lacustrine gravity flow oil layer of lower Es3 in Wuhaozhuang Oilfield, divides it into four short-term base level cycle sequences, and establishes the high-resolution isochronous stratigraphic framework of this interval. It is found that the mid-term, short-term and ultra short-term base level cycles correspond to the oil formation, sand layer group and single layer in the oil layer correlation unit of the oilfield respectively. Based on this, the oil layer correlation unit of the interval is divided, and the sublayer correlation model is established according to the identification characteristics of the short-term base level cycle.

2型糖尿病易感基因SNP位点对生活方式干预降低血糖应答效果的修饰效应

近年来的研究发现,一些2型糖尿病(type 2 diabetes mellitus,T2DM)易感基因位点不仅与T2DM的发病风险有关,还会影响生活方式干预效果。为进一步探究T2DM易感基因单核苷酸多态性(single nucleotide polymorphism,SNP)位点对生活方式干预降低高危人群血糖应答效果的修饰作用,本课题组在德清农村社区开展了生活方式干预试验(2017年6月~12月,对干预组的研究对象进行强化生活方式干预,对照组仅接受常规健康知识宣教),并对研究对象进行SNP基因分型。研究发现,对于rs9502570,干预组中的CC+CT基因型人群的空腹血糖降低值显著高于TT基因型(P=0.031);干预组中CC+CT基因型人群的糖化血红蛋白值降低值为0.03%,TT基因型人群的糖化血红蛋白值升高了0.27%(P=0.012);CC+CT和TT基因型干预组和对照组的空腹血糖和糖化血红蛋白前后差值差之间也有统计学差异(均为P<0.001)。对于rs10811661,干预组中TT基因型人群的空腹血糖降低值显著高于CC+CT基因型(P=0.021);TT和CC+CT基因型干预组和对照组的空腹血糖前后差值差之间亦有统计学差异(P<0.001)。上述研究结果表明,rs9502570、rs10811661两个位点会在一定程度上修饰高危人群对T2DM生活方式干预降低血糖的应答效果,为今后进一步研制糖尿病高危人群个体化干预措施提供了客观依据。

大学写作课程的参与研讨式教学设计与实践

《写作》是面向汉语言文学专业的本科生传授写作基本知识和培养写作能力的必修课程,具有很强的实践性,学生的积极参与、深度思考、主动研究在该课程的学习中显得尤为重要。通过参与研讨课的整体设计,探讨符合写作活动的规律和学生学习特点的教学模式,以期提升写作课堂的教学质量,促进教学目标的达成,并为同类院校及相关课程的教学改革提供依据与经验借鉴。

A one-for-all strategy of polyimide coating layer for resolving the comprehensive issues of phosphorus anode

Phosphorus is a promising anode with high capacity (2596 mAh g^(-1)and 6075~6924 mAh cm^(-3)),low lithium-ion diffusion barrier (0.08 e V),and appropriate lithiation potential (~0.7 V vs Li+/Li).However,it faces the problems of huge volume expansion (~300%),low electronic conductivity (10^(-14)~10^(2)S cm^(-1)),soluble intermediates (lithium polyphosphides,Li_(x)Ps),degradation in air,and low thermal stability.In this work,phosphorus/carbon nanotube composites were coated with a polyimide layer,which plays the roles of a buffer layer to relieve the volume expansion of phosphorus,an obstruct layer to confine LixPs,an inert layer to prevent the degradation of phosphorus in air,a heat resistant layer to improve the thermal stability of the anode.The resulting composites (P/CNT@PI) display high capacity retention of798.1 m Ah g^(-1)after 150 cycles at 1 A g^(-1),achieving 17 times as much as the control sample (P/CNT).

35 km amplifier-less four-level pulse amplitude modulation signals enabled by a 23 GHz ultrabroadband directly modulated laser

The 4-level pulse amplitude modulation(PAM4)based on an 23 GHz ultrabroadband directly modulated laser(DML)was proposed.We have experimentally demonstrated that based on intensity modulation and direct detection(IMDD)56 Gbps per wavelength PAM4 signals transferred over 35 km standard single mode fiber(SSMF)without any optical amplification and we have achieved the bit error rate(BER)of the PAM4 transmission was under 2.9×10–4 by using feed forward equalization(FFE).

Effect of Different Combined Treatments on Tomato Seedling Growth in High-temperature Season

The study on raising of strong tomato seedlings in high-temperature season is of great practical significance,because high-temperature condition in summer and autumn causes excessive growth of tomato seedlings easily. ‘Fenniya＇variety was selected as an experimental material,an orthogonal experiment was designed with rhizospheric temperature（ A）,light intensity（ B） and nutrient salt concentration（ C） as three factors which were designed with three levels,so as to study the effects of different treatments on root activity,strong seedling index,hypocotyl length and average internode length. The results showed that the most important factor for tomato seedling＇s root activity,hypocotyl length and internode length was nutrient salt concentration. In terms of effect on seedling index,substrate temperature should be reduced properly,to avoid excessive shading. It was primarily determined that the effects of three factors on the raising of strong tomato seedlings ranked as factor C,factor B and factor A from high to low; and the screened optimal seedling raising conditions were the rhizospheric temperature at（ 3 ＋ 1）℃,the shading rate of（ 50 ＋ 5） % and the EC value of（ 5. 0 ＋ 0. 5） mS/cm.