Small extracellular vesicles derived from human induced pluripotent stem cell-differentiated neural progenitor cells mitigate retinal ganglion cell degeneration in a mouse model of optic nerve injury

Several studies have found that transplantation of neural progenitor cells(NPCs)promotes the survival of injured neurons.However,a poor integration rate and high risk of tumorigenicity after cell transplantation limits their clinical application.Small extracellular vesicles(sEVs)contain bioactive molecules for neuronal protection and regeneration.Previous studies have shown that stem/progenitor cell-derived sEVs can promote neuronal survival and recovery of neurological function in neurodegenerative eye diseases and other eye diseases.In this study,we intravitreally transplanted sEVs derived from human induced pluripotent stem cells(hiPSCs)and hiPSCs-differentiated NPCs(hiPSC-NPC)in a mouse model of optic nerve crush.Our results show that these intravitreally injected sEVs were ingested by retinal cells,especially those localized in the ganglion cell layer.Treatment with hiPSC-NPC-derived sEVs mitigated optic nerve crush-induced retinal ganglion cell degeneration,and regulated the retinal microenvironment by inhibiting excessive activation of microglia.Component analysis further revealed that hiPSC-NPC derived sEVs transported neuroprotective and anti-inflammatory miRNA cargos to target cells,which had protective effects on RGCs after optic nerve injury.These findings suggest that sEVs derived from hiPSC-NPC are a promising cell-free therapeutic strategy for optic neuropathy.

Hydrothermal treatment of metallic-monolith catalyst support with self-growing porous anodic-alumina film

Metallic-monolith catalyst support with self-growing porous anodic alumina(PAA)film was prepared by anodizing Al plate.The effect of hydrothermal treatment(HTT)on the crystalline state and textural properties of PAA film was investigated by XRD,BET,SEM and TG.The HTT treatment above 50°C and the subsequent calcination above 300°C could convert the amorphous skeleton alumina intoγ-alumina and increase the specific surface area(SBET).However,SEM images showed the HTT modification was a non-uniform process along the thickness of PAA film.The promotion effect of HTT on SBETwas non-linear,and the slope of SBETgradually decreased with the HTT temperature or time increased.The limited HTT effect should be attributed to a changed pore structure caused by an unfavorable pore sealing limitation.Pore widening treatment(PWT)before HTT could break the pore sealing limitation,because of the reduced internal diffusion resistance of hydrothermal reaction.The synergistic combination of PWT and HTT developed a PAA support with a large SBETcomparable to commercialγ-alumina.In the catalytic combustion of toluene,the Pt-based catalyst prepared by using the PWT and HTT comodified PAA support gave higher Pt dispersion and more favorable catalytic activity than that treated by HTT alone.The presence of a bimodal pore structure was suggested to be a decisive reason.

Enhancing Li NiO_(2) cathode materials by concentration-gradient yttrium modification for rechargeable lithium-ion batteries

Lithium nickel oxide(LiNiO_(2)) cathode materials are featured with high capacity and low cost for rechargeable lithium-ion batteries but suffer from severe interface and structure instability.Here we report that rationally designed LiNiO_(2) via concentration-gradient yttrium modification exhibits alleviative side reactions and improved electrochemical performance.The LiNiO_(2) cathode with LiYO_(2)-Y_(2) O_(3) coating layer delivers a discharge capacity of 225 mAh g^(-1) with a high initial Coulombic efficiency of 93.4%.These improvements can be attributed to the formation of in-situ modified hybrid LiYO_(2)-Y_(2 O3) coating layer,which suppresses phase transformation,electrolyte oxidation and salt dissociation due to the formation of protective cathode electrolyte interface.The results indicate promising application of concentration-gradient yttrium coating as a facile approach to stabilize nickel-rich cathode materials.

Evaluation of Ambient Light Display for High Information Capacity

Ambient light display presents peripheral information unobtrusively,and it can be context aware and aesthetically enhance specific environment.However,since the abstract characteristic of light,people should attentively keep agood balance between unobtrusiveness and effectiveness,when designing an ambient light display.Especially,in the condition of high information capacity,ambient light display need a mechanism to portray information effectively.In this paper,a framework with an overlay mechanism is evaluated for high information capacity.Based on the framework,two ambient light displays are designed to support the evaluation work.The evaluation questions are related with three aspects including information understanding,transition and encoding,special output channel.From the perception level,interpretation level and experience level,the process of evaluation is implemented.The results indicate that the framework with the overlay mechanism can effectively support varied and specific communicating information.The transitions and information encoding benefit from the proper mapping of states and notification levels in the framework.

Power Estimation of Acoustic Sources by Sensor Array Processing

A constant problem is to localize a number of acoustic sources, to separate their individual signals and to estimate their strengths in a propagation medium. An acoustic receiving array with signal processing algorithms is then used. The most widely used algorithm is the conventional beamforming algorithm but it has a very low resolution and high sidelobes that may cause a signal leakage problem. Several new signal processors for arrays of sensors are derived to evaluate the strengths of acoustic signals arriving at an array of sensors. In particular, we present the covariance vector estimator and the pseudoinverse of the array manifold matrix estimator. The covariance vector estimator uses only the correlations between sensors and the pseudoinverse of the array manifold matrix estimator operates with the minimum eigenvalues of the covariance matrix. Numerical and experimental results are presented.

Effect of filter-feeding fish silver carp on phytoplankton species and size distribution in surface water:A field study in water works

Silver carp were introduced into the pre-sedimentation pond to control excessive phytoplankton in raw water. The effectiveness of the filter-feeding silver carp on phytoplankton control and the effect of silver carp on phytoplankton community were investigated. The results showed that Microcystis could be effectively removed by silver carp stocked in the pre-sedimentation pond, and simultaneously, the concentration of single-cell phytoplankton increased obviously. The difference in phytoplankton species and single- cell phytoplankton size between in the water and in the gut of silver carp indicated that phytoplankton smaller than 5 μm, such as Chamydomonas and Platymonas, were almost not be filtered by silver carp, phytoplankton with the size between 5 and 20μm could be partly filtered, and large size phytoplankton, mainly colony-forming Microcystis could be filtered almost completely. These filter- feeding characteristics directly caused the phytoplankton size distribution biased toward miniaturization. Therefore, this biological treatment using silver carp could be applied only to deal with groups of Microcystis-dominated eutrophic water, and was not appropriate in water bodies where single-cell micro phytoplankton were dominant. Especially when silver carp are used in water treatment, a cautious attitude should be taken based on the evaluation of phytoplankton biomass and species structure features in raw water.

Ultra-thin and light-weight spoof surface plasmon polariton coupler achieved by broadside coupled split ring resonators

Low profile and light weight are very important for practical applications of a spoof surface plasmon polariton（SSPP）coupler, especially at low frequencies. In this paper, we propose and design an ultra-thin, light-weight SSPP coupler based on broadside coupled split ring resonators（BC-SRRs）. The size of BC-SRR can be far less than λ/100 and can extremely well control the reflective phases within a subwavelength thickness. Due to the broadside capacitive coupling, the electrical size of BC-SRR is dramatically reduced to guarantee the ultra-thin thickness of the SSPP coupler. The weight of the SSPP coupler is reduced by a low occupation ratio of BC-SRR in the unit cell volume. As an example, a C-band SSPP coupler composed of phase gradient BC-SRRs is designed, fabricated, and measured. Due to the ultra-small size and low occupation ratio of BC-SRRs, the thickness of the coupler is λ/12 and the surface density is only 0.98 kg/m^2. Both simulation and experiment results verify that the coupler can achieve high-efficiency SPP coupling at 5.27 GHz under normal incidence.

GTK:A Hybrid-Search Algorithm of Top-Rank-k Frequent Patterns Based on Greedy Strategy

Currently,the top-rank-k has been widely applied to mine frequent patterns with a rank not exceeding k.In the existing algorithms,although a level-wise-search could fully mine the target patterns,it usually leads to the delay of high rank patterns generation,resulting in the slow growth of the support threshold and the mining efficiency.Aiming at this problem,a greedy-strategy-based top-rank-k frequent patterns hybrid mining algorithm(GTK)is proposed in this paper.In this algorithm,top-rank-k patterns are stored in a static doubly linked list called RSL,and the patterns are divided into short patterns and long patterns.The short patterns generated by a rank-first-search always joins the two patterns of the highest rank in RSL that have not yet been joined.On the basis of the short patterns satisfying specific conditions,the long patterns are extracted through level-wise-search.To reduce redundancy,GTK improves the generation method of subsume index and designs the new pruning strategies of candidates.This algorithm also takes the use of reasonable pruning strategies to reduce the amount of computation to improve the computational speed.Real datasets and synthetic datasets are adopted in experiments to evaluate the proposed algorithm.The experimental results show the obvious advantages in both time efficiency and space efficiency of GTK.

医学信息类专业教学体系的创新设计

教学体系的设计是高等教育人才培养的质量保证,为了满足医学信息类专业对医工融合人才培养的需求,达到创新教育的目的,从理论和实验实践教学的两个角度对教学体系的创新方法进行了探索,分别从专业知识、教学思维、教学方法、教学模式和实践内容、实践体系、科研创新、校内实践平台、校外实践基础、实习机制等方面进行了以创新为目的的教学设计。

Leaky cavity modes in metasurfaces:a route to low-loss wideband anomalous dispersion

Metasurfaces have provided unprecedented degrees of freedom in manipulating electromagnetic waves upon interfaces.In this work,we first explore the condition of wide operating bandwidth in the view of reflective scheme,which indicates the necessity of anomalous dispersion.To this end,the leaky cavity modes(LCMs)in the metaatom are analyzed and can make effective permittivity inversely proportional to frequency.Here we employ the longitudinal Fabry-Perot(F-P)resonances and transverse plasmonic resonances to improve the LCMs efficiency.It is shown that the order of F-P resonance can be customized by the plasmonic modes,that is,the F-P cavity propagation phase should match the phase delay of surface currents excited on the meta-atom.The nth order F-P resonance will multiply the permittivity by a factor of n,allowing larger phase accumulation with increasing frequencies and forming nonlinear phase distribution which can be applied in weak chromatic-aberration focusing design.As a proof-of-concept,we demonstrate a planar weak chromatic-aberration focusing reflector with a thickness ofλ_(0)∕9 at 16.0-21.0 GHz.This work paves a robust way to advanced functional materials with anomalous dispersion and can be extended to higher frequencies such as terahertz,infrared,and optical frequencies.

Six-channel programmable coding metasurface simultaneously for orthogonal circular and linear polarizations

Metasurfaces have intrigued long-standing research interests and developed multitudinous compelling applications owing to their unprecedented capability for manipulating electromagnetic waves,and the emerging programmable coding metasurfaces(PCMs)provide a real-time reconfigurable platform to dynamically implement customized functions.Nevertheless,most existing PCMs can only act on the single polarization state or perform in the limited polarization channel,which immensely restricts their practical application in multitask intelligent metadevices.Herein,an appealing strategy of the PCM is proposed to realize tunable functions in co-polarized reflection channels of orthogonal circularly polarized waves and in co-polarized and cross-polarized reflection channels of orthogonal linearly polarized waves from 9.0 to 10.5 GHz.In the above six channels,the spindecoupled programmable meta-atom can achieve high-efficiency reflection and 1-bit digital phase modulation by selecting the specific ON/OFF states of two diodes,and the phase coding sequence of the PCM is dynamically regulated by the field-programmable gate array to generate the desired function.A proof-of-concept prototype is constructed to verify the feasibility of our methodology,and numerous simulation and experimental results are in excellent agreement with the theoretical predictions.This inspiring design opens a new avenue for constructing intelligent metasurfaces with higher serviceability and flexibility,and has tremendous application potential in communication,sensing,and other multifunctional smart metadevices.

A Novel Recommendation Service Method Based on Cloud Model and User Personality

The number of Internet Web services has become increasingly large recently.Cloud services consumers face a critical challenge in selecting services from abundant candidates.Due to the uncertainty of Web service QoS and the diversity of user characteristics,this paper proposes a Web service recommendation method based on cloud model and user personality(WSRCP),which employs cloud model similarity method to analyze the similarity of QoS feedback data among different users,to identify the user with high similarity to the potential user.Based on the QoS data of the users’feedback,Finally,user characteristic attribute Web service recommendation is implemented by personalized collaborative filtering algorithm.The experimental results on the WS-Dream dataset show that our approach not only solves the drawbacks of the sparse user service,but also improves the recommend accuracy.

Effect of nitrate supply on the facilitation between two salt-marsh plants (Suaeda salsa and Scirpus planiculmis)

在河口盐沼中,硝酸盐浓度和土壤盐分是两个主要的环境驱动因素,它们同时影响着植物物种之间的相互作用。然而,迄今为止,它们的交互作用对盐沼植物种间相互作用的影响还没有得到针对性的研究。在被漂洗过的河沙中种植盐地碱蓬(Suaeda salsa L.)和扁秆藨草(Scirpus planiculmis Fr.)的幼株,实验中设置三种处理:种间相互作用处理(混合培养或者单独培养)、三个盐度水平处理(1、50和100 mmol L^(-1))以及三个硝酸盐水平处理(0.5、5和10 mmol L^(-1))。首先测量了所有植物植株的高度和生物量,然后分析了这两个物种的生长数据、种间相对关系指数和竞争重要性指数。在三个盐度处理中,盐地碱蓬和扁秆藨草的种间相互作用为种间促进。高浓度的硝酸盐促进了盐地碱蓬的生长,但并没有增强该物种的种间促进作用效果,特别是在低盐度处理中。然而,在高盐度处理中,高浓度的硝酸盐显著地将扁秆藨草的种间相互作用从促进转变为竞争。我们的结果表明,过量施用硝酸盐会在盐度梯度中改变胁迫梯度假说的预测,从而导致在盐沼中这两个物种共存的崩溃。这些发现有助于人们理解盐地碱蓬和扁秆藨草以及盐沼植物群落如何响应由人类活动导致的河口营养水平的改变。秆藨草以及盐沼植物群落如何响应由人类活动导致的河口营养水平的改变。

Quadruple-band metamaterial absorber based on the cuboid dielectric particles

In this work,a quadruple-band dielectric metamaterial absorber(MMA)was proposed and studied,which is composed of eight cuboid dielectric particles and a metallic ground plate.When electromagnetic wave is incident on the dielectric particles,dielectric particles act as resonators and produce abundant resonant modes,which can result in perfect absorption.In simulation,four absorption peaks are observed at 9.13,9.62,10.0 and 10.46 GHz with 88%,89%,100%and 96%,respectively.By adjusting geometry parameters of the dielectric particles,dielectric MMAs with different bands can be obtained.Further investigation shows that the absorption peaks can be changed by increasing the permittivity of the dielectric.Based on the designing technique of using simple cuboid dielectric particles directly acting as resonator,this work provides a simple method to construct multiband alldielectric MMA.

All-dielectric metamaterial frequency selective surface

Frequency selective surface(FSS)has been extensively studied due to its potential applications in radomes,antenna reflectors,high-impedance surfaces and absorbers.Recently,a new principle of designing FSS has been proposed and mainly studied in two levels.In the level of materials,dielectric materials instead of metallic patterns are capable of achieving more functional performance in FSS design.Moreover,FSSs made of dielectric materials can be used in different extreme environments,depending on their electrical,thermal or mechanical properties.In the level of design principle,the theory of metamaterial can be used to design FSS in a convenient and concise way.In this review paper,we provide a brief summary about the recent progress in all-dielectric metamaterial frequency selective surface(ADM-FSS).The basic principle of designing ADM-FSS is summarized.As significant tools,Mie theory and dielectric resonator(DR)theory are given which illustrate clearly how they are used in the FSS design.Then,several design cases including dielectric particle-based ADM-FSS and dielectric network-based ADM-FSS are introduced and reviewed.After a discussion of these two types of ADM-FSSs,we reviewed the existing fabrication techniques that are used in building the experiment samples.Finally,issues and challenges regarding the rapid fabrication techniques and further development aspects are discussed.

Synthesis and electromagnetic absorption properties of micro-nano nickel powders prepared with liquid phase reduction method

Monodisperse micro-nano nickel powders have been prepared by chemical reduction of aqueous solution NiSO_(4),NaOH and NaH_(2)PO_(2),and the influence of pH value and initial concentration of NiSO_(4) on the size,structure,morphology and microwave absorption properties of nickel powders were investigated.The crystal structure of nickel powders was characterized by X-ray diffraction(XRD).And the morphology of the as-synthesized products was characterized by scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The microwave absorption properties of the composite materials were characterized by network analyzer.The result indicates that the growth of nickel powders produced by NiSO_(4) and NaH_(2)PO_(2) at alkaline condition deeply relies on pH value and initial concentration of NiSO_(4) in reaction system.Different sizes of nickel powders with the diameter of 1.5μm and 180 nm were produced at the pH value of 10 and initial concentration of NiSO_(4) at 0.5 mol/L.The network analyzer showed definite microwave absorption properties of nickel powders with different sizes in the range of 0.5-18.0 GHz.

Optical transparent infrared high absorption metamaterial absorbers

In this work,an optical transparent infrared high absorption metamaterial absorber is proposed based on indium tin oxide(ITO)substrate.Due to the fact that ITO holds high reflectivity property in infrared region while transparent in optical region,ITO can be used in the application of Surface Plasmon Polaritons.In this design,three kinds of infrared metamaterial absorbers were proposed.All of them can achieve high absorption at 10.6μm while remaining transparent in visible region.LC equivalent circuit model was served as design foundation.The infrared absorption efficiency was numerically calculated and the mechanism analysis is given in the paper.The simulation results show that all three structures can achieve high absorption efficiency at 10.6μm under TE/TM polarization.The absorption remains high when the incident angle is less than 70°.Experimental results exhibit good accordance with simulation.

All-dielectric metamaterial frequency selective surface based on spatialarrangement ceramic resonators

In this paper,we demonstrate a method of designing all-dielectric metamaterial frequency selective surface(FSS)with ceramic resonators in spatial arrangement.Compared with the traditional way,spatial arrangement provides a flexible way to handle the permutation and combination of different ceramic resonators.With this method,the resonance response can be adjusted easily to achieve pass/stop band effects.As an example,a stop band spatial arrangement all-dielectric metamaterial FSS is designed.Its working band is in 11.65–12.23 GHz.By adjusting permittivity and geometrical parameters of ceramic resonators,we can easily modulate the resonances,band pass or band stop characteristic,as well as the working band.