Focus control of wide-angle metalens based on digitally encoded metasurface

Based on the principle of super-symmetric lens with quadratic phase gradient transformation, combined with the principle of digital coding of metasurface, we propose a wide-angle coded metalens for focusing control in two-dimensional space. This metalens achieves focus shift in the x-direction by changing the oblique incidence angle of the incident wave,and focus control in the y-direction by combining with the convolution principle of the digitally coded metasurface to achieve flexible control of light focusing in the two-dimensional plane. The metasurface unit is mainly composed of threelayer of metal structure and two layers of medium, and the transmission phase is obtained by changing the middle layer of metal structure, which in turn obtains the required phase distribution of the metalens. The design of the metalens realizes the function of the lens with a large viewing angle at the x-polarized incidence, and realizes two-dimensional focus control. Experimentally, we prepared the designed coding metalens and tested the focus control function of the wide-angle coding metalens. The experimental results are in good agreement with the design results.

The potential of gene therapies for spinal cord injury repair:a systematic review and meta-analysis of pre-clinical studies

Currently,there is no cure for traumatic spinal co rd injury but one therapeutic approach showing promise is gene therapy.In this systematic review and meta-analysis,we aim to assess the efficacy of gene therapies in pre-clinical models of spinal cord injury and the risk of bias.In this metaanalysis,registe red at PROSPERO(Registration ID:CRD42020185008),we identified relevant controlled in vivo studies published in English by searching the PubMed,Web of Science,and Embase databases.No restrictions of the year of publication were applied and the last literature search was conducted on August 3,2020.We then conducted a random-effects meta-analysis using the restricted maximum likelihood estimator.A total of 71 studies met our inclusion crite ria and were included in the systematic review.Our results showed that overall,gene therapies were associated with improvements in locomotor score(standardized mean difference[SMD]:2.07,95%confidence interval[CI]:1.68-2.47,Tau^(2)=2.13,I^(2)=83.6%)and axonal regrowth(SMD:2.78,95%CI:1.92-3.65,Tau^(2)=4.13,I^(2)=85.5%).There was significant asymmetry in the funnel plots of both outcome measures indicating the presence of publication bias.We used a modified CAMARADES(Collaborative Approach to M eta-Analysis and Review of Animal Data in Experimental Studies)checklist to assess the risk of bias,finding that the median score was 4(IQR:3-5).In particula r,reports of allocation concealment and sample size calculations were lacking.In conclusion,gene therapies are showing promise as therapies for spinal co rd injury repair,but there is no consensus on which gene or genes should be targeted.

Superior lithium storage performance in MoO_(3) by synergistic effects:Oxygen vacancies and nanostructures

Molybdenum trioxide(MoO_(3))has recently attracted wide attention as a typical conversion-type anode of Li-ion batteries(LIBs).Nevertheless,the inferior intrinsic conductivity and rapid capacity fading during charge/discharge process seriously limit large-scale commercial application of MoO_(3).Herein,the density function theory(DFT)calculations show that electron-proton co-doping preferentially bonds symmetric oxygen to form unstable HxMoO_(3).When the-OH-group in HxMoO_(3) is released into the solution in the form of H_(2)O,it is going to form MoO_(3-x)with lower binding energy.By the means of both electron-proton co-doping and high-energy nanosizing,oxygen vacancies and nanoflower structure are introduced into MoO_(3) to accelerate the ion and electronic diffusion/transport kinetics.Benefitting from the promotion of ion diffusion kinetics related to nanostructures,as well as both the augmentation of active sites and the improvement of electrical conductivity induced by oxygen vacancies,the MoO_(3-x)/nanoflower structures show excellent lithium-ion storage performance.The prepared specimen has a high lithium-ion storage capacity of 1261 mA h g^(-1)at 0.1 A g^(-1)and cyclic stability(450 cycle),remarkably higher than those of previously reported MoO_(3)-based anode materials.

Dynamic Weapon Target Assignment Based on Intuitionistic Fuzzy Entropy of Discrete Particle Swarm

Aiming at the problems of convergence-slow and convergence-free of Discrete Particle Swarm Optimization Algorithm(DPSO) in solving large scale or complicated discrete problem, this article proposes Intuitionistic Fuzzy Entropy of Discrete Particle Swarm Optimization(IFDPSO) and makes it applied to Dynamic Weapon Target Assignment(WTA). First, the strategy of choosing intuitionistic fuzzy parameters of particle swarm is defined, making intuitionistic fuzzy entropy as a basic parameter for measure and velocity mutation. Second, through analyzing the defects of DPSO, an adjusting parameter for balancing two cognition, velocity mutation mechanism and position mutation strategy are designed, and then two sets of improved and derivative algorithms for IFDPSO are put forward, which ensures the IFDPSO possibly search as much as possible sub-optimal positions and its neighborhood and the algorithm ability of searching global optimal value in solving large scale 0-1 knapsack problem is intensified. Third, focusing on the problem of WTA, some parameters including dynamic parameter for shifting firepower and constraints are designed to solve the problems of weapon target assignment. In addition, WTA Optimization Model with time and resource constraints is finally set up, which also intensifies the algorithm ability of searching global and local best value in the solution of WTA problem. Finally, the superiority of IFDPSO is proved by several simulation experiments. Particularly, IFDPSO, IFDPSO1~IFDPSO3 are respectively effective in solving large scale, medium scale or strict constraint problems such as 0-1 knapsack problem and WTA problem.

The therapeutic potential of targeting exchange protein directly activated by cyclic adenosine 3',5'-monophosphate(Epac)for central nervous system trauma

Millions of people worldwide are affected by traumatic spinal cord injury,which usually results in permanent sensorimotor disability.Damage to the spinal cord leads to a series of detrimental events including ischaemia,haemorrhage and neuroinflammation,which over time result in further neural tissue loss.Eventually,at chronic stages of traumatic spinal cord injury,the formation of a glial scar,cystic cavitation and the presence of numerous inhibitory molecules act as physical and chemical barriers to axonal regrowth.This is further hindered by a lack of intrinsic regrowth ability of adult neurons in the central nervous system.The intracellular signalling molecule,cyclic adenosine 3′,5′-monophosphate(cAMP),is known to play many important roles in the central nervous system,and elevating its levels as shown to improve axonal regeneration outcomes following traumatic spinal cord injury in animal models.However,therapies directly targeting cAMP have not found their way into the clinic,as cAMP is ubiquitously present in all cell types and its manipulation may have additional deleterious effects.A downstream effector of cAMP,exchange protein directly activated by cAMP 2(Epac2),is mainly expressed in the adult central nervous system,and its activation has been shown to mediate the positive effects of cAMP on axonal guidance and regeneration.Recently,using ex vivo modelling of traumatic spinal cord injury,Epac2 activation was found to profoundly modulate the post-lesion environment,such as decreasing the activation of astrocytes and microglia.Pilot data with Epac2 activation also suggested functional improvement assessed by in vivo models of traumatic spinal cord injury.Therefore,targeting Epac2 in traumatic spinal cord injury could represent a novel strategy in traumatic spinal cord injury repair,and future work is needed to fully establish its therapeutic potential.

Hydrogen Bonding-Assisted Synthesis of Silica/Oxidized Mesocarbon Microbeads Encapsulated in Amorphous Carbon as Stable Anode for Optimized/Enhanced Lithium Storage

The practical application of silica-based composites as an alternative to commercial graphite anode materials is hampered by their large volumetric expansion,poor conductivity,and low Coulombic efficiency.In this work,a novel silica/oxidized mesocarbon microbead/amorphous carbon(SiO2/O’MCMB/C)hierarchical structure in which SiO2 is sandwiched between spherical graphite and amorphous carbon shell was succes sfully fabricated through hydrogen bonding-assisted self-assembly and post-carbon coating method.The obtained three-layer hierarchical structure effectively accommodates the volumetric expansion of SiO2 and significantly enhances the electronic conductivity of composite materials.Moreover,the outer layer of amorphous carbon effectively increases the diffusion rate of lithium ions and promotes the formation of stable SEI film.As a result,the SiO2/O’MCMB/C composite exhibits superior electrochemical performance with a reversible capacity of 459.5 mA h/g in the first cycle,and the corresponding Coulombic efficiency is 62.8%.After 300 cycles,the capacity climbs to around 600 mA h/g.This synthetic route provides an efficient method for preparing SiO2 supported on graphite with excellent electrochemical performance,which is likely to promote its commercial applications.

Immune adaptive Gaussian mixture particle filter for state estimation

The particle filter （PF） is a flexible and powerful sequen- tial Monte Carlo （SMC） technique capable of modeling nonlinear, non-Gaussian, and nonstationary dynamical systems. However, the generic PF suffers from particle degeneracy and sample im- poverishment, which greatly affects its performance for nonlinear, non-Gaussian tracking problems. To deal with those issues, an improved PF is proposed. The algorithm consists of a PF that uses an immune adaptive Gaussian mixture model （IAGM） based immune algorithm to re-approximate the posterior density. At the same time, three immune antibody operators are embed in the new filter. Instead of using a resample strategy, the newest obser- vation and conditional likelihood are integrated into those immune antibody operators to update the particles, which can further im- prove the diversity of particles, and drive particles toward their close local maximum of the posterior probability. The improved PF algorithm can produce a closed-form expression for the posterior state distribution. Simulation results show the proposed algorithm can maintain the effectiveness and diversity of particles and avoid sample impoverishment, and its performance is superior to several PFs and Kalman filters.

Silkworm silk biomaterials for spinal cord repair: promise for combinatorial therapies

Background：Traumatic injury to the adult mammalian spinal cord results in minimal axonal regrowth,cystic cavity formation at the injury site,poor functional recovery and there is no cure available.Due to the complex nature of spinal cord injury（SCI）,a combination of therapeutic strategies may offer the most promise for successful regeneration（Ahuja et al.,2017）.

Woven fabric triboelectric nanogenerators for human-computer interaction and physical health monitoring

Triboelectric nanogenerator(TENG)converts mechanical energy into valuable electrical energy,offering a solution for future energy needs.As an indispensable part of TENG,textile TENG(T-TENG)has incredible advantages in harvesting biomechanical energy and physiological signal monitoring.However,the application of T-TENG is restricted,partly because the fabric structure parameter and structure on T-TENG performance have not been fully exploited.This study comprehensively investigates the effect of weaving structure on fabric TENGs(F-TENGs)for direct-weaving yarn TENGs and post-coating fabric TENGs.For direct-weaving F-TENGs,a single-yarn TENG(Y-TENG)with a core-sheath structure is fabricated using conductive yarn as the core layer yarn and polytetrafluoroethylene(PTFE)filaments as the sheath yarn.Twelve fabrics with five different sets of parameters were designed and investigated.For post-coating F-TENGs,fabrics with weaving structures of plain,twill,satin,and reinforced twill were fabricated and coated with conductive silver paint.Overall,the twill F-TENGs have the best electrical outputs,followed by the satin F-TENGs and plain weave F-TENGs.Besides,the increase of the Y-TENG gap spacing was demonstrated to improve the electrical output performance.Moreover,T-TENGs are demonstrated for human-computer interaction and self-powered real-time monitoring.This systematic work provides guidance for the future T-TENG’s design.

Identification of highly efficacious PROTACs targeting BRD4 against acute myeloid leukemia:Design,synthesis,and biological evaluations

The abnormal activation of BRD4 accelerates the progression of acute myeloid leukemia(AML),developing more precise therapeutics to intervene BRD4 promise to be an excellent opportunity to avoid current limitations of chemotherapy in clinic.Herein,a range of small-molecule PROTACs with the privileged 8-methyl-pyrrolo[1,2-a]pyrazin-1(2H)-one scaffold were rationally designed,which harbored different carbon or ethylenedioxy chains to degrade BRD4 mediated by the E3 ubiquitin ligase CRBN.Among them,the most potential B24 exhibited remarkable BRD4 degradation and excellent anti-proliferative activities in MV4-11 cells,with values of DC_(50)and IC_(50)for 0.75 nmol/L and 0.4 nmol/L,respectively,which were better than the BRD4 inhibitor(+)-JQ-1.Notably,this compound could time-dependently degrade the target protein in the BRD4-,CRBN-,and proteasome-dependent manner.Besides,B24 dramatically decreased the level of proto-oncogene c-Myc,and induced cell apoptosis by arresting the cell cycle in G0/G1 phase,down-regulating Bcl-2 and up-regulating Bax to amplify apoptotic effectors.This proof-of-concept study also highlighted the feasibility of BRD4-based PROTACs as a more powerful strategy against AML.

Design,synthesis and antitumor activities of fluoroquinolone C-3 heterocycles(Ⅳ):s-triazole Schiff-Mannich bases derived from of loxacin

The aim of this research was to produce novel antitumor fluoroquinolones from antibacterial analogs by introduction of a heterocyclic ring as a bioisostere of the C-3 carboxylic acid group.To this end,two series of eleven s-triazole derivatives bearing functionalized side chains of Schiff bases and Schiff Mannich bases were designed and synthesized.Structures were characterized by elemental analysis and spectral data after which in vitro antitumor activity against L1210,CHO and HL60 cell lines was evaluated in the MTT assay.Compounds posssing a free phenol group were particularly active and warrant further development.

Histology and antitumor activity study of PTX-loaded micelle,a fluorescent drug delivery system prepared by PEG-TPP

We synthesized PEG-TPP as carrier to encapsulate paclitaxel (PTX) in the form of micelles to overcome its water-solubility problem. PTX-loaded micelles possess a-week stability and appropriate particle size (152.1 ±1.2 nm) which is beneficial for enhanced permeability and retention (EPR) effect. Strong pH dependence of PTX releasing from micelles is verified by in vitro release study. At cellular level, PTX-loaded micelles can target mitochondria effectively which may results a better cytotoxicity of micelles (especially IC50 = 0.123 ± 0.035μmol/L of micelles and 0.298 ± 0.067μmol/L of PTX alone on MCF-7 cells). The fluorescence distributions of both isolated and sliced organs show that the micelles can effectively target tumors. Moreover, we further prove the enhanced therapeutic effects of micelles in tumor-bearing mice comparing with PTX alone. The results show that the biodegradable drug delivery system prepared by PEG-TPP can overcome the poor solubility of paclitaxel and improve its tumor targeting and antitumor activity.