Gamma oscillations and their role in orchestrating balance and communication following stroke

Induced brain oscillations in the gamma range have recently garnered attention due to their reported neuroprotective effects in the treatment of Alzheimer’s disease.This method differs from pharmacological approaches by tapping into the neuronal population dynamics that underlie the homeostatic processes in the brain that are crucial for the recovery of function.Recently,induced gamma-range oscillations have been used to improve cerebral blood flow,motor function,and synaptic plasticity in a mouse model of focal stroke,highlighting the broad potential of recruiting intrinsic recovery processes for the treatment of neurological conditions.Addressing open questions,such as the frequency specificity of the benefits,will shed light on the intrinsic processes involved and allow clinicians to optimize recovery after stroke.

A phenology-based vegetation index for improving ratoon rice mapping using harmonized Landsat and Sentinel-2 data

Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in Hubei Province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRVI based on HLS data can effectively identify ratoon rice in fragmented croplands at crucial phenological stages,which is promising for identifying the earliest timing of ratoon rice planting and can provide a fundamental dataset for crop management activities.

In Situ Deposition of Drug and Gene Nanoparticles on a Patterned Supramolecular Hydrogel to Construct a Directionally Osteochondral Plug

The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,spatially oriented scaffolds to stimulate osteochondral regeneration,has immense significance.Herein,targeted drugs,namely kartogenin@polydopamine(KGN@PDA)nanoparticles for cartilage repair and miRNA@calcium phosphate(miRNA@CaP)NPs for bone regeneration,were in situ deposited on a patterned supramolecular-assembled 2-ureido-4[lH]-pyrimidinone(UPy)modified gelation hydrogel film,facilitated by the dynamic and responsive coordination and complexation of metal ions and their ligands.This hydrogel film can be rolled into a cylindrical plug,mimicking the Haversian canal structure of natural bone.The resultant hydrogel demonstrates stable mechanical properties,a self-healing ability,a high capability for reactive oxygen species capture,and controlled release of KGN and miR-26a.In vitro,KGN@PDA and miRNA@CaP promote chondrogenic and osteogenic differentiation of mesenchymal stem cells via the JNK/RUNX1 and GSK-3β/β-catenin pathways,respectively.In vivo,the osteochondral plug exhibits optimal subchondral bone and cartilage regeneration,evidenced by a significant increase in glycosaminoglycan and collagen accumulation in specific zones,along with the successful integration of neocartilage with subchondral bone.This biomaterial delivery approach represents a significant toward improved osteochondral repair.

绿色智慧体育场馆——丰台区科丰仓储用房的转型

北京市丰台区科丰仓储用房更新改造项目是一项创新的城市更新实践,将一座废弃的储煤仓库转变为多功能体育场馆。该项目位于北京丰台科技园附近,原为科丰热力公司的储煤仓库。通过低成本、快节奏的改造方式,该项目在不改变原有建筑结构的前提下,优化了空间功能,提供了乒乓球、羽毛球和篮球等体育设施,满足了周边社区居民的体育活动需求。同时,项目引入智能化管理系统,实现了绿色、环保、节能的运营目标。这一改造不仅提升了城市空间利用效率,也为社区居民提供了便利的体育生活服务,增强了社区活力。

Optimal parameter space for stabilizing the ferroelectric phase of Hf_(0.5)Zr_(0.5)O_(2) thin films under strain and electric fields

Hafnia-based ferroelectric materials, like Hf_(0.5)Zr_(0.5)O_(2)(HZO), have received tremendous attention owing to their potentials for building ultra-thin ferroelectric devices. The orthorhombic(O)-phase of HZO is ferroelectric but metastable in its bulk form under ambient conditions, which poses a considerable challenge to maintaining the operation performance of HZO-based ferroelectric devices. Here, we theoretically addressed this issue that provides parameter spaces for stabilizing the O-phase of HZO thin-films under various conditions. Three mechanisms were found to be capable of lowering the relative energy of the O-phase, namely, more significant surface-bulk portion of(111) surfaces, compressive c-axis strain,and positive electric fields. Considering these mechanisms, we plotted two ternary phase diagrams for HZO thin-films where the strain was applied along the in-plane uniaxial and biaxial, respectively. These diagrams indicate the O-phase could be stabilized by solely shrinking the film-thickness below 12.26 nm, ascribed to its lower surface energies. All these results shed considerable light on designing more robust and higher-performance ferroelectric devices.

Evolution of the porous structure for phosphoric acid etching carbon as cathodes in Li–O_(2) batteries:Pyrolysis temperature-induced characteristics changes

Although biomass-derived carbon(biochar)has been widely used in the energy field,the relation between the carbonization condition and the physical/chemical property of the product remains elusive.Here,we revealed the carbonization condition's effect on the morphology,surface property,and electrochemical performance of the obtained carbon.An open slit pore structure with shower-puff-like nanoparticles can be obtained by finely tuning the carbonization temperature,and its unique pore structure and surface properties enable the Li–O_(2) battery with cycling longevity(221 cycles with 99.8%Coulombic efficiency at 0.2 mA cm^(−2) and controlled discharge–charge depths of 500 mAh g^(−1))and high capacity(16,334 mAh g^(−1) at 0.02 mA cm^(−2)).This work provides a greater understanding of the mechanism of the biochar carbonization procedure under various pyrolysis conditions,paving the way for future study of energy storage devices.

Memristive feature and mechanism induced by laser-doping in defect-free 2D semiconductor materials

Memristors as non-volatile memory devices have gained numerous attentions owing to their advantages in storage,in-memory computing, synaptic applications, etc. In recent years, two-dimensional(2D) materials with moderate defects have been discovered to exist memristive feature. However, it is very difficult to obtain moderate defect degree in 2D materials, and studied on modulation means and mechanism becomes urgent and essential. In this work, we realized memristive feature with a bipolar switching and a configurable on/off ratio in a two-terminal MoS_(2) device(on/off ratio ~100), for the first time, from absent to present using laser-modulation to few-layer defect-free MoS_(2)(about 10 layers), and its retention time in both high resistance state and low resistance state can reach 2×10^(4) s. The mechanism of the laser-induced memristive feature has been cleared by dynamic Monte Carlo simulations and first-principles calculations. Furthermore, we verified the universality of the laser-modulation by investigating other 2D materials of TMDs. Our work will open a route to modulate and optimize the performance of 2D semiconductor memristive devices.

Influence of Flap Parameters on the Aerodynamic Performance of a Wind-Turbine Airfoil

A numerical method has been used to analyze the flow field related to a NACA 0015 airfoil with and without a flap and assess the influence of the flap height and angle on the surface pressure coefficient,lift coefficient,and drag coefficient.The numerical results demonstrate that the flap can effectively improve the lift coefficient of the airfoil;however,at small attack angles,its influence is significantly reduced.When the angle of attack exceeds the critical stall angle and the flap height is 1.5%of the chord length,the influence of the flap becomes very evident.As the flap height increases,the starting point of the separation vortex gradually moves forward and generates a larger wake vortex.Optimal aerodynamic characteristics are obtained for 1.5%(of the chord length)flap height and a 45°flap angle;in this case,the separation vortex is effectively reduced.

Influence of Trailing-Edge Wear on the Vibrational Behavior of Wind Turbine Blades

To study the impact of the trailing-edge wear on the vibrational behavior of wind-turbine blades,unworn blades and trailing-edge worn blades have been assessed through relevant modal tests.According to these experiments,the natural frequencies of trailing-edge worn blades-1,-2,and-3 increase the most in the second to fourth order,thefifth order increases in the middle,and thefirst order increases the least.The damping ratio data indi-cate that,in general,thefirstfive-order damping ratios of trailing-edge worn blades-1 and trailing-edge worn blades-2 are reduced,and thefirstfive-order damping ratios of trailing-edge worn blades-3 are slightly improved.The mode shape diagram shows that the trailing-edge worn blades-1 and-2 have a large swing in the tip and the blade,whereas the second-and third-order vibration shapes of the trailing edge-worn blade-3 tend to be improved.Overall,all these results reveal that the blade’s mass and the wear area are the main fac-tors affecting the vibration characteristics of wind turbine blades.

Orbital-Ordering Driven Simultaneous Tunability of Magnetism and Electric Polarization in Strained Monolayer VCl_(3)

Two-dimensional(2D)van der Waals magnetic materials have promising and versatile electronic and magnetic properties in the 2D limit,indicating a considerable potential to advance spintronic applications.Theoretical predictions thus far have not ascertained whether monolayer VCl_(3) is a ferromagnetic(FM)or anti-FM monolayer;this also remains to be experimentally verified.We theoretically investigate the influence of potential factors,including C_(3) symmetry breaking,orbital ordering,epitaxial strain,and charge doping,on the magnetic ground state.Utilizing first-principles calculations,we predict a collinear type-Ⅲ FM ground state in monolayer VCl_(3) with a broken C_(3) symmetry,wherein only the former two of three t_(2g)orbitals(a_(1g),e_(g2)^(π)and e_(g1)^(π))are occupied.The atomic layer thickness and bond angles of monolayer VCl_(3) undergo abrupt changes driven by an orbital ordering switch,resulting in concomitant structural and magnetic phase transitions.Introducing doping to the underlying Cl atoms of monolayer VCl_(3) without C_(3) symmetry simultaneously induces in-and out-of-plane polarizations.This can achieve a multiferroic phase transition if combined with the discovered adjustments of magnetic ground state and polarization magnitude under strain.The establishment of an orbital-ordering driven regulatory mechanism can facilitate deeper exploration and comprehension of magnetic properties of strongly correlated systems in monolayer VCl_(3).

Deterministic Learning-Based Neural PID Control for Nonlinear Robotic Systems

Traditional proportional-integral-derivative(PID)controllers have achieved widespread success in industrial applications.However,the nonlinearity and uncertainty of practical systems cannot be ignored,even though most of the existing research on PID controllers is focused on linear systems.Therefore,developing a PID controller with learning ability is of great significance for complex nonlinear systems.This article proposes a deterministic learning-based advanced PID controller for robot manipulator systems with uncertainties.The introduction of neural networks(NNs)overcomes the upper limit of the traditional PID feedback mechanism’s capability.The proposed control scheme not only guarantees system stability and tracking error convergence but also provides a simple way to choose the three parameters of PID by setting the proportional coefficients.Under the partial persistent excitation(PE)condition,the closed-loop system unknown dynamics of robot manipulator systems are accurately approximated by NNs.Based on the acquired knowledge from the stable control process,a learning PID controller is developed to further improve overall control performance,while overcoming the problem of repeated online weight updates.Simulation studies and physical experiments demonstrate the validity and practicality of the proposed strategy discussed in this article.

Gait Recognition Under Different Clothing Conditions Via Deterministic Learning

Dear Editor,This letter deals with the robustness problem of gait recognition method against maximum number of clothing conditions.By selecting four kinds of time-varying silhouette features,gait dynamics underlying different individuals’gait features is effectively modeled by radial basis function(RBF)neural networks through deterministic learning.This kind of dynamics information has little sensitivity to the variance between gait patterns under different clothing conditions.In order to eliminate the effect of clothing differences,the training patterns under different clothing conditions further constitute a uniform training dataset,containing all kinds of gait dynamics under different clothing conditions.A rapid recognition scheme is presented on published gait databases.Extensive experiments demonstrate the efficacy of the proposed method.

悟空巧饰磷脂膜,囊泡大败癌细胞

“我们能人工合成一个细胞吗?Can a cell be artificially synthesized?”——这是2021年《科学》期刊新发布的世界最前沿的125个重大科学问题之一。科学家为了揭示“生命起源”的奥秘以及解决世界关注的重大基础科学问题,设计出人造细胞这类仿生材料。它们最明显的特点就是具有与生物细胞类似的结构与功能。因此,深入研究人造细胞,不仅有利于研究真实细胞的结构与功能机制,还有助于建立非生物物质与真实细胞之间的联系,从而搭建非生命系统与生命系统之间的桥梁,为生命起源等相关研究提供实验与理论依据。而磷脂囊泡作为目前应用最为广泛的人造细胞更是有着广阔的应用前景。为了使“磷脂囊泡”这类材料以及相关研究技术得到更广泛的认识,本文基于耳熟能详的四大名著之一——《西游记》,讲述了孙悟空凭借火眼金睛帮助磷脂囊泡战胜癌细胞的故事,介绍了磷脂囊泡的设计和制备、代表功能以及体内治疗案例,以期促进广大读者对该技术的理解,并激发更多该技术潜在的应用可能。

Fast and robust strain signal processing for aircraft structural health monitoring

This work elaborates a fast and robust structural health monitoring scheme for copying with aircraft structural fatigue.The type of noise in structural strain signals is determined by using a statistical analysis method,which can be regarded as a mixture of Gaussian-like(tiny hairy signals)and impulse-like noise(single signals with anomalous movements in peak and valley areas).Based on this,a least squares filtering method is employed to preprocess strain signals.To precisely eliminate noise or outliers in strain signals,we propose a novel variational model to generate step signals instead of strain ones.Expert judgments are employed to classify the generated signals.Based on the classification labels,whether the aircraft is structurally healthy is accurately judged.By taking the generated step count vectors and labels as an input,a discriminative neural network is proposed to realize automatic signal discrimination.The network output means whether the aircraft structure is healthy or not.Experimental results demonstrate that the proposed scheme is effective and efficient,as well as achieves more satisfactory results than other peers.

基于强化学习的可持续联邦学习激励机制设计

随着数据在互联网、物联网和人工智能等技术中的广泛应用,数据共享成为促进经济和科技发展的关键引擎之一。然而,由于数据隐私和法律等多方面的顾虑,数据共享面临挑战。联邦学习作为一种新兴的机器学习范式,以保护数据隐私的同时促进多方协作而备受关注。本文关注跨孤岛的长期联邦学习合作,旨在解决数据所有者参与合作的成本和风险问题。本文首先建立了动态博弈模型,考虑了联邦客户端之间的互动策略;然后,提出了一种基于强化学习的激励机制,通过中央计划者为不同训练期设定激励,有效地促进客户端的参与。实验证明,该激励方案在提高系统总收益和控制激励成本方面具有显著效果。本文为可持续联邦学习提供了一种有效的激励设计,有望推动数据共享和合作模型在不同领域的应用。

LC-3和P62在非小细胞肺癌中的表达及其临床特征分析

背景与目的 LC-3和P62是参与自噬过程的两个重要蛋白,在许多恶性肿瘤中高表达并与预后有关。本研究的目的在于探讨自噬标记物LC-3、P62蛋白在非小细胞肺癌中的表达及其临床特征。方法应用免疫组化法检测66例非小细胞肺癌患者肿瘤组织中LC-3和P62的表达情况,分析其表达状态与临床特征的关系。结果 LC-3在非小细胞肺癌组织中阳性表达率为40.9%(27/66),P62在非小细胞肺癌组织中阳性表达率为65.2%(43/66)。LC-3的阳性表达与患者的病理类型及转移情况明显相关(P<0.05);而P62的阳性表达与患者的病理类型,临床分期及淋巴结转移明显相关(P<0.05)。LC-3和P62的阳性表达与患者的性别、年龄和吸烟史无明显相关性(P>0.05)。LC-3与P62在非小细胞肺癌组织中的表达呈负相关性(rs=-0.0 6 5,P<0.0 0 1)。K a p l a n-M e i e r分析显示L C-3蛋白阳性表达的患者5年生存率明显高于阴性表达的患者(P<0.05),而P62蛋白的阳性表达确与患者的生存率无显著相关性。结论 LC-3和P62在非小细胞肺癌组织中呈现异常表达,提示自噬参与了非小细胞肺癌的发生及发展过程。

高敏感性肌钙蛋白T检测ACS的临床价值分析

目的分析高敏感性肌钙蛋白T(high sensitivity cardiac troponin T,hs-cTnT)检测冠心病急性冠脉综合症(acute coronary syndrome,ACS)患者的临床价值。方法选取2015年10月-2016年10月收治的80例ACS患者为观察组,同期80例稳定性冠心病患者为对照组,对两组研究对象的血清进行hs-cTnT、肌酸激酶同工酶、肌钙蛋白I检测的检测。结果两组观察对象在4 h、12 h的时间段进行的hs-cTnT、肌钙蛋白I、肌酸激酶同工酶检测结果对比有统计学差异(P<0.05);两组研究对象在0 h肌钙蛋白I与肌酸激酶同工酶检测结果对比无统计学差异(P>0.05),只有hs-cTnT的检测结果对比有明显差异(P<0.05)。结论 hs-cTnT检测对ACS早期检测具有重要意义。

等线我国涂料行业消费税实施效果及优化探析

为了合理引导涂料消费并改善生态环境质量,我国自2015年开始对涂料征收消费税,开征后涂料行业取得了一定的环保产品发展和技术更新。然而,由于我国涂料消费税存在征税环节过前、税率设置单一、相关税目解释不够精细等问题,导致涂料消费税限制高污染型涂料的职能未能得到充分发挥。因此,建议将涂料消费税的征收环节后移至零售环节,根据VOC含量设置累进阶梯式税率,进一步明确税目解释,并考虑将征收方式从“价内税”变为“价外税”形式。

Microstructural characteristics and aging response of Zn-containing Al-Mg-Si-Cu alloy

Al-Mg-Si-Cu alloys with and without Zn addition were fabricated by conventional ingot metallurgy method. The microstructures and properties were investigated using optical microscopy （OM）, field emission scanning electron microscopy （FE-SEM）, transmission electron microscopy （TEM）, tensile test, hardness test, and electrical conductivity measurement. It is found that the as-cast A1-Mg-Si-Cu-Zn alloy is composed of coarse dendritic grains, long needle-like ~/5-A1FeSi white intermetallics, and Chinese script-like a-A1FeSi compounds. During high temperature homogenization treatment, only harmful needle-like ^-A1FeSi phase undergoes fragmentation and spheroidizing at its tips, and the destruc- tive needle-like 5-phase does not show any morphological and size changes. Phase transitions from ^-A1FeSi to ^-A1FeSi and from 6-A1FeSi to [3-A1FeSi are also not found. Zn addition improves the aging hardening response during the former aging stage and postpones the peak-aged hardness to a long aging time. In T4 condition, Zn addition does not obviously increase the yield strength and decrease the elongation, but it markedly improves paint-bake hardening response during paint-bake cycle. The addition of 0.5wt% Zn can lead to an increment of 99 MPa in yield strength compared with the value of 69 MPa for the alloy without Zn after paint-bake cycle.

肺腺癌胸水标本中PD-L1的蛋白表达与临床病理特征及分子改变的相关性研究

背景与目的非小细胞肺癌的免疫治疗药物pembrolizumab需要基于包括免疫组织化学(immunohistochemistry,IHC)在内的检测结果,即通过检测程序性死亡配体1(programmed cell death protein 1,PD-L1)的表达等手段来预测治疗反应。评估肺腺癌细胞学标本免疫细胞化学(immunocytochemistry,ICC)方法检测PD-L1的可行性,并探讨PD-L1表达与临床病理及分子特征的相关性。方法收集60例肺腺癌胸水细胞学标本应用PD-L1 sp263试剂按照生产说明书进行免疫细胞化学染色,同时对胸水细胞学标本做高通量二代测序(next-generation sequencing,NGS),探讨PD-L1与驱动基因突变的相关性。结果60例肺腺癌胸水细胞块标本ICC检测中,有35例PD-L1表达阳性,阳性表达率为58.3%。本院57例组织学标本PD-L1 IHC表达的阳性率为33.3%,细胞学标本与组织学标本差异无统计学意义(P>0.05)。60例细胞学标本中26例接受NGS检测,15例(57.7%)发现表皮生长因子受体(epidermal growth factorreceptor,EGFR)突变,经统计PD-L1表达与EGFR突变未发现相关性。PD-L1的阳性表达率与研究人群的年龄、性别、是否淋巴结或远处转移及是否进行放化疗或靶向治疗均未发现相关性(P>0.05)。结论在无手术标本可取时,胸水细胞学细胞块标本可以对PD-L1进行免疫细胞化学检测,其结果具有可行性。