摘要：The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep *** microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise *** this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain *** results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned *** addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the ***,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN *** with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned *** may be a cause of sleep and motor disorders associated with ***,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei.

摘要：在智能凝胶防伪系统中使用的光、热、电、pH等刺激响应性水凝胶,是一种有前途的信息加密和解密材料.然而单一刺激会限制高水平的防伪.因此,需要协同使用多种刺激来提升信息安全等级.本研究设计了一种高透明度的海藻酸钠-聚丙烯酰胺(SA-PAM)水凝胶作为基体,利用无机变色材料钼酸铵(Mo7)赋予其凝胶光致变色特性.此外,温敏材料聚N-异丙基丙烯酰胺(PNIPAM)可使凝胶在最低临界相变温度(LCST)下发生体积相变,进而改变凝胶的宏观状态,可以通过调整凝胶体系中亲水单体和疏水单体的比例来控制LCST.利用紫外线(UV)作为“墨水”输入信息,以温度作为“开关”来加密/解密信息.总之,该水凝胶具有出色的光致变色能力,可在10 s内着色,紫外光吸收率最高可达96.23%.利用水凝胶对光-热刺激展现出的非凡响应能力,可以实现其迅速显示和隐藏信息的功能,从而确保信息安全,这为光致变色水凝胶在信息加密领域的应用提供了一种新方法.

摘要：A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as *** hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a ***,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo ***,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular *** key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the *** and multiple tissue compartments with different geometries can be established using either straight or curved DTB *** effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor *** a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan ***,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies.

摘要：Traditional tumor models do not tend to accurately simulate tumor growth in vitro or enable personalized treatment and are particularly unable to discover more beneficial targeted *** address this,this study describes the use of threedimensional(3D)bioprinting technology to construct a 3D model with human hepatocarcinoma SMMC-7721 cells(3DP-7721)by combining gelatin methacrylate(GelMA)and poly(ethylene oxide)(PEO)as two immiscible aqueous phases to form a bioink and innovatively applying fluorescent carbon quantum dots for long-term tracking of *** GelMA(10%,mass fraction)and PEO(1.6%,mass fraction)hydrogel with 3:1 volume ratio offered distinct pore-forming characteristics,satisfactorymechanical properties,and biocompatibility for the creation of the 3DP-7721 *** analysis and quantitative real-time fluorescence polymerase chain reaction(PCR)were used to evaluate the biological properties of the *** with the two-dimensional culture cell model(2D-7721)and the 3D mixed culture cell model(3DM-7721),3DP-7721 significantly improved the proliferation of cells and expression of tumor-related proteins and ***,we evaluated the differences between the three culture models and the effectiveness of antitumor drugs in the three models and discovered that the efficacy of antitumor drugs varied because of significant differences in resistance proteins and genes between the three *** addition,the comparison of tumor formation in the three models found that the cells cultured by the 3DP-7721 model had strong tumorigenicity in nude *** evaluation of the levels of biochemical indicators related to the formation of solid tumors showed that the 3DP-7721 model group exhibited pathological characteristics of malignant tumors,the generated solid tumors were similar to actual tumors,and the deterioration was *** research therefore acts as a foundation for the application of 3DP-7721 models in drug devel

摘要：随着对X射线成像,特别是对弯曲和不规则物体的三维成像的需求不断增加,高性能柔性闪烁膜的开发引起了人们的极大关注.镧系(Ⅲ)-有机闪烁体由于其在结构设计和光学可调谐方面的巨大灵活性,最近成为一类新的有前途的X射线闪烁体.然而,设计具有高光产额和良好溶液分散性的镧系元素(Ⅲ)-有机闪烁体仍然具有挑战性.本文报道了一种具有高效X射线激发发光(XEL)和良好溶液分散性的铕-钛氧簇合物(Eu-TiOCs)闪烁体.笼状镧-钛氧原子簇核作为X射线吸收剂,产生高能电子并引发二次电子热弛豫.有机配体作为能量转移桥和天线,通过级联能量转移来敏化Ln^(3+);离子的发光.Eu-TiOCs闪烁体表现出高的稳态X射线光产额(高达26,816±2000 photons MeV^(-1)).此外,EuTiOCs闪烁体和聚合物的羟基之间的弱氢键相互作用增强了Eu-TiOCs的溶液分散性,有利于制备低光散射和均匀闪烁膜.铕-钛氧簇与聚合物之间的通过无机簇笼和有机配体之间的协同作用,所得到的柔性闪烁膜对平面和非平面物体都表现出的高空间分辨率和低剂量X射线成像.本工作为进一步设计和制备高性能X射线闪烁体和高分辨率柔性闪烁膜提供了新思路.

摘要：化学取代是有效调节分子电导,产生多通道输运、量子干涉效应和其他机制的关键方法.但分子骨架和侧基之间存在复杂的相互作用,目前仍未被研究清楚.在本工作中,我们结合扫描隧道显微镜裂结实验技术和第一性原理计算方法,深入研究了具有不同σ和π侧基的分子电导.实验结果及理论分析表明,σ侧基的加入引起了分子前线轨道的对称性破缺并加剧了分子内散射,从而导致电导的降低.相反,π侧基引入了额外的电荷传输通道,实现了电荷传输的多通道效应,增加了分子的电导.这些发现为未来分子功能化和分子电子器件的设计提供了坚实的基础.

摘要：Owing to the inherent central information processing and resource management ability,the cloud radio access network(C-RAN)is a promising network structure for an intelligent and simplified sixth-generation(6G)wireless ***,to further enhance the capacity and coverage,more radio remote heads(RRHs)as well as high-fidelity and low-latency fronthaul links are required,which may lead to high implementation *** address this issue,we propose to exploit the intelligent reflecting surface(IRS)as an alternative way to enhance the C-RAN,which is a low-cost and energy-efficient ***,we consider the uplink transmission where multi-antenna users communicate with the baseband unit(BBU)pool through multi-antenna RRHs and multiple IRSs are deployed between the users and *** can conduct either point-to-point(P2P)compression or Wyner-Ziv coding to compress the received signals,which are then forwarded to the BBU pool through fronthaul *** investigate the joint design and optimization of user transmit beamformers,IRS passive beamformers,and fronthaul compression noise covariance matrices to maximize the uplink sum rate subject to fronthaul capacity constraints under P2P compression and Wyner-Ziv *** exploiting the Arimoto-Blahut algorithm and semi-definite relaxation(SDR),we propose a successive convex approximation approach to solve non-convex problems,and two iterative algorithms corresponding to P2P compression and Wyner-Ziv coding are *** results verify the performance gain brought about by deploying IRS in C-RAN and the superiority of the proposed joint design.

摘要：如何进一步提高存储密度是相变存储(PCM)应用于存储级内存(SCM)的关键挑战.然而,相变存储器主要通过尺寸微缩和多值操作来提高存储密度,往往面临严重的热串扰和相分离问题.为此,我们提出了一种高长宽比(25:1)的横向纳米线器件,该器件采用传统的硫系化合物Ge_(2)Sb_(2)Te_(5)就可以实现稳定的多值操作,并且器件具有较好的一致性以及较低的电阻漂移系数(0.009),其优异的多值性能主要是由于在设计的高长宽比结构中,绝缘层侧壁的限制使得相变材料的非晶区域可以精确控制,这也被透射电子显微镜分析证实.本文设计的纳米线器件为提升高深宽比三维相变存储器的多值存储能力提供了重要指导.

摘要：Two-dimensional apodized grating couplers are proposed with grating grooves realized by a series of nano- rectangles, with the feasibility of digital tailoring the equivalent refractive index of each groove in order to obtain the Gaussian output diffractive mode in order to enhance the coupling efficiency to the optical fiber. According to the requirement of leakage factor distribution for a Gaussian output profile, the corresponding effective re- fractive index of the grating groove, duty cycle, and period are designed according to the equivalent medium theory. The peak coupling efficiency of 93.1% at 1550 nm and 3 dB bandwidth of 82 nm are achieved.

摘要：增材制造技术凭借其生产几何复杂结构(如晶格结构)的能力而广受欢迎.在航天航空和汽车领域轻量化设计中,晶格结构具有极大的优势.众所周知,振动问题是航天航空结构设计广泛关注的问题之一,为了避免结构动力破坏,有必要开展结构振动频率研究,尤其是结构自振频率研究.本文针对一阶频率最大化问题,提出了一种维诺梯度随机晶格结构多尺度优化设计方法.首先,在微观尺度上进行了维诺随机晶格微观结构生成和分析.然后,采用无惩罚密度法进行宏观结构优化.最后,基于得到的相对密度分布和映射关系,重构了全尺度维诺梯度随机晶格结构.数值算例验证了该方法在维诺梯度随机晶格结构设计中的正确性和有效性,振动试验也验证了所提出的多尺度方法的有效性和优化的梯度晶格结构在结构动力响应方面的优势.