摘要：Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor ***,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor *** study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I *** also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and ***,it compares two-dimensional(2D)and 3D *** comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D ***,the two models yielded significantly different cell ***,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D *** results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture *** developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.

摘要：目的探讨基于智能手机应用的健康教育能否降低学龄儿童及其家庭成员的盐摄入量。设计平行、整群随机对照试验,将学校随机分配到干预组或对照组(1∶1)。背景从2018年9月15日至2019年12月27日,在中国北部、中部和南部3个省份纳入54所小学。参与者592名小学3年级儿童[每所学校约11名儿童,其中308名(52.0%)男孩;平均年龄8.58岁(标准差0.41)],以及1184名成年家庭成员[其中551名(46.5%)男性;平均年龄45.80岁(12.87)]。干预在手机应用程序的支持下,对干预组中的儿童进行关于减盐的健康教育,并布置家庭作业,以带动全家参与减盐的相关活动。主要结局测量干预组和对照组在第12个月随访时盐摄入量(通过24小时尿钠排泄量测量)改变值的差值。结果基线调查后,来自27所学校的297名儿童和594名成年家庭成员被分配到干预组,另外27所学校的295名儿童和590名成年家庭成员被分配到对照组。在试验期间,由于儿童转到另一所学校或成年家庭成员无法参加随访评估,27名(4.6%)儿童和112名(9.5%)成年人失去随访。干预组其余287名儿童和546名成人,以及对照组的278名儿童和526名成人完成了12个月的随访评估。干预组儿童基线时的平均盐摄入量为5.5[标准差(SD)1.9]g/天,干预组成人10.0(SD 3.5)g/天,对照组儿童5.6(SD 2.1)g/天,成人10.0(SD 3.6)g/天。在研究期间,干预组和对照组儿童的盐摄入量均有所增加,但干预组增加的幅度较小[调整混杂偏倚变量后平均干预效果为-0.25 g/天,95%可信区间(CI):-0.61~0.12;P=0.18]。干预组和对照组成人的盐摄入量均有所下降,但干预组的盐摄入量变化更大(平均效果-0.82 g/天,-1.24~-0.40;P<0.001)。对儿童收缩压的平均效果为-0.76 mmHg(-2.37~0.86;P=0.36),成人为-1.64 mmHg(-3.01~-0.27;P=0.02)。结论采用儿童带动家长的方式,基于手机应用程序的健康教育可有效降低成人的盐摄入量和收缩压,但对儿童的效果并不显著。这种新颖的方法有可能被更大规模地推广,但在此之前方案需要进一步加强,才能减少包括学童在内的人群盐摄入量。试验注册中国临床试验注册ChiCTR1800017553。

摘要：Suitable optimization and simulation were performed using a powerful software package with a mature database as well as modem measurement facilities, which led to the successful designing and manufacturing of advanced steels. In the course of designing, the composition of a large section of prehardened mold steel for plastics was estimated so as to lower the quantities of oxide inclusions to change the type of carbides and to raise the machinability. The composition and process were adjusted to obtain satisfactory surface quality for the prevailing galvanization in transformation-induced plasticity （TRIP） steel. The refuting process of low-carbon steel was simulated in the light of both Thermo-Calc and Factsage. Thermodynamic and kinetic analyses were always conducted during the test and the procedure.

摘要：基于经典泰曼-格林干涉理论提出了一种改进的干涉仪光路设计方案。与经典干涉理论对比,该方案具有共光路、结构紧凑、对环境因素不敏感、系统使用效率高等特点。通过对光学系统及标准平面的优化设计,其理论精度极值(PV)<1/12λ(λ=632.8nm)。对具体的光学系统、微调机构组件进行了三维设计,对干涉仪进行了实际装配调整,并与Mo¨ller像移式干涉仪做了比对测试实验,结果表明,该小型干涉仪的实际测量精度PV值<1/10λ。

摘要：目的:为使零件在设计阶段实现公差的自动分配,研究线轮廓度在计算机中的表达模型。创新点:1.提出一种新的构建线轮廓度公差T-Map图的方法;2.用运动学等效的方法表示理想轮廓公差域的允许偏差。方法:1.将零件轮廓分解成多段,然后分别为每段生成一个实体模型T-Map(图6和7);2.利用布尔交运算将所有分段T-Map合成一个完整线轮廓度的T-Map(图8);3.以弧形短槽为例,演示创建线轮廓度的方法步骤。结论:将弧形短槽轮廓分成多段,先实现每一段的T-Map,再利用布尔交实现整体线轮廓度公差的T-Map图,证明该方法在构建任意轮廓的线轮廓度公差上的有效性。

摘要：植物的生态过程依赖于叶片和根系的功能运行,但少有研究同时关注这两类性状在群落中的分布格局(CTD)。本文测定了广东亚热带森林44种共生木本植物的16个叶片和根系性状,旨在检验类比的叶片和根系性状是否耦合,是否沿类似的功能性状谱变异,是否表现出类似的CTD,其CTD和群落加权平均性状值(CWM)是否沿环境梯度表现出类似的响应。研究结果表明,叶片和根系性状变异的第一轴均呈显出由资源获取向资源保守变异的经济学谱,但叶片变异的第二轴主要由叶片碳含量表征,而根系变异的第二轴主要由反映菌根协作程度的根系粗细表征。类比的叶片和根系化学性状整体正相关,但形态性状的耦合程度较低。在群落水平上,叶片和根系性状第一轴的CWM均随海拔升高而变得更保守,而第二轴的变化则不一致。随土壤磷含量的降低或钾含量的升高,根系变得更细和在养分性状上更保守,而叶片性状无显著变化。当整合多维性状轴时,叶片性状呈发散格局,且随海拔、土壤磷和钾含量的增加呈收敛趋势;而根系性状呈收敛格局,但沿上述环境梯度呈发散趋势。该研究强调,叶片和根系性状与环境互作的差异可能导致不同的性状分布格局;植物可通过多样的地上和地下功能设计应对环境异质性。

摘要：针对航空发动机压气机健康监测提出了一种基于线性矩阵不等式(LMI)和H∞优化理论的航空发动机压气机传感器鲁棒故障诊断的方法.在航空发动机具有模型不确定性和外界噪声的情况下,应用基于神经网络的线性拟合方法实现航空发动机压气机离散模型的建立;并通过LMI和H∞优化问题的求解得到未知输入观测器的设计参数,实现具有强鲁棒性的传感器故障诊断.该方法比以前研究中未知输入观测器故障诊断方法的优点在于能够同时处理模型不确定性和外界噪声.应用ALSTOM公司提供的燃气涡轮压气机模型进行了仿真验证,在压气机具有白噪声模型误差和正弦外界干扰的情况下,实现对小于测量范围2%的传感器故障的检测和诊断.

摘要：通过综述城市设计与交通工程学科文献,从新西兰视角明确共享空间概念的起源和演变。综述过程包括研究公众期望变化背景下的公共道路空间的功能与使用以及如何与一些相互关联的街道设计方法(如交通稳静化和自适应道路)联系起来。这些方法从机动车时代初期就被用于最小化机动车影响。应用于城市活动中心的公共道路环境中的共享空间概念,正逐渐被城市规划师、交通工程师和管理部门所接受。共享空间不同于传统道路,它鼓励通过少量物理隔离使全体道路使用者合理地使用同一道路空间。为了以安全有效的方式实现共享空间,在设计上需要通过促进步行与骑行活动来降低机动车主导性,同时应将道路空间作为场所来利用而非仅仅出于其机动性与可达性目的。基于交通稳静化街道与共享空间在基础概念上的差异,认为共享空间由一些设计要素组成,若缺少这些要素,公共街道将难以对全体道路使用者发挥其真正的共享空间功能。

摘要：Zinc-ion hybrid supercapacitors(ZHSs)are highly desirable for large-scale energy storage applications owing to the merits of high safety,low cost and ultra-long cycle *** poor rate performance of cathodes,however,severely hinders their ***,aqueous ZHSs with superior performance were fabricated by employing a series of ultrathin carbon nanobelts modified with B,N,O(CPTHBBx).The heteroatom doping can significantly modify the chemical behaviors of carbon frameworks,which could generate numerous active sites and accelerate the charge *** systematic investigation reveals that the B-N groups are active species for fast Zn-ion adsorption and *** a result,the best-performed CPTHB-B2 exhibits an excellent electrochemical performance as cathodes in ZHSs,delivering a high specific capacitance of 415.3 F g^(−1) at 0.5 A g^(−1),a record high capacitance retention of 81%when increasing the current densities from 0.5 to 100 A g^(−1),an outstanding energy density of 131.9 W h kg^(−1) and an exceptionally high power density of 42.1 kW kg^(−1).Our work provides a new cathode design for ultrafast charging Zn-ion storage devices.

摘要：Information storage and corresponding encryption/decryption are highly important owing to the prevalence of counterfeit activities and information leakage in the current age. herein, we propose a novel method to store information via controllable ionoprinting onto fluorescent hydrogel for hierarchical and multi-dimensional *** incorporating pyrene moieties and carboxylic groups into polymeric hydrogel network, fluorescence changing and controllable shape deformation behaviors could be achieved and integrated by ionoprinting of Fe3+ions. The diffusion of Fe^3+ions into fluorescent hydrogel can quench the fluorescence of pyrene moieties, and chelate with carboxylic groups to generate anisotropic structures for shape deformation simultaneously. Thus, fluorescence quenching-based 2D information and actuation-based 3D information could be hierarchically decrypted when exposed to UV light and being put into water, respectively. Importantly, the stored information could be erased by replacing Fe^3+with H^+, which allows the fluorescent hydrogel as a recyclable information storage material. This work may provide new insights in designing and fabricating novel soft devices for hierarchical and multidimensional information encryption, against the rising problems of counterfeiting and confidential information disclosure.