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：临床上常用的广谱抗生素无法有效解决抗生素高度耐药ESKAPE菌感染的难题,ESKAPE耐药菌已经成为人类生命健康的重大威胁.抗生素与佐剂的联合治疗是解决抗生素耐药菌感染的重要途径,但是探索对所有ESKAPE耐药菌都具有广谱和高效抗菌活性的抗生素-佐剂组合仍然面临巨大挑战.在这里,我们提出了一种抗生素-佐剂的有效设计策略,将对ESKAPE中耐药阴性菌具有高活性的多粘菌素B(PMB)与模拟宿主防御肽的细菌膜靶向阳离子聚(2-噁唑啉)相结合.我们通过2-噁唑啉单体可控聚合,合成了一系列具有不同疏水性侧链的阳离子聚(2-噁唑啉).研究表明,聚(2-噁唑啉)和PMB的组合效果随着聚(2-噁唑啉)侧链疏水性的提高呈现出从拮抗效应到协同效应的逐渐变化.其中,优选的聚(2-噁唑啉)EACA-POX_(20)显著增强了PMB的抗菌活性,尤其是对于ESKAPE耐药阳性菌的抗菌活性增强了16–32倍.聚(2-噁唑啉)EACA-POX_(20)有效增强了PMB的抗菌活性并扩展了PMB的抗菌谱.聚(2-噁唑啉)和PMB的组合策略能够有效对抗所有耐药ESKAPE病原体,为解决ESKAPE耐药菌提供了新的思路.

摘要：受电弓区域是列车气动阻力的重要来源,其贡献率约为10%,是列车气动阻力的关键区域。因此,改善受电弓区压力分布成为减小列车气动阻力的潜在有效方法。基于鞘翅目昆虫的生物形态,提出了一种新型的仿生鞘翅目导流罩,将其安装在8节编组的高速列车受电弓区域,以实现该区域的空气流动平顺。建立了原始模型(模型Ⅰ)、带导流罩的受电弓Ⅰ(模型Ⅱ)、带导流罩的受电弓Ⅱ(模型Ⅲ)、带导流罩的受电弓Ⅰ和受电弓Ⅱ(模型Ⅳ)4个计算模型,探讨列车气动减阻机理,提高列车气动性能。结果表明,安装受电弓导流罩后,受在电弓区域的气动阻力显著减小。受电弓Ⅰ区域最大减阻达84.5%,受电弓Ⅱ区域最大减阻为25.0%。当受电弓Ⅰ区域和受电弓Ⅱ区域同时安装导流罩时,受电弓Ⅰ区和受电弓Ⅱ区总减阻可达49.6%。与没有导流罩的原始模型相比,受电弓区域的空气流动更顺畅,堵塞效应更小。但是,下游流速加快,冲击风挡区域,导致气动阻力增大。在受电弓Ⅰ区域或受电弓Ⅱ区域安装导流罩时,8节列车的总阻力分别降低了4.6%和1.8%,而在受电弓Ⅰ区域和受电弓Ⅱ区域同时安装导流罩时,列车的总阻力降低了6.3%。本文可为新一代高速列车的气动设计提供参考。

摘要：工频干扰是指由电网产生的基频及其奇次谐波干扰,它是大地电磁信号采集过程中最为普遍的干扰之一。尽管大部分采集设备都设计有抑制工频干扰的陷波电路,但由于电网中电流的实际频率会随着负载的变化有所波动,而陷波器的中心频率是固定的,因此在实际采集时,大地电磁信号依然受到工频噪声的严重影响。实践经验表明,当受工频干扰影响时,远参考法时常难以奏效;工频干扰奇次谐波的幅值随着频率的增大而骤减,在时间域难以准确识别,因此时间域编辑法效果不佳;此外,由于干扰源是固定的,工频干扰通常存在于整个采集过程中,通过数据段筛选也无法去除噪声。本文基于频域稀疏分解,先对采集的大地电磁信号进行傅里叶变换。然后设计与干扰信号相匹配而对有用信号不敏感的冗余字典原子,结合IOMP算法分离出频域信号中的工频干扰成分。最后将处理后的频域信号进行傅里叶逆变换。仿真实验及案例分析表明,所述方法能够在较好地保留有用信号的前提下有效压制工频干扰,在大大降低时间消耗的基础上取得比时域稀疏分解更好的效果,改善大地电磁数据质量。

摘要：This paper mainly discusses the power and solidarity among participants in the community correction discourse from sociolinguistic perspective by adopting the methodology of conversation *** the comparative study of the steps of Initial Evaluation and Entry Ceremony in community correction,this paper analyses the power and solidarity in the features of adjacency pair and turn-taking,and finds that the step of Initial Evaluation is relatively negotiable and represents the social relationship of solidarity,while the step of Entry Ceremony stresses more on social distance and power *** reasons that cause the power and solidarity in the Initial Evaluation and the Entry Ceremony from the perspective of social identity and social purposes are also explored.