Multi-objective and multi-case reliability-based design optimization for tailor rolled blank (TRB) structures

Structural and Multidisciplinary Optimization - Light weight and crashworthiness signify two main challenges facing in vehicle industry, which often conflict with each other. In order to achieve...     

岩溶区嵌岩桩的试验研究与分析

基于室内模型试验,对岩溶区嵌岩桩的承载能力与破坏模式进行了研究。试验表明,随顶板厚度与溶洞位置偏移距离的增大,极限承载力逐渐增大,随溶洞直径、赤道半径与极半径的增大,极限承载力逐渐减小;破坏核体在竖直方向上基本未超过3d,在水平方向上基本未超过4d;嵌岩桩与基岩相互作用系统的破坏模式主要有冲切破坏、冒落区塌落、扇形塑性区破坏和"撕裂"破坏,破坏模式主要受顶板厚度、溶洞赤道半径b以及c/b的影响;嵌岩桩承载能力还与溶洞形状有关,建议引进形状系数ζ。结合不同条件下岩溶区嵌岩桩的破坏模式,提出一系列安全可靠、便于工程应用的计算公式。     

基于点模式匹配的BGA芯片视觉检测与定位算法及其实现

点模式匹配是视觉测量中的一种新方法;针对贴片机生产中BGA芯片的图像识别对中问题,系统地介绍了BGA的视觉检测任务,提出了基于点模式匹配的快速定位算法;该算法针对BGA焊球分布特点,对传统点模式匹配算法进行优化,大大减少了运算量;现场实际运行结果表明该算法的速度和精度都能满足实际生产的需要,并具有较强的鲁棒性。     

Tumor Microenvironment‐Responsive Dual Drug Dimer‐Loaded PEGylated Bilirubin Nanoparticles for Improved Drug Delivery and Enhanced Immune‐Chemotherapy of Breast Cancer

The application of combinational therapy makes up for the limitation of monotherapy and achieves superior treatment against cancer. However, the combinational therapy remains restricted by the poor tumor‐specific delivery and the abscopal effect. Herein, reactive oxygen species (ROS)‐responsive PEGylated bilirubin nanoparticles (BRNPs) are developed to encapsulate two glutathione‐activatable drugs, including dimer‐7‐ethyl‐10‐hydroxycamptothecin (d‐SN38) and dimer‐lonidamine (d‐LND). Dimerization of the drugs significantly increases the drug loading capacity and the encapsulation efficiency of nanoparticles. With the assistance of iRGD peptide (cRGDKGPDC), the cellular uptake of BRNPs is more than double when compared with the control. In response to high levels of intracellular ROS, d‐SN38 and d‐LND are rapidly released from nanoparticles (SL@BRNPs). Furthermore, the pharmacodynamic experiments verify combining SL@BRNPs with anti‐PD‐L1 antibody greatly inhibits the primary tumor of breast cancer, improves CD8+ T cells levels, and CD8+ T cells/Tregs ratios in the tumor. Additionally, it shows high immune memory effect and can prevent the growth of lung metastasis. Taken together, the strategy pioneers a new way for the rational design of nanoassemblies through the combination of activatable drug dimers and stimuli‐responsive drug release, and a successful application of novel drug delivery systems in combination with the immune checkpoint blockade antibody.     

Hierarchically Porous Multimetal‐Based Carbon Nanorod Hybrid as an Efficient Oxygen Catalyst for Rechargeable Zinc–Air Batteries

The lack of efficient strategies to address the intrinsic activity, site accessibility, and structural stability issues of metal‐carbon hybrid catalysts is restricting their real‐world implementation on the basis of rechargeable zinc–air batteries. Herein, a dual metal–organic frameworks (MOFs) pyrolysis strategy is developed to regulate the intrinsic activity and porous structure of the derived catalysts, where a Fe₂Ni_MIL‐88@ZnCo_zeolitic imidazolate framework (ZIF), with a hierarchically porous structure, multifunctional components, and an integrated architecture, acts as an ideal precursor to obtain multimetal based porous nanorod (FeNiCo@NC‐P). Benefitting from the synergetic effect of the multimetal components, facilitated reactant accessibility, and the well‐retained integrated structure, the resultant FeNiCo@NC‐P catalyst exhibits an oxygen reduction reaction half‐wave potential of 0.84 V as well as an oxygen evolution reaction potential of 1.54 V at 10 mA cm^–2. Furthermore, the practical application of FeNiCo@NC‐P in the zinc–air battery displays a low voltage gap and long‐term durability (over 130 h at a current density of 10 mA cm^–2), which outperforms the commercial noble metal benchmarks. This work not only affords a competitive bifunctional oxygen electrocatalyst for zinc–air batteries but also paves a new way to design and fabricate MOF‐derived materials with tunable catalytic properties.     

Endo/Lysosome‐Escapable Delivery Depot for Improving BBB Transcytosis and Neuron Targeted Therapy of Alzheimer's Disease

The effective treatment of Alzheimer's disease (AD) is hindered due to the hard blood–brain barrier (BBB) penetration and non‐selective distribution of drugs in the brain. Moreover, the complicated pathological mechanism of AD involves various pathway dysfunctions that limit the effectiveness of a single therapeutic drug. Herein, a dendrigraft poly‐l ‐lysines (DGL)‐based siRNA and D peptide (Dp) loaded nanoparticle is designed that could target and penetrate through the BBB, enter the brain parenchyma, and further accumulate at the AD lesion. In this system, T7 peptide, which specifically targets transferrin receptors on the BBB, is linked to DGL via acid‐cleavable long polyethylene glycol (PEG) to achieve high internalization, quick escape from endo/lysosome, and effective transcytosis. Then, the Tet1, which specifically targets diseased neurons, is modified onto DGL by short PEG. After being exposed, Tet1 could drive the nanoparticles to the AD lesion and release the drugs. As a result, the production of β amyloid plaques (Aβ) is inhibited. Neurotoxicity induced by Aβ plaques and tau proten phosphorylation (p‐tau) tangle is also alleviated, and the cognition of AD mice is significantly improved. Overall, this system programmatically targets BBB and neurons, thus, significantly enhances the intracephalic drug accumulation and AD treatment efficacy.     

Strong Graphene 3D Assemblies with High Elastic Recovery and Hardness

The rational design and construction of 3D graphene assemblies is a crucial step to extend the graphene properties for practical applications. Here, a novel interfacially reactive self‐assembling process is reported to prepare well‐organized 3D honeycomb‐like graphene assemblies with unique polygonal nanopores interconnected by silicon‐oxygen chemical bonds. The newly developed silicate‐bridged graphene assembly (SGA) exhibits an exceptionally high hardness of 13.09 GPa, outperforming all existing 3D graphene materials, while maintains high Young's modulus (162.96 GPa), elastic recovery (75.27%), and superb thermal stability (600 °C in air). The observed unusual merits are resulted from unique pore structure combining the mechanical stability of the trihedral‐nanopore structure and the deformability of the other polygonal nanopores. As a filling material, a merely 0.05% (w/w) addition of SGA could double the impact resistance of unsaturated resins (e.g., polyester). While SGA is attractive for various applications, including body armors, wearable electronics, space elevators, and multifunctional reinforcement fibers for automobiles, and aerospace vehicles, the novel liquid sodium–water interfacial reactive self‐assembling developed in this study could open avenues for further development of various well‐defined 3D assemblies from graphene and many other materials.     

Acid‐Responsive Transferrin Dissociation and GLUT Mediated Exocytosis for Increased Blood–Brain Barrier Transcytosis and Programmed Glioma Targeting Delivery

Receptor mediated transcytosis (RMT) is a common mechanism used for nanotherapeutics to traverse the blood–brain barrier (BBB). However, the transcytosis of ligand modified nanoparticles via RMT is likely to be trapped within brain capillary endothelial cells due to the high binding affinity of ligand with receptors, which greatly reduces the amount of nanoparticles across BBB. Here, P‐aminophenyl‐α‐D‐mannopyranoside (MAN) decorated doxorubicin‐loaded dendrigraft poly‐l‐lysine with acid‐cleavable transferrin (Tf) coating outside (DD‐MCT) is proposed. The DD‐MCT is engineered to specifically recognize the Tf receptor (TfR) on the luminal side of BBB endothelium. Then the DD‐MCT undergoes an acid‐responsive cleavage of Tf, leading to the separation of MAN‐decorated DGL‐DOX (DD‐M) from the Tf–TfR complex in endo/lysosomes. The detached DD‐M is more prone to escape from endo/lysosomes and can further be exocytosed into brain parenchyma via the mediation of glucose transporter located on the abluminal endothelial membrane. Moreover, the DD‐M in brain parenchyma can target glioma cells. Significantly, the DD‐MCT enters into brain parenchyma in greater amounts, resulting in enhanced accumulation at glioma site and thus improved antiglioma therapeutic outcome. This strategy pioneers a new path for reducing the trapping of nanotherapeutics within BBB endothelium but increasing their transcytosis into brain parenchyma.     

Shape Transformable Strategies for Drug Delivery

In tumor therapy, nanodrug delivery systems have gained momentum in the last decade. However, its efficacy remains insufficient for clinical applications. The physical properties of nanoparticles, including size, shape, and surface characteristics, can strongly affect the delivery efficacy. Ironically, research on shape function is relatively scarce, although the nanoparticle shape greatly impacts their performance; for example, nanorods with a high aspect ratio (AR) achieve greater accumulation, but their penetration is relatively weak. Hence, rather than selecting a suitable AR to balance them, the strategy of a transformable AR (i.e., transformation) is ideal in this case. Nanoparticle transformation can be achieved by either internal stimuli (such as pH and enzymes) or external stimuli (such as light) spatially and temporally with precision, thereby dramatically enhancing the efficiency of drug delivery. Thus, nanoparticle transformation is becoming a promising prospect for improving cancer treatment. In this review, first, the effect of shape on drug delivery is summarized, then, the recently transformable drug delivery systems are reviewed, and finally, the future direction of shape-transformable nanoparticles in tumor therapy is discussed.     

Multiobjective reliability-based optimization for crashworthy structures coupled with metal forming process

Structural and Multidisciplinary Optimization - Crashworthiness design for manufacturing of thin-walled structures remains a main challenge in vehicle industry. Conventionally, there have been two...