A Concrete Core Void Imaging Approach and Parameter Analysis of Concrete-Filled Steel Tube Members Using Travel Time Tomography: Multi-Physics Simulations and Experimental Studies.

Concrete-filled steel tube (CFST) members have been widely used in civil engineering due to their advanced mechanical properties. However, internal defects such as the concrete core voids and interface debonding in CFST structures are likely to weaken their load-carrying capacity and stiffness, which affects the safety and serviceability. Visualizing the inner defects of the concrete cores in CFST members is a critical requirement and a challenging task due to the obvious difference in the material mechanical parameters of the concrete core and steel tube in CFST members. In this study, a curved ray theory-based travel time tomography (TTT) with a least square iterative linear inversion algorithm is first introduced to quantitatively identify and visualize the sizes and positions of the concrete core voids in CFST members. Secondly, a numerical investigation of the influence of different parameters on the inversion algorithm for the defect imaging of CFST members, including the effects of the model weighting matrix, weighting factor and grid size on the void's imaging quality and accuracy, is carried out. Finally, an experimental study on six CFST specimens with mimicked concrete core void defects is performed in a laboratory and the mimicked defects are visualized. The results demonstrate that TTT can identify the sizes and positions of the concrete core void defects in CFST members efficiently with the use of optimal parameters.

Macrophage balance fraction determines the degree of immunosuppression and metastatic ability of breast cancer.

Macrophages are important immune cells in the tumor microenvironment and can be divided into two polarized subtypes, M1 and M2. M1 type macrophages have anti-tumor effects, while M2 type macrophages have pro-tumor effect. Most of the current researches are limited to the effect of M1 or M2 macrophages on tumors, while ignoring the overall balance of macrophages. Our research suggests that the macrophage balance fraction (MBF) can more effectively and comprehensively reflect the balance of tumor associated macrophages. Using bioinformatics analysis and in vitro experiments, we found that MBF is also an effective indicator of the degree of immunosuppression and metastatic ability of breast cancer, and different MBF environment can impact the migration and invasion ability of breast cancer cells. Finally, we also found that the mechanism of MBF changes in breast cancer may be affected by breast cancer-derived exosomes. In summary, MBF was proposed and validated as a novel indicator of macrophage balance state. Using this indicator, we found that the balance of macrophages can affect the degree of immunosuppression and metastatic ability of breast cancer.

Heterogeneous macrophages: Supersensors of exogenous inducing factors.

As heterogeneous immune cells, macrophages mount effective responses to various internal and external changes during disease progression. Macrophage polarization, rather than macrophage heterogenization, is often used to describe the functional differences between macrophages. While macrophage polarization partially contributes to heterogeneity, it does not completely explain the concept of macrophage heterogeneity. At the same time, there are abundant and sophisticated endogenous and exogenous substances that can affect macrophage heterogeneity. While the research on endogenous factors has been systematically reviewed, the findings on exogenous factors have not been well summarized. Hence, we reviewed the characteristics and inducing factors of heterogeneous macrophages to reveal their functional plasticity as well as their targeting manoeuvreability. In the process of constructing and analysing a network organized by disease-related cells and molecules, paying more attention to heterogeneous macrophages as mediators of this network may help to explore a novel entry point for early prevention of and intervention in disease.