Nonlinear Magneto-Electro-Mechanical Response of Physical Cross-Linked Magneto-Electric Polymer Gel

This work reports on a novel magnetorheological polymer gel with carbon nanotubes and carbonyl iron particles mixed into the physical cross-linked polymer gel matrix. The resulting composites show unusual nonlinear magneto-electro-mechanical responses. Because of the low matrix viscosity, effective conductive paths formed by the CNTs were mobile and high-performance sensing characteristics were observed. In particular, due to the transient and mutable physical cross-linked bonds in the polymer gel, the electromechanical behavior acted in a rate-dependent manner. External stimulus at a high rate significantly enhanced the electrical resistance response during mechanical deformation. Meanwhile, the rheological properties were regulated by the external magnetic field when magnetic particles were added. This dual enhancement mechanism further contributes to the active control of electromechanical performance. These polymer composites could be adopted as electromechanical sensitive sensors to measure impact and vibration under different frequencies. There is great potential for this magnetorheological polymer gel in the application of intelligent vibration controls

Effect of nanostructured silica additives on the extrusion-based 3D concrete printing application

Recently, 3D printing technology has become more popular in the field of construction. For the extrusion-based 3D concrete printing (3DCP) process, the cementitious material needs to be strong and flowable enough to ensure buildability and pumpability. Nanostructured silica, a kind of additive, has been used to modify the 3DCP concrete to meet these requests. However, most previous studies focused on the effect of nanostructured silica on rheological properties and failed to link the obtained rheological properties of nanostructured-silica-modified cementitious materials to the performance in 3D printing. In this paper, the 3DCP mixture based on premix cement, river sand, silica fume, and water was modified by different dosages of nanostructured silica (from 0.25% to 1.00% by the total weight of the 3DCP mixture). The effects of nanostructured silica on the rheological, hydration, printing, and microstructural properties were determined by rheological tests, stress growth tests, setting time tests, printing tests, and scanning electron microscopy (SEM) tests, respectively. This paper revealed that the nanostructured silica has a positive effect on 3DCP buildability but negatively affects the printing quality, which fits the effect of nanostructured silica on the rheological properties. Hence, the determined rheological properties can qualitatively evaluate the printing performance of nanostructured-silica-modified cementitious materials.Nanyang Technological UniversityNational Research Foundation (NRF)Published versionThis research is supported by the National Research Foundation, Singapore, Prime Minister’s Office, Singapore, under its Medium-Sized Centre funding scheme, Singapore Centre for 3D Printing, and EVONIK (SEA) PTE. LTD

TREM2 suppresses the proinflammatory response to facilitate PRRSV infection via PI3K/NF-κB signaling.

Triggering receptor expressed on myeloid cells 2 (TREM2) serves as an anti-inflammatory receptor, negatively regulating the innate immune response. TREM2 is mainly expressed on dendritic cells and macrophages, the target cells of porcine reproductive and respiratory syndrome virus (PRRSV). Thus, we investigated the potential role of TREM2 in PRRSV infection in porcine alveolar macrophages (PAMs). We found that there was an increased expression of TREM2 upon PRRSV infection in vitro. TREM2 silencing restrained the replication of PRRSV, whereas TREM2 overexpression facilitated viral replication. The cytoplasmic tail domain of TREM2 interacted with PRRSV Nsp2 to promote infection. TREM2 downregulation led to early activation of PI3K/NF-κB signaling, thus reinforcing the expression of proinflammatory cytokines and type I interferons. Due to the enhanced cytokine expression, a disintegrin and metalloproteinase 17 was activated to promote the cleavage of membrane CD163, which resulted in suppression of infection. Furthermore, exogenous soluble TREM2 (sTREM2)-mediated inhibition of PRRSV attachment might be attributed to its competitive binding to viral envelope proteins. In pigs, following PRRSV challenge in vivo, the expression of TREM2 in lungs and lymph nodes as well as the production of sTREM2 were significantly increased. These novel findings indicate that TREM2 plays a role in regulating PRRSV replication via the inflammatory response. Therefore, our work describes a novel antiviral mechanism against PRRSV infection and suggests that targeting TREM2 could be a new approach in the control of the PRRSV infection