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Auxetic chiral structures consisting of circular ring nodes and tangentially connected ligaments are engineered systems that exhibit excellent flexibility, vibration attenuation, impact resistance performances. In this paper, the out-of-plane dynamic crash behaviors of anti-tetrachiral, hexachiral and hierarchical chiral structures are studied. The energy absorption efficiency, plateau stress, peak stress of chiral structures with different ligament length, node radius, ligament thickness and level of structural hierarchy under different external crashing conditions are compared, and identical mass per area of different unit cell configurations are assumed. It is found that anti-tetrachiral structure is able to generate higher plateau stress and better energy absorption efficiency than hexachiral structures. Making use of the mechanical benefits of structural hierarchy, novel hierarchical chiral structures are proposed for improving the crash energy absorption abilities of chiral structures, and relations between crash energy absorption performances and unit cell geometries are explored, such as: energy absorption efficiency, plateau stress of chiral structures. Based on systematical analysis, optimized chiral and hierarchical chiral cellular structure can be designed for impact energy absorption in protective sandwich structures. • Novel hierarchical chiral metastructures are designed for energy absorption. • Energy absorption performances of ordinary and hierarchcal chiral metastructures are investigated systematically. • Hierarchical design can improve the impact energy absorption abilities of chiral structures drastically. [ABSTRACT FROM AUTHOR]

Deep reservoir in-situ environments enhance rock plasticity. Most current experiments that combine temperature and pressure are difficult to observe the crack tip directly, impeding the understanding of deep rock fracture properties. This paper used a digital image correlation method and the principle of fracture mechanics to establish an innovative visual experimental rock fracture system with in-situ environment. Crack tip initiation and propagation were captured dynamically in real-time temperature and pressure coupling conditions, and the influence on shale fracture properties was analyzed, providing a feasible method for examining the fracture behavior of deep reservoir rocks. The results showed that the fracture characteristics of deep shale should be reflected and characterized by jointly considering temperature and confining pressure. Shale plasticity produced crack tip passivation in combined in-situ temperature and pressure conditions, and reduced the local stress concentration effect. The post-peak softening relationship showed a nonlinear "convex" trend, indicating nonlinear fracture characteristics with increased toughness. The exponential coefficient representing the degree of nonlinearity rose as the buried depth increased. The exponential coefficient related to the buried depth was introduced to modify the constitutive model, which was used to effectively characterize the nonlinear fracture behavior of deep reservoirs and provide a basis for deep reservoir fracturing reform research. [ABSTRACT FROM AUTHOR]

• RGS10 inhibition in the knees exacerbates the severity of CIA manifestation. • RGS10 negatively regulates the NF-κB signaling pathway in CIA mouse model. • RGS10 regulation demonstrated a feedback mechanism of inflammation in macrophages. Rheumatoid arthritis (RA) is the most common inflammatory arthropathy, with evidence pointing to an immune-mediated etiology that propagates chronic inflammation. Although targeted immune therapeutics and aggressive treatment strategies have substantially improved, a complete understanding of the associated pathological mechanisms of the disease remains elusive. This study aimed at investigating whether regulator of G protein signaling 10 (RGS10) could affect rheumatoid arthritis (RA) pathology by regulating the immune response. A DBA/J1 mouse model of RA was established and evaluated for disease severity. RGS10 expression was inhibited by adeno-associated virus in vivo. Moreover, small interfering RNA was used to downregulate RGS10 expression in raw 264.7 cells in vitro. Results showed that RGS10 inhibition augmented RA severity, and attenuated the increase in expression of inflammatory factors. Furthermore, activated NF-κB signaling pathways were detected following RGS10 inhibition. These results revealed that RGS10 inhibition directly aggravated the RA pathological process by activating the NF-κB signaling pathway. Therefore, RGS10 is a promising novel therapeutic target for RA treatment with a potential clinical impact. [ABSTRACT FROM AUTHOR]

Abstract: Latex-formed core–shell nanoparticles composed of cross-linked polystyrene (PS) core and polyisoprene (PI) shell were successfully synthesized by means of a two-stage emulsion polymerization. The PS core possessed a Z-average diameter of 50.3nm, and the PS–PI particles took a spherical shape with a Z-average size of 50–70nm in diameter. Shell thickness was controlled by varying isoprene loading. Necessary interphase interactions between the core and shell domains were also achieved by grafting and swelling polymerization. Latex compounding method was employed to prepare the filled elastomer compounds. As expected, the PS–PI core–shell nanoparticles exhibited excellent reinforcement to elastomeric matrix, enhancing the tensile strength of the styrene–butadiene rubber by approximately 400%. The lower density, better interfacial interactions, and latex compounding process would benefit the PS–PI nanoparticles reinforced elastomer nanocomposites in energy saving. [Copyright &y& Elsevier]