Performance deterioration of sustainable recycled aggregate concrete under combined cyclic loading and environmental actions
JOURNAL OF SUSTAINABLE CEMENT-BASED MATERIALS
Authors: Lei, Bin; Li, Wengui; Luo, Zhiyu; Li, Xitao; Tam, Vivian. W. Y.; Tang, Zhuo
Abstract
The effects of strength grades, loading modes, and stress levels on the performance deterioration of sustainable recycled aggregate concrete (RAC) subjected to mechanical loading or coupled mechanical loading and environmental actions are investigated in this study. Comparison analysis of residual properties of RAC suffered from single mechanical loading, coupled actions of mechanical loading, and salt-solution freeze-thaw cycles, as well as the combined actions of mechanical loading and salt-solution corrosion were experimentally studied. The results indicate that the stress level is the most influential factor affecting the durability of RAC followed by the RAC strength grade and the number of times the alternating load applied. Moreover, applying novel intermittent loading mode to simulate the durability of RAC under the coupled actions of sustained loading and environmental factors is feasible and reasonable. Additionally, the fitting equations were proposed to discuss the effects of number of times the alternating load applied, stress level, and mechanical strength on the mechanical strength loss and durability of RAC.
Light-emitting diode irradiation induces AKT/mTOR-mediated apoptosis in human pancreatic cancer cells and xenograft mouse model
JOURNAL OF CELLULAR PHYSIOLOGY
Authors: Kim, Young Mi; Ko, Sung-Hwa; Shin, Yong-Il; Kim, Yeonye; Kim, Taehyung; Jung, Jaehoon; Lee, Sang-Yull; Kim, Nam Gyun; Park, Kyoung-Jun; Ryu, Ji Hyeon
Abstract
The beneficial effects of light-emitting diode (LED) irradiation have been reported in various pathologies, including cancer. However, its effect in pancreatic cancer cells remains unclear. Herein, we demonstrated that blue LED of 460 nm regulated pancreatic cancer cell proliferation and apoptosis by suppressing the expression of apoptosis-related factors, such as mutant p53 and B-cell lymphoma 2 (Bcl-2), and decreasing the expression of RAC-beta serine/threonine kinase 2 (AKT2), the phosphorylation of protein kinase B (AKT), and mammalian target of rapamycin (mTOR). Blue LED irradiation also increased the levels of cleaved poly-(ADP-ribose) polymerase (PARP) and caspase-3 in pancreatic cancer cells, while it suppressed AKT2 expression and inhibited tumor growth in xenograft tumor tissues. In conclusion, blue LED irradiation suppressed pancreatic cancer cell and tumor growth by regulating AKT/mTOR signaling. Our findings indicated that blue LEDs could be used as a nonpharmacological treatment for pancreatic cancer.