The effects of environmental parameters on the radon exhalation rate from the ground surface in HBRA in ramsar with a regression model

An important radioactive, colorless and odorless gas emitted from natural radium existing in the ground, radon is an element of the U238 chain. Based on conducted studies, Ramsar has been recognized as one of the most polluted areas in the world as far as the exhalation of radon is concerned. The most important resources of radon in Ramsar are soil resources, water resources, groundwater, surface water and hot springs. In this study, 50 stations in high radioactivity areas of Ramsar were selected and the position of each station in terms of latitude and longitude was recorded with a GPS device; then, radon exhalation and gamma dose rates were measured using an AlphaGuard device and a portable gamma spectroscopy system, respectively. Furthermore, some environmental parameters such as temperature, pressure, relative humidity, the distance of each station from the mineral hot springs, the time interval between the rainfall and the day of measurement, soil moisture status and also weather conditions at the time of measurement were recorded, and the effect of measured environmental parameters on the radon exhalation rate was subsequently evaluated using Spss software and finally modeled by linear regression method. The gamma dose rate was around 58-7100 n.sv/hr and the radon exhalation rate was about 9-15370 mBq/m2.s. In this study, only the variables of gamma dose rate and soil moisture were effective on exhalation rate. The correlation between gamma dose and radon exhalation rate was significant and higher than the other variables. Results indicate that the estimated average annual effective Radon exhalation rate for the study area is much higher than the worldwide average figure of 16 mBq/m2.s reported by UNSCEAR. It can therefore be concluded that an assessment of the radiological hazard of living these area is crucial

Targeted regulation of autophagy using nanoparticles: New insight into cancer therapy

Normal cells depend on autophagy to maintain cellular homeostasis by recycling damaged organelles and misfolded proteins and degrading toxic agents. Similar to apoptosis, targeting autophagy has been under attention in cancer therapy. However, autophagy has both pro-survival and pro-death functions in tumors, and its targeting requires further elucidation. The current review focuses on using nanoparticles for targeting autophagy in cancer treatment. Nanocarriers can deliver autophagy regulators along with chemotherapeutic agents leading to intracellular accumulation in cancer cells and synergistic cancer therapy. Furthermore, genetic tools such as siRNA and shRNA can be used for targeting molecular components that regulate autophagy, such as the ATG12-ATG5-ATG16L1 complex. A number of nanostructures, such as gold and zinc oxide nanoparticles, can be used to enhance oxidative stress-mediated apoptosis and autophagy, reducing cancer progression. Further, using nanoparticles to modulate autophagy potentiates the anti-tumor effects of cisplatin and gefitinib during chemotherapy. Polymeric nanoparticles, lipid-based nanostructures and carbon-based nanomaterials are among other nanoparticles capable of regulating autophagy in cancer cells. Of note, various regulatory components of autophagy such as ATGs, Beclin-1 and LC3-II can be affected by nanomaterials. Based on the role of nanomaterial-induced autophagy as pro-survival or pro-death, further targeting can potentiate the fight against cancer cells. © 2021 Elsevier B.V