ABSTRACT
This study aimed to determine the effects of fine dust reduction, as well as the energy load reduction in association with the improvement plans by measuring the airtightness and indoor and outdoor fine dust concentrations in middle and high school classrooms and by identifying the fine dust inflow paths. The air tightness and indoor and outdoor fine dust concentrations were measured at two schools, and the paths of outdoor fine dust inflow were identified for an extensive analysis of the effects of fine dust reduction and the energy load reduction in association with improvement plans. Air tightness in the classroom at school A and B was improved by 32.26% and 38.58% with sealing, respectively. Analyzing the outdoor air inflow paths at school B according to the variation in air tightness, the probability of outdoor air inflow increased in the following order from the highest to the lowest: corridor windows, corridor doors, exterior windows, supply and exhaust units. For the rate of reduction in heating load, the highest rate was shown to be 27% at school A with improved air tightness at the exterior windows and 32% at school B with improved air tightness at the interior doors. This is expected to be reflected in the selection of equipment such as heat pumps and show cost-saving effects such as capacity reduction.
ABSTRACT
Among brain tumors, glioblastoma (GBM) is the most aggressive type and is associated with the lowest patient survival rate. Numerous lines of evidence have established that omega-3-polyunsaturated fatty acids (ω3-PUFAs) have potential for the prevention and therapy of several types of cancers. Docosahexaenoic acid (DHA), an ω3-PUFA, was reported to inhibit growth and induce apoptotic and autophagic cell death in several cancer cell lines; however, its effects on GBM cells are still unknown. in the present study, we examined the cytotoxic effect of DHA on the GBM cell lines, D54MG, U87MG, U251MG and GL261. Treatment of GBM cells with DHA induced PARP cleavage, increased the population of sub-G1 cells, and increased the number of TUNEL-positive cells, which are all indicative of apoptosis. Furthermore, treatment of GBM cells with DHA resulted in a significant increase in autophagic activity, as revealed by increased LC3-II levels, GFP-LC3 puncta, and autophagic flux activation, accompanied by activation of 5'-AMP-activated protein kinase (AMPK) and decreases in phosphorylated Akt (p-AktSer473) levels and mTOR activity. In vivo, endogenous expression of Caenorhabditis elegans ω3-desaturase, which converts ω6-PUFAs to ω3-PUFAs, in fat-1 transgenic mice yielded a significant decrease in tumor volume following subcutaneous injection of mouse glioma cells (GL261), when compared with wild-type mice. TUNEL-positive cell numbers and LC3-II levels were elevated in tumor tissue from the fat-1 transgenic mice compared with tumor tissue from the wild-type mice. In addition, p-Akt levels were decreased and p-AMPK levels were increased in tumor tissue from the fat-1 transgenic mice. These results indicate that ω3-PUFAs induce cell death through apoptosis and autophagy in GBM cells; thus, it may be possible to use ω3-PUFAs as chemopreventive and therapeutic agents for GBM.
