https://ir.cnu.edu.tw/handle/310902800/34159 IAQRC Search the Channel s https://ir.cnu.edu.tw//simple-search https://ir.cnu.edu.tw/handle/310902800/34904 title: Exploring nanoparticle emissions and size distributions during incense burning and filtration in an indoor space abstract: Indoor air pollution is a critical health issue. We studied particle emissions, concentration changes and size distribution mechanisms using an indoor space with air quality monitors, incense stick burning, and ventilation. Temporal changes in the concentrations of particles with sizes of 10 nm to 10 mu m were monitored. Our findings show that particles affecting particle number concentration (PNC) were mainly in the Aitken mode (50-100 nm) and accumulation mode I (100-200 nm). Particle surface area concentration (PAC) was primarily in the 100-300 nm range, while particle volume concentration (PVC) was in the 100-200 nm and 300-1000 nm ranges. After extinguishing the incense sticks, ventilation was initiated. The ventilation period was split into FAO(1-3) (i.e., the first 3 min, 1-3 min of ventilation system operation) and FAO(4-15) (i.e., the last 12 min, 4-15 min of ventilation system operation). During FAO(1-3), particle concentrations increased by 18.3 to 21.5%. This rise was due to the initial activation of the ventilation system, dispersing settled particles (mostly >= 41.2 nm) into the air. The FAO(4-15)/FAO(1-3) ratio for 12.3-2489.3 nm particles was always < 1, indicating that as the ventilation continued, it effectively removed particles of < 2.5 mu m. After subsequent ventilation of 15-min operation, total PNC, PAC, and PVC were 70.3%, 70.0%, and 67.8% lower than during FAO(1-3) and the particle number mode diameter was 106.0 nm, with geometric standard deviations of 1.50 and 1.51 (left and right), indicating that the ventilation system was successful in removing smoke particles of all sizes simultaneously and evenly and achieved an approximate total removal efficiency of 70%, effectively filtering particles and reducing indoor air pollution. <br> Wed, 25 Dec 2024 03:05:23 GMT https://ir.cnu.edu.tw/handle/310902800/34539 title: A comprehensive analysis of the intervention of a fresh air ventilation system on indoor air quality in classrooms abstract: Adequate classroom air quality is vital to student health and learning outcomes. Prolonged periods of air conditioner use in enclosed classrooms may result in poor air quality. However, opening classroom windows may expose students to air pollutants if the outdoor air quality is poor. This study investigated CO2 and PM2.5 concentrations in 86 classrooms installed with air conditioners in elementary and middle schools in southern Taiwan, each additionally installed with a fresh air ventilation system equipped with an Ell-class filter. Enclosed air-conditioned classrooms generally have a CO2 concentration greater than 2500 ppm; occasionally, this figure reaches 3500 ppm. With the installed air ventilation system operating, the mean classroom CO2 concentration decreased to 1084 +/- 203 ppm, and the median CO2 concentration decreased to 1120 ppm. However, the CO2 concentrations of over half the classrooms remained higher than the concentration advised by the World Health Organization (1000 ppm). This high CO2 concentration was a result of the short distance (1.5-2 m) between the indoor air outlet and the recirculated air inlet resulting in a shortened circuit of air travel. Also, the initial filter installed over the indoor air outlet of the system reduced air penetration into the classroom. When the ventilation system was manually activated without activating the air conditioners, the median PM2.5 concentration measured at the indoor air outlet and the median classroom PM2.5 concentration were 2 mu g/m(3) and 20 mu g/m(3), respectively. This implied the presence of other sources of PM2.5 in classrooms, particularly ceiling and wall-mounted fans. The activation of these fans spread dust onto classroom furniture. Overall, fresh air ventilation systems providing filtered air improve classroom ventilation efficiency and indoor air quality by reducing CO2 and PM2.5 concentrations, but the cleanliness of fans and furniture must be maintained. <br> Mon, 11 Dec 2023 05:56:47 GMT https://ir.cnu.edu.tw/handle/310902800/34440 title: The Fibronectin Expression Determines the Distinct Progressions of Malignant Gliomas via Transforming Growth Factor-Beta Pathway abstract: Due to the increasing incidence of malignant gliomas, particularly glioblastoma multiforme (GBM), a simple and reliable GBM diagnosis is needed to screen early the death-threaten patients. This study aimed to identify a protein that can be used to discriminate GBM from low-grade astrocytoma and elucidate further that it has a functional role during malignant glioma progressions. To identify proteins that display low or no expression in low-grade astrocytoma but elevated levels in GBM, glycoprotein fibronectin (FN) was particularly examined according to the mining of the Human Protein Atlas. Web-based open megadata minings revealed that FN was mainly mutated in the cBio Cancer Genomic Portal but dominantly overexpressed in the ONCOMINE (a cancer microarray database and integrated data-mining platform) in distinct tumor types. Furthermore, numerous different cancer patients with high FN indeed exhibited a poor prognosis in the PrognoScan mining, indicating that FN involves in tumor malignancy. To investigate further the significance of FN expression in glioma progression, tumor specimens from five malignant gliomas with recurrences that received at least two surgeries were enrolled and examined. The immunohistochemical staining showed that FN expression indeed determined the distinct progressions of malignant gliomas. Furthermore, the expression of vimentin (VIM), a mesenchymal protein that is strongly expressed in malignant cancers, was similar to the FN pattern. Moreover, the level of epithelial-mesenchymal transition (EMT) inducer transforming growth factor-beta (TGF-beta) was almost recapitulated with the FN expression. Together, this study identifies a protein FN that can be used to diagnose GBM from low-grade astrocytoma; moreover, its expression functionally determines the malignant glioma progressions via TGF-beta-induced EMT pathway. <br> Sat, 11 Nov 2023 03:52:58 GMT https://ir.cnu.edu.tw/handle/310902800/34389 title: Verification of fugitive emission of aeolian river dust and impact on air quality in central western Taiwan by observed evidence and simulation abstract: Taiwan's rivers dry during the winter, exposing large areas of river bed and leading to airborne aeolian river dust. This study used PM10 and windspeed data taken from monitoring stations local to the Zhuoshui River (the river with the largest exposed area in Taiwan) to investigate the relationship between airborne river dust and air quality, and subsequently to estimate river dust emissions. During river dust events, PM10 concentrations were significantly and positively correlated with wind speeds exceeding 5 m/s (the critical wind speed). FPG Lunbei station, located downwind (south of the river) and the closest station to the river, recorded an average hourly PM10 concentration of 189 +/- 193 mu g/m3 an average correlation coefficient (r) of 0.94 between hourly PM10 concentration and average hourly wind speed, an average annual dust occurrence rate of 15%, and a maximum PM10 concentration exceeding 1000 mu g/m3. PM2.5 increased with PM10, albeit at a disproportional rate. When hourly PM10 concentration exceeded 200 mu g/m3, most of the particulates in the dust were coarse particulates (PM2.5-10). An hourly PM2.5/PM10 ratio of <20% was used to determine whether air quality is affected by river dust. As the PM10 concentration increases, the PM2.5/PM10 ratio decreases. It was concluded that soil moisture and surface roughness must be added into the estimations for producing simulated data. With these added, simulated results were highly consistent with observed hourly PM10 concentrations, with a Pearson correlation coefficient of 0.82. The simulations of hourly PM10 concentration were highly accurate and indicated that river dust from the Zhuoshui River contributed to substantial increases in downwind PM10 concentrations. December was the worst single month, accounting for 28.0% of PM10 dust created by the Zhuoshui River in the entire year. Air quality was, however, severely reduced just south of the Zhuoshui River throughout the fall and winter. <br> Sat, 11 Nov 2023 03:48:54 GMT