Application of thermal desorption for measuring PAHs on PM2.5.

PM2.5 and polycyclic aromatic hydrocarbons (PAHs) emitted from various sources may cause respiratory disease and lung cancer. Additionally, PAHs deposited on PM2.5 would aggravate the hazard to human health once inhaled. Therefore, it is essential to investigate the PAHs adsorbed on PM2.5 in ambient air. However, analysis of PAHs on PM2.5 is limited so far due to high detection limit of the analytical method and complex pretreatment procedures of the sample. In this study, thermal desorption (TD) is combined with GC-HRMS for direct analysis of PAHs on PM2.5 collected by the filter without pretreatment. The results indicate that distribution of PAHs on the filter is uniform and each filter section is representative for direct analysis of PAHs on PM2.5. The optimal thermal desorption temperature and purge time of analysis are found at 320°C and 60 s, respectively. Furthermore, the PAHs on PM2.5 of ambient air in Taiwan including traffic area, industrial area, suburban area, and background site are investigated. The results indicate that the concentrations of PAHs on PM2.5 in ambient air of Northern, Central, and Eastern Taiwan are in the range of 0.13-6.63 ng/m3, with an average concentration of 2.23 ng/m3. The PAH concentration measured in winter is significantly higher than that in summer, and the concentration of PAHs on PM2.5 ranges from 0.071 to 0.280 ng/µg while the average concentration is 0.133 ng/µg. The technology optimized in this study can be applied for rapid and accurate measurement of PAHs present on fine particles.

Emissions of PAHs, PCDD/Fs, dl-PCBs, chlorophenols and chlorobenzenes from municipal waste incinerator cofiring industrial waste.

Concentrations and distributions of PAHs and chlorinated aromatic compounds including PCDD/Fs, dl-PCBs, chlorophenols (CPs), and chlorobenzenes (CBz) in the municipal waste incinerator are investigated to characterize their formation and emission via intensive stack sampling. In addition, the toxicity of fly ash contribution by PCDD/Fs and dl-PCBs is evaluated in this study. The results reveal that concentrations of PCDD/Fs and dl-PCBs in flue gas are significantly lower than those of CPs, CBz, and PAHs. Additionally, the removal efficiencies of PAHs and chlorinated aromatic compounds achieved with existing air pollution control devices are evaluated, indicating that the removal efficiencies achieved with activated carbon injection + baghouse (95-99%) are higher than those with semi-dry scrubber (SDS). Besides, PCDD/Fs and PCBs TEQ concentrations in SDS and BH ashes are within 1.61-2.66 WHO-TEQ/g and 0.09-0.19 WHO-TEQ/g, respectively. Furthermore, the calculated mass flow rates suggest that the input rate of PCDD/Fs and dl-PCBs of SDS are 60.24 mg/h and 59.74 mg/h, respectively. The mass flow rates of PCDD/Fs and dl-PCBs after SDS in flue gas are 32.47 mg/h and 49.73 mg/h, respectively. However, the discharge rates of PCDD/Fs and dl-PCBs from SDS are 120.60 mg/h and 27.05 mg/h, respectively, indicating that PCDD/Fs are significantly formed within the SDS. PCDD/Fs formation is attributed to the operating temperature of SDS (240 ± 11.5 °C), which is within the temperature window for de novo synthesis. Thus, operating parameters of the APCDs should be optimized to reduce the formation of PAHs and chlorinated aromatic pollutants from MWI.

Emission characteristics of dl-PCNs, PCDD/Fs, and dl-PCBs from secondary copper metallurgical plants: Control technology and policy.

This study investigated the characteristics of dl-PCNs, PCDD/Fs and dl-PCBs emitted from two typical secondary copper metallurgical plants processing copper sludge equipped with different sets of air pollution control devices (APCDs). Results indicated that the emission factors of dl-PCNs and PCDD/Fs of plant A are 0.00775 and 1.09 µg TEQ/ton, respectively, which are remarkably lower than those of plant B (3.12, 181 and 25.5 µg TEQ/ton for dl-PCNs, PCDD/Fs and dl-PCBs, respectively). Dl-PCNs contributed 0.7-2.7% of total TEQ for flue gases and up to 2.6% of TEQ for ash samples. The TEQ concentration of dl-PCNs in fly ash individually exceeds the regulated level of 1 ng TEQ/g regulated by Taiwan EPA, indicating that emission and discharge of dl-PCNs should be regulated. The combination of semidry scrubber and activated carbon injection (ACI) + baghouse (BH) is effective for simultaneous removals of dl-PCNs and PCDD/Fs in plant A; while the combination of cyclone, secondary combustion chamber, ACI + BH and wet scrubber (WS) is not optimal for removing dl-PCNs, PCDD/Fs and dl-PCBs. Memory effect occurring within BH and WS is responsible for low removal efficiencies of these POPs in plant B. This study suggests appropriate APCDs for simultaneous removal of three POP groups and recommends the inclusion of dl-PCNs in emission standard.

Efficacy of the novel continuous sampling system for PCDD/Fs and unintentional persistent organic pollutants.

Long-term sampling is essential for monitoring the air pollutants emitted from stack since it can monitor the pollutants emission continuously including the stages of start-up, shutdown and normal operation. However, commercial continuous sampling equipment such as AMESA faces the challenges of high weight and complicated sampling procedures. This study has developed a long-term and automatic sampling system (National Central University continuous stack sampling system, NCU-CS3), and compared the efficiency with manual sampling train (MST). The results indicate that relative standard deviation (RSD) of PCDD/Fs concentrations measured between NCU-CS3 and MST is <20%, demonstrating that the difference between NCU-CS3 and MST in measuring PCDD/Fs is insignificant. Besides, the effects of adsorbent temperature, adsorbent amount and type of adsorbent on breakthroughs of PAHs and unintentional-persistent organic pollutants (UPOPs) such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), chlorinated phenols (CPs), chlorinated benzenes (CBs) and polychlorinated naphthalenes (PCNs) are evaluated. The results indicate that the breakthrough of pollutants increases with increasing temperature of XAD-2 and decreases with increasing XAD-2 amount. Moreover, XAD-4 is used as alternative adsorbent to test the breakthrough and the results indicate that the breakthroughs of UPOPs of XAD-4 as adsorbent are lower than that with XAD-2 due to higher specific surface area of XAD-4. Furthermore, the residual of PCDD/Fs with NCU-CS3 as the sampling train is relatively low (1.5-3.8%), which meets the regulation of EN 1948-5 (10%).

Honokiol Is a Potential Therapeutic Agent and Has a Synergistic Effect With 5-FU in Human Urothelial Cell Carcinoma Cells.

BACKGROUND/AIM: Honokiol is a biphenolic component of the bark of Magnolia, and has been shown to exert several activities, including anti-depressant, anti-emetic, anti-oxidative, anti-thrombotic, anti-angiogenesis, anti-anxiolytic, anti-inflammatory and anti-tumor effects. MATERIALS AND METHODS: The anti-tumor activities of honokiol and its synergistic effect with 5-fluorouracil (5-FU) in human urothelial cell carcinoma (UCC) cells were investigated. RESULTS: Honokiol significantly suppressed the proliferation of UCC cells in a dose- and time-dependent manner. Moreover, honokiol inhibited the tumorigenesis of UCC cells in vitro. In addition, honokiol induced cell cycle arrest at G0/G1 phase and caused apoptosis of UCC cells through the intrinsic pathway. Importantly, we demonstrated that honokiol potentiated the cytotoxic effect of 5-FU, and displayed a synergistic effect with 5-FU in UCC cells. CONCLUSION: Honokiol causes growth inhibition, tumorigenesis suppression, cell cycle arrest, apoptosis, and importantly has a synergistic effect with 5-FU in human UCC cells. Therefore, this agent displays a therapeutic potential for treating human UCC.

Photocatalytic removal of trichloroethylene from water with LaFeO3.

Tricholorethylene (TCE) has been recognized as second common organic pollutant found in groundwater in Taiwan. Several advanced oxidation processes (AOPs) have been applied for TCE removal and photocatalytic is one of promising AOP techniques. In this study, LaFeO3 is successfully synthesized via sol-gel method and investigated for its photocatalytic oxidation rate toward TCE in water. Experimental results indicate that 95% removal efficiency of TCE can be achieved in aqueous solution with LaFeO3 (2 g/L) as photocatalyst within 1 h of Xenon lamp illumination. Additionally, the influences of initial TCE concentration, light intensity, photocatalyst loading, and pH value on the TCE removal efficiency are evaluated as well. The highest energy efficiency obtained in this study is 10.8 mg TCE/kWh and the value is higher than those reported in previous studies. Besides, removal mechanisms have been identified and the results indicate that the overall removal efficiency reaches 82%, with adsorption and photolysis accounting for 20% and 39%, respectively.

Removal of PCDD/Fs, PCP and mercury from sediments: Thermal oxidation versus pyrolysis.

A continuous pilot-scale system (CPS) equipped with effective air pollution control devices (APCDs) is used for remediating the sediments contaminated with PCDD/Fs, PCP and Hg simultaneously. The removal efficiencies of these three pollutants in sediments collected from seawater pond and river, respectively, are evaluated via thermal treatment processes. PAHs and CBz formed during thermal oxidation and pyrolysis are also analyzed for better understanding the behaviors of chlorinated organic compounds. Experimental results indicate that low-molecular-weight PAHs are closely related to the formation of CBz, PCDD/Fs, and CPs, while low chlorinated PCDD/Fs and CBz are predominant in flue gas with thermal oxidation. However, the PM concentration is higher in thermal oxidation than pyrolysis due to the higher air flow rate of thermal oxidation. It may bring more particles out of the furnace and have a greater potential to form PCDD/Fs within APCDs. Besides, the high air flow also dilutes the Hg vapor in flue gas and would require more energy to condense and collect Hg with the quench tower. Furthermore, for removal of total amount of PCDD/Fs, pyrolysis is better than thermal oxidation. Thus, pyrolysis is more suitable for remediating the contaminated sediment. The removal efficiencies of PCDD/Fs, PCP and Hg in sediments achieved with pyrolysis increase with increasing operating temperature and retention time in CPS. Overall, the residual concentrations of PCDD/Fs and PCP in river sediment are higher than that in seawater-pond sediment since significant formation of tar is observed due to higher organic matter content in river sediment.

Telecare Services for Elderly: Predictive Factors of Continued Use Intention.

BACKGROUND: Several countries have recently attempted to implement telecare information technology to provide health care to older adults. This study applied self-determination theory (autonomy, relatedness, and competence) and the theory of planned behavior (subjective norm, perceived behavioral control, and attitudes toward using tools) to investigate a theoretical model for explaining the predictive factors influencing the intention of elderly patients to continue using telecare services. METHODS: Elderly patients in Taiwan (N = 160) who used telecare systems and fall-detection systems completed a questionnaire. Hierarchical multiple regression analysis was applied to test hypotheses. RESULTS: The results revealed that the main effects related to identification supported the notion that autonomy, relatedness, subjective norm, and attitudes toward using tools positively affect elderly patients' intention to continue using telecare services. But, perceived competence and perceived behavioral control cannot be used as a predictor of intention to adopt telecare services. CONCLUSION: For an aging society, to provide appropriate ways to enhance elderly patients' willingness to use telecare services is important. Our findings indicate that elderly patients' perceived relatedness and subjective norm are both crucial predictors in intention to adopt telecare services. And it means that social influence may play a critical role in elderly patients' intention to adopt telecare services; therefore, researchers can investigate social influence mechanisms in depth and examine them more closely in future research.

Modulation of notch-1 signaling alleviates vascular endothelial growth factor-mediated diabetic nephropathy.

OBJECTIVE: Disturbances in podocytes are typically associated with marked proteinuria, a hallmark of diabetic nephropathy. This study was conducted to investigate modulation of Notch-1 signaling in high glucose (HG)-stressed human podocytes and in a diabetic animal model. RESEARCH DESIGN AND METHODS: Expression of the Notch signaling components was examined in HG-treated podocytes, human embryonic kidney cells (HEK293), and kidneys from diabetic animals by RT-qPCR, Western blot analysis, and immunohistochemical staining. The association between the Notch signaling, VEGF expression, and podocyte integrity was evaluated. RESULTS: Notch-1 signaling was significantly activated in HG-cultured human podocytes and HEK293 cells and kidneys from diabetic animals. HG also augmented VEGF expression, decreasing nephrin expression and podocyte number-a critical event for the development of proteinuria in diabetic nephropathy. After use of pharmacological modulators or specific shRNA knockdown strategies, inhibition of Notch-1 signaling significantly abrogated VEGF activation and nephrin repression in HG-stressed cells and ameliorated proteinuria in the diabetic kidney. CONCLUSIONS: Our findings suggest that upregulation of Notch-1 signaling in HG-treated renal podocytes induces VEGF expression and subsequent nephrin repression and apoptosis. Modulation of Notch-1 signaling may hold promise as a novel therapeutic strategy for the treatment of diabetic nephropathy.

Simvastatin alleviates diabetes-induced VEGF-mediated nephropathy via the modulation of Ras signaling pathway.

AIMS: The activation of Ras signaling and vascular endothelial growth factor (VEGF) expression in mesangial cells is a pathogenic consequence of diabetic nephropathy. We examined the role of simvastatin in modulating Ras signaling and the expression of VEGF in mesangial cells stressed with high doses of glucose in vitro and in vivo. METHODS: For the in vitro studies, we cultured mesangial cells, with or without simvastatin or manumycin A pretreatment, in 35 mM glucose and assayed VEGF activity. For the in vivo studies, we administered simvastatin or manumycin A to streptozocin-induced diabetic rats for 28 days and dissected renal tissues for an immunohistological assessment of Ras and VEGF expression in glomerular cells. RESULTS: We showed that high glucose significantly increased VEGF gene expression and Ras activation. The pretreatment with 10 microM simvastatin and inhibition of Ras activity by manumycin A significantly reversed high glucose promotion of VEGF mRNA expression. Pretreatment with simvastatin and manumycin A clearly affected the activation of Ras promoted by high glucose. Tube-like formations were abundant in high glucose-treated mesangial cells co-cultured with HUVEC. However, the simvastatin and manumycin A treatment group's down-regulated tube formation was comparable to the mesangial cells treated only with high glucose. Exogenous simvastatin and manumycin A treatment alleviated urinary albumin secretion and attenuated Ras activation and VEGF protein expression in the kidneys of diabetic rats. CONCLUSIONS: Ras protein activation is a key mediator of VEGF-induced diabetic nephropathy. By inhibiting Ras activation, simvastatin modulates the high glucose-induced VEGF-mediated signaling pathway in vitro and in vivo.

Methylglyoxal-induced fibronectin gene expression through Ras-mediated NADPH oxidase activation in renal mesangial cells.

BACKGROUND: The formation of methylglyoxal (MGO), a highly reactive dicarbonyl compound, is accelerated under diabetic conditions. Although recent studies have suggested that apoptotic cell death is involved in diabetic nephropathy, the precise mechanism of MGO-induced renal fibrosis remains to be elucidated. METHODS: Rat kidney mesangial cells with or without pretreatment with inhibitors, including superoxide dismutase, catalase, L-NAME, diphenylene iodonium, rotenone, allopurinol, PD98059, SB203580 and SP600125 were cultured in medium containing 100 microM MGO. In the MGO-treated cell culture system, fibrosis-related signalling pathway was assessed by enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction and western blotting. RESULTS: Expression of fibronectin induced by MGO was highest after 48 h treatment. Superoxide production rapidly increased after 2 h and remained at a high level for 24 h. Scavenging O(2) (-) reversed transforming growth factor beta 1 (TGF-beta1) and fibronectin mRNA level. Pretreatment with diphenylene iodonium significantly suppressed MGO-induced superoxide, TGF-beta1 expression and fibronectin gene expression, indicating that NADPH oxidase is responsible for inducing superoxide formation and subsequently induced renal fibrosis. High MGO rapidly enhanced Ras activation in 1 h and progressively increased cytosolic p38 activation. Additionally, SB203580 pretreatment reduced MGO promotion of fibronectin gene activation suggesting that cytosolic p38 activation might affect MGO-induced renal mesangial fibrosis. Inhibiting Ras activity with manumycin A significantly reduced the promoting effect of MGO on superoxide synthesis, and fibronectin expression. CONCLUSION: Induction of superxoide by Ras via p38 pathway activates fibrotic gene transcription of mesangial cells. Reduction of oxidative stress by scavenging superoxide may offer an alternative strategy for controlling MGO-induced renal fibrosis.