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Li P.-H.,Tianjin University of Technology | Wang Y.,Shandong University | Li Y.-H.,Shandong Environmental Monitoring Center | Li H.-L.,Shandong Environmental Monitoring Center | And 2 more authors.
Advances in Meteorology | Year: 2015

To understand the deposition and transport of PAHs in southern China, a measurement campaign was conducted at a high-elevation site (the summit of Mount Heng, 1269 m A.S.L.) from April 4 to May 31, 2009, and a total of 39 total suspended particulate samples were collected for measurement of PAH concentrations. The observed particulate-bound PAHs concentrations ranged from 1.63 to 29.83 ng/m3, with a mean concentration of 6.03 ng/m3. BbF, FLA, and PYR were the predominant compounds. Good correlations were found between individual PAHs and meteorological parameters such as atmospheric pressure, relative humidity, and ambient temperature. The backward trajectory analysis suggested that particulate samples measured at the Mount Heng region were predominantly associated with the air masses from southern China, while the air masses transported over northern and northwestern China had relative higher PAHs concentrations. Based on the diagnostic ratios and factor analysis, vehicular emission, coal combustion, industry emission, and unburned fossil fuels were suggested to be the PAHs sources at Mount Heng site. However, the reactivity and degradation of individual PAHs could influence the results of PAH source profiles, which deserves further investigations in the future. © 2015 Peng-hui Li et al. Source


Guan J.,Shandong University | Liu G.,Shandong Institute for Food and Drug Control | Cai K.,Shandong Environmental Monitoring Center | Gao C.,Shandong University | Liu R.,Shandong University
Luminescence | Year: 2015

In order to evaluate the toxicity of multi-walled carbon nanotubes (MWCNTs-COOH) at a molecular level, the effect of MWCNTs-COOH on antioxidant enzyme copper-zinc superoxide dismutase (Cu/ZnSOD) was investigated using fluorescence spectroscopy, UV/vis absorption spectroscopy, circular dichroism (CD) spectroscopy and isothermal titration calorimetry (ITC). By deducting the inner filter effect (IFE), the fluorescence emission spectra and synchronous fluorescence spectra indicated that there were interactions between MWCNTs-COOH and Cu/ZnSOD. Moreover, the microenvironment of the amino acid residues in the enzyme was changed slightly. The UV/vis absorption and CD spectroscopic results showed appreciable conformational changes in Cu/ZnSOD. However, the results of a Cu/ZnSOD activity determination did not show any significant difference. In other words, MWCNTs-COOH has no significant effect on enzyme activity. The ITC results showed that the binding of MWCNTs-COOH to Cu/ZnSOD was a weak endothermic process, indicating that the predominant force of the binding was hydrophobic interaction. Moreover, it was essential to consider the IFE in fluorescence assays, which might affect the accuracy and precision of the results. The above results are helpful in evaluating the oxidative stress induced by MWCNTs-COOH in vivo. © 2014 John Wiley & Sons, Ltd. Source


Wang Y.,Shandong University | Li P.-h.,Shandong University | Li H.-l.,Shandong Environmental Monitoring Center | Liu X.-h.,Shandong University | Wang W.-x.,Shandong University
Atmospheric Research | Year: 2010

Polycyclic aromatic hydrocarbons (PAHs) in precipitation samples collected at Mount Taishan were determined by HPLC, to evaluate their concentrations and variations. Individual precipitation events were sampled for 2 years from Sep. 2005 to Aug. 2007. Low concentrations of PAHs were found at the site. Phenanthrene was the most abundant compound with a volume-weighted mean concentration of 33.31 ng/L. The next most abundant compound was fluorene, with a concentration of 16.61 ng/L. Other individual PAHs occurred at concentrations lower than 10 ng/L. The volume-weighted mean concentration of the total PAHs in winter precipitation was much higher than in summer, showing a seasonal variation. Most of the individual PAHs compounds have strong correlations with rainfall amount. Pyrene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene and benzo(a)pyrene all had strong correlations with Na+ and Cl-. Diagnostic ratio analysis and factor analysis indicated that the sources of PAHs are mainly from fossil fuel combustion, especially coal. Crown Copyright © 2009. Source


Chai J.,Shandong University | Xu Q.,Shandong University | Dai J.,Shandong Environmental Monitoring Center | Liu R.,Shandong University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

Clenbuterol (CLB) is a kind of β2-adrenergic agonists which was illegally used as feed additives nowadays. The toxic interaction of CLB with trypsin, an important digestive enzyme, was studied in vitro using multi-spectroscopic methods and molecular modeling methods. CLB was proved to bind with trypsin in S1 pocket, forming a complex driven by the dominant force of H-bond. The binding constant was calculated to be 1.79887 × 10 5 L mol-1 at 289 K and 0.32584 × 105 L mol-1 at 310 K, respectively. The skeleton of trypsin became loosened and unfolded with the amino residues microenvironment changed. The secondary and tertiary structure of trypsin also varied. Molecular modeling studies illustrated specific display of the binding information and explained most of the experiment phenomena. The binding site of CLB induced the fluorescence quenching as well as inhibition of enzyme activity of trypsin. The study confirmed that CLB had potential toxicity on both the structure and function of trypsin and the effects enhanced with the increasing concentration of CLB. © 2012 Elsevier B.V. All rights reserved. Source


Yang M.,Shandong University | Wang Y.,Shandong University | Liu Q.,Nanjing University | Ding A.,Nanjing University | Li Y.,Shandong Environmental Monitoring Center
Atmosphere | Year: 2015

PM2.5 (Particulate Matter 2.5) samples were collected at Mount Heng and analyzed for polycyclic aromatic hydrocarbons (PAHs). During sampling, a sandstorm from northern China struck Mount Heng and resulted in a mean PM2.5 concentration of 150.61 μg/m3, which greatly exceeded the concentration measured under normal conditions (no sandstorm: 58.50 μg/m3). The average mass of PAHs in PM2.5 was 30.70 μg/g, which was much lower than in the non-sandstorm samples (80.80 μg/g). Therefore, the sandstorm increased particle levels but decreased PAH concentrations due to dilution and turbulence. During the sandstorm, the concentrations of 4- and 5-ring PAHs were below their detection limits, and 6-ring PAHs were the most abundant. Under normal conditions, the concentrations of 2-, 3- and 6-ring PAHs were higher, and 4- and 5-ring PAHs were lower relative to the other sampling sites. In general, the PAH contamination was low to medium at Mount Heng. Higher LMW (low molecular weight) concentrations were primarily linked to meteorological conditions, and higher HMW (high molecular weight) concentrations primarily resulted from long-range transport. Analysis of diagnostic ratios indicated that PM2.5 PAHs had been emitted during the combustion of coal, wood or petroleum. The transport characteristics and origins of the PAHs were investigated using backwards Lagrangian particle dispersion modeling. Under normal conditions, the "footprint" retroplumes and potential source contributions of PAHs for the highest and lowest concentrations indicated that local sources had little effect. In contrast, long-range transport played a vital role in the levels of PM2.5 and PAHs in the high-altitude atmosphere. © 2015 by the authors. Source

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