Owing to an increase in the critical mineral resources exploration and national ecological security construction, an environmental impact assessment was performed to evaluate the thallium contamination and ecological risk of soil in Jiulong alpine mountain area, western Sichuan Province, China. Based on the analysis of thallium content in 1037 soil samples, the pollution level and spatial variation of the thallium in all of the soil samples of the study area were comprehensively evaluated by multiple evaluation methods. The results show that, the thallium content in soil of the study region was 0.30–2.23 mg/kg with the mean of 0.94 mg/kg, which was slightly higher than soil background of “Three Rivers” regions (0.7 mg/kg) of southwest China and soil background value (0.6 mg/kg) of China. The overall trend is gradually decreasing from northwest to southeast. The parameters of geo-accumulation index indicates that the thallium pollution level in Jiulong alpine mountain area was generally low, most of them are less than 0.5, with the max Igeo 0.97. The soil as a whole has no potential ecological risk of thallium, which mainly under the control of natural geological background. Additionally, the investigation of this type of ecological environment survey provides insights for the sustainable development possibilities of critical mineral resources exploration in western Sichuan, China.
Lower to middle (0.5−3.0 km altitude) tropospheric aerosols (PM2.5) collected by aircraft over inland and east coastal China were, for the first time, characterized for organic molecular compositions to understand anthropogenic, natural, and photochemical contribution to the air quality. n-Alkanes, fatty acids, sugars, polyacids are detected as major compound classes, whereas lignin and resin products, sterols, polycyclic aromatic hydrocarbons, and phthalic acids are minor species. Average concentrations of all the identified compounds excluding malic acid correspond to 40−50% of those reported on the ground sites. Relative abundances of secondary organic aerosol (SOA) components such as malic acid are much higher in the aircraft samples, suggesting an enhanced photochemical production over China. Organic carbon (OC) concentrations in summer (average, 24.3 μg m-3) were equivalent to those reported on the ground sites. Higher OC/EC (elemental carbon) ratios in the summer aircraft samples also support a significant production of SOA over China. High loadings of organic aerosols in the Chinese troposphere may be responsible to an intercontinental transport of the pollutants and potential impact on the regional and global climate changes.
Purpose: To study the pharmacokinetics of morroniside (MR) and loganin (LG) in rats after oral administration of raw and wine-processed Corni fructus by UPLC-QqQ-MS/MS.
Methods: Arctiin (AT) was used as internal standard, and the plasma or tissue samples were extracted twice using ethyl acetate. Electrospray ionization (ESI) negative ion mode was used, and the multiple reaction monitoring mode (MRM) was set in acquisition mode. The extraction and detection method is supported by selectivity, sensitivity, precision, accuracy, stability, extraction, recovery and matrix effect. The non-atrioventricular model of das2.0 software was used to calculate the pharmacokinetic parameters.
Results: The absorption rate of MR (PTmax=0.092) and LG (PTmax=0.092) in Corni Fructus after wine-processing was faster in rats. The mean residence time was longer, and distribution of MR (PMRT0~t = 0.294) and LG (PMRT0~t = 0.000) in wine-processed Corni Fructus group increased in liver and kidneys.
Conclusion: The proposed method has been successfully validated and is suitable for studying the pharmacokinetics of the two analytes in rats.
Mercury contamination is one of the most serious environmental problems. It can cause serious effects on the human health, such as case damage in the brain, nervous system, immune system, and kidney failure. Therefore, development of an accurate, sensitive, and simple operational detection method for mercury is very necessary. Herein, we report a new strategy for mercury ion detection based on commonly used PCR technique. High selectivity and sensitivity were achieved by the formation of the thymine-Hg-thymine (T-Hg-T) unnatural base pair at the 3'-end of PCR primers. The detection results of PCR amplification in presence of mercury ion could be reported either by using agarose gel analysis or through real-time fluorometric dye tracing for different detection purposes. To our knowledge, this study represents the first application of PCR based technique to the detection of metal ions.
There is a large population and high number of death in the Beijing-Tianjin-Hebei (BTH) region, therefore the amount of cremation and the incineration of sacrificial offerings is also high. Due to the loose pollution control in crematoria, the surrounding environment and human health were affected by the pollutants emitted from crematoria. To further explore the characteristics of pollution emissions from the BTH crematoria, this study carried out on-site emission monitoring of 19 cremators and 6 incinerators of sacrificial offerings in 19 crematoria in this region. The concentrations and chemical components of PM2.5 and volatile organic compounds (VOCs) and the emission levels of other gaseous pollutants from crematoria flue gas were obtained. The emission factors of air pollutants were calculated. Based on the activity level data, the emission inventory of atmospheric pollutants from the crematoria was established and its emission reduction potential was analyzed. Results showed that:(1) The average emission concentrations of TSP, CO and NOx from the crematoria in the BTH were seriously exceeding the national standard limits. Flue gas purification devices had significant effect on the removal of pollutants. (2) PM2.5/TSP=0.73 indicated that fine particles accounted for a large proportion in the flue gas of cremator; the concentration of organic matter (OC) was high and accounted for 25.3% in PM2.5. (3) The concentrations of benzene and benzene series, olefins, alkane were high in VOCs, accounting for 88.7%, which might pose health risks to exposed populations. (4) According to the emission inventory, the emissions of TSP, PM10, PM2.5 and CO in the BTH crematoria in 2016 decreased by 47.8%, 47.8%, 47.9% and 26.1% respectively compared with those for 2007. The proportion of installation purification devices for crematorium was low in the BTH region and it was common that flue gas discharged directly into atmosphere which had considerable potential of emission reduction.
In this study, a reliable protocol for determination of total cholesterol in serum using gas chromatography-mass spectrometry was established.The total free cholesterol was extracted from the serum with chloroform and derivatized with bis(trimethylsilyl)trifluoroacetamide, analyzed without the saponification step commonly used.Linear calibration curves of cholesterol were obtained from the concentration 0.1 to 15 mmol L -1 .The limit of detection was 0.04 mmol L -1 .Finally, the proposed method was to explore the influence of high cholesterol diet on total cholesterol in serum of rats.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
'/%3e%3cuse xlink:href='%23a' transform='rotate(144 450 300)'/%3e%3cuse xlink:href='%23a' transform='rotate(216 450 300)'/%3e%3cuse xlink:href='%23a' transform='rotate(288 450 300)'/%3e%3c/svg%3e)