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Sci Total Environ ; 703: 134475, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31759721


Organic molecular composition of fine aerosols in the free troposphere is poorly understood. Here, PM2.5 (particles with aerodynamic diameters ≤ 2.5 µm) samples were collected at the summit of Mt. Emei (3080 m a.s.l.) in the Southwestern China on a daytime and nighttime basis during summer 2016 (June-July). The samples were analyzed by solvent-extraction followed by derivatization and gas chromatography/mass spectrometry (GC/MS). Four classes of organic compounds, i.e. n-alkanes, fatty acids, saccharides and lignin/resin acids were measured quantitatively. Fatty acids were found to be the most abundant species with an average concentration of 401 ±â€¯419 ng m-3 (range 25.7-1490 ng m-3) in the daytime, similar to the average concentration at night (399 ±â€¯447 ng m-3, 19.6-1970 ng m-3). However, the concentrations of biomass burning tracers (e.g., levoglucosan), primary biological aerosol tracers (e.g., mannitol and arabitol) and low molecular weight n-alkanes derived from fossil fuel combustion in daytime samples were obviously higher than those in nighttime samples. The results suggest that valley breezes transported a large number of aerosols and their precursors from the ground surface to the summit of Mt. Emei in the daytime. Estimated with tracer-based methods, the contributions of biogenic primary sources (plant debris, fungal spore, and biomass burning) to organic carbon was in the range of 3.28-83.5% (22.0 ±â€¯17.5%) in the daytime and 3.45-37.4% (10.9 ±â€¯8.97%) at night. As the largest contributor, biomass burning was an important anthropogenic/natural source of aerosol particles in the free troposphere over Mt. Emei. CAPSULE: Valley/mountain breeze is an important constraint to the temporal variations in organic aerosols over Mt. Emei.

Asian Pac J Trop Med ; 9(7): 694-7, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27393100


OBJECTIVE: To discuss the liver function damage mechanism of patients with clonorchiasis by analyzing the ultrasound characteristics, liver function, change of the serum inflammatory factors and cell apoptosis factors. METHODS: Color Doppler ultrasound technique was adopted to detect the portal vein and blood flow change of patients with clonorchiasis; ELISA was used to determine the level of different serum inflammatory factors. The levels of serum total bilirubin, serum albumin and glutamic-pyruvic transaminase were detected by automatic biochemical analyzer. Western blot was used to determine the expression of proteins relevant to apoptosis. RESULTS: Compared with the health control group, the trunk diameter of portal vein and the thickness of spleen, as well as the hepatic artery pulsation index of clonorchiasis patients increased obviously, the mean blood flow velocity of portal vein (P < 0.05 or P < 0.01) decreased. The content of total bilirubin and transaminase in plasma increased significantly, but albumin decreased (P < 0.05). Levels of TNF-α, IL-6 and IFN-γ increased remarkably, and the level of every factor was significantly different among patients with Child-Pugh , Child-Pugh II and Child-Pugh III classification of liver function (P < 0.05 or P < 0.01). With the exacerbation of liver dysfunction, levels of TNF-α, IL-6 and IFN-γ gradually increased (P < 0.05). Compared with the healthy control group, the expression quantity of apoptosis protein Fas, FasL, Bax and Caspase-3 increased significantly (P < 0.05 or P < 0.01), but Bcl-2 decreased (P < 0.05). CONCLUSIONS: Changes of ultrasonic characteristics and liver dysfunction, caused by liver fluke infection, may be related to that both inflammatory response and apoptosis response have participated in the pathogenic process and liver damage course of clonorchiasis.