Distribution of rare earth elements in PM10 emitted from burning coals and soil-mixed coal briquettes.

Emission from burning coals is one of the major sources of the airborne particles in China. We carried out a study on the rare earth elements (REEs) in the inhalable particulate matter (PM10) emitted from burning coals and soil-coal honeycomb briquettes with different volatile contents and ash yields in a combustion-dilution system. Gravimetric analysis indicates that the equivalent mass concentration of the PM10 emitted from burning the coals is higher than that emitted from burning the briquettes. The ICP-MS analysis indicates that the contents of total REEs in the coal-burning PM10 are lower than those in the briquette-burning PM10. In addition, the contents of the light rare earth elements (LREEs) are higher than those of the heavy rare earth elements (HREEs) in the PM10 emitted from burning the coals and briquettes, demonstrating that the REEs in both the coal-burning and briquette-burning PM10 are dominated by LREEs. The higher contents of total REEs and LREEs in the coal-burning PM10 are associated with the higher ash yields and lower volatile contents in the raw coals. A comparative analysis indicates that the La/Sm ratios in the PM10 emitted from burning the coals and briquettes, being lower than 2, are lower than those in the particles from gasoline-powered vehicle emission.

Lansoprazole-based sequential and concomitant therapy for the first-line Helicobacter pylori eradication.

OBJECTIVE: The aim of this prospective study was to compare the efficacy of the first-line lansoprazole-based sequential therapy and concomitant therapy (lansoprazole, amoxicillin, clarithromycin and metronidazole) for Helicobacter pylori (H. pylori) eradication. METHODS: A total of 169 patients with H. pylori infection were randomly assigned to either the sequential therapy group (n = 85) or the concomitant therapy group (n = 84). A follow-up endoscopy or urea breath test was examined at least 12 weeks after eradication. RESULTS: Comparable H. pylori eradication rate was observed in both the sequential therapy and concomitant therapy groups by either intention-to-treat analysis [sequential 80.0% (68/85) vs concomitant 88.1% (74/84); P = 0.27] or per protocol analysis [sequential, 85.3% (64/75) vs concomitant, 94.6% (70/74); P = 0.60]. Adverse effects were reported and good compliance was observed in both groups (P = 0.72). Although dual antibiotics resistance affected the therapeutic efficacy of sequential therapy (P = 0.03), not concomitant therapy (P = 0.74), it was not an independent factor for predicting the treatment outcome. CONCLUSION: First-line lansoprazole-based sequential and concomitant therapy were well-tolerated and comparable in terms of their H. pylori eradication rate.