The effect of the tramway track construction on the aerosol pollution in Debrecen, Hungary

In this study the effect of a new tramway track construction on the atmospheric aerosol concentration and composition in Debrecen, Hungary, was investigated. The tramway track construction started in 2011 and it was finished in 2013. PM2.5 and PM10 daily samples were collected with a Gent type filter unit in an urban background site 2 times a week. In addition, a sampling campaign direct next to the construction site was performed with 2-stage personal samplers between the 21st and 30th of September, 2011 – four hours a day, during work- ing hours. We studied the change in concentration and composition of fine and coarse fraction aerosol in comparison with the average of the past 5 years. An additional goal was to investigate the personal aerosol exposure near to the construction sites. In the urban background site a significant increase could be observed both for the PM2.5 and PM10 concentrations for 2012 and 2013. In the elemental composition the concentration of Fe, Mn, Ni, and Cr increased significantly for the construction period. The PM10 concentrations measured direct next to the construction site were 10–20 higher than those measured at our urban background site or the data provided by the Hungarian Air Quality monitoring network. Days with very high Pb pollution level (3000 ng/m3) was also recorded

1,3-Dipolar Cycloaddition of Isatin-Derived Azomethine Ylides with 2H‐Azirines: Stereoselective Synthesis of 1,3- Diazaspiro[bicyclo[3.1.0]hexane]oxindoles

A regio- and diastereoselective 1,3-dipolar cycloaddition of 2H-azirines with azomethine ylides generated in situ from isatins and α-amino acids has been elaborated, affording an unprecedented aziridine-fused spiro[imidazolidine-4,3′-oxindole] framework. This one-pot three-component reaction tolerates a wide range of substrates and enables the construction of highly diverse 1,3-diazaspiro[bicyclo[3.1.0]hexane]oxindoles in isolated yields up to 81% under mild conditions