Browsing by Author "Sen, B"

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    Dinuclear silver-bis(N-heterocyclic carbene) complexes: Synthesis, catalytic activity in propargylamine formation and computational studies
    Atli, DD; Sen, B
    Preparation of a series of 1,1 '-dialkyl-3,3 '-(2-methylenepropane-1,3-diyl)dibenzimidazolium salts (alkyl = ethyl, propyl, butyl) (2a-2c) and their dinuclear bis(N-heterocyclic carbene) silver complexes (3a-3c) is reported. The silver complexes were synthesized via in situ deprotonation with Ag2O in 67-74% yields. The structural definitions of the synthesized compounds were performed by H-1 NMR, C-13 NMR, elemental analysis, FT-IR and also LC-MSMS techniques (only for 3a-3c). The silver complexes were utilized for three-component coupling reactions of aldehydes, amines and alkynes (A(3)-coupling). It was found that increasing the chain length of the alkyl substituent on the N-heterocyclic carbene ligand led to increase in catalytic performance. 3c showed the highest activity with 81% yield and with TON of 27 for N,N-diethyl-3-phenylprop-2-yn-1-amine formation. Geometry optimization was performed and geometric parameters were calculated for the compounds. The theoretical harmonic vibration frequencies of molecules were computed by DFT/B3LYP methods for their optimized geometries.
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    Indoor airborne fungal pollution in newborn units in Turkey
    Demirel, R; Sen, B; Kadaifciler, D; Yoltas, A; Okten, S; Ozkale, E; Berikten, D; Samson, RA; Uztan, AH; Yilmaz, N; Gunyar, OA; Aydogdu, H; Asan, A; Kivanc, M; Ozdil, S; Sakartepe, E
    Pathogenic and/or opportunistic fungal species are major causes of nosocomial infections, especially in controlled environments where immunocompromised patients are hospitalized. Indoor fungal contamination in hospital air is associated with a wide range of adverse health effects. Regular determination of fungal spore counts in controlled hospital environments may help reduce the risk of fungal infections. Because infants have inchoate immune systems, they are given immunocompromised patient status. The aim of the present study was to evaluate culturable airborne fungi in the air of hospital newborn units in the Thrace, Marmara, Aegean, and Central Anatolia regions of Turkey. A total of 108 air samples were collected seasonally from newborn units in July 2012, October 2012, January 2013, and April 2013 by using an air sampler and dichloran 18% glycerol agar (DG18) as isolation media. We obtained 2593 fungal colonies comprising 370 fungal isolates representing 109 species of 28 genera, which were identified through multi-loci gene sequencing. Penicillium, Aspergillus, Cladosporium, Talaromyces, and Alternaria were the most abundant genera identified (35.14, 25.40, 17.57, 2.70, and 6.22% of the total, respectively).