Iron(II) modified natural zeolites for hexavalent chromium removal from contaminated water

Abstract Three different types of Fe(II)-modified natural zeolites were tested as supports in continuous-flow columns for the treatment of Cr(VI) contaminated water. The natural zeolites chosen as support were commercially available Zeosand (80% clinoptilolite), ATZ (79% phillipsite/chabazite), and ZS-55RW (90% Chabazite). All the examined modified zeolites turned out active for hexavalent chromium abatement, lowering its concentration below the European regulation level, even at relatively high flow rates (40 mL/h, linear velocity 15 cm/h). Zeosand, having a broader pH range of stability, was found to be the best one in terms of both Fe(II) uptake (0.54 wt%) and Cr removal (90 mg Cr/Kg zeolite)

MYC-containing double minutes in hematologic malignancies: evidence in favor of the episome model and exclusion of MYC as the target gene

Double minutes (dmin)—circular, extra-chromosomal amplifications of specific acentric DNA fragments—are relatively frequent in malignant disorders, particularly in solid tumors. In acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), dmin are observed in ∼1% of the cases. Most of them consist of an amplified segment from chromosome band 8q24, always including the MYC gene. Besides this information, little is known about their internal structure. We have characterized in detail the genomic organization of 32 AML and two MDS cases with MYC-containing dmin. The minimally amplified region was shown to be 4.26 Mb in size, harboring five known genes, with the proximal and the distal amplicon breakpoints clustering in two regions of ∼500 and 600 kb, respectively. Interestingly, in 23 (68%) of the studied cases, the amplified region was deleted in one of the chromosome 8 homologs at 8q24, suggesting excision of a DNA segment from the original chromosomal location according to the ‘episome model'. In one case, sequencing of both the dmin and del(8q) junctions was achieved and provided definitive evidence in favor of the episome model for the formation of dmin. Expression status of the TRIB1 and MYC genes, encompassed by the minimally amplified region, was assessed by northern blot analysis. The TRIB1 gene was found over-expressed in only a subset of the AML/MDS cases, whereas MYC, contrary to expectations, was always silent. The present study, therefore, strongly suggests that MYC is not the target gene of the 8q24 amplification

Microscopic Transanal Therapy (TEM) our experience

Sourcerecord Id Scopus 2834

Oxidation of benzyl alcohols to aldehydes and ketones under air in water using a polymer supported palladium catalyst

This work deals with the catalytic conversion of benzyl alcohols to aldehydes or ketones using a polymer supported palladium catalyst which formed metal nanoparticles under reaction condition. The oxidation reaction was carried out on a series of substituted benzylic alcohols under air in water. The obtained results showed high selectivity also for the oxidation of primary alcohols to aldehydes without over-oxidation products. In addition, the catalyst was recycled several times with negligible metal leaching into solution. © 2014 Elsevier B.V

Ionic Liquids in Palladium‐Catalyzed Cross‐Coupling Reactions

This chapter surveys the most significant developments in the field of palladium-catalyzed cross-coupling reactions in ionic liquids. The beneficial effect of the ionic liquids in terms of activity, selectivity, and recyclability is commented for all types of reactions discussed, namely the Heck, Suzuki–Miyaura, Stille, Sonogashira, Ullmann, and Negishi cross-couplings. Insights into the reaction mechanisms reveal that the effect of the ionic liquid on C–C bond forming reactions manifests itself not only in the energy lowering of polar transition states (or intermediates) involved in the catalytic cycles but also, depending on the cases, in the stabilization of palladium nanoparticles, the synthesis of molecular Pd complexes with the IL anions, the enhancement of the chemical reactivity of reactants, and others. The synergistic effect found by using appropriate mixtures of ionic liquids is also discussed. © Springer-Verlag Berlin Heidelberg 2013