Silver(I) and copper(II)-imidazolium carboxylates: Efficient catalysts in Ullmann coupling reactions

The silver(I) and copper(II)-imidazolium carboxylate coordination assemblies were derived from the reaction between corresponding carboxylic acid ligands and metal salts. These new metal derivatives depict a novel structural motif with variable chemical and thermal properties. These metal complexes act as potential catalysts in Ullmann coupling reactions. The imidazolium linker present in these complexes plays a role as both ligand and counter ion to balance the metal charge.[Figure not available: see fulltext.]

Dynamic instability analysis of variable angle tow composite plate with delamination around a cutout

The dynamic instability analysis of a simply supported variable angle tow (VAT) composite with delamination around a cutout subjected to periodic axial compression load is investigated. The governing equations of motion for the VAT plate are derived based on first-order shear deformation theory and solved using finite element method. The equations of motion contain time periodic coefficients and their stability is determined using the Bolotin’s approach. A parametric study is carried out to analyze the effect of linearly varying fiber orientation angle on the dynamic instability of VAT laminate with delamination around a circular cutout

Intravenous urography supplemented with computerised tomography urogram: A pragmatic hybrid imaging approach to hydronephrosis

Background: Image quality in an Intravenous Urogram (IVU) can occasionally be compromised by variables like bowel preparation, renal function and radiographic factors, posing a challenge to all Uroradiologists. The Computerised Tomography Urogram (CTU) yields better diagnostic information than an IVU, due to its inherent superior anatomic delineation and contrast sensitivity, against a trade-off involving radiation dose and cost. Our study was conducted to assess the utility and timing of performing a single-phase CTU, as a problem-solving tool, to clear the diagnostic dilemma in a selected subset of patients, in whom an ongoing IVU could potentially be inconclusive. Material and Methods: Five hundred and twelve patients who underwent IVU studies for urologic referrals at a tertiary care hospital, during the period of January to December 2009, formed the subject of the study, of whom 33 patients with inconclusive IVU findings after the first three radiographs underwent a single-phase CTU, to reach definitive imaging diagnoses. Results: The percentage of inconclusive IVU studies amounted to only 33 / 512 (6.4%), in whom a CTU study revealed definitive diagnoses in 30 patients and no abnormality in three patients, thus conclusively clearing the ambiguities raised on the IVU in all the selected patients. Conclusions: The concept of a CTU limited to a single-phase study to supplement an inconclusive IVU optimizes the contrast and radiation dose to the affected patients. It is a cost-effective, timely, and definitive ′imaging intervention′ and should be considered a viable hybrid technique to be utilized selectively and judiciously