The complexation reactions between Tl+ and Pb2+ ions and crown ethers 12-crown-4(12C4), 15-crown-5 (15C5), benzo-15-crown-5 (B15C5), 18-crown-6 (18C6), dicyclohexyl-18-crown-6 (DC18C6) and aza-18-crown-6 (A18C6) were studied in 90% acetonitrile and 90% ethanol solutions at 25 °C, using an a.c. polarographic technique. The stoichiometry and stability of the complexes we...

We have developed intelligent polymerized crystalline colloidal array (IPCCA) chemical-sensing materials for detection of Pb(2+) in high ionic-strength environments such as body fluids with a detection limit of <500 nmol L(-1) Pb(2+) (100 ppb). This IPCCA lead sensor consists of a mesoscopically periodic array of colloidal particles polymerized into an acrylamide hydrogel. The array Bragg-diffr...

Perennial ryegrass is the most abundant grass species in temperate climates. An increased herbage intake of dairy cows by breeding new cultivars could have a large potential impact on agriculture. The effects of cultivars on sward structure, nutritive value, physical characteristics and disease resistance of perennial ryegrass are discussed. Cultivar differences were found in several studies fo...

Crown class, an ordinal tree-level mensuration attribute used extensively by foresters, is di#icult to ass ign in thefield because def ini t ions of individual classes are confounded by ambiguous references to the position the tree in the canopy and amount of light received by its crown. When crown class is decomposed into its two elements-crown position and crown light exposure--field assignme...

BACKGROUND Dentinal hypersensitivity is a very common complaint of patients undergoing crown and bridge restorations on vital teeth. Of the many desensitizing agents used to counter this issue, desensitizing laser treatment is emerging as one of the most successful treatment modality. However, the dentinal changes brought about by the desensitizing laser application could affect the bond streng...

PURPOSE The purpose of the present study was to evaluate the flexural strength of the joint between glass-infiltrated alumina frames and the experimental adjusting agent (MA modifier) that contains alumina and magnesia. METHODS A commercially available adjusting agent (Optimizer), a slurry of alumina powder (Alumina modifier), and a bulk specimen (joint-free alumina) were used as controls. Be...

The aim of this study was to investigate the fracture strength of endodontically treated teeth restored with different posts and variable ferrule heights. Sixty freshly extracted human canines were treated endodontically and randomly assigned to 6 groups (n=10), being restored with custom-made cast post-and-core (CP0 and CP3 groups), prefabricated post and composite resin core (PF0 and PF3 grou...

Crown roots are the main components of the fibrous root system in rice (Oryza sativa). WOX11, a WUSCHEL-related homeobox gene specifically expressed in the emerging crown root meristem, is a key regulator in crown root development. However, the nature of WOX11 function in crown root development has remained elusive. Here, we identified a rice AP2/ERF protein, ERF3, which interacts with WOX11 an...

This study demonstrates the spectral data for two triarylmethane dyes, malachite green (MG) and crystal violet (CV) at room temperature. Effects of micellar environment, and crown ether addition on the spectral behaviour of the dyes were studied using absorption spectroscopic method. The dye-anionic surfactant interactions in micellar media were investigated. The chosen surfactants with differe...