Three-Dimensional Control on Lingually Rolled in Molars using a 3D Lingual Arch.

The fixed lingual arches that are used for mandibular molar uprighting works in two dimensions, whereas the 3D lingual arch works in all the three dimensions. The 3D lingual arch was fabricated from a 0.028 "round S.S wire with parts consisting of an adaptor, activator, friction lock and extender. The friction lock was inserted into the vertical stubs welded on the molar bands of the lingually tipped molar. They provided greater stability and anchorage to the molars. Up righting of the lingually tipped mandibular molars was attained within one month after insertion of the Wilson's 3D lingual arch. Correction was attained in all three dimensions with a buccal crown torque and lingual root torque. Levelling and alignment of the anterior segment was also attained by this multipurpose modular appliance. The 3D lingual arch enabled the clinician to set up a more positive anchorage for a greater variety of treatment applications than earlier lingual arches. Quality treatment results were attained with less span of time and were cost effective.

Recent advances in synthetic transformations mediated by cerium(IV) ammonium nitrate.

Cerium(IV) ammonium nitrate (CAN) has recently emerged as a versatile reagent for oxidative electron transfer; the overwhelming number of reports serve as a testimony to the unparalleled utility of CAN in a variety of transformations of synthetic importance. Our recent work has uncovered novel carbon-carbon bond-forming reactions leading to the one-pot synthesis of dihydrofurans, tetrahydrofurans, and aminotetralins. In addition, we have developed a number of facile carbon-heteroatom bond-forming reactions by the CAN-mediated oxidative addition of soft anions to alkenes. A mechanistic rationale has been provided for the reactions explored. As might be expected of very powerful one-electron oxidants, the chemistry of cerium(IV) oxidation of organic molecules is dominated by radical and radical cation chemistry.

Synthesis of 7-oxasphingosine and -ceramide analogues and their evaluation in a model for apoptosis.

The 7-oxasphingosine (1), 7-oxaceramide (2), the thio-oxaceramide 3, and N-methyloxaceramide 4 were synthesised from D-galactose via the building block 9. The apoptosis-inducing properties of 1-4 were compared to those of sphingosine (Sph) and ceramide (Cer) using a human neuroblastoma (SK-N-BE) and a murine-promyelocyte-derived (32d) cell line. There were no differences between 2-4 and Cer in terms of their effects on the viability of cells and their ability to trigger cell proliferation. However, in the presence of N,N-dimethylsphingosine, an inhibitor of sphingosine kinase (SPHK), Cer was more potent than thio-ceramide 3 in 32d cells, while thio-ceramide 3 was more potent and efficacious in SK-N-BE cells, where it showed an IC50 value of 3 nM compared to 100 nM for Cer. In both SK-N-BE and 32d cells, 7-oxasphingosine (1) and Sph were equally toxic, even in the presence of N,N-dimethylsphingosine.

A CAN-induced cyclodimerization-Ritter trapping strategy for the one-pot synthesis of 1-amino-4-aryltetralins from styrenes.

[reaction: see text]. A facile one-pot synthesis of 1-amino-4-aryl-tetralin derivatives by the CAN-induced cyclodimerization of various styrenes in acetonitrile and acrylonitrile is described.