997 resultados para 2-8A
Resumo:
The Climatological Database for the World's Oceans: 1750-1854 (CLIWOC) project, which concluded in 2004, abstracted more than 280,000 daily weather observations from ships' logbooks from British, Dutch, French, and Spanish naval vessels engaged in imperial business in the eighteenth and nineteenth centuries. These data, now compiled into a database, provide valuable information for the reconstruction of oceanic wind field patterns for this key period that precedes the time in which anthropogenic influences on climate became evident. These reconstructions, in turn, provide evidence for such phenomena as the El Niño-Southern Oscillation and the North Atlantic Oscillation. Of equal importance is the finding that the CLIWOC database the first coordinated attempt to harness the scientific potential of this resource represents less than 10 percent of the volume of data currently known to reside in this important but hitherto neglected source.
Resumo:
Copper(II) complexes of some pyridine-2-carboxamidrazones have been prepared and characterized. The crystal structures of the copper complex cis-[dichloro(N1-2-acetylthiophene-pyridine-2-carboxamidrazone) copper(II)] 8a and one of the free ligands, viz. {(p-chloro-2-thioloxy-benzylidine-pyridine-2-carboxamidrazone)} 6, have been determined. The former shows a highly distorted square planar geometry around copper, with weak intermolecular coordination from the thiophenyl sulfur resulting in a stacking arrangement in the crystal lattice. The in vitro activities of the synthesized compounds against the malarial parasite Plasmodium falciparum are reported for the first time, which clearly shows the advantage of copper complexation and the requirement of four coordinate geometry around copper as some of the key structural features for designing such metal-based antimalarials. © 2003 Elsevier Science B.V. All rights reserved.