Studies on the synthesis of tedanolide: synthesis of the C(5)-C(21) segment via a highly stereoselective fragment assembly aldol reaction of a chiral beta,gamma-unsaturated methyl ketone

[formula: see text] A highly diastereoselective synthesis of 3, corresponding to the C(5)-C(21) segment of tedanolide, has been accomplished by a route utilizing the aldol reaction of aldehyde 4 and the beta,gamma-unsaturated methyl ketone 5.     

Hypothermic renal preservation with a sucrose/ polyethylene glycol solution in a rabbit renal transplant model

Renal preservation at for 24 hours at hypothermia was studied in a rabbit model after flush cooling with sucrose-based solution (SBS), compared with a standard preservation solution (in this case, Marshall's Hypertonic Citrate solution - HCA). Polyethylene glycol supplementation to SBS (SBS-PEG) was also investigated. Renal function was measured by plasma creatinine assays during 1 months post transplantation, and pathology of the explanted kidneys was undertaken. Results showed that survival at 28 days was similar in all groups, (HCA - 3 out of 6; SBS - 2 out of 5; SBS-PEG - 3 out of 5), and there were no differences in recovery of plasma creatinine values. Histopathological evaluation of the grafts indicated that SBS preservation resulted in more severe damage after transplantation (P less than 0.05 in both corticomedullary region and medulla compared to HCA), whilst addition of PEG reduced the damage score to that seen with HCA. SBS can be used as a simple, inexpensive preservation solution for kidney cold storage provided that PEG is used as an additional colloid.     

Evidence for new isotopes of element 107: 266Bh and 267Bh

New neutron rich isotopes 267107Bh and 266107Bh were produced in bombardments of a 249Bk target with 117-MeV and 123-MeV 22Ne ions at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. Identification was made by observation of correlated alpha-particle decays between the Bh isotopes and their Db and Lr daughters using a rotating wheel system. 267Bh was produced with a cross section of approximately 70 pb and decays with a 17(+14)(-6) s half life by emission of alpha particles with an average energy of 8.83+/-0.03 MeV. One atom of 266Bh was observed, decaying within 1 s by emission of a 9.29-MeV alpha particle.     

Preordered affine Hjelmslev planes

An affine Hjelmslev plane (AH-plane)H is preordered if it is endowed with a betweenness relation which is preserved by bijective parallel projections. Preordered biternary rings are defined and are used to construct preordered AH-planes. Conversely, a preordered AH-plane induces a preordering on any of its biternary rings. The concepts used in this paper are compared with those in a recent independent study of preordered affine Klingenberg planes by F. Machala. Unlike the Klingenberg case, preordered AH-planes always possess convex neighbour classes and unlike ordered ordinary affine planes, preordered AH-planes are never archimedian.The authors gratefully acknowledge the support of the Natural Sciences and Engineering Research Council of Canada.     

On a Resurgence of Management Simulations and Games

The past few years have seen a significant resurgence of interest in ‘management games’ and ‘management flight simulators’, one particularly active source of such work being the system dynamics community. After proposing a distinction between games and simulations, this paper provides some background to these developments by briefly describing the historical roots of the field and the fundamental ideas of the system dynamics community, which are now giving rise to ‘microworlds’. The training advantages of management simulations and games are then discussed. The paper closes with a note on the research and findings of the system dynamics field and by offering some words of warning on the perils of simulation and game use. Two scenarios for how the use of simulations and games as management education devices might develop in the future are proposed. An Appendix describes five examples of very different types of management simulations and games.     

Direct C-arylation of free (NH)-indoles and pyrroles catalyzed by Ar-Rh(III) complexes assembled in situ

Ar-Rh(III) pivalate complexes assembled in situ from the reaction of [RhCl(coe)2]2 (coe = cis-cyclooctene), [p-(CF3)C6H4]3P, and CsOPiv effectively catalyzed the direct C-arylation of free (NH)-indoles and (NH)-pyrroles in good yields and with high regioselectivity. The reaction displayed excellent functional group compatibility and low moisture sensitivity. Kinetics studies support a mechanism involving phosphine displacement by indole in complex 2 (resting state of the catalyst), followed by a rate-limiting C-H bond metalation.     

Excitation energies of superdeformed States in 196Pb: towards a systematic study of the second well in Pb isotopes

The excitation energy of the lowest-energy superdeformed band in 196Pb is established using the techniques of time-correlated gamma-ray spectroscopy. Together with previous measurements on 192Pb and 194Pb, this result allows superdeformed excitation energies, binding energies, and two-proton and two-neutron separation energies to be studied systematically, providing stringent tests for current nuclear models. The results are examined for evidence of a "superdeformed shell gap."