Nanoscale octadecacobalta- and hexacosacobaltaclusters: Synthesis and spectroscopic fingerprinting

Strategies for the construction of TMS-protected first generation star and dendritic polyynes, which are subsequently metallated to give multiple Co₂C₂(CO)₆ clusters, are reported. In the absence of crystallographic data, well-resolved ¹³C NMR spectroscopy is a powerful technique for confirming the presence of core, inner and peripheral cluster domains.     

Voice changes in women treated for endometriosis and related conditions: The need for comprehensive vocal assessment

Hormonal treatments which have an androgenic effect have the potential to cause vocal changes. The changes in vocal fold structure and voice quality are considered to be irreversible. To date, studies have documented subjective vocal changes or documented single cases without detailed, baseline voice assessments. The impact on laryngeal function of women taking these androgenic treatments requires further detailed, objective assessment. The need for increased awareness of the actions of androgenic hormones on womns' voices, and the benefits of a thorough voice assessment are discussed.     

Stochastic programming for nurse assignment

We present a brief overview of four phases of nurse planning. For the last phase, which assigns nurses to patients, a stochastic integer programming model is developed. A Benders’ decomposition approach is proposed to solve this problem, and a greedy algorithm is employed to solve the recourse subproblem. To improve the efficiency of the algorithm, we introduce sets of valid inequalities to strengthen a relaxed master problem. Computational results are provided based upon data from Baylor Regional Medical Center in Grapevine, Texas. Finally, areas of future research are discussed.     

Crystallographic study of restricted rotation ino-formanilides

The crystal structures ofcis- andtrans-o-methylformanilide, of itscis-thio analogue, and oftrans-o-phenylformanilide have been studied with a view to clarifying the anomalously high barrier to rotation of the carbonyl group. The pair of resolved geometrical isomers is shown to be stabilized in the solid state primarily by hydrogen bonding. The increased barrier to rotation is inferred not to arise from mesomeric involvement of the carbonyl group, but from nuclear screening by the nitrogen lone pair.     

The numerical integration of a molecular integral using two different techniques

A two-electron integral which commonly occurs in molecular calculations is evaluated numerically using the different methods of Boys and Conroy and the results are discussed.This paper was presented during the session on numerical integration methods for molecules of the 1970 Quantum Theory Conference in Nottingham. It has been revised in the light of the interesting discussion which followed.