Combinatorial discovery of oxidative dehydrogenation catalysts within the Mo-V-Nb-O system

Combinatorial methodologies were used for the synthesis and screening of mixed metal oxide heterogeneous catalysts. Primary screening at low reactant conversions at a throughput of greater than 10,000 catalyst compositions per month was performed by using simultaneous MS and photothermal deflection spectroscopy on spatially separated thick film catalysts with approximately 200 microg per catalyst prepared by using automated liquid dispensing. Secondary screening under realistic operating conditions was performed at a throughput of greater than 3,000 catalyst compositions per month on approximately 50 mg of catalyst in an array of fixed bed microreactors with gas chromatograph detection. The approach was validated by the discovery of catalysts with superior performance to those previously described for the oxidative dehydrogenation of ethane to ethylene. We show the full implementation and integration of combinatorial methodologies for synthesis, screening, discovery, and optimization of multicomponent heterogeneous catalysts.

A rare-earth phosphor containing one-dimensional chains identified through combinatorial methods

An unusual luminescent inorganic oxide, Sr2CeO4, was identified by parallel screening techniques from within a combinatorial library of more than 25,000 members prepared by automated thin-film synthesis. A bulk sample of single-phase Sr2CeO4 was prepared, and its structure, determined from powder x-ray diffraction data, reveals one-dimensional chains of edge-sharing CeO6 octahedra, with two terminal oxygen atoms per cerium center, that are isolated from one another by Sr2+ cations. The emission maximum at 485 nanometers appears blue-white and has a quantum yield of 0.48 +/- 0.02. The excited-state lifetime, electron spin resonance, magnetic susceptibility, and structural data all suggest that luminescence originates from a ligand-to-metal Ce4+ charge transfer.

Drug formularies--good or evil? A view from a managed care provider

Formularies have been developed in response to specific forces which have affected pharmaceutical utilization and costs. Specifically, this is in response to an increase in the aging population requiring more drugs, inflation in the acquisition cost of drugs, increasing utilization, and the introduction of new technology. Well-researched formularies will provide the drug therapy needs for 85-90% of the population. Patients unresponsive to listed formulary drugs may use nonformulary drugs if appropriate methods of authorization are instigated. Various types of formulary management exist: open, where they can be used as a guideline, and drug benefits are not limited to the formulary; restricted or closed, where only drugs on the formulary or those previously authorized will be paid for; incentive based, where patients pay a higher price for nonformulary drugs, and patient driven, where the patient holds a list of drugs they can be supplied with. Effective formulary performance requires the joint co-operation of the pharmacists, payers, physicians, the pharmaceutical industry, and patients. These clinically based formularies then form an important measure to control costs while providing quality care. This paper will discuss the advantages of a formulary, its development, administration, and management.

Evolving pathogens in vulvovaginal candidiasis: implications for patient care

Over the past two decades, an increasing trend in the number of vaginal infections attributable to yeasts other than Candida albicans has emerged. Of these non-albicans species, C. tropicalis and C. glabrata appear to be the most important. The change in incidence pattern of yeast vaginitis can be expected to impact greatly on the treatment of this condition, because many currently used drug therapies (e.g., imidazoles) for C. albicans vaginitis do not adequately eradicate non-albicans species. A possible explanation for the recent increased selection of these species may be the shortened antifungal therapies that have been introduced during the past decade. These 1- to 3-day regimens with the older imidazoles may suppress C. albicans, but create an imbalance of flora that facilitate an overgrowth of non-albicans species. The recognition of yeast speciation and the need for use of a broad-spectrum antifungal preparation that covers these organisms is now apparent.