Glycopolymer Code: Programming Synthetic Macromolecules for Biological Targeting

Targeting in a cellular level is still one of the major challenges in biomedical treatments. However, new synthetic and analytical techniques now allow the development of precisely prepared macromolecules. Thus, glycopolymer chains are reported to be prepared with controlled length, monomer sequences, as well as chain‐folded structures. A high level of complexity in synthetic macromolecules also allows increased selectivity in targeting, which is a key factor in biomedical applications.     

Optimal control of a revenue management system with dynamic pricing facing linear demand

This paper considers a dynamic pricing problem over a finite horizon where demand for a product is a time‐varying linear function of price. It is assumed that at the start of the horizon there is a fixed amount of the product available. The decision problem is to determine the optimal price at each time period in order to maximize the total revenue generated from the sale of the product. In order to obtain structural results we formulate the decision problem as an optimal control problem and solve it using Pontryagin's principle. For those problems which are not easily solvable when formulated as an optimal control problem, we present a simple convergent algorithm based on Pontryagin's principle that involves solving a sequence of very small quadratic programming (QP) problems. We also consider the case where the initial inventory of the product is a decision variable. We then analyse the two‐product version of the problem where the linear demand functions are defined in the sense of Bertrand and we again solve the problem using Pontryagin's principle. A special case of the optimal control problem is solved by transforming it into a linear complementarity problem. For the two‐product problem we again present a simple algorithm that involves solving a sequence of small QP problems and also consider the case where the initial inventory levels are decision variables. Copyright © 2006 John Wiley & Sons, Ltd.     

Clinical and epidemiologic evaluation of pressure ulcers in patients at a university hospital in Turkey.

OBJECTIVE: We sought to measure the incidence of pressure ulcer development at a university health center in Turkey, and to determine whether the Waterlow Pressure Sore Risk (PSR) Scale score predicted pressure ulcer development, stage, or number of ulcers. DESIGN: We prospectively evaluated patients who were hospitalized at our university-based medical center. SETTING AND SUBJECTS: We analyzed data from 22,834 patients hospitalized at the Baskent University Adana Teaching and Medical Research Center in Ankara, Turkey from January 1, 2004 to December 31, 2004, including 360 patients who developed pressure ulcers. INSTRUMENTS: The Waterlow PSR Scale was used to assess pressure ulcer risk. In addition, age, sex, the ward or unit in which the patient was hospitalized, reason for hospitalization, and location and stage of ulcers were collected on a data form designed specifically for this study. METHODS: A single nurse physiotherapist assessed all patients daily during their hospitalization. When a pressure ulcer was diagnosed by the nurse physiotherapist, a physician staged the pressure ulcers based on the US National Pressure Ulcer Advisory Panel (NPUAP) staging system. RESULTS: Three hundred sixty out of 22,834 patients developed 1 or more pressure ulcers, resulting in an incidence rate of 1.6%. Most ulcers (59.2%) occurred in patients hospitalized in the intensive care unit (n = 213). A positive correlation between the Waterlow PSR Scale score and number of ulcers per patient (r: 0.178, P < .01) was identified. No significant correlation was found linking Waterlow PSR Scale score and ulcer stage or the development of a single ulcer. CONCLUSION: We found significantly lower pressure ulcer incidence rates than those commonly reported in the literature, which we believe is principally attributable to short hospital stays and a strong emphasis on preventive nursing care. While high Waterlow PSR scale Scores correlated positively with development of multiple ulcers, this did not predict ulcer stage or the presence of a single pressure ulcer.     

Formulation and in Vitro-in Vivo Evaluation of Sustained-Release Lithium Carbonate Tablets

The release of lithium carbonate incorporated into polymethylmethacrylate, poly vinyl chloride, hy-drogenated vegetable oil, and carbomer matrix tablets was studied in vitro. The formulation containing 10% carbomer showed a sustained-release profile comparable to that of a standard, commercially available, sustained-release preparation containing 400 mg lithium carbonate embedded in a composite material. In vivo the newly formulated and standard sustained-release lithium carbonate tablets were compared to an oral solution and conventional lithium carbonate tablets in 12 healthy subjects. These crossover studies showed that the sustained-release tablets produced a flatter serum concentration curve than the oral solution and conventional tablet, without loss of total bioavailability.