Modeling the equilibrium moisture content of desorption and adsorption of yam (Dente)

The experimental equilibrium moisture content of yam (Dioscorea rotundata; cultivar: Dente) at temperatures of 25 and 50°C were determined at relative humidities from 0 to 95% employing the Dynamic Vapour Sorption analyzer. Wet yam samples with about 68% initial moisture content were used, first for desorption and subsequently for sorption. Water activity decreased with increased temperature at constant equilibrium moisture content. The desorption and adsorption isotherms were fitted by the GAB, Henderson, Halsey, Oswin, Smith, BET and Peleg models. On the basis of the fit the Peleg, GAB and Oswin models were most suitable for describing the observed data. When the focus is on drying, the GAB (3 parameters) and empirical Peleg model (4 parameters) performed best. Of these, GAB is preferable because it has fewer parameters, which, moreover, have a physical meaning

Quantifying In Vitro Growth and Metabolism Kinetics of Human Mesenchymal Stem Cells Using a Mathematical Model

Better quantitative understanding of human mesenchymal stem cells (hMSCs) metabolism is needed to identify, understand, and subsequently optimize the processes in expansion of hMSCs in vitro. For this purpose, we analyzed growth of hMSCs in vitro with a mathematical model based on the mass balances for viable cell numbers, glucose, lactate, glutamine, and glutamate. The mathematical modeling had two aims: (1) to estimate kinetic parameters of important metabolites for hMSC monolayer cultures, and (2) to quantitatively assess assumptions on growth of hMSCs. Two cell seeding densities were used to investigate growth and metabolism kinetics of MSCs from three human donors. We analyzed growth up to confluency and used metabolic assumptions described in literature. Results showed a longer initial phase, a slower growth rate, and a higher glucose, lactate, glutamine, and glutamate metabolic rates at the lower cell seeding density. Higher metabolic rates could be induced by a lower contact inhibition effect when seeding at 100cells/cm2 than when seeding at 1000cells/cm2. In addition, parameter estimation describing kinetics of hMSCs in culture, depending on the seeding density, showed doubling times in the order of 17–32h, specific glucose consumption in the order of 1.25×10−1 to 3.77×10−1pmol/cell/h, specific lactate production in the order of 2.48×10−1 to 7.67×10−1pmol/cell/h, specific glutamine production in the order of 7.04×10−3 to 2.27pmol/cell/h, and specific glutamate production in the order of 4.87×10−1 to 23.4pmol/cell/h. Lactate-to-glucose yield ratios confirmed that hMSCs use glucose via anaerobic glycolysis. In addition, glutamine and glutamate metabolic shifts were identified that could be important for understanding growth of hMSCs in vitro. This study showed that the mathematical modeling approach supports quantitative analysis of important mechanisms in proliferation of hMSCs in vitro

European recommendations on the proper indication and use of peripheral venous access devices (the ERPIUP consensus): A WoCoVA project

Since several innovations have recently changed the criteria of choice and management of peripheral venous access (new devices, new techniques of insertion, new recommendations for maintenance), the WoCoVA Foundation (WoCoVA = World Conference on Vascular Access) has developed an international Consensus with the following objectives: to propose a clear and useful classification of the currently available peripheral venous access devices; to clarify the proper indication of central versus peripheral venous access; discuss the indications of the different peripheral venous access devices (short peripheral cannulas vs long peripheral cannulas vs midline catheters); to define the proper techniques of insertion and maintenance that should be recommended today. To achieve these purposes, WoCoVA have decided to adopt a European point of view, considering some relevant differences of terminology between North America and Europe in this area of venous access and the need for a common basis of understanding among the experts recruited for this project. The ERPIUP Consensus (ERPIUP = European Recommendations for Proper Indication and Use of Peripheral venous access) was designed to offer systematic recommendations for clinical practice, covering every aspect of management of peripheral venous access devices in the adult patient: indication, insertion, maintenance, prevention and treatment of complications, removal. Also, our purpose was to improve the standardization of the terminology, bringing clarity of definition, and classification

[In Press] WoCoVA consensus on the clinical use of in-line filtration during intravenous infusions : current evidence and recommendations for future research

The need for filtering intravenous infusions has long been recognized in the field of venous access, though hard scientific evidence about the actual indications for in-line filters has been scarce. In the last few years, several papers and a few clinical studies have raised again this issue, suggesting that the time has come for a proper definition of the type of filtration, of its potential benefit, and of its proper indications in clinical practice. The WoCoVA Foundation, whose goal is to increase the global awareness on the risk of intravenous access and on patients’ safety, developed the project of a consensus on intravenous filtration. A panel of experts in different aspects of intravenous infusion was chosen to express the current state of knowledge about filtration and to indicate the direction of future research in this field. The present document reports the final conclusions of the panel