Advanced Mixing Techniques | Introduction

2019 ◽  
pp. 285-287
Author(s):  
Hans Weekhout
Keyword(s):  
1990 ◽  
Vol 68 (5) ◽  
pp. 1854-1864 ◽  
Author(s):  
E. Heidelberger ◽  
R. B. Reeves

A planar monocellular layer of whole blood (WB) sandwiched between two Gore-Tex membranes is used to study O2 uptake and release kinetics at 37 degrees C. Gore-Tex, a highly gas-permeable open mesh of Teflon fibrils (78% porosity, 0.2-microns pore size, 75-microns thick), constrains WB to form a thin film without imposing an appreciable gas diffusion barrier. WB layer thickness, measured by isotope dilution, is 1.7 +/- 0.2 microns. WB films are mounted between fiber optics in a gas flow tube for dual-wavelength (536/558 nm) oxyhemoglobin saturation measurements after a step change in PO2. For isocapnic (6% CO2) step changes in PO2 between 0 and 104 Torr, WB O2 uptake half time is 10.4 +/- 0.9 ms; WB O2 release half time is 20.6 +/- 2.4 ms. Half-time values are half of those previously reported. The thin-layer method reduces erythrocyte diffusion boundary layer error and thereby offers an attractive alternative to classical rapid fluid-mixing techniques.


1998 ◽  
Author(s):  
Mohammed E. Ali ◽  
Daipayan Bhattacharya ◽  
Hernan Erlig ◽  
Harold R. Fetterman ◽  
Mehran Matloubian

2021 ◽  
Vol 11 (5) ◽  
pp. 2075
Author(s):  
Massimiliano Dapporto ◽  
Davide Gardini ◽  
Anna Tampieri ◽  
Simone Sprio

Calcium phosphate cements (CPCs) have been extensively studied in last decades as nanostructured biomaterials for the regeneration of bone defects, both for dental and orthopedic applications. However, the precise control of their handling properties (setting time, viscosity, and injectability) still represents a remarkable challenge because a complicated adjustment of multiple correlated processing parameters is requested, including powder particle size and the chemical composition of solid and liquid components. This study proposes, for the first time, a multifactorial investigation about the effects of powder and liquid variation on the final performance of Sr-doped apatitic CPCs, based on the Design of Experiment approach. In addition, the effects of two mixing techniques, hand spatula (low-energy) and planetary shear mixing (high-energy), on viscosity and extrusion force were compared. This work aims to shed light on the various steps involved in the processing of CPCs, thus enabling a more precise and tailored design of the device, based on the clinical need.


2018 ◽  
Vol 85 (1) ◽  
pp. 252-257 ◽  
Author(s):  
Kerry Layne ◽  
Louise Hope ◽  
Edmund Rab ◽  
John Archer ◽  
David M. Wood ◽  
...  
Keyword(s):  

1997 ◽  
Vol 31 (11) ◽  
pp. 1287-1291 ◽  
Author(s):  
Merry Liau-Chu ◽  
Jochen GW Theis ◽  
Gideon Koren

BACKGROUND: During a Phase I/II trial of high-dose intravenous cyclosporine, a high incidence of anaphylactoid reactions was observed. Epidemiologic investigations revealed that the occurrence of anaphylactoid reactions was significantly associated with improper mixing during preparation of the infusions. It was hypothesized that improper mixing during the preparation of the infusion may have caused initial bolus infusions of the vehicle, Cremophor EL. These inadvertent bolus infusions may have caused the anaphylactoid reactions. OBJECTIVE: To investigate the effect of different mixing techniques on the distribution of the components of cyclosporine concentrate for infusion: cyclosporine, Cremophor EL, and ethanol in the infusions administered to the patients. METHODS: Infusions were prepared in a similar fashion as those administered to study patients enrolled in a high-dose cyclosporine therapy protocol. Samples were collected at defined time points of the infusions. Concentrations of cyclosporine and Cremophor EL were spectrophotometrically determined; ethanol concentrations were measured enzymatically. RESULTS: Cyclosporine and Cremophor EL concentrations were up to ninefold higher than intended during the first 10 minutes of the infusions that were not appropriately mixed. In contrast, the concentrations of cyclosporine and Cremophor EL were similar to the intended concentrations in all of the well-mixed infusions. CONCLUSIONS: Inappropriate mixing of high-dose cyclosporine infusions can lead to initial bolus infusion of cyclosporine and Cremophor EL. Bolus infusions of Cremophor EL have been associated with anaphylactoid reactions. Thus, thorough mixing of high-dose cyclosporine infusions may be important to reduce the possibility of life-threatening anaphylactoid reactions.


2009 ◽  
pp. 155-182 ◽  
Author(s):  
Lorne Bregitzer
Keyword(s):  

2019 ◽  
pp. 309-311
Author(s):  
Hans Weekhout
Keyword(s):  

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