BACKGROUND AND PURPOSE Time-resolved MRA imaging is a promising technique for blood flow evaluation in case of cerebrovascular malformations. Unfortunately, 4D MRA imaging is a trade-off between spatial and temporal resolution. The aim of this study was to investigate the influence of temporal resolution on the error associated with TTP estimation from indicator dilution curves derived from dif...

The method has been developed and validated for the determination of hydroquinone in liposomal formulation. The samples were dissolved in methanol and evaluated in 293 nm. The validation parameters such as linearity, accuracy, precision, specificity, limit of detection (LOD) and limit of quantitation (LOQ) were determined. The calibration curve was linear in 1-50 µg /mL range of hydroquinone an...

A method to measure the deuterium concentration in basic solutions, using Attenuated Total Reflection Fourier Transformed Infrared Spectroscopy (ATR-FTIR) is described. Deuterium quantification is based on the O-D bond stretching peak. A calibration curve is drawn, representing the peak intensity versus the deuterium percentage in a neutral solution. No calibration curve can be obtained with ba...

A reliable, sensitive and specific laser nephelometric (LN) assay for the quantitative measurement of specific proteins in body fluids by equivalence point titration is described. The method is relatively free from interference encountered in conventional LN assays, e.g. unspecific background scatter, antigen excess, and the inhibition of complex formation by high ionic strength and salt concen...

A new indicator dilution technique for measurement of cardiac output is described. Lithium chloride is injected via a central venous catheter and its dilution curve measured in arterial blood using a lithium-selective electrode. We assessed the lithium dilution cardiac output measurement (LiDCO) and a conventional thermodilution cardiac output measurement (ThDCO) by comparing the results of bot...

The theoretical basis of the use of the multiple indicator dilution technique to account for the heterogeneous distribution (or zonation) of enzymes in the liver was explored. The microcirculation was assumed to consist of identical capillaries perfused in parallel, with enzymatic activities for drug metabolism being distributed uniformly over the upstream half (periportal or pp) or the downstr...

1. Determinations were made on the activity of cytochrome oxidase of individual Japanese beetles during growth, diapause, and metamorphosis. All readings were made on homogenates at a dilution of 1:1,000, except for adult beetles, when the final dilution was 1:10,000. 2. The activity of the enzyme increased during larval growth from a low value of 0.022 in the second instar, to high values rang...

We adapted an inhibition assay for methotrexate, involving dihydrofolate reductase from bovine liver, for use with a discrete analyzer (the ABA-100). The analyzer waused both for dilution and a 5-mm pre-incubation of the sample with NADPH-enzyme reagent, and for the assay itself. The standard curve was linear between 10 and 120 tg/L. Without pre-incubation the standard curve was nonlinear. The ...

A single volume of 0.075 ml. of a 1 in 10 dilution of whole blood in isotonic NaCl solution is introduced into a container cell, two walls of which are made of a dialysing membrane. The container cell is introduced into a test tube of distilled water, placed in an instrument which is essentially a colorimeter with a recorder, between the source of light and the photoelectric cell. Dialysis thro...