PURPOSE To develop a population pharmacokinetic-pharmacodynamic (PK-PD) model that defines the dose-concentration-effect relationship of 5,6-dimethylxanthenone-4-acetic acid (DMXAA), using plasma 5-hydroxyindole-3-acetic acid (5-HIAA) as a biomarker for the antivascular effect of DMXAA. EXPERIMENTAL DESIGN The plasma DMXAA and 5-HIAA concentration data were obtained from 124 patients receivin...

Perfusion heterogeneities in organs such as the heart obey a power law as a function of scale, a behavior termed "fractal." An explanation of why vascular systems produce such a specific perfusion pattern is still lacking. An intuitive branching tree model is presented that reveals how this behavior can be generated as a consequence of scale-independent branching asymmetry and fractal vessel re...

PURPOSE An ancillary phase II study was conducted to study interindividual variability in cetuximab pharmacokinetics and its influence on progression-free survival (PFS) in metastatic colorectal cancer patients cotreated with irinotecan and 5-fluorouracil. EXPERIMENTAL DESIGN Ninety-six patients received cetuximab as an infusion loading dose of 400 mg/m(2) followed by weekly infusions of 250 ...

In this paper, the fractal characteristics of goose down assembly are described by determining the pore area fractal dimension and the tortuosity fractal dimension. The goose down assembly, filled with mass of down fibers and pores, is loose and ductile. The pores are varying shapes and sizes, and distribute unevenly. Firstly, micro computed tomography is used to observe the internal microstruc...

BACKGROUND Previous in vivo data suggest that high airway resistance (R(aw)) promotes dynamic hyperinflation, especially when coupled to high minute ventilation (V(E)). However, no studies have systematically examined the relative effects of various mechanical parameters on dynamic hyperinflation. METHODS Intrinsic positive end-expiratory pressure (PEEPi) was measured with a ventilator-lung m...

Introduction: Dynamic contrast enhanced MRI (DCEMRI) involves measurement and analysis of contrast media uptake and washout following bolus injection. These studies are critical for detecting and evaluating tumor vasculature and changes during therapy. However, there is no accepted method for analyzing contrast media uptake and washout. The two-compartment model (TCM) [1], though widely used, i...

Sir,—MacDonald and Mackenzie (1976) reported an alinear relationship between peak height and halothane concentration when measuring halothane (0.2—4.0%) with a gas chromatograph equipped with a flame ionization detector. Alinearity persisted when the sample loop size was reduced from 2 ml to 0.1 ml, and a linear response was obtained only when the flame ionization detector was replaced with a k...

Understanding the folding of the human genome is a key challenge of modern structural biology. The emergence of chromatin conformation capture assays (e.g., Hi-C) has revolutionized chromosome biology and provided new insights into the three dimensional structure of the genome. The experimental data are highly complex and need to be analyzed with quantitative tools. It has been argued that the ...

Classically, percolation critical exponents are linked to the power laws that characterize percolation cluster fractal properties. It is found here that the gradient percolation power laws are conserved even for extreme gradient values for which the frontier of the infinite cluster is no more fractal. In particular the exponent 7/4 which was recently demonstrated to be the exact value for the d...