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Gradient echo imaging of flowing hyperpolarized nuclei : theory and phantom studies on 129Xe dissolved in ethanol

The influence of flip angle and flow velocity on the signal intensity achieved when imaging a hyperpolarized substance with a spoiled gradient echo sequence was investigated. The study was performed both theoretically and experimentally using hyperpolarized xenon dissolved in ethanol. Analytical expressions regarding the optimal flip angle with respect to signal and the corresponding signal level

MRI-guided thermal therapy of transplanted tumors in the canine prostate using a directional transurethral ultrasound applicator

PURPOSE: To evaluate MRI-based techniques for visual guidance, thermal monitoring, and assessment during transurethral ultrasound thermal therapy of implanted tumors in an in vivo canine prostate model.MATERIALS AND METHODS: Transmissible venereal tumors (TVT) were grown in the right lobe of the prostate in four dogs. High-temperature thermal therapy was selectively applied to the tumor-bearing lo

MRI image plane nonuniformity in evaluation of ferrous sulphate dosimeter gel (FeGel) by means of T1-relaxation time

MR image nonuniformity can vary significantly with the spin-echo pulse sequence repetition time. When MR images with different nonuniformity shapes are used in a T1-calculation the resulting T1-image becomes nonuniform. As shown in this work the uniformity TR-dependence of the spin-echo pulse sequence is a critical property for T1 measurements in general and for ferrous sulfate dosimeter gel (FeGe

Monte Carlo procedure for protein design

A method for sequence optimization in protein models is presented. The approach, which has inherited its basic philosophy from recent work by Deutsch and Kurosky [Phys. Rev. Lett. 76, 323 (1996)] by maximizing conditional probabilities rather than minimizing energy functions, is based upon a different and very efficient multisequence Monte Carlo scheme. By construction, the method ensures that the

Short-time behavior of advecting-diffusing scalar fields in Stokes flows

This article addresses the short-term decay of advecting-diffusing scalar fields in Stokes flows. The analysis is developed in two main subparts. In the first part, we present an analytic approach for a class of simple flow systems expressed mathematically by the one-dimensional advection-diffusion equation w(y)∂ξ=É∂y2+iV(y)-É′, where ξ is either time or axial coordinate and iV(y) an imaginary pot

The effects of a HTR2B stop codon and testosterone on energy metabolism and beta cell function among antisocial Finnish males

Herein, we examined insulin resistance (IR), insulin sensitivity (IS), beta cell activity, and glucose metabolism in subjects with antisocial personality disorder (ASPD), and whether the serotonin 2B (5-HT2B) receptor and testosterone have a role in energy metabolism. A cohort of subjects belonging to a founder population that included 98 ASPD males, aged 25–30, was divided into groups based on th

Barriers to continuity in the pathway toward occupational engagement among ethnic minorities with mental illness

Ethnic minorities have particular needs and difficulties in terms of support for meaningful occupations, lack of access to and use of occupation-based rehabilitation services. They are not established in the labour market and are seldom in paid employment. This study aimed to investigate how mentally ill ethnic minority clients experience, feel and think about participation in occupation-based reh

Agent of change : street art and environmental thinking

This paper applied an ecocritical perspective on street art to expand on the notion that street art can have an impact on how we relate to urban public space. In doing so, it argued that street art is particularly well positioned to affect the way we think and act with regard to the environment.

Polyhedral Lyapunov functions for structural stability of biochemical systems in concentration and reaction coordinates

Structural properties, independent of specific parameter values, can explain the robustness of biochemical systems. In this paper we consider the framework previously proposed by the authors to assess structural stability of biochemical reaction networks with monotone reaction rates, which considers systems in concentration coordinates, and we show that the results can be applied to systems in rea

Determining the structural properties of a class of biological models

A property for a class of systems is said to be structural if it is met by any system in the class regardless of the adopted parameters. In this paper we investigate the structural nature of oscillatory behaviors, adaptation and monotonicity in a class of sign-invariant systems, capturing a wide variety of biological models. We employ standard robustness analysis tools, suitably tailored to the ca

Selection of antibodies for intracellular function using a two-hybrid in vivo system

Expression of antibodies inside cells has been used successfully to ablate protein function. This finding suggests that the technology should have an impact on disease treatment and in functional genomics where proteins of unknown function are predicted from genomic sequences. A major hindrance is the paucity of antibodies that function in eukaryotic cells, presumably because the antibodies fold i

Drell-Yan phenomenology in the color dipole picture revisited

An extensive phenomenological study of the Drell-Yan (DY) process in pp collisions at various energies is performed in the color dipole framework. Besides previously studied γ∗ production we also include the Z0 contribution relevant at large dilepton invariant masses. We investigate the DY cross section differential in invariant mass, rapidity and transverse momentum of the dilepton pair in pp col