Salvage lymph node dissection for prostate cancer nodal recurrence detected by 11C-choline positron emission tomography/computerized tomography.

Purpose: We report salvage lymph node dissections for prostate cancer nodal recurrence detected by (11)C-choline positron emission tomography/computerized tomography in the setting of increasing prostate specific antigen after radical prostatectomy.

Materials And Methods: Retrospective chart review was performed for all patients who underwent salvage lymph node dissection for prostate cancer nodal recurrence. Only patients previously treated with radical prostatectomy were included in the study and those with evidence of local recurrence were excluded from analysis.

Magnetic field generation in Rayleigh-Taylor unstable inertial confinement fusion plasmas.

Rayleigh-Taylor instabilities (RTI) in inertial confinement fusion implosions are expected to generate magnetic fields. A Hall-MHD model is used to study the field generation by 2D single-mode and multimode RTI in a stratified two-fluid plasma. Self-generated magnetic fields are predicted and these fields grow as the RTI progresses via the ∇n(e)×∇T(e) term in the generalized Ohm's law.

Use of the Richtmyer-Meshkov instability to infer yield stress at high-energy densities.

We use the Richtmyer-Meshkov instability (RMI) at a metal-gas interface to infer the metal's yield stress (Y) under shock loading and release. We first model how Y stabilizes the RMI using hydrodynamics simulations with a perfectly plastic constitutive relation for copper (Cu). The model is then tested with molecular dynamics (MD) of crystalline Cu by comparing the inferred Y from RMI simulations with direct stress-strain calculations, both with MD at the same conditions.

Use of tumor dynamics to clarify the observed variability among biochemical recurrence nomograms for prostate cancer.

Background: Nomograms for biochemical recurrence (BCR) of prostate cancer (PC) after radical prostatectomy can yield very different prognoses for individual patients. Since the nomograms are optimized on different cohorts, the variations may be due to differences in patient risk-factor distributions. In addition, the nomograms assign different relative scores to the same PC risk factors and rarely stratify for tumor growth rate.

A cell kinetics model for prostate cancer and its application to clinical data and individual patients.

A cell kinetics model is developed to describe the evolution of prostate cancer (PC) from diagnosis to PC specific death. Such a model can be used to estimate an individual's eventual outcome and thus to inform decisions about therapy. To describe the observed clinical progression, the model must postulate three PC cell populations that are (1) local to the prostate and sensitive to hormones, (2) regional and hormone sensitive, and (3) systemic and hormone resistant.

Correlation effects on the temperature-relaxation rates in dense plasmas.

We present a model for the rate of temperature relaxation between electrons and ions in plasmas. The model includes self-consistently the effects of particle screening, electron degeneracy, and correlations between electrons and ions. We successfully validate the model over a wide range of plasma coupling against molecular-dynamics simulations of classical plasmas of like-charged electrons and ions.

Molecular-dynamics simulations of electron-ion temperature relaxation in a classical Coulomb plasma.

Molecular-dynamics simulations are used to investigate temperature relaxation between electrons and ions in a fully ionized, classical Coulomb plasma with minimal assumptions. Recombination is avoided by using like charges. The relaxation rate agrees with theory in the weak coupling limit (g identical with potential/kinetic energy << 1), whereas it saturates at g > 1 due to correlation effects.

Rayleigh-Taylor instability with complex acceleration history.

Experiments and numerical simulations are performed on the Rayleigh-Taylor instability with a complex acceleration history g(t) consisting of consecutive periods of acceleration, deceleration, and acceleration. The dominant bubbles and spikes that grow in the initial unstable phase are found to be shredded by the trailing structures during the stable deceleration phase. This reduces their diameter at the front and increases the atomic mixing such that the growth during the final unstable acceleration is retarded.

Limits of the potential flow approach to the single-mode Rayleigh-Taylor problem.

We report on the behavior of a single-wavelength Rayleigh-Taylor flow at late times. The calculations were performed in a long square duct (lambda x lambda x 8lambda), using four different numerical simulations. In contradiction with potential flow theories that predict a constant terminal velocity, the single-wavelength Rayleigh-Taylor problem exhibits late-time acceleration.

Single-mode dynamics of the Rayleigh-Taylor instability at any density ratio.

The behavior of a periodic array of Rayleigh-Taylor bubbles (and spikes) of wavelength lambda is investigated at different density ratios using three-dimensional numerical simulations. The scaled bubble and spike velocities (v(b,s)/sqrt[Aglambda/2]), are found to vary with the Atwood number A, and are compared with recent potential flow theories. Simulations at different grid resolutions reveal that the convergence rates of bubble velocities improve with increasing A, while the converse holds true for spike velocities.

Dependence of turbulent Rayleigh-Taylor instability on initial perturbations.

The dependency of the self-similar Rayleigh-Taylor bubble acceleration constant alpha(b)(identical with [(amplitude)/2] x (displacement) x (Atwood number)) on the initial perturbation amplitude h(0k) is described with a model in which the exponential growth of a small amplitude packet of modes makes a continuous nonlinear transition to its "terminal" bubble velocity proportional, variant Fr[equal to(Froude number)(1/2)]. Then, by applying self-similarity (diameter proportional, variant amplitude), alpha(b) is found to increase proportional to Fr and logarithmically with h(0k). The model has two free parameters that are determined from experiments and simulations.

Nanohydrodynamics simulations: an atomistic view of the Rayleigh-Taylor instability.

Nanohydrodynamics simulations, hydrodynamics on the nanometer and nanosecond scale by molecular dynamics simulations for up to 100 million particles, are performed on the latest generation of supercomputers. Such simulations exhibit Rayleigh-Taylor instability, the mixing of a heavy fluid on top of a light in the presence of a gravitational field, initiated by thermal fluctuations at the interface, leading to the chaotic regime in the long-time evolution of the mixing process. The early-time behavior is in general agreement with linear analysis of continuum theory (Navier-Stokes), and the late-time behavior agrees quantitatively with experimental observations.