Thermal management in microfluidics using micro-Peltier junctions

We report refrigeration and heating of nanoliter fluid volumes with micro-Peltier junctions. The temperature of small liquid reservoirs can be rapidly changed and controlled within a range between -3 degrees C to over 120 degrees C with good long-term stability. These thermal management systems enable the fabrication of complex chip-based chemical and biochemical reaction systems in which the temperature of many processes can be controlled independently

Optimization of three-dimensional micropost microcavities for cavity quantum electrodynamics

This article presents a detailed analysis, based on the first-principles finite-difference time-domain method, of the resonant frequency, quality factor (Q), mode volume (V), and radiation pattern of the fundamental (HE11) mode in a three-dimensional distributed-Bragg-reflector (DBR) micropost microcavity. By treating this structure as a one-dimensional cylindrical photonic crystal containing a single defect, we are able to push the limits of Q/V beyond those achievable by standard micropost designs, based on the simple rules established for planar DBR microcavities. We show that some of the rules that work well for designing large-diameter microposts (e.g., high-refractive index contrast) fail to provide high-quality cavities with small diameters. By tuning the thicknesses of mirror layers and the spacer, the number of mirror pairs, the refractive indices of high and low refractive index regions, and the cavity diameter, we are able to achieve Q as high as 10^4, together with a mode volume of 1.6 cubic wavelengths of light in the high-refractive-index material. The combination of high Q and small V makes these structures promising candidates for the observation of such cavity quantum electrodynamics phenomena as strong coupling between a quantum dot and the cavity field, and single-quantum-dot lasing.Comment: 11 pages, 8 figure

Healer, Witness, or Double Agent? Reexamining the Ethics of Forensic Psychiatry

In recent years, psychiatrists have become ever more prevalent in American courtrooms. Consequently, the issue of when the usual rules of medical ethics should apply to forensic psychiatric encounters has taken on increased importance and is a continuing topic of discussion among both legal and medical scholars. A number of approaches to the problem of forensic psychiatric ethics have been proposed, but none adequately addresses the issues that arise when a forensic encounter develops therapeutic characteristics. This article looks to the rules governing the lawyer-client relationship as a model for a new approach to forensic psychiatric ethics. This new model focuses on the expectations of the evaluee and the ways in which the evaluating psychiatrist shapes those expectations to determine how and when the rules of medical ethics should apply to forensic psychiatric encounters. This article describes and analyzes three previously proposed approaches to that question and the closely related question of when and how a doctor-patient relationship can form in the context of a forensic psychiatric evaluation. It also explains why each of these prior approaches does not sufficiently address the issues that arise when a forensic encounter takes on therapeutic characteristics. Finally, it proposes a new approach that draws inspiration from the rules governing the lawyer-client relationship

Healer, Witness, or Double Agent? Reexamining the Ethics of Forensic Psychiatry

In recent years, psychiatrists have become ever more prevalent in American courtrooms. Consequently, the issue of when the usual rules of medical ethics should apply to forensic psychiatric encounters has taken on increased importance and is a continuing topic of discussion among both legal and medical scholars. A number of approaches to the problem of forensic psychiatric ethics have been proposed, but none adequately addresses the issues that arise when a forensic encounter develops therapeutic characteristics. This article looks to the rules governing the lawyer-client relationship as a model for a new approach to forensic psychiatric ethics. This new model focuses on the expectations of the evaluee and the ways in which the evaluating psychiatrist shapes those expectations to determine how and when the rules of medical ethics should apply to forensic psychiatric encounters. This article describes and analyzes three previously proposed approaches to that question and the closely related question of when and how a doctor-patient relationship can form in the context of a forensic psychiatric evaluation. It also explains why each of these prior approaches does not sufficiently address the issues that arise when a forensic encounter takes on therapeutic characteristics. Finally, it proposes a new approach that draws inspiration from the rules governing the lawyer-client relationship

Ultrafast resonant optical scattering from single gold nanorods: Large nonlinearities and plasmon saturation

We measure nonlinear optical scattering from individual Au nanorods excited by ultrafast laser pulses on resonance with their longitudinal plasmon mode. Isolating single rods removes inhomogeneous broadening and allows the measurement of a large nonlinearity, much greater than that of nanorod ensembles. Surprisingly, the ultrafast nonlinearity can be attributed entirely to heating of conduction electrons and does not exhibit any response associated with coherent plasmon oscillation. This indicates a previously unobserved damping of strongly driven plasmons.Comment: Revised tex