Lifetime cost effectiveness of simvastatin in a range of risk groups and age groups derived from a randomised trial of 20,536 people

<i>Objectives</i>: To evaluate the cost effectiveness of 40 mg simvastatin daily continued for life in people of different ages with differing risks of vascular disease. Design A model developed from a randomised trial was used to estimate lifetime risks of vascular events and costs of treatment and hospital admissions in the United Kingdom. <i>Setting</i>: 69 hospitals in the UK. <i>Participants</i>: 20 536 men and women (aged 40-80) with coronary disease, other occlusive arterial disease, or diabetes. <i>Interventions</i>: 40 mg simvastatin daily versus placebo for an average of 5 years. <i>Main</i> <i>outcome</i> <i>measures</i>: Cost effectiveness of 40 mg simvastatin daily expressed as additional cost per life year gained. Major vascular event defined as non-fatal myocardial infarction or death from coronary disease, any stroke, or revascularisation procedure. Results were extrapolated to younger and older age groups at lower risk of vascular disease than were studied directly, as well as to lifetime treatment. <i>Results</i>: At the April 2005 UK price of £4.87 (€7; $9) per 28 day pack of generic 40 mg simvastatin, lifetime treatment was cost saving in most age groups and vascular disease risk groups studied directly. Gains in life expectancy and cost savings decreased with increasing age and with decreasing risk of vascular disease. People aged 40-49 with 5 year risks of major vascular events of 42% and 12% at start of treatment gained 2.49 and 1.67 life years, respectively. Treatment with statins remained cost saving or cost less than £2500 per life year gained in people as young as 35 years or as old as 85 with 5 year risks of a major vascular event as low as 5% at the start of treatment. <i>Conclusions</i>: Treatment with statins is cost effective in a wider population than is routinely treated at present

Classical magnetotransport of inhomogeneous conductors

We present a model of magnetotransport of inhomogeneous conductors based on an array of coupled four-terminal elements. We show that this model generically yields non-saturating magnetoresistance at large fields. We also discuss how this approach simplifies finite-element analysis of bulk inhomogeneous semiconductors in complex geometries. We argue that this is an explanation of the observed non-saturating magnetoresistance in silver chalcogenides and potentially in other disordered conductors. Our method may be used to design the magnetoresistive response of a microfabricated array.Comment: 12 pages, 13 figures. Minor typos correcte

Pairing in spin polarized two-species fermionic mixtures with mass asymmetry

We discuss on the pairing mechanism of fermions with mismatch in their fermi momenta due to a mass asymmetry. Using a variational ansatz for the ground state we also discuss the BCS -BEC crossover of this system. It is shown that the breached pairing solution with a single fermi surface is stable in the BEC regime. We also include the temperatures effect on the fermion pairing within an approximation that is valid for temperatures much below the critical temperature.Comment: 8 pages and 6 figures, few typos corrected, version to appear in EPJ

Asymmetric Fermi superfluid with different atomic species in a harmonic trap

We study the dilute fermion gas with pairing between two species and unequal concentrations in a harmonic trap using the mean field theory and the local density approximation. We found that the system can exhibit a superfluid shell structure sandwiched by the normal fermions. This superfluid shell structure occurs if the mass ratio is larger then certain critical value which increases from the weak-coupling BCS region to the strong-coupling BEC side. In the strong coupling BEC regime, the radii of superfluid phase are less sensitive to the mass ratios and are similar to the case of pairing with equal masses. However, the lighter leftover fermions are easier to mix with the superfluid core than the heavier ones. A partially polarized superfluid can be found if the majority fermions are lighter, whereas phase separation is still found if they are heavier.Comment: 12 pages, 7 figure

4H–SiC photoconductive switching devices for use in high-power applications

Siliconcarbide is a wide-band-gapsemiconductor suitable for high-power high-voltage devices and it has excellent properties for use in photoconductive semiconductor switches (PCSSs). PCSS were fabricated as planar structures on high-resistivity 4H–SiC and tested at dc bias voltages up to 1000 V. The typical maximum photocurrent of the device at 1000 V was about 49.4 A. The average on-state resistance and the ratio of on-state to off-state currents were about 20 Ω and 3×1011, respectively. Photoconductivity pulse widths for all applied voltages were 8–10 ns. These excellent results are due in part to the removal of the surface damage by high-temperature H2 etching and surface preparation. Atomic force microscopy images revealed that very good surface morphology, atomic layer flatness, and large step width were achieved

p-wave phase shift and scattering length of 6^6Li

We have calculated the p-wave phase shifts and scattering length of $^6$Li. For this we solve the $p$ partial wave Schr\"odinger equation and analyze the validity of adopting the semiclassical solution to evaluate the constant factors in the solution. Unlike in the $s$ wave case, the semiclassical solution does not provide unique value of the constants. We suggest an approximate analytic solution, which provides reliable results in special cases. Further more, we also use the variable phase method to evaluate the phase shifts. The p-wave scattering lengths of $^{132}$Cs and $^{134}$Cs are calculated to validate the schemes followed. Based on our calculations, the value of the $p$ wave scattering length of $^6$Li is $-45a_o$.Comment: 10 figure

Ultra-cold Polarized Fermi Gases

Recent experiments with ultra-cold atoms have demonstrated the possibility of realizing experimentally fermionic superfluids with imbalanced spin populations. We discuss how these developments have shed a new light on a half- century old open problem in condensed matter physics, and raised new interrogations of their own.Comment: 27 pages; 8 figures; Published in Report in Rep. Prog. Phys. 73 112401 (2010

Quantum Non-Demolition Detection of Strongly Correlated Systems

Preparation, manipulation, and detection of strongly correlated states of quantum many body systems are among the most important goals and challenges of modern physics. Ultracold atoms offer an unprecedented playground for realization of these goals. Here we show how strongly correlated states of ultracold atoms can be detected in a quantum non-demolition scheme, that is, in the fundamentally least destructive way permitted by quantum mechanics. In our method, spatially resolved components of atomic spins couple to quantum polarization degrees of freedom of light. In this way quantum correlations of matter are faithfully mapped on those of light; the latter can then be efficiently measured using homodyne detection. We illustrate the power of such spatially resolved quantum noise limited polarization measurement by applying it to detect various standard and "exotic" types of antiferromagnetic order in lattice systems and by indicating the feasibility of detection of superfluid order in Fermi liquids.Comment: Published versio

Effect of vessel wettability on the foamability of "ideal" surfactants and "real-world" beer heads

The ability to tailor the foaming properties of a solution by controlling its chemical composition is highly desirable and has been the subject of extensive research driven by a range of applications. However, the control of foams by varying the wettability of the foaming vessel has been less widely reported. This work investigates the effect of the wettability of the side walls of vessels used for the in situ generation of foam by shaking aqueous solutions of three different types of model surfactant systems (non-ionic, anionic and cationic surfactants) along with four different beers (Guinness Original, Banks’s Bitter, Bass No 1 and Harvest Pale). We found that hydrophilic vials increased the foamability only for the three model systems but increased foam stability for all foams except the model cationic system. We then compared stability of beer foams produced by shaking and pouring and demonstrated weak qualitative agreement between both foam methods. We also showed how wettability of the glass controls bubble nucleation for beers and champagne and used this effect to control exactly where bubbles form using simple wettability patterns