Minimally Invasive Cardiology for Everyone: Challenging the Transradial Access

Transradial access is now well established as the safest route for percutaneous coronary intervention. Nevertheless, its use is often restricted to “easy” cases, switch to the transfemoral route being too rapidly advocated/mandated. We will discuss the different challenges associated with a “TRA for everybody” strategy. (1) The vascular access per se is challenging. TRA failure is most of the time an operator failure to cannulate this vessel. There are some ways to overcome the technical problems and to improve the operator skill and his success rate. (2) TRA is systematically denied for some patient populations: patients with previous coronary artery bypass graft surgery are particularly at risk of not being catheterized by TRA despite excellent performance of this route for diagnostic or intervention. In the same way, MI patients in unstable condition are also at risk to be catheterized by TFA although, most of the time, their condition is addressable through TRA and will largely benefit from this route. (3) Frailty and small body-sized ill patients are also at risk of TFA for PCI when proximal coronary artery disease must be treated. There are alternatives to the use of large and very large catheters for treatment of proximal coronary artery disease. (4) The radial occlusion is a manageable problem, with simple and effective solutions

Bifurcations and Averages in the Homoclinic Chaos of a Laser with a Saturable Absorber

The dynamical bifurcations of a laser with a saturable absorber were calculated, with the 3-2 level model, as function of the gain parameter. The average power of the laser is shown to have specific behavior at bifurcations. The succession of periodic-chaotic windows, known to occur in the homoclinic chaos, was studied numerically. A critical exponent of 1/2 is found on the tangent bifurcations from chaotic into periodic pulsations.Comment: 6 or 7 pages, 3 figures, publishe

Short-term and medium-term survival of critically ill patients with solid tumours admitted to the intensive care unit:A retrospective analysis

OBJECTIVES: Patients with cancer frequently require unplanned admission to the intensive care unit (ICU). Our objectives were to assess hospital and 180-day mortality in patients with a non-haematological malignancy and unplanned ICU admission and to identify which factors present on admission were the best predictors of mortality. DESIGN: Retrospective review of all patients with a diagnosis of solid tumours following unplanned admission to the ICU between 1 August 2008 and 31 July 2012. SETTING: Single centre tertiary care hospital in London (UK). PARTICIPANTS: 300 adult patients with non-haematological solid tumours requiring unplanned admission to the ICU. INTERVENTIONS: None. PRIMARY AND SECONDARY OUTCOMES: Hospital and 180-day survival. RESULTS: 300 patients were admitted to the ICU (median age 66.5 years; 61.7% men). Survival to hospital discharge and 180 days were 69% and 47.8%, respectively. Greater number of failed organ systems on admission was associated with significantly worse hospital survival (p<0.001) but not with 180-day survival (p=0.24). In multivariate analysis, predictors of hospital mortality were the presence of metastases (OR 1.97, 95% CI 1.08 to 3.59), Acute Physiology and Chronic Health Evaluation II (APACHE II) Score (OR 1.07, 95% CI 1.01 to 1.13) and a Glasgow Coma Scale Score <7 on admission to ICU (OR 5.21, 95% CI 1.65 to 16.43). Predictors of worse 180-day survival were the presence of metastases (OR 2.82, 95% CI 1.57 to 5.06), APACHE II Score (OR 1.07, 95% CI 1.01 to 1.13) and sepsis (OR 1.92, 95% CI 1.09 to 3.38). CONCLUSIONS: Short-term and medium-term survival in patients with solid tumours admitted to ICU is better than previously reported, suggesting that the presence of cancer alone should not be a barrier to ICU admission

Coexisting periodic attractors in injection locked diode lasers

We present experimental evidence for coexisting periodic attractors in a semiconductor laser subject to external optical injection. The coexisting attractors appear after the semiconductor laser has undergone a Hopf bifurcation from the locked steady state. We consider the single mode rate equations and derive a third order differential equation for the phase of the laser field. We then analyze the bifurcation diagram of the time periodic states in terms of the frequency detuning and the injection rate and show the existence of multiple periodic attractors.Comment: LaTex, 14 pages, 6 postscript figures include

Probabilistic Approach to Pattern Selection

The problem of pattern selection arises when the evolution equations have many solutions, whereas observed patterns constitute a much more restricted set. An approach is advanced for treating the problem of pattern selection by defining the probability distribution of patterns. Then the most probable pattern naturally corresponds to the largest probability weight. This approach provides the ordering principle for the multiplicity of solutions explaining why some of them are more preferable than other. The approach is applied to solving the problem of turbulent photon filamentation in resonant media.Comment: LaTex, 22 page

Sudden chaotic transitions in an optically injected semiconductor laser

We study sudden changes in the chaotic output of an optically injected semiconductor laser. For what is believed to be the first time in this system, we identify bifurcations that cause abrupt changes between different chaotic outputs, or even sudden jumps between chaotic and periodic output. These sudden chaotic transitions involve attractors that exist for large regions in parameter space. © 2001 Optical Society of Americ

Time resolved pattern evolution in a large aperture laser

We have measured quasi-instantaneous transverse patterns in a broad aperture laser. Non-ordered patterns yielding to boundary determined regular structures in progressive time-integrated recording are observed. The linear analysis and numerical integration of the full Maxwell-Bloch equations allow us to interpret the features of the experiment. We show that this system being far from threshold cannot be fully understood with a perturbative model.Comment: 7 pages, 5 GIF figures . To be published in Phys. Rev. Let