Conical refraction healing after partially blocking the input beam

In conical refraction, when a focused Gaussian beam passes along one of the optic axes of a biaxial crystal it is transformed into a pair of concentric bright rings at the focal plane. We demonstrate both theoretically and experimentally that this transformation is hardly affected by partially blocking the Gaussian input beam with an obstacle. We analyze the influence of the size of the obstruction both on the transverse intensity pattern of the beam and on its state of polarization, which is shown to be very robust

Conical refraction healing after partially blocking the input beam

In conical refraction, when a focused Gaussian beam passes along one of the optic axes of a biaxial crystal, it is transformed into a pair of concentric bright rings at the focal plane. We demonstrate both theoretically and experimentally that this transformation is hardly affected by partially blocking the Gaussian input beam with an obstacle. We analyze the influence of the size of the obstruction both on the transverse intensity pattern of the beam and on its state of polarization, which is shown to be very robust

Comparison of acute myocardial infarction evolution in men and women Infarto agudo del miocardio en Chile: Diferencias entre hombres y mujeres en su evolución y pronóstico

Background: Gender may be a prognostic factor for the evolution of acute myocardial infarction and women may have higher mortality and complication rates. Aim: To study if there are differences in the evolution of acute myocardial infarction between men and women. Patients and methods: We have recorded information on risk factors, clinical evolution, treatment and complications of 2052 patients hospitalized for acute myocardial infarction in 36 Chilean hospitals. The odds ratio for female sex and mortality was calculated using a logistic regression analysis adjusted for risk factors, treatment, invasive procedures and complications. Results: Twenty six percent of analyzed patients were female. Mortality rates among females and males were 11.8 and 20.2% respectively (p< 0.01). Women had higher frequency of smoking, diabetes, obesity and hypertension. Blood lipid levels were similar in both sexes. Compared to men, a lesser proportion of women were treated with thrombolytic agents (25 an

Usefulness of thrombolytic therapy with low doses of streptokinase in acute myocardial infarction Utilidad de la terapia trombolítica con estreptokinasa a dosis baja en infarto agudo del miocardio

Background: The optimal dose of Streptokinase in the treatment of acute myocardial infarction is not well established. Apparently, the thrombolytic efficacy would not increase with doses over 750.000 units. Aim: To compare the effectiveness and safety of treatment with low doses of Streptokinase, ranging from 500.000 to 750.000 units, in patients with ST elevation acute myocardial infarction. Patients and methods: From September 1993 to September 1998, the GEMI register of patients with acute myocardial infarction, was carried out in 37 hospitals, incorporating 4,938 patients. Of these, 1,631 patients received Streptokinase. According to the administered dose of Streptokinase, patients were divided in two groups: 1,465 patients who received 1.5 millions U in 60 minutes (classical therapy group), and 166 patients with ischemic chest discomfort and either ST-segment elevation or left bundle-branch block on the electrocardiogram, who received 500.000 to 750.000 U streptokinase administer