ABSTRACT
We present implementation of the energy-efficient and flexible laser beam shaping technique in a high-power and high-energy laser amplifier system. The beam shaping is based on a spatially variable wave plate (SVWP) fabricated by femtosecond laser nanostructuring of glass. We reshaped the initially Gaussian beam into a super-Gaussian (SG) of the 12th order with efficiency of about 50%. The 12th order of the SG beam provided the best compromise between large fill factor, low diffraction on the edges of the active media, and moderate intensity distribution modification during free-space propagation. We obtained 150 mJ pulses of 532 nm radiation. High-energy, pulse duration of 85 ps and the nearly flat-top spatial profile of the beam make it ideal for pumping optical parametric chirped pulse amplification systems.
ABSTRACT
AIMS/HYPOTHESIS: Diabetes mellitus is associated with several changes in coagulation and fibrinolysis that may lead to a thrombogenic propensity. However, it is not known whether these perturbations actually cause increased risk of venous thromboembolism. METHODS: In a retrospective population-based study we evaluated the medical records of all 302 adult patients who were admitted to the Umea University Hospital with verified deep vein thrombosis or pulmonary embolism during the years 1997 to 1999. The patients were classified as diabetic (n=56) and non-diabetic (n=246) according to clinical information. The total number of diagnosed diabetic patients in different age groups in the catchment area was obtained from computerised registries in the primary health care centres and the Umea University Hospital, and data on the background population were collected from the Swedish population registry. RESULTS: The annual incidence rate of venous thromboembolism among diabetic patients in the population was 432 per 100,000 individuals (95% CI 375-496). In non-diabetic individuals it was 78 (95% CI 68-88). The age-adjusted incidence rate among the diabetic population was 274 (95% CI 262-286). The annual incidence rate of venous thromboembolism was elevated in type 1 and type 2 diabetic patients and the incidence rates were 704 (95% CI 314-1,566) and 412 (95% CI 312-544) respectively. The overall standardised morbidity ratio was 2.27 (95% CI 1.75-2.95), i.e. diabetic patients were more prone to venous thromboembolism after adjustment for age differences. CONCLUSIONS/INTERPRETATION: These results suggest that the age-adjusted risk for venous thromboembolism is more than two-fold higher among diabetic patients than in the non-diabetic background population.