Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

We present a series of experimental results, and their interpretation, connected to various aspects of the hydrodynamics of laser produced plasmas. Experiments were performed using the Prague PALS iodine laser working at 0.44 μm wavelength and irradiances up to a few 1014 W/cm2. By adopting large focal spots and smoothed laser beams, the lateral energy transport and lateral expansion have been avoided. Therefore we could reach a quasi one-dimensional regime for which experimental results can be more easily and properly compared to available analytical models.

The aim of this study was to estimate the burden of infectious intestinal disease (IID) and cost of illness at the community level from a societal aspect. A retrospective, age-stratified cross-sectional telephone study was carried out in Malta in 2004–2005. The number of cases, resources used and cost of resources were computed. The resources involved direct costs (health-care services, stool culture tests, medicines and personal costs) and indirect costs (costs from lost employment by cases and caregivers). This study estimated 0·421 (95% CI 0·092–0·771) separate episodes of IID per person per year in Malta which corresponds to 164 471 (95% CI 35 941–301 205) episodes of IID per year or 450 (95% CI 98–825) episodes of IID each day. The largest proportion of cost is due to provision of health-care services with €10 454 901 [Maltese liri (Lm) 4 558 970] per year; followed by €963 295 (Lm 2 209 393) in lost productivity; €1 286 286 (Lm 561 078) in medicines; €152 335 (Lm 66 452) in stool culture testing and €71 487 (Lm 31 183) in personal costs, giving a total cost of illness of over €16 million (7 million Lm) per year. The burden and cost of IID are high enough to justify efforts to control the illness. Such estimates are important to assess the cost-effectiveness of proposed specific interventions.

Routine sources of information on infectious intestinal disease (IID) capture a fraction of the actual disease burden. Population studies are required to measure the burden of illness. A retrospective age-stratified cross-sectional telephone study was carried out in Malta in order to estimate the magnitude and distribution of IID at population level. A random sample of 3504 persons was interviewed by a structured questionnaire between April 2004 and December 2005. The response rate was 99·7%. From the study, the observed standardized monthly prevalence was 3·18% (95% CI 0·7–5·74) with 0·421 (95% CI 0·092–0·771) episodes of IID per person per year. The monthly prevalence was higher in the <5 years age group and in females aged 31–44 years. The mean duration of illness was 6·8 days and a median duration of 3 days. A bimodal seasonal distribution was observed with peaks in June–July and October–November.

Routine surveillance systems capture only a fraction of infectious intestinal disease (IID) that is actually occurring in the community. Different methodologies utilized among various international studies in the field were reviewed in order to devise an appropriate survey to obtain current estimates of prevalence of IID in Malta. An age-stratified retrospective cross-sectional telephone study was selected for the study due to its feasibility in terms of limited resources necessary (funds, time and human). The disadvantages of this type of study include the inherent biases such as selection bias (sampling, ascertainment and participation bias) and information bias (recall and observer bias). A pilot study was carried out using a random age-stratified sample of 100 persons over a 3-month period. A total of 5·0% (95% CI ±4·27) of the population was estimated to have suffered from IID during that period. This estimate was used in order to assist in sample size calculations for a large-scale community study. It also served to test the survey instrument and methodology and to identify operational problems.

Shock pressure generated in aluminum targets due to the interaction of 0.44 μm (3 ω of iodine laser) laser radiation has been studied. The laser intensity profile was smoothed using phase zone plates. Aluminum step targets were irradiated at an intensity I ≈ 1014 W/cm2. Shock velocity in the aluminum target was estimated by detecting the shock luminosity from the target rear using a streak camera to infer the shock pressure. Experimental results show a good agreement with the theoretical model based on the delocalized laser absorption approximation. In the present report, we explicitly discuss the importance of target thickness on the shock pressure scaling.