Efficacy of the natural antioxidant astaxanthin in the treatment of functional dyspepsia in patients with or without Helicobacter pylori infection: a prospective, randomized, double blind, and placebo-controlled study5

Objectives: The aim of this study was to evaluate the efficacy of the natural antioxidant astaxanthin in functional dyspepsia in different doses and compared with placebo. Design: The study was a controlled, prospective, randomized, and double blind trial. Participants: Patients with functional dyspepsia, divided into three groups with 44 individuals in each group (placebo, 16 mg, or 40 mg astaxanthin, respectively). Interventions: Participants were asked to accept gastroscopy before treatment, together with questionnaires: GSRS and SF-36. Urea breath test (UBT) was done before the treatment. Main outcome: The primary objective was to test the hypothesis that the antioxidant astaxanthin at two doses regimens compared to placebo should ameliorate gastrointestinal discomfort measured as GSRS in patients with functional dyspepsia, who were either positive or negative for Helicobacter pylori, after 4 weeks of treatment. Results: At the end of therapy (week 4) no difference between the three treatment groups was observed regarding mean Gastrointestinal Symptom Rating Scale (GSRS) scores of abdominal pain, indigestion and reflux syndromes. The same results were observed at the end of follow-up. However reduction of reflux syndrome before treatment to week 4 was significantly pronounced in the higher (40 mg) dose compared to the other treatment groups (16 mg and placebo, p = 0.04). Conclusion: In general, no curative effect of astaxanthin was found in functional dyspepsia patients. Significantly greater reduction of reflux symptoms were detected in patients treated with the highest dose of the natural antioxidant astaxanthin. The response was more pronounced in H. pylori-infected patients. (c) 2008 Elsevier GmbH. All rights reserved

SYLOS lasers – the frontier of few-cycle, multi-TW, kHz lasers for ultrafast applications at extreme light infrastructure attosecond light pulse source

The extreme light infrastructure attosecond light pulse source offers beamtime for users of various attosecond and particle sources driven by versatile laser systems. Here we report on the state of the art of a few-cycle, multi-TW, 1kHz repetition rate laser system, now fully operational in the facility. The system is based on four stages of optical parametric amplifiers (OPAs) pumped by a total of 320mJ, 80ps frequency-doubled Nd:YAG laser pulses. All OPA stages utilize double crystal configuration, which design has been also confirmed by model calculations. The 1kHz SYLOS 2 system produces 32mJ laser pulses around a central wavelength of 891nm with 6.6fs (<2.3 optical cycles) pulse duration exceeding the peak power of 4.8 TW on a daily basis. The recorded best pulse duration is 6.3fs, which corresponds to 2.12 cycles and 5.1 TW peak power. During long-term (24h) performance tests, energy stability of 1.2%, carrier-envelope phase (CEP) stability of 210mrad, and pointing stability of 0.4 mu rad were demonstrated, while the Strehl ratio of the beam is kept above 0.75. In order to help the alignment of all the different experiments at the facility and to reduce the workload on SYLOS 2 system, a second laser system has been developed. The so-called SYLOS Experimental Alignment (SEA) laser mimicks the performance of the SYLOS 2 laser, but at a repetition rate two orders of magnitude lower and without CEP-stabilization. The three single-crystal OPA stages of the SEA laser provide 42mJ pulse energy for the users, while having energy stability of 0.87% and sub-13fs pulse duration at a repetition rate ranging from a single shot up to 10Hz