Low FODMAP Diet: Evidence, Doubts, and Hopes.

Food is often considered to be a precipitating factor of irritable bowel syndrome (IBS) symptoms. In recent years, there has been a growing interest in FODMAPs (Fermentable Oligo-, Di-, Mono-saccharides, And Polyols), which can be found in many common foods. A low FODMAP diet (LFD) is increasingly suggested for IBS treatment. However, long-term, large, randomized controlled studies are still lacking, and certainties and doubts regarding LFDs have grown, often in a disorderly and confused manner. Some potential LFD limitations and concerns have been raised, including nutritional adequacy, cost, and difficulty in teaching the diet and maintaining it. Most of these limitations can be solved with the involvement of a skilled nutritionist, who can clearly explain the different phases of the LFD and ensure nutritional adequacy and compliance. Further studies should focus on new methods of teaching and learning the LFD and on predictors of response. Moreover, particular interest should be focused on the possible use of LFD in gastrointestinal diseases other than functional disorders and, possibly, also in non-gastrointestinal diseases. The aim of the present review was to clarify the effective and appropriate indications and limitations of an LFD and to discuss its possible future uses.

Optical measurement of the high temperature ballooning of nuclear fuel claddings.

During the last decades, several experiments revealed interesting details about the ballooning and burst of nuclear cladding tubes in accident conditions involving high temperature and high pressure. A new set of experiments was conducted at MTA EK to further improve our understanding of this phenomenon. The research goal was to determine the pressure of the burst at different temperatures. These data represent a durability and usability limit of fuel cladding tubes under loss of coolant accident conditions. A large tube furnace was fitted with two optical telescopes on opposite sides to observe the ballooning and burst of zirconium alloy fuel cladding samples. These telescopes gave an opportunity to capture the ballooning and also to use a high-speed camera to record details of the crack formation and crack propagation during the burst. A precise pressurization system was constructed to feed high-pressure argon into the samples at a given pressurization rate. The previous data were reproduced accurately in this new apparatus with further insight into the phenomena. The change in tube diameter was observed using regular HD cameras. Based on the captured images, an algorithmic method was developed to separate the contours of the cladding tubes from the background and the diameter increase was measured. It was found to be mostly uniform at lower pressures. The formation of a bulge started at 85% of actual burst pressure. Crack formation at high temperature was recorded using a high-speed camera at speeds up to 100.000 fps. The details of the planning, facility construction, and gauge calibration are detailed in this article.