Cherenkov radiation in the soft X-ray region : towards a compact narrowband source

IX+125hlm.;24c

Observation of soft X-ray Cherenkov radiation in Al

The soft X-ray radiation generated by 5.7 MeV electrons from both an Al foil and a Mylar film in forward direction was experimentally studied. A narrow specific directivity, an ultra-narrow spectral bandwidth and a good consistency between the experiment and theory prove that the Cherenkov radiation (CR) with photon energy near the L-edge of absorption in Al was observed. The results demonstrate that the CR spectral-angular properties and the absolute photon yield can be described well enough using Pafomov's theoretical model and Henke's refractive index database, which is essential for all practical applications

High-brightness, narrowband, compact soft x-ray Cherenkov sources in the water window

Narrowband, soft x-ray Cherenkov radiation at energies of 453 and 512 eV has been generated by 10 MeV electrons in, respectively, titanium and vanadium foils. The measured spectral and angular distribution of the radiation, and the measured total yield (10–4 photon per electron) are in agreement with theoretical predictions based on refractive index data. We show that the brightness that can be achieved using a small electron accelerator is sufficient for practical x-ray microscopy in the water-window spectral region

A tabletop soft X-ray source based on 5-10 MeV LINACs

We are investigating the feasibility of a novel, tabletop, high-brightness soft X-ray source

Assessment of allelic diversity in intron-containing Mal d 1 genes and their association to apple allergenicity

<p>Abstract</p> <p>Background</p> <p>Mal d 1 is a major apple allergen causing food allergic symptoms of the oral allergy syndrome (OAS) in birch-pollen sensitised patients. The <it>Mal d 1 </it>gene family is known to have at least 7 intron-containing and 11 intronless members that have been mapped in clusters on three linkage groups. In this study, the allelic diversity of the seven intron-containing <it>Mal d 1 </it>genes was assessed among a set of apple cultivars by sequencing or indirectly through pedigree genotyping. Protein variant constitutions were subsequently compared with <b>S</b>kin <b>P</b>rick <b>T</b>est (SPT) responses to study the association of deduced protein variants with allergenicity in a set of 14 cultivars.</p> <p>Results</p> <p>From the seven intron-containing <it>Mal d 1 </it>genes investigated, <it>Mal d 1.01 </it>and <it>Mal d 1.02 </it>were highly conserved, as nine out of ten cultivars coded for the same protein variant, while only one cultivar coded for a second variant. <it>Mal d 1.04</it>, <it>Mal d 1.05 </it>and <it>Mal d 1.06 A, B </it>and <it>C </it>were more variable, coding for three to six different protein variants. Comparison of <it>Mal d 1 </it>allelic composition between the high-allergenic cultivar Golden Delicious and the low-allergenic cultivars Santana and Priscilla, which are linked in pedigree, showed an association between the protein variants coded by the <it>Mal d 1.04 </it>and <it>-1.06A </it>genes (both located on linkage group 16) with allergenicity. This association was confirmed in 10 other cultivars. In addition, <it>Mal d 1.06A </it>allele dosage effects associated with the degree of allergenicity based on prick to prick testing. Conversely, no associations were observed for the protein variants coded by the <it>Mal d 1.01 </it>(on linkage group 13), -<it>1.02</it>, -<it>1.06B, -1.06C </it>genes (all on linkage group 16), nor by the <it>Mal d 1.05 </it>gene (on linkage group 6).</p> <p>Conclusion</p> <p>Protein variant compositions of Mal d 1.04 and -1.06A and, in case of <it>Mal d 1.06A</it>, allele doses are associated with the differences in allergenicity among fourteen apple cultivars. This information indicates the involvement of qualitative as well as quantitative factors in allergenicity and warrants further research in the relative importance of quantitative and qualitative aspects of <it>Mal d 1 </it>gene expression on allergenicity. Results from this study have implications for medical diagnostics, immunotherapy, clinical research and breeding schemes for new hypo-allergenic cultivars.</p

Systemic glucocorticoid use and the occurrence of flares in psoriatic arthritis and psoriasis: a systematic review

OBJECTIVES: The use of systemic glucocorticoids (SGCs) is traditionally discouraged in the treatment of PsA and psoriasis due to the risk of psoriatic flares. However, despite this recommendation, SGCs are frequently prescribed for these patients. In this study we reappraise the old paradigm that SGCs are contra-indicated in the treatment of PsA and psoriasis. METHODS: A systematic search of MEDLINE, EMBASE and the Cochrane Library databases was performed in November 2019 to identify articles on any SGC use compared with no use in the PsA and psoriasis population. Topical glucocorticoid treatment was excluded. Our two primary outcomes focused on the prescribing characteristics and the occurrence of any type of flare. RESULTS: Our search yielded 4922 articles, and of these 21 full-text articles were eligible for inclusion. There were 11 retro- and prospective cohorts involving a total of 4,171,307 patients. Of these, 6727 (37.82%) of the patients with PsA and 1 460 793 (35.17%) of the patients with psoriasis were treated with any type of SGC. Ten observational/interventional studies did not report an increased risk or occurrence of psoriatic flares related to SGC use. CONCLUSION: Our results indicate that SGCs are frequently prescribed for PsA and psoriasis patients. The occurrence of psoriatic flares appears to be low upon SGC exposure. In patients with a clear indication for SGCs, e.g. in need of rapid anti-inflammatory therapy or bridging of therapies, the use of SGCs should be considered in view of the low risk of skin flaring. It remains of importance to weigh risks for short- and long-term SGC-related side effects in clinical decision making

Home media and science performance:A cross-national study

This study examines the effects of media resources in the parental home on the science performance of 15-year-old students. It employs data from the 2006 Programme for International Student Assessment (PISA) containing information on 345,967 respondents from 53 countries. Results show that media assets in the family home are indeed meaningful for children’s science performance, as a beneficial resource but also as a disadvantage. A positive reading climate in the parental home and the availability of computers benefits science performance. However, a television-rich home seems to hinder children’s school success. Furthermore, results indicate that, compared to less developed countries, in more modernized societies parental reading investments are even more beneficial to their children’s science performance, whereas a television-rich parental home is even more disadvantageous

Precautionary allergen labeling: Current communication problems and potential for future improvements

While there are EU laws for priority allergenic ingredients information on food product packaging, there is no legislation about Precautionary Allergen Labelling (PAL) for unintended allergen presence (UAP). As a result, PAL is used in different ways by different manufacturers and retailers, which hampers consumers’ interpretation of the information in the PAL. Previous research has focused on the forms of PAL that are used and on the way they are interpreted and used by consumers. This study adds the perspective of producers, retailers and branch organizations. Thirteen interviews with QA- and QC-professionals were conducted to find out more about the reasoning behind their PAL-use and to find out how PAL could be optimized. Results show that harmonization is needed, on different levels: in the way information on UAP is shared between parties involved in the food chain; in the way PAL is presented and phrased; and in the rules and regulations on PAL. More research is needed on possible ways to share (updates on) information on UAP with consumers