| 1. |
- Athanasakis-Kaklamanakisa, Michail, et al.
(författare)
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Voltage scanning and technical upgrades at the Collinear Resonance Ionization Spectroscopy experiment
- 2023
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Ingår i: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS. - 0168-583X .- 1872-9584. ; 541, s. 86-89
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Tidskriftsartikel (refereegranskat)abstract
- To optimize the performance of the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at CERN-ISOLDE, technical upgrades are continuously introduced, aiming to enhance its sensitivity, precision, stability, and efficiency. Recently, a voltage-scanning setup was developed and commissioned at CRIS, which improved the scanning speed by a factor of three as compared to the current laser-frequency scanning approach. This leads to faster measurements of the hyperfine structure for systems with high yields (more than a few thousand ions per second). Additionally, several beamline sections have been redesigned and manufactured, including a new field-ionization unit, an electrostatic bend with a larger deflection angle, and improved ion optics. The beamline upgrades are expected to yield an improvement of at least a factor of 5 in the signal-to-noise ratio by avoiding the use of high-power lasers (which yield non-resonantly produced ions) and providing time-of-flight separation between the resonant ions and the collisional background.
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| 2. |
- Hunt, Karen, et al.
(författare)
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Classical enterotoxins of coagulase-positive Staphylococcus aureus isolates from raw milk and products for raw milk cheese production in Ireland
- 2012
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Ingår i: Dairy Science & Technology. - : Springer Science and Business Media LLC. - 1958-5586 .- 1958-5594. ; 92:5, s. 487-499
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Tidskriftsartikel (refereegranskat)abstract
- Toxin-producing Staphylococcus aureus can be present in raw milk and therefore in cheese made from raw milk. To determine the number and type of toxin producers in raw milk used for raw milk cheese production in Ireland, 117 samples of raw milk and related products from five raw milk suppliers, to four raw milk cheesemakers in the South of Ireland, were analysed for coagulase positive S. aureus. Enumeration, using ISO 688-2 and plating on Baird Parker Rabbit Plasma Fibrinogen selective agar showed samples were within limits set by EC regulations. Isolates (151 from 81 positive samples) were characterised for production of staphylococcal enterotoxins (SEs) SEA, SEB, SEC and SED by reverse passive latex agglutination (SET-RPLA) and by multiplex polymerase chain reaction for the sea, seb, sec, sed and see genes. The results showed 83.2% of the isolates did not contain the se genes or the toxin producing capability tested for. From only one supplier, 26 isolates contained the sec gene and produced SEC. Within these 26 isolates, there were only two PFGE types. One SEC-producing isolate showed no toxin production when grown in sterile 10% reconstituted skim milk at 10 degrees C and 12 degrees C for 96 and 74 h, respectively. Low concentrations of SEC were produced at 14 degrees C and 16 degrees C after 74 and 55 h, respectively. The results of this survey indicate that milk used for raw milk cheese production in Ireland poses a limited risk to public health, although further studies on occurrence of toxin producing S. aureus should be undertaken.
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