| 1. |
- Rofors, E., et al.
(författare)
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Response of a Li-glass/multi-anode photomultiplier detector to focused proton and deuteron beams
- 2020
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 984
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Tidskriftsartikel (refereegranskat)abstract
- The response of a position-sensitive Li-glass based scintillation detector being developed for thermal-neutron detection with 6 mm position resolution has been investigated using focused beams of 2.5MeV protons and deuterons. The beams were scanned across the detector in 0.5 mm horizontal and vertical steps perpendicular to the beams. Scintillation light was registered using an 8 × 8 pixel multi-anode photomultiplier tube. The signal amplitudes were recorded for each pixel on an event-by-event basis. Several pixels generally registered considerable signals at each beam location. To optimize planned detector operation at the European Spallation Source, the number of pixels above set thresholds was investigated, with the maximization of the single-hit efficiency over the largest possible area as the primary goal. For both beams, at a threshold of ∼50% of the mean of the full-deposition peak, ∼80% of the events were registered in a single pixel, resulting in an effective position resolution of ∼5 mm in X and Y. Lower thresholds resulted in higher pixel multiplicities. These events could also be localized with the same effective position resolution.
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| 2. |
- Frost, R. J. W., et al.
(författare)
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A compact accelerator driven neutron source at the Applied Nuclear Physics Laboratory, Lund University
- 2023
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Ingår i: EPJ TECHNIQUES AND INSTRUMENTATION. - : Springer Nature. - 2195-7045. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The Applied Nuclear Physics Group at Lund University has constructed a CANS (Compact Accelerator-driven Neutron Source). The CANS is based around a 3 MV, single-ended, Pelletron accelerator, which is used to impinge a 2.8 MeV deuterium beam into a beryllium target. The anticipated neutron production will be on the order of 10(10) n/s in 4 pi sr, with future upgrades expected to increase neutron production to 10(11) n/s. Neutron energy will be up to 9 MeV with peak emission at similar to 5 MeV. Shielding and moderation will be provided by a large water tank surrounding the target, with exit ports to allow moderated neutrons to be directed to experiments. The thermal-neutron flux at the exit of the extraction ports is anticipated to be up to 10(6) n/cm(2)/s. The CANS will be used to forward the activities of the group in the area of neutron-activation analysis, in addition to a broader range of neutron related applications.
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| 3. |
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| 4. |
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| 5. |
- Kristiansson, P., et al.
(författare)
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Optical dot gain on newsprint determined with the Lund nuclear microprobe
- 1997
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - Amsterdam : Elsevier. - 0168-583X .- 1872-9584. ; 130:1-4, s. 303-307
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Tidskriftsartikel (refereegranskat)abstract
- A technique for measuring optical dot gain, i.e. the relative difference between the actual screen dot and the optically perceived one, is presented. By combining measurements from the non-optical nuclear microprobe with data from image analyzing technique the optical dot gain can be determined. The procedure to reach pixel by pixel correlation on a micrometer scale is discussed. In the newsprint sample studied in this investigation a typical optical dot gain between 15 and 20% was deduced. The variation in the optical dot gain was correlated with other characteristic parameters of the print and newsprint and especially a positive correlation to the mass density of the newsprint was observed. (C) 1997 Elsevier Science Ltd.
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| 6. |
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| 7. |
- Zhang, SB, et al.
(författare)
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GIT1 protects against breast cancer growth through negative regulation of Notch
- 2022
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1, s. 1537-
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Tidskriftsartikel (refereegranskat)abstract
- Hyperactive Notch signalling is frequently observed in breast cancer and correlates with poor prognosis. However, relatively few mutations in the core Notch signalling pathway have been identified in breast cancer, suggesting that as yet unknown mechanisms increase Notch activity. Here we show that increased expression levels of GIT1 correlate with high relapse-free survival in oestrogen receptor-negative (ER(-)) breast cancer patients and that GIT1 mediates negative regulation of Notch. GIT1 knockdown in ER(-) breast tumour cells increased signalling downstream of Notch and activity of aldehyde dehydrogenase, a predictor of poor clinical outcome. GIT1 interacts with the Notch intracellular domain (ICD) and influences signalling by inhibiting the cytoplasm-to-nucleus transport of the Notch ICD. In xenograft experiments, overexpression of GIT1 in ER(-) cells prevented or reduced Notch-driven tumour formation. These results identify GIT1 as a modulator of Notch signalling and a guardian against breast cancer growth.
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| 8. |
- Bulow, K, et al.
(författare)
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The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 189, s. 308-314
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Tidskriftsartikel (refereegranskat)abstract
- The interaction of ink and newspaper has been investigated and the specific question of penetration of ink into the paper has been addressed with a nuclear microprobe using particle induced X-ray emission, The penetration depth of the newsprint is a critical factor in terms of increasing the quality of newsprint and minimising the amount of ink used. The objective of the experiment was to relate the penetration depth of pigment with the calendering of the paper, The dependence of the penetration depth on the pigment grain size was also Studied, To Study the penetration depth of pigment in paper, cyan ink with Cu as a tracer of the coloured pigment was used, For the study of the penetration depth dependence of pigment size. specially grounded Japanese ink with well-defined pigment grain size was used. This was compared to Swedish ink with pigment grains with normal size-distribution, The results show that the calendering of the paper considerably affects the penetration depth of ink. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 9. |
- Dahl, F, et al.
(författare)
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Imaging single DNA molecules for high precision NIPT
- 2018
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1, s. 4549-
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Tidskriftsartikel (refereegranskat)abstract
- Cell-free DNA analysis is becoming adopted for first line aneuploidy screening, however for most healthcare programs, cost and workflow complexity is limiting adoption of the test. We report a novel cost effective method, the Vanadis NIPT assay, designed for high precision digitally-enabled measurement of chromosomal aneuploidies in maternal plasma. Reducing NIPT assay complexity is achieved by using novel molecular probe technology that specifically label target chromosomes combined with a new readout format using a nanofilter to enrich single molecules for imaging and counting without DNA amplification, microarrays or sequencing. The primary objective of this study was to assess the Vanadis NIPT assay with respect to analytical precision and clinical feasibility. Analysis of reference DNA samples indicate that samples which are challenging to analyze with low fetal-fraction can be readily detected with a limit of detection determined at <2% fetal-fraction. In total of 286 clinical samples were analysed and 30 out of 30 pregnancies affected by trisomy 21 were classified correctly. This method has the potential to make cost effective NIPT more widely available with more women benefiting from superior detection and false positive rates.
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| 10. |
- Frost, Robert J. W., et al.
(författare)
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Preliminary results from a study of luminescent materials : For application in the beam imaging system at the ESS
- 2023
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier. - 0168-583X .- 1872-9584. ; 540, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- As part of the development of the beam imaging system at the European Spallation Source, luminescent screens have been fabricated by the flame spraying of scintillating materials onto stainless steel backings. A total of seven screens were produced, three of chromia alumina (Al2O3:Cr), two of YAG (Y3Al5O12:Ce) and two of a 50/50 mix of these. The properties of these screens under proton irradiation were evaluated using a2.55 MeV proton beam at currents of up to 10 μA. Irradiation times were up to 25 h per sample, during which luminescence-, spectrographic-, thermal- and current-data was sampled at a rate of 1 Hz. Preliminary results of these measurements are reported here; with a quantitative analysis presented for one of the chromia alumina screens and a qualitative comparison of all three material types. The luminescent yield for chromia alumina was determined to be around 2000 photons/MeV for a virgin screen, and was found to drop to 1.5% after 167 mC of proton irradiation. A recovery of the luminescence of chromia alumina to >60% was observed after beam current was reduced for an 8 h period. Observations indicate that the YAG and mixed composition screens retain higher luminescence than the chromia alumina even at temperatures of over 200 ◦C. It is indicated that the luminescence from YAG feeds the R-lines of chromia alumina in the mixed composition screens.
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