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- Serra Filho, L. A., et al.
(författare)
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Double-GEM based thermal neutron detector prototype
- 2022
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Ingår i: Journal of Instrumentation. - : IOP Publishing Ltd. - 1748-0221 .- 1748-0221. ; 17:9
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Tidskriftsartikel (refereegranskat)abstract
- The Helium-3 shortage and the growing interest in neutron science constitute a driving factor in developing new neutron detection technologies. In this work, we report the development of a double-GEM detector prototype that uses a (B4C)-B-10 layer as a neutron converter material. GEANT4 simulations were performed predicting an efficiency of (3.14 +/- 0.10)%, agreeing within 2.7 sigma with the experimental and analytic detection efficiencies obtained by the detector when tested in a 41.8 meV thermal neutron beam. The detector is position sensitive, equipped with a 256+256 strip readout connected to resistive chains, and achieves a spatial resolution better than 3 mm. The gain stability over time was also measured with a fluctuation of about 0.2% h(-1) of the signal amplitude. A simple data acquisition with only 5 electronic channels is sufficient to operate this detector.
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- Stratmann, Svea, 1989-, et al.
(författare)
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Proteogenomic analysis of acute myeloid leukemia associates relapsed disease with reprogrammed energy metabolism both in adults and children
- 2023
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 0887-6924 .- 1476-5551.
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Tidskriftsartikel (refereegranskat)abstract
- Despite improvement of current treatment strategies and novel targeted drugs, relapse and treatment resistance largely determine the outcome for acute myeloid leukemia (AML) patients. To identify the underlying molecular characteristics, numerous studies have been aimed to decipher the genomic- and transcriptomic landscape of AML. Nevertheless, further molecular changes allowing malignant cells to escape treatment remain to be elucidated. Mass spectrometry is a powerful tool enabling detailed insights into proteomic changes that could explain AML relapse and resistance. Here, we investigated AML samples from 47 adult and 22 pediatric patients at serial time-points during disease progression using mass spectrometry-based in-depth proteomics. We show that the proteomic profile at relapse is enriched for mitochondrial ribosomal proteins and subunits of the respiratory chain complex, indicative of reprogrammed energy metabolism from diagnosis to relapse. Further, higher levels of granzymes and lower levels of the anti-inflammatory protein CR1/CD35 suggest an inflammatory signature promoting disease progression. Finally, through a proteogenomic approach, we detected novel peptides, which present a promising repertoire in the search for biomarkers and tumor-specific druggable targets. Altogether, this study highlights the importance of proteomic studies in holistic approaches to improve treatment and survival of AML patients.
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- Backis, A., et al.
(författare)
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Time- and energy-resolved effects in the boron-10 based multi-grid and helium-3 based thermal neutron detectors
- 2021
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Ingår i: Measurement science and technology. - : IOP PUBLISHING LTD. - 0957-0233 .- 1361-6501. ; 32:3
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Tidskriftsartikel (refereegranskat)abstract
- The boron-10 based multi-grid detector is being developed as an alternative to helium-3 based neutron detectors. At the European Spallation Source, the detector will be used for time-of-flight neutron spectroscopy at cold to thermal neutron energies. The objective of this work is to investigate fine time- and energy-resolved effects of the Multi-Grid detector, down to a few mu eV, while comparing it to the performance of a typical helium-3 tube. Furthermore, it is to characterize differences between the detector technologies in terms of internal scattering, as well as the time reconstruction of similar to mu s short neutron pulses. The data were taken at the Helmholtz Zentrum Berlin, where the Multi-Grid detector and a helium-3 tube were installed at the ESS test beamline, V20. Using a Fermi-chopper, the neutron beam of the reactor was chopped into a few tens of mu s wide pulses before reaching the detector, located a few tens of cm downstream. The data of the measurements show an agreement between the derived and calculated neutron detection efficiency curve. The data also provide fine details on the effect of internal scattering, and how it can be reduced. For the first time, the chopper resolution was comparable to the timing resolution of the Multi-Grid detector. This allowed a detailed study of time- and energy resolved effects, as well as a comparison with a typical helium-3 tube.
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- Onatsu, J., et al.
(författare)
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Tau, S100B and NSE as Blood Biomarkers in Acute Cerebrovascular Events
- 2020
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Ingår i: In Vivo. - : Anticancer Research USA Inc.. - 0258-851X .- 1791-7549. ; 34:5, s. 2577-2586
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Tidskriftsartikel (refereegranskat)abstract
- Background/Aim: We aimed to analyze the diagnostic value of total tau (T- tau), S-100 calcium-binding protein B (S100B) and neuron-specific enolase (NSE) as blood-based biomarkers in acute ischemic stroke (AIS) or transient ischemic attack (TIA), and their correlation with symptom severity, infarct size, etiology and outcome. Patients and Methods: A total of 102 patients with stroke and 35 with TIA were analyzed. Subacute (63.8 +/- 50.1 h) plasma T-tau was measured with the single-molecule array (Simoa) method and NSE and S100B were evaluated for comparison. We evaluated biomarkers associations with: (i) diagnosis of AIS or TIA, (ii) cerebral infarction volume in the brain computed tomography, (iii) stroke etiology, (iv) clinical stroke severity and (iv) functional outcome after three months. Results: T-tau was higher in patients with stroke (1.0 pg/ml (IQR=0.3-2 2)] than with TIA (05 pg/ml (IQR=0.2- 1 .0), p=0.02] . The levels of S100B were also increased in stroke [0.082 mu g/l (IQR=0.049-0.157)] patients compared to TIA patients (0.045 mu g/l (IQR=0.03 -0.073 ), p<0.001]. However, when the results were adjusted for confounders, significance was lost. Serum levels of NSE among patients with AIS [11.85 mu g/l (IQR=9.30-16.14)] compared to those with TIA (10.96 mu g/l (IQR=7 .98-15.33), p=0.301 were equal. T-tau and S100B concentrations significantly correlated with cerebral infarction volume (r=0.412, p<0.001) and (r=0.597, p<0.001), also after corrections (p<0.001). mRS scores at three-month follow-up correlated with T-tau (r=0.248, p=0.016) and S100B concentrations (r=0.205, p=0.045). Conclusion: For the diagnosis of TIA vs. AIS, blood T-tau and S100B concentrations discriminated only modestly. Additionally, groups were not separable after measuring of T-tau and S100B levels in the blood. T-tau and S100B concentrations correlated with the infarct size, but were not alone predictive for functional outcome at 3 months.
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- Birgersson, Sofia, 1976, et al.
(författare)
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Population pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant women with uncomplicated Plasmodium falciparum malaria in Burkina Faso: An open label trial [version 2; peer review: 2 approved]
- 2020
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Ingår i: Wellcome Open Research. - : F1000 Research Ltd. - 2398-502X. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Malaria during pregnancy is a major health risk for both the mother and the foetus. Pregnancy has been shown to influence the pharmacokinetics of a number of different antimalarial drugs. This might lead to an under-exposure in these patients which could increase the risk of treatment failure and the development of drug resistance. The study aim was to evaluate the pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant patients using a population modelling approach. Methods: Twenty-four women in their second and third trimester of pregnancy and twenty-four paired non-pregnant women, all with uncomplicated P. falciparum malaria, were enrolled in this study. Treatment was a fixed-dose combination of oral artesunate and mefloquine once daily for three days. Frequent blood samples were collected and concentration-time data for artesunate and dihydroartemisinin were analysed simultaneously using nonlinear mixed-effects modelling. Results: Artesunate pharmacokinetics was best described by a transit-compartment absorption model followed by a one-compartment disposition model under the assumption of complete in vivo conversion of artesunate into dihydroartemisinin. Dihydroartemisinin pharmacokinetics was best described by a one-compartment disposition model with first-order elimination. Pregnant women had a 21% higher elimination clearance of dihydroartemisinin, compared to non-pregnant women resulting in proportionally lower drug exposure. In addition, initial parasitaemia and liver enzyme levels (alanine aminotransferase) were found to affect the relative bioavailability of artesunate. Conclusions: Results presented here show a substantially lower drug exposure to the antimalarial drug dihydroartemisinin during pregnancy after standard oral treatment of artesunate and mefloquine. This might result in an increased risk of treatment failure and drug resistance development especially in low transmission settings where relative immunity is lower. Trial registration: ClinicalTrials.gov NCT00701961 (19/06/2008). © 2020 Birgersson S et al.
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