| 1. |
- Chartkunchand, Kiattichart C., et al.
(författare)
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Dianion diagnostics in DESIREE : High-sensitivity detection of C-n(2-) from a sputter ion source
- 2018
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 89:3
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Tidskriftsartikel (refereegranskat)abstract
- A sputter ion source with a solid graphite target has been used to produce dianions with a focus on carbon cluster dianions, C-n(2-), with n = 7-24. Singly and doubly charged anions from the source were accelerated together to kinetic energies of 10 keV per atomic unit of charge and injected into one of the cryogenic (13 K) ion-beam storage rings of the Double ElectroStatic Ion Ring Experiment facility at Stockholm University. Spontaneous decay of internally hot C-n(2-) dianions injected into the ring yielded C-n(2-) anions with kinetic energies of 20 keV, which were counted with a microchannel plate detector. Mass spectra produced by scanning the magnetic field of a 90 degrees analyzing magnet on the ion injection line reflect the production of internally hot C-7(2-) - C-24(2-) dianions with lifetimes in the range of tens of microseconds to milliseconds. In spite of the high sensitivity of this method, no conclusive evidence of C-6(2-) was found while there was a clear C-7(2-) signal with the expected isotopic distribution. This is consistent with earlier experimental studies and with theoretical predictions. An upper limit is deduced for a C-6(2-) signal that is two orders-of-magnitude smaller than that for C-7(2-). In addition, CnO2- and CnCu2- dianions were detected.
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| 2. |
- Chartkunchand, Kiattichart C., et al.
(författare)
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Radiative lifetimes of the bound excited states of Pt-
- 2016
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Ingår i: Physical Review A - Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 94:3
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Tidskriftsartikel (refereegranskat)abstract
- © 2016 American Physical Society.The intrinsic radiative lifetimes of the 5d106sS1/22 and 5d96s2 D3/22 bound excited states in the platinum anion Pt- have been studied at cryogenic temperatures at the Double ElectroStatic Ion Ring Experiment (DESIREE) facility at Stockholm University. The intrinsic lifetime of the higher-lying 5d106s S1/22 state was measured to be 2.54±0.10s, while only a lifetime in the range of 50-200 ms could be estimated for the 5d96s2 D3/22 fine-structure level. The storage lifetime of the Pt- ion beam was measured to be a little over 15 min at a ring temperature of 13K. The present study reports the lifetime of an atomic negative ion in an excited bound state with an electron configuration different from that of the ground state.
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| 3. |
- Holm, Anna, et al.
(författare)
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Fokus på individuell behandling vid akut koronart syndrom utan ST-höjning
- 2021
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 118
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Tidskriftsartikel (refereegranskat)abstract
- New guidelines from the European Society of Cardiology (ESC) for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation (NSTEMI-ACS) stress the importance of more individualized diagnostics and therapy based on the patients' initial risk profile balancing risk of ischemia with risk of bleeding. In this commentary, the Working Group on Coronary Artery Disease of the Swedish Society of Cardiology points out what is new in the 2020 NSTEMI guidelines.
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| 4. |
- Kristiansson, Moa K., 1989-, et al.
(författare)
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High-precision electron affinity of oxygen
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Negative ions are important in many areas of science and technology, e.g., in interstellar chemistry, for accelerator-based radionuclide dating, and in anti-matter research. They are unique quantum systems where electron-correlation effects govern their properties. Atomic anions are loosely bound systems, which with very few exceptions lack optically allowed transitions. This limits prospects for high-resolution spectroscopy, and related negative-ion detection methods. Here, we present a method to measure negative ion binding energies with an order of magnitude higher precision than what has been possible before. By laser-manipulation of quantum-state populations, we are able to strongly reduce the background from photodetachment of excited states using a cryogenic electrostatic ion-beam storage ring where keV ion beams can circulate for up to hours. The method is applicable to negative ions in general and here we report an electron affinity of 1.461 112 972(87) eV for O-16. High-precision measurements are useful to find isotopic shifts and electron correlation. Here the authors measure electron affinity and hyperfine splitting of atomic oxygen with higher precision than previous studies.
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| 5. |
- Najeeb, P. K., 1986-, et al.
(författare)
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Stability and Cooling of the C72- Dianion
- 2023
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 131:11
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the stability of the smallest long-lived all carbon molecular dianion (C72-) in new time domains and with a single ion at a time using a cryogenic electrostatic ion-beam storage ring. We observe spontaneous electron emission from internally excited dianions on millisecond timescales and monitor the survival of single colder C72- molecules on much longer timescales. We find that their intrinsic lifetime exceeds several minutes - 6 orders of magnitude longer than established from earlier experiments on C72-. This is consistent with our calculations of vertical electron detachment energies predicting one inherently stable isomer and one isomer which is stable or effectively stable behind a large Coulomb barrier for C72-→C7-+e- separation.
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| 6. |
- Najeeb, P. K., 1986-, et al.
(författare)
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Stability and Cooling of the C2−7 Dianion
- 2023
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 131:11
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the stability of the smallest long-lived all carbon molecular dianion () in new time domains and with a single ion at a time using a cryogenic electrostatic ion-beam storage ring. We observe spontaneous electron emission from internally excited dianions on millisecond timescales and monitor the survival of single colder molecules on much longer timescales. We find that their intrinsic lifetime exceeds several minutes—6 orders of magnitude longer than established from earlier experiments on . This is consistent with our calculations of vertical electron detachment energies predicting one inherently stable isomer and one isomer which is stable or effectively stable behind a large Coulomb barrier for →+e− separation.
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| 7. |
- Persson, Sofia, et al.
(författare)
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Validation of an optimised method for quantitative detection of hepatitis E virus in pork sausage
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Hepatitis E virus (HEV) is an emerging zoonosis that can be transmitted to humans through the consumption of raw or undercooked pork meat products. Several methods for detecting the virus in food have been described, but there are still few robust data on qualitative and quantitative performance characteristics. In this study, we developed an optimised workflow for quantitative detection of HEV in pork sausage based on a combination of previously existing protocols. The protocol uses sample disruption and phase separation with tri-reagent and 1-bromo-3-chloropropane, followed by RNA concentration with isopropanol precipitation. We validated the protocol for use on reverse transcription quantitative real-time PCR (RT-qPCR) and reverse transcription droplet digital (RT-ddPCR). The 95% limit of detection and limit of quantification was 200 copies/g for both RT-qPCR and RT-ddPCR. The RT-ddPCR technology has previously shown promise as a more precise alternative to RT-qPCR. However, we found no evidence for improved performance using RT-ddPCR instead of RT-qPCR in this method. Furthermore, we also evaluated different combinations of RNA concentration methods and PCR detection strategies. This showed that isopropanol precipitation of viral RNA was more than twice as efficient as magnetic silica bead-based extraction when an inhibitor tolerant RT-PCR detection strategy was used. In conclusion, we present an efficient and well-characterised method for quantitative detection of HEV in pork sausage. Such methods are valuable to provide high quality data for risk assessments and food monitoring.
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| 8. |
- Schmidt, Henning T., et al.
(författare)
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Rotationally Cold OH- Ions in the Cryogenic Electrostatic Ion-Beam Storage Ring DESIREE
- 2017
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 119:7
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Tidskriftsartikel (refereegranskat)abstract
- We apply near-threshold laser photodetachment to characterize the rotational quantum level distribution of OH- ions stored in the cryogenic ion-beam storage ring DESIREE at Stockholm University. We find that the stored ions relax to a rotational temperature of 13.4 +/- 0.2 K with 94.9 +/- 0.3% of the ions in the rotational ground state. This is consistent with the storage ring temperature of 13.5 +/- 0.5 K as measured with eight silicon diodes but in contrast to all earlier studies in cryogenic traps and rings where the rotational temperatures were always much higher than those of the storage devices at their lowest temperatures. Furthermore, we actively modify the rotational distribution through selective photodetachment to produce an OH- beam where 99.1 +/- 0.1% of approximately one million stored ions are in the J = 0 rotational ground state. We measure the intrinsic lifetime of the J = 1 rotational level to be 145 +/- 28 s.
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| 9. |
- Simonsson, Moa, et al.
(författare)
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Association of Ischemic and Bleeding Events With Mortality Among Patients in Sweden With Recent Acute Myocardial Infarction Receiving Antithrombotic Therapy
- 2022
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Ingår i: JAMA Network Open. - : American Medical Association. - 2574-3805. ; 5:8
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE Antithrombotic treatment after myocardial infarction (MI) should be individualized based on the patients risk of ischemic and bleeding events. Uncertainty remains regarding the relative prognostic importance of the 2 types of events, and further study would be useful. OBJECTIVES To compare the association of ischemic vs bleeding events with mortality in patients with a recent MI and assess whether the relative mortality risk for the 2 types of events has changed over the past 2 decades. DESIGN, SETTING, AND PARTICIPANTS A cohort study based on nationwide registers in Sweden, 2012-2017, was conducted. Data were analyzed between July 2021 and May 2022. Patients with MI who were discharged alive with antithrombotic therapy (antiplatelet therapy or oral anticoagulation) were included in the analysis. MAIN OUTCOMES AND MEASURES The incidence of a first ischemic event (hospitalization for MI or ischemic stroke) or bleeding event (hospitalization with bleeding) up to 1 year after discharge and the mortality risk up to 1 year after each type of event were assessed. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (a HRs) for 1-year mortality after an ischemic and bleeding event vs no event, and after an ischemic vs bleeding event. Adjusted HRs for mortality after ischemic vs bleeding events were compared among patients discharged in 1997-2000, 2001-2011, and 2012-2017. RESULTS Of 86 736 patients discharged after MI in 2012-2017 (median age, 71 [IQR, 62-80] years; 57 287 [66.0%] men), 4039 individuals experienced a first ischemic event (5.7 per 100 person-years) and 3399 experienced a first bleeding event (4.8 per 100 person-years). The mortality rate was 46.2 per 100 person-years after an ischemic event and 27.1per 100 person-years after a bleeding event. The aHR for 1-year mortality vs no event was 4.16 (95% CI, 3.91-4.43) after an ischemic event and 3.43 (95% CI. 3.17-3.71) after a bleeding event. When the 2 types of events were compared, the aHR was 1.27 (95% CI, 1.15-1.40) for an ischemic vs bleeding event. There was no statistically significant difference in the aHR of an ischemic vs bleeding event in 1997-2000, 2001-2011, and 2012-2017. CONCLUSIONS AND RELEVANCE In this nationwide cohort study of patients with a recent MI, postdischarge ischemic events were more common and associated with higher mortality risk compared with bleeding events.
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| 10. |
- Simonsson, Moa
(författare)
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Bleeding complications following acute myocardial infarction : time trends, risk assessment and associated prognosis
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: In patients with acute myocardial infarction (MI), bleeding complications are common and associated with worse prognosis. This thesis aimed to investigate the epidemiology, risk assessment and associated outcomes of bleeding complications in patients with acute MI. Methods and results: Study I: Patients with acute MI enrolled in the SWEDEHEART registry from 1995–2018 were included (n=371 431). The incidence of in-hospital and out-of-hospital bleeding at one-year was investigated parallel to treatment changes and ischemic outcomes. From 1995 to 2018, in-hospital bleeding increased from 0.5% to 1.3% and out-of-hospital bleeding increased from 2.5% to 4.8% along with increased use of invasive revascularisation and more efficient antithrombotic treatment. Meanwhile in-hospital and out-of-hospital ischemic outcomes decreased from 12.1% to 5.6% and 27.5% to 15.1%, respectively. Study II: Patients with acute MI enrolled in the SWEDEHEART registry from 2009– 2014 were included (n=97 597). A prediction model for in-hospital bleeding was created using logistic regression and the performance was compared to that of the CRUSADE and ACTION scores. Due to miscalibration, the CRUSADE and ACTION scores were recalibrated. The SWEDEHEART score, consisting of five baseline variables (haemoglobin, age, sex, creatinine, and C-reactive protein) plus one interaction term (haemoglobin and sex) had a C-index of 0.80 as compared with 0.72 and 0.73 for the recalibrated CRUSADE and ACTION scores, respectively. Study III: Patients with acute MI enrolled in the SWEDEHEART registry from 2007–2016 and discharged alive on any antithrombotic treatment were included (n=149 447). The incidence, associated outcomes and predictors of upper gastrointestinal bleeding (UGIB) was investigated. The incidence of UGIB within one year after discharge was 1.5% and experiencing UGIB was associated with increased risk of mortality and stroke, but not significantly associated with MI. Using both logistic regression and machine-learning models, new potential predictors of UGIB were found, such as smoking status and blood glucose. Study IV: Patients with acute MI enrolled in the SWEDEHEART registry and discharged alive on any antithrombotic treatment from 2012–2017 were included (n=86 736). The incidence and associated mortality risk of ischemic (MI or ischemic stroke) and bleeding events was investigated. Within one year after discharge, the incidence rate of ischemic and bleeding events was 5.7/100 person years and 4.8/100 person years, respectively. Both ischemic and bleeding events were associated with higher risk of mortality as compared with no event, with adjusted hazard ratios (HR)s of 4.16 (95% CI 3.91 to 4.43) and 3.43 (95% CI 3.17 to 3.71), respectively. In a direct comparison of ischemic vs bleeding event, the adjusted HR was 1.27 (95% CI 1.15 to 1.40.). Conclusion: In the past two decades, the incidence of both short- and long-term bleeding events has nearly doubled in patients with acute MI. The five-item SWEDEHEART score predicts inhospital bleeding in patients with acute MI more accurately than the recalibrated CRUSADE and ACTION scores. Among patients with a recent MI, upper gastrointestinal bleeding is common and associated with poorer prognosis. Beyond the known risk factors for bleeding, other predictors for upper gastrointestinal bleeding may be present. In patients discharged after an acute MI, ischemic events were more common and associated with higher risk of mortality than bleeding events.
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