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| 2. |
- Thalmann, R., et al.
(författare)
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Key comparison EURAMET.L-K8.2013 calibration of surface roughness standards
- 2016
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Ingår i: Metrologia. - 0026-1394 .- 1681-7575. ; 53:1A
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Tidskriftsartikel (refereegranskat)abstract
- The key comparison EURAMET.L-K8.2013 on roughness was carried out in the framework of a EURAMET project starting in 2013 and ending in 2015. It involved the participation of 17 National Metrology Institutes from Europe, Asia, South America and Africa representing four regional metrology organisations. Five surface texture standards of different type were circulated and on each of the standards several roughness parameters according to the standard ISO 4287 had to be determined. 32 out of 395 individual results were not consistent with the reference value. After some corrective actions the number of inconsistent results could be reduced to 20, which correspond to about 5% of the total and can statistically be expected. In addition to the material standards, two softgauges were circulated, which allow to test the software of the instruments used in the comparison. The comparison results help to support the calibraton and measurement capabilities (CMCs) of the laboratories involved in the CIPM MRA.
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| 5. |
- Johanson, Per, 1963, et al.
(författare)
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ST-segment analyses and residual thrombi in the infarct-related artery: a report from the ASSENT PLUS ST-monitoring substudy
- 2004
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Ingår i: Am Heart J. - 1097-6744. ; 147:5, s. 853-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Evolution of the ST segment during ST-elevation myocardial infarction (STEMI) has been shown to yield more information on prognosis than widely used invasive measurements. With continuous ST monitoring, even very occasional dynamic changes can be analyzed. We have recently suggested that ST variability during the reperfusion-phase is of prognostic importance. We wanted to further investigate this and relate it to angiographic findings. METHODS: A total of 177 patients with STEMI were examined in the ST-monitoring substudy of the ASessment of the Safety and Efficacy of a New Thrombolytic (ASSENT) PLUS trial, comparing dalteparin with heparin as adjunctive therapy to t-PA. Patients underwent 24 hours of ST monitoring. These recordings were blindly analyzed by 2 independent observers. A coronary angiogram was performed on days 4 to 7, also blindly evaluated by 2 persons. RESULTS: Occurrence of ST re-elevations during and after the reperfusion-phase was significantly associated with residual thrombi and TIMI-flow in the infarct-related artery. Patients without any ST re-elevations showed a thrombus in only 5% of cases, as compared with 86% of patients with prolonged (lasting >30 minutes) ST re-elevations. In a multivariate comparison including baseline-data and treatment, most information on persistence of thrombi was contributed by the presence of any ST re-elevations (odds ratio, 5.8; 95% CI, 1.3-26). CONCLUSION: ST re-elevations during the first day of an acute myocardial infarction are associated with residual thrombi in the infarct-related artery even 4 to 7 days after the STEMI.
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| 8. |
- Tavakol, P, et al.
(författare)
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Effects of outsourcing magnetic resonance examinations from a public university hospital to a private agent
- 2011
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 52:1, s. 81-85
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Tidskriftsartikel (refereegranskat)abstract
- Sometimes the measures taken to make a radiology department more effective, such as prioritizing the workload and keeping equipment running for as many hours as staffing permits, are not enough. In such cases, outsourcing radiological examinations is a potential solution for reducing waiting times. Purpose To investigate differences in waiting time, quality and costs between magnetic resonance (MR) examinations performed in a university hospital and examinations outsourced to private service. Material and Methods We retrospectively selected a group of consecutive, outsourced MR examinations ( n = 97) and a control group of in-house MR examinations, matched for type of examination. In each group there were referrals that had a specified preferred timeframe for completion. We measured the percentage of cases in which this timeframe was met and if it was not met, how many days exceeded the preferred time. In referrals without a specified preferred timeframe, we also calculated the waiting time. Quality standards were measured by the percentage of examinations that had to be re-done and re-assessed. Finally, we calculated the cumulative costs, taking into account the costs for re-doing and re-assessing examinations. Results There was no statistically significant difference between the groups, in either the number of examinations that were not performed within the preferred time or the number of days that exceeded the preferred timeframe. For referrals without a preferred timeframe, the waiting time was shorter for outsourced examinations than those not outsourced. There were no differences in the number of examinations that had to be re-done, but more examinations needed to be re-assessed in the outsourced group than in the in-house group. The calculated costs for outsourced examinations were lower than the costs for internally performed examinations. Conclusion Outsourcing magnetic resonance examinations may be an effective way of reducing a radiology department's workload. Ways in which to reduce the additional costs incurred for re-assessment of outsourced examinations must be investigated further.
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| 16. |
- Bergstrand, S, et al.
(författare)
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Small Cajal body-associated RNA 2 (scaRNA2) regulates DNA repair pathway choice by inhibiting DNA-PK
- 2022
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1, s. 1015-
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Tidskriftsartikel (refereegranskat)abstract
- Evidence that long non-coding RNAs (lncRNAs) participate in DNA repair is accumulating, however, whether they can control DNA repair pathway choice is unknown. Here we show that the small Cajal body-specific RNA 2 (scaRNA2) can promote HR by inhibiting DNA-dependent protein kinase (DNA-PK) and, thereby, NHEJ. By binding to the catalytic subunit of DNA-PK (DNA-PKcs), scaRNA2 weakens its interaction with the Ku70/80 subunits, as well as with the LINP1 lncRNA, thereby preventing catalytic activation of the enzyme. Inhibition of DNA-PK by scaRNA2 stimulates DNA end resection by the MRN/CtIP complex, activation of ATM at DNA lesions and subsequent repair by HR. ScaRNA2 is regulated in turn by WRAP53β, which binds this RNA, sequestering it away from DNA-PKcs and allowing NHEJ to proceed. These findings reveal that RNA-dependent control of DNA-PK catalytic activity is involved in regulating whether the cell utilizes NHEJ or HR.
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| 19. |
- Cederlund, K, et al.
(författare)
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Visual grading of emphysema severity in candidates for lung volume reduction surgery. Comparison between HRCT, spiral CT and "density-masked" images
- 2002
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 43:1, s. 48-53
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate which of three types of CT imaging yielded the best results in estimating the degree of emphysema in patients undergoing evaluation for lung volume reduction surgery (LVRS), whether there was any difference in this regard between the cranial and caudal part of the lung, and whether the degree of emphysema had an impact on the estimation. Material and Methods: Four radiologists visually classified different degrees of emphysema on three different types of CT images into four groups. The degree of emphysema was calculated by a computer. The three types of images were as follows: HRCT images (2-mm slice thickness); spiral CT images (10-mm slice thickness); and density-masked images (spiral CT images printed with pixels below -960 HU, depicted in white). Results: The conventionally presented images from HRCT and spiral CT yielded the same results (60% respective 62% correct classifications) in assessing the degree of emphysema irrespective of localisation. Significantly improved results were obtained when the spiral CT images were presented as density-masked images (74%). Conclusion: There was no difference between HRCT and spiral CT in assessing the degree of emphysema in candidates for LVRS. Improvement can be achieved by the use of density-masked images.
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| 20. |
- Christiansson, Maria, et al.
(författare)
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OSL in NaCl vs. TL in LiF for absorbed dose measurements and radiation quality assessment in the photon energy range 20 keV to 1.3 MeV
- 2018
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Ingår i: Radiation Measurements. - : Elsevier BV. - 1350-4487. ; 112, s. 11-15
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine the photon energy dependence of absorbed dose measurements, in a comparison of optically stimulated luminescence (OSL) in NaCl with thermoluminescence (TL) in LiF:Mg,Cu,P. The comparisons were made at exposure to ionizing radiation in the photon energy range 20 keV to 1.3 MeV. Specially designed dosemeter kits containing both NaCl and LiF were used under i) laboratory conditions using defined radiation fields, ii) laboratory conditions using sealed point sources mimicking unintentional exposures, and iii) field conditions in areas in Japan that were affected by the Fukushima Daiichi nuclear disaster in 2011. The dosemeter kits used in Japan showed that absorbed doses as low as 100 μGy can be assessed from the OSL signal in NaCl. The ratio of the dosemeter readings using OSL in NaCl and TL in LiF increases after irradiation at lower photon energies (less than a few hundred keV) as determined under laboratory conditions. Compensating for this energy dependence of the absorbed dose determinations obtained from OSL in NaCl would thus require an energy-dependent conversion factor for photon energies below 600 keV. On the other hand, the difference in the photon energy dependence between NaCl and LiF may be used to assess the mean effective energy of the photon field. The signal ratios between NaCl and LiF after exposure to radiation in the Fukushima Dashii contaminated areas in Japan, 1.67 ± 0.26 (2013) and 1.63 ± 0.32 (2015), indicate that the mean photon energy in this area was 300–400 keV during the years of the survey.
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| 21. |
- Christiansson, M., et al.
(författare)
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Retrospective dosimetry using salted snacks and nuts : A feasibility study
- 2017
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Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 174:1, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- The possibility of using ordinary household table salt for dosimetry is suggested by its high sensitivity to ionising radiation, which generates a readout of optically stimulated luminescence (OSL). However, to exploit this finding for retrospective human dosimetry, it would be needed to find salt in close proximity to the exposed individual. Finding salty snacks frequently tucked into handbags, backpacks or pockets seemed to be a possibility; these items therefore became the test materials of the present study. The aluminium or cardboard packages used to exclude the moisture that makes crisps and nuts go soft and stale also helps to retain the induced OSL signal. Therefore, different snacks, either their salt component alone or mixed with the snack, are exposed to ionising radiation and then were assessed for their dosimetric properties. The results indicate the feasibility of using some salty snacks for dosimetry, with a minimum detectable dose as low as 0.2 mGy.
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| 22. |
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| 23. |
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| 24. |
- Geber-Bergstrand, Therése, et al.
(författare)
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Optically stimulated luminescence (OSL) dosimetry in irradiated alumina substrates from mobile phone resistors
- 2018
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Ingår i: Radiation and Environmental Biophysics. - : Springer Science and Business Media LLC. - 0301-634X .- 1432-2099. ; 57:1, s. 69-75
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Tidskriftsartikel (refereegranskat)abstract
- In this study the dosimetric properties of alumina (Al2O3) substrates found in resistors retrieved from mobile phones were investigated. Measurements of the decline of optically stimulated luminescence (OSL) generated following exposure of these substrates to ionising radiation showed that 16% of the signal could still be detected after 2 years (735 days). Further, the magnitude of the regenerative dose (calibration dose; Di) had no impact on the accuracy of dose estimates. Therefore, it is recommended that the Di be set as low as is practicable, so as to accelerate data retrieval. The critical dose, DCL, and dose limit of detection, DDL, taking into account the uncertainty in the dose–response relation as well as the uncertainty in the background signal, was estimated to be 7 and 13 mGy, respectively, 1 h after exposure. It is concluded that given the significant long-term component of fading, an absorbed dose of 0.5 Gy might still be detectable up to 6 years after the exposure. Thus, OSL from alumina substrates can be used for dosimetry for time periods far in excess of those previously thought.
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| 27. |
- Matus, M., et al.
(författare)
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Key Comparison EURAMET.L-K1.2011 Measurement of gauge blocks by interferometry
- 2016
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Ingår i: Metrologia. - 0026-1394 .- 1681-7575. ; 53:1A
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Tidskriftsartikel (refereegranskat)abstract
- The key comparison EURAMET.L-K1.2011 on gauge blocks was carried out in the framework of a EURAMET project starting in 2012 and ending in 2015. It involved the participation of 24 National Metrology Institutes from Europe and Egypt, respectively. 38 gauge blocks of steel and ceramic with nominal central lengths between 0.5 mm and 500 mm were circulated. The comparison was conducted in two loops with two sets of artifacts. A statistical technique for linking the reference values was applied. As a consequence the reference value of one loop is influenced by the measurements of the other loop although they did not even see the artifacts of the others. This influence comes solely from three "linking laboratories" which measure both sets of artifacts. In total there were 44 results were not fully consistent with the reference values. This represents 10% of the full set of 420 results which is a considerable high number. At least 12 of them are clearly outliers where the participants have been informed by the pilot as soon as possible. The comparison results help to support the calibration and measurement capabilities (CMCs) of the laboratories involved in the CIPM MRA.
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| 28. |
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| 29. |
- Oxenstierna, G, et al.
(författare)
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Increased frequency of aberrant CSF circulation in schizophrenic patients compared to healthy volunteers
- 1996
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Ingår i: European psychiatry : the journal of the Association of European Psychiatrists. - : Cambridge University Press (CUP). - 0924-9338. ; 11:1, s. 16-20
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Tidskriftsartikel (refereegranskat)abstract
- In a previous cisternographic study of the cerebrospinal fluid (CSF) circulation in schizophrenic patients, indications for disturbed flow dynamics were found in 10 of 30 subjects. In order to replicate and investigate the clinical and pathophysiological significance of this finding, 39 schizophrenic patients and 42 healthy subjects were examined with an improved method for measurement of CSF circulation. 99mTc-DTPA was injected intrathecally and the gamma cisternograms were evaluated blindly. Correlations between cisternography findings and age, duration of disease, previous hospitalizations, positive or negative symptomatology, exposure to neuroleptics, psychiatric family history, CT findings and CSF levels of protein, tryptophan and monoamine metabolites, were calculated. Seven of the patients showed abnormalities in the cisternograms with a slow or obstructed flow of CSF over the convexities (P < 0.01) whereas none of the healthy volunteers showed abnormalities. There were no correlations between disturbed CSF circulation in the patients and the clinical and biochemical parameters, thus the significance of the deviations, similar to other biological aberrations found in schizophrenic patients, is not known. Recent developments in magnetic resonance imaging offer new possibilities to further examine CSF circulation abnormalities in schizophrenia.
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| 33. |
- Sender, Vicky, et al.
(författare)
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Capillary leakage provides nutrients and antioxidants for rapid pneumococcal proliferation in influenza-infected lower airways
- 2020
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 117:49, s. 31386-31397
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Tidskriftsartikel (refereegranskat)abstract
- Influenza A virus (IAV)-related mortality is often due to secondary bacterial infections, primarily by pneumococci. Here, we study how IAV-modulated changes in the lungs affect bacterial replication in the lower respiratory tract (LRT). Bronchoalveolar lavages (BALs) from coinfected mice showed rapid bacterial proliferation 4 to 6 h after pneumococcal challenge. Metabolomic and quantitative proteomic analyses demonstrated capillary leakage with efflux of nutrients and antioxidants into the alveolar space. Pneumococcal adaptation to IAV-induced inflammation and redox imbalance increased the expression of the pneumococcal chaperone/protease HtrA. Presence of HtrA resulted in bacterial growth advantage in the IAV-infected LRT and protection from complement-mediated opsonophagocytosis due to capsular production. Absence of HtrA led to growth arrest in vitro that was partially restored by antioxidants. Pneumococcal ability to grow in the IAV-infected LRT depends on the nutrient-rich milieu with increased levels of antioxidants such as ascorbic acid and its ability to adapt to and cope with oxidative damage and immune clearance.
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| 36. |
- Smedby, Örjan, et al.
(författare)
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Development of femoral atherosclerosis in relation to flow disturbances.
- 1996
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Ingår i: Journal of Biomechanics. - : Elsevier BV. - 0021-9290 .- 1873-2380. ; 29:4, s. 543-547
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Tidskriftsartikel (refereegranskat)abstract
- Angiography and post-mortem studies have indicated that disturbed blood flow may promote atherogenesis. Our aim was to demonstrate flow disturbances in vivo and correlate them to the subsequent development of atherosclerosis. The femoral arteries of 17 patients with early atherosclerosis were studied with cineangiography. The films are digitized and analyzed with an image analysis computer. From the time-intensity curves, the arrival time of the contrast medium at each pixel was calculated. In the resulting parametric images, the computer identified zones of delayed contrast filling, (ZDF) which have been shown to correspond to disturbed flow. The progression or regression of atherosclerosis was followed with another angiography 3 years later by computing changes in edge roughness. Arterial segments without flow disturbances (defined as ZDF) showed a more marked decrease in edge roughness than those with flow disturbances (p < 0.05). In addition, the edge roughness tended to increase more in segments with larger ZDF area. Angiographic studies of fluid mechanics and atherogenesis are feasible, but larger patient materials are needed.
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| 37. |
- Smedby, Örjan, et al.
(författare)
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Tortuosity and atherosclerosis in the femoral artery : what is cause and what is effect?
- 1996
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Ingår i: Annals of Biomedical Engineering. - 0090-6964 .- 1573-9686. ; 24:4, s. 474-480
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Tidskriftsartikel (refereegranskat)abstract
- Earlier studies have demonstrated a correlation between tortuosity and atherosclerosis in the femoral artery. One conceivable explanation is that atherosclerosis causes an elongation of the artery, resulting in vessel tortuosity, another is that blood flow phenomena (such as flow separation) due to the vessel geometry may affect the progression of atherosclerosis. To determine which of these hypotheses is most likely, a group of 232 hyperlipidemic patients was followed with angiography for 3 years during lipid-lowering treatment. After digitization of the films, a tortuosity value and an atherosclerosis measure (edge roughness) were computed. In the group with lower tortuosity values, there was a significant (p < 0.0001) decrease in edge roughness, but not in the group with a higher tortuosity values. On the other hand, neither the group with higher edge roughness values nor that with lower edge roughness values displayed a significant change in tortuosity. When tortuosity, roughness, and treatment were studied simultaneously, only the effect of tortuosity on roughness change was significant. These findings are more consistent with tortuosity influencing the development of atherosclerosis than with its being a consequence of atherosclerosis.
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| 38. |
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| 39. |
- Tornvall, P, et al.
(författare)
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Plasma C-reactive protein and lipoprotein levels, and progression of coronary artery disease after myocardial infarction treated with thrombolysis
- 2005
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Ingår i: Cardiology. - : S. Karger AG. - 0008-6312 .- 1421-9751. ; 104:2, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> There is a paucity of studies using quantitative coronary angiography (QCA) to determine progression of coronary artery disease (CAD) after an acute coronary event. Furthermore, despite a great interest in effects of inflammation and ‘early’ lipid lowering therapy, no data have been published on the role of plasma C-reactive protein (CRP) and lipoprotein levels in CAD progression after myocardial infarction. <i>Methods:</i> Seventy-two patients with myocardial infarction treated with thrombolysis, but not with statins, were investigated with QCA during admission and after 6 months. Plasma CRP concentrations were measured by a high sensitive method 2 days after the acute event, and plasma high-sensitive CRP and lipoprotein levels were determined 3 months after myocardial infarction. <i>Results:</i> Overall, there was no significant progression of CAD, but when stenoses were grouped into those reducing the lumen diameter greater or less than 50%, progression was seen in stenoses originally <50%, whereas regression was seen in stenoses >50%. No consistent associations were seen between plasma CRP, lipoprotein lipid or lipoprotein(a) levels and CAD. <i>Conclusions:</i> Progression of stenoses <50% might be of clinical importance since these stenoses are more prone to rupture. Furthermore, the lack of associations between change in minimum lumen diameter and plasma CRP and lipoprotein concentrations suggests that positive effects on CAD progression of early treatment with anti-inflammatory or lipid-lowering drug therapy may not be expected in this subset of patients.
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| 40. |
- Venge, Per, et al.
(författare)
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Neutrophils and eosinophils
- 1996. - 5th ed
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Ingår i: Textbook of rheumatology. - Philadelphia, Pa : Saunders Elsevier. - 0721656927 - 9780721656922 ; , s. 146-160
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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