| 1. |
- Akselsson, Cecilia, et al.
(författare)
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Impact of harvest intensity on long-term base cation budgets in Swedish forest soils
- 2007
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Ingår i: Water, Air, & Soil Pollution: Focus. - : Springer Science and Business Media LLC. - 1573-2940 .- 1567-7230. ; 7:1, s. 201-210
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedThe effects of harvesting on the long-term mass balances of calcium (Ca), magnesium (Mg) and potassium (K) were evaluated on a regional level in Sweden. A new high-resolution weathering database was used together with estimates of total deposition, losses through harvest and leaching. Estimates were made for pine and spruce separately and for two harvesting intensity scenarios: stem harvesting and whole-tree harvesting. The mass balance calculations showed net losses of Ca and Mg in almost the whole country for both scenarios. The losses were smaller for pine than for spruce. The K balances were mainly positive for pine but negative for spruce. Leaching was a main factor in the mass balances, especially for Ca and Mg. Whole-tree harvesting in spruce forests led to substantially higher net losses of K and Ca than stem harvesting, according to the calculations. In the whole-tree harvesting scenario in spruce forests the estimated yearly net losses of Ca, Mg and K corresponded to at least 5%, 8% and 3% of the pools of exchangeable base cations, respectively, at 25% of the analysed sites. If losses of this magnitude continue the depletion of the pools of Ca, Mg and K may lead to very low base saturation of the soils, possibly accompanied by negative effects on soil fertility, runoff water quality, tree vitality and tree growth within a forest rotation in parts of Sweden. Avoiding whole-tree harvesting can improve the situation substantially for K, but the losses of Ca and Mg will still be significant.
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| 2. |
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| 3. |
- Tovedal, Thomas, et al.
(författare)
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Blood Flow Quantitation by Positron Emission Tomography During Selective Antegrade Cerebral Perfusion
- 2017
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Ingår i: Annals of Thoracic Surgery. - : Elsevier BV. - 0003-4975 .- 1552-6259. ; 103:2, s. 610-616
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Perfusion strategies during aortic surgery usually comprise hypothermic circulatory arrest (HCA), often combined with selective antegrade cerebral perfusion (SACP) or retrograde cerebral perfusion. Cerebral blood flow (CBF) is a fundamental parameter for which the optimal level has not been clearly defined. We sought to determine the CBF at a pump flow level of 6 mL/kg/min, previously shown likely to provide adequate SACP at 20°C in pigs.METHODS: Repeated positron emission tomography (PET) scans were used to quantify the CBF and glucose metabolism throughout HCA and SACP including cooling and rewarming. Eight pigs on cardiopulmonary bypass were assigned to either HCA alone (n = 4) or HCA+SACP (n = 4). The CBF was measured by repeated [(15)O]water PET scans from baseline to rewarming. The cerebral glucose metabolism was examined by [(18)F]fluorodeoxyglucose PET scans after rewarming to 37°C.RESULTS: Cooling to 20°C decreased the cortical CBF from 0.31 ± 0.06 at baseline to 0.10 ± 0.02 mL/cm(3)/min (p = 0.008). The CBF was maintained stable by SACP of 6 mL/kg/min during 45 minutes. After rewarming to 37°C, the mean CBF increased to 0.24 ± 0.07 mL/cm(3)/min, without significant differences between the groups at any time-point exclusive of the HCA period. The net cortical uptake (Ki) of [(18)F]fluorodeoxyglucose after rewarming showed no significant difference between the groups.CONCLUSIONS: Cooling autoregulated the CBF to 0.10 mL/cm(3)/min, and 45 minutes of SACP at 6 mL/kg/min maintained the CBF in the present model. Cerebral glucose metabolism after rewarming was similar in the study groups.
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| 4. |
- Akselsson, Cecilia, et al.
(författare)
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The influence of N load and harvest intensity on the risk of P limitation in Swedish forest soils
- 2008
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 1879-1026 .- 0048-9697. ; 404, s. 284-289
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Tidskriftsartikel (refereegranskat)abstract
- Nitrogen (N) is often considered to be the major factor limiting tree growth in northern forest ecosystems. An increased N availability, however, increases the demand for other nutrients such as base cations and phosphorous (P) which in turn may change which nutrient is the limiting factor. If P or base cations become limiting, N will start to leach which means a risk of increased eutrophication of surface waters. As many studies focus on base cations, this study instead aims at estimating P budgets on a regional scale for different harvesting scenarios relevant for Swedish conditions. P budget calculations were carried out for 14,550 coniferous sites from the Swedish National Forest Inventory, as weathering+deposition–harvesting–leaching. Three scenarios with different harvest intensities were used: 1) no harvesting, 2) stem harvesting and 3) wholetree harvesting. The input data were derived from measurements and model results. The P budget estimates indicate that harvesting, especially whole-tree harvesting, result in net losses of P in large parts of Sweden. The highest losses were found in southern Sweden due to high growth rate in this area. In the whole-tree harvesting scenario the losses exceeded 1 kg ha−1 y−1 on many sites. N budget calculations on the same sites indicate that N generally accumulates in the whole country and especially in the southern parts. Consequently, the N and P budget calculations indicate that the forests in southern Sweden are in a transition phase from N-to P-limitation to growth. This transition will proceed as long as the accumulation of N continues. These results are important in a sustainable forestry context, as a basis for assessing the risk of future N leaching, and in designing recommendations for abatement strategies of N deposition and for application of wood ash recycling and N fertilization.
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| 5. |
- Edvinsson, Marie, 1976-
(författare)
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Chlamydophila pneumoniae in Cardiovascular Diseases : Clinical and Experimental Studies
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chlamydophila pneumoniae (C. pneumoniae) has been suggested as a stimulator of chronic inflammation in atherosclerosis. C. pneumoniae DNA was demonstrated in aortic biopsies in 50% of patients with stable angina pectoris or acute coronary syndrome undergoing coronary artery bypass grafting. C. pneumoniae mRNA, a marker of replicating bacteria, was demonstrated in 18% of the aortic biopsies. Inflammation may have a role in the pathogenesis of thoracic aortic aneurysm, aortic dissection and aortic valve stenosis. C. pneumoniae DNA was demonstrated in aortic biopsies in 26% of thoracic aortic aneurysm patients and in 11% of aortic dissection patients undergoing thoracic surgery and in 22% of stenotic aortic heart valves from patients undergoing aortic valve replacement. No bacterial mRNA was demonstrated in these aortic biopsies, nor in the valves, suggesting that the infection has passed into a persistent state. C. pneumoniae DNA was demonstrated in peripheral blood mononuclear cells in only 5% of aortic valve stenosis patients and not in thoracic aortic aneurysm or aortic dissection patients, suggesting that the bacterium disseminated to the cardiovascular tissue long before the patient required surgery. The copper/zinc ratio in serum, a marker of infection/inflammation, was significantly elevated in thoracic aortic aneurysm patients, supporting an inflammatory pathogenesis. Patients positive for C. pneumoniae in the aortic valve had more advanced coronary atherosclerosis, further supporting a possible role for C. pneumoniae in atherosclerosis. Mice were infected with C. pneumoniae that disseminated to all organs investigated (i.e. lungs, heart, aorta, liver and spleen). Trace element concentrations were altered in infected animals with an increased copper/zinc ratio in serum, a progressively increased iron concentration in the liver and a progressively decreased iron concentration in serum. Iron is important for C. pneumoniae metabolism, and a changed iron homeostasis was noted in infected mice by alterations in iron-regulating proteins, such as DMT1 and hepcidin.
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| 6. |
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| 7. |
- Edvinsson, Marie, et al.
(författare)
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Trace Element Changes in Thoracic Aortic Dissection
- 2016
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Ingår i: Biological Trace Element Research. - : Springer Science and Business Media LLC. - 0163-4984 .- 1559-0720. ; 169:2, s. 159-163
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Tidskriftsartikel (refereegranskat)abstract
- Thoracic aortic dissection is a life-threatening condition with an incompletely understood pathogenesis. Trace elements are essential for the functioning of different processes in the body, including the immune system and associated responses to infection/inflammation. Because inflammation may be part of the pathogenesis of thoracic aortic dissection, we investigated whether trace element changes associated with inflammation occur in serum and tissue samples during the disease. The study included 21 patients undergoing surgery for thoracic aortic dissection, 10 forensic autopsy specimens for tissue controls and 23 healthy blood donors for serum controls. Levels of magnesium (Mg), calcium (Ca), vanadium (V), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd) and mercury (Hg) were measured in the aortic tissue and serum by inductively coupled plasma-mass spectrometry (ICP-MS). In the serum, Ca, V, Cu and Zn decreased, whereas Fe increased. In the tissue, Cu and Zn decreased and Fe tended to increase. The Cu/Zn ratio in the serum, a marker of infection/inflammation, did not change in the patients. Concerning trace element changes in the serum and tissue, our data do not support the hypothesis that inflammation is involved in the pathogenesis of thoracic aortic dissection.
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| 8. |
- Enell, Anja, et al.
(författare)
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Polycyclic aromatic hydrocarbons in ash: Determination of total and leachable concentrations
- 2008
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 152:2, s. 285-292
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Tidskriftsartikel (refereegranskat)abstract
- Before wood ash can be used as a soil fertilizer, concentrations of environmentally hazardous compounds must be investigated. In this study, total and leachable concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in four ash samples and one green liquor sludge. The ash sample with the highest carbon content also contained high levels of PAHs; three of the ash samples had total concentrations exceeding the limit permitted by the Swedish Forest Agency for recycling to forest soils. The leachable concentrations were higher for the nonstabilized samples; this was probably due to colloid-facilitated transport of the contaminants in these samples. However, the leachable concentrations were overall relatively low in all the samples studied. The amounts of PAHs introduced to forest soils by additions of stabilized, recyclable ash products will be determined primarily by the rate of weathering of the ash particles and the total concentration of contaminants.
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| 9. |
- Eriksson, Mats-Ola, et al.
(författare)
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Morphologic Outcome after Endovascular Treatment of Complicated Type B Aortic Dissection
- 2013
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Ingår i: Journal of Vascular and Interventional Radiology. - : Elsevier BV. - 1051-0443 .- 1535-7732. ; 24:12, s. 1826-1833
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE:To investigate the long-term morphologic changes of the aorta after thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissection and to analyze whether these changes differed between DeBakey class IIIa and IIIb dissections.MATERIALS AND METHODS:During the period 1999-2009, 58 patients with acute complicated type B aortic dissection were treated with TEVAR. Seven patients lacked follow-up data, leaving 51 patients-17 patients with DeBakey IIIa aortic dissection and 34 patients with DeBakey IIIa aortic dissection IIIb-for inclusion in the study. Computed tomography scans performed before and after TEVAR were evaluated. Maximum thoracic and abdominal aortic diameters and diameters of the true lumen and false lumen at the level of the maximum aortic diameter in the thorax and abdomen were analyzed as well as degree of thrombosis of the false lumen.RESULTS:There was an overall significant reduction of the thoracic aortic diameter, increased true lumen diameter, and reduced false lumen diameter (P < .05). Total thrombosis of the false lumen, with or without reintervention, was seen in 53% of all patients, in 41% primarily and in 12% after reintervention. The IIIa group had a higher degree of total false lumen thrombosis. All patients in the IIIb group had total thrombosis of the false lumen along the stent graft.CONCLUSIONS:Long-term follow-up showed favorable aortic remodeling after TEVAR for acute complicated type B aortic dissection. Total thrombosis of the false lumen occurred more often in patients with DeBakey IIIa aortic dissection compared with patients with DeBakey IIIb aortic dissection.
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