| 1. |
|
|
| 2. |
- Dahlbäck, Charlotte, et al.
(författare)
-
Abnormal ductus venosus pulsatility index in the absence of concurrent umbilical venous pulsations does not indicate worsening fetal condition.
- 2013
-
Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 42:3, s. 322-328
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Recordings of blood flow velocity waveform in the ductus venosus (DV) and the umbilical vein (UV) are routinely used in order to predict the fetal condition in high-risk pregnancies. This study investigates the relationship between pathological blood flow in the two vessels and perinatal outcome. METHODS: High-risk pregnancies (n=11865) admitted during 1993-2011 for blood flow examinations, including recordings of DV pulsatility index for veins (PIV) and UV pulsations, were included. The results were related to perinatal outcome, using the last Doppler examination prior to delivery in analysis. RESULTS: Abnormal DV PIV was observed in 3,96%, intra-abdominal UV-pulsations in 1,3% and pulsations in the cord in 0,7% of the cases. As expected, the rate of UV-pulsations increased with increasing DV PIV z-score. Fetuses with a pathological DV PIV, but without UV pulsations showed no signs of compromise. This was also true for cases with a DV PIV >4 SD above the mean (53.7 % had a steady flow in the UV). In contrast, the occurrence of UV-pulsations seems to be an indicator of fetal compromise regardless of level of DV PIV. CONCLUSIONS: Abnormal fetal venous blood velocity is related to adverse outcome of high-risk pregnancies. However, abnormal DV PIV is not an indicator of fetal compromise unless UV-pulsations are concurrently present and should be regarded as an artifact and not an indication for emergency delivery.
|
|
| 3. |
- Garcia Wernersson, Joakim, et al.
(författare)
-
Non-destructive density measurements of pharmaceutical products by THz imaging
- 2016
-
Ingår i: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. - 9781467384858 ; 2016-November, s. Art. no 7758615-
-
Konferensbidrag (refereegranskat)abstract
- In this paper, measurements with a THz imaging system at 346 GHz together with electromagnetic simulations have demonstrated the capability of THz sensing for the non-destructive density determination of intermediate products in the pharmaceutical industry. The results confirm the ability of THz imaging to detect density changes in pharmaceutical samples by measuring the phase variation of the wave transmitted through the sample.
|
|
| 4. |
|
|
| 5. |
- Ljunggren, Stefan, 1988-
(författare)
-
Lipoproteomics : Environmental and Genetic Factors Affecting High-Density Lipoprotein (HDL)
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lipoprotein particles act as lipid transporters in the blood stream, and measuring cholesterol content in specific subclasses of lipoprotein particles has long been, and still is, a frequently used tool to estimate the risk of cardiovascular disease (CVD). High-density lipoprotein (HDL) is a subclass of lipoproteins often regarded as providing protection against CVD via several functions including reverse cholesterol transport and anti-inflammatory capacities. However, the precise relationship between HDL cholesterol levels and health outcome is still unclear. Lately, new approaches to study HDL composition and function have therefore become more important.HDL function is to a large extent dependent on its proteome, containing more than 100 proteins. Investigating the proteome in individuals with altered gene expression for HDL-associated proteins or with known exposure to environmental contaminants may reveal new insights into how HDL metabolism is affected by various factors. This is of interest in order to better understand the role of HDL in CVD.Papers I and II focus on two different mutations in a structural HDL protein, apolipoprotein A-I (L202P and K131del), and one mutation in the scavenger receptor class B-1 (P297S), which is involved in selective lipid uptake of cholesterol mainly into hepatocytes and adrenal cells. The HDL proteome was analyzed using two-dimensional gel electrophoresis and mass spectrometry. The L202P mutation was identified in HDL of the heterozygote carriers together with a significant decrease of apolipoprotein E and increased zinc-alpha-2-glycoprotein. By contrast, the second apolipoprotein AI mutation (K131del) was associated with significantly elevated alpha-1-antitrypsin and transthyretin levels. Protein analyses of the scavenger receptor class B1 P297S heterozygotes showed a significant increase in HDL apoL-1 along with increased free apoE. The carriers showed no difference in antioxidative capability but a significant increase in apoA-I methionine oxidation.Papers III and IV focus on persistent organic pollutants that may influence HDL composition and function. These compounds accumulate in humans, and exposure has been linked to an increased risk of CVD. To provide a better understanding of the HDL system in relation to pollutants, a population living in a contaminated area was studied. Persistent organic pollutants in isolated HDL were quantified using high-resolution gas chromatography mass spectrometry and significantly increased levels were found in individuals with CVD as compared to healthy controls. Furthermore, there was a significant negative association between the pollutants and paraoxonase-1 anti-oxidant activity. Studying the proteome with nano-liquid chromatography tandem mass spectrometry led to the identification of 118 proteins in HDL, of which ten were significantly associated with the persistent organic pollutants.In summary, the present studies demonstrate protein pattern alterations in HDL associated with inherited genetic variants or pollutant exposure. The studies also provide a set of methods that are useful tools to further comprehend the complexity of lipoprotein metabolism and function. The results are important in order to improve our understanding of HDL in CVD and to explain an increased risk of CVD associated with exposure to organic pollutants.
|
|
| 6. |
- Lundström, Ludvig, et al.
(författare)
-
Influence on the stability of generator rotors due to radial and tangential magnetic pull force
- 2007
-
Ingår i: IET Electric Power Applications. - : Institution of Engineering and Technology (IET). - 1751-8660 .- 1751-8679. ; 1:1, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- Forces due to nonuniform airgaps in rotating electrical machines have been a researchtopic for over 100 years. However, most research in the area of rotating electrical machines hasbeen performed on motors. Large forces in hydropower generators can lead to expensive damageand failures. Therefore, it is of interest to calculate the forces that arise in a large synchronousgenerator with an eccentric rotor and study the influence these forces have on the stability of thegenerator rotor. A 74 MVA synchronous hydropower generator was simulated with an eccentricrotor, using a time-stepping finite-element technique. The forces were calculated using Coulomb’svirtual-work method and simulations were performed for no-load and load cases. The resultingforce was found to be reduced significantly when a damper winding was taken into account. Aninteresting effect of the rotor damper winding was that it reduced the eccentricity force andintroduced a force component perpendicular to the direction of eccentricity. The results from thefinite-element simulations were used to determine how the forces affect the stability of the generatorrotor. Damped natural eigenfrequencies and damping ratio for load and no-load conditions arepresented. When applying the forces computed in the time-dependent model, the damped naturaleigenfrequencies were found to increase and the stability of the generator rotor was found to bereduced compared with when the forces were computed in a stationary model.
|
|
| 7. |
- Segergren, Erik, 1974-
(författare)
-
Direct Drive Generator for Renewable Power Conversion from Water Currents
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis permanent magnet direct drive generator for power conversion from water currents is studied. Water currents as a power source involves a number of constrains as well as possibilities, especially when direct drive and permanent magnets are considered. The high power fluxes and low current velocities of a water current, in combination with its natural variations, will affect the way the generator is operated and, flowingly, the appearance of the generator. The work in this thesis can, thus, be categorized into two general topics, generator technology and optimization. Under the first topic, fundamental generator technology is used to increase the efficiency of a water current generator. Under the latter topic, water current generators are optimized to a specific environment. The conclusion drawn from this work is that it is possible to design very low speed direct drive generators with good electromagnetic properties and wide efficiency peak.
|
|
| 8. |
- Sundell, Gustav, 1985, et al.
(författare)
-
Redistribution of alloying elements in Zircaloy-2 after in-reactor exposure
- 2014
-
Ingår i: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115. ; 454:1-3, s. 178-185
-
Tidskriftsartikel (refereegranskat)abstract
- An atom probe tomography study of the microstructure of a Zircaloy-2 material subjected to 9 annual cycles of BWR exposure has been conducted. Upon dissolution of secondary phase particles, Fe and Cr are seen to reprecipitate in large numbers of clusters and particles of 1-5 nm sizes throughout the Zr metal matrix. Fe and Sn were observed to segregate to ring-shaped features in the metal that are interpreted to be -component vacancy loops. This implies that these two elements play a major role in the irradiation growth phenomenon in Zr alloys, which is believed to be caused by the formation of -loops. Similarly to autoclave-corroded Zr alloys, the formation of a sub-oxide layer of approximate composition ZrO was observed. On the other hand, no oxygen saturated metal phase was detected underneath the oxide scale.
|
|
| 9. |
- Tejland, Pia, 1978, et al.
(författare)
-
Detailed analysis of the microstructure of the metal/oxide interface region in Zircaloy-2 after autoclave corrosion testing
- 2011
-
Ingår i: ASTM Special Technical Publication. 16th International Symposium on Zirconium in the Nuclear Industry, Chengdu, Sinchuan Province, 9-13 May 2010. - 0066-0558. - 9780803175150 ; 1529 STP, s. 595-617
-
Konferensbidrag (refereegranskat)abstract
- Two varieties of Zircaloy-2, with different second phase particle (SPP) size distributions and different corrosion resistance, were oxidized in a steam autoclave. Transmission electron microscopy (TEM) of large thin-foil cross-sections of the oxide and the adjacent metal shows an undulating metal/oxide interface in both materials with a periodicity of slightly less than 1 μm and an amplitude of around 100 nm. The SPPs oxidize slower than the surrounding metal, and the absence of volume increase leads to void and crack formation as the SPPs become embedded in the oxide. On SPP oxidation, iron diffuses out of the particles into the surrounding oxide. A sub-oxide with an oxygen content of approximately 50 at. % and a layer thickness of about 200 nm was observed close to the metal/oxide interface. There is a 200 nm oxygen concentration gradient into the metal, from the level close to the sub-oxide of about 30 at. % down to a few atomic percent. All tin in the matrix is incorporated in the sub-oxide, and no segregation to the metal/oxide interface was found.
|
|
| 10. |
|
|
