| 1. |
- Fellinger, Joris, et al.
(författare)
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Tungsten based divertor development for Wendelstein 7-X
- 2023
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Ingår i: Nuclear Materials and Energy. - 2352-1791. ; 37
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Tidskriftsartikel (refereegranskat)abstract
- Wendelstein 7-X, the world’s largest superconducting stellarator in Greifswald (Germany), started plasma experiments with a water-cooled plasma-facing wall in 2022, allowing for long pulse operation. In parallel, a project was launched in 2021 to develop a W based divertor, replacing the current CFC divertor, to demonstrate plasma performance of a stellarator with a reactor relevant plasma facing materials with low tritium retention. The project consists of two tasks: Based on experience from the previous experimental campaigns and improved physics modelling, the geometry of the plasma-facing surface of the divertor and baffles is optimized to prevent overloads and to improve exhaust. In parallel, the manufacturing technology for a W based target module is qualified. This paper gives a status update of project. It focusses on the conceptual design of a W based target module, the manufacturing technology and its qualification, which is conducted in the framework of the EUROfusion funded WPDIV program. A flat tile design in which a target module is made of a single target element is pursued. The technology must allow for moderate curvatures of the plasma-facing surface to follow the magnetic field lines. The target element is designed for steady state heat loads of 10 MW/m2 (as for the CFC divertor). Target modules of a similar size and weight as for the CFC divertor are assumed (approx. < 0.25 m2 and < 60 kg) using the existing water cooling infrastructure providing 5 l/s and roughly maximum 15 bar pressure drop per module. The main technology under qualification is based on a CuCrZr heat sink made either by additive manufacturing using laser powder bed fusion (LPBF) or by uniaxial diffusion welding of pre-machined forged CuCrZr plates. After heat treatment, the plasma-facing side of the heat sink is covered by W or if feasible by the more ductile WNiFe, preferably by coating or alternatively by hot isostatic pressing W based tiles with a soft OFE-Cu interlayer. Last step is a final machining of the plasma-exposed surface and the interfaces to the water supply lines and supports to correct manufacturing deformations.
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| 2. |
- Vrethem, Magnus, 1955-, et al.
(författare)
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Chronic symptoms are common in patients with neuroborreliosis - A questionnaire follow-up study
- 2002
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Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 106:4, s. 205-208
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Tidskriftsartikel (refereegranskat)abstract
- Objectives - The existence of chronic neuroborreliosis is controversial. The aim of our study was to investigate the existence and kind of persistent symptoms in patients previously treated because of neurological symptoms as a result of neuroborreliosis. Material and methods - A total of 106 patients with neuroborreliosis, according to established criteria, and a control group of 123 patients with Borrelia induced erythema migrans diagnosed in a general practitioner office were studied. A questionnaire was sent to patients and controls concerning their health situation. Time from onset of neurological symptoms to the questionnaire sendout was 32 months (mean) for the patients with neuroborreliosis and 33 months (mean) for the controls. Results - Fifty per cent of the individuals in the patient group compared with 16% of the individuals in the control group showed persistent complaints after their Borrelia infection (P < 0.0001). The most significant differences between the groups were the presence of neuropsychiatric symptoms such as headache, attention problems, memory difficulties and depression. Paresthesia, pain and persistent facial palsy was also significantly more common in patients treated because of neuroborreliosis. Conclusion - Our study shows that persisting neurological symptoms are common after a neuroborreliosis infection. The pathological mechanisms that lay behind the development of chronic symptoms, however, are still uncertain.
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| 3. |
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| 4. |
- Elmstedt, Nina, et al.
(författare)
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Temporal frequency requirements for tissue velocity imaging of the fetal heart
- 2011
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Ingår i: Ultrasound in Obstetrics and Gynecology. - : Wiley. - 0960-7692 .- 1469-0705. ; 38:4, s. 413-417
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The high velocity and short duration of myocardial motion requires a high sampling rate to obtain adequate temporal resolution; this issue becomes even more important when taking into consideration the high fetal heart rate. In this study we have established optimal sampling requirements for assessing the duration of various cardiac cycle events and myocardial velocities of the fetal heart using color-coded tissue velocity imaging (TVI). Methods Recordings from 30 fetuses were acquired at an initial frame rate of 180-273 frames/s. All TVI recordings were performed from an apical four-chamber view and stored as cineloops of five to 10 consecutive cardiac cycles for subsequent offline analysis using software enabling a reduction in frame rate. Different components of the myocardial velocity curve, obtained from the basal part of the ventricular septum, were measured at the initial frame rate and compared with their equivalents at gradually decreased frame rates. Results As acquisition frame rate was reduced, there was a marked increase in deviation from the initial values, resulting in an underestimation of all systolic and diastolic velocities. For the measured durations, there was a clear tendency to underestimate isovolumetric contraction and relaxation, and a clear tendency to overestimate ventricular ejection and diastolic E-wave and A-wave. An acceptable <= 5% deviation from the value obtained at the highest frame rate corresponded to measurements obtained at above 150-200 frames/s. Conclusions A high sampling rate of at least 200 frames/s is necessary for adequate reconstruction of TVI data for the fetal heart. Frame rates that are too low result in considerable loss of temporal and velocity information.
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| 5. |
- Herling, L., et al.
(författare)
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Automated analysis of fetal cardiac function using color tissue Doppler imaging
- 2018
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Ingår i: Ultrasound in Obstetrics and Gynecology. - : Wiley. - 0960-7692 .- 1469-0705. ; 52:5, s. 599-608
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Tidskriftsartikel (refereegranskat)abstract
- Objective To evaluate the feasibility of automated analysis of fetal myocardial velocity recordings obtained by color tissue Doppler imaging (cTDI). Methods This was a prospective cross-sectional observational study of 107 singleton pregnancies >= 41 weeks of gestation. Myocardial velocity recordings were obtained by cTDI in a long-axis four-chamber view of the fetal heart. Regions of interest were placed in the septum and the right (RV) and left (LV) ventricular walls at the level of the atrioventricular plane. Peak myocardial velocities and mechanical cardiac time intervals were measured both manually and by an automated algorithm and agreement between the two methods was evaluated. Results In total, 321 myocardial velocity traces were analyzed using each method. It was possible to analyze all velocity traces obtained from the LV, RV and septal walls with the automated algorithm, and myocardial velocities and cardiac mechanical time intervals could be measured in 96% of all traces. The same results were obtained when the algorithm was run repeatedly. The myocardial velocities measured using the automated method correlated significantly with those measured manually. The agreement between methods was not consistent and some cTDI parameters had considerable bias and poor precision. Conclusions Automated analysis of myocardial velocity recordings obtained by cTDI was feasible, suggesting that this technique could simplify and facilitate the use of cTDI in the evaluation of fetal cardiac function, both in research and in clinical practice.
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| 6. |
- Herling, L., et al.
(författare)
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Automated analysis of fetal cardiac function using color tissue Doppler imaging in second half of normal pregnancy
- 2019
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Ingår i: Ultrasound in Obstetrics and Gynecology. - : WILEY. - 0960-7692 .- 1469-0705. ; 53:3, s. 348-357
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Color tissue Doppler imaging (cTDI) is a promising tool for the assessment of fetal cardiac function. However, the analysis of myocardial velocity traces is cumbersome and time-consuming, limiting its application in clinical practice. The aim of this study was to evaluate fetal cardiac function during the second half of pregnancy and to develop reference ranges using an automated method to analyze cTDI recordings from a cardiac four-chamber view. Methods This was a cross-sectional study including 201 normal singleton pregnancies between 18 and 42weeks of gestation. During fetal echocardiography, a four-chamber view of the heart was visualized and cTDI was performed. Regions of interest were positioned at the level of the atrioventricular plane in the left ventricular (LV), right ventricular (RV) and septal walls of the fetal heart, to obtain myocardial velocity traces that were analyzed offline using the automated algorithm. Peak myocardial velocities during atrial contraction (Am), ventricular ejection (Sm) and rapid ventricular filling, i. e. early diastole (Em), as well as the Em/Am ratio, mechanical cardiac time intervals and myocardial performance index (cMPI) were evaluated, and gestational age-specific reference ranges were constructed. Results At 18 weeks of gestation, the peak myocardial velocities, presented as fitted mean with 95% CI, were: LV Am, 3.39 (3.09-3.70) cm/s; LV Sm, 1.62 (1.46-1.79) cm/s; LV Em, 1.95 (1.75-2.15) cm/s; septal Am, 3.07 (2.80-3.36) cm/s; septal Sm, 1.93 (1.81-2.06) cm/s; septal Em, 2.57 (2.32-2.84) cm/s; RV Am, 4.89 (4.59-5.20) cm/s; RV Sm, 2.31 (2.16-2.46) cm/s; and RV Em, 2.94 (2.69-3.21) cm/s. At 42weeks of gestation, the peak myocardial velocities had increased to: LV Am, 4.25 (3.87-4.65) cm/s; LV Sm, 3.53 (3.19-3.89) cm/s; LV Em, 4.55 (4.18-4.94) cm/s; septal Am, 4.49 (4.17-4.82) cm/s; septal Sm, 3.36 (3.17-3.55) cm/s; septal Em, 3.76 (3.51-4.03) cm/s; RV Am, 6.52 (6.09-6.96) cm/s; RV Sm, 4.95 (4.59-5.32) cm/s; and RV Em, 5.42 (4.99-5.88) cm/s. The mechanical cardiac time intervals generally remained more stable throughout the second half of pregnancy, although, with increased gestational age, there was an increase in duration of septal and RV atrial contraction, LV pre-ejection and septal and RV ventricular ejection, while there was a decrease in duration of septal postejection. Regression equations used for the construction of gestational age-specific reference ranges for peak myocardial velocities, Em/Am ratios, mechanical cardiac time intervals and cMPI are presented. Conclusion Peak myocardial velocities increase with gestational age, while the mechanical time intervals remain more stable throughout the second half of pregnancy. Using an automated method to analyze cTDI-derived myocardial velocity traces, it was possible to construct reference ranges, which could be used in distinguishing between normal and abnormal fetal cardiac function.
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| 7. |
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| 8. |
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| 9. |
- Rondelet, A., et al.
(författare)
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Clathrin's adaptor interaction sites are repurposed to stabilize microtubules during mitosis
- 2020
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Ingår i: Journal of Cell Biology. - : Rockefeller University Press. - 0021-9525 .- 1540-8140. ; 219:2
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Tidskriftsartikel (refereegranskat)abstract
- Clathrin ensures mitotic spindle stability and efficient chromosome alignment, independently of its vesicle trafficking function. Although clathrin localizes to the mitotic spindle and kinetochore fiber microtubule bundles, the mechanisms by which clathrin stabilizes microtubules are unclear. We show that clathrin adaptor interaction sites on clathrin heavy chain (CHC) are repurposed during mitosis to directly recruit the microtubule-stabilizing protein GTSE1 to the spindle. Structural analyses reveal that these sites interact directly with clathrin-box motifs on GTSE1. Disruption of this interaction releases GTSE1 from spindles, causing defects in chromosome alignment. Surprisingly, this disruption destabilizes astral microtubules, but not kinetochore-microtubule attachments, and chromosome alignment defects are due to a failure of chromosome congression independent of kinetochore-microtubule attachment stability. GTSE1 recruited to the spindle by clathrin stabilizes microtubules by inhibiting the microtubule depolymerase MCAK. This work uncovers a novel role of clathrin adaptor-type interactions to stabilize nonkinetochore fiber microtubules to support chromosome congression, defining for the first time a repurposing of this endocytic interaction mechanism during mitosis.
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| 10. |
- Troein, Margareta, et al.
(författare)
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Understanding the unperceivable: ideas about cholesterol expressed by middle-aged men with recently discovered hypercholesterolaemia
- 1997
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Ingår i: Family Practice. - 1460-2229. ; 14:5, s. 376-381
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We aimed to describe the perception of hypercholesterolaemia among middle-aged, urban men who had recently received the diagnosis of moderate hypercholesterolaemia. METHOD: Within a project screening for risk factors for coronary heart disease among 453 men, 63 were identified as moderately hypercholesterolaemic. Among these, 62 agreed to tape-recording and transcription of the first counselling on lipid-lowering, supplied by a registered nurse. The counselling was tailored to fit the needs of the individual patient, taking a starting point in whatever questions the patient expressed. The transcripts of the counselling sessions were analysed for their content. RESULTS: Five major themes were addressed by the men. It was hard to understand and accept the concept of hypercholesterolaemia, as the men did not feel unwell, and thus they did not receive any cues to taking action. Obesity and smoking was regarded as causes of hypercholesterolaemia, although the link between life-style and cholesterol level was unclear. Some men were aware of heredity traits of hypercholesterolaemia. Treatment suggestions included weight reduction and drug treatment, although there were ambiguous feelings towards drugs. Numerous misconceptions about diet were found. Many men expressed resistance to life-style changes and questioned the benefits of risk reduction. Information about hypercholesterolaemia was regarded as unreliable, as different sources gave incongruent information, and the information from individual sources changed over time. CONCLUSION: Unless medical professionals counselling patients for asymptomatic risk factors make efforts to disclose patients' conceptions of the condition, patients may misunderstand and counselling may become ineffective.
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| 11. |
- Widlund, Hans R., et al.
(författare)
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Identification and characterization of genomic nucleosome-positioning sequences
- 1997
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836. ; 267, s. 807-817
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Tidskriftsartikel (refereegranskat)abstract
- Positioned nucleosomes are believed to play important roles in transcriptional regulation and for the organization of chromatin in cell nuclei. Here, we have isolated the DNA segments in the mouse genome that form the most stable nucleosomes yet characterized. In separate molecules we find phased runs of three to four adenine nucleotides, extensive CA repeats, and in a few cases phased TATA tetranucleotides. The latter forms the most stable nucleosome yet characterized. One sequence with CAG repeats was also found. By fluorescence in situ hydridization the selected sequences are shown to be localized at the centromeric regions of mouse metaphase chromosomes.
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| 12. |
- Woodruff, J. B., et al.
(författare)
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Regulated assembly of a supramolecular centrosome scaffold in vitro
- 2015
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 348:6236, s. 808-812
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Tidskriftsartikel (refereegranskat)abstract
- The centrosome organizes microtubule arrays within animal cells and comprises two centrioles surrounded by an amorphous protein mass called the pericentriolar material (PCM). Despite the importance of centrosomes as microtubule-organizing centers, the mechanism and regulation of PCM assembly are not well understood. In Caenorhabditis elegans, PCM assembly requires the coiled-coil protein SPD-5.We found that recombinant SPD-5 could polymerize to form micrometer-sized porous networks in vitro. Network assembly was accelerated by two conserved regulators that control PCM assembly in vivo, Polo-like kinase-1 and SPD-2/Cep192. Only the assembled SPD-5 networks, and not unassembled SPD-5 protein, functioned as a scaffold for other PCM proteins. Thus, PCM size and binding capacity emerge from the regulated polymerization of one coiled-coil protein to form a porous network.
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| 13. |
- Zabeo, Davide, 1992, et al.
(författare)
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A lumenal interrupted helix in human sperm tail microtubules
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Eukaryotic flagella are complex cellular extensions involved in many human diseases gathered under the term ciliopathies. Currently, detailed insights on flagellar structure come mostly from studies on protists. Here, cryo-electron tomography (cryo-ET) was performed on intact human spermatozoon tails and showed a variable number of microtubules in the singlet region (inside the end-piece). Inside the microtubule plus end, a novel left-handed interrupted helix which extends several micrometers was discovered. This structure was named Tail Axoneme Intra-Lumenal Spiral (TAILS) and binds directly to 11 protofilaments on the internal microtubule wall, in a coaxial fashion with the surrounding microtubule lattice. It leaves a gap over the microtubule seam, which was directly visualized in both singlet and doublet microtubules. We speculate that TAILS may stabilize microtubules, enable rapid swimming or play a role in controlling the swimming direction of spermatozoa.
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