| 61. |
- Gustafsson, Anders, et al.
(författare)
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Cathodoluminescence investigations of dark-line defects in platelet-based InGaN nano-LED structures
- 2024
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Ingår i: Nanotechnology. - : IOP Publishing Ltd. - 0957-4484 .- 1361-6528. ; 35:25
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the optical properties of heterostructured InGaN platelets aiming at red emission, intended for use as nano-scaled light-emitting diodes. The focus is on the presence of non-radiative emission in the form of dark line defects. We have performed the study using hyperspectral cathodoluminescence imaging. The platelets were grown on a template consisting of InGaN pyramids, flattened by chemical mechanical polishing. These templates are defect free, whereas the dark line defects are introduced in the lower barrier and tend to propagate through all the subsequent layers, as revealed by the imaging of different layers in the structure. We conclude that the dark line defects are caused by stacking mismatch boundaries introduced by multiple seeding and step bunching at the edges of the as-polished, dome shaped templates. To avoid these defects, we suggest that the starting material must be flat rather than dome shaped.
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| 62. |
- Gustafsson, Anders, et al.
(författare)
-
Cathodoluminescence investigations of dark-line defects in platelet-based InGaN nano-LED structures
- 2024
-
Ingår i: Nanotechnology. - : IOP Publishing Ltd. - 0957-4484 .- 1361-6528. ; 35:25
-
Tidskriftsartikel (refereegranskat)abstract
- We have investigated the optical properties of heterostructured InGaN platelets aiming at red emission, intended for use as nano-scaled light-emitting diodes. The focus is on the presence of non-radiative emission in the form of dark line defects. We have performed the study using hyperspectral cathodoluminescence imaging. The platelets were grown on a template consisting of InGaN pyramids, flattened by chemical mechanical polishing. These templates are defect free, whereas the dark line defects are introduced in the lower barrier and tend to propagate through all the subsequent layers, as revealed by the imaging of different layers in the structure. We conclude that the dark line defects are caused by stacking mismatch boundaries introduced by multiple seeding and step bunching at the edges of the as-polished, dome shaped templates. To avoid these defects, we suggest that the starting material must be flat rather than dome shaped.
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| 63. |
- Gyllensvärd, Frida, 1980-
(författare)
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Efficient Methods for Volumetric Illumination
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modern imaging modalities can generate three-dimensional datasets with a very high detail level. To transfer all the information to the user in an efficient way there is a need for three-dimensional visualization. In order to enhance the diagnostic capabilities the utilized methods must supply the user with fast renderings that are easy to interpret correctly.It can thus be a challenge to visualize a three-dimensional dataset in a way that allows the user to perceive depth and shapes. A number of stereoscopic solutions are available on the market but it is in many situations more practical and less expensive to use ordinary two-dimensional displays. Incorporation of advanced illumination can, however, improve the perception of depth in a rendering of a volume. Cast shadows provide the user with clues of distances and object hierarchy. Simulating realistic light conditions is, however, complex and it can be difficult to reach interactive frame rates. Approximations and clever implementations are consequently required.This thesis presents efficient methods for calculation of illumination with the objective of providing the user with high spatial and shape perception. Two main types of light conditions, a single point light source and omni-directional illumination, are considered. Global transport of light is efficiently estimated using local piecewise integration which allows a graceful speed up compared to brute force techniques. Ambient light conditions are calculated by integrating the incident light along rays within a local neighborhood around each point in the volume.Furthermore, an approach that allows the user to highlight different tissues, using luminous materials, is also available in this thesis. A multiresolution data structure is employed in all the presented methods in order to support evaluation of illumination for large scale data at interactive frame rates.
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| 64. |
- Haflidadottir, Benedikta, et al.
(författare)
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Upregulation of miR-96 Enhances Cellular Proliferation of Prostate Cancer Cells through FOXO1.
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:8
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Tidskriftsartikel (refereegranskat)abstract
- Aberrant expression of miR-96 in prostate cancer has previously been reported. However, the role and mechanism of action of miR-96 in prostate cancer has not been determined. In this study, the diagnostic and prognostic properties of miR-96 expression levels were investigated by qRT-PCR in two well documented prostate cancer cohorts. The miR-96 expression was found to be significantly higher in prostate cancer patients and correlate with WHO grade, and decreased overall survival time; patients with low levels of miR-96 lived 1.5 years longer than patients with high miR-96 levels. The therapeutic potential was further investigated in vitro, showing that ectopic levels of miR-96 enhances growth and cellular proliferation in prostate cancer cells, implying that miR-96 has oncogenic properties in this setting. We demonstrate that miR-96 expression decreases the transcript and protein levels of FOXO1 by binding to one of two predicted binding sites in the FOXO1 3'UTR sequence. Blocking this binding site completely inhibited the growth enhancement conveyed by miR-96. This finding was corroborated in a large external prostate cancer patient cohort where miR-96 expression inversely correlated to FOXO1 expression. Taken together these findings indicate that miR-96 plays a key role in prostate cancer cellular proliferation and can enhance prostate cancer progression. This knowledge might be utilized for the development of novel therapeutic tools for prostate cancer.
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| 65. |
- Hagman, Zandra, et al.
(författare)
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The tumour suppressor miR-34c targets MET in prostate cancer cells.
- 2013
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 109:5, s. 1271-1278
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Tidskriftsartikel (refereegranskat)abstract
- Background:The microRNA, miR-34c, is a well-established regulator of tumour suppression. It is downregulated in most forms of cancers and inhibits malignant growth by repressing genes involved in processes such as proliferation, anti-apoptosis, stemness, and migration. We have previously reported downregulation and tumour suppressive properties for miR-34c in prostate cancer (PCa).Methods:In this study, we set out to further characterize the mechanisms by which miR-34c deregulation contributes to PCa progression. The genes regulated by miR-34c in the PCa cell line PC3 were identified by microarray analyses and were found to be enriched in cell death, cell cycle, cellular growth, and cellular movement pathways. One of the identified targets was MET, a receptor tyrosine kinase activated by hepatocyte growth factor, that is crucial for metastatic progression.Results:We confirmed the inhibitory effect of miR-34c on both MET transcript and protein levels. The binding of miR-34c to two binding sites in the 3'-UTR of MET was validated using luciferase reporter assays and target site blockers. The effect of this regulation on the miR-34c inhibition of the migratory phenotype was also confirmed. In addition, a significant inverse correlation between miR-34c expression levels and MET immunostaining was found in PCa patients.Conclusion:These findings provide a novel molecular mechanism of MET regulation in PCa and contribute to the increasing evidence that miR-34c has a key tumour suppressive role in PCa.British Journal of Cancer advance online publication, 6 August 2013; doi:10.1038/bjc.2013.449 www.bjcancer.com.
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| 66. |
- Hagstrom, Emil, et al.
(författare)
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IMPACT OF BODY WEIGHT AT AGE 20 AND WEIGHT GAIN DURING ADULTHOOD ON MIDLIFE CORONARY ARTERY CALCIUM IN 15,000 MEN AND WOMEN : AN INTERIM ANALYSIS OF THE SWEDISH CARDIOPULMONARY BIOIMAGE STUDY
- 2019
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Ingår i: Journal of the American College of Cardiology. - : ELSEVIER SCIENCE INC. - 0735-1097 .- 1558-3597. ; 73:9, s. 1692-1692
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundElevated body weight in adolescence is strongly associated with early cardiovascular disease, but whether this association is traceable to weight in early adulthood, or to weight gain with subsequent high adult weight is not known. Using data from the Swedish CArdioPulmonary bioImage Study (SCAPIS), we investigated the association between weight at age 20, weight gain to midlife and coronary artery calcium score (CACS) at midlife.MethodsIn the first 15,810 participants in SCAPIS (mean age 58 years, 52% women), data on CACS at midlife, self-reported body weight at age 20 and weight at examination in SCAPIS were recorded.ResultsCACS in midlife was significantly higher with increasing weight at age 20 (p<0.001 for both sexes), and then increased with weight gain until midlife at all levels of body weight at age 20 after adjusting for age, height, smoking, alcohol intake, education level, exercise levels and LDL cholesterol. However, the association with weight gain was only significant in men (p = 0.047), not in women (p=0.474). No significant interaction was seen between weight at age 20 and midlife weight with CACS. The effect of weight at age 20 on CACS was significantly more marked in men than in women, as was the effect of weight gain (p<0.001 for both interactions).ConclusionWeight at age 20 and weight gain to midlife were both related to CACS, but much more markedly so in men than in women, indicating a generally larger effect of both early adult weight and further weight gain until midlife on CACS in men, compared to women.
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| 67. |
- Hallgren, Per, et al.
(författare)
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Synthetic estrogen directly affects fish biomass and may indirectly disrupt aquatic food webs
- 2014
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268. ; 33:4, s. 930-936
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Tidskriftsartikel (refereegranskat)abstract
- Endocrine-disrupting chemicals are known to alter the fitness of individual organisms via changes in growth, behavior, and reproduction. It is largely unknown, however, whether these effects cascade through the food web and indirectly affect other, less sensitive organisms. The authors present results from a mesocosm experiment whereby the effects of the synthetic estrogen 17α-ethinylestradiol (EE2) were quantified in pelagic communities. Treatment with EE2 at a concentration of 28 ng/L had no large effects on the pelagic communities composed only of phytoplankton and zooplankton. In communities where planktivorous roach (Rutilus rutilus) were also present, however, EE2 caused a significant reduction in fish biomass. Moreover, zooplankton biomass was higher in the EE2 treatments, suggesting that zooplankton may have been released from fish predation. Hence, the direct effect of EE2 on roach may have cascaded down the food web to produce positive indirect effects on zooplankton. This result was supported in complementary foraging experiments with roach, showing reduced foraging performance after exposure to EE2. Despite the observed negative effect of EE2 on roach and the positive indirect effect on zooplankton, these effects did not cascade to phytoplankton, possibly because only copepods, but not cladocerans—the major grazers in these systems—were released from fish predation. The authors conclude that the known reproductive impairment in fish by EE2 in combination with the disturbed foraging performance observed in the present study may be a disadvantage to fish that may result in increasing abundance or biomass of prey such as zooplankton. Hence, EE2 may have consequences for both the structure and function of freshwater communities.
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| 68. |
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| 69. |
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| 70. |
- Jacobsson, Amanda, et al.
(författare)
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”Ambulanssjukvården behöver genomgripande förändringar”
- 2021
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Ingår i: Dagens Medicin. - : Dagens Medicin. - 1402-1943. ; :2021-06-23
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Debattörer från Ambulance health research network vill se en nationell ledningsstruktur, ökad evidens för vården, akademisk kompetens i ledningsfunktioner samt en nationell utbildnings- och kompetensstandard.
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