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Sökning: WFRF:(Mikkelsen L. H.)

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1.
  • Kanai, M, et al. (författare)
  • 2023
  • swepub:Mat__t
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2.
  • Campbell, PJ, et al. (författare)
  • Pan-cancer analysis of whole genomes
  • 2020
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
  • Tidskriftsartikel (refereegranskat)abstract
    • Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
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  • Stormlund, S., et al. (författare)
  • Freeze-all versus fresh blastocyst transfer strategy during in vitro fertilisation in women with regular menstrual cycles: multicentre randomised controlled trial
  • 2020
  • Ingår i: Bmj-British Medical Journal. - : BMJ. - 1756-1833. ; 370
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE To compare the ongoing pregnancy rate between a freeze-all strategy and a fresh transfer strategy in assisted reproductive technology treatment. DESIGN Multicentre, randomised controlled superiority trial. SETTING Outpatient fertility clinics at eight public hospitals in Denmark, Sweden, and Spain. PARTICIPANTS 460 women aged 18-39 years with regular menstrual cycles starting their first, second, or third treatment cycle of in vitro fertilisation or intracytoplasmic sperm injection. INTERVENTIONS Women were randomised at baseline on cycle day 2 or 3 to one of two treatment groups: the freeze-all group (elective freezing of all embryos) who received gonadotropin releasing hormone agonist triggering and single frozen-thawed blastocyst transfer in a subsequent modified natural cycle; or the fresh transfer group who received human chorionic gonadotropin triggering and single blastocyst transfer in the fresh cycle. Women in the fresh transfer group with more than 18 follicles larger than 11 mm on the day of triggering had elective freezing of all embryos and postponement of transfer as a safety measure. MAIN OUTCOME MEASURES The primary outcome was the ongoing pregnancy rate defined as a detectable fetal heart beat after eight weeks of gestation. Secondary outcomes were live birth rate, positive human chorionic gonadotropin rate, time to pregnancy, and pregnancy related, obstetric, and neonatal complications. The primary analysis was performed according to the intention-to-treat principle. RESULTS Ongoing pregnancy rate did not differ significantly between the freeze-all and fresh transfer groups (27.8% (62/223) v 29.6% (68/230); risk ratio 0.98, 95% confidence interval 0.87 to 1.10, P=0.76). Additionally, no significant difference was found in the live birth rate (27.4% (61/223) for the freeze-all group and 28.7% (66/230) for the fresh transfer group; risk ratio 0.98, 95% confidence interval 0.87 to 1.10, P=0.83). No significant differences between groups were observed for positive human chorionic gonadotropin rate or pregnancy loss, and none of the women had severe ovarian hyperstimulation syndrome; only one hospital admission related to this condition occurred in the fresh transfer group. The risks of pregnancy related, obstetric, and neonatal complications did not differ between the two groups except for a higher mean birth weight after frozen blastocyst transfer and an increased risk of prematurity after fresh blastocyst transfer. Time to pregnancy was longer in the freeze-all group. CONCLUSIONS In women with regular menstrual cycles, a freeze-all strategy with gonadotropin releasing hormone agonist triggering for final oocyte maturation did not result in higher ongoing pregnancy and live birth rates than a fresh transfer strategy. The findings warrant caution in the indiscriminate application of a freeze-all strategy when no apparent risk of ovarian hyperstimulation syndrome is present.
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6.
  • Alexopoulou, E., et al. (författare)
  • Embryo Morphokinetics and Blastocyst Development After GnRH Agonist versus hCG Triggering in Normo-ovulatory Women: a Secondary Analysis of a Multicenter Randomized Controlled Trial
  • 2021
  • Ingår i: Reproductive Sciences. - : Springer Science and Business Media LLC. - 1933-7191 .- 1933-7205. ; 28, s. 2972-2981
  • Tidskriftsartikel (refereegranskat)abstract
    • Gonadotropin-releasing hormone agonist (GnRHa) for final oocyte maturation, along with vitrification of all usable embryos followed by transfer in a subsequent frozen-thawed cycle, is the most effective strategy to avoid ovarian hyperstimulation syndrome (OHSS). However, less is known about the ovulation induction triggers effect on early embryo development and blastocyst formation. This study is a secondary analysis of a multicenter, randomized controlled trial, with the aim to compare embryo development in normo-ovulatory women, randomized to GnRHa or human chorionic gonadotropin (hCG) trigger. In all, 4056 retrieved oocytes were observed, 1998 from the GnRHa group (216 women) and 2058 from the hCG group (218 women). A number of retrieved oocytes, mature and fertilized oocytes, and high-quality embryos and blastocysts were similar between the groups. A sub-analysis in 250 women enrolled at the main trial site including 2073 oocytes was conducted to compare embryo morphokinetics and cleavage patterns with EmbryoScope time-lapse system. In total, 1013 oocytes were retrieved from the GnRHa group (124 women) and 1060 oocytes were retrieved from the hCG group (126 women). Morphokinetic parameters and cleavage patterns were comparable between the groups. However, embryos derived from the GnRHa group were less likely to perform rolling during their development than the embryos from the hCG trigger group (OR = 0.41 (95%CI 0.25; 0.67), p-value 0.0003). The comparable results on embryo development and utilization rates between the GnRHa and hCG triggers is of clinical relevance to professionals and infertile patients, when GnRHa trigger and freeze-all is performed to avoid OHSS development. ClinicalTrials.gov Identifier: NCT02746562
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7.
  • Hait, A. S., et al. (författare)
  • Defects in LC3B2 and ATG4A underlie HSV2 meningitis and reveal a critical role for autophagy in antiviral defense in humans
  • 2020
  • Ingår i: Science Immunology. - : American Association for the Advancement of Science (AAAS). - 2470-9468. ; 5:54
  • Tidskriftsartikel (refereegranskat)abstract
    • Recurrent herpesvirus infections can manifest in different forms of disease, including cold sores, genital herpes, and encephalitis. There is an incomplete understanding of the genetic and immunological factors conferring susceptibility to recurrent herpes simplex virus 2 (HSV2) infection in the central nervous system (CNS). Here, we describe two adult patients with recurrent HSV2 lymphocytic Mollaret's meningitis that each carry a rare monoallelic variant in the autophagy proteins ATG4A or LC3B2. HSV2-activated autophagy was abrogated in patient primary fibroblasts, which also exhibited significantly increased viral replication and enhanced cell death. HSV2 antigen was captured in autophagosomes of infected cells, and genetic inhibition of autophagy by disruption of autophagy genes, including ATG4A and LC3B2, led to enhanced viral replication and cell death in primary fibroblasts and a neuroblastoma cell line. Activation of autophagy by HSV2 was sensitive to ultraviolet (UV) irradiation of the virus and inhibited in the presence of acyclovir, but HSV2-induced autophagy was independent of the DNA-activated STING pathway. Reconstitution of wild-type ATG4A and LC3B2 expression using lentiviral gene delivery or electroporation of in vitro transcribed mRNA into patient cells restored virus-induced autophagy and the ability to control HSV2 replication. This study describes a previously unknown link between defective autophagy and an inborn error of immunity that can lead to increased susceptibility to HSV2 infection, suggesting an important role for autophagy in antiviral immunity in the CNS.
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8.
  • Aidas, Kestutis, et al. (författare)
  • The Dalton quantum chemistry program system
  • 2014
  • Ingår i: WIREs Computational Molecular Science. - : Wiley. - 1759-0876 .- 1759-0884. ; 4:3, s. 269-284
  • Tidskriftsartikel (refereegranskat)abstract
    • Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, MOller-Plesset, configuration-interaction, and coupled-cluster levels of theory. Apart from the total energy, a wide variety of molecular properties may be calculated using these electronic-structure models. Molecular gradients and Hessians are available for geometry optimizations, molecular dynamics, and vibrational studies, whereas magnetic resonance and optical activity can be studied in a gauge-origin-invariant manner. Frequency-dependent molecular properties can be calculated using linear, quadratic, and cubic response theory. A large number of singlet and triplet perturbation operators are available for the study of one-, two-, and three-photon processes. Environmental effects may be included using various dielectric-medium and quantum-mechanics/molecular-mechanics models. Large molecules may be studied using linear-scaling and massively parallel algorithms. Dalton is distributed at no cost from for a number of UNIX platforms.
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  • de Graan, Anne-Joy M., et al. (författare)
  • Influence of Polymorphic OATP1B-Type Carriers on the Disposition of Docetaxel
  • 2012
  • Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 18:16, s. 4433-4440
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Docetaxel is extensively metabolized by CYP3A4 in the liver but mechanisms by which the drug is taken up into hepatocytes remain poorly understood. We hypothesized that (i) liver uptake of docetaxel is mediated by the polymorphic solute carriers OATP1B1 and OATP1B3 and (ii) inherited genetic defects in this process may impair systemic drug elimination.Experimental Design: Transport of docetaxel was studied in vitro using various cell lines stably transfected with OATP1B1*1A (wild-type), OATP1B1*5 [c.521T>C (V174A); rs4149056], OATP1B3, or the mouse transporter Oatp1b2. Docetaxel clearance was evaluated in wild-type and Oatp1b2-knockout mice as well as in two cohorts of patients with multiple variant transporter genotypes (n = 213).Results: Docetaxel was found to be a substrate for OATP1B1, OATP1B3, and Oatp1b2 but was not transported by OATP1B1*5. Deficiency of Oatp1b2 in mice was associated with an 18-fold decrease in docetaxel clearance (P = 0.0099), which was unrelated to changes in intrinsic metabolic capacity in mouse liver microsomes. In patients, however, none of the studied common reduced function variants in OATP1B1 or OATP1B3 were associated with docetaxel clearance (P > 0.05).Conclusions: The existence of at least two potentially redundant uptake transporters in the human liver with similar affinity for docetaxel supports the possibility that functional defects in both of these proteins may be required to confer substantially altered disposition phenotypes. In view of the established exposure-toxicity relationships for docetaxel, we suggest that caution is warranted if docetaxel has to be administered together with agents that potently inhibit both OATP1B1 and OATP1B3.
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10.
  • Fowler, D., et al. (författare)
  • Atmospheric composition change : Ecosystems-Atmosphere interactions
  • 2009
  • Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 43:33, s. 5193-5267
  • Forskningsöversikt (refereegranskat)abstract
    • Ecosystems and the atmosphere: This review describes the state of understanding the processes involved in the exchange of trace gases and aerosols between the earth's surface and the atmosphere. The gases covered include NO, NO2, HONO, HNO3, NH3, SO2, DMS, Biogenic VOC, O-3, CH4, N2O and particles in the size range 1 nm-10 mu m including organic and inorganic chemical species. The main focus of the review is on the exchange between terrestrial ecosystems, both managed and natural and the atmosphere, although some new developments in ocean-atmosphere exchange are included. The material presented is biased towards the last decade, but includes earlier work, where more recent developments are limited or absent. New methodologies and instrumentation have enabled, if not driven technical advances in measurement. These developments have advanced the process understanding and upscaling of fluxes, especially for particles, VOC and NH3. Examples of these applications include mass spectrometric methods, such as Aerosol Mass Spectrometry (AMS) adapted for field measurement of atmosphere-surface fluxes using micrometeorological methods for chemically resolved aerosols. Also briefly described are some advances in theory and techniques in micrometeorology. For some of the compounds there have been paradigm shifts in approach and application of both techniques and assessment. These include flux measurements over marine surfaces and urban areas using micrometeorological methods and the up-scaling of flux measurements using aircraft and satellite remote sensing. The application of a flux-based approach in assessment of O-3 effects on vegetation at regional scales is an important policy linked development secured through improved quantification of fluxes. The coupling of monitoring, modelling and intensive flux measurement at a continental scale within the NitroEurope network represents a quantum development in the application of research teams to address the underpinning science of reactive nitrogen in the cycling between ecosystems and the atmosphere in Europe. Some important developments of the science have been applied to assist in addressing policy questions, which have been the main driver of the research agenda, while other developments in understanding have not been applied to their wider field especially in chemistry-transport models through deficiencies in obtaining appropriate data to enable application or inertia within the modelling community. The paper identifies applications, gaps and research questions that have remained intractable at least since 2000 within the specialized sections of the paper, and where possible these have been focussed on research questions for the coming decade. 
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16.
  • Mackey, Abigail L., et al. (författare)
  • The influence of anti-inflammatory medication on exercise-induced myogenic precursor cell responses in humans
  • 2007
  • Ingår i: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 103:2, s. 425-431
  • Tidskriftsartikel (refereegranskat)abstract
    • The consumption of nonsteroidal anti-inflammatory drugs (NSAIDs) is widespread among athletes when faced with muscle soreness or injury, but the effects of NSAIDs on satellite cell activity in humans are unknown. To investigate this, 14 healthy male endurance athletes (mean peak oxygen consumption 62 ml x kg(-1) x min(-1)) volunteered for the study, which involved running 36 km. They were divided into two groups and received either 100 mg indomethacin per day or placebo. Muscle biopsies collected before the run and on days 1, 3, and 8 afterward were analyzed for satellite cells by immunohistochemistry with the aid of neural cell adhesion molecule (NCAM) and fetal antigen-1 (FA1) antibodies. Muscle biopsies were also collected from untrained individuals for comparison. Compared with preexercise levels, a 27% increase in the number of NCAM+ cells was observed on day 8 postexercise in the placebo group (P < 0.05), while levels remained similar at all time points in the NSAID group. No change was seen in the proportion of FA1+ cells, although lower levels were found in the muscle of endurance-trained athletes compared with untrained individuals (P < 0.05). These results suggest that ingestion of anti-inflammatory drugs attenuates the exercise-induced increase in satellite cell number, supporting the role of the cyclooxygenase pathway in satellite cell activity.
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17.
  • Mikkelsen, L. H., et al. (författare)
  • Genomic and immunohistochemical characterisation of a lacrimal gland oncocytoma and review of literature
  • 2017
  • Ingår i: Oncology Letters. - : Spandidos Publications. - 1792-1074 .- 1792-1082. ; 14:4, s. 4176-4182
  • Tidskriftsartikel (refereegranskat)abstract
    • The aim of the present study was to report the genetic and immunohistochemical profile of a rare case of lacrimal gland oncocytoma. A 20-year-old male underwent magnetic resonance imaging (MRI) due to viral encephalitis. Notably, the MRI revealed a multicystic tumor in the left lacrimal gland. A lateral orbitotomy was performed and the tumor was completely excised. Four months following surgery, the patient was free of symptoms. Histopathologically, the tumor was composed of large, eosinophilic and polyhedral cells with small round nuclei. The tumor cells stained strongly for antimitochondrial antibody MU213-UC, cytokeratin (CK) 5/6, CK 7, CK 17, CK 8/18 and CK 19. The final diagnosis was an oncocytoma of the lacrimal gland without any signs of malignancy. Array-based comparative genomic hybridisation demonstrated a gain of one copy of chromosome 8 and loss of one copy of chromosome 22 as the sole genomic imbalances. These chromosomal alterations have not previously been identified in oncocytoma and may be specific to lacrimal gland oncocytoma. Sequencing of the mitochondrial genome demonstrated multiple alterations of the NADH-ubiquinone oxidoreductase chain 5 (ND5) gene involved in mitochondrial oxidative phosphorylation. This may support the notion of a common genetic background of oncocytic lesions in the lacrimal gland and other anatomical sites. © 2017, Spandidos Publications. All rights reserved.
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18.
  • Mikkelsen, T N, et al. (författare)
  • Experimental design of multifactor climate change experiments with elevated CO2, warming and drought: the CLIMAITE project
  • 2008
  • Ingår i: Functional Ecology. - : Wiley. - 1365-2435 .- 0269-8463. ; 22:1, s. 185-195
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent findings indicate that the interactions among CO2, temperature and water can be substantial, and that the combined effects on the biological systems of several factors may not be predicted from experiments with one or a few factors. Therefore realistic multifactorial experiments involving a larger set of main factors are needed. We describe a new Danish climate change-related field scale experiment, CLIMAITE, in a heath/grassland ecosystem. CLIMAITE is a full factorial combination of elevated CO2, elevated temperature and prolonged summer drought. The manipulations are intended to mimic anticipated major environmental changes at the site by year 2075 as closely as possible. The impacts on ecosystem processes and functioning (at ecophysiological levels, through responses by individuals and communities to ecosystem-level responses) are investigated simultaneously. The increase of [CO2] closely corresponds with the scenarios for year 2075, while the warming treatment is at the lower end of the predictions and seems to be the most difficult treatment to increase without unwanted side effects on the other variables. The drought treatment follows predictions of increased frequency of drought periods in summer. The combination of the treatments does not create new unwanted side effects on the treatments relative to the treatments alone.
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  • Stenman, Göran, 1953, et al. (författare)
  • Chromosome Translocations, Gene Fusions, and Their Molecular Consequences in Pleomorphic Salivary Gland Adenomas
  • 2022
  • Ingår i: Biomedicines. - : MDPI AG. - 2227-9059. ; 10:8
  • Tidskriftsartikel (refereegranskat)abstract
    • Salivary gland tumors are a heterogeneous group of tumors originating from the major and minor salivary glands. The pleomorphic adenoma (PA), which is the most common subtype, is a benign lesion showing a remarkable morphologic diversity and that, upon recurrence or malignant transformation, can cause significant clinical problems. Cytogenetic studies of >500 PAs have revealed a complex and recurrent pattern of chromosome rearrangements. In this review, we discuss the specificity and frequency of these rearrangements and their molecular/clinical consequences. The genomic hallmark of PA is translocations with breakpoints in 8q12 and 12q13-15 resulting in gene fusions involving the transcription factor genes PLAG1 and HMGA2. Until recently, the association between these two oncogenic drivers was obscure. Studies of the Silver-Russel syndrome, a growth retardation condition infrequently caused by mutations in IGF2/HMGA2/PLAG1, have provided new clues to the understanding of the molecular pathogenesis of PA. These studies have demonstrated that HMGA2 is an upstream regulator of PLAG1 and that HMGA2 regulates the expression of IGF2 via PLAG1. This provides a novel explanation for the 8q12/12q13-15 aberrations in PA and identifies IGF2 as a major oncogenic driver and therapeutic target in PA. These studies have important diagnostic and therapeutic implications for patients with PA.
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21.
  • Stormlund, S., et al. (författare)
  • Comparison of a 'freeze-all' strategy including GnRH agonist trigger versus a 'fresh transfer' strategy including hCG trigger in assisted reproductive technology (ART): A study protocol for a randomised controlled trial
  • 2017
  • Ingår i: Bmj Open. - : BMJ. - 2044-6055. ; 7:7
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction Pregnancy rates after frozen embryo transfer (FET) have improved in recent years and are now approaching or even exceeding those obtained after fresh embryo transfer. This is partly due to improved laboratory techniques, but may also be caused by a more physiological hormonal and endometrial environment in FET cycles. Furthermore, the risk of ovarian hyperstimulation syndrome is practically eliminated in segmentation cycles followed by FET and the use of natural cycles in FETs may be beneficial for the postimplantational conditions of fetal development. However, a freeze-all strategy is not yet implemented as standard care due to limitations of large randomised trials showing a benefit of such a strategy. Thus, there is a need to test the concept against standard care in a randomised controlled design. This study aims to compare ongoing pregnancy and live birth rates between a freeze-all strategy with gonadotropin-releasing hormone (GnRH) agonist triggering versus human chorionic gonadotropin (hCG) trigger and fresh embryo transfer in a multicentre randomised controlled trial. Methods and analysis Multicentre randomised, controlled, double-blinded trial of women undergoing assisted reproductive technology treatment including 424 normo-ovulatory women aged 18-39 years from Denmark and Sweden. Participants will be randomised (1:1) to either (1) GnRH agonist trigger and single vitrified-warmed blastocyst transfer in a subsequent hCG triggered natural menstrual cycle or (2) hCG trigger and single blastocyst transfer in the fresh (stimulated) cycle. The primary endpoint is to compare ongoing pregnancy rates per randomised patient in the two treatment groups after the first single blastocyst transfer. Ethics and dissemination The study will be performed in accordance with the ethical principles in the Helsinki Declaration. The study is approved by the Scientific Ethical Committees in Denmark and Sweden. The results of the study will be publically disseminated. Trial registration number NCT02746562; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article).
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22.
  • Trajkovska, V., et al. (författare)
  • BDNF downregulates 5-HT2A receptor protein levels in hippocampal cultures
  • 2009
  • Ingår i: Neurochemistry International. - : Elsevier BV. - 0197-0186. ; 55:7, s. 697-702
  • Tidskriftsartikel (refereegranskat)abstract
    • Both brain-derived neurotrophic factor (BDNF) and the serotonin receptor 2A (5-HT2A) have been related to depression pathology. Specific 5-HT2A receptor changes seen in BDNF conditional mutant mice suggest that BDNF regulates the 5-HT2A receptor level. Here we show a direct effect of BDNF on 5-HT2A receptor protein levels in primary hippocampal neuronal and mature hippocampal organotypic cultures exposed to different BDNF concentrations for either 1, 3, 5 or 7 days. In vivo effects of BDNF on hippocampal 5-HT2A receptor levels were further corroborated in (BDNF +/-) mice with reduced BDNF levels. In primary neuronal cultures, 7 days exposure to 25 and 50 ng/mL BDNF resulted in downregulation of 5-HT2A, but not of 5-HT1A, receptor protein levels. The BDNF-associated downregulation of 5-HT2A receptor levels was also observed in mature hippocampal organotypic cultures, excluding confounding effects of BDNF on immature tissue. BDNF +/- mice showed significant increased 5-HT2A receptor levels in hippocampus confirming the association between 5-HT2A receptor and BDNF levels in vivo. In conclusion, our results point to a regulatory role of BDNF on 5-HT2A receptor levels. This interaction may be an important mechanism in the role of BDNF in affective disorders emphasizing the need for further elucidating the specificity and the mechanism behind this regulation. (C) 2009 Elsevier Ltd. All rights reserved.
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23.
  • A. B. Marçal, L., et al. (författare)
  • Spatially resolved structural and chemical properties of the white layer in machined Inconel 718 super alloy
  • 2024
  • Ingår i: Materials and Design. - 0264-1275. ; 239
  • Tidskriftsartikel (refereegranskat)abstract
    • Inconel 718 is one type of nickel-based alloy used for a large range of applications, including gas turbines and aeroengines components. Although mechanical and thermodynamic properties of this material have been deeply studied in the past years, a method able to investigate local properties of the thin white layer formed on the alloy surface after machining remains challenging. Here, a 90 nm X-ray beam is used to probe the local strain, crystal orientation, and chemical composition of grains in the white layer. Data reveals mosaicity induced by the tool during machining. The high spatial resolution, combined with crystal lattice sensitivity, shows that the average grain size is around 30 nm throughout the white layer, while the strain is anisotropic nearest to the surface. Results provide new insights on the basic properties of the white layer in super alloys, revealing important information about the impact of finish machining which might help to explain fatigue and cracking formation on these materials during their usage phase.
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24.
  • Dos Santos, E. C., et al. (författare)
  • Ciprofloxacin intercalated in fluorohectorite clay : Identical pure drug activity and toxicity with higher adsorption and controlled release rate
  • 2017
  • Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 7:43, s. 26537-26545
  • Tidskriftsartikel (refereegranskat)abstract
    • Different natural clay minerals, including halloysite, montmorillonite and kaolinite, have been proven to be efficient drug carriers providing for high and long lasting drug concentrations owing to their adsorption capacity and ion exchange property. Synthetic clays, however, are advantageous over the natural clay minerals in terms of purity of composition and controllable cation exchange capacity, factors that contribute to improve reproducibility of the host system. Here we studied a synthetic smectite clay as a candidate for high adsorption and controlled release rate. Via X-ray powder diffraction we verified that, under acidic conditions, the antibiotic ciprofloxacin was successfully incorporated in the synthetic clay fluorohectorite, while via UV-VIS spectroscopy we showed that the degree of the drug incorporation is at least 25% higher than for other systems reported in the literature. Furthermore, temperature dependent release studies allowed us to show that the release process is thermally activated and diffusion-controlled. Finally, via bacterial and toxicological tests, we demonstrated that the effectiveness and toxicity of pure ciprofloxacin is unaffected in the clay-drug complex.
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25.
  • Gustafson, Johan, et al. (författare)
  • Structure of a thin oxide film on Rh(100)
  • 2005
  • Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 71:11
  • Tidskriftsartikel (refereegranskat)abstract
    • The initial oxidation of Rh(100) has been studied using high resolution core level spectroscopy, low energy electron diffraction, surface x-ray diffraction, scanning tunneling microscopy, and density functional theory. We report a structural study of an oxygen induced structure displaying a c(8x2) periodicity at an oxygen pressure above 10(-5) mbar and using a sample temperature of 700 K. Our experimental and theoretical data demonstrate that this structure is due to the formation of a thin surface oxide with a hexagonal trilayer O-Rh-O structure.
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26.
  • Hartoog, O. E., et al. (författare)
  • VLT/X-Shooter spectroscopy of the afterglow of the Swift GRB 130606A Chemical abundances and reionisation at z similar to 6
  • 2015
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 580
  • Tidskriftsartikel (refereegranskat)abstract
    • Context: The reionisation of the Universe is a process that is thought to have ended around z similar to 6, as inferred from spectroscopy of distant bright background sources, such as quasars (QSO) and gamma-ray burst (GRB) afterglows. Furthermore, spectroscopy of a GRB afterglow provides insight in its host galaxy, which is often too dim and distant to study otherwise.Aims: For the Swift GRB 130606A at z = 5.913 we have obtained a high S/N spectrum covering the full optical and near-IR wavelength region at intermediate spectral resolution with VLT/X-Shooter. We aim to measure the degree of ionisation of the intergalactic medium (IGM) between z = 5.02-5.84 and to study the chemical abundance pattern and dust content of its host galaxy.Methods: We estimated the UV continuum of the GRB afterglow using a power-law extrapolation, then measured the flux decrement due to absorption at Ly alpha,beta, and gamma wavelength regions. Furthermore, we fitted the shape of the red damping wing of Lya. The hydrogen and metal absorption lines formed in the host galaxy were fitted with Voigt profiles to obtain column densities. We investigated whether ionisation corrections needed to be applied.Results: Our measurements of the Ly alpha-forest optical depth are consistent with previous measurements of QSOs, but have a much smaller uncertainty. The analysis of the red damping wing yields a neutral fraction x(HI) < 0.05 (3 sigma). We obtain column density measurements of H, Al, Si, and Fe; for C, O, S and Ni we obtain limits. The ionisation due to the GRB is estimated to be negligible (corrections < 0.03 dex), but larger corrections may apply due to the pre-existing radiation field (up to 0.4 dex based on sub-DLA studies). Assuming that [Si/Fe] = +0.79 +/- 0.13 is due to dust depletion, the dust-to-metal ratio is similar to the Galactic value.Conclusions: Our measurements confirm that the Universe is already predominantly ionised over the redshift range probed in this work, but was slightly more neutral at z > 5.6. GRBs are useful probes of the ionisation state of the IGM in the early Universe, but because of internal scatter we need a larger statistical sample to draw robust conclusions. The high [Si/Fe] in the host can be due to dust depletion, a-element enhancement, or a combination of both. The very high value of [Al/Fe] = 2.40 +/- 0.78 might be due to a proton capture process and is probably connected to the stellar population history. We estimate the host metallicity to be -1.7 < [M/H] < -0.9 (2%-13% of solar).
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27.
  • Joshi, Vicky L., et al. (författare)
  • Observer-reported cognitive decline in out-of-hospital cardiac arrest survivors and its association with long-term survivor and relative outcomes
  • 2024
  • Ingår i: Resuscitation. - 0300-9572. ; 197
  • Tidskriftsartikel (refereegranskat)abstract
    • AimLong-term cognitive decline after out-of-hospital cardiac arrest (OHCA) is still poorly understood. This study describes long-term observer-reported cognitive decline among Danish OHCA survivors, including differences in years since the event, and investigates characteristics and self-reported outcomes associated with observer-reported cognitive decline.MethodsAdults who survived an OHCA from 2016 to 2019, and their relatives, completed the national DANish Cardiac Arrest Survivorship survey. Relatives completed the Informant Questionnaire on Cognitive Decline in the Elderly, Cardiac Arrest version (IQCODE-CA), the Hospital Anxiety and Depression Scale (HADS) and the World Health Organisation-Five Well-being index; and survivors completed the Two Simple Questions (everyday activities and mental recovery), the Modified Fatigue Impact Scale, HADS, and the Short World Health Organisation Disability Assessment Schedule 2.0. Potential associations between survivor characteristics and the IQCODE-CA were investigated using a multivariable logistic regression model. Self-reported outcomes among survivors and relatives, and the association with IQCODE-CA scores were investigated using separate logistic regression models.ResultsTotal median IQCODE-CA score was 3.04 (IQR: 3.00–3.27), with 47% having possible cognitive decline (score ≥ 3.04), consistent across time groups. Increasing age (OR 0.98, 95% CI: 0.97–0.99) and worse self-reported mental and physical outcomes for survivors and relatives, except ‘everyday activities’ were significantly associated with possible cognitive decline among survivors.ConclusionsNearly half of OHCA survivors may suffer long-term cognitive decline. Worse self-reported mental and physical outcomes among survivors and their relatives are associated with potential cognitive decline emphasising the need for post-OHCA care to include systematic neurocognitive assessment, tailored support and effective rehabilitation.
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28.
  • Lindbäck, Katrin, et al. (författare)
  • Subglacial water drainage, storage, and piracy beneath the Greenland Ice Sheet
  • 2015
  • Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 42:18, s. 7606-7614
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • Meltwater drainage across the surface of the Greenland Ice Sheet (GrIS) is well constrained by measurements and modeling, yet despite its critical role, knowledge of its transit through the subglacial environment remains limited. Here we present a subglacial hydrological analysis of a land-terminating sector of the GrIS at unprecedented resolution that predicts the routing of surface-derived meltwater once it has entered the basal drainage system. Our analysis indicates the probable existence of small subglacial lakes that remain undetectable by methods using surface elevation change or radar techniques. Furthermore, the analysis suggests transient behavior with rapid switching of subglacial drainage between competing catchments driven by seasonal changes in the basal water pressure. Our findings provide a cautionary note that should be considered in studies that attempt to relate and infer future response from surface temperature, melt, and runoff from point measurements and/or modeling with measurements of proglacial discharge and ice dynamics.
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29.
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30.
  • Mikkelsen, Andreas Bech, et al. (författare)
  • Extraordinary runoff from the Greenland ice sheet in 2012 amplified by hypsometry and depleted firn retention
  • 2016
  • Ingår i: The Cryosphere. - : Copernicus GmbH. - 1994-0416 .- 1994-0424. ; 10:3, s. 1147-1159
  • Tidskriftsartikel (refereegranskat)abstract
    • It has been argued that the infiltration and retention of meltwater within firn across the percolation zone of the Greenland ice sheet has the potential to buffer up to similar to 3.6aEuro-mm of global sea-level rise (Harper et al., 2012). Despite evidence confirming active refreezing processes above the equilibrium line, their impact on runoff and proglacial discharge has yet to be assessed. Here, we compare meteorological, melt, firn stratigraphy and discharge data from the extreme 2010 and 2012 summers to determine the relationship between atmospheric forcing and melt runoff at the land-terminating Kangerlussuaq sector of the Greenland ice sheet, which drains into the Watson River. The 6.8aEuro-km(3) bulk discharge in 2012 exceeded that in 2010 by 28aEuro-%, despite only a 3aEuro-% difference in net incoming melt energy between the two years. This large disparity can be explained by a 10aEuro-% contribution of runoff originating from above the long-term equilibrium line in 2012 caused by diminished firn retention. The amplified 2012 response was compounded by catchment hypsometry; the disproportionate increase in area contributing to runoff as the melt-level rose high into the accumulation area. Satellite imagery and aerial photographs reveal an extensive supraglacial network extending 140aEuro-km from the ice margin that confirms active meltwater runoff originating well above the equilibrium line. This runoff culminated in three days with record discharge of 3100aEuro-m(3)aEuro-s(-1) (0.27aEuro-GtaEuro-d(-1)) that peaked on 11 July and washed out the Watson River Bridge. Our findings corroborate melt infiltration processes in the percolation zone, though the resulting patterns of refreezing are complex and can lead to spatially extensive, perched superimposed ice layers within the firn. In 2012, such layers extended to an elevation of at least 1840aEuro-m and provided a semi-impermeable barrier to further meltwater storage, thereby promoting widespread runoff from the accumulation area of the Greenland ice sheet that contributed directly to proglacial discharge and global sea-level rise.
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31.
  • Tchaplyguine, M., et al. (författare)
  • Tin-oxide nanoparticles deposited from a beam : what happens to the composition?
  • 2019
  • Ingår i: Physical chemistry chemical physics : PCCP. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 21:11, s. 6287-6295
  • Tidskriftsartikel (refereegranskat)abstract
    • The debate around the oxidation states occurring in laboratory-prepared tin-oxide samples has been for a long time an obstacle for an unambiguous assignment of characterization studies performed on such samples. In particular the changes in the Sn core-level energies caused by oxidation - i.e. the chemical shifts - as measured by photoelectron spectroscopy (PES) have been under discussion. The assignment problem is especially pronounced for nanoscale structures, which are important for photovoltaics, electronics, catalysis, and gas sensing. The reasons for the difficulties lie both in the natural properties of tin oxides, which can have substantial deficiencies of oxygen and tin in the lattice, and in the shortcomings of the fabrication and PES-characterization procedures themselves. Our recent PES study on tin-oxide nanoparticles fabricated by vapour-aggregation gave a chemical shift two times larger than earlier reported for Sn(iv) oxide for the Sn 4d level. The implemented fabrication technique forms an in-vacuum beam of particles whose composition can be both controlled and characterized by PES. In the present work SnO and SnO2 nanoparticles fabricated this way were deposited from the beam and probed by PES directly, as well as after exposure to air. The deposited nanoparticle films were also imaged by TEM (Transmission Electron Microscopy). The effects of the deposition process and exposure to air on the chemical composition were studied. The PES study of deposited SnO2 nanoparticles in the Sn 4d and Sn 3d core-level regions revealed the same core level shift as for unsupported nanoparticles, indicating that the chemical composition is preserved in the deposition process. The TEM study demonstrated a crystalline structure of separate SnO2 particles with lattice constants close to the macroscopic Sn(iv)-oxide. The PES study on the particles exposed to air showed changes in the composition. For the film of initially SnO particles a higher intermediate oxide was created. For the SnO2 nanoparticle film a lower, but strong, intermediate oxide was observed, likely at the surface.
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32.
  • Timotijevic, L., et al. (författare)
  • Designing a research infrastructure (RI) on food behaviour and health : Balancing user needs, business model, governance mechanisms and technology
  • 2021
  • Ingår i: Trends in Food Science & Technology. - : Elsevier Ltd. - 0924-2244 .- 1879-3053. ; 116, s. 405-414
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: A better understanding of food-related behaviour and its determinants can be achieved through harmonisation and linking of the various data-sources and knowledge platforms. Scope: We describe the key decision-making in the development of a prototype of the Determinants and Intake Platform (DI Platform), a data platform that aims to harmonise and link data on consumer food behaviour. It will be part of the Food Nutrition Health Research Infrastructure (FNH-RI) that will facilitate health, social and food sciences. Approach: The decision-making was based on the evidence of user needs and data characteristics that guided the specification of the key building blocks of the DI Platform. Eight studies were carried out, including consumer online survey; interview studies of key DI Platform stakeholders; desk research and workshops. Key findings: Consumers were most willing to share data with universities, then industry and government. Trust, risk perception and altruism predicted willingness to share. For most other stakeholders non-proprietary data was most likely to be shared. Lack of data standards, and incentives for sharing were the main barriers for sharing data among the key stakeholders. The value of various data types would hugely increase if linked with other sources. Finding the right balance between optimizing data sharing and minimizing ethical and legal risks was considered a key challenge. Conclusions: The development of DI Platform is based on careful balancing of the user, technical, business, legal and ethical requirements, following the FAIR principles and the need for financial sustainability, technical flexibility, transparency and multi-layered organisational governance.
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33.
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