| 1. |
- Strakova, A., et al.
(författare)
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Recurrent horizontal transfer identifies mitochondrial positive selection in a transmissible cancer
- 2020
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Autonomous replication and segregation of mitochondrial DNA (mtDNA) creates the potential for evolutionary conflict driven by emergence of haplotypes under positive selection for 'selfish' traits, such as replicative advantage. However, few cases of this phenomenon arising within natural populations have been described. Here, we survey the frequency of mtDNA horizontal transfer within the canine transmissible venereal tumour (CTVT), a contagious cancer clone that occasionally acquires mtDNA from its hosts. Remarkably, one canine mtDNA haplotype, A1d1a, has repeatedly and recently colonised CTVT cells, recurrently replacing incumbent CTVT haplotypes. An A1d1a control region polymorphism predicted to influence transcription is fixed in the products of an A1d1a recombination event and occurs somatically on other CTVT mtDNA backgrounds. We present a model whereby 'selfish' positive selection acting on a regulatory variant drives repeated fixation of A1d1a within CTVT cells.
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| 2. |
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| 3. |
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| 5. |
- Garg, D., et al.
(författare)
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Fragmentation Dynamics of Fluorene Explored Using Ultrafast XUV-Vis Pump-Probe Spectroscopy
- 2022
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Ingår i: Frontiers in Physics. - : Frontiers Media SA. - 2296-424X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- We report on the use of extreme ultraviolet (XUV, 30.3 nm) radiation from the Free-electron LASer in Hamburg (FLASH) and visible (Vis, 405 nm) photons from an optical laser to investigate the relaxation and fragmentation dynamics of fluorene ions. The ultrashort laser pulses allow to resolve the molecular processes occurring on the femtosecond timescales. Fluorene is a prototypical small polycyclic aromatic hydrocarbon (PAH). Through their infrared emission signature, PAHs have been shown to be ubiquitous in the universe, and they are assumed to play an important role in the chemistry of the interstellar medium. Our experiments track the ionization and dissociative ionization products of fluorene through time-of-flight mass spectrometry and velocity-map imaging. Multiple processes involved in the formation of each of the fragment ions are disentangled through analysis of the ion images. The relaxation lifetimes of the excited fluorene monocation and dication obtained through the fragment formation channels are reported to be in the range of a few tens of femtoseconds to a few picoseconds.
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| 6. |
- Lee, J. W. L., et al.
(författare)
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The kinetic energy of PAH dication and trication dissociation determined by recoil-frame covariance map imaging
- 2022
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 24:38, s. 23096-23105
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the dissociation of dications and trications of three polycyclic aromatic hydrocarbons (PAHs), fluorene, phenanthrene, and pyrene. PAHs are a family of molecules ubiquitous in space and involved in much of the chemistry of the interstellar medium. In our experiments, ions are formed by interaction with 30.3 nm extreme ultraviolet (XUV) photons, and their velocity map images are recorded using a PImMS2 multi-mass imaging sensor. Application of recoil-frame covariance analysis allows the total kinetic energy release (TKER) associated with multiple fragmentation channels to be determined to high precision, ranging 1.94-2.60 eV and 2.95-5.29 eV for the dications and trications, respectively. Experimental measurements are supported by Born-Oppenheimer molecular dynamics (BOMD) simulations.
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| 7. |
- Lee, J. W.L., et al.
(författare)
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Time-resolved relaxation and fragmentation of polycyclic aromatic hydrocarbons investigated in the ultrafast XUV-IR regime
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Polycyclic aromatic hydrocarbons (PAHs) play an important role in interstellar chemistry and are subject to high energy photons that can induce excitation, ionization, and fragmentation. Previous studies have demonstrated electronic relaxation of parent PAH monocations over 10-100 femtoseconds as a result of beyond-Born-Oppenheimer coupling between the electronic and nuclear dynamics. Here, we investigate three PAH molecules: fluorene, phenanthrene, and pyrene, using ultrafast XUV and IR laser pulses. Simultaneous measurements of the ion yields, ion momenta, and electron momenta as a function of laser pulse delay allow a detailed insight into the various molecular processes. We report relaxation times for the electronically excited PAH*, PAH(+*) and PAH(2+*) states, and show the time-dependent conversion between fragmentation pathways. Additionally, using recoil-frame covariance analysis between ion images, we demonstrate that the dissociation of the PAH(2+) ions favors reaction pathways involving two-body breakup and/or loss of neutral fragments totaling an even number of carbon atoms. Polycyclic aromatic hydrocarbons play an important role in interstellar chemistry, where interaction with high energy photons can induce ionization and fragmentation reactions. Here the authors, with XUV-IR pump-probe experiments, investigate the ultrafast photoinduced dynamics of fluorene, phenanthrene and pyrene, providing insight into their preferred reaction channels.
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| 8. |
- Manschwetus, B., et al.
(författare)
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Ultrafast ionization and fragmentation dynamics of polycyclic atomatic hydro-carbons by XUV radiation
- 2020
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Ingår i: Free Electron Laser. - : IOP Publishing. - 1742-6588. ; 1412
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Konferensbidrag (refereegranskat)abstract
- In the interstellar medium polycyclic aromatic hydrocarbon molecules (PAH) are exposed to strong ionizing radation leading to complex organic photochemistry. We investigated these ultrafast fragmentation reac-tions after ionization of the PAHs phenanthrene, fluorene and pyrene at a wavelength of 30.3 nm using pump probe spectroscopy at a free electron laser. We observe double ionization and afterwards hydrogen abstraction and acetylene loss with characteristic time scales for the reaction processes below one hundred femtoseconds.
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| 9. |
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| 11. |
- Walmsley, T., et al.
(författare)
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Characterizing the multi-dimensional reaction dynamics of dihalomethanes using XUV-induced Coulomb explosion imaging
- 2023
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Ingår i: Journal of Chemical Physics. - 0021-9606. ; 159:14
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Tidskriftsartikel (refereegranskat)abstract
- Site-selective probing of iodine 4d orbitals at 13.1 nm was used to characterize the photolysis of CH2I2 and CH2BrI initiated at 202.5 nm. Time-dependent fragment ion momenta were recorded using Coulomb explosion imaging mass spectrometry and used to determine the structural dynamics of the dissociating molecules. Correlations between these fragment momenta, as well as the onset times of electron transfer reactions between them, indicate that each molecule can undergo neutral three-body photolysis. For CH2I2, the structural evolution of the neutral molecule was simultaneously characterized along the C-I and I-C-I coordinates, demonstrating the sensitivity of these measurements to nuclear motion along multiple degrees of freedom.
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| 12. |
- Allum, F., et al.
(författare)
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A localized view on molecular dissociation via electron-ion partial covariance
- 2022
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Ingår i: Communications Chemistry. - : Springer Science and Business Media LLC. - 2399-3669. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Inner-shell photoelectron spectroscopy provides an element-specific probe of molecular structure, as core-electron binding energies are sensitive to the chemical environment. Short-wavelength femtosecond light sources, such as Free-Electron Lasers (FELs), even enable time-resolved site-specific investigations of molecular photochemistry. Here, we study the ultraviolet photodissociation of the prototypical chiral molecule 1-iodo-2-methylbutane, probed by extreme-ultraviolet (XUV) pulses from the Free-electron LASer in Hamburg (FLASH) through the ultrafast evolution of the iodine 4d binding energy. Methodologically, we employ electron-ion partial covariance imaging as a technique to isolate otherwise elusive features in a two-dimensional photoelectron spectrum arising from different photofragmentation pathways. The experimental and theoretical results for the time-resolved electron spectra of the 4d(3/2) and 4d(5/2) atomic and molecular levels that are disentangled by this method provide a key step towards studying structural and chemical changes from a specific spectator site. Coincidence experiments at free-electron lasers enable time resolved site-specific investigations of molecular photochemistry at high signal rates, but isolating individual dissociation processes still poses a considerable technical challenge. Here, the authors use electron-ion partial covariance imaging to isolate otherwise elusive chemical shifts in UV-induced photofragmentation pathways of the prototypical chiral molecule 1-iodo-2-methylbutane.
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| 13. |
- Allum, W., et al.
(författare)
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ECCO essential requirements for quality cancer care: Oesophageal and gastric cancer
- 2018
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Ingår i: Critical reviews in oncology/hematology. - : Elsevier BV. - 1040-8428. ; 122, s. 179-193
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Tidskriftsartikel (refereegranskat)abstract
- Background: ECCO essential requirements for quality cancer care (ERQCC) are checklists and explanations of organisation and actions that are necessary to give high-quality care to patients who have a specific type of cancer. They are written by European experts representing all disciplines involved in cancer care. ERQCC papers give oncology teams, patients, policymakers and managers an overview of the elements needed in any healthcare system to provide high quality of care throughout the patient journey. References are made to clinical guidelines and other resources where appropriate, and the focus is on care in Europe. Oesophageal and gastric: essential requirements for quality care: • Oesophageal and gastric (OG) cancers are a challenging tumour group with a poor prognosis and wide variation in outcomes among European countries. Increasing numbers of older people are contracting the diseases, and treatments and care pathways are becoming more complex in both curative and palliative settings.• High-quality care can only be a carried out in specialised OG cancer units or centres which have both a core multidisciplinary team and an extended team of allied professionals, and which are subject to quality and audit procedures. Such units or centres are far from universal in all European countries.• It is essential that, to meet European aspirations for comprehensive cancer control, healthcare organisations implement the essential requirements in this paper, paying particular attention to multidisciplinarity and patient-centred pathways from diagnosis, to treatment, to survivorship. Conclusion: Taken together, the information presented in this paper provides a comprehensive description of the essential requirements for establishing a high-quality OG cancer service. The ERQCC expert group is aware that it is not possible to propose a ‘one size fits all’ system for all countries, but urges that access to multidisciplinary units or centres must be guaranteed for all those with OG cancer.
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| 14. |
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| 15. |
- Claassen, Y. H.M., et al.
(författare)
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North European comparison of treatment strategy and survival in older patients with resectable gastric cancer : A EURECCA upper gastrointestinal group analysis
- 2018
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Ingår i: European Journal of Surgical Oncology. - : Elsevier BV. - 0748-7983. ; 44:12, s. 1982-1989
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Tidskriftsartikel (refereegranskat)abstract
- Background: As older gastric cancer patients are often excluded from randomized clinical trials, the most appropriate treatment strategy for these patients remains unclear. The current study aimed to gain more insight in treatment strategies and relative survival of older patients with resectable gastric cancer across Europe. Methods: Population-based cohorts from Belgium, Denmark, The Netherlands, Norway, and Sweden were combined. Patients ≥70 years with resectable gastric cancer (cT1-4a, cN0-2, cM0), diagnosed between 2004 and 2014 were included. Resection rates, administration of chemotherapy (irrespective of surgery), and relative survival within a country according to stage were determined. Results: Overall, 6698 patients were included. The percentage of operated patients was highest in Belgium and lowest in Sweden for both stage II (74% versus 56%) and stage III disease (57% versus 25%). For stage III, chemotherapy administration was highest in Belgium (44%) and lowest in Sweden (2%). Three year relative survival for stage I, II, and III disease in Belgium was 67.8% (95% CI:62.8–72.6), 41.2% (95% CI:37.3–45.2), 17.8% (95% CI:12.5–24.0), compared with 56.7% (95% CI:51.5–61.7), 31.3% (95% CI:27.6–35.2), 8.2% (95% CI:4.4–13.4) in Sweden. There were no significant differences in treatment strategies of patients with stage I disease. Conclusion: Substantial treatment differences are observed across North European countries for patients with stages II and III resectable gastric cancer aged 70 years or older. In the present comparison, treatment strategies with a higher proportion of patients undergoing surgery seemed to be associated with higher survival rates for patients with stages II or III disease.
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| 16. |
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| 17. |
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| 18. |
- Allum, F, et al.
(författare)
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Dissecting features of epigenetic variants underlying cardiometabolic risk using full-resolution epigenome profiling in regulatory elements
- 2019
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1, s. 1209-
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Tidskriftsartikel (refereegranskat)abstract
- Sparse profiling of CpG methylation in blood by microarrays has identified epigenetic links to common diseases. Here we apply methylC-capture sequencing (MCC-Seq) in a clinical population of ~200 adipose tissue and matched blood samples (Ntotal~400), providing high-resolution methylation profiling (>1.3 M CpGs) at regulatory elements. We link methylation to cardiometabolic risk through associations to circulating plasma lipid levels and identify lipid-associated CpGs with unique localization patterns in regulatory elements. We show distinct features of tissue-specific versus tissue-independent lipid-linked regulatory regions by contrasting with parallel assessments in ~800 independent adipose tissue and blood samples from the general population. We follow-up on adipose-specific regulatory regions under (1) genetic and (2) epigenetic (environmental) regulation via integrational studies. Overall, the comprehensive sequencing of regulatory element methylomes reveals a rich landscape of functional variants linked genetically as well as epigenetically to plasma lipid traits.
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| 19. |
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| 20. |
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| 21. |
- Claassen, Y. H. M., et al.
(författare)
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International comparison of treatment strategy and survival in metastatic gastric cancer
- 2019
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Ingår i: BJS Open. - : JOHN WILEY & SONS LTD. - 2474-9842. ; 3:1, s. 56-61
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundIn the randomized Asian REGATTA trial, no survival benefit was shown for additional gastrectomy over chemotherapy alone in patients with advanced gastric cancer with a single incurable factor, thereby discouraging surgery for these patients. The purpose of this study was to evaluate treatment strategies for patients with metastatic gastric cancer in daily practice in five European countries, along with relative survival in each country. MethodsNationwide population-based data from Belgium, Denmark, the Netherlands, Norway and Sweden were combined. Patients with primary metastatic gastric cancer diagnosed between 2006 and 2014 were included. The proportion of gastric resections performed and the administration of chemotherapy (irrespective of surgery) within each country were determined. Relative survival according to country was calculated. ResultsOverall, 15 057 patients with gastric cancer were included. The proportion of gastric resections varied from 81 per cent in the Netherlands and Denmark to 183 per cent in Belgium. Administration of chemotherapy was 392 per cent in the Netherlands, compared with 632 per cent in Belgium. The 6-month relative survival rate was between 390 (95 per cent c.i. 378 to 402) per cent in the Netherlands and 541 (521 to 569) per cent in Belgium. ConclusionThere is variation in the use of gastrectomy and chemotherapy in patients with metastatic gastric cancer, and subsequent differences in survival.
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| 22. |
- Einsiedel, Edna, et al.
(författare)
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Brave new sheep : the clone named Dolly
- 2002
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Ingår i: Biotechnology. - Cambridge : Cambridge University Press. - 052177439X
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 23. |
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| 24. |
- Love-Gregory, Latisha, et al.
(författare)
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Higher chylomicron remnants and LDL particle numbers associate with CD36 SNPs and DNA methylation sites that reduce CD36
- 2016
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Ingår i: Journal of Lipid Research. - 0022-2275 .- 1539-7262. ; 57:12, s. 2176-2184
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Tidskriftsartikel (refereegranskat)abstract
- Cluster of differentiation 36 (CD36) variants influence fasting lipids and risk of metabolic syndrome, but their impact on postprandial lipids, an independent risk factor for cardiovascular disease, is unclear. We determined the effects of SNPs within a approximate to 410 kb region encompassing CD36 and its proximal and distal promoters on chylomicron (CM) remnants and LDL particles at fasting and at 3.5 and 6 h following a high-fat meal (Genetics of Lipid Lowering Drugs and Diet Network study, n = 1,117). Five promoter variants associated with CMs, four with delayed TG clearance and five with LDL particle number. To assess mechanisms underlying the associations, we queried expression quantitative trait loci, DNA methylation, and ChIP-seq datasets for adipose and heart tissues that function in postprandial lipid clearance. Several SNPs that associated with higher serum lipids correlated with lower adipose and heart CD36 mRNA and aligned to active motifs for PPAR, a major CD36 regulator. The SNPs also associated with DNA methylation sites that related to reduced CD36 mRNA and higher serum lipids, but mixed-model analyses indicated that the SNPs and methylation independently influence CD36 mRNA. The findings support contributions of CD36 SNPs that reduce adipose and heart CD36 RNA expression to inter-individual variability of postprandial lipid metabolism and document changes in CD36 DNA methylation that influence both CD36 expression and lipids.
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