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- Campbell, PJ, et al.
(författare)
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Pan-cancer analysis of whole genomes
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
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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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| 2. |
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| 3. |
- Sinding, Mikkel-Holger S., et al.
(författare)
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Arctic-adapted dogs emerged at the Pleistocene-Holocene transition
- 2020
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 368:6498
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Tidskriftsartikel (refereegranskat)abstract
- Although sled dogs are one of the most specialized groups of dogs, their origin and evolution has received much less attention than many other dog groups. We applied a genomic approach to investigate their spatiotemporal emergence by sequencing the genomes of 10 modern Greenland sled dogs, an similar to 9500-year-old Siberian dog associated with archaeological evidence for sled technology, and an similar to 33,000-year-old Siberian wolf. We found noteworthy genetic similarity between the ancient dog and modern sled dogs. We detected gene flow from Pleistocene Siberian wolves, but not modern American wolves, to present-day sled dogs. The results indicate that the major ancestry of modern sled dogs traces back to Siberia, where sled dog-specific haplotypes of genes that potentially relate to Arctic adaptation were established by 9500 years ago.
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| 4. |
- Torell, Lena M., et al.
(författare)
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A Raman study of ion solvation and association in polymer electrolytes
- 1993
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Ingår i: Polymers for Advanced Technologies. - : John Wiley & Sons. - 1042-7147 .- 1099-1581. ; 4:2-3, s. 152-163
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Tidskriftsartikel (refereegranskat)abstract
- Ion–polymer and ion–ion interactions in polymer electrolytes have been investigated at different temperatures and pressures, and for different polymer molecular weights. Salt–polymer complexes of various triflate salts, M(CF3SO3)x (M = Li+, Na+, Ca2+, Cu2+ and Nd3+), in low molecular weight polyethers (PEO and PPO) have been studied using Raman and Brillouin scattering. It is found that anions coordinated to the OH end groups of the polyethers are more stable than cations forming crosslinks between oxygens of adjacent chains, which in turn are more stable than cations coordinated to single chains. We have observed that the number of ion pairs increases as the polymer molecular weight increases. Furthermore, the ion–ion interaction is strongly temperature-dependent and shows widely different behavior in different systems. In the case of Li+-, Na+- and Ca2+-containing polyether complexes the ion association increases with increasing T. It is constant in Cu2+–triflate complexes, while it decreases for complexes containing trivalent Nd3+ cations. Pressure observations in LiCF3SO3–PPO complexes reveal increasing solubility and fewer ion pairs as pressure increases. It is shown that theories which consider volume changes in the salt dissociation process can qualitatively explain the effects of molecular weight, temperature and pressure using entropy considerations. The entropy effect includes contributions due to free-volume dissimilarities between the solvated ions and the macromolecules, structural ordering induced via cationic crosslinking of adjacent chains and electrostriction. Comparing the spectroscopic data with conductivity data, it is found that differences in the “free” solvated ion concentration can account for differences in conductivity.
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