113 research outputs found
“Страна городов” и ее столица: Новгород в картине мира средневековых скандинавов
The paper presents data preserved in Old Norse-Icelandic literature on Hólmgarðr, a place that is traditionally identified with Novgorod. Hólmgarðr appears in these writings as a capital of Garðaríki (Old Rus’): all Russian princes familiar from these sources have their seat in this place. Almost all the events occurring in Russia are associated in the sagas with Hólmgarðr: Scandinavians come to Hólmgarðr to seek refuge or service; four Norwegian kings stay in Hólmgarðr for a period of time; Scandinavians return to their homeland or sail to distant lands from this place; and Scandinavian merchants also come to this town. Hólmgarðr is described in a generalized way. It has the prince’s court, the chamber of the princess, a special hall built for the Varangian guards, the Church of St. Olav, and a marketplace; in other words, we are dealing with a traditional set of characteristics of a capital city. Novgorod on the mental map of medieval Scandinavians belongs to the eastern quarter (Austrhálfa) of the oekumene, and to get there travelers had to go austr ‘east,’ to cross the Baltic Sea (Austmarr, Eystrasalt), and to pass Ladoga (Aldeigja, Aldeigjuborg), where they changed from ocean-going ships to river vessels and where they waited for a guaranty of safe travel (grið) from the prince of Novgorod (konungr í Hólmgarði).В статье наиболее полно собраны известия древнескандинавских письменных памятников о Хольмгарде, который традиционно принято отождествлять с Новгородом. Хольмгард выступает здесь в качестве столицы Гардарики (Руси): в нем находятся все известные по этим источникам русские князья. Почти все события, происходящие на Руси, связываются в сагах с Хольмгардом: сюда приходят скандинавы искать прибежища или наниматься на службу, здесь живут некоторое время четыре норвежских конунга, отсюда скандинавы отправляются в обратный путь на родину или плывут в дальние страны, сюда приезжают скандинавские купцы. Хольмгард описан в самом обобщенном виде: здесь находится двор конунга (князя), палаты княгини, палаты для варяжской дружины, церковь св. Олава, торговая площадь — т. е. перед нами как бы некий традиционный набор характеристик столичного города. Новгород на ментальной карте мира средневековых скандинавов находится в Восточной четверти (Austrhálfa) ойкумены. Чтобы попасть туда, путешественники должны плыть austr “на восток”, пересечь Балтийское море (Austmarr, Eystrasalt) и миновать Ладогу (Aldeigja, Aldeigjuborg), где им приходится менять свои морские суда на речные и дожидаться гарантии безопасного проезда (grið) от “конунга Новгорода” (konungr í Hólmgarði)
Signatures of TOP1 transcription-associated mutagenesis in cancer and germline
The mutational landscape is shaped by many processes. Genic regions are vulnerable to mutation but are preferentially protected by transcription-coupled repair1. In microorganisms, transcription has been demonstrated to be mutagenic2,3; however, the impact of transcription-associated mutagenesis remains to be established in higher eukaryotes4. Here we show that ID4—a cancer insertion–deletion (indel) mutation signature of unknown aetiology5 characterized by short (2 to 5 base pair) deletions —is due to a transcription-associated mutagenesis process. We demonstrate that defective ribonucleotide excision repair in mammals is associated with the ID4 signature, with mutations occurring at a TNT sequence motif, implicating topoisomerase 1 (TOP1) activity at sites of genome-embedded ribonucleotides as a mechanistic basis. Such TOP1-mediated deletions occur somatically in cancer, and the ID-TOP1 signature is also found in physiological settings, contributing to genic de novo indel mutations in the germline. Thus, although topoisomerases protect against genome instability by relieving topological stress6, their activity may also be an important source of mutations in the human genome
Signatures of TOP1 transcription-associated mutagenesis in cancer and germline
The mutational landscape is shaped by many processes. Genic regions are vulnerable to mutation but are preferentially protected by transcription-coupled repair1. In microorganisms, transcription has been demonstrated to be mutagenic2,3; however, the impact of transcription-associated mutagenesis remains to be established in higher eukaryotes4. Here we show that ID4—a cancer insertion–deletion (indel) mutation signature of unknown aetiology5 characterized by short (2 to 5 base pair) deletions —is due to a transcription-associated mutagenesis process. We demonstrate that defective ribonucleotide excision repair in mammals is associated with the ID4 signature, with mutations occurring at a TNT sequence motif, implicating topoisomerase 1 (TOP1) activity at sites of genome-embedded ribonucleotides as a mechanistic basis. Such TOP1-mediated deletions occur somatically in cancer, and the ID-TOP1 signature is also found in physiological settings, contributing to genic de novo indel mutations in the germline. Thus, although topoisomerases protect against genome instability by relieving topological stress6, their activity may also be an important source of mutations in the human genome.We thank S. Jinks-Robertson for suggesting the traffic light reporter approach; H. Klein for guidance on fluctuation assays; R. van Boxtel for sharing sequencing data for MLH1-KO organoids; A. Bretherick, O. B. Reina and G. Kudla for advice on HygroR re-coding; staff at the IGC core services (L. Murphy, C. Nicol, C. Warnock, E. Freyer, S. Brown and J. Joseph), C. Logan, A. Fluteau, A. Robertson and the staff at Edinburgh Genomics for technical assistance; staff at Liverpool CLL Biobank (funded by Blood Cancer UK) for samples used to generate GEL WGS data; A. Ewing, C.-A. Martin, N. Hastie and W. Bickmore for discussions. Funding for this work: UK Medical Research Council Human Genetics Unit core grants (MC_UU_00007/5 to A.P.J., MC_UU_00007/11 to M.S.T.); Edinburgh Clinical Academic Track PhD programme (Wellcome Trust 204802/Z/16/Z) to T.C.W.; 2021 AACR-Amgen Fellowship in Clinical/Translational Cancer Research (grant number 21-40-11-NADE) to F.N.; a CRUK Brain Tumour Centre of Excellence Award (C157/A27589) to M.D.N.; EKFS research grant (2019_A09), Wilhelm Sander-Stiftung (2019.046.1) to K.A., CRUK programme grant (C20807/A2864) to T.S.; La Caixa Foundation (CLLEvolution-LCF/PR/HR17/52150017, Health Research 2017 Program HR17-00221) to E.C.; E.C. is an Academia Researcher of the Institució Catalana de Recerca i Estudis Avançats of the Generalitat de Catalunya. Edinburgh Genomics is partly supported by NERC (R8/H10/56), MRC (MR/K001744/1) and BBSRC (BB/J004243/1). This research was made possible through access to the data and findings generated by the 100,000 Genomes Project. The 100,000 Genomes Project is managed by Genomics England Limited (a wholly owned company of the Department of Health and Social Care). The 100,000 Genomes Project is funded by the National Institute for Health Research and NHS England. The Wellcome Trust, Cancer Research UK and the Medical Research Council have also funded research infrastructure. The 100,000 Genomes Project uses data provided by patients and collected by the National Health Service as part of their care and support.Peer Reviewed"Article signat per 22 autors/es: Martin A. M. Reijns, David A. Parry, Thomas C. Williams, Ferran Nadeu, Rebecca L. Hindshaw, Diana O. Rios Szwed, Michael D. Nicholson, Paula Carroll, Shelagh Boyle, Romina Royo, Alex J. Cornish, Hang Xiang, Kate Ridout, The Genomics England Research Consortium, Colorectal Cancer Domain UK 100,000 Genomes Project, Anna Schuh, Konrad Aden, Claire Palles, Elias Campo, Tatjana Stankovic, Martin S. Taylor & Andrew P. Jackson "Postprint (published version
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents
Biocompatible poly-[N-(2-hydroxyethyl)-d,l-aspartamide]-methoxypoly(ethyleneglycol)-hexadecylamine (PHEA-mPEG-C16) conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd) via ethylenediamine (ED) was synthesized as a magnetic resonance imaging (MRI) contrast agent. Amphiphilic PHEA-mPEG-C16-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Micelle size and shape were examined by dynamic light scattering (DLS) and atomic force microscopy (AFM). Micelles with PHEA-mPEG-C16-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C16-ED-DOTA-Gd
Contribution of Common Genetic Variants to Risk of Early-Onset Ischemic Stroke
Background and Objectives Current genome-wide association studies of ischemic stroke have focused primarily on late-onset disease. As a complement to these studies, we sought to identify the contribution of common genetic variants to risk of early-onset ischemic stroke. Methods We performed a meta-analysis of genome-wide association studies of early-onset stroke (EOS), ages 18-59 years, using individual-level data or summary statistics in 16,730 cases and 599,237 nonstroke controls obtained across 48 different studies. We further compared effect sizes at associated loci between EOS and late-onset stroke (LOS) and compared polygenic risk scores (PRS) for venous thromboembolism (VTE) between EOS and LOS. Results We observed genome-wide significant associations of EOS with 2 variants in ABO, a known stroke locus. These variants tag blood subgroups O1 and A1, and the effect sizes of both variants were significantly larger in EOS compared with LOS. The odds ratio (OR) for rs529565, tagging O1, was 0.88 (95% confidence interval [CI]: 0.85-0.91) in EOS vs 0.96 (95% CI: 0.92-1.00) in LOS, and the OR for rs635634, tagging A1, was 1.16 (1.11-1.21) for EOS vs 1.05 (0.99-1.11) in LOS; p-values for interaction = 0.001 and 0.005, respectively. Using PRSs, we observed that greater genetic risk for VTE, another prothrombotic condition, was more strongly associated with EOS compared with LOS (p = 0.008). Discussion The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with EOS than with LOS, supporting a stronger role of prothrombotic factors in EOS.Peer reviewe
Study of ordered hadron chains with the ATLAS detector
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Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial
Background:
Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events.
Methods:
The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627).
Findings:
Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92).
Interpretation:
These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention
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