Stochastic TDHF in an exactly solvable model

We apply in a schematic model a theory beyond mean-field, namely Stochastic Time-Dependent Hartree-Fock (STDHF), which includes dynamical electron-electron collisions on top of an incoherent ensemble of mean-field states by occasional 2-particle-2-hole ($2p2h$) jumps. The model considered here is inspired by a Lipkin-Meshkov-Glick model of $\Omega$ particles distributed into two bands of energy and coupled by a two-body interaction. Such a model can be exactly solved (numerically though) for small $\Omega$. It therefore allows a direct comparison of STDHF and the exact propagation. The systematic impact of the model parameters as the density of states, the excitation energy and the bandwidth is presented and discussed. The time evolution of the STDHF compares fairly well with the exact entropy, as soon as the excitation energy is sufficiently large to allow $2p2h$ transitions. Limitations concerning low energy excitations and memory effects are also discussed.Comment: 23 pages, 8 figures, accepted in Annals of Physic

Comparaison des vis verrouillées et vis standard pour l'ostéosynthèse par plaque vissée d'une perte de substance médiodiaphysaire expérimentale : étude mécanique en compression axiale

Dans le cadre du traitement des fractures diaphysaires comminutives du tibia, via l’utilisation de plaques LCP, l’auteur se propose de comparer deux types de montages, le premier constitué de 6 vis bicorticales verrouillées et le second constitué de 6 vis bicorticales standard. L’étude a été réalisée sur 4 groupes de 6 ovins. Les os appareillés (tibias gauches) et les os controlatéraux (tibias droits) ont été soumis à des tests quasi-statiques en compression. Le comportement biomécanique des différents montages a été évalué à 6 et à 12 semaines de cicatrisation osseuse. L'évaluation biomécanique n'a pas montré de supériorité des propriétés mécaniques globales et locales des tibias appareillés à 6 semaines de cicatrisation. En revanche, à 12 semaines, pour les os appareillés, la déformation interfragmentaire en compression a été significativement plus faible pour le groupe vis verrouillées. Concernant les cals osseux, une supériorité significative des propriétés mécaniques globales du groupe vis verrouillées a été relevée en compression

The European Organisation for Research and Treatment of Cancer, State of Science in radiation oncology and priorities for clinical trials meeting report

Background: New technologies and techniques in radiation oncology and imaging offer opportunities to enhance the benefit of loco-regional treatments, expand treatment to new patient populations such as those with oligometastatic disease and decrease normal tissue toxicity. Furthermore, novel agents have become available which may be combined with radiation therapy, and identification of radiation-related biomarkers can be studied to refine treatment prescriptions. Finally, the use of artificial intelligence (AI) capabilities may also improve treatment quality assurance or the ease with which radiation dosing is prescribed. All of these potential advances present both opportunities and challenges for academic clinical researchers. Methods: Recently, the European Organisation for Research and Treatment of Cancer addressed these topics in a meeting of multiple stakeholders from Europe and North America. The following five themes radiobiology-based biomarkers, new technologies - particularly proton beam therapy, combination systemic and radiation therapy, management of oligometastatic disease and AI opportunities in radiation oncology were discussed in a State of Science format to define key controversies, unanswered questions and propose clinical trial priorities for development. Conclusions: Priorities for clinical trials implementing new science and technologies have been defined. Solutions to integrate the multidimensional complexity of data have been explored. New types of platforms and partnerships can support innovative approaches for clinical research in radiation oncology. (C) 2020 The Authors. Published by Elsevier Ltd

The contribution of hydrogen to the corrosion of 2024 aluminium alloy exposed to thermal and environmental cycling in chloride media

This work is focused on the role of hydrogen in corrosion damage induced by the cyclic exposure of 2024 aluminium alloy to chloride media with air emersion periods at room and/or negative temperatures. Various analysis and microscopic observation techniques were applied at intergranular corrosion defects. A mechanism involving the contribution of hydrogen to the degradation of the alloy mechanical properties is presented. Several consecutive stress states appear during cycling, resulting from volume expansion of the electrolyte trapped in the intergranular defects during emersion phases at -20°C. These stress states lead to hydrogen diffusion, transport and trapping

EgMYB2, a new transcriptional activator from Eucalyptus xylem, regulates secondary cell wall formation and lignin biosynthesis

International audienceEgMYB2, a member of a new subgroup of the R2R3 MYB family of transcription factors, was cloned from a library consisting of RNA from differentiating Eucalyptus xylem. EgMYB2 maps to a unique locus on the Eucalyptus grandis linkage map and co-localizes with a quantitative trait locus (QTL) for lignin content. Recombinant EgMYB2 protein was able to bind specifically the cis-regulatory regions of the promoters of two lignin biosynthetic genes, cinnamoyl-coenzyme A reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD), which contain MYB consensus binding sites. EgMYB2 was also able to regulate their transcription in both transient and stable expression assays. Transgenic tobacco plants over-expressing EgMYB2 displayed phenotypic changes relative to wild-type plants, among which were a dramatic increase in secondary cell wall thickness, and an alteration of the lignin profiles. Transcript abundance of genes encoding enzymes specific to lignin biosynthesis was increased to varying extents according to the position of individual genes in the pathway,whereas core phenylpropanoid geneswere not significantly affected. Together these results suggest a role for EgMYB2 in the co-ordinated control of genes belonging to the monolignol-specific pathway, and therefore in the biosynthesis of lignin and the regulation of secondary cell wall formation

The Five AhMTP1 Zinc Transporters Undergo Different Evolutionary Fates towards Adaptive Evolution to Zinc Tolerance in Arabidopsis halleri

Gene duplication is a major mechanism facilitating adaptation to changing environments. From recent genomic analyses, the acquisition of zinc hypertolerance and hyperaccumulation characters discriminating Arabidopsis halleri from its zinc sensitive/non-accumulator closest relatives Arabidopsis lyrata and Arabidopsis thaliana was proposed to rely on duplication of genes controlling zinc transport or zinc tolerance. Metal Tolerance Protein 1 (MTP1) is one of these genes. It encodes a Zn2+/H+ antiporter involved in cytoplasmic zinc detoxification and thus in zinc tolerance. MTP1 was proposed to be triplicated in A. halleri, while it is present in single copy in A. thaliana and A. lyrata. Two of the three AhMTP1 paralogues were shown to co-segregate with zinc tolerance in a BC1 progeny from a cross between A. halleri and A. lyrata. In this work, the MTP1 family was characterized at both the genomic and functional levels in A. halleri. Five MTP1 paralogues were found to be present in A. halleri, AhMTP1-A1, -A2, -B, -C, and -D. Interestingly, one of the two newly identified AhMTP1 paralogues was not fixed at least in one A. halleri population. All MTP1s were expressed, but transcript accumulation of the paralogues co-segregating with zinc tolerance in the A. halleri X A. lyrata BC1 progeny was markedly higher than that of the other paralogues. All MTP1s displayed the ability to functionally complement a Saccharomyces cerevisiæ zinc hypersensitive mutant. However, the paralogue showing the least complementation of the yeast mutant phenotype was one of the paralogues co-segregating with zinc tolerance. From our results, the hypothesis that pentaplication of MTP1 could be a major basis of the zinc tolerance character in A. halleri is strongly counter-balanced by the fact that members of the MTP1 family are likely to experience different evolutionary fates, some of which not concurring to increase zinc tolerance

FLIM FRET Technology for Drug Discovery: Automated Multiwell-Plate High-Content Analysis, Multiplexed Readouts and Application in Situ**

A fluorescence lifetime imaging (FLIM) technology platform intended to read out changes in Förster resonance energy transfer (FRET) efficiency is presented for the study of protein interactions across the drug-discovery pipeline. FLIM provides a robust, inherently ratiometric imaging modality for drug discovery that could allow the same sensor constructs to be translated from automated cell-based assays through small transparent organisms such as zebrafish to mammals. To this end, an automated FLIM multiwell-plate reader is described for high content analysis of fixed and live cells, tomographic FLIM in zebrafish and FLIM FRET of live cells via confocal endomicroscopy. For cell-based assays, an exemplar application reading out protein aggregation using FLIM FRET is presented, and the potential for multiple simultaneous FLIM (FRET) readouts in microscopy is illustrated

PLoS One

Compared to the general population, HIV-infected patients are at higher risk of developing non-AIDS-defining cancers. Chronic HCV infection has also been associated with a higher risk than that of the general population of developing cancers other than hepatocarcinoma. Evaluation of the impact of HCV-related factors on non-AIDS-defining and non HCV-liver (NANL) related cancers among HIV/HCV co-infected patients are scarce. The aim of this study was to identify the impact of HIV/HCV clinical characteristics on NANL related cancers in a large cohort of HIV/HCV-coinfected patients followed from 2005 to 2017. Cox proportional hazards models with delayed entry were used to estimate factors associated with NANL related cancer. Among 1391 patients followed for a median of 5 years, 60 patients developed NANL related cancers, yielding an incidence rate of 8.9 per 1000 person-years (95% CI, [6.6-11.1]). By final multivariable analysis, after adjustment for sex, tobacco or alcohol consumption, baseline CD4 cell count and HCV sustained viral response (SVR), age and a longer duration since HIV diagnosis were independently associated with a higher risk of NANL related cancer (aHR for each additional year 1.10, 95% CI 1.06-1.14, p<0.0001 and 1.06, 95% CI 1.01-1.11, p = 0.02, respectively). Duration of HCV infection, cirrhosis, HCV viral load, genotype and SVR were not associated with the occurrence of NANL related cancer. Among HIV/HCV-coinfected patients, age and the duration of HIV infection were the only characteristics found to be associated with the occurrence of NANL related cancer. In contrast, no association was observed with any HCV-related variables

Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts