Illustrating the value of Open Access for text mining

International audienc

Leveraging Knowledge Graph Embeddings to Enhance Contextual Representations for Relation Extraction

Relation extraction task is a crucial and challenging aspect of Natural Language Processing. Several methods have surfaced as of late, exhibiting notable performance in addressing the task; however, most of these approaches rely on vast amounts of data from large-scale knowledge graphs or language models pretrained on voluminous corpora. In this paper, we hone in on the effective utilization of solely the knowledge supplied by a corpus to create a high-performing model. Our objective is to showcase that by leveraging the hierarchical structure and relational distribution of entities within a corpus without introducing external knowledge, a relation extraction model can achieve significantly enhanced performance. We therefore proposed a relation extraction approach based on the incorporation of pretrained knowledge graph embeddings at the corpus scale into the sentence-level contextual representation. We conducted a series of experiments which revealed promising and very interesting results for our proposed approach.The obtained results demonstrated an outperformance of our method compared to context-based relation extraction models.Comment: 15 pages, 1 figures, The 17th International Conference on Document Analysis and Recognitio

First Palladium-Catalyzed Direct Regioselective C-5 (Het)Arylation of Mono- or Disubstituted Thiazolo[3,2- b ][1,2,4]triazoles

International audienc

Innovation Ouverte : 10 recommandations pour plus d’innovation et de compétitivité

International audienc

Polymer Blend Solar Cells Based on a High-Mobility Naphthalenediimide-Based Polymer Acceptor: Device Physics, Photophysics and Morphology

A high electron mobility polymer, poly{[N,N’-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5’-(2,2’-bithiophene) (P(NDI2OD-T2)) is investigated for use as an electron acceptor in all-polymer blends. Despite the high bulk electron mobility, near-infrared absorption band and compatible energy levels, bulk heterojunction devices fabricated with poly(3-hexylthiophene) (P3HT) as the electron donor exhibit power conversion efficiencies of only 0.2%. In order to understand this disappointing photovoltaic performance, systematic investigations of the photophysics, device physics and morphology of this system are performed. Ultra-fast transient absorption spectroscopy reveals a two-stage decay process with an initial rapid loss of photoinduced polarons, followed by a second slower decay. This second slower decay is similar to what is observed for efficient P3HT:PCBM ([6,6]-phenyl C61-butyric acid methyl ester) blends, however the initial fast decay that is absent in P3HT:PCBM blends suggests rapid, geminate recombination of charge pairs shortly after charge transfer. X-ray microscopy reveals coarse phase separation of P3HT:P(NDI2OD-T2) blends with domains of size 0.2 to 1 micrometer. P3HT photoluminescence, however, is still found to be efficiently quenched indicating intermixing within these mesoscale domains. This hierarchy of phase separation is consistent with the transient absorption, whereby localized confinement of charges on isolated chains in the matrix of the other polymer hinders the separation of interfacial electron-hole pairs. These results indicate that local, interfacial processes are the key factor determining the overall efficiency of this system and highlight the need for improved morphological control in order for the potential benefit of high-mobility electron accepting polymers to be realized

Design of α\alpha7 nicotinic acetylcholine receptor ligands in quinuclidine, tropane and quinazoline series. Chemistry, molecular modeling, radiochemistry, in vitro and in rats evaluations of a [18^{18}F] quinuclidine derivative

International audienceIn this report, we describe the synthesis of a novel library of $\alpha$7 nAChR ligands based on the modulationof the quinuclidine, quinazoline and tropane moieties. Spirane derivatives were newly synthesized understereo specific 1,3 dipolar cylcoadditions. Only amide derivatives bonded efficiently to the receptor withKi measured between 14 and 133 nM. The best fluorinated candidate was selected and radiolabeled. Thepotent [$^{18}$F]4 PET tracer was evaluated in rats and its brain accumulation quantified

Trap-Induced Losses in Hybrid Photovoltaics

We investigate the loss mechanisms in hybrid photovoltaics based on blends of poly(3-hexylthiophene) with CdSe nanocrystals of various sizes. By combining the spectroscopic and electrical measurements on working devices as well as films, we identify that high trap-mediated recombination is responsible for the loss of photogenerated charge carriers in devices with small nanocrystals. In addition, we demonstrate that the reduced open-circuit voltage for devices with small nanocrystals is also caused by the traps