Charge Carrier Extraction in Organic Solar Cells Governed by Steady-State Mobilities

Charge transport in organic photovoltaic (OPV) devices is often characterized by steady-state mobilities. However, the suitability of steady-state mobilities to describe charge transport has recently been called into question, and it has been argued that dispersion plays a significant role. In this paper, the importance of the dispersion of charge carrier motion on the performance of organic photovoltaic devices is investigated. An experiment to measure the charge extraction time under realistic operating conditions is set up. This experiment is applied to different blends and shows that extraction time is directly related to the geometrical average of the steady-state mobilities. This demonstrates that under realistic operating conditions the steady-state mobilities govern the charge extraction of OPV and gives a valuable insight in device performance

Photostability of Fullerene and Non-Fullerene Polymer Solar Cells:The Role of the Acceptor

Recently, the advent of non-fullerene acceptors (NFAs) made it possible for organic solar cells (OSCs) to break the 10% efficiency barrier hardly attained by fullerene acceptors (FAs). In the past five years alone, more than hundreds of NFAs with applications in organic photovoltaics (OPVs) have been synthesized, enabling a notable current record efficiency of above 15%. Hence, there is a shift in interest towards the use of NFAs in OPVs. However, there has been little work on the stability of these new materials in devices. More importantly, there is very little comparative work on the photo-stability of FAs vs. NFAs solar cells, to ascertain the pros and cons of the two systems. Here, we show the photo-stability of solar cells based on two workhorse acceptors, in both conventional and inverted structures, namely ITIC (as NFA) and [70]PCBM (as FA) blended with either PBDB-T or PTB7-Th polymer. We found that irrespective of the polymer, the cell structure, or the initial efficiency, the [70]PCBM devices are more photo-stable than the ITIC ones. This observation, however, opposes the assumption that NFA solar cells are more photo-chemically stable. These findings suggest that complementary absorption should not take precedence in the design rules for the synthesis of new molecules and there is still work left to be done to achieve stable as well as efficient OSCs

Future directions in conservation research on petrels and shearwaters

Shearwaters and petrels (hereafter petrels) are highly adapted seabirds that occur across all the world's oceans. Petrels are a threatened seabird group comprising 124 species. They have bet-hedging life histories typified by extended chick rearing periods, low fecundity, high adult survival, strong philopatry, monogamy and long-term mate fidelity and are thus vulnerable to change. Anthropogenic alterations on land and at sea have led to a poor conservation status of many petrels with 52 (42%) threatened species based on IUCN criteria and 65 (52%) suffering population declines. Some species are well-studied, even being used as bioindicators of ocean health, yet for others there are major knowledge gaps regarding their breeding grounds, migratory areas or other key aspects of their biology and ecology. We assembled 38 petrel conservation researchers to summarize information regarding the most important threats according to the IUCN Red List of threatened species to identify knowledge gaps that must be filled to improve conservation and management of petrels. We highlight research advances on the main threats for petrels (invasive species at breeding grounds, bycatch, overfishing, light pollution, climate change, and pollution). We propose an ambitious goal to reverse at least some of these six main threats, through active efforts such as restoring island habitats (e.g., invasive species removal, control and prevention), improving policies and regulations at global and regional levels, and engaging local communities in conservation efforts

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Revealing Photodegradation Pathways of Organic Solar Cells by Spectrally Resolved Accelerated Lifetime Analysis

A method for organic solar cell (OSC) stability testing is presented that aims to provide more unique insight into the causes of degradation patterns of OSCs. The method involves using monochromatic light at high irradiation doses to accelerate isolated degradation mechanisms while monitoring the device with a series of in-situ steady-state and transient electrical measurements. The experimental results are accompanied by drift-diffusion simulations to localize degradation pathways. PM6:Y6-based OSCs are tested, which are known to show a rather broad range of lifetimes as a function of device architecture, material batches, or degradation conditions. The experiments reveal a degradation mechanism that causes an increased trap-state density inside the PM6:Y6 layer. The transient simulations suggest that these states are formed at or around the interface between the PM6:Y6 and the electron transport layer. Furthermore, the surprisingly dominant impact of the illuminating wavelength on the degradation pattern is evidenced. Lastly, the degradation rate of the devices scales linearly with light intensity, making high intensity and spectrally selective degradation the most promising way to accelerate stability testing for the faster development of stable OSCs

Parallel FISH and Immunohistochemical Studies of ALK Status in 3244 Non-Small-Cell Lung Cancers Reveal Major Discordances

International audienceIntroduction: Anaplastic lymphoma kinase (ALK) rearrangements occur in 1% to 7% of non-small-cell lung cancers (NSCLCs). Crizotinib, an ALK inhibitor, has been demonstrated to provide dramatic clinical benefits in ALK-positive advanced-stage NSCLC. Fluorescent in situ hybridization (FISH) has been established in clinical trials as the standard procedure method for detecting ALK rearrangements. Although the detection of ALK by immunohistochemistry (IHC) has been proposed for the screening of patients, large-scale studies are warranted to validate such a hierarchical approach. Methods: In this article, we report the largest series thus far of parallel FISH and IHC ALK testing in 3244 consecutive NSCLC cases analyzed at two independent French centers. Results: FISH-positive and/or IHC-positive results were demonstrated in 150 of 3244 cases (4.6%). An imbalanced sex ratio was detected, with women exhibiting a 2.2-fold relative risk for an alteration. Strikingly, only 80 of 150 specimens were classified as ALK positive by both techniques. The specimens with discordant FISH/IHC analyses were FISH-positive/IHC-negative (36), FISH-negative/IHC-positive (19), or FISH-noncontributive/IHC-positive (15). Thus, a single FISH or IHC analysis performed alone would have failed to detect approximately one-fourth of the ALK-positive cases with similar findings in our two centers. Conclusions: This study highlights the feasibility of systematic NSCLC testing by both FISH and IHC in routine practice. Many preanalytical factors may account for the apparent discrepancies between both methods, suggesting that hierarchical screening may underscore ALK-positive cases. This significant level of discrepancy supports the need of combined testing to optimize the detection of ALK-inhibitor-eligible patients given that some patients with discordant testing were found to respond to crizotinib

Les crises de la dette publique

Ce livre a pour objectif de soumettre à l’expertise des historiens la question qui agite autant le monde savant que les politiques, les citoyens et les médias : comment un État ou un groupe d’États peut-il entrer dans une crise de la dette publique et comment peut-il s’en sortir ? Il semble bien en effet que les historiens disposent d’un vaste champ expérimental, susceptible d’autoriser les comparaisons dans le temps et dans l’espace. Au-delà des variations fortes du contexte dans lequel leurs observations s’insèrent, leurs constats peuvent ainsi entrer en résonance avec les théories ou les faits énoncés ou révélés par les économistes et les sociologues, ouvrant ainsi la voie à un véritable dialogue interdisciplinaire. Les exemples ne manquent pas, ils foisonnent, de moments critiques où les États se sont trouvés dans une situation de surendettement qu’ils ne parvenaient plus à surmonter. Ce livre entend rendre compte de ces épisodes sans doute improprement appelés « crises ». Il s’agit, en effet, d’interroger les auteurs sur un faisceau d’expériences historiques depuis le XVIIIe siècle jusqu’à nos jours, et de leur demander d’analyser à la fois les évolutions qui ont conduit à une montée de la dette publique et les remèdes qui ont pu être appliqués pour tenter de la juguler. De l’Amérique latine à la Russie, le spectre géographique de cette publication a une large portée internationale, l’ouvrage ne délivre certes pas de recettes mais apporte un nouvel éclairage sur des processus qui peuvent faire déraper la dette publique et sur les méthodes employées pour la réduire, l’endiguer, voire l’annuler

Hsa-miR-31-3p expression is linked to progression-free survival in patients with KRAS wild-type metastatic colorectal cancer treated with anti-EGFR therapy.

To identify microRNAs (miRNA) that predict response to anti-EGFR antibodies in patients with wild-type KRAS metastatic colorectal cancer (mCRC).SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Programme Collectif de Recherche "Espaces et subsistance au Paléolithique moyen dans le sud du Massif central".

Ce PCR regroupait en première année de fonctionnement 47 chercheurs professionnels et bénévoles, plusieurs collaborateurs occssionnels et un prestataire privé pour analyses spécialisées, autour de la thématique « espaces et subsistances » dans le sud-est du Massif central, entre moyenne montagne et couloir rhodanien. Les travaux conduits s’appuient sur les résultats mutualisés de fouilles programmées de longue durée menées tant en Ardèche qu’en Haute-Loire, mais ausi sur les matériaux provenant de fouilles anciennes revisitées. Ils s’attachent au terrain (prospections, sondages,reprises de stratigraphies), aux études de matières premières (pétroarchéologie) et d’outillages lithiques (technologie, typologie, fonctionnalités), aux ressources carnées (archéozoologie) et à leur exploitation comparée (taphonomie), aux caractéristiques intimes des témoins archéologiques par une panoplie analytique diversifiée à haute résolution(isotopes, mico-traces, tracéologie et résidus, combustions...), à la chronologie révisée des occupations humaines par des méthodes de datation croisées (AMS, TL, OSL, RPE, U/Th), à la modélisation des niches éco-culturelles concernées et à la facilitation des échanges entre acteurs concernés (missions et réunions).Les résultats obtenus avant 2014 ont fait l’objet de synthèses et ont été principalement publiées ou soumises à des revues expertisées : Quaternary International, ERAUL, Comptes Rendus Palévol, L’Anthropologie, RST, Society of American Archaeology, Société préhistorique française, PlosOne