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Self-organized metal-semiconductor epitaxial graphene layer on off-axis 4H-SiC（0001）

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Nano Research 2015年第3期8卷 1026-1037页

作者： Debora Pierucci Haikel Sediri Mahdi Haj.aoui Emilio Velez-Fort yannick j. dappe Mathieu G. Silly Rachid Belkhou Abhay Shukla Fausto Sirotti Noelle Gogneau Abdelkarim Ouerghi CNRS- Laboratoire de Photonique et de Nanostructures Route de Nozay 91460 Marcoussis France Synchrotron-SOLEIL Saint-Aubin BP48 F91192 Gifsur Yvette Cedex France Universite Pierre et Marie Curie (CNRS - IMPMC) 4 PI. Jussieu 75005 Paris France Service de Physique de rEtat Condense (CNRS URA2464) IRAMIS CEA Saclay 91191 Gif-Sur-Yvette France

The remarkable properties of graphene have shown promise for new perspectives in future electronics, notably for nanometer scale devices. Here we grow graphene epitaxially on an off-axis 4H-SiC（0001） substrate and demonstrate the formation of periodic arrangement of monolayer graphene on planar （0001） terraces and Bernal bilayer graphene on （1120） nanofacets of SiC. We investigate these lateral superlattices using Raman spectroscopy, atomic force microscopy/ electrostatic force microscopy （AFM/EFM） and X-ray and angle resolved photoemission spectroscopy （XPS/ARPES）. The correlation of EFM and ARPES reveals the appearance of permanent electronic band gaps in AB-stacked bilayer graphene on （1120） SiC nanofacets of 150 meV. This feature is confirmed by density functional theory （DFT） calculations. The charge transfer between the substrate and graphene bilayer results in an asymmetric charge distribution between the top and the bottom graphene layers opening an energy gap. This surface organization can be thus defined as self-organized metal-semiconductor graphene.

关键词： epitaxial graphene layer monolayer bilayer band gap opening Bernal stacking off-axis silicon carbide electronic properties

Influence of"protective"symbionts throughout the different steps of an aphid-parasitoid interaction

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Current Zoology 2021年第4期67卷 441-453页

作者： Corentin Sochard Laura Bellec j.an-Christophe Simon yannick Outreman IGEPP INRAEInstitut AgroUniv Rennes35000RennesFrance IGEPP INRAEInstitut AgroUniv Rennes35650Le RheuFrance

Microbial associates are widespread in insects,some conferring a protection to their hosts against natural enemies like *** protective symbionts may affect the infection success of the parasitoid by modifying behavioral defenses of their hosts,the development success of the parasitoid by conferring a resistance against it or by altering life-history traits of the emerging ***,we assessed the effects of different protective bacterial symbionts on the entire sequence of the host-parasitoid interaction(i.e.,from parasitoid attack to offspring emergence)between the pea aphid,Acyrthosiphon pisum,and its main parasitoid,Aphidius ervi and their impacts on the life-history traits of the emerging *** test whether symbiont-mediated phenotypes were general or specific to particular aphid-symbiont associations,we considered several aphid lineages,each harboring a different strain of either Hamiltonella defensa or Regiella insecticola,two protective symbionts commonly found in *** found that symbiont species and strains had a weak effect on the ability of aphids to defend themselves against the parasitic wasps during the attack and a strong effect on aphid resistance against parasitoid *** parasitism resistance was mainly determined by symbionts,their effects on host defensive behaviors varied from one aphid-symbiont association to ***,the symbiotic status of the aphid individuals had no impact on the attack rate of the parasitic wasps,the parasitoid emergence rate from parasitized aphids nor the life-history traits of the emerging ***,no correlations between symbiont effects on the different stages of the host-parasitoid interaction was observed,suggesting no trade-offs or positive associations between symbiont-mediated *** study highlights the need to consider various sequences of the host-parasitoid interaction to better assess the outcomes of protective symbioses and understand the

关键词： Acyrthosiphon pisum defensive behaviors Hamiltonella defensa host-parasitoid interactions protective symbioses Regiella insecticola

Photonic properties of novel Yb3＋ doped germanium-lead oxyfluoride glass-ceramics for laser cooling applications

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Frontiers of Optoelectronics 2018年第2期11卷 189-198页

作者： Lauro j. Q. MAIA j.othis THOMAS yannick LEDEMI Kummara V. KRISHNAIAH Denis SELETSKIY Younes MESSADDEQ Raman KASHYAP Instituto de Fisica Universidade Federal de Goias Av. Esperanga 1533 Campus Samambaia Goiania GO 74690-900 Brazil Department of Electrical Engineering Ecole Polytechnique de Montrral P.O. Box 6079 Station Centre-ville Montreal QC H3C 3A7 Canada Department of Engineering Physics Ecole Polytechnique de Montrral P.O. Box 6079 Station Centre-ville Montreal QC H3C 3A7 Canada Centre d'Optique Photonique et Laser 2375 Rue de la Terrasse Universite Laval Qurbec QC G1V 0A6 Canada

Abstract In recent years, our research group has developed and studied new rare-earth doped materials for the promising technology of solid-state laser cooling, which is based on anti-stokes fluorescence. To the best of our knowledge, our group is the only one in Canada leading the research into the properties of nanoparticles, glasses and glass-ceramics for optical refrigeration appli- cations. In the present work, optical properties of 50GeO2- 30PbF2-18PbO-2YbF3 glass-ceramics for laser cooling are presented and discussed as a function of crystallization temperature. Spectroscopic results show that samples have near infrared photoluminescence emission due to the 2F5/2 - 2F7/2 Yb3＋ transition, centered at -1016 nm with an excitation wavelength of 920 nm or 1011 nm, and the highest photoluminescence emission efficiency occurs for heat-treatment for 5 h at 350℃. The internal photolumi- nescence quantum yield varies between 99% and 80%, depending on the temperature of heat-treatment, being the most efficient under 1011 nm excitation. The 2F5/2 lifetime increases from 1.472 to 1.970 ms for heat treatments at 330℃ to 350℃, respectively, due to energy trapping and the low phonon energy of the nanocrystals. The sample temperature dependence was measured with a fiber Bragg grating sensor, as a function of input pump laser wavelength and processing temperature. These measure- ments show that the heating process approaches near zero for an excitation wavelength between 1020 and 1030 nm, which is an indication that phonons are removed effectivelly from the glass-ceramic materials, and they can be used for optical laser cooling applications. On theother hand, the temperature increase as a function of input laser power into samples remains constant between 920 and 980 nm wavelength excitation, a temperature variation of 36 K/W （temperature of 58℃/W） was attained under excitation at 950 nm, showing a possible use for biomedical applications to be explored.

关键词： optical refrigeration oxyfluoride glass-cera-mics Yb3+ doping quantum yield infrared emission lifetime

ScY@C_(3v)(8)-C_(82):Metal-Metalσ^(2)Bond in Mixed Rare-Earth Di-metallofullerenes

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Chinese j.urnal of Chemistry 2023年第15期41卷 1809-1814页

作者： Lihao Zheng yannick Roselló Yingj.ng Yan Yang-Rong Yao Xiaolin Fan j.sep M.Poblet Antonio Rodríguez-Fortea Ning Chen College of Chemistry Chemical Engineering and Materials Scienceand State Key Laboratory of Radiation Medicine and ProtectionSoochow UniversitySuzhouJiangsu 215123China Departament de Quimica Fisica i Inorganica Universitat Rovira i VirgiliMarcelli Domingo 143007 TarragonaSpain Department of Materials Science and Engineering CAS Key Laboratory of Materials for Energy ConversionAnhui Laboratory of Advanced Photon Science and TechnologyUniversity of Science and Technology of ChinaHefeiAnhui 230026China

Comprehensive Summary The experimental investigation of rare-earth metal-metal bonds remains a challenge in the study of chemical ***,we report the synthesis and characterization of a novel heteronuclear di-metallofullerene,ScY@C_(3v)(8)-C_(82),which contains a mixed rare-earth metal-metal ***@C_(3v)(8)-C_(82)was successfully synthesized by arc-discharging method and characterized by mass spectrometry,UV-vis-NIR spectroscopy and single-crystal X-ray diffraction crystallography,which unambiguously determined its molecular *** calculations were also performed to study the optimized positions of Sc-Y metallic dimer and the electronic *** combined experimental and theoretical results confirmed that both Sc and Y atoms transfer two electrons to the C_(3v)(8)-C_(82)cage,i.e.,(ScY)4+@(C_(3v)(8)-C_(82))4-.In particular,a covalent Sc-Yσ2 bond,which has never been reported before,is proven to be formed inside C_(3v)(8)-C_(82)fullerene *** work presents a novel di-metallofullerene containing mixed rare-earth metal-metal bond and expands the understanding of metal-metal bonding of rare earth elements.

关键词： Fullerenes Endohedral fullerenes Rare earths Densityfunctional calculations Metal-metal bond

Dobutamine Infusion and Absence of Pulmonary Hypertension Are Associated with Decreased Mortality in a Cohort of 249 Patients with Cardiogenic Shock

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Health 2014年第18期6卷 2408-2415页

作者： Sébastien Champion Bernard A. Gaüzère David Vandroux Bruno j. Bouchet Didier Drouet yannick Lefort Réanimation Polyvalente CHU de la Réunion H&ocirc pital Félix Guyon Saint Denis France

Obj.ctive: Prognostic analysis of 249 patients admitted for cardiogenic shock (CS) of various origins. Background: Little is known about prognosis of CS from non-ischemic cardiomyopathy. Methods: Retrospective monocentric study of patients referred to an ICU during 2 years. Results: Despite aggressive management including intra-aortic balloon pump (31%), extra-renal replacement therapy (36%), extra-corporeal life support (8%), and catecholamine infusion (97%), in-hospital mortality was 46%. Toxic CS or CS related to deficiency carried a better outcome (mortality 5%). Post-myocardial infarction or post-cardiac arrest CS was associated with higher mortality. In the multivariate analyses, only SAPS II (OR 1.037;1.013 - 1.056;p = 0.0001), pulmonary hypertension (OR 4.8;1.3 - 17;p = 0.02), extra-renal replacement therapy (OR 2.9;1.3 - 6;p = 0.006), and dobutamine infusion (OR 0.44;0.2 - 0.96;p = 0.04) were significantly associated with in-hospital mortality. Conclusion: Dobutamine infusion was associated with a better outcome. Higher SAPS II, pulmonary hypertension, and extra-renal replacement therapy were associated with increased in-hospital mortality.

关键词： Cardiogenic Shock Myocardial Infarction Catecholamine Pulmonary Hypertension Dobutamine Critically Ill

Distinct and combined impacts of climate and land use scenarios on water availability and sediment loads for a water supply reservoir in northern Morocco

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International Soil and Water Conservation Research 2020年第2期8卷 141-153页

作者： Fatiha Choukri Damien Raclot Mustapha Naimi Mohamed Chikhaoui j.ao Pedro Nunes Frédéric Huard Cécile Hérivaux Mohamed Sabir yannick Pépin IAV Hassan II Department of Natural Resources and EnvironmentMadinat Al IrfaneRabatMorocco LISAH Univ MontpellierINRAEIRDInstitut AgroMontpellierFrance CE3C-Centre for Ecology Evolution and Environmental ChangesFaculdade de CienciasUniversidade de Lisboa1749-016LisboaPortugal INRAE-AgroClim 228 Route de l’AérodromeCS 4050984914AvignonCedex 9France BRGM Univ Montpellier1039 Rue de Pinville34000MontpellierFrance ENFI bd Moulay YoussefTabriquetSALEMorocco

The obj.ctive of this study was to examine the impacts of climate and land use changes on wateravailability and sediment loads for a water supply reservoir in northern Morocco using data-intensive simulation models in a data-scarce region. Impacts were assessed by comparing the simulated water and sediment entering the reservoir between the future period 2031-2050 and the 1983-2010 reference period. Three scenarios of land use change and two scenarios of climate change were developed in the Tleta watershed. Simulations under current and future conditions were performed using the Soil and Water Assessment Tool (SWAT) model. The simulations showed that climate change will lead to a sig-nificant decrease in the annual water supply to the reservoir (-16.9% and -27.5%) and in the annual volume of sediment entering the reservoir (-7.4% and -12.6%), depending on the climate change sce-narios tested. The three scenarios of land use change will lead to a moderate change in annual water inflow into the reservoir (between-6.7% and +6.2%), while causing a significant decrease in sediment entering the reservoir (-37%to-24%). The combined impacts of climate and land use changes will cause a reduction in annual water availability (-9.9%to-33.3%) and sediment supplies (-28.7%to-45.8%). As a result, the lifetime of the reservoir will be extended, but at the same time, the risk of water shortages will increase, especially from j.ly to March. Therefore, alternative water resources must be considered.

关键词： Climate change Land use change SWAT Runoff Reservoir management Morocco

Multi-analyte biosensor interface for real-time monitoring of 3D microtissue spheroids in hanging-drop networks

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Microsystems & Nanoengineering 2016年第1期2卷 204-212页

作者： Patrick M.Misun j.rg Rothe yannick R.F.Schmid Andreas Hierlemann Olivier Frey ETH Zürich Department of Biosystems Science and EngineeringBio Engineering LaboratoryMattenstrasse 26Basel CH-4058Switzerland

Microfluidics is becoming a technology of growing interest for building microphysiological systems with integrated read-out *** we present the integration of enzyme-based multi-analyte biosensors into a multi-tissue culture platform for‘body-on-a-chip’*** microfluidic platform is based on the technology of hanging-drop networks,which is designed for the formation,cultivation,and analysis of fluidically interconnected organotypic spherical three-dimensional(3D)microtissues of multiple cell *** sensor modules were designed as small glass plug-ins featuring four platinum working electrodes,a platinum counter electrode,and an Ag/AgCl reference *** were placed directly into the ceiling substrate from which the hanging drops that host the spheroid cultures are *** electrodes were functionalized with oxidase enzymes to enable continuous monitoring of lactate and glucose through *** biosensors featured high sensitivities of 322±41 nA mM^(−1) mm^(−2) for glucose and 443±37 nA mM^(−1) mm^(−2) for lactate;the corresponding limits of detection were below 10μ*** proposed technology enabled tissue-size-dependent,real-time detection of lactate secretion from single human colon cancer microtissues cultured in the hanging ***,glucose consumption and lactate secretion were monitored in parallel,and the impact of different culture conditions on the metabolism of cancer microtissues was recorded in real-time.

关键词： biosensor body on a chip glucose hanging drop lactate metabolism spheroid

Single Platform Integration Environment for Turbine Rotor Design and Analysis

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j.urnal of Energy and Power Engineering 2014年第9期8卷 1590-1598页

作者： Francois Lagloire yannick Ouellet Benoit Blondin Francois Gamier Hany Moustapha Ecole de technologie superieure Montreal H3C 3R9 Canada Pratt and Whitney Canada Montreal J4G 1A1 Canada

The present article covers briefly state of the art software interoperability technical solutions and the development of the first module of a new single platform D ＆ A （design ＆ analysis） tool for simulation and prediction of stress and burst behavior of turbine rotating disc a preliminary design stage. This platform singularity requires integration of multiple CAD （computer assisted design）＆ FEA （finite element analysis） tools processing in batch mode and driven from a SPIE （single platform integration environment）. This first module is also to demonstrate, for an axial turbine disc hub axi-symmetric component, feasibility and usefulness of such a platform at preliminary design stage. Expected benefits of the D ＆ A single platform are to improve output accuracy, reduce cycle time, improve process quality and improve resource productivity.

关键词： Aero-engines gas turbines preliminary design turbines optimisation.

MicroRNAs as emerging biomarkers and therapeutic targets for pancreatic cancer

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World j.urnal of Gastroenterology 2014年第32期20卷 11199-11209页

作者： Marion Gayral Sébastien j. Naima Hanoun Alix Vignolle-Vidoni Hubert Lulka yannick Delpu Aline Meulle Marlène Dufresne Marine Humeau Maёl Chalret du Rieu Barbara Bournet j.nick Sèlves Rosine Guimbaud Nicolas Carrère Louis Buscail j.rome Torrisani Pierre Cordelier Cancer Research Center of Toulouse Team 10 UMR INSERM U1037Université Paul Sabatier P?le Digestif Centre Hospitalier Universitaire Toulouse

Despite tremendous efforts from scientists and clinicians worldwide, pancreatic adenocarcinoma(PDAC) remains a deadly disease due to the lack of early diagnostic tools and reliable therapeutic approaches. Consequently, a maj.rity of patients(80%) display an advanced disease that results in a low resection rate leading to an overall median survival of less than 6 months. Accordingly, robust markers for the early diagnosis and prognosis of pancreatic cancer, or markers indicative of survival and/or metastatic disease are des-perately needed to help alleviate the dismal prognosis of this cancer. In addition, the discovery of new therapeutic targets is mandatory to design effective treatments. In this review, we will highlight the translational studies demonstrating that microRNAs may soon translate into clinical applications as long-awaited screening tools and therapeutic targets for PDAC.

关键词： MicroRNAs Biomarkers Pancreatic cancer Therapeutic targets Precancerous lesions