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Three decades of unveiling the complex chemistry of C-nitroso species with computational chemistry

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Organic Chemistry Frontiers 2022年第1期9卷 223-264页

作者： Pauline Bianchi Jean-christophe M.Monbaliu Center for Integrated Technology and Organic Synthesis MolSys Research UnitUniversity of LiègeB-4000 Liège(Sart Tilman)Belgium

C-Nitroso species are characterized by a unique nitrogen–oxygen combination located next to a carbon backbone,which confers them a unique ambiphilic and high reactivity towards nucleophilic,electrophilic but also radical *** this ambivalence can be seen as a strong asset for developing versatile synthetic aminohydroxylation and/or hydroxylamination processes mainly through nitroso Diels–Alder,nitroso ene,and nitrosoaldol reactions,it also contributes to complex optimization and rationalization arising from the many competitive pathways,that is,the occurrence of regioisomers and stereoisomers,as well as dimerization and tautomerization *** reactivity profiles are usually seen by synthetic organic chemists as major hurdles to overcome,despite the armada of analytical and purification methods available to them,and hence to achieve selective and exploitable developments of such *** rise of computational chemistry and resources has certainly changed their perspectives,since it provides a very different angle to gather insights on intrinsic properties,reactivity,and *** silico chemistry also provides a robust alternative to time and resource-consuming synthetic work and can therefore contribute to alleviate wasteful preparations by guiding the chemist toward the best combination of reagents to achieve high selectivity and *** synergistic combination of synthetic organic chemistry and computational chemistry,within the specific context of the complex chemistry of C-nitroso species,is discussed in this *** review aims at giving an overview of the molecular and chemical properties obtained through computational chemistry as an enabling support for the rationalization and optimization of reactions relying on ambiphilic C-nitroso species over the 3 last *** provides clear,concise,and illustrated guidelines for the synthetic chemist in search of inspiration through computations.

关键词： chemistry reactivity isomers

Morphological Characterization of Arbuscular Mycorrhizal Fungi Associated with the Rhizosphere According to the Age of Xanthosoma sagittifolium L. Schott Plants in the Field

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American Journal of Plant Sciences 2024年第3期15卷 161-179页

作者： Audrey Maguy Bengono Nyimiebolo Astride Carole Djeuani Hermann Désiré Mbouobda Antoine Marie Kevin Tiki Theresa Akinimbom Moma Diobe Motassy Manuela Samuel Brice Adounga christophe Fendju Pangueko Jones Nshanji Issofa Nguetrapouna Rose Theophine Derricka Djem Moutamal A. Ziem Amang Amang Nicolas Niemenak Laboratory of Plant Physiology Department of Biological Sciences Higher Teacher Training College (HTTC) University of Yaoundé I Yaoundé Cameroon Department of Plant Biology Faculty of Sciences University of Yaoundé I Yaoundé Cameroon Department of Biology Higher Teacher Training College Bambili (HTTC) The University of Bamenda Bamenda Cameroon Departments of Microbiology Faculty of Science University of Yaoundé 1 Yaoundé Cameroon

The objective of this work was to carry out a morphological characterization of arbuscular mycorrhizal fungi in the rhizosphere of Xanthosoma sagittifolium L. Schott plants. The plant material used was the white and red cultivars of X. sagittifolium, belonging to age intervals of 3 - 6, 6 - 9, and 9 - 12 months. Three harvest sites were chosen in the Central Region of Cameroon. In each site, soil from the rhizosphere and plant roots was collected in a randomized manner. In the field, the agronomic parameters were evaluated. The physicochemical characteristics of the soils, the mycorrhization index, and the morphological characterization of the mycorrhizal types of each site were carried out. The results obtained show that the agronomic growth parameters varied significantly using the Student Newman and Keuls Test depending on the harvest sites. The soils’ pH in all sites was acidic and ranged between 4.6 and 5.8. The Nkometou site has a loamy texture while the Olembe and Soa sites have loam-clay-sandy and loam-clay textures respectively. The highest mycorrhization frequencies appeared at the Nkometou site, with 75 and 87.33% of the white and red cultivars plant roots at 6 - 9 and 3 - 6 months. The relative abundance of AMF arbuscular mycorrhizal fungal spores in the rhizosphere of X. sagittifolium plants varied with age and cultivar. There were 673 spores between 9 - 12 months in Nkometou in the red cultivar. Six AMF genera were identified in all the different soils collected: Acaulospora sp., Funneliformis sp., Gigaspora sp., Glomus sp., Scutellospora sp., and Septoglomus sp. The genus Glomus sp. was the most present at all age intervals in both cultivars.

关键词： Xanthosoma sagittifolium L. Schott Rhizosphere Harvest Site Arbuscular Mycorrhizal Fungi Diversity

In vacuo XPS investigation of surface engineering for lithium metal anodes with plasma treatment

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Journal of Energy Chemistry 2022年第3期31卷 295-305,I0009页

作者： Bo Zhao Jin Li Maxime Guillaume Jolien Dendooven christophe Detavernier Department of Solid State Sciences COCOON Research GroupGhent UniversityKrijgslaan 281/S19000 GhentBelgium Solid State Battery Applicability Lab Research and InnovationSolvay SARue de Tansbeek 3101120 BrusselsBelgium

Lithium(Li)metal is an attractive anode material with high capacity(3860 mAh g^(−1))and low potential(−3.04 V *** hydrogen electrode)that shows highly promising for applications requiring high energy ***,the low electrochemical potential of Li metal makes it extremely reactive and inevitably forming a native oxidized layer in the ambient environment and repeatedly being consumed when exposed to liquid *** is therefore beneficial to replace the poorly controlled native passivation layer with a tailored artificial SEI to improve interface management between Li and electrolyte and enhance the stability of Li metal ***,we use an integrated glovebox-atomic layer deposition(ALD)-X-ray photoelectron spectroscopy(XPS)setup to in-situ investigating the pristine Li surface and the surface composition after Ar,H_(2)O_(2),N_(2)and NH_(3)plasma treatment *** find that the pristine Li foil is naturally being covered with a native oxidized layer,which is mainly composed of LiOH,Li_(2)O and Li_(2)CO_(3).These investigated plasmas can efficiently remove the oxidized layer from the Li metal surface,in which metallic Li surface is obtained after Ar or H2 plasma treatments,where Ar plasma is more *** O_(2)plasma treatment produces a Li_(2)O layer,and N_(2)or NH_(3)plasma treatment leads to a Li3N(including a certain amount of LiON)layer on the Li *** employing the representative metallic Li(by Ar plasma treatment),Li_(2)O layer coated Li(by O_(2)plasma treatment)and Li3N layer coated Li(by N_(2)plasma treatment)foils as electrodes in symmetric Li metal batteries,the Li3N coated Li electrode exhibits much higher stability than that of metallic and Li_(2)O layer coated Li *** electrochemical performance has also been achieved in LiMn_(2)O_(4)(LMO)||Li full cells using Li anode with Li3N protective coating *** work reveals the detailed process of surface engineering of Li metal anodes with plasma treat

关键词： Plasma treatment In vacuo XPS Lithium metal anode Metallic Li Li_(2)O layer Li_(3)N layer

Structural characteristics of electrohydrodynamic jets induced by a blade-plane actuator subjected to highly non-uniform electric fields:Parametric investigation through the particle image velocimetry techniques

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High Voltage 2023年第1期8卷 183-195页

作者： Zelu Yan christophe Louste Philippe Traoré Jian Wu Jian'an Fang Logistics Engineering College Shanghai Maritime UniversityShanghaiChina Institut PPRIME Universitéde PoitiersPoitiersFrance Key Laboratory of Aerospace Thermophysics School of Energy Science and EngineeringHarbin Institute of TechnologyHarbinChina College of Information Science and Technology Donghua UniversityShanghaiChina

This study set out to systematically investigate the structural characteristics of plane electrohydrodynamic jets through the particle image velocimetry(PIV)*** to the wide range of applied voltages and electrode gaps under various experimental conditions,an assessment of the image quality and a statistical analysis of the velocity fields are first performed to ensure the validity of the PIV measurements,which were originally applied purely to fluid *** results indicate that the time interval between two consecutive images should be pre-adjusted to reduce the number of uncorrelated vector ***,the minimum number of instantaneous fields should be achieved for an accurate calculation of the time-averaged *** equivalent electric field criterion adapted to the asymmetric electrode configuration is defined to find similarities in flow structures under different voltage and electrode gap *** the applied electric field increases,three injection regimes are identified and the current increases almost linearly,indicating a large conduction current *** decrease in charge density due to recombination proves to be relevant in all cases of this *** to the parametric analysis approach for classical jets and thermal plumes,the evolution of the coefficients of axial velocity,half-width and turbulence intensity are investigated.

关键词： plane particle blade

Small-world networks of neuroblastoma cells cultured in three-dimensional polymeric scaffolds featuring multi-scale roughness

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Neural Regeneration Research 2020年第4期15卷 759-768页

作者： Valentina Onesto Angelo Accardo christophe Vieu Francesco Gentile Center for Advanced Biomaterials for Healthcare Italian Institute of TechnologyNaplesItaly Laboratoire d’Analyse et d’Architecture des Systemes(LAAS) Centre National de la Recherche ScientifiqueUniversite de ToulouseCNRSToulouseFrance Institut National des Sciences Appliquees–INSA ToulouseFrance Department of Electric Engineering and Information Technology University Federico IINaplesItaly Department of Precision and Microsystems Engineering Delft University of TechnologyMekelweg 22628 CD DelftThe Netherlands

Understanding the mechanisms underlying cell-surface interaction is of fundamental importance for the rational design of scaffolds aiming at tissue engineering,tissue repair and neural regeneration ***,we examined patterns of neuroblastoma cells cultured in three-dimensional polymeric scaffolds obtained by two-photon *** of the intrinsic resolution of the technique,the micrometric cylinders composing the scaffold have a lateral step size of^200 nm,a surface roughness of around 20 nm,and large values of fractal dimension approaching *** found that cells in the scaffold assemble into separate groups with many elements per *** cell wiring,we found that resulting networks exhibit high clustering,small path lengths,and small-world *** values of the topological characteristics of the network can potentially enhance the quality,quantity and density of information transported in the network compared to equivalent random graphs of the same *** is one of the first direct observations of cells developing into 3D small-world networks in an artificial matrix.

关键词： 3D networks biomaterials nano-topography network topology neuro-regeneration small-world networks tissue engineering two-photon lithography

COVID-19 and flu:conserved or specific immune signature?

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Cellular & Molecular Immunology 2021年第2期18卷 245-246页

作者： christophe Paget François Trottein Centre d’Etude des Pathologies Respiratoires INSERM U1100Universitéde ToursFacultéde Médecine de Tours37000ToursFrance Centre d’Infection et d’Immunitéde Lille INSERM U1019CNRS UMR 9017Universitéde LilleCHU LilleUMS 2014-PLBSU1019Institut Pasteur de Lille59000LilleFrance

Respiratory viruses are a major cause of infectious disease and mortality *** respiratory viruses,emerging and well-known coronaviruses and influenza viruses cause seasonal epidemics and pandemics and rank as very important *** clinical signs of viral respiratory infections range from asymptomatic forms to life-threatening acute respiratory distress syndrome(ARDS,associated with a high mortality rate).Another reported cause of mortality is multiple organ *** ongoing pandemic of coronavirus disease 19(COVID-19,caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2))is a serious public health ***-CoV-2 infection induces to a clinical signature distinct from that associated with other types of pneumonia,and SARS-CoV-2 differs from influenza viruses with regard to target cells and replicative *** morbidity and mortality rates are higher for COVID-19 than for seasonal influenza.

关键词： mortality acute respiratory

Canonical Workflow for Machine Learning Tasks

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Data Intelligence 2022年第2期4卷 173-185页

作者： christophe Blanchi Binyam Gebre Peter Wittenburg DONA Foundation C/O Universitede GeneveRuedu General-Dufour 241204 GeneveSwitzerland *** Papendorpseweg 1003528 BJ UtrechtThe Netherlands FDO Forum Gemeindweg 5547533 KleveGermany

There is a huge gap between(1)the state of workflow technology on the one hand and the practices in the many labs working with data driven methods on the other and(2)the awareness of the FAIR principles and the lack of changes in practices during the last 5 *** CWFR concept has been defined which is meant to combine these two intentions,increasing the use of workflow technology and improving FAIR *** the study described in this paper we indicate how this could be applied to machine learning which is now used by almost all research disciplines with the well-known effects of a huge lack of repeatability and *** will only change practices if they can work efficiently and are not loaded with additional tasks.A comprehensive CWFR framework would be an umbrella for all steps that need to be carried out to do machine learning on selected data collections and immediately create a comprehensive and FAIR compliant *** researcher is guided by such a framework and information once entered can easily be shared and *** many iterations normally required in machine learning can be dealt with efficiently using CWFR *** of components that can be easily orchestrated using FAIR Digital Objects as a common entity to document all actions and to exchange information between steps without the researcher needing to understand anything about PIDs and FDO details is probably the way to increase efficiency in repeating research *** the Galaxy project indicates,the availability of supporting tools will be important to let researchers use these *** as the Galaxy framework suggests,however,it would be necessary to include allsteps necessary for doing amachine learning task including those that require human interaction andtodocument all phases with the help of structured FDOs.

关键词： Workflow Machine learning Digital objects FAIR Datamanagement

AnAll-Regime Lagrange-Projection Like Scheme for the Gas Dynamics Equations on Unstructured Meshes

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Communications in Computational Physics 2016年第6期20卷 188-233页

作者： christophe Chalons Mathieu Girardin Samuel Kokh LMV-UMR 8100 Univ.Versailles Saint-Quentin-en-YvelinesUFR des SciencesBatiment Fermat45 avenue des Etats-Unis78035 Versailles cedexFrance DEN/DANS/DM2S/STMF/LMEC CEA Saclay bat.454 PC 4791191 Gif sur Yvette CedexFrance LRC MANON Laboratoire de Recherche Conventionne CEA/DEN/DANS/DM2S and UPMC-CNRS/LJLL Maison de la Simulation USR 3441 Digiteo Labsbat.565PC 190CEA Saclay91191 Gif-sur-YvetteFrance DEN/DANS/DM2S/STMF CEA Saclay91191 Gif-sur-YvetteFrance

We propose an all regime Lagrange-Projection like numerical scheme for the gas dynamics *** all regime,we mean that the numerical scheme is able to compute accurate approximate solutions with an under-resolved discretization with respect to the Mach number M,*** that the ratio between the Mach number M and the mesh size or the time step is small with respect to *** key idea is to decouple acoustic and transport phenomenon and then alter the numerical flux in the acoustic approximation to obtain a uniform truncation error in term of *** modified scheme is conservative and endowed with good stability properties with respect to the positivity of the density and the internal energy.A discrete entropy inequality under a condition on the modification is obtained thanks to a reinterpretation of the modified scheme in the Harten Lax and van Leer formalism.A natural extension to multi-dimensional problems discretized over unstructured mesh is *** a simple and efficient semi implicit scheme is also *** resulting scheme is stable under a CFL condition driven by the(slow)material waves and not by the(fast)acoustic waves and so verifies the all regime *** evidences are proposed and show the ability of the scheme to deal with tests where the flow regime may vary from low to high Mach values.

关键词： Gas dynamics equations low-Mach regime finite volume schemes all-regime schemes Lagrange-Projection like schemes large time-steps

Sperm limitation affects sex allocation in a parasitoid wasp Nasonia vitripennis

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Insect Science 2019年第5期26卷 853-862页

作者： Marlene Chirault christophe Bressac Marlene Goubault Charlotte Lecureuil Institut de Recherche sur la Biologie de I'lnsecte UMR 7261 CNRS - Universite de ToursFaculte des Sciences et TechniquesParc GrandmontToursFrance

Insect reproduction is influenced by various external factors including temperature, a well-studied constraint. We investigated to what extent different levels of sperm limitation of males exposed to different heat stresses (34 and 36℃) afFect fem ales' offspring production and sex allocation in Nasonia vitripennis. In this haplodiploid parasitoid wasp attacking different species of pest flies, we investigated the effect of the quantity of sperm females received and stored in their spermatheca on their sperm use decisions, hence sex allocation, over successive ovipositions. In particular, we compared the sex allocation of females presenting three levels of sperm limitation (i.e.,mated with control, 34 ℃ heat-stressed or 36℃heat-stressed males) on each host they parasitized. To disentangle the potential reduction of sperm quality after a heat stress exposure from that of sperm quantity, we also explored the clutch size and sex ratio produced by fem ales that were partially sperm limited after copulating with multiply mated males. Independently of their sperm numbers, all types of fem ales produced a similar total number of offspring, but the more limited ones had fewer daughters. Sperm limitation further affected the distribution of daughters' production across *** addition to constraints acting on female physiology, male fertility should therefore be considered in studies measuring reproductive outputs of insects submitted to heat stresses.

关键词： heat stress multiple mating offspring production dynamic sex ratio sperm stock sperm use