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A tiny dural arteriovenous fistula

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Chinese Medical Journal 2003年第7期116卷 1113-1114页

作者：张鹏朱风水凌锋 christophe COGNARD Cerebral Vascular Disease Institute Interventional Center of Xuanwu HospitalBeijing 100053 China Neurointerventional

Pulsatile tinnitus is commonly encountered in approximately 10% of a given population.1 Since causes of the disease vary, selecting appropriate protocols of imaging strategies is quite challenging.2 Vascular anormalies or diseases including anormalies of the carotid arteries and jugular veins, intracranial arteriovenous malformation and dural arteriovenous fistula (DAVF) are major causative factors of the disease. Before imaging studies, history inquiry and physical examination are important for detect the possible causes of pulsatile tinnitus. Different imaging examinations are depended on histories and clinical signs of different patients.

关键词： ICA A tiny dural arteriovenous fistula

Mechanical strength of soda-lime glass sandblasted by gravitation

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Friction 2015年第1期3卷 65-71页

作者： Fouad ROUMILI Saci BENBAHOUCHE Jean-christophe SANGLEBOEUF Laboratoire de Mécanique de Précision Appliquée Institut d’Optique et Mécanique de PrécisionUniversitéFerhat AbbasSétif19000Algérie Institut de Physique de Rennes UMR CNRS 6251 Bât.10BCampus de Beaulieu35042 Rennes cedexFrance

Damage to a glass surface by sandblasting has a remarkable effect on its mechanical properties and *** this study,we analyze the superficial deterioration of soda-lime glass and its influence on the mechanical *** by gravitation from a fixed height causes damages by the free fall of different quantities of sand,which we performed for a selected grain size and at different angles of *** characterize the surface state,we used different roughness measures(the arithmetic mean value of the roughness Ra,the root mean square roughness Rq,and the maximum roughness Rmax)and measured the optical transmission(transmittance)at different points on the specimen surface using a *** determine the mechanical strength,we proceeded by two methods:first,by a shock ball(falling ball),and then by biaxial bending using circular *** effects of the surface damage on the optical transmission and the mechanical strength of the glass are graphically presented and discussed in this paper.

关键词： sandblasting mechanical strength roughness soda lime glass

Elastic modulus of claystone evaluated by nano-/micro-indentation tests and meso-compression tests

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第1期9卷 84-91页

作者： christophe Auvray Noémie Lafrance Danièle Bartier Université de Lorraine CNRS CREGU Lab. GeoRessources UMR 7359 Vandoeuvre-lès-Nancy F-54518 France

Toarcian claystone such as that of the Callovo-Oxfordian is a qualified multiphase material. The claystone samples tested in this study are composed of four main mineral phases: silicates(clay minerals, quartz,feldspars, micas)(z86%), sulphides(pyrite)(z3%), carbonates(calcite, dolomite)(z10%) and organic kerogen(z1%). Three sets of measurements of the modulus of deformability were compared as determined in(i) nanoindentation tests with a constant indentation depth of 2 mm,(ii) micro-indentation tests with a constant indentation depth of 20 mm, and(iii) meso-compression tests with a constant displacement of 200 mm. These three experimental methods have already been validated in earlier studies. The main objective of this study is to demonstrate the influence of the scaling effect on the modulus of deformability of the material. Different frequency distributions of the modulus of deformability were obtained at the different sample scales:(i) in nano-indentation tests, the distribution was spread between 15 GPa and 90 GPa and contained one peak at34 GPa and another at 51 GPa;(ii) in the micro-indentation tests, the distribution was spread between 25 GPa and 60 GPa and displayed peaks at 26 GPa and 37 GPa; and(iii) in the meso-compression tests, a narrow frequency distribution was obtained, ranging from 25 GPa to 50 GPa and with a maximum at around 35 GPa.

关键词： Claystone Elastic modulus Scaling effect Nano-and micro-indentation Meso-compression tests Multi-scale mechanical tests

Chemical Availability of Cd, Pb and Zn in Anthropogenically Polluted Soil: Assessing the Geochemical Reactivity and Oral Bioaccessibility

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Pedosphere 2017年第3期27卷 616-629页

作者： christophe WATERLOT Francis DOUAY Aurélie PELFRENE Yncréa Hauts-de-France Laboratoire Génie Civil et géo Environnement (LGCgE)

The most recent in vitro tests used to determine metal bioaccessiblility are generally time-consuming and expensive. This study aimed at determining potential relationships between the concentrations of metals extracted using single-extraction methods and the concentrations of bioaccessible metals assessed by a harmonised in vitro test, the Unified BARGE Method （UBM）. A total number of 27 soil samples were collected from kitchen gardens and lawns with various physicochemical parameters and contamination levels. Significant relationships were obtained between Cd, Pb and Zn extracted in gastric and gastrointestinal phases and using single extractions. The best relationhips were established using acetic and citric acids for Cd, whereas for Pb, citric acid and ethylenedi- aminetetraacetic acid （EDTA） were identified as the best extractants. These relationships were improved by means of a linear multiple regression with a downward stepwise procedure involving agronomic parameters （soil cation exchange capacity and assimilated P）. This method highlighted the fact that the cation exchange capacity and P contents in soils were the two main parameters that controlled the human bioaccessibility of Cd, Pb and Zn in the gastric phase. Besides, the metal concentrations extracted with the acetic and citric acids correlated well with the metal concentrations in the gastric and gastrointestinal phases, suggesting that the bioaceessible metals were mainly in a soluble form, weakly bound to the organic matter and associated with the carbonates and the Fe and Mn oxides/hydroxides in soils.

关键词： gastric phase gastrointestinal phase linear multiple regression single extractant urban soil

The Séchilienne (France) Landslide:a Non-typical Progressive Failure Implying Major Risks

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Journal of Mountain Science 2011年第2期8卷 117-123页

作者： Jean-Louis DURVILLE christophe BONNARD Pierre POTHERAT Conseil général de l'environnement et du développement durable Paris France Independent expert PBBG SA Lausanne Switzerland Centred'études techniques de l'équipement Lyon France

The National Road RN 91 has been threatened for about twenty-five years by a huge landslide, located 25 km south-east to the town of Grenoble (France). If several million cubic meters of rock fall down, the debris will dam the valley. Then the failure of the dam by overtopping and rapid erosion might result in a catastrophic flood and dramatic consequences for human life, environment and economy throughout the valley. The paper presents the hazard assessment based on geological and hydrological surveys, including small scale hydraulic tests, as well as the risk evaluation that has been performed. The risk management relies first upon a high level monitoring and an emergency plan; various mitigation strategies have been considered.

关键词： Landslide Progressive failure Séchilienne France

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

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

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