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A SEM-based method to determine the mineralogical composition and the particle size distribution of suspended sediment

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International Journal of Sediment Research 2019年第2期34卷 85-94页

作者： sylvain Pinet Bruno Lartiges Jean-Michel Martinez sylvain Ouillonc University of Toulouse (Paul Sabatier) Geosciences Environment ToulouseCNRS(Centre National de la Recherche Scientifique)IRD(Institut de Recherche pour le Développement) Instituto de Geosciencias Universidade de BrasiliaCampus Universitario Darcy RibeiroICC Centro University of Toulouse LEGOS(Laboratoire d'Etudes en Géophysique et Océanographie Spatiales)

A robust method for characterizing the mineralogy of suspended sediment in continental rivers is *** encompasses 3 steps:the filtration of a few milliliters of water,measurements of X-ray energy dispersive spectra using Scanning Electron Microscopy(SEM),and robust machine learning tools of *** method is applied to suspended particles collected from various Amazonian rivers.A total of more than 204,000 particles were analyzed by SEM-EDXS(Energy Dispersive X-ray Spectroscopy),*** 15,700 particles per sampling station,which lead to the identification of 15 distinct groups of mineralogical *** size distribution of particles collected on the filters was derived from the SEM micrographs taken in the backscattered electron imaging mode and analyzed with ImageJ *** determination of the main mineralogical groups composing the bulk sediment associated with physical parameters such as particle size distribution or aspect ratio allows a precise characterization of the load of the terrigenous particles in rivers or *** the case of the Amazonian rivers investigated,the results show that the identified mineralogies are consistent with previous studies as well as between the different samples *** method enabled the evolution of grain size distribution from fine to coarse material to be described in the water *** about hydrodynamic sorting of mineral particles in the water column are also briefly *** proposed method appears well suited for intensive routine monitoring of suspended sediment in river systems.

关键词： Mineralogy Scanning Electron Microscopy Suspended sediment Machine learning Particle size distribution

Stop-and-go waves induced by correlated noise in pedestrian models without inertia

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第1期7卷 52-60页

作者： Antoine Tordeux Andreas Schadschneider sylvain Lassarre School of Mechanical Engineering and Safety Engineering University of WuppertalWuppertal 42119Germany Institute for Theoretical Physics University of CologneCologne 50937Germany Engineering of Surface Transportation Networks and Advanced Computing Laboratory French Institute of Science and Technology for TransportDevelopment and NetworksMarne La Vallee E-77447France

Stop-and-go waves are commonly observed in traffic and pedestrian *** most microscopic traffic models,they occur through a phase transition and instability of the homogeneous solution after fine tuning of *** effects are believed to play an important role in this *** this article,we present a novel explanation for stop-and-go waves based on stochastic effects in the absence of *** model used is a first order optimal velocity(OV)model including an additive stochastic noise.A power spectral analysis for single-file pedestrian trajectories highlights the existence of Brownian speed *** use the Ornstein-Uhlenbeck process to describe such a correlated *** introduction of this specific colored noise in the first order OV model allows describing realistic stop-and-go behavior without requiring instabilities or phase transitions,the homogeneous configurations being systematically stochastically *** compare the stochastic model to deterministic unstable OV models and analyze individual speed autocorrelation to describe the nature of the waves in stationary *** apply the approach to pedestrian single-file motion and compare simulation results to real pedestrian *** simulation results are quantitatively very similar to the real *** discuss plausible values for the model parameters and their meaning.

关键词： Transportation engineering Pedestrian single-file motion Stop-and-go dynamics First order microscopic model Brownian noise Simulation

Inhibition of p53 inhibitors:progress,challenges and perspectives

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Journal of Molecular Cell Biology 2019年第7期11卷 586-599页

作者： Gema Sanz Madhurendra Singh sylvain Peuget Galina Selivanova Department of Microbiology Tumor and Cell BiologyBiomedicum 8CKarolinska InstituteSE17165Sweden

p53 is the major tumor suppressor and the most frequently inactivated gene in cancer.p53 could be disabled either by mutations or by upstream negative regulators,including,but not limited to MDM2 and MDMX.p53 activity is required for the prevention as well as for the eradication of *** of p53 activity in mouse models leads to the suppression of established tumors of different *** findings provide a strong support to the anti-cancer strategy aimed for p53 *** this review,we summarize recent progress in the development of small molecules,which restore the tumor suppressor function of wild-type p53 and discuss their clinical *** discuss different aspects of p53-mediated response,which contribute to suppression of tumors,including non-canonical p53 activities,such as regulation of immune *** targeting p53 inhibitors is a very promising approach,there are certain limitations and concerns that the intensive research and clinical evaluation of compounds will hopefully help to overcome.

关键词： p53 tumor suppression anti-cancer therapy targeted drugs transcription factor immune response

Natural gas pyrolysis in double-walled reactor tubes using thermal plasma or concentrated solar radiation as external heating source

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Journal of Natural Gas Chemistry 2009年第1期18卷 1-8页

作者： Stphane Abanades Stefania Tescari sylvain Rodat Gilles Flamant Processes Materials and Solar Energy Laboratory (PROMES-CNRS) 7 Rue du Four Solaire 66120 Font-Romeu France

The thermal pyrolysis of natural gas as a clean hydrogen production route is examined. The concept of a double-walled reactor tube is proposed and implemented. Preliminary experiments using an external plasma heating source are carried out to validate this concept. The results point out the efficient CH4 dissociation above 1850 K （CH4 conversion over 90%） and the key influence of the gas residence time. Simulations are performed to predict the conversion rate of CH4 at the reactor outlet, and are consistent with experimental tendencies. A solar reactor prototype featuring four independent double-walled tubes is then developed. The heat in high temperature process required for the endothermic reaction of natural gas pyrolysis is supplied by concentrated solar energy. The tubes are heated uniformly by radiation using the blackbody effect of a cavity-receiver absorbing the concentrated solar irradiation through a quartz window. The gas composition at the reactor outlet, the chemical conversion of CH4, and the yield to H2 are determined with respect to reaction temperature, inlet gas flow-rates, and feed gas composition. The longer the gas residence time, the higher the CH4 conversion and H2 yield, whereas the lower the amount of acetylene. A CH4 conversion of 99% and H2 yield of about 85% are measured at 1880 K with 30% CH4 in the feed gas （6 L/min injected and residence time of 18 ms）, A temperature increase from 1870 K to 1970 K does not improve the H2 yield.

关键词： methane hydrogen thermal cracking plasma concentrated solar energy tubular reactor

Sirolimus,bevacizumab,5-Fluorouracil and irinotecan for advanced colorectal cancer:A pilot study

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World Journal of Gastroenterology 2009年第34期15卷 4278-4283页

作者： Francois Ghiringhelli Boris Guiu Bruno Chauffert sylvain Ladoire Department of Medical Oncology Georges-Francois Leclerc Cancer Center Department of Radiology Georges-Francois Leclerc Cancer Center

AIM： To evaluate the efficacy and the safety of combined 5-Fluorouracil, irinotecan, bevacizumab and sirolimus in refractory advanced colorectal carcinoma. METHODS： We initiated a regimen with at day 1 an injection （iv） of bevacizumab at 5 mg/kg, followed by 180 mg/m^2 irinotecan, followed by Leucovorin 400 mg/m^2, followed by a 5-Fluorouracil bolus 400 mg/m^2 and a 46-h infusion 2400 mg/m^2. Sirolimus was given orally as continuous administration of 2 mg twice a day every days. This treatment was repeated every 14 d. RESULTS： A total of 12 patients were enrolled. All patients presented with metastatic disease that had failed at least three lines of chemotherapy that contained oxaliplatin, irinotecan and bevacizumab. Cetuximab failure was also observed in all K-Ras wildtype patients. The median number of cycles was 8.5 （range 2-20） and clinical benefit was observed in eight patients. The median time to progression was 5 mo and the median survival was 8 too. Grade 3 neutropenia developed in four patients, and grade 3 diarrhea and stomatitis in ***： The combination regimen of 5-Fluorouracil,irinotecan, bevacizumab and sirolimus in advanced colorectal carcinoma after failure of dassical *** is feasible and promising. Further evaluation of this combination is required.

关键词： Colorectal cancer Bevacizumab 5-Fluorouracil Irinotecan Sirolimus Antineoplastic combinedchemotherapy protocols Angiogenesis

On the notions of singular domination and(multi-)singular hyperbolicity

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Science China Mathematics 2020年第9期63卷 1721-1744页

作者： sylvain Crovisier Adriana da Luz Dawei Yang Jinhua zhang Laboratoire de Mathematiques d'Orsay CNRSUniversite Paris-SudOrsay 91405France Beijing International Center for Mathematical Research Peking UniversityBeijing 100871China School of Mathematical Sciences Soochow UniversitySuzhou 215006China School of Mathematical Sciences Beihang UniversityBeijing 100191China

The properties of uniform hyperbolicity and dominated splitting have been introduced to study the stability of the dynamics of *** meets difficulties when trying to extend these definitions to vector fields and Shantao Liao has shown that it is more relevant to consider the linear Poincare flow rather than the tangent flow in order to study the properties of the *** this paper,we define the notion of singular domination,an analog of the dominated splitting for the linear Poincar´e flow which is robust under *** on this,we give a new definition of multi-singular hyperbolicity which is equivalent to the one recently introduced by Bonatti and da Luz(2017).The novelty of our definition is that it does not involve the blow-up of the singular set and the rescaling cocycle of the linear flows.

关键词： multi-singular hyperbolicity singular domination star vector field linear Poincar´e flow

Molecular Detection of Pathogens Involved in Sexually Transmitted Infections in Brazzaville, Congo

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Open Journal of Medical Microbiology 2024年第3期14卷 190-205页

作者： Jeanine Mireille Sita Maboundou Bitsi Nina Esther Ngoyi Ontsira Edith Sophie Kombo Bayonne Tanguy Mieret Geril Sekangue Obili Herlen Tsoumou Lina Foungou Kessengue Samantha Potokoue Mpia Chloé Dupont Guilhem Conquet Gickel Mpika Bitsene Bienvenu Roland Ibara Ossibi Axel Aloumba Etienne Nguimbi sylvain Godreuil Faculty of Sciences and Technology Marien NGOUABI University Brazzaville Republic of the Congo Faculty of Health Sciences Marien NGOUABI University Brazzaville Republic of the Congo Bacteriology-Virology Laboratory University Hospital Center Brazzaville Republic of the Congo Department of Infectious Diseases Referral Hospital Center of Talanga Brazzaville Republic of the Congo Parasitology-Mycology Laboratory University Hospital Center Brazzaville Republic of the Congo Department of Gynecology-Obstetrics University Hospital Center Brazzaville Republic of the Congo UMR IRD224-CNRS5290-UM MIVEGEC Infectious Diseases and Vectors: Ecology Genetics Evolution and Control CREES (Reshearch Center in Ecology and Evolution Health) Montpellier France Bacteriology Laboratory Arnaud de Villeneuve University Hospital CHU of Montpellier Montpellier France Department of Infectious Diseases University Hospital Center Brazzaville Republic of the Congo

The objective of this multicentric study was to assess the prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma génitalium and Trichomonas vaginalis infections in Brazzaville, in the Republic of Congo, using molecular methods. From January to December 2021, the sexually transmitted disease risk participants were recruited from six centers: The Association of Young HIV-Positive People of Congo, The Congolese Association for Family Welfare, The Association for Support to Vulnerable Groups, Talangaï hospital, Brazzaville university hospital (outpatient service) and the private clinic COGEMO (outpatient service). The real-time multiplex PCR was carried out to detect these pathogens. Each patient had at least one specimen (urine, urethral, anal and/or vaginal samples). The patients were considered infected when one of their samples was positive. 287 participants made of 227 women and 60 men were tested. The general prevalence of these infections was: Chlamydia trachomatis 2.79%, Neisseria gonorrhoeae 3.14%, Mycoplasma génitalium 3.45% and Trichomonas vaginalis 2.97. The prevalence rates according to sex were: C. trachomatis, M. génitalium, N. gonorrhea and T. vaginalis were 1.32%, 2.05%, 1.32% and 3.42% in women and 8.33%, 7.02%, 10% and 1.75% in men, respectively. Most infected patients were asymptomatic. Prevalence rates were higher in bisexual individuals, with the exception of T. vaginalis which showed higher prevalence in heterosexual patients. The bisexual and homosexual individuals represent a major public health problem in sexually active young adults, particularly among men having sex with men. These sexually transmitted infections are mainly asymptomatic, their diagnosis and management remain difficult in developing countries.

关键词： Prevalence Chlamydia trachomatis Neisseria gonorrhoeae Mycoplasma génitalium Trichomonas vaginalis

Beyond vertebrates:the amphioxus as a relevant model system to explore the formation,organization,and regeneration of neuromuscular synapses

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Neural Regeneration Research 2022年第11期17卷 2425-2426页

作者： Esperanza Martínez sylvain Marcellini Juan Pablo Henríquez Neuromuscular Studies Lab (NeSt Lab) Group for the Study of Developmental Processes (GDeP) Department of Cell BiologyFaculty of Biological SciencesUniversidad de Concepción Laboratory of Development and Evolution (LADE)

The neuromuscular junction(NMJ)is the peripheral synapse controlling muscle contraction and coordinated movement in a wide variety of *** humans,the mature NMJ is the primary target of morphological disassembly and fu... 详细信息

关键词： system contraction synapse

Novel imaging biomarkers of response to transcatheter arterial chemoembolization in hepatocellular carcinoma patients

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Chinese Journal of Cancer Research 2015年第6期27卷 611-616页

作者： sylvain Favelier Louis Estivalet Pierre Pottecher Romaric Loffroy Department of Vascular Oncologic and Interventional Radiology University of Dijon School of Medicine Bocage Teaching Hospital

Hepatocellular carcinoma common cause of cancer death （HCC） is the third most worldwide （1）. Most patients present with intermediate or advanced disease that is not amenable to curative treatment, and the median survival in this group is 6-8 months （2）. Several studies and well- designed randomized trials have shown a positive effect of transcatheter arterial chemoembolization （TACE） on patient outcome and survival （3-8）. As nicely described in the present article from Wring et al., assessment of tumor response is of extreme importance in patients undergoing locoregional treatments of liver cancer （9）. Early assessment of the effectiveness of TACE and monitoring of tumor response are paramount to the identification of treatment failure, guidance of future therapy, and determination of the interval for repeat treatment.

关键词： TACE Novel imaging biomarkers of response to transcatheter arterial chemoembolization in hepatocellular carcinoma patients HCC CBCT