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Machine-learning-assisted discovery of polymers with high thermal conductivity using a molecular design algorithm

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npj Computational Materials 2019年第1期5卷 569-579页

作者： Stephen Wu Yukiko Kondo Masa-aki Kakimoto Bin Yang Hironao Yamada Isao Kuwajima Guillaume Lambard Kenta Hongo Yibin Xu Junichiro Shiomi Christoph Schick Junko Morikawa Ryo Yoshida The institute of Statistical Mathematics Research Organization of Information and SystemsTachikawaTokyo 190-8562Japan The Graduate University for Advanced Studies TachikawaTokyo 190-8562Japan Center for Materials research by Information Integration(CMI2) Research and Services Division of Materials Data and Integrated System(MaDIS)National Institute for Materials Science(NIMS)TsukubaIbaraki 305-0047Japan Institute of Physics and Competence Centre CALOR University of Rostock18059 RostockGermany Japan Advanced institute of Science and Technology NomiIshikawa 923-1292Japan PRESTO JSTKawaguchiSaitama 332-0012Japan The University of Tokyo Bunkyo-kuTokyo 113-8656Japan Tokyo Tech World Research Hub Initiative(WRHI) Tokyo Institute of TechnologyTokyo 226-8503Japan Tokyo institute of Technology Meguro-kuTokyo 152-8550Japan

The use of machine learning in computational molecular design has great potential to accelerate the discovery of innovative materials.However,its practical benefits still remain unproven in real-world applications,particularly in polymer science.We demonstrate the successful discovery of new polymers with high thermal conductivity,inspired by machine-learning-assisted polymer chemistry.This discovery was made by the interplay between machine intelligence trained on a substantially limited amount of polymeric properties data,expertise from laboratory synthesis and advanced technologies for thermophysical property measurements.Using a molecular design algorithm trained to recognize quantitative structure—property relationships with respect to thermal conductivity and other targeted polymeric properties,we identified thousands of promising hypothetical polymers.From these candidates,three were selected for monomer synthesis and polymerization because of their synthetic accessibility and their potential for ease of processing in further applications.The synthesized polymers reached thermal conductivities of 0.18–0.41 W/mK,which are comparable to those of state-of-the-art polymers in non-composite thermo-plastics.

关键词： conductivity thermal property

Ultrafast Imaging of Electronic Relaxation in Ortho-xylene： New Features from Fragmentation-Ion Spectroscopy

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Chinese physics Letters 2014年第12期31卷 130-133页

作者：刘玉柱 KNOPP Gregor 肖韶荣 GERBER Thomas College of physics and Opto-electronics Engineering Nanjing University of Information Science & Technology Nanjing 210044 Paul Scherrer institute Villigen 5232 Switzerland

After light absorption, a molecule can undergo ra- diationless processes, and photophysics is one of the important general types. The photophysical pro- cesses involve internal conversion （IC） due to elec- tronic nonadiabaticity and intersystem crossing （ISC） induced by spin-orbit coupling. In polyatomic molecules that are excited IC and ISC to vibronic to higher electronic states, levels of lower electronic states are two dominant mechanisms. With the ad- vent of femtosecond ultrashort pulse, tracking and controlling the ultrafast photophysical processes be- come realizable. Due to the fact that ISC requires a change in the spin of an electron, it is usually a slower process than IC. However, extensive reports show that ultrafast competing ISC exists in a number of systems. Re- cently, Richter et al. reported femtosecond ISC in cytosine. Martinez-Fernandez et al. simulated the deactivation dynamics of photo-excited 6-thioguanine using a direct surface hopping dynamics approach Their simulations show that 6-thioguanine is another example of a system showing ultrafast ISC that can compete with IC in the same time scale. Both the spin-orbit and the dynamic couplings are important to describe realistically the excited state dynamics of 6-thioguanine. A similar phenomenon has also been evidenced in the S1 state of benzene. The exper- imental results show that the ultrafast decay of the S1 state is due to competing IC and ISC processes and both processes occur on a femtosecond timescale. Spin-orbit coupling is highly effective when the in- volved states are nearly isoenergetic.

关键词： Ultrafast Imaging Electronic Relaxation Fragmentation-Ion Spectroscopy

Climatic and Physiographic Variables to Evaluate Culex pipiens s.l. Risk and Habitat

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Journal of Geoscience and Environment Protection 2022年第8期10卷 1-8页

作者： Maria da Conceição Proença Maria João Alves Maria Teresa Rebelo MARE—Marine and Environmental Sciences centre & ARNET Aquatic Research Infrastructure Network Associated Laboratory Faculty of Sciences University of Lisbon Lisbon Portugal Department of physics Faculty of Sciences University of Lisbon Lisbon Portugal National Health institute Doutor Ricardo Jorge (INSA) &#193 guas de Moura Portugal CESAM-Ciências—centre for Environmental and Marine Studies Faculty of Sciences University of Lisbon Lisbon Portugal Department of Animal Biology Faculty of Sciences University of Lisbon Lisbon Portugal

Using a geographic information system (GIS), the relations between a georeferenced data set of Culex pipiens s.l. collected in Portugal mainland during seven years (2006-2012) and meteorological and physiographic parameters are evaluated. This work is one of the results of a long-term surveillance program of pernicious insects that act as vectors of various diseases;its focus is on the possibility of prevention that can be achieved with abundance data. The focus on Culex pipiens is justified by its abundance and its competence as a vector for numerous health issues. The cumulative distribution of monthly captures by each meteorological parameter allows to compute thresholds corresponding to mosquito massive presence related to 90% of the captures. Using the weather parameters measured in the network of weather stations across the country, a monthly average of each parameter of interest (temperature, humidity, etc.) is computed and an interpolation of the results is made to produce raster maps corresponding to each month. The previously obtained thresholds are applied to each map, producing spatial masks with the relevant zones for each parameter. The intersection of the various masks for each month shows the most densely populated area of Culex, and the ensemble allows us to observe the evolution of mosquito presence through the critical season, which is from May to October at these latitudes. In parallel, mosquito abundance data are related to physiographic parameters. The relative distribution of female mosquitoes across land cover types in each month allows identifying which classes and seasons are most relevant. Orthometric altitude related to the presence of 90% of the catches shows the limits reached by mosquitoes in each month. The results are applied to the previously obtained climate envelopes, delimiting critical areas where the level of risk of transmission of the pathogens for which Culex pipiens is a competent vector is high and countermeasures should be concentrated, allowing its planning, and targe

关键词： Vector-Borne Diseases Transmission Risk Culex pipiens s.l. GIS Global Changes

Common workflows for computing material properties using different quantum engines

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npj Computational Materials 2021年第1期7卷 1202-1213页

作者： Sebastiaan P.Huber Emanuele Bosoni Marnik Bercx Jens Bröder Augustin Degomme Vladimir Dikan Kristjan Eimre Espen Flage-Larsen Alberto Garcia Luigi Genovese Dominik Gresch Conrad Johnston Guido Petretto Samuel Poncé Gian-Marco Rignanese Christopher J.Sewell Berend Smit Vasily Tseplyaev Martin Uhrin Daniel Wortmann Aliaksandr V.Yakutovich Austin Zadoks Pezhman Zarabadi-Poor Bonan Zhu Nicola Marzari Giovanni Pizzi Theory and Simulation of Materials(THEOS)and National centre for Computational Design and Discovery of Novel Materials(MARVEL) École Polytechnique Fédérale de LausanneLausanneSwitzerland Institut de Ciència de Materials de Barcelona ICMAB-CSICBellaterraSpain Peter Grünberg Institut and institute for Advanced Simulation Forschungszentrum JülichJülichGermany Department of physics RWTH Aachen UniversityAachenGermany CEA IRIG-MEM-L_SimUniv.Grenoble-AlpesGrenobleFrance Nanotech@surfaces Laboratory Swiss Federal Laboratories for Materials Science and Technology(Empa)DübendorfSwitzerland SINTEF Industry Materials PhysicsOsloNorway Department of physics University of OsloOsloNorway Microsoft Station Q University of CaliforniaSanta BarbaraCAUSA Atomistic Simulation centre School of Mathematics and PhysicsQueen’s University BelfastBelfastUK UCLouvain Institut de la Matière Condensée et des Nanosciences(IMCN)Louvain-la-NeuveBelgium Laboratory of Molecular Simulation(LSMO) Institut des sciences et ingénierie chimiques(ISIC)École Polytechnique Fédérale de Lausanne(EPFL)ValaisSionSwitzerland Department of Chemistry Claverton DownUniversity of BathBathUK The Faraday Institution DidcotUK Department of Chemistry University College LondonLondonUK

The prediction of material properties based on density-functional theory has become routinely common,thanks,in part,to the steady increase in the number and robustness of available simulation packages.This plurality of codes and methods is both a boon and a burden.While providing great opportunities for cross-verification,these packages adopt different methods,algorithms,and paradigms,making it challenging to choose,master,and efficiently use them.We demonstrate how developing common interfaces for workflows that automatically compute material properties greatly simplifies interoperability and cross-verification.We introduce design rules for reusable,code-agnostic,workflow interfaces to compute well-defined material properties,which we implement for eleven quantum engines and use to compute various material properties.Each implementation encodes carefully selected simulation parameters and workflow logic,making the implementer’s expertise of the quantum engine directly available to nonexperts.All workflows are made available as open-source and full reproducibility of the workflows is guaranteed through the use of the AiiDA infrastructure.

关键词： quantum routine material

A cellular hierarchy in melanoma uncouples growth and metastasis

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四川生理科学杂志 2022年第9期44卷 1633-1633页

作者： Panagiotis Karras Laboratory for Molecular Cancer Biology Center for Cancer Biology VIB Leuven Belgium Department of Oncology KU Leuven Leuven Belgium Laboratory of Tumor Microenvironment and Therapeutic Resistance Center for Cancer Biology VIB Leuven Belgium Department of Applied Mathematics and Theoretical physics Centre for Mathematical Sciences University of Cambridge Cambridge UK The Wellcome Trust/CRUK Gurdon institute University of Cambridge Cambridge UK Wellcome Trust-MRC Stem Cell institute University of Cambridge Cambridge UK Department of General Medical Oncology UZ Leuven Leuven Belgium BGI-Shenzhen Shenzhen China VIB BioImaging Core VIB Center for Brain and Disease Research Leuven Belgium VIB Bioimaging Core VIB Center for Inflammation Research Ghent Belgium Department of Biomedical Molecular Biology Ghent University Ghent Belgium FACS Expertise Center Center for Cancer Biology VIB Leuven Belgium Center for Brain & Disease Research VIB-KU Leuven Leuven Belgium Department of Human Genetics KU Leuven Leuven Belgium Data Mining and Modeling for Biomedicine Group VIB Center for Inflammation Research Ghent Belgium Department of Applied Mathematics Computer Science and Statistics Ghent University Ghent Belgium Laboratory for Translational Cell and Tissue Research Department of Imaging and Pathology KU Leuven Leuven Belgium Laboratory of Translational Genetics Center for Cancer Biology VIB Leuven Belgium Laboratory of Translational Genetics Center for Human Genetics KU Leuven Leuven Belgium Herbert Irving Comprehensive Center Columbia University Irving Medical Center New York USA Laboratory of Stem Cells and Cancer Université Libre de Bruxelles (ULB) Brussels Belgium

Although melanoma is notorious for its high degree of heterogeneity and plasticity1,2,the origin and magnitude of cell-state diversity remains poorly understood.Equally,it is unclear whether growth and metastatic dissemination are supported by overlapping or distinct melanoma subpopulations.Here,by combining mouse genetics,single-cell and spatial transcriptomics,lineage tracing and quantitative modelling,we provide evidence of a hierarchical model of tumour growth that mirrors the cellular and molecular logic underlying the cell-fate specification and differentiation of the embryonic neural crest.We show that tumorigenic competence is associated with a spatially localized perivascular niche,a phenotype acquired through an intercellular communication pathway established by endothelial cells.Consistent with a model in which only a fraction of cells are fated to fuel growth,temporal single-cell tracing of a population of melanoma cells with a mesenchymal-like state revealed that these cells do not contribute to primary tumour growth but,instead,constitute a pool of metastatic initiating cells that switch cell identity while disseminating to secondary organs.Our data provide a spatially and temporally resolved map of the diversity and trajectories of melanoma cell states and suggest that the ability to support growth and metastasis are limited to distinct pools of cells.The observation that these phenotypic competencies can be dynamically acquired after exposure to specific niche signals warrant the development of therapeutic strategies that interfere with the cancer cell reprogramming activity of such microenvironmental cues.

关键词： melanoma metastasis organs

Entomological Survey of Malaria Vectors within the Kumasi Metropolitan AreamA Study of Three Communities： Emena, Atonsu and Akropong

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Journal of Environmental Science and Engineering(B) 2012年第2期1卷 144-154页

作者： Samuel C.K. Tay Sylvester K. Danuor Andy Morse Caminade Caminade Kingsley Badu Harry Hoffman Abruquah School of Medical Sciences Kwame Nkrumah University of Science and Technology Kumasi 40100 Ghana Meteorology and Climate Science Unit Department of Physics Kumasi 40100 Ghana School of Environmental Sciences University of Liverpool Liverpool L69 7ZT UK Climate and Human Research Unit Centre for Global Health Kenya Medical Research Institute Kisumu 40100 Kenya Department of Pure and Applied Biology Kwame Nkrumah University of Science and Technology Kumasi 40100 Ghana University Hospital Kwame Nkrumah University of Science and Technology Kumasi 40100 Ghana

This study describes the bio-ecology of local Anopheles vectors, their abundance, type and vectoral competence in three communities around Kumasi Metropolis. The study sites were selected based on bio-ecologic zones (urban, peri-urban and rural) which influence habitat and behavior. Pyrethrum spray catch was used in the collection of indoor resting mosquitoes from bedrooms of study communities (June-August 2008). The identification of mosquitoes was based on morphological keys earlier described. The blood meal taken and the stage of digestion and egg development were also observed. A total of 293 mosquitoes were collected and 50.5% were A. gambiae s. l. Of the three bio-ecologic zones: urban, 53.4% were A. gambiae s. l, 27.2% Culex and 19.4% Mansonia; peri-urban, 58% A. gambiae s.1 and 42% Culex pipien s.1 and rural, 40.2% A. gambiae s.1, and 58.8% Culex sp respectively. About 96.6% of all mosquitoes collected had taken blood meals, with 50% of these being Anopheles gambiae s. l. Our findings indicate that urban rather exhibits rural characteristics and can best be described as "urban poor". However, more data need to be collected to ascertain this. The anopheline mosquitoes in the study communities are highly endophillic and anthropophagic and thus have high vectoral competence. The authors recommend frequent mosquito surveillance to avert malaria epidemic.

关键词：社区昆虫调查生物生态疾病农村地区致倦库蚊城市贫民冈比亚