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New flavan and unusual chalcone glycosides from Drypetes parvifolia

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Chinese Chemical Letters 2008年第8期19卷 943-946页

作者： Viviane Nadège Nenkep Jovita Chi Shirri Hanh Trinh Van-Dufat Falindor Sipepnou Philippe Vérité Elisabeth Seguin Francois Tillequin jean wandji Department of Organic Chemistry University of Yaounde-1Faculty of ScienceP.O.Box 812YaoundeCameroon Laboratoire de Pharmacognosie de l'Université Paris Descartes UMR/CNRS N 8638Faculté des Sciences Biologiques et Pharmaceutiques4-Avenue de l'Observatoire75006 ParisFrance Laboratoire de Chimie Analytique UFR de Médecine Pharmacie Rouen22-Bid Gambetta76183 Rouen Cedex 1France Laboratoire de Pharmacognosie UFR de Médecine Pharmacie Rouen22-Bld Gambetta76183 Rouen Cedex 1France

Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. Their structures were established on the basis of spectroscopic analysis and chemical evidence.

关键词： Drypetes parvifolia Flavonoid glycosides 7-Hydroxy-5-O-(β-D-glucopyranoside) flavan (Z)-4',6'-Dihydroxy-2'-O-(β-D-glucopyr-anoside) chalcone

Antimicrobial Activity of the Methanolic Extract and Compounds from the Stem Bark of Drypetes tessmanniana

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Chinese Journal of Integrative Medicine 2010年第4期16卷 337-343页

作者： Victor Kuete Marlise D.J.Dongfack Armelle T.Mbaveng Marie-Christine Lallemand Hanh T.Van-Dufat jean-Duplex Wansi Elisabeth Seguin Francois Tillequin jean wandji Department of Biochemistry Faculty of ScienceUniversity of Dschang.P.O.Box 67 DschangCameroon Department of Organic Chemistry Faculty of ScienceUniversity of Yaounde I.P.O.Box 812 YaoundeCameroon Laboratoire de Pharmacognosie de I'Universite Paris Descartes UMR/CNRS N° 8638Faculte des Sciences Biologiques et Pharmaceutiques4-Avenue de I'Observatoire75006 ParisFrance Department of Biochemistry Faculty of ScienceUniversity of Yaounde IP.O.Box 812 YaoundeCameroon Department of Chemistry University of DoualaFaculty of ScienceP.O.Box 24157 DoualaCameroon Laboratoire de Pharmacognosie UFR de Medecine Pharmacie Rouen22-Bid Gambetta76183 Rouen Cedex 1France

Objective： To evaluate the antimicrobial activity of the methanol extract from the stem bark of Drypetes tessmanniana, fractions （DTB1-5） as well as compounds [friedelin （2）, 3,7-dioxofriedelane （3）, 3,15-dioxofriedelane （4）, 313 -O-（E）-3,5-dihydroxycinnamoyl-11 -oxo-olean-12-ene （6）, and 313,6 α -dihydroxylup- 20（29）-ene （7）. Methods： Agar disc diffusion was used to determine the sensitivity of the above samples, whilst the microdilution method was used for the determination of the minimal inhibitory concentration （MIC） and the minimal microbicidal concentrations （MMC）. Results： The diffusion test showed that the crude extract was able to prevent the growth of all tested organisms. All other samples showed selective activity. The inhibitory effect of the fraction DTB2 was noted on 63.7%, that of DTB1 and DBT3 on 54.6%, whilst DTB4 and DTB5 were active on 9.1% of the 11 tested organisms. The tested compounds prevented the growth of 81.8% of the tested microbial species for compounds 3 and 4, 36.7% for compound 6, and 18.2% for compound 7. The results of the MIC determinations indicated perceptible values for DTB and compound 4 on 81.8% of the tested organisms. For other samples, MICs were detected on 0-63.7%. The lowest MIC value （78.12 μg/mL） for the crude extract and fractions （DTB2） was observed on M. audouinii. The corresponding value for isolated compounds （156.25 μg/ mL） was noted with compounds 3 on S. faecalis and 4 on M. audouinii. The results of the MMC determination suggested that the microbicidal effect of most of the tested samples on the studied microorganisms could be expected. Conclusion： The methanol extract from the stem bark of Drypetes. tessmanniana （Euphorbiaceae） as well as some of the isolated compounds might be potential sources of new antimicrobial drues.

关键词： Drypetes tessmanniana Euphorbiaceae compounds antimicrobial activity

Bound and Resonating Multiquark Configurations

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Chinese Physics Letters 2024年第8期41卷 8-12页

作者： jean-Marc Richard Institut de Physique des 2 Infinis de Lyon Université Claude Bernard(Lyon 1) CNRS-IN2P34 rue Enrico Fermi69622 VilleurbanneFrance

We review the predictions of quark models for multiquark configurations that are bound or resonant states,and compare different methods for estimating the properties of resonances.

关键词： quark Configuration resonant

Multi-source information fusion:Progress and future

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Chinese Journal of Aeronautics 2024年第7期37卷 24-58页

作者： Xinde LI Fir DUNKIN jean DEZERT School of Automation Southeast UniversityNanjing 210008China Nanjing Center for Applied Mathematics Nanjing 211135China Key Laboratory of Measurement and Control of CSE Ministry of EducationNanjing 210096China Southeast University Shenzhen Research Institute Shenzhen 518063China Information Modeling and Processing Department ONERAPalaiseau 92320France

Multi-Source Information Fusion(MSIF),as a comprehensive interdisciplinary field based on modern information technology,has gained significant research value and extensive application prospects in various domains,attracting high attention and interest from scholars,engineering experts,and practitioners *** achieving fruitful results in both theoretical and applied aspects over the past five decades,there remains a lack of comprehensive and systematic review articles that provide an overview of recent development in *** light of this,this paper aims to assist researchers and individuals interested in gaining a quick understanding of the relevant theoretical techniques and development trends in MSIF,which conducts a statistical analysis of academic reports and related application achievements in the field of MSIF over the past two decades,and provides a brief overview of the relevant theories,methodologies,and application domains,as well as key issues and challenges currently ***,an analysis and outlook on the future development directions of MSIF are presented.

关键词： Multi-sensor system Information fusion Artificial intelligence Pattern recognition Human-machine integration

Microplastics and microbiota:Unraveling the hidden environmental challenge

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World Journal of Gastroenterology 2024年第16期30卷 2191-2194页

作者： jean Demarquoy Universitéde Bourgogne Institut Agro-DijonDijon 21000France

This editorial explores the intricate relationship between microplastics(MPs)and gut microbiota,emphasizing the complexity and environmental health *** gut microbiota,a crucial component of gastrointestinal health,is examined in the context of potential microbial degradation of ***,dysbiosis induced by MPs emerges as a consensus,disrupting the balance of gut microbiota and decreasing *** mechanisms triggering dysbiosis,including physical interactions and chemical composition,are under *** research addresses the consequences of MPs on immune function,nutrient metabolism,and overall host *** bidirectional relationship between MPs and gut microbiota has significant implications for environmental and human *** uncertainties,MPs negatively impact gut microbiota and *** research is essential to unravel the complex interactions and assess the long-term consequences of MPs on both environmental and human well-being.

关键词： Microplastics Microbiota Gut Dysbiosis

Design and Experimental Testing of a Moving Coil Actuator with Compensation Coil

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 707-716页

作者： Boyuan Yin Xianwu Zeng John Frederick Eastham Emelie Nilsson jean-francois Rouquette jean Rivenc Ludovic Ybanez Xiaoze Pei Department of Electronics&Electrical Engineering University of BathBathBA27AYUnited Kingdom Airbus UpNext BlangnacFrance Airbus CRT BlangnacFrance Department of Mechanical Engineering University of BathBathBA27AYUnited Kingdom

Hydrogen-powered electric aircraft have attracted significant interests aiming to achieve decarbonization *** DC electric networks are facing great challenges in DC fault protection *** interrupters are widely used in low voltage and medium voltage power systems due to being environmentally friendly with low *** this paper a moving coil actuator with compensation coils for a vacuum interrupter,as part of a hybrid direct current circuit breaker,is designed and experimentally *** coils are used to improve operating speed compared with original moving coil *** between four possible connections of compensation coils and original moving coil actuator are carried *** results show comparisons between different connections of actuator coils in terms of opening time and coil current with a range of pre-charged capacitor *** performance of each actuator connection is also *** actuator with compensation coils is shown to have a higher current rising rate and achieve faster opening speed,which is a critical requirement for electric aircraft network *** parallel connection actuator achieves the highest opening speed within 3.5 ms with capacitor voltage of 50 V.

关键词： Circuit breaker compensation coil moving coil actuator vacuum interrupter

Tanaka Formula and Local Time for a Class of Interacting Branching Measure-valued Diffusions

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1059-1098页

作者： Donald A.DAWSON jean VAILLANCOURT Hao WANG School of Mathematics and Statistics Carleton UniversityOttawaCanada Department of Decision Sciences HECMontrealCanada Department of Mathematics University of OregonEugeneUSA

We construct superprocesses with dependent spatial motion(SDSMs)in Euclidean spaces R^(d)with d≥1 and show that,even when they start at some unbounded initial positive Radon measure such as Lebesgue measure on R^(d),... 详细信息

关键词： Measure-valued diffusions stochastic partial differential equations superprocesses branching processes local time Tanaka formula

High-performance nickel metal hydride battery anode with enhanced durability and excellent low-temperature discharge capability

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Nano Research 2024年第10期17卷 8819-8825页

作者： Zhitao Chen Huitian Liu jean Nei Nian Liu School of Chemical and Biomolecular Engineering Georgia Institute of TechnologyAtlantaGA 30332USA GP Batteries HongkongChina

Current AB_(5)-type hydrogen storage alloys employed in nickel-metal hydride(NiMH)batteries exhibit exceptional low-temperature discharge performance but suffer from limited cycle life and insufficient high-temperature *** overcome these challenges,we introduce a hydrothermal synthesized LaF_(3)coating layer on the surface of the AB_(5)anode *** LaF_(3)coating layer adds a protective barrier for the active material,significantly improving the battery's cycle life and high-temperature *** findings indicate that(1)the LaF_(3)coated anode demonstrates an extended cycle life with increased specific capacity and a capacity retention of 88%after 40 cycles of abusive overcharging and rapid discharging at room temperature.(2)The synthesized anode exhibits a 97%recovery of its specific capacity of 292.7 mAh/g following 144 h of high-temperature storage.(3)The low-temperature discharge capacity of the synthesized anode remains on par with the pristine AB_(5)alloy at 230.4 mAh/g in a-40℃*** research presents a significant advancement in hydrogen storage alloy coatings and offers valuable insights for designing electrodes in NiMH batteries.

关键词： nickel metal hydride(NiMH)batteries hydrothermal synthesis lanthanum fluoride discharge capacity low temperature

A convolutional neural network to detect possible hidden data in spatial domain images

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Cybersecurity 2024年第1期7卷 37-52页

作者： jean De La Croix Ntivuguruzwa Tohari Ahmad Department of Informatics Institut Teknologi Sepuluh Nopember(ITS)Kampus ITS Keputih SukoliloSurabaya60111Indonesia African Center of Excellence in the Internet of Things College of Science and TechnologyUniversity of Rwanda3900KigaliRwanda

Hiding secret data in digital multimedia has been essential to protect the ***,attackers with a steganalysis technique may break *** steganalysis methods have good results with conventional Machine Learning(ML)techniques;however,the introduction of Convolutional Neural Network(CNN),a deep learning paradigm,achieved better performance over the previously proposed ML-based *** the existing CNN-based approaches yield good results,they present performance issues in classification accuracy and stability in the network training *** research proposes a new method with a CNN architecture to improve the hidden data detection accuracy and the training phase stability in spatial domain *** proposed method comprises three phases:pre-processing,feature extraction,and ***,in the pre-processing phase,we use spatial rich model filters to enhance the noise within images altered by data hiding;secondly,in the feature extraction phase,we use two-dimensional depthwise separable convolutions to improve the signal-to-noise and regular convolutions to model local features;and finally,in the classification,we use multi-scale average pooling for local features aggregation and representability enhancement regardless of the input size variation,followed by three fully connected layers to form the final feature maps that we transform into class probabilities using the softmax *** results identify an improvement in the accuracy of the considered recent scheme ranging between 4.6 and 10.2%with reduced training time up to 30.81%.

关键词： Information security Spatial domain steganalysis Deep learning Convolutional neural network Infrastructure