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Characterization of Extracts from the Bark of the Gabon Hazel Tree (Coula edulis baill) for Antioxidant,Antifungal and Anti-termite Products

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Journal of Renewable Materials 2021年第1期9卷 17-33页

作者： Christ Stone Arnaud Bopenga Bopenga Henri Meyo Degboevi kevin Candelier Prosper Edou Engonga Stéphane Dumarçay Marie France Thévenon Christine Gérardin Charbonnier Philippe Gérardin Universitéde Lorraine Institut National de Recherche pour l’Agriculturel’Alimentation et l’EnvironnementLaboratoire d’Etudes et de Recherche sur le Matériau BoisNancyFrance Universitéde Montpellier Centre de Coopération Internationale en Recherche Agronomique pour le Développement-Research Unit BiomassWoodEnergyBioproductsMontpellierFrance Multidisciplinary Laboratory of Sciences of Libreville Normal Superior SchoolLibrevilleGabon

Chemical composition of the bark extracts of Coula edulis was investigated to find potential antioxidant,anti-termite and antifungal compounds which can find useful applications in the fields of food,nutraceuticals,cosmetics or *** screening revealed the presence of several groups of active molecules such as alkaloids,polyphenols,flavonoids,saponins and sterols and/or terpenes in the different *** phenols,condensed tannins and flavonoids contents corroborated phytochemical *** chromatographymass spectrometry(GC-MS)analysis revealed compounds in dichloromethane extract different from those obtained with all the other *** and trans-9-octadecenoic acids,as well as stigmasterol andβ-sitosterol have been identified as the major compounds in the dichloromethane *** obtained with acetone and toluene/ethanol mixture(2/1,v/v)indicated the presence of few amounts of fatty acids and sugars,catechin in small amount and huge amounts of phenolic acids like gallic and ellagic *** radical 2,2-diphenyl-1-picrylhydrazyle(DPPH)and the cationic radical 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS+)were used for evaluation of antioxidant properties of the different *** dichloromethane extracts had a very low antioxidant activity,while acetone and toluene/ethanol extracts presented EC50 values similar to those of catechin and BHT used as reference antioxidant *** of the different extracts of the bark of *** on fungal growth inhibition indicated better inhibition of the mycelium growth of brown rot fungi compared to white rot *** anti-termite activities were recorded with the aqueous extracts,while stronger activities were recorded with dichloromethane,acetone and toluene/ethanol extracts.

关键词： Antifungal antioxidant anti-termite Coula edulis baill extracts valorisation

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Discovery of high-entropy ceramics via machine learning

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npj Computational Materials 2020年第1期6卷 1323-1331页

作者： kevin Kaufmann Daniel Maryanovsky William M.Mellor Chaoyi Zhu Alexander S.Rosengarten Tyler J.Harrington Corey Oses Cormac Toher Stefano Curtarolo Kenneth S.vecchio Department of NanoEngineering UC San DiegoLa JollaCA 92093USA Department of Cognitive Science UC San DiegoLa JollaCA 92093USA Materials Science and Engineering Program UC San DiegoLa JollaCA 92093USA Department of Mechanical Engineering and Materials Science Duke UniversityDurhamNC 27708USA Materials Science Electrical EngineeringPhysics and ChemistryDuke UniversityDurhamNC 27708USA

Although high-entropy materials are attracting considerable interest due to a combination of useful properties and promising applications,predicting their formation remains a hindrance for rational discovery of new *** approaches are based on physical intuition and/or expensive trial and error *** computational methods rely on the availability of sufficient experimental data and computational *** learning(ML)applied to materials science can accelerate development and reduce *** this study,we propose an ML method,leveraging thermodynamic and compositional attributes of a given material for predicting the synthesizability(i.e.,entropy-forming ability)of disordered metal carbides.

关键词： ceramics entropy attracting

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Cytokine analysis of livers from patients with seronegative viral hepatitis

Cytokine analysis of livers from patients with seronegative ...

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第三届全国重型肝病及人工肝血液净化学术年会

作者： Susan Wong Atanu Basu Neal S.Young kevin E.kevin. Hematology Branch NHLBIBethesdaMD 20892

Although the hepatitis viruses A,B,C,D and E account for the majority of cases of acute viral hepatitis,the etiology is unknown in～3% of *** addition,the etiological agent of hepatitis-associated aplastie anemia (HAA,severe bone marrow failure following an episode of acute hepatitis),and most cases of fulminant hepatitis (FH) is unknown,but does not appear to be caused by any of the known hepatitis agents,and including B19v, HGv,TTv,SENv,herpesviruses (including CMv,EBv and HHv-6/7),or adenoviruses (Brown et al NEJM 1997,Wong et al,JID 2003,Brown et al Br J Haematol 1997,Umemura et al JID,2003,our unpublished

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基于加压毛细管电色谱-激光诱导荧光联用技术研究离子强度对维生素B2光解反应的影响

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色谱 2018年第4期36卷 381-387页

作者：肖汉 kevin YAN 郑怡婷王彦阎超上海交通大学药学院上海200240 University of California Riverside 92521USA

基于加压毛细管电色谱-激光诱导荧光检测法建立了分析维生素B2及其荧光性光解产物的方法,并用于研究维生素B2在水溶液和磷酸盐缓冲液中的光解反应速率与离子强度之间的关系。发现在C18毛细管色谱柱,流动相为含0.1%(v/v)三氟乙酸的乙腈... 详细信息

基于加压毛细管电色谱-激光诱导荧光检测法建立了分析维生素B2及其荧光性光解产物的方法,并用于研究维生素B2在水溶液和磷酸盐缓冲液中的光解反应速率与离子强度之间的关系。发现在C18毛细管色谱柱,流动相为含0.1%(v/v)三氟乙酸的乙腈水溶液,梯度洗脱,激发波长为488 nm,发射波长为520 nm的条件下,维生素B2及多种荧光性光解产物均得到很好的分离和检测,维生素B2的定量限为5×10-8mol/L。在此基础上研究了维生素B2的光降解反应受光照时间和离子强度等的影响。发现离子强度对维生素B2溶液的光解反应有显著影响,离子强度越大,光解速度越快。并进一步通过动力学计算得到维生素B2在水溶液和磷酸盐缓冲液中光解反应的表观速率常数。该研究为维生素B2的光稳定研究提供了一种高效分离和检测的方法,并为维生素B2的保存及临床使用提供了参考。

关键词：加压毛细管电色谱激光诱导荧光检测维生素B2 光解反应反应速率常数

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Fullerene/MWCNT/Nafion Modified Glassy Carbon Electrode for the Electrochemical Determination of Caffeine

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American Journal of Analytical Chemistry 2020年第2期11卷 114-127页

作者： kevin Yemele Tajeu Liliane Medonbou Dongmo Ignas Kenfack Tonle Electrochemistry and Chemistry of Materials Department of Chemistry University of Dschang Dschang Cameroon

Herein, a convenient method based on a fullerene/multiwalled carbon nanotube/Nafion modified glassy carbon electrode (fullerene/MWCNT/Naf/GCE) for the electrochemical determination of caffeine (CAF) is reported. Cyclic voltammetry (Cv) and electrochemical impedance spectroscopy (EIS) were used to study ionic exchange properties and conductivity the proposed electrode using [Fe(CN)6]3-/4- redox couple. Caffeine gave an irreversible oxidation peak around +1.33 v (vs. Ag/AgCl reference electrode) in HClO4 (pH 1). The linear dependence of the peak current with the square root of the scan rate showed that the electron transfer process is controlled by diffusion. After optimization of key analytical parameters involved in differential pulse voltammetry (DPv), the oxidation peak current varied linearly with CAF concentration in the range of 10 to 1000 μM. A detection limit of 7.289 × 10-8 M (S/N = 3) was found. Kinetic and chronocoulometric studies were also performed to characterize the diffusion of CAF. The developed electrode exhibited good stability and was easily regenerated. The influence of some potential interfering compounds such as dopamine, uric acid, glucose and sulfite ions on the anodic peak current of CAF was also examined. The proposed method was successfully employed in the determination of CAF in some commercial drugs.

关键词： Caffeine Fullerene/MWCNT Nafion Film Modified Electrode Electroanalysis

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新型Si_3N_4层部分固定正电荷AlGaN/GaNHEMTs器件耐压分析

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物理学报 2012年第24期61卷 464-469页

作者：段宝兴杨银堂 kevin J.Chen 西安电子科技大学微电子学院宽禁带半导体材料与器件教育部重点实验室西安710071 Department of Electronic and Computer Engineering Hong Kong University of Science and TechnologyClear Water BayHong KongChina

为了优化传统AlGaN/GaN high electron mobility transistors结构表面电场分布,提高器件击穿电压和可靠性,本文利用不影响AlGaN/GaN异质结极化效应的Si3N4钝化层电荷分布,提出了一种Si3N4钝化层部分固定正电荷AlGaN/GaN high electron m... 详细信息

为了优化传统AlGaN/GaN high electron mobility transistors结构表面电场分布,提高器件击穿电压和可靠性,本文利用不影响AlGaN/GaN异质结极化效应的Si3N4钝化层电荷分布,提出了一种Si3N4钝化层部分固定正电荷AlGaN/GaN high electron mobility transistors新结构.Si3N4钝化层中部分固定正电荷通过电场调制效应使表面电场分布中产生新的电场峰而趋于均匀.新电场峰使得新结构栅边缘和漏端高电场有效降低,器件击穿电压从传统结构的296v提高到新结构的650v,而且可靠性改善.通过Si3N4与AlGaN界面横、纵向电场分布,说明了产生表面电场峰的电场调制效应,为设计Si3N4层部分固定正电荷新结构提供了科学依据.Si3N4钝化层部分固定正电荷的补偿作用,使沟道二维电子气浓度增加,导通电阻减小,输出电流提高.

关键词： AlGaN GaN high electron mobility transistors 固定电荷电场调制

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Intracellular Delivery of mRNA in Adherent and Suspension Cells by vapor Nanobubble Photoporation

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Nano-Micro Letters 2020年第12期12卷 404-420页

作者： Laurens Raes Stephan Stremersch Juan CFraire Toon Brans Glenn Goetgeluk Stijn De Munter Lien van Hoecke Rein verbeke Jelter van Hoeck Ranhua Xiong Xavier Saelens Bart vandekerckhove Stefaan De Smedt Koen Raemdonck kevin Braeckmans Laboratory of General Biochemistry&Physical Pharmacy Ghent University9000 GhentBelgium Cancer Research Institute Ghent(CRIG) 9000 GhentBelgium Department of Diagnostic Sciences Ghent University9000 GhentBelgium vIB-UGent Center for Medical Biotechnology 9052 GhentBelgium Department of Biomedical Molecular Biology Ghent University9000 GhentBelgium Department of Biochemistry and Microbiology Ghent University9000 GhentBelgium

Efficient and safe cell engineering by transfection of nucleic acids remains one of the long-standing hurdles for fundamental biomedical research and many new therapeutic applications,such as CAR T cell-based *** has recently gained increasing attention as a more safe and versatile alternative tool over viral-or DNA transposon-based approaches for the generation of adoptive T ***,limitations associated with existing nonviral mRNA delivery approaches hamper progress on genetic engineering of these hard-to-transfect immune *** this study,we demonstrate that gold nanoparticle-mediated vapor nanobubble(vNB)photoporation is a promising upcoming physical transfection method capable of delivering mRNA in both adherent and suspension *** transfection experiments on HeLa cells showed the importance of transfection buffer and cargo concentration,while the technology was furthermore shown to be effective for mRNA delivery in Jurkat T cells with transfection efficiencies up to 45%.Importantly,compared to electroporation,which is the reference technology for nonviral transfection of T cells,a fivefold increase in the number of transfected viable Jurkat T cells was ***,our results point toward the use of vNB photoporation as a more gentle and efficient technology for intracellular mRNA delivery in adherent and suspension cells,with promising potential for the future engineering of cells in therapeutic and fundamental research applications.

关键词： Transfection mRNA Photoporation Optoporation Gold nanoparticles vapor nanobubbles

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verification and Dosimetric Impact of Acuros XB Algorithm for Stereotactic Body Radiation Therapy (SBRT) and RapidArc Planning for Non-Small-Cell Lung Cancer (NSCLC) Patients

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2013年第1期2卷 6-14页

作者： Suresh Rana kevin Rogers Terry Lee Daniel Reed Christopher Biggs Department of Medical Physics ProCure Proton Therapy Center Oklahoma City USA Department of Radiation Oncology Arizona Center for Cancer Care Peoria USA

Purpose: The experimental verification of the Acuros XB (AXB) algorithm was conducted in a heterogeneous rectangular slab phantom, and compared to the Anisotropic Analytical Algorithm (AAA). The dosimetric impact of the AXB for stereotactic body radiation therapy (SBRT) and RapidArc planning for 16 non-small-cell lung cancer (NSCLC) patients was assessed due to the dose recalculation from the AAA to the AXB. Methods: The calculated central axis percentage depth doses (PDD) in a heterogeneous slab phantom for an open field size of 3 ×3 cm2 were compared against the PDD measured by an ionization chamber. For 16 NSCLC patients, the dose-volume parameters from the treatment plans calculated by the AXB and the AAA were compared using identical jaw settings, leaf positions, and monitor units (MUs). Results: The results from the heterogeneous slab phantom study showed that the AXB was more accurate than the AAA;however, the dose underestimation by the AXB (up to ?3.9%) and AAA (up to ?13.5%) was observed. For a planning target volume (PTv) in the NSCLC patients, in comparison to the AAA, the AXB predicted lower mean and minimum doses by average 0.3% and 4.3% respectively, but a higher maximum dose by average 2.3%. The averaged maximum doses to the heart and spinal cord predicted by the AXB were lower by 1.3% and 2.6% respectively;whereas the doses to the lungs predicted by the AXB were higher by up to 0.5% compared to the AAA. The percentage of ipsilateral lung volume receiving at least 20 and 5 Gy (v20 and v5 respectively) were higher in the AXB plans than in the AAA plans by average 1.1% and 2.8% respectively. The AXB plans produced higher target heterogeneity by average 4.5% and lower plan conformity by average 5.8% compared to the AAA plans. Using the AXB, the PTv coverage (95% of the PTv covered by the 100% of the prescribed dose) was reduced by average 8.2% than using the AAA. The AXB plans required about 2.3% increment in the number of MUs in order to achieve the sa

关键词： Acuros XB AAA Heterogeneity Correction SBRT RapidArc Lung Cancer

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2003“HelloMoto”新机SHOW

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数字通信 2003年第3期30卷 6-11页

作者： kevin

2003年3月在德国汉诺威举行的CeBIT2003展会上,摩托罗拉公司推出的新款手机可谓姹紫嫣红、各争其艳,让摩记的机迷们很是过了一把瘾。而就在CeBIT尚未收场的3月17日,该公司又在美国新奥尔良举办的2003年度的CTIA无线大会上一举推出了4款... 详细信息

2003年3月在德国汉诺威举行的CeBIT2003展会上,摩托罗拉公司推出的新款手机可谓姹紫嫣红、各争其艳,让摩记的机迷们很是过了一把瘾。而就在CeBIT尚未收场的3月17日,该公司又在美国新奥尔良举办的2003年度的CTIA无线大会上一举推出了4款新型手机产品,即T722i、E310、v60x、v810。尽管摩记的执行官高尔文在CTIA2003展会上言之凿凿地称无线通讯业当回归基本,改良通话质量,但这并不妨碍该公司推出应时应景的新型电话,至少目前摩托罗拉的机迷还无须担心他们以后买到的手机只能用来打电话。

关键词：彩屏手机摩托罗拉公司 3G和机产品介绍相机手机

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“柔软的”硬件

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数字通信 2003年第13期30卷 10-11页

作者： kevin

曾经设计了Paim v的IDED公司与Ilectrotextiles公司一起系列令人瞠目的柔性硬件。对于IDED这个名字，大家或许都听说过，因为这家公司曾有过许多了色的创意，其中最为PDA玩家熟悉的就是Palm v了，它的硬件设计就出自IDED之手。而另外一... 详细信息

曾经设计了Paim v的IDED公司与Ilectrotextiles公司一起系列令人瞠目的柔性硬件。对于IDED这个名字，大家或许都听说过，因为这家公司曾有过许多了色的创意，其中最为PDA玩家熟悉的就是Palm v了，它的硬件设计就出自IDED之手。而另外一家公司，Ilectrotextiles，曾经率行凶研制准出过一款Palm上用的柔性变形键盘。一家在产品设计领域信誉卓著的公司，另一家则是致力于最新的。

关键词： IDED公司 Palm 产品设计手机通讯功能

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