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Evaluation of Subacute Toxicity of Hydroethanolic Extracts Combinations from Gnetum africanum (Welv.) and Gnetum buchholzianum (Engl.) (Genetaceae) Leaves: Two Botanical with Antiproliferative and Antioxidant Potential

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Open Journal of Applied Sciences 2022年第6期12卷 944-963页

作者： Bertin Sone Enone jean-pierre ngene Angèle Foyet Fondjo Charles Christian Ngoule Loé Gisèle Etame Loick Pradel Kojom Foko Christophe Manz Koule François Siewe Ronald Bidingha Goufani Josiane Etang Albert Mouelle Sone Laboratory of Microbiology Immunology-Hematology and Morphological Sciences Doctoral Training Unit of Health Sciences Faculty of Medicine and Pharmaceutical Sciences Douala University Douala Cameroon Department of Pharmaceutical Sciences Faculty of Medicine and Pharmaceutical Sciences Douala University Douala Cameroon Department of Medical Health Sciences Golf of Guinea University Institute (IUG) Douala Cameroon Department of Animal Biology and Physiology Faculty of Science University of Douala Douala Cameroon Department of Biochemistry and Nutrition Faculty of Science University of Douala Douala Cameroon Department of Technology and Biomedical Sciences Golf of Guinea University Institut (IUG) Douala Cameroon Laboratory of Animal Physiology Department of Animal Biology Faculty of Science University of Yaoundé I Yaoundé Cameroon

This study was conducted to assess the toxic effect of hydroethanolic extract combinations of Gnetum africanum Welv. leaves and Gnetum buchholzianum Engl. (Gnetaceae) in experimental rats to test the validity of the treatment of liver disorders related to oxidative stress. The Combinations (m/m) 50-50 for E2 and 75-25 for E3 of ethanol-water extracts from plant leaves at the respective doses of 100, 200, and 400 mg/kg of body weight were used for 32-day toxicity. They were obtained after harvesting leaves, sorting, drying in the air cover for three weeks, and grinding. The resulting powder was doubly macerated with 70% ethanol for 48 hours and filtered. The filtrate was concentrated with the Heidolph-brand rotary rotavapor and each extract obtained was preserved. The administrations were carried out by gavage to wistar, male and non-pregnant female albino rats. In the end, the animals were sacrificed. The serum and organ homogenates were obtained for biochemical, tissue, and histopathological analyses respectively. The analyses revealed insignificant variations at the 5% probability threshold of the weight growth of experimental animals. These variations were found to be statistically significant at the same probability for biochemical and tissue parameters based on the dose of plant extracts and compared to control animals. Histopathological analysis of liver tissue showed leukodate infiltration that indicates extract-induced inflammation of the hepatocytes at the 400 mg/kg dose of body weight in females. However, this infiltration of the cells would have improved the regeneration of hepatocytes justified by the normal rate of transaminases. These results showed that combinations of hydroethanolic extracts of G. africanum and G. buchholzianumare non-toxicand may be potential candidates in the Cameroonian flora medicinal plant database shown in the monitoring of oxidative stress-related diseases.

关键词： Gnetum africanum Gnetum buchholzianum Subacute Toxicity Oxidative Stress Albino Rats

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Characterization and Quantification of Phenolic Compounds of Hydroethanolic Extracts and Fractions of Leaves Gnetum africanum (Welv.) and Gnetum buchholzianum (Engl.) (Gnetaceae)

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Open Journal of Applied Sciences 2022年第7期12卷 1304-1318页

作者： Bertin Sone Enone Gisèle Marie-Marguerite Etame-Loe Charles Christian Ngoule jean-pierre ngene Juliette Koube Lahngong Methodius Shinyuy Simone Véronique Fannang Moïse Henri Julien Nko’o jean Baptiste Hzounda Fokou Hans Denis Bamal Celestine Magne Valdi Steve Djova Wilfred Ndogmo Tekapi Sandrine Sikadeu Josiane Etang Albert Mouelle Sone Laboratory of Microbiology Immunology-Hematology and Morphological Sciences Doctoral Training Unit in Health Sciences Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Department of Pharmaceutical Sciences Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Department of Microbiology University of Yaounde I Yaounde Cameroon Chemistry Laboratory Faculty of Sciences University of Douala Douala Cameroon Department of Biology and plant Organisms Faculty of Science Douala Cameroon

Research for bioactive molecules and not resistant to infectious agents remains topical for science. The total polyphenols (TPP) and total flavonoids (TFv) of the hydroethanolic extracts and fractions obtained were quantified according to the spectrophotometric method described in the literature using the Folin-Ciocalteu reagent and the colorless solutions of sodium nitrite 2.5% and aluminum chloride 10% respectively. The characterization of chemical compounds was made by coupling liquid chromatography (LC) and mass spectroscopy (MS). Thus, 15 chemical compounds were characterized, seven from Gnetum africanum (EBa) and eight from Gnetum buchholzianum (EBb). The majority of which were stilbens, such as Gnetupendin D, Dimethoxygnetulin, Methoxyparvifolol D, Isorhaponcitin from Eba and Gnetuhaidin P, Gnetupendin D, Gnetuhainin C, phenols (Alcohol Homovanillyl, Alcohol Erythro guaiacylglycerol-β-O-4'-coniferyl, and Alcohol Homovanillyl from EBb. The minority were flavonoids such as Dimethoxydihydropyraneriodictyol, Dimethoxyeriodictyol (EBa) and Dimethoxydihydropyraneriodictyol, Trimethoxyluteolin (EBb). The levels of total polyphenolics and total flavonoids content were respectively 14.520 ± 0.557 mg EAA/g Extract and 29.870 ± 2.485 mg EQ/g Extract for EBa. The levels of total polyphenolics and total flavonoids content for EBb were respectively 4.560 ± 0.010 mg EAA/g Extract and 2.233 ± 0.251 mg EQ/g Extract. The high levels of flavonoids content respectively 220.200 ± 35.500 and 335.300 ± 57.810 mg EQ/g Extract were shown in Dichlorometan fraction from EBa and EBb. These bioactive compounds identified and total phenolics compounds quantified can be exploited in pharmacological and pharmacokinetical activities to fight against multi-resistant infectious agents and as well as oxidative stress and antiinflammatory diseases.

关键词： Gnetum africanum Gnetum buchholzianum Phenolic Compounds Liquid Chromatography Mass Spectroscopy

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旋量理论及其在材料力学中的应用

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力学与实践 2025年第6期46卷 1262-1270页

作者：黄行蓉李敏 LAINE jean-pierre 北京航空航天大学中法工程师学院/国际通用工程学院北京 100191 北京航空航天大学航空科学与工程学院北京 100191

旋量理论是为力学量身定制的数学工具，在描绘刚体运动时表现出独特优势。基于材料力学中的平截面假设，构件的截面运动可分解为形心位移以及截面绕形心的旋转，从而可将截面运动视为刚体运动，故可采用旋量理论刻画构件截面的运动和受... 详细信息

旋量理论是为力学量身定制的数学工具，在描绘刚体运动时表现出独特优势。基于材料力学中的平截面假设，构件的截面运动可分解为形心位移以及截面绕形心的旋转，从而可将截面运动视为刚体运动，故可采用旋量理论刻画构件截面的运动和受力。该描述方式在数学形式上具有统一性，在物理现象上能对应实际受载和变形的一般性，可将力学问题转变成基于旋量运算法则求解的数学问题。本研究期望能为我国材料力学教学提供新视角和新思路。

关键词：旋量理论材料力学数学工具

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Foreword to the special section on synchronous programming

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Frontiers of Computer Science 2013年第5期7卷 595-597页

作者： jean-pierre TALPIN INRIA Rennes-Bretagne-Atlantique Rennes 35042 France

1 Introduction Embedded systems are ubiquitous. In applications ranging from avionics, automotive, and industrial process control all the way to the handheld personal digital assistants （PDAs）, cell phones, and bio-...

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Evidence of a Light-Sensing Role for Folate in Arabidopsis Cryptochrome Blue-Light Receptors

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Molecular Plant 2008年第1期1卷 68-74页

作者： Nathalie Hoang jean-pierre Bouly Margaret Ahmad Universite Paris Vl Casier 156 4 Place Jussieu 75005 Paris France Penn State University 25 Yearsley Mill Road Media PA 19063 USA

Arabidopsis cryptochromes cry1 and cry2 are blue-light signalling molecules with significant structural similarity to photolyases-a class of blue-light-sensing DNA repair enzymes. Like photolyases, purified plant cryptochromes have been shown to bind both flavin and pterin chromophores. The flavin functions as a light sensor and undergoes reduction in response to blue light that initiates the signalling cascade. However, the role of the pterin in plant cryptochromes has until now been unknown. Here, we show that the action spectrum for light-dependent degradation of cry2 has a significant peak of activity at 380 nm, consistent with absorption by a pterin cofactor. We further show that cry1 protein expressed in living insect ceils responds with greater sensitivity to 380 nm light than to 450 nm, consistent with a light-harvesting antenna pigment that transfers excitation energy to the oxidized flavin of cry1. The pterin biosynthesis inhibitor DHAP selectively reduces cryptochrome responsivity at 380 nm but not 450 nm blue light in these cell cultures, indicating that the antenna pigment is a folate cofactor similar to that of photolyases.

关键词： ARABIDOPSIS thaliana CRYPTOCHROMES PLANT growth SEEDLINGS BLUE light

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Useful zero friction simulations for assessing MBS codes Pascal’s formula giving wheelsets frequency for zero wheel-rail friction

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Theoretical & Applied Mechanics Letters 2022年第3期12卷 145-155页

作者： jean pierre Pascal Pascal Coding Rue d’ErquyPleneuf-Val-Andre F-22370France

Present study provides a simple analytical formula,the“Klingel-like formula”or“Pascal’s Formula”that can be used as a reference to test some results of existing railway codes and specifically those using rigid *** develops properly the 3D Newton-Euler equations governing the 6 degrees of freedom(DoF)of unsuspended loaded wheelsets in case of zero wheel-rail friction and constant ***,by solving numerically these equations,we got pendulum like harmonic oscillations of which the calculated angular frequency is used for assessing the accuracy of the proposed formula so that it can in turn be used as a fast practical target for testing multi-body system(MBS)railway *** to the harmonic property of these pendulum-like oscillations,the squareω2 of their angular frequency can be made in the form of a ratio K/M where K depends on the wheelset geometry and load and M on its *** on K and M are useful to understand wheelsets *** analytical formula is derived from the first order writing of full trigonometric Newton-Euler equations by setting zero elastic wheel-rail penetration and by assuming small *** trigonometric equations are numerically solved to assess that the formula providesω2 inside a 1%accuracy for usual wheelsets *** decreasing the conicity down to 1×10^(−4) rad,the relative formula accuracy is under 3×10^(−5).In order to test the formula reliability for rigid contact formulations,the stiffness of elastic contacts can be increased up to practical rigidity(Hertz stiffness×1000).

关键词： Unsuspended wheelsets Klingel formula Rigid contact Harmonic oscillation Multi body system railway codes Code validation

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Relation between silico-aluminous fly ash and its coal of origin

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Particuology 2008年第2期6卷 85-92页

作者： jean-Charles Benezet pierre Adamiec Ali Benhassaine Ecole des Mines d'Alès 6 Avenue de Clavieres30319 ALES CedexFrance

Fly ashes are typical complex solids which incorporate at the same time intrinsic properties derived from the layers （various mineralogical and dimensional spectra） and major transformations generated during prior processing. To use fly ashes in various applications, it is necessary to characterise them completely. The first research to date carried out on silico-aluminous fly ashes in order to characterise them physically, morphologically, chemically and mineralogically, resulted in the recognition that they are relatively simple materials. In the present study, a silico-aluminous fly ash coming from the power station of Albi （France） was selected. Heat treatment at 450 and 1200℃ together with coal simulated the treatment undergone by coal in the power station in order to mimic real coal residue. In conclusion, the diversity of the particles contained in fly ash could only be exolained by the relation existing between the fly ash and its coal of origin.

关键词： Fly ash Selection Thermal treatment

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Pozzolanic reactivity of silico-aluminous fly ash

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Particuology 2008年第2期6卷 93-98页

作者： pierre Adamiec jean-Charles Benezet Ali Benhassaine Ecole des Mines d'Alès 6 Avenue de Clavières30319 ALES CedexFrance

For some years it has been possible to control the particle size of fly ashes, by-products of thermal power stations. Incorporating these very fine particles （obtained by grinding and/or pneumatic selection） improves the physical-mechanical characteristics of mortars and concretes. In this study, we measured the lime consumption of the various fractions （granulometric and densimetric） and identified by X-ray diffraction the neoformed phases by the pozzolanic reaction, to show that it is not sufficient to simply define the pozzolanicity of products based on lime consumption since it does not take into account the nature of the phases formed. The size of the particles used in the test samples also has a determining effect on the quantity of lime consumed. Before comparing results, it is necessary to ensure that the size of the particles （of the global ash and its constituents） be the same. Two distinct neoformed ohases appear： CSH in the largest granular fractions （d〉 40 μm） and C3AH6 in the smaller fractions.

关键词： Fly ash Pozzolanic reaction Particle size

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Ocean-based climate actions recommended by academicians from Europe and China

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Science China Earth Sciences 2022年第8期65卷 1612-1614页

作者： jean-pierre GATTUSO Nianzhi JIAO Laboratoire d’Océanographie de Villefranche CNRS-Sorbonne University-IddriParis75006France Carbon Neutral Innovation Reaserch Center Xiamen UniversityXiamen361005China

Ocean acidification,deoxygenation and sea level Rise impacted by global warming intertwined with anthropogenic activities have resulted in tremendous ecological losses at species,diversity and ecosystem levels,leading... 详细信息

关键词： warming climate consequences

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Reconstructing the cruise-phase trajectory of deep-space probes in a general relativistic framework:An application to the Cassini gravitational wave experiment

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Astrodynamics 2023年第3期7卷 301-314页

作者： Joseph O’Leary jean-pierre Barriot School of Physics University of MelbourneParkvilleVIC3010Australia Australian Research Council Centre of Excellence for Gravitational Wave Discovery(OzGrav) ParkvilleVIC3010Australia Observatoire Géodésique de Tahiti University of French PolynesiaBP 657098702Faa’aTahitiFrench Polynesia

Einstein’s theory of general relativity is playing an increasingly important role in fields such as interplanetary navigation,astrometry,and *** spacecraft and interplanetary probe prediction and estimation platforms employ a perturbed Newtonian framework,supplemented with the Einstein-Infeld-Hoffmann n-body equations of *** time in Newtonian mechanics is formally universal,the accuracy of modern radiometric tracking systems necessitate linear corrections via increasingly complex and error-prone post-Newtonian techniques—to account for light deflection due to the solar system *** flagship projects such as the ESA/JAXA BepiColombo mission now operating at unprecedented levels of accuracy,we believe the standard corrected Newtonian paradigm is approaching its limits in terms of *** this paper,we employ a novel prototype software,General Relativistic Accelerometer-based Propagation Environment,to reconstruct the Cassini cruise-phase trajectory during its first gravitational wave experiment in a fully relativistic *** results presented herein agree with post-processed trajectory information obtained from NASA’s SPICE kernels at the order of centimetres.

关键词： general relativity planetary orbitography orbit prediction and determination

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