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Phytochemical analyses, antimicrobial and antioxidant activities of stem bark extracts of Distemonanthus benthamianus H. Baill. and fruit extracts of Solanum torvum Sw. from Gabon

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Asian Pacific Journal of Tropical Biomedicine 2019年第5期9卷 209-216页

作者： Cédric Sima Obiang Rick Léonid Ngoua Meye Misso Guy roger Ndong Atome Joseph Privat Ondo Louis clément Obame Engonga Edouard Nsi Emvo Laboratory of Research in Biochemistry University of Sciences and Technology of Masuku Laboratory of Natural Substances and Organometallic Synthesis University of Sciences and Technology of Masuku

Objective: To evaluate the phytochemical constituents, antimicrobial and antioxidant activities of the extracts of Distemonanthus benthamianus(D. benthamianus) stem bark and Solanum torvum(S. torvum) fruit which have been used as traditional medicinal herbs in Gabon. Methods: Plant extracts were subjected to a qualitative study(phytochemical screening) and a quantitative(dosing) study of secondary metabolites. Antioxidant activity was tested by 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid assay. Bacteria and fungi susceptibility tests were performed on Mueller Hinton medium and solid Sabouraud, respectively, using the diffusion method, while minimum inhibitory concentration, minimum fungicidal concentration and minimum bactericidal concentration were evaluated by microdilution ***: The total phenol and tannin contents were significantly higher in the water-ethanol extract compared to the other extracts of D. benthamianus and S. torvum. The water-ethanol and water-acetone extracts showed significantly higher antioxidant activity than the aqueous extracts of the two medicinal plants. However, the extracts presented weak antioxidant activities compared to standards(Vitamin C, BHA). The water-acetone and water-ethanol extracts of S. torvum showed the highest antimicrobial activity against Bacillus cereus LMG 13569 BHI, Shigella dysenteriae 5451 CIP, Shigella dysenteriae and Neisseria gonorrhoeae. Conclusions: Our results show that D. benthamianus and S. torvum can be promising sources of natural products with potential antimicrobial and antioxidant activities.

关键词： Antioxidants Phytochemical Antimicrobial Distemonanthus benthamianus Solanum torvum

Prevalence and Risk Factors of Vaginal Trichomoniasis in Women: Study at the University Hospital of Pikine in the Suburbs of Dakar, Senegal

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Advances in Infectious Diseases 2023年第2期13卷 291-302页

作者： Isaac Akhénaton Manga David Ngom Marie Pierre Diouf Carole Pab Minlekib Souleye Lelo Cheikh Binetou Fall Khadime Sylla Doudou Sow Jean Louis Ndiaye Magatte Ndiaye roger clément tine Babacar Faye Parasitology-Mycology Department Faculty of Medicine-Pharmacy-Odontology Cheikh Anta Diop University Dakar Senegal Gynecology Department Keur Massar Health Centre Dakar Senegal Parasitology-Mycology Laboratory University Hospital of Pikine Dakar Senegal Parasitology-Mycology Department UFR Santé Gaston Berger University Saint Louis Senegal Parasitology-Mycology Department UFR Santé Iba Der Thiam University Thiès Senegal

Introduction: This study aimed to investigate the epidemiology of genital trichomoniasis in Senegal. It sought to determine the prevalence and risk factors associated with this condition in Senegal. Methodology: The study took place at the university hospital of Pikine in the suburbs of Dakar. For each of the women recruited, socio-demographic data, clinical examination data and the results of direct examination of the vaginal sample were collected in a questionnaire designed for this purpose. Results: A total of 312 women with a mean age of 31.13 (±8.41) years were recruited in this study. The majority of these women (59.94%;95% CI = 54.25 - 65.38), were seen for an infectious diseases assessment. Leucorrhea (58.33%;95% CI = 52.63 - 63.83) and genital discharge on vaginal touch (99.36%;95% CI = 97.45 - 99.89) were the predominant signs on clinical examination. The overall prevalence of vaginal trichomoniasis after direct examination of the specimens was 1.28% (95% CI = 0.41 - 3.47). Only the distribution of this prevalence by occupation was statistically significant (p = 0.0004). Conclusion: The low prevalence of genital trichomoniasis in women and the risk factors associated with it found in this study, which took place about ten years ago, should prompt an update of the data to better define the problem in Senegal.

关键词： Vaginal Trichomoniasis Prevalence Risk Factors Dakar Suburb Senegal

Towards the solution of urban transport problems in China

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Journal of Environmental Sciences 1999年第3期11卷 334-338页

作者： roger Mackett Centre for Transport Studies, University College London, Gower Street, London, WC1E 6BT, UK University College London 英国

The number of cars is increasing rapidly in most cities around the world including those in China. Access to a car increases the range of opportunities available and confers status. The construction of cars can also be a major contributor to a national economy and provide many jobs. However, mass car ownership brings many problems including environmental damage, resource depletion, congestion and inequality. In this paper the nature of urban transport problems in general is examined, and then the extent to which these are applicable in Chinese cities is considered. Then the future of transport in such cities is considered using some projections by the World Bank. It is shown that the problems will become much worse if no policy intervention occurs, but even with significant investment, the quality of the environment will deteriorate.

关键词： transport China Beijing cars policy cities.

Oregano and Rosemary Essential Oils in Collagen Fiber and Polyvinyl Alcohol Films: Application as Biodegradable Active Packaging for Ready-to-Eat Meat Products

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Food and Nutrition Sciences 2025年第1期16卷 1-27页

作者： Suslin Raatz Thiel Cássio Poerschke Rodrigues José Dilson Francisco da Silva Mari Silvia Rodrigues de Oliveira Stephanie Reis Ribeiro Rosa Cristina Prestes Ernesto Hashime Kubota roger Wagner Renius Mello Department of Food Science and Technology Universidade Federal de Santa Maria Rio Grande do Sul Brazil

Developing packaging using biomaterials offers a solution to the problem of solid plastic waste in urban areas. However, selecting suitable materials remains challenging, particularly when the packaging is intended for food products with high moisture content, such as meat. In response to this challenge, a novel film comprising a blend of collagen fiber and polyvinyl alcohol, supplemented with varying concentrations of oregano and rosemary essential oils, was developed. The mechanical properties, in vitro antioxidant activity, and chemical composition of these collagen fiber and polyvinyl alcohol films, enhanced with oregano and rosemary essential oils, were thoroughly characterized. The compounds γ-terpinene and ρ-cymene played a significant role in the antioxidant activity of the packaging. The impact of this active packaging on the quality of sliced mortadella was evaluated over 0, 3, 6, and 9 days of refrigeration. Time significantly influenced most of the variables examined. The concentration of essential oils (0%, 2%, 4%, and 6%) significantly affected the moisture level, water activity, pH, and Escherichia coli count in the packaged product. For lipid oxidation analysis, the type of essential oil proved significant, with oregano essential oil demonstrating superior activity. A pro-oxidant effect was noted in products with 6% rosemary essential oil. Packages containing essential oils from oregano and rosemary exhibited lower E. coli counts. Films enriched with essential oils showed a higher rate of biodegradation.

关键词： Lipid Oxidation Escherichia coli Principal Component Analysis Bioactive Compounds Shelf Life Mechanical Properties

Correction of disturbed pathophysiology of hepatic failure by albumin dialysis

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Hepatobiliary & Pancreatic Diseases International 2008年第1期7卷 19-24页

作者： roger Williams Institute of Hepatology University College London Medical School 69-75 Chenies MewsLondonWC1E 6HXUK

Introduction In my presentation to the 4th International Symposium on Hepatic Failure and Artificial Liver Support in Chongqing on which this paper is based, I was specifically asked to address the question of whether albumin dialysis, as in the Molecular Adsorbents Recirculating System (MARS) did correct known abnormalities of the disturbed pathophysiology in liver failure. Before doing this

关键词： albumin dialysis

Transplantation of primary and reversibly immortalized human liver cells and other gene therapies in acute liver failure and decompensated chronic liver disease

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World Journal of Gastroenterology 2000年第5期6卷 636-642页

作者： Stephen M.Riordan roger Williams Institute of Hepatology University College London and University College London HospitalsLondonEngland Department of GastroenterologyThe Prince of Wales HospitalSydneyAustralia Institute of Hepatology University College London and University College London HospitalsLondonEngland

Studies performed in experimental small animalswith hepatic-based metabolic disorders but nostructural liver disease,including Gunn andanalbuminaemic rats and rabbits with inherited low-density lipoprotein receptor deficiency,have shownthat up to 95% of hepatocytes transplanted into thespleen or liver remain in these sites,withimprovement in metabolic function

关键词： liver failure acute liver diseases liver transplantation gene therapy animals laboratory transfering growth factor beta

A Variational Finite Element Model for Large-Eddy Simulations of Turbulent Flows

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Chinese Annals of Mathematics,Series B 2013年第5期34卷 667-682页

作者： Toma's Chac'on REBOLLO roger LEWANDOWSKI Dpto. EDAN & IMUS Universidad de SevillaC/Tarfias/n. 41012 SevillaSpain BCAM-Basque Center for Applied Mathematics AvdaMazarredo14. 48009 BilbaoSpain. Mathematical Research Institute of Rennes UMR CNRS 6625University of Rennes 1 & Fluminance teamINRIABat 22Campus Beaulieu35042 Rennes cedexFrance.

The authors introduce a new Large Eddy Simulation model in a channel, based on the projection on finite element spaces as filtering operation in its variationM form, for a given triangulation （Th）h〉0. The eddy viscosity is expressed in terms of the friction velocity in the boundary layer due to the wall, and is of a standard sub grid-model form outside the boundary layer. The mixing length scale is locally equal to the grid size. The computational domain is the channel without the linear sub-layer of the boundary layer. The no-slip boundary condition （or BC for short） is replaced by a Navier （BC） at the computational wall. Considering the steady state case, the authors show that the variational finite element model they have introduced, has a solution （Vh,Ph）h〉O that converges to a solution of the steady state Navier-Stokes equation with Navier BC.

关键词： Navier-Stokes equations Turbulence modeling Finite elements

Synthetic Channel-forming Peptides and Ion Selectivity

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Chemical Research in Chinese Universities 2006年第2期22卷 265-266页

作者： roger W. Roeske Department of Biochemistry and Molecular Biology School of Medicine Indiana University Indianapolis IN 46-202 USA

Introduction Peptides made up of alternating L- and D- amino acids can form β-helices as in gramicidin A or cyclic peptides that aggregate to form tubes In both cases the structures are hollow with all the side chains projecting outwards. Kennedy et al. postulated that. peptides having the （LLLD）n configuration could form helices with every fourth side chain projecting inward. It is a fact that synthetic N-formyl- （LeuSerLeuGly） 6- OH, when added to a lipid bilayer, dimerizes, to form ion channels having conductances greater than that of gramicidin.

关键词： Cyclic peptide Ion channels Ion selectivity

Time Discrete Approximation of Weak Solutions to Stochastic Equations of Geophysical Fluid Dynamics and Applications(Dedicated to Haim Brézis on the occasion of his 70th birthday)

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Chinese Annals of Mathematics,Series B 2017年第2期38卷 425-472页

作者： Nathan GLATT-HOLTZ roger TEMAM Chuntian WANG department of mathematics tulane universityLA 70118USA department of mathematics and the institute for scientific computing and applied mathematics indiana universityBloomingtonIN 47405USA department of mathematics university of los angelesCA 90059USA

As a first step towards the numerical analysis of the stochastic primitive equations of the atmosphere and the oceans, the time discretization of these equations by an implicit Euler scheme is studied. From the deterministic point of view, the 3D primitive equations are studied in their full form on a general domain and with physically realistic boundary conditions. From the probabilistic viewpoint, this paper deals with a wide class of nonlinear, state dependent, white noise forcings which may be interpreted in either the Itor the Stratonovich sense. The proof of convergence of the Euler scheme,which is carried out within an abstract framework, covers the equations for the oceans, the atmosphere, the coupled oceanic-atmospheric system as well as other related geophysical equations. The authors obtain the existence of solutions which are weak in both the PDE and probabilistic sense, a result which is new by itself to the best of our knowledge.

关键词： Nonlinear stochastic partial differential equations, Geophysical fluid dy-namics, Primitive equations, Discrete time approximation, Martingalesolutions~ Numerical analysis of stochastic PDEs