Charradi K.,Center de Biotechnologie de la Technopole de Borj-Cedria
Canadian journal of physiology and pharmacology | Year: 2013
Obesity is a public health problem contributing to morbidity and mortality from metabolic syndrome. It has long been recognized that there is a gender dependency in several obesity-related health risks. Using a high fat diet (HFD) to induce obesity in Wistar rats, we studied the gender dependency of fat-induced oxidative stress in the heart and liver, with a special emphasis on the distribution of transition metals, as well as the protective effects of grape seed and skin extract (GSSE). HFD induced obesity in both male and female rats, characterized by increased body weight as well as relative liver mass in both genders, and increased relative heart mass in the males only. HFD also provoked the accumulation of triglycerides and total cholesterol into the male hearts, and into the livers of both genders. HFD induced oxidative stress in the male hearts and also in the livers of both genders. Furthermore, HFD affected cardiac levels of copper in the males, and hepatic levels of copper and zinc in both genders, whereas HFD affected free iron in the male hearts and female livers, specifically. In conclusion, HFD treatment altered transition metal homeostasis more drastically in the male heart than in the female liver, and GSSE efficiently protected these organs against fat-induced disturbances, regardless of gender.
Gammoudi S.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Frini-Srasra N.,Tunis el Manar University |
Srasra E.,Center de Biotechnologie de la Technopole de Borj-Cedria
Applied Clay Science | Year: 2012
Organically modified clays ('organo-clays') have attracted a great deal of interest because of their wide applications in industry and environmental protection. The objective of this study was to synthesize organo-clays using Tunisian smectite saturated with Na+, Ca2+ and Zn2+ ions and the cationic surfactant hexadecyltrimethylammonium bromide (HDTMAB). The effects of initial concentration (0.1-3.0 CEC), contact time (0.5-48h) and temperature (293-333K) were studied. The changes in the surfaces and structures of the smectites modified with HDTMA surfactant were characterized using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR).For all clays, the adsorbed HDTMA increased with increasing initial concentration; at high surfactant concentrations, Zn-exchanged clay displayed a high affinity for HDTMA surfactant suggesting that adsorption could be described by a different process. The kinetic adsorption data were modeled using pseudo-first-order and pseudo-second-order equations. It was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. The enthalpy (δ°H) and entropy (δ°S) of adsorption were calculated from the slope and intercept of the linear plot of Log Kd against 1/T. Calculations on the thermodynamics of adsorption showed that principal contribution to the negative value of δ°G (-14 to 14kJ·mol-1), is the large positive value of δ°S (0.06-0.07kJ·mol-1·K-1), whereas δ°H is positive ranging between 4 and 7kJ·mol-1. It follows that adsorption of HDTMA onto smectite was feasible, spontaneous and endothermic process. Different configurations of surfactants within smectite interlayer were proposed based on the d(001) basal spacings which increased with surfactant loading. The presence of symmetrical and asymmetrical vibration bands of the CH2 group in the IR spectrum of the modified clays and the variation of their frequencies and their intensities confirmed the results obtained by XRD. © 2011.
Djebali N.,Center de Biotechnologie de la Technopole de Borj-Cedria
Phytopathologia Mediterranea | Year: 2013
Aggressiveness of 14 Phoma medicaginis isolates obtained from Medicago truncatula (barrel medic) and M. ciliaris (ciliate medic) growing in Tunisia was measured after inoculation on leaves and roots of M. truncatula. The ability of one isolate to cause disease on M. sativa (alfalfa), Cicer arietinum (chickpea), Pisum sativum (pea), Lens culinaris (lentil) and Phaseolus vulgaris (common bean) was also tested. The pathogen caused dark lesions that enlarged and coalesced causing yellowing and premature abscission of leaves, resulting in decreased shoot fresh weight in barrel medic plants. All P. medicaginis isolates infected barrel medic roots causing collar rot, brown root discoloration, yellowing of cotyledons and reduced shoot and root development. The pathogen colonized the cortex and the stele of plants and produced fertile pycnidia on infected roots. Symptoms on leaves allowed for greater discrimination in aggressiveness among isolates in comparison to symptoms on roots. No correlations were observed between the parameters measured on leaves and roots suggesting organ specialization in this pathogen. Phoma medicaginis infected leaves of alfalfa, pea, common bean and chickpea causing necrosis and tissue yellowing at 15 d post inoculation (dpi). Pycnidium production was observed on dead and dying foliar tissues of alfalfa, pea and common bean, but not on chickpea. The pathogen caused symptoms of collar rot and brown root discoloration on alfalfa, chickpea, pea and common bean, but did not cause symptoms on leaves or roots of lentil at 15 dpi. Phoma medicaginis was more pathogenic on barrel medic, the host of origin, in comparison to the other legumes, suggesting that these species are likely to be secondary hosts for this pathogen. © Firenze University Press.
Frini-Srasra N.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Srasra E.,Center de Biotechnologie de la Technopole de Borj-Cedria
Desalination | Year: 2010
The object of this work is to study the modifications of Tunisian palygorskite upon HCl treatment and to investigate the ability of natural and acid treated palygorskite to adsorb heavy metal ions. Chemical analysis, X ray diffraction, infrared spectra, MAS-NMR methods, BET surface and surface charge of HCl treated palygorskite have been reported. It was established that acid leaching at reflux temperature resulted in an increase in the amount of Mg, Fe and Al extracted and in surface area from 59.7 to 437 m2 g- 1 for 2 M HCl samples and from 59.7 to 360 m2 g- 1 for 4 M HCl samples, due to a dissolution of the octahedral sheet and the creation of mesoporosity. 29Si-MAS-NMR studies yield information on changes occurring in the structure of the mineral. During acid treatment the clay structure is progressively transformed into amorphous silica (essentially for samples treated by HCl 4 M for 10 h and HCl 2 M for 35 h). Natural palygorskite and the activated samples were applied as adsorbents for the removal of Cd(II) from aqueous solutions. The effects of various experimental parameters were investigated. The adsorption isotherms of activated palygorskites for Cd(II) could be described by the Freundlich model. The acid activated sample showed a higher adsorption capacity for Cd(II) than the natural palygorskite. The retention of Cd(II) ions by palygorskite occurs dominantly by specific adsorption. A different behaviour was observed in the phosphoric acid medium. Despite increases in the surface areas upon acid activation, improvements in the adsorption were not observed, as a result of the decreasing number of negative surface sites, as main centers for specific adsorption. © 2009 Elsevier B.V. All rights reserved.
Hafsi C.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Debez A.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Abdelly C.,Center de Biotechnologie de la Technopole de Borj-Cedria
Acta Physiologiae Plantarum | Year: 2014
Potassium (K+) is an important macronutrient for plant growth and productivity. It fulfills important functions and it is widely included in fertilization management strategies to increase crop production. Although K+ is one of the most abundant elements of the earth crust, its availability to plants is usually limited leading to severe reduction in plant growth and yield. In plants, K+ shortage induces several responses at different levels: morphological, physiological, biochemical, and molecular. Activation of signaling cascades including reactive oxygen species, phytohormones (ethylene, auxin, and jasmonic acid), Ca2+, and phosphatidic acid is also triggered. In this review, we summarize the main of these adaptive responses evolved by plants to cope with K+ deficiency in the rhizosphere. © 2014 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.
Ben Rejeb K.,University Pierre and Marie Curie |
Ben Rejeb K.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Abdelly C.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Savoure A.,University Pierre and Marie Curie
Plant Physiology and Biochemistry | Year: 2014
Reactive oxygen species (ROS) are continuously generated as a consequence of plant metabolic processes due to incomplete reduction of O2. Previously considered to be only toxic by-products of metabolism, ROS are now known to act as second messengers in intracellular signalling cascades to trigger tolerance of various abiotic and biotic stresses. The accumulation of proline is frequently observed during the exposure of plants to adverse environmental conditions. Interestingly proline metabolism may also contribute to ROS formation in mitochondria, which play notably a role in hypersensitive response in plants, life-span extension in worms and tumor suppression in animals. Here we review current knowledge about the regulation of proline metabolism in response to environmental constraints and highlight the key role of ROS in the regulation of this metabolism. The impact of proline on ROS generation is also investigated. Deciphering and integrating these relationships at the whole plant level will bring new perspectives on how plants adapt to environmental stresses. © 2014.
Garbout A.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Ben Taazayet-Belgacem I.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Ferid M.,Center de Biotechnologie de la Technopole de Borj-Cedria
Journal of Alloys and Compounds | Year: 2013
We report the synthesis and structural study of mixed oxides in LnEuTi 2O7 series. We are presently investigating new phases with Ln = Gd and Dy, including the pyrochlore family Re2Ti 2O7 (Re = Eu, Gd and Dy). Starting from stoichiometric mixtures of elemental oxides TiO2, Eu2O3 and Ln2O3 (Ln = Gd and Dy), single-phase samples were obtained using a conventional ceramic method. The presence of crystalline phases after heat treatment from 1000 to 1200 C was studied by combining XRD and Raman spectroscopy. X-ray diffraction combined to the Raman analysis confirmed the powder's single-phase nature at 1200 C. The expected compositions GdEuTi 2O7 and DyEuTi2O7 were confirmed by energy dispersive spectroscopy (EDAX) and X-ray diffraction (XRD). FT-IR spectra of the obtained compounds also show the absorption bands corresponding to the pyrochlore structure A2B2O7 and give information about the distribution of ions between the A and B sites. X-ray powder diffraction results showed that the resulting phases GdEuTi 2O7 and DyEuTi2O7 crystallize with the pyrochlore type structure, cubic Fd3m space group. The structures are determined by Rietveld refinement. The evolution of cell parameters and interatomic distances as a function of lanthanide cation size is discussed. The refined cell parameter a, and the positional coordinate, x, for O, determinated from Rietveld refinements, were related to the Ln3+ ions (Ln 3+ = Gd3+, Dy3+) occupying the Re site. © 2013 Elsevier B.V. All rights reserved.
Agency: European Commission | Branch: FP7 | Program: CSA-CA | Phase: KBBE.2010.4-04 | Award Amount: 1.15M | Year: 2011
The main objective of BIO CIRCLE 2 is to foster the knowledge base about FP7 FAFB & the networking capacities of Third Country researchers in order to reinforce their participation in FP7 projects. 3 project goals are distinguished: 1.Disseminate information effectively to Third Country researchers; 2.Organise information days and training for Third Country researchers; 3.Provide Third Country researchers with efficient networking opportunities. 5 European plus 16 Third Country partners (International Cooperation Partner Countries ICPC and Industrialised Countries) will all be involved in the activities. Apart from Kazakhstan and Thailand all involved countries (and the African continent represented by FARA) have signed a bilateral S&T agreement with the EU. The expected impacts are supported by various activities: Enhanced awareness of the Third Country researchers on the FP7 FAFB: WP2 will develop the regional strategies for the Third Country partners. Increased Third Country researchers participation in EU projects: WP3 will organise at least 2 trainings for Third Country researchers at national and regional level, 3 trainings of Third Country BIO NCPs and the organisation of 1 Regional Event per World Region. Strengthened collaborations with Third Countries signatories of bilateral S&T agreements with the EU: WP4 will implement networking activities for Third Country researchers, including brokerage events and working visits of Third Country researchers to EU research institutes and vice versa. Finally WP5 on dissemination activities will increase the awareness of European researchers about the international cooperation in FP7 FAFB. The impact of the activities will be further maximised by: 1.involving other countries that are not partners through a regional approach; 2.linking the BIO CIRCLE 2 activities to the activities of related INCO projects; 3.involving industrialised countries that are global S&T leaders in FAFB related research.
Center de Biotechnologie de la Technopole de Borj-Cedria and University of Tsukuba | Date: 2012-11-26
Obesity is one of the major health concerns in the Twenty-First Century and is one of the leading causes of preventable death. It is a strong risk factor for Type 2 Diabetes. Disclosed herein are compositions and methods using Nitraria retusa extracts for enhancing energy metabolism, inhibiting fat accumulation, inhibiting preadipocyte differentiation, reducing diabetic hypercholesterolemia, and for treating or ameliorating obesity.
Agency: European Commission | Branch: FP7 | Program: CSA-SA | Phase: KBBE-2008-4-01 | Award Amount: 1.64M | Year: 2008
BIO CIRCLE will extend the network of National Contact Points for the FP7 theme Food, Agriculture and Fisheries and Biotechnology (BIO NCP) to National Information Points (NIP) from Third Countries over a two year period. The European Commission needs to implement the bilateral Scientific & Technological Agreements signed with Third Countries (TC), for increasing their participation in FAFB FP7 and strengthening the collaboration between European and TC researchers. The main focus of the project will be on identifying, sharing and implementing good practices between NCPs and NIPs. The expected results of BIO CIRCLE are: 1. Capacities built for Third Country BIO NIPs (through SWOT analysis, training of NIPs and twinning); 2. Strengthened consortium building in FAFB international cooperation projects (through mapping of Third Country research potential and the organisation of 2 international Brokerage Events); 3. Capacities built for Third Country Researchers to participate in FP7 (through preparation of specific training materials, training and networking with EU researchers); 4. Strengthened identification, development and sharing of Good Practices to enhance cooperation between the NCP and NIP networks (through 5 Regional Benchmarking Workshops, a Common Benchmarking Workshop and the design of a Good Practices Guide). The 6% of budget is foreseen to grant researchers from TCs to attend the 2 International Brokerage Events. The 5 BIO NCP partners of BIO CIRCLE led by APRE will assure the successful implementation of the project. The 18 NIPs partners of BIO CIRCLE will be embraced in this circle of activities aimed at ensuring quality and dynamism in implementing the Scientific & Technological Agreements between the EU and Third Countries. BIO CIRCLE will work in synergy with and be closely linked to the BIO-NET project, the complete NCP FAFB network.