43 results on '"Ben Khalifa, M."'
Search Results
2. Rotational excitation of interstellar benzonitrile by helium atoms.
- Author
-
Ben Khalifa, M and Loreau, J
- Subjects
- *
BENZONITRILE , *INTERSTELLAR molecules , *POTENTIAL energy surfaces , *POLAR molecules , *MOLECULAR clouds , *HELIUM atom - Abstract
Interstellar aromatic molecules such as polycyclic aromatic hydrocarbons and polycyclic nitrogen and oxygen bearing molecules are thought to be abundant in the interstellar medium (ISM). In this class of molecules, benzonitrile (c-C6H5CN) plays an important role as a proxy for benzene. It has been detected through rotational emission in several astrophysical sources and is one of the simplest N-bearing polar aromatic molecules. Even in the cold ISM, the population of the rotational levels of benzonitrile might not be at equilibrium. Consequently, modelling its detected emission lines requires a prior computation of its quenching rate coefficients by the most abundant species in the ISM (He or H2). In this paper, we focus on the excitation of c-C6H5CN by collision with He. We compute the first potential energy surface (PES) using the explicitly correlated coupled cluster method in conjunction with large basis sets. The PES obtained is characterized by a potential well depth of −97.2 cm−1 and an important anisotropy. Scattering computations of the rotational (de-)excitation of c-C6H5CN by He atoms are performed by means of the coupled states approximation that allow to obtain collisional rates for rotational states up to j = 9 and temperatures up to 40 K. These rate coefficients are then used to examine the effect of C6H5CN excitation induced by collisions with para-H2 in molecular clouds by carrying out simple radiative transfer calculations of the excitation temperatures and show that non-equilibrium effects can be expected for H2 densities up to 105–106 cm−3. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Collisional excitation of methyl (iso)cyanide by He atoms: rate coefficients and isomerism effects.
- Author
-
Ben Khalifa, M, Dagdigian, P J, and Loreau, J
- Subjects
- *
COLLISIONAL excitation , *ISOMERISM , *ACETONITRILE , *MOLECULAR clouds , *INTERSTELLAR medium - Abstract
Among all closed-shell species observed in molecular clouds, molecules with C3 v symmetry play a crucial role, as their rotational spectroscopy allows them to behave as a gas thermometer. In the interstellar medium, methyl cyanide (CH3CN) is the second most abundant of those (after ammonia, NH3). Its isomer, methyl isocyanide (CH3NC), is less abundant but has been detected in many astrophysical sources. In order to assess their absolute and relative abundances, it is essential to understand their collisional excitation properties. This paper reports the calculation of rate coefficients for rotational excitation of CH3CN and CH3NC molecules with He atoms, from low (5 K) to moderate (100 K) temperatures. We include the first 74 and 66 rotational states of both para and ortho symmetries of CH3CN and CH3NC, respectively. A propensity for Δ j = 2 transitions is observed in the case of CH3CN-He collisions, whereas in the case of CH3NC-He a propensity for Δ j = 1 is observed for transitions involving low values of j and at low temperatures, a propensity for Δ j = 2 is observed for higher values of j and at high temperatures. A comparison of rate coefficients shows differences up to a factor of 3, depending on temperature and on the ortho / para symmetries for dominant transitions. This confirms the importance of having specific collisional data for each isomer. We also examined the effect of these new rates on the CH3CN and CH3NC excitation in molecular clouds by performing radiative transfer calculations of the excitation and brightness temperatures for several detected lines. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Tunisian Potato virus Y isolates with unnecessary pathogenicity towards pepper: support for the matching allele model in eIF4E resistance–potyvirus interactions
- Author
-
Ben Khalifa, M., Simon, V., Fakhfakh, H., and Moury, B.
- Published
- 2012
- Full Text
- View/download PDF
5. Contribution of host plant resistance and geographic distance to the structure of Potato virus Y (PVY) populations in pepper in northern Tunisia
- Author
-
Ben Khalifa, M., Simon, V., Marrakchi, M., Fakhfakh, H., and Moury, B.
- Published
- 2009
- Full Text
- View/download PDF
6. Opposing influence of hole blocking layer and a doped transport layer on the performance of heterostructure OLEDs
- Author
-
Ben Khalifa, M, Vaufrey, D, and Tardy, J
- Published
- 2004
- Full Text
- View/download PDF
7. Fine and hyperfine excitation of nitric oxide by collision with para-H2 at low temperature.
- Author
-
Ben Khalifa, M and Loreau, J
- Subjects
- *
NITRIC oxide , *LOCAL thermodynamic equilibrium , *LOW temperatures , *QUANTUM scattering , *RADIATIVE transfer , *ULTRAMICROELECTRODES - Abstract
Nitric oxide is an open-shell molecule abundantly detected in the interstellar medium. A precise modelling of its radiative and collisional processes opens the path to a precise estimate of its abundance. We present here the first rate coefficients for fine and hyperfine (de-)excitation of NO by collisions with the most ubiquitous collision partner in the interstellar medium, para -H2 hydrogen molecules, using a recently developed accurate interaction potential. We report quantum scattering calculations for transitions involving the first 74 fine levels and the corresponding 442 hyperfine levels belonging to both F 1 and F 2 spin–orbit manifolds. To do so, we have calculated cross-sections by means of the quantum mechanical close-coupling approach up to 1000 cm−1 of total energy and rate coefficients from 5 to 100 K. Propensity rules are discussed and the new NO–H2 rates are compared to those available in the literature, based on scaled NO–He rates. Large differences are observed between the two sets of rate coefficients, and this comparison shows that the new collision rates must be used in interpreting NO emission lines. We also examined the effect of these new rates on the NO excitation in cold clouds by performing radiative transfer calculations of the excitation and brightness temperatures for the two NO lines at 150.176 and 250.4368 GHz. This shows that the local thermodynamic equilibrium is not fulfilled for this species for typical conditions. We expect the use of the rates presented in this study to improve the constraints on the abundance of NO. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
8. Rotational (de)-excitation of C5 by collision with He at low temperature.
- Author
-
Chefai, A., Ben Khalifa, M., Khadri, F., and Hammami, K.
- Abstract
An appropriate estimation of the abundance of the observed C
5 radical in the interstellar medium requires accurate radiative and collisional rate coefficients. We present the first two-dimensional potential energy surface (2D-PES) for the ground electronic state of the C5 (X1 Σ+ )–He(X1 S) van der Waals system, obtained using an explicitly correlated coupled-cluster method with single, double, and perturbative triple excitations (RCCSD(T)-F12). This PES is subsequently used in quantum close-coupling (CC) scattering calculations. Collisional excitation cross-sections of the rotational levels of C5 by He were calculated for energies up to 1500 cm−1 using the standard (CC) method. The thermal dependence of the corresponding rate coefficients is given for the low and moderate temperature T ≤ 300 K regime of interstellar molecular clouds. This is the first study on the collisional rate coefficients for this system and may have important implications for the astrophysical detection of C5 (X1 Σ+ ) and modeling of carbon-rich media. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
9. Reactive ion etching of sol–gel-processed SnO 2 transparent conducting oxide as a new material for organic light emitting diodes
- Author
-
Vaufrey, D, Ben Khalifa, M, Besland, M.P, Sandu, C, Blanchin, M.G, Teodorescu, V, Roger, J.A, and Tardy, J
- Published
- 2002
- Full Text
- View/download PDF
10. Rotational de-excitation of tricarbon monosulfide (C3S) in collision with (He): potential energy surface and rates.
- Author
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Sahnoun, E., Ben Khalifa, M., Khadri, F., and Hammami, K.
- Abstract
Despite that the tricarbon monosulfide (C3S) is among the first sulfur-containing carbon-chain molecules to be detected in the interstellar medium, no studies focused on the determination of its collisional rates. These rate coefficients are essential to estimate the abundance of C3S in the interstellar medium. Computations of the C3S( Σ + 1 ) downward rate coefficients, induced by collision with He, are performed by averaging the integral cross sections at low temperature (below 25 K ). Calculations of the cross sections in the close-coupling quantum time independent formalism for E c ≤ 110 cm − 1 and J ≤ 10 are based on a new 2-D potential energy surface. This PES is obtained from the explicit correlated coupled cluster with a single, double and perturbative triple excitation [ccsd(t)-f12] ab initio approach and the aug-cc-pVTZ basis sets. The PES have a global minimum of − 55.69 cm − 1 located at R = 6.25 bohr and θ = 94 ∘ , and a second minimum of − 36.95 cm − 1 at R = 9.35 bohr and θ = 0 ∘ . A comparison of C3S rates with those of the isoelectronic molecule C3O was made. The results indicate a great temperature dependence of the rates for transitions of Δ J > 2 . We expect that the new collisional data will allow for accurate determination of the C3S abundance in several interstellar regions. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
11. Rotational quenching of an interstellar gas thermometer: CH3CN⋯He collisions.
- Author
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Ben Khalifa, M., Quintas-Sánchez, E., Dawes, R., Hammami, K., and Wiesenfeld, L.
- Abstract
Among all the molecular species found in the interstellar medium, molecules with threefold symmetry axes play a special role, as their rotational spectroscopy allows them to act as practical gas thermometers. Methyl-cyanide (CH
3 CN) is the second most abundant of those (after ammonia). We compute in this paper the collisional dynamics of methyl-cyanide in collision with helium, for both the A- and the E-symmetries of CH3 CN. The potential energy surface is determined using the CCSD(T)-F12b formalism and fit with convenient analytic functions. We compute the rotationally inelastic cross sections for all levels up to 510 cm−1 of collision energy, employing at low energy exact Coupled Channels methods, and at higher energies, approximate Coupled States methods. For temperatures from 7 K up to 300 K, rates of quenching are computed and most are found to differ from those reported earlier (up to a factor of a thousand), calling for a possible reexamination of the temperatures assigned to low density gasses. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
12. Interaction of the simple carbene c-C3H2 with H2: potential energy surface and low-energy scattering.
- Author
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Ben Khalifa, M., Wiesenfeld, L., and Hammami, K.
- Abstract
Cyclopropenylidene, c-C
3 H2 , is a simple hydrocarbon, ubiquitous in astrophysical gases, and possessing a permanent electric dipole moment. Its readily observed rotational transitions make it an excellent probe for the physics and history of interstellar matter. The collisional properties of c-C3 H2 with the main background gas, H2 , are computed here. We present a full 5-D Potential Energy Surface in the rigid molecule approach, and fit it to relevant functionals for subsequent scattering. We perform low-energy quantum scattering at energies less than 50 cm−1 . We use both ortho and para H2 as projectiles. We determine the quality of the various approximations to exact coupled channel scattering and examine paths to go towards higher energy scattering relevant for astrophysics. We compare the results obtained here with earlier ones for scattering with helium. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
13. Rotational (de)-excitation of cyclic and linear C3H2 by collision with He.
- Author
-
Ben Khalifa, M., Sahnoun, E., Wiesenfeld, L., Khadri, F., Hammami, K., Dulieu, O., Spezzano, S., and Caselli, P.
- Abstract
Among the closed-shell hydrocarbons, the carbenes c- and l-C
3 H2 are the lightest ones to display a permanent electric dipole moment and be detectable by rotational spectroscopy. The cyclic form, cyclopropenylidene, is ubiquitous in the InterStellar Matter (ISM) of the Milky Way and external galaxies. As such, it serves as a marker to help in characterizing the physical conditions of the ISM. The linear form, propadienylidene, is less abundant. In order to get access to their absolute and relative abundances, it is essential to understand their collisional excitation/quenching schemes. We compute here a precise ab initio potential energy surface for the interaction of c- and l-C3 H2 with helium, by means of a CCSD(T)-F12a formalism and a fit onto relevant spherical harmonics functions. We conduct quantum dynamical scattering in order to get precise cross sections using a coupled-channel approach for solving the nuclear motion. We average sections to have rates for rotational quenching from 5 to 150 K. We show that these new rates are vastly different, up to more than an order of magnitude, from the older rates presented in the literature, computed with angular momentum algebra only. We expect large differences in the astrophysical analyses of C3 H2 , including the chemical history of those ubiquitous carbenes. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
14. CANDIDATUS PHYTOPLASMA PYRI INFECTIONS IN PEAR ORCHARDS IN TUNISIA.
- Author
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Ben Khalifa, M., Marrakchi, M., and Fakhfakh, H.
- Published
- 2007
15. Reactive ion etching of sol–gel-processed SnO2 transparent conducting oxide as a new material for organic light emitting diodes
- Author
-
Vaufrey, D., Ben Khalifa, M., Besland, M.P., Sandu, C., Blanchin, M.G., Teodorescu, V., Roger, J.A., and Tardy, J.
- Subjects
- *
OXIDES , *ANODES , *LIGHT emitting diodes - Abstract
This paper reports on the potentialities of sol–gel-deposited Sb-doped SnO2 (TO) as a new transparent conducting oxide (TCO) for anode in organic light emitting diodes (OLED). Multilayered films with transparency over 85% and resistivity lower than
5×10−3 Ω cm were obtained. The films are nano-crystallized and the surface roughness does not exceed 20 A˚. TO films are very stable and cannot be chemically etched. Anode patterning by reactive ion etching in a methane–hydrogen plasma is described. Typical etching around 250 A˚/min were obtained. TO/PEDOT/PVK/Al hole only diodes were realized to assess the TO material as hole injection electrode. Devices with threshold voltages of 6 V were obtained. A comparison with indium tin oxide deposited by low temperature cathodic sputtering is given. [Copyright &y& Elsevier]- Published
- 2002
- Full Text
- View/download PDF
16. “Physiologic” (hyaluronic acid-carried) ICSI results in the same embryo quality and pregnancy rates as with the use of potentially toxic polyvinylpyrrolidone (PVP)
- Author
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Menezo, Y., Junca, A.-M., Dumont, M., De Mouzon, J., Cohen-Bacrie, P., and Ben Khalifa, M.
- Published
- 2010
- Full Text
- View/download PDF
17. Impact of sperm concentration on chromatin decondensation
- Author
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Menezo, Y., Belloc, S., de Mouzon, J., Cohen-Bacrie, M., Ben Khalifa, M., and Cohen-Bacrie, P.
- Published
- 2009
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- View/download PDF
18. Very Long Operational Lifetime at High Initial Luminance of Deep Red Phosphorescent Organic Light-Emitting Diodes With Double Emission Layers.
- Author
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Maiorano, V., Mazzeo, M., Mariano, F., Ben Khalifa, M., Carallo, S., Dussert-Vidalet, B., Cingolani, R., and Gigli, G.
- Abstract
We report a double emission layer structure, incorporating a double phosphorescent ldquoguest/host systemrdquo of tris (1-Phenylisoquinoline) iridium (III) (Ir(piq)3) 15wt% doped into two different host molecules, 4,4'-bis[N-(1-napthyl)-N-phenyl-amino] biphenyl (NPB) and bis-(2-methyl-8-quinolinolato)-4-(phenyl-phenolato) aluminum-(III) (BAlq). The proposed configuration reduces the efficiency rolloff, providing high stability at high operating luminance. A maximum current efficiency of 9.5 cd/A, at a driving voltage of 3 V, and a remarkably long device lifetime of more than 2500 h at a starting luminance of 6000 cd/m2 have been measured. [ABSTRACT FROM PUBLISHER]
- Published
- 2008
- Full Text
- View/download PDF
19. 500 - Agreement among the three metabolic syndrome definitions and their performance in the prediction of acute coronary syndrome.
- Author
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Allal-Elasmi, M., Zidi, W., Zayani, Y., Ben Khalifa, M., Sanhaji, H., Hammami, M.B., Jemaa, R., Hadjtaieb, S., Feki, M., Mebazaa, A., and Kaabachi, N.
- Published
- 2017
- Full Text
- View/download PDF
20. Molecular Characterization of Bemisia tabaci Populations in Tunisia: Genetic Structure and Evidence for Multiple Acquisition of Secondary Symbionts
- Author
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Gorsane, F., Ben Halima, A., Ben Khalifa, M., Bel-Kadhi, M. S., and Fakhfakh, H.
- Published
- 2011
- Full Text
- View/download PDF
21. Spontaneous transomental hernia: a case report of a rare internal hernia with a challenging diagnosis.
- Author
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Ben Khalifa M, Ghannouchi M, Sarraj A, Aouadi S, Maatouk M, and Boudokhane M
- Abstract
Introduction and Importance: Transomental hernia (TOH) is an extremely rare clinical condition that represents 1-4% of all internal hernias. Spontaneous TOH occurs in patients with no history of surgery or previous abdominal trauma. It happens after protrusion of the abdominal viscera, commonly the small bowel loops through a defect on the great omentum., Presentation of the Case: We present a case of occlusion due to TOH in a 66-year-old man who underwent a laparotomy, and operative exploration showed 10 cm of small bowel incarcerated through a defect in the right side of the greater omentum of 4 cm in diameter., Discussion: The diagnosis is usually delayed because symptoms are nonspecific. Postoperative morbidity and mortality are important because patients present most frequently with gangrenous bowel, making morbidity and mortality higher. Therefore, it constitutes a critical surgical emergency and must be quickly recognized and managed. Computed tomography (CT) scan plays a prominent role in diagnosis. Midline laparotomy is the main emergency approach for patients with unknown bowel obstruction. Some authors suggest a laparoscopic approach, but it requires a surgeon's experience and propitious patient's conditions., Conclusion: TOH is the rarest type of internal hernia with extremely difficult preoperative diagnosis due to nonspecific semiology. This type of hernia has the highest morbidity and mortality rates of all internal hernias. Thus, it must be suspected whenever there is bowel obstruction of unknown origin and quickly managed., Competing Interests: The authors declare no conflicts of interest.Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)
- Published
- 2024
- Full Text
- View/download PDF
22. Collisional excitation of propargylimine by helium: new ab initio 3D-potential energy surfaces and scattering calculations.
- Author
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Tebai Y, Ben Khalifa M, Khadri F, and Hammami K
- Abstract
We present quantum coupled-state calculations for the rotational excitation of interstellar propargylimine due to collisions with helium. The calculations are based on new high-accurate three-dimensional potential energy surfaces (3D-PESs) adapted for rigid-rotor scattering computations. The two PESs ( Z / E -PGIM-He) were determined using the explicitly correlated coupled-cluster approach with single, double and perturbative triple excitation [CCSCD(T)-F12] and the standard aug-cc-pVTZ basis set. These PESs present many minima with a global minimum of -47.61 cm
-1 for Z -PGIM-He and -54.16 cm-1 for E -PGIM-He. While the PESs for both complexes are qualitatively similar, that of E -PGIM-He is more anisotropic. The state-to-state collisional cross-section calculations are performed for all rotational levels J ≤ 12 with energies below Erot = 30 cm-1 and for total energies up to 500 cm-1 . The corresponding collisional rate coefficients are derived for kinetic temperatures up to 120 K. A propensity rule is seen, for rotational excitation cross sections and de-excitation rate coefficients, that favors even Δ J transitions but with different orders of magnitude. We expect that the retrieved results will contribute to improving atmospheric and astrophysics models.- Published
- 2024
- Full Text
- View/download PDF
23. Intrauterine administration of paternal and maternal peripheral blood mononuclear cells mix as solution for repeated implantation failure.
- Author
-
Elloumi H, Ben Khelifa M, Mnallah S, Khrouf M, Rekik S, Zhioua F, Ben Khalifa M, Braham M, Jemaà M, and Mahmoud K
- Subjects
- Humans, Female, Pregnancy, Male, Adult, Endometrium cytology, Insemination, Artificial methods, Embryo Implantation, Leukocytes, Mononuclear metabolism, Pregnancy Rate, Embryo Transfer methods, Fertilization in Vitro methods
- Abstract
To date, implantation is the rate-limiting step for the success of in vitro fertilization (IVF) treatment. Accumulating evidence suggests that immune cells contribute to embryo implantation, and several therapeutic approaches have been proposed for the treatment of recurrent implantation failure (RIF). Endometrial immune modulation with autologous activated peripheral blood mononuclear cells (PBMCs) is one of the most widely used protocols. However, the effect of intrauterine insemination of mixed paternal and maternal-activated PBMCs has not yet been attempted and studied. The aim of our study is to test the effect of the addition of paternal lymphocytes on the implantation rate in RIF patients. Mononuclear cells were isolated from the peripheral blood of 98 RIF patients and cultured for 72 h before insemination into the endometrial cavity 48 h before embryo transfer. Our patients were divided into 4 groups according to the type and number of PBMCs inseminations. Our study shows that activated PBMCs promoted clinical pregnancy rates (CPR) in all groups. Moreover, we found that the groups injected with more than 2 million cells showed a better clinical outcome and, more interestingly, patients inseminated with both paternal and maternal activated PBMCs showed the highest CPR, reaching 47.2%, in addition to the highest implantation rate 31. 2% and the live birth rate 41.39%. Our work demonstrates the importance of administering a large number of activated PBMCs with the addition of paternal activated PBMCs to immunomodulate the endometrium for the success of in vitro fertilization in RIF patients.
- Published
- 2024
- Full Text
- View/download PDF
24. First close-coupling study of the excitation of a large cyclic molecule: collision of c-C 5 H 6 with He.
- Author
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Demes S, Bop CT, Ben Khalifa M, and Lique F
- Abstract
Recent astronomical observations revealed an increasing molecular complexity in the interstellar medium through the detection of a series of large cyclic carbon species. To correctly interpret these detections, a complex analysis is necessary that takes into account the non-local thermodynamic equilibrium (non-LTE) conditions of the emitting media ( e.g. when energy level populations deviate from a Boltzman distribution). This requires proper state-to-state collisional data for the excitation and de-excitation processes of the molecular levels. Cyclopentadiene (c-C
5 H6 ), which was recently detected in cold interstellar clouds, is extensively studied in many aspects due to its large importance for chemistry in general. At the same time, there are no collisional data available for this species, which are necessary for a more precise interpretation of the corresponding detections. In this work, we first provide an accurate 3D rigid-rotor interaction potential for the [c-C5 H6 + He] complex from high-level of ab initio theories, which has been used to study their inelastic collision by the exact close coupling quantum scattering method. To the best of our knowledge, this is the first study where this method is systematically applied to treat the dynamics of molecular collisions involving more than ten atoms. We also analyse the collisional propensity rules and the differences in contrast to calculations, where the approximate coupled states scattering methods is used.- Published
- 2024
- Full Text
- View/download PDF
25. Interaction of CH 3 CN and CH 3 NC with He: Potential Energy Surfaces and Low-Energy Scattering.
- Author
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Ben Khalifa M, Dagdigian PJ, and Loreau J
- Abstract
Several nitrogen-bearing molecules, such as methyl cyanide (or acetonitrile, CH
3 CN) and methyl isocyanide (CH3 NC) of interest here, have been observed in various astrophysical environments. The accurate modeling of their abundance requires the calculation of rate coefficients for their collisional excitation with species such as He atoms or H2 molecules at low temperatures. In this work we compute new three-dimensional potential energy surfaces for the CH3 NC-He and CH3 CN-He van der Waals complexes by means of the explicitly correlated coupled cluster approach with single, double and perturbative triple excitation CCSD(T)/F12a in conjunction with the aug-cc-pVTZ basis set. We find a global minimum with De = 55.10 and 58.61 cm-1 for CH3 CN-He and CH3 NC-He, respectively, while the dissociation energy D0 of the complexes are 18.64 and 18.65 cm-1 , respectively. Low-energy scattering calculations of pure rotational (de-)excitation of CH3 CN and CH3 NC by collision with He atoms are carried out with the close-coupling method, and the collisional cross sections of ortho - and para -CH3 NC and CH3 CN are computed for kinetic energies up to 100 cm-1 . While the PESs for both complexes are qualitatively similar, that of CH3 NC-He is more anisotropic, leading to different propensity rules for rotational excitation. For CH3 NC-He, we find that |Δ j | = 1 transitions are dominant at low kinetic energy and a propensity rule that favors odd Δ j transitions is observed, whereas for CH3 CN the dominant cross sections are associated with transitions with |Δ j | = 2. We expect that the findings of this study will be beneficial for astrophysical investigations as well as laboratory experiments.- Published
- 2022
- Full Text
- View/download PDF
26. Job Disengagement Among Physical Education Teachers: Insights From a Cross-sectional Web-Based Survey With Path Modeling Analysis.
- Author
-
Chalghaf N, Chen W, Tannoubi A, Guelmami N, Puce L, Ben Said N, Ben Khalifa M, Azaiez F, and Bragazzi NL
- Abstract
Background: Physical education teachers often experience stress and job disengagement., Objective: This study's aims were as follows: (1) to adapt in the Arabic language and test the reliability and the validity of the work-family conflict (WFC) and family-work conflict (FWC) scales, (2) to develop and assess the psychometric properties of work disengagement among physical education teachers, and (3) to evaluate an explanatory model by presenting the mediating role of perceived stress as a major influencing factor in work disengagement and job satisfaction., Methods: A total of 303 primary and secondary school physical education teachers, comprising 165 (54.5%) men and 138 (45.5%) women participated voluntarily in our study. The measuring instruments are the Work Disengagement Scale, the Perceived Stress Scale, the WFC scale, the FWC scale, and the 9-item Teacher of Physical Education Job Satisfaction Inventory., Results: The Arabic language versions of the WFC and FWC scales had reasonably adequate psychometric properties, which were justified by confirmatory factor analyses and by the measurement of reliability, convergent, and discriminant validity through the measurement model using SmartPLS software. Similarly, the structural model established with SmartPLS confirmed strong links of the concepts of FWC, WFC, the job satisfaction questionnaire, and perceived stress with work disengagement among teachers of physical education., Conclusions: There is a growing interest in helping teachers cope with the daily pressures of work and family. A positive organizational context is a context with clear values regarding work priorities, which constitutes the basis of a feeling of shared responsibility and professional support. Good conditions can act as protective factors reducing work stress and positively influencing personal well-being, work attitudes, work commitment, and professional efficiency. Additional research on teachers is needed to examine the relationship between perceived work stress and the role of families, along with the extent to which this association can have a significant impact on teachers' commitment to work., (©Nasr Chalghaf, Wen Chen, Amayra Tannoubi, Noomen Guelmami, Luca Puce, Noureddine Ben Said, Maher Ben Khalifa, Fairouz Azaiez, Nicola Luigi Bragazzi. Originally published in JMIR Formative Research (https://formative.jmir.org), 01.12.2022.)
- Published
- 2022
- Full Text
- View/download PDF
27. Primary cutaneous natural killer/T-cell lymphoma presenting as sacrococcygeal and perianal ulcers.
- Author
-
Ghannem A, Aounallah A, Ghannouchi M, Karim N, Ben Khalifa M, Boudokhan M, Nihed A, Badreddine S, Belajouza C, and Denguezli M
- Subjects
- Humans, Killer Cells, Natural pathology, Ulcer, Epstein-Barr Virus Infections pathology, Lymphoma, T-Cell, Cutaneous diagnosis, Lymphoma, T-Cell, Cutaneous pathology, Skin Neoplasms pathology
- Published
- 2022
- Full Text
- View/download PDF
28. Primary subcutaneous hydatid cyst: An exceptional location.
- Author
-
Ben Khalifa M, Ghannouchi M, Hammouda S, Taboubi W, Omri A, Nacef K, and Boudokhane M
- Abstract
Competing Interests: We declare no financial support or relationships that may pose a conflict of interest.
- Published
- 2022
- Full Text
- View/download PDF
29. Postoperative morbidity risk factors after conservative surgery of hydatic cyst of the liver: a retrospective study of 151 hydatic cysts of the liver.
- Author
-
Ghannouchi M, Rodayna H, Ben Khalifa M, Nacef K, and Boudokhan M
- Subjects
- Adult, Female, Humans, Liver, Male, Morbidity, Retrospective Studies, Risk Factors, Cysts epidemiology, Cysts surgery
- Abstract
Background: The purpose of the present paper is to assess the morbidity specifics risk factors of hepatic hydatid cyst after conservative surgery., Methods: We conducted a retrospective study of 102 patients over a period of 13 years, from 2006 to 2019. We included all patients operated on hydatid cyst of the liver, complicated and uncomplicated, in the Department of General Surgery in Tahar Sfar hospital, Mahdia, Tunisia. We excluded patients who received an exclusive medical treatment and those who have other hydatic cyst localizations., Results: The cohort was composed of 102 patients with a total of 151 cysts operated on using conservative surgery, among them there was 75 women (73.5%) and 27 men (26.5%). The median age was 43, with extremes ranging from 12 to 88 years. The majority of patients (94.1%) were from rural areas. The cysts were uncomplicated in about half of the cases (48%), elsewhere complications such as compression of neighboring organs (25.5%), opening in the bile ducts (16.7%), infection (9.8%), and rupture in the peritoneum (2%) were found. Conservative surgery was the mainstay of treatment with an overall mortality rate of 1.9%. The overall morbidity rate was 22%: 14% specific morbidity and 8% non-specific morbidity. External biliary fistula was the most common postoperative complication (9%). The predictive factors of morbidity in univariate analysis were: preoperative hydatid cyst infection (P = 0.01), Compressive cysts (P = 0.05), preoperative fever and jaundice, (respectively P = 0.03 and P = 0.02), no one achieved statistical significance in the multivariate model., Conclusions: Preoperative hydatid cyst infection, compressive cysts and preoperative fever and jaundice could be predictor factors of morbidity after conservative surgery for liver hydatid cyst. They must be considered in the treatment and the surgical decision for patients with hydatid cyst., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
30. Growth hormone replacement improved oocyte quality in a patient with hypopituitarism: A study of follicular fluid.
- Author
-
Scheffler F, Cabry R, Soyez M, Copin H, Ben Khalifa M, Devaux A, and Desailloud R
- Subjects
- Adult, Female, Fertilization in Vitro methods, Humans, Follicular Fluid metabolism, Hormone Replacement Therapy methods, Human Growth Hormone therapeutic use, Hypopituitarism drug therapy, Oocytes metabolism
- Abstract
Background: Growth hormone (GH) is known to be involved in ovarian folliculogenesis and oocyte maturation. In patients with poor ovarian response without growth hormone deficiency (GHD), adjuvant GH treatment improves in-vitro fertilization (IVF) results. Improvement of oocyte quality in IVF by GH replacement was reported in only a few patients with GHD. We report on a new case with study of follicular fluid., Methods: A 29-year-old patient with hypopituitarism was referred to our infertility center. She was undergoing hormonal replacement for hypogonadotropic hypogonadism and diabetes insipidus, and did not consider at first GH replacement. Four IVF procedures were performed between 2011 and 2014. Growth hormone replacement (somatotropin 1.1mg/day) was initiated before the fourth IVF procedure and unmasked central hypothyroidism; levothyroxine (75mg/day) was introduced. It took 10 months to reach the treatment objectives for insulin-like growth factor 1 (IGF1), free triiodothyronine (fT3) and free thyroxine (fT4). GH, IGF1 and thyroid hormones were measured in the blood and follicular fluid before and after GH and thyroid hormone replacement. Oocyte and embryo quality were also compared., Results: The first 3 IVF procedures were performed without GH replacement. 62% to 100% of mature oocytes presented one or more morphologic abnormalities: diffuse cytoplasmic granularity, large perivitelline space with fragments, fragmentation of the first polar body, ovoid shape, or difficult denudation. Embryo quality was moderate to poor (grade B to D), and no pregnancy was obtained after embryo transfer. After GH replacement, hormones levels increased in follicular fluid: GH [7.68 vs. 1.39 mIU/L], IGF1 [109 vs. <25ng/mL], fT3 [3.7 vs. 2.5pmol/L] and fT4 [1.45 vs. 0.84ng/mL]. Concomitantly, there was dramatic improvement in oocyte quality (no abnormal morphologies) and embryo quality (grade A), allowing an embryo transfer with successful pregnancy., Conclusions: This is the first report illustrating changes in hormonal levels in follicular fluid and the beneficial effect of GH replacement on oocyte and embryo quality during an IVF procedure in a patient with hypopituitarism. These results suggest that GH replacement is beneficial for oocyte quality in patients with GHD., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)
- Published
- 2021
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31. Rotational (de)-excitation of C 5 by collision with He at low temperature.
- Author
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Chefai A, Ben Khalifa M, Khadri F, and Hammami K
- Abstract
An appropriate estimation of the abundance of the observed C
5 radical in the interstellar medium requires accurate radiative and collisional rate coefficients. We present the first two-dimensional potential energy surface (2D-PES) for the ground electronic state of the C5 (X1 Σ+ )-He(X1 S) van der Waals system, obtained using an explicitly correlated coupled-cluster method with single, double, and perturbative triple excitations (RCCSD(T)-F12). This PES is subsequently used in quantum close-coupling (CC) scattering calculations. Collisional excitation cross-sections of the rotational levels of C5 by He were calculated for energies up to 1500 cm-1 using the standard (CC) method. The thermal dependence of the corresponding rate coefficients is given for the low and moderate temperature T ≤ 300 K regime of interstellar molecular clouds. This is the first study on the collisional rate coefficients for this system and may have important implications for the astrophysical detection of C5 (X1 Σ+ ) and modeling of carbon-rich media.- Published
- 2021
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32. Development of the 12-Item Social Media Disinformation Scale and its Association With Social Media Addiction and Mental Health Related to COVID-19 in Tunisia: Survey-Based Pilot Case Study.
- Author
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Guelmami N, Ben Khalifa M, Chalghaf N, Kong JD, Amayra T, Wu J, Azaiez F, and Bragazzi NL
- Abstract
Background: In recent years, online disinformation has increased. Fake news has been spreading about the COVID-19 pandemic. Since January 2020, the culprits and antidotes to disinformation have been digital media and social media., Objective: Our study aimed to develop and test the psychometric properties of the 12-item Social Media Disinformation Scale (SMDS-12), which assesses the consumption, confidence, and sharing of information related to COVID-19 by social media users., Methods: A total of 874 subjects were recruited over two phases: the exploratory phase group had a mean age of 28.39 years (SD 9.32) and the confirmatory phase group had a mean age of 32.84 years (SD 12.72). Participants completed the SMDS-12, the Internet Addiction Test, the COVID-19 Fear Scale, and the 10-item Perceived Stress Scale. The SMDS-12 was initially tested by exploratory factor analysis and was subsequently tested by confirmatory factor analysis., Results: The test supported the three-factor structure. In addition, no items were removed from the measurement scale, with three factors explaining up to 73.72% of the total variance, and the items had a lambda factor loading ranging from 0.73 to 0.85. Subsequently, confirmatory factor analysis confirmed the robustness of the measure by referring to a wide range of goodness-of-fit indices that met the recommended standards. The construct validity of the scale was supported by its convergent and discriminant validity. The reliability of the instrument examined by means of three internal consistency indices, and the corrected item-total correlation, demonstrated that the three dimensions of the instrument were reliable: Cronbach α values were .89, .88, and .88 for the consumption, confidence, and sharing subscales, respectively. The corrected item-total correlation ranged from 0.70 to 0.78. The correlation of the instrument's dimensions with internet addiction and mental health factors showed positive associations., Conclusions: The SMDS-12 can be reliably utilized to measure the credibility of social media disinformation and can be adapted to measure the credibility of disinformation in other contexts., (©Noomen Guelmami, Maher Ben Khalifa, Nasr Chalghaf, Jude Dzevela Kong, Tannoubi Amayra, Jianhong Wu, Fairouz Azaiez, Nicola Luigi Bragazzi. Originally published in JMIR Formative Research (https://formative.jmir.org), 09.06.2021.)
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- 2021
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33. Decline in semen quality of North African men: a retrospective study of 20,958 sperm analyses of men from different North African countries tested in Tunisia over a period of 6 years (2013-2018).
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Bahri H, Ben Khalifa M, Ben Rhouma M, Abidi Z, Abbassi E, Ben Rhouma K, and Benkhalifa M
- Subjects
- Adult, Aged, Humans, Male, Middle Aged, Retrospective Studies, Semen, Sperm Count, Spermatozoa, Tunisia, Young Adult, Infertility, Male, Semen Analysis
- Abstract
Background: According to numerous studies from around the world, semen quality seems to have declined dramatically in recent times. However, the data available on male fertility status and semen quality in North Africa are limited., Aim: To investigate the status of semen quality in North-African men and to understand its variations., Subjects & Methods: 20,958 sperm-analyses (Spermogram - Spermocytogram) of North-African men (19-77 years old) consulting for infertility, performed in a private laboratory of medical analyses (Tunis, Tunisia) over a period of 6 years (2013-2018), were investigated. All patients had at least 1 year of unprotected intercourse with their partners before the test. Statistical analyses were performed using SPSS 22.0 software for windows., Results: Libyan men presented a clear decline in all sperm parameters. A continuous decline in sperm morphology quality was shown in Tunisian and Algerian men. Mauritanian men presented a significant increase in sperm vitality with pseudo-stability in the rest of the sperm parameters during the whole study period., Conclusion: North-African men presented remarkable decreases in their semen quality over the last decade. This data could confirm possible global common-causes that need to be identified in order to limit their negative impact on sperm quality, and consequently on male-fertility.
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- 2021
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34. Rotational quenching of an interstellar gas thermometer: CH 3 CNHe collisions.
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Ben Khalifa M, Quintas-Sánchez E, Dawes R, Hammami K, and Wiesenfeld L
- Abstract
Among all the molecular species found in the interstellar medium, molecules with threefold symmetry axes play a special role, as their rotational spectroscopy allows them to act as practical gas thermometers. Methyl-cyanide (CH3CN) is the second most abundant of those (after ammonia). We compute in this paper the collisional dynamics of methyl-cyanide in collision with helium, for both the A- and the E-symmetries of CH3CN. The potential energy surface is determined using the CCSD(T)-F12b formalism and fit with convenient analytic functions. We compute the rotationally inelastic cross sections for all levels up to 510 cm-1 of collision energy, employing at low energy exact Coupled Channels methods, and at higher energies, approximate Coupled States methods. For temperatures from 7 K up to 300 K, rates of quenching are computed and most are found to differ from those reported earlier (up to a factor of a thousand), calling for a possible reexamination of the temperatures assigned to low density gasses.
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- 2020
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35. Knock-out mutation of eukaryotic initiation factor 4E2 (eIF4E2) confers resistance to pepper veinal mottle virus in tomato.
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Moury B, Lebaron C, Szadkowski M, Ben Khalifa M, Girardot G, Bolou Bi BA, Koné D, Nitiema LW, Fakhfakh H, and Gallois JL
- Subjects
- Capsicum genetics, Capsicum virology, Host-Pathogen Interactions, Loss of Function Mutation, Solanum lycopersicum virology, Multigene Family, Plant Diseases virology, Potyvirus isolation & purification, Viral Load, Disease Resistance genetics, Eukaryotic Initiation Factor-4E genetics, Solanum lycopersicum genetics, Potyvirus pathogenicity
- Abstract
Translation initiation factors 4E (eIF4E) are the main source of resistance to potyvirus. We systematically assessed tomato single and double knock-out (KO) mutants of members of the eIF4E-coding gene family for resistance to Pepper veinal mottle virus (PVMV), a major constraint to tomato production. We show that the KO mutant of eIF4E2 has partial resistance to PVMV isolate IC, with plants harboring weak symptoms and low virus loads at the systemic level. The causal effect of eIF4E2 loss-of-function on resistance was confirmed on a progeny segregating for the KO mutation. The eIF4E2 KO mutant was resistant to six of the eight PVMV isolates tested and no resistance to other potyviruses was observed. This is the first evidence that mutation of eIF4E2 is in itself conferring resistance to a potyvirus and 3D protein modelling suggests that the eIF4E2 gene could be converted into a functional resistance allele., (Copyright © 2019 Elsevier Inc. All rights reserved.)
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- 2020
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36. Male Oxidative Stress Infertility (MOSI): Proposed Terminology and Clinical Practice Guidelines for Management of Idiopathic Male Infertility.
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Agarwal A, Parekh N, Panner Selvam MK, Henkel R, Shah R, Homa ST, Ramasamy R, Ko E, Tremellen K, Esteves S, Majzoub A, Alvarez JG, Gardner DK, Jayasena CN, Ramsay JW, Cho CL, Saleh R, Sakkas D, Hotaling JM, Lundy SD, Vij S, Marmar J, Gosalvez J, Sabanegh E, Park HJ, Zini A, Kavoussi P, Micic S, Smith R, Busetto GM, Bakırcıoğlu ME, Haidl G, Balercia G, Puchalt NG, Ben-Khalifa M, Tadros N, Kirkman-Browne J, Moskovtsev S, Huang X, Borges E, Franken D, Bar-Chama N, Morimoto Y, Tomita K, Srini VS, Ombelet W, Baldi E, Muratori M, Yumura Y, La Vignera S, Kosgi R, Martinez MP, Evenson DP, Zylbersztejn DS, Roque M, Cocuzza M, Vieira M, Ben-Meir A, Orvieto R, Levitas E, Wiser A, Arafa M, Malhotra V, Parekattil SJ, Elbardisi H, Carvalho L, Dada R, Sifer C, Talwar P, Gudeloglu A, Mahmoud AMA, Terras K, Yazbeck C, Nebojsa B, Durairajanayagam D, Mounir A, Kahn LG, Baskaran S, Pai RD, Paoli D, Leisegang K, Moein MR, Malik S, Yaman O, Samanta L, Bayane F, Jindal SK, Kendirci M, Altay B, Perovic D, and Harlev A
- Abstract
Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm's potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause., Competing Interests: None of the authors declares competing financial interests. The authors do not have any potential interest in promoting MiOXSYS., (Copyright © 2019 Korean Society for Sexual Medicine and Andrology.)
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- 2019
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37. Interaction of the simple carbene c-C 3 H 2 with H 2 : potential energy surface and low-energy scattering.
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Ben Khalifa M, Wiesenfeld L, and Hammami K
- Abstract
Cyclopropenylidene, c-C3H2, is a simple hydrocarbon, ubiquitous in astrophysical gases, and possessing a permanent electric dipole moment. Its readily observed rotational transitions make it an excellent probe for the physics and history of interstellar matter. The collisional properties of c-C3H2 with the main background gas, H2, are computed here. We present a full 5-D Potential Energy Surface in the rigid molecule approach, and fit it to relevant functionals for subsequent scattering. We perform low-energy quantum scattering at energies less than 50 cm-1. We use both ortho and para H2 as projectiles. We determine the quality of the various approximations to exact coupled channel scattering and examine paths to go towards higher energy scattering relevant for astrophysics. We compare the results obtained here with earlier ones for scattering with helium.
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- 2019
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38. Rotational (de)-excitation of cyclic and linear C 3 H 2 by collision with He.
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Ben Khalifa M, Sahnoun E, Wiesenfeld L, Khadri F, Hammami K, Dulieu O, Spezzano S, and Caselli P
- Abstract
Among the closed-shell hydrocarbons, the carbenes c- and l-C
3 H2 are the lightest ones to display a permanent electric dipole moment and be detectable by rotational spectroscopy. The cyclic form, cyclopropenylidene, is ubiquitous in the InterStellar Matter (ISM) of the Milky Way and external galaxies. As such, it serves as a marker to help in characterizing the physical conditions of the ISM. The linear form, propadienylidene, is less abundant. In order to get access to their absolute and relative abundances, it is essential to understand their collisional excitation/quenching schemes. We compute here a precise ab initio potential energy surface for the interaction of c- and l-C3 H2 with helium, by means of a CCSD(T)-F12a formalism and a fit onto relevant spherical harmonics functions. We conduct quantum dynamical scattering in order to get precise cross sections using a coupled-channel approach for solving the nuclear motion. We average sections to have rates for rotational quenching from 5 to 150 K. We show that these new rates are vastly different, up to more than an order of magnitude, from the older rates presented in the literature, computed with angular momentum algebra only. We expect large differences in the astrophysical analyses of C3 H2 , including the chemical history of those ubiquitous carbenes.- Published
- 2019
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39. 46th Medical Maghrebian Congress. November 9-10, 2018. Tunis.
- Author
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Alami Aroussi A, Fouad A, Omrane A, Razzak A, Aissa A, Akkad A, Amraoui A, Aouam A, Arfaoui A, Belkouchi A, Ben Chaaben A, Ben Cheikh A, Ben Khélifa A, Ben Mabrouk A, Benhima A, Bezza A, Bezzine A, Bourrahouat A, Chaieb A, Chakib A, Chetoui A, Daoudi A, Ech-Chenbouli A, Gaaliche A, Hassani A, Kassimi A, Khachane A, Labidi A, Lalaoui A, Masrar A, McHachi A, Nakhli A, Ouakaa A, Siati A, Toumi A, Zaouali A, Condé AY, Haggui A, Belaguid A, El Hangouche AJ, Gharbi A, Mahfoudh A, Bouzouita A, Aissaoui A, Ben Hamouda A, Hedhli A, Ammous A, Bahlous A, Ben Halima A, Belhadj A, Bezzine A, Blel A, Brahem A, Banasr A, Meherzi A, Saadi A, Sellami A, Turki A, Ben Miled A, Ben Slama A, Daib A, Zommiti A, Chadly A, Jmaa A, Mtiraoui A, Ksentini A, Methnani A, Zehani A, Kessantini A, Farah A, Mankai A, Mellouli A, Zaouali A, Touil A, Hssine A, Ben Safta A, Derouiche A, Jmal A, Ferjani A, Djobbi A, Dridi A, Aridhi A, Bahdoudi A, Ben Amara A, Benzarti A, Ben Slama AY, Oueslati A, Soltani A, Chadli A, Aloui A, Belghuith Sriha A, Bouden A, Laabidi A, Mensi A, Ouakaa A, Sabbek A, Zribi A, Green A, Ben Nasr A, Azaiez A, Yeades A, Belhaj A, Mediouni A, Sammoud A, Slim A, Amine B, Chelly B, Jatik B, Lmimouni B, Daouahi B, Ben Khelifa B, Louzir B, Dorra A, Dhahri B, Ben Nasrallah C, Chefchaouni C, Konzi C, Loussaief C, Makni C, Dziri C, Bouguerra C, Kays C, Zedini C, Dhouha C, Mohamed C, Aichaouia C, Dhieb C, Fofana D, Gargouri D, Chebil D, Issaoui D, Gouiaa D, Brahim D, Essid D, Jarraya D, Trad D, Ben Hmida E, Sboui E, Ben Brahim E, Baati E, Talbi E, Chaari E, Hammami E, Ghazouani E, Ayari F, Ben Hariz F, Bennaoui F, Chebbi F, Chigr F, Guemira F, Harrar F, Benmoula FZ, Ouali FZ, Maoulainine FMR, Bouden F, Fdhila F, Améziani F, Bouhaouala F, Charfi F, Chermiti Ben Abdallah F, Hammemi F, Jarraya F, Khanchel F, Ourda F, Sellami F, Trabelsi F, Yangui F, Fekih Romdhane F, Mellouli F, Nacef Jomli F, Mghaieth F, Draiss G, Elamine G, Kablouti G, Touzani G, Manzeki GB, Garali G, Drissi G, Besbes G, Abaza H, Azzouz H, Said Latiri H, Rejeb H, Ben Ammar H, Ben Brahim H, Ben Jeddi H, Ben Mahjouba H, Besbes H, Dabbebi H, Douik H, El Haoury H, Elannaz H, Elloumi H, Hachim H, Iraqi H, Kalboussi H, Khadhraoui H, Khouni H, Mamad H, Metjaouel H, Naoui H, Zargouni H, Elmalki HO, Feki H, Haouala H, Jaafoura H, Drissa H, Mizouni H, Kamoun H, Ouerda H, Zaibi H, Chiha H, Kamoun H, Saibi H, Skhiri H, Boussaffa H, Majed H, Blibech H, Daami H, Harzallah H, Rkain H, Ben Massoud H, Jaziri H, Ben Said H, Ayed H, Harrabi H, Chaabouni H, Ladida Debbache H, Harbi H, Yacoub H, Abroug H, Ghali H, Kchir H, Msaad H, Ghali H, Manai H, Riahi H, Bousselmi H, Limem H, Aouina H, Jerraya H, Ben Ayed H, Chahed H, Snéne H, Lahlou Amine I, Nouiser I, Ait Sab I, Chelly I, Elboukhani I, Ghanmi I, Kallala I, Kooli I, Bouasker I, Fetni I, Bachouch I, Bouguecha I, Chaabani I, Gazzeh I, Samaali I, Youssef I, Zemni I, Bachouche I, Youssef I, Bouannene I, Kasraoui I, Laouini I, Mahjoubi I, Maoudoud I, Riahi I, Selmi I, Tka I, Hadj Khalifa I, Mejri I, Béjia I, Bellagha J, Boubaker J, Daghfous J, Dammak J, Hleli J, Ben Amar J, Jedidi J, Marrakchi J, Kaoutar K, Arjouni K, Ben Helel K, Benouhoud K, Rjeb K, Imene K, Samoud K, El Jeri K, Abid K, Chaker K, Abid K, Bouzghaîa K, Kamoun K, Zitouna K, Oughlani K, Lassoued K, Letaif K, Hakim K, Cherif Alami L, Benhmidoune L, Boumhil L, Bouzgarrou L, Dhidah L, Ifrine L, Kallel L, Merzougui L, Errguig L, Mouelhi L, Sahli L, Maoua M, Rejeb M, Ben Rejeb M, Bouchrik M, Bouhoula M, Bourrous M, Bouskraoui M, El Belhadji M, El Belhadji M, Essakhi M, Essid M, Gharbaoui M, Haboub M, Iken M, Krifa M, Lagrine M, Leboyer M, Najimi M, Rahoui M, Sabbah M, Sbihi M, Zouine M, Chefchaouni MC, Gharbi MH, El Fakiri MM, Tagajdid MR, Shimi M, Touaibia M, Jguirim M, Barsaoui M, Belghith M, Ben Jmaa M, Koubaa M, Tbini M, Boughdir M, Ben Salah M, Ben Fraj M, Ben Halima M, Ben Khalifa M, Bousleh M, Limam M, Mabrouk M, Mallouli M, Rebeii M, Ayari M, Belhadj M, Ben Hmida M, Boughattas M, Drissa M, El Ghardallou M, Fejjeri M, Hamza M, Jaidane M, Jrad M, Kacem M, Mersni M, Mjid M, Sabbah M, Serghini M, Triki M, Ben Abbes M, Boussaid M, Gharbi M, Hafi M, Slama M, Trigui M, Taoueb M, Chakroun M, Ben Cheikh M, Chebbi M, Hadj Taieb M, Kacem M, Ben Khelil M, Hammami M, Khalfallah M, Ksiaa M, Mechri M, Mrad M, Sboui M, Bani M, Hajri M, Mellouli M, Allouche M, Mesrati MA, Mseddi MA, Amri M, Bejaoui M, Bellali M, Ben Amor M, Ben Dhieb M, Ben Moussa M, Chebil M, Cherif M, Fourati M, Kahloul M, Khaled M, Machghoul M, Mansour M, Abdesslem MM, Ben Chehida MA, Chaouch MA, Essid MA, Meddeb MA, Gharbi MC, Elleuch MH, Loueslati MH, Sboui MM, Mhiri MN, Kilani MO, Ben Slama MR, Charfi MR, Nakhli MS, Mourali MS, El Asli MS, Lamouchi MT, Cherti M, Khadhraoui M, Bibi M, Hamdoun M, Kassis M, Touzi M, Ben Khaled M, Fekih M, Khemiri M, Ouederni M, Hchicha M, Kassis M, Ben Attia M, Yahyaoui M, Ben Azaiez M, Bousnina M, Ben Jemaa M, Ben Yahia M, Daghfous M, Haj Slimen M, Assidi M, Belhadj N, Ben Mustapha N, El Idrissislitine N, Hikki N, Kchir N, Mars N, Meddeb N, Ouni N, Rada N, Rezg N, Trabelsi N, Bouafia N, Haloui N, Benfenatki N, Bergaoui N, Yomn N, Ben Mustapha N, Maamouri N, Mehiri N, Siala N, Beltaief N, Aridhi N, Sidaoui N, Walid N, Mechergui N, Mnif N, Ben Chekaya N, Bellil N, Dhouib N, Achour N, Kaabar N, Mrizak N, Mnif N, Chaouech N, Hasni N, Issaoui N, Ati N, Balloumi N, Haj Salem N, Ladhari N, Akif N, Liani N, Hajji N, Trad N, Elleuch N, Marzouki NEH, Larbi N, M'barek N, Rebai N, Bibani N, Ben Salah N, Belmaachi O, Elmaalel O, Jlassi O, Mihoub O, Ben Zaid O, Bouallègue O, Bousnina O, Bouyahia O, El Maalel O, Fendri O, Azzabi O, Borgi O, Ghdes O, Ben Rejeb O, Rachid R, Abi R, Bahiri R, Boulma R, Elkhayat R, Habbal R, Rachid R, Tamouza R, Jomli R, Ben Abdallah R, Smaoui R, Debbeche R, Fakhfakh R, El Kamel R, Gargouri R, Jouini R, Nouira R, Fessi R, Bannour R, Ben Rabeh R, Kacem R, Khmakhem R, Ben Younes R, Karray R, Cheikh R, Ben Malek R, Ben Slama R, Kouki R, Baati R, Bechraoui R, Fakhfakh R, Fradi R, Lahiani R, Ridha R, Zainine R, Kallel R, Rostom S, Ben Abdallah S, Ben Hammamia S, Benchérifa S, Benkirane S, Chatti S, El Guedri S, El Oussaoui S, Elkochri S, Elmoussaoui S, Enbili S, Gara S, Haouet S, Khammeri S, Khefecha S, Khtrouche S, Macheghoul S, Mallouli S, Rharrit S, Skouri S, Helali S, Boulehmi S, Abid S, Naouar S, Zelfani S, Ben Amar S, Ajmi S, Braiek S, Yahiaoui S, Ghezaiel S, Ben Toumia S, Thabeti S, Daboussi S, Ben Abderahman S, Rhaiem S, Ben Rhouma S, Rekaya S, Haddad S, Kammoun S, Merai S, Mhamdi S, Ben Ali R, Gaaloul S, Ouali S, Taleb S, Zrour S, Hamdi S, Zaghdoudi S, Ammari S, Ben Abderrahim S, Karaa S, Maazaoui S, Saidani S, Stambouli S, Mokadem S, Boudiche S, Zaghbib S, Ayedi S, Jardek S, Bouselmi S, Chtourou S, Manoubi S, Bahri S, Halioui S, Jrad S, Mazigh S, Ouerghi S, Toujani S, Fenniche S, Aboudrar S, Meriem Amari S, Karouia S, Bourgou S, Halayem S, Rammeh S, Yaïch S, Ben Nasrallah S, Chouchane S, Ftini S, Makni S, Manoubi S, Miri S, Saadi S, Manoubi SA, Khalfallah T, Mechergui T, Dakka T, Barhoumi T, M'rad TEB, Ajmi T, Dorra T, Ouali U, Hannachi W, Ferjaoui W, Aissi W, Dahmani W, Dhouib W, Koubaa W, Zhir W, Gheriani W, Arfa W, Dougaz W, Sahnoun W, Naija W, Sami Y, Bouteraa Y, Elhamdaoui Y, Hama Y, Ouahchi Y, Guebsi Y, Nouira Y, Daly Y, Mahjoubi Y, Mejdoub Y, Mosbahi Y, Said Y, Zaimi Y, Zgueb Y, Dridi Y, Mesbahi Y, Gharbi Y, Hellal Y, Hechmi Z, Zid Z, Elmouatassim Z, Ghorbel Z, Habbadi Z, Marrakchi Z, Hidouri Z, Abbes Z, Ouhachi Z, Khessairi Z, Khlayfia Z, Mahjoubi Z, and Moatemri Z
- Subjects
- Africa, Northern epidemiology, Anatomy education, Education, Medical history, Education, Medical methods, Education, Medical organization & administration, History, 21st Century, Humans, Internship and Residency standards, Internship and Residency trends, Job Satisfaction, Pathology, Clinical education, Tunisia epidemiology, Education, Medical trends, Medicine methods, Medicine organization & administration, Medicine trends
- Published
- 2019
40. Interaction patterns between potato virus Y and eIF4E-mediated recessive resistance in the Solanaceae.
- Author
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Moury B, Janzac B, Ruellan Y, Simon V, Ben Khalifa M, Fakhfakh H, Fabre F, and Palloix A
- Subjects
- Adaptation, Biological, Eukaryotic Initiation Factor-4E genetics, Mutation, Potyvirus genetics, Solanaceae metabolism, Eukaryotic Initiation Factor-4E metabolism, Host Specificity, Host-Pathogen Interactions, Potyvirus physiology, Protein Biosynthesis, Solanaceae immunology, Solanaceae virology
- Abstract
Unlabelled: The structural pattern of infectivity matrices, which contains infection data resulting from inoculations of a set of hosts by a set of parasites, is a key parameter for our understanding of biological interactions and their evolution. This pattern determines the evolution of parasite pathogenicity and host resistance, the spatiotemporal distribution of host and parasite genotypes, and the efficiency of disease control strategies. Two major patterns have been proposed for plant-virus genotype infectivity matrices. In the gene-for-gene model, infectivity matrices show a nested pattern, where the host ranges of specialist virus genotypes are subsets of the host ranges of less specialized viruses. In contrast, in the matching-allele (MA) model, each virus genotype is specialized to infect one (or a small set of) host genotype(s). The corresponding infectivity matrix shows a modular pattern where infection is frequent for plants and viruses belonging to the same module but rare for those belonging to different modules. We analyzed the structure of infectivity matrices between Potato virus Y (PVY) and plant genotypes in the family Solanaceae carrying different eukaryotic initiation factor 4E (eIF4E)-coding alleles conferring recessive resistance. Whereas this system corresponds mechanistically to an MA model, the expected modular pattern was rejected based on our experimental data. This was mostly because PVY mutations involved in adaptation to a particular plant genotype displayed frequent pleiotropic effects, conferring simultaneously an adaptation to additional plant genotypes with different eIF4E alleles. Such effects should be taken into account for the design of strategies of sustainable control of PVY through plant varietal mixtures or rotations., Importance: The interaction pattern between host and virus genotypes has important consequences on their respective evolution and on issues regarding the application of disease control strategies. We found that the structure of the interaction between Potato virus Y (PVY) variants and host plants in the family Solanaceae departs significantly from the current model of interaction considered for these organisms because of frequent pleiotropic effects of virus mutations. These mutational effects allow the virus to expand rapidly its range of host plant genotypes, make it very difficult to predict the effects of mutations in PVY infectivity factors, and raise concerns about strategies of sustainable management of plant genetic resistance to viruses., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)
- Published
- 2014
- Full Text
- View/download PDF
41. Comparative properties of two peptide-antibody interactions as deduced from epitope delineation.
- Author
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Choulier L, Orfanoudakis G, Robinson P, Laune D, Ben Khalifa M, Granier C, Weiss E, and Altschuh D
- Subjects
- Animals, Antibody Specificity immunology, Antigen-Antibody Reactions, Epitopes genetics, Epitopes immunology, Humans, Mice, Oncogene Proteins, Viral genetics, Papillomaviridae immunology, Peptide Library, Peptides genetics, Antibodies, Monoclonal immunology, Epitope Mapping, Oncogene Proteins, Viral immunology, Peptides immunology
- Abstract
The linear epitope recognized by three closely related antibodies specific for the E6 oncoprotein of papillomavirus type 16 was delineated by phage display, spot peptide synthesis on cellulose membranes, and kinetic measurements with antigenic variants using a BIACORE. The same approaches, recently applied to an antibody specific for tobacco mosaic virus protein, led to the clear-cut delineation of a functional epitope comprising four key positions with well defined physico-chemical properties. In contrast, the E6 system is characterized by a non-essential contribution to binding of various factors, so that combinations of alternative properties are compatible with measurable binding activity.
- Published
- 2002
- Full Text
- View/download PDF
42. Kinetic analysis of the effect on Fab binding of identical substitutions in a peptide and its parent protein.
- Author
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Choulier L, Rauffer-Bruyère N, Ben Khalifa M, Martin F, Vernet T, and Altschuh D
- Subjects
- Antibody Affinity, Antibody Specificity, Binding Sites, Circular Dichroism, Cross Reactions, Epitopes, B-Lymphocyte immunology, Immunoglobulin Fab Fragments chemistry, Kinetics, Mutagenesis, Site-Directed, Peptides chemistry, Peptides immunology, Protein Conformation, Viral Proteins genetics, Capsid Proteins, Immunoglobulin Fab Fragments immunology, Viral Proteins immunology
- Abstract
Monoclonal antibody 57P, which was raised against tobacco mosaic virus protein, cross-reacts with a peptide corresponding to residues 134-146 of this protein. Previous studies using peptide variants suggested that the peptide in the antibody combining site adopts a helical configuration that mimics the structure in the protein. In this study, we carried out a detailed comparison of Fab-peptide and Fab-protein interactions. The same five amino acid substitutions were introduced in the peptide (residues 134-151) and the parent protein, and the effect of these substitutions on antibody binding parameters have been measured with a Biacore instrument. Fabs that recognize epitopes located away from the site of mutations were used as indirect probes for the conformational integrity of protein antigens. Their interaction kinetics with all proteins were similar, suggesting that the substitutions had no drastic effect on their conformation. The five substitutions introduced in the peptide and the protein had minor effects on association rate constants (ka) and significant effects on dissociation rate constants (kd) of the antigen-Fab 57P interactions. In four out of five cases, the effect on binding affinity of the substitutions was identical when the epitope was presented in the form of a peptide or a protein antigen, indicating that antibody binding specifity was not affected by epitope presentation. However, ka values were about 10 times larger and kd values about 5 times larger for the peptide-Fab compared to the protein-Fab interaction, suggesting a different binding mechanism. Circular dichroism measurements performed for three of the peptides showed that they were mainly lacking structure in solution. Differences in conformational properties of the peptide and protein antigens in solution and/or in the paratope could explain differences in binding kinetics. Our results demonstrate that the peptides were able to mimic correctly some but not all properties of the protein-Fab 57P interaction and highlight the importance of quantitative analysis of both equilibrium and kinetic binding parameters in the design of synthetic vaccines and drugs.
- Published
- 1999
- Full Text
- View/download PDF
43. Cytogenetic and cryobiology of human cocultured embryos: a 3-year experience.
- Author
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Ménézo YJ and Ben Khalifa M
- Subjects
- Abortion, Spontaneous physiopathology, Aneuploidy, Blastocyst ultrastructure, Chromosomes, Human, Cryopreservation, Embryo Implantation, Embryo Transfer statistics & numerical data, Endometrium physiopathology, Female, Fertilization in Vitro, Humans, In Situ Hybridization, Fluorescence, Infertility, Female physiopathology, Karyotyping, Pregnancy, Pregnancy Rate, Embryo, Mammalian physiology, Embryo, Mammalian ultrastructure, Organ Culture Techniques methods, Trophoblasts cytology
- Abstract
Purpose: Coculture, which allows good-quality human blastocysts with good yields to be obtained, has been designed mainly to select the best embryos for transfers., Methods: In a first attempt during coculture, we have studied by fluorescent in situ hybridization the chromosomic content of the in vitro blocked embryos, using centrometric probes for chromosomes 1, 12, and 18. Close to 37% of the arrested embryos show aneuploidymosaicism., Results: Freezing cocultured blastocysts gives good recovery rates after transfer (83%). The ongoing pregnancy rates per transfer (19%) are high, and the implantation rate per embryo is 13%. This compares favorably with freezing at an early stage., Conclusions: We observed that the quality of the endometrium is always the limiting step, as first of all we observed wide variations according to the hormonal preparation of the patients. Moreover the implantation per embryo in the pregnant patients is very high (57%), indicating that most of the losses are directly related to the receptivity of the endometrium.
- Published
- 1995
- Full Text
- View/download PDF
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