The effect of the process on mechanical properties of polylactic acid - date palm leaf fibers composite films produced by extrusion blowing

Biocomposite films prepared with melt compounding and film blowing have become a new trend in plastic research to deliver more eco-friendly packages. Polylactic acid (PLA) was melt compounded with minimally processed date palm leaf fiber (DPLF) and converted into films by blown film extrusion. The compounding was done in order to enhance the film mechanical properties in one hand, and to decrease the film production cost in the other hand. In this present study, a reference PLA film and films with 1%, 2%, and 5% of DPLF (weight %) were produced with different process parameters. The spatial variations in films thickness and lay flat width indicate that the addition of DPLF up to 2% enhances the bubble stability for the tested process parameters. However, the composite with 5% DPLF shows nearly the same processability window as the neat PLA. The structural and mechanical characterizations of films suggest a reinforcing effect of the PLA matrix up to 2% of fiber (with an optimum at 1%). Larger DPLF loading leads to depressed and more anisotropic mechanical properties, related to an increased density of defects at the fiber-PLA fragile interface and to a DPLF-induced enhanced PLA thermal degradation and amorphous phase orientatio

Les facteurs prédictifs de malignité des nodules thyroïdiens: à propos de 412 cas

Introduction : Les nodules thyroïdiens constituent la pathologie thyroïdienne la plus fréquente. Ils posent surtout le problème de leur prise en charge. La recherche d’une étiologie cancéreuse reste la principale préoccupation. Matériels et méthodes : Nous proposons une étude rétrospective, portant sur 412 patients porteurs de nodules thyroïdiens uniques ou multiples, colligés sur une période de 5 ans (1998-2002). Nous avons réalisé une étude statistique comparant deux groupes de patients : le groupe I comprenant tous les patients porteurs de nodules malins pris en charge au cours de la période d’étude, ils sont au nombre de 103. Et le groupe II est constitué de 309 patients témoins pris au hasard porteurs de nodules bénins également pris en charge entre 1998 et 2002. Résultats : Les facteurs prédictifs de malignité d’un nodule thyroïdien, jugés significatifs au terme de l’étude statistique univariée, étaient : l’âge inférieur à 30 ans, l’adénopathie révélatrice, la consistance dure du nodule, sa fixité, son caractère irrégulier et ses limites floues à la palpation, la présence d’une adénopathie à l’examen, l’association à une anémie. Et à l’échographie, la structure mixte, les limites irrégulières, la présence de microcalcifications et la visualisation d’une vascularisation intranodulaire avec ou sans vascularisation périnodulaire. Seuls 4 facteurs étaient significatifs à l’étude multivariée : l’âge inférieur à 30 ans, l’anémie, l’échostructure mixte et l’hypervascularisation au doppler. Conclusion : Bien que ces facteurs sont fortement prédictifs de malignité, aucun examen clinique ou paraclinique n’est suffisant à lui seul, le clinicien doit alors se baser sur un faisceau d’arguments pour adopter une conduite pratique parfois lourde de conséquences.Mots clés : nodules thyroïdiens, malignité, dépistage, échographi

L\'amylose Laryngée À Propos D\'un Cas

L\'amylose localisée est caractérisée par un dépôt de protéines fibrillaires dans un site de l\'organisme sans atteinte systémique. La localisation laryngée est très rare. Ce diagnostic doit être évoqué devant toute lésion d\'allure bénigne du larynx. Les auteurs rapportent un cas d\'amylose laryngée colligé sur une période de 10 ans.Localized amyloidosis is characterized by the deposition of amyloid fibres in a particular site or organ system in the absence of systemic involvement. The laryngeal location of amylosis is rare. The diagnosis must be suspected in front of any tumor of benign speed of the larynx. Authors report a case of laryngeal amyloidosis brought during a period of 10 years. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 16 2006: pp. 30-3

Mucocèle sphénoïdale bilatérale : a propos d’un cas

Les mucocèles sphénoïdales sont des formations pseudokystiques expansives, d’évolution lente, qui se développent au sein de la cavité sinusienne sphénoïdale. Elles possèdent la capacité d’éroder les parois osseuses et présentent une évolution pseudotumorale. Les rapports neuroméningés et orbitaires font la gravité de cette localisation sinusienne  la présentation clinique qui est souvent d’apparition retardée par rapport à la constitution de la mucocèle. L’imagerie (TDM et IRM) permet le diagnostic positif et le diagnostic différentiel avec certains processus développés au niveau de l’étage moyen de la base du crâne. La marsupialisation chirurgicale par voie endoscopique endonasale permet l’effondrement de la mucocèle.Mots-clés : mucocèle, sinus sphénoïda

The impact of moderate endurance exercise on cardiac telomeres and cardiovascular remodeling in obese rats

Introduction: Hypercaloric nutrition and physical inactivity cause obesity, a potential driver of myocardial apoptosis and senescence that may accelerate cardiac aging. Although physical activity reduces mortality, its impact on myocardial aging is insufficiently understood. Here we investigated the effects of a hypercaloric high-fat diet (HFD) and regular exercise training on cardiac cells telomeres and histomorphometric indices of cardiac aging. Methods: Ninety-six 4-months old female Sprague-Dawley rats were fed for 10 months normal (ND) or a HFD diet. Half of the animals in each group performed 30 min treadmill-running sessions on 5 consecutive days per week. At study end, cardiomyocyte cross-sectional area (CSA), interstitial collagen content, vascular density, apoptotic and senescent cells, relative telomere length (RTL), and expression of telomerase-reverse transcriptase (Tert) as marker of telomere-related senescence and apoptosis were analyzed. Results: Compared to ND, the HFD group developed obesity, higher CSA, lower capillary density and tended to have more apoptotic cardiomyocytes and interstitials cells. Myocardial RTL and the expression of Terf-1 and Terf-2 were comparable in sedentary HFD and ND animals. In the HFD group, regular moderate endurance exercise improved myocardial vascularization, but had no effect on CSA or apoptosis. Notably, the combination of exercise and HFD increased senescence when compared to sedentary ND or HFD, and reduced RTL when compared to exercise ND animals. Exercising HFD animals also showed a trend toward higher Tert expression compared to all other groups. In addition, exercise reduced Terf-1 expression regardless of diet. Conclusion: HFD-induced obesity showed no effects on myocardial telomeres and induced only mild morphologic alterations. Summarized, long-term moderate endurance exercise partially reverses HFD-induced effects but may even trigger cardiac remodeling in the context of obesity

Plasmocytome Ganglionnaire A Propos D\'un Cas

Les plasmocytomes ganglionnaires sont très rares. Ils peuvent être en rapport avec des métastases à partir d\'un myélome multiple ou d\'un plasmocytome extramédullaire. Les localisations primaires ganglionnaires restent exceptionnelles. Nous rapportons un cas colligé et opéré au service d\'ORL et CMF de l\'hôpital la Rabta. Il s\'agit d\'une femme de 74 ans opérée d\'une tuméfaction submandibulaire gauche. Le diagnostic est fait à l\'examen histologique qui a révélé un plasmocytome ganglionnaire primaire. Le traitement est radiochirurgical. Nous présentons les aspects histopatologiques, cliniques, biologiques et thérapeuthiques de cette affection rare. Keywords: plasmocytomes ganglionnaires, adénopathie cervicale. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 53-5

Le Carcinome Mucoépidermoïde De La Parotide : Apropos De 5 Cas

Les tumeurs des glandes salivaires représentent moins de 5% de toutes les tumeurs de la tête et du cou. Parmi eux, le carcinome mucoépidermoïde est la tumeur la plus fréquente. Quarante cinq pour cent des carcinomes mucoépidermoïdes se développent au niveau de la glande parotide. Cette lésion se voit surtout chez l\'adulte vers la 5ème décade. Le diagnostic est confirmé seulement à l\'examen anatomopathologique. Son pronostic est fonction des critères histologiques.Salivary gland tumors account for less than 5% of the head and neck neoplasms. Among them, mucoepidermoid carcinoma is the most common malignant salivary gland tumor. About 45% of mucoepidermoid carcinomas occur in the parotid gland, and appear around the fifth decade of life. A certain diagnostic can be obtained only after post-operative histological examination. Histological examination indicates the patient prognosis. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 16 2006: pp. 39-4

Genome-wide footprints in the carob tree (Ceratonia siliqua) unveil a new domestication pattern of a fruit tree in the Mediterranean

Intense research efforts over the last two decades have renewed our understanding of plant phylogeography and domestication in the Mediterranean basin. Here we aim to investigate the evolutionary history and the origin of domestication of the carob tree (Ceratonia siliqua), which has been cultivated for millennia for food and fodder. We used >1000 microsatellite genotypes to delimit seven carob evolutionary units (CEUs). We investigated genome-wide diversity and evolutionary patterns of the CEUs with 3557 single nucleotide polymorphisms generated by restriction-site associated DNA sequencing (RADseq). To address the complex wild vs. cultivated status of sampled trees, we classified 56 sampled populations across the Mediterranean basin as wild, seminatural or cultivated. Nuclear and cytoplasmic loci were identified from RADseq data and separated for analyses. Phylogenetic analyses of these genomic-wide data allowed us to resolve west-to-east expansions from a single long-term refugium probably located in the foothills of the High Atlas Mountains near the Atlantic coast. Our findings support multiple origins of domestication with a low impact on the genetic diversity at range-wide level. The carob was mostly domesticated from locally selected wild genotypes and scattered long-distance westward dispersals of domesticated varieties by humans, concomitant with major historical migrations by Romans, Greeks and Arabs. Ex situ efforts to preserve carob genetic resources should prioritize accessions from both western and eastern populations, with emphasis on the most differentiated CEUs situated in southwest Morocco, south Spain and eastern Mediterranean. Our study highlights the relevance of wild and seminatural habitats in the conservation of genetic resources for cultivated trees

Electrical tuning of elastic wave propagation in nanomechanical lattices at MHz frequencies

Nanoelectromechanical systems (NEMS) that operate in the megahertz (MHz) regime allow energy transducibility between different physical domains. For example, they convert optical or electrical signals into mechanical motions and vice versa. This coupling of different physical quantities leads to frequency-tunable NEMS resonators via electromechanical non-linearities. NEMS platforms with single- or low-degrees of freedom have been employed to demonstrate quantum-like effects, such as mode cooling, mechanically induced transparency, Rabi oscillation, two-mode squeezing and phonon lasing. Periodic arrays of NEMS resonators with architected unit cells enable fundamental studies of lattice-based solid-state phenomena, such as bandgaps, energy transport, non-linear dynamics and localization, and topological properties, directly transferrable to on-chip devices. Here we describe one-dimensional, non-linear, nanoelectromechanical lattices (NEML) with active control of the frequency band dispersion in the radio-frequency domain (10–30 MHz). The design of our systems is inspired by NEMS-based phonon waveguides and includes the voltage-induced frequency tuning of the individual resonators. Our NEMLs consist of a periodic arrangement of mechanically coupled, free-standing nanomembranes with circular clamped boundaries. This design forms a flexural phononic crystal with a well-defined bandgap, 1.8 MHz wide. The application of a d.c. gate voltage creates voltage-dependent on-site potentials, which can significantly shift the frequency bands of the device. Additionally, a dynamic modulation of the voltage triggers non-linear effects, which induce the formation of a phononic bandgap in the acoustic branch, analogous to Peierls transition in condensed matter. The gating approach employed here makes the devices more compact than recently proposed systems, whose tunability mostly relies on materials’ compliance and mechanical non-linearities

Nucleolin, a Shuttle Protein Promoting Infection of Human Monocytes by Francisella tularensis

International audienceWe herein confirm the importance of nucleolin expression for LVS binding and its specificity as nucleolin is not involved in binding of another intracellular pathogen as L. monocytogenes or an inert particle. Association of nucleolin with F. tularensis during infection continues intracellularly after endocytosis of the bacteria. The present work therefore unravels for the first time the presence of nucleolin in the phagosomal compartment of macrophages