Invagination colo-colique sur des adénomes

L’invagination intestinale chez l’adulte est rare, et l’invagination colo-colique est encore plus rare. Contrairement à l’enfant où l’invagination intestinale est idiopathique, chez l’adulte elle survient presque toujours sur une lésion organique notamment sur des lésions malignes.Notre objectif est de rapporter deux nouveaux cas d’invaginations colo-coliques chez l’adulte les différentes étiologies, et leurs circonstances de découverte.Nos deux patients ont consulté en urgence pour un tableau d’occlusion intestinale aigue. Le diagnostic a été posé en préopératoire sur le scanner qui a révélé l’existence d’une invagination intestinale sur des lésions tumorales. Nos deux patient ont été opérés en urgence par laparotomie médiane à cheval sur l’ombilic. L’exploration peropératoire a confirmé le diagnostic d’invagination colo-colique sur une lésion tumorale. Ne disposant pas d’examen extemporané en urgence, et n’ayant pas ainsi, de certitude sur bénignité ou la malignité de ces lésions organiques, nous avons opté pour des colectomies carcinologiques pour pallier à toutes surprise sur lors de l’étude anatomopathologique de la pièce opératoire. L’absence de souffrance intestinale et l’absence de distension colique importante, nous a motivé à rétablir immédiatement la continuité digestive a été faite immédiatement.L’étude anatomopathologique est revenue en faveur d’un polype adénomateux inflammatoire pour le premier patient et d’une adénome villeux pour le 2ème patient.Conclusion :L’invagination intestinale colo-colique est rare chez l’adulte, elle survient presque toujours sur une lésion organique. Les tumeurs malignes sont la principale cause d’invagination intestinale chez l’adulte. Le traitement reste chirurgical la seule arme thérapeutique

Finite element analysis of a fluid-structure interaction in flexible pipe line

This paper describes the basic theory and computing method for transient flow of liquid in flexible pipe such as rubber tubing and arterial system. A mathematical model taking into account tube wall axial and radial motion (in which the dynamic fluid pressure causes circumferential and axial motion of the tube wall) is presented. The tube wall is assumed to be elastic material and the compressibility of the liquid is neglected. Circumferential and axial strain-stress relationships for the tube are considered. The obtained mathematical system is constituted of four non-linear hyperbolic partial differential equations describing the wave  propagation in both pipe wall and liquid flow. The fluid-structure interaction is found to be governed by Poisson’s ratio. In this steady finite element method based on Galerkin formulation is applied. Numerical results show a good similarity with those of the literature obtained by the characteristics method.Key words : Fluid-structure interaction, flexible pipe, rubber, finite element method

Cognitive Radio Networks: Realistic or Not?

A large volume of research has been conducted in the cognitive radio (CR) area the last decade. However, the deployment of a commercial CR network is yet to emerge. A large portion of the existing literature does not build on real world scenarios, hence, neglecting various important interactions of the research with commercial telecommunication networks. For instance, a lot of attention has been paid to spectrum sensing as the front line functionality that needs to be completed in an efficient and accurate manner to enable an opportunistic CR network architecture. This is necessary to detect the existence of spectrum holes without which no other procedure can be fulfilled. However, simply sensing (cooperatively or not) the energy received from a primary transmitter cannot enable correct dynamic spectrum access. For example, the low strength of a primary transmitter's signal does not assure that there will be no interference to a nearby primary receiver. In addition, the presence of a primary transmitter's signal does not mean that CR network users cannot access the spectrum since there might not be any primary receiver in the vicinity. Despite the existing elegant and clever solutions to the DSA problem no robust, implementable scheme has emerged. In this paper, we challenge the basic premises of the proposed schemes. We further argue that addressing the technical challenges we face in deploying robust CR networks can only be achieved if we radically change the way we design their basic functionalities. In support of our argument, we present a set of real-world scenarios, inspired by realistic settings in commercial telecommunications networks, focusing on spectrum sensing as a basic and critical functionality in the deployment of CRs. We use these scenarios to show why existing DSA paradigms are not amenable to realistic deployment in complex wireless environments.Comment: Work in progres

Preliminary study of haplotypes linked to the rare cystic fibrosis E1104X mutation

The analysis of some extra- and intragenic markers within or closely linked to the cystic fibrosis transmembrane regulator (CFTR) gene is useful as a molecular method in clinical linkage analysis. Indeed, knowing that the molecular basis of cystic fibrosis (CF) is highly heterogeneous in our population, the study of haplotype association with normal and CF chromosomes could be very helpful in cases where one or both mutations remain unidentified. In this study, we analysed with PCR-RFLP and capillary electrophoresis some extra (pJ3.11, KM19 and XV2C) and intragenic (IVS8CA, IVS17bTA and IVS17bCA) polymorphic markers in 50 normal and 10 Tunisian patients carrying the rare E1104X mutation in order to determine the haplotype associated with this mutation. For the extragenic markers, 8 haplotypes were identified. The most frequent of them are the 221 and 112 accounting for 80% of total haplotypes. For the intragenic markers, five haplotypes were present on the E1104X chromosomes. One of them 16-31-13 accounted for 50%. To our knowledge, this is the first work to be interested to the haplotypes linked to the E1104X mutation. This preliminary study of haplotypes could be a helpful method to determine the molecular lesions responsible of this pathology

Isotopic and velocity distributions of Bi produced in charge-pickup reactions of 208Pb at 1 A GeV

Isotopically resolved cross sections and velocity distributions have been measured in charge-pickup reactions of 1 A GeV 208Pb with proton, deuterium and titanium target. The total and partial charge-pickup cross sections in the reactions 208Pb + 1H and 208Pb + 2H are measured to be the same in the limits of the error bars. A weak increase in the total charge-pickup cross section is seen in the reaction of 208Pb with the titanium target. The measured velocity distributions show different contributions - quasi-elastic scattering and Delta-resonance excitation - to the charge-pickup production. Data on total and partial charge-pickup cross sections from these three reactions are compared with other existing data and also with model calculations based on the coupling of different intra-nuclear cascade codes and an evaporation code.Comment: 20 pages, 12 figures, background information on http://www-w2k.gsi.de/kschmidt