Primary hepatoid carcinoma of the ovary: A case report

Primary hepatoid carcinoma of the ovary (HCO) is a very rare type of high-grade invasive malignant ovarian tumor with hepatic differentiation and production of á-fetoprotein (AFP). We describe a 78-year-old Moroccan woman who presented to our hospital with abdominal distension andpurplish nodules infiltrating the para umbilical skin with weight loss and impairment of her performance status. Excisional biopsy of the paraumbilical nodule revealed a cutaneous localization of moderately   differentiated adenocarcinoma and pelvic ultrasonography noted the presence of a tumoral right adnexal mass. The patient underwent an exploratory laparoscopy which found peritoneal carcinomatosis with pelvic adhesions allowing only a peritoneal biopsy. Diagnosis of primary hepatoid carcinoma of the ovary was established on the basis of classic   histopathologic findings, immunohistochemical staining and marked elevation in serum of á-fetoprotein more than the carbohydrate antigen 125. The patient received 3 cycles of chemotherapy based on Carboplatin and Paclitaxel with disease progression. No second line chemotherapy was given because of the drop of patient's performance status to 3. The patient died one month later

Wear Debris in Prothesis for Biomaterials

La technique des remplacements des joints synovial endommagés ou malades représente l’une des plus grandes avancées dans la chirurgie orthopédique du vingtième siècle. Ces remplacements concernent l'épaule, la cheville, le coude, le genou, et la hanche qui occupe une place particulière dans les interventions chirurgicales. Actuellement plusieurs milliers de prothèses de hanche sont remplacées par année et tous les implants se composent d'un ensemble représenté par une cupule couplée avec un cotyle dur, en métal ou en céramique, et un polymère plus mou. Depuis les années 60, le polymère à haute densité (PEHD) domine les applications concernant les surfaces d'appui utilisées dans la chirurgie orthopédique. Cependant la genèse des débris d’usure du PEHD au niveau des surfaces d’appui reste un sérieux problème pour les patients portant les implants de longue durée. Le volume et la morphologie des particules d'usure sont importants pour la détermination de la réponse du corps aux débris et aux effets entraînant le blocage de la mobilité. Cet article présente un examen des types de particules les plus fréquents trouvés dans les biopsies des tissus arrachés des prothèses. En effet, la taille et la quantité de ces des débris sont des facteurs très importants pour une meilleure compréhension des processus d'utilisation dans les joints artificiels. Des particules réelles sont également décrites en cet article.Mots-clés: Débris d’usure, joints artificiels, méthodologie de séparation.Abstract :The total replacement of damaged or diseased synovial joints represents one of the greatest advances in orthopaedic surgery of the 20th century. Whereas replacements are available for the shoulder, ankle, elbow, knee, hip accounts particularly for the most surgical interventions. Currently in the world several thousand hip joints per year are replaced and all the implants consist of a sliding pair represented by a hard counterface, either metal or ceramic, and a softer polymer. Since the early of 1960’s, Ultra High Molecular Weight Polyethylene (UHMWPE) became the dominant polymer for bearing surfaces in orthopaedic surgery. However, generation of UHMPWE wear debris from bearing surfaces in patients still the major problem for the long term implants. Both volume and morphology of the wear particles are important to determine the response of the body to debris and subsequent effects on secure fixing. This paper presents a review of the type of particles which are the most frequently, found in biopsies of tissues from explanted prostheses. Indeed, the size and the amount of these debris are very important factors for a better understanding of wear processes in artificial joints. Real wear particles are also described in this paper

Breathing Current Domains in Globally Coupled Electrochemical Systems: A Comparison with a Semiconductor Model

Spatio-temporal bifurcations and complex dynamics in globally coupled intrinsically bistable electrochemical systems with an S-shaped current-voltage characteristic under galvanostatic control are studied theoretically on a one-dimensional domain. The results are compared with the dynamics and the bifurcation scenarios occurring in a closely related model which describes pattern formation in semiconductors. Under galvanostatic control both systems are unstable with respect to the formation of stationary large amplitude current domains. The current domains as well as the homogeneous steady state exhibit oscillatory instabilities for slow dynamics of the potential drop across the double layer, or across the semiconductor device, respectively. The interplay of the different instabilities leads to complex spatio-temporal behavior. We find breathing current domains and chaotic spatio-temporal dynamics in the electrochemical system. Comparing these findings with the results obtained earlier for the semiconductor system, we outline bifurcation scenarios leading to complex dynamics in globally coupled bistable systems with subcritical spatial bifurcations.Comment: 13 pages, 11 figures, 70 references, RevTex4 accepted by PRE http://pre.aps.or

Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering

We present the first measurements of the ep → epγ cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q2 dependence (from 1.5 to 2.3 GeV2) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q2. The helicity-independent cross section is also measured at Q2=2.3 GeV2. We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation

Deeply Virtual Compton Scattering off the neutron

The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\vec e},e'\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.Comment: Published in Phys. Rev. Let

The E00-110 experiment in Jefferson Lab's Hall A: Deeply Virtual Compton Scattering off the Proton at 6 GeV

We present final results on the photon electroproduction ($\vec{e}p\rightarrow ep\gamma$) cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region from Jefferson Lab experiment E00-110. Results from an analysis of a subset of these data were published before, but the analysis has been improved which is described here at length, together with details on the experimental setup. Furthermore, additional data have been analyzed resulting in photon electroproduction cross sections at new kinematic settings, for a total of 588 experimental bins. Results of the $Q^2$- and $x_B$-dependences of both the helicity-dependent and helicity-independent cross sections are discussed. The $Q^2$-dependence illustrates the dominance of the twist-2 handbag amplitude in the kinematics of the experiment, as previously noted. Thanks to the excellent accuracy of this high luminosity experiment, it becomes clear that the unpolarized cross section shows a significant deviation from the Bethe-Heitler process in our kinematics, compatible with a large contribution from the leading twist-2 DVCS$^2$ term to the photon electroproduction cross section. The necessity to include higher-twist corrections in order to fully reproduce the shape of the data is also discussed. The DVCS cross sections in this paper represent the final set of experimental results from E00-110, superseding the previous publication.Comment: 48 pages, 32 figure

Measurement of the 12C(e,e'p)11B Two-Body Breakup Reaction at High Missing Momentum Values

The five-fold differential cross section for the 12C(e,e'p)11B reaction was determined over a missing momentum range of 200-400 MeV/c, in a kinematics regime with Bjorken x > 1 and Q2 = 2.0 (GeV/c)2. A comparison of the results and theoretical models and previous lower missing momentum data is shown. The theoretical calculations agree well with the data up to a missing momentum value of 325 MeV/c and then diverge for larger missing momenta. The extracted distorted momentum distribution is shown to be consistent with previous data and extends the range of available data up to 400 MeV/c.Comment: 12 pages, 1 table and 3 figures for submission to Journal Physics

Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering

We present the first measurements of the \vec{e}p->epg cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q^2 dependence (from 1.5 to 2.3 GeV^2) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q^2. The helicity-independent cross section is also measured at Q^2=2.3 GeV^2. We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation.Comment: 5 pages, 4 figures, 2 tables. Text shortened for publication. References added. One figure remove

Exclusive Neutral Pion Electroproduction in the Deeply Virtual Regime

We present measurements of the ep->ep pi^0 cross section extracted at two values of four-momentum transfer Q^2=1.9 GeV^2 and Q^2=2.3 GeV^2 at Jefferson Lab Hall A. The kinematic range allows to study the evolution of the extracted hadronic tensor as a function of Q^2 and W. Results will be confronted with Regge inspired calculations and GPD predictions. An intepretation of our data within the framework of semi-inclusive deep inelastic scattering has also been attempted