116 research outputs found

    Hydatid Cyst of the Heart: Six Clinical Cases

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    Hydatidosis is a cosmopolitan disease due to Echinococcus granulosus. The hydatid cyst of the heart (HCH) occurs in 0.5 to 2% of all hydatid locations. We report of six cases of HCH surgery under cardiopulmonary bypass, done in cardiovascular surgery department at Hassan II university teaching hospital in Fez, Morocco to analyze their diagnostic and therapeutic aspects. This is a retrospective study done, from January 2012 to April 2015. Six cases of hydatid cyst of the heart were collected among 760 cardiac surgery patients, with a frequency of 0.8%. The average age was 29 years, a sex ratio of 1.5 in favour of women. The hydatid cysts (HC) were in the wall and the inter septum of the right atrium in 2 cases and in the wall of the left ventricle in 4 cases. The association with other locations were noted with three patients with lung HC, one patient with liver HC, and the other one with a brain and peritoneal location.Cardiac hydatid disease is mainly characterized by its clinical polymorphism, latency and severity of complications that are often indicative of the condition and can immediately be life-threatening. Advances in medical imaging has significantly contributed to improving its diagnosis, and echocardiography is one of the key tests for specifying the location. The CT scan, MRI contribute to the staging the disease. Hydatid serology is an important test and is necessary both for diagnostic purposes and for monitoring. Curative treatment of HCH is primarily surgical, which must be done as soon as the diagnosis is made and before the complications occur

    Understanding the origins of the intrinsic dead-layer effect in nanocapacitors

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    Thin films of high-permittivity dielectrics are considered ideal candidates for realizing high charge density nanosized capacitors for use in next generation energy storage and nanoelectronic applications. The experimentally observed capacitance of such film nanocapacitors is, however, an order of magnitude lower than expected. This dramatic drop in capacitance is attributed to the so called dead layer - a low-permittivity layer at the metal-dielectric interface in series with the high-permittivity dielectric. The exact nature of the dead layer and the reasons for its origin still remain somewhat unclear. Based on insights gained from recently published ab initio work on SrRuO3/SrTiO3/SrRuO3 and our first principle simulations on Au/MgO/Au and Pt/MgO/Pt nanocapacitors, we construct an analytical model that isolates the contributions of various physical mechanisms to the intrinsic dead layer. In particular we argue that strain-gradients automatically arise in very thin films even in absence of external strain inducers and, due to flexoelectric coupling, are dominant contributors to the dead layer effect. Our theoretical results compare well with existing as well as our own ab initio calculations and suggest that inclusion of flexoelectricity is necessary for qualitative reconciliation of atomistic results. Our results also hint at some novel remedies for mitigating the dead layer effect.Comment: 17 pages, 6 figure

    Study of State Estimation Using Weighted Least Squares Method

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    Power state estimation constitutes the core of the on-line security analysis function. The challenge number one of a state estimator is to provide the optimal estimates of system state with minimum of measurement data. This paper describes weighted least squares state estimation method and investigates how the efficiency of WLS state estimation changes according to 4 parameters: number of measurements, measurement type, measurement weight and level of noise. Different simulation cases are tested on 3-bus system and IEEE 14-bus system. The results show that accurate estimates of system state can be obtained with minimum of measurement data on condition to choose a good combination of accurate measurements with a minimum of voltage measurements and power injection measurements and these data should be properly distributed throughout the system. For best results, the two factors (weight and noise) must be combined to obtain the best estimation. Indeed, the most accurate measurements (lower level of noise) should have greater weight compared to bad measurements (higher level of noise), specially voltage measurements due to their big impact

    A general wavelet-based profile decomposition in the critical embedding of function spaces

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    We characterize the lack of compactness in the critical embedding of functions spaces X⊂YX\subset Y having similar scaling properties in the following terms : a sequence (un)n≄0(u_n)_{n\geq 0} bounded in XX has a subsequence that can be expressed as a finite sum of translations and dilations of functions (ϕl)l>0(\phi_l)_{l>0} such that the remainder converges to zero in YY as the number of functions in the sum and nn tend to +∞+\infty. Such a decomposition was established by G\'erard for the embedding of the homogeneous Sobolev space X=H˙sX=\dot H^s into the Y=LpY=L^p in dd dimensions with 0<s=d/2−d/p0<s=d/2-d/p, and then generalized by Jaffard to the case where XX is a Riesz potential space, using wavelet expansions. In this paper, we revisit the wavelet-based profile decomposition, in order to treat a larger range of examples of critical embedding in a hopefully simplified way. In particular we identify two generic properties on the spaces XX and YY that are of key use in building the profile decomposition. These properties may then easily be checked for typical choices of XX and YY satisfying critical embedding properties. These includes Sobolev, Besov, Triebel-Lizorkin, Lorentz, H\"older and BMO spaces.Comment: 24 page

    Zn treatment effects on biological potential of fennel bulbs as affected by in vitro digestion process

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    Zn treatment effects on the stability of polyphenols, MDA (malondialdehyde) content, antioxidant and lipoxygenase inhibition activities of two varieties of fennel bulbs were studied by using an in vitro gastrointestinal digestion model. Likewise, the effect of Zn on viability cells of E. coli was also performed. The results revealed that high amounts of total phenolic and flavonoid compounds were released during the digestion process, especially after the intestinal phase. Additionally, the antioxidant and lipoxygenase inhibitory activity were affected by the gastrointestinal digestion process and seems to be correlated with total phenol contents. On the other hand, the viability of E. coli was not affected by the activity of our tested bulbs during passage through the artificial digestion model, but the treated bulbs activity contribute relatively to the inhibition growth of bacteria. The survival of E. coli in fennel bulbs was challenged with simulated gastrointestinal fluids and the results showed that the E. coli strains, despite having experienced a viability reduction at the intestinal phase, were able to overcome the exposure to the gastrointestinal synthetic fluids. This E. coli ability reinforces the need for good hygienic measures to assure safe fresh produce, even for those that are rich in antibacterial compounds.info:eu-repo/semantics/publishedVersio
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