37 research outputs found
Optical Coherence Tomographic Findings in Berlin’s Edema
Purpose: To describe optical coherence tomography (OCT) findings in a patient with Berlin′s edema following blunt ocular trauma.
Case Report: A 26-year-old man presented with acute loss of vision in his left eye following blunt trauma. He underwent a complete ophthalmologic examination and OCT. Fundus examination revealed abnormal yellow discoloration in the macula. OCT disclosed thickening of outer retinal structures and increased reflectivity in the area of photoreceptor outer segments with preservation of inner retinal architecture. Re-examination was conducted one month later at the time which OCT changes resolved leading to a surprisingly normal appearance.
Conclusion: OCT can be a useful tool in the diagnosis and follow-up of eyes with Berlin′s edema and may reveal ultrastructural macular changes
Paravalvular Leaks: From Diagnosis to Management
Paravalvular leaks (PVLs) are complications of a surgical or percutaneous valve replacement. They are persistent defects between the native annulus and the sewing ring, which result in a regurgitant prosthesis. They are observed in 2–18% of patients after a surgical valve replacement (SVR) and in 7–40% after a transcatheter aortic valve replacement (TAVR). Clinical manifestations are heart failure and hemolysis. They develop in 1–5% of PVL patients, and they have a poor prognosis. Surgery was the only available treatment to improve the patient’s outcome. But it is a high-risk surgery in frail patients and PVL relapse is not rare. Percutaneous PVL closure has emerged as a promising technique. Nevertheless, it needs a careful assessment, demands high technical expertise, and still has limitations. This chapter focuses on the diagnosis of PVL after a SVR and transcatheter PVL closure (TPVL)
Acute myocardial infarction in a patient with hypofibrinogenemia: a case report
<p>Abstract</p> <p>Introduction</p> <p>Congenital fibrinogen deficiency is a rare coagulation disorder usually responsible for hemorrhagic diathesis. However, it can be associated with thrombosis and there have been limited reports of arterial thrombotic complications in these patients.</p> <p>Case presentation</p> <p>A 42-year-old Tunisian man with congenital hypofibrinogenemia and no cardiovascular risk factors presented with new onset prolonged angina pectoris. An electrocardiogram showed features of inferior acute myocardial infarction. His troponin levels had reached 17 ng/L. Laboratory findings confirmed hypofibrinogenemia and ruled out thrombophilia. Echocardiography was not useful in providing diagnostic elements but did show preserved left ventricular function. Coronary angiography was not performed and our patient did not receive any anticoagulant treatment due to the major risk of bleeding. Magnetic resonance imaging confirmed myocardial necrosis. Our patient was managed with aspirin, a beta-blocker, an angiotensin-converting enzyme inhibitor and statin medication. The treatment was well tolerated and no ischemic recurrence was detected.</p> <p>Conclusion</p> <p>Although coronary thrombosis is a rare event in patients with fibrinogen deficiency, this condition is of major interest in view of the difficulties observed in managing these patients.</p
MWCSGA—Multi Weight Chicken Swarm Based Genetic Algorithm for Energy Efficient Clustered Wireless Sensor Network
Nowadays due to smart environment creation there is a rapid growth in wireless sensor network (WSN) technology real time applications. The most critical resource in in WSN is battery power. One of the familiar methods which mainly concentrate in increasing the power factor in WSN is clustering. In this research work, a novel concept for clustering is introduced which is multi weight chicken swarm based genetic algorithm for energy efficient clustering (MWCSGA). It mainly consists of six sections. They are system model, chicken swarm optimization, genetic algorithm, CCSO-GA cluster head selection, multi weight clustering model, inter cluster, and intra cluster communication. In the performance evaluation the proposed model is compared with few earlier methods such as Genetic Algorithm-Based Energy-Efficient Adaptive Clustering Protocol For Wireless Sensor Networks (GA-LEACH), Low energy adaptive Clustering hierarchy approach for WSN (MW-LEACH) and Chicken Swarm Optimization based Genetic Algorithm (CSOGA). During the comparison it is proved that our proposed method performed well in terms of energy efficiency, end to end delay, packet drop, packet delivery ratio and network throughput
MWCSGA—Multi Weight Chicken Swarm Based Genetic Algorithm for Energy Efficient Clustered Wireless Sensor Network
Nowadays due to smart environment creation there is a rapid growth in wireless sensor network (WSN) technology real time applications. The most critical resource in in WSN is battery power. One of the familiar methods which mainly concentrate in increasing the power factor in WSN is clustering. In this research work, a novel concept for clustering is introduced which is multi weight chicken swarm based genetic algorithm for energy efficient clustering (MWCSGA). It mainly consists of six sections. They are system model, chicken swarm optimization, genetic algorithm, CCSO-GA cluster head selection, multi weight clustering model, inter cluster, and intra cluster communication. In the performance evaluation the proposed model is compared with few earlier methods such as Genetic Algorithm-Based Energy-Efficient Adaptive Clustering Protocol For Wireless Sensor Networks (GA-LEACH), Low energy adaptive Clustering hierarchy approach for WSN (MW-LEACH) and Chicken Swarm Optimization based Genetic Algorithm (CSOGA). During the comparison it is proved that our proposed method performed well in terms of energy efficiency, end to end delay, packet drop, packet delivery ratio and network throughput
Stress Engineering of a Window Porous Silicon Layer based on Pseudo Substrate Suitable for III-V Monolithic Integration
Due to Silicon (Si) material abundance and specific properties, monolithic integration of III-V semiconductors on (Si) is of paramount importance for the next-generation in Optoelectronic devises. An alternative approach to lattice mismatched single silicon crystal substrates for heteroepitaxy is proposed. In this work, we have suggested a design of a compliant virtual substrate and we have explored the modulation of stress/lattice parameter of a window layer based on porous silicon pseudo-substrates allowing a defect free epitaxial growth. We prepared a silicon window layer with low porosity and variable thicknesses whose stress is modulated by the succession of several layers with gradual porosity. As a result, we evaluated the stress and the lattice parameter in compliant substrate before and after thermal annealing. The pores reorganization process was supported in Argon atmosphere at constant temperature (900 °C). The samples were studied morphologically by Field Emission scanning Electron Microscope (FE-SEM) and structurally by High Resolution X-Ray Diffraction (HR-XRD) and Nano-Raman
Evolution de la methode de tirage EPR de Si polycristallins destines a la fabrication de photopiles
SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Comparison of ZnO thin films on different substrates obtained by sol-gel process and deposited by spin-coating technique
521-529In the present
paper, zinc oxide thin films obtained by sol gel process and deposited on
glass, sapphire, Si (100),
Si (111) and ZnO substrates by spin-coating technique have been studied.
Effects of using different substrates on the structural, morphological and
optical properties have been investigated. The structural properties have been
analyzed using X-ray diffraction (XRD) and the recorded patterns indicated that
all the deposited films are polycrystalline with a hexagonal Wurtzite structure
and exhibit preferentially oriented along the c-axis direction. The surface
morphology has been examined by Scanning Electron Microscopy which revealed
that the microstructure of the films strongly affected by the nature and
orientation of substrate namely grain shape and size. Optical absorbance
measurements have been taken using UV-Vis spectrophotometer and the calculated
values of the direct band gap energy are around 3, 3.08 and 3.19 eV, for the
ZnO films deposited on ZnO, sapphire c and glass substrates, respectively.
Photoluminescence measurements taken at 4 K exhibit a near band edge composed
by two principal’s peaks situated at 3.36 and 3.31 eV and attributed to the
neutral donor bound exciton (D°X) and to the deep acceptor (A°X), their
intensity varied with the nature of substrate