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Search Results: 1 - 10 of 2061 matches for " Ioannis Koktzoglou "
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Optimization of single shot 3D breath-hold non-enhanced MR angiography of the renal arteries
Huan Tan, Ioannis Koktzoglou, Christopher Glielmi, Mauricio Galizia, Robert R Edelman
Journal of Cardiovascular Magnetic Resonance , 2012, DOI: 10.1186/1532-429x-14-30
Abstract: Technical optimization of the breath-hold technique was performed with fourteen healthy volunteers. An alternative magnetization preparation scheme was tested to maximize inflow signal. Quantitative and qualitative comparisons were made between the breath-hold technique and the clinically accepted navigator-gated technique in both volunteers and patients on a 1.5?T scanner.The breath-hold technique provided an average of seven fold reduction in imaging time, without significant loss of image quality. Comparable single-to-noise and contrast-to-noise ratios of intra- and extra-renal arteries were found between the breath-hold and the navigator-gated techniques in volunteers. Furthermore, the breath-hold technique demonstrated good image quality for diagnostic purposes in a small number of patients in a pilot study.The single-shot, breath-hold technique offers an alternative to navigator-gated methods for non-enhanced renal magnetic resonance angiography. The initial results suggest a potential supplementary clinical role for the breath-hold technique in the evaluation of suspected renal artery diseases.
Risk Management in On-Line Banking  [PDF]
Ioannis V. Koskosas
Intelligent Information Management (IIM) , 2011, DOI: 10.4236/iim.2011.34013
Abstract: In the context of goal setting, the more difficult the goal, given feedback on performance, the more focused is individuals’ attention and persistence to accomplish the goal and in turn, their performance is also improved. Similarly, when the goal is multi-complex and performance time constraint, the deployment of specific strategies maybe the best approach developed. In effect of the above, this investigation takes a socio-psychological and organizational perspective in setting information systems (IS) security goals. In doing so, three important issues of goal setting are identified, these are: trust, culture and risk communication. Since system security breaches are still on the rise, the performance of managing such online risks is not the one expected. The framework suggested in this paper aims to contribute to socio-psychological and organizational values by enhancing the performance of the IS risk management process with a focus on security risks.
Study the Critical Role of Admixtures in Cement Production: The Optimum State of Cassiterite (SnO2) Addition as a Natural Mineralizer-Oxide Influencing the Cement Properties  [PDF]
Ioannis Baziotis, Andreas Chandrinos
Advances in Chemical Engineering and Science (ACES) , 2011, DOI: 10.4236/aces.2011.14031
Abstract: In this work we evaluate the role of a natural mineralizer-oxide like cassiterite (SnO2) on the cement properties. In particular, we study the effect of different quantities of SnO2 with 0.5, 1.0, 1.5 and 2.0 wt% on burnability of industrial raw mix by free lime evaluation. We obtain four datasets, with successive increase of temperature at 1250℃, 1350℃, 1400℃ and 1450℃. We study the produced cassiterite-added clinker with X-ray diffraction (XRD), thermal analysis (DTA) and scanning electron microscopy (SEM). Though, we characterize the new phases formed and whether, adding excess SnO2 is promote forms of C3S, C2S influencing the final quality of cement.
Experimental Testing of Composite Panels Reinforced with Cotton Fibers  [PDF]
Ioannis G. Raftoyiannis
Open Journal of Composite Materials (OJCM) , 2012, DOI: 10.4236/ojcm.2012.22005
Abstract: A research project has been carried out at the National Technical University of Athens, Greece, to develop composite panels reinforced with cotton fibers. The primary aim of the project is to examine the mechanical properties of such panels for use in secondary structural members such as wall or door systems. The use of natural fibers such as cotton, flax or sisal fibers has the primary advantage of being eco-friendly, low cost and low weight compared to glass fibers on the expense of lower structural properties. This paper presents results from experimental work on composite plates made from polyester resin reinforced with cotton fibers, with special attention given to the effect of the fiber type on the structural properties of the plates. The results from this study showed that the structural performance of cotton fiber composites is satisfactory for structural parts with low requirements, such as wall panels or doors. The present results for cotton fiber composites are also compared to testing results from previous studies on composites with flax/sisal fibers.
Feature Extraction for Audio Classification of Gunshots Using the Hartley Transform  [PDF]
Ioannis Paraskevas, Maria Rangoussi
Open Journal of Acoustics (OJA) , 2012, DOI: 10.4236/oja.2012.23015
Abstract: In audio classification applications, features extracted from the frequency domain representation of signals are typically focused on the magnitude spectral content, while the phase spectral content is ignored. The conventional Fourier Phase Spectrum is a highly discontinuous function; thus, it is not appropriate for feature extraction for classification applications, where function continuity is required. In this work, the sources of phase spectral discontinuities are detected, categorized and compensated, resulting in a phase spectrum with significantly reduced discontinuities. The Hartley Phase Spectrum, introduced as an alternative to the conventional Fourier Phase Spectrum, encapsulates the phase content of the signal more efficiently compared with its Fourier counterpart because, among its other properties, it does not suffer from the phase ‘wrapping ambiguities’ introduced due to the inverse tangent function employed in the Fourier Phase Spectrum computation. In the proposed feature extraction method, statistical features extracted from the Hartley Phase Spectrum are combined with statistical features extracted from the magnitude related spectrum of the signals. The experimental results show that the classification score is higher in case the magnitude and the phase related features are combined, as compared with the case where only magnitude features are used.
Erythropoiesis Stimulating Agents (ESAs) in the Treatment of Cardio-Renal Syndrome Anaemia  [PDF]
Ioannis Koulouridis, Efstathios Koulouridis
Open Journal of Nephrology (OJNeph) , 2012, DOI: 10.4236/ojneph.2012.23004
Abstract: Coexistence of chronic kidney disease (CKD) and chronic heart failure (CHF) define a recently recognized clinical entity known as cardio-renal syndrome. Sufficient evidence suggests that the two pathological conditions share common pathogenic etiology which is not yet fully defined. Superimposed anaemia is a common finding among patients suffering from cardio-renal syndrome. The combination of CKD, CHF and anaemia increase the probability of death by 6 times compared to normal individuals. Early attempts to restore anaemia either by iron supplementation, erythropoiesis stimulating agents (ESAs) or combination of the two have reported to improve quality of life, morbidity and mortality especially among patients treated by cardiologists. Recent publications of well controlled epidemiological studies failed to prove convincing beneficial effect of the above mentioned therapy moreover skepticism has raised concerning the safety of restoring anaemia among patients with cardio-renal syndrome as well as used medications. There are still unresolved problems concerning the definition of anaemia, by means of hemoglobin level among these patients, the target hemoglobin level and the therapeutic regimen of ESAs administration and iron supplementation. We need much more evidence in order to define an effective and safe treatment strategy correcting anaemia among patients with cardio-renal syndrome.
Third-Order Corrections and Mass-Shedding Limit of Rotating Neutron Stars Computed By a Complex-Plane Strategy  [PDF]
Ioannis Sfaelos, Vassilis Geroyannis
International Journal of Astronomy and Astrophysics (IJAA) , 2012, DOI: 10.4236/ijaa.2012.24027
Abstract: We implement the so-called “complex-plane strategy” for computing general-relativistic polytropic models of uniformly rotating neutron stars. This method manages the problem by performing all numerical integrations, required within the framework of Hartle’s perturbation method, in the complex plane. We give emphasis on computing corrections up to third order in the angular velocity, and the mass-shedding limit. We also compute the angular momentum, moment of inertia, rotational kinetic energy, and gravitational potential energy of the models considered.
Genetic Implications in COPD. The Current Knowledge  [PDF]
Ioannis Sotiriou, Demosthenes Makris
Open Journal of Respiratory Diseases (OJRD) , 2013, DOI: 10.4236/ojrd.2013.32009
Abstract: Chronic Obstructive Pulmonary Disease (COPD) is a multifactorial disease in the pathogenesis of which contributes a variety of causative factors including genetic and environmental ones. They may also be interactions of genetic susceptibilities and environmental influences. Towards to that in the pathogenesis of the disease except smoking, it seems to have a great impact the genetic predisposition of the individuals suffering from that serious progressive disease. Regarding to these observations and findings very interesting studies have been conducted in order to elucidate the implications of different genes, and their polymorphisms in disease aetiology. This is a review which elucidates the impact of genetic susceptibility in COPD.
A Survey among Texas Pain Society Physicians Regarding the Types and Dosages of Steroids Utilized Clinically in Epidural Steroid Injectates  [PDF]
Thuan Dao, Ioannis Skaribas
Open Journal of Anesthesiology (OJAnes) , 2014, DOI: 10.4236/ojanes.2014.411042
Abstract: Objective: Epidural steroid injections (ESI) are used extensively to treat radicular back pain. This study is designed to evaluate the types and dosages of steroids commonly used and understand prescribing habits of the Texas Pain Society pain management physicians. Method: From April to May 2014, we sent all 270 Texas Pain Society members a questionnaire to complete online. We collected 45 responses. Result: Type of steroid commonly used in injectate: Eighteen (41.9%) phy-sicians reported using methylprednisolone most. Fifteen (34.9%) physicians use triamcinolone, 9 (20.9%) physicians use dexamethasone, 1 (2.3%) uses betamethasone, and 2 skipped this question. Important factors influencing the type of steroid use in injectate: Half of the physicians reported that the location of the ESI was most important (19 responses, 48.7%). Ten (25.6%) reported that the approach of the ESI was most important. Another ten (25.6%) agreed that the potency of the steroid was most important. Dosage of steroid used in injectate: About half of the physicians use a fixed dose of steroid (22, 51.2%) while 21 (48.8%) use a variable dose of steroid. Of those who use a fixed dose of steroid, many use methylprednisolone 80 mg (9, 39.1%). Of those who use a variable dosage of steroid, the most important factor in their determination of the dosage is the patient’s comorbidities (20 responses, 58.8%). The use of depo-steroid in injectate: Thirty-two out of 43 (74.4%) use depo-steroid while 11 out of 43 (25.6%) wouldn’t use depo-steroid. Of those who use depo-steroid, the duration and availability in the epidural space is the most common reason for its use (23, 76.7%). Conclusion: By using a simple questionnaire detailing what types and dosages of steroids are used, compiling a list of best practices can help Texas Pain Society physicians tremendously in the treatment of radicular back pain.
DC Maturation: A Brief Comparison between Three Different Processes  [PDF]
Maria Toloudi, Ioannis Papasotiriou
Journal of Cancer Therapy (JCT) , 2015, DOI: 10.4236/jct.2015.610095
Abstract: Dendritic cell (DC) maturation approved to be a pivotal process for initiating immunity. Many protocols were established in order the isolated peripheral blood mononuclear cells (PBMCs) from healthy donors to mature into dendritic cells (DCs). The purpose of this study was to present an effective and reliable DC maturation procedure by comparing three different protocols (Interleukin-4/Tumor Necrosis Factor-appha (IL-4/TNFa) DC protocol, Interferon alpha (IFNa) DC protocol and FAST DC protocol). Whole blood was collected from six healthy donors and PBMCs were isolated by Ficoll gradient centrifugation. The counted cells were incubated with the addition of three different cocktails of supplements for appropriate time period. The final mature DC population was examined either by its phenotypic characteristics under light microscope or by measuring the expression of antigen presenting molecules such as CD80 and CD86 by flow cytometry. It was found that the mature DCs, generated from the IL-4/TNFa DC protocol, expressed higher levels of CD80 and CD86. Furthermore, they sharply exhibited their phenotypic hallmarks.
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