Stelios Zimeras

Cardioprotective effect of metoprolol and enalapril in doxorubicin-treated lymphoma patients: A prospective, parallel-group, randomized, controlled study with 36-month follow-up†

Anthracyclines have contributed to a marked increase in survival in different types of cancer [1,2]. Unfortunately, they are associated with dose-dependent cardiotoxicity and heart failure (HF) [3–8]. Change to a weekly dosage schedule with slow infusions has been tested, a strategy that requires more frequent hospital visits and increased storage resources[7,9]. Liposomal anthracycline formulations with reduced drug exposure and lower plasma concentrations may still be cardiotoxic at higher cumulative doses [10]. Beta-blockers and angiotensin converting enzyme(ACE) inhibitors have been shown to reduce anthracycline-induced cardiotoxicity,but have not been tested in long-term prospective, randomized,controlled studies with well defined cardiotoxicity criteria and careful cardiac function monitoring [11–16]. We investigated doxorubicin-induced clinical or subclinical cardiotoxicity in lymphoma patients after concomitant prophylactic therapy with metoprolol or enalapril or no concomitant treatment. We examined whether cardiotoxicity was related to the treatment or any other variable. We found that HF was less frequent under concomitant treatment than no treatment, especially in the metoprolol group, but the differences were not significant. No association was found between the presence of cardiotoxicity and concomitant treatment or other variable apart of age that had a significant impact. The marginal benefit seen with metoprolol should be investigated further.

Inhomogeneous Prior Models for Image Reconstruction

Abstract Over recent years, the use of homogeneous Gibbs prior models in image processing has become widely accepted. There has been, however, much discussion over precisely which models are most appropriate. For most applications, the simplest Gaussian model tends to oversmooth reconstructions, so it has been rejected in favor of various edge-preserving alternatives. We claim that the problem is not with the Gaussian family, but rather with the assumption of homogeneity. In this article we propose an inhomogeneous Gaussian random field as a general prior model for many image-processing applications. The simplicity of the Gaussian model allows rapid calculation, and the flexibility of the spatially varying prior parameter allows varying degrees of spatial smoothing. This approach is in the spirit of adaptive kernel density methods where only the choice of the variable window width is important. The analysis of real single-photon emission computed tomography data is used to illustrate the methods, and simu...

An Accurate 3D Segmentation Method of the Spinal Canal Applied to CT Data

With the modern treatment planning techniques the accurate definition of the target volume as well as the organs at risk is a crucial step for the treatment outcome. One of the key organs that must be protected during the irradiation treatment is the spinal cord. Nowadays, high resolution computed tomography (CT) data are required to perform accurate treatment planning, and there is the demand for quick but accurate segmentation tools. In this work we present a very simple approach that can accurately extract the spinal canal in three dimensions (3D) from CT images. The user must define only the starting point for the algorithm and the rest of the process is performed automatically. The core of our method is a boundary-tracing algorithm combined with linear interpolation techniques in the longitudinal (z) direction.

Unexpected spatial patterns in exponential family auto models

Models based on Markov random fields are now widely used to model spatial processes. Key components of any statistical analysis using such models are the choice of an appropriate model as the prior distribution and the estimation of prior model parameters. In this paper, we shall investigate spatial behavior of auto models, concentrating on the first-order neighborhood system in a rectangular lattice, but also considering the second-order neighborhood system in a rectangular lattice and first-order neighborhood system in a hexagonal lattice. We present a simple deterministic model based on a univariate iterative scheme which appears to emulate the behavior of auto models and allows us to make predictions regarding the behavior of the spatial models. For well-defined regions in the parameter space this iterative scheme is unstable leading to catastrophic and 2-cycle behavior. We claim that this instability coincides with structural changes in the corresponding spatial model and that the critical boundaries for the iterative scheme coincide with those for the spatial model. We use the Gibbs sampler to produce realizations illustrating the wide range of possible models, and to reinforce the predictions made using the simple iterative scheme.

Data Hiding Techniques in Steganography Using Fibonacci and Catalan Numbers

During the last decades, Steganography has found many applications. Many steganographic systems have been developed and used in various areas, e.g., in digital assets (DRM), Telecommunications, Medicine etc. In this paper, we prove that the set CF, which is a union of a certain set of Fibonacci numbers and a certain set of Catalan numbers, satisfies conditions, similar to those of Zeckendorfs Theorem. Therefore, it can be used for the encoding of data. Using this result, we propose a method that improves the Fibonacci data hiding technique.

Investigation of the Impact of Extracting and Exchanging Health Information by Using Internet and Social Networks.

Introduction: Social networks (1) have been embedded in our daily life for a long time. They constitute a powerful tool used nowadays for both searching and exchanging information on different issues by using Internet searching engines (Google, Bing, etc.) and Social Networks (Facebook, Twitter etc.). In this paper, are presented the results of a research based on the frequency and the type of the usage of the Internet and the Social Networks by the general public and the health professionals. Objectives: The objectives of the research were focused on the investigation of the frequency of seeking and meticulously searching for health information in the social media by both individuals and health practitioners. The exchanging of information is a procedure that involves the issues of reliability and quality of information. Methods: In this research, by using advanced statistical techniques an effort is made to investigate the participant’s profile in using social networks for searching and exchanging information on health issues. Results: Based on the answers 93 % of the people, use the Internet to find information on health-subjects. Considering principal component analysis, the most important health subjects were nutrition (0.719 %), respiratory issues (0.79 %), cardiological issues (0.777%), psychological issues (0.667%) and total (73.8%). Conclusions: The research results, based on different statistical techniques revealed that the 61.2% of the males and 56.4% of the females intended to use the social networks for searching medical information. Based on the principal components analysis, the most important sources that the participants mentioned, were the use of the Internet and social networks for exchanging information on health issues. These sources proved to be of paramount importance to the participants of the study. The same holds for nursing, medical and administrative staff in hospitals.

LSB Steganographic Detection Using Compressive Sensing

People have always been using several techniques in order to protect their privacy. For centuries, steganography has been used, but only in the last decades the proper mathematical background has been developed. Due technological advances, steganography has found many applications, with most important the protection of digital assets through DRM.

Diverse Radiofrequency Sensitivity and Radiofrequency Effects of Mobile or Cordless Phone near Fields Exposure in Drosophila melanogaster

Introduction The impact of electromagnetic fields on health is of increasing scientific interest. The aim of this study was to examine how the Drosophila melanogaster animal model is affected when exposed to portable or mobile phone fields. Methods/Results Two experiments have been designed and performed in the same laboratory conditions. Insect cultures were exposed to the near field of a 2G mobile phone (the GSM 2G networks support and complement in parallel the 3G wide band or in other words the transmission of information via voice signals is served by the 2G technology in both mobile phones generations) and a 1880 MHz cordless phone both digitally modulated by human voice. Comparison with advanced statistics of the egg laying of the second generation exposed and non-exposed cultures showed limited statistical significance for the cordless phone exposed culture and statistical significance for the 900 MHz exposed insects. We calculated by physics, simulated and illustrated in three dimensional figures the calculated near fields of radiation inside the experimenting vials and their difference. Comparison of the power of the two fields showed that the difference between them becomes null when the experimental cylinder radius and the height of the antenna increase. Conclusions/Significance Our results suggest a possible radiofrequency sensitivity difference in insects which may be due to the distance from the antenna or to unexplored intimate factors. Comparing the near fields of the two frequencies bands, we see similar not identical geometry in length and height from the antenna and that lower frequencies tend to drive to increased radiofrequency effects.

Evaluation for Web-Based Applications

Web applications are of the following categories: document-centric, interactive, transactional, workflow-based, portal-oriented, collaborative, social web, ubiquitous and semantic web. The web application modelling methods (content, hypertext, presentation, customization) and architectures (layered or data-aspect) influence the quality of a web application. Technology-aware web application design involves presentation, interaction and functional design. Testing involves planning, preparing, performing, reporting and agile approaches. In this chapter a model is proposed to evaluate web applications.

Social Networks Medical Image Steganography Using Sub-Fibonacci Sequences

Social network sites such as Google+, Facebook, Linkedin and Twitter have become a significant part of our modern lives. It is very true that social networks have changed our lives in many ways. One of them is private messaging, through this, people can share not only messages but pictures, videos and sounds with other users. The ability of picture sharing gives users the opportunity to use social networks to exchange secret information using steganographic methods. Nowadays, the transmission of medical images is a daily routine and it is necessary to find an efficient way using steganography to transmit them securely over the social networks. In this paper we examine social networks picture sharing possibilities and we propose a unique and safe steganographic method using sub-Fibonacci sequences.