Immune Microenvironment and Immunotherapeutic Management in Virus-Associated Digestive System Tumors

The development of cancer is a multifactorial phenomenon, while it constitutes a major global health problem. Viruses are an important factor that is involved in tumorigenesis and is associated with 12.1% of all cancer cases. Major examples of oncogenic viruses which are closely associated with the digestive system are HBV, HCV, EBV, HPV, JCV, and CMV. EBV, HPV, JCV, and CMV directly cause oncogenesis by expressing oncogenic proteins that are encoded in their genome. In contrast, HBV and HCV are correlated indirectly with carcinogenesis by causing chronic inflammation in the infected organs. In addition, the tumor microenvironment contains various immune cells, endothelial cells, and fibroblasts, as well as several growth factors, cytokines, and other tumor-secreted molecules that play a key role in tumor growth, progression, and migration, while they are closely interrelated with the virus. The presence of T-regulatory and B-regulatory cells in the tumor microenvironment plays an important role in the anti-tumor immune reaction. The tumor immune microenvironments differ in each type of cancer and depend on viral infection. The alterations in the immune microenvironment caused by viruses are also reflected in the effectiveness of immunotherapy. The present review aims at shedding light on the association between viruses and digestive system malignancies, the characteristics of the tumor immune microenvironment that develop, and the possible treatments that can be administered.     

Use of natural clinoptilolite for the removal of lead, copper and zinc in fixed bed column

This work deals with the removal of lead, copper and zinc from aqueous solutions by using natural zeolite (clinoptilolite). Fixed bed experiments were performed, using three different volumetric flow rates of 5, 7 and 10bed volume/h, under a total normality of 0.01N, at initial pH of 4 and ambient temperature (25 degrees C). The removal efficiency increased when decreasing the flow rate and the following selectivity series was found: Pb(2+)>Zn(2+)> or =Cu(2+). Conductivity measurements showed that lead removal follows mainly ion exchange mechanism, while copper and zinc removal follows ion exchange and sorption mechanism as well.     

Angiogenesis-Related Pathways in the Pathogenesis of Ovarian Cancer

Ovarian Cancer represents the most fatal type of gynecological malignancies. A number of processes are involved in the pathogenesis of ovarian cancer, especially within the tumor microenvironment. Angiogenesis represents a hallmark phenomenon in cancer, and it is responsible for tumor spread and metastasis in ovarian cancer, among other tumor types, as it leads to new blood vessel formation. In recent years angiogenesis has been given considerable attention in order to identify targets for developing effective anti-tumor therapies. Growth factors have been identified to play key roles in driving angiogenesis and, thus, the formation of new blood vessels that assist in “feeding” cancer. Such molecules include the vascular endothelial growth factor (VEGF), the platelet derived growth factor (PDGF), the fibroblast growth factor (FGF), and the angiopoietin/Tie2 receptor complex. These proteins are key players in complex molecular pathways within the tumor cell and they have been in the spotlight of the development of anti-angiogenic molecules that may act as stand-alone therapeutics, or in concert with standard treatment regimes such as chemotherapy. The pathways involved in angiogenesis and molecules that have been developed in order to combat angiogenesis are described in this paper.     

A survey on student dropout rates and dropout causes concerning the students in the Course of Informatics of the Hellenic Open University

This paper focuses on university-level education offered by methods of distance learning in the field of computers and aims at the investigation of the main causes for student dropouts. The presented study is based on the students of the Course of “Informatics”, Faculty of Science and Technology of the Hellenic Open University and investigates the particularities of education provided through the use of computers and technology in general. This paper presents information about the students' profile, the use of computer technology, the percentage of dropouts, as well as a classification of the reasons for dropouts based on interviews with the students. The study shows that dropouts are correlated with the use of technological means and, based on this fact, the Hellenic Open University implemented interventions in the use of such means. It also proves that a correlation exists between dropouts and students' age, but not gender, although female students are more reluctant to start following a course. However, it is also shown that female students' commitment to a course is stronger and thus, they do not drop out as easily as male students do. Furthermore, the results of this study strongly correlate dropouts to the existence of previous education in the field of Informatics or to working with computers, but not to the degree of specialisation in computers. Finally, the paper presents the reasons provided by the students for drooping out, with the main reasons being the inability to estimate the time required for university-level studies and the perceived difficulty of the computers course.     

An integrated routing and rate adaptation framework for multi-rate multi-hop wireless networks

In this paper, we propose a new integrated framework for joint routing and rate adaptation in multi-rate multi-hop wireless networks. Unlike many previous efforts, our framework considers several factors that affect end-to-end performance. Among these factors, the framework takes into account the effect of the relative positions of the links on a path when choosing the rates of operation and the importance of avoiding congested areas. The key element of our framework is a new comprehensive path metric that we call ETM (for expected transmission cost in multi-rate wireless networks). We analytically derive the ETM metric. We show that the ETM metric can be used to determine the best end-to-end path with a greedy routing approach. We also show that the metric can be used to dynamically select the best transmission rate for each link on the path via a dynamic programming approach. We implement the ETM-framework on an indoor wireless mesh network and compare its performance with that of frameworks based on the popular ETT and the recently proposed ETOP metrics. Our experiments demonstrate that the ETM-framework can yield throughput improvements of up to 253 and 368 % as compared with the ETT and ETOP frameworks.     

Visual impact evaluation of a wind park in a Greek island

The visual impact of wind turbines is one of the main factors affecting public acceptance of wind parks. This paper evaluates the visual impact of a wind park in Chania, Crete, using the Spanish method of evaluation. The outcomes are combined with the psychometric testing of the residents by the use of questionnaires and with the values of the Spanish method about various scenarios concerning the size of the wind park (double, half, one wind turbine). The results of the study prove that the quantification of the potential visual impact could minimize this, apparently, main reason that affects public acceptance.     

α‐Alumina nanospheres from nano‐dispersed boehmite synthesized by a wet chemical route

In this work, stable aqueous suspensions of nano‐boehmite were developed through a hybrid wet‐chemical route that uses hyperbranched dendritic poly(ethylene)imine (PEI) as template material for boehmite formation aiming at the development of a deagglomerated α‐alumina nanopowder after calcination. The method involves firstly the interaction between the Al precursor and PEI followed by the hydrolysis and polycondensation reactions. The study was aiming to investigate the effect of solids content and pH during reactions on both the stability of the final suspension and the morphology of the resulting nanocrystals. For this purpose, the suspensions were evaluated through viscosity measurements, zeta potential analyses, FT‐IR, DLS and sedimentation studies, whereas after the proper centrifugation, drying, and calcination steps, the as‐received nanocrystals were evaluated through SEM, TEM and XRD studies. In addition, the boehmite nanopowder was studied using Thermogravimetric and Differential Thermal Analysis, whereas its sinterability was evaluated by dilatometric measurements. The investigation showed that the conditions employed affect greatly both the morphology of nanocrystals as well as the dispersion and the stability of the suspensions. The boehmite suspension with the optimum dispersion and stability can lead, after calcination at 1050°C, to a fine deagglomerated α‐alumina nanopowder with a mean size at about 10 nm.     

Application of land-use planning criteria for the control of major accident hazards: a case-study

Land-use planning (LUP) with respect to major accident hazards is one of the more important requirements of Directive 96/82/EC (the so-called Seveso II Directive). Different approaches were developed by the Member States of the European Union in order to implement this aspect of the Directive. This study focuses on the comparison of the specific approaches developed for LUP with respect to major accidents hazards. An Italian industrial area has been selected to perform a case study. The different LUP criteria have been used both to evaluate the present state of the area and the effect of several proposed hazard reduction actions. The results obtained have allowed a comparison of the different LUP methodologies. Critical steps in the application of the different LUP criteria have been identified, and the different priorities of hazard reduction actions resulting from risk-based and consequence-based approaches have been highlighted.     

The Impact of Angiogenesis in the Most Common Salivary Gland Malignant Tumors

Salivary gland carcinomas (SGCs) represent a group of rare tumors, with complete surgical resection being the main treatment option. Therapeutic armory for cases of locally aggressive, recurrent, and/or metastatic SGCs, though, remains poor since they exhibit high rates of resistance to systematic therapy. Angiogenesis is considered one of the contemporary hallmarks of cancer and anti-angiogenic factors have already been approved for the treatment of several cancer types. This review aims to summarize, in a histotype-specific manner, the most current available data on the angiogenic factors implicated in SGC angiogenesis, in order to highlight the differences between the most common SGC histotypes and the factors that may have a potential role as therapeutic targets.