Is computer science science or are computer scientists scientists?

Editorial

Is computer science science or are computer scientists scientists?     

Bioactivity of Greek honey extracts on breast cancer (MCF-7), prostate cancer (PC-3) and endometrial cancer (Ishikawa) cells: Profile analysis of extracts

Historically, honey has been important in Greek culture. The chemical composition and the potential of Greek honey extracts (thyme, pine and fir honey) to influence the oestrogenic activity and the cell viability of breast (MCF-7), endometrial (Ishikawa) and prostate (PC-3) cancer cells were investigated. All honeys contained total phenolics, phenolic acids and hydroxymethylfurfural, the levels being highest in thyme honey. Sugars and volatile compounds, but not fatty acids, were detected in all honey extracts. Thyme, pine and fir honey showed both antioestrogenic and a weak oestrogenic effect at low and high concentration, respectively, in MCF-7 cells. Thyme honey reduced the viability of Ishikawa and PC-3 cells, whereas fir honey stimulated the viability of MCF-7 cells. In conclusion, Greek honeys are rich in phenolic compounds, they modulate oestrogenic activity whereas a thyme honey-enriched diet may prevent cancer-related processes in breast, prostate and endometrial cancer cells.     

Effect of Citrus essential oil addition upon growth and cellular lipids of Yarrowia lipolytica yeast

The chemical composition of the essential oil from fruits of the Greek citrus hybrid Citrus sinensis cv New Hall – Citrus aurantium was investigated by GC and GC-MS. Forty-four compounds were identified, representing 92.83% of the total oil. Limonene, myrcene, β-pinene, α-pinene and α-terpineol constituted the major components of the oil. The effect of the addition of this oil upon the behavior of Yarrowia lipolytica yeast was also investigated. The microorganism was aerobically grown on glucose and oil was added to the culture medium in various initial quantities (from 0.0 to 1.5 mL/L). The strain underwent significant inhibition exerted by the added essential oil; a decrease of the highest achieved biomass concentration, even if the oil was added to the culture medium at small concentrations (e.g. 0.3 mL/L), was observed. The more oil was added, the more the lag phase of the growth increased, while the biomass yield on glucose consumed decreased with the addition of the oil. When the essential oil was added to the medium, even at small concentrations, a significant increase of cellular medium-chain saturated fatty acids (12:0 and 14:0) resulting in an increase of saturated fatty acid content in the cellular lipids, was observed.     

Phase relations in the calcium carbonate/ammonium phosphate system under aqueous conditions and 25°C

A theoretical and experimental approach was applied to investigate phase relations in a system containing calcium carbonate and different ammonium phosphate solutions. Using laboratory experiments and thermodynamic modeling, this paper provides an insight into the formation of stable phase assemblages in the calcium carbonate and mono-, di-, triammonium phosphate aqueous system . Focus is placed on the morphological and mineralogical characterization and thermodynamic calculation of calcium phosphates precipitating due to the reaction between the calcium carbonate and ammonium phosphate solutions. Correlations between the formed stable calcium phosphate phases and the ammonium phosphate precursors are provided. Advantages and limitations of various analytical and modeling techniques used in this study such as geochemical equilibrium-based modeling, X-ray diffraction, scanning electron microscopy, and thermal analysis, are critically evaluated. Additionally, possible impacts of the ammonium phosphate solution type on the kinetics of phase transformations are discussed.     

Reevaluation of bioactivity and antioxidant activity of <Emphasis Type="Italic">Myrtus communis</Emphasis> extract before and after encapsulation in liposomes

The antioxidant and antimicrobial activity of Myrtus communis extract was determined before and after its encapsulation in liposomes of different composition. Evaluation of the sunflower oil oxidation by the Rancimat stability test and malondialdehyde formation by HPLC were used to measure the antioxidant action in comparison with common commercial antioxidants, such as butylated hydroxytoluene and α-tocopherol. The thermal-oxidative decomposition of the samples, the modification of the main transition temperature for the lipid mixture and the splitting of the calorimetric peak in the presence of the antioxidants were studied by differential scanning calorimetry. The size and the surface charge of liposomes were also studied. The extract showed antioxidant and antimicrobial activity. Αt concentrations up to 160 ppm, the extract showed superior activity than α-tocopherol. When the extract was encapsulated in liposomes, its antioxidant as well as its antimicrobial activity proved to be superior from that of itself in pure form.     

Microfluidic Biosensing Systems Using Magnetic Nanoparticles

In recent years, there has been rapidly growing interest in developing hand held, sensitive and cost-effective on-chip biosensing systems that directly translate the presence of certain bioanalytes (e.g., biomolecules, cells and viruses) into an electronic signal. The impressive and rapid progress in micro- and nanotechnology as well as in biotechnology enables the integration of a variety of analytical functions in a single chip. All necessary sample handling and analysis steps are then performed within the chip. Microfluidic systems for biomedical analysis usually consist of a set of units, which guarantees the manipulation, detection and recognition of bioanalytes in a reliable and flexible manner. Additionally, the use of magnetic fields for performing the aforementioned tasks has been steadily gaining interest. This is because magnetic fields can be well tuned and applied either externally or from a directly integrated solution in the biosensing system. In combination with these applied magnetic fields, magnetic nanoparticles are utilized. Some of the merits of magnetic nanoparticles are the possibility of manipulating them inside microfluidic channels by utilizing high gradient magnetic fields, their detection by integrated magnetic microsensors, and their flexibility due to functionalization by means of surface modification and specific binding. Their multi-functionality is what makes them ideal candidates as the active component in miniaturized on-chip biosensing systems. In this review, focus will be given to the type of biosening systems that use microfluidics in combination with magnetoresistive sensors and detect the presence of bioanalyte tagged with magnetic nanoparticles.     

Effect of inulin on texture and clarity of gellan gels

The effect of inulin on the gelation of 0.5 wt% low acyl gellan in the presence of increasing concentrations of potassium chloride was investigated by large deformation compression experiments and visible light absorbance. The sugar and salt concentrations varied from 0 to 15 wt% and 40-100 mM, respectively. Stress and strain at failure along with Young’s modulus were calculated from each compression curve. Samples prior to compression were refrigerated at 5 °C for 24 h. Reduced gel strength and firmness were observed for all inulin and salt concentrations. Increasing amounts of inulin resulted in an increase in gel strength which was greater for higher potassium concentrations. Elasticity values did not exhibit great diversion. Inulin at concentrations of 5 and 10 wt% led to less turbid gels than those with only gellan. Samples containing 15 wt% inulin gave absorbance readings greater than 1.     

Reputation,framing strategies and user's choice of content on the Web: an empirical study

Current trends on the Internet indicate an increasing supply of content from anonymous users (e.g. blogs), which may become popular among website visitors. Motivated by these Internet trends, the present study explores the tradeoffs between the source's reputation and the way content is displayed or offered on the web page as well as the effects of both on the Internet user's choice of information services. The study builds upon behavioral economics and focuses on the interaction between background and local context effects on the individual's choice. In particular, the study investigates the tradeoffs between the source's reputation, representing the background context and the provision of enriched content (e.g. source bundled with a picture or a video) representing local context. The research involved a set of experiments based on hypothetical choice or matching tasks. The main findings indicate that there are significant interaction effects between reputation and enriched content, in the form of content related pictures, video and users' recommendations, which affect the user's choice of information services. Copyright © 2009 John Wiley & Sons, Ltd.     

The Citizen Health System (CHS): a modular medical contact center providing quality telemedicine services.

In the context of the Citizen Health System (CHS) project, a modular Medical Contact Center (MCC) was developed, which can be used in the monitoring, treatment, and management of chronically ill patients at home, such as diabetic or congestive heart failure patients. The virtue of the CHS contact center is that, using any type of communication and telematics technology, it is able to provide timely and preventive prompting to the patients, thus, achieving better disease management. In this paper, we present the structure of the CHS system, describing the modules that enable its flexible and extensible architecture. It is shown, through specific examples, how quality of healthcare delivery can be increased by using such a system.