Synthesis of ferronickel slag-based geopolymers

This paper deals with the synthesis of geopolymers utilizing ferronickel slag as raw material. The utilized slag is produced in the Greek plant LARCO during the pyrometallurgical treatment of laterites for the production of ferronickel, specifically at the step of the reductive smelting in electric arc furnaces. The performed work includes the optimization of the slag-based geopolymeric system through the study of the effect of the synthesis parameters on the mechanical properties of the produced materials. The structure of geopolymers was determined with X-ray diffractometry (XRD), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The obtained results showed that the ferronickel slag is an excellent raw material for the production of inorganic polymers using the geopolymerization technology. The materials produced under the optimum synthesis conditions were compact and rigid and presented high compressive strength (118 MPa), as well as extremely low water absorption (0.7–0.8%).     

Consumer behaviour in the mobile telecommunications’ market: The individual’s adoption decision of innovative services

Research in the adoption of innovative services in mobile communications markets has not offered a comprehensive explanation of how the individual makes a choice. This article proposes a theoretical framework for the analysis of the adoption decision of innovative mobile services such as mobile TV. The decision to adopt the service can be viewed as a choice based on two cognitive processes of reasoning and referencing, as postulated in behavioural decision making. The framework has both theoretical and practical value. From a theoretical perspective, it illustrates the manner in which referencing and reasoning influence the individual’s decision to adopt innovative services in the mobile telecommunications market. From a practical perspective the framework offers a market analysis tool which can generate useful insights for the vendors.     

Tamoxifen derivatives for delivery of the antitumoral (DACH)Pt group: selective synthesis by McMurry coupling,and biochemical behaviour

The goal of our study was to potentiate the effects of the ((R,R)-trans-1,2-diaminocyclohexane)-platinum(II) fragment [(DACH)Pt], known for its cytotoxic properties, either with tamoxifen (Tam), the most widely used antiestrogen in the treatment of hormone-dependent breast cancers, or with its active metabolite hydroxytamoxifen (hydroxy-Tam). We coupled Tam or hydroxy-Tam derivatives bearing a malonato group at the para position of the beta aromatic ring with the (DACH)Pt fragment. The malonato-Tam and malonato-hydroxy-Tam compounds were prepared through McMurry coupling of the appropriate ketones. The presence of the malonate group resulted in a pronounced stereospecificity in the reaction, since malonato-Tam was obtained only as the Z isomer, while malonato-hydroxy-Tam was obtained as an 80/20 E/Z mixture. Attribution of the isomeric structures was achieved by 2D NMR spectroscopy. The platinum complexes (DACH)Pt-malonato-Tam and (DACH)Pt-malonato-hydroxy-Tam were then prepared by coupling the barium salts derived from the malonato-Tam and malonato-hydroxy-Tam with the nitrate derived from (DACH)PtCl(2). Study of the biochemical properties of these two platinum complexes showed that, while the hydroxy-Tam complex is satisfactorily recognized by the estrogen receptor (relative binding affinity, RBA=6.4 %), the Tam complex is less well recognized (RBA=0.5 %). The effects of these complexes on two hormone-dependent breast cancer cell lines (MCF7 and MVLN) were studied in vitro. Both complexes showed an antiproliferative effect on MCF7 cells, and an antiestrogenic effect on MVLN cells. The observed effects appear to be essentially antihormonal, since incorporation of the (DACH)Pt fragment into the tamoxifen skeleton did not cause an increase in the cytotoxicity of the complexes.     

Efficacy of different chemicals on shelf life extension of parsley stored at two temperatures

Four different chemical treatments, GA₃, 1‐MCP, essential oils and nano‐Cu, were applied immediately after harvest to Petroselinum crispum (Mill) plants. The efficacy of the above chemicals on shelf life extension of parsley stored at 5 °C and 20 °C was determined by analysing physiological and biochemical factors that determine quality standards of storage fresh parsley. Nonsprayed parsley revealed the highest loss of weight, ascorbic acid, pigments and an enhancement of CO₂ production and lipid peroxidation at 5 °C and 20 °C of storage. Nano‐Cu was more effective for delaying weight loss and revealed a better storage capacity. GA₃, 1‐MCP and essential oils sprays were more effective in ascorbic acid retention at 20 °C than at 5 °C, whereas all substances protect samples from lipid peroxidation. Essential oils were more clearly inhibitory towards both total viable counts and yeast infection. Our results suggest that GA₃, 1‐MCP, essential oils and Nano‐Cu exert their function through different mechanisms during ripening and could provide an effective and complementary means for maintaining high‐quality parsley leaves after harvest.     

Sensory characteristics and iron dialyzability of gluten-free bread fortified with iron

The objectives of the present study were (a) to produce gluten-free bread, fortified with iron (GFB-Fe), using selected iron compounds (ferric pyrophosphate, ferric pyrophosphate with emulsifiers, NaFeEDTA, electrolytic iron, ferrous gluconate, ferrous lactate and ferrous sulphate) (b) to test sensory characteristics of the GFB-Fe (feel-mouth texture, crumb colour, aroma and taste) (c) to compare iron dialyzability of various iron compounds in GFB-Fe. The most acceptable products were those fortified with ferric pyrophosphate with emulsifiers and ferric pyrophosphate. Ferrous dialyzable iron (ferrous iron with molecular weight lower than 8000 Da, an index for prediction of iron bioavailability) was measured under simulated gastrointestinal conditions. Ferrous dialyzable iron in GFB-Fe fortified with ferric pyrophosphate with emulsifiers, NaFeEDTA, ferrous bis-glycinate, ferrous gluconate or ferrous sulphate was higher than that in GFB-Fe fortified with electrolytic iron, ferrous lactate or ferric pyrophosphate (P < 0.05). These results are promising for the development of GFB-Fe products in the future.     

Rheological,Physical, and Sensory Attributes of Gluten‐Free Rice Cakes Containing Resistant Starch

In this study the effect of resistant starch (RS) addition on gluten‐free cakes from rice flour and tapioca starch physical and sensorial properties was investigated. Increase in RS concentration made cake batters less elastic (drop of G'(ω), G''(ω) values) and thinner (viscosity decreased). Cakes specific volume increased with an increase in RS level and was maximized for 15 g/100 g RS, although porosity values were significantly unaffected by RS content. Crumb grain analysis exhibited a decrease in surface porosity, number of pores and an increase in average pore diameter as RS concentration increased. During storage, cake crumb remained softer in formulations with increasing amounts of RS. Sensory evaluation of cakes demonstrated the acceptance of all formulations, with cake containing 20 g/100 g RS mostly preferred. Gluten‐free cakes with improved quality characteristics and high nutritional value can be manufactured by the incorporation of RS.     

Information Extraction and Knowledge Acquisition from Texts Using Bilingual Question–Answering

A novel approach is introduced in this paper for the implementation of a question–answering based tool for the extraction of information and knowledge from texts. This effort resulted in the computer implementation of a system answering bilingual questions directly from a text using Natural Language Processing. The system uses domain knowledge concerning categories of actions and implicit semantic relations. The present state of the art in information extraction is based on the template approach which relies on a predefined user model. The model guides the extraction of information and the instantiation of a template that is similar to a frame or set of attribute value pairs as the result of the extraction process. Our question–answering based approach aims to create flexible information extraction tools accepting natural language questions and generating answers that contain information extracted from text either directly or after applying deductive inference. Our approach also addresses the problem of implicit semantic relations occurring either in the questions or in the texts from which information is extracted. These relations are made explicit with the use of domain knowledge. Examples of application of our methods are presented in this paper concerning four domains of quite different nature. These domains are: oceanography, medical physiology, aspirin pharmacology and ancient Greek law. Questions are expressed both in Greek and English. Another important point of our method is to process text directly avoiding any kind of formal representation when inference is required for the extraction of facts not mentioned explicitly in the text. This idea of using text as knowledge base was first presented in Kontos [7] and further elaborated in [9,11,12] as the ARISTA method. This is a new method for knowledge acquisition from texts that is based on using natural language itself for knowledge representation.     

Nanometric Micelles with Photo‐Triggered Cytotoxicity

The development of a photo‐responsive micellar system capable of triggering cell death is reported. Precursors of the micelles are synthesized by connecting a lipophilic chain to a hydrophilic polyethylene glycol via a photo‐labile nitrobenzyl group. The resulting amphiphilic units are self‐assembled in water forming 12 nm micelles that are readily internalized into cells. Upon photo‐irradiation, micelles undergo cleavage and yield a cytotoxic nitrosobenzaldehyde derivative, which significantly inhibits the proliferation of MDA‐MB‐231 cells under standard in vitro conditions.     

ApoA1 Deficiency Reshapes the Phenotypic and Molecular Characteristics of Bone Marrow Adipocytes in Mice

In the present study, we studied the effect of apolipoprotein A-1 (APOA1) on the spatial and molecular characteristics of bone marrow adipocytes, using well-characterized ApoA1 knockout mice. APOA1 is a central regulator of high-density lipoprotein cholesterol (HDL-C) metabolism, and thus HDL; our recent work showed that deficiency of APOA1 increases bone marrow adiposity in mice. We found that ApoA1 deficient mice have greatly elevated adipocytes within their bone marrow compared to wild type counterparts. Morphologically, the increased adipocytes were similar to white adipocytes, and displayed proximal tibial-end localization. Marrow adipocytes from wild type mice were significantly fewer and did not display a bone-end distribution pattern. The mRNA levels of the brown/beige adipocyte-specific markers Ucp1, Dio2, Pat2, and Pgc1a; and the expression of leptin were greatly reduced in the ApoA1 knock-out in comparison to the wild-type mice. In the knock-out mice, adiponectin was remarkably elevated. In keeping with the close ties of hematopoietic stem cells and marrow adipocytes, using flow cytometry we found that the elevated adiposity in the ApoA1 knockout mice is associated with a significant reduction in the compartments of hematopoietic stem cells and common myeloid, but not of the common lymphoid, progenitors. Moreover, the ‘beiging’-related marker osteopontin and the angiogenic factor VEGF were also reduced in the ApoA1 knock-out mice, further supporting the notion that APOA1—and most probably HDL-C—regulate bone marrow microenvironment, favoring beige/brown adipocyte characteristics.     

The Role of Leptin in Childhood Immune Thrombocytopenia (ITP): An Anti-Inflammatory Agent?

To investigate the effect of leptin in childhood ITP, we measured plasma leptin in 39 children with acute ITP, after treatment and in remission, and in 33 healthy age/BMI-matched controls. We also cultured ITP and control peripheral blood mononuclear cells (PBMCs) with recombinant leptin to assess its direct effect on pro/anti-inflammatory cytokine gene expression. A significant increase in leptin was observed in children with active disease compared to controls. A significant inverse correlation of leptin with platelet count was also observed in children with acute ITP. Leptin remained high after treatment with IVIg, whereas steroid treatment lowered leptin below control levels. In remission, leptin was in the control range. Cytokine gene expression was significantly increased in children with acute ITP compared with controls, with highest expression for IFN-γ and IL-10. IVIg/steroid treatment significantly decreased IFN-γ and IL-10 expression. In remission, IFN-γ and IL-10 expression remained low. Addition of leptin to PBMCs isolated from patients in remission resulted in a significant increase in IL-10 gene expression compared to controls. Further experiments with purified T-cells and monocytes identified monocytes as the source of leptin-induced IL-10. We suggest that leptin acts as an active anti-inflammatory agent in childhood ITP by promoting IL-10 secretion by monocytes.