Designed spiro-bicyclic analogues targeting the ribosomal decoding center

The bacterial ribosome represents the confirmed biological target for many known antibiotics that interfere with bacterial protein synthesis. Aminoglycosides represent a lead paradigm in RNA molecular recognition and constitute ideal starting points for the design and synthesis of novel RNA binders. Previous rational design approaches of RNA-targeting small molecules have been mainly concentrated on direct functionalization of aminoglycosidic substructures. Herein, we successfully designed and synthesized rigid spirocyclic scaffolds locked in a predicted ribosome-bound "bioactive" conformation. These analogues are able to mimic many of the interactions of the natural products for the A-site, as proven by their obtained binding affinities. The development of an optimized approach for their synthesis and their potential to inhibit protein production in vitro are presented. Our results could be further utilized for the development of analogues with improved antibiotic profiles.     

Contribution of thermal,rheological and physical measurements to the determination of sensorially perceived quality of ice cream containing bulk sweeteners

The role of rheological measurements, thermal analysis and physical properties such as overrun, instrumental hardness and melting behavior on sensorial profile mapping of vanilla ice cream was evaluated. Samples with different functional characteristics were prepared partially substituting sucrose by bulk sweeteners. Creaminess apart from thermal properties (glass transition temperature-T_g, ice crystal uniformity-ΔΤ_mcurve and unfrozen water content-UFW) was poorly related with rheological and physical properties. On the contrary, coarseness, wateriness, greasiness and gumminess perception were found to be well correlated with rheological and thermal properties, overrun, air cells mean size and melting rate. Flavor and taste characteristics were interrelated particularly with melting and thermal characteristics, overrun and air cells mean size. Multivariate exploratory statistical methods revealed that the use of T_g, ΔΤ_mcurve, UFW, instrumental hardness, and melting rate can be used for the effective discrimination of ice creams differing in their sweetener composition suggesting their importance in the design of novel ice cream formulations.     

Binary Mixtures of Modified Starch, Maltodextrin and Chitosan as Efficient Encapsulating Agents of Fennel Oleoresin

The present study reports on the encapsulation of fennel oleoresin by freeze-drying method using binary mixtures of modified starch, maltodextrin and chitosan, while a ternary one was also evaluated. The encapsulation ability of the used agents was evaluated based on their microencapsulating efficiency and storage stability towards the main compounds of fennel oleoresin. The properties of the initial formed emulsions (emulsion mean diameter, stability and viscosity) and the freeze-dried final products (moisture content, redispersibility, topography and storage stability) were also examined. Comparing the protection offered by the encapsulating agents, modified starch–chitosan mixture provided the greatest protection in terms of storage stability.     

Spray Drying of Raisin Juice Concentrate

Raisin juice concentrate is a natural sweetener in syrup or paste form and it is produced from second-grade dry raisins by leaching them with water. Dried raisin juice, although is easier to handle and has more potential applications than the syrup, is not available in the market. In the present study, raisin juice powder was produced with a lab-scale spray dryer. The problem of stickiness in the drying chamber was overcome through the use of 21 DE, 12 DE, and 6 DE maltodextrins as drying aid agents. For each type of maltodextrin, the dryer operating conditions and the minimum concentration of maltodextrin in the feed, necessary for successful powder production, were determined. The maximum ratio of (raisin juice solids)/(maltodextrin solids) achieved was 67/33 and was made possible with the use of 6 DE maltodextrin. The inlet and outlet drying air temperatures were 110 and 77°C respectively, while the feed contained 40% w/w total solids. The physical and sensory properties of all powders produced were determined and found to be satisfactory, the only exception being their high hygroscopicity.     

Experimental studies and analysis of the draping of woven fabrics

This study investigates and compares the draping and forming of four types of woven fabrics, namely a loose plain weave (basket weave), a tight plain weave, a satin and a twill weave. The fabrics were draped over a hat mould consisting of a hemispherical dome surrounded by a flat base. The draping of each fabric was examined in terms of wrinkle formation, boundary profile of the draped fabric, distribution of fibre orientation and local shear angles. A theoretical analysis of the experimental results involved the calculation of the distributions of the fibre volume fraction and mechanical properties, in terms of components of the reduced stiffness matrix, from the experimental data of local shear angles.     

Effect of Different Raisin Juice Preparations on Selected Properties of Gluten-Free Bread

Incorporation of sucrose and raisin juice (in concentrated or in dried form) at 3 and 5% of flour weight to commercial wheat starch (Codex Alimentarius) gluten-free flour was carried out to examine the effects on baking, textural, and sensory properties of bread. Breads made with gluten-free flour are usually characterized by poor color and baking characteristics, as well as short shelf life. The current study was conducted to help solve these problems by using raisin juice, a natural sweetener that contains no preservatives, has lower caloric content than sucrose, and includes a number of important vitamins and minerals that are very important for the coeliac disease patients. The study showed that 3% raisin juice in concentrated form contributes to a great improvement in loaf volume, color, and hardness characteristics of gluten-free bread during the first day after baking but a higher staling rate because of its high moisture content. Dried raisin juice gave bread higher loaf volume and better color compared to the control gluten-free bread and also increased its shelf life because of its moisture absorption properties. Sensory analysis revealed a preference for breads containing concentrated raisin juice because of its fruity flavor, whereas all the samples that contained 5% raisin juice had very dark color.     

Effect of poly(3,4-ethylenedioxythiophene) (PEDOT) in carbon-based composite electrodes for electrochemical supercapacitors

Electrochemical double layer supercapacitor cells were fabricated and tested using composite electrodes of activated carbon with carbon black and poly(3,4-ethylenedioxythiophene) (PEDOT), and an organic electrolyte 1 M TEABF₄/PC solution. The effect of PEDOT on the performance of the EDLC cells was explored and the cells were characterised by electrochemical impedance spectroscopy (EIS), cyclic voltammetry and galvanostatic charge-discharge. A generalised equivalent circuit model was developed for which numerical simulations were performed to determine the properties and parameters of its components from the EIS data. It was found that the proposed model fitted successfully the data of all tested cells. PEDOT enhanced the electrode and cell capacitance via its pseudo-capacitance effect up to a maximum value for an optimum PEDOT loading and greatly increased the energy density of the cell while the maximum power density has been still maintained at supercapacitor levels. Furthermore, PEDOT replaced PVDF as a binder and harmful solvent release was reduced during electrode processing. Activated carbon-carbon black composite electrodes with PEDOT as binder were found to have specific capacitance superior to that of activated carbon-carbon black electrodes with PVDF binder.     

The effect of process time and temperature on the accumulation of polar compounds in cottonseed oil during deep‐fat frying

The deterioration of oil during successive fryings of potato chips, especially the accumulation of polar compounds, was studied in the temperature range 155–195 °C. The content of polar compounds increased linearly with process time. The analysis of individual polar compounds showed that the products of thermal and oxidative degradation dominated over the products of hydrolytic cleavage as frying proceeded. Dimeric triglycerides increased linearly with process time, while polymerised triglycerides increased exponentially. The rate constants of the degradation reactions increased slightly with temperature, following an Arrhenius‐type equation. Oxidised triglycerides increased with frying time up to 6 h, thereafter remaining constant or increasing further upon prolonged frying. The increase was greater at higher temperature. The products of hydrolytic cleavage were not significantly affected by temperature. Mono‐ and diglycerides increased initially to reach a plateau, while free fatty acids remained almost constant throughout frying. The thermo‐oxidative alterations induced by heating the oil were also measured and compared with those observed during frying at the same temperature. Dimeric and polymerised triglycerides showed higher rates of increase during heating as compared with frying at the same temperature. © 2003 Society of Chemical Industry     

Numerical simulation of overbank flood discharges

A full computer based investigation of the factors influencing the modelling of overbank flood discharges has been carried out. Several floods of differing magnitudes and peak curvatures were routed down regular channels using an implicit finite difference scheme and the influence of time and distance steps used for the numerical solution of the flow equations were investigated. Spillage over sharp crested weirs was assumed to satisfactorily simulate the overbank flood discharge; the importance of a correct estimation of the coefficient of discharge was also checked. It was shown that sensibly chosen values of the time step had little effect on the simulations. This was also true for the value of the coefficient of discharge when the sideweir flow was predominately drowned, but not for free flow conditions. It was also shown that close spacing of computational nodes was required at the onset of overbank flow to accurately simulate the overflow and also model the occurrence of large water level gradients.     

Study of Formulation and Stability of Co-surfactant Free Water-in-Olive Oil Nano- and Submicron Emulsions with Food Grade Non-ionic Surfactants

Nanoemulsions are of great interest in food industry finding various food applications. However, oil-in-water (o/w) nanoemulsions have been intensively investigated, but there are few studies on w/o nanoemulsions. In the present work the preparation of nanoemulsions with olive oil using non-ionic surfactants (Tween 20, 40, 60, 80, Span 20, 80) without the addition of a co-surfactant was studied and their emulsion properties and stability were examined. The stable nanoemulsions were presented in ternary phase diagrams (oil–water-surfactant) for each surfactant and the emulsifying ability of the efficient surfactants was determined. The nanoemulsions properties were evaluated in relationship to compositional components. From the results of this study it can be concluded that stable olive oil nanoemulsions without use of a co-surfactant were obtained and moreover the most efficient type of emulsifier and its ratio of addition in the system were determined.