Changes in sugar,organic acid,flavonol and carotenoid composition during ripening of berries of three seabuckthorn (<Emphasis Type="Italic">Hippophae rhamnoides</Emphasis> L.) cultivars

Soluble solid, sugar, organic acid, flavonol and carotenoid content were determined in seabuckthorn berries of the three German cultivars Askola, Hergo and Leikora, collected at different harvesting times, to provide a more thorough knowledge of quality changes occurring during ripening of the berries. The main organic acids were malic (1940–4660 mg/100 g), quinic (810–2820 mg/100 g), ascorbic (180–370 mg/100 g) and citric acid (90–160 mg/100 g). In all three cultivars a marked decline in total organic acid concentration was observed during ripening. The pattern of variation of sugars, glucose (0.26–2.10 g/100 g) and fructose (0.14–0.54 g/100 g), was somewhat different among the three cultivars. In all three cultivars ascorbic acid concentration decreased during ripening. The main flavonols were isorhamnetin (350–660 mg/kg), quercetin (30–100 mg/kg) and kaempferol (2–5 mg/kg). The trends of flavonol content during ripening were quite different among the three cultivars. The main carotenoids were zeaxanthin (30–150 mg/kg), -carotene (3–50 mg/kg) and -criptoxanthin (5–19 mg/kg). The genotype seemed to affect both the extent of carotenoid accumulation and the carotenoid profile but in all three cultivars ripening was accompanied by an increase in total carotenoid concentration. The various classes of antioxidants showed quite different patterns of variation during ripening, achieving their maximum level at different harvesting dates.     

Characterization of the mechanism of interaction in ibuprofen-Eudragit RL100 coevaporates

The present study is a preliminary exploration of the affinity between a carboxylic model drug, the nonsteroidal antiinflammatory agent ibuprofen (IBU) and Eudragit RL100 (RL) polymer. Due to the presence of a variable amount of quaternary ammonium groups in this matrix, physical and chemical interaction with the carboxylic drug can occur, which reinforces its scant mechanical dispersion in the polymer network and can ultimately affect its release profile in vitro and in vivo. To study these aspects, IBU was mixed at increasing weight ratios and in different chemical forms (free acid, sodium salt, and n-butyl ester), to investigate further the role of the carboxylic group in the interaction with the RL polymer. Therefore, IBU-RL solid dispersions (coevaporates) were obtained and fully characterized in the solid state through spectroscopic, calorimetric, and x-ray diffractometric analyses. The in vitro release pattern of the drug, in the different chemical states, was studied for the coevaporates, compared with drug-RL physical mixtures, along with drug adsorption profiles from aqueous solutions on the surface of the polymer granules.     

EXPERIMENTAL IMPLEMENTATION OF AN ARTIFICIAL IMMUNE SYSTEM ON A ROBOTIC MANIPULATOR

An artificial immune system (AIS) has been used to realize robust control of a robotic manipulator. The AIS recognizes “self” and “non-self” operation of a closed-loop system, where self is defined as a condition where controller gains are appropriate for a given manipulator configuration. As configuration changes occur, the changing performance of the system indicates a transition to non-self. When non-self operation is first detected, the corresponding dynamic response is defined as a receptor and a genetic algorithm (GA) is called to optimize the controller for the new configuration. A library of receptors is built as additional configuration changes are experienced. For subsequent self to non-self transitions, new and recorded receptors are compared. In the event of a high correlation between the receptors, previously determined controller gains are implemented without calling the GA. The system is agile and robust and can recognize and respond to recognized receptors within a single reference step.     

Observations of wind and ocean wave fields using ERS Synthetic Aperture Radar imagery

The aim of the research reported here is to evaluate Synthetic Aperture Radar (SAR) capability to estimate the wind vector and associated directional wave spectrum. Two ERS–2 SAR images of the Mediterranean Sea, one over the Sicily Channel and one over the Ligurian Sea, were selected as case studies. Wind speed was estimated using SAR calibrated backscatter response, in conjunction with empirically derived ERS scatterometer models such as CMOD4 and CMOD–IFREMER. The predictions of these models were then compared with the actual sea surface wave spectra either provided by in situ measurements or resulting from the inversion of the SAR image spectrum. SAR-detected effects of both wind and wave features, induced either by atmospheric boundary layer instability or by land shadowing, were also used as reliable indicators of wind direction.     

Modeling failure of heterogeneous viscoelastic solids under dynamic/impact loading due to multiple evolving cracks using a two-way coupled multiscale model

This paper presents a model for predicting damage evolution in heterogeneous viscoelastic solids under dynamic/impact loading. Some theoretical developments associated with the model have been previously reported. These are reviewed briefly, with the main focus of this paper on new developments and applications. A two-way coupled multiscale approach is employed and damage is considered in the form of multiple cracks evolving in the local (micro) scale. The objective of such a model is to develop the ability to consider energy dissipation due to both bulk dissipation and the development of multiple cracks occurring on multiple length and time scales. While predictions of these events may seem extraordinarily costly and complex, there are multiple structural applications where effective models would save considerable expense. In some applications, such as protective devices, viscoelastic materials may be preferred because of the considerable amount of energy dissipated in the bulk as well as in the fracture process. In such applications, experimentally based design methodologies are extremely costly, therefore suggesting the need for improved models. In this paper, the authors focus on the application of the newly developed multiscale model to the solution of some example problems involving dynamic and impact loading of viscoelastic heterogeneous materials with growing cracks at the local scale.     

19-Azasqualene-2,3-epoxide and its N-oxide: Metabolic fate and inhibitory effect on sterol biosynthesis in Saccharomyces cerevisiae

19-Azasqualene-2,3-epoxide was more inhibitory than the corresponding N-oxide against 2,3-oxidosqualene cyclase (OSC) solubilized from Saccharomyces cerevisiae (IC₅₀ 7±2 and 25±5 μM, respectively). Both compounds showed a reversible, noncompetitive-type inhibition on solubilized OSC. Different inhibitory properties between the compounds were especially evident when measuring [¹⁴C]acetate incorporation into nonsaponifiable lipids extracted from treated cells. In cells treated with 19-azasqualene-2,3-epoxide at 30 μM, the radioactivity associated with the oxidosqualene fraction, which was negligible in the controls, rose to over 40% of the nonsaponifiable lipids, whereas it remained at a slightly appreciable level in cells treated with the N-oxide derivative under the same conditions. 19-Azasqualene-2,3-epoxide was also more effective than the N-oxide as a cell growth inhibitor (minimal concentration of compound needed to inhibit yeast growth: 45 and >100 μM, respectively). The two inhibitors underwent different metabolic fates in the yeast: while 19-azasqualene-2,3-epoxide did not undergo any transformation, its N-oxide was actively reduced to the corresponding amine in whole and in “ultrasonically stimulated” cells. The N-oxide reductases responsible for this transformation appear to be largely confined within the microsomal fractions and require NADPH for their activity. A possible relationship between the inhibitory properties of the two compounds and their metabolic fates is discussed.     

Image Analysis Techniques for Automated Hazelnut Peeling Determination

According to FAO statistics, in 2000, Italy was the second largest hazelnut (Corylus avellana, L. 1753) producer in the world. The price of the stock depends on the nut quality (kernel/nut ratio, nut and seed defect, percentage of peeling, and taste panel scores). The evaluation of peeling efficiency after toasting is generally conducted by trained operators in sight on 100 kernels. This work tests two alternative objective methods of after toasting peeling evaluation based on image analysis. Eleven hazelnut cultivars were analyzed and results were compared with the ones assessed by trained operators. Images were analyzed with two statistical approaches: fixed values of RGB thresholding and trained K Nearest Neighbors (KNN). Root mean squared error (RMSE), estimating the comparison between operators and the two image analysis-based techniques, shows better results for KNN (6.6) with respect to fixed threshold (15.9).     

Electrochemical properties of self-assembled monolayer based on mono-(6-deoxy-6-mercapto)-β-cyclodextrin toward controlled molecular recognition

The present work describes the construction of nanoporous assemblies based on single self-assembled monolayer (SAM) of mono-(6-deoxy-6-mercapto)-β-cyclodextrin (βCDSH) and two-component monolayers of βCDSH and 11-mercaptoundecanoic acid. An investigation of its supramolecular properties toward the tricyclic antidepressants drugs chlorprothixene and imipramine is also presented. The adsorption process was investigated by using surface plasmon resonance and the selectivity of the SAM was verified by using electroactive species permeable and not permeable into the cyclodextrin SAM, such as ferrocenemonocarboxylic acid, hexacyanoferrate, methylene blue and hexamineruthenium (II). The redox probe was chosen based on its capability to permeate the grafted cyclodextrin molecules and its electrochemical characteristics. It was applied to imipramine and chlorprothixene competitive assay by the mono-(6-deoxy-6-mercapto)-β-cyclodextrin self-assembled cavity. Finally, the pK_a of the surface and its effects on thee host-guest interaction properties were also investigated.