Exploring new potential health‐promoting vegetables: glucosinolates and sensory attributes of rocket salads and related Diplotaxis and Eruca species

BACKGROUND: Rocket salads (Diplotaxis tenuifolia and Eruca vesicaria) are presently highly appreciated salad vegetables. Related species are consumed as food plants in several regions, and may contribute to differentiation in the fresh food supply chain. Glucosinolates are well‐known healthy phytochemicals and responsible for positive and negative sensory properties of edible Brassicaceae. To investigate the potential for exploitation of new crops, Diplotaxis and Eruca germplasm was subject to sensory evaluation and glucosinolate analysis. RESULTS: Typical rocket salad flavour and pungency were perceived as positive sensory traits. Bitter, and especially herbaceous notes, characterised the groups of less accepted accessions. The groups classified as significantly unpleasant were characterised by high glucosinolate content, with either sinigrin (strong perceived pungency, flavour and several other additional sensory notes), or sinalbin/gluconapin (strong herbaceous note, low flavour perceived), as the dominant components. CONCLUSIONS: Low glucosinolate content, and a composition rich in recognised health‐promoting components (glucoerucin, glucoraphanin) were associated with higher acceptance. In relation to food uses, moderate glucosinolate content and high acceptance may be a better option to enhance the intake of healthy phytochemicals than high glucosinolates and potential rejection. High glucosinolate types may find better perspectives in the field of food integrators. Copyright © 2009 Society of Chemical Industry     

User authentication using keystroke dynamics for cellular phones

A new approach for keystroke-based authentication when using a cellular phone keypad as input device is presented. In the proposed method, users are authenticated using keystroke dynamics acquired when typing fixed alphabetic strings on a mobile phone keypad. The employed statistical classifier is able to perform user verification with an average equal error rate of about 13%. The obtained experimental results suggest that, when using mobile devices, a strong secure authentication scheme cannot rely on the sole keystroke dynamics, which however can be a module of a more complex system including, as basic security, a password-based protocol eventually hardened by keystroke analysis.     

Phase selection enabled formation of abrupt axial heterojunctions in branched oxide nanowires

Rational synthesis of nanowires via the vapor-liquid-solid (VLS) mechanism with compositional and structural controls is vitally important for fabricating functional nanodevices from bottom up. Here, we show that branched indium tin oxide nanowires can be in situ seeded in vapor transport growth using tailored Au-Cu alloys as catalyst. Furthermore, we demonstrate that VLS synthesis gives unprecedented freedom to navigate the ternary In-Sn-O phase diagram, and a rare and bulk-unstable cubic phase can be selectively stabilized in nanowires. The stabilized cubic fluorite phase possesses an unusual almost equimolar concentration of In and Sn, forming a defect-free epitaxial interface with the conventional bixbyite phase of tin-doped indium oxide that is the most employed transparent conducting oxide. This rational methodology of selecting phases and making abrupt axial heterojunctions in nanowires presents advantages over the conventional synthesis routes, promising novel composition-modulated nanomaterials.     

Origin of informational polymers: The concurrent roles of formamide and phosphates

Formamide chemistry provides a unitary system by gathering all of the precursors needed to synthesise pregenetic informational polymers in a single milieu. This is not observed with HCN chemistry. With common catalysts, formamide affords all of the precursor nucleobases, photochemically condenses into acyclonucleosides, favours transphosphorylation and enhances micellar aggregation of surfactants. Also, formamide provides a set of physicochemical conditions that thermodynamically favour the polymeric state of nucleotides over the monomers. In the origin-of-informational-polymers scenario, formamide acts in every step, the least characterised being the set of its reactions with phosphates. On this matter, we report two complementary sets of results: 1) the synthesis of prebiotic precursors from formamide, which are catalysed by soluble and mineral phosphates-we observed the formation of rich mixtures that include uracil, 9H-purine, cytosine, dihydrouracil, hypoxanthine, adenosine, urea, parabanic acid, the amino acid N-formylglycine and the peptide-condensing agent carbodiimide; and 2) the protection of ribo- and deoxyribophosphoester bonds by phosphates. The relevance of these effects with respect to the origin of informational polymers is discussed.     

Lamin A is part of the internal nucleoskeleton of human erythroleukemia cells

Nuclear lamins are the most abundant components of the nuclear lamina, a 10-50-nm-thick fibrous layer underlying the inner nuclear envelope membrane. Nevertheless, a number of recent investigations performed on epithelial and fibroblast cells have suggested that nuclear lamins are also present within the nucleoplasm and could be important constituents of the nucleoskeleton. We have studied the subnuclear distribution of lamins A and B1 in human erythroleukemia cells by using immunoblotting analysis and immunofluorescent staining of fractionated nuclei. In intact cells and isolated nuclei, antibodies to lamins A and B1 mainly stained the nuclear periphery, although some immunoreactivity was detected in the nuclear interior. However, when chromatin was removed by nuclease digestion and extraction with nonionic detergent or solutions of high ionic strength, a previously masked immunoreactivity for lamin A, but not for lamin B1, became evident in the internal part of the residual structures representing the nuclear matrix or scaffold. Preferential localization of lamin A to the inner part of the nucleus was also demonstrated by the presence of the majority of lamin A in the solubilized inner nuclear network subfraction. In contrast, lamin B1 was mainly recovered in the fraction corresponding to the nuclear periphery. Double labeling experiments showed that lamin A, but not lamin B1, colocalized with coiled and GATA-1 bodies. Thus, our results support the hypothesis that lamin A, but not lamin B1, may be a component of an internal nucleoskeleton in human erythroleukemia cells.     

Towards the design of an antibody that recognises a given protein epitope

We have explored the possibility of designing repertoires of antibodies complementary to a given protein epitope, specifically the face of the ribonuclease inhibitor barstar that binds to the enzyme barnase. An antibody repertoire was created by mutation of ten residues in the hypervariable loops of a synthetic antibody fragment and displayed on filamentous bacteriophage. The positions of three of the ten residues of the antibody (VL 32, 50 and 94) were chosen to match a triangle of three negative charges on the face of barstar and mutated to favour residues of opposite charge or those with hydrogen-bonding potential. The other seven residues, chosen to allow for variation in the surface of interaction, were mutated at random. One of the antibody fragments isolated after selection of the repertoire (10(8) clones per library) was shown to bind to barstar with an affinity of 1.0x10(-7) M and the binding was competed by barnase. Furthermore, the binding of the antibody to barstar was highly sensitive to mutation of any of five residues of barstar known to contact barnase. This indicates that it may be possible, by a combination of design and selection, to build antibodies to a given epitope.     

Initial code synchronization of W-CDMA mobile systems exploiting local phase coherence and Pisarenko estimation

Noncoherent techniques can be adopted for pseudonoise code synchronization in the presence of random phase. Differentially coherent methods conversely operate with linear phase shifts, such as when a systematic frequency error occurs. This letter presents a method exploiting local phase coherence (inspired by the Pisarenko estimation), allowing global frequency estimation in the presence of random phase noise. Its accuracy is numerically compared with noncoherent and differential techniques for the initial stage of wideband code-division multiple-access code synchronization.     

Scale-up of sulphur resistant promoted-vanadium oxide catalysts for self-regenerating catalytic filters in off-road diesel engines and domestic apparatus

Wall-flow catalytic filters were prepared by impregnation of porous cordierite honeycombs with Cs-Fe-V catalysts. The catalytic filters were tested at the exhaust of a gas-oil burner. Results reported indicate that the trapped soot begin to burn at a temperature around 300–320 °C allowing the self-regeneration of the filter. Performances were found to remain stable also under high SO₂ concentrations, making these catalytic filters suitable for soot removal in off-road diesel engines and domestic apparatus.     

Usefulness of Leifson staining method in diagnosis of Helicobacter pylori infection

The Leifson staining method was used to diagnose Helicobacter pylori infection and was compared to histology, culture, and the rapid urease test (RUT). Histology gave the best sensitivity (98%), compared to Leifson staining (97%), culture (92%), and RUT (85%) (P < 0.005). Leifson staining is a sensitive, rapid, economical method for diagnosis of H. pylori infection in dyspeptic patients.