Electrostatic Anchoring of Mn4 Single‐Molecule Magnets onto Chemically Modified Multiwalled Carbon Nanotubes

Two different routes that enable the electrostatic grafting of cationic single‐molecule magnets (SMMs) onto the surface of chemically modified anionic multi‐walled carbon nanotubes (MWNTs) are described. The chemical nature and physical properties of the resulting hybrids are discussed on the basis of a complete battery of experimental techniques. The data show that the chemical nature of the SMM unit remains intact, while its magnetic response is significantly affected by the grafting process, which is likely due to surface effects.     

Impact of High Hydrostatic Pressure on Protein Aggregation and Rheological Properties of Legume Batters

The impact of high hydrostatic pressure (HP) treatment on protein aggregation and rheological properties of legume batters has been investigated. Gelatinisation/pasting and gelling profiles, rheological parameters and protein solubility of HP-hydrated chickpea (CP), green pea (GP) and soybean (SB) flours were determined. CP, GP and SB hydrated flours, at dough yield (DY) 160 and 200, were treated for 10 min at 0.1, 200, 350 or 450 MPa. Pressures of ≥350 MPa downward shifts gelatinisation temperatures in CP and GP regardless the hydration level. For all legume batters, HP provokes changes on the rheology of hydrated samples, particularly in softer batters (DY 200), leading to an increased stiff/solid character. Analysis of proteins extracted in different buffers revealed that pressures of >200 MPa induced the formation of urea-insoluble complexes, disulphide bonds and/or other strong protein aggregates. Although the extent of protein modification was dependent on the applied pressure, the results collected so far show that high HP can be used to improve the breadmaking functionality of CP, GP and SB batters.     

Effect of dietary supplementation of vitamin E on characteristics of lamb meat packed under modified atmosphere

The effect of dietary vitamin E supplementation on modified-atmosphere packed lamb meat during storage was studied. Thirty-six weaned male Manchego breed lambs were fed diets supplemented with three different vitamin E concentrations (0, 250, 500 and 1000 mg/kg feed) for an average of 37 days, in the 13–26 kg live weight growth range. Slices of m. longissimus dorsi were packaged under modified atmosphere (70% O₂ and 30% CO₂), stored at 2 ± 1 °C in darkness for 14 and 28 days. Meat quality parameters after both storage periods were assessed. Dietary vitamin E supplementation significantly increased -tocopherol concentration in muscle. Initially, lipid oxidation (TBARS), meat colour and bacterial load were similar in all groups. Lipid and colour oxidation of meat increased significantly (P < 0.001) throughout storage. The increase was greater in non-supplemented lambs than in supplemented ones. The bacterial counts after 28 days of storage reached the limit for microbiological shelf life (7 log₁₀cfu/cm²). Dietary vitamin E supplementation increased the shelf life of meat packaged under modified atmosphere to 14 days. TBARS, pigment oxidation and bacterial load were inside the acceptable limit. The meat maintained its quality for 28 days of storage only when lambs were fed with the 1000 mg/kg dietary supplement, though the bacterial load was at the limit of acceptability.     

Combined effect of HLA-DRB1*1501 and interleukin-1 receptor antagonist gene allele 2 in susceptibility to relapsing/remitting multiple sclerosis

Susceptibility to multiple sclerosis (MS) is associated with HLA-DRB1*1501. Many reports have suggested associations with other loci but these results remain unconfirmed. We studied the IL-1 receptor antagonist (IL-1ra) gene polymorphism and the HLA-DR and DQ allele frequencies by DNA-based methods in both the primary chronic progressive form (PP MS) and the relapsing/remitting form (R/R MS). The frequency of DRB1*1501 and IL-1ra allele 2 were significantly higher in R/R MS. Association was more marked in the female sex and in patients with benign forms of R/R MS. On the other hand DR4 subtypes carrying a Val at position 86 in the DR beta chain were increased in PP MS. The present study indicates that MS is genetically heterogeneous and shows a combined effect of HLA-DR and IL-1ra genes in susceptibility to the R/R form of the disease.     

Using Bayesian networks to discover relationships between bibliometric indices. A case study of computer science and artificial intelligence journals

As they are used to evaluate the importance of research at different levels by funding agencies and promotion committees, bibliometric indices have received a lot of attention from the scientific community over the last few years. Many bibliometric indices have been developed in order to take into account aspects not previously covered. The result is that, nowadays, the scientific community faces the challenge of selecting which of this pool of indices meets the required quality standards. In view of the vast number of bibliometric indices, it is necessary to analyze how they relate to each other (irrelevant, dependent and so on). Our main purpose is to learn a Bayesian network model from data to analyze the relationships among bibliometric indices. The induced Bayesian network is then used to discover probabilistic conditional (in)dependencies among the indices and, also for probabilistic reasoning. We also run a case study of 14 well-known bibliometric indices on computer science and artificial intelligence journals.     

Axial symmetric flow model for a flat bottom hydrocyclone

Experiments with laser Doppler velocimetry show that, for flat bottom hydrocyclones, the axial velocity field is a function of the radius and a linear function of the axial co-ordinate, while the tangential velocity is a function of the radial co-ordinate only. Based on these results, a physical model is presented, where the flow field is divided in two zones. Zone I corresponds to the feed inlet, which occurs through a ring in the upper portion of the cylinder, the length of which depends on the length of the vortex finder tube. Zone II includes the rest of the cylinder. The axial symmetric solution of Reynolds equations for the isotropic turbulent flow leads to two sets of field equations, one for each zone in the hydrocyclone. In zone II, where experimental data were determined, simulation compares favourably with the flow pattern determined experimentally for water in a 100-mm flat bottom hydrocyclone.     

Applications of the phenomenological theory to several published experimental cases of sedimentation processes

In one space dimension, the phenomenological theory of sedimentation predicts the sedimentation–consolidation behavior of a flocculated suspension in dependence of two constitutive functions describing its material behavior, the solids flux density (or hindered settling function) and the solid effective stress. These functions are assumed to depend only on the local volumetric solids concentration. In this contribution, we review several experimental and theoretical studies of sedimentation in settling columns. We first resume the theories that have been employed to interpret the experimental measurements and then apply the phenomenological model to the available data. The two constitutive functions involved are determined from the published concentration, permeability and effective stress data. The mathematical model is then solved numerically using these functions, and the resulting predictions of settling behavior are compared with the respective authors’ experimental findings and interpretations. In one case, the information obtained from a batch settling experiment is used to simulate continuous sedimentation.     

Assertiveness predicts threat and challenge reactions to potential stress among women.

In this study assertiveness as a moderator of stress reactions among women was examined. Specifically, the experimenters examined how high and low assertive women cognitively appraised, affectively and physiologically responded to, and behaviorally coped with the stress of giving an impromptu speech. High assertive women appraised the speech stressor as challenging, whereas low assertive women appraised the stressor as threatening. High assertive women also had a challenge pattern of autonomic response during the task, compared with the threat response of low assertive women. Afterward, the high assertive women reported experiencing less stress and negative emotion and greater positive emotion than did the low assertive women. Overall, the high assertive women's stress-related reactions indicated challenge, whereas the low assertive women's reactions indicated threat (see J. Tomaka, J. Blascovich, R. M. Kelsey, & C. L. Leitten, 1993). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bread crumb quality assessment: a plural physical approach

The aim of this study was the assessment of pan bread crumb quality attributes of commercial samples using a plural physical approach to better match consumer awareness. Static (texture profile analysis, firmness AACC and relaxation test) and dynamic (innovative oscillatory test) deformation techniques, image analysis, sensory analysis and colour measurements (colorimeter and Photoshop system) were used for white/whole commercial pan bread quality evaluation over 10 days of storage. Static (k ₁, k ₂, cohesiveness, springiness, hardness, chewiness and resilience) and dynamic (stress) bread crumb rheological properties were correlated illustrating that both techniques can be useful in evaluating crumb physical characteristics. In addition, sensory perceiveness with regard to softness and overall acceptability exhibited dependence with either dynamic stress or static firmness. Despite the fact that empirical measurements are closely linked to macroscopic features whilst dynamic tests are strongly linked to molecular characteristics, the obtained results support that both techniques are complementary since derived instrumental parameters are related to some sensory attributes. As data achieved using the proposed novel approaches might be better linked to the consumer awareness than those obtained from classical analyses, the obtained results are promising for a proper bread crumb quality assessment.     

Copolymerization without initiator of 1-(2-hydroxyethyl)aziridine and acrylamide

Summary 1-(2-Hydroxyethyl)aziridine as nucleophilic monomer was copolymerized in the absence of an initiator under various experimental conditions with acrylamide as electrophilic monomer. All copolymers were characterized by elemental analysis, IR, and ¹H-NMR spectroscopy. The viscosity measurements showed that the copolymers behave as polyelectrolytes. The copolymer composition was determined from elemental analysis and ¹H-NMR spectra.