A low-cost environmentally friendly approach to isolate lignin containing micro and nanofibrillated cellulose from Eucalyptus globulus bark by steam explosion

Cellulose - Micro- and Nano-Fibrillated Cellulose (MNFC) have gained increasing attention due to their remarkable properties, but their production usually requires an intensive multi-step process....     

Immunochemical characterisation of structure and allergenicity of peanut 2S albumins using different formats of immunoassays

Proteins of the 2S albumin family, such as Ara h2 and Ara h6, are most frequently involved in peanut allergy. We have developed a reverse enzyme allergo-sorbent test (EAST) in which total serum IgE antibodies are first captured by immobilised anti-human IgE monoclonal antibodies, and then the binding of the anti-Ara h2 and anti-Ara h6 specific IgE to the corresponding labelled allergens is measured. This reverse immunoassay was used either as a direct EAST or as an EAST inhibition assay to study the interactions of whole peanut protein extract and purified Ara h2 and Ara h6 with IgE antibodies from peanut-allergic patients. Finally, we identified some IgE-binding epitopes on Ara h6 using a format of EAST in which the protein is immobilised in a particular, well defined, manner through interactions with specific monoclonal antibodies (mAbs) coated on the micro-plates. The fine specificity of those mAbs has been characterised at the epitope level, and their binding to the allergen thus masks a known particular epitope and makes it unavailable for recognition by IgE antibodies. The reverse EAST increased the ratio specific signal/background. It avoids interferences with competitors such as anti-peanut protein IgG antibodies and allows the study of the specificity and/or affinity of the interactions between IgE antibodies and Ara h2 or Ara h6 with a higher sensitivity and accuracy than the conventional EAST. The EAST results obtained when the allergens are presented by specific mAbs suggest that the homologous molecular domain(s) in peanut 2S albumins encompass major IgE epitope(s) and are strongly involved in peanut allergenicity.     

Hamiltonicity and pancyclicity of cartesian products of graphs

The cartesian product of a graph G with K₂ is called a prism over G. We extend known conditions for hamiltonicity and pancyclicity of the prism over a graph G to the cartesian product of G with paths, cycles, cliques and general graphs. In particular we give results involving cubic graphs and almost claw-free graphs.We also prove the following: Let G and H be two connected graphs. Let both G and H have a 2-factor. If Δ(G)≤g^′(H) and Δ(H)≤g^′(G) (we denote by g^′(F) the length of a shortest cycle in a 2-factor of a graph F taken over all 2-factorization of F), then G□H is hamiltonian.     

Immobilisation of enzymes on poly(aniline)-poly(anion) composite films. Preparation of bioanodes for biofuel cell applications.

Immobilisation of enzymes is important for applications such as biosensors or biofuel cells. A poly(histidine) tag had been introduced on the C terminus of a lactate dehydrogenase enzyme. This mutant enzyme was then immobilised onto poly(aniline) (PANi)-poly(anion) composite films, PANi-poly(vinylsulfonate) (PVS) or PANi-poly(acrylate) (PAA). The NADH produced by the immobilised enzyme in the presence of beta-nicotinamide adenine dinucleotide (NAD(+)) and lactate is oxidised at the poly(aniline)-coated electrode at 0.05 to 0.1 V vs. saturated calomel electrode (SCE) at 35 degrees C.     

Investigating cellular signaling reactions in single attoliter vesicles

Understanding cellular signaling mediated by cell surface receptors is key to modern biomedical research and drug development. The discovery of a growing number of potential molecular targets and therapeutic compounds requires downscaling and accelerated functional screening. Receptor-mediated cellular responses are typically investigated on single cells or cell populations. Here, we show how to monitor cellular signaling reactions at a yet unreached miniaturization level. On the basis of our observations, cytochalasin induces mammalian cells to extrude from their plasma membrane submicrometer-sized native vesicles. They comprise functional cell surface receptors correctly exposing their extracellular ligand binding sites on the outer vesicle surface and retaining cytosolic proteins in the vesicle interior. As a prototypical example, ligand binding to the ionotropic 5-HT(3) receptor and subsequent transmembrane Ca(2+) signaling were monitored in single attoliter vesicles. Thus, native vesicles are the smallest autonomous containers capable of performing cellular signaling reactions under physiological conditions. Because a single cell delivers about 50 native vesicles, which can be isolated and addressed as individuals, our concept allows multiple functional analyses of individual cells having a limited availability and opens new vistas for miniaturized bioanalytics.     

Sparse Interpolation in Terms of Multivariate Chebyshev Polynomials

Foundations of Computational Mathematics - Sparse interpolation refers to the exact recovery of a function as a short linear combination of basis functions from a limited number of evaluations. For...     

The Soave,Twu and Boston–Mathias alpha functions in cubic equations of state. Part II. Modeling of thermodynamic properties of pure compounds

Cubic equations of state (EoS) are commonly used for industrial applications, due to their simplicity in predicting pure compound and mixture thermodynamic properties in vapor and liquid phases. The accuracy of their predictions mainly depends on the choice of the attractive term a(T) and numerous models were developed in literature for this purpose. Among them, the Soave and the Twu models have acquired a wide popularity, as well as the Boston–Mathias model commonly used for supercritical applications. However, most of the works concerned with the comparison of literature attractive terms only focuses on the representation of pure component saturation properties. In particular, the analysis of the respective influence of the EoS and the first and second derivatives of the alpha function on the modeling of enthalpies and heat capacities with respect to temperature and pressure, especially in the supercritical range, was never reported in literature. This is precisely the purpose of the present study.     

Scaling Invariants and Symmetry Reduction of Dynamical Systems

Scalings form a class of group actions that have theoretical and practical importance. A scaling is accurately described by a matrix of integers. Tools from linear algebra over the integers are exploited to compute their invariants, rational sections (a.k.a. global cross-sections), and offer an algorithmic scheme for the symmetry reduction of dynamical systems. A special case of the symmetry reduction algorithm applies to reduce the number of parameters in physical, chemical or biological models.