Unconventional model of neutrino masses

Gelmini and Roncadelli have proposed a model of neutrino masses in which B?L symmetry is spontaneously broken by a small vacuum expectation value of a Higgs triplet. We give an exegesis of this model. We show that the massive neutrinos in this model cannot be cosmologically relevant today and that conflicting analyses of double beta decay experiments can be reconciled.     

Adsorption integral equation via complex approximation with constraints: kernel of general form

For the monolayer adsorption on a homogeneous surface, including arbitrary range lateral interactions, the isotherm can be written as a power series of the Langmuir isotherm. If this isotherm is used as the kernel in the adsorption integral equation, this integral equation can be solved in an analytical form. Because the global isotherm is usually known as a set of experimental values, the use of a numerical method is inevitable. A new numerical method for solving the adsorption integral equation with a kernel of general form is developed. It is based on recent results concerning the structure of the local isotherm and on the ideas of complex approximation with constraints, and allows reduction of the problem under consideration to a linear‐quadratic programming problem. Results of numerical experiments are presented. The method can be useful for the evaluation of the adsorption energy distribution from experimental data. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1058–1066, 2001     

Observer-based reliable exponential stabilization and H∞ control for switched systems with faulty actuators: An average dwell time approach

This paper deals with the problem of reliable stabilization and $H_{\infty }$ control for a class of continuous-time switched Lipschitz nonlinear systems with actuator failures. We consider the case that actuators suffer “serious failure”—the never failed actuators cannot stabilize the given system. The differential mean value theorem (DMVT) allows transforming the switched Lipschitz nonlinear systems into switched linear parameter varying (LPV) systems. Based on average dwell time scheme and under the condition that activation time ratio between stabilizable subsystems and unstabilizable ones is not less than a specified constant, sufficient conditions for reliable exponential stabilization of the switched systems are derived by hybrid observer-based output feedback control. The result is also extended to the reliable $H_{\infty }$ control problem.     

Aging-related changes in the calorimetric profile of red blood cells from women with miscarriages

The backward-facing step or the sudden expansion in internal flows is an important problem in different areas. In this study, a porous baffle is mounted on the opposite wall of a sudden expansion to enhance heat transfer near the step. Unlike the solid baffle, which is extensively studied in the literature, the porous baffle has a lower pressure drop, and its properties can be tuned to reach the optimal prospected performance. Effects of different porous baffle geometrical parameters including its normalized height (H_b?=?0.5, 1.0, 1.5, 1.75), width (W_b?=?0.5, 1, 1.5, 2.0, 2.5), porous baffle-step relative distance (D?=?1, 2, 3, 4), Darcy number (10^?2, 10^?3, 10^?4, 10^?6), and Reynolds number (100, 200, 300, 400, 500) on the heat transfer and pressure drop are investigated. The simulation indicates that higher Reynolds numbers enhance more the heat transfer (35% improvement at Re?=?500 with respect to 10% at Re?=?100). Also, longer baffles can lead to higher heat transfer rates (5% improvement in H_b?=?0.5 with respect to 32% at H_b?=?1.5).

     

Hybrid Plasmonic–Aerogel Materials as Optical Superheaters with Engineered Resonances

Solar radiation is a versatile source of energy, convertible to different forms of power. A direct path to exploit it is the generation of heat, for applications including passive building heating, but it can also drive secondary energy‐conversion steps. We present a novel concept for a hybrid material which is both strongly photo‐absorbing and with superior characteristics for the insulation of heat. The combination of that two properties is rather unique, and make this material an optical superheater. To realize such a material, we are combining plasmonic nanoheaters with alumina aerogel. The aerogel has the double function of providing structural support for plasmonic nanocrystals, which serve as nanoheaters, and reducing the diffusion rate of the heat generated by them, resulting in large local temperature increases under a relatively low radiation intensity. This work includes theoretical discussion on the physical mechanisms impacting the system's balanced thermal equilibrium.     

Interfacial rheology of mixed layers of food proteins and surfactants

Mixed protein–surfactant adsorption layers at liquid interfaces are described including the thermodynamic basis, the adsorption kinetics and the shear and dilational interfacial rheology. It is shown that due to the protrusion of hydrophobic protein parts into the oil phase the adsorption layers at the water–hexane interface are stronger anchored as compared to the water-air surface. Based on the different adsorption protocols, a sequential and a simultaneous scheme, the peculiarities of complexes between proteins and added surfactants are shown when formed in the solution bulk or at a liquid interface. The picture drawn from adsorption studies is supported by the findings of interfacial rheology.     

Non-extractive procedure followed by LC/APCI MS/MS analysis of trimetazidine in plasma samples for assessing bioequivalence of immediate/modified release formulations

Trimetazidine and internal standard [1-(2,4,5-trimethoxybenzyl)piperazine] were isolated from plasma by protein precipitation with trifluoroacetic acid. The neutralized supernatant was separated on a C(8) column with methanol-aqueous 0.11% triethylamine adjusted to pH 3.3 with formic acid (1:4, v/v) at a flow rate of 0.85 mL/min. The separation was achieved within 8 min and the column ef fluent was transferred into an ion trap analyzer via an atmospheric pressure chemical ionization interface. The mass analyzer was used in the selected reaction monitoring mode, to enhance detection selectivity. The method was fully validated with a quantitation limit for trimetazidine of 1.5 ng/mL. The method was successfully applied to assess bioequivalence of two immediate and two modified commercially available pharmaceutical formulations containing 20 and 35 mg of trimetazidine, respectively.     

Preparation and physicochemical characterization of novel chlorambucil-loaded nanoparticles of poly(butylcyanoacrylate)

The aim of the present study is the preparation and physicochemical characterization of chlorambucil-loaded poly(butylcyanoacrylate) nanoparticles. Chlorambucil is a lipophilic drug, which is used clinically against chronic lymphocytic leukemia, lymphomas, and other types of malignant diseases. However, the chlorambucil use is limited by its chemical instability and toxic side effects. A promising approach to circumvent these drawbacks is the entrapment of chlorambucil in a suitable nanosized carrier. Toward this goal, poly(butylcyanoacrylate) nanoparticles meet the requirements for a drug carrier system due to their biocompatibility, biodegradability, low toxicity, and ability to overcome the multidrug resistance in cancer cells. We prepared chlorambucil-loaded poly(butylcyanoacrylate) nanoparticles, which are characterized for chemical composition, particle size, drug content, and drug release. It is expected that the utilization of poly(butylcyanoacrylate) nanoparticles as a drug carrier system will pave the way toward more effective use of chlorambucil in the treatment of cancer.     

A Single‐Molecule Perspective on the Role of Solvent Hydrogen Bonds in Protein Folding and Chemical Reactions

We present an array of force spectroscopy experiments that aim to identify the role of solvent hydrogen bonds in protein folding and chemical reactions at the single‐molecule level. In our experiments we control the strength of hydrogen bonds in the solvent environment by substituting water (H₂O) with deuterium oxide (D₂O). Using a combination of force protocols, we demonstrate that protein unfolding, protein collapse, protein folding and a chemical reaction are affected in different ways by substituting H₂O with D₂O. We find that D₂O molecules form an integral part of the unfolding transition structure of the immunoglobulin module of human cardiac titin, I27. Strikingly, we find that D₂O is a worse solvent than H₂O for the protein I27, in direct contrast with the behaviour of simple hydrocarbons. We measure the effect of substituting H₂O with D₂O on the force dependent rate of reduction of a disulphide bond engineered within a single protein. Altogether, these experiments provide new information on the nature of the underlying interactions in protein folding and chemical reactions and demonstrate the power of single‐molecule techniques to identify the changes induced by a small change in hydrogen bond strength.     

Integrable discretisations for a class of nonlinear Schrödinger equations on Grassmann algebras

Integrable discretisations for a class of coupled (super) nonlinear Schrödinger (NLS) type of equations are presented. The class corresponds to a Lax operator with entries in a Grassmann algebra. Elementary Darboux transformations are constructed. As a result, Grassmann generalisations of the Toda lattice and the NLS dressing chain are obtained. The compatibility (Bianchi commutativity) of these Darboux transformations leads to integrable Grassmann generalisations of the difference Toda and NLS equations. The resulting systems will have discrete Lax representations provided by the set of two consistent elementary Darboux transformations. For the two discrete systems obtained, initial value and initial-boundary problems are formulated.