DFT study of the structure and property of small organic hole‐transporting molecules

In this article, all calculations are performed at B3LYP/6‐31G** level. For each one of the molecule, including triphenylamine (TPA), N,N′‐diphenyl‐N,N′‐bis(3‐methyllphenyl)‐(1,1′‐biphenyl)‐4,4′‐diamine (TPD), biphenyl (Bp), and their derivatives (TPAs, TPDs, Bps, respectively), the geometry is optimized for both neutral and radical‐cation states. Their reorganization energy is then compared. It seems that it is the monomer, TPAs, and not the central biphenyl moiety that determines the properties of TPDs. However, this is contradictory of some previous results. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

On the effect of friend feedbacks

Given ?? an (A,B)‐invariant subspace, we prove that the set of friend feedbacks is a linear variety, which can be considered as the direct sum of the feedbacks of the restriction to ?? and the co‐restriction to ??^⊥. In particular, when the natural controllability hypothesis hold, both pole assignments are simultaneously possible by means of a convenient friend feedback. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis,characterization and anticancer activity of new palladacycles derived from chiral α‐diimines

Optically pure α‐diimines quantitatively obtained in solvent‐free conditions starting from 2,3‐butanedione and (S)‐(?)‐1‐phenylethylamine and (S)‐(?)‐1‐(4‐methylphenyl)ethylamine, respectively, yielded the new chiral mono‐Pd complexes 2a–b, which have been partly characterized by IR, ¹H‐ and ¹³C‐NMR spectroscopies along with MS‐FAB⁺ spectrometry. The crystal and molecular structure for palladacycle 2a has been fully confirmed by single‐crystal X‐ray studies. Studies in vitro of 2a–b have displayed growth inhibition against different classes of cancer: leukemia (K‐562 CML), colon cancer (HCT‐15), breast cancer (MCF‐7), central nervous system (U‐251 Glio) and prostate cancer (PC‐3) cell lines. Copyright © 2009 John Wiley & Sons, Ltd.     

Development of a new reference material for the validation of molecular detection methods for microbiological analysis

The standard methodology used for the detection of bacteria in environmental samples and food is primarily based on bacterial growth on specific culture media and confirmation by biochemical and/or immunological tests of all presumptive colonies. However, this methodology presents a number of drawbacks, such as low sensitivity and specificity, and the long time needed to obtain results. For this reason, the implementation of molecular methods in diagnostic laboratories has increased over the past several years. Nevertheless, most of these newer methods have not been included in current legislation, and, in most of cases, they have not yet been normalized. In this sense, the availability of appropriate reference materials (RMs) can help to overcome these deficiencies. The aim of this study was to develop and validate, following ISO Guide 34, a new RM, in a tablet format, for the quantification of Legionella pneumophila and Salmonella spp. by quantitative PCR (qPCR). This new RM can be used as a work reference sample in internal quality control, in the organization of proficiency testing schemes (PTS), as well as for the validation of molecular methods based on qPCR.     

The chromatographic quantification of hydrophobicity using micellar mobile phases

Summary In micellar liquid chromatography (MLC), the hydrophobicity of a compound is the predominant factor in its retention and interaction with micelles. A non-linear empirical model can describe the dependence between the retention factor (logk) in MLC and the logarithm of partition coefficients octanol-water (logP). An algorithm based on such a model has been used to makelogP predictions. Retention data for series of neutral compounds eluted with different mobile phases and alkyl-bonded stationary phases have been used to test the predictive ability of the algorithm. The results of this approach are compared with those obtained from automatic computational software packages.     

Study of prehispanic wall paintings from Xochicalco, Mexico, using PIXE, XRD, SEM and FTIR

The characterization of samples of painted plasters obtained from the archaeological site of Xochicalco, in Central Mexico, is presented. Elemental concentrations of the painted layers were obtained by using proton induced X-ray emission (PIXE). The main crystalline structures of the samples are identified with the help of X-ray diffraction (XRD), while the microstructure is studied by scanning electron microscopy (SEM). The information resulting from the application of these three techniques is used to achieve more accurate values for the elemental concentrations. Additional data regarding organic components of the paintings was obtained through Fourier transform infrared spectrometry (FTIR). Although the latter results only provided reliable data on inorganic components, they help to clarify the results from XRD and confirm those of SEM.     

Variation Operators for Semigroups and Riesz Transforms on BMO in the Schrödinger Setting

In this paper we prove that the variation operators of the heat semigroup and the truncations of Riesz transforms associated to the Schrödinger operator are bounded on a suitable BMO type space.     

Analyzing completeness of axiomatic functional systems for temporal × modal logics

In previous works, we presented a modification of the usual possible world semantics by introducing an independent temporal structure in each world and using accessibility functions to represent the relation among them. Different properties ofthe accessibility functions (being injective, surjective, increasing, etc.) have been considered and axiomatic systems (called functional) which define these properties have been given. Only a few ofthese systems have been proved tobe complete. The aim ofthis paper is to make a progress in the study ofcompleteness for functional systems. For this end, we use indexes as names for temporal flows and give new proofs of completeness. Specifically, we focus our attention on the system which defines injectivity, because the system which defines this property without using indexes was proved to be incomplete in previous works. The only system considered which remains incomplete is the one which defines surjectivity, even ifwe consider a sequence ofnatural extensions ofthe previous one (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)