A doubly-convergent and regioselective synthesis of (±)-daunomycinone

The monoadduct of benzoquinone to 2,3,5,6-tetramethylidene-7-oxabicyclo[2.2. l]heptane (7) was transformed into (1RS,4RS,4aSR)-2,3-dimethylidene-l,4-epoxy-l,2,3,4,4a,10-hexahydro-8-methoxyanthracene (28). 3The exocyclic diene added to methy into (±)-7,9-dideoxydaunomycinone (54), a known precursor of(±)-daunomycinone     

Modelling a P-FAIMS with multiphysics FEM

A micro Planar high-Field Asymmetric waveform Ion Mobility Spectrometer (P-FAIMS) operating at ambient pressure and temperature has been simulated using COMSOL Multiphysics software. P-FAIMS is based on ion gas-phase separation due to the dependence of ion mobility with electric field. Ions are selected by a DC voltage characteristic of each ion kind. Physics of ion behaviour in high electric fields conditions is well known but not the chemistry behind ion reactions and kinetics. The aim of this work is the modelling of different kind of ions in a P-FAIMS having account of the main factors involved in their movement in the drift tube. Simulations of vapour phase ions of three compounds have been studied for different values of drift electric field amplitude to gas number density (E/N) ratio: protonated water clusters H⁺(H₂O) _n and O₂^-(H₂O)_n{{\rm O}_{2}^{-}({\rm H}_{2}{\rm O})_{n}} ions obtained in air, and a chemical warfare agent simulant DMMPH⁺ that emulates gas sarin. Ions were selected due to simulation needs of experimental data of the main quantities involved in the definition of ions mobilities. Results show that simulations of ions behaviour in a P-FAIMS are possible with COMSOL Multiphysics software and that the time and intensity at which ions are detected are in good agreement with experimental data from literature.     

Enhancing the efficiency of directed evolution in focused enzyme libraries by the adaptive substituent reordering algorithm

Directed evolution is a broadly successful strategy for protein engineering in the quest to enhance the stereoselectivity, activity, and thermostability of enzymes. To increase the efficiency of directed evolution based on iterative saturation mutagenesis, the adaptive substituent reordering algorithm (ASRA) is introduced here as an alternative to traditional quantitative structure-activity relationship (QSAR) methods for identifying potential protein mutants with desired properties from minimal sampling of focused libraries. The operation of ASRA depends on identifying the underlying regularity of the protein property landscape, allowing it to make predictions without explicit knowledge of the structure-property relationships. In a proof-of-principle study, ASRA identified all or most of the best enantioselective mutants among the synthesized epoxide hydrolase from Aspergillus niger, in the absence of peptide seeds with high E-values. ASRA even revealed a laboratory error from irregularities of the reordered E-value landscape alone.     

Accounting for slacks to measure and decompose revenue efficiency in the Spanish Designation of Origin wines with DEA

In this paper, we show how Data Envelopment Analysis (DEA) may be used to measure and decompose revenue inefficiency, taking into account all sources of technical waste in the context of an application to assess the Spanish quality wine sector, in particular Designation of Origin (DO) wines. We try to go beyond the standard approaches, which use Shephard distance functions or directional distance functions, to provide decomposition that incorporates slacks as a source of technical inefficiency. To accomplish this, we will base our analysis on a recent approach introduced in Cooper et al. (2011a). In particular, we show how an output-oriented version of the Weighted Additive model can be used to properly identify revenue, technical, and allocative inefficiencies in Spanish DOs. In the application, we conclude that the main source of revenue inefficiency in this sector is technical waste, and that Cava can be highlighted as the DO that performs as a benchmark for more numbers of units.     

Toeplitz operators on weighted Hardy and Besov spaces

We obtain estimates of the norm of Toeplitz operators on weighted Hardy and Besov spaces. As an application we give characterizations of some spaces of pointwise multipliers.     

K5Nd(MoO4)4: a self-tunable laser crystal

We report for the first time to our knowledge an experimental demonstration of wavelength self-tuning in a K5Nd(MoO4)4 broadband-emitting laser crystal (KNM), as well as a theoretical treatment of the system based on its birefringence properties. The self-frequency-tuning of the laser along the full spectral range of the KNM crystal was obtained by rotating a birefringent gain plate in its own plane. The gain plate was placed inside a resonator at Brewster's angle. The tuning characteristics of the spectral filter were obtained by use of the Jones vector formalism. The calculated wavelength-selective tuning precisely matches the experimental observations.