Use ofK L a as a criterion for scaling up the inulinase fermentation process

Applied Biochemistry and Biotechnology - The scale-up of inulinase production in aerated cultures ofCandida kefyr DSM 70106 was studied, taking into account the criterion of maintainingK L a...     

Approximating the chance-constrained capacitated vehicle routing problem with robust optimization

4OR - The Capacitated Vehicle Routing Problem (CVRP) is a classical combinatorial optimization problem that aims to serve a set of customers, using a set of identical vehicles, satisfying the...     

Quinones from plants of northeastern Brazil: structural diversity, chemical transformations, NMR data and biological activities

The present review focus in quinones found in species of Brazilian northeastern Capraria biflora, Lippia sidoides, Lippia microphylla and Tabebuia serratifolia. The review cover ethnopharmacological aspects including photography of species, chemical structure feature, NMR datea and biological properties. Chemical transformations of lapachol to form enamine derivatives and biological activities are discussed.     

Entropic Dynamics on Gibbs Statistical Manifolds

Entropic dynamics is a framework in which the laws of dynamics are derived as an application of entropic methods of inference. Its successes include the derivation of quantum mechanics and quantum field theory from probabilistic principles. Here, we develop the entropic dynamics of a system, the state of which is described by a probability distribution. Thus, the dynamics unfolds on a statistical manifold that is automatically endowed by a metric structure provided by information geometry. The curvature of the manifold has a significant influence. We focus our dynamics on the statistical manifold of Gibbs distributions (also known as canonical distributions or the exponential family). The model includes an “entropic” notion of time that is tailored to the system under study; the system is its own clock. As one might expect that entropic time is intrinsically directional; there is a natural arrow of time that is led by entropic considerations. As illustrative examples, we discuss dynamics on a space of Gaussians and the discrete three-state system.     

β-Xylosidase recovery by reversed micelles

β-Xylosidase, an enzyme produced by Penicillium janthinellum fungus, was prepurified by fractionated precipitation with ethanol and extracted by reversed micelles of N-benzyl-N-dodecyl-N-bis(2-hydroxyethyl) ammonium chloride (BDBAC) cationic surfactant. A 2^5-1 fractional factorial design was employed to evaluate the influence of the following factors on the enzyme extraction: pH (A), conductivity (B), surfactant concentration (C), cosolvent concentration (D) and temperature (E). A statistical analysis of the results revealed that, of the five variables studied, pH, surfactant concentration, and temperature had significant main effects (p<0.05) on the recovery of β-xylosidase (Y). However, the interactions between pH and temperature, conductivity and cosolvent concentration, conductivity and temperature, BDBAC concentration and temperature also had significant influences. A first-order model (R ²=0.98) expressed by the equation Y=7.73−5.55A−0.67B+3.49C−0.41D+5.26E+2.05AB−3.26AC+0.96AD−7.07AE−3.93BD−2.19BE+0.99CD+0.78CE was proposed to represent the enzyme recovery as a function of the effects that were really significant. This model predicts a recovery value of about 40%, which is similar to that obtained experimentally (39.5%).     

Branch-and-cut with lazy separation for the vehicle routing problem with simultaneous pickup and delivery

We propose a branch-and-cut algorithm for the VRPSPD where the constraints that ensure that the capacities are not exceeded in the middle of a route are applied in a lazy fashion. The algorithm was tested in 87 instances with 50–200 customers, finding improved lower bounds and several new optimal solutions.     

Synthesis,characterization, and electrochemical studies of new 5‐ and 6‐nitro N‐acyl‐1H‐indazoles

Two series of new N‐1 acylindazoles containing 5‐ or 6‐nitro groups were synthesized with moderate to good yields and characterized by IR and NMR spectroscopy. Cyclic voltammetry in aprotic media was utilized for the electrochemical characterization of the compounds. The calculated reduction potentials in physiological conditions are similar to those of known commercial antichagasic drugs. Therefore, the novel series reported herein are prospective candidates for antichagasic biological evaluation. Theoretical calculation results indicate that the studied dinitro derivatives undergo a single step reduction process because of the energy proximity of their radical and anionic state. Copyright © 2011 John Wiley & Sons, Ltd.     

Further Withaphysalin Derivatives from Acnistus arborescens

Two new epimeric chlorinated withaphysalins, rel‐(4β,5β,6α,18S,22R)‐ and rel‐(4β,5β,6α,18R,22R)‐6‐chloro‐18,20‐epoxy‐18‐ethoxy‐4,5‐dihydroxy‐1‐oxowitha‐2,24‐diene‐26,22‐lactone ( 1 and 2 resp.), together with the new rel‐(4β,5β,6α,18R,22R)‐6‐chloro‐18,20‐epoxy‐4,5‐dihydroxy‐18‐methoxy‐1‐oxowitha‐2,24‐diene‐26,22‐lactone ( 3 ) and rel‐(3β,4β,5β,6β,18R,22R)‐5,6:18,20‐diepoxy‐3,18‐diethoxy‐4‐hydroxy‐1‐oxowith‐24‐ene‐26,22‐lactone ( 4 ) were isolated from the leaves of Acnistus arborescens and named withaphysalins T–W, respectively. The final structures and the complete ¹H‐ and ¹³C‐NMR assignments of the three chlorowithaphysalins 1 – 3 were performed by means of HR‐ESI‐MS and 1D‐ and 2D‐NMR experiments, including COSY, HSQC, and HMBC, beside comparison with spectral data of analogous compounds from the literature. The structure of 4 was also confirmed by means of a single‐crystal X‐ray diffraction analysis.