Tissue-specific and neural activity-regulated expression of human BDNF gene in BAC transgenic mice

Background  

Brain-derived neurotrophic factor (BDNF) is a small secreted protein that has important roles in the developing and adult nervous system. Altered expression or changes in the regulation of the BDNF gene have been implicated in a variety of human nervous system disorders. Although regulation of the rodent BDNF gene has been extensively investigated, in vivo studies regarding the human BDNF gene are largely limited to postmortem analysis. Bacterial artificial chromosome (BAC) transgenic mice harboring the human BDNF gene and its regulatory flanking sequences constitute a useful tool for studying human BDNF gene regulation and for identification of therapeutic compounds modulating BDNF expression.     

A robust, efficient catalyst system for enolate arylation leading to quaternary 3-aminooxindoles

A catalyst screening programme has revealed that a combination of Pd(0) and the N-heterocyclic carbene ligand SIPr forms a particularly robust and efficient catalyst for the formation of important quaternary 3-aminooxindoles via intramolecular enolate arylation. Catalyst loadings of 0.1 mol % give complete conversion in under 4 h.     

All‐Optical Integrated Logic Operations Based on Chemical Communication between Molecular Switches

Molecular logic gates process physical or chemical “inputs” to generate “outputs” based on a set of logical operators. We report the design and operation of a chemical ensemble in solution that behaves as integrated AND, OR, and XNOR gates with optical input and output signals. The ensemble is composed of a reversible merocyanine‐type photoacid and a ruthenium polypyridine complex that functions as a pH‐controlled three‐state luminescent switch. The light‐triggered release of protons from the photoacid is used to control the state of the transition‐metal complex. Therefore, the two molecular switching devices communicate with one another through the exchange of ionic signals. By means of such a double (optical–chemical–optical) signal‐transduction mechanism, inputs of violet light modulate a luminescence output in the red/far‐red region of the visible spectrum. Nondestructive reading is guaranteed because the green light used for excitation in the photoluminescence experiments does not affect the state of the gate. The reset is thermally driven and, thus, does not involve the addition of chemicals and accumulation of byproducts. Owing to its reversibility and stability, this molecular device can afford many cycles of digital operation.     

Application of ultra-high-pressure liquid chromatography–tandem mass spectrometry to the determination of multi-class pesticides in environmental and wastewater samples: Study of matrix effects

An ultra-high-pressure liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method for the determination of 37 pesticides (herbicides, insecticides and fungicides) in environmental and wastewater has been developed. To efficiently combine UHPLC with MS/MS, a fast-acquisition triple quadrupole mass analyzer was used. This analyzer (minimum dwell time, 5 ms) allows acquiring up to three simultaneous transitions in the selected reaction monitoring mode for each compound assuring a reliable identification without resolution or sensitivity losses. A pre-concentration step based on solid-phase extraction using Waters Oasis HLB cartridges (0.2 g) was applied with a 100-fold pre-concentration factor along the whole analytical procedure. The method was validated based on European SANCO guidelines using surface, ground, drinking and treated water (from an urban solid residues treatment plant) spiked at two concentration levels (0.025 and 0.1 μg/L), the lowest having been established as the limit of quantification objective. The method showed excellent sensitivity, with instrumental limits of detection ranging from 0.1 to 7 pg. It was applied to environmental water samples (ground and surface water) as well as to samples of urban solid waste leachates (raw leachate and treated leachate after applying reversed osmosis) collected from a municipal treatment plant. Matrix effects have been studied in the different types of water samples analyzed, and several isotope-labelled internal standards have been evaluated as a way to compensate the signal suppression observed for most of the compounds studied, especially in wastewater samples. As a general remark, only those pesticides which response was corrected using their own isotope-labelled molecule, could be satisfactorily corrected in all type of samples, assuring in this way the accurate quantification in all matrix samples.     

Self‐healing of high elasticity block copolymers

A new route for adding self‐healing properties to soluble polymers is presented briefly. Self‐healing block copolymers (polystyrene‐block‐polybutadiene block‐polystyrene from Sigma‐Aldrich) were obtained by dissolving the polymer in a solvent that neither dissolves the microbubbles nor deactivate the Grubbs catalyst. The self‐healing block copolymer has been obtained by mixing the polymer, the solvent, the microbubbles filled with monomer (dicyclopentadiene), and the Grubbs' catalyst followed by the evaporation of the solvent. The structure of self‐healed high elasticity block copolymer has been investigated by optical and Scanning Electron Microscopy. Raman spectroscopy and mechanical data suggested that the block copolymer exhibits self‐healing features. Copyright © 2008 John Wiley & Sons, Ltd.     

Cost estimation algorithm and decision-making model for curriculum modification in educational organization

The decision about curriculum modification usually takes place at the knowledge level, mainly with consideration of individual academic staff competences and qualifications. However, traditional approaches to cost estimation of curriculum modification are focused on material resources only. In this paper we present a cost estimation method and decision model for curriculum modification in educational organizations. The proposed method works at the knowledge level and employs competence sets as knowledge representation models in educational organizations. Authors used the theory of hierarchical, multilevel systems in order to define the model of the decision-making process of curriculum modification and its dimension. Basing on this and also using a fuzzy competence model the cost estimation algorithm in the form of a group competences expansion algorithm is proposed. The algorithm focuses on the cost of staff competence expansion caused by the knowledge development process.     

Prevalence and structure of adding machines for cellular automata

Consider the collection of left permutive cellular automata Φ with no memory, defined on the space S of all doubly infinite sequences from a finite alphabet. There exists , a dense subset of S, such that is topologically conjugate to an odometer for all so long as Φm is not the identity map for any m. Moreover, Φ generates the same odometer for all . The set is a dense Gδ subset with full measure of a particular subspace of S.     

Representation in the (Artificial) Immune System

Much of contemporary research in Artificial Immune Systems (AIS) has partitioned into either algorithmic machine learning and optimisation, or, modelling biologically plausible dynamical systems, with little overlap between. We propose that this dichotomy is somewhat to blame for the lack of significant advancement of the field in either direction and demonstrate how a simplistic interpretation of Perelson’s shape-space formalism may have largely contributed to this dichotomy. In this paper, we motivate and derive an alternative representational abstraction. To do so we consider the validity of shape-space from both the biological and machine learning perspectives. We then take steps towards formally integrating these perspectives into a coherent computational model of notions such as life-long learning, degeneracy, constructive representations and contextual recognition—rhetoric that has long inspired work in AIS, while remaining largely devoid of operational definition.     

Polystachyne F, a 5,10-seco-neoclerodane from Salvia polystachya

A new 5,10-seco-neoclerodane diterpene, polystachyne F (1), was isolated from the aerial parts of Salvia polystachya. Its structure was established on the basis of its spectroscopic properties and X-ray crystallographic analysis. Some correlations in the NOESY spectrum of 1 suggested the existence of a conformational equilibrium.     

Noncovalent interactions between organometallic metallocene complexes and single-walled carbon nanotubes

First principles density functional pseudopotential calculations have been used to investigate the nature of interactions between single-walled carbon nanotubes (SWNTs) and intercalated transition metal metallocene complexes, M(eta-C(5)H(5))(2) (MCp(2)). Three composites, MCp(2)-graphene (d(t)=infinity), MCp(2)@(17,0) (d(t)=1.33 nm), and MCp(2)@(12,0) (d(t)=0.94 nm) (where M=Fe,Co), have been studied to probe the influence of the nanotube diameter (d(t)) on the nature and magnitude of the interactions. Theoretical results presented here demonstrate that these MCp(2)@SWNT composites are stabilized by weak pi-stacking and CH...pi interactions, and in the case of the CoCp(2)@SWNT composites there is an additional electrostatic contribution as a result of charge transfer from CoCp(2) to the nanotube. The extent of charge transfer (MCp(2)-->SWNT) can be rationalized in terms of the electronic structures of the two fragments, or more specifically, the relative positions of the metallocene highest occupied molecular orbital and the conduction band of the nanotube in the electronic structure of the composite.