Battle for the bulge: directing small molecules to DNA and RNA defects

Small molecules were tailored to specifically bind bulged DNA by complementing the geometry and nucleotide size of the bulge site. The prospect of generating small molecules that influence the secondary structure of DNA and RNA holds great promise for clinical applications.     

Bid-Based Dispatch of Hydrothermal Systems in Competitive Markets

The objective of this work is to investigate possible hydro-scheduling inefficiencies under a bidding scheme. It will be shown that the market-based dispatch of hydro-plants, under a perfect competitive market, converges to its least-cost dispatch. Besides, it will be shown that the usual spot payment scheme does not provide the correct incentive for upstream reservoirs to regulate downstream production, thus causing an operating distortion. The implementation of a Wholesale Water Market is proposed for trading stored water and so to correct such distortion. Case studies will be presented, with data taken from the Brazilian System.     

A Global Glance on Categories in Logic

We explore the possibility and some potential payoffs of using the theory of accessible categories in the study of categories of logics. We illustrate this by two case studies focusing on the category of finitary structural logics and its subcategory of algebraizable logics. Mathematics Subject Classification (2000): Primary 03B22; Secondary 18C35.     

Connected Components of Open Semigroups in Semi-Simple Lie Groups

This paper studies connected components of open subsemigroups of non-compact semi-simple Lie groups by using control sets in the flag manifolds and their coverings. The concept of recurrent component is introduced and a method is given by which their number can be computed. It is shown that the union of all recurrent components is a semigroup. The idea of mid-reversibility comes up to show that an open semigroup has just one semigroup component if the identity belongs to its closure. A necessary and sufficient condition for mid-reversibility is proved showing that e.g. in a complex group any open semigroup is mid-reversible.     

The Homotopy Type of Lie Semigroups in Semi-Simple Lie Groups

 Let G be a noncompact semi-simple Lie group and a Lie semigroup with nonempty interior. We study the homotopy groups , , of S. Generalizing a well known fact for G, it is proved that there exists a compact and connected subgroup such that is isomorphic to . Furthermore, there exists a coset z contained in int S which is a deformation retract of S.     

Development of a mimetic system for electrochemical detection of glutamate

This paper describes the development of a biosensor to detect neurodegenerative diseases, focusing on Alzheimer’s disease, the most common type of dementia, based on the use of a small protein-like chain designed to mimic a peptide that recognizes glutamate, the main excitatory neurotransmitter present in the central nervous system of mammals. This system is based on the immobilization of the mimetic peptide for glutamate onto graphite electrodes. The produced bioelectrode showed interesting characteristics, such as short response time (about 10 s) and linear response range between 1 and 10 mmol L^?1 for glutamate, indicating a promising approach for the diagnosis of neurological diseases. In addition, it was possible to observe differences in charge transfer resistance and in surface topography of the electrode, after the interaction with the glutamate target. Theoretical calculations suggest that the anchoring of glutamate indicates conformational changes in the peptide. The mimetic bioelectrode discriminates samples from patients with Alzheimer’s disease.     

Direct Analysis of Amphetamine Stimulants in a Whole Urine Sample by Atmospheric Solids Analysis Probe Tandem Mass Spectrometry

Amphetamine-type stimulants (ATS) are among illicit stimulant drugs that are most often used worldwide. A major challenge is to develop a fast and efficient methodology involving minimal sample preparation to analyze ATS in biological fluids. In this study, a urine pool solution containing amphetamine, methamphetamine, ephedrine, sibutramine, and fenfluramine at concentrations ranging from 0.5 pg/mL to 100 ng/mL was prepared and analyzed by atmospheric solids analysis probe tandem mass spectrometry (ASAP-MS/MS) and multiple reaction monitoring (MRM). A urine sample and saliva collected from a volunteer contributor (V1) were also analyzed. The limit of detection of the tested compounds ranged between 0.002 and 0.4 ng/mL in urine samples; the signal-to-noise ratio was 5. These results demonstrated that the ASAP-MS/MS methodology is applicable for the fast detection of ATS in urine samples with great sensitivity and specificity, without the need for cleanup, preconcentration, or chromatographic separation. Thus ASAP-MS/MS could potentially be used in clinical and forensic toxicology applications.

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Versatility of tandem mass spectrometry for focused analysis of oxylipids

Liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) in the multiple reaction monitoring (MRM) scan mode has been the primary MS method applied for the target identification of specific and minor oxylipids in complex matrices, such as eicosanoids and docosanoids, which are potent lipid mediators derived from polyunsaturated fatty acid oxygenation. However, the high specificity of MRM can limit the detection of species with m/z MRM transitions not covered by the method. In addition to MRM, tandem‐quadrupole mass analyzers enable other experiments to be conducted, by fragmenting ions via collision‐induced dissociation process (CID). This paper presents the potential of tandem mass spectrometry for the focused analysis of oxylipids. We have successfully developed an LC‐MS/MS method for the identification of precursor ions of m/z 115, a diagnostic product ion of 5‐hydroxy‐ and 5‐epoxy‐fatty acids. As a proof of concept, the developed method was used to discover several oxylipids oxidized at C5 derived from arachidonic acid (C20 : 4) oxygenation in a hypothalamus rat extract that were not identified using the target MRM methodology. The proposed focused MS/MS‐based approach in a tandem mass analyzer has proven to be a powerful strategy to accelerate the identification of oxylipids with structural similarities and assist the field of lipidomic research. Copyright © 2015 John Wiley & Sons, Ltd.