832 research outputs found

    Reward modulates spatial neglect

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    Copyright @ 2012 The Authors. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and 85 reproduction in any medium, provided the original author and source are credited. The article was made available through the Brunel University Open Access Publishing Fund.BACKGROUND: Reward has been shown to affect attention in healthy individuals, but there have been no studies addressing whether reward influences attentional impairments in patients with focal brain damage. METHODS: Using two novel variants of a widely-used clinical cancellation task, we assessed whether reward modulated impaired attention in 10 individuals with left neglect secondary to right hemisphere stroke. RESULTS: Reward exposure significantly reduced neglect, as measured by total targets found, left-sided targets found and centre of cancellation, across the patient group. Lesion analysis showed that lack of response to reward was associated with damage to the ipsilateral striatum. CONCLUSIONS: This is the first experimental evidence that reward can modulate attentional impairments following brain damage. These results have significant implications for the development of behavioural and pharmacological therapies for patients with attentional disorders.PM is supported by a HEFCE Clinical Senior Lectureship Award and this research was funded by grants from the UK Academy of Medical Sciences/Wellcome Trust and the NIHR Biomedical Research Centre at Imperial College London. DS is supported by a grant from the UK Medical Research Council (89631). CR is supported by a Brunel Research Initiative Award (BRIEF) and a scientific bursary from the Bial foundation, Portugal

    Evidence of Andreev bound states as a hallmark of the FFLO phase in κ\kappa-(BEDT-TTF)2_2Cu(NCS)2_2

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    Superconductivity is a quantum phenomena arising, in its simplest form, from pairing of fermions with opposite spin into a state with zero net momentum. Whether superconductivity can occur in fermionic systems with unequal number of two species distinguished by spin, atomic hyperfine states, flavor, presents an important open question in condensed matter, cold atoms, and quantum chromodynamics, physics. In the former case the imbalance between spin-up and spin-down electrons forming the Cooper pairs is indyced by the magnetic field. Nearly fifty years ago Fulde, Ferrell, Larkin and Ovchinnikov (FFLO) proposed that such imbalanced system can lead to exotic superconductivity in which pairs acquire finite momentum. The finite pair momentum leads to spatially inhomogeneous state consisting of of a periodic alternation of "normal" and "superconducting" regions. Here, we report nuclear magnetic resonance (NMR) measurements providing microscopic evidence for the existence of this new superconducting state through the observation of spin-polarized quasiparticles forming so-called Andreev bound states.Comment: 6 pages, 5 fig

    Evaluation of Linked Determinants Between Diabetes and Caries

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    Dental caries and diabetes mellitus, represent two chronic diseases of public health that present statistics of high prevalence worldwide. One of the main problems that affect these conditions is demography, since the least developed countries are those that have less access to public health services and are limited by the economic costs that represent the treatments. In this work is presented the univariate analysis, of a set of demographic determinants obtained from the National Health and Nutrition Examination Surveys (NHANES), in order to identify those that present the most significant information related to estimation of these diseases. According to the results, the age of the subjects is the main determinant describing the simultaneous presence of these diseases, obtaining an area under the curve (AUC) value ≥ 0.846, concluding that age can be used as tool for their preventive diagnosis

    Structure-Based Design and Optimization of Multitarget-Directed 2H-Chromen-2-one Derivatives as Potent Inhibitors of Monoamine Oxidase B and Cholinesterases

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    The multifactorial nature of Alzheimer’s disease calls for the development of multitarget agents addressing key pathogenic processes. To this end, by following a docking-assisted hybridization strategy, a number of aminocoumarins were designed, prepared, and tested as monoamine oxidases (MAOs) and acetyl- and butyryl-cholinesterase (AChE and BChE) inhibitors. Highly flexible N-benzyl-N-alkyloxy coumarins 2–12 showed good inhibitory activities at MAO-B, AChE, and BChE but low selectivity. More rigid inhibitors, bearing meta- and para-xylyl linkers, displayed good inhibitory activities and high MAO-B selectivity. Compounds 21, 24, 37, and 39, the last two featuring an improved hydrophilic/lipophilic balance, exhibited excellent activity profiles with nanomolar inhibitory potency toward hMAO-B, high hMAO-B over hMAO-A selectivity and submicromolar potency at hAChE. Cell-based assays of BBB permeation, neurotoxicity, and neuroprotection supported the potential of compound 37 as a BBB-permeant neuroprotective agent against H2O2-induced oxidative stress with poor interaction as P-gp substrate and very low cytotoxicity

    Extensive experience of disease control with gefitinib and the role of prognostic markers

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    Traditionally, the efficacy of an anticancer agent has been measured by response rate. With the development of biological molecular-targeted agents, which have a different mechanism of action from conventional agents, it may be appropriate to consider alternative criteria that reflect the positive effect of these biological agents on disease control, palliation, symptom improvement and quality of life. One such targeted agent is the orally active epidermal growth factor receptor tyrosine kinase inhibitor gefitinib (‘Iressa’, ZD1839). This article reviews the clinical experience of patients with advanced/metastatic non-small-cell lung cancer, who have received gefitinib as part of a clinical trial or through the ‘Iressa’ Expanded Access Programme. Disease-control rates of ∼50% were observed in some Expanded Access Programme series, comparable with results obtained from Phase II trials. Symptom improvement was also reported. Information that will help identify those patients most likely to respond to treatment will become increasingly important. Therefore, the possible role of prognostic markers and the relationship between epidermal growth factor receptor status and response to gefitinib has been investigated. No clear association between epidermal growth factor receptor expression and response was observed. Future studies of other biomarkers in the epidermal growth factor receptor pathway should help to identify which patients are likely to benefit most from gefitinib

    Serratamolide is a hemolytic factor produced by Serratia marcescens

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    Serratia marcescens is a common contaminant of contact lens cases and lenses. Hemolytic factors of S. marcescens contribute to the virulence of this opportunistic bacterial pathogen. We took advantage of an observed hyper-hemolytic phenotype of crp mutants to investigate mechanisms of hemolysis. A genetic screen revealed that swrW is necessary for the hyper-hemolysis phenotype of crp mutants. The swrW gene is required for biosynthesis of the biosurfactant serratamolide, previously shown to be a broad-spectrum antibiotic and to contribute to swarming motility. Multicopy expression of swrW or mutation of the hexS transcription factor gene, a known inhibitor of swrW expression, led to an increase in hemolysis. Surfactant zones and expression from an swrW-transcriptional reporter were elevated in a crp mutant compared to the wild type. Purified serratamolide was hemolytic to sheep and murine red blood cells and cytotoxic to human airway and corneal limbal epithelial cells in vitro. The swrW gene was found in the majority of contact lens isolates tested. Genetic and biochemical analysis implicate the biosurfactant serratamolide as a hemolysin. This novel hemolysin may contribute to irritation and infections associated with contact lens use. © 2012 Shanks et al

    Scattering Theory and PT\mathcal{P}\mathcal{T}-Symmetry

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    We outline a global approach to scattering theory in one dimension that allows for the description of a large class of scattering systems and their P\mathcal{P}-, T\mathcal{T}-, and PT\mathcal{P}\mathcal{T}-symmetries. In particular, we review various relevant concepts such as Jost solutions, transfer and scattering matrices, reciprocity principle, unidirectional reflection and invisibility, and spectral singularities. We discuss in some detail the mathematical conditions that imply or forbid reciprocal transmission, reciprocal reflection, and the presence of spectral singularities and their time-reversal. We also derive generalized unitarity relations for time-reversal-invariant and PT\mathcal{P}\mathcal{T}-symmetric scattering systems, and explore the consequences of breaking them. The results reported here apply to the scattering systems defined by a real or complex local potential as well as those determined by energy-dependent potentials, nonlocal potentials, and general point interactions.Comment: Slightly expanded revised version, 38 page

    Small molecule anionophores promote transmembrane anion permeation matching CFTR activity

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    Anion selective ionophores, anionophores, are small molecules capable of facilitating the transmembrane transport of anions. Inspired in the structure of natural product prodigiosin, four novel anionophores 1a-d, including a 1,2,3-triazole group, were prepared. These compounds proved highly efficient anion exchangers in model phospholipid liposomes. The changes in the hydrogen bond cleft modified the anion transport selectivity exhibited by these compounds compared to prodigiosin and suppressed the characteristic high toxicity of the natural product. Their activity as anionophores in living cells was studied and chloride efflux and iodine influx from living cells mediated by these derivatives was demonstrated. These compounds were shown to permeabilize cellular membranes to halides with efficiencies close to the natural anion channel CFTR at doses that do not compromise cellular viability. Remarkably, optimal transport efficiency was measured in the presence of pH gradients mimicking those found in the airway epithelia of Cystic Fibrosis patients. These results support the viability of developing small molecule anionophores as anion channel protein surrogates with potential applications in the treatment of conditions such as Cystic Fibrosis derived from the malfunction of natural anion transport mechanisms.European Union’s Horizon 2020 research and innovation programme under grant agreement No. 667079, La Marató de TV3 Foundation (20132730), Consejería de Educación de la Junta de Castilla y León (Projects BU340U13 and BU092U16

    Male reproductive health and environmental xenoestrogens

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    EHP is a publication of the U.S. government. Publication of EHP lies in the public domain and is therefore without copyright. Research articles from EHP may be used freely; however, articles from the News section of EHP may contain photographs or figures copyrighted by other commercial organizations and individuals that may not be used without obtaining prior approval from both the EHP editors and the holder of the copyright. Use of any materials published in EHP should be acknowledged (for example, "Reproduced with permission from Environmental Health Perspectives") and a reference provided for the article from which the material was reproduced.Male reproductive health has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality has been reported from Belgium, Denmark, France, and Great Britain. The incidence of testicular cancer has increased during the same time incidences of hypospadias and cryptorchidism also appear to be increasing. Similar reproductive problems occur in many wildlife species. There are marked geographic differences in the prevalence of male reproductive disorders. While the reasons for these differences are currently unknown, both clinical and laboratory research suggest that the adverse changes may be inter-related and have a common origin in fetal life or childhood. Exposure of the male fetus to supranormal levels of estrogens, such as diethlylstilbestrol, can result in the above-mentioned reproductive defects. The growing number of reports demonstrating that common environmental contaminants and natural factors possess estrogenic activity presents the working hypothesis that the adverse trends in male reproductive health may be, at least in part, associated with exposure to estrogenic or other hormonally active (e.g., antiandrogenic) environmental chemicals during fetal and childhood development. An extensive research program is needed to understand the extent of the problem, its underlying etiology, and the development of a strategy for prevention and intervention.Supported by EU Contract BMH4-CT96-0314
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