853 research outputs found

    New Concepts of Fluorescent Probes for Specific Detection of DNA Sequences: Bis-Modified Oligonucleotides in Excimer and Exciplex Detection

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    The detection of single base mismatches in DNA is important for diagnostics, treatment of genetic diseases, and identification of single nucleotide polymorphisms. Highly sensitive, specific assays are needed to investigate genetic samples from patients. The use of a simple fluorescent nucleoside analogue in detection of DNA sequence and point mutations by hybridisation in solution is described in this study. The 5′-bispyrene and 3′-naphthalene oligonucleotide probes form an exciplex on hybridisation to target in water and the 5′-bispyrene oligonucleotide alone is an adequate probe to determine concentration of target present. It was also indicated that this system has a potential to identify mismatches and insertions. The aim of this work was to investigate experimental structures and conditions that permit strong exciplex emission for nucleic acid detectors, and show how such exciplexes can register the presence of mismatches as required in SNP analysis. This study revealed that the hybridisation of 5′-bispyrenyl fluorophore to a DNA target results in formation of a fluorescent probe with high signal intensity change and specificity for detecting a complementary target in a homogeneous system. Detection of SNP mutations using this split-probe system is a highly specific, simple, and accessible method to meet the rigorous requirements of pharmacogenomic studies. Thus, it is possible for the system to act as SNP detectors and it shows promise for future applications in genetic testing

    Parents’ experiences of health visiting for children with Down syndrome

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    © MA Healthcare Limited.Children with Down syndrome have an increased likelihoodof experiencing serious health conditions. Health visitors canhave an important role in monitoring and promoting healthand development for young children with Down syndrome.This study aimed to explore parents’ experiences of healthvisiting services for children with Down syndrome. Twentyfour parents of children with Down syndrome aged 0–5 yearscompleted a brief questionnaire about the number and natureof visits from health visitors in the previous 12 months andtheir support needs. Some parents commented that otherprofessionals met the needs of their child, whereas others saidthat they would like more advice and support from healthvisitors. A further exploration of broader health serviceprovision, including health visiting, for young children withDown syndrome is needed.Peer reviewedFinal Accepted Versio

    Decompactifications and Massless D-Branes in Hybrid Models

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    A method of determining the mass spectrum of BPS D-branes in any phase limit of a gauged linear sigma model is introduced. A ring associated to monodromy is defined and one considers K-theory to be a module over this ring. A simple but interesting class of hybrid models with Landau-Ginzburg fibres over CPn are analyzed using special Kaehler geometry and D-brane probes. In some cases the hybrid limit is an infinite distance in moduli space and corresponds to a decompactification. In other cases the hybrid limit is at a finite distance and acquires massless D-branes. An example studied appears to correspond to a novel theory of supergravity with an SU(2) gauge symmetry where the gauge and gravitational couplings are necessarily tied to each other.Comment: PDF-LaTeX, 34 pages, 2 mps figure

    Effectiveness of a training-of-trainers model in a HIV counseling and testing program in the Caribbean Region

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    <p>Abstract</p> <p>Objectives</p> <p>To evaluate the effectiveness and sustainability of a voluntary counseling and testing (VCT) training program based on a training-of-trainers (TOT) model in the Caribbean Region, we gathered data on the percentage of participants trained as VCT providers who were providing VCT services, and those trained as VCT trainers who were conducting VCT training.</p> <p>Methods</p> <p>The VCT training program trained 3,489 providers in VCT clinical skills and 167 in VCT training skills within a defined timeframe. An information-monitoring system tracked HIV trainings conducted, along with information about course participants and trainers. Drawing from this database, a telephone survey followed up on program-trained VCT providers; an external evaluation analyzed data on VCT trainers.</p> <p>Results</p> <p>Almost 65% of trained VCT providers could be confirmed as currently providing VCT services. This percentage did not decrease significantly with time. Of the VCT trainers, 80% became certified as trainers by teaching at least one course; of these, 66% taught more than one course.</p> <p>Conclusion</p> <p>A TOT-based training program is an effective and sustainable method for rapid scale-up of VCT services and training capacity in a large-scale VCT program.</p

    Electrophysiological Heterogeneity of Fast-Spiking Interneurons: Chandelier versus Basket Cells

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    In the prefrontal cortex, parvalbumin-positive inhibitory neurons play a prominent role in the neural circuitry that subserves working memory, and alterations in these neurons contribute to the pathophysiology of schizophrenia. Two morphologically distinct classes of parvalbumin neurons that target the perisomatic region of pyramidal neurons, chandelier cells (ChCs) and basket cells (BCs), are generally thought to have the same "fast-spiking" phenotype, which is characterized by a short action potential and high frequency firing without adaptation. However, findings from studies in different species suggest that certain electrophysiological membrane properties might differ between these two cell classes. In this study, we assessed the physiological heterogeneity of fast-spiking interneurons as a function of two factors: species (macaque monkey vs. rat) and morphology (chandelier vs. basket). We showed previously that electrophysiological membrane properties of BCs differ between these two species. Here, for the first time, we report differences in ChCs membrane properties between monkey and rat. We also found that a number of membrane properties differentiate ChCs from BCs. Some of these differences were species-independent (e.g., fast and medium afterhyperpolarization, firing frequency, and depolarizing sag), whereas the differences in the first spike latency between ChCs and BCs were species-specific. Our findings indicate that different combinations of electrophysiological membrane properties distinguish ChCs from BCs in rodents and primates. Such electrophysiological differences between ChCs and BCs likely contribute to their distinctive roles in cortical circuitry in each species. © 2013 Povysheva et al

    Soft branes in supersymmetry-breaking backgrounds

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    We revisit the analysis of effective field theories resulting from non-supersymmetric perturbations to supersymmetric flux compactifications of the type-IIB superstring with an eye towards those resulting from the backreaction of a small number of anti-D3-branes. Independently of the background, we show that the low-energy Lagrangian describing the fluctuations of a stack of probe D3-branes exhibits soft supersymmetry breaking, despite perturbations to marginal operators that were not fully considered in some previous treatments. We take this as an indication that the breaking of supersymmetry by anti-D3-branes or other sources may be spontaneous rather than explicit. In support of this, we consider the action of an anti-D3-brane probing an otherwise supersymmetric configuration and identify a candidate for the corresponding goldstino.Comment: 36+5 pages. References added, minor typos correcte

    Quality of life and symptoms among patients with relapsed/refractory AL amyloidosis treated with ixazomib-dexamethasone versus physician's choice

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    Patient-reported outcomes in AL amyloidosis have not been well-studied. We analyzed health-related quality of life (HRQOL) and AL amyloidosis symptoms data from the phase 3 TOURMALINE-AL1 trial (NCT01659658) (ixazomib-dexamethasone, n = 85; physician's choice of chemotherapy [PC], n = 83). HRQOL and symptom burden were measured with the SF-36v2, Functional Assessment of Cancer Therapy/Gynecologic Oncology Group Neurotoxicity subscale (FACT/GOG-Ntx), and an amyloidosis symptom questionnaire (ASQ). Score changes during treatment were analyzed descriptively and using repeated-measures linear mixed models; analyses were not adjusted for multiplicity. Least-squares (LS) mean changes from baseline were significantly higher (better HRQOL) for ixazomib-dexamethasone at several cycles for SF-36v2 Role Physical and Vitality subscales (p <.05); no subscales demonstrated significant differences favoring PC. For FACT/GOG-Ntx, small but significant differences in LS mean changes favored ixazomib-dexamethasone over PC at multiple cycles for seven items and both summary scores; significant differences favored PC for one item (trouble hearing) at multiple cycles. ASQ total score trended downward (lower burden) in both arms; significant LS mean differences favored ixazomib-dexamethasone over PC at some cycles (p <.05). Patients with relapsed/refractory AL amyloidosis treated with ixazomib-dexamethasone experienced HRQOL and symptoms that were similar to or trended better than patients treated with PC despite longer duration of therapy

    Tetrahydropyrazolo[1,5-a]Pyrimidine-3-Carboxamide and N-Benzyl-6′,7′-Dihydrospiro[Piperidine-4,4′-Thieno[3,2-c]Pyran] analogues with bactericidal efficacy against Mycobacterium tuberculosis targeting MmpL3

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    Mycobacterium tuberculosis is a major human pathogen and the causative agent for the pulmonary disease, tuberculosis (TB). Current treatment programs to combat TB are under threat due to the emergence of multi-drug and extensively-drug resistant TB. As part of our efforts towards the discovery of new anti-tubercular leads, a number of potent tetrahydropyrazolo[1,5-a]pyrimidine-3-ca​rboxamide(THPP) and N-benzyl-6′,7′-dihydrospiro[piperidine-4,​4′-thieno[3,2-c]pyran](Spiro) analogues were recently identified against Mycobacterium tuberculosis and Mycobacterium bovis BCG through a high-throughput whole-cell screening campaign. Herein, we describe the attractive in vitro and in vivo anti-tubercular profiles of both lead series. The generation of M. tuberculosis spontaneous mutants and subsequent whole genome sequencing of several resistant mutants identified single mutations in the essential mmpL3 gene. This ‘genetic phenotype’ was further confirmed by a ‘chemical phenotype’, whereby M. bovis BCG treated with both the THPP and Spiro series resulted in the accumulation of trehalose monomycolate. In vivo efficacy evaluation of two optimized THPP and Spiro leads showed how the compounds were able to reduce >2 logs bacterial cfu counts in the lungs of infected mice
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