5,352 research outputs found

    Perinatal factors associate with vertebral size and shape but not lumbar lordosis in 10-year-old children

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    Acknowledgements Ethical approval for this study was granted by the North of Scotland Research Ethics Committees (13/NS/0162). We would like to thank the authors and radiographers and participants involved in the original study from which MR images and data were used. We thank Dr Onyedikachi Eseonu for his contribution to data generation and marking up spinal images. AVP was supported by a PhD studentship kindly donated by Roemex Ltd. to the Aberdeen Centre of the Oliver Bird Rheumatism Programme at the Nuffield Foundation. The funders played no part in the design, execution or publication of this study and the authors have no interests to declarePeer reviewedPostprintPostprin

    Dissociation of CH₃–O as a Driving Force for Methoxyacetophenone Adsorption on Si(001)

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    The coverage-dependent behavior of p-methoxyacetophenone on the clean Si(001) surface was followed using X-ray photoelectron spectroscopy and supporting density functional theory calculations. Unlike other multifunctional organic molecules, this compound exhibits a high selectivity of adsorbate species formation by forming only two distinct adsorbate structures at low coverage, with a third configuration forming at high coverages. At low coverage, surface chemisorption is driven by methoxy group dissociation. However, at high coverage, the surface footprint required for this process is no longer available, leading to the formation of less thermodynamically stable adsorbates that are datively bonded to the surface with a smaller footprint. This coverage-dependent but well-defined behavior is promising in designing functional organic–inorganic interfaces on silicon

    Adsorption and Dissociation of a Bicyclic Tertiary Diamine, Triethylenediamine, on a Si(100)-2 x 1 Surface

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    This study investigates the adsorption and thermal transformations of a bicyclic tertiary amine, triethylenediamine, on the clean Si(100)-2 × 1 surface. Below room temperature, triethylenediamine adsorption leads to the formation of a strong dative bond between one of the nitrogen atoms of this compound and the silicon surface. In contrast to previously studied amines, the datively adsorbed triethylenediamine features a second tertiary amine entity that is not bonded to the surface, with a lone pair orbital that is directed away from the surface and is available for further reactions. The thermal chemistry and electronic properties of triethylenediamine on silicon are studied using thermal desorption spectroscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy. Near-edge X-ray absorption fine structure measurements are utilized to clarify the geometry of the adsorbates at room temperature. Density functional theory calculations are used to describe the binding geometry and electronic properties of the resulting surface species and the likely reaction paths at elevated temperatures

    The almost ubiquitous association of 6.7-GHz methanol masers with dust

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    We report the results of 870-μm continuum observations, using the Large APEX Bolometer Camera, towards 77 class-II, 6.7-GHz methanol masers identified by the Methanol MultiBeam (MMB) survey to map the thermal emission from cool dust towards these objects. These data complement a study of 630 methanol masers associated with compact dense clumps identified from the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) survey. Compact dust emission is detected towards 70 sources, which implies a dust-association rate of 99 per cent for the full MMB catalogue. Evaluation of the derived dust and maser properties leads us to conclude that the combined sample represents a single population tracing the same phenomenon. We find median clump masses of a few 103 M⊙ and that all but a handful of sources satisfy the mass–size criterion required for massive star formation. This study provides the strongest evidence of the almost ubiquitous association of methanol masers with massive, star-forming clumps. The fraction of methanol-maser associated clumps is a factor of ∼2 lower in the outer Galaxy than the inner Galaxy, possibly a result of the lower metallicity environment of the former. We find no difference in the clump-mass and maser-luminosity distributions of the inner and outer Galaxy. The maser-pumping and clump formation mechanisms are therefore likely to be relatively invariant to Galactic location. Finally, we use the ratio of maser luminosity and clump mass to investigate the hypothesis that the maser luminosity is a good indicator of the evolutionary stage of the embedded source, however, we find no evidence to support this

    A ubiquitous amino acid source for prokaryotic and eukaryotic cell-free transcription-translation systems

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    Cell-free gene expression (CFE) systems are an attractive tool for engineering within synthetic biology and for industrial production of high-value recombinant proteins. CFE reactions require a cell extract, energy system, amino acids, and DNA, to catalyse mRNA transcription and protein synthesis. To provide an amino acid source, CFE systems typically use a commercial standard, which is often proprietary. Herein we show that a range of common microbiology rich media (i.e., tryptone, peptone, yeast extract and casamino acids) unexpectedly provide an effective and low-cost amino acid source. We show that this approach is generalisable, by comparing batch variability and protein production in the following range of CFE systems: Escherichia coli (Rosettaâ„¢ 2 (DE3), BL21(DE3)), Streptomyces venezuelae and Pichia pastoris. In all CFE systems, we show equivalent or increased protein synthesis capacity upon replacement of the commercial amino acid source. In conclusion, we suggest rich microbiology media provides a new amino acid source for CFE systems with potential broad use in synthetic biology and industrial biotechnology applications

    ATLASGAL - environments of 6.7 GHz methanol masers

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    Using the 870 μm APEX Telescope large area survey of the Galaxy, we have identified 577 submillimetre continuum sources with masers from the methanol multibeam survey in the region 280° 20 M. Furthermore, almost all clumps satisfy the empirical mass-size criterion for massive star formation. Bolometric luminosities taken from the literature for ∼100 clumps range between ∼100 and 10 L. This confirms the link between methanol masers and massive young stars for 90 per cent of our sample. The Galactic distribution of sources suggests that the star formation efficiency is significantly reduced in the Galactic Centre region, compared to the rest of the survey area, where it is broadly constant, and shows a significant drop in the massive star formation rate density in the outer Galaxy. We find no enhancement in source counts towards the southern Scutum-Centaurus arm tangent at ℓ ∼ 315°, which suggests that this arm is not actively forming stars. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society

    Quantitative trait loci for bone traits segregating independently of those for growth in an F-2 broiler X layer cross

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    An F broiler-layer cross was phenotyped for 18 skeletal traits at 6, 7 and 9 weeks of age and genotyped with 120 microsatellite markers. Interval mapping identified 61 suggestive and significant QTL on 16 of the 25 linkage groups for 16 traits. Thirty-six additional QTL were identified when the assumption that QTL were fixed in the grandparent lines was relaxed. QTL with large effects on the lengths of the tarsometatarsus, tibia and femur, and the weights of the tibia and femur were identified on GGA4 between 217 and 249 cM. Six QTL for skeletal traits were identified that did not co-locate with genome wide significant QTL for body weight and two body weight QTL did not coincide with skeletal trait QTL. Significant evidence of imprinting was found in ten of the QTL and QTL x sex interactions were identified for 22 traits. Six alleles from the broiler line for weight- and size-related skeletal QTL were positive. Negative alleles for bone quality traits such as tibial dyschondroplasia, leg bowing and tibia twisting generally originated from the layer line suggesting that the allele inherited from the broiler is more protective than the allele originating from the layer

    Standardization of epidemiological surveillance of acute rheumatic fever

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    Acute rheumatic fever (ARF) is a multiorgan inflammatory disorder that results from the body’s autoimmune response to pharyngitis or a skin infection caused by Streptococcus pyogenes (Strep A). Acute rheumatic fever mainly affects those in low- and middle-income nations, as well as in indigenous populations in wealthy nations, where initial Strep A infections may go undetected. A single episode of ARF puts a person at increased risk of developing long-term cardiac damage known as rheumatic heart disease. We present case definitions for both definite and possible ARF, including initial and recurrent episodes, according to the 2015 Jones Criteria, and we discuss current tests available to aid in the diagnosis. We outline the considerations specific to ARF surveillance methodology, including discussion on where and how to conduct active or passive surveillance (eg, early childhood centers/schools, households, primary healthcare, administrative database review), participant eligibility, and the surveillance population. Additional considerations for ARF surveillance, including implications for secondary prophylaxis and follow-up, ARF registers, community engagement, and the impact of surveillance, are addressed. Finally, the core elements of case report forms for ARF, monitoring and audit requirements, quality control and assurance, and the ethics of conducting surveillance are discussed

    Simvastatin improves the sexual health-related quality of life in men aged 40 years and over with erectile dysfunction : Additional data from the Erectile Dysfunction and Statin trial

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    © 2014 Trivedi et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background: Erectile dysfunction is prevalent in men over 40 years, affecting their quality of life and that of their partners. The aims of this study were:a)To evaluate the internal reliability of the male erectile dysfunction specific quality of life (MED-QoL) scale and explore its factor structure.b)To evaluate the effect of simvastatin on subscales of the MED-QoL in men over forty years with erectile dysfunction. Methods: This is a double blind randomised controlled trial of 40 mg simvastatin or placebo given once daily for six months to men over forty years with untreated erectile dysfunction, who were not at high cardiovascular risk and were not on anti-hypertensive or lipid-lowering medication. 173 eligible men were recruited from 10 general practices in East of England. Data were collected at two points over 30 weeks. We report on the factor structure of MED-QoL, the internal reliability of the scale and the derived subscales, and the effect of simvastatin on MED-QoL subscales. Results: An initial analysis of the MED-QoL items suggested that a number of items should be removed (MED-QoL-R). Exploratory factor analysis identified three subscales within the MED-QoL-R which accounted for 96% of the variance, related to feelings of Control, initiating Intimacy, and Emotional response to erectile dysfunction. The alpha value for the revised scale (MED-Qol-R) was >0.95 and exceeded .82 for each subscale. Regression analysis showed that patients in the placebo group experienced a significantly reduced feeling of Control over erectile dysfunction than those in the statin group. Those in the placebo group had significantly lower Emotional response than those in the statin group at the close of trial, but there was no significant treatment effect on Intimacy. Conclusions: Our revised MED-QoL-R identified three subscales. Secondary analysis showed a significant improvement in sexual health related quality of life, specifically in relation to perception of control and emotional health in men with untreated erectile dysfunction given 40 mg simvastatin for six months. Trial registration: Current Controlled Trials ISRCTN66772971.Peer reviewe
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