89 research outputs found

    A genome-wide scan for quantitative trait loci affecting limb bone lengths and areal bone mineral density of the distal femur in a White Duroc × Erhualian F2 population

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    <p>Abstract</p> <p>Background</p> <p>Limb bone lengths and bone mineral density (BMD) have been used to assess the bone growth and the risk of bone fractures in pigs, respectively. It has been suggested that limb bone lengths and BMD are under genetic control. However, the knowledge about the genetic basis of the limb bone lengths and mineralisatinon is limited in pigs. The aim of this study was to identify quantitative trait loci (QTL) affecting limb bone lengths and BMD of the distal femur in a White Duroc × Erhualian resource population.</p> <p>Results</p> <p>Limb bone lengths and femoral bone mineral density (fBMD) were measured in a total of 1021 and 116 F<sub>2 </sub>animals, respectively. There were strong positive correlations among the lengths of limb bones and medium positive correlations between the lengths of limb bones and fBMD. A whole-genome scan involving 183 microsatellite markers across the pig genome revealed 35 QTL for the limb bone lengths and 2 for femoral BMD. The most significant QTL for the lengths of five limb bones were mapped on two chromosomes affecting all 5 limb bones traits. One was detected around 57 cM on pig chromosome (SSC) 7 with the largest <it>F</it>-value of more than 26 and 95% confidence intervals of less than 5 cM, providing a crucial start point to identify the causal genes for these traits. The Erhualian alleles were associated with longer limb bones. The other was located on SSCX with a peak at 50–53 cM, whereas alleles from the White Duroc breed increased the bone length. Many QTL identified are homologous to the human genomic regions containing QTL for bone-related traits and a list of interesting candidate genes.</p> <p>Conclusion</p> <p>This study detected the QTL for the lengths of scapula, ulna, humerus and tibia and fBMD in the pig for the first time. Moreover, several new QTL for the pig femoral length were found. As correlated traits, QTL for the lengths of five limb bones were mainly located in the same genomic regions. The most promising QTL for the lengths of five limb bones on SSC7 merits further investigation.</p

    Preparation of CL-20 Explosive Nanoparticles and Their Thermal Decomposition Property

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    Herein, we develop a novel method for preparing nanohexanitrohexaazaisowurtzitane (nano-CL-20) via ultrasonic spray-assisted electrostatic adsorption (USEA) technology. Various experimental conditions which influence safety factors and the crystallization process were studied. Meanwhile, the prepared nano-CL-20 particles were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The results show that the obtained nano-CL-20 showed a wide size distribution in the range from 150 to 600 nm with an average of 270 nm. Moreover, their thermal properties were also investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG). For nano-CL-20, the exothermal peak is 232.9°C increased by 12°C compared with conventionally manufactured (CM) CL-20, and they exhibit fast energy release efficiency as well as more energy release. The simple and continuous approach presented here is expected to be an attractive potential for fabricating other organic nanoparticles

    Genome-wide identification of QTL for age at puberty in gilts using a large intercross F2 population between White Duroc and Erhualian

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    Puberty is a fundamental development process experienced by all reproductively competent adults, yet the specific factors regulating age at puberty remain elusive in pigs. In this study, we performed a genome scan to identify quantitative trait loci (QTL) affecting age at puberty in gilts using a White Duroc × Erhualian intercross. A total of 183 microsatellites covering 19 porcine chromosomes were genotyped in 454 F2 gilts and their parents and grandparents in the White Duroc × Erhualian intercross. A linear regression method was used to map QTL for age at puberty via QTLexpress. One 1% genome-wise significant QTL and one 0.1% genome-wise significant QTL were detected at 114 cM (centimorgan) on SSC1 and at 54 cM on SSC7, respectively. Moreover, two suggestive QTL were found on SSC8 and SSC17, respectively. This study confirmed the QTL for age at puberty previously identified on SSC1, 7 and 8, and reports for the first time a QTL for age at puberty in gilts on SSC17. Interestingly, the Chinese Erhualian alleles were not systematically favourable for younger age at puberty

    Crosslinked carbon nanofiber films with hierarchical pores as flexible electrodes for high performance supercapacitors

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    © 2017 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 24 month embargo from date of publication (Dec 2017) in accordance with the publisher’s archiving policyFlexible, cross-linked carbon nanofibers (CNFs) film with hierarchical micro-meso-macro-porous structure is prepared by carbonization of the elestrospun polyacrylonitrile (PAN)/NaN3 composite nanofiber mats. The gas liberation of NaN3 during the carbonization is responsible for the tuning of both specific surface area and the pore size distribution. In addition, the exothermal decomposition of NaN3 at the heating stage of carbonization leads to the melting of the PAN/NaN3 composite fibers, resulting in a cross-linked CNF structure. The CNF film with 5 wt% NaN3 carbonized at 900 °C (CNF-5-900) shows a high specific capacitance of 222.92 F g− 1, nearly twice as high as that of the CNF film without NaN3 (CNF-0-900). It also shows an excellent capacitance retention ratio of 81.97% of its initial capacitance from 0.5 A/g to 50 A/g, much superior to the value of 51.02 % for CNF-0-900. Moreover, it has an excellent cycling stability with cycling retention ratio achieves 94.5% after 10,000 charge-discharge cycles. Coupled with its excellent mechanical stability (only 1.6% conductivity loss after bending of CNF-5-900 film at curvature radii (r) = 2.5 × 10− 3 m for 10,000 cycles) and facile fabrication process, the flexible, cross-linked CNF films with hierarchical micro-meso-macro-porous structure is a potential electrode materials and/or backbone to support other active materials for various application, including the flexible energy storage and electrocatalytic

    Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst

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    The recently discovered neutron star transient Swift J0243.6+6124 has been monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT). Based on the obtained data, we investigate the broadband spectrum of the source throughout the outburst. We estimate the broadband flux of the source and search for possible cyclotron line in the broadband spectrum. No evidence of line-like features is, however, found up to 150 keV\rm 150~keV. In the absence of any cyclotron line in its energy spectrum, we estimate the magnetic field of the source based on the observed spin evolution of the neutron star by applying two accretion torque models. In both cases, we get consistent results with B∼1013 GB\rm \sim 10^{13}~G, D∼6 kpcD\rm \sim 6~kpc and peak luminosity of >1039 erg s−1\rm >10^{39}~erg~s^{-1} which makes the source the first Galactic ultraluminous X-ray source hosting a neutron star.Comment: publishe

    Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

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    As China's first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.Comment: 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech. Astron. arXiv admin note: text overlap with arXiv:1910.0443

    An overview: metal-based inhibitors of urease

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    AbstractUrease is a kind of nickel-dependent metalloenzyme, which exists in the biological world widely, and can catalyse the hydrolysis of urea into ammonia and carbon dioxide to provide a nitrogen source for organisms. Urease has important uses in agriculture and medicine because it can catalyse the production of ammonia. Therefore, in this review, metal-based inhibitors of urease will be summarised according to different transition metal ions. Including the urease inhibition, structure–activity relationship, and molecular docking. Importantly, among these reviewed effective urease inhibitors, most of copper metal complexes exhibited stronger urease inhibition with IC50 values ranging from 0.46 μM to 41.1 μM. Significantly, the collected comprehensive information looks forward to providing rational guidance and effective strategies for the development of novel, potent, and safe metal-based urease inhibitors, which are better for practical applications in the future
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