41 research outputs found

    Integrative metabolomic and transcriptomic analysis reveals difference in glucose and lipid metabolism in the longissimus muscle of Luchuan and Duroc pigs

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    Luchuan pig, an obese indigenous Chinese porcine breed, has a desirable meat quality and reproductive capacity. Duroc, a traditional western breed, shows a faster growth rate, high feed efficiency and high lean meat rate. Given the unique features these two porcine breeds have, it is of interest to investigate the underlying molecular mechanisms behind their distinctive nature. In this study, the metabolic and transcriptomic profiles of longissimus dorsi muscle from Duroc and Luchuan pigs were compared. A total of 609 metabolites were identified, 77 of which were significantly decreased in Luchuan compared to Duroc, and 71 of which were significantly elevated. Most differentially accumulated metabolites (DAMs) upregulated in Luchuan were glycerophospholipids, fatty acids, oxidized lipids, alcohols, and amines, while metabolites downregulated in Luchuan were mostly amino acids, organic acids and nucleic acids, bile acids and hormones. From our RNA-sequencing (RNA-seq) data we identified a total of 3638 differentially expressed genes (DEGs), 1802 upregulated and 1836 downregulated in Luchuan skeletal muscle compared to Duroc. Combined multivariate and pathway enrichment analyses of metabolome and transcriptome results revealed that many of the DEGs and DAMs are associated with critical energy metabolic pathways, especially those related to glucose and lipid metabolism. We examined the expression of important DEGs in two pathways, AMP-activated protein kinase (AMPK) signaling pathway and fructose and mannose metabolism, using Real-Time Quantitative Reverse Transcription PCR (qRT-PCR). Genes related to glucose uptake, glycolysis, glycogen synthesis, fatty acid synthesis (PFKFB1, PFKFB4, MPI, TPI1, GYS1, SLC2A4, FASN, IRS1, ULK1) are more activated in Luchuan, while genes related to fatty acid oxidation, cholesterol synthesis (CPT1A, HMGCR, FOXO3) are more suppressed. Energy utilization can be a decisive factor to the distinctive metabolic, physiological and nutritional characteristics in skeletal muscle of the two breeds we studied. Our research may facilitate future porcine breeding projects and can be used to reveal the potential molecular basis of differences in complex traits between various breeds

    A novel understanding of the normalized fatigue delamination model for composite multidirectional laminates

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    Normalized fatigue delamination models have been widely applied by researchers in the characterization of the fatigue delamination behavior of composite laminates. However, the inherent mechanism of this normalization method has not been explored. This study aims to present a physical understanding on the normalized fatigue delamination model from a viewpoint of energy. The fatigue delamination behavior is considered to be governed by the driving force and delamination resistance, and based on this principle the physical mechanism of the fatigue delamination is studied. A new physics-based normalized fatigue delamination model is proposed in this paper. In order to experimentally validate the proposed fatigue delamination model, mode I fatigue delamination tests are performed on double cantilever beam specimens to obtain the experimental data with different amounts of the fiber bridging. The results show that the normalized model is suitable to accurately characterize the fatigue delamination behavior of the composite laminates by using a single master curve. The master curve is finally employed as a standard approach to predict the fatigue results. Good agreement between the predicted and the experimental results is achieved, therefore it approves the applicability of the proposed fatigue delamination model in characterizing the fatigue delamination growth behavior

    Polarization-insensitive wide-angle multiband metamaterial absorber with a double-layer modified electric ring resonator array

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    In this letter, we report the design, demonstration and discussion of a multi- and broad- band metamaterial absorber (MMA) with wide angle polarization insensitive at microwave region. The MMA consisting of double layered electric ring resonator (ERR) with four fold rotational symmetry structure is used to realize a desirable absorption. Strong triple absorption peaks in 2∌8 GHz and broadband microwave absorption in 10∌18 GHz are demonstrated. The absorption can be reached as high as 0.73, 0.73 and 0.94 at 4.41, 5.15, 6.37 GHz, respectively. The multiband absorbing features originate from the synergetic effects of dipole resonance and Fabry-PĂ©rot interference between two or three metasurfaces. This design is of high practical for constructing broad band and multiband absorber for electromagnetic intereference/compatibility (EMI/EMC) applications

    Exploring Multi-Tissue Alternative Splicing and Skeletal Muscle Metabolism Regulation in Obese- and Lean-Type Pigs

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    Alternative splicing (AS) is a crucial mechanism in post-transcriptional regulation, contributing significantly to the diversity of the transcriptome and proteome. In this study, we performed a comprehensive AS profile in nine tissues obtained from Duroc (lean-type) and Luchuan (obese-type) pigs. Notably, 94,990 AS events from 14,393 genes were identified. Among these AS events, it was observed that 80% belonged to the skipped exon (SE) type. Functional enrichment analysis showed that genes with more than ten AS events were closely associated with tissue-specific functions. Additionally, the analysis of overlap between differentially alternative splicing genes (DSGs) and differentially expressed genes (DEGs) revealed the highest number of overlapped genes in the heart and skeletal muscle. The novelty of our study is that it identified and validated three genes (PYGM, MAPK11 and CAMK2B) in the glucagon signaling pathway, and their alternative splicing differences were highly significant across two pig breeds. In conclusion, our study offers novel insights into the molecular regulation of diverse tissue physiologies and the phenotypic differences between obese- and lean-type pigs, which are helpful for pig breeding

    Preparation and Physical Properties of Stretchable FeRh Films with Periodic Wrinkle Structure

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    Abstract Stretchable magnetic materials are highly desirable for developing flexible high‐performance magnetoelectronic devices. However, it is still challenge to fabricate stretchable magnetic films with high growth temperature. In this work, metamagnetic FeRh films are grown on mica substrates at high temperature and then transferred onto the prestrained polydimethylsiloxane (PDMS). Due to the large modulus mismatch between FeRh films and PDMS, FeRh films with periodic wrinkle pattern is formed after releasing the prestrain, enabling a controllable stretchability up to a few tens of percent. Moreover, the meta‐magnetic phase transition temperature can be effectively controlled by the prestrain, with an increase of ≈4 K for every 10% increase in the prestrain. In case of the applied tensile strain less than the prestrain, the obtained flexible FeRh films can maintain stable performance after thousands of stretches, making it promising for applications in flexible magnetoelectronic devices

    Injection Molding and Sintering of ZrO2 Ceramic Powder Modified by a Zirconate Coupling Agent

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    Ceramic injection molding is a near-net shape-processing technique, producing ceramic components with low tooling costs and complex shapes. In this paper, ZrO2 ceramics with high loading content in the green part were prepared by powder modification using zirconate coupling agent, injection molding and sintering, which benefited decreasing the usage of binders and deformation of ceramics. The rheological characteristics of feedstocks, densities, microstructures and mechanical properties of green and sintered parts with the different coupling media and sintering temperatures were studied. The results showed that the addition of a zirconate coupling agent with ethanol medium obviously increased the flowability of feedstocks and benefited achieving the green parts with high powder loading (86.5 wt.%) and bending strength (12.9 MPa) and the final unbroken ceramics. In addition, the sintering temperatures from 1500–1575 °C had no significant effects on the density, hardness, and surface morphology of the ceramic samples. However, the bending strength increased and some large grains with transgranular fracture occurred on the fractural surface at the sintering temperature of 1575 °C

    Carbothermal Reduction Synthesis of Aluminum Nitride from Al(OH)3/C/PVB Slurries Prepared by Three-Roll Mixing

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    Polyvinyl butyral (PVB) was used in the Al(OH)3/carbon black/ethanol slurries by the three-roll mixing to prepare AlN powder using the carbothermal reduction–nitridation (CRN) process in the experiments. The effects of PVB addition on the synthesis of AlN powder were studied by viscosity, tap density, XRD, SEM and TG measurements. The results showed that the PVB layer covering on the surface of Al(OH)3 particles reduced the viscosity of Al(OH)3/carbon/ethanol slurry and increased the dispersion homogeneity of Al(OH)3/carbon raw powder. The tap densities of the Al(OH)3/carbon mixtures after three-roll milling could be increased with the increase in PVB addition. In the CRN process, most of the PVB covering Al(OH)3 particles evaporated and supplied the passage for nitrogen removal to the particles. Based on the experimental data, the role of PVB on the mixing and CRN process was discussed

    Magnetic Properties and Microstructure of Ce-Cu-Al Low Melting Alloy Bonding Sm<sub>2</sub>Fe<sub>17</sub>N<sub>3</sub> Magnet Fabricated by the Hot-Pressing Method

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    Sm2Fe17N3 compounds, having excellent intrinsic magnetic properties, are prone to decomposition at high temperatures; thus, a low melting point metal binder is the key to prepare high performance bulk magnets at low temperatures. In this paper, a new low melting point alloy Ce72Cu28-xAlx was used as the binders, and high-performance Ce-based alloy bonding Sm2Fe17N3 magnets were realized by the hot-pressing method. The experimental results demonstrated that the content of Al in the Ce-based alloys had an important influence on the performance of the magnets. High performance Sm-Fe-N bonded magnets with remanence of 10.19 KGs and maximum magnetic energy product of 21.06 MGOe were achieved by using 5 wt.% Ce72Cu22Al6 alloy as a binder. At the same time, it was found that the Ce72Cu28-xAlx alloy has a lower density and better bonding effect than the common Zn binder. Its bonding magnets still have higher performance even with extremely high oxygen content. Therefore, Ce72Cu28-xAlx alloy with low melting point is a promising new rare earth-based alloy binder. If the oxygen content of the alloy powders could be reduced, higher performance Sm2Fe17N3 bonded magnets can be prepared

    Effect of chloride ion on crystalline phase transition of iron oxide produced by ultrasonic spray pyrolysis

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    Ultrafine spherical Fe2O3 powders with controllable morphology and crystal phase were synthesized by ultrasonic spray pyrolysis. In this experiment, we chose three common ferric salts (Fe(NO3)(3)center dot 9H(2)O, FeSO4 center dot 7H(2)O or FeCl2 center dot 4H(2)O) as precursor solution and regulated the concentration of chlorine ion (Cl-) in precursor solution to produce Fe2O3 particles. The morphology, crystal structure and magnetic property of prepared Fe2O3 particles were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Vibrating sample magnetometer (VSM). The diameter of the obtained Fe2O3 products ranged from 0.2 to 2 mu m. And the product obtained from FeCl2 precursor solution was magnetic, which was composed of hexagonal alpha-Fe2O3 and cubic gamma-Fe2O3 from XRD results. We also calculated the weight percent of alpha-Fe2O3 and gamma-Fe2O3 in the product through XRD quantitative analysis. However, with the addition of Cl- in Fe(NO3)(3) or FeSO4 precursor solution, the products turned from non-magnetic to magnetic, whose pure alpha-Fe2O3 phase became to alpha-Fe2O3 and gamma-Fe2O3 multi-phase. Besides, the weight percent of gamma-Fe2O3 and the amount of M-s increased with the Cl- concentration in precursor solution improving. According to the research, it can be inferred that the presence of Cl- inhibits the phase transition of gamma-Fe2O3 to alpha-Fe2O3 at high temperature. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved

    Magnetic Properties and Microstructure of Ce-Cu-Al Low Melting Alloy Bonding Sm2Fe17N3 Magnet Fabricated by the Hot-Pressing Method

    No full text
    Sm2Fe17N3 compounds, having excellent intrinsic magnetic properties, are prone to decomposition at high temperatures; thus, a low melting point metal binder is the key to prepare high performance bulk magnets at low temperatures. In this paper, a new low melting point alloy Ce72Cu28-xAlx was used as the binders, and high-performance Ce-based alloy bonding Sm2Fe17N3 magnets were realized by the hot-pressing method. The experimental results demonstrated that the content of Al in the Ce-based alloys had an important influence on the performance of the magnets. High performance Sm-Fe-N bonded magnets with remanence of 10.19 KGs and maximum magnetic energy product of 21.06 MGOe were achieved by using 5 wt.% Ce72Cu22Al6 alloy as a binder. At the same time, it was found that the Ce72Cu28-xAlx alloy has a lower density and better bonding effect than the common Zn binder. Its bonding magnets still have higher performance even with extremely high oxygen content. Therefore, Ce72Cu28-xAlx alloy with low melting point is a promising new rare earth-based alloy binder. If the oxygen content of the alloy powders could be reduced, higher performance Sm2Fe17N3 bonded magnets can be prepared
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