183 research outputs found

    Low Mass X-ray Binary As the Progenitor of PSR J1713+0747

    Full text link
    We have calculated the evolution of low-mass X-ray binaries that leads to the formation of the binary radio pulsars like PSR J1713+0747. We show that the mass transfer is most likely to be nonconservative, due to unstable disk accretion, to account for the mass of PSR J1713+0747, which is close to its initial value. We assume that part of the lost material from the binary may form a circumbinary disk, and find that it can significantly influence the mass transfer processes. We briefly discuss the implications of the circumbinary disks on the evolution of low-mass X-ray binaries and the formation of low-mass binary pulsars.Comment: 8 pages, 4 figures, accepted for publication in PAS

    The birth rate of subluminous and overluminous type Ia supernovae

    Full text link
    Based on the results of Chen & Li (2009) and Pakmor et al. (2010), we carried out a series of binary population synthesis calculations and considered two treatment of common envelope (CE) evolution, i.e. α\alpha-formalism and γ\gamma-algorithm. We found that the evolution of birth rate of these peculiar SNe Ia is heavily dependent on how to treat the CE evolution. The over-luminous SNe Ia may only occur for α\alpha-formalism with low CE ejection efficiency and the delay time of the SNe Ia is between 0.4 and 0.8 Gyr. The upper limit of the contribution rate of the supernovae to all SN Ia is less than 0.3%. The delay time of sub-luminous SNe Ia from equal-mass DD systems is between 0.1 and 0.3 Gyr for α\alpha-formalism with α=3.0\alpha=3.0, while longer than 9 Gyr for α=1.0\alpha=1.0. The range of the delay time for γ\gamma-algorithm is very wide, i.e. longer than 0.22 Gyr, even as long as 15 Gyr. The sub-luminous SNe Ia from equal-mass DD systems may only account for no more than 1% of all SNe Ia observed. The super-Chandrasekhar mass model of Chen & Li (2009) may account for a part of 2003fg-like supernovae and the equal-mass DD model developed by Pakmor et al. (2010) may explain some 1991bg-like events, too. In addition, based on the comparison between theories and observations, including the birth rate and delay time of the 1991bg-like events, we found that the γ\gamma-algorithm is more likely to be an appropriate prescription of the CE evolution of DD systems than the α\alpha-formalism if the equal-mass DD systems is the progenitor of 1991bg-like SNe Ia.Comment: 8 pages, 2 figures, accepted for publication in A&

    Dir-MUSIC Algorithm for DOA Estimation of Partial Discharge Based on Signal Strength represented by Antenna Gain Array Manifold

    Full text link
    Inspection robots are widely used in the field of smart grid monitoring in substations, and partial discharge (PD) is an important sign of the insulation state of equipments. PD direction of arrival (DOA) algorithms using conventional beamforming and time difference of arrival (TDOA) require large-scale antenna arrays and high computational complexity, which make them difficult to implement on inspection robots. To address this problem, a novel directional multiple signal classification (Dir-MUSIC) algorithm for PD direction finding based on signal strength is proposed, and a miniaturized directional spiral antenna circular array is designed in this paper. First, the Dir-MUSIC algorithm is derived based on the array manifold characteristics. This method uses strength intensity information rather than the TDOA information, which could reduce the computational difficulty and the requirement of array size. Second, the effects of signal-to-noise ratio (SNR) and array manifold error on the performance of the algorithm are discussed through simulations in detail. Then according to the positioning requirements, the antenna array and its arrangement are developed, optimized, and simulation results suggested that the algorithm has reliable direction-finding performance in the form of 6 elements. Finally, the effectiveness of the algorithm is tested by using the designed spiral circular array in real scenarios. The experimental results show that the PD direction-finding error is 3.39{\deg}, which can meet the need for Partial discharge DOA estimation using inspection robots in substations.Comment: 8 pages,13 figures,24 reference

    A thermal behavior of low-substituted hydroxyethyl cellulose and cellulose solutions in NaOH-water

    No full text
    The articles belonging to the special issue are open access, all published articles are freely available online.International audienceHydroxyethyl cellulose (HEC) with low molar substitution has better solubility in 8%NaOH-water solution than pure cellulose. The thermal behavior of ternary HEC/NaOH/water mixtures was investigated by DSC, and the results are compared with those of cellulose/NaOH/water solutions, aiming at providing better understanding about cellulose dissolution mechanism in NaOH-water. At low polymer concentrations and below 0°C, HEC and cellulose solutions exhibit a similar thermal behavior with ice, eutectic and/or melting and recrystallization peaks, showing that the overall interactions between NaOH, water and cellulose or HEC are identical. However, when the concentration increases above 2%, the eutectic peak of HEC solutions disappeared, leaving only the ice peak, which is different from previous results for cellulose where the disappearance of the eutectic peak was related to the maximum solubility of cellulose (around 8 wt%). This implies that the dissolution behavior of HEC in NaOH solution is changed due to possible changes of chain flexibility and/or increased attractions to water caused by the hydrophilic hydroxyethyl groups. The melting and recrystallization peaks visible only at low concentrations of HEC or cellulose in solution also support the conclusion that dissolution of cellulose and HEC at low concentrations bears features which are not yet understood

    Probiotic consumption and hepatic steatosis: results from the NHANES 2011–2016 and Mendelian randomization study

    Get PDF
    BackgroundRecent research showed that probiotics treatment may reduce insulin resistance, regulate lipid metabolism, raise liver enzyme levels, and ameliorate inflammation in individuals with metabolic associated fatty liver disease (MAFLD). However, the possible effects of probiotic use on the progression of hepatic steatosis (HS) have not been identified. The purpose of this study was to investigate this in a large population database.MethodsThe cross-sectional research was conducted among adults with complete data on probiotic yogurt consumption and HS in the 2011–2016 National Health and Nutrition Examination Survey (NHANES). Probiotic yogurt consumption was assessed using a dietary supplement questionnaire, while HS was evaluated with HS index (HSI). To explore their relationship, weighted univariate regression analysis, subgroup analysis, and interaction analysis were conducted. To evaluate the causal association between yogurt consumption and NAFLD, mendelian randomization analysis (MR) were performed. A restricted cubic spline (RCS) was used to analyze the relationship curve between the leves of yogurt consumption and hepatic steatosis.ResultsA total of 7,891 participants were included in the study represented 146.7 million non-institutionalized residents of the United States, of whom 4,322 (54.77%) were diagnosed with HS. Multivariable logistic regression showed probiotic yogurt consumption had significantly inverse relationship for HS (OR = 0.84, 95% CI: 0.72–0.97, p = 0.02) after adjusting for all covariates. Once more, the independent relationship between probiotic yogurt consumption and HS was verified by subgroup analysis and interaction analysis. The MR analysis results indicate that there is no causal relationship between yogurt consumption and NAFLD. The RCS model demonstrated a robust J-shaped link between yogurt consumption and HS, revealing a significant decrease in risk within the lower range of yogurt consumption, which attained the lowest risk close to 0.4 cup.ConclusionAccording to the NHANES data, the consumption of probiotics and yogurt has a beneficial effect on HS, whereas the MR results indicated it was not related to NAFLD. The RCS analysis indicates a J-shaped relationship between yogurt consumption and HS, which may account for the inconsistency in the results. Based on these findings, we recommend that adults take half a cup of yogurt daily

    Generation of Human Epidermis-Derived Mesenchymal Stem Cell-like Pluripotent Cells and their reprogramming in mouse chimeras

    Get PDF
    Stem cells can be derived from the embryo (embryonic stem cells, ESCs), from adult tissues (adult stem cells, ASCs), and by induction of fibroblasts (induced pluripotent stem cells, iPSs). Ethical problems, immunological rejection, and difficulties in obtaining human tissues limit the use of ESCs in clinical medicine. Induced pluripotent stem cells are difficult to maintain in vitro and carry a greater risk of tumor formation. Furthermore, the complexity of maintenance and propagation is especially difficult in the clinic. Adult stem cells can be isolated from several adult tissues and present the possibility of self-transplantation for the clinical treatment of a variety of human diseases. Recently, several ASCs have been successfully isolated and cultured in vitro, including hematopoietic stem cells (HSCs) , mesenchymal stem cells (MSCs), epidermis stem cells, neural stem cells (NSCs), adipose-derived stem cells (ADSCs), islet stem cells, and germ line stem cells. Human mesenchymal stem cells originate mainly from bone marrow, cord blood, and placenta, but epidermis-derived MSCs have not yet been isolated. We isolated small spindle-shaped cells with strong proliferative potential during the culture of human epidermis cells and designed a medium to isolate and propagate these cells. They resembled MSCs morphologically and demonstrated pluripotency in vivo; thus, we defined these cells as human epidermis-derived mesenchymal stem cell-like pluripotent cells (hEMSCPCs). These hEMSCPCs present a possible new cell resource for tissue engineering and regenerative medicine

    Keggin-type P-W-Mo-V polyoxometalates in electrocatalyzed CO2 reduction using indium electrodes

    Get PDF
    Electrochemical CO2 reduction reaction (CO2RR) driven by indium-based catalysts can convert CO2 into C1 products with specific energy densities and relatively low mass. However, it is promising to obtain C2 products by introducing Keggin-type polyoxometalates (POMs) that can effectively regulate the proton-coupled electron transfer at the electrode–electrolyte interface. Here, the commercial indium sheets were combined with Keggin-type POMs (H4PVMoW10O40·15H2O, PVMoW10; H5PV2MoW9O40·10H2O, PV2MoW9) to process CO2RR. The highest Faradaic efficiency (FE) toward acetate reached 75.6% in the PVMoW10 system, and the highest FEethanol reached 85.1% in the PV2MoW9 system. The X-ray photoelectron spectroscopy (XPS) results indicated that the electron transfer by the POMs had a positive interaction with the active In0 sites, which provided a special electron channel to improve the FEs of the C2 products in CO2RR

    FusionAD: Multi-modality Fusion for Prediction and Planning Tasks of Autonomous Driving

    Full text link
    Building a multi-modality multi-task neural network toward accurate and robust performance is a de-facto standard in perception task of autonomous driving. However, leveraging such data from multiple sensors to jointly optimize the prediction and planning tasks remains largely unexplored. In this paper, we present FusionAD, to the best of our knowledge, the first unified framework that fuse the information from two most critical sensors, camera and LiDAR, goes beyond perception task. Concretely, we first build a transformer based multi-modality fusion network to effectively produce fusion based features. In constrast to camera-based end-to-end method UniAD, we then establish a fusion aided modality-aware prediction and status-aware planning modules, dubbed FMSPnP that take advantages of multi-modality features. We conduct extensive experiments on commonly used benchmark nuScenes dataset, our FusionAD achieves state-of-the-art performance and surpassing baselines on average 15% on perception tasks like detection and tracking, 10% on occupancy prediction accuracy, reducing prediction error from 0.708 to 0.389 in ADE score and reduces the collision rate from 0.31% to only 0.12%

    Three exonic variants in the PHEX gene cause aberrant splicing in a minigene assay

    Get PDF
    Background: X-linked hypophosphatemia (XLH, OMIM 307800) is a rare phosphorus metabolism disorder caused by PHEX gene variants. Many variants simply classified as missense or nonsense variants were only analyzed at the DNA level. However, growing evidence indicates that some of these variants may alter pre-mRNA splicing, causing diseases. Therefore, this study aimed to use bioinformatics tools and a minigene assay to ascertain the effects of PHEX variations on pre-mRNA splicing.Methods: We analyzed 174 variants in the PHEX gene described as missense or nonsense variants. Finally, we selected eight candidate variants using bioinformatics tools to evaluate their effects on pre-mRNA splicing using a minigene assay system. The complementary DNA (cDNA) sequence for the PHEX gene (RefSeq NM_000444.6) serves as the basis for DNA variant numbering.Results: Of the eight candidate variants, three were found to cause abnormal splicing. Variants c.617T>G p.(Leu206Trp) and c.621T>A p.(Tyr207*) in exon 5 altered the splicing of pre-mRNA, owing to the activation of a cryptic splice site in exon 5, which produced an aberrant transcript lacking a part of exon 5, whereas variant c.1700G>C p.(Arg567Pro) in exon 16 led to the activation of a cryptic splice site in intron 16, resulting in a partial inclusion of intron 16.Conclusion: Our study employed a minigene system, which has a great degree of flexibility to assess abnormal splicing patterns under the circumstances of patient mRNA samples that are not available, to explore the impact of the exonic variants on pre-mRNA splicing. Based on the aforementioned experimental findings, we demonstrated the importance of analyzing exonic variants at the mRNA level
    • …
    corecore