600 research outputs found

    Sea Ice Extraction via Remote Sensed Imagery: Algorithms, Datasets, Applications and Challenges

    Full text link
    The deep learning, which is a dominating technique in artificial intelligence, has completely changed the image understanding over the past decade. As a consequence, the sea ice extraction (SIE) problem has reached a new era. We present a comprehensive review of four important aspects of SIE, including algorithms, datasets, applications, and the future trends. Our review focuses on researches published from 2016 to the present, with a specific focus on deep learning-based approaches in the last five years. We divided all relegated algorithms into 3 categories, including classical image segmentation approach, machine learning-based approach and deep learning-based methods. We reviewed the accessible ice datasets including SAR-based datasets, the optical-based datasets and others. The applications are presented in 4 aspects including climate research, navigation, geographic information systems (GIS) production and others. It also provides insightful observations and inspiring future research directions.Comment: 24 pages, 6 figure

    Evidence of Hadronic Emission from the brightest-of-all-time GRB 221009A

    Full text link
    Acceleration of hadrons in relativistic shocks has been long expected and invoked to model GRB high-energy photon and neutrino emissions. However, so far there has been no direct observational evidence of hadronic emission from GRBs. The B.O.A.T. ("brightest of all time") gamma-ray burst (GRB) 221009A had extreme energies (with an isotropic energy exceeding 105510^{55} erg) and was detected in broad-band including the very-high-energy (VHE, >100GeV>100\,\rm GeV) band up to >10>10 TeV. Here we perform a comprehensive spectral analysis of the GRB from keV to TeV energy range and perform detailed spectral and light curve modelings considering both the traditional synchrotron self-Compton process and the electromagnetic (EM) cascade process initiated by hadronic interactions by accelerated cosmic rays in the external shock. We find that the leptonic scenario alone is not adequate to account for the observations, whereas the proposed scenario with the combination of hadronic and leptonic components can well reproduce the multi-wavelength spectra and the light curve. This result reveals the existence of the accelerated hadronic component in the early afterglow of this extreme burst. According to this scenario, the observed TeV light curve should contain imprints of the prompt MeV emission.Comment: 15 pages, 4 figures, 3 tables. originally submitted version for Nature Astronom

    Shearing and Mixing Performance of Ultrahigh-Molecular-Weight Hydrolyzed Polyacrylamide (HPAM) Solution in a Helixes Static Mixer

    Get PDF
    Static mixers have been widely used to dilute high viscosity, high-molecular-weight polymer mother liquor for polymer flooding, in which the mixing performance plays a critical role. In this work, a novel mixing configuration, named as Helixes static mixer, was proposed to reduce high viscosity degradation rate of polyacrylamide solution resulting from mechanical shear during mixing process. Computational fluid dynamics simulations along with experiments were performed to investigate the mixing process. Several criteria such as the intensity of segregation, mixing distance, pressure loss, and shear strain rate were used to evaluate the mixing and shear performance of static mixers. Compared to the SMX and Kenics static mixer, a longer mixing distance is needed for the Helixes static mixer to achieve an ideal mixture. A lower shear strain rate along with less viscosity degradation rate is obtained in flow field of Helixes static mixer. The spiral-lead and helical directions of mixing elements were optimized to improve mixing performance. Experimental results are in good agreement with the numerical simulations on the intensity of segregation. The viscosity degradation rate of HPAM solution which flows through Helixes static mixer is lower than that of SMX and Kenics static mixers

    Attenuating effect of pretreatment with Yiqifumai on lipopolysaccharide-induced intestine injury and survival rate in rat

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Yiqifumai is a traditional Chinese medicine compound preparation used for treatment of microcirculatory disturbance-related diseases in China. We have previous reported that pretreatment with Yiqifumai could improve the lipopolysaccharide (LPS) -induced microcirculatory disturbance in rat mesentery. The present study intended to investigate the effect of pretreatment with Yiqifumai on intestine injury and survival rate of the rats subjected to LPS challenge.</p> <p>Methods</p> <p>Male Wistar rats were continuously infused with LPS (5 mg kg<sup>-1 </sup>body weight h<sup>-1</sup>) via the left jugular vein for 90 min. In some rats, Yiqifumai 80 (mg/kg) was administrated through the left jugular vein 10 min before LPS infusion. The mean arterial pressure (MAP), heart rate (HR), rectal temperature (RT), respiratory rate (RR) and survival rate were measured at 24 h, 48 h and 72 h after LPS infusion. At 72 h after exposure to LPS, the intestine morphology was observed under a stereomicroscope and the immunohistochemistry staining of intestine was conducted to evaluate the expression of intercellular adhesion molecule 1 (ICAM-1) and the number of myeloperoxidase (MPO) positive cells in tissue. After observation of intestine microcirculation, blood was collected from the abdominal aorta of each animal to analyze the level of inflammatory markers in plasma, including TNF-α and MCP-1.</p> <p>Results</p> <p>Compared to the control, LPS infusion significantly decreased MAP and the survival rate and increased the HR, RT and RR, as well as elicited leukocyte infiltration, intestine hemorrhage, enhanced expression of ICAM-1 and raised level of inflammatory markers. All of indicators, except for the RT, were significantly attenuated by Yiqifumai, in contrast to the LPS group.</p> <p>Conclusions</p> <p>The results demonstrated the potential of pretreatment with Yiqifumai to ameliorate rat intestine injury, inflammatory response to LPS and the decrease in survival rate caused by LPS challenge.</p

    Evolutional selection of a combinatorial phage library displaying randomly-rearranged various single domains of immunoglobulin (Ig)-binding proteins (IBPs) with four kinds of Ig molecules

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Protein A, protein G and protein L are three well-defined immunoglobulin (Ig)-binding proteins (IBPs), which show affinity for specific sites on Ig of mammalian hosts. Although the precise functions of these molecules are not fully understood, it is thought that they play an important role in pathogenicity of bacteria. The single domains of protein A, protein G and protein L were all demonstrated to have function to bind to Ig. Whether combinations of Ig-binding domains of various IBPs could exhibit useful novel binding is interesting.</p> <p>Results</p> <p>We used a combinatorial phage library which displayed randomly-rearranged various-peptide-linked molecules of D and A domains of protein A, designated PA(D) and PA(A) respectively, B2 domain of protein G (PG) and B3 domain of protein L (PL) for affinity selection with human IgG (hIgG), human IgM (hIgM), human IgA (hIgA) and recombinant hIgG1-Fc as bait respectively. Two kinds of novel combinatorial molecules with characteristic structure of PA(A)-PG and PA(A)-PL were obtained in hIgG (hIgG1-Fc) and hIgM (hIgA) post-selection populations respectively. In addition, the linking peptides among all PA(A)-PG and PA(A)-PL structures was strongly selected, and showed interestingly divergent and convergent distribution. The phage binding assays and competitive inhibition experiments demonstrated that PA(A)-PG and PA(A)-PL combinations possess comparable binding advantages with hIgG/hIgG1-Fc and hIgM/hIgA respectively.</p> <p>Conclusion</p> <p>In this work, a combinatorial phage library displaying Ig-binding domains of protein A, protein G, or protein L joined by various random linking peptides was used to conducted evolutional selection <it>in vitro</it> with four kinds of Ig molecules. Two kinds of novel combinations of Ig-binding domains, PA(A)-PG and PA(A)-PL, were obtained, and demonstrate the novel Ig binding properties.</p

    Variants of Interleukin-22 Gene Confer Predisposition to Autoimmune Thyroid Disease

    Get PDF
    As there are no previous studies on the interleukin-22 (IL-22) variants in autoimmune thyroid disease (AITD), the present study aimed to explore the association between polymorphisms of IL-22 and the predisposition to AITD. The study had 975 AITD patients, including 639 Graves’ disease (GD) and 336 Hashimoto’s thyroiditis (HT) individuals and 851 healthy cohorts. Ligase detection reaction (LDR) and direct sequencing method were used for genotyping the IL-22 gene polymorphisms at rs2046068, rs2227478, rs2227485, rs11611206, and rs1179251. In comparison to female controls, genotype CC of rs1179251 was increased in the female AITD patients. Alleles C at rs2046068, C at rs2227478, and C at rs1179251 linked to the susceptibility of HT males. Genotype CC in rs1179251 was higher in male HT. Variants at rs2046068, rs2227478, and rs1179251 were associated with the AITD teenagers. Besides, genotype GG in rs11611206 was correlated with thyroid-associated ophthalmopathy (TAO). Moreover, allele G at rs11611206 was associated with decreased risk for TAO by 28.9%. Similarly, genotype CC of rs1179251 and genotype GG of rs11611206 were associated with Graves’ ophthalmopathy (GO). Allele G in rs11611206 increased people with HT towards the predisposition of hypothyroidism. In conclusion, genetic variants of IL-22 are associated with the occurrence of AITD
    corecore