118 research outputs found

    Determination and Validation of Parameters for Riedel-Hiermaier-Thoma Concrete Model

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    Numerical modelling of the complex physical processes such as concrete structures subjected to high-impulsive loads relies on suitable material models appropriate for impact and explosion problems. One of theextensive used concrete material models, the RHT model, contains all essential features of concrete materialssubjected to high dynamic loading. However, the application of the RHT model requires a set of material propertiesand model parameters without which reliable results cannot be expected. The present paper provides adetailed valuation of the RHT model and proposes a method of determining the model parameters for C40 concrete.Furthermore, the dynamic compressive and tensile strength function of the model formulation are modified toenhance the performance of the model as implemented in the hydrocode AUTODYN. The performance of thedetermined parameters of the modified RHT model is demonstrated by comparing to available experimentaldata, and further verified via simulations of physical experiments of concrete penetration by steel projectiles.The results of numerical analyses are found closely match the penetration depth and the crater size in the frontsurface of the concrete targets.Defence Science Journal, 2013, 63(5), pp.524-530, DOI:http://dx.doi.org/10.14429/dsj.63.386

    Effect of Corilagin on the Proliferation and NF- κ

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    Background. This study is to explore the effect of corilagin on the proliferation and NF-κB signaling pathway in U251 glioblastoma cells and U251 glioblastoma stem-like cells. Methods. CD133 positive U251 glioblastoma cells were separated by immunomagnetic beads to isolate glioblastoma stem-like cells. U251 cells and stem-like cells were intervened by different corilagin concentrations (0, 25, 50, and 100 μg/mL) for 48 h, respectively. Cell morphology, cell counting kit-8 assay, flow cytometry, dual luciferase reporter assay, and a western blot were used to detect and analyze the cell proliferation and cell cycle and investigate the expression of IKBα protein in cytoplasm and NF-κB/p65 in nucleus. Results. Corilagin inhibited the cell proliferation of U251 cells and their stem-like cells and the inhibition role was stronger in U251 stem-like cells (P<0.05). The cell cycle was arrested at G2/M phase in the U251 cells following corilagin intervention; the proportion of cells in G2/M phase increased as the concentration of corilagin increased (P<0.05). The U251 stem-like cells were arrested at the S phase following treatment with corilagin; the proportion of cells in the S phase increased as the concentration of corilagin increased (P<0.05). The ratio of dual luciferase activities of U251 stem-like cells was lower than that of U251 cells in the same corilagin concentration. With increasing concentrations of corilagin, the IKBα expression in cytoplasm of U251 cells and U251 stem-like cells was increased, but the p65 expression in nucleus of U251 cells and U251 stem-like cells was decreased (P<0.05). Conclusion. Corilagin can inhibit the proliferation of glioblastoma cells and glioblastoma stem-like cells; the inhibition on glioblastoma stem-like cell proliferation is stronger than glioblastoma cells. This different result indicates that the effect of corilagin on U251 cells and U251 stem-like cells may have close relationships with mechanism of cell cycle and NF-κB signaling pathway; however, the real antitumor mechanism of corilagin is not yet clear and requires further study

    Trends of overweight and obesity prevalence in school-aged children among Henan Province from 2000 to 2019

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    ObjectivesOverweight and obesity are harmful to human health. However, the latest trends of Chinese childhood overweight and obesity prevalence are not available. The aim of this study was to examine the trends from 2000 to 2019 among students in China.MethodsWe analyzed data of 66,072 students in the Chinese National Survey on Students' Constitution and Health from 2000 to 2019. Overweight and obesity were defined based on the standard formulated by the International Obesity Task Force (IOTF standard), the World Health Organization (WHO standard), and the Working Group on Obesity in China (WGOC standard), respectively. The χ2-test was used to test the trends of overweight and obesity prevalence and logistic regression was conducted to evaluate the prevalence odds ratios of boys vs. girls and urban vs. rural areas.ResultsThe prevalence of obesity/overweight and obesity combined was 6.03/23.58% (IOTF standard), 10.56/25.88% (WGOC standard) and 10.75/29.69% (WHO standard) in 2019. From 2000 to 2019, according to the WGOC standard, the prevalence increased from 2.51 to 10.56% for obesity and increased from 9.81 to 25.88% for overweight and obesity combined (P for trend &lt; 0.001). Obesity/overweight and obesity were greater problems in boys than girls and urban than rural areas, but urban-rural differences decreased over time.ConclusionOverweight and obesity prevalence increased significantly in children and adolescents in China from 2000 to 2019. The prevalence of overweight and obesity in rural areas may contribute to a large percentage of children with overweight and obesity

    Liquefaction structures induced by the M5.7 earthquake on May 28, 2018 in Songyuan, Jilin Province, NE China and research implication

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    Acknowledgements Many thanks to Yang Wang, Wei Chen and Dong-Hao Peng from Jilin Oilfield for their help in the field investigation. We thank Dr. Lv Wang from Monash University and Dr. Gail Maxwell from the University of Aberdeen for their valuable advice on sedimentology, and we also thank Dr. Gui-Dong Ping and Dr. Zhao-Han Xie for the discussion we had about the regional tectonic stress field. We are grateful to Professor Zeng-Zhao Feng, editors and two anonymous reviewers for their editorial work and many constructive comments and suggestions that greatly improved this manuscript. Funding This study is supported by the “Natural Science Foundation of Heilongjiang Province (No. JJ2016ZR0573)”, “Youth Foundation of Northeast Petroleum University (No. NEPUBS201503)”, “Northeast Petroleum University Scientific Research Start-up Fund”, “Shandong Provincial Key Laboratory of Depositional Mineralization and Mineral Foundation (No. DMSMZO17009)”, and “Natural Science Foundation of Shandong Province (No. ZR2016DB15)”. Authors’ contributions ZFS applied for the funding, performed the research, analyzed the data, compiled a few figures and wrote the manuscript. JHZ designed the work, took part in the field trip and interpreted the data. JH interpreted part of the data and revised the manuscript. BH took part in the field trip, collected data and compiled Fig. 5. XWL interpreted part of the data and revised the manuscript. ZXL collected papers and completed some figures. WMR collected some data and compiled Fig. 2. YFZ, HQY, and JLL interpreted some of the data. LTN and GXS took part in fieldwork and collected data. JJL, WXZ and BZ interpreted some data and compiled some figures. All authors approved the final manuscript. Availability of data and materials All data generated or analyzed during this study are included in this published article. Additional data related to this paper can be requested from the corresponding author.Peer reviewedPublisher PD

    Temperature-dependent conductivity of Emim(+) (Emim(+)=1-ethyl-3-methyl imidazolium) confined in channels of a metal-organic framework

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    A 3D metal-organic framework, featuring three kinds of cation channels, was obtained through an ionothermal reaction. Investigation on its temperature-dependent conductivity indicates the contribution of order and disorder of the Emim(+) (Emim(+) = 1-ethyl-3-methyl imidazolium bromide) in the channel to its conductivity.NNSFC[20825103, 90922031, 21021061]; MSTC[2007CB815304, 2012CB821704

    Pairing symmetry and properties of iron-based high temperature superconductors

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    Pairing symmetry is important to indentify the pairing mechanism. The analysis becomes particularly timely and important for the newly discovered iron-based multi-orbital superconductors. From group theory point of view we classified all pairing matrices (in the orbital space) that carry irreducible representations of the system. The quasiparticle gap falls into three categories: full, nodal and gapless. The nodal-gap states show conventional Volovik effect even for on-site pairing. The gapless states are odd in orbital space, have a negative superfluid density and are therefore unstable. In connection to experiments we proposed possible pairing states and implications for the pairing mechanism.Comment: 4 pages, 1 table, 2 figures, polished versio

    Management of granulomatous lobular mastitis: an international multidisciplinary consensus (2021 edition)

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    Granulomatous lobular mastitis (GLM) is a rare and chronic benign inflammatory disease of the breast. Difficulties exist in the management of GLM for many front-line surgeons and medical specialists who care for patients with inflammatory disorders of the breast. This consensus is summarized to establish evidence-based recommendations for the management of GLM. Literature was reviewed using PubMed from January 1, 1971 to July 31, 2020. Sixty-six international experienced multidisciplinary experts from 11 countries or regions were invited to review the evidence. Levels of evidence were determined using the American College of Physicians grading system, and recommendations were discussed until consensus. Experts discussed and concluded 30 recommendations on historical definitions, etiology and predisposing factors, diagnosis criteria, treatment, clinical stages, relapse and recurrence of GLM. GLM was recommended as a widely accepted definition. In addition, this consensus introduced a new clinical stages and management algorithm for GLM to provide individual treatment strategies. In conclusion, diagnosis of GLM depends on a combination of history, clinical manifestations, imaging examinations, laboratory examinations and pathology. The approach to treatment of GLM should be applied according to the different clinical stage of GLM. This evidence-based consensus would be valuable to assist front-line surgeons and medical specialists in the optimal management of GLM.Improving the Ability of Diagnosis and Treatment of Difficult Disease
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