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237 results on '"XU, Z. L."'

1. Hadronic cross section measurements with the DAMPE space mission using 20GeV-10TeV cosmic-ray protons and $^4$He

Author

Alemanno, F., An, Q., Azzarello, P., Barbato, F. C. T., Bernardini, P., Bi, X. J., Cagnoli, I., Cai, M. S., Casilli, E., Catanzani, E., Chang, J., Chen, D. Y., Chen, J. L., Chen, Z. F., Coppin, P., Cui, M. Y., Cui, T. S., Cui, Y. X., Dai, H. T., De Benedittis, A., De Mitri, I., de Palma, F., Di Giovanni, A., Ding, Q., Dong, T. K., Dong, Z. X., Donvito, G., Droz, D., Duan, J. L., Duan, K. K., Fan, R. R., Fan, Y. Z., Fang, F., Fang, K., Feng, C. Q., Feng, L., Frieden, J. M., Fusco, P., Gao, M., Gargano, F., Gong, K., Gong, Y. Z., Guo, D. Y., Guo, J. H., Han, S. X., Hu, Y. M., Huang, G. S., Huang, X. Y., Huang, Y. Y., Ionica, M., Jiang, L. Y., Jiang, Y. Z., Jiang, W., Kong, J., Kotenko, A., Kyratzis, D., Lei, S. J., Li, W. H., Li, W. L., Li, X., Li, X. Q., Liang, Y. M., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, Y., Loparco, F., Luo, C. N., Ma, M., Ma, P. X., Ma, T., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Niu, X. Y., Pan, X., Parenti, A., Peng, W. X., Peng, X. Y., Perrina, C., Putti-Garcia, E., Qiao, R., Rao, J. N., Ruina, A., Sarkar, R., Savina, P., Serpolla, A., Shangguan, Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Silveri, L., Song, J. X., Stolpovskiy, M., Su, H., Su, M., Sun, H. R., Sun, Z. Y., Surdo, A., Teng, X. J., Tykhonov, A., Wang, J. Z., Wang, L. G., Wang, S., Wang, S. X., Wang, X. L., Wang, Y., Wang, Y. F., Wang, Y. Z., Wang, Z. M., Wei, D. M., Wei, J. J., Wei, Y. F., Wu, D., Wu, J., Wu, S. S., Wu, X., Xia, Z. Q., Xu, H. T., Xu, J., Xu, Z. H., Xu, Z. L., Xu, E. H., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yao, H. J., Yu, Y. H., Yuan, G. W., Yuan, Q., Yue, C., Zang, J. J., Zhang, S. X., Zhang, W. Z., Zhang, Yan, Zhang, Yi, Zhang, Y. J., Zhang, Y. L., Zhang, Y. P., Zhang, Y. Q., Zhang, Z., Zhang, Z. Y., Zhao, C., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., and Zhu, Y.

Subjects
High Energy Physics - Experiment
Abstract

Precise direct cosmic-ray (CR) measurements provide an important probe to study the energetic particle sources in our Galaxy, and the interstellar environment through which these particles propagate. Uncertainties on hadronic models, ion-nucleon cross sections in particular, are currently the limiting factor towards obtaining more accurate CR ion flux measurements with calorimetric space-based experiments. We present an energy-dependent measurement of the inelastic cross section of protons and helium-4 nuclei (alpha particles) on a Bi$_4$Ge$_3$O$_{12}$ target, using 88 months of data collected by the DAMPE space mission. The kinetic energy range per nucleon of the measurement points ranges from 18 GeV to 9 TeV for protons, and from 5 GeV/n to 3 TeV/n for helium-4 nuclei. Our results lead to a significant improvement of the CR flux normalisation. In the case of helium-4, these results correspond to the first cross section measurements on a heavy target material at energies above 10 GeV/n., Comment: 17 pages, submitted to PRD

Published
2024

2. Measurement of the cosmic p+He energy spectrum from 50 GeV to 0.5 PeV with the DAMPE space mission

Author

DAMPE Collaboration, Alemanno, F., Altomare, C., An, Q., Azzarello, P., Barbato, F. C. T., Bernardini, P., Bi, X. J., Cagnoli, I., Cai, M. S., Casilli, E., Catanzani, E., Chang, J., Chen, D. Y., Chen, J. L., Chen, Z. F., Coppin, P., Cui, M. Y., Cui, T. S., Cui, Y. X., Dai, H. T., De Benedittis, A., De Mitri, I., de Palma, F., Deliyergiyev, M., Di Giovanni, A., Di Santo, M., Ding, Q., Dong, T. K., Dong, Z. X., Donvito, G., Droz, D., Duan, J. L., Duan, K. K., Fan, R. R., Fan, Y. Z., Fang, F., Fang, K., Feng, C. Q., Feng, L., Alonso, M. Fernandez, Frieden, J. M., Fusco, P., Gao, M., Gargano, F., Gong, K., Gong, Y. Z., Guo, D. Y., Guo, J. H., Han, S. X., Hu, Y. M., Huang, G. S., Huang, X. Y., Huang, Y. Y., Ionica, M., Jiang, L. Y., Jiang, Y. Z., Jiang, W., Kong, J., Kotenko, A., Kyratzis, D., Lei, S. J., Li, W. H., Li, W. L., Li, X., Li, X. Q., Liang, Y. M., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, Y., Loparco, F., Luo, C. N., Ma, M., Ma, P. X., Ma, T., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Salinas, M. Muñoz, Niu, X. Y., Pan, X., Parenti, A., Peng, W. X., Peng, X. Y., Perrina, C., Putti-Garcia, E., Qiao, R., Rao, J. N., Ruina, A., Shangguan, Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Silveri, L., Song, J. X., Stolpovskiy, M., Su, H., Su, M., Sun, H. R., Sun, Z. Y., Surdo, A., Teng, X. J., Tykhonov, A., Wang, J. Z., Wang, L. G., Wang, S., Wang, S. X., Wang, X. L., Wang, Y., Wang, Y. F., Wang, Y. Z., Wang, Z. M., Wei, D. M., Wei, J. J., Wei, Y. F., Wu, D., Wu, J., Wu, L. B., Wu, S. S., Wu, X., Xia, Z. Q., Xu, H. T., Xu, J., Xu, Z. H., Xu, Z. L., Xu, E. H., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yao, H. J., Yu, Y. H., Yuan, G. W., Yuan, Q., Yue, C., Zang, J. J., Zhang, S. X., Zhang, W. Z., Zhang, Yan, Zhang, Yi, Zhang, Y. J., Zhang, Y. L., Zhang, Y. P., Zhang, Y. Q., Zhang, Z., Zhang, Z. Y., Zhao, C., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., and Zhu, Y.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract

Recent observations of the light component of the cosmic-ray spectrum have revealed unexpected features that motivate further and more precise measurements up to the highest energies. The Dark Matter Particle Explorer is a satellite-based cosmic-ray experiment that has been operational since December 2015, continuously collecting data on high-energy cosmic particles with very good statistics, energy resolution, and particle identification capabilities. In this work, the latest measurements of the energy spectrum of proton+helium in the energy range from 46 GeV to 464 TeV are presented. Among the most distinctive features of the spectrum, a spectral hardening at 600 GeV has been observed, along with a softening at 29 TeV measured with a 6.6{\sigma} significance. Moreover, the detector features and the analysis approach allowed for the extension of the spectral measurement up to the sub-PeV region. Even if with small statistical significance due to the low number of events, data suggest a new spectral hardening at about 150 TeV., Comment: Published on PRD

Published
2023
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3. Search for relativistic fractionally charged particles in space

Author

DAMPE Collaboration, Alemanno, F., Altomare, C., An, Q., Azzarello, P., Barbato, F. C. T., Bernardini, P., Bi, X. J., Cai, M. S., Casilli, E., Catanzani, E., Chang, J., Chen, D. Y., Chen, J. L., Chen, Z. F., Cui, M. Y., Cui, T. S., Cui, Y. X., Dai, H. T., De-Benedittis, A., De Mitri, I., de Palma, F., Deliyergiyev, M., Di Giovanni, A., Di Santo, M., Ding, Q., Dong, T. K., Dong, Z. X., Donvito, G., Droz, D., Duan, J. L., Duan, K. K., D'Urso, D., Fan, R. R., Fan, Y. Z., Fang, F., Fang, K., Feng, C. Q., Feng, L., Alonso, M. F., Frieden, J. M., Fusco, P., Gao, M., Gargano, F., Gong, K., Gong, Y. Z., Guo, D. Y., Guo, J. H., Han, S. X., Hu, Y. M., Huang, G. S., Huang, X. Y., Huang, Y. Y., Ionica, M., Jiang, L. Y., Jiang, W., Kong, J., Kotenko, A., Kyratzis, D., Lei, S. J., Li, W. L., Li, W. H., Li, X., Li, X. Q., Liang, Y. M., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, Y., Loparco, F., Luo, C. N., Ma, M., Ma, P. X., Ma, T., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Salinas, M. M., Niu, X. Y., Pan, X., Parenti, A., Peng, W. X., Peng, X. Y., Perrina, C., Qiao, R., Rao, J. N., Ruina, A., Shangguan, Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Silveri, L., Song, J. X., Stolpovskiy, M., Su, H., Su, M., Sun, H. R., Sun, Z. Y., Surdo, A., Teng, X. J., Tykhonov, A., Wang, J. Z., Wang, L. G., Wang, S., Wang, S. X., Wang, X. L., Wang, Y., Wang, Y. F., Wang, Y. Z., Wei, D. M., Wei, J. J., Wei, Y. F., Wu, D., Wu, J., Wu, L. B., Wu, S. S., Wu, X., Xia, Z. Q., Xu, E. H., Xu, H. T., Xu, J., Xu, Z. H., Xu, Z. L., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yao, H. J., Yu, Y. H., Yuan, G. W., Yuan, Q., Yue, C., Zang, J. J., Zhang, S. X., Zhang, W. Z., Zhang, Yan, Zhang, Yi., Zhang, Y. J., Zhang, Y. L., Zhang, Y. P., Zhang, Y. Q., Zhang, Z., Zhang, Z. Y., Zhao, C., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., and Zhu, Y.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Space Physics
Abstract

More than a century after the performance of the oil drop experiment, the possible existence of fractionally charged particles FCP still remains unsettled. The search for FCPs is crucial for some extensions of the Standard Model in particle physics. Most of the previously conducted searches for FCPs in cosmic rays were based on experiments underground or at high altitudes. However, there have been few searches for FCPs in cosmic rays carried out in orbit other than AMS-01 flown by a space shuttle and BESS by a balloon at the top of the atmosphere. In this study, we conduct an FCP search in space based on on-orbit data obtained using the DArk Matter Particle Explorer (DAMPE) satellite over a period of five years. Unlike underground experiments, which require an FCP energy of the order of hundreds of GeV, our FCP search starts at only a few GeV. An upper limit of $6.2\times 10^{-10}~~\mathrm{cm^{-2}sr^{-1} s^{-1}}$ is obtained for the flux. Our results demonstrate that DAMPE exhibits higher sensitivity than experiments of similar types by three orders of magnitude that more stringently restricts the conditions for the existence of FCP in primary cosmic rays., Comment: 19 pages, 6 figures, accepted by PRD

Published
2022
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4. A Study on Monte Carlo simulation of the radiation environment above GeV at the DAMPE orbit

Author

Wang, S. X., Zang, J. J., Jiang, W., Lei, S. J., Luo, C. N., Xu, Z. L., and Chang, J.

Subjects
High Energy Physics - Experiment
Abstract

The Dark Matter Particle Explorer (DAMPE) has been undergoing a stable on-orbit operation for more than 6 years and acquired observation of over 11 billion events. And a better understanding of the overall radiation environment on the DAMPE orbit is crucial for both simulation data production and flight data analysis. In this work, we study the radiation environment at the low Earth orbit and develop a simulation software package using the framework of ATMNC3, in which state-of-the-art full 3D models of the Earth's atmospheric and magnetic-field configurations is integrated. We consider in our Monte Carlo procedure event-by-event propagation of the cosmic rays in the geomagnetic field and their interaction with the Earth's atmosphere, focusing on the particles above GeV that are able to trigger the DAMPE data acquisition system. We compare the simulation results with the cosmic-ray electrons and positrons (CREs) flux measurements made by DAMPE. The overall agreement on both the spectral and angular distribution of the CREs flux demonstrates that our simulation is well established. Our software package could be of more general usage for the simulation of the radiation environment at the low Earth orbit of various altitudes.

Published
2022
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5. Measurement of the cosmic ray helium energy spectrum from 70 GeV to 80 TeV with the DAMPE space mission

Author

Alemanno, F., An, Q., Azzarello, P., Barbato, F. C. T., Bernardini, P., Bi, X. J., Cai, M. S., Catanzani, E., Chang, J., Chen, D. Y., Chen, J. L., Chen, Z. F., Cui, M. Y., Cui, T. S., Cui, Y. X., Dai, H. T., D'Amone, A., De Benedittis, A., De Mitri, I., de Palma, F., Deliyergiyev, M., Di Santo, M., Dong, T. K., Dong, Z. X., Donvito, G., Droz, D., Duan, J. L., Duan, K. K., D'Urso, D., Fan, R. R., Fan, Y. Z., Fang, K., Fang, F., Feng, C. Q., Feng, L., Fusco, P., Gao, M., Gargano, F., Gong, K., Gong, Y. Z., Guo, D. Y., Guo, J. H., Guo, X. L., Han, S. X., Hu, Y. M., Huang, G. S., Huang, X. Y., Huang, Y. Y., Ionica, M., Jiang, W., Kong, J., Kotenko, A., Kyratzis, D., Lei, S. J., Li, S., Li, W. L., Li, X., Li, X. Q., Liang, Y. M., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, W. Q., Liu, Y., Loparco, F., Luo, C. N., Ma, M., Ma, P. X., Ma, T., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Niu, X. Y., Pan, X., Parenti, A., Peng, W. X., Peng, X. Y., Perrina, C., Qiao, R., Rao, J. N., Ruina, A., Salinas, M. M., Shang, G. Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Silveri, L., Song, J. X., Stolpovskiy, M., Su, H., Su, M., Sun, Z. Y., Surdo, A., Teng, X. J., Tykhonov, A., Wang, H., Wang, J. Z., Wang, L. G., Wang, S., Wang, X. L., Wang, Y., Wang, Y. F., Wang, Y. Z., Wang, Z. M., Wei, D. M., Wei, J. J., Wei, Y. F., Wen, S. C., Wu, D., Wu, J., Wu, L. B., Wu, S. S., Wu, X., Xia, Z. Q., Xu, H. T., Xu, Z. H., Xu, Z. L., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yao, H. J., Yu, Y. H., Yuan, G. W., Yuan, Q., Yue, C., Zang, J. J., Zhang, F., Zhang, S. X., Zhang, W. Z., Zhang, Y., Zhang, Y. J., Zhang, Y. L., Zhang, Y. P., Zhang, Y. Q., Zhang, Z., Zhang, Z. Y., Zhao, C., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., and Zhu, Y.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the DArk Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of $4.3\sigma$. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out., Comment: 11 pages, 13 figures, published in Phys. Rev. Lett. Add one more digit for first three columns in Table S2

Published
2021
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6. Measurement of the cosmic-ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

Author

An, Q., Asfandiyarov, R., Azzarello, P., Bernardini, P., Bi, X. J., Cai, M. S., Chang, J., Chen, D. Y., Chen, H. F., Chen, J. L., Chen, W., Cui, M. Y., Cui, T. S., Dai, H. T., D'Amone, A., De Benedittis, A., De Mitri, I., Di Santo, M., Ding, M., Dong, T. K., Dong, Y. F., Dong, Z. X., Donvito, G., Droz, D., Duan, J. L., Duan, K. K., D'Urso, D., Fan, R. R., Fan, Y. Z., Fang, F., Feng, C. Q., Feng, L., Fusco, P., Gallo, V., Gan, F. J., Gao, M., Gargano, F., Gong, K., Gong, Y. Z., Guo, D. Y., Guo, J. H., Guo, X. L., Han, S. X., Hu, Y. M., Huang, G. S., Huang, X. Y., Huang, Y. Y., Ionica, M., Jiang, W., Jin, X., Kong, J., Lei, S. J., Li, S., Li, W. L., Li, X., Li, X. Q., Li, Y., Liang, Y. F., Liang, Y. M., Liao, N. H., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, W. Q., Liu, Y., Loparco, F., Luo, C. N., Ma, M., Ma, P. X., Ma, S. Y., Ma, T., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Niu, X. Y., Pan, X., Peng, W. X., Peng, X. Y., Qiao, R., Rao, J. N., Salinas, M. M., Shang, G. Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Song, J. X., Su, H., Su, M., Sun, Z. Y., Surdo, A., Teng, X. J., Tykhonov, A., Vitillo, S., Wang, C., Wang, H., Wang, H. Y., Wang, J. Z., Wang, L. G., Wang, Q., Wang, S., Wang, X. H., Wang, X. L., Wang, Y. F., Wang, Y. P., Wang, Y. Z., Wang, Z. M., Wei, D. M., Wei, J. J., Wei, Y. F., Wen, S. C., Wu, D., Wu, J., Wu, L. B., Wu, S. S., Wu, X., Xi, K., Xia, Z. Q., Xu, H. T., Xu, Z. H., Xu, Z. L., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yang, Z. L., Yao, H. J., Yu, Y. H., Yuan, Q., Yue, C., Zang, J. J., Zhang, F., Zhang, J. Y., Zhang, J. Z., Zhang, P. F., Zhang, S. X., Zhang, W. Z., Zhang, Y., Zhang, Y. J., Zhang, Y. L., Zhang, Y. P., Zhang, Y. Q., Zhang, Z., Zhang, Z. Y., Zhao, H., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., Zhou, Y., Zhu, X., Zhu, Y., and Zimmer, S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with two and a half years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time an experiment directly measures the cosmic ray protons up to ~100 TeV with a high statistics. The measured spectrum confirms the spectral hardening found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee, and sheds new light on the origin of Galactic cosmic rays., Comment: 37 pages, 5 figures, published in Science Advances

Published
2019
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7. The on-orbit calibration of DArk Matter Particle Explorer

Author

Ambrosi, G., An, Q., Asfandiyarov, R., Azzarello, P., Bernardini, P., Cai, M. S., Caragiulo, M., Chang, J., Chen, D. Y., Chen, H. F., Chen, J. L., Chen, W., Cui, M. Y., Cui, T. S., Dai, H. T., D'Amone, A., De Benedittis, A., De Mitri, I., Ding, M., Di Santo, M., Dong, J. N., Dong, T. K., Dong, Y. F., Dong, Z. X., Droz, D., Duan, K. K., Duan, J. L., D'Urso, D., Fan, R. R., Fan, Y. Z., Fang, F., Feng, C. Q., Feng, L., Fusco, P., Gallo, V., Gan, F. J., Gao, M., Gao, S. S., Gargano, F., Garrappa, S., Gong, K., Gong, Y. Z., Guo, J. H., Hu, Y. M., Huang, G. S., Huang, Y. Y., Ionica, M., Jiang, D., Jiang, W., Jin, X., Kong, J., Lei, S. J., Li, S., Li, X., Li, W. L., Li, Y., Liang, Y. F., Liang, Y. M., Liao, N. H., Liu, C. M., Liu, H., Liu, J., Liu, S. B., Liu, W. Q., Liu, Y., Loparco, F., Ma, M., Ma, P. X., Ma, S. Y., Ma, T., Ma, X. Q., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Niu, X. Y., Pan, X., Peng, X. Y., Peng, W. X., Qiao, R., Rao, J. N., Salinas, M. M., Shang, G. Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Song, J. X., Su, H., Su, M., Sun, Z. Y., Surdo, A., Teng, X. J., Tian, X. B., Tykhonov, A., Vitillo, S., Wang, C., Wang, H., Wang, H. Y., Wang, J. Z., Wang, L. G., Wang, Q., Wang, S., Wang, X. H., Wang, X. L., Wang, Y. F., Wang, Y. P., Wang, Y. Z., Wang, Z. M., Wen, S. C., Wei, D. M., Wei, J. J., Wei, Y. F., Wu, D., Wu, J., Wu, L. B., Wu, S. S., Wu, X., Xi, K., Xia, Z. Q., Xin, Y. L., Xu, H. T., Xu, Z. H., Xu, Z. L., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yang, Z. L., Yao, H. J., Yu, Y. H., Yuan, Q., Yue, C., Zang, J. J., Zhang, D. L., Zhang, F., Zhang, J. B., Zhang, J. Y., Zhang, J. Z., Zhang, L., Zhang, P. F., Zhang, S. X., Zhang, W. Z., Zhang, Y., Zhang, Y. J., Zhang, Y. Q., Zhang, Y. L., Zhang, Y. P., Zhang, Z., Zhang, Z. Y., Zhao, H., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., Zhou, Y., Zhu, X., Zhu, Y., and Zimmer, S.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment
Abstract

The DArk Matter Particle Explorer (DAMPE), a satellite-based cosmic ray and gamma-ray detector, was launched on December 17, 2015, and began its on-orbit operation on December 24, 2015. In this work we document the on-orbit calibration procedures used by DAMPE and report the calibration results of the Plastic Scintillator strip Detector (PSD), the Silicon-Tungsten tracKer-converter (STK), the BGO imaging calorimeter (BGO), and the Neutron Detector (NUD). The results are obtained using Galactic cosmic rays, bright known GeV gamma-ray sources, and charge injection into the front-end electronics of each sub-detector. The determination of the boundary of the South Atlantic Anomaly (SAA), the measurement of the live time, and the alignments of the detectors are also introduced. The calibration results demonstrate the stability of the detectors in almost two years of the on-orbit operation.

Published
2019
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8. An algorithm to resolve {\gamma}-rays from charged cosmic rays with DAMPE

Author

Xu, Z. L., Duan, K. K., Shen, Z. Q., Lei, S. J., Dong, T. K., Gargano, F., Garrappa, S., Guo, D. Y., Jiang, W., Li, X., Liang, Y. F., Mazziotta, M. N., Salinas, M. M., Su, M., Vagelli, V., Yuan, Q., Yue, C., Zang, J. J., Zhang, Y. P., Zhang, Y. L., and Zimmer, S.

Subjects
Physics - Instrumentation and Detectors, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment
Abstract

The DArk Matter Particle Explorer (DAMPE), also known as Wukong in China, launched on December 17, 2015, is a new high energy cosmic ray and {\gamma}-ray satellite-borne observatory in space. One of the main scientific goals of DAMPE is to observe GeV-TeV high energy {\gamma}-rays with accurate energy, angular, and time resolution, to indirectly search for dark matter particles and for the study of high energy astrophysics. Due to the comparatively higher fluxes of charged cosmic rays with respect to {\gamma}-rays, it is challenging to identify {\gamma}-rays with sufficiently high efficiency minimizing the amount of charged cosmic ray contamination. In this work we present a method to identify {\gamma}-rays in DAMPE data based on Monte Carlo simulations, using the powerful electromagnetic/hadronic shower discrimination provided by the calorimeter and the veto detection of charged particles provided by the plastic scintillation detector. Monte Carlo simulations show that after this selection the number of electrons and protons that contaminate the selected {\gamma}-ray events at $\sim10$ GeV amounts to less than 1% of the selected sample. Finally, we use flight data to verify the effectiveness of the method by highlighting known {\gamma}-ray sources in the sky and by reconstructing preliminary light curves of the Geminga pulsar., Comment: 15 pages,16 figures

Published
2017
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9. Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons

Author

Ambrosi, G., An, Q., Asfandiyarov, R., Azzarello, P., Bernardini, P., Bertucci, B., Cai, M. S., Chang, J., Chen, D. Y., Chen, H. F., Chen, J. L., Chen, W., Cui, M. Y., Cui, T. S., D'Amone, A., De Benedittis, A., De Mitri, I., Di Santo, M., Dong, J. N., Dong, T. K., Dong, Y. F., Dong, Z. X., Donvito, G., Droz, D., Duan, K. K., Duan, J. L., Duranti, M., D'Urso, D., Fan, R. R., Fan, Y. Z., Fang, F., Feng, C. Q., Feng, L., Fusco, P., Gallo, V., Gan, F. J., Gao, M., Gao, S. S., Gargano, F., Garrappa, S., Gong, K., Gong, Y. Z., Guo, D. Y., Guo, J. H., Hu, Y. M., Huang, G. S., Huang, Y. Y., Ionica, M., Jiang, D., Jiang, W., Jin, X., Kong, J., Lei, S. J., Li, S., Li, X., Li, W. L., Li, Y., Liang, Y. F., Liang, Y. M., Liao, N. H., Liu, H., Liu, J., Liu, S. B., Liu, W. Q., Liu, Y., Loparco, F., Ma, M., Ma, P. X., Ma, S. Y., Ma, T., Ma, X. Q., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Niu, X. Y., Peng, X. Y., Peng, W. X., Qiao, R., Rao, J. N., Salinas, M. M., Shang, G. Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Song, J. X., Su, H., Su, M., Sun, Z. Y., Surdo, A., Teng, X. J., Tian, X. B., Tykhonov, A., Vagelli, V., Vitillo, S., Wang, C., Wang, H., Wang, H. Y., Wang, J. Z., Wang, L. G., Wang, Q., Wang, S., Wang, X. H., Wang, X. L., Wang, Y. F., Wang, Y. P., Wang, Y. Z., Wen, S. C., Wang, Z. M., Wei, D. M., Wei, J. J., Wei, Y. F., Wu, D., Wu, J., Wu, L. B., Wu, S. S., Wu, X., Xi, K., Xia, Z. Q., Xin, Y. L., Xu, H. T., Xu, Z. L., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, P., Yang, Y. Q., Yang, Z. L., Yao, H. J., Yu, Y. H., Yuan, Q., Yue, C., Zang, J. J., Zhang, C., Zhang, D. L., Zhang, F., Zhang, J. B., Zhang, J. Y., Zhang, J. Z., Zhang, L., Zhang, P. F., Zhang, S. X., Zhang, W. Z., Zhang, Y., Zhang, Y. J., Zhang, Y. Q., Zhang, Y. L., Zhang, Y. P., Zhang, Z., Zhang, Z. Y., Zhao, H., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., Zhou, Y., Zhu, X., Zhu, Y., and Zimmer, S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

High energy cosmic ray electrons plus positrons (CREs), which lose energy quickly during their propagation, provide an ideal probe of Galactic high-energy processes and may enable the observation of phenomena such as dark-matter particle annihilation or decay. The CRE spectrum has been directly measured up to $\sim 2$ TeV in previous balloon- or space-borne experiments, and indirectly up to $\sim 5$ TeV by ground-based Cherenkov $\gamma$-ray telescope arrays. Evidence for a spectral break in the TeV energy range has been provided by indirect measurements of H.E.S.S., although the results were qualified by sizeable systematic uncertainties. Here we report a direct measurement of CREs in the energy range $25~{\rm GeV}-4.6~{\rm TeV}$ by the DArk Matter Particle Explorer (DAMPE) with unprecedentedly high energy resolution and low background. The majority of the spectrum can be properly fitted by a smoothly broken power-law model rather than a single power-law model. The direct detection of a spectral break at $E \sim0.9$ TeV confirms the evidence found by H.E.S.S., clarifies the behavior of the CRE spectrum at energies above 1 TeV and sheds light on the physical origin of the sub-TeV CREs., Comment: 18 pages, 6 figures, Nature in press, doi:10.1038/nature24475

Published
2017
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10. The DArk Matter Particle Explorer mission

Author

Chang, J., Ambrosi, G., An, Q., Asfandiyarov, R., Azzarello, P., Bernardini, P., Bertucci, B., Cai, M. S., Caragiulo, M., Chen, D. Y., Chen, H. F., Chen, J. L., Chen, W., Cui, M. Y., Cui, T. S., D'Amone, A., De Benedittis, A., De Mitri, I., Di Santo, M., Dong, J. N., Dong, T. K., Dong, Y. F., Dong, Z. X., Donvito, G., Droz, D., Duan, K. K., Duan, J. L., Duranti, M., D'Urso, D., Fan, R. R., Fan, Y. Z., Fang, F., Feng, C. Q., Feng, L., Fusco, P., Gallo, V., Gan, F. J., Gan, W. Q., Gao, M., Gao, S. S., Gargano, F., Gong, K., Gong, Y. Z., Guo, J. H., Hu, Y. M., Huang, G. S., Huang, Y. Y., Ionica, M., Jiang, D., Jiang, W., Jin, X., Kong, J., Lei, S. J., Li, S., Li, X., Li, W. L., Li, Y., Liang, Y. F., Liang, Y. M., Liao, N. H., Liu, Q. Z., Liu, H., Liu, J., Liu, S. B., Liu, W. Q., Liu, Y., Loparco, F., Lü, J., Ma, M., Ma, P. X., Ma, S. Y., Ma, T., Ma, X. Q., Ma, X. Y., Marsella, G., Mazziotta, M. N., Mo, D., Miao, T. T., Niu, X. Y., Pohl, M., Peng, X. Y., Peng, W. X., Qiao, R., Rao, J. N., Salinas, M. M., Shang, G. Z., Shen, W. H., Shen, Z. Q., Shen, Z. T., Song, J. X., Su, H., Su, M., Sun, Z. Y., Surdo, A., Teng, X. J., Tian, X. B., Tykhonov, A., Vagelli, V., Vitillo, S., Wang, C., Wang, Chi, Wang, H., Wang, H. Y., Wang, J. Z., Wang, L. G., Wang, Q., Wang, S., Wang, X. H., Wang, X. L., Wang, Y. F., Wang, Y. P., Wang, Y. Z., Wen, S. C., Wang, Z. M., Wei, D. M., Wei, J. J., Wei, Y. F., Wu, D., Wu, J., Wu, S. S., Wu, X., Xi, K., Xia, Z. Q., Xin, Y. L., Xu, H. T., Xu, Z. L., Xu, Z. Z., Xue, G. F., Yang, H. B., Yang, J., Yang, P., Yang, Y. Q., Yang, Z. L., Yao, H. J., Yu, Y. H., Yuan, Q., Yue, C., Zang, J. J., Zhang, C., Zhang, D. L., Zhang, F., Zhang, J. B., Zhang, J. Y., Zhang, J. Z., Zhang, L., Zhang, P. F., Zhang, S. X., Zhang, W. Z., Zhang, Y., Zhang, Y. J., Zhang, Y. Q., Zhang, Y. L., Zhang, Y. P., Zhang, Z., Zhang, Z. Y., Zhao, H., Zhao, H. Y., Zhao, X. F., Zhou, C. Y., Zhou, Y., Zhu, X., Zhu, Y., and Zimmer, S.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

The DArk Matter Particle Explorer (DAMPE), one of the four scientific space science missions within the framework of the Strategic Pioneer Program on Space Science of the Chinese Academy of Sciences, is a general purpose high energy cosmic-ray and gamma-ray observatory, which was successfully launched on December 17th, 2015 from the Jiuquan Satellite Launch Center. The DAMPE scientific objectives include the study of galactic cosmic rays up to $\sim 10$ TeV and hundreds of TeV for electrons/gammas and nuclei respectively, and the search for dark matter signatures in their spectra. In this paper we illustrate the layout of the DAMPE instrument, and discuss the results of beam tests and calibrations performed on ground. Finally we present the expected performance in space and give an overview of the mission key scientific goals., Comment: 45 pages, including 29 figures and 6 tables. Published in Astropart. Phys

Published
2017
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11. Resistance of Lattice Core Sandwich Cylinders to Internal Blast Loading

Author

Li, J. F., Zhang, W., Zhang, J. X., Li, H. M., Xu, Z. L., Qin, Q. H., di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Dao, Vinh, editor, and Kitipornchai, Sritawat, editor

Published
2021
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17. No causal effects between rosiglitazone and cardiovascular disease or risk factors: a Mendelian randomization study.

Author

LI, X.-M., WU, Z.-J., XU, Z.-L., LI, A., LIU, M.-Q., SONG, C.-G., and WU, K.

Abstract

OBJECTIVE: Although many observational studies have shown an association between rosiglitazone and cardiovascular disease (CVD) or risk factors, controversy remains. We conducted a Mendelian randomized (MR) study to explore whether rosiglitazone is causally related to CVDs and risk factors. PATIENTS AND METHODS: Single-nucleotide polymorphisms associated with rosiglitazone at genome-wide significance were identified from a genome-wide association study of 337,159 European-ancestry individuals. Four treatments with rosiglitazone-associated single-nucleotide polymorphisms associated with a higher risk of CVDs were used as an instrumental variable (IV). Summary-level data for 7 CVDs and 7 risk factors were obtained from UK Biobank and consortia. RESULTS: We found no causal effects of rosiglitazone, either on CVDs or risk factors. The results were consistent in sensitivity analyses using Cochran’s Q test, MR-PRESSO method, leave-oneout analysis and Mendelian randomization-Egger method (MR-Egger), and no directional pleiotropy was observed. Sensitivity analyses confirmed that rosiglitazone was not significantly associated with CVDs and risk factors. CONCLUSIONS: The findings from this MR study indicate no causal relationship between rosiglitazone and CVDs or risk factors. Hence, previous observational studies may have been biased. [ABSTRACT FROM AUTHOR]

Published
2023

18. S234: CLINICAL-GRADE MBIL21/4-1BBL EXPANDED NK CELLS EXHIBIT STRONGER COMPETENCE COMPARED WITH PRIMARY NK CELLS AGAINST HCMV INFECTION

Author

Shang, Q.-N., primary, Yu, X.-X., additional, Xu, Z.-L., additional, Han, T.-T., additional, Xie, J., additional, Fan, Z.-Y., additional, Zhao, M., additional, Cao, X.-H., additional, Liu, X.-F., additional, Chen, Y.-H., additional, Lv, M., additional, Sun, Y.-Q., additional, Chang, Y.-J., additional, Wang, Y., additional, Xu, L.-P., additional, Zhang, X.-H., additional, Liu, K.-Y., additional, Zhao, X.-Y., additional, and Huang, X.-J., additional

Published
2022
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20. Numerical valuation of European and American options under Merton's model.

Author

Yang, P. and Xu, Z. L.

Subjects
*COMPLEMENTARITY constraints (Mathematics), *VALUATION, *FINITE element method, *OPTIONS (Finance), *UNIFORM spaces, *LINEAR complementarity problem, *INTEGRO-differential equations
Abstract

In this paper, a new combination of time and spatial discretization is proposed for a partial integro-differential equation (PIDE) arising in the valuation of European options under Merton's model. We first present a high-order compact (HOC) difference scheme in space based on a uniform mesh to obtain a highly accurate result, and the discontinuous Galerkin (DG) finite element method in time is introduced that can deal with the loss of the time analyticity. A penalty method is proposed for a partial integro-differential complementarity problem arising in the valuation of the American put option. Numerical experiments are performed to verify the accuracy and efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

Published
2023
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22. Three new andrastin derivatives from the endophytic fungus Penicillium vulpinum

Author

Qin, Y.-Y., Huang, X.-S., Liu, X.-B., Mo, T.-X., Xu, Z.-L., Li, B.-C., Qin, X.-Y., Li, J., Schäberle, T.F., Yang, R.-Y., and Publica

Abstract

Three new andrastin derivatives, 10-formyl andrastone A (1), 10-demethylated andrastone A (2) and andrastin G (3), together with four known andrastin analogues (4-7) were isolated from an endophytic fungus Penicillium vulpinum. Their structures were determined by 1 D, 2 D NMR, and the absolute configurations were further determined by experimental and calculated ECD spectra. Compound 5 exhibited significant antibacterial activity against Bacillus paratyphosus B with an MIC value of 6.25 µg·mL-1. Compounds 2 and 6 showed remarkable inhibitory activities against Bacillus megaterium with the MIC value of 6.25 µg·mL-1, respectively.

Published
2022

30. Effects of miR-490-5p targeting CDK1 on proliferation and apoptosis of colon cancer cells via ERK signaling pathway.

Author

YANG, Y.-J., LUO, S., and XU, Z.-L.

Abstract

OBJECTIVE: The aim of this study was to investigate the effects of micro ribonucleic acid (miR)-490-5p on the proliferation and apoptosis of colon cancer cells, and to explore its potential mechanism. PATIENTS AND METHODS: The mRNA expression of miR-490-5p in 30 pairs of colon cancer tissues and adjacent normal tissues was detected via reverse transcription-polymerase chain reaction (RT-PCR). Human colon cancer SW480 cell lines were cultured in vitro and divided into Control group and miR-490-5p overexpression group (miR-490-5p mimic group). The nonsense sequence and miR-490-5p mimic were transfected using liposome transfection technique into colon cancer cells in control group and miR-490- 5p mimic group, respectively. Cell proliferation and apoptosis in each group were then observed. At the same time, the effect of miR-490-5p on the growth of colon cancer in vivo was explored using subcutaneous tumorigenesis assay. The protein expressions of extracellular signal-regulated kinase (ERK)1/2 signaling pathway and cyclin- dependent kinase 1 (CDK1) were determined via Western blotting. Furthermore, immunohistochemical staining was performed to verify the protein expression of CDK1 in vivo. RESULTS: The expression of miR-490-5p in colon cancer tissues was significantly lower than that in adjacent normal tissues (p<0.05). After transfection with miR-490-5p mimic in vitro, EdU staining and colony formation assay showed that the proliferation ability of SW480 cells was significantly weakened (p<0.05). Meanwhile, the number of colonies in miR-490-5p mimic group was markedly less than that in Control group (p<0.05). The results of Western blotting revealed that overexpression of miR-490-5p remarkably up-regulated the Bax/Bcl-2 and C-Caspase3/TCaspase3 ratios in cancer cells (p<0.05). Subsequent results indicated that the subcutaneous tumorigenesis of colon cancer cells was markedly inhibited by overexpression of miR-490-5p (p<0.05). According to the results of Western blotting, the activation of ERK signaling pathway and the protein expression of CDK1 were significantly suppressed by overexpression of miR-4905p (p<0.05). In vivo experiments further revealed that the protein expression of CDK1 in colon cancer tissues increased significantly (p<0.05). CONCLUSIONS: MiR-490-5p was found lowly expressed in colon cancer patients. In addition, overexpression of miR-490-5p inhibited the proliferation and promoted the apoptosis of colon cancer cells via down-regulating CDK1 both in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Published
2022

31. A comparison of experimental, theoretical, and numerical simulation Rayleigh-Taylor mixing rates

Author

George, E., Glimm, J., Li, X.-L., Marchese, A., and Xu, Z.-L.

Subjects
Rayleigh waves -- Analysis, Buoyant ascent (Hydrodynamics) -- Analysis, Diffusion -- Analysis, Science and technology
Abstract

We present a Rayleigh-Taylor mixing rate simulation with an acceleration rate falling within the range of experiments. The simulation uses front tracking to prevent interfacial mass diffusion. We present evidence to support the assertion that the lower acceleration rate found in untracked simulations is caused, at least to a large extent, by a reduced buoyancy force due to numerical interfacial mass diffusion. Quantitative evidence includes results from a time-dependent Atwood number analysis of the diffusive simulation, which yields a renormalized mixing rate coefficient for the diffusive simulation in agreement with experiment.

Published
2002

37. An algorithm to resolve ��-rays from charged cosmic rays with DAMPE

Author

Xu, Z. L., Duan, K. K., Shen, Z. Q., Lei, S. J., Dong, T. K., Gargano, F., Garrappa, S., Guo, D. Y., Jiang, W., Li, X., Liang, Y. F., Mazziotta, M. N., Salinas, M. M., Su, M., Vagelli, V., Yuan, Q., Yue, C., Zang, J. J., Zhang, Y. P., Zhang, Y. L., and Zimmer, S.

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), High Energy Physics - Experiment (hep-ex), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

The DArk Matter Particle Explorer (DAMPE), also known as Wukong in China, launched on December 17, 2015, is a new high energy cosmic ray and ��-ray satellite-borne observatory in space. One of the main scientific goals of DAMPE is to observe GeV-TeV high energy ��-rays with accurate energy, angular, and time resolution, to indirectly search for dark matter particles and for the study of high energy astrophysics. Due to the comparatively higher fluxes of charged cosmic rays with respect to ��-rays, it is challenging to identify ��-rays with sufficiently high efficiency minimizing the amount of charged cosmic ray contamination. In this work we present a method to identify ��-rays in DAMPE data based on Monte Carlo simulations, using the powerful electromagnetic/hadronic shower discrimination provided by the calorimeter and the veto detection of charged particles provided by the plastic scintillation detector. Monte Carlo simulations show that after this selection the number of electrons and protons that contaminate the selected ��-ray events at $\sim10$ GeV amounts to less than 1% of the selected sample. Finally, we use flight data to verify the effectiveness of the method by highlighting known ��-ray sources in the sky and by reconstructing preliminary light curves of the Geminga pulsar., 15 pages,16 figures

Published
2017
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40. MicroRNA-424-5p inhibits the development of non-small cell LCa by binding to ITGB1.

Author

XU, Z. L., ZHANG, M., CHEN, S. X., QIU, M., ZHANG, Q., GAO, L. P., DU, J. W., and LI, X. Q.

Abstract

OBJECTIVE: The aim of this study was to explore the effect of microRNA-424-5p on the proliferation and apoptosis of non-small cell lung cancer (NSCLC) cells, and to investigate its influence on the expression of ITGB1 and potential regulatory mechanism. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the level of microRNA-424-5p in 44 paired NSCLC tissues and adjacent tissues. The relation between microRNA-424-5p expression and NSCLC clinical indicators was analyzed. Subsequently, microRNA-424-5p mimics and inhibitors were transfected into NSCLC cells to construct microRNA-424-5p overexpression or knockdown models, respectively. QRTPCR was used to further verify the transfection efficiency. A series of experiments, including cell counting kit-8 (CCK-8) assay, colony formation, 5-Ethynyl-2'-deoxyuridine (EdU), and flow cytometry were used to analyze the effect of microRNA-424-5p on the biological function of NSCLC A549 and H358 cells. Finally, the potential association between microRNA-424-5p and its downstream gene ITGB1 was explored through luciferase reporter gene assay and cell recovery experiment. RESULTS: QRT-PCR results showed that microRNA-424-5p level was significantly lower in NSCLC tissues than that of adjacent normal tissues. Compared with patients with high expression of microRNA-424-5p, the pathological stage of those with low expression of microRNA-424-5p was significantly higher. In vitro experiments showed that microRNA-424-5p overexpression remarkably decreased cell proliferation and increased cell apoptosis, which were further validated in microRNA-424-5p inhibitor group. Subsequently, ITGB1 expression was found significantly up-regulated in NSCLC cell lines and tissues. Meanwhile, ITGB1 expression was negatively correlated with microRNA-424-5p level. In addition, a recovery experiment indicated that overexpression of ITGB1 could counteract the effect of microRNA-424-5p mimics on the proliferation and apoptosis of NSCLC cells. All these findings revealed that microRNA-424-5p and ITGB1 affected the malignant progression of NSCLC. CONCLUSIONS: MicroRNA-424-5p was closely correlated with the pathological stage and poor prognosis of NSCLC, thereby inhibiting the occurrence and development of NSCLC. [ABSTRACT FROM AUTHOR]

Published
2019

41. Effects of MiR-21 on the proliferation and migration of vascular smooth muscle cells in rats with atherosclerosis via the Akt/ERK signaling pathway.

Author

SUN, P., TANG, L. -N., LI, G. -Z., XU, Z. -L., XU, Q.-H., WANG, M., and LI, L.

Abstract

OBJECTIVE: To explore the effects and mechanism of action of micro ribonucleic acid (miR)-21 on the proliferation and migration of vascular smooth muscle (VSM) in atherosclerosis (AS). MATERIALS AND METHODS: The rats were fed with a high-fat diet, and the oil red staining was adopted to compare AS between Sprague Dawley (SD) rats and miR-21 knockdown rats. At the in-vitro level, primary rat VSM cells (VSMCs) were selected and divided into miR-NC blank control group [miR-normal control (NC) group] and miR-21 overexpression group (miR- 21 group) for relevant experimental detection. Wound healing assay and transwell assay were used to detect the effects of miR-21 on the proliferation and migration of VSMCs. Westernn blotting was applied to examine the changes in the levels of Cyclin D, a cell cycle-related protein, and the key factors of the Akt/ERK signaling pathway, such as phosphorylated-Akt (p-AKT), AKT, p-ERK1/2, and ERK1/2. The 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell activity assay kit was applied to determine the effects of miR-21 on the proliferation of VSMCs through regulating the Akt/ERK signaling pathway after the ERK signaling pathway inhibitor PD98059 and AKT inhibitor MK- 2206 were given. RESULTS: Compared with that in miR-NC group, the level of AS in miR-21 knockdown rats were decreased significantly (p < 0.05). In the cell-level experiment, the overexpression of miR-21 promoted abnormal proliferation of VSMCs and activated the Akt/ERK signaling pathway (p < 0.05). MTT assay results revealed that inhibiting the Akt/ERK pathway could reverse the effects of miR-21 promoting proliferation and migration. CONCLUSIONS: MiR-21 promotes the proliferation and migration of VSMCs by activating the Akt/ERK pathway and aggravates AS. Knocking down miR-21 or inhibiting the Akt/ERK pathway can suppress the activation of VSMCs. [ABSTRACT FROM AUTHOR]

Published
2019

45. miRNA211 induces apoptosis of cervical cancer SiHa cells via down-regulation of inhibitor of apoptosis proteins.

Author

LIU, Y.-L., WANG, G.-Q., CUI, H.-X., LI, X.-X., XU, Z.-L., and WANG, X.-Y.

Abstract

OBJECTIVE: Cervical cancer severely threatens patients' lives. MicroRNAs contribute to regulatory function in the growth and apoptosis of cells. The present study investigated the effect of miRNA211 on growth and apoptosis of cervical cancer SiHa cells. MATERIALS AND METHODS: miRNA211 and control miRNA were synthesized and transfected into cervical cancer SiHa cells. MTT assay and flow cytometry were used to study the effect of miRNA211 on growth and apoptosis of Si- Ha cells. RT-PCR and Western blot were used to detect the expression of inhibitor of apoptosis proteins (IAPs) at both mRNA and protein levels. Groups of miRNA (NC), miRNA211, miRNA+siRNA IAP, miRNA211+siRNA IAP were established and levels of IAP and caspase 3 from each group were measured after transfection. RESULTS: After transfection with miRNA211, the growth of SiHa cells was significantly inhibited and apoptosis of SiHa cells was induced, with the reduction of IAPs at both mRNA and protein levels (p<0.05). Knockdown of IAPs enhanced the apoptosis of SiHa cells that were induced by miRNA211, while the overexpression of limited the pro-apoptotic effect of miRNA211 on Si- Ha cells. CONCLUSIONS: MiRNA211 inhibits the growth of SiHa cells via down-regulation of IAPs. [ABSTRACT FROM AUTHOR]

Published
2018

49. Risk factors for predicting central lymph node metastasis in papillary thyroid microcarcinoma (CN0): a study of 273 resections.

Author

LI, M., ZHU, X.-Y., LV, J., LU, K., SHEN, M.-P., XU, Z.-L., and WU, Z.-S.

Abstract

OBJECTIVE: The role of routine central lymph node dissection (CLND) for clinically central lymph node negative (CN0) papillary thyroid microcarcinoma (PTMC) remains uncertain. We aim to determine the predictive factors for central lymph node metastasis (CLNM) in papillary thyroid microcarcinoma. PATIENTS AND METHODS: A total of 273 patients diagnosed with clinically central lymph node negative PTMC from 2014 to 2016 were included. The predictive risk factors for CLNM were analyzed with respect to age, sex, tumor size, tumor multifocal, lymphadenectasis of lateral neck, capsular invasion, extra capsular spread (ECS), coexistence of chronic lymphocytic thyroiditis (Hashimoto thyroiditis, HT) and nodular goiter (NG), BRAFV600E mutation and subtype of papillary thyroid carcinoma (PTC). Univariate and multivariate analyses were performed to identify the risk factors for CLNM. RESULTS: Among the 273 patients, the CLNM occurred in 80 patients (29.3%). By univariate and multivariate analyses, tumor size (OR 2.07; p<0.001), multifocal (OR 2.67; p<0.004), lymphadenectasis of lateral neck (OR 9.28; p<0.001), tumor extent (OR 42.01; p<0.001) were independently correlated with CLNM. In further study, dorsal part of solitary lesion (OR: 16.312, 95%CI: 3.349-79.455, p=0.001), capsular invasion (OR: 42.012, 95% CI: 5.209-338.861, p<0.001), 6 6 mm, dorsal part of solitary lesion, multifocal, lymphadenectasis of lateral neck and capsular invasion. [ABSTRACT FROM AUTHOR]

Published
2017

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