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31 results on '"Cheng, H. Q."'

1. An Intermediate-mass Black Hole Lurking in A Galactic Halo Caught Alive during Outburst

Author

Jin, C. -C., Li, D. -Y., Jiang, N., Dai, L. -X., Cheng, H. -Q., Zhu, J. -Z., Yang, C. -W., Rau, A., Baldini, P., Wang, T. -G., Zhou, H. -Y., Yuan, W., Zhang, C., Shu, X. -W., Shen, R. -F., Wang, Y. -L., Wen, S. -X., Wu, Q. -Y., Wang, Y. -B., Thomsen, L. L., Zhang, Z. -J., Zhang, W. -J., Coleiro, A., Eyles-Ferris, R., Fang, X., Ho, L. C., Hu, J. -W., Jin, J. -J., Li, W. -X., Liu, B. -F., Liu, F. -K., Liu, M. -J., Liu, Z., Lu, Y. -J., Merloni, A., Qiao, E. -L., Saxton, R., Soria, R., Wang, S., Xue, Y. -Q., Yang, H. -N., Zhang, B., Zhang, W. -D., Cai, Z. -M., Chen, F. -S., Chen, H. -L., Chen, T. -X., Chen, W., Chen, Y. -H., Chen, Y. -F., Chen, Y., Cordier, B., Cui, C. -Z., Cui, W. -W., Dai, Y. -F., Ding, H. -C., Fan, D. -W., Fan, Z., Feng, H., Garcia, J. A., Guan, J., Han, D. -W., Hou, D. -J., Hu, H. -B., Huang, M. -H., Huo, J., Jia, S. -M., Jia, Z. -Q., Jiang, B. -W., Jin, G., Kong, X., Kuulkers, E., Lei, W. -H., Li, C. -K., Li, J. -F., Li, L. -H., Li, M. -S., Li, W., Li, Z. -D., Lian, T. -Y., Ling, Z. -X., Liu, C. -Z., Liu, H. -Y, Liu, H. -Q., Liu, J. -F., Liu, Y., Lu, F. -J., Luo, L. -D., Ma, J., Mao, X., Mu, H. -Y., Nandra, K., O'Brien, P., Pan, H. -W., Pan, X., Qin, G. -J., Rea, N., Sanders, J., Song, L. -M., Sun, H., Sun, S. -L., Sun, X. -J., Tan, Y. -Y., Tang, Q. -J., Tao, Y. -H., Wang, B. -C., Wang, J., Wang, J. -F., Wang, L., Wang, W. -X., Wang, Y. -S., Wang, Z. -X., Wu, Q. -W., Wu, X. -F., Xu, H. -T., Xu, J. -J., Xu, X. -P., Xu, Y. -F., Xu, Z., Xue, C. -B., Xue, S. -J., Xue, Y. -L., Yan, A. -L., Yang, X. -T., Yang, Y. -J., Zhang, J., Zhang, M., Zhang, S. -N., Zhang, Y. -H., Zhang, Z., Zhang, Z. -L., Zhao, D. -H., Zhao, H. -S., Zhao, X. -F., Zhao, Z. -J., Zheng, J., Zhu, Q. -F., Zhu, Y. -X., Zhu, Z. -C., and Zou, H.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

Stellar-mass and supermassive black holes abound in the Universe, whereas intermediate-mass black holes (IMBHs) of ~10^2-10^5 solar masses in between are largely missing observationally, with few cases found only. Here we report the real-time discovery of a long-duration X-ray transient, EP240222a, accompanied by an optical flare with prominent H and He emission lines revealed by prompt follow-up observations. Its observed properties evidence an IMBH located unambiguously in the halo of a nearby galaxy and flaring by tidally disrupting a star -- the only confirmed off-nucleus IMBH-tidal disruption event so far. This work demonstrates the potential of sensitive time-domain X-ray surveys, complemented by timely multi-wavelength follow-ups, in probing IMBHs, their environments, demographics, origins and connections to stellar-mass and supermassive black holes., Comment: 64 pages, 15 figures, submitted

Published
2025

2. Broadband study of the Be X-ray binary RX J0520.5-6932 during its outburst in 2024

Author

Yang, H. N., Maitra, C., Vasilopoulos, G., Haberl, F., Jenke, P. A., Karaferias, A. S., Sharma, R., Beri, A., Ji, L., Jin, C., Yuan, W., Zhang, Y. J., Wang, C. Y., Xu, X. P., Liu, Y., Zhang, W. D., Zhang, C., Ling, Z. X., Liu, H. Y., Cheng, H. Q., and Pan, H. W.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

A new giant outburst of the Be X-ray binary RX J0520.5-6932 was detected and subsequently observed with several space-borne and ground-based instruments. This study presents a comprehensive analysis of the optical and X-ray data, focusing on the spectral and timing characteristics of selected X-ray observations. A joint fit of spectra from simultaneous observations performed by the X-ray telescope (XRT) on the Neil Gehrels Swift Observatory (Swift) and Nuclear Spectroscopic Telescope ARray (NuSTAR) provides broadband parameter constraints, including a cyclotron resonant scattering feature (CRSF) at 32.2(+0.8/-0.7) keV with no significant energy change since 2014, and a weaker Fe line. Independent spectral analyses of observations by the Lobster Eye Imager for Astronomy (LEIA), Einstein Probe (EP), Swift-XRT, and NuSTAR demonstrate the consistency of parameters across different bands. Luminosity variations during the current outburst were tracked. The light curve of the Optical Gravitational Lensing Experiment (OGLE) aligns with the X-ray data in both 2014 and 2024. Spin evolution over 10 years is studied after adding Fermi Gamma-ray Burst Monitor (GBM) data, improving the orbital parameters, with an estimated orbital period of 24.39 days, slightly differing from OGLE data. Despite intrinsic spin-up during outbursts, a spin-down of ~0.04s over 10.3 years is suggested. For the new outburst, the pulse profiles indicate a complicated energy-dependent shape, with decreases around 15 keV and 25 keV in the pulsed fraction, a first for an extragalactic source. Phase-resolved NuSTAR data indicate variations in parameters such as flux, photon index, and CRSF energy with rotation phase., Comment: 17 pages, 15 figures, accepted for publication in MNRAS

Published
2024
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3. Extragalactic fast X-ray transient from a weak relativistic jet associated with a Type Ic-BL supernova

Author

Sun, H., Li, W. -X., Liu, L. -D., Gao, H., Wang, X. -F., Yuan, W., Zhang, B., Filippenko, A. V., Xu, D., An, T., Ai, S., Brink, T. G., Liu, Y., Liu, Y. -Q., Wang, C. -Y., Wu, Q. -Y., Wu, X. -F., Yang, Y., Zhang, B. -B., Zheng, W. -K., Ahumada, T., Dai, Z. -G., Delaunay, J., Elias-Rosa, N., Benetti, S., Fu, S. -Y., Howell, D. A., Huang, Y. -F., Kasliwal, M. M., Karambelkar, V., Stein, R., Lei, W. -H., Lian, T. -Y., Peng, Z. -K., Ridnaia, A. V., Svinkin, D. S., Wang, X. -Y., Wang, A. -L., Wei, D. -M., An, J., Andrews, M., Bai, J. -M, Dai, C. -Y., Ehgamberdiev, S. A., Fan, Z., Farah, J., Feng, H. -C., Fynbo, J. P. U., Guo, W. -J., Guo, Z., Hu, M. -K., Hu, J. -W., Jiang, S. -Q., Jin, J. -J., Li, A., Li, J. -D., Li, R. -Z., Liang, Y. -F., Ling, Z. -X., Liu, X., Mao, J. -R., McCully, C., Mirzaqulov, D., Newsome, M., Gonzalez, E. Padilla, Pan, X., Terreran, G., Tinyanont, S., Wang, B. -T., Wang, L. -Z., Wen, X. -D., Xiang, D. -F., Xue, S. -J., Yang, J., Zhu, Z. -P., Cai, Z. -M., Castro-Tirado, A. J., Chen, F. -S., Chen, H. -L., Chen, T. -X., Chen, W., Chen, Y. -H., Chen, Y. -F., Chen, Y., Cheng, H. -Q., Cordier, B., Cui, C. -Z., Cui, W. -W., Dai, Y. -F., Fan, D. -W., Feng, H., Guan, J., Han, D. -W., Hou, D. -J., Hu, H. -B., Huang, M. -H., Huo, J., Jia, S. -M., Jia, Z. -Q., Jiang, B. -W., Jin, C. -C., Jin, G., Kuulkers, E., Li, C. -K., Li, D. -Y., Li, J. -F., Li, L. -H., Li, M. -S., Li, W., Li, Z. -D., Liu, C. -Z, Liu, H. -Y., Liu, H. -Q., Liu, M. -J., Lu, F. -J., Luo, L. -D., Ma, J., Mao, X., Nandra, K., O'Brien, P., Pan, H. -W., Rau, A., Rea, N., Sanders, J., Song, L. -M., Sun, S. -L., Sun, X. -J., Tan, Y. -Y., Tang, Q. -J., Tao, Y. -H., Wang, H., Wang, J., Wang, L., Wang, W. -X., Wang, Y. -L., Wang, Y. -S., Xiong, D. -R., Xu, H. -T., Xu, J. -J., Xu, X. -P., Xu, Y. -F., Xu, Z., Xue, C. -B., Xue, Y. -L., Yan, A. -L., Yang, H. -N., Yang, X. -T., Yang, Y. -J., Zhang, C., Zhang, J., Zhang, M., Zhang, S. -N., Zhang, W. -D., Zhang, W. -J., Zhang, Y. -H., Zhang, Z., Zhang, Z. -L., Zhao, D. -H., Zhao, H. -S., Zhao, X. -F., Zhao, Z. -J., Zhou, Y. -L., Zhu, Y. -X., and Zhu, Z. -C.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Massive stars end their life as core-collapse supernovae, amongst which some extremes are Type Ic broad-lined supernovae associated with long-duration gamma-ray bursts (LGRBs) having powerful relativistic jets. Their less-extreme brethren make unsuccessful jets that are choked inside the stars, appearing as X-ray flashes or low-luminosity GRBs. On the other hand, there exists a population of extragalactic fast X-ray transients (EFXTs) with timescales ranging from seconds to thousands of seconds, whose origins remain obscure. Known sources that contribute to the observed EFXT population include the softer analogs of LGRBs, shock breakouts of supernovae, or unsuccessful jets. Here, we report the discovery of the bright X-ray transient EP240414a detected by the Einstein Probe (EP), which is associated with the Type Ic supernova SN 2024gsa at a redshift of 0.401. The X-ray emission evolution is characterised by a very soft energy spectrum peaking at < 1.3 keV, which makes it distinct from known LGRBs, X-ray flashes, or low-luminosity GRBs. Follow-up observations at optical and radio bands revealed the existence of a weak relativistic jet that interacts with an extended shell surrounding the progenitor star. Located on the outskirts of a massive galaxy, this event reveals a new population of explosions of Wolf-Rayet stars characterised by a less powerful engine that drives a successful but weak jet, possibly owing to a progenitor star with a smaller core angular momentum than in traditional LGRB progenitors., Comment: 43 pages, 9 figures, 4 tables, submitted. Comments are welcome

Published
2024

4. Einstein Probe discovery of EP J005245.1-722843: a rare BeWD binary in the Small Magellanic Cloud?

Author

Marino, A., Yang, H., Zelati, F. Coti, Rea, N., Guillot, S., Jaisawal, G. K., Maitra, C., Ness, J. -U., Haberl, F., Kuulkers, E., Yuan, W., Feng, H., Tao, L., Jin, C., Sun, H., Zhang, W., Chen, W., Heuvel, E. P. J. van den, Soria, R., Zhang, B., Weng, S. -S., Ji, L., Zhang, G. B., Pan, X., Lv, Z., Zhang, C., Ling, Z., Chen, Y., Jia, S., Liu, Y., Cheng, H. Q., Li, D. Y., Gendreau, K. C., Ng, M., and Strohmayer, T. E.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

On May 27 2024, the Wide-field X-ray Telescope onboard the Einstein Probe (EP) mission detected enhanced X-ray emission from a new transient source in the Small Magellanic Cloud (SMC) during its commissioning phase. Prompt follow-up with the EP Follow-up X-ray Telescope, the Swift X-ray Telescope and NICER have revealed a very soft, thermally emitting source (kT$\sim$0.1 keV at the outburst peak) with an X-ray luminosity of $L\sim4\times10^{38}$ erg s$^{-1}$, labelled EP J005245.1-722843. This super-soft outburst faded very quickly in a week time. Several emission lines and absorption edges were present in the X-ray spectrum, including deep Nitrogen (0.67 keV) and Oxygen (0.87 keV) absorption edges. The X-ray emission resembles the SSS phase of typical nova outbursts from an accreting white dwarf (WD) in a binary system, despite the X-ray source being historically associated with an O9-B0e massive star exhibiting a 17.55 days periodicity in the optical band. The discovery of this super-soft outburst suggests that EP J005245.1-722843 is a BeWD X-ray binary: an elusive evolutionary stage where two main-sequence massive stars have undergone a common envelope phase and experienced at least two episodes of mass transfer. In addition, the very short duration of the outburst and the presence of Ne features hint at a rather massive, i.e., close to the Chandrasekhar limit, Ne-O WD in the system., Comment: 9 pages, 5 figures; accepted for publication in ApJL

Published
2024

5. Soft X-ray prompt emission from the high-redshift gamma-ray burst EP240315a

Author

Liu, Y., Sun, H., Xu, D., Svinkin, D. S., Delaunay, J., Tanvir, N. R., Gao, H., Zhang, C., Chen, Y., Wu, X.-F., Zhang, B., Yuan, W., An, J., Bruni, G., Frederiks, D. D., Ghirlanda, G., Hu, J.-W., Li, A., Li, C.-K., Li, J.-D., Malesani, D. B., Piro, L., Raman, G., Ricci, R., Troja, E., Vergani, S. D., Wu, Q.-Y., Yang, J., Zhang, B.-B., Zhu, Z.-P., de Ugarte Postigo, A., Demin, A. G., Dobie, D., Fan, Z., Fu, S.-Y., Fynbo, J. P. U., Geng, J.-J., Gianfagna, G., Hu, Y.-D., Huang, Y.-F., Jiang, S.-Q., Jonker, P. G., Julakanti, Y., Kennea, J. A., Kokomov, A. A., Kuulkers, E., Lei, W.-H., Leung, J. K., Levan, A. J., Li, D.-Y., Li, Y., Littlefair, S. P., Liu, X., Lysenko, A. L., Ma, Y.-N., Martin-Carrillo, A., O’Brien, P., Parsotan, T., Quirola-Vásquez, J., Ridnaia, A. V., Ronchini, S., Rossi, A., Mata-Sánchez, D., Schneider, B., Shen, R.-F., Thakur, A. L., Tohuvavohu, A., Torres, M. A. P., Tsvetkova, A. E., Ulanov, M. V., Wei, J.-J., Xiao, D., Yin, Y.-H. I., Bai, M., Burwitz, V., Cai, Z.-M., Chen, F.-S., Chen, H.-L., Chen, T.-X., Chen, W., Chen, Y.-F., Chen, Y.-H., Cheng, H.-Q., Cordier, B., Cui, C.-Z., Cui, W.-W., Dai, Y.-F., Dai, Z.-G., Eder, J., Eyles-Ferris, R. A. J., Fan, D.-W., Feldman, C., Feng, H., Feng, Z., Friedrich, P., Gao, X., Gonzalez, J.-F., Guan, J., Han, D.-W, Han, J., Hou, D.-J., Hu, H.-B., Hu, T., Huang, M.-H., Huo, J., Hutchinson, I., Ji, Z., Jia, S.-M., Jia, Z.-Q., Jiang, B.-W., Jin, C.-C., Jin, G., Jin, J.-J., Keereman, A., Lerman, H., Li, J.-F., Li, L.-H., Li, M.-S., Li, W., Li, Z.-D., Lian, T.-Y., Liang, E.-W., Ling, Z.-X., Liu, C.-Z., Liu, H.-Y., Liu, H.-Q., Liu, M.-J., Liu, Y.-R., Lu, F.-J., Lü, H.-J., Luo, L.-D., Ma, F. L., Ma, J., Mao, J.-R., Mao, X., McHugh, M., Meidinger, N., Nandra, K., Osborne, J. P., Pan, H.-W., Pan, X., Ravasio, M. E., Rau, A., Rea, N., Rehman, U., Sanders, J., Santovincenzo, A., Song, L.-M., Su, J., Sun, L.-J., Sun, S.-L., Sun, X.-J., Tan, Y.-Y., Tang, Q.-J., Tao, Y.-H., Tong, J.-Z., Wang, C.-Y., Wang, H., Wang, J., Wang, L., Wang, W.-X., Wang, X.-F., Wang, X.-Y., Wang, Y.-L., Wang, Y.-S., Wei, D.-M., Willingale, R., Xiong, S.-L., Xu, H.-T., Xu, J.-J., Xu, X.-P., Xu, Y.-F., Xu, Z., Xue, C.-B., Xue, Y.-L., Yan, A.-L., Yang, F., Yang, H.-N., Yang, X.-T., Yang, Y.-J, Yu, Y.-W., Zhang, J., Zhang, M., Zhang, S.-N., Zhang, W.-D., Zhang, W.-J., Zhang, Y.-H., Zhang, Z., Zhang, Z., Zhang, Z.-L., Zhao, D.-H., Zhao, H.-S., Zhao, X.-F., Zhao, Z.-J., Zhou, L.-X., Zhou, Y.-L., Zhu, Y.-X., Zhu, Z.-C., and Zuo, X.-X.

Published
2025
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6. Soft X-ray prompt emission from a high-redshift gamma-ray burst EP240315a

Author

Liu, Y., Sun, H., Xu, D., Svinkin, D. S., Delaunay, J., Tanvir, N. R., Gao, H., Zhang, C., Chen, Y., Wu, X. -F., Zhang, B., Yuan, W., An, J., Bruni, G., Frederiks, D. D., Ghirlanda, G., Hu, J. -W., Li, A., Li, C. -K., Li, J. -D., Malesani, D. B., Piro, L., Raman, G., Ricci, R., Troja, E., Vergani, S. D., Wu, Q. -Y., Yang, J., Zhang, B. -B., Zhu, Z. -P., Postigo, A. de Ugarte, Demin, A. G., Dobie, D., Fan, Z., Fu, S. -Y., Fynbo, J. P. U., Geng, J. -J., Gianfagna, G., Hu, Y. -D., Huang, Y. -F., Jiang, S. -Q., Jonker, P. G., Julakanti, Y., Kennea, J. A., Kokomov, A. A., Kuulkers, E., Lei, W. -H., Leung, J. K., Levan, A. J., Li, D. -Y., Li, Y., Littlefair, S. P., Liu, X., Lysenko, A. L., Ma, Y. -N., Martin-Carrillo, A., O'Brien, P., Parsotan, T., Quirola-Vasquez, J., Ridnaia, A. V., Ronchini, S., Rossi, A., Mata-Sanchez, D., Schneider, B., Shen, R. -F., Thakur, A. L., Tohuvavohu, A., Torres, M. A. P., Tsvetkova, A. E., Ulanov, M. V., Wei, J. -J., Xiao, D., Yin, Y. -H. I., Bai, M., Burwitz, V., Cai, Z. -M., Chen, F. -S., Chen, H. -L., Chen, T. -X., Chen, W., Chen, Y. -F., Chen, Y. -H., Cheng, H. -Q., Cui, C. -Z., Cui, W. -W., Dai, Y. -F., Dai, Z. -G., Eder, J., Fan, D. -W., Feldman, C., Feng, H., Feng, Z., Friedrich, P., Gao, X., Guan, J., Han, D. -W, Han, J., Hou, D. -J., Hu, H. -B., Hu, T., Huang, M. -H., Huo, J., Hutchinson, I., Ji, Z., Jia, S. -M., Jia, Z. -Q., Jiang, B. -W., Jin, C. -C., Jin, G., Jin, J. -J., Keereman, A., Lerman, H., Li, J. -F., Li, L. -H., Li, M. -S., Li, W., Li, Z. -D., Lian, T. -Y., Liang, E. -W., Ling, Z. -X., Liu, C. -Z., Liu, H. -Y., Liu, H. -Q., Liu, M. -J., Liu, Y. -R., Lu, F. -J., LU, H. -J., Luo, L. -D., Ma, F. L., Ma, J., Mao, J. -R., Mao, X., McHugh, M., Meidinger, N., Nandra, K., Osborne, J. P., Pan, H. -W., Pan, X., Ravasio, M. E., Rau, A., Rea, N., Rehman, U., Sanders, J., Santovincenzo, A., Song, L. -M., Su, J., Sun, L. -J., Sun, S. -L., Sun, X. -J., Tan, Y. -Y., Tang, Q. -J., Tao, Y. -H., Tong, J. -Z., Wang, H., Wang, J., Wang, L., Wang, W. -X., Wang, X. -F., Wang, X. -Y., Wang, Y. -L., Wang, Y. -S., Wei, D. -M., Willingale, R., Xiong, S. -L., Xu, H. -T., Xu, J. -J., Xu, X. -P., Xu, Y. -F., Xu, Z., Xue, C. -B., Xue, Y. -L., Yan, A. -L., Yang, F., Yang, H. -N., Yang, X. -T., Yang, Y. -J, Yu, Y. -W., Zhang, J., Zhang, M., Zhang, S. -N., Zhang, W. -D., Zhang, W. -J., Zhang, Y. -H., Zhang, Z., Zhang, Z. -L., Zhao, D. -H., Zhao, H. -S., Zhao, X. -F., Zhao, Z. -J., Zhou, L. -X., Zhou, Y. -L., Zhu, Y. -X., Zhu, Z. -C., and Zuo, X. -X.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Long gamma-ray bursts (GRBs) are believed to originate from core collapse of massive stars. High-redshift GRBs can probe the star formation and reionization history of the early universe, but their detection remains rare. Here we report the detection of a GRB triggered in the 0.5--4 keV band by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated as EP240315a, whose bright peak was also detected by the Swift Burst Alert Telescope and Konus-Wind through off-line analyses. At a redshift of $z=4.859$, EP240315a showed a much longer and more complicated light curve in the soft X-ray band than in gamma-rays. Benefiting from a large field-of-view ($\sim$3600 deg$^2$) and a high sensitivity, EP-WXT captured the earlier engine activation and extended late engine activity through a continuous detection. With a peak X-ray flux at the faint end of previously known high-$z$ GRBs, the detection of EP240315a demonstrates the great potential for EP to study the early universe via GRBs., Comment: 41 pages, 8 figures, 7 tables

Published
2024

7. Magnetar emergence in a peculiar gamma-ray burst from a compact star merger

Author

Sun, H., Wang, C. -W., Yang, J., Zhang, B. -B., Xiong, S. -L., Yin, Y. -H. I., Liu, Y., Li, Y., Xue, W. -C., Yan, Z., Zhang, C., Tan, W. -J., Pan, H. -W., Liu, J. -C., Cheng, H. -Q., Zhang, Y. -Q., Hu, J. -W., Zheng, C., An, Z. -H., Cai, C., Cai, Z. -M., Hu, L., Jin, C., Li, D. -Y., Li, X. -Q., Liu, H. -Y., Liu, M., Peng, W. -X., Song, L. -M., Sun, S. -L., Sun, X. -J., Wang, X. -L., Wen, X. -Y., Xiao, S., Yi, S. -X., Zhang, F., Zhang, W. -D., Zhang, X. -F., Zhang, Y. -H., Zhao, D. -H., Zheng, S. -J., Ling, Z. -X., Zhang, S. -N., Yuan, W., and Zhang, B.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The central engine that powers gamma-ray bursts (GRBs), the most powerful explosions in the universe, is still not identified. Besides hyper-accreting black holes, rapidly spinning and highly magnetized neutron stars, known as millisecond magnetars, have been suggested to power both long and short GRBs. The presence of a magnetar engine following compact star mergers is of particular interest as it would provide essential constraints on the poorly understood equation of state for neutron stars. Indirect indications of a magnetar engine in these merger sources have been observed in the form of plateau features present in the X-ray afterglow light curves of some short GRBs. Additionally, some X-ray transients lacking gamma-ray bursts (GRB-less) have been identified as potential magnetar candidates originating from compact star mergers. Nevertheless, smoking gun evidence is still lacking for a magnetar engine in short GRBs, and the associated theoretical challenges have been raised. Here we present a comprehensive analysis of the broad-band prompt emission data of a peculiar, very bright GRB 230307A. Despite its apparently long duration, the prompt emission and host galaxy properties are consistent with a compact star merger origin, as suggested by its association with a kilonova. Intriguingly, an extended X-ray emission component shows up as the $\gamma$-ray emission dies out, signifying the likely emergence of a magnetar central engine. We also identify an achromatic temporal break in the high-energy band during the prompt emission phase, which was never observed in previous bursts and reveals a narrow jet with half opening angle of approximately $\sim 3.4^\circ (R_{GRB}/10^{15}~{cm})^{-1/2}$, where $R_{GRB}$ is the GRB prompt emission radius., Comment: 54 pages, 11 figures, 5 tables, accepted for publication in National Science Review

Published
2023

8. The Lobster Eye Imager for Astronomy Onboard the SATech-01 Satellite

Author

Ling, Z. X., Sun, X. J., Zhang, C., Sun, S. L., Jin, G., Zhang, S. N., Zhang, X. F., Chang, J. B., Chen, F. S., Chen, Y. F., Cheng, Z. W., Fu, W., Han, Y. X., Li, H., Li, J. F., Li, Y., Li, Z. D., Liu, P. R., Lv, Y. H., Ma, X. H., Tang, Y. J., Wang, C. B., Xie, R. J., Xue, Y. L., Yan, A. L., Zhang, Q., Bao, C. Y., Cai, H. B., Cheng, H. Q., Cui, C. Z., Dai, Y. F., Fan, D. W., Hu, H. B., Hu, J. W., Huang, M. H., Jia, Z. Q., Jin, C. C., Li, D. Y., Li, J. Q., Liu, H. Y., Liu, M. J., Liu, Y., Pan, H. W., Qiu, Y. L., Sugizaki, M., Sun, H., Wang, W. X., Wang, Y. L., Wu, Q. Y., Xu, X. P., Xu, Y. F., Yang, H. N., Yang, X., Zhang, B., Zhang, M., Zhang, W. D., Zhang, Z., Zhao, D. H., Cong, X. Q., Jiang, B. W., Li, L. H., Qiu, X. B., Sun, J. N., Su, D. T., Wang, J., Wu, C., Xu, Z., Yang, X. M., Zhang, S. K., Zhang, N., Zhu, Y. F., Ban, H. Y., Bi, X. Z., Cai, Z. M., Chen, W., Chen, X., Chen, Y. H., Cui, Y., Duan, X. L., Feng, Z. G, Gao, Y., He, J. W., He, T., Huang, J. J., Li, F., Li, J. S., Li, T. J., Li, T. T., Liu, H. Q., Liu, L., Liu, R., Liu, S., Meng, N., Shi, Q., Sun, A. T., Wang, Y. M., Wang, Y. B., Wu, H. C., Xu, D. X, Yang, Y. Q, Yang, Y., Yu, X. S., Zhang, K. X., Zhang, Y. L., Zhang, Y. H., Zhang, Y. T., Zhou, H., Zhu, X. C., Cheng, J. S., Qin, L., Wang, L., Wang, Q. L., Bai, M., Gao, R. L., Ji, Z., Liu, Y. R., Ma, F. L., Shi, Y. J., Su, J., Tan, Y. Y., Tong, J. Z., Xu, H. T., Xue, C. B., Xue, G. F., and Yuan, W.

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

The Lobster Eye Imager for Astronomy (LEIA), a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe (EP) mission, was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on 27 July 2022. In this paper, we introduce the design and on-ground test results of the LEIA instrument. Using state-of-the-art Micro-Pore Optics (MPO), a wide field-of-view (FoV) of 346 square degrees (18.6 degrees * 18.6 degrees) of the X-ray imager is realized. An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons, and four large-format complementary metal-oxide semiconductor (CMOS) sensors, each of 6 cm * 6 cm, are used as the focal plane detectors. The instrument has an angular resolution of 4 - 8 arcmin (in FWHM) for the central focal spot of the point spread function, and an effective area of 2 - 3 cm2 at 1 keV in essentially all the directions within the field of view. The detection passband is 0.5 - 4 keV in the soft X-rays and the sensitivity is 2 - 3 * 10-11 erg s-1 cm-2 (about 1 mini-Crab) at 1,000 second observation. The total weight of LEIA is 56 kg and the power is 85 W. The satellite, with a design lifetime of 2 years, operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes. LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation, and by optimizing the working setups of the instrumental parameters. In addition, LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band, albeit limited useful observing time available., Comment: Accepted by RAA

Published
2023
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9. First wide field-of-view X-ray observations by a lobster eye focusing telescope in orbit

Author

Zhang, C., Ling, Z. X., Sun, X. J., Sun, S. L., Liu, Y., Li, Z. D., Xue, Y. L., Chen, Y. F., Dai, Y. F., Jia, Z. Q., Liu, H. Y., Zhang, X. F., Zhang, Y. H., Zhang, S. N., Chen, F. S., Cheng, Z. W., Fu, W., Han, Y. X., Li, H., Li, J. F., Li, Y., Liu, P. R., Ma, X. H., Tang, Y. J., Wang, C. B., Xie, R. J., Yan, A. L., Zhang, Q., Jiang, B. W., Jin, G., Li, L. H., Qiu, X. B., Su, D. T., Sun, J. N., Xu, Z., Zhang, S. K., Zhang, Z., Zhang, N., Bi, X. Z., Cai, Z. M., He, J. W., Liu, H. Q., Zhu, X. C., Cheng, H. Q., Cui, C. Z., Fan, D. W., Hu, H. B., Huang, M. H., Jin, C. C., Li, D. Y., Pan, H. W., Wang, W. X., Xu, Y. F., Yang, X., Zhang, B., Zhang, M., Zhang, W. D., Zhao, D. H., Bai, M., Ji, Z., Liu, Y. R., Ma, F. L., Su, J., Tong, J. Z., Wang, Y. S., Zhao, Z. J., Feldman, C., O'Brien, P., Osborne, J. P., Willingale, R., Burwitz, V., Hartner, G., Langmeier, A., Müller, T., Rukdee, S., Schmidt, T., Kuulkers, E., and Yuan, W.

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

As a novel X-ray focusing technology, lobster eye micro-pore optics (MPO) feature both a wide observing field of view and true imaging capability, promising sky monitoring with significantly improved sensitivity and spatial resolution in soft X-rays. Since first proposed by Angel (1979), the optics have been extensively studied, developed and trialed over the past decades. In this Letter, we report on the first-light results from a flight experiment of the Lobster Eye Imager for Astronomy ($LEIA$), a pathfinder of the wide-field X-ray telescope of the Einstein Probe mission. The piggyback imager, launched in July 2022, has a mostly un-vignetted field of view of $18.6^\circ \times 18.6^\circ $. Its spatial resolution is in the range of 4$-$7 arcmin in FWHM and the focal spot effective area is 2$-$3 cm$^2$, both showing only mild fluctuations across the field of view. We present images of the Galactic center region, Sco X-1 and the diffuse Cygnus Loop nebular taken in snapshot observations over 0.5$-$4 keV. These are truly wide-field X-ray images of celestial bodies observed, for the first time, by a focusing imaging telescope. Initial analyses of the in-flight data show excellent agreement between the observed images and the on-ground calibration and simulations. The instrument and its characterization are briefly described, as well as the flight experiment. The results provide a solid basis for the development of the present and proposed wide-field X-ray missions using lobster eye MPO., Comment: 11 pages, 4 figures. Accepted for publication in Astrophysical Journal Letter

Published
2022
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10. Broad-band study of the Be X-ray binary RX J0520.5–6932 during its outburst in 2024.

Author

Yang, H N, Maitra, C, Vasilopoulos, G, Haberl, F, Jenke, P A, Karaferias, A S, Sharma, R, Beri, A, Ji, L, Jin, C, Yuan, W, Zhang, Y J, Wang, C Y, Xu, X P, Liu, Y, Zhang, W D, Zhang, C, Ling, Z X, Liu, H Y, and Cheng, H Q

Subjects
X-ray binaries, BINARY pulsars, X-ray telescopes, MAGELLANIC clouds, GRAVITATIONAL lenses
Abstract

A new giant outburst of the Be X-ray binary RX J0520.5–6932 was detected and subsequently observed with several space-borne and ground-based instruments. This study presents a comprehensive analysis of the optical and X-ray data, focusing on the spectral and timing characteristics of selected X-ray observations. A joint fit of spectra from simultaneous observations performed by the X-ray telescope (XRT) on the Neil Gehrels Swift Observatory (Swift) and Nuclear Spectroscopic Telescope ARray (NuSTAR) provides broad-band parameter constraints, including a cyclotron resonant scattering feature (CRSF) at |$32.2_{-0.7}^{+0.8}$|  keV with no significant energy change since 2014, and a weaker Fe line. Independent spectral analyses of observations by the Lobster Eye Imager for Astronomy, Einstein Probe (EP), Swift –XRT, and NuSTAR demonstrate the consistency of parameters across different bands. Luminosity variations during the current outburst were tracked. The light curve of the Optical Gravitational Lensing Experiment (OGLE) aligns with the X-ray data in both 2014 and 2024. Spin evolution over 10 yr is studied after adding Fermi Gamma-ray Burst Monitor data, improving the orbital parameters, with an estimated orbital period of 24.39 d, slightly differing from OGLE data. Despite intrinsic spin-up during outbursts, a spin-down of |$\sim$| 0.04 s over 10.3 yr is suggested. For the new outburst, the pulse profiles indicate a complicated energy-dependent shape, with decreases around 15 and 25 keV in the pulsed fraction, a first for an extragalactic source. Phase-resolved NuSTAR data indicate variations in parameters such as flux, photon index, and CRSF energy with rotation phase. [ABSTRACT FROM AUTHOR]

Published
2025
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12. A large population of neutron star low-mass X-ray binaries with long outburst recurrence time?

Author

Meyer-Hofmeister, E, Cheng, H Q, and Liu, B F

Subjects
*X-ray binaries, *STELLAR populations, *NEUTRON stars, *BINARY black holes, *MASS transfer, *ACCRETION disks
Abstract

Low-mass X-ray binaries (LMXBs) with neutron stars show quite different features that depend on the rate of mass transfer from the donor star. With a high transfer rate, the Z sources are in a persistent soft spectral state, and with a moderate transfer rate the transient Atoll sources have outburst cycles like the black hole X-ray binaries. The observations document very long outburst recurrence times for quite a number of sources. We follow with our computations the evolution of the accretion disc until the onset of the ionization instability. For sources with a low mass transfer rate, the accumulation of matter in the disc is essentially reduced due to the continuous evaporation of matter from the disc to the coronal flow. Different mass transfer rates result in nearly the same amount of matter accumulated for the outburst, which means that the outburst properties are similar for sources with short outburst cycles and sources with long outburst cycles, contrary to some expectations. Then, for systems with long recurrence time, less sources will be detected and the total population of LMXBs could be larger than it appears. This would relieve the apparent problem that the observed number of LMXBs as progenitors of millisecond pulsars (MSPs) is too small compared to the number of MSPs. Concerning the few quasi-persistent sources with year-long soft states, we argue that these states are not outbursts, but quasi-stationary hot states as in Z sources. [ABSTRACT FROM AUTHOR]

Published
2024
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13. First Wide Field-of-view X-Ray Observations by a Lobster-eye Focusing Telescope in Orbit

Author

Zhang, C., primary, Ling, Z. X., additional, Sun, X. J., additional, Sun, S. L., additional, Liu, Y., additional, Li, Z. D., additional, Xue, Y. L., additional, Chen, Y. F., additional, Dai, Y. F., additional, Jia, Z. Q., additional, Liu, H. Y., additional, Zhang, X. F., additional, Zhang, Y. H., additional, Zhang, S. N., additional, Chen, F. S., additional, Cheng, Z. W., additional, Fu, W., additional, Han, Y. X., additional, Li, H., additional, Li, J. F., additional, Li, Y., additional, Liu, P. R., additional, Ma, X. H., additional, Tang, Y. J., additional, Wang, C. B., additional, Xie, R. J., additional, Yan, A. L., additional, Zhang, Q., additional, Jiang, B. W., additional, Jin, G., additional, Li, L. H., additional, Qiu, X. B., additional, Su, D. T., additional, Sun, J. N., additional, Xu, Z., additional, Zhang, S. K., additional, Zhang, Z., additional, Zhang, N., additional, Bi, X. Z., additional, Cai, Z. M., additional, He, J. W., additional, Liu, H. Q., additional, Zhu, X. C., additional, Cheng, H. Q., additional, Cui, C. Z., additional, Fan, D. W., additional, Hu, H. B., additional, Huang, M. H., additional, Jin, C. C., additional, Li, D. Y., additional, Pan, H. W., additional, Wang, W. X., additional, Xu, Y. F., additional, Yang, X., additional, Zhang, B., additional, Zhang, M., additional, Zhang, W. D., additional, Zhao, D. H., additional, Bai, M., additional, Ji, Z., additional, Liu, Y. R., additional, Ma, F. L., additional, Su, J., additional, Tong, J. Z., additional, Wang, Y. S., additional, Zhao, Z. J., additional, Feldman, C., additional, O’Brien, P., additional, Osborne, J. P., additional, Willingale, R., additional, Burwitz, V., additional, Hartner, G., additional, Langmeier, A., additional, Müller, T., additional, Rukdee, S., additional, Schmidt, T., additional, Kuulkers, E., additional, and Yuan, W., additional

Published
2022
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14. Morphodynamic changes in the Yangtze Estuary under the impact of the Three Gorges Dam, estuarine engineering interventions and climate-induced sea level rise

Author

Cheng, H. Q. (author), Chen, W. (author), Li, J. F. (author), Jiang, Y. H. (author), Hu, X. (author), Zhang, X. L. (author), Zhou, F. N. (author), Hu, F. X. (author), Stive, M.J.F. (author), Cheng, H. Q. (author), Chen, W. (author), Li, J. F. (author), Jiang, Y. H. (author), Hu, X. (author), Zhang, X. L. (author), Zhou, F. N. (author), Hu, F. X. (author), and Stive, M.J.F. (author)

Abstract

The estuarine turbidity maximum (ETM) in the Yangtze Estuary Delta (YED) is muddy by definition and lacks bottom undulations. However, since 2013, a remarkable change has occurred in the YED. Recent images detected by a multibeam echosounder system, SeaBat 7125, for the first time have confirmed widespread regions of subaqueous dunes in the Yangtze ETM channel. This abnormal change is the result of morphodynamic transformation from the combination of an abrupt decline in sediment supply resulting from the construction of the Three Gorges Dam (TGD) and hydrodynamic changes caused by sea level rise. The latter includes anthropogenic-induced sea level rises (from land subsidence and coastal engineering) of 7–37 cm and a climate-induced sea level rise of 8 cm during the past four decades. Obvious evidence of hydrodynamic changes includes tidal amplification, i.e., a 10–28 cm rise in the tidal range, 42–65 cm rise in the lowest tidal level in the dry season, 45–67 cm rise in the highest tidal level in the flood season and 10–30% increase in the amplitude of the major tidal component. These findings will likely have global implications in formulating strategies to combat the superimposed effects of human interventions and climate change on upstream river and downstream coastal developments., Coastal Engineering

Published
2022
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19. Controversies in perioperative medicine

Author

Cheng, H Q

Subjects
Blood Glucose, Heart Diseases, Adrenergic beta-Antagonists, Anticoagulants, Guidelines as Topic, Endocarditis, Bacterial, Perioperative Care, Postoperative Complications, Heart Valve Prosthesis, Surgical Procedures, Operative, Diabetes Mellitus, Humans, Disease, Research Article
Abstract

Coexisting medical problems are common in surgical patients. Due to the lack of convincing studies, however, the optimal strategies for perioperative management of many medical problems remain unclear. Thus, practices are often based on inconclusive clinical studies or extrapolated from current understanding of pathophysiology. This article reviews guidelines and practices for endocarditis prophylaxis, perioperative anticoagulation in patients with mechanical heart valves, glucose control in diabetic patients undergoing surgery, and the use of beta-blockers to prevent postoperative cardiac complications. In addition, the strength of the evidence supporting these practices is evaluated.

Published
1998

20. Quinacrine treatment trial for sporadic Creutzfeldt-Jakob disease

Author

Geschwind, M. D., primary, Kuo, A. L., additional, Wong, K. S., additional, Haman, A., additional, Devereux, G., additional, Raudabaugh, B. J., additional, Johnson, D. Y., additional, Torres-Chae, C. C., additional, Finley, R., additional, Garcia, P., additional, Thai, J. N., additional, Cheng, H. Q., additional, Neuhaus, J. M., additional, Forner, S. A., additional, Duncan, J. L., additional, Possin, K. L., additional, DeArmond, S. J., additional, Prusiner, S. B., additional, and Miller, B. L., additional

Published
2013
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21. Mapping Sea Level Rise Behavior in an Estuarine Delta System: A Case Study along the Shanghai Coast.

Author

Cheng, H. Q., Chen, J. Y., Chen, Z. J., Ruan, R. L., Xu, G. Q., Zeng, G., Zhu, J. R., Dai, Z. J., Chen, X. Y., Gu, S. H., Zhang, X. L., and Wang, H. M.

Subjects
ABSOLUTE sea level change, URBAN land use
Abstract

Sea level rise (SLR) is a major projected threat of climate change that is expected to affect developing coastal cities located in estuarine delta regions. Shanghai is one such city, being located in the Yangtze River Delta (YRD). It is difficult, however, for decision-makers to implement adaptation due to the uncertain causes, magnitudes, and timings of SLR behaviors. This paper attempts to map the causes and magnitudes of SLR behaviors on a decadal scale. We analyze the tidal level records from 11 tidal gauge stations and the corresponding bathymetry measurements around these stations since 1921. We identify three new SLR behaviors along the Shanghai coast due to anthropogenic geomorphologic changes (AGCs), besides the well-known eustatic sea level rise (ESLR), tectonic subsidence (TS), and urban land subsidence (ULS). The first new behavior is regional sea level rise (RSLR), which occurs as a result of land reclamation and deep waterway regulation. The second is regional sea level fall (RSLF), which occurs because the channel bed is eroded due to sediment supply decline in the river catchment. The last SLR behavior is local tidal datum rise (LTDR). Thus, we project that the magnitude of SLR for the Shanghai coast ranges from 10 cm to 16 cm from 2011 to 2030. Clarifying SLR behaviors is important to aid local decisionmakers in planning structural and non-structural measures to combat escalating flood damage costs in an estuarine delta system; this field is full of future challenges. [ABSTRACT FROM AUTHOR]

Published
2018
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22. Study of the Redox Properties of Metallothionein In Vitroby Reacting with DsbA Protein

Author

Hu, H. Y., Cheng, H. Q., Li, Q., Zou, Y. S., and Xu, G. J.

Abstract

Mammalian metallothionein (MT) contains 20 cysteine residues involved in the two metal clusters without a disulfide bond. The redox reaction of the Cys thiols was proposed to be associated with the metal distribution of MT. The E. coliDsbA protein is extremely active in facilitating thiol/disulfide exchange both in vivoand in vitro.To further investigate the redox properties of MT, reaction between MT and DsbA was carried out in vitroby fluorescence detection. Equilibrium characterization indicates that the reaction is stoichiometric (1:1) under certain conditions. Kinetic study gives a rate constant of the redox reaction of 4.42 × 105sec−1M−1, which is 103-fold larger than that of glutathione reacting with DsbA. Metal-free MT (apo-MT) shows a higher equilibrium reduction potential than MT, but exhibits an indistinguishable kinetic rate. Oxidation of MT by DsbA leads to metal release from the clusters. The characteristic fluorescence increase during reduction of DsbA may provide a sensitive probe for exploring the redox properties of some reductants of biological interest. The result also implies that oxidation of Cys thiols may influence the metal release or delivery from MT.

Published
1999
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26. Mutation analysis of PVRL1 in patients with non-syndromic cleft of the lip and/or palate in Guangdong.

Author

Shu SY, Zhang MJ, Cheng HQ, Tang SJ, Chen WL, Wu SR, Lin Y, and Chen QS

Subjects
Adolescent, Adult, Alternative Splicing, Base Sequence, Case-Control Studies, Cell Adhesion Molecules metabolism, Child, Child, Preschool, China, DNA Mutational Analysis, Female, Genetic Association Studies, Humans, Infant, Male, Nectins, Young Adult, Cell Adhesion Molecules genetics, Cleft Lip genetics, Cleft Palate genetics
Abstract

Non-syndromic cleft of the lip and/or palate (NSCLP) is a very common birth defect; the poliovirus receptor-like 1 gene (PVRL1) has been identified as a genetic risk factor for NSCLP in patients from Norway, the Philippines, and South America. Given the considerable variation in allele frequencies across these geographical regions, this study explored the relationship between NSCLP and mutations of PVRL1 in patients from Guangdong, China. We recruited 171 NSCLP patients and 100 volunteers, and divided our samples into 2 groups: a sequencing group and a mass spectrometry group. In the sequencing group, we screened for mutations in exons 2 and 5 of PVRL1 by polymerase chain reaction and direct sequencing in 71 NSCLP patients and 100 volunteers. In the mass spectrometry group, we screened for amino acid mutations in α-spliced transcript codons 112, 131, and 395, and in the β-spliced transcript codon 1082 using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis in 100 NSCLP patients and 100 volunteers. No mutations were detected in either PVRL1 exons 2 or 5 in the 71 NSCLP patients and 100 volunteers, nor did we find mutations of α-spliced transcript codons 112, 131, 395 and the β-spliced transcript codon 1082 in any of the 100 NSCLP patients and 100 volunteers. Thus, mutations in exons 2 and 5 of PVRL1, and T334A, A391T, G1183A in the α-spliced transcript, and G1082T in the β-spliced transcript do not participate in the development of NSCLP in patients from Guangdong.

Published
2015
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27. Controversies in perioperative medicine.

Author

Cheng HQ

Subjects
Adrenergic beta-Antagonists therapeutic use, Anticoagulants therapeutic use, Blood Glucose analysis, Diabetes Mellitus blood, Diabetes Mellitus prevention & control, Disease, Endocarditis, Bacterial prevention & control, Guidelines as Topic, Heart Diseases prevention & control, Heart Valve Prosthesis, Humans, Postoperative Complications prevention & control, Surgical Procedures, Operative, Perioperative Care
Abstract

Coexisting medical problems are common in surgical patients. Due to the lack of convincing studies, however, the optimal strategies for perioperative management of many medical problems remain unclear. Thus, practices are often based on inconclusive clinical studies or extrapolated from current understanding of pathophysiology. This article reviews guidelines and practices for endocarditis prophylaxis, perioperative anticoagulation in patients with mechanical heart valves, glucose control in diabetic patients undergoing surgery, and the use of beta-blockers to prevent postoperative cardiac complications. In addition, the strength of the evidence supporting these practices is evaluated.

Published
1998

28. Expression of exogenous NF-IL6 induces apoptosis in Sp2/0-Ag14 myeloma cells.

Author

Zhu MS, Liu DG, Cheng HQ, Xu XY, and Li ZP

Subjects
Animals, CCAAT-Enhancer-Binding Proteins, Cell Division, Cell Nucleus pathology, DNA, Neoplasm analysis, DNA-Binding Proteins genetics, Gene Expression, Genetic Vectors genetics, Mice, Multiple Myeloma metabolism, Mutation, Nuclear Proteins genetics, Retroviridae genetics, Transcription Factors genetics, Tumor Cells, Cultured, Apoptosis physiology, DNA-Binding Proteins physiology, Multiple Myeloma pathology, Nuclear Proteins physiology, Transcription Factors physiology
Abstract

NF-IL6 (or C/EBP beta) is a multifunctional transcription factor of the C/EBP family. To study the effects of exogenous expression of NF-IL6 on the growth of cells of hematopoietic tumors, we infected SP2/0-Ag14 myeloma cells with pLXSN recombinant retrovirus harboring the NF-IL6 cDNA. We found that the transfected cells revealed changes typical of the apoptosis and finally died. The expression of NF-IL6 protein was shown by a "supershift" assay in the NF-IL6-transfected cells. In controls, where cells were infected by the retroviral vector with a mutant NF-IL6 coding region as well as the vector without insert, no sign for expression of NF-IL6 and apoptosis was observed. Therefore, our work shows that the apoptosis of this myeloma cell line was induced by the exogenous NF-IL6 expression. This is significantly different from the apparent effects of NF-IL6 in leukemia cells and in fibroblasts. These facts indicate that NF-IL6 exerts different functions in different cell types. We discuss possible mechanisms for the NF-IL6-induced apoptosis.

Published
1997
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29. [Surgical anatomy of the epitympanic sinus].

Author

Wang AL and Cheng HQ

Subjects
Ear, Middle surgery, Facial Nerve surgery, Humans, Ear, Middle anatomy & histology, Temporal Bone anatomy & histology
Published
1983

31. [Homostatic grafts in otology: experimental study].

Author

Cheng HQ, Cheng DC, Feng YZ, Zhan HM, Zhao QY, and Yé CJ

Subjects
Animals, Bronchi transplantation, Eustachian Tube surgery, Guinea Pigs, Macaca mulatta, Rabbits, Transplantation, Heterologous, Ear, Middle surgery, Tympanoplasty
Published
1985

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