| 1. |
- Andreoni, Igor, et al.
(författare)
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GROWTH on S190510g : DECam Observation Planning and Follow-up of a Distant Binary Neutron Star Merger Candidate
- 2019
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 881:1
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Tidskriftsartikel (refereegranskat)abstract
- The first two months of the third Advanced LIGO and Virgo observing run (2019 April-May) showed that distant gravitational-wave (GW) events can now be readily detected. Three candidate mergers containing neutron stars (NS) were reported in a span of 15 days, all likely located more than 100 Mpc away. However, distant events such as the three new NS mergers are likely to be coarsely localized, which highlights the importance of facilities and scheduling systems that enable deep observations over hundreds to thousands of square degrees to detect the electromagnetic counterparts. On 2019 May 10 02: 59:39.292 UT the GW candidate S190510g was discovered and initially classified as a binary neutron star (BNS) merger with 98% probability. The GW event was localized within an area of 3462 deg(2), later refined to 1166 deg(2) (90%) at a distance of 227 +/- 92 Mpc. We triggered Target-of-Opportunity observations with the Dark Energy Camera (DECam), a wide-field optical imager mounted at the prime focus of the 4 m Blanco Telescope at Cerro Tololo Inter-American Observatory in Chile. This Letter describes our DECam observations and our real-time analysis results, focusing in particular on the design and implementation of the observing strategy. Within 24 hr of the merger time, we observed 65% of the total enclosed probability of the final skymap with an observing efficiency of 94%. We identified and publicly announced 13 candidate counterparts. S190510g was reclassified 1.7 days after the merger, after our observations were completed, with a BNS merger probability reduced from 98% to 42% in favor of a terrestrial classification.
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| 2. |
- Chen, Tao, et al.
(författare)
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Comprehensive applicability evaluation of multi-source snow depth datasets over the Tibetan Plateau
- 2022
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Ingår i: Journal of Glaciology and Geocryology. - 1000-0240. ; 44:3, s. 795-809
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Tidskriftsartikel (refereegranskat)abstract
- Snow cover over the Tibetan Plateau has an important impact on the regional climate and water cycle. At present, the existing snow cover datasets have great uncertainty across this region, so the applicability assessment is indispensable in order to make best use of the advantages and bypass the disadvantages. In this study, a comprehensive quantitative evaluation of multiple variables and multiple evaluation indicators was carried out for three snow depth datasets over the Tibetan Plateau against the meteorological station observations（OBS）. The three snow depth datasets include one passive microwave remote sensing dataset（CHE）and two reanalysis datasets（ERA5-Land and MERRA2）. The variables are the annual mean snow depth, the annual maximum snow depth, and the annual snow cover days. In addition, the evaluation indicators are seasonal cycle, climatology, maximum value, standard deviation, interannual variation, and trend. A rank score（RS）value of 0~1 is computed for each evaluation indicator of each variable, the larger value of RS indicate relatively better performance of a snow depth dataset. Assessment results imply that, comprehensively considered, MERRA2 exhibits best agreement with OBS, followed by ERA5-Land, and finally CHE. Evaluate based on the RS of each variable, MERRA2 shows better performance on annual maximum snow depth and annual snow cover days, CHE shows better performance on annual mean snow depth. Evaluate based on the RS of each evaluation indicator, CHE shows advantages in describing trend, ERA5-Land exhibits better agreement with OBS on interannual variation, and MERRA2 show better performance on the rest of the indicators including seasonal cycle, climatology, maximum value and standard deviation. The RS statistics in terms of regional average and spatial distribution show that CHE performs better in the former, and ERA5-Land performs better in the latter. On the other hand, there are obvious deficiencies in all three snow depth datasets. MERRA2 has insufficient ability to characterize the interdecadal variation in snow cover, and its qualitative results for trend in snow cover is inconsistent with OBS, the reason for the first deficiency needs to be further studied and the second deficiency may be mainly related to its simulation capability to precipitation trend. ERA5-Land significantly overestimates the snow cover over the Tibetan Plateau, this may be mostly related to its data assimilation scheme. CHE has poor ability to characterize the spatial distribution of snow cover, coarse spatial resolution of passive microwave remote sensing may be the main reason. The conclusions are only applicable to the central and eastern part of the Tibetan Plateau due to the scarcity of meteorological station in west part of the Tibetan Plateau. Based on the remote sensing and reanalysis data, there is great uncertainty in the trend of snow cover in the western part of the Tibetan Plateau. These systematic classification evaluation of the three representative snow depth datasets provides information on data selection and data refinement.
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| 3. |
- He, Xingkang, et al.
(författare)
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Visualization of human T lymphocyte-mediated eradication of cancer cells in vivo
- 2020
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 117:37, s. 22910-22919
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Tidskriftsartikel (refereegranskat)abstract
- Lymphocyte-based immunotherapy has emerged as a break-through in cancer therapy for both hematologic and solid malignancies. In a subpopulation of cancer patients, this powerful therapeutic modality converts malignancy to clinically manageable disease. However, the T cell- and chimeric antigen receptor T (CAR-T) cell-mediated antimetastatic activity, especially their impacts on microscopic metastatic lesions, has not yet been investigated. Here we report a living zebrafish model that allows us to visualize the metastatic cancer cell killing effect by tumor- infiltrating lymphocytes (TILs) and CAR-T cells in vivo at the single-cell level. In a freshly isolated primary human melanoma, specific TILs effectively eliminated metastatic cancer cells in the living body. This potent metastasis-eradicating effect was validated using a human lymphoma model with CAR-T cells. Furthermore, cancer-associated fibroblasts protected metastatic cancer cells from T cell-mediated killing. Our data provide an in vivo platform to validate antimetastatic effects by human T cell-mediated immunotherapy. This unique technology may serve as a precision medicine platform for assessing anticancer effects of cellular immunotherapy in vivo before administration to human cancer patients.
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| 4. |
- Zhang, Hui, et al.
(författare)
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Comprehensive electronic structure characterization of pristine and nitrogen/phosphorus doped carbon nanocages
- 2016
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Ingår i: Carbon. - : Elsevier. - 0008-6223 .- 1873-3891. ; 103, s. 480-487
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Tidskriftsartikel (refereegranskat)abstract
- The electronic structures of carbon nanocages (CNCs) and nitrogen/phosphorus doped carbon nanocages (N-CNCs/P-CNCs) have been studied by X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES) and resonant X-ray emission spectroscopy (RXES). The doping configurations for N/P dopants are identified from the experiments. The results have shown that there are three major doping configurations for nitrogen but only one doping configuration for phosphorus. The nitrogen doping reveals the complex coexistence of graphite-like, pyridine-like and pyrrole-like configurations that are proved by density functional theory (DFT) simulations, while the phosphorus doping presents only the "graphite-like" configuration. The different configuration profiles result in less atomic structure ordering of N-CNCs than that of P-CNCs. XAS spectra obtained from both surface and bulk sensitive detection suggest different chemical environments between the interior and shell for all types of nanocages. The electronic structure modifications show significant difference between nitrogen and phosphorus doping from the DOS calculations. (C) 2016 Elsevier Ltd. All rights reserved.
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