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  • End-to-end computational design for an EUV solar corona multispectral imager with stray light suppression

    分类: 天文学 >> 天文仪器与技术 提交时间: 2024-01-22 合作期刊: 《天文技术与仪器(英文)》

    摘要:An extreme ultraviolet solar corona multispectral imager can allow direct observation of high temperature coronal plasma, which is related to solar flares, coronal mass ejections and other significant coronal activities. This manuscript proposes a novel end-to-end computational design method for an extreme ultraviolet (EUV) solar corona multispectral imager operating at wavelengths near 100 nm, including a stray light suppression design and computational image recovery. To suppress the strong stray light from the solar disk, an outer opto-mechanical structure is designed to protect the imaging component of the system. Considering the low reflectivity (less than 70%) and strong-scattering (roughness) of existing extreme ultraviolet optical elements, the imaging component comprises only a primary mirror and a curved grating. A Lyot aperture is used to further suppress any residual stray light. Finally, a deep learning computational imaging method is used to correct the individual multi-wavelength images from the original recorded multi-slit data. In results and data, this can achieve a far-field angular resolution below 7", and spectral resolution below 0.05 nm. The field of view is ±3 R☉ along the multi-slit moving direction, where R☉ represents the radius of the solar disk. The ratio of the corona's stray light intensity to the solar center's irradiation intensity is less than 10−6 at the circle of 1.3 R☉.

  • Transplantation of ACE2- mesenchymal stem cells improves the outcome of patients with COVID-19 pneumonia

    分类: 医学、药学 >> 临床医学 提交时间: 2020-02-28

    摘要: A coronavirus (HCoV-19) has caused the novel coronavirus disease (COVID-19) outbreak in Wuhan, China, Preventing and reversing the cytokine storm may be the key to save the patients with severe COVID-19 pneumonia. Mesenchymal stem cells (MSCs) have been shown to possess a comprehensive powerful immunomodulatory function. This study aims to investigate whether MSC transplantation improve the outcome of 7 enrolled patients with COVID-19 pneumonia in Beijing YouAn Hospital, China from Jan 23, 2020. to Feb 16, 2020. The clinical outcomes, as well as changes of inflammatory and immune function levels and adverse effects of 7 enrolled patients were assessed for 14 days after MSC injection. MSCs could cure or significantly improve the functional outcomes of seven patients with COVID-19 pneumonia in 14 days without observed adverse effect. The pulmonary function and symptoms of all patients with COVID-19 pneumonia were significantly improved in 2 days after MSC transplantation. Among them, two common and one severe patient were recovered and discharged in 10 days after treatment. After treatment, the peripheral lymphocytes were increased and the overactivated cytokine-secreting immune cells CXCR3 CD4 T cells, CXCR3 CD8 T cells, and CXCR3 NK cells were disappeared in 3-6 days. And a group of CD14 CD11c CD11bmid regulatory DC cell population dramatically increased. Meanwhile, the level TNF-α is significantly decreased while IL-10 increased in MSC treatment group compared to the placebo control group. Furthermore, the gene expression profile showed MSCs were ACE2- and TMPRSS2- which indicated MSCs are free from COVID-19 infection. Thus, the intravenous transplantation of MSCs was safe and effective for treatment in patients with COVID-19 pneumonia, especially for the patients in critically severe condition.