Removal of 26 corticosteroids, potential COVID-19 remedies, at environmentally relevant concentrations in water using UV/free chlorine, UV/monochloramine, and UV/hydrogen peroxide

As a class of endocrine disrupting compounds (EDCs), corticosteroids (CSs) have attracted increasing attention due to their large excretion masses and toxic effects. However, compared to the very well-studied estrogens and androgens, few studies have been made dealing with the removal of CSs at environmentally relevant concentrations using advanced water and wastewater treatment processes. In this study, degradation performances of 26 natural and synthetic CSs in secondary effluent at environmentally relevant concentrations were comparatively investigated during UV/free chlorine (UV/Cl-2), UV/monochloramine (UV/NH2Cl) and UV/hydrogen peroxide (UV/H2O2) treatments. The 26 CSs could be divided into two groups: UV sensitive CSs, which have two double bonds in ring A (Delta(1,4)), and UV insensitive CSs, which have only one double bond in ring A (Delta(4)). The UV sensitive CSs could be effectively removed (removal efficiency >60%) by a UV dose of 100 mJ cm(-2) while the UV insensitive CSs could be removed (removal efficiency >40%) by a UV dose of 800 mJ cm(-2). The removal efficiencies of UV insensitive CSs increased with the increase of UV dose. Most of the CSs were poorly removed by sole Cl-2, NH2Cl, or H2O2 treatment (removal efficiency <40%). However, the addition of Cl-2, NH2Cl, and H2O2 promoted the UV degradation of CSs, especially for UV-insensitive CSs. UV photolysis would be the predominant mechanism in the UV/Cl-2, UV/NH2Cl, and UV/H2O2 processes for removing CSs in water. Besides the UV photolysis, HO radicals also functioned for CS removal. Compared with the insignificant effects of reactive chlorine species (RCS), the reactive nitrogen species (RNS) showed obvious selectivity in CS degradation. This study expanded the UV induced oxidation performances of CSs, which lays a foundation for exploring degradation mechanisms and eliminating the pollution from CSs.

[From SARS to COVID-19: pathogens, receptor, pathogenesis and principles of the treatment].

COVID-19 is an infectious disease caused by 2019-nCoV and characterizes as an atypical pneumonia. Since 2019-nCoV is a newly emerging virus, the pathogenesis of COVID-19 is not well known. Most patients had a self-limited course, and some became severe even death. In this review, the authors compared two coronavirus outbreaks during the past two decades: the SARS-CoV and 2019-nCoV. Among the biological nature of the pathogens, viral receptor distribution on the human cells, and the pathological findings in the targeted organs and clinical features of the patients with the diseases, found similarities and differences between the two diseases had been found. Due to the shared receptor ACE2 and the pathological similarities of the SARS-CoV and 2019-nCoV diseases,authors proposed a pathogenesis model for COVID-19. Like the SARS-CoV disease, COVID-19 is a systematic disease and targets the lungs, vasculatures, and the immune system. The basic pathogenesis involves two interlinked processes: a severe lung inflammation and immune deficiency, both of which were related to an inappropriate immune response and over-production of cytokines. Thus, treatment approaches should include antiviral and anti-proinflammatory cytokines, anti-infectious and life support therapies, especially in patients with severe diseases.

[A pathological report of three COVID-19 cases by minimal invasive autopsies].

Objective: To investigate the pathological characteristics and the clinical significance of novel coronavirus (2019-nCoV)-infected pneumonia (termed by WHO as coronavirus disease 2019, COVID-19). Methods: Minimally invasive autopsies from lung, heart, kidney, spleen, bone marrow, liver, pancreas, stomach, intestine, thyroid and skin were performed on three patients died of novel coronavirus pneumonia in Chongqing, China. Hematoxylin and eosin staining (HE), transmission electron microcopy, and histochemical staining were performed to investigate the pathological changes of indicated organs or tissues. Immunohistochemical staining was conducted to evaluate the infiltration of immune cells as well as the expression of 2019-nCoV proteins. Real time PCR was carried out to detect the RNA of 2019-nCoV. Results: Various damages were observed in the alveolar structure, with minor serous exudation and fibrin exudation. Hyaline membrane formation was observed in some alveoli. The infiltrated immune cells in alveoli were majorly macrophages and monocytes. Moderate multinucleated giant cells, minimal lymphocytes, eosinophils and neutrophils were also observed. Most of infiltrated lymphocytes were CD4-positive T cells. Significant proliferation of type Ⅱ alveolar epithelia and focal desquamation of alveolar epithelia were also indicated. The blood vessels of alveolar septum were congested, edematous and widened, with modest infiltration of monocytes and lymphocytes. Hyaline thrombi were found in a minority of microvessels. Focal hemorrhage in lung tissue, organization of exudates in some alveolar cavities, and pulmonary interstitial fibrosis were observed. Part of the bronchial epithelia were exfoliated. Coronavirus particles in bronchial mucosal epithelia and type Ⅱ alveolar epithelia were observed under electron microscope. Immunohistochemical staining showed that part of the alveolar epithelia and macrophages were positive for 2019-nCoV antigen. Real time PCR analyses identified positive signals for 2019-nCoV nucleic acid. Decreased numbers of lymphocyte, cell degeneration and necrosis were observed in spleen. Furthermore, degeneration and necrosis of parenchymal cells, formation of hyaline thrombus in small vessels, and pathological changes of chronic diseases were observed in other organs and tissues, while no evidence of coronavirus infection was observed in these organs. Conclusions: The lungs from novel coronavirus pneumonia patients manifest significant pathological lesions, including the alveolar exudative inflammation and interstitial inflammation, alveolar epithelium proliferation and hyaline membrane formation. While the 2019-nCoV is mainly distributed in lung, the infection also involves in the damages of heart, vessels, liver, kidney and other organs. Further studies are warranted to investigate the mechanism underlying pathological changes of this disease.