Background: Recently, Coronavirus Disease 2019 (COVID-19) outbreak started in Wuhan, China. Although the clinical features of have been reported previously, data regarding the risk factors associated with the clinical outcomes are lacking.Objectives: To summary and analyze the clinical characteristics and identify the predictors of disease severity and mortality. Methods:The PubMed, Web of Science Core Collection, Embase, Cochrane and MedRxiv databases were searched through February 25, 2020. Meta-analysis of Observational Studies in Epidemiology (MOOSE) recommendations were followed. We extracted and pooled data using random-e ects meta-analysis to summary the clinical feature of the confirmed COVID-19 patients, and further identify risk factors for disease severity and death. Heterogeneity was evaluated using the I² method and explained with subgroup analysis and meta-regression. Results:A total of 30 studies including 53000 patients with were included in this study, the mean age was 49.8 years (95% CI, 47.5-52.2 yrs) and 55.5% were male. The pooled incidence of severity and mortality were 20.2% (95% CI, 15.1-25.2%) and 3.1% (95% CI, 1.9-4.2%), respectively. The predictor for disease severity included old age (≥ 50 yrs, odds ratio [OR] = 2.61; 95% CI, 2.29-2.98), male (OR =1.348, 95% CI, 1.195-1.521), smoking (OR =1.734, 95% CI, All rights reserved. No reuse allowed without permission. : medRxiv preprint 1.146-2.626) and any comorbidity (OR = 2.635, 95% CI, 2.098-3.309), especially chronic kidney disease (CKD, OR = 6.017; 95% CI, 2.192-16.514), chronic obstructive pulmonary disease (COPD, OR = 5.323; 95% CI, 2.613-10.847) and cerebrovascular disease (OR = 3.219; 95% CI, 1.486-6.972). In terms of laboratory results, increased lactate dehydrogenase (LDH), C-reactive protein (CRP) and D-dimer and decreased blood platelet and lymphocytes count were highly associated with severe COVID-19 (all for P < 0.001). Meanwhile, old age (≥ 60 yrs, RR = 9.45; 95% CI, 8.09-11.04), followed by cardiovascular disease (RR = 6.75; 95% CI, 5.40-8.43) hypertension (RR = 4.48; 95% CI, and diabetes (RR = 4.43; 95% CI, 3.49-5.61) were found to be independent prognostic factors for the COVID-19 related death. Conclusions:To our knowledge, this is the first evidence-based medicine research to explore the risk factors of prognosis in patients with COVID-19, which is helpful to identify early-stage patients with poor prognosis and adapt effective treatment.Compared with two other types of coronaviruses, the present new coronavirus is spreading far more quickly and has higher contagiousness 5 .As of March 17, 2020, a total of 187, 361 COVID-19 cases in 151 countries have been confirmed, which almost 22.2 times the number of people infected by the SARS in 2003. Although COVID-19 has a relatively low mortality rate, it can be highly deadly and lethal, especially in high-risk patients 6 . The reported incidence of COVID-19 accompanied with underlying comorbidities in the literature were up to 26.0%, and most of them (65.3%) had cardiovascula...

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A novel photocatalyst, carbon-sulfur-codoped TiO 2 (TCS) was synthesized by the hydrolysis of tetrabutyl titanate in a mixed aqueous solution containing thiourea and urea. The codoped TiO 2 was also prepared directly by calcining amorphous or anatase TiO 2 with a mixture of thiourea and urea. The as-prepared powders were characterized by X-ray diffraction (XRD), UV-visible reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, and thermal analysis-thermogravimetry (TG-DSC). The photocatalytic activity was evaluated by the photodegradation of 4-chlorophenol under both UV and visible irradiation. By investigating the crystal structures, optical properties, and photocatalytic activities of various samples, we found that the wet chemistry process and the crystal transition process from amorphous to anatase seemed to be critical to the doping process.

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