A simple approach to prepare carbon quantum dots is presented in this communication by laser rapid passivation of nano carbon particles in ordinary organic solvent. The as-prepared carbon dots exhibited visible, tunable and stable photoluminescence (PL). XPS analysis showed that the increased oxygen concentration might be concerned with the origin of PL.

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Background and objectivesPrevious reports on the outbreak of coronavirus disease 2019 were on the basis of data from the general population. Our study aimed to investigate the clinical features of patients on maintenance hemodialysis.Design, setting, participants, & measurements In this retrospective, single-center study, we included 49 hospitalized patients on maintenance hemodialysis and 52 hospitalized patients without kidney failure (controls) with confirmed coronavirus disease 2019 at Tongren Hospital of Wuhan University from January 30, 2020 to March 10, 2020. Demographic, clinical, laboratory, and radiologic characteristics and treatment and outcomes data were analyzed. The final date of follow-up was March 19, 2020.ResultsThe median age of 101 patients was 62 years (interquartile range, 49–72). All patients were local residents of Wuhan. In terms of common symptoms, there were differences between patients on hemodialysis and controls (fatigue [59% versus 83%], dry cough [49% versus 71%], and fever [47% versus 90%]). Lymphocyte counts were decreased (0.8×109/L [patients on hemodialysis] versus 0.9×109/L [controls], P=0.02). Comparing patients on hemodialysis with controls, creatine kinase–muscle and brain type, myoglobin, hypersensitive troponin I, B-type natriuretic peptide, and procalcitonin were increased, and the percentage of abnormalities in bilateral lung was higher in computed tomographic scan (82% versus 69%, P=0.15) and unilateral lung was lower (10% versus 27%, P=0.03). Common complications including shock, acute respiratory distress syndrome, arrhythmia, and acute cardiac injury in patients on hemodialysis were significantly higher. Compared with controls, more patients on hemodialysis received noninvasive ventilation (25% versus 6%, P=0.008). As of March 19, 2020, three patients on hemodialysis (6%) were transferred to the intensive care unit and received invasive ventilation. Seven patients on hemodialysis (14%) had died.ConclusionsThe main symptoms of coronavirus disease 2019 pneumonia, including fever and cough, were less common in patients on hemodialysis. Patients on hemodialysis with coronavirus disease 2019 were at higher risk of death.