Prolonged prothrombin time at admission predicts poor clinical outcome in COVID-19 patients.

BACKGROUND: The prognostic value of coagulation disorder in coronavirus disease 2019 (COVID-19) patients should be demonstrated. AIM: To investigate the abnormalities of coagulation parameters in the patients with COVID-19 and their prognostic values. METHODS: Consecutive patients admitted in the isolation ward of Renmin Hospital of Wuhan University from January 31 to February 5, 2020 with confirmed COVID-19 were included. The primary outcomes were death and survival as of March 11. Demographics, vital signs, comorbidities and laboratory tests were collected and compared between those who died and survivors. Logistic regression analysis for prognostic factors was performed. Kaplan-Meier analysis was used to compare the estimated survival rate between patients with prolonged prothrombin time and normal prothrombin time. RESULTS: The total number of patients with confirmed COVID-19 who were enrolled was 213. The median age was 62 years, and 95 patients (44.6%) were men. Fifty-one patients were critical (23.9%), 79 patients were severe (37.1%) and 83 patients were moderate (39%). As of March 11, 2020, 99 patients were discharged (46.5%), 79 patients (37.1%) stayed in the hospital and 35 patients (16.2%) died. Median time to death was 6 (4-8) d, while median hospital stay was 32 (22-36) d in survivors (P < 0.001). More men (P = 0.002) and elderly patients (P < 0.001) were found in the group of those who died. The respiration rate at admission was higher in the group of those who died (P < 0.001). The incidences of hypertension (P = 0.028), cerebrovascular disease (P < 0.001), chronic kidney disease (P = 0.02) and chronic obstructive pulmonary disease (P < 0.001) were higher in the group of those who died. Platelet count was decreased in the group of those who died (P = 0.002) whereas prothrombin time (P < 0.001), activated partial thromboplastin time (P = 0.033), concentration of D-dimer (P < 0.001) and fibrin degradation products (P < 0.001) were increased in the group of those who died. Prothrombin time [odds ratio (OR): 2.19, P = 0.004], respiration rate (OR: 1.223, P < 0.001), age (OR: 1.074, P < 0.001) and fibrin degradation products concentration (OR: 1.02, P = 0.014) were predictors of death. The survival rate was significantly lower in patients with prolonged prothrombin time compare to those with normal prothrombin time (P < 0.001). CONCLUSION: Prothrombin time, concentration of fibrin degradation products, respiration rate and age were predictive factors for clinical outcomes of COVID-19 patients.

[Spectral Characteristics of Dissolved Organic Matters in Reject Water from Wastewater Treatment Plants].

Reject water generated from sludge thickening, dewatering and stabilization process contains high-content and complex dissolved organic matters (DOM). The spectral characteristics of DOM in the reject water were investigated by three-dimensional excitation-emission matrix and Fourier transform infrared spectroscopy. Fluorescent DOM (FDOM) from reject water were decomposed into six components by parallel factor analysis, the protein-like C1 (275/355 nm), C4 (235/350 nm) and C6 (275/305 nm) and the humic-like C2 (250, 340/440 nm) , C3 (320/380 nm) and CS (250/465 nm). Soluble COD in the sludge thickening reject water was positively correlated with all the three humic-like substances at P < 0.01 level, and was insignificantly influenced by protein-like substances. The tryptophan-like C1, C4 and humic-like CS increased in the centrifugal dewatering reject water (CDRW). FDOM in the advanced dewatering reject water (ADRW) were significantly different from those of other reject water in fluorescence peak locations and intensities, and humic-like C3 and tyrosine-like C6 in the DOM were 15.63 and 7.30 times higher than those in CDRW. Compared to sludge thickening reject water, infrared peaks related to polysaccharide and humic substances in CDRW were enhanced and massive proteins were released into ADRW. DOM structures in ADRW were changed owing to the complexation between metals and both humic substances and proteins.

[Optimization for phosphorous removal in thickening and dewatering sludge water by polyaluminum chloride].

Based on the comparison of phosphorous removal in sludge water and its supernatant by polyaluminum chloride (PAC), separate and combined effects of Al/P mole ratio, pH and mixing speed (MS) on phosphorus removal by PAC for the supernatant of thickening and dewatering sludge water were analyzed by the response surface methodology (RSM), and kinetics of phosphorous removal by PAC was also investigated. The results showed that direct addition of PAC into sludge water deteriorated its settling characteristics, and suspended solids in the sludge water could decrease the phosphorus removal efficiency. The RSM analysis results demonstrated that the effect of individual operation parameter on phosphorus removal was followed as the order of Al/P > pH > MS, and the optimal process parameters with phosphorus removal efficiency of 97.8% were Al/P = 2.49, pH = 8.3 and MS 398 r x min(-1), respectively. The verification experiment showed that the RSM model was valid and effective. Kinetic analysis illustrated that phosphorus removal by PAC was divided into two stages, a chemical precipitation and rapid adsorption stage, followed by a chemical precipitation stage that conformed to the second-order kinetics.