Effect of modification degrees on the interfacial properties and EOR efficiency of amphiphilic Janus graphene oxide

Asymmetrically modified Janus graphene oxide(JGO)has attracted great attention due to its unique physical chemistry properties and wide applications.The modification degree of Janus nanosheets inevitably affects their interfacial activity,which is essential for their performances in enhanced oil recovery(EOR).In this study,the interfacial properties of Janus graphene oxide(JGO)with various modification degrees at liquid-liquid and liquid-solid interfaces were systematically evaluated via the measurements of interfacial tension(IFT),dilatational modulus,contact angle,and EOR efficiency was further assessed by core flooding tests.It is found that JGO-5 with higher modification degree exhibits the greater ability to reduce IFT(15.16 mN/m)and dilatational modulus(26 mN/m).Furthermore,JGO can construct interfacial and climbing film with the assistance of hydrodynamic power to effectively detach the oil from the rock surface and greatly enhance oil recovery.Moderately modified JGO-2 can highly improve recovery of residual crude oil(11.53%),which is regarded as the promising EOR agent in practical application.The present study firstly focuses on the effects of modification degrees on the JGO interfacial properties and proposes diverse EOR mechanisms for JGO with different modification degrees.

Value of Kidney Disease Improving Global Outcomes Urine Output Criteria in Critically III Patients： A Secondary Analysis of a Multicenter Prospective Cohort Study

Background： Urine output （UO） is an essential criterion of the Kidney Disease Improving Global Outcomes （KD1GO） definition and classification system tbr acute kidney injury （AKI）, of which the diagnostic value has not been extensively studied. We aimed to determine whether AKI based on KDIGO UO criteria （KDtGOLro） could improve the diagnostic and prognostic accuracy, compared with KDIGO serum creatinine criteria （KDIGOscr）.Methods： We conducted a secondary analysis of the database of a previous study conducted by China Critical Care Clinical Trial Group （CCCCTG）, which was a 2-month prospective cohort study （July 1,2009 to August 31,2009） involving 3063 patients in 22 tertiary Intensive Care Units in Mainland of China. AKI was diagnosed and classified separately based on KDIGOt,o and KDlGOsc,. Hospital mortality of patients with more severe AKI classification based on KDIGOvo was compared with other patients by univariate and multivariate regression analyses. Results： The prevalence of AKl increased from 52.4% based on KDIGOscr to 55.4% based on KD1GOsc~ combined with KDIGOuo. KDIGOv~~ also restllted in an upgrade of AKI classification in 7.3% of patients, representing those with more severe AK1 classification based on KDIGOvo. Compared with non-AKI patients or those with maximum AKI classification by KDIGOscr, those with maximum AKI classification by KDIGOuo had a significantly higher hospital mortality of 58.4% （odds ratio [OR]： 7.580, 95% confidence interval [CI]： 4.141-13.873, P 〈 0.001）. In a multivariate logistic regression analysis, AKI based on KDIGOuo （OR： 2.891, 95% CI： 1.964-4.254, P 〈 0.001）, but not based on KDIGOscr （OR： 1.322, 95% CI： 0.902-1.939, P = 0.152）, was an independent risk factor for hospital mortality. Conclusion： UO was a criterion with additional value beyond creatinine criterion for AKI diagnosis and classification, which can help identify a group of patients with high risk of death.