Alternating spin splitting of electronic and magnon bands in two-dimensional altermagnetic materials

Unconventional antiferromagnetism dubbed as altermagnetism was first discovered in rutile structured magnets,which is featured by spin splitting even without the spin–orbital coupling effect.This interesting phenomenon has been discovered in more altermagnetic materials.In this work,we explore two-dimensional altermagnetic materials by studying two series of two-dimensional magnets,including MF4 with M covering all 3d and 4d transition metal elements,as well as TS2 with T=V,Cr,Mn,Fe.Through the magnetic symmetry operation of RuF4 and MnS2,it is verified that breaking the time inversion is a necessary condition for spin splitting.Based on symmetry analysis and first-principles calculations,we find that the electronic bands and magnon dispersion experience alternating spin splitting along the same path.This work paves the way for exploring altermagnetism in two-dimensional materials.

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.