NOTES ON THE SPECTRAL PROPERTIES OF THE WEIGHTED MEAN DIFFERENCE OPERATOR G(u,v;?) OVER THE SEQUENCE SPACE ?_1

In the study by Baliarsingh and Dutta [Internat. J.Anal., Vol.2014（2014）, Article ID 786437], the authors computed the spectrum and the fine spectrum of the product operator G （u, v; A） over the sequence space e1. The product operator G （u, v; △） over l1 is defined by （G（u,v;△）x）k=^k∑i=0ukvi（xi- xi-1） with xk = 0 for all k 〈 0, where x = （xk）∈e1,and u and v axe either constant or strictly decreasing sequences of positive real numbers satisfying certain conditions. In this article we give some improvements of the computation of the spectrum of the operator G （u, v; △） on the sequence space gl.

Circulating glycated albumin levels and gestational diabetes mellitus

BACKGROUND Gestational diabetes mellitus(GDM)is characterized by glucose intolerance that is first diagnosed during pregnancy,making it the most common complication associated with this period.Early detection and targeted treatment of GDM can minimize foetal exposure to maternal hyperglycaemia and subsequently reduce the associated adverse pregnancy outcomes.Previous studies have inconsistently suggested that the level of glycated albumin(GA)might predict GDM.AIM To review and synthesize existing evidence to evaluate the relationship between GA levels and the development of GDM.METHODS We sought to compare GA levels between GDM and control groups in this metaanalysis by systematically searching the Web of Science,PubMed,Cochrane Library,and Embase databases for articles published up to June 2023.The analysis utilized the weighted mean difference(WMD)as the primary metric.The data were meticulously extracted,and the quality of the included studies was assessed.Additionally,we conducted a subgroup analysis based on study region and sample size.We assessed heterogeneity using I2 statistics and evaluated publication bias through funnel plots.Additionally,trim-and-fill analysis was employed to detect and address any potential publication bias.RESULTS The meta-analysis included a total of 11 studies involving 5477 participants,comprising 1900 patients with GDM and 3577 control individuals.The synthesized results revealed a notable correlation between elevated GA levels and increased susceptibility to GDM.The calculated WMD was 0.42,with a 95%confidence interval(95%CI)ranging from 0.11 to 0.74,yielding a P value less than 0.001.Concerning specific GA levels,the mean GA level in the GDM group was 12.6,while for the control group,it was lower,at 11.6.This discrepancy underscores the potential of GA as a biomarker for assessing GDM risk.Moreover,we explored the levels of glycated haemoglobin(HbA1c)in both cohorts.The WMD for HbA1c was 0.19,with a 95%CI ranging from 0.15 to 0.22 and a P value less than 0.001.This observation suggested that both GA and HbA1c levels were elevated in individuals in the GDM group compared to those in the control group.CONCLUSION Our meta-analysis revealed a substantial correlation between elevated GA levels and increased GDM risk.Furthermore,our findings revealed elevated levels of HbA1c in GDM patients,emphasizing the significance of monitoring both GA and HbA1c levels for early GDM detection and effective management.