The improvement of the electroosmotic pump properties and the effects of the bi-directional electrostacking system on the pre-concentration factor were investigated.A portable electrokinetic flow analysis system with electroosmotic driving and bi-directional electrostacking unit was introduced.The improved system with graphite furnace atomic absorption spectrometry was employed to separate,pre-concentrate and determine Cr(Ⅵ) and Cd(Ⅱ)in mineral water.The detection limit of Cr(Ⅵ)and Cd(Ⅱ)was 9 ng/L and 10 ng/L(3б of blank,n=11),respectively.Their recoveries of 200ng/L Cr(Ⅵ) and 100ng/L Cd(Ⅱ) added to samples were(105～107)±2% and (104～106)±2%(n=3).

Objectives To screen the high-risk population of stroke in China using color Doppler flow imaging (CDFI)and to establish a stroke risk prediction model in Chinese population in order to prevent and treat stroke early. Methods Forty-one base hospitals and 715 286 people in the project areas of the first 6 provinces of China conducted routine physical examinations and investigated the related risk factors for cardiocerebrovascular diseases from July 2011 to April 2012 using a cross-sectional study,among them 61 860 patients underwent carotid CDFI screening,and 49 386 of them were high-risk population (exposed to≥3 risk factors). The bilateral common carotid interma-media thickness (IMT),the number of plaques and the degree of carotid stenosis were screened and documented. And whether carotid IMT thickening or not,with or without carotid plaques,and degree of carotid artery stenotic rate 0-49% and≥50% were performed by multivariate logistic regression analysis with the risk factors for stroke,respectively. Results (1)Logistic regression analysis showed that hypertension,atrial fibrillation,smoking,and lack of physical exercise were the independent risk factors for carotid IMT thickening (hypertension:OR,1. 17;95%CI 1. 12-1. 22;atrial fibrillation:OR,1. 15;95%CI 1. 09-1. 21;smoking:OR,1. 13;95%CI 1. 08-1. 17;and lack of physical exercise:OR,1. 12;95%CI 1.08-1. 16). (2)Hypertension,atrial fibrillation, smoking,and diabetes were the independent risk factors for carotid plaque and carotid artery stenosis rate≥50%(carotid plaque,hypertension:OR,1. 55;95%CI 1. 47-1. 62;atrial fibrillation:OR,1. 13;95%CI 1.06-1. 21;smoking:OR,1. 16;95%CI 1. 11-1. 22;and diabetes:OR,1. 30;95%CI 1. 24-1. 37). Carotid stenosis rate≥50%,hypertension:OR,1. 78;95%CI 1.55-2. 03;atrial fibrillation:OR,1. 59;95%CI 1. 39-1. 81;smoking:OR,1. 33;95%CI 1. 20-1. 48;and diabetes:OR,1. 30;95%CI 1. 17-1. 45. Simple obesity did not increase the incidences of carotid atherosclerotic plaque and carotid artery stenosis ≥50%(OR,0. 78, 0.83;95%CI 0. 75-0. 82 ,0. 75-0. 92,respectively). Conclusions Neck vascular ultrasound can be used as a valuable means for screening high-risk population and detecting risk factors of stroke. It has an important clinical significance for the early diagnosis and treatment of carotid atherosclerosis disease.

Objective:To discuss the value of real-time three-dimensional speckle tracking imaging(RT3D-STI) in the evaluation of the left atrial (LA) volume and function in end-stage renal disease (ESRD) patients with different dialysis methods.Methods:Eighty-three ESRD patients who were treated in the Affiliated Hospital of Qingdao University from February to August 2019 were enrolled and divided into non-dialysis group ( n=25), hemodialysis group (HD group, n=31) and peritoneal dialysis group (PD group, n=27). And 30 healthy volunteers were enrolled as control group. Subsequently, the LA volume indexs including LA maximal volume index (LAVImax), LA minimal volume index (LAVImin) and LA presystolic volume index (LAVIpre), the LA function parameters including LA ejection fraction (LAEF), LA passive ejection fraction(LApEF) and LA active ejection fraction (LAaEF) and the LA global strain parameters including global longitudinal strain(GLS), global radial strain(GRS) and global circumferential strain(GCS) were obtained by RT3D-STI. The differences of the parameters among these groups were compared and the correlations between the myocardial strain parameters and dialysis time were analyzed. Results:①The LAVImax, LAVImin and LAVIpre of the non-dialysis group, PD group and HD group were higher than those in the control group, while the LAEF, LApEF, GLS, GRS and GCS were lower than those in the control group(all P<0.05); the LAVImin of the PD group as well as the LAVImin, LAVIpre and LAVImax of HD group were higher than those of non-dialysis group, while the LAEF, LApEF, GLS, GCS of the PD group and the LAEF, LApEF, GLS, GRS, GCS of HD group were lower than those of non-dialysis group (all P<0.05). The LAVImax, LAVImin, LAVIpre of HD group were higher than those of PD group, while the LAEF, LApEF, GLS, GRS and GCS of HD group were lower than those of PD group (all P<0.05). ②The GLS and GCS in PD group were negatively correlated with the dialysis time( r=-0.670, -0.596, all P<0.05), and the GLS, GCS and GRS in HD group were negatively correlated with the dialysis time( r=-0.624, -0.631, -0.551, all P<0.05). Conclusions:RT3D-STI can assess the LA volume and function of ESRD patients with different dialysis methods effectively and can further evaluate the prognosis of patients and guide timely clinical intervention.

Objective:To explore the risk factors affecting the incidence of acute kidney injury(AKI)after liver transplantation(LT).Methods:From November 2019 to November 2022, clinical data were retrospectively reviewed for 105 recipients of classic orthotopic LT.There are 89 males and 16 females with an age range of(50.52±10.35)years.They are assigned into two groups of AKI(66 cases)and non-AKI(39 cases)according to the AKI diagnostic and staging criteria of Global Kidney Disease Prognosis Organization in 2012.General profiles and clinical data(e.g.previous medical history, MELD score, total bilirubin, albumin, serum creatinine level, coagulation function, anhepatic phase and time to surgery)of two groups of recipients are compared.The factors with statistically significant differences are included into multivariate Logistic regression analysis for obtaining independent risk factors for early AKI post-LT.Results:Among them, 66 patients developed AKI within 7 days post-operation with an incidence rate of 62.86%(66/105).The clinical stages of AKI are Ⅰ(46 cases, 69.70%), Ⅱ(10 cases, 15.15%)and Ⅲ(10 cases, 15.15%).Statistically significant inter-group differences exists in age, abdominal surgery history, preoperative serum level of creatinine, operative duration, anhepatic phase and intraoperative plasma transfusion(all P<0.05).Multivariate Logistic regression analysis indicated that abdominal surgery history( OR=5.803, 95% CI: 1.008~33.401, P=0.049), anhepatic phase( OR=1.054, 95% CI: 1.008~1.101, P=0.020)and preoperative serum level of creatinine( OR=0.968, 95% CI: 0.943~0.994, P=0.016)are independent risk factors for early AKI after classical orthotopic LT recipients. Conclusions:Abdominal surgery history, anhepatic phase, and preoperative serum level of creatinine are independent risk factors for early AKI in classic orthotopic LT recipients.