1.Preparation and Application of Polyimide Coated Stir Bar for Extraction of Phenols in Environmental Water Samples
Shenghong LI ; Dapeng WU ; Yafeng GUAN
Chinese Journal of Analytical Chemistry 2016;44(6):842-849
A polyimide coated stir bar for sorptive extraction (SBSE) was prepared by immersion precipitation method, and evaluated by using 5 phenols and chlorinated phenols as model samples. The extraction efficiency of the prepared stir bar was the highest compared with commercial extraction phases of SBSE. Experimental parameters including stir speed, ionic strength, extraction temperature, extraction time, desorption temperature and time were optimized. Under the optimal conditions such as 100 mL of sample, 30 g of NaCl, extraction time of 30 min, stirring speed of 800 r/ min and at 25℃, the target compounds were recovered by thermal desorption at 300℃ for 4 min, more than two orders of magnitude of linearity was obtained (R≥0. 9995), LOQs (S/ N=10) were 0. 028-0. 123 μg/ L, and RSDs were in the range of 1. 6% -9. 7% . The polyimide SBSE coupled with gas chromatography-mass spectrometry was applied to the extraction/ enrichment and analysis of phenols in real samples, including tap water, sea water, and waste water. It was found that the polyimide SBSE showed high selectivity towards polar compounds and high thermostability up to 350℃.
2.Postsystolic shortening in regional myocardium of myocardial infarction patients assessed by quantitative tissue velocity imaging
Juan ZHANG ; Yafeng WU ; Dingyin ZENG
Chinese Journal of Ultrasonography 2003;0(10):-
Objective By quantitative tissue velocity i maging(QTVI),to observe longitudinal wall motion characteristics during isovolumic contraction, ejection, isovolumic relaxation, early relaxation, atrial systole phases in regional myocardium of myocardial infarction patients with three diseased blood vessels, and to assess postsystolic shortening in isovolumic relaxation phase and its clinical meanings. Methods Left ventricular regional myocardium of 30 myocardial infarction patients (MI group) and 30 non-cardiac disease subjects (control group) was assessed by QTVI. After dynamic images were collected and information was analyzed off-line, left ventricular myocardial velocity and time velocity integral profiles were acquired along long axis asynchronously in basal and middle segments of different walls, peak velocities (V IC , V S, V IR , V E, V A) during different phases and maximum time velocity integral (TVI max )in regional myocardium was measured. Results Peak velocities(V IC , V S, V IR , V E, V A) in different segments of left ventricular regional myocardium in MI group were lower than those of control group, especially more obviously in infarcted segments. Peak velocity amplitude in ejection declined, but it had positive velocity spike; abnormal positive velocity in isovolumic relaxation phase suggested postsystolic shortening. What's more, time velocity integrals in some segments of MI group had two wave crests, reached maximum in isovolumic relaxation phase, but were still lower than that of control group. Conclusions Systolic and diastolic function in MI patients with three diseased blood vessels are apparently impaired; abnormal movement in isovolumic relaxation phase suggests existence of postsystolic shortening and abnormal wall motion in regional myocardium.V IR is a marker of abnormal regional wall motion and ischemic myocardium.
3.Assess dyssynchrony in left bundle branch block by tissue Doppler imaging
Juan ZHANG ; Xinchun YANG ; Yafeng WU
Chinese Journal of Ultrasonography 2003;0(10):-
Objective To observe longitudinal motion characteristics of regional myocardium in left bundle branch block(LBBB) patients. Methods Left ventricular regional myocardium of 15 LBBB patients and 15 normal subjects were assessed by tissue Doppler imaging(TDI). Peak velocities(V_S,V_E,V_A) during isovolumic contraction, ejection, isovolumic relaxation, early relaxation, atrial systole phases and maximum time velocity integral(TVI_(max)), displacement(D_(max)) in mitral(tricuspidal) annulets of different walls were measured. Furthermore, the different parameters from the beginning of electrocardiogram QRS wave to the beginning of S wave(Q-Sb),to the tip of S wave(TTP), the acceleration time of IVC wave(IVA), the acceleration time of the E wave(Eac),the durations of different phases(IVC,S,IVR,D)and IVC/S and others were acquired. Results Peak velocities(V_S,V_E)and TVI_(max) in left ventricular septal, inferior, anterior, posterior walls were lower in LBBB group than control group; those parameters in different segments of left and right ventricular lateral myocardium were not significantly lower in LBBB group than control group. What is more, D_(max) of mitral annular sites in LBBB group were lower than control group. Q-Sb, TTP and IVC in left ventricular septal, inferior, anterior, posterior walls were longer in LBBB group than in control group; IVA lengthened, Eac and Edc shortened in left ventricular septal, inferior walls; IVR lengthened, diastole shortened, IVC/S increased in left ventricular septal, inferior, and posterior walls. Conclusions Abnormal left ventricular activation sequence during LBBB caused obvious impairment in total and regional systolic and diastolic function. And delayed contraction with different degrees were resulted from different walls of left ventricle with intraventricular dyssynchrony; but contraction in right ventricle was not significantly delayed, with interventricular dyssynchrony.
4.Suprasternal notch echocardiography determination of right pulmonary artery lesions
Wei JIANG ; Yafeng WU ; Xiuzhang Lü
Chinese Journal of Ultrasonography 2013;22(11):932-935
Objective To evaluate the value of suprasternal long axis view in echocardiography for right pulmonary artery (RPA) lesions.Methods Echocardiography was performed in 31 patients with clinical suspicion of pulmonary vascular disease.Through suprasternal long axis view,RPA,right superior pulmonary artery and right inferior pulmonary artery were identified,and the vessel wall,intraluminal echoes,and location of the lesion were obtained.Blood flow in pulmonary artery was detected with color Doppler flow imaging.The results of echocardiography were compared with those of computer tomography of pulmonary angiography (CTPA) and clinical diagnosis.Results With suprasternal notch echocardiography,RPA lesions were identified in 27 patients.H owever,RPA could not be clearly identified in four patients.There were 22 patients with moderate or low echo mass in RPA,and five patients with intimal thickening and artery stenosis/obliteration.In the 27 patients with detected lesions,20 lesions were located in RPA,seven lesions were located in distal RPA or its branches.Among the results obtained with echocardiography,25 were in accordance with CT results,6 were not in accordance with CT results.Conclusions The suprasternal long axis view of RPA can be an important alternative imaging modality in identification of pulmonary vascular diseases.
5.Assessment of wall motion in myocardial infarction patients with Doppler tissue tracking quantitative score
Juan ZHANG ; Xinchun YANG ; Yafeng WU
Chinese Journal of Ultrasonography 2003;0(08):-
Objective To measure various parameters with tissue Doppler imaging, quantitatively score left ventricular wall motion, assess longitudinal wall motion in total and regional myocardium of myocardial infarction patients. Methods Tissue tracking was adopted for assessing left ventricular regional myocardium of 30 myocardial infarction patients (MI group) and 30 normal subjects (control group). After collecting dynamic images and analyzing information off-line, maximum displacement along long axis asynchronously in annular, basal, mid and apical segments of different walls were acquired, and left ventricular wall motion score indexes(TT score indexes) were calculated. Results Maximum displacement in different segments of left ventricular regional myocardium was lower in MI group than control group, especially in infarcted segments. TT score indexes were lower in MI group than control group( 6.23? 1.93 vs 9.71? 1.08, P
6.Evaluation of right ventricular performance using volumetric pulmonary artery catheter in patients undergoing off-pump coronary artery bypass grafting
Qiuhua ZHAO ; Yun WE ; Yafeng WU
Chinese Journal of Anesthesiology 1995;0(02):-
Objective To evaluate the right ventricular function using volumetric pulmonary artery catheter (VPAC) in patients undergoing off-pump coronary artery bypass grafting (CABG) .Methods Thirty-two patients (18 males, 14 females) aged 45-63 yrs weighing 58-74 kg undergoing CABG were studied. Their cardiac functions were graded according to NYHA classification as Ⅰ or Ⅱ. Radial artery was cannulated before induction of anesthesia for BP monitoring. Anesthesia was induced with midazolam 0.03-0.05 mg?kg-1, fentanyl 10-15 ?g?kg-1 and pipecuronium 0.1-0.15 mg?kg-1 and maintained with 1.0-1.5% isoflurane. The probe (7 MHz) of the transesophageal echocardiography (TEE, Sonos 2500, HP) was placed in esophagus after tracheal intubation for measurement of both right and left ventricular end-diastolic, end-systolic volume and ejection fraction (LVEDV, LVESV, LVEF, RVEDV, RVESV, RVEF). VPAC (type 774HF75, Edwards Life Science Co) was placed via right internal jugular vein for measurement of RVEDV, RVESV and RVEF. 6% HAES 10 ml?kg-1 was infused over 10 min. The cardiovascular parameters mentioned above were measured before and immediately after 6% HAES infusion using both TEE and VPAC, and compared.Results The RVEDV and RVESV (measured by TEE and VPAC) and LVEDV, LVESV (by TEE) were significantly increased after HAES infusion as compared with the baseline values (P
7.Relationship between echocardiographic and magnetic resonance derived measures of right ventricular function in patients with chronic thromboembolic pulmonary hypertension
Yidan LI ; Xiuzhang LYU ; Xiaojuan GUO ; Yafeng WU ; Li WANG
Chinese Journal of Ultrasonography 2014;23(9):737-740
Objective To evaluate right ventricular function of chronic thromboembolic pulmonary hypertension (CTEPH) patients by echocardiography and cardiac magnetic resonance (CMR),and to evaluate the value of clinical application of those right heart function indexes.Methods 32 patients with CTEPH who underwent CMR and echocardiography were involved in the study.Right ventricular index of myocardial performance (RIMP),fractional area change (FAC),tricuspid annular plane systolic excursion (TAPSE) and tissue Doppler-derived tricuspid lateral annular systolic velocity (S') were measured by echocardiography.Right ventricular end-diastolic volume (RVEDV) and end-systolic volume (RVESV) were measured by cardiac magnetic resonance and right ventricular ejection fraction (RVEF) was calculated.Results A positive correlation was found between FAC and RVEF (r =0.423,P =0.022),there was a negative correlation between RIMP and RVEF (r =-0.387,P =0.048),there was no correlation between TAPSE and RVEF (r =0.451,P =0.22),a positive correlation was found between S' and RVEF (r =0.689,P =0.000).Conclusions The echocardiographic parameters FAC,RIMP and S' can reflect right ventricular function in patients with CTEPH and can be used as a routine clinical parameters.
8.Evaluation of right ventricular function in patients with pulmonary arterial hypertension by real-time three-dimensional echocardiography
Yidan LI ; Xiuzhang LYU ; Yafeng WU ; Xiaojuan GUO ; Yidan WANG
Chinese Journal of Ultrasonography 2015;24(3):191-195
Objective To evaluate right ventricular systolic function in patients with pulmonary hypertension (PH) by real-time three-dimensional echocardiography (RT-3DE),and compared with cardiac magnetic resonance.Methods A total of 23 patients with PH who underwent MRI and echocardiography in the study.Right ventricular index of myocardial performance (RIMP),fractional area change (RVFAC),tricuspid annular plane systolic excursion (TAPSE) and tissue Doppler-derived tricuspid lateral annular systolic velocity (S') were measured by echocardiography.RV end-diastolic volume (RVEDV) and endsystolic volume (RVESV) were measured by RT-3DE and cardiac magnetic resonance and RV ejection fraction (RVEF) was calculated.Results A positive correlation was found between RVFAC and RVEF (r =0.595,P =0.003),there was a negative correlation between RIMP and RVEF (r =-0.745,P =0.000),has no correlation between TAPSE and RVEF (r =-0.029,P =0.896),a positive correlation was found between S' and RVEF (r =0.489,P =0.018).There were close correlation between RVEDV,RVESV and RVEF measured by RT-3DE and MRI (P <0.001,respectively);Bland-Altman analyses showed good agreement between them.Conclusions RT-3DE can noninvasive,accurate assessment right ventricular systolic function in patients with PH,and provide prognosis and treatment choice for clinical demands.
9.Clinical and echocardiographic features of left ventricular diverticulum in adults: a report of 4 cases
Lingyun KONG ; Yidan LI ; Yafeng WU ; Xiuzhang LYV
Chinese Journal of General Practitioners 2015;14(11):862-865
To explore the clinical and imaging profiles of left ventricular (LV) diverticulum in adults and review the key points for its differential diagnosis.The clinical and imaging features were reviewed for 2 female and 2 male patients clinically diagnosed with LV diverticulum.Their clinical manifestations and electrocardio graphic presentations were nonspecific.On echocardiography,all diverticula,located at LV apex,had a thinned and weakened wall continuing and contracting synchronously with the adjacent LV wall.Two cases were diagnosed as congenital diverticulum without any other cardiac or thoraco-abdominal anomaly.And the other two had existing coronary artery diseases with significantly reduced global and apical LV systolic function.Mural thrombosis in diverticulum was determined in one congenital case.One patient died of cardiac failue.It suggested that LV diverticulum in adults may be congenital and secondary etiologically.The former is mostly isolated and apically situated while the latter often results from regional myocardial ischemia and elevated intracavitary LV pressure at an ill-perfused area.Echocardiography can demonstrate the 2-dimensional and flow hemodynamics of diverticulum in real time so as to facilitate its diagnosis and differential diagnosis.
10.Echocardiography evaluation of pulmonary hypertension in hemodialysis patients
Wei JIANG ; Juan MENG ; Yafeng WU ; Zhongxin LI ; Qianmei SUN
Chinese Journal of Medical Imaging Technology 2010;26(2):285-287
Objective To investigate the incidence and the relation between pulmonary hypertension (PH) and cardiac output in hemodialysis (HD) patients with PH. Methods The incidence of PH was estimated with Doppler echocardiography in 78 patients receiving HD. Left ventricular ejection fraction, cardiac volume, cardiac output and cardiac index were compared between patients with or without PH. Results PH was found in 20 patients (25.64%), among them15 had mild PH, 4 had moderate PH and 1 had severe PH. There was no statistical difference of ejection fraction, cardiac volume, cardiac output and cardiac index between the two groups. PH was not related to cardiac output. Conclusion HD can lead to PH, but cardiac output can not result in PH. Further investigations about the effect of elevated cardiac output induced by internal arteriovenous fistula and other factors on PH are needed.