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.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.
3.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.
4.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
5.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.
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.Value of left ventricular contrast echocardiography in diagnosis of left ventricular myocardium noncompaction
Xiaowei LIU ; Yafeng WU ; Yidan LI ; Lanlan SUN ; Wei JIANG
Chinese Journal of Ultrasonography 2011;20(3):201-204
Objective To assess the usefulness of left ventricular contrast echocardiography in diagnosis of left ventricular myocardium noncompaction.Methods Contrast echocardiography was done in ten patients who were diagnosed or suspected with left ventricular noncompaction by common transthoracic echocardiography,for further study of the trabecular muscles extent,the continuity of the endocardium,the compact myocardium thickness,and the contrast agent in the trabecula recessus.Results By contrast echocardiography,noncompaction myocardium thickness can be perspicuously observed,the turgor of the contrast agent was vividly detected in the trabecular recessus.Especially for the measurement of compaction myocardium,the contrast echocardiography was more accurate than in the condition of the common echocardiography.Conclusions Left ventricular contrast echocardiography can be used in the diagnosis of left ventricular noncompaction,it was a good added method of conventional echocardiography.
8.Assessing longitudinal wall motion characteristics at different phases in regional myocardial in patients with myocardial infarction by quantitative tissue velocity imaging
Juan ZHANG ; Xinchun YANG ; Dingyin ZENG ; Yafeng WU
Chinese Journal of Tissue Engineering Research 2005;9(43):164-166
BACKGROUND: At present, Doppler tissue imaging can be used extensively to make a quantitative assessment of left ventricular regional myocardial function. Postsystolic shortening is a delayed relaxation in regional myocardium following acute ischemia.OBJECTIVE: To observe longitudinal wall motion characteristics in left ventricular regional myocardiun and evaluate the clinical significance of postsystolic shortening in isovolumic relaxation period.DESIGN: Case-control observation.SETTING: Heart Center of Beijing Chaoyang Hospital.PARTICIPANTS: We selected 30 myocardial infarction inpatients hospitalized in the Heart Center of Beijing Chaoyang Hospital between April 2003 and September 2003 as myocardial infarction group; another 30 patients with non-cardiac diseases were set as control group. Subjects of the two groups volunteered in the experiment.METHODS: 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 mid- segments of different walls. Peak velocity of isovolumic contraction period (VIC), ejection period (Ye), isovolumie relaxation period (VIR), rapid filling period (VRF) and atrial systole (VAS) and maximum time velocity integral (TVIMAX) in regional myocardium were measured.Doppler in different segments at longitudinal wall of myocardium in the the two groups.RESULTS: Thirty patients were recruited in myocardial infarction group and control group separately and all of them entered the result analysis ocardium was lower in myocardial infarction group than in control group,especially in infarcted segments, suggesting that the function of cardiac contraction and relaxation in patients with myocardial infarction was demyocardial isovolumic relaxation in myocardial infarction group, indicating period and isovolumic relaxation period in TVIMAX in myocardial infarction group.mal movement at isovolumic relaxation phase suggests the presence of postsystolic shortening and abnormal wall motion in regional myocardium.chemic myocardium.
9.Diagnostic value of echocardiography combined with lower-limb venous ultrasonography in pulmonary thromboembolism
Yafeng WU ; Ling ZHU ; Zhenguo ZHAI ; Yuanhua YANG ; Chen WANG
Chinese Journal of Ultrasonography 2008;17(11):948-951
Objective To evaluate the diagnostic value of deep venous thrombosis(DVT)on lowerlimb venous ultrasonography combined with right ventricular dysfunction (RVD) on transthoracic echocardiography(TTE) in patients with acute pulmonary thrombo embolism(PTE). Methods This prospective multicenter control trial included 520 patients with confirmed acute PTE from 41 hospitals between June 2002 and February 2005.Results The incidence of RVD and DVT was associated with the severity of PTE.There were 57.0%(207/363)patients with RVD,49.6%(1 80/363)patients with DVT,265(73.0%)patients with RVD and/or DVT,and 121(33.3%)patients with combined sign of DVT plus RVD in the whole population.As to major PTE population,206(99.5%)patients had RVD and 121 (58.5%)patients had DVT.In addition,the rate of RVD was much greater in proximal PTE than in lobar PTE and segmental PTE(78.7%,51.4%and 21.7%,respectively,P<0.001).DVT occurred more frequently in proximal PTE than in lobar PTE and segmental PTE(61.7%,46.8%and 37.0%,respectively,P<O.001).The incidence of the combined sign was 51.1%,24.3%and 8.7%,respenctively (P<0.001).Conclusions The incidence of the combined sign of RVD plus DVT was associated with the severity of PTE and the localization of emboli.The combined sign of RVD plus DVT help diagnose major PTE especially in emergency department.
10.Detection of pulmonary vascular by transesophageal echocardiography during lung transplantation
Yafeng WU ; Shengcai HOU ; Yidan LI ; Hui LI
Chinese Journal of Ultrasonography 2010;19(6):465-467
Objective To detect the new views for pulmonary vascular by transesophageal echocardiography(TEE) during lung transplantation.Methods Seventeen cases with respiratory failure underwent lung transplantation.A series of scans were detected by TEE during preoperative anesthesia, preand pro-pulmonary vascular occlusion and pro-donor lung, and bronchus, pulmonary veins, pulmonary artery anastomoses.Left and right lung veins open and left and right pulmonary artery branch were key to observed.Pulmonary artery trunk and branch diameter, velocity of blood flow were measured.Results All left and right pulmonary artery,pulmonary vein images were given by TEE.TEE detected the normal blood flow velocity of pulmonary artery branches during pre-operation,average of 65 cm/s.After clipping the side of the pulmonary artery, the lateral pulmonary blood flow disappeared.TEE detected pulmonary veins,pulmonary artery anastomoses pro-operation.Except for 1 case of anastomotic pulmonary vein flow velocity increased,all the pulmonary vein and pulmonary artery branch anastomoses flow velocity increased slightly faster than those before transplantation (mean pulmonary artery branch of 160 cm/s, the average pulmonary vein 149 cm/s).Conclusions TEE can monitor diameter and flow velocity of pulmonary artery branch and pulmonary vein during lung transplantation,and can detect the rightventricular function.The views of left and right branch pulmonary artery and pulmonary vein branches play an important role during lung transplantation.