Objective To evaluate the left ventricular (LV) systolic dyssynchrony after the acute myocardial infarction (AMI) with two-dimensional speckle tracking echocardiography (STE). Methods STE were performed in 65 patients within 72 h of AMI and compared with 60 age- and sex-matched healthy volunteers. The peak longitudinal strain (LS_(peak)) was measured at LV myocardium. LV dyssynchrony was defined as an interval ≥130 ms for the absolute difference in time to peak radial strain for the anteroseptal wall versus the posterior wall (TAS-POST). Size of myocardial infarction (MIS)was confirmed by wall-motion score index (WMSI). Results The LS_(peak) and LV ejection fraction (LVEF) were lower, and WMSI and TAS-POST were larger in AMI patients compared with controls. Forty-two patients had developed LV dyssynchrony (64.62%), and there were strong correlation between LV dyssynchrony (TAS-POST) and LS_(peak), LVEF, and WMSI (MIS). MIS was the most independent predictor for systolic dyssynchrony. Conclusion AMI with normal QRS can induce LV dyssynchrony, which is mainly determined by MIS. STE is a reliable technique for accurate evaluation of LV synchrony.

Objective To explore the variation of E-index and M-index of rabbits with acute pulmonary embolism (APE) under the status of pulmonary hypertension (PHT). Methods Rabbit models of APE with PHT were established. A series of parameters [including peak early diastolic mitral inflow velocity (EM), peak late diastolic mitral inflow velocity (AM) and so on] were obtained with routine echocardiography and tissue Doppler imaging (TDI);and then E-index, M-index were calculated. The parameters before and after APE were compared. Results Twenty-three rabbit models with APE were successfully established, but 3 with atrial fibrillation were excluded. After APE, pulmonary artery pressure increased significantly, EM decreased observably, whereas right ventricular myocardial performance index (RVMPI) increased more evidently than left ventricular myocardial performance index (LVMPI) (P<0.01) did and E-index decreased and M-index increased remarkably. Conclusion Changes of E-index and M-index may provide reference for quantitative assessment of early APE.

Objective To assess the value of two-dimensional speckle tracking echocardiography (2D-STE) of predicting the acute response to cardiac resynchronization therapy (CRT) in patients with congestive heart failure. Methods Twenty-four patients with congestive heart failure scheduled for CRT were included. 2D-STE was performed within 7 days of implantation with device ON and OFF. Left ventricular (LV) dyssynchrony was defined as an interval ≥130 ms for the absolute difference in time to peak radial strain for the anteroseptal wall versus the posterior wall (T_(AS-POST)) with 2D-STE. Acute hemodynamic response was measured as LVdp/dt, and percentage change in LVdp/dt was used to classify responders (Δdp/dt%＞25%) and nonresponders (Δdp/dt%≤25%). Results Fifteen patients (62.50%) were classified as acute responders. Compared with nonresponders, the responders demonstrated significant increase of LV ejection fraction and reduction of TAS-POST after CRT-ON. T_(AS-POST)was the only determinants of Δdp/dt%＞25%. T_(AS-POST)≥130 ms prognosticated acute response to CRT with sensitivity of 86.24% and specificity of 70.38%. Conclusion CRT can immediately increase the LV systolic function and synchrony. 2D-STE is highly predictive for acute response to CRT.

Objective To evaluate large field diffusion-weighted imaging (DWI) in detection of bone metastases of malignant tumors. Methods Eighteen patients with various malignant tumors were enrolled in this study. All the patients underwent large field DWI and 99mTc-MDP bone scintigraphy within one month. Results Fifteen of 18 patients were diagnosed as bone metastases with conventional MRI; 7 of them were found more than 10 bone metastases, and 23 bone metastases were confirmed in the other 8 patients. When seven patients with multiple bone metastases (>10) were excluded, and lesions in the residual 11 patients with or without bone metastases were counted, the diagnostic sensitivity of bone metastases with large field DWI and bone scintigraphy was both 100%, and specificity were 100% and 33.33%, respectively. ROC study showed the area under curve (AUC) of large field DWI and bone scintigraphy were 1.00 and 0.67, respectively (P=0.04). With lesion numbers as study unit, the diagnostic sensitivity of large field DWI and bone scintigraphy were 86.96% and 78.26%, and the specificity was both 60.00%. ROC study showed the AUC of large field DWI and bone scintigraphy was 0.74, 0.69, respectively; and no statistical difference was found. Conclusion Large field DWI can be used in screening the bone metastases of malignant tumors.

Oceanic carbon monoxide(CO) has been of biogeochemical interest due to its significant role in global carbon cycle and the greenhouse effect. A headspace method coupled with ta3000 trace gas analyzer system for the determination of CO in seawater was developed. The effects of temperature, equilibrium time and water/gas volume ratio on the sensitivity of headspace analysis were studied in detail. The results showed that CO concentrations in seawater were measured successfully by the 50-mL glass-only syringes with a water/gas volume ratio of 44∶ 6 and an equilibrium time of 5 min at 20 ℃ room temperature. Under the optimized conditions, the linear range of concentrations of CO was 0-2.7×10~(-6), r=0.999,p<0.0001. The relative standard deviation of the analysis method was <4.4%, with a detection limit of 0.02 nmol/L. The average recovery of CO was 90.5%. The concentrations of CO in surface waters of the North Yellow Sea were measured using this method and ranged from 0.20 nmol/L to 3.13 nmol/L, indicating that this method can be successfully applied to the detection of the in situ CO concentrations in seawater.