This paper analyzes the dynamic characteristics of the variations of the beach volumes for three level zonesof the Yanjing Beach in the Shuidong Bay of the western Guangdong Province by using the methods of dynamic sy...This paper analyzes the dynamic characteristics of the variations of the beach volumes for three level zonesof the Yanjing Beach in the Shuidong Bay of the western Guangdong Province by using the methods of dynamic systemanalysis and the multi-dimensional spectral estimation. The results show that the variations of the beach volume arecharaCterized by the multiband oscillations with a dominant semimonth period. Upwards the low tide level, the beachtends to be stable. The estimates of the partial coherences and the partial phases indicate that the variations of thebeach volumes are mainly the results of the direct actions of the waves which are influenced by the tidal level changesand driven by the wind stress. The simulation results of the beach volume series for different beach heart zones bythreshold mixed regressive models indicate that the influence of the tide on the variations of the beach volumes is weakened and the direct actions of the wave energy and the wind stress are apparently enhanced with the increase of thebeach height.(This project was supported by the National Natural Science Foundation of China.)展开更多
Objective: SVV is derived from the cardiopulmonary interaction, which is used to predict the responsiveness of cardiac preload guiding fluid therapy in patients under general anesthesia in non-opened chest surgery. Fr...Objective: SVV is derived from the cardiopulmonary interaction, which is used to predict the responsiveness of cardiac preload guiding fluid therapy in patients under general anesthesia in non-opened chest surgery. From a clinical point of view, it is important to know how well SVV reflects preload and fluid responsiveness during cardiac surgery. This study was undertaken to assess the accuracy and reliability of SVV derived from the FloTrac/Vigileo system in monitoring changes in blood volume in patients undergoing off-pump coronary artery bypass grafting (OPCABG) under general anesthesia. Methods: After approval from the ethics committee and obtaining the permission of the patients, twenty-nine patients, ASA II-III and NYHA II-III, aged 44-7 yr, undergoing elective off-pump coronary artery bypass grafting, were randomly divided into 2 groups: the control group (group C, n = 8) and volume expansion group (group V, n = 21). After patients entered the operating room, veins were put in line, ECG, HR, SpO2, and PETCO2 were continuously monitored. Left radial arterial and right internal jugular vein catheters were inserted under local anesthesia. The FloTracTM/VigileoTM system was connected and MAP, CO, CI, SVV, SV, SVI, SVR, SVRI, CVP were continuously monitored. BIS values were kept at 45%-55.6% hydroxyethyl starch 130/0.4 sodium chloride solution 7 ml/kg was intravenously infused after completion of sternotomy and pericardiotomy at a rate of 0.25 ml/kg–1/min–1 in group V. MAP, HR, CVP, systemic vascular resistance (SVR), SVV, and stroke volume index (SVI) were determined 10 min before (T1) and after the infusion of finished (T2), and the change rate (ΔHR, ΔMAP, ΔCVP, ΔSVR, ΔSVV, ΔSVI) was calculated. Sodium chloride injection 3 ml/kg was infused in group C. Results: CVP, SVI, CO and CI were increased after volume expansion, SVRI and SVV significantly decreased in group V(P < 0.01), while MAP and HR were not changed. Changes in HR(r = –0.737, P and SVR(r = –0.480, P were significantly correlated to ch展开更多
文摘This paper analyzes the dynamic characteristics of the variations of the beach volumes for three level zonesof the Yanjing Beach in the Shuidong Bay of the western Guangdong Province by using the methods of dynamic systemanalysis and the multi-dimensional spectral estimation. The results show that the variations of the beach volume arecharaCterized by the multiband oscillations with a dominant semimonth period. Upwards the low tide level, the beachtends to be stable. The estimates of the partial coherences and the partial phases indicate that the variations of thebeach volumes are mainly the results of the direct actions of the waves which are influenced by the tidal level changesand driven by the wind stress. The simulation results of the beach volume series for different beach heart zones bythreshold mixed regressive models indicate that the influence of the tide on the variations of the beach volumes is weakened and the direct actions of the wave energy and the wind stress are apparently enhanced with the increase of thebeach height.(This project was supported by the National Natural Science Foundation of China.)
文摘Objective: SVV is derived from the cardiopulmonary interaction, which is used to predict the responsiveness of cardiac preload guiding fluid therapy in patients under general anesthesia in non-opened chest surgery. From a clinical point of view, it is important to know how well SVV reflects preload and fluid responsiveness during cardiac surgery. This study was undertaken to assess the accuracy and reliability of SVV derived from the FloTrac/Vigileo system in monitoring changes in blood volume in patients undergoing off-pump coronary artery bypass grafting (OPCABG) under general anesthesia. Methods: After approval from the ethics committee and obtaining the permission of the patients, twenty-nine patients, ASA II-III and NYHA II-III, aged 44-7 yr, undergoing elective off-pump coronary artery bypass grafting, were randomly divided into 2 groups: the control group (group C, n = 8) and volume expansion group (group V, n = 21). After patients entered the operating room, veins were put in line, ECG, HR, SpO2, and PETCO2 were continuously monitored. Left radial arterial and right internal jugular vein catheters were inserted under local anesthesia. The FloTracTM/VigileoTM system was connected and MAP, CO, CI, SVV, SV, SVI, SVR, SVRI, CVP were continuously monitored. BIS values were kept at 45%-55.6% hydroxyethyl starch 130/0.4 sodium chloride solution 7 ml/kg was intravenously infused after completion of sternotomy and pericardiotomy at a rate of 0.25 ml/kg–1/min–1 in group V. MAP, HR, CVP, systemic vascular resistance (SVR), SVV, and stroke volume index (SVI) were determined 10 min before (T1) and after the infusion of finished (T2), and the change rate (ΔHR, ΔMAP, ΔCVP, ΔSVR, ΔSVV, ΔSVI) was calculated. Sodium chloride injection 3 ml/kg was infused in group C. Results: CVP, SVI, CO and CI were increased after volume expansion, SVRI and SVV significantly decreased in group V(P < 0.01), while MAP and HR were not changed. Changes in HR(r = –0.737, P and SVR(r = –0.480, P were significantly correlated to ch
