Background QT dispersion （QTd） is a predictor of ventricular arrhythmia. Ventricular arrhythmia is an important factor influencing morbidity and mortality in patients with aortic stenosis. Surgical aortic valve repl...Background QT dispersion （QTd） is a predictor of ventricular arrhythmia. Ventricular arrhythmia is an important factor influencing morbidity and mortality in patients with aortic stenosis. Surgical aortic valve replacement reduced the QTd in this patients group. However, the effect of transcatheter aortic valve implantation （TAVI） on QTd in patients with aortic stenosis is unknown. The aim of this study was to investigate the effect of TAVI on QTd in patients with aortic stenosis. Methods Patients with severe aortic stenosis, who were not candi-dates for surgical aortic valve replacement due to contraindications or high surgical risk, were included in the study. All patients underwent electrocardiographic and echocardiographic evaluation before, and at the 6th month after TAVI, computed QTd and left ventricular mass index （LVMI）. Results A total 30 patients were admitted to the study （mean age 83.2 ± 1.0 years, female 21 and male 9, mean valve area 0.7 ± 3 mm2）. Edwards SAPIEN heart valves, 23 mm （21 patients） and 26 mm （9 patients）, by the transfemoral approach were used in the TAVI procedures. All TAVI procedures were successful. Both QTd and LVMI at the 6th month after TAVI were significantly reduced com-pared with baseline values of QTd and LVMI before TAVI （73.8 ± 4 ms vs. 68 ± 2 ms, P=0.001 and 198 ± 51 g/m2 vs. 184 ± 40 g/m2, P=0.04, respectively）. There was a significant correlation between QTd and LVMI （r=0.646, P〈0.001）. Conclusions QTd, which malign ventricular arrhythmia marker, and LVMI were significantly reduced after TAVI procedure. TAVI may decrease the possibility of ventricu-lar arrhythmia in patients with aortic stenosis.展开更多
An 82-year-old female patient undergoing cardiogenic shock caused by atrioventficular junctional rhythm immediately after percutaneous coronary intervention （PCI） is described. Pharmacotherapy was invalid, and subse...An 82-year-old female patient undergoing cardiogenic shock caused by atrioventficular junctional rhythm immediately after percutaneous coronary intervention （PCI） is described. Pharmacotherapy was invalid, and subsequent application of atrial pacing reversed the cardiogenic shock. PCI-related injury of sinuatrial nodal artery leading to acute atrial contractility loss, accompanied by atrioventricular junctional arrhythmia, was diagnosed. We recommend that preoperative risk evaluation be required for multi-risk patients. Likewise, emergent measures should to be established in advance. This case reminds us that atrial pacing can be an optimal management technique once cardiogenic shock has occurred.展开更多
Coronary artery anomalies （CAAs） may be discovered more often as incidental findings during the normal diagnostic process for other cardiac diseases or less frequently on the basis of manifestations of myocardial is...Coronary artery anomalies （CAAs） may be discovered more often as incidental findings during the normal diagnostic process for other cardiac diseases or less frequently on the basis of manifestations of myocardial ischemia. The cardiovascular professional may be involved in their angiographic diagnosis, fimctional assessment and eventual endovascular treatment. A complete angiographic definition is mandatory in order to understand the functional effects and plan any intervention in CAAs： computed tomography and magnetic resonance imaging are useful non-invasive tools to detect three-dimensional morphology of the anomalies and its relationships with contiguous cardiac structures, whereas coronary arteriography remains the gold standard for a definitive anatomic picture. A practical idea of the possible functional sig- nificance is mandatory for deciding how to manage CAAs： non-invasive stress tests and in particular the invasive pharmacological stress tests with or without intravascular ultrasound monitoring can assess correctly the functional significance of the most CAAs. Finally, the knowledge of the particular endovascular techniques and material is of paramount importance for achieving technical and clinical success. CAAs represent a complex issue, which rarely involve the cardiovascular professional at different levels. A timely practical knowledge of the main issues regarding CAAs is important in the management of such entities.展开更多
Because currently intrusion detection systems cannot detect undefined intrusion behavior effectively, according to the robustness and adaptability of the genetic algorithms, this paper integrates the genetic algorithm...Because currently intrusion detection systems cannot detect undefined intrusion behavior effectively, according to the robustness and adaptability of the genetic algorithms, this paper integrates the genetic algorithms into an intrusion detection system, and a detection algorithm based on network traffic is proposed. This algorithm is a real-time and self-study algorithm and can detect undefined intrusion behaviors effectively.展开更多
We studied the driving force of the Kuroshio intrusion into the South China Sea （SCS） during the winter monsoon, using satellite-tracked drifters entering the Luzon Strait （LS） through the Balintany and Babuyan Ch...We studied the driving force of the Kuroshio intrusion into the South China Sea （SCS） during the winter monsoon, using satellite-tracked drifters entering the Luzon Strait （LS） through the Balintany and Babuyan Channels from the Philippine Sea. Most drifters passing through the Babuyan Channel in winter entered the interior SCS without a significant change in velocity. However, half of the drifters passing through the Balintany Channel entered the SCS at -30 cn/s, which was faster than when they entered the LS. The other half continued moving northwestward into the Kuroshio and returned to the North Pacific. Quantitative analyses, using surface climatological wind and sea surface height anomaly （SSHa） data explained both the difference in velocity of drifters between the two channels and their acceleration through the Balintany Channel. The results suggest that the positive meridional gradient of sea surface height in the Luzon Strait, caused by the pileup of seawater driven by the Northeast monsoon, as well as Ekman flow, contribute to the Kuroshio intrusion into the SCS through the Babuyan and Balintany Channels. The former may be the main driving force.展开更多
B^0(B+s)→γvv decays are useful to determining the decay constants f_B(f_B_s) and B(B_s) meson wavefunction.Using the B meson wave function determined in hadronic B(Bs) decays,we study the uncertainties due tothe typ...B^0(B+s)→γvv decays are useful to determining the decay constants f_B(f_B_s) and B(B_s) meson wavefunction.Using the B meson wave function determined in hadronic B(Bs) decays,we study the uncertainties due tothe types of B meson wave functions.We find that the branching ratios are sensitive to the type of wave functions andinput parameters,but the energy spectrum is independent.The predicted branching ratios are (0.45-1.04) ×10^(-9) and(2.14-3.27) × 10^(-8) for B^0 and B_s decay,respectively.展开更多
Ostial lesions present many challenges for percutaneous coronary intervention （PCI）. Coronary anomaly will further increase difficulties in performing PCI for the patient. We present such a case as ostial occlusion ...Ostial lesions present many challenges for percutaneous coronary intervention （PCI）. Coronary anomaly will further increase difficulties in performing PCI for the patient. We present such a case as ostial occlusion of an right coronary artery with high takeoff. A 77-year-old male was referred to our institution with a diagnosis of non-ST elevated acute myocardial infarction. Selective coronary angiography and nonselective ascending aortography could not identify the origin of the right coronary artery. Multi-slices computed tomography showed RCA ostial totally occluded. A successful PCI was performed and a perfect final result was achieved utilized with many tips and tricks, including buddy wtre technique and focused-force angloplasty（J Genatr Cardio12009, 6：189-192）.展开更多
This paper investigates adaptive blind source separation and equalization for Multiple Input Multiple Output (MIMO) systems. To effectively recover input signals, remove Inter-Symbol Interference (ISI) and suppress In...This paper investigates adaptive blind source separation and equalization for Multiple Input Multiple Output (MIMO) systems. To effectively recover input signals, remove Inter-Symbol Interference (ISI) and suppress Inter-User Interference (IUI), the array input is first transformed into the signal subspace, then with the derived orthogonality between weight vectors of different input signals, a new orthogonal Constant Modulus Algorithm (CMA) is proposed. Computer simulation results illustrate the promising performance of the proposed method. Without channel identification, the proposed method can recover all the system inputs simultaneously and can be adaptive to channel changes without prior knowledge about signals.展开更多
A set of general expressions for photoionization cross sections of atoms or molecules embedded in a medium and a dielectric influence function are derived based on Maxwell＇s equations and the Beer-Lambert＇s law in t...A set of general expressions for photoionization cross sections of atoms or molecules embedded in a medium and a dielectric influence function are derived based on Maxwell＇s equations and the Beer-Lambert＇s law in this work. The applications are performed for the photoionization process of solid gold both in the Clausius-Mossotti （virtual cavity） model and the Glauber-Lewenstein （real cavity） model firstly. The results show that the present theoretical expressions of photoionization cross section can be used to describe the photoionization process of atoms in condensed matter properly.展开更多
The a＋^2＋ Ne elastic scattering angular distributions at lower incident energies of Eα= 12.7-31.1 Me V have been analyzed by using the a-folding potential based on the α＋^16O structure model of the ^20Ne nucleus....The a＋^2＋ Ne elastic scattering angular distributions at lower incident energies of Eα= 12.7-31.1 Me V have been analyzed by using the a-folding potential based on the α＋^16O structure model of the ^20Ne nucleus. The a-folding potential with a standard Woods-Saxon type imaginary part, can reasonably describe experimental cross sections and the anomalous large angle scattering （ALAS） features. The anomaly of the a＋^20Ne scattering system is further confirmed , in the lower incident energy region.展开更多
Observations indicate an abnormal characteristic of saltwater intrusion in the upper Modaomen Waterway of the Pearl River Estuary,i.e.,the maximum salinity occurs during the neap tide or the coming moderate tide inste...Observations indicate an abnormal characteristic of saltwater intrusion in the upper Modaomen Waterway of the Pearl River Estuary,i.e.,the maximum salinity occurs during the neap tide or the coming moderate tide instead of during the spring tide.To explore the associated dynamic mechanisms,a high resolution three-dimensional numerical model was set up based on the Finite Volume Coastal Ocean Model(FVCOM),which covered the entire river network,the Pearl River Estuary,and the adjacent sea.Numerical experiments illustrated that the upper Modaomen Waterway is significantly influenced by the saltwater intrusion from the Hongwan Waterway,a narrow and shallow channel connecting the Modaomen Waterway to the sea.Specific topography,spring-neap tidal variation,local wind stress,and their interaction drive an up-estuary residual current in the Hongwan Waterway,which is much stronger during the neap tide than during the spring tide.As a result,more saltwater in the Hongwan Waterway is spilled over into the Modaomen Waterway during the neap tide or the coming moderate tide.This is the inherent dynamic mechanism why the saltwater intrusion in the upper Modaomen Waterway reaches its maximum during the neap tide or the coming moderate tide.Besides,we also found that the winter prevailing wind can pronouncedly enhance the saltwater intrusion in the Modaomen Waterway.展开更多
In this study,we have formulated the phase description of the neuronal oscillator with non-instantaneous synaptic inputs and external periodic stimulus by using the phase sensitivity function.By numerical simulation,w...In this study,we have formulated the phase description of the neuronal oscillator with non-instantaneous synaptic inputs and external periodic stimulus by using the phase sensitivity function.By numerical simulation,we have found that the phase of a neuronal oscillator undergoes periodic evolution or locked state,which is determined by the synaptic time constant.The synaptic time constant is also an important condition under which the global network is synchronized.When the synaptic time constant is relatively small,perfectly synchronized behavior quickly occurs in the neuronal population.As the synaptic time constant becomes slightly larger,periodic synchronization emerges in the neuronal population.However,synchronized activity in the neuronal population is lost for larger synaptic time constant.The external periodic stimulus can change the synchronization patterns in the neuronal population.With a weak low-frequency stimulus,the neuronal populations quick synchronized bursting;whereas a high-frequency stimulus can produce synchronized overlapping bursting.We have also found that neuronal oscillators with type-II phase response curves are more susceptible to synchronization than those with type-I phase response curves.展开更多
It has been found in our past studies that the installation of asymmetric plate at the inlet of inducer is effective for the suppression of cavitation surge phenomenon.In the present study,the suction performance of 2...It has been found in our past studies that the installation of asymmetric plate at the inlet of inducer is effective for the suppression of cavitation surge phenomenon.In the present study,the suction performance of 2-bladed helical inducer with an inlet asymmetric plate is experimentally investigated.It is observed that the suction performance in large flow rate conditions is not significantly influenced by the asymmetric plate,whereas the head of inducer with the asymmetric plate increases just before the head breakdown in partial flow conditions.To understand the mechanism of this additional head,the flow measurements and the numerical simulations are carried out.It is found that the circumferential component of absolute velocity at the exit of inducer slightly increases with the development of cavitation in both cases with and without the inlet asymmetric plate,indicating the increase of the theoretical head.The theoretical head increase with the inlet asymmetric plate is also confirmed by the unsteady numerical simulations,suggesting that the additional head is achieved through the increase of the theoretical head with the change of the exiting flow from the inducer associated with some amount of cavitation.展开更多
文摘Background QT dispersion （QTd） is a predictor of ventricular arrhythmia. Ventricular arrhythmia is an important factor influencing morbidity and mortality in patients with aortic stenosis. Surgical aortic valve replacement reduced the QTd in this patients group. However, the effect of transcatheter aortic valve implantation （TAVI） on QTd in patients with aortic stenosis is unknown. The aim of this study was to investigate the effect of TAVI on QTd in patients with aortic stenosis. Methods Patients with severe aortic stenosis, who were not candi-dates for surgical aortic valve replacement due to contraindications or high surgical risk, were included in the study. All patients underwent electrocardiographic and echocardiographic evaluation before, and at the 6th month after TAVI, computed QTd and left ventricular mass index （LVMI）. Results A total 30 patients were admitted to the study （mean age 83.2 ± 1.0 years, female 21 and male 9, mean valve area 0.7 ± 3 mm2）. Edwards SAPIEN heart valves, 23 mm （21 patients） and 26 mm （9 patients）, by the transfemoral approach were used in the TAVI procedures. All TAVI procedures were successful. Both QTd and LVMI at the 6th month after TAVI were significantly reduced com-pared with baseline values of QTd and LVMI before TAVI （73.8 ± 4 ms vs. 68 ± 2 ms, P=0.001 and 198 ± 51 g/m2 vs. 184 ± 40 g/m2, P=0.04, respectively）. There was a significant correlation between QTd and LVMI （r=0.646, P〈0.001）. Conclusions QTd, which malign ventricular arrhythmia marker, and LVMI were significantly reduced after TAVI procedure. TAVI may decrease the possibility of ventricu-lar arrhythmia in patients with aortic stenosis.
文摘An 82-year-old female patient undergoing cardiogenic shock caused by atrioventficular junctional rhythm immediately after percutaneous coronary intervention （PCI） is described. Pharmacotherapy was invalid, and subsequent application of atrial pacing reversed the cardiogenic shock. PCI-related injury of sinuatrial nodal artery leading to acute atrial contractility loss, accompanied by atrioventricular junctional arrhythmia, was diagnosed. We recommend that preoperative risk evaluation be required for multi-risk patients. Likewise, emergent measures should to be established in advance. This case reminds us that atrial pacing can be an optimal management technique once cardiogenic shock has occurred.
文摘Coronary artery anomalies （CAAs） may be discovered more often as incidental findings during the normal diagnostic process for other cardiac diseases or less frequently on the basis of manifestations of myocardial ischemia. The cardiovascular professional may be involved in their angiographic diagnosis, fimctional assessment and eventual endovascular treatment. A complete angiographic definition is mandatory in order to understand the functional effects and plan any intervention in CAAs： computed tomography and magnetic resonance imaging are useful non-invasive tools to detect three-dimensional morphology of the anomalies and its relationships with contiguous cardiac structures, whereas coronary arteriography remains the gold standard for a definitive anatomic picture. A practical idea of the possible functional sig- nificance is mandatory for deciding how to manage CAAs： non-invasive stress tests and in particular the invasive pharmacological stress tests with or without intravascular ultrasound monitoring can assess correctly the functional significance of the most CAAs. Finally, the knowledge of the particular endovascular techniques and material is of paramount importance for achieving technical and clinical success. CAAs represent a complex issue, which rarely involve the cardiovascular professional at different levels. A timely practical knowledge of the main issues regarding CAAs is important in the management of such entities.
文摘Because currently intrusion detection systems cannot detect undefined intrusion behavior effectively, according to the robustness and adaptability of the genetic algorithms, this paper integrates the genetic algorithms into an intrusion detection system, and a detection algorithm based on network traffic is proposed. This algorithm is a real-time and self-study algorithm and can detect undefined intrusion behaviors effectively.
基金Supported by the National Basic Research Program of China (973 Program) (Nos. 2007CB816002, 2005CB422303)the National Natural Science Foundation of China (Nos. 40776018, 41176029)
文摘We studied the driving force of the Kuroshio intrusion into the South China Sea （SCS） during the winter monsoon, using satellite-tracked drifters entering the Luzon Strait （LS） through the Balintany and Babuyan Channels from the Philippine Sea. Most drifters passing through the Babuyan Channel in winter entered the interior SCS without a significant change in velocity. However, half of the drifters passing through the Balintany Channel entered the SCS at -30 cn/s, which was faster than when they entered the LS. The other half continued moving northwestward into the Kuroshio and returned to the North Pacific. Quantitative analyses, using surface climatological wind and sea surface height anomaly （SSHa） data explained both the difference in velocity of drifters between the two channels and their acceleration through the Balintany Channel. The results suggest that the positive meridional gradient of sea surface height in the Luzon Strait, caused by the pileup of seawater driven by the Northeast monsoon, as well as Ekman flow, contribute to the Kuroshio intrusion into the SCS through the Babuyan and Balintany Channels. The former may be the main driving force.
基金Supported by the National Natural Science Foundation of China (30170394) the Special Fund for Promotion of Education Ministry of Science P.R.C (985) and "973"Foundation of China (001cb51010201).
基金Supported by National Science Foundation of Hebei Province of China under Grant No.A2008000421the Natural Science Foundation of Zhejiang Province of China under Grant No.Y606252the Scientific Research Fund of Zhejiang Provincial Education Department of China under Grant No.20051357
文摘B^0(B+s)→γvv decays are useful to determining the decay constants f_B(f_B_s) and B(B_s) meson wavefunction.Using the B meson wave function determined in hadronic B(Bs) decays,we study the uncertainties due tothe types of B meson wave functions.We find that the branching ratios are sensitive to the type of wave functions andinput parameters,but the energy spectrum is independent.The predicted branching ratios are (0.45-1.04) ×10^(-9) and(2.14-3.27) × 10^(-8) for B^0 and B_s decay,respectively.
文摘Ostial lesions present many challenges for percutaneous coronary intervention （PCI）. Coronary anomaly will further increase difficulties in performing PCI for the patient. We present such a case as ostial occlusion of an right coronary artery with high takeoff. A 77-year-old male was referred to our institution with a diagnosis of non-ST elevated acute myocardial infarction. Selective coronary angiography and nonselective ascending aortography could not identify the origin of the right coronary artery. Multi-slices computed tomography showed RCA ostial totally occluded. A successful PCI was performed and a perfect final result was achieved utilized with many tips and tricks, including buddy wtre technique and focused-force angloplasty（J Genatr Cardio12009, 6：189-192）.
文摘This paper investigates adaptive blind source separation and equalization for Multiple Input Multiple Output (MIMO) systems. To effectively recover input signals, remove Inter-Symbol Interference (ISI) and suppress Inter-User Interference (IUI), the array input is first transformed into the signal subspace, then with the derived orthogonality between weight vectors of different input signals, a new orthogonal Constant Modulus Algorithm (CMA) is proposed. Computer simulation results illustrate the promising performance of the proposed method. Without channel identification, the proposed method can recover all the system inputs simultaneously and can be adaptive to channel changes without prior knowledge about signals.
基金The project supported by the Natural Science Foundation of Yantai Normal University under Grant No. 22270301. Computational work was carried out on the supercomputer Dawning-4000A at Yantai Normal University.
文摘A set of general expressions for photoionization cross sections of atoms or molecules embedded in a medium and a dielectric influence function are derived based on Maxwell＇s equations and the Beer-Lambert＇s law in this work. The applications are performed for the photoionization process of solid gold both in the Clausius-Mossotti （virtual cavity） model and the Glauber-Lewenstein （real cavity） model firstly. The results show that the present theoretical expressions of photoionization cross section can be used to describe the photoionization process of atoms in condensed matter properly.
基金Supported by National Natural Science Foundation of China under Grant No.10865002
文摘The a＋^2＋ Ne elastic scattering angular distributions at lower incident energies of Eα= 12.7-31.1 Me V have been analyzed by using the a-folding potential based on the α＋^16O structure model of the ^20Ne nucleus. The a-folding potential with a standard Woods-Saxon type imaginary part, can reasonably describe experimental cross sections and the anomalous large angle scattering （ALAS） features. The anomaly of the a＋^20Ne scattering system is further confirmed , in the lower incident energy region.
基金supported by the "Creative Research Group" of National Natural Science Foundation of China (Grant No. 41021064)the National Basic Scientific Research Program of Global Change (Grant No.2010CB951201)Marine Special Program for Scientific Research on Public Causes (Grant No. 200705019)
文摘Observations indicate an abnormal characteristic of saltwater intrusion in the upper Modaomen Waterway of the Pearl River Estuary,i.e.,the maximum salinity occurs during the neap tide or the coming moderate tide instead of during the spring tide.To explore the associated dynamic mechanisms,a high resolution three-dimensional numerical model was set up based on the Finite Volume Coastal Ocean Model(FVCOM),which covered the entire river network,the Pearl River Estuary,and the adjacent sea.Numerical experiments illustrated that the upper Modaomen Waterway is significantly influenced by the saltwater intrusion from the Hongwan Waterway,a narrow and shallow channel connecting the Modaomen Waterway to the sea.Specific topography,spring-neap tidal variation,local wind stress,and their interaction drive an up-estuary residual current in the Hongwan Waterway,which is much stronger during the neap tide than during the spring tide.As a result,more saltwater in the Hongwan Waterway is spilled over into the Modaomen Waterway during the neap tide or the coming moderate tide.This is the inherent dynamic mechanism why the saltwater intrusion in the upper Modaomen Waterway reaches its maximum during the neap tide or the coming moderate tide.Besides,we also found that the winter prevailing wind can pronouncedly enhance the saltwater intrusion in the Modaomen Waterway.
基金supported by the National Natural Science Foundation of China(Grant Nos.1123200511172086)
文摘In this study,we have formulated the phase description of the neuronal oscillator with non-instantaneous synaptic inputs and external periodic stimulus by using the phase sensitivity function.By numerical simulation,we have found that the phase of a neuronal oscillator undergoes periodic evolution or locked state,which is determined by the synaptic time constant.The synaptic time constant is also an important condition under which the global network is synchronized.When the synaptic time constant is relatively small,perfectly synchronized behavior quickly occurs in the neuronal population.As the synaptic time constant becomes slightly larger,periodic synchronization emerges in the neuronal population.However,synchronized activity in the neuronal population is lost for larger synaptic time constant.The external periodic stimulus can change the synchronization patterns in the neuronal population.With a weak low-frequency stimulus,the neuronal populations quick synchronized bursting;whereas a high-frequency stimulus can produce synchronized overlapping bursting.We have also found that neuronal oscillators with type-II phase response curves are more susceptible to synchronization than those with type-I phase response curves.
文摘It has been found in our past studies that the installation of asymmetric plate at the inlet of inducer is effective for the suppression of cavitation surge phenomenon.In the present study,the suction performance of 2-bladed helical inducer with an inlet asymmetric plate is experimentally investigated.It is observed that the suction performance in large flow rate conditions is not significantly influenced by the asymmetric plate,whereas the head of inducer with the asymmetric plate increases just before the head breakdown in partial flow conditions.To understand the mechanism of this additional head,the flow measurements and the numerical simulations are carried out.It is found that the circumferential component of absolute velocity at the exit of inducer slightly increases with the development of cavitation in both cases with and without the inlet asymmetric plate,indicating the increase of the theoretical head.The theoretical head increase with the inlet asymmetric plate is also confirmed by the unsteady numerical simulations,suggesting that the additional head is achieved through the increase of the theoretical head with the change of the exiting flow from the inducer associated with some amount of cavitation.
