Background The factors influencing the q-wave changes in V5 and V6 during anterior acute myocardial in- farction （AMI） have not been thoroughly described. Methods We studied 70 patients with a first anterior AMI, in...Background The factors influencing the q-wave changes in V5 and V6 during anterior acute myocardial in- farction （AMI） have not been thoroughly described. Methods We studied 70 patients with a first anterior AMI, in whom the electrocardiogram （ECG） showed either disappearance of the normal septal q wave （n = 24） or presence of pathological Q wave in V5 and V6 （n = 46） during follow-up. The ECG and coronary angiography findings were correlated. Results There was no difference between the 2 groups in the culprit site proximal to S1 （46% vs. 36%, P = 0.405）, but the culprit site was more frequently located proximal to DI in the group with abnormal Q wave （21% vs. 67%, P = 0.001）. Patients with disappearance of the septal q wave more often had a large obtuse marginal branch （46 % vs. 22%, P = 0.037） and disappearance of the r wave in V1 （88% vs. 7%, P = 0.001）. Patients with abnormal Q-wave more often had a large LAD （42% vs. 71%）, small r wave or tall or wide R wave in V1 （0 % vs. 89 %, P = 0.001） and abnormal Q waves in the inferior leads （33% vs. 59%, P = 0.044）. Conclusions In patients with first anterior AMI, q wave changes in V5 and V6 correlated with the morphology in V1. Emerging abnormal Q wave in Vs/V6 predicted the culprit lesion in a large LAD proximal to D1, but disappearance of the septal q wave could not predict the culprit lesion proximal to S1.展开更多
The study of seismic attenuation property is a major subject in seismology. Seismic waves recorded by seismic stations （seismographs） contain source effect, seismic wave propagation effect, site response of seismic ...The study of seismic attenuation property is a major subject in seismology. Seismic waves recorded by seismic stations （seismographs） contain source effect, seismic wave propagation effect, site response of seismic stations and instrumental response. The path effect of seismic wave propagation, site response of seismic stations and instrumental response must be taken out in the study of source property with seismic data. The path effect of seismic wave propagation （seismic attenuation） involves an important influential factor, the anelastic attenuation of medium, which is measured with quality factor Q, apart from geometric attenuation with the distance. As a basic physical parameter of the Earth medium, Q value is essential for quantitative study of earthquakes and source property （e.g. determination of source parameters）, which is widely used in earthquake source physics and engineering seismology.展开更多
All-optical regenerators can be used to suppress amplified spontaneous emission(ASE) noise introduced by cascaded erbium doped fiber amplifiers(EDFAs) in optical fiber communication systems and lead to the improvement...All-optical regenerators can be used to suppress amplified spontaneous emission(ASE) noise introduced by cascaded erbium doped fiber amplifiers(EDFAs) in optical fiber communication systems and lead to the improvement of optical receiver sensitivity. By introducing the Q-factor transfer function(QTF), we evaluate the Q-factor performance of degenerate four-wave mixing(DFWM) regenerators with clock pump and reveal the differences between the optimal input powers determined from the static and dynamic power tranfer function(PTF) and the QTF curves. Our simulation shows that the clock-pump regnerator is capable of improving the Q-facor and receiver sensitivity for 40 Gbit/s ASE-degraded return-to-zero on-off keying(RZ-OOK) signal by 2.58 dB and 4.2 d B, respectively.展开更多
Objectives: There is a high rate of sudden death in epilepsy patients, part of which is sudden cardiac death. By investigating ECG T wave alternans and Q-T dispersion changes of epilepsy patients, we may predict the p...Objectives: There is a high rate of sudden death in epilepsy patients, part of which is sudden cardiac death. By investigating ECG T wave alternans and Q-T dispersion changes of epilepsy patients, we may predict the possibility of the occurrence of sudden death and provide basis for clinical prevention. Methods: Selecting 587 cases of epilepsy patients as the study group, 672 same period cases of healthy persons as the control group;Analyzing the effect of epilepsy on ECG T wave alternans and Q-T dispersion with the standard 12 lead ECG. Results: The study group had a significantly prolonged Q-T dispersion and an increased incidence of T wave alternans than that of the control group;Compared with other seizure types, tonic clonic seizure and absence seizure had a significantly prolonged Q-T dispersion and an increased occurrence rate of T wave alternans. Conclusions: Epilepsy patients ECG T wave alternans and Q-T dispersion has higher abnormal rate, and are prone to sudden cardiac death;Routine ECG(RECG) T wave alternans and Q-T dispersion changes can provide guidance for clinical prevention of sudden unexpected death in epilepsy (SUDEP).展开更多
Based on the waveform data of 5,076 local earthquakes recorded at 25 stations in Xinjiang during the period from 2009 to 2014 and the observation reports provided by the Xinjiang Digital Seismic Network,a data set of ...Based on the waveform data of 5,076 local earthquakes recorded at 25 stations in Xinjiang during the period from 2009 to 2014 and the observation reports provided by the Xinjiang Digital Seismic Network,a data set of 19,140 attenuation factors t*is obtained by fitting the high-frequency attenuation of S-wave spectra with a genetic algorithm. The spatial distribution of Q_S is determined by inverting the t*data with seismic tomography. The results show that the average Q0 in eastern Tianshan is 520,and there is a significant correlation between the Q_S value distribution or attenuation characteristics it disclosed and the surface structure of the study area. The Q_S value is lower in the intersection area of the mountain basin which is located on the north and south sides of the Tianshan Mountains,and the high Q_S distribution is more concentrated inside the Tianshan orogenic belt. The M≥6. 0 earthquakes have been basically located in the Low-Q_S region since 1900. 24 high heat flow points in eastern Tianshan are located at the north and south of Tianshan Mountains where low Q_S exists,indicating a negative correlation. In addition,there is a positive correlation between the velocity structure and the attenuation structure in the study area,which reflects the consistency of the 2-D attenuation structure with the velocity structure and the two-dimensional density structure.展开更多
基金supported by Hubei Provincial Department of Education (No. Q20102102)
文摘Background The factors influencing the q-wave changes in V5 and V6 during anterior acute myocardial in- farction （AMI） have not been thoroughly described. Methods We studied 70 patients with a first anterior AMI, in whom the electrocardiogram （ECG） showed either disappearance of the normal septal q wave （n = 24） or presence of pathological Q wave in V5 and V6 （n = 46） during follow-up. The ECG and coronary angiography findings were correlated. Results There was no difference between the 2 groups in the culprit site proximal to S1 （46% vs. 36%, P = 0.405）, but the culprit site was more frequently located proximal to DI in the group with abnormal Q wave （21% vs. 67%, P = 0.001）. Patients with disappearance of the septal q wave more often had a large obtuse marginal branch （46 % vs. 22%, P = 0.037） and disappearance of the r wave in V1 （88% vs. 7%, P = 0.001）. Patients with abnormal Q-wave more often had a large LAD （42% vs. 71%）, small r wave or tall or wide R wave in V1 （0 % vs. 89 %, P = 0.001） and abnormal Q waves in the inferior leads （33% vs. 59%, P = 0.044）. Conclusions In patients with first anterior AMI, q wave changes in V5 and V6 correlated with the morphology in V1. Emerging abnormal Q wave in Vs/V6 predicted the culprit lesion in a large LAD proximal to D1, but disappearance of the septal q wave could not predict the culprit lesion proximal to S1.
基金Early-stage study project of the national key foundation research (2002CCD01700) and the key project of Yunnan Province during the 10th Five-year plan.
文摘The study of seismic attenuation property is a major subject in seismology. Seismic waves recorded by seismic stations （seismographs） contain source effect, seismic wave propagation effect, site response of seismic stations and instrumental response. The path effect of seismic wave propagation, site response of seismic stations and instrumental response must be taken out in the study of source property with seismic data. The path effect of seismic wave propagation （seismic attenuation） involves an important influential factor, the anelastic attenuation of medium, which is measured with quality factor Q, apart from geometric attenuation with the distance. As a basic physical parameter of the Earth medium, Q value is essential for quantitative study of earthquakes and source property （e.g. determination of source parameters）, which is widely used in earthquake source physics and engineering seismology.
基金supported by the National Natural Science Foundation of China(No.61671108)the Fundamental Research Funds for the Central Universities(No.ZYGX2014J005)the Program for Changjiang Scholars and Innovative Research Team in University
文摘All-optical regenerators can be used to suppress amplified spontaneous emission(ASE) noise introduced by cascaded erbium doped fiber amplifiers(EDFAs) in optical fiber communication systems and lead to the improvement of optical receiver sensitivity. By introducing the Q-factor transfer function(QTF), we evaluate the Q-factor performance of degenerate four-wave mixing(DFWM) regenerators with clock pump and reveal the differences between the optimal input powers determined from the static and dynamic power tranfer function(PTF) and the QTF curves. Our simulation shows that the clock-pump regnerator is capable of improving the Q-facor and receiver sensitivity for 40 Gbit/s ASE-degraded return-to-zero on-off keying(RZ-OOK) signal by 2.58 dB and 4.2 d B, respectively.
文摘Objectives: There is a high rate of sudden death in epilepsy patients, part of which is sudden cardiac death. By investigating ECG T wave alternans and Q-T dispersion changes of epilepsy patients, we may predict the possibility of the occurrence of sudden death and provide basis for clinical prevention. Methods: Selecting 587 cases of epilepsy patients as the study group, 672 same period cases of healthy persons as the control group;Analyzing the effect of epilepsy on ECG T wave alternans and Q-T dispersion with the standard 12 lead ECG. Results: The study group had a significantly prolonged Q-T dispersion and an increased incidence of T wave alternans than that of the control group;Compared with other seizure types, tonic clonic seizure and absence seizure had a significantly prolonged Q-T dispersion and an increased occurrence rate of T wave alternans. Conclusions: Epilepsy patients ECG T wave alternans and Q-T dispersion has higher abnormal rate, and are prone to sudden cardiac death;Routine ECG(RECG) T wave alternans and Q-T dispersion changes can provide guidance for clinical prevention of sudden unexpected death in epilepsy (SUDEP).
基金jointly funded by the Contract Oriented Work Task for Seismic Situation in 2017(2017010104)Science for Earthquake Resilience(XH17041Y)Fund of Earthquake Agency of Xinjiang Uygur Autonomous Region(201401)
文摘Based on the waveform data of 5,076 local earthquakes recorded at 25 stations in Xinjiang during the period from 2009 to 2014 and the observation reports provided by the Xinjiang Digital Seismic Network,a data set of 19,140 attenuation factors t*is obtained by fitting the high-frequency attenuation of S-wave spectra with a genetic algorithm. The spatial distribution of Q_S is determined by inverting the t*data with seismic tomography. The results show that the average Q0 in eastern Tianshan is 520,and there is a significant correlation between the Q_S value distribution or attenuation characteristics it disclosed and the surface structure of the study area. The Q_S value is lower in the intersection area of the mountain basin which is located on the north and south sides of the Tianshan Mountains,and the high Q_S distribution is more concentrated inside the Tianshan orogenic belt. The M≥6. 0 earthquakes have been basically located in the Low-Q_S region since 1900. 24 high heat flow points in eastern Tianshan are located at the north and south of Tianshan Mountains where low Q_S exists,indicating a negative correlation. In addition,there is a positive correlation between the velocity structure and the attenuation structure in the study area,which reflects the consistency of the 2-D attenuation structure with the velocity structure and the two-dimensional density structure.
