1 Introduction Heart rhythm disorders, including bradyarrhythmias, atrial fibrillation （AF）, and ventricular arrhythmias, become increasingly common with aging and represent important causes of morbidity and mortal...1 Introduction Heart rhythm disorders, including bradyarrhythmias, atrial fibrillation （AF）, and ventricular arrhythmias, become increasingly common with aging and represent important causes of morbidity and mortality among older adults.[1-3] Older adults are particularly predisposed to these conditions due to the high prevalence of cardiovascular disease in con- junction with age-related changes that occur in the heart and cardiac conduction system.展开更多
The structure of Ni active sites supported on amorphous silica-alumina supports with different contents of Al_(2)O_(3)loadings in relation to their activities in ethylene oligomerization were investigated.Two kinds of...The structure of Ni active sites supported on amorphous silica-alumina supports with different contents of Al_(2)O_(3)loadings in relation to their activities in ethylene oligomerization were investigated.Two kinds of Ni sites were detected by in situ FTIR-CO and H_(2)-TPR experiments,that are Ni^(2+)cations as grafted on weak acidic silanols and Ni^(2+)cations at ion-exchange positions.The ethylene oligomerization activities of these Ni/ASA catalysts were found an ascending tendency as the Al_(2)O_(3)loading decreased,which could be attributed to the enriched concentration of Ni^(2+)species on acidic silanols with a weaker interaction with the amorphous silica-alumina support.These Ni^(2+)species were more easily to be evolved into Ni^(+)species,which has been identified to be the active sites of ethylene oligomerization.Thus,it seems reasonable to conclude that Ni^(2+)species grafted on acidic silanols were the precursors of active sites.展开更多
The displacement of the origin of the accelerometer coordinate system relative to the origin of the base coordinate system is calculated by homogeneous transformation. The second order derivative of this displacement ...The displacement of the origin of the accelerometer coordinate system relative to the origin of the base coordinate system is calculated by homogeneous transformation. The second order derivative of this displacement is the acceleration of the origin to the accelerometer coordinate system. By means of the attitude relationship between the base coordinate system and the accelerometer coordinate system, the acceleration components on the three coordinate axes is obtained. Utilizing the Coriolis rotation coordinate theorem, the three components are also calculated. The homogeneous transtbrmation method and vector differential method lead to identical results.展开更多
Brugada syndrome （BrS） is primary electrical disorder characterized by ST segment elevation with right bundle branch block morphology in patients with apparent structurally normal hearts, It predisposes affected in...Brugada syndrome （BrS） is primary electrical disorder characterized by ST segment elevation with right bundle branch block morphology in patients with apparent structurally normal hearts, It predisposes affected individuals to ventricular tachycardia/fibrillation （VT/VF） and sudden cardiac death （SCD）.A number of studies have identified risk factors that are associated with a more malignant course of disease. These include male gender, syncope, a spontaneous type 1 ECG pattern, family history of SCD, family history of Brugada syndrome,展开更多
Objective To explore fetal arrhythmia clinical significance and its correlation with fetal prognosis. Methods Twenty-six cases of fetal arrhythmia detected among 12 799 pregnant women recorded over a ten-year period i...Objective To explore fetal arrhythmia clinical significance and its correlation with fetal prognosis. Methods Twenty-six cases of fetal arrhythmia detected among 12 799 pregnant women recorded over a ten-year period in Peking Uinon Medical College (PUMC) Hospital were reviewed retrospectively. Fetal arrhythmia was diagnosed by fetal auscultation, ultrasonography, electric fetal heart monitoring, and fetal echocardiography. Results Twenty-six fetuses were documented with fetal arrhythmia (3 tachycardia, 4 bradycardia, 19 normal heart rate with irregular fetal cardiac rhythm). The incidence of fetal arrhythmia in our hospital was 0.2%. They were diagnosed at the average of 35 weeks’ gestation (15 to 41 weeks). Twenty-two cases were diagnosed by antenatal fetal auscultation, 1 case was diagnosed by ultrasonography, and 3 cases were diagnosed by electric fetal heart monitoring. Fetal echocardiograms were per-formed on 17 fetuses, 6 cases (35.3%) of which showed that ventricular premature beats with normal structure of fetal heart. All neonates survived postnatally and 24 of them (92.3%) were followed up. Echocardiograms were performed for 16 neonates and 2 of them were identified as atrial septal defects with normal heart rhythms. The results of follow-up showed that the two patients had no apparent clinical manifestation. The echocardiogram showed that atrial septal defect obliterated already. Conclusion The prognosis is well for most of the fetuses with arrhythmias, with low incidence of heart deformation.展开更多
A precision centrifuge is an inertial navigation test equipment used for calibrating the characteristics of accelerometers with high overloading, and a two axis centrifuge can be used to generate either constant accel...A precision centrifuge is an inertial navigation test equipment used for calibrating the characteristics of accelerometers with high overloading, and a two axis centrifuge can be used to generate either constant acceleration or harmonic acceleration. The moving trajectory equation about the origin of the accelerometer coordinate system in a two axis centrifuge was directly deduced through homogeneous transformation. The acceleration vector of the origin in accelerometer coordinate system was achieved by making the second derivative of this trajectory equation. The acceleration components were acquired by decomposing this acceleration vector along the three axes of the accelerometer coordinate system. The correctness of the homogeneous transformation was verified through vector analysis.展开更多
From August 1989 to May 1994, 84 cases of ventricular premature beat (VPB) with deficiency syndrome were treated with our empirical prescription called Qi Lu Tang Decoction for Improving Abnormal Heart Beat). The tota...From August 1989 to May 1994, 84 cases of ventricular premature beat (VPB) with deficiency syndrome were treated with our empirical prescription called Qi Lu Tang Decoction for Improving Abnormal Heart Beat). The total effective rate was 88.10%, being significantly different from that of the control group treated with the Western drug propafenone (P展开更多
文摘1 Introduction Heart rhythm disorders, including bradyarrhythmias, atrial fibrillation （AF）, and ventricular arrhythmias, become increasingly common with aging and represent important causes of morbidity and mortality among older adults.[1-3] Older adults are particularly predisposed to these conditions due to the high prevalence of cardiovascular disease in con- junction with age-related changes that occur in the heart and cardiac conduction system.
文摘The structure of Ni active sites supported on amorphous silica-alumina supports with different contents of Al_(2)O_(3)loadings in relation to their activities in ethylene oligomerization were investigated.Two kinds of Ni sites were detected by in situ FTIR-CO and H_(2)-TPR experiments,that are Ni^(2+)cations as grafted on weak acidic silanols and Ni^(2+)cations at ion-exchange positions.The ethylene oligomerization activities of these Ni/ASA catalysts were found an ascending tendency as the Al_(2)O_(3)loading decreased,which could be attributed to the enriched concentration of Ni^(2+)species on acidic silanols with a weaker interaction with the amorphous silica-alumina support.These Ni^(2+)species were more easily to be evolved into Ni^(+)species,which has been identified to be the active sites of ethylene oligomerization.Thus,it seems reasonable to conclude that Ni^(2+)species grafted on acidic silanols were the precursors of active sites.
文摘The displacement of the origin of the accelerometer coordinate system relative to the origin of the base coordinate system is calculated by homogeneous transformation. The second order derivative of this displacement is the acceleration of the origin to the accelerometer coordinate system. By means of the attitude relationship between the base coordinate system and the accelerometer coordinate system, the acceleration components on the three coordinate axes is obtained. Utilizing the Coriolis rotation coordinate theorem, the three components are also calculated. The homogeneous transtbrmation method and vector differential method lead to identical results.
文摘Brugada syndrome （BrS） is primary electrical disorder characterized by ST segment elevation with right bundle branch block morphology in patients with apparent structurally normal hearts, It predisposes affected individuals to ventricular tachycardia/fibrillation （VT/VF） and sudden cardiac death （SCD）.A number of studies have identified risk factors that are associated with a more malignant course of disease. These include male gender, syncope, a spontaneous type 1 ECG pattern, family history of SCD, family history of Brugada syndrome,
文摘Objective To explore fetal arrhythmia clinical significance and its correlation with fetal prognosis. Methods Twenty-six cases of fetal arrhythmia detected among 12 799 pregnant women recorded over a ten-year period in Peking Uinon Medical College (PUMC) Hospital were reviewed retrospectively. Fetal arrhythmia was diagnosed by fetal auscultation, ultrasonography, electric fetal heart monitoring, and fetal echocardiography. Results Twenty-six fetuses were documented with fetal arrhythmia (3 tachycardia, 4 bradycardia, 19 normal heart rate with irregular fetal cardiac rhythm). The incidence of fetal arrhythmia in our hospital was 0.2%. They were diagnosed at the average of 35 weeks’ gestation (15 to 41 weeks). Twenty-two cases were diagnosed by antenatal fetal auscultation, 1 case was diagnosed by ultrasonography, and 3 cases were diagnosed by electric fetal heart monitoring. Fetal echocardiograms were per-formed on 17 fetuses, 6 cases (35.3%) of which showed that ventricular premature beats with normal structure of fetal heart. All neonates survived postnatally and 24 of them (92.3%) were followed up. Echocardiograms were performed for 16 neonates and 2 of them were identified as atrial septal defects with normal heart rhythms. The results of follow-up showed that the two patients had no apparent clinical manifestation. The echocardiogram showed that atrial septal defect obliterated already. Conclusion The prognosis is well for most of the fetuses with arrhythmias, with low incidence of heart deformation.
文摘A precision centrifuge is an inertial navigation test equipment used for calibrating the characteristics of accelerometers with high overloading, and a two axis centrifuge can be used to generate either constant acceleration or harmonic acceleration. The moving trajectory equation about the origin of the accelerometer coordinate system in a two axis centrifuge was directly deduced through homogeneous transformation. The acceleration vector of the origin in accelerometer coordinate system was achieved by making the second derivative of this trajectory equation. The acceleration components were acquired by decomposing this acceleration vector along the three axes of the accelerometer coordinate system. The correctness of the homogeneous transformation was verified through vector analysis.
文摘From August 1989 to May 1994, 84 cases of ventricular premature beat (VPB) with deficiency syndrome were treated with our empirical prescription called Qi Lu Tang Decoction for Improving Abnormal Heart Beat). The total effective rate was 88.10%, being significantly different from that of the control group treated with the Western drug propafenone (P
