The common reflection surface （CRS） stack is based on the local dip of the reflector and the reflection response within the first Fresnel zone. During the CRS stack all the information given by a multi-coverage refl...The common reflection surface （CRS） stack is based on the local dip of the reflector and the reflection response within the first Fresnel zone. During the CRS stack all the information given by a multi-coverage reflection dataset can be successfully utilized. By now, it is known as the best zero-offset （ZO） imaging method. In this paper high quality CRS kinematic parameter sections are obtained by a modified CRS optimization strategy. Then stack apertures are calculated using the parameter sections which finally results in the realization of the CRS stack based on optimized aperture. Thus the advantages of CRS parameters are fully developed. Application to model and real seismic data reveals that, compared with the image section by a conventional CRS stack, the image section by CRS stack based on an optimized aperture improves both the signal-to-noise ratio and the continuity of reflection events.展开更多
Background Chronic heart failure （CHF） is life-threatening without timely or effective intervention. In this study, we investigated the association between QT dispersion corrected for heart rate （cQTd） and heart f...Background Chronic heart failure （CHF） is life-threatening without timely or effective intervention. In this study, we investigated the association between QT dispersion corrected for heart rate （cQTd） and heart function in patients with CHF. Methods From January 2013 to December 2015, we continuously enrolled 240 patients categorized as New York Heart Association functional class （NYHA） III-IV with a left ventricular ejection fraction （LVEF） 〈 40%. Based on the etiology, the patients were divided into a dilated cardiomyopathy （DCM） group （n = 120） and an ischemic cardiomyopathy （ICM） group （n = 120）. Then, based on the cQTd width, the ICM group was divided into two subgroups： a QS group （cQTd ≤60 ms, n = 70） and a QL group （cQTd 〉 60 ms, n = 50）. All patients were examined by echocardiography and 12-lead electrocardiography （ECG） at 1, 3, 6, and 12 months after enrollment. Results After one year of optimized medical treatment, patients in both groups showed significant improvement in LVEF and NYHA classification from baseline. However, the cQTd in the ICM group, especially the QL, was significantly shorter than that in the DCM group at each time point. In addition, the cQTd was negatively correlated with LVEF and 6-min walking test and positively correlated with NYHA class in the ICM group. Conclusions The present findings clearly demonstrate that cQTd is a meaningful parameter for assessing heart function in the follow-up of ICM patients.展开更多
A mutual information-based non-rigid medical image registration algorithm is presented. An approximate function of Hanning windowed sinc is used as kernel function of partial volume (PV) interpolation to estimate the ...A mutual information-based non-rigid medical image registration algorithm is presented. An approximate function of Hanning windowed sinc is used as kernel function of partial volume (PV) interpolation to estimate the joint histogram, which is the key to calculating the mutual information. And a new method is proposed to compute the gradient of mutual information with respect to the model parameters. The transformation of object is modeled by a free-form deformation (FFD) based on B-splines. The experiments on 3D synthetic and real image data show that the algorithm can converge at the global optimum and restrain the emergency of local extreme.展开更多
Background Although previous studies using Korean data have already reported higher rates of mortality in women, it is less clear whether these gender differences in prognosis post ST-segment elevation myocardial infa...Background Although previous studies using Korean data have already reported higher rates of mortality in women, it is less clear whether these gender differences in prognosis post ST-segment elevation myocardial infarction （STEMI）, are age dependent. The aim of this study is to examine the gender-age interaction with early and late mortality in patients with STEMI enrolled in the Korean nationwide regis-try. Methods This prospective study stratified outcomes according to gender and age from 17,021 STEMI patients. We compared in-hospital, early （30 days） and late （12 months） mortality between gender to examine the gender-age interaction in multivariable models. Results In younger women （〈 60 years）, in-hospital [5.8% vs. 2.5%, P 〈 0.001; unadjusted odds ratios （OR）： 2.41, 95% confidence inter-vals （CI）： 1.59-3.66], early （6.2% vs. 2.6%, P 〈 0.001; unadjusted OR： 2.4, 95% CI： 2.12-2.72） and late mortality （7.0% vs. 3.1%, P 〉 0.001; unadjusted OR： 2.33, 95% CI： 2.08-2.61） were significantly higher compared with men. However, after adjustment for patient characteristics, Killip class ≥ 3, symptom to balloon time and major bleeding, and in-hospital bleeding, overall early and late mortality were no longer re-lated to gender in any age groups. Conclusions Among a Korean population with STEMI, higher early and late mortality in younger women may be explained by poor patient characteristics, higher Killip class ≥3, longer symptom to balloon time and more frequent major bleeding. Therefore, based on gender-age differences, more precise and aggressive preventive strategies focused on risk factor reduction, education and more intensive management for yotmger women should be performed.展开更多
基金sponsored by the 863 Program (Grant No.2006AA06Z206)the 973 Program (Grant No.2007CB209605)
文摘The common reflection surface （CRS） stack is based on the local dip of the reflector and the reflection response within the first Fresnel zone. During the CRS stack all the information given by a multi-coverage reflection dataset can be successfully utilized. By now, it is known as the best zero-offset （ZO） imaging method. In this paper high quality CRS kinematic parameter sections are obtained by a modified CRS optimization strategy. Then stack apertures are calculated using the parameter sections which finally results in the realization of the CRS stack based on optimized aperture. Thus the advantages of CRS parameters are fully developed. Application to model and real seismic data reveals that, compared with the image section by a conventional CRS stack, the image section by CRS stack based on an optimized aperture improves both the signal-to-noise ratio and the continuity of reflection events.
基金Acknowledgments This study was supported by the National Natural Science Foundation of China （No. 8130 1276） and the Heilongjiang Provincial Department of Education （No. 12541544）. The authors declare that there are no competing interests.
文摘Background Chronic heart failure （CHF） is life-threatening without timely or effective intervention. In this study, we investigated the association between QT dispersion corrected for heart rate （cQTd） and heart function in patients with CHF. Methods From January 2013 to December 2015, we continuously enrolled 240 patients categorized as New York Heart Association functional class （NYHA） III-IV with a left ventricular ejection fraction （LVEF） 〈 40%. Based on the etiology, the patients were divided into a dilated cardiomyopathy （DCM） group （n = 120） and an ischemic cardiomyopathy （ICM） group （n = 120）. Then, based on the cQTd width, the ICM group was divided into two subgroups： a QS group （cQTd ≤60 ms, n = 70） and a QL group （cQTd 〉 60 ms, n = 50）. All patients were examined by echocardiography and 12-lead electrocardiography （ECG） at 1, 3, 6, and 12 months after enrollment. Results After one year of optimized medical treatment, patients in both groups showed significant improvement in LVEF and NYHA classification from baseline. However, the cQTd in the ICM group, especially the QL, was significantly shorter than that in the DCM group at each time point. In addition, the cQTd was negatively correlated with LVEF and 6-min walking test and positively correlated with NYHA class in the ICM group. Conclusions The present findings clearly demonstrate that cQTd is a meaningful parameter for assessing heart function in the follow-up of ICM patients.
基金Supported bythe National Basic Research Programof China ("973"Program) (No2003CB716103)Key Project of Shanghai Scienceand Technology Committee(No05DZ19509)
文摘A mutual information-based non-rigid medical image registration algorithm is presented. An approximate function of Hanning windowed sinc is used as kernel function of partial volume (PV) interpolation to estimate the joint histogram, which is the key to calculating the mutual information. And a new method is proposed to compute the gradient of mutual information with respect to the model parameters. The transformation of object is modeled by a free-form deformation (FFD) based on B-splines. The experiments on 3D synthetic and real image data show that the algorithm can converge at the global optimum and restrain the emergency of local extreme.
文摘Background Although previous studies using Korean data have already reported higher rates of mortality in women, it is less clear whether these gender differences in prognosis post ST-segment elevation myocardial infarction （STEMI）, are age dependent. The aim of this study is to examine the gender-age interaction with early and late mortality in patients with STEMI enrolled in the Korean nationwide regis-try. Methods This prospective study stratified outcomes according to gender and age from 17,021 STEMI patients. We compared in-hospital, early （30 days） and late （12 months） mortality between gender to examine the gender-age interaction in multivariable models. Results In younger women （〈 60 years）, in-hospital [5.8% vs. 2.5%, P 〈 0.001; unadjusted odds ratios （OR）： 2.41, 95% confidence inter-vals （CI）： 1.59-3.66], early （6.2% vs. 2.6%, P 〈 0.001; unadjusted OR： 2.4, 95% CI： 2.12-2.72） and late mortality （7.0% vs. 3.1%, P 〉 0.001; unadjusted OR： 2.33, 95% CI： 2.08-2.61） were significantly higher compared with men. However, after adjustment for patient characteristics, Killip class ≥ 3, symptom to balloon time and major bleeding, and in-hospital bleeding, overall early and late mortality were no longer re-lated to gender in any age groups. Conclusions Among a Korean population with STEMI, higher early and late mortality in younger women may be explained by poor patient characteristics, higher Killip class ≥3, longer symptom to balloon time and more frequent major bleeding. Therefore, based on gender-age differences, more precise and aggressive preventive strategies focused on risk factor reduction, education and more intensive management for yotmger women should be performed.
