Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which ...Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which enhanced whistler mode waves(~10^(−11) V^(2)/m^(2)/Hz)with frequency of 0.1 f_(ce)-0.5 f_(ce) occurred,based on MAVEN data,exactly corresponding to a significant decrease of suprathermal electron fluxes.The diffusion coefficients are calculated by using the observed electric field wave spectra.The pitch angle diffusion coefficient can approach 10^(−2) s^(−1),which is much larger,by~100 times,than the momentum diffusion coefficient,indicating that pitch angle scattering dominates the whistler-electron resonance process.The current results can successfully explain the dropout of the suprathermal electrons in this event.This study provides direct evidence for whistler-driven electron losses in the Martian magnetosphere.展开更多
Background:Current studies have confirmed that fetal congenital heart diseases(CHDs)are caused by various factors.However,the quantitative risk of CHD is not clear given the combined effects of multiple factors.Object...Background:Current studies have confirmed that fetal congenital heart diseases(CHDs)are caused by various factors.However,the quantitative risk of CHD is not clear given the combined effects of multiple factors.Objective:This cross-sectional study aimed to detect associated factors of fetal CHD using a Bayesian network in a large sample and quantitatively analyze relative risk ratios(RRs).Methods:Pregnant women who underwent fetal echocardiography(N=16,086 including 3,312 with CHD fetuses)were analyzed.Twenty-six maternal and fetal factors were obtained.A Bayesian network is constructed based on all variables through structural learning and parameter learning methods to find the environmental factors that directly and indirectly associated with outcome,and the probability of fetal CHD in the two groups is predicted through a junction tree reasoning algorithm,so as to obtain RR for fetal CHD under different exposure factor combinations.Taking into account the effect of gestational week on the accuracy of model prediction,we conducted sensitivity analysis on gestational week groups.Results:The single-factor analysis showed that the RRs for the numbers of births,spontaneous abortions,and parental smoking were 1.50,1.38,and 1.11(P<0.001),respectively.The risk gradually increased with the synergistic effect of ranging from one to more environmental factors above.The risk was higher among subjects with five synergistic factors,including the number of births,upper respiratory tract infection during early pregnancy,anemia,and mental stress as well as a history of spontaneous abortions or parental smoking,than in those with less than 5 factors(RR=2.62 or 2.28,P<0.001).This result was consistent across the participants grouped by GWs.Conclusion:We identified six factors that were directly associated with fetal CHD.A higher number of these factors led to a higher risk of CHD.These findings suggest that it is important to strengthen healthcare and prenatal counseling for women with these factors.展开更多
Plasma density is an important factor in determining wave-particle interactions in the magnetosphere.We develop a machine-learning-based electron density(MLED)model in the inner magnetosphere using electron density da...Plasma density is an important factor in determining wave-particle interactions in the magnetosphere.We develop a machine-learning-based electron density(MLED)model in the inner magnetosphere using electron density data from Van Allen Probes between September 25,2012 and August 30,2019.This MLED model is a physics-based nonlinear network that employs fundamental physical principles to describe variations of electron density.It predicts the plasmapause location under different geomagnetic conditions,and models separately the electron densities of the plasmasphere and of the trough.We train the model using gradient descent and backpropagation algorithms,which are widely used to deal effectively with nonlinear relationships among physical quantities in space plasma environments.The model gives explicit expressions with few parameters and describes the associations of electron density with geomagnetic activity,solar cycle,and seasonal effects.Under various geomagnetic conditions,the electron densities calculated by this model agree well with empirical observations and provide a good description of plasmapause movement.This MLED model,which can be easily incorporated into previously developed radiation belt models,promises to be very helpful in modeling and improving forecasting of radiation belt electron dynamics.展开更多
Background:Atrioventricular septal defects(AVSDs)are screened and diagnosed usually rely on the imaging characteristics of fetal echocardiography(FE).However,diagnosis on images is heavily depended on sonographers’ex...Background:Atrioventricular septal defects(AVSDs)are screened and diagnosed usually rely on the imaging characteristics of fetal echocardiography(FE).However,diagnosis on images is heavily depended on sonographers’experience and the quantitative data are rarely studied.Objective:This study aimed to realize the prenatal diagnosis of AVSDs by analyzing the quantitative data on FE.Methods:One hundred and thirteen cardiac quantitative data was analyzed in 370 normal and 49 AVSDs fetuses retrospectively.The top six with the highest diagnostic accuracy rate were acquired according to the area under the curve(AUC),and the diagnostic value of six variables was analyzed.Results:Six parameters obtained on the four-chamber view(4CHV),including the atrial to ventricular length ratio in end-diastole(AVLR-ED),AVLR-ED combined with the atrial to ventricular length ratio in end-systole(AVLR-ES),quantile score(Q score)of AVLR-ED,Q score of AVLR-ES,Q score of ventricle length in end-diastole(VL-ED),and AVLR-ES,were the top six with the highest diagnostic value,and the AUC was 0.99(95%CI 0.99–1.00),0.99(95%CI 0.99–1.00),0.99(95%CI 0.98–1.00),0.95(95%CI 0.91–0.99),0.93(95%CI 0.87–0.99),and 0.91(95%CI 0.83–1.00),respectively.And within the 20%false positive rate,the diagnostic sensitivity was greater than 100%,100%,100%,90%,90%,and 88%,respectively.Conclusions:Six variables could be used for prenatal diagnosis of AVSDs.Among them,AVLR-ED and Q score of AVLR-ED,obtained on the 4CHV,were more convenient to acquire and had higher diagnostic accuracy.展开更多
Inherited cardiovascular diseases(CVDs)threaten human health and pose an enormous economic burden worldwide.Genetic alteration is a major risk factor for many CVDs.These disorders are usually controlled by a pair of a...Inherited cardiovascular diseases(CVDs)threaten human health and pose an enormous economic burden worldwide.Genetic alteration is a major risk factor for many CVDs.These disorders are usually controlled by a pair of alleles,affecting offspring according to the Mendelian principle,regardless of isolated primary damage or secondary injury from other syndromes or deficiency.To date,there are hundreds of inherited CVDs.With advances in nextgeneration sequencing(NGS)technologies,rapid and accurate molecular diagnosis of patients with inherited CVDs is clinically practical.Besides,great improvements have been made in recent years,and targeted therapy and assist devices have been used in clinical practice.Yet there is still no totally efficient strategy for dealing with inherited CVDs.Accordingly.展开更多
Marfan syndrome (MFS)(OMIM 154700) is a relatively common autosomal dominant genetic disease that causes skeletal, ocular, and cardiovascular defects and was first described by a French pediatrician in 1896 (Bitterman...Marfan syndrome (MFS)(OMIM 154700) is a relatively common autosomal dominant genetic disease that causes skeletal, ocular, and cardiovascular defects and was first described by a French pediatrician in 1896 (Bitterman and Sponseller, 2017). Its prevalence rate is 1/3000—1/5000, and more than 25% of cases are sporadic (Chiu et al., 2014). Studies have shown that about 90% of MFS is caused by variants in the fibrillin-1 gene (FBN1, OMIM 134797). FBN1, located on chromosome 15q21.1, encodes a macromolecular glycoprotein-fibrin 1, which aggregates to form microfibers in the extracellular matrix and distributes in various human connective tissues, such as periosteum, vessel wall, and crystal suspensor ligament. Variants in FNB1 have been reported in 65 exons, but the relationship between genotype and phenotype remains rather unclear (Sakai et al., 2016). Studies have also shown that patients with MFS and similar diseases may have variants in other related genes such as members of the transforming growth factor beta receptor (TGFBR) family (Mizuguchi et al., 2004;Sakai et al., 2006;Bolar et al., 2012;De Cario et al., 2018). For better prevention and treatment of MFS as well as for suspected MFS patients, there is a strong need for efficient genetic testing for early diagnosis and differential diagnoses of patients with related phenotypes (Aubart et al., 2018).展开更多
基金the National Natural Science Foundation of China grants 42230209, 42241136, 42374199, 42204171, 42274212the Natural Science Foundation of Hunan province Grant 2021JJ20010, 2023JJ20038
文摘Whistler mode waves are critical emissions in magnetized plasmas that usually influence the electron dynamics in a planetary magnetosphere.In this paper,we present a unique event in the Martian magnetosphere in which enhanced whistler mode waves(~10^(−11) V^(2)/m^(2)/Hz)with frequency of 0.1 f_(ce)-0.5 f_(ce) occurred,based on MAVEN data,exactly corresponding to a significant decrease of suprathermal electron fluxes.The diffusion coefficients are calculated by using the observed electric field wave spectra.The pitch angle diffusion coefficient can approach 10^(−2) s^(−1),which is much larger,by~100 times,than the momentum diffusion coefficient,indicating that pitch angle scattering dominates the whistler-electron resonance process.The current results can successfully explain the dropout of the suprathermal electrons in this event.This study provides direct evidence for whistler-driven electron losses in the Martian magnetosphere.
基金National Key R&D Program of China(2018YFC1002300).
文摘Background:Current studies have confirmed that fetal congenital heart diseases(CHDs)are caused by various factors.However,the quantitative risk of CHD is not clear given the combined effects of multiple factors.Objective:This cross-sectional study aimed to detect associated factors of fetal CHD using a Bayesian network in a large sample and quantitatively analyze relative risk ratios(RRs).Methods:Pregnant women who underwent fetal echocardiography(N=16,086 including 3,312 with CHD fetuses)were analyzed.Twenty-six maternal and fetal factors were obtained.A Bayesian network is constructed based on all variables through structural learning and parameter learning methods to find the environmental factors that directly and indirectly associated with outcome,and the probability of fetal CHD in the two groups is predicted through a junction tree reasoning algorithm,so as to obtain RR for fetal CHD under different exposure factor combinations.Taking into account the effect of gestational week on the accuracy of model prediction,we conducted sensitivity analysis on gestational week groups.Results:The single-factor analysis showed that the RRs for the numbers of births,spontaneous abortions,and parental smoking were 1.50,1.38,and 1.11(P<0.001),respectively.The risk gradually increased with the synergistic effect of ranging from one to more environmental factors above.The risk was higher among subjects with five synergistic factors,including the number of births,upper respiratory tract infection during early pregnancy,anemia,and mental stress as well as a history of spontaneous abortions or parental smoking,than in those with less than 5 factors(RR=2.62 or 2.28,P<0.001).This result was consistent across the participants grouped by GWs.Conclusion:We identified six factors that were directly associated with fetal CHD.A higher number of these factors led to a higher risk of CHD.These findings suggest that it is important to strengthen healthcare and prenatal counseling for women with these factors.
基金This work is supported by the National Natural Science Foundation of China grants 42074198,41774194,41974212 and 42004141Natural Science Foundation of Hunan Province 2021JJ20010+1 种基金Science and Technology Innovation Program of Hunan Province 2021RC3098Foundation of Education Bureau of Hunan Province for Distinguished Young Scientists 20B004.
文摘Plasma density is an important factor in determining wave-particle interactions in the magnetosphere.We develop a machine-learning-based electron density(MLED)model in the inner magnetosphere using electron density data from Van Allen Probes between September 25,2012 and August 30,2019.This MLED model is a physics-based nonlinear network that employs fundamental physical principles to describe variations of electron density.It predicts the plasmapause location under different geomagnetic conditions,and models separately the electron densities of the plasmasphere and of the trough.We train the model using gradient descent and backpropagation algorithms,which are widely used to deal effectively with nonlinear relationships among physical quantities in space plasma environments.The model gives explicit expressions with few parameters and describes the associations of electron density with geomagnetic activity,solar cycle,and seasonal effects.Under various geomagnetic conditions,the electron densities calculated by this model agree well with empirical observations and provide a good description of plasmapause movement.This MLED model,which can be easily incorporated into previously developed radiation belt models,promises to be very helpful in modeling and improving forecasting of radiation belt electron dynamics.
基金“Dengfeng”Project of Talent Training Plan of Beijing Medical Management Center(Number DFL20220601)Beijing Municipal Administration of Hospitals Incubating Program(Number PX2023023)+3 种基金National Natural Science Foundation of China(Number 82170301)Beijing Municipal Administration of Hospitals Incubating Program(Number PX2022026)Beijing Natural Science Foundation(Number L222152)the Ethics Committee of Beijing Anzhen Hospital(2020016X).
文摘Background:Atrioventricular septal defects(AVSDs)are screened and diagnosed usually rely on the imaging characteristics of fetal echocardiography(FE).However,diagnosis on images is heavily depended on sonographers’experience and the quantitative data are rarely studied.Objective:This study aimed to realize the prenatal diagnosis of AVSDs by analyzing the quantitative data on FE.Methods:One hundred and thirteen cardiac quantitative data was analyzed in 370 normal and 49 AVSDs fetuses retrospectively.The top six with the highest diagnostic accuracy rate were acquired according to the area under the curve(AUC),and the diagnostic value of six variables was analyzed.Results:Six parameters obtained on the four-chamber view(4CHV),including the atrial to ventricular length ratio in end-diastole(AVLR-ED),AVLR-ED combined with the atrial to ventricular length ratio in end-systole(AVLR-ES),quantile score(Q score)of AVLR-ED,Q score of AVLR-ES,Q score of ventricle length in end-diastole(VL-ED),and AVLR-ES,were the top six with the highest diagnostic value,and the AUC was 0.99(95%CI 0.99–1.00),0.99(95%CI 0.99–1.00),0.99(95%CI 0.98–1.00),0.95(95%CI 0.91–0.99),0.93(95%CI 0.87–0.99),and 0.91(95%CI 0.83–1.00),respectively.And within the 20%false positive rate,the diagnostic sensitivity was greater than 100%,100%,100%,90%,90%,and 88%,respectively.Conclusions:Six variables could be used for prenatal diagnosis of AVSDs.Among them,AVLR-ED and Q score of AVLR-ED,obtained on the 4CHV,were more convenient to acquire and had higher diagnostic accuracy.
基金Key R&D Program of Sichuan Province of China(No.2021YFQ0061)Science and Technology Department of Sichuan Province(No.2022ZYD0067 and MSGC20230024)+2 种基金Natural Science Foundation of China(Nos.82070324,82001496,and 82270249)Project of Chengdu Science and Technology Bureau(No.2021-YF05-02110-SN)China Postdoctoral Science Foundation(Nos.2020M680149 and 2020T130087ZX)
文摘Inherited cardiovascular diseases(CVDs)threaten human health and pose an enormous economic burden worldwide.Genetic alteration is a major risk factor for many CVDs.These disorders are usually controlled by a pair of alleles,affecting offspring according to the Mendelian principle,regardless of isolated primary damage or secondary injury from other syndromes or deficiency.To date,there are hundreds of inherited CVDs.With advances in nextgeneration sequencing(NGS)technologies,rapid and accurate molecular diagnosis of patients with inherited CVDs is clinically practical.Besides,great improvements have been made in recent years,and targeted therapy and assist devices have been used in clinical practice.Yet there is still no totally efficient strategy for dealing with inherited CVDs.Accordingly.
基金supported by the National Key R&D Program of China (2018YFC1002302, 2016YFC0900103)National Natural Science Foundation of China (81671458)+1 种基金Beijing Lab for Cardiovascular Precision Medicine (PXM2018_014226_000013)supported by the Reproduction Center Biobank at Peking University Third Hospital
文摘Marfan syndrome (MFS)(OMIM 154700) is a relatively common autosomal dominant genetic disease that causes skeletal, ocular, and cardiovascular defects and was first described by a French pediatrician in 1896 (Bitterman and Sponseller, 2017). Its prevalence rate is 1/3000—1/5000, and more than 25% of cases are sporadic (Chiu et al., 2014). Studies have shown that about 90% of MFS is caused by variants in the fibrillin-1 gene (FBN1, OMIM 134797). FBN1, located on chromosome 15q21.1, encodes a macromolecular glycoprotein-fibrin 1, which aggregates to form microfibers in the extracellular matrix and distributes in various human connective tissues, such as periosteum, vessel wall, and crystal suspensor ligament. Variants in FNB1 have been reported in 65 exons, but the relationship between genotype and phenotype remains rather unclear (Sakai et al., 2016). Studies have also shown that patients with MFS and similar diseases may have variants in other related genes such as members of the transforming growth factor beta receptor (TGFBR) family (Mizuguchi et al., 2004;Sakai et al., 2006;Bolar et al., 2012;De Cario et al., 2018). For better prevention and treatment of MFS as well as for suspected MFS patients, there is a strong need for efficient genetic testing for early diagnosis and differential diagnoses of patients with related phenotypes (Aubart et al., 2018).
