背景呼吸窘迫综合征(RDS)是导致早产儿死亡的重要原因,需不断加强临床预防及治疗,但目前关于脐血维生素A、E水平与早产儿发生RDS的关系研究报道较少。目的探讨脐血维生素A、E水平与早产儿发生RDS的关系。方法选取2021年1月—2022年1月...背景呼吸窘迫综合征(RDS)是导致早产儿死亡的重要原因,需不断加强临床预防及治疗,但目前关于脐血维生素A、E水平与早产儿发生RDS的关系研究报道较少。目的探讨脐血维生素A、E水平与早产儿发生RDS的关系。方法选取2021年1月—2022年1月在石家庄市第四医院出生的早产儿304例,根据RDS发生情况将其分为RDS组120例与非RDS组184例。收集与早产儿发生RDS可能相关的临床特征并检测脐血维生素A、E水平;早产儿发生RDS及RDS严重程度的影响因素分析采用多因素Logistic回归分析。结果RDS组早产儿胎龄、出生体质量小于非RDS组,1 min Apgar评分≤7分比例、5 min Apgar评分≤7分比例、维生素A缺乏发生率高于非RDS组,脐血维生素A、E水平低于非RDS组(P<0.05)。RDS组早产儿中轻症86例,重症34例;重症RDS早产儿脐血维生素A水平低于轻症RDS早产儿,维生素A缺乏发生率高于轻症RDS早产儿(P<0.05)。多因素Logistic回归分析结果显示,脐血维生素A水平为早产儿发生RDS的影响因素[OR=2.208,95%CI(1.156,4.218),P<0.05];维生素A缺乏为早产儿发生重症RDS的影响因素[OR=6.835,95%CI(2.537,18.416),P<0.05]。结论发生RDS的早产儿脐血维生素A、E水平较低,脐血维生素A水平为早产儿发生RDS及其严重程度的影响因素,建议在妊娠期适当补充维生素A以减少早产儿RDS的发生及减轻其严重程度。展开更多
In order to solve the problem of DOA （direction of arrival） estimation of underwater remote targets, a novel subspace-decomposition method based on the cross covariance matrix of the pressure and the particle veloci...In order to solve the problem of DOA （direction of arrival） estimation of underwater remote targets, a novel subspace-decomposition method based on the cross covariance matrix of the pressure and the particle velocity of acoustic vector sensor arrays （AVSA） was proposed. Whereafter, using spatio-temporal virtual tapped-delay-line, a new eigenvector-based criteria of detection of number of sources and of subspace partition is also presented. The theoretical analysis shows that the new source detection and direction finding method is different from existing AVSA based DOA estimation methods using particle velocity information of acoustic vector sensor （AVS） as an independent array element. It is entirely based on the combined information processing of pressure and particle velocity, has better estimation performance than existing methods in isotropic noise field. Computer simulations with data from lake trials demonstrate, the proposed method is effective and obviously outperforms existing methods in resolution and accuracy in the case of low signal-to-noise ratio （SNR）.展开更多
In order to solve the problem of DOA （Direction of Arrival） estimation of underwater distant wideband targets, a novel coherent signal-subspace method based on the cross spectral matrix of pressure and particle velo...In order to solve the problem of DOA （Direction of Arrival） estimation of underwater distant wideband targets, a novel coherent signal-subspace method based on the cross spectral matrix of pressure and particle velocity using the Acoustic Vector Sensor Array （AVSA） is proposed in this paper. The proposed method is different from existing AVSA based DOA estimation methods in using particle velocity information of Acoustic Vector Sensor （AVS） as an independent array element. It is entirely based on the combined information processing of pressure and particle velocity, namely, the P-V cross spectrum, has better DOA estimation performance than existing methods in isotropic noise field. By theoretical analysis, both focusing principle and eigendecomposition theory based on the P-V cross spectral matrix are given. At the same time, the corresponding criteria for source number detection is also presented. Computer simulations with data from lake trials demonstrate that the proposed method is effective and obviously outperforms existing methods in resolution and accuracy in the case of low Signal-to-Noise Ratio （SNR）.展开更多
文摘背景呼吸窘迫综合征(RDS)是导致早产儿死亡的重要原因,需不断加强临床预防及治疗,但目前关于脐血维生素A、E水平与早产儿发生RDS的关系研究报道较少。目的探讨脐血维生素A、E水平与早产儿发生RDS的关系。方法选取2021年1月—2022年1月在石家庄市第四医院出生的早产儿304例,根据RDS发生情况将其分为RDS组120例与非RDS组184例。收集与早产儿发生RDS可能相关的临床特征并检测脐血维生素A、E水平;早产儿发生RDS及RDS严重程度的影响因素分析采用多因素Logistic回归分析。结果RDS组早产儿胎龄、出生体质量小于非RDS组,1 min Apgar评分≤7分比例、5 min Apgar评分≤7分比例、维生素A缺乏发生率高于非RDS组,脐血维生素A、E水平低于非RDS组(P<0.05)。RDS组早产儿中轻症86例,重症34例;重症RDS早产儿脐血维生素A水平低于轻症RDS早产儿,维生素A缺乏发生率高于轻症RDS早产儿(P<0.05)。多因素Logistic回归分析结果显示,脐血维生素A水平为早产儿发生RDS的影响因素[OR=2.208,95%CI(1.156,4.218),P<0.05];维生素A缺乏为早产儿发生重症RDS的影响因素[OR=6.835,95%CI(2.537,18.416),P<0.05]。结论发生RDS的早产儿脐血维生素A、E水平较低,脐血维生素A水平为早产儿发生RDS及其严重程度的影响因素,建议在妊娠期适当补充维生素A以减少早产儿RDS的发生及减轻其严重程度。
文摘In order to solve the problem of DOA （direction of arrival） estimation of underwater remote targets, a novel subspace-decomposition method based on the cross covariance matrix of the pressure and the particle velocity of acoustic vector sensor arrays （AVSA） was proposed. Whereafter, using spatio-temporal virtual tapped-delay-line, a new eigenvector-based criteria of detection of number of sources and of subspace partition is also presented. The theoretical analysis shows that the new source detection and direction finding method is different from existing AVSA based DOA estimation methods using particle velocity information of acoustic vector sensor （AVS） as an independent array element. It is entirely based on the combined information processing of pressure and particle velocity, has better estimation performance than existing methods in isotropic noise field. Computer simulations with data from lake trials demonstrate, the proposed method is effective and obviously outperforms existing methods in resolution and accuracy in the case of low signal-to-noise ratio （SNR）.
文摘In order to solve the problem of DOA （Direction of Arrival） estimation of underwater distant wideband targets, a novel coherent signal-subspace method based on the cross spectral matrix of pressure and particle velocity using the Acoustic Vector Sensor Array （AVSA） is proposed in this paper. The proposed method is different from existing AVSA based DOA estimation methods in using particle velocity information of Acoustic Vector Sensor （AVS） as an independent array element. It is entirely based on the combined information processing of pressure and particle velocity, namely, the P-V cross spectrum, has better DOA estimation performance than existing methods in isotropic noise field. By theoretical analysis, both focusing principle and eigendecomposition theory based on the P-V cross spectral matrix are given. At the same time, the corresponding criteria for source number detection is also presented. Computer simulations with data from lake trials demonstrate that the proposed method is effective and obviously outperforms existing methods in resolution and accuracy in the case of low Signal-to-Noise Ratio （SNR）.
