Flow velocity waveforms from the left and right uterine artery were studied relative to transcervical chorionic villus sampling (CVS) between 9 and 11 weeks of gestation in 12 uncomplicated pregnancies and 5 pregnancies resulting in second trimester fetal loss. There was no significant difference in mean pulsatility index (PI) as a measure of downstream impedance, between the left and right uterine artery. There were also no significant changes in PI relative to the CVS procedure both in uncomplicated pregnancies and in pregnancies ending in second trimester fetal loss.
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http://dx.doi.org/10.1016/0301-5629(90)90140-8 | DOI Listing |
Sci Rep
January 2025
Yunnan Institute of Building Research Ltd, Kunming, Yunnan, 650223, China.
Due to various factors, the concrete may contain mud, a condition that can lead to a decrease in strength and changes in the ultrasonic acoustic parameters of the concrete. In order to study the effect of concrete mud content ([Formula: see text]) on ultrasonic acoustic parameters and compressive strength, this paper firstly derived the relationship equations between concrete mud content and acoustic parameters and compressive strength. Subsequently, the acoustic parameters and compressive strength were tested for concrete specimens with different mud contents cast on site.
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January 2025
School of Engineering, The University of Manchester, Manchester, UK.
This study examines how heart rate (HR) affects hemodynamics in a South African infant with Coarctation of the Aorta. Computed tomography angiography segments aortic coarctation anatomy; Doppler echocardiography derives inlet flow waveforms. Simulations occur at 100, 120, and 160 beats per minute, representing reduced, resting, and elevated HR levels.
View Article and Find Full Text PDFInt J Gynaecol Obstet
January 2025
Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan.
Objectives: To assess hotspot micro-vessel flow velocity waveforms in human papillomavirus (HPV) cervical infections using transvaginal power Doppler ultrasound (TV-PDU) and explore associations with high-grade squamous intraepithelial lesions (HSIL, cervical intraepithelial neoplasia [CIN] II and III).
Methods: In all, 62 patients with confirmed HPV-HSIL (14 CIN II, 48 CIN III) and 65 age- and parity-matched women with neither HPV infection nor CIN were compared. Seven parameters by TV-PDU were used to assess vascular classification and micro-vessel flow velocity, including vascular grading (class I, II, III), lowest pulsatility index (PI), resistance index (RI), peak systolic velocity (PS), end-diastolic velocity (ED), time average maximum velocity (TAMV), and the vascular index (VI = PS/ED).
Biomech Model Mechanobiol
January 2025
Laboratoire d'Imagerie Biomédicale (LIB), Institut National de La Recherche Médicale (INSERM), Centre National de La Recherche Scientifique (CNRS), Sorbonne Université, Paris, France.
Atrial fibrillation (AF) is characterized by rapid and irregular contraction of the left atrium (LA). Impacting LA haemodynamics, this increases the risk of thrombi development and stroke. Flow conditions preceding stroke in these patients are not well defined, partly due the limited resolution of 4D flow magnetic resonance imaging (MRI).
View Article and Find Full Text PDFUltrasonics
January 2025
Medical Ultrasound Department for the Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu 215163, China. Electronic address:
Shear Wave Elastography (SWE) is an imaging technique that detects shear waves generated by tissue excited by Acoustic Radiation Force (ARF), and characterizes the mechanical properties of soft tissue by analyzing the propagation velocity of shear wave. ARF induces a change in energy density through the nonlinear propagation of ultrasound waves, which drives the tissue to generate shear waves. However, the amplitude of shear waves generated by ARF is weak, and the shear waves are strongly attenuated in vivo.
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