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Doppler velocimetry

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https://www.readbyqxmd.com/read/28059254/nonmechanical-scanning-laser-doppler-velocimetry-for-distribution-measurements-of-two-dimensional-velocity-vectors-based-on-optical-quadrature-detection
#1
Koichi Maru
This paper proposes a nonmechanical scanning laser Doppler velocimeter (LDV) for measuring the distribution of two-dimensional velocity vectors. In the proposed LDV, an optical quadrature detection technique and a nonmechanical axial scanning technique are introduced into a reference-type LDV. Consequently, the LDV has a simple optical system without multiple light sources or frequency shifting and does not have any moving mechanisms in the probe. The experimental results obtained using a sensor probe setup indicate that the function of measuring two-dimensional velocity vectors and the scanning function are successfully demonstrated...
December 20, 2016: Applied Optics
https://www.readbyqxmd.com/read/28050448/accuracy-of-pelvic-mass-score-in-pre-operative-determination-of-malignancy-in-adnexal-masses
#2
Lakshmi Mohan, Arun Rao, Sonali Ullal, Gowtham Krishna
INTRODUCTION: Suspicious adnexal masses are common clinical problems in gynaecological practice. A reliable diagnostic tool for the early detection of the ovarian malignancy is essential. AIM: To validate a new scoring system -Pelvic Mass Score (PMS) in predicting the nature of the adnexal mass pre-operatively. MATERIALS AND METHODS: A prospective observational study was carried out in 100 consenting women with an undiagnosed adnexal mass requiring operative intervention...
November 2016: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28029583/acr-appropriateness-criteria-assessment-of-fetal-well-being
#3
Lynn Simpson, Nadia J Khati, Sandeep P Deshmukh, Kika M Dudiak, Mukesh G Harisinghani, Tara L Henrichsen, Benjamin J Meyer, David A Nyberg, Liina Poder, Thomas D Shipp, Carolyn M Zelop, Phyllis Glanc
Although there is limited evidence that antepartum testing decreases the risk for fetal death in low-risk pregnancies, women with high-risk factors for stillbirth should undergo antenatal fetal surveillance. The strongest evidence supporting antepartum testing pertains to pregnancies complicated by intrauterine fetal growth restriction secondary to uteroplacental insufficiency. The main ultrasound-based modalities to determine fetal health are the biophysical profile, modified biophysical profile, and duplex Doppler velocimetry...
October 28, 2016: Journal of the American College of Radiology: JACR
https://www.readbyqxmd.com/read/27957524/fetal-hemodynamic-parameters-in-low-risk-pregnancies-doppler-velocimetry-of-uterine-umbilical-and-middle-cerebral-artery
#4
C O Figueira, F G Surita, M S Dertkigil, S L Pereira, J R Bennini, S S Morais, J Mayrink, J G Cecatti
Objective. To elaborate curves of longitudinal reference intervals of pulsatility index (PI) and systolic velocity (SV) for uterine (UtA), umbilical (UA), and middle cerebral arteries (MCA), in low risk pregnancies. Methods. Doppler velocimetric measurements of PI and SV from 63 low risk pregnant women between 16 and 41 weeks of gestational age. Means (±SD) for intervals of gestational age and percentiles 5, 50, and 95 were calculated for each parameter. The Intraclass Correlation Coefficients (ICC) were also estimated for assessing intra- and intervariability of measurements...
2016: TheScientificWorldJournal
https://www.readbyqxmd.com/read/27956506/hugoniot-equation-of-state-of-rock-materials-under-shock-compression
#5
Q B Zhang, C H Braithwaite, J Zhao
Two sets of shock compression tests (i.e. conventional and reverse impact) were conducted to determine the shock response of two rock materials using a plate impact facility. Embedded manganin stress gauges were used for the measurements of longitudinal stress and shock velocity. Photon Doppler velocimetry was used to capture the free surface velocity of the target. Experimental data were obtained on a fine-grained marble and a coarse-grained gabbro over a shock pressure range of approximately 1.5-12 GPa...
January 28, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/27941711/recurrent-acute-myocardial-infarction-in-a-patient-with-severe-coronary-artery-ectasia-implication-of-antithrombotic-therapy
#6
Tomoko Tomioka, Satoshi Takeuchi, Yoshitaka Ito, Hiroki Shioiri, Jiro Koyama, Kanichi Inoue
BACKGROUND Acute myocardial infarction (AMI) can be caused not only by plaque rupture/erosion, but also by many other mechanisms. Thromboembolism due to atrial fibrillation and coronary thrombosis due to coronary artery ectasia are among the causes. Here we report on a case of recurrent myocardial infarction with coronary artery ectasia. CASE REPORT Our case was a 78-year-old woman with hypertension. Within a one-month interval, she developed AMI twice at the distal portion of her right coronary artery along with coronary artery ectasia...
December 12, 2016: American Journal of Case Reports
https://www.readbyqxmd.com/read/27939906/hypoperfusion-in-response-to-epinephrine-in-local-anaesthetics-investigation-of-dependence-on-epinephrine-concentration-spread-of-hypoperfusion-and-time-to-maximal-cutaneous-vasoconstriction
#7
Rafi Sheikh, Khashayar Memarzadeh, Christian Torbrand, Jonas Blohmé, Malin Malmsjö
OBJECTIVES: The present study aimed to examine hypoperfusion in response to epinephrine following the administration of a local anaesthetic. The concentration of epinephrine that causes maximal hypoperfusion, the spread of hypoperfusion in the tissue and the time to the stabilization of hypoperfusion were investigated. METHODS: Blood perfusion was monitored using laser Doppler velocimetry and laser speckle contrast imaging of random-pattern advancement flaps (1 × 4 cm) or intact skin on the pig flank...
November 11, 2016: Journal of Plastic, Reconstructive & Aesthetic Surgery: JPRAS
https://www.readbyqxmd.com/read/27939473/bedside-cardiovascular-maternal-interrogation-in-the-first-trimester-to-predict-different-phenotypes-of-hypertensive-disorders-in-pregnancy
#8
Daniela Denis Di Martino, Tamara Stampalija, Eleonora Rosti, Daniela Casati, Valentina Signorelli, Sara Zullino, Cristina Mastroianni, Mariachiara Quadrifoglio, Enrico Ferrazzi
OBJECTIVE: The aim is to evaluate if maternal cardiovascular indices, in the first trimester of pregnancy, might be useful to differentiate women who develop different hypertensive disorders of pregnancy (HDP). STUDY DESIGN: Method: 1399 pregnant women attending screening for chromosomal aneuploidies were recruited. The following parameters were measured: Doppler Velocimetry of uterine arteries; Peripheral blood pressure; Aortic Pressure derived from applanation tonometry...
October 2016: Pregnancy Hypertension
https://www.readbyqxmd.com/read/27934516/impact-of-spatial-distribution-of-charged-groups-in-core-poly-n-isopropylacrylamide-based-microgels-on-the-resultant-composite-structures-prepared-by-seeded-emulsion-polymerization-of-styrene
#9
Takumi Watanabe, Chiaki Kobayashi, Chihong Song, Kazuyoshi Murata, Takuma Kureha, Daisuke Suzuki
A series of raspberry-shaped composite microgels were synthesized by seeded emulsion polymerization of styrene in the presence of hydrogel particles with different distributions of charged groups. Unlike microgels whose charged groups are localized in their center,29 polystyrene nanoparticles were formed inside the core microgels when the microgels whose charged groups were localized on their surface were used as cores for seeded emulsion polymerization. The effects of the surface charge densities of the core microgels and the concentration of styrene monomer during the polymerization on the resultant structures of composite microgels were investigated...
December 6, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/27925050/fetal-thrombotic-vasculopathy-a-case-report-and-literature-review
#10
Ana Berquo Peleja, Silvio Martinelli, Renata Lopes Ribeiro, Roberto Eduardo Bittar, Regina Schultz, Rossana Pulcineli Vieira Francisco
Introduction: Fetal thrombotic vasculopathy is a recently described placental alteration with varying degrees of involvement and often associated with adverse perinatal outcomes. The diagnosis is made histologically and therefore is postnatal, which makes it a challenge in clinical practice. Method: Case report and review of literature on the subject. Results: The present case refers to a pregnant woman presenting fetal growth restriction, with poor obstetrical past, and sent late to our service...
October 2016: Revista da Associação Médica Brasileira
https://www.readbyqxmd.com/read/27923143/monolayers-of-immunoglobulin-g-on-polystyrene-microparticles-and-their-interactions-with-human-serum-albumin
#11
Paulina Żeliszewska, Monika Wasilewska, Zbigniew Adamczyk
The adsorption of mouse monoclonal immunoglobulin G (IgG) on negatively charged polystyrene microparticles was studied by the laser Doppler velocimetry (LDV) electrophoretic mobility measurements. The dependence of the electrophoretic mobility of microparticles on the IgG concentration in the suspension was determined for different ionic strengths and pHs (3.5, 7.4). The increase in the electrophoretic mobility was quantitatively interpreted in terms of the 3D electrokinetic model. The maximum coverage of IgG on latex was determined by the depletion method aided by AFM imaging...
November 27, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27868455/identification-of-patients-at-risk-for-preeclampsia-with-the-use-of-uterine-artery-doppler-velocimetry-and-copeptin
#12
Ali Yeşil, Ammar Kanawati, Çağlar Helvacıoğlu, Cihan Kaya, Çağseli Göksu Özgün, Hüseyin Cengiz
PURPOSE: To investigate the relationship between maternal copeptin levels and uterine artery Doppler examination and progress of preeclampsia. MATERIALS AND METHODS: A cross-sectional study was designed with women those were screened at 20 + 0 - 24+  6 weeks' gestation between May 2014 and August 2014. The obstetric records of all normotensive women were examined. Uterine artery Doppler velocimetry results and serum copeptin levels were measured. The patients were divided into two groups according to normal (n = 67) and abnormal uterine artery Doppler (n = 21) findings...
December 7, 2016: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/27855988/development-of-a-platelet-adhesion-transport-equation-for-a-computational-thrombosis-model
#13
Joshua O Taylor, Ling Yang, Steven Deutsch, Keefe B Manning
Thrombosis is a significant issue for cardiovascular device development and use. While thrombosis models are available, very few are device-related and none have been thoroughly validated experimentally. Here, we introduce a surface adherent platelet transport equation into a continuum model to account for the biomaterial interface/blood interaction. Using a rotating disc system and polyurethane-urea material, we characterize steady and pulsatile flow fields using laser Doppler velocimetry. In vitro measurements of platelet adhesion are used in combination with the LDV data to provide further experimental validation...
January 4, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/27828276/fundamental-uncertainty-limit-of-optical-flow-velocimetry-according-to-heisenberg-s-uncertainty-principle
#14
Andreas Fischer
Optical flow velocity measurements are important for understanding the complex behavior of flows. Although a huge variety of methods exist, they are either based on a Doppler or a time-of-flight measurement principle. Doppler velocimetry evaluates the velocity-dependent frequency shift of light scattered at a moving particle, whereas time-of-flight velocimetry evaluates the traveled distance of a scattering particle per time interval. Regarding the aim of achieving a minimal measurement uncertainty, it is unclear if one principle allows to achieve lower uncertainties or if both principles can achieve equal uncertainties...
November 1, 2016: Applied Optics
https://www.readbyqxmd.com/read/27795833/timing-and-cause-of-perinatal-mortality-for-small-for-gestational-age-babies-in-south-africa-critical-periods-and-challenges-with-detection
#15
Tina Lavin, David B Preen, Robert Pattinson
BACKGROUND: Little information exists on timing and cause of death for small-for-gestational-age (SGA) babies in low-and-middle-income-countries (LMICs), despite evidence from high-income countries suggesting critical periods for SGA babies. This study explored the timing and cause of stillbirth and early neonatal mortality (END, <7 days) by small-for-gestational age in three provinces in South Africa. In South Africa, the largest category of perinatal deaths is unexplained stillbirth, of which up to one-quarter have intra-uterine growth restriction...
2016: Maternal Health, Neonatology and Perinatology
https://www.readbyqxmd.com/read/27734717/association-between-uterine-artery-doppler-blood-flow-changes-and-arterial-wall-elasticity-in-pregnant-women
#16
Emma von Wowern, Jakob Andersson, Ida Dalene Skarping, Maria T Howie, Per Olofsson
INTRODUCTION: Uterine artery (UtA) Doppler velocimetry changes and increased arterial stiffness are associated with preeclampsia. We aimed to investigate the relation between UtA velocimetry changes and arterial stiffness in pregnant women. METHODS: Doppler velocimetry and photoplethysmographic digital pulse wave analysis (DPA) were performed in 173 pregnant women in the second or third trimester, where UtA Doppler pulsatility index (PI), diastolic notching, and UtA score (UAS) combining notching and high PI were calculated...
October 13, 2016: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/27680818/h2-maternal-hemodynamic-status-in-pregnancies-complicated-by-intrauterine-growth-restriction-iugr-and-post-partum-follow-up
#17
D Di Martino, S Zullino, D Casati, A S Grimaldi, V Sterpi, G Principato, M Garbin, E Ferrazzi
AIMS: To investigate maternal hemodynamic status in pregnancies complicated by IUGR and in the post-partum. METHODS: In this prospective study, we enrolled pregnant women between 24 and 38 weeks divided in severe and mild IUGR and a group of controls matched for gestational age. Severe IUGR was defined as abdominal circumference <5th centile and a Doppler velocimetry in umbilical artery42SD. Mild IUGR was defined as an abdominal circumference <10th centile and a Doppler velocimetry in umbilical artery <2SD...
August 2016: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/27680812/g1-maternal-haemodynamics-assessment-in-preterm-delivery-two-different-haemodynamic-profiles
#18
D Farsetti, D Lo Presti, I Pisani, G M Tiralongo, G Gagliardi, B Vasapollo, G P Novelli, H Valensise
INTRODUCTION: The purpose of our study was to evaluate the maternal haemodynamic profile in women diagnosed with threatened preterm delivery (TPD) in order to understand the possible pathophysiologic mechanism leading to an increased lifetime risk for future cardiovascular disease. METHODS: Sixty-eight patients diagnosed with TPD were enrolled and assessed using a non-invasive method (USCOM®) to determine the haemodynamic parameters. Cervix length assessment, vaginal and rectal swabs, blood inflammatory indexes, foetal vessel Doppler velocimetry, gestational age at the delivery and neonatal outcomes were considered...
August 2016: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/27680792/c1-maternal-hemodynamic-profile-in-hypertensive-disorders-of-pregnancy-hdp-and-intrauterine-growth-restriction
#19
D Di Martino, S Zullino, D Casati, A S Grimaldi, C Mastroianni, G Principato, E Rosti, M Garbin, E Ferrazzi
AIMS: To investigate maternal hemodynamic status in pregnancies complicated by HDP and/or IUGR and by severe IUGR without HDP. METHODS: In this prospective study we enrolled pregnant women between 24 and 38 weeks divided in: HDP with appropriate for gestational age fetuses (HDP-AGA), HDP associated with IUGR (HDPIUGR), severe IUGR and a group of controls matched for gestational age. Severe IUGR was defined as abdominal circumference <5th centile and a Doppler velocimetry in umbilical artery42SD...
August 2016: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/27665076/monolayers-of-poly-amido-amine-dendrimers-on-mica-in-situ-streaming-potential-measurements
#20
Aneta Michna, Zbigniew Adamczyk, Kamila Sofińska, Katarzyna Matusik
The deposition of poly(amido amine) dendrimers on mica at various pHs was studied by the atomic force microscopy (AFM) and in situ streaming potential measurements. Bulk characteristics of dendrimers were acquired by using the dynamic light scattering (DLS) and the laser Doppler velocimetry (LDV). The hydrodynamic radius derived from DLS measurements was 5.2nm for the ionic strength of 10(-2)M and pH range 4-10. The electrophoretic mobility, the zeta potential and the number of electrokinetic charges per molecule were derived as a function of pH from the LDV measurements...
January 1, 2017: Journal of Colloid and Interface Science
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