7 research outputs found
Umbillical venous volume inflow and liver size in normal and abnormal fetal development
In this thesis the following research objectives were addressed:
To calculate umbilical venous volume flow from cross-sectional area and flow velocity
measurements with emphasis on: (i) the reproducibility of component measurements;
(ii) normal and abnormal fetal development, the latter also relative to umbilical artery
velocimetry.
To establish: (i) reproducibility and normal values for fetal liver volume as obtained by 3-
dimensional ultrasound; (ii) its significance in identifying fetal growth restriction relative to
head and upper abdominal circumference; (iii) its significance in identifying accelerated
growth in fetuses of insulin dependent diabetic mothers.
To determine: (i) normal values for fetal brain/liver volume ratio relative to gestational age;
(ii) the relation between fetal brain/liver volume ratio and umbilical venous volume flow
during normal and abnormal fetal development with emphasis on fetal growth restriction.
To establish: (i) fetal behavioural state dependency of umbilical venous volume flow in late
third trimester normal pregnancy; (ii) the impact of maternal plasma expansion and
antihypertensive treatment on umbilical venous volume flow in pre-eclampsi
Three-dimensional sonographic measurement of normal fetal brain volume during the second half of pregnancy
Objectives: This study was undertaken to develop a three-dimensional (3D) ultrasound method of measuring fetal brain volume. Study design: Serial 3D sonographic measurements of fetal brain volume were made in 68 normal singleton pregnancies a
Three-dimensional US assessment of hepatic volume, head circumference, and abdominal circumference in healthy and growth-restricted fetuses
PURPOSE: To establish reproducibility and normal values for fetal hepatic
volume and its significance in identification of fetal growth restriction
relative to head and upper abdominal circumferences according to a
cross-sectional study design. MATERIALS AND METHODS: Pregnant women (n =
135) underwent ultrasonography. The coefficient of variation (CV) for
hepatic volume scans obtained at 0 and 20 minutes and hepatic area
tracings, performed twice for each scan, was determined (n = 20; range,
23-36 weeks). Normal data for hepatic volume and head and upper abdominal
circumferences were obtained (n = 85; range, 20-36 weeks) and related to
data from growth-restricted fetuses (birth weight < P5 centile; n = 24;
range, 22-36 weeks). RESULTS: CV was 2.9% for volume scans and 1.6% for
area tracings. In 85 uncomplicated cases, mean fetal hepatic volume (P50
centile) was 9.7 mL +/- 4.4 (SD) at 20 weeks and 96.4 mL +/- 8.2 at 36
weeks of gestation. In 24 growth-restricted fetuses, hepatic volume, head
circumference, and upper abdominal circumference expressed as percentages
of the normal P50 centile were 45%, 90%, and 82%, respectively. Mean
difference in hepatic volume between fetal growth restriction and normal
fetal development, as expressed with the z score, -4.32 +/- 1.4, was
significantly different (P <.05) from that for head circumference, -3.04
+/- 1.3, but not from that for upper abdominal circumference, -4.7 +/-
1.2. Fetal hepatic measurement was obtained in 109 pregnancies.
CONCLUSION: Acceptable reproducibility exists for hepatic volume
determinations. In fetal growth restriction, reduction is more pronounced
for hepatic volume than for head or upper abdominal circumference; hepatic
volume is a better discriminator than head circumference but not upper
abdominal circumference
K pi vector form factor, dispersive constraints and tau -> nu_tau K pi decays
Recent experimental data for the differential decay distribution of the decay
by the Belle collaboration are described by a
theoretical model which is composed of the contributing vector and scalar form
factors and . Both form factors are constructed
such that they fulfil constraints posed by analyticity and unitarity. A good
description of the experimental measurement is achieved by incorporating two
vector resonances and working with a three-times subtracted dispersion relation
in order to suppress higher-energy contributions. The resonance parameters of
the charged meson, defined as the pole of in the
complex -plane, can be extracted, with the result MeV and MeV. Finally, employing the
three-subtracted dispersion relation allows to determine the slope and
curvature parameters and
of the vector form factor
directly from the data.Comment: 16 pages, 1 figure, version to appear in Eur. Phys. J.
Physics with the KLOE-2 experiment at the upgraded DANE
Investigation at a --factory can shed light on several debated issues
in particle physics. We discuss: i) recent theoretical development and
experimental progress in kaon physics relevant for the Standard Model tests in
the flavor sector, ii) the sensitivity we can reach in probing CPT and Quantum
Mechanics from time evolution of entangled kaon states, iii) the interest for
improving on the present measurements of non-leptonic and radiative decays of
kaons and eta/eta mesons, iv) the contribution to understand the
nature of light scalar mesons, and v) the opportunity to search for narrow
di-lepton resonances suggested by recent models proposing a hidden dark-matter
sector. We also report on the physics in the continuum with the
measurements of (multi)hadronic cross sections and the study of gamma gamma
processes.Comment: 60 pages, 41 figures; added affiliation for one of the authors; added
reference to section
Physics with the KLOE-2 experiment at the upgraded DAFNE
Investigation at a φ-factory can shed light on several debated issues in particle physics. We discuss: (i) recent theoretical development and experimental progress in kaon physics relevant for the Standard Model tests in the flavor sector, (ii) the sensitivity we can reach in probing CPT and Quantum Mechanics from time evolution of entangled-kaon states, (iii) the interest for improving on the present measurements of non-leptonic and radiative decays of kaons and η/ η' mesons, (iv) the contribution to understand the nature of light scalar mesons, and (v) the opportunity to search for narrow di-lepton resonances suggested by recent models proposing a hidden dark-matter sector. We also report on the e + e - physics in the continuum with the measurements of (multi)hadronic cross sections and the study of γ γ processes