Curves of Placental Weights of Live-Born Twins

The purpose of this study is to present curves of estimated placental growth in twins and to evaluate the relative contribution of gestational age, zygosity, chorionicity, fusion of the placentas, sex of the individual and of the twin pair, site of the umbilical cord insertion, birth order, maternal age, and parity. Perinatal data and placental data were obtained from 6315 live-born twin pairs from the East Flanders Prospective Twin Survey. Of 4318 twin pairs, with no missing values, the placental weights of different gestational ages were analyzed using a nonlinear multivariate Gaussian regression. Two groups were distinguished: (1) twins with two separate placentas, and (2) twins with only one placental mass (one placenta in case of monochorionic twins or two fused placentas in case of dichorionic placentas). Overall, placental weight was influenced by gestational age, fusion of the placentas, and parity. In the case of one placental mass, monozygotic dichorionic twins had the lowest weights. If two separate placentas were present, birth order played a role in favor of the first-born twin. For parity and zygosity, the differences were most pronounced between 27 and 29 weeks, whereas the difference for birth order was most pronounced between 33 and 37 weeks. In conclusion, basic physiological characteristics, routinely examined at birth, influence placental weight. Taking these covariates into account allows a better evaluation of the placental weight given a gestational age, as an indicator of growth

Interaction of Atmospheric Pressure Plasma Jets with Liquids

In this work, the interaction of atmospheric pressure plasmas with liquids is investigated. On the exampleof hydrogen peroxide, generation and transport mechanisms are studied from the plasma to the gas- andliquid phase. Interaction with the ambient surroundings is investigated and effects of nitrogen and oxygenspecies on the plasma dynamics a well as on the reactive species generation in the liquid phase arediscusse

The spatial distribution of HO2in an atmospheric pressure plasma jet investigated by cavity ring-down spectroscopy

Cold atmospheric pressure plasma jets make important contributions to a range of fields, such as materials processing and plasma medicine. In order to optimise the effect of those plasma sources, a detailed understanding of the chemical reaction networks is pivotal. However, the small diameter of plasma jets makes diagnostics challenging. A promising approach to obtain absolute number densities is the utilisation of cavity-enhanced absorption spectroscopy methods, by which line-of-sight averaged densities are determined. Here, we present first measurements on how the spatial distribution of HO2 in the effluent of a cold atmospheric pressure plasma jet can be obtained by cavity ring-down spectroscopy in an efficient way. Instead of recording fully wavelength resolved spectra, we will demonstrate that it is sufficient to measure the absorption coefficient at two wavelengths, corresponding to the laser being on and off the molecular resonance. By sampling the effluent from the 1.6 mm diameter nozzle in the radial direction at various axial positions, we determined that the distances over which the HO2 density was distributed were (3.9 ± 0.5) mm and (6.7 ± 0.1) mm at a distance of 2 mm and 10 mm below the nozzle of the plasma jet, respectively. We performed an Abel inversion in order to obtain the spatial distribution of HO2 that is presented along the symmetry axis of the effluent. Based on that localised density, which was (4.8 ± 0.6) ⋅ 1014 cm-3 at the maximum, we will discuss the importance of the plasma zone for the production of HO2

Continuous gas temperature measurement of cold plasma jets containing microdroplets, using a focussed spot IR sensor

Controlling gas temperature via continuous monitoring is essential in various plasma applications especially for biomedical treatments and nanomaterial synthesis but traditional techniques have limitations due to low accuracy, high cost or experimental complexity. We demonstrate continuous high-accuracy gas temperature measurements of low-temperature atmospheric pressure plasma jets using a small focal spot infrared sensor directed at the outer quartz wall of the plasma. The impact of heat transfer across the capillary tube was determined using calibration measurements of the inner wall temperature. Measured gas temperatures varied from 25 °C–50 °C, increasing with absorbed power and decreased gas flow. The introduction into the plasma of a stream (∼105 s−1) of microdroplets, in the size range 12 μm–15 μm, led to a reduction in gas temperature of up to 10 °C, for the same absorbed power. This is an important parameter in determining droplet evaporation and its impact on plasma chemistry

Gas mixing enhanced by power modulations in atmospheric pressure microwave plasma jet

Microwave plasma jet operating in atmospheric pressure argon was power modulated by audio frequency sine envelope in the 10^2 W power range. Its effluent was imaged using interference filters and ICCD camera for several different phases of the modulating signal. The combination of this fast imaging with spatially resolved optical emission spectroscopy provides useful insights into the plasmachemical processes involved. Phase-resolved schlieren photography was performed to visualize the gas dynamics. The results show that for higher modulation frequencies the plasma chemistry is strongly influenced by formation of transient flow perturbation resembling a vortex during each period. The perturbation formation and speed are strongly influenced by the frequency and power variations while they depend only weakly on the working gas flow rate. From application point of view, the perturbation presence significantly broadened lateral distribution of active species, effectively increasing cross-sectional area suitable for applications

Regional perinatal mortality differences in the Netherlands; care is the question

Background. Perinatal mortality is an important indicator of health. European comparisons of perinatal mortality show an unfavourable position for the Netherlands. Our objective was to study regional variation in perinatal mortality within the Netherlands and to identify possible explanatory factors for the found differences. Methods. Our study population comprised of all singleton births (904,003) derived from the Netherlands Perinatal Registry for the period 2000-2004. Perinatal mortality including stillbirth from 22+0weeks gestation and early neonatal death (0-6 days) was our main outcome measure. Differences in perinatal mortality were calculated between 4 distinct geographical regions North-East-South-West. We tried to explain regional differences by adjustment for the demographic factors maternal age, parity and ethnicity and by socio-economic status and urbanisation degree using logistic modelling. In addition, regional differences in mode of delivery and risk selection were analysed as health care factors. Finally, perinatal mortality was analysed among five distinct clinical risk groups based on the mediating risk factors gestational age and congenital anomalies. Results. Overall perinatal mortality was 10.1 per 1,000 total births over the period 2000-2004. Perinatal mortality was elevated in the northern region (11.2 per 1,000 total births). Perinatal mortality in the eastern, western and southern region was 10.2, 10.1 and 9.6 per 1,000 total births respectively. Adjustment for demographic factors increased the perinatal mortality risk in the northern region (odds ratio 1.20, 95% CI 1.12-1.28, compared to reference western region), subsequent adjustment for socio-economic status and urbanisation explained a small part of the elevated risk (odds ratio 1.11, 95% CI 1.03-1.20). Risk group analysis showed that regional differences were absent among very preterm births (22+0- 25+6weeks gestation) and most prominent among births from 32+0gestation weeks onwards and among children with severe congenital anomalies. Among term births (37+0weeks) regional mortality differences were largest for births in women transferred from low to high risk during delivery. Conclusion. Regional differences in perinatal mortality exist in the Netherlands. These differences could not be explained by demographic or socio-economic factors, however clinical risk group analysis showed indications for a role of health care factors

Fetal programming of neuropsychiatric disorders by maternal pregnancy depression: a systematic mini review

BACKGROUND: Maternal depression complicates a large proportion of pregnancies. Current evidence shows numerous harmful effects on the offspring. Reviews, which include depression, concluded that stress has harmful effects on the offspring's outcomes neuro-cognitive development, temperament traits, and mental disorders. OBJECTIVE: This mini review of recent studies, sought to narrow the scope of exposure and identify studies specifically assessing prenatal depression and offspring neuropsychiatric outcomes. STUDY ELIGIBILITY CRITERIA: The review included longitudinal, cohort, cross-sectional, clinical, quasi-experimental, epidemiological, or intervention study designs published in English from 2014 to 2018. PARTICIPANTS: Study populations included mother-child dyads, mother-father-child triads, mother-alternative caregiver-child triads, and family studies utilizing sibling comparisons. METHODS: We searched PubMED and Web of Science. Study inclusion and data extraction were based on standardized templates. The quality of evidence was assessed using the Newcastle-Ottawa Scale (NOS). RESULTS: Thirteen studies examining neuropsychiatric outcomes were included. We judged the evidence to be moderate to high quality. CONCLUSIONS: Our review supports that maternal prenatal depression is associated with neuropsychiatric adversities in children.Peer reviewe

Theodor and Marcella Boveri : chromosomes and cytoplasm in heredity and development

The chromosome theory of heredity, developed in 1902–1904, became one of the foundation stones of twentieth-century genetics. It is usually referred to as the Sutton-Boveri theory after Walter Sutton and Theodor Boveri. However, the contributions of Theodor Boveri and his co-worker, Marcella O’Grady Boveri (also his wife), to the understanding of heredity and development go beyond the localization of the Mendelian hereditary factors onto the chromosomes. They investigated the interaction of cytoplasm and chromosomes, and demonstrated its relevance in heredity and development