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

Hypothalamic-pituitary-adrenal axis and autonomic nervous system reactivity in children prenatally exposed to maternal depression:A systematic review of prospective studies

Depression is a common condition affecting up to 20% of all pregnant women, and is associated with subsequent developmental and behavioral problems in children, such as conduct disorder and ADHD. One proposed mechanism underlying these associations is modification of the fetal hypothalamic pituitary adrenal (HPA)-axis and the autonomic nervous system (ANS), resulting in altered responses to stress. This review examined the evidence regarding altered HPA-axis and ANS reactivity in children prenatally exposed to high maternal depressive symptoms. A systematic search was conducted in the electronic databases MEDLINE, EMBASE and PsycINFO, for studies published till 25 July 2017. A total of 13 studies comprising 2271 mother-infant dyads were included. None of the studies were suitable for meta-analysis. Risk of bias assessment showed low risk for four studies. Only three studies described an independent association between exposure to high maternal prenatal depressive symptoms and altered stress reactivity in children. There is limited evidence of an independent association between prenatal exposure to maternal depression and altered HPA or ANS reactivity in children

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

Numerical analysis of the effect of nitrogen and oxygen admixtures on the chemistry of an argon plasma jet operating at atmospheric pressure

In this paper we study the cold atmospheric pressure plasma jet, called kinpen, operating in Ar with different admixture fractions up to 1% pure ${{{\rm N}}_{2}}$, ${{{\rm O}}_{2}}$ and ${{{\rm N}}_{2}}$ + ${{{\rm O}}_{2}}$. Moreover, the device is operating with a gas curtain of dry air. The absolute net production rates of the biologically active ozone (${{{\rm O}}_{3}}$) and nitrogen dioxide (${\rm N}{{{\rm O}}_{2}}$) species are measured in the far effluent by quantum cascade laser absorption spectroscopy in the mid-infrared. Additionally, a zero-dimensional semi-empirical reaction kinetics model is used to calculate the net production rates of these reactive molecules, which are compared to the experimental data. The latter model is applied throughout the entire plasma jet, starting already within the device itself. Very good qualitative and even quantitative agreement between the calculated and measured data is demonstrated. The numerical model thus yields very useful information about the chemical pathways of both the ${{{\rm O}}_{3}}$ and the ${\rm N}{{{\rm O}}_{2}}$ generation. It is shown that the production of these species can be manipulated by up to one order of magnitude by varying the amount of admixture or the admixture type, since this affects the electron kinetics significantly at these low concentration levels

Cognitive Behavioral Therapy for Antenatal Depression in a Pilot Randomized Controlled Trial and Effects on Neurobiological, Behavioral and Cognitive Outcomes in Offspring 3-7 Years Postpartum:A Perspective Article on Study Findings, Limitations and Future Aims

Purpose of Article: In a previous pilot randomized controlled trial including 54 pregnant women with depression, maternal mood improved after Cognitive Behavioural Therapy (CBT) compared to treatment as usual (TAU), showing medium to large effect sizes. The effect persisted up to 9 months postpartum, with infant outcomes also showing medium to large effects favoring CBT in various child domains. This perspective article summarizes the results of a follow-up that was performed approximately 5 years later in the same cohort, assessing the effects of antenatal Cognitive Behavioural Therapy for depression and anxiety on child buccal cell DNA-methylation, brain morphology, behavior and cognition. Findings: Children from the CBT group had overall lower DNA-methylation compared to children from the TAU group. Mean DNA-methylation of all NR3C1 promoter-associated probes did not differ significantly between the CBT and TAU groups. Children from the CBT group had a thicker right lateral occipital cortex and lingual gyrus. In the CBT group, Voxel-Based-Morphometry analysis identified one cluster showing increased gray matter concentration in the right medial temporal lobe, and fixel-based analysis revealed reduced fiber-bundle-cross-section in the Fornix, the Optical Tract, and the Stria Terminalis. No differences were observed in full-scale IQ or Total Problems Score. When the total of hypotheses tests in this study was considered, differences in DNA-methylation and brain measurements were no longer significant. Summary: Our explorative findings suggest that antenatal depression treatment decreases overall child DNA-methylation, increases cortical thickness, and decreases white matter fiber-bundle cross-section in regions involved in cognitive function and the stress response. Nevertheless, larger studies are warranted to confirm our preliminary conclusion that CBT in pregnancy alters neurobiological outcomes in children. Clinical relevance remains unclear as we found no effects of antenatal CBT on child behavior or cognition (yet)

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

Determinants of Cortisol During Pregnancy − the ABCD Cohort

BACKGROUND: Psychosocial stress during pregnancy has been proposed as a major contributor of glucocorticoid-mediated programming of the fetal hypothalamic-pituitary adrenal (HPA) axis, with later adverse health consequences. However, evidence linking maternal stress to maternal cortisol values during pregnancy is inconclusive. A possible explanation for this is that other maternal factors overshadow any potential effects of stress on cortisol levels. We studied a large cohort of pregnant women with extensive data on pregnancy characteristics to determine the respective contributions of biological, environmental and psychosocial stress factors to cortisol levels in pregnancy. METHODS: We used data from 3039 women from the Amsterdam Born Children and their Development-study cohort. Serum cortisol was measured in blood, collected at the first prenatal visit, at different gestational ages (median=91days, range=40-256days), and at various time points during the day (median=11:45h, range=08:00-18:30h). We assessed associations between maternal serum cortisol in pregnancy and biological factors, lifestyle factors and stress factors, including depression, anxiety, pregnancy-related anxiety, work stress, parenting stress and fatigue. RESULTS: In multivariable analysis, variables that were associated with higher cortisol levels in pregnancy were lower maternal age [1.5nmol/l, 95%CI (0.6-2.4)], being nulliparous [21.5 nmol/l (15.9-27.1)], lower pre-pregnancy body mass index (BMI) [1.3nmol/l (0.3-2.4)], higher C-reactive protein (CRP) [1.0nmol/l (0.4-1.5)], carrying a female fetus [9.2nmol/l (1.8-16.5)], non-smoking [14.2nmol/l (0.6-27.7)], sufficient sleep [8.5nmol/l (0.9-16.1)], and being unemployed [12.7nmol/l (2.2-23.2)]. None of the psychosocial stressors was significantly associated with serum cortisol levels in pregnancy. A total of 32% of all variance in cortisol was explained by gestational age, maternal age, time of day, parity, pre-pregnancy BMI, CRP, fetal sex, smoking behavior, self-reported sleep sufficiency, and employment. CONCLUSIONS: Our data suggest that maternal cortisol during pregnancy is mainly affected by biological and lifestyle factors, but not by psychosocial factors. We suggest that psychosocial stress in pregnancy might program the fetus through other mechanisms than through altering maternal cortisol levels

Intra- and Inter-Subunit Disulfide Bond Formation Is Nonessential in Adeno-Associated Viral Capsids

The capsid proteins of adeno-associated viruses (AAV) have five conserved cysteine residues. Structural analysis of AAV serotype 2 reveals that Cys289 and Cys361 are located adjacent to each other within each monomer, while Cys230 and Cys394 are located on opposite edges of each subunit and juxtaposed at the pentamer interface. The Cys482 residue is located at the base of a surface loop within the trimer region. Although plausible based on molecular dynamics simulations, intra- or inter-subunit disulfides have not been observed in structural studies. In the current study, we generated a panel of Cys-to-Ser mutants to interrogate the potential for disulfide bond formation in AAV capsids. The C289S, C361S and C482S mutants were similar to wild type AAV with regard to titer and transduction efficiency. However, AAV capsid protein subunits with C230S or C394S mutations were prone to proteasomal degradation within the host cells. Proteasomal inhibition partially blocked degradation of mutant capsid proteins, but failed to rescue infectious virions. While these results suggest that the Cys230/394 pair is critical, a C394V mutant was found viable, but not the corresponding C230V mutant. Although the exact nature of the structural contribution(s) of Cys230 and Cys394 residues to AAV capsid formation remains to be determined, these results support the notion that disulfide bond formation within the Cys289/361 or Cys230/394 pair appears to be nonessential. These studies represent an important step towards understanding the role of inter-subunit interactions that drive AAV capsid assembly

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