Glucocorticoid Receptor Gene Variants and Neonatal Outcome in Very-Low-Birth-Weight Preterm Infants

Background: Induction of lung maturation by prenatal steroid treatment has become the standard of care for pregnant women at risk for preterm birth. In addition to the beneficial effects on lung maturation, prenatal steroids have been shown to reduce the incidence of neonatal death, necrotizing enterocolitis, sepsis, and intraventricular hemorrhage. However, little is known about the role of interindividual differences in corticoid sensitivity arising from polymorphisms in the glucocorticoid receptor (GR) gene. Objectives: To assess the impact of GR polymorphisms N363S (rs56149945), R23K (rs6190), and BclI (rs41423247) on neonatal outcome. Methods: The GR polymorphisms N363S, R23K, and BclI were examined in 10,490 very-low-birth-weight (VLBW) preterm infants from 49 German tertiary level neonatal units (German Neonatal Network, GNN) with respect to neonatal outcome. Results: Infants carrying the BclI genotype were at higher risk to develop bronchopulmonary dysplasia (BPD) (OR 1.12 per BclI allele, 95% CI: 1.02-1.23, p = 0.013) in a logistic regression model adjusted for gestational age, mechanical ventilation, and small for gestational age status. A similar relative risk was seen in the children (89.4%) who received antenatal betamethasone treatment (OR 1.16, 95% CI: 1.05-1.27, p = 0.003), whereas no such effect was detectable in infants without antenatal steroids. N363S and R23K did not show any stable association with neonatal outcome parameters. Conclusion: Except for a slightly higher risk of BPD in carriers of the GRBclI variant, the GR gene polymorphisms BclI, N363S, and R23K did not affect neonatal outcome parameters in this large multicenter cohort of VLBW preterm infants

Noninvasive 3D Field Mapping of Complex Static Electric Fields

Many upcoming experiments in antimatter research require low-energy antiproton beams. With a kinetic energy in the order of 100 keV, the standard magnetic components to control and focus the beams become less effective. Therefore, electrostatic components are being developed and installed in transfer lines and storage rings. However, there is no equipment available to precisely map and check the electric field generated by these elements. Instead, one has to trust in simulations and, therefore, depend on tight fabrication tolerances. Here we present, for the first time, a noninvasive way to experimentally probe the electrostatic field in a 3D volume with a microsensor. Using the example of an electrostatic quadrupole focusing component, we find excellent agreement between a simulated and real field. Furthermore, it is shown that the spatial resolution of the probe is limited by the electric field curvature which is almost zero for the quadrupole. With a sensor resolution of 61V/m/√Hz, the field deviation due to a noncompliance with the tolerances can be resolved. We anticipate that this compact and practical field strength probe will be relevant also for other scientific and technological disciplines such as atmospheric electricity or safeguarding near power infrastructure

Design and Optimization of Electrostatic Deflectors for ELENA

The ELENA ring will decelerate the antiprotons ejected from the Antiproton Decelerator (AD) at 5.3 MeV down to 100 keV kinetic energy. The slow antiprotons will be delivered to experiments using electrostatic beamlines, consisting of quadrupoles, correctors and deflectors. An extensive simulation study was carried out to find solutions to minimize the aberrations of the deflectors. These solutions will be presented together with the actual design of these devices

Neurodevelopmental pathways to preterm children's specific and general mathematic abilities

Background Preterm children have problems with mathematics but knowledge about the predictors of specific mathematic abilities in preterm populations is scarce. Aims This study investigated neurodevelopmental pathways to children's general and specific mathematic abilities across the full gestational age range. Study design Prospective geographically defined longitudinal investigation in Germany. Subjects 947 children across the full gestational age range (23–41 weeks). Outcome measures. At 8 years, children's cognitive and mathematic abilities were measured and residuals of a regression predicting mathematic scores by IQ were used to identify specific mathematic abilities. Results Neurodevelopmental cascade models revealed that adverse effects of preterm birth on mathematic abilities were mediated by neonatal risk. Specific mathematic abilities were uniquely predicted by the duration of hospitalization and ventilation. Conclusions Prolonged neonatal medical treatment and, in particular, mechanical ventilation may lead to specific impairments in mathematic tasks. These findings have implications for the mode of respiratory support in neonates, routine follow-up and intervention planning as well as research about brain reorganization after preterm birth

Beam Dynamics Studies of the ELENA Electrostatic Transfer Lines

The low-energy ELENA ring at the Antiproton Decelerator (AD) facility at CERN will lower the kinetic energy of antiproton beams from 5.3 MeV to 100 keV, significantly increasing the antiproton trapping efficiency at the experiments. The antiprotons from ELENA will be distributed to two experimental areas housing several different experiments through a system of electrostatic transfer lines totalling 90 m in length. A significant optimisation of the electrostatic optical elements (deflectors, quadrupoles, and correctors) has been carried out to improve the beam quality delivered to the experiments and facilitate installation of the beam lines into the AD hall. A general overview of the beam optics is presented, including end-to-end particle tracking and error studies from the extraction point in the ELENA ring to the experiments

Beam-Based Kicker Waveform Measurements Using Long Bunches

The increased bunch length demanded by the LHC Injectors Upgrade (LIU) project to mitigate emittance growth from space-charge on the PS injection plateau puts strong constraints on the rise-times of the recombination kickers in the transfer lines between the CERN Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS). A beam-based technique has been developed to validate the waveforms of the recombination kickers. In this paper high-resolution measurements are presented by extracting the intra-bunch deflection along bunches with lengths comparable to or longer than the rise-time of the kicker being probed. The methodology has been successfully applied to the three vertical recombination kickers named BT1. KFA10, BT4. KFA10 and BT2. KFA20, and benchmarked with direct measurements of the kicker field made using a magnetic field probe. This paper describes the beam-based technique, summarises the main characteristics of the measured waveforms, such as rise-time and flat-top ripple, and estimates their impact on beam brightness

Preliminary Estimate of Beam Induced Power Deposition in a FCC-hh Injection Kicker Magnet

The Future Circular Collider for hadrons (FCC-hh) will require a fast injection kicker system that is highly reliable and that does not limit accelerator performance. Important considerations in the design of such a system are machine protection constraints, collider filling factor and hence rise and fall times of the kicker magnet field. Fast rise time kicker magnets are generally ferrite loaded transmission line type magnets with a rectangular shaped aperture. The beam coupling impedance of the kicker magnets is crucial, as this can be a dominant contribution to beam instabilities. In addition, beam-induced heating of the ferrite yoke due to the real component of the longitudinal beam coupling impedance needs to be controlled: if the ferrite temperature exceeds the Curie point this impacts the ability to inject beam and hence the availability of the machine. This paper presents estimates for the beam induced power deposition in the ferrite yoke, based on a calculated FCC beam spectrum and an analytical model of longitudinal impedance for unshielded kicker magnets

LHC injection losses and trajectories during Run 1 and 2 and outlook to injection of HL-LHC beams

The LHC turn-around time is impacted by the control of injection losses and trajectories. While shot-to-shot trajectory variations dominated the injection efficiency during LHC Run 1, several improvements of hardware and operational settings allowed for a high rate of successful injections during Run 2. Injection losses and trajectories are analysed and presented for the high intensity proton runs, as well as for different beam types used from the injectors. Based on this analysis, an outlook is shown for the HL-LHC era, where double the bunch intensity will have to be injected

Reliability Considerations for the LHC MKB Re-trigger Upgrade During LS2

An upgrade of the LHC dilution kicker system (MKB) during LS2 foresees the new implementation of a MKB re-trigger mechanism. Immediate re-triggering of the remaining MKB in case of a pre-firing module through the currently existing re-trigger line will be enabled. A decoupling system in the re-trigger line is proposed to inhibit asynchronous extraction kicker triggering in case of such self-triggering MKBs. In this report, different design proposals for this decoupling mechanism are evaluated and reliability assessments for the newly introduced system are conducted

Beam Based Measurements to Check Integrity of LHC Dump Protection Elements

LHC operation is approaching its nominal operating goals and several upgrades are also being prepared to increase the beam intensity and brightness. In case of an asynchronous beam dump at 6.5 - 7 TeV a non-negligible fraction of the stored energy (360 MJ during nominal operation) will be deposited on the protection elements (TCDQ and TCDS) located downstream of the extraction kickers. These elements are designed to protect the machine aperture from the large amplitude particles resulting from the asynchronous dump. A number of checks and measurements with beam have been worked out to verify the integrity of these elements, after a potentially harmful event, without opening the machine vacuum. Details on measurements and simulations performed to evaluate the validity of the proposed method are presented in this paper