Grounding philosophy

Two aspects of commonly used definitions of the ideal ground are inconsistent with Maxwell's laws. First, a ground cannot be a "perfect sink or source for currents"; not even the large capacitance of our globe acts as a sink. Secondly, a "perfect equipotential point or plane" can be a reality for small dc currents only. For alternating currents however, distributed magnetic fluxes near ground leads make the potential concept, as used in Kirchhoff's laws, meaningless. In this situation where network theory fails, we should concentrate on the ground currents and on the circuits in which these currents flow. Examples are given how these current loops should be designed to minimize impedance and interference. A proper design leads to compact and local grounding and to much reduced currents flowing to Mother Earth

Multi Agent System to Optimize Comfort and Energy Flows in the Built Environment

This paper discusses the control of building energy comfort management systems led by the economic movement within the energy market resulting in different prices. This new generation of building management systems focuses on the application of multi-agent systems for autonomous flexible operation of building services systems to obtain overall improvement energy efficiency and comfort. Multi-agent systems have proven to be successful in many applications to detach the timely interdependencies between systems and applications and come to a decentralize approach. In this study a multi-agent system (MAS) is developed to control and manage building services systems. A case study on an existing building system pointed out that energy consumption is reduced of a central air conditioning unit and local heating and cooling units with help of the proposed market driven multi-agent system, while maintaining comfort within the bands of user preferences. Furthermore it can be concluded that the system adapts to the dynamic changing situation and amount of momentary available resources

Improvement of Cardiac Function After Roux-en-Y Gastric Bypass in Morbidly Obese Patients Without Cardiac History Measured by Cardiac MRI

Purpose: Metabolic syndrome in patients with morbid obesity causes a higher cardiovascular morbidity, eventually leading to left ventricular hypertrophy and decreased left ventricular ejection fraction (LVEF). Roux-en-Y gastric bypass (RYGB) is considered the gold standard modality for treatment of morbid obesity and might even lead to improved cardiac function. Our objective is to investigate whether cardiac function in patients with morbid obesity improves after RYGB. Materials and Methods: In this single center pilot study, 15 patients with an uneventful cardiac history who underwent RYGB were included from May 2015 to March 2016. Cardiac function was measured by cardiac magnetic resonance imaging (CMRI), performed preoperatively and 3, 6, and 12 months postoperative. LVEF and myocardial mass and cardiac output were measured. Results: A total of 13 patients without decreased LVEF preoperative completed follow-up (mean age 37, 48.0 ± 8.8). There was a significant decrease of cardiac output 12 months postoperative (8.3 ± 1.8 preoperative vs. 6.8 ± 1.8 after 12 months, P = 0.001). Average myocardial mass declined by 15.2% (P < 0.001). After correction for body surface area (BSA), this appeared to be non-significant (P = 0.36). There was a significant improvement of LVEF/BSA at 6 and 12 months postoperative (26.2 ± 4.1 preoperative vs. 28.4 ± 3.4 and 29.2 ± 3.6 respectively, both P = 0.002). Additionally, there was a significant improvement of stroke volume/BSA 12 months after surgery (45.8 ± 8.0 vs. 51.9 ± 10.7, P = 0.033). Conclusion: RYGB in patients with morbid obesity with uneventful history of cardiac disease leads to improvement of cardiac function

Umbilical cord procalcitonin to detect early-onset sepsis in newborns: a promising biomarker

Background: Up to 7% of neonates born in high-income countries receive antibiotics for suspected early-onset sepsis (EOS). Culture-proven neonatal sepsis has a prevalence of 0.2%, suggesting considerable overtreatment. We studied the diagnostic accuracy of umbilical cord blood and infant blood procalcitonin (PCT) in diagnosing EOS to improve antibiotic stewardship.Methods: Umbilical cord blood PCT was tested in newborns >= 32 weeks of gestation. Groups were defined as following: A) culture-proven or probable EOS (n = 25); B) Possible EOS, based on risk factors for which antibiotics were administered for = 32 weeks with a proven or probable EOS and low in newborns with risk factors for infection, but PCT seems not a reliable marker after maternal antibiotic treatment. PCT could be useful to distinguish infected from healthy newborns with or without EOS risk factors.Afdeling Klinische Chemie en Laboratoriumgeneeskunde (AKCL

Two-subband electron transport in nonideal quantum wells

Electron transport in nonideal quantum wells (QW) with large-scale variations of energy levels is studied when two subbands are occupied. Although the mean fluctuations of these two levels are screened by the in-plane redistribution of electrons, the energies of both levels remain nonuniform over the plane. The effect of random inhomogeneities on the classical transport is studied within the framework of a local response approach for weak disorder. Both short-range and small-angle scattering mechanisms are considered. Magnetotransport characteristics and the modulation of the effective conductivity by transverse voltage are evaluated for different kinds of confinement potentials (hard wall QW, parabolic QW, and stepped QW).Comment: 10 pages, 6 figure

Severe pediatric COVID-19 and multisystem inflammatory syndrome in children from wild-type to population immunity: a prospective multicenter cohort study with real-time reporting

Background:SARS-CoV-2 variant evolution and increasing immunity altered the impact of pediatric SARS-CoV-2 infection. Public health decision-making relies on accurate and timely reporting of clinical data.Methods:This international hospital-based multicenter, prospective cohort study with real-time reporting was active from March 2020 to December 2022. We evaluated longitudinal incident rates and risk factors for disease severity.Results:We included 564 hospitalized children with acute COVID-19 (n = 375) or multisystem inflammatory syndrome in children (n = 189) from the Netherlands, Curacao and Surinam. In COVID-19, 134/375 patients (36%) needed supplemental oxygen therapy and 35 (9.3%) required intensive care treatment. Age above 12 years and preexisting pulmonary conditions were predictors for severe COVID-19. During omicron, hospitalized children had milder disease. During population immunity, the incidence rate of pediatric COVID-19 infection declined for older children but was stable for children below 1 year. The incidence rate of multisystem inflammatory syndrome in children was highest during the delta wave and has decreased rapidly since omicron emerged. Real-time reporting of our data impacted national pediatric SARS-CoV-2 vaccination- and booster-policies.Conclusions:Our data supports the notion that similar to adults, prior immunity protects against severe sequelae of SARS-CoV-2 infections in children. Real-time reporting of accurate and high-quality data is feasible and impacts clinical and public health decision-making. The reporting framework of our consortium is readily accessible for future SARS-CoV-2 waves and other emerging infections.Transplantation and immunomodulatio