Inflammatory responses in SARS-CoV-2 associated Multisystem Inflammatory Syndrome and Kawasaki Disease in children: An observational study.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a severe inflammatory disease in children related to SARS-CoV-2 with multisystem involvement including marked cardiac dysfunction and clinical symptoms that can resemble Kawasaki Disease (KD). We hypothesized that MIS-C and KD might have commonalities as well as unique inflammatory responses and studied these responses in both diseases. In total, fourteen children with MIS-C (n=8) and KD (n=6) were included in the period of March-June 2020. Clinical and routine blood parameters, cardiac follow-up, SARS-CoV-2-specific antibodies and CD4+ T-cell responses, and cytokine-profiles were determined in both groups. In contrast to KD patients, all MIS-C patients had positive Spike protein-specific CD3+CD4+ T-cell responses. MIS-C and KD patients displayed marked hyper-inflammation with high expression of serum cytokines, including the drug-targetable interleukin (IL)-6 and IFN-γ associated chemokines CXCL9, 10 and 11, which decreased at follow-up. No statistical differences were observed between groups. Clinical outcomes were all favourable without cardiac sequelae at 6 months follow-up. In conclusion, MIS-C and KD-patients both displayed cytokine-associated hyper-inflammation with several high levels of drug-targetable cytokines.

Using Nonequilibrium Dynamics to Probe Competing Orders in a Mott-Peierls System.

Competition between ordered phases, and their associated phase transitions, are significant in the study of strongly correlated systems. Here, we examine one aspect, the nonequilibrium dynamics of a photoexcited Mott-Peierls system, using an effective Peierls-Hubbard model and exact diagonalization. Near a transition where spin and charge become strongly intertwined, we observe antiphase dynamics and a coupling-strength-dependent suppression or enhancement in the static structure factors. The renormalized bosonic excitations coupled to a particular photoexcited electron can be extracted, which provides an approach for characterizing the underlying bosonic modes. The results from this analysis for different electronic momenta show an uneven softening due to a stronger coupling near k_{F}. This behavior reflects the strong link between the fermionic momenta, the coupling vertices, and ultimately, the bosonic susceptibilities when multiple phases compete for the ground state of the system.

Pressure tuning of the spin-orbit coupled ground state in Sr2IrO4.

X-ray absorption spectroscopy studies of the magnetic-insulating ground state of Sr2IrO4 at ambient pressure show a clear deviation from a strong spin-orbit (SO) limit J(eff)=1/2 state, a result of local exchange interactions and a nonzero tetragonal crystal field mixing SO split J(eff)=1/2, 3/2 states. X-ray magnetic circular dichroism measurements in a diamond anvil cell show a magnetic transition at a pressure of ∼17 GPa, where the "weak" ferromagnetic moment is quenched despite transport measurements showing insulating behavior to at least 40 GPa. The magnetic transition has implications for the origin of the insulating gap and the nature of exchange interactions in this SO coupled system. The expectation value of the angular part of the SO interaction, , extrapolates to zero at ∼80-90 GPa where an increased bandwidth strongly mixes J(eff)=1/2, 3/2 states and SO interactions no longer dominate the electronic ground state of Sr2IrO4.

Magnetic excitation spectra of Sr2IrO4 probed by resonant inelastic x-ray scattering: establishing links to cuprate superconductors.

We used resonant inelastic x-ray scattering to reveal the nature of magnetic interactions in Sr2IrO4, a 5d transition-metal oxide with a spin-orbit entangled ground state and J(eff)=1/2 magnetic moments. The magnon dispersion in Sr2IrO4 is well-described by an antiferromagnetic Heisenberg model with an effective spin one-half on a square lattice, which renders the low-energy effective physics of Sr2IrO4 much akin to that in superconducting cuprates. This point is further supported by the observation of exciton modes in Sr2IrO4, whose dispersion is strongly renormalized by magnons, which can be understood by analogy to hole propagation in the background of antiferromagnetically ordered spins in the cuprates.

Predictors of health-related quality of life in children and adolescents with juvenile idiopathic arthritis: results from a Web-based survey.

OBJECTIVE: Children with juvenile idiopathic arthritis (JIA) experience functional impairment due to joint manifestations of the disease. The aim of our present study was to assess health-related quality of life (HRQOL) and its predictors in a group of children and adolescents with JIA. METHODS: The study sample includes all JIA patients (ages 6-18 years) who consulted a pediatric rheumatologist in Amsterdam, The Netherlands, between February 2009 and March 2010. HRQOL was measured using the Paediatric Quality of Life Inventory 4.0 (ages 6-18 years). Functional ability was measured using the Childhood Health Assessment Questionnaire, and medical and sociodemographic parameters were assessed. The study sample was compared to a Dutch youth norm population including children with other chronic health conditions. The proportion of children with JIA with an impaired HRQOL (<1 SD) was evaluated and multivariate regression analyses were performed to predict HRQOL outcome. RESULTS: Of the eligible patients, 64.1% (n = 152) participated. Both children (ages 6-12 years) and adolescents (ages 13-18 years) with JIA reported a significantly lower HRQOL in almost all domains compared to either healthy controls or children with other chronic health conditions. Approximately half of the children with JIA showed an impaired HRQOL. The main predictors of HRQOL were functional ability, pain, subjective burden of medication use, and school absence. CONCLUSION: The HRQOL is severely affected in children and adolescents with JIA. These findings underline the necessity to systematically monitor HRQOL in daily clinical practice.

Pneumothorax in a preterm infant monitored by electrical impedance tomography: a case report.

Electrical impedance tomography (EIT) is a noninvasive bedside tool for monitoring regional changes in ventilation. We report, for the first time, the EIT images of a ventilated preterm infant with a unilateral pneumothorax, showing a loss of regional ventilation in the affected lung during both high-frequency oscillation and spontaneous ventilation.

Orbital magnetism and spin-orbit effects in the electronic structure of BaIrO3.

The electronic structure and magnetism of Ir 5d5 states in nonmetallic, weakly ferromagnetic BaIrO3 are probed with x-ray absorption techniques. Contrary to expectation, the Ir 5d orbital moment is found to be ~1.5 times larger than the spin moment. This unusual, atomiclike nature of the 5d moment is driven by a strong spin-orbit interaction in heavy Ir ions, as confirmed by the nonstatistical large branching ratio at Ir L(2,3) absorption edges. As a consequence, orbital interactions cannot be neglected when addressing the nature of magnetic ordering in BaIrO3. The local moment behavior persists even as the metallic-paramagnetic phase boundary is approached with Sr doping or applied pressure.

Observation of phonons with resonant inelastic x-ray scattering.

Phonons, the quantum mechanical representation of lattice vibrations, and their coupling to the electronic degrees of freedom are important for understanding thermal and electric properties of materials. For the first time, phonons have been measured using resonant inelastic x-ray scattering (RIXS) across the Cu K-edge in cupric oxide (CuO). Analyzing these spectra using an ultra-short core-hole lifetime approximation and exact diagonalization techniques, we can explain the essential inelastic features. The relative spectral intensities are related to the electron-phonon coupling strengths.

Thermally or magnetically induced polarization reversal in the Multiferroic CoCr2O4.

We report the unexpected evolution, with thermal and magnetic-field (H) variations, of the interrelation between the polarization P, magnetization M, and spiral wave vector Q in CoCr2O4, which has a ferrimagnetic conical-spiral magnetic order. For example, P suddenly jumps and changes its sign at the magnetic lock-in transition (T_{L}) with thermal variation, or with isothermal variation of H (without changing its direction) at T_{L}, which surprisingly occurs without change in spiral handedness (i.e., the sign of Q). The presence of multiple spiral sublattices may be behind this unusual behavior.

Orbital reconstruction and covalent bonding at an oxide interface.

Orbital reconstructions and covalent bonding must be considered as important factors in the rational design of oxide heterostructures with engineered physical properties. We have investigated the interface between high-temperature superconducting (Y,Ca)Ba(2)Cu3O7 and metallic La(0.67)Ca(0.33)MnO3 by resonant x-ray spectroscopy. A charge of about -0.2 electron is transferred from Mn to Cu ions across the interface and induces a major reconstruction of the orbital occupation and orbital symmetry in the interfacial CuO2 layers. In particular, the Cu d(3z(2)-r(2)) orbital, which is fully occupied and electronically inactive in the bulk, is partially occupied at the interface. Supported by exact-diagonalization calculations, these data indicate the formation of a strong chemical bond between Cu and Mn atoms across the interface. Orbital reconstructions and associated covalent bonding are thus important factors in determining the physical properties of oxide heterostructures.

[Neonatal respiratory distress caused by primary ciliary dyskinesia]. / Neonatale respiratoire problemen door primaire ciliaire dyskinesie.

Two newborns, both boys, presented with unexplained respiratory distress. One developed recurrent pneumonias in the first neonatal week and was diagnosed with primary ciliary dyskinesia at the age of 2.5 years. The other had respiratory problems besides a situs inversus totalis and was diagnosed with primary ciliary dyskinesia in the neonatal period. Although 65-90% of children with primary ciliary dyskinesia present with neonatal respiratory distress, the disease is often diagnosed after a considerable delay. Primary ciliary dyskinesia should be considered in newborns with unexplained respiratory problems and in children with recurrent respiratory problems. The disease is diagnosed by taking a nasal brush biopsy of the cilia and examining it using electron microscopy or using phase contrast microscopy. Early diagnosis and adequate treatment may prevent further lung damage.

Atomic origin of magnetocrystalline anisotropy in Nd(2)Fe(14)B.

The magnetic moment reversal at each of the two inequivalent Nd sites in a single crystal of ferromagnetic Nd(2)Fe(14)B is probed by dichroic resonant diffraction of circularly polarized x rays. The results, supported by theory, show that the c-axis intrinsic magnetic stability of this superior permanent magnetic material arises predominantly at one of the Nd sites (g). The other site (f) undermines magnetic stability by favoring a magnetic moment orientation in the basal plane.

Further evidence for an ischemic origin of perforation of the appendix in the neonatal period.

A full-term baby girl presented on the 14th day of life with an appendiceal abscess on a basis of appendicular perforation. Pathologic examination found focal transmural coagulation necrosis suggesting an ischemic origin for the perforation. It is argued that appendiceal perforation in the newborn period is a different disease entity than appendiceal perforation later in life. In the newborn, ischemia seems to be the leading pathogenetic factor, and neonatal appendiceal perforation seems, therefore, related to neonatal necrotizing enterocolitis.

Soft x-ray resonant diffraction study of magnetic and orbital correlations in a manganite near half doping.

We have utilized resonant x-ray diffraction at the Mn L(II,III) edges in order to directly compare magnetic and orbital correlations in Pr0.6Ca0.4MnO3. Comparing the widths of the magnetic and orbital diffraction peaks, we find that the magnetic correlation length exceeds that of the orbital order by nearly a factor of 2. Furthermore, we observe a large (approximately 3 eV) spectral weight shift between the magnetic and orbital resonant line shapes, which cannot be explained within the classic Goodenough picture of a charge-ordered ground state. To explain the shift, we calculate the orbital and magnetic resonant diffraction line shapes based on a relaxed charge-ordered model.

Congenital absence of the trachea.

UNLABELLED: Congenital absence of the trachea is a rare cause of severe neonatal respiratory distress. Experimental studies show that it is probably caused by disorders in a system of folds in the tracheo-oesophageal space rather than abnormalities of a tracheo-oesophageal septum. A literature review disclosed 82 cases of tracheal agenesis, which showed male predominance and an association with prematurity and polyhydramnios. In 90% of cases associated congenital malformations were present, most frequently affecting the cardiovascular or gastro-intestinal systems and the genito-urinary tract. Clinical signs of tracheal agenesis or atresia are respiratory insufficiency, often with severe respiratory distress, absence of audible crying and difficult or impossible endotracheal intubation. At present, curative repair and survival are impossible unless there is enough proximal or distal trachea to create a tracheostoma. Important ongoing research is aimed at tissue-engineered cartilage for surgical repair of tracheal defects. CONCLUSION: Tracheal agenesis, although very rare, can be recognised from a characteristic clinical pattern. Mostly associated congenital malformations are present. Research into tissue-engineering might lead to possibilities for definitive surgical repair of tracheal agenesis or atresia; however, until curative repair becomes possible, prolonged ventilation via the oesophageal tube does not seem to be worthwhile.