Engeloliver1006

Pediatric acute-onset neuropsychiatric syndrome (PANS) is an abrupt debilitating psychiatric illness. We anecdotally observed hypoferritinemia and iron deficiency in a subset of patients with PANS, prompting this study.

In this IRB-approved prospective cohort study, we included patients seen at the Stanford PANS Clinic who met study criteria. The prevalence of hypoferritinemia (using cut-offs of 7 ng/ml in children ≤ 15 years and 18 ng/ml in adolescents > 15 years) and iron deficiency was estimated. Differences in patients with and without hypoferritinemia during PANS flare were explored.

Seventy-nine subjects (mean age of PANS onset of 8.7 years) met study criteria. Hypoferritinemia was observed in 27% and three quarters occurred during a PANS flare. Compared to patients without hypoferritinemia during PANS flare, patients with hypoferritinemia had worse global impairment, more comorbid inflammatory diseases, and exhibited a chronic course of PANS illness. The estimated prevalence of iron deficiencyudy suggests hypoferritinemia and iron deficiency are more common in patients with pediatric acute-onset neuropsychiatric syndrome (PANS) than in the sex- and age-matched US population.Hypoferritinemia was commonly observed during a disease flare but not associated with dietary or demographic factors. In patients with PANS and iron deficiency, clinicians should consider possibility of inflammation as the cause especially if iron deficiency cannot be explained by diet and blood loss.Future research should include larger cohorts to corroborate our study findings and consider examining the iron dynamics on MRI brain imaging in order to better understand the pathophysiology of PANS.

Previous genetic research in pediatric cardiomyopathy (CM) has focused on pathogenic variants for diagnostic purposes, with limited data evaluating genotype-outcome correlations. We explored whether greater genetic variant burden (pathogenic or variants of unknown significance, VUS) correlates with worse outcomes.

Children with dilated CM (DCM) and hypertrophic CM (HCM) who underwent multigene testing between 2010 and 2018 were included. Composite endpoint was freedom from major adverse cardiac event (MACE).

Three hundred and thirty-eight subjects were included [49% DCM, median age 5.7 (interquartile range (IQR) 0.2-13.4) years, 51% HCM, median age 3.0 (IQR 0.1-12.5) years]. Pathogenic variants alone were not associated with MACE in either cohort (DCM p = 0.44; HCM p = 0.46). In DCM, VUS alone [odds ratio (OR) 4.0, 95% confidence interval (CI) 1.9-8.3] and in addition to pathogenic variants (OR 5.2, 95% CI 1.7-15.9) was associated with MACE. The presence of VUS alone or in addition to pathogenic variantve been shown between genotype and phenotype severity when only pathogenic variants have been considered.Increased genetic variant burden (including both pathogenic variants and VUS) is associated with worse clinical outcomes in DCM but not HCM.Genomic variants that influence CM onset may be distinct from those variants that drive disease progression and influence outcomes in phenotype-positive individuals.Incorporation of both pathogenic variants and VUS may improve risk stratification models in pediatric CM.Correlating the structure and composition of nanowires grown by the vapour-liquid-solid (VLS) mechanism with their electrical properties is essential for designing nanowire devices. In situ transmission electron microscopy (TEM) that can image while simultaneously measuring the current-voltage (I-V) characteristics of individual isolated nanowires is a unique tool for linking changes in structure with electronic transport. Here we grow and electrically connect silicon nanowires inside a TEM to perform in situ electrical measurements on individual nanowires both at high temperature and upon surface oxidation, as well as under ambient conditions. As-grown, the oxide-free nanowires have nonlinear I-V characteristics. We analyse the I-V measurements in terms of both bulk and injection limited transport models, finding Joule heating effects, bulk-limiting effects for thin nanowires and an injection-limiting effect for thick wires when high voltages are applied. When the nanowire surface is modified by in situ oxidation, drastic changes occur in the electronic properties. We investigate the relation between the observed geometry, changes in the surface structure and changes in electronic transport, obtaining information for individual nanowires that is inaccessible to other measuring techniques.We study the electronic heat capacity in doped graphene under magnetic fields. The partition function is calculated considering only the thermal excitations in the last occupied energy levels. Due to the large energy separation between the Landau levels (LLs) and the Zeeman splitting, at low temperatures the heat capacity is dominated by the spin excitations in the last occupied LL. Correspondingly the heat capacity oscillates with maximum amplitude at half filling of each LL. At higher temperatures the inter-LLs excitations dominate the heat capacity, with maximum amplitude at full filling factors. The oscillation amplitudes are compared with the phonon heat capacity C p. It is shown that the spin induced heat capacity oscillations have a maximum amplitude approaching 3% of C p, whereas for the inter-LLs excitations the maximum amplitude is only 0.1% of C p. Tacrolimus in vivo These amplitudes decrease in the presence of impurities, although the effect is appreciable if the LLs broadening is bigger than the excitation energies.Twin boundary (TB) plays an important role on the plastic deformation of high entropy alloy (HEA). The strong effects of TB on the deformation response of HEA are revealed from atomic level based on the defect structure, shear strain and surface morphology, by comparing the nanoindentation behavior of nanotwinned FeNiCrCoCu HEA (nt-HEA) and single-crystal FeNiCrCoCu HEA (single-HEA). The plastic deformation of nt-HEA is mainly dominated by the dislocations slip confined by first twinning layer, the TB migration, the dislocation nucleation at TB and the stacking fault tetrahedron (SFT) formation, while the dislocation loop emission is the main plastic deformation feature of single-HEA. Compared to the case for single-HEA, the nanoindentation induces more dislocations in nt-HEA. The shear strain in nt-HEA mainly distributes in the first twinning layer, due to the obstacle effect of TB. The shear zone is larger in nt-HEA, and the distribution of shear strain on the nt-HEA surface is more symmetric. The nanoindentation generates fewer steps on the nt-HEA surface, and then brings about a relatively smooth surface for nt-HEA.