Damage evolution during fracture by correlative microscopy with hyperspectral electron microscopy and laboratory-based microtomography.

Damage evolution during fracture of metals is a critical factor in determining the reliability and integrity of the infrastructure that the society relies upon. However, experimental techniques for directly observing these phenomena have remained challenged. We have addressed this gap by developing a correlative microscopy framework combining high-resolution hyperspectral electron microscopy with laboratory x-ray microtomography (XMT) and applied it to study fracture mechanisms in a steel inclusion system. We observed damage nucleation and growth to be inhomogeneous and anisotropic. Fracture resistance was observed to be controlled by inclusion distribution and the size scale of an inclusion-depleted zone. Furthermore, our studies demonstrate that laboratory XMT can characterize damage to the micrometer scale with a large field of view in dense metals like steel, offering a more accessible alternative to synchrotron-based tomography. The framework presented provides a means to broadly adopt correlative microscopy for studies of degradation phenomena and help accelerate discovery of new materials solutions.

Infantile spasms and hyperekplexia associated with isolated sulfite oxidase deficiency.

IMPORTANCE: Isolated sulfite oxidase deficiency (ISOD) causes severe intellectual disability, epilepsy, and shortened life expectancy. Intractable seizures are invariable in children with ISOD; however, to our knowledge, infantile spasms with a corresponding hypsarrhythmia pattern on electroencephalogram have never been reported. In addition, the nonepileptic paroxysmal movement disorder hyperekplexia has not previously been reported with ISOD. OBSERVATIONS: We describe an infant with ISOD who initially presented with neonatal seizures, diffusion restriction noted on magnetic resonance imaging, and elevated serum S-sulfocysteine consistent with ISOD. A homozygous mutation in the SUOX gene was identified, confirming the diagnosis. Uniquely, this patient developed a profound accentuated startle response that did not have a corresponding electrographic change on electroencephalogram consistent with hyperekplexia. This was followed by a change in the child's electroencephalogram to the chaotic pattern of hypsarrhythmia and brief tonic seizures with attenuation of the hypsarrhythmia pattern characteristic of infantile spasms. CONCLUSIONS AND RELEVANCE: The evolution of seizures associated with ISOD is poorly characterized because of the small number of patients. We report what we believe to be the first case of a child with ISOD who developed infantile spasms and hyperekplexia. This expands the phenotypes associated with ISOD and also should caution clinicians to not assume that all abnormal movements are seizures.

Tropical lowland mosses disjunct between Africa and the Americas, including Calyptothecium planifrons (Ren. & Par.) Argent, new to the Western Hemisphere

Calyptothecium planifrons (Ren. & Par.) Argent is reported new to the Western Hemisphere based on two recent collections from Brazilian Amazonia, in Pará and Rondônia; C. planifrons was originally described from Madagascar. Forteen Other species of mosses with apparently disjunct distributions between tropical Africa and tropical America are also discussed. It is likely that mos or all of this species discussed will prove to have wider distributions in the tropics when world-wide revisions are carried out.

Calyptothecium planifrons (Ren. & Par.) Argent (Pterobryaceae) é uma nova ocorrência para o Brasil, sendo baseada nas coletas dos Estados do Pará e Rondônia. Outras 14 espécies de musgos com distribuição disjuncta entre África e América tropical são também discutidas na literatura.