Phenotypic Spectrum of STXBP1 Gene Mutations in an Emirati Case Series.

Genetic mutations are increasingly recognized as etiologic factors for epilepsy and neurodevelopmental disorders. Loss of function mutations in STXBP1, one of such genes, has, in recent years, been demonstrated to cause a broad spectrum of epilepsy syndromes and chronic neurodisabilities. Syntaxin-binding protein 1 (STXBP1) is a well-recognized membrane trafficking protein responsible for synaptic transmission and is expressed ubiquitously across the brain. Our case series presents the neurodevelopmental phenotype of children with STXBP1 mutations and is the first to be reported in an Emirati patient cohort. We gathered data on five children with genetically confirmed STXBP1 mutations, each displaying varying symptomatology, EEG features, response to antiepileptic medications, and eventual disease progression. This report reveals that a majority of STXBP1 mutations were de-novo in origin; heterozygous; pathogenic to likely pathogenic variants; clinical disease onset was predominantly during infancy in the form of developmental delays with or without seizures; most of the children had co-existing ADHD or autism spectrum disorders; typical seizure semiology at onset was in the form of infantile spasms, progressing to a melange of mixed seizure types; seizure control on antiepileptic drug therapy was variable, with all cases requiring more than two medications; global developmental delay was noted in all studied children; and MRI brain findings were unremarkable in all cases. This case series demonstrates a degree of uniformity of STXBP1 mutation disease phenotypes with international literature and provides a unique insight into the genetic profile of affected children within the Emirati population.

Sequential metamaterials with alternating Poisson's ratios.

Mechanical metamaterials have been designed to achieve custom Poisson's ratios via the deformation of their microarchitecture. These designs, however, have yet to achieve the capability of exhibiting Poisson's ratios that alternate by design both temporally and spatially according to deformation. This capability would enable dynamic shape-morphing applications including smart materials that process mechanical information according to multiple time-ordered output signals without requiring active control or power. Herein, both periodic and graded metamaterials are introduced that leverage principles of differential stiffness and self-contact to passively achieve sequential deformations, which manifest as user-specified alternating Poisson's ratios. An analytical approach is provided with a complementary software tool that enables the design of such materials in two- and three-dimensions. This advance in design capability is due to the fact that the tool computes sequential deformations more than an order of magnitude faster than contemporary finite-element packages. Experiments on macro- and micro-scale designs validate their predicted alternating Poisson's ratios.

Imidacloprid Poisoning: An Emerging Cause of Potentially Fatal Poisoning.

There are a variety of pesticides that are used to control the pests in agricultural lands and other places. Newer pesticides, developed as an alternative to highly toxic organophosphates such as imidacloprid including other neonicotinoid compounds, are being increasingly used considering their less harmful effects in case of human exposures. Though it is considered relatively safer to human beings, it can lead to potentially life-threatening complications and acute poisoning with these compounds may be fatal in large ingestion. We report a case of poisoning with imidacloprid compound presenting with a variety of systemic features including respiratory failure and patient's improvement with conservative management.