Pseudoamniotic Band Syndrome After Fetoscopic Laser Ablation of Placental Anastomoses for Twin‐Twin Transfusion Syndrome: Two Case Reports and Systematic Review

Pseudoamniotic band syndrome is a rare complication that occurs after invasive procedures for complicated monochorionic twins. We report 2 cases of intrauterine recipient fetal death after laser therapy for twin‐twin transfusion syndrome due to umbilical cord constriction by the amniotic band.     

The Upper Limb Tension Test: Inter-tester Reliability for Assessing the Onset of Passive Resistance R 1

Abstract

The aim of this trial was to assess the inter-tester reliability of the Upper Limb Tension Test (ULTT). The onset of passive resistance (R1) of the left elbow was determined by four experienced manual therapists in a group of asymptomatic subjects. A recording of the degrees of elbow extension was obtained using a goniometer, having first positioned the upper extremity in a bracket maintaining 110 degrees of shoulder abduction and 10 degrees of shoulder extension. Each rater then moved the subjects' left shoulder into full external rotation and the forearm into full supination with the wrist and fingers in a neutral position. Data was collected four consecutive days. The data was analyzed by a two-way analysis of variance. The means of the readings among the four raters was found to be significantly different. It was concluded that the ULTT has a low inter-tester reliability when R1 is compared. Several suggestions are made for future research projects in this area.     

The Microstructural Evolution and Mechanical Properties of Zr-Based Metallic Glass under Different Strain Rate Compressions

In this study, the high strain rate deformation behavior and the microstructure evolution of Zr-Cu-Al-Ni metallic glasses under various strain rates were investigated. The influence of strain and strain rate on the mechanical properties and fracture behavior, as well as microstructural properties was also investigated. Before mechanical testing, the structure and thermal stability of the Zr-Cu-Al-Ni metallic glasses were studied with X-ray diffraction (XRD) and differential scanning calorimeter. The mechanical property experiments and microstructural observations of Zr-Cu-Al-Ni metallic glasses under different strain rates ranging from 10⁻³ to 5.1 × 10³ s⁻¹ and at temperatures of 25 °C were investigated using compressive split-Hopkinson bar (SHPB) and an MTS tester. An in situ transmission electron microscope (TEM) nanoindenter was used to carry out compression tests and investigate the deformation behavior arising at nanopillars of the Zr-based metallic glass. The formation and interaction of shear band during the plastic deformation were investigated. Moreover, it was clearly apparent that the mechanical strength and ductility could be enhanced by impeding the penetration of shear bands with reinforced particles.     

Speech‐in‐noise understanding in older age: The role of inhibitory cortical responses

Studies of central auditory processing underlying speech‐in‐noise (SIN) recognition in aging have mainly concerned the degrading neural representation of speech sound in the auditory brainstem and cortex. Less attention has been paid to the aging‐related decline of inhibitory function, which reduces the ability to suppress distraction from irrelevant sensory input. In a response suppression paradigm, young and older adults listened to sequences of three short sounds during MEG recording. The amplitudes of the cortical P30 response and the 40‐Hz transient gamma response were compared with age, hearing loss and SIN performance. Sensory gating, indicated by the P30 amplitude ratio between the last and the first responses, was reduced in older compared to young listeners. Sensory gating was correlated with age in the older adults but not with hearing loss nor with SIN understanding. The transient gamma response expressed less response suppression. However, the gamma amplitude increased with age and SIN loss. Comparisons of linear multi‐variable modeling showed a stronger brain–behavior relationship between the gamma amplitude and SIN performance than between gamma and age or hearing loss. The findings support the hypothesis that aging‐related changes in the balance between inhibitory and excitatory neural mechanisms modify the generation of gamma oscillations, which impacts on perceptual binding and consequently on SIN understanding abilities. In conclusion, SIN recognition in older age is less affected by central auditory processing at the level of sensation, indicated by sensory gating, but is strongly affected at the level of perceptual organization, indicated by the correlation with the gamma responses.