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Context Cortical abnormalities have been noted in previous studies of major depressive disorder (MDD). Objective We hypothesized differences in regional cortical thickness in children with MDD, with obsessive-compulsive disorder (OCD) and healthy controls. Design Cross-sectional examination of the groups. Setting Children's Hospital of Michigan. Patients or Other Participants Twenty-four psychotropic drug-naïve pediatric MDD patients (9 males, 15 females), twenty-four psychotropic drug-naïve pediatric outpatients with OCD (8 males, 16 females) and thirty healthy pediatric controls (10 males, 20 females). Intervention Subjects underwent magnetic resonance imaging (MRI). Main Outcome Measure Cortical thickness. Results In the right hemisphere, the pericalcarine (p = 0.002, p = 0.04), post central (p = 0.002, p = 0.02) and superior parietal gyri (p = 0.008, p = 0.03) were thinner in MDD compared to both OCD and controls subjects respectively. OCD and control subjects did not differ in these regions. The temporal pole was thicker in MDD patients than both OCD patients (p = 0.0007) and controls (p = 0.01), which did not differ. The cuneus was thinner in MDD patients compared to OCD patients (p = 0.008), but did not differ from controls. In the left hemisphere, the supramarginal gyrus was comparably thinner in both MDD (p = 0.04) and OCD (p = 0.01) than in controls, and the temporal pole was thicker in MDD patients than in both controls and OCD patients, (p = 0.0009). Conclusions To our knowledge, this is the first study to explore cortical thickness in pediatric MDD patients. While differences in some regions would be expected given neurobiological models of MDD, this study highlights some unexpected regions (i.e. supramarginal, superior parietal) that merit further investigation. These results underscore the need to expand exploration beyond the frontal-limbic circuit.

I. (2021). Cortical volume abnormalities in posttraumatic stress disorder: an ENIGMA-psychiatric genomics consortium PTSD workgroup megaanalysis. Molecular Psychiatry,26,[4331][4332][4333][4334][4335][4336][4337][4338][4339][4340][4341][4342][4343]

Traumatic brain injury (TBI) disrupts brain communication and increases risk for post-traumatic stress disorder (PTSD). However, mechanisms by which TBI-related disruption of brain communication confers PTSD risk have not been successfully elucidated in humans. This may be in part because functional MRI (fMRI), the most common technique for measuring functional brain communication, is unreliable for characterizing individual patients. However, this unreliability can be overcome with sufficient within-individual data. Here, we examined whether relationships could be observed among TBI, structural and functional brain connectivity, and PTSD severity by collecting ∼3.5 hours of resting-state fMRI and diffusion tensor imaging (DTI) data in each of 26 United States military veterans. We observed that a TBI history was associated with decreased whole-brain resting-state functional connectivity (RSFC), while the number of lifetime TBIs was associated with reduced whole-brain fractional anisotropy (FA). Both RSFC and FA explained independent variance in PTSD severity, with RSFC mediating the TBI-PTSD relationship. Finally, we showed that large amounts of per-individual data produced highly reliable RSFC measures, and that relationships among TBI, RSFC/FA, and PTSD could not be observed with typical data quantities. These results demonstrate links among TBI, brain connectivity, and PTSD severity, and illustrate the need for precise characterization of individual patients using high-data fMRI scanning.

The tensile behaviour of single crystals of the unidirectionally-solidified AI-AI3Ni fibrous and AI-CuAI2 lamellar eutectics has been investigated at ambient and elevated temperatures. Fractured specimens have been studied directly by scanning electron microscopy, and longitudinal sections through each fracture surface by optical microscopy. At low temperatures, fracture of the AI-AIzNi eutectic is caused by the brittle failure of AI3Ni fibres. At intermediate temperatures broken fibres may be present without causing composite fracture, whilst at high temperatures fibre pull-out occurs. The properties of the AI-CuAI2 eutectic are controlled by the brittle CuAI2 phase, except when the temperature is such that both phases are plastic. During fracture at high temperature the AI-CuAI2 eutectic undergoes micromorphological degradation in the vicinity of the fracture surface. q. IntroductionUnidirectionally-solidified eutectics have been studied because their strength coupled with good thermal stability may well give advantages over more conventional materials. The high temperature strength of a number of systems has been measured [1][2][3][4][5] but no work has been done specifically on the fractography of eutectic composites at varying temperatures. Salkind and co-workers [6,7] have studied the tensile properties of aligned polycrystalline A1-AI~Ni fibrous and A1-CuA12 lamellar eutectics up to 773K (500~ They found that the strength of both materials was reduced at elevated temperatures and that the A1-CuAlz eutectic began to show large elongations at temperatures greater than approximately 623K (350~ Crossman et al [8] confirmed these results for the A1-CuA12 eutectic, as did Butcher et al [9] who also observed microstructural coarsening after fracturing at high temperatures. Fractographic techniques have been used to study the room-temperature fracture of aligned polycrystalline A1-A13Ni eutectic in tension [6,7,10] and aligned polycrystalline A1-CuA12 eutectic in tension [6,7,10] and compression [11]. Tidy and Chadwick [12] have used scanning electron microscopy to study fracture surfaces of aligned single crystals of the A1-CuA12 eutectic deformed in bending at various temperatures.The aim of the present work was to study the effect of temperature on the fracture characteristics of aligned single-crystal specimens of the AI-A13Ni eutectic and the A1-CuA12 eutectic. The fracture surfaces were studied by scanning electron microscopy and longitudinal sections were taken through the fracture surfaces and studied by optical microscopy. Experimental procedureAlloys of eutectic composition were made up from aluminium of 99.998 ~ purity and copper and nickel of 99.999 ~ purity. They were melted under argon in recrystallized alumina crucibles and cast into long flat ingots of rectangular cross-section. These ingots were placed singly in graphite moulds, enclosed in a silica tube, and directionally solidified horizontally under

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