Publications by authors named "Luis Lacerda"

This research presents, for the first time, a comprehensive and rigorous investigation of ruthenium(II) chalcogenonitrosyl bonding situations in two sets of coordination compounds: [Ru(NE)Cl(L)] (1a-4a) and [Ru(NE)Cl(L)] (1b-4b), where E = O, S, Se, Te. Prior to and following the one-electron reduction, the Ru-NE bonding situations were subjected to analysis. The calculated geometric parameters indicate that both the Ru-NE and N-E bond lengths are susceptible to variation depending on the nature of the chalcogen employed.

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MgB material has a simple composition and structure that is well-reported and characterized. This material has been widely studied and applied in the last 20 years as a superconductor in wire devices and storage material for H in the hydride form. MgB doped with transition metals improves the superconductor behavior, such as the critical temperature ( ) or critical current ( ) for the superconducting state.

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The ratio of T1-weighted/T2-weighted magnetic resonance images (T1w/T2w MRI) has been successfully applied at the cortical level since 2011 and is now one of the most used myelin mapping methods. However, no reports have explored the histological validity of T1w/T2w myelin mapping in white matter. Here we compare T1w/T2w with ex vivo postmortem histology and in vivo MRI methods, namely quantitative susceptibility mapping (QSM) and multi-echo T2 myelin water fraction (MWF) mapping techniques.

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Unlabelled: The MnMoO is an environmentally friendly semiconductor material widely employed in technological devices. This material can be obtained on three different polymorphs, and although such phases were reported decades ago, some obscurity over their structure and properties is still perceived. Thus, this work provides a comprehensive DFT investigation of the α, β, and ω phases of MnMoO analyzing their crystalline structure, stability, and electronic and magnetic properties.

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Objective: Although hemidisconnection surgery may eliminate or reduce seizure activity in patients with epilepsy, there are visual, cognitive and motor deficits which affect patients' function post-operatively, with varying severity and according to pathology. Consequently, there is a need to map microstructural changes over long time periods and develop/apply methods that work with legacy data.

Methods: In this study, we applied the novel single shell 3-Tissue method to data from a cohort of 4 patients who were scanned 20-years following childhood hemidisconnection surgery and presented with variable clinical outcomes.

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The dentato-rubro-thalamo-cortical tract (DRTC) is the main outflow pathway of the cerebellum, contributing to a finely balanced corticocerebellar loop involved in cognitive and sensorimotor functions. Damage to the DRTC has been implicated in cerebellar mutism syndrome seen in up to 25% of children after cerebellar tumor resection. Multi-shell diffusion MRI (dMRI) combined with quantitative constrained spherical deconvolution tractography and multi-compartment spherical mean technique modeling was used to explore the frontocerebellar connections and microstructural signature of the DRTC in 30 healthy children.

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Over the years, the possibility of using solar radiation in photocatalysis or photodegradation processes has attracted remarkable interest from scientists around the world. In such processes, due to its electronic properties, AgPO is one of the most important semiconductors. This work delves into the photocatalytic activity, stability, and reactivity of AgPO surfaces by comparing plane waves with projector augmented wave and localized Gaussian basis set simulations, at the atomic level.

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It is unclear to what extent cerebellar networks show long-term plasticity and accompanied changes in cortical structures. Using drumming as a demanding multimodal motor training, we compared cerebellar lobular volume and white matter microstructure, as well as cortical thickness of 15 healthy non-musicians before and after learning to drum, and 16 age matched novice control participants. After 8 weeks of group drumming instruction, 3 ×30 minutes per week, we observed the cerebellum significantly changing its grey (volume increase of left VIIIa, relative decrease of VIIIb and vermis Crus I volume) and white matter microstructure in the inferior cerebellar peduncle.

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Background: Surgery is a key approach for achieving seizure freedom in children with focal onset epilepsy. However, the resection can affect or be in the vicinity of the optic radiations. Multi-shell diffusion MRI and tractography can better characterize tissue structure and provide guidance to help minimize surgical related deficits.

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Tractography based on non-invasive diffusion imaging is central to the study of human brain connectivity. To date, the approach has not been systematically validated in ground truth studies. Based on a simulated human brain data set with ground truth tracts, we organized an open international tractography challenge, which resulted in 96 distinct submissions from 20 research groups.

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Purpose: Diffusion spectrum imaging (DSI) is an imaging technique that has been successfully applied to resolve white matter crossings in the human brain. However, its accuracy in complex microstructure environments has not been well characterized.

Theory And Methods: Here we have simulated different tissue configurations, sampling schemes, and processing steps to evaluate DSI performances' under realistic biophysical conditions.

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Aim. In recent years, connectivity studies using neuroimaging data have increased the understanding of the organization of large-scale structural and functional brain networks. However, data analysis is time consuming as rigorous procedures must be assured, from structuring data and pre-processing to modality specific data procedures.

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Introduction: The supplementary motor area (SMA) is frequently involved by brain tumours (particularly WHO grade II gliomas). Surgery in this area can be followed by the 'SMA syndrome', characterised by contralateral akinesia and mutism. Knowledge of the connections of the SMA can provide new insights on the genesis of the SMA syndrome, and a better understanding of the challenges related to operating in this region.

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