The degeneration of locus coeruleus occurring during Alzheimer’s disease clinical progression: a neuroimaging follow-up investigation

\ua9 The Author(s) 2024.The noradrenergic nucleus Locus Coeruleus (LC) is precociously involved in Alzheimer’s Disease (AD) pathology, and its degeneration progresses during the course of the disease. Using Magnetic Resonance Imaging (MRI), researchers showed also in vivo in patients the disruption of LC, which can be observed both in Mild Cognitively Impaired individuals and AD demented patients. In this study, we report the results of a follow-up neuroradiological assessment, in which we evaluated the LC degeneration overtime in a group of cognitively impaired patients, submitted to MRI both at baseline and at the end of a 2.5-year follow-up. We found that a progressive LC disruption can be observed also in vivo, involving the entire nucleus and associated with clinical diagnosis. Our findings parallel neuropathological ones, which showed a continuous increase of neuronal death and volumetric atrophy within the LC with the progression of Braak’s stages for neurofibrillary pathology. This supports the reliability of MRI as a tool for exploring the integrity of the central noradrenergic system in neurodegenerative disorders

A Novel Magnetic Resonance Phased-Array Coil Designed with FDTD Algorithm

Radio-frequency receiver phased-array coils in magnetic resonance imaging systems are used to pick up the signals emitted by the nuclei with high signal-to-noise ratio and a large region of sensitivity. Since the quality of obtained images strongly depends upon the correct choice of the coil geometry and position, array coils have to be designed by minimizing the mutual interaction among nearby coil elements and this is generally achieved by overlapping such adjacent elements. In this paper, we describe the use of a numerical solver based on finite-difference time-domain method to determine the optimal overlap distance, which guarantees the maximum decoupling level between the coil loops, for array coils constituted by various geometry elements. A novel array coil was designed, constituted by a couple of elliptical geometry elements in "folding" version around the animals' spine curvature, for small animals' imaging applications

Elemental and isotopic fingerprints during the life cycle of the manila clams Ruditapes philippinarum in the Goro Lagoon (north Adriatic Sea): tools

In Italy, the production of manila clams (Ruditapes philippinarum, Adams and Reeve, 1850) is mainly localized in northern Adriatic lagoons of the Po River delta, where shellfish farming provides important economic revenue (Giani et al., 2012). However, the seafood market is threated by fraudulent activities in which agri-food products, whose provenance is not certified, are sold posing a risk to consumers health. Multiisotope ratios and elemental analyses are commonly used to trace the provenance of food products in different countries, included seafood and to assess their safety. However, the variability of geochemical fingerprints during the life-cycle of the manila clams where never investigated. In this study, the elemental concentrations and isotopic ratios in seeded manila clams (both shells and tissue) were monitored during mollusks growth at two sites of the Goro Lagoon (Emilia-Romagna). Tissues of juvenile ( 1.6 cm) organisms were analyzed with an elemental analyzer coupled with an isotopic ratio mass spectrometer (EA-IRMS) for total carbon, organic carbon, nitrogen, and sulphur elemental contents and the relative isotopic ratios (d13CTC, d13COC, d15N, d34S). Shells of the same organisms were analyzed with a head-space analyzer coupled with an IRMS for carbon and oxygen isotopic fingerprints (d13C, d18O) and with an inductively coupled plasma mass spectrometer (ICP-MS) for the trace elemental compositions. Total Hg concentrations in manila clam tissues were also determined with a Direct Mercury Analyser (DMA-80, Milestone) according to EPA Method 7473 in order to assess contamination levels and potential risk for human consumption. The environmental conditions of the Goro Lagoon during shellfish sampling were also monitored through the in-situ measure of pH, temperature and electrical conductivity of the water. Anions and cations of water samples were measured with ion-chromatography. Finally, also sediment samples from the two sites were collected during the different sampling seasons and CaCO3 content measurements, grain size and geochemical (isotopes and elemental concentrations) analyses were performed. The obtained results complement earlier works on tracing the provenance of manila clams in the northern Adriatic lagoons (Bianchini et al., 2021; Brombin et al., 2022) by adding physico-chemical, elemental and isotopic parameters during the entire life-cycle of the mollusks. This will allow to test the reliability of the food traceability geochemical techniques. Finally, the outcomes of this work might help to monitor the resilience of these organisms to the effects of anthropogenic and natural factors (e.g. pollution, water circulation, nutrient supply, climate changes) occurring in the Goro Lagoon

Relationships Between Morphologic and Functional Patterns in the Polymicrogyric Cortex

Polymicrogyria is a malformation of cortical folding and layering underlying different cognitive and neurological manifestations. The polymicrogyric cortex has heterogeneous morphofunctional patterns, qualitatively described at magnetic resonance imaging (MRI) by variable severity gradients and functional activations. We investigated the link between abnormal cortical folding and cortical function in order to improve surgical planning for patients with polymicrogyria and intractable epilepsy. We performed structural and functional MRI on 14 patients with perisylvian polymicrogyria and adopted surface-based methods to detect alterations of cortical thickness (CT) and local gyrification index (LGI) compared with normal cortex (30 age-matched subjects). We quantitatively assessed the grade of anatomic disruption of the polymicrogyric cortex and defined its relationship with decreased cortical function. We observed a good matching between visual analysis and morphometric measurements. CT maps revealed sparse clusters of thickening, while LGI maps disclosed circumscribed regions of maximal alteration with a uniformly decreasing centrifugal gradient. In polymicrogyric areas in which gyral and sulcal patterns were preserved, functional activation maintained the expected location, but was reduced in extent. Morphofunctional correlations, evaluated along cortico-cortical paths between maximum morphologic alterations and significant activations, identified an interindividual threshold for LGI (z-value = −1.09) beyond which functional activations were no longer identifiable