Archivio della ricerca della Scuola Superiore Sant'Anna
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Prevalence and Correlates of Dilated and Non-Dilated Left Ventricular Cardiomyopathy in Transfusion-Dependent Thalassemia: Data from a National, Multicenter, Observational Registry
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Personalized brain models link cognitive decline progression to underlying synaptic and connectivity degeneration
Get PDFCognitive decline is a condition affecting almost one sixth of the elder population and is widely regarded as one of the first manifestations of Alzheimer's disease. Despite the extensive body of knowledge on the condition, there is no clear consensus on the structural defects and neurodegeneration processes determining cognitive decline evolution. Here, we introduce a Brain Network Model (BNM) simulating the effects of neurodegeneration on neural activity during cognitive processing. The model incorporates two key parameters accounting for distinct pathological mechanisms: synaptic degeneration, primarily leading to hyperexcitation, and brain disconnection. Through parameter optimization, we successfully replicated individual electroencephalography (EEG) responses recorded during task execution from 145 participants spanning different stages of cognitive decline. The cohort included healthy controls, patients with subjective cognitive decline (SCD), and those with mild cognitive impairment (MCI) of the Alzheimer type. Through model inversion, we generated personalized BNMs for each participant based on individual EEG recordings. These models revealed distinct network configurations corresponding to the patient's cognitive condition, with virtual neurodegeneration levels directly proportional to the severity of cognitive decline. Strikingly, the model uncovered a neurodegeneration-driven phase transition leading to two distinct regimes of neural activity underlying task execution. On either side of this phase transition, increasing synaptic degeneration induced changes in neural activity that closely mirrored experimental observations across cognitive decline stages. This enabled the model to directly link synaptic degeneration and hyperexcitation to cognitive decline severity. Furthermore, the model pinpointed posterior cingulum fiber degeneration as the structural driver of this phase transition. Our findings highlight the potential of BNMs to account for the evolution of neural activity across stages of cognitive decline while elucidating the underlying neurodegenerative mechanisms. This approach provides a novel framework for understanding how structural and functional brain alterations contribute to cognitive deterioration along the Alzheimer's continuum
Arrhythmic risk prediction in non-dilated left ventricular cardiomyopathy: The role of overlap with arrhythmogenic cardiomyopathy
No full textBackground: Non-dilated left ventricular cardiomyopathy (NDLVC) has been defined as non-ischemic LV scarring or fatty replacement regardless of global or regional wall motion abnormalities, or isolated global LV hypokinesia without scarring. We evaluated the arrhythmic risk in NDLVC and assessed the prognostic value of overlapping features with arrhythmogenic cardiomyopathy (ACM). Methods: All patients who underwent cardiovascular magnetic resonance (CMR) scan and genetic testing between 2012 and 2022 and met the diagnostic criteria for NDLVC were selected. All patients were evaluated for the presence of the 2024 diagnostic criteria for ACM. The primary endpoint was a composite of sudden cardiac death (SCD), ventricular fibrillation (VF) or sustained ventricular tachycardia (VT),. Results: The cohort included 225 patients (35 % women, median age 55 years [interquartile range 44–64]). The etiology was genetic in 44 % of cases, with 51 pathogenetic/likely pathogenetic (P/LP) variant and 49 variant of uncertain significance (VUS). Over 3.3 years (1.5–6.0), 12 patients (5 %) developed an endpoint event. The risk increased in patients meeting the criteria for definite or borderline arrhythmogenic left ventricular (ALVC) and biventricular (ABVC) cardiomyopathy. In the whole cohort, LGE >9 % of LV mass was the most significant predictor of outcome. In patients with LGE >9 %, fatty replacement significantly increased the risk of arrhythmic events. Conclusions: LGE >9 % of LV mass and fatty replacement are associated with an increased arrhythmic risk in NDLVC. The risk is also higher if patients meet the 2024 criteria for definite or borderline ALVC/ABVC
Integrated Photonics for Radio Access: Where We Are
No full textIntegrated photonics is essential in Radio Access Networks (RAN). For example, current pluggable optics and upcoming co-packaged optics (CPO) rely on it to increase capacity and energy efficiency. In addition, Photonic Integrated Circuits (PIC) may perform in future processing functions such as radiofrequency (RF) generation and mixing. This paper provides a comprehensive review of the current and future applications of integrated photonics to radio systems. It starts with the most mature technology (pluggable optics), discussing the challenges to meet the demand for the increase of bandwidth (BW) density expected with the Sixth mobile Generation (6G). Then, it moves to more advanced short reach interconnection technologies, based on CPO and optical Printed Circuit Boards (PCB). These technologies will allow to meet that demand, provided that certain RAN-specific developments, discussed in the paper, are undertaken. The potential of Artificial Intelligence (AI) to further improve the energy efficiency of short reach optical interconnects is also shortly introduced. Finally, Micro-Wave Photonics (MWP) techniques to process the RF signal in the optical domain are presented. The paper elaborates on their potential to improve the performance of radio systems and on the challenges remaining to move these techniques from lab to market. As a conclusion, integrated photonic technologies will expand their role in the evolution of radio systems, but with a variable timescale depending on their degree of compatibility with existing production processes
Estimated total amyloid burden from 18F-florbetaben positron emission tomography predicts all-cause mortality in light-chain cardiac amyloidosis
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Automated Strategy for Tissue Analysis in Anatomic Pathology: Fiducial Marker Integration and Multisurface Tissue Comparison
No full textIn anatomic pathology laboratories, several processes are still manual. Automated solutions can help standardizing the fabrication/processing of paraffin-embedded tissue blocks (PETBs) for a reliable and more effective diagnosis, in accordance with the requirement to work with unique and heterogeneous biological samples. We present a novel and automated approach to introduce a fiducial marker within PETBs, serving as a reliable reference point. This would assist the clinician in identifying specific regions of biological tissue in paraffin-embedded tissue blocks and paraffin-free tissue slices, in case the patient requires further laboratory analysis on that tissue portion to indicate a tailored treatment (e.g., oncological treatment). Two automated platforms are integrated into the conventional anatomic pathology workflow, according to the proposed strategy. The first one, named 'Indexing', involves the insertion of a fiducial marker into tissue-free areas within PETBs. The second one, named 'Virtual marker reconstruction', is based on image analysis and virtually reconstructs the fiducial marker on the paraffin-free tissue slice. An algorithm that analyzes the similarity of the tissue was also developed to assist in the traceability of the biological tissue along its processing from the embedding to the post-staining phase. Together, these platforms could assist the work of anatomopathologists avoid errors and support the final diagnosis in a future automated laboratory. Note to Practitioners - This research addresses a specific challenge encountered in anatomic pathology laboratories. The manual procedures involved in the fabrication and processing of paraffin-embedded tissue blocks highlight the pressing need for continuous verification and traceability at various stages of tissue processing and analysis. A lack of proper traceability poses challenges for anatomopathologists, leading to difficulties in managing the accurate identification of tissue blocks and slices, which contain unique biological tissues. This deficiency may lead to delayed or inaccurate diagnoses, with severe consequences for patients. We propose an innovative solution that focuses on two automated platforms that can seamlessly integrate into an anatomic pathology laboratory, and provide a way to correctly recognize and monitor biological tissue all along different procedures
Factoring in the Micro: A Transaction‐Level Dynamic Factor Approach to the Decomposition of Export Volatility
Get PDFThis paper analyzes the export volatility sources estimating a dynamic factor model
on transaction-level data. Utilizing an exhaustive dataset of French export transactions
from 1993 to 2017, we reconstruct the latent factors space associated with global
and destination-specific macroeconomic shocks through a Quasi-Maximum likelihood
approach which allows accommodating both the high share of missing values and the
high dimensionality of the microeconomic time series. The estimated parameters are then
used to derive a volatility decomposition of the aggregate and firm-level export growth
rates, highlighting structural spatial patterns and the role of geographical diversification
in mitigating export risks