24 research outputs found

    Differential diagnosis of neurodegenerative dementias with the explainable MRI based machine learning algorithm MUQUBIA

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    Biomarker-based differential diagnosis of the most common forms of dementia is becoming increasingly important. Machine learning (ML) may be able to address this challenge. The aim of this study was to develop and interpret a ML algorithm capable of differentiating Alzheimer's dementia, frontotemporal dementia, dementia with Lewy bodies and cognitively normal control subjects based on sociodemographic, clinical, and magnetic resonance imaging (MRI) variables. 506 subjects from 5 databases were included. MRI images were processed with FreeSurfer, LPA, and TRACULA to obtain brain volumes and thicknesses, white matter lesions and diffusion metrics. MRI metrics were used in conjunction with clinical and demographic data to perform differential diagnosis based on a Support Vector Machine model called MUQUBIA (Multimodal Quantification of Brain whIte matter biomArkers). Age, gender, Clinical Dementia Rating (CDR) Dementia Staging Instrument, and 19 imaging features formed the best set of discriminative features. The predictive model performed with an overall Area Under the Curve of 98%, high overall precision (88%), recall (88%), and F1 scores (88%) in the test group, and good Label Ranking Average Precision score (0.95) in a subset of neuropathologically assessed patients. The results of MUQUBIA were explained by the SHapley Additive exPlanations (SHAP) method. The MUQUBIA algorithm successfully classified various dementias with good performance using cost-effective clinical and MRI information, and with independent validation, has the potential to assist physicians in their clinical diagnosis

    Photochemical Transformation of Acifluorfen under Laboratory and Natural Conditions.

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    Abstract not availableJRC.I-Institute for Health and Consumer Protection (Ispra

    Phototransformation of 4-Chloro-2-Methylphenol in Water: Influence of Humic Substances on the Reactions.

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    The phototransformation of 4-chloro-2-methylphenol was studied using distilled water, solutions of humic substances and natural waters. Samples were irradiated at 280 nm, with polychromatic lamps emitting within the wavelenght ranges 290-350 and 300-450 nm or exposed to sunlight. The photolysis of 4-chloro-2-methylphenol at 280 nm in pure aerated water leads to methylbenzoquinone as the main primary photoproduct; the quantum yield of the direct photolysis is equal to 0.66. When 4-chloro-2-methylphenol is irradiated alone by polychromatic light or exposed to solar-light, methylhydroquinone and methylhydroxybenzoquinone are found as main photoproducts because secondary photolysis of methylbenzoquinone occurs. Humic substances enhance the rate of photodegradation of 4-chloro-2-methylphenol at lambda > 300nm. In these conditions, 4-chloro-2-methylphenol is transformed into methylhydroquinone, methylhydroxybenzoquinone essentially via direct photolysis and into 3-chloro-trans-trans and cis-trans-1-methyl-1-one-2, 4-hexadienoic acids through photoinduced reactions. These four photoproducts are found when 4-chloro-2-methylphenol is irradiated in natural waters at lambda > 300 nm. The phototransformation of 4-chloro-2-methylphenol under environmental conditions occurs therefore through both direct and humic substances-photoinduced processes.JRC.(EI)-Environment Institut

    Mechanism of the Photochemical Transformation of Naphtalene in Water.

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    Abstract not availableJRC.I-Institute for Health and Consumer Protection (Ispra

    Speciation of Organic Matter, Nitrogen and Phosphorus on Soils Irrigated with Industrial Wastewater.

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    The present work analyses the quality of wastewater produced in a citrus processing industry whose effluent, after a primary treatment, is applied on an experimental plot of Pinus pinea situated in Sicily (I). Heavy metals (Cd, Cr, Cu, Ni, Zn, Fe, Pb) in wastewater were at concentrations below permitted levels regarding the application of sewage sludge to agricultural soils (Council Directives 86/278/EEC on protection of the environment).JRC.I-Institute for Health and Consumer Protection (Ispra

    Derivatisation/Solid-Phase Microextraction Followed by Gas Chromatography-Mass Spectrometry for the Analysis of Phenoxy Acid Herbicides in Aqueous Samples.

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    Solid-phase microextraction (SPME) coupled with high performance liquid chromatography (HPLC) was optimized for the combined analysis of the herbicides bentazone, 2,4-D, MCPA, dichlorprop, mecopro, atrazine and dinoseb in aqueous samples. The detection limits were in the low ug/L range for atrazine and the phenoxy acid herbicides, while detection limits below ug/L level were found for bentazone and dinoseb. By aqueous-phase derivatization with benzyl bromide followed by SPME-GC-MS analysis detection limits below ug/L level were obtained also for the phenoxy acid herbicides.JRC.(EI)-Environment Institut

    Selection Processing in Noun and Verb Production in Left- and Right-Sided Parkinson's Disease Patients

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    Verbs are more difficult to produce than nouns. Thus, if executive resources are reduced as in Parkinson's disease (PD), verbs are penalized compared to nouns. However, in an experimental condition in which it is the noun that must be selected from a larger number of alternatives compared to the verb, it is the noun production that becomes slower and more prone to errors. Indeed, patients are slower and less accurate than normal subjects when required to produce nouns from verbs (VN) in a morphology derivation tasks (e.g., ā€œosservazioneā€ from ā€œosservareā€) [ā€œobservationā€ from ā€œobserveā€] than verbs from nouns in a morphology generation task, in which only a verb can be generated from the noun (NV) (e.g., ā€œfallireā€ from ā€œfallimentoā€) [ā€œto failā€ from ā€œfailureā€]. In the Italian language morphology, in fact, generation and derivation tasks differ in the number of lexical entries among which the response must be selected. The left Inferior Frontal Gyrus (IFG) has been demonstrated to be involved in selection processes. In the present study, we explored if the ability to select words is related to the cortical thickness of the left IFG. Twelve right-sided PD with nigrostriatal hypofunctionality in the left hemisphere (RPD-LH), 9 left-sided PD with nigrostriatal hypofunctionality in the right hemisphere (LPD-RH) and 19 healthy controls (HC) took part in the study. NV and VN production tasks were administered; accuracy and reaction times (RTs) were collected. All 40 subjects received a structural MRI examination. Cortical thickness of the IFG and volumetric measurements for subcortical regions, thought to support selection processes, were computed using FreeSurfer. In VN derivation tasks RPD-LH patients were less accurate than LPD-RH patients (accuracy: 66% vs. 77%). No difference emerged among the three groups in RTs. Task accuracy/RTs and IFG thickness showed a significant correlation only in RPD-LH. Not only nouns (as expected) but also verbs were correlated with cortical thickness. This suggests that the linguistic nature of the stimuli along with executive resources are both relevant during word selection processes. Our data confirm that executive resources and language interact in the left IFG in word production tasks
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