278 results match your criteria: "Centre d'etudes de Saclay[Affiliation]"

Neuroimaging Insights into Brain Mechanisms of Early-onset Restrictive Eating Disorders.

medRxiv

November 2024

Institut Pasteur, Université de Paris, CNRS UMR 3571, Human Genetics and Cognitive Functions, 25 rue du Dr. Roux, Paris, France.

Article Synopsis
  • Early-onset restrictive eating disorders (rEO-ED), including early-onset anorexia nervosa (EO-AN) and avoidant restrictive food intake disorders (ARFID), have unknown impacts on brain development.
  • A study comparing brain features through MRI in children under 13 with EO-AN, ARFID, and typically developing peers revealed differing brain structures despite similar BMI, indicating unique brain mechanisms for each disorder.
  • Findings suggest EO-AN is linked to thinner cortex structures, while ARFID patients showed reduced surface area and subcortical volume, highlighting the need for further research on the relationship between low BMI and neurodevelopmental impacts in eating disorders.
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On the Origin of fMRI Species.

J Magn Reson Imaging

November 2024

NeuroSpin, Frédéric Joliot Institute for Life Sciences (Commissariat à l'Energie Atomique, CEA), Centre d'études de Saclay, Paris-Saclay University, Gif-sur-Yvette, France.

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Article Synopsis
  • The Letter reports the most accurate measurement so far of the matter-antimatter imbalance during Pb-Pb collisions at a high energy level of 5.02 TeV.
  • It utilizes the Statistical Hadronization framework to determine precise values for the electric charge and baryon chemical potentials, μ_{Q} and μ_{B}.
  • The analysis of antiparticle-to-particle yield ratios shows that the collisions create a system that is generally baryon-free and electrically neutral at midrapidity.
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The ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high p_{T}) hadron trigger in proton-proton and central Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb-Pb collisions.

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We propose the angular distribution of lepton pairs produced in ultrarelativistic heavy-ion collisions as a probe of thermalization of the quark-gluon plasma. We focus on dileptons with invariant masses large enough that they are produced through quark-antiquark annihilation in the early stages of the collision. The angular distribution of the lepton in the rest frame of the pair then reflects the angular distribution of quark momenta.

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K^{+}K^{-} pairs may be produced in photonuclear collisions, either from the decays of photoproduced ϕ(1020) mesons or directly as nonresonant K^{+}K^{-} pairs. Measurements of K^{+}K^{-} photoproduction probe the couplings between the ϕ(1020) and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere.

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Article Synopsis
  • - This Letter discusses the measurement of ridge yields from charged hadron angular correlations in proton-proton collisions at a high energy of 13 TeV, specifically within certain pseudorapidity and transverse momentum ranges.
  • - The research extends ridge yield measurements to low charged-particle multiplicity regions, where typically a strong interacting medium is not expected to form during collisions.
  • - Findings indicate that ridge yields in pp collisions are significantly higher than those observed in e^{+}e^{-} collisions, suggesting that processes in e^{+}e^{-} annihilations do not significantly influence long-range correlations in proton-proton interactions.
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Article Synopsis
  • The ALICE detector measured the cross section for incoherent photonuclear production of J/ψ vector mesons, focusing on the Mandelstam |t| variable, during ultraperipheral collisions of Pb nuclei at a very high energy of 5.02 TeV.
  • The measurement was conducted within a rapidity interval of |y|<0.8 and covers a specific range of Bjorken-x values.
  • Analysis showed that models without quantum fluctuations in the gluon density predicted a much steeper |t|-dependence than observed, but including these fluctuations improved the models' alignment with the data.
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[F]2-fluoro-2-deoxy-sorbitol ([F]FDS) PET imaging repurposed for quantitative estimation of blood-brain barrier permeability in a rat model of Alzheimer's disease.

Ann Pharm Fr

September 2024

Service hospitalier Frédéric-Joliot, laboratoire d'imagerie biomédicale multimodale (BioMaps), Inserm, CNRS, CEA, université Paris-Saclay, 91401 Orsay, France. Electronic address:

Numerous studies suggest that blood-brain barrier (BBB) dysfunction may contribute to the progression of Alzheimer's disease (AD). Clinically available neuroimaging methods are needed for quantitative "scoring" of BBB permeability in AD patients. [F]2-fluoro-2-deoxy-sorbitol ([F]FDS), which can be easily obtained from simple chemical reduction of commercial [F]2-fluoro-2-deoxy-glucose ([F]FDG), was investigated as a small-molecule marker of BBB permeability, in a pre-clinical model of AD using in vivo PET imaging.

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ψ(2S) Suppression in Pb-Pb Collisions at the LHC.

Phys Rev Lett

January 2024

INFN, Sezione di Pavia, Pavia, Italy.

The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.

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From Black Holes Entropy to Consciousness: The Dimensions of the Brain Connectome.

Entropy (Basel)

December 2023

NeuroSpin, Frédéric Joliot Institute for Life Sciences (Commissariat à l'Energie Atomique, CEA), Centre d'Études de Saclay, Paris-Saclay University, Bâtiment 145, 91191 Gif-sur-Yvette, France.

It has been shown that the theory of relativity can be applied physically to the functioning brain, so that the brain connectome should be considered as a four-dimensional spacetime entity curved by brain activity, just as gravity curves the four-dimensional spacetime of the physical world. Following the most recent developments in modern theoretical physics (black hole entropy, holographic principle, AdS/CFT duality), we conjecture that consciousness can naturally emerge from this four-dimensional brain connectome when a fifth dimension is considered, in the same way that gravity emerges from a 'flat' four-dimensional quantum world, without gravitation, present at the boundaries of a five-dimensional spacetime. This vision makes it possible to envisage quantitative signatures of consciousness based on the entropy of the connectome and the curvature of spacetime estimated from data obtained by fMRI in the resting state (nodal activity and functional connectivity) and constrained by the anatomical connectivity derived from diffusion tensor imaging.

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Introduction: Fetal alcohol spectrum disorders (FASD) range from fetal alcohol syndrome (FAS) to non-syndromic forms (NS-FASD). The neuroanatomical consequences of prenatal alcohol exposure are mainly the reduction in brain size, but also focal abnormalities such as those of the corpus callosum (CC). We previously showed a narrowing of the CC for brain size, using manual measurement and its usefulness to improve diagnostic certainty.

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Article Synopsis
  • Understanding how parton mass and Casimir color factors affect heavy quark emissions is key to studying quantum chromodynamics (QCD).
  • This research presents the first experimental constraint on the charm-quark splitting function, obtained through measurements in proton-proton collisions at 13 TeV.
  • Findings indicate that charm quarks show a steeper splitting function compared to gluons and light quarks, experiencing fewer emissions with a lower likelihood of large-angle emissions.
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The passage of antibodies through the blood-brain barrier (BBB) and the blood-tumoral barrier (BTB) is determinant not only to increase the immune checkpoint inhibitors efficacy but also to monitor prognostic and predictive biomarkers such as the programmed death ligand 1 (PD-L1) via immunoPET. Although the involvement of neonatal Fc receptor (FcRn) in antibody distribution has been demonstrated, its function at the BBB remains controversial, while it is unknown at the BTB. In this context, we assessed FcRn's role by pharmacokinetic immunoPET imaging combined with focused ultrasounds (FUS) using unmodified and FcRn low-affinity IgGs targeting PD-L1 in a preclinical orthotopic glioblastoma model.

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Astrocytes Undergo Metabolic Reprogramming in the Multiple Sclerosis Animal Model.

Cells

October 2023

Life and Health Sciences Research Institute (ICVS), School of Medicine, Campus Gualtar, University of Minho, 4710-057 Braga, Portugal.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that presents a largely unknown etiopathology. The presence of reactive astrocytes in MS lesions has been described for a long time; however, the role that these cells play in the pathophysiology of MS is still not fully understood. Recently, we used an MS animal model to perform high-throughput sequencing of astrocytes' transcriptome during disease progression.

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The most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process).

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The mesencephalic locomotor region recruits V2a reticulospinal neurons to drive forward locomotion in larval zebrafish.

Nat Neurosci

October 2023

Sorbonne Université, Paris Brain Institute (Institut du Cerveau, ICM), Institut National de la Santé et de la Recherche Médicale U1127, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7225, Assistance Publique-Hôpitaux de Paris, Campus Hospitalier Pitié-Salpêtrière, Paris, France.

The mesencephalic locomotor region (MLR) is a brain stem area whose stimulation triggers graded forward locomotion. How MLR neurons recruit downstream vsx2 (V2a) reticulospinal neurons (RSNs) is poorly understood. Here, to overcome this challenge, we uncovered the locus of MLR in transparent larval zebrafish and show that the MLR locus is distinct from the nucleus of the medial longitudinal fasciculus.

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The therapeutic management of gliomas remains particularly challenging. Brain tumors present multiple obstacles that make therapeutic innovation complex, mainly due to the presence of blood-tumor and blood-brain barriers (BTB and BBB, respectively) which prevent penetration of anticancer agents into the brain parenchyma. Focused ultrasound-mediated BBB disruption (FUS-BBBD) provides a physical method for non-invasive, local, and reversible BBB disruption.

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Longitudinal MicroRNA Signature of Conversion to Psychosis.

Schizophr Bull

March 2024

Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, GDR 3557-Institut de Psychiatrie, Université de Paris, Paris, France.

Background And Hypothesis: The emergence of psychosis in ultra-high-risk subjects (UHR) is influenced by gene-environment interactions that rely on epigenetic mechanisms such as microRNAs. However, whether they can be relevant pathophysiological biomarkers of psychosis' onset remains unknown.

Study Design: We present a longitudinal study of microRNA expression, measured in plasma by high-throughput sequencing at baseline and follow-up, in a prospective cohort of 81 UHR, 35 of whom developed psychosis at follow-up (converters).

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Article Synopsis
  • * A notable negative correlation between the production of antiprotons and antideuterons was found across various collision centralities.
  • * Comparisons with theoretical models show that while a coalescence calculation explains certain statistical features, it struggles with the specifics of antiproton-antideuteron correlations, whereas thermal-statistical models can align with observations but imply different correlation volumes.
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The transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrt[s]=13  TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5  GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE.

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We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.

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Article Synopsis
  • Fetal alcohol spectrum disorders (FASD) are conditions caused by drinking alcohol during pregnancy, affecting brain development, and can show up in many ways from mild to severe.
  • Researchers studied brain scans of kids and young adults with FASD and compared them to those without the condition, to see how their brains were different.
  • They found that parts of the brain called the corpus callosum (CC) were smaller in those with FASD, especially in specific areas, suggesting that there may be helpful markers in brain scans for diagnosing these disorders.
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Structural basis of envelope and phase intrinsic coupling modes in the cerebral cortex.

Neuroimage

August 2023

Institute of Computational Neuroscience, Hamburg Center of Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg University, Martinistraße 52, Hamburg 20246, Germany; Department of Health Sciences, Boston University, 635 Commonwealth Avenue, Boston, Massachusetts 02215, USA.

Article Synopsis
  • Intrinsic coupling modes (ICMs) in brain activity can be divided into two types: phase ICMs and envelope ICMs, with their principles still not fully understood, especially regarding their connection to brain structure.
  • Researchers studied the relationship between ICMs, measured through micro-ECoG arrays, and the brain's structural connectivity using high-resolution diffusion MRI in ferrets.
  • The findings reveal that both ICM types correlate with structural connectivity, particularly at higher frequencies, but the strength of this relationship varies; phase ICMs show a unique correlation pattern when adjusting for zero-lag coupling effects.
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In fetal alcohol spectrum disorders (FASD), brain growth deficiency is a hallmark of subjects both with fetal alcohol syndrome (FAS) and with non-syndromic FASD (NS-FASD, i.e., those without specific diagnostic features).

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