Clustered ultra-small iron oxide nanoparticles as potential T/Tdual-modal magnetic resonance imaging contrast agents and application to tumor model.

Many studies have been conducted on the use of ultra-small iron oxide nanoparticles (USIONs) (d < 3 nm) as potential positive magnetic resonance imaging (MRI)-contrast agents (CAs); however, there is dearth of research on clustered USIONs. In this study, nearly monodispersed clustered USIONs were synthesized using a simple two-step one-pot polyol method. First, USIONs (d = 2.

Quantification of Glutathione and Its Associated Spontaneous Neuronal Activity in Major Depressive Disorder and Obsessive-Compulsive Disorder.

Background: Glutathione (GSH) is a crucial antioxidant in the human brain. Although proton magnetic resonance spectroscopy using the Mescher-Garwood point-resolved spectroscopy sequence is highly recommended, limited literature has measured cortical GSH using this method in major psychiatric disorders.

Methods: By combining magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging, we quantified brain GSH and glutamate in the medial prefrontal cortex and precuneus and explored relationships between GSH levels and intrinsic neuronal activity as well as clinical symptoms among healthy control (HC) participants (n = 30), people with major depressive disorder (MDD) (n = 28), and people with obsessive-compulsive disorder (OCD) (n = 28).

Core-Shell FeO@C Nanoparticles as Highly Effective T Magnetic Resonance Imaging Contrast Agents: In Vitro and In Vivo Studies.

Magnetite nanoparticles (FeO NPs) have been intensively investigated because of their potential biomedical applications due to their high saturation magnetization. In this study, core-shell FeO@C NPs (core = FeO NPs and shell = amorphous carbons, d = 35.1 nm) were synthesized in an aqueous solution.

Neural mechanisms of acceptance-commitment therapy for obsessive-compulsive disorder: a resting-state and task-based fMRI study.

Background: There is growing evidence for the use of acceptance-commitment therapy (ACT) for the treatment of obsessive-compulsive disorder (OCD). However, few fully implemented ACT have been conducted on the neural mechanisms underlying its effect on OCD. Thus, this study aimed to elucidate the neural correlates of ACT in patients with OCD using task-based and resting-state functional magnetic resonance imaging (fMRI).

Connectome-based predictive models using resting-state fMRI for studying brain aging.

Changes in the brain with age can provide useful information regarding an individual's chronological age. studies have suggested that functional connectomes identified via resting-state functional magnetic resonance imaging (fMRI) could be a powerful feature for predicting an individual's age. We applied connectome-based predictive modeling (CPM) to investigate individual chronological age predictions via resting-state fMRI using open-source datasets.

The Neural Correlates of Positive Versus Negative Thought-action Fusion in Healthy Young Adults.

Objective: Thought-action fusion (TAF), one of the most-studied dysfunctional beliefs in obsessive-compulsive disorder, represents an individual's belief that his/her thoughts directly influence events. TAF belief types are divided into personal thoughts relating to positive (positive TAF) and negative outcomes (negative TAF). However, the neural mechanisms underlying both aspects of the TAF response remain elusive.

Impact of fractional amplitude of low-frequency fluctuations in motor- and sensory-related brain networks on spinal cord injury severity.

Spinal cord injury (SCI) can cause motor, sensory, and autonomic dysfunctions and may affect the cerebral functions. However, the mechanisms of plastic changes in the brain according to SCI severity remain poorly understood. Therefore, in the current study, we compared the brain activity of the entire neural network according to severity of SCI using fractional amplitude of low-frequency fluctuations (fALFF) analysis in resting-state functional magnetic resonance imaging (rs-fMRI).

Reconciliation of Two Cognitive Models in Obsessive-Compulsive Disorder: An fMRI Study.

Objective: Although cognitive models of obsessive-compulsive disorder (OCD) fall into two categories: cognitive deficit models and dysfunctional belief models, these approaches have their own ways and have hardly been reconciled. Therefore, this study aimed to investigate the potential relationships between cognitive deficit (using the Wisconsin Card Sorting Task, WCST) and dysfunctional belief (measured by scales of dysfunctional beliefs) mediated by neural activity in OCD patients.

Methods: Thirty OCD patients and 30 healthy participants performed the WCST condition and a baseline MATCH condition during the 3T-functional magnetic resonance imaging (fMRI) acquisition.

Improved white matter integrity after contralateral seventh cervical nerve transfer measured by tractographic representation.

Contralateral C7 (CC7) nerve transfer surgery was shown to significantly improve the spasticity condition and the motor function of paralyzed arms. However, the involvement of the white matter tract in the recovery process is not well established. We here investigated the possible biologic explanation for this phenomenon.

Synthesis, Characterizations, and 9.4 Tesla T MR Images of Polyacrylic Acid-Coated Terbium(III) and Holmium(III) Oxide Nanoparticles.

Polyacrylic acid (PAA)-coated lanthanide oxide (LnO) nanoparticles (NPs) (Ln = Tb and Ho) with high colloidal stability and good biocompatibility were synthesized, characterized, and investigated as a new class of negative (T) magnetic resonance imaging (MRI) contrast agents at high MR fields. Their r values were appreciable at a 3.0 T MR field and higher at a 9.

Chitosan Oligosaccharide Lactate-Coated Ultrasmall Gadolinium Oxide Nanoparticles: Synthesis, Cytotoxicity, and Relaxometric Properties.

In this study, hydrophilic and biocompatible chitosan oligosaccharide lactate (COL)-coated ultra-small gadolinium oxide nanoparticles (NPs) were synthesized through a one-pot polyol method and characterized by various experimental techniques. The cellular cytotoxicity assay indicated that the COL-coated gadolinium oxide NPs were non-toxic up to 500 M Gd. In addition, their water proton spin relaxivities (i.

Hydrophilic Biocompatible Poly(Acrylic Acid-co-Maleic Acid) Polymer as a Surface-Coating Ligand of Ultrasmall GdO Nanoparticles to Obtain a High r Value and T MR Images.

The water proton spin relaxivity, colloidal stability, and biocompatibility of nanoparticle-based magnetic resonance imaging (MRI) contrast agents depend on the surface-coating ligands. Here, poly(acrylic acid-co-maleic acid) (PAAMA) (M = ~3000 amu) is explored as a surface-coating ligand of ultrasmall gadolinium oxide (GdO) nanoparticles. Owing to the numerous carboxylic groups in PAAMA, which allow its strong conjugation with the nanoparticle surfaces and the attraction of abundant water molecules to the nanoparticles, the synthesized PAAMA-coated ultrasmall GdO nanoparticles (d = 1.

Effects of Cognitive Training in Mild Cognitive Impairmentmeasured by Resting State Functional Imaging.

Mild cognitive impairment (MCI) is defined as an intermediate state of cognitive alteration between normal aging and dementia. In this study, we performed a functional network connectivity analysis using resting-state functional magnetic resonance imaging to investigate the association between changes in functional connectivity in the brain and the improvement in cognitive abilities after cognitive training. A computerized cognitive training program was used to improve the abilities of fifteen participants with MCI.

Aberrant functional connectivity of neural circuits associated with thought-action fusion in patients with obsessive-compulsive disorder.

Background: Cognitive theories of obsessive-compulsive disorder (OCD) stress the importance of dysfunctional beliefs in the development and maintenance of the disorder. However, a neurobiological understanding of these cognitive models, including thought-action fusion (TAF), is surprisingly lacking. Thus, this functional magnetic resonance imaging study aimed to investigate whether altered functional connectivity (FC) is associated with the TAF paradigm in OCD patients.

New Class of Efficient T Magnetic Resonance Imaging Contrast Agent: Carbon-Coated Paramagnetic Dysprosium Oxide Nanoparticles.

Nanoparticles are considered potential candidates for a new class of magnetic resonance imaging (MRI) contrast agents. Negative MRI contrast agents require high magnetic moments. However, if nanoparticles can exclusively induce transverse water proton spin relaxation with negligible induction of longitudinal water proton spin relaxation, they may provide negative contrast MR images despite having low magnetic moments, thus acting as an efficient T MRI contrast agent.

Alterations in power spectral density in motor- and pain-related networks on neuropathic pain after spinal cord injury.

Background: The mechanisms by which mobility function and neuropathic pain are mutually influenced by supraspinal plasticity in motor- and pain-related brain networks following spinal cord injury (SCI) remains poorly understood.

Objective: To determine cortical and subcortical resting-state network alterations using power spectral density (PSD) analysis and investigate the relationships between these intrinsic alterations and mobility function and neuropathic pain following SCI.

Methods: A total of 41 patients with incomplete SCI and 33 healthy controls were included.

Effects of emotional maltreatment on semantic network activity during cognitive reappraisal.

Maltreatment experiences alter brain development associated with emotion processing, and dysregulation of emotion may trigger mental health problems in maltreated people. However, studies revealing alterations in brain networks during cognitive reappraisal in victims of maltreatment are strikingly insufficient. In this study, 27 healthy subjects were recruited.

Interhemispheric Functional Connectivity in the Primary Motor Cortex Assessed by Resting-State Functional Magnetic Resonance Imaging Aids Long-Term Recovery Prediction among Subacute Stroke Patients with Severe Hand Weakness.

This study aimed to evaluate the usefulness of interhemispheric functional connectivity (FC) as a predictor of motor recovery in severe hand impairment and to determine the cutoff FC level as a clinically useful parameter. Patients with stroke ( = 22; age, 59.9 ± 13.

In Vivo Positive Magnetic Resonance Imaging Applications of Poly(methyl vinyl ether-alt-maleic acid)-coated Ultra-small Paramagnetic Gadolinium Oxide Nanoparticles.

The study of ultra-small paramagnetic gadolinium oxide (GdO) nanoparticles (NPs) as in vivo positive (T) magnetic resonance imaging (MRI) contrast agents is one of the most attractive fields in nanomedicine. The performance of the GdO NP imaging agents depends on the surface-coating materials. In this study, poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was used as a surface-coating polymer.

Believing is seeing: an fMRI study of thought-action fusion in healthy male adults.

Thought-action fusion (TAF) is a tendency of individuals to establish causal relations between their own thoughts and external reality. TAF can lead to maladaptive behaviors typically observed in obsessional thoughts. However, neural mechanisms underlying TAF are still unknown.

Effects of a Mixed Reality-based Cognitive Training System Compared to a Conventional Computer-assisted Cognitive Training System on Mild Cognitive Impairment: A Pilot Study.

Background: Mixed reality (MR) technology, which combines the best features of augmented reality and virtual reality, has recently emerged as a promising tool in cognitive rehabilitation therapy.

Objective: To investigate the effectiveness of an MR-based cognitive training system for individuals with mild cognitive impairment (MCI).

Methods: Twenty-one individuals aged 65 years and older who had been diagnosed with MCI were recruited for this study and were divided into two groups.

The neural correlates of thought-action fusion in healthy adults: A functional magnetic resonance imaging study.

Background: Thought-action fusion (TAF) represents an individual's belief that a thought is like action. Inflated TAF has been considered a central mechanism for developing obsessive thoughts. However, the neural mechanisms underlying TAF are yet unknown.

Diffusion tensor imaging and voxel-based morphometry reveal corticospinal tract involvement in the motor dysfunction of adult-onset myotonic dystrophy type 1.

Magnetic resonance imaging (MRI) studies have demonstrated that patients with myotonic dystrophy type 1 (DM1) exhibit gray and white matter abnormalities that are correlated with various genetic and neuropsychological measures. However, few MRI studies have focused on the correlations between brain abnormalities and overall motor function including gait performance. Here, we investigated the correlations between brain abnormalities, as assessed with MRI including diffusion tensor imaging (DTI), and motor performance, as assessed with the Medical Research Council sum score (MRCSS), 6-minute walk test (6MWT), and hand grip power, in patients with DM1.

Relaxometric, Optical and Cell Viability Properties of D-Glucuronic Acid Coated Cr₂O₃ Nanoparticles.

D-glucuronic acid-coated ultrasmall chromium oxide (Cr2O3) nanoparticles were synthesized by a one-pot polyol method and their relaxometric and optical properties were investigated. The as-synthesized D-glucuronic acid-coated nanoparticles were amorphous owing to ultrasmall particle diameters (davg = 2.0 nm), whereas orthorhombic Cr2O3 nanoparticles with two size groups (davg = 3.

Longitudinal Water Proton Relaxivity and In Vivo T₁ MR Images of Mixed Zn(II)/Gd(III) Oxide Nanoparticles.

Mixed Zn(II)/Gd(III) oxide nanoparticles (~8 mole%Zn) with d(avg) of 2.1 nm were synthesized. The D-glucuronic acid coated Zn(II)/Gd(III) oxide nanoparticles showed a longitudinal water proton relaxivity (r₁) of 12.