Size-induced exchange bias in single-phase CoO nanoparticles.

The tuning of exchange bias (EB) in nanoparticles has garnered significant attention due to its diverse range of applications. Here, we demonstrate EB in single-phase CoO nanoparticles, where two magnetic phases naturally emerge as the crystallite size decreases from 34.6 ± 0.

Photocatalytic Activity of BaAlO for Water Purification.

Degradation of dyes under natural light sources is one of the most active research areas in basic science for greener technology. In this context, the photocatalytic activity of semiconductors has received massive attention in solving water treatment-related issues as these possess enormous potential for degrading organic impurities. Here, we report that barium aluminate (BaAlO, BAO), which has been extensively studied for photoluminescence applications, is found to be a highly potent candidate for photocatalytic activities.

Aberrant Frontostriatal Connectivity in Negative Symptoms of Schizophrenia.

Negative symptoms represent a distinct component of psychopathology in schizophrenia (SCZ) and are a stable construct over time. Although impaired frontostriatal connectivity has been frequently described in SCZ, its link with negative symptoms has not been carefully studied. We tested the hypothesis that frontostriatal connectivity at rest may be associated with the severity of negative symptoms in SCZ.

Anterior Cingulate Glutamate and GABA Associations on Functional Connectivity in Schizophrenia.

Background: The underlying neurobiological mechanism for abnormal functional connectivity in schizophrenia (SCZ) remains unknown. This project investigated whether glutamate and GABA, 2 metabolites that contribute to excitatory and inhibitory functions, may influence functional connectivity in SCZ.

Methods: Resting-state functional magnetic resonance imaging and proton magnetic resonance spectroscopy were acquired from 58 SCZ patients and 61 healthy controls (HC).

Imaging studies of the HIV-infected brain.

Human immunodeficiency virus (HIV) enters the brain early after infecting humans and may remain in the central nervous system despite successful antiretroviral treatment. Many neuroimaging techniques were used to study HIV+ patients with or without opportunistic infections. These techniques assessed abnormalities in brain structures (using computed tomography, structural magnetic resonance imaging (MRI), diffusion MRI) and function (using functional MRI at rest or during a task, and perfusion MRI with or without a contrast agent).

Fornix Structural Connectivity and Allostatic Load: Empirical Evidence From Schizophrenia Patients and Healthy Controls.

Objective: The fornix is a white matter tract carrying the fibers connecting the hippocampus and the hypothalamus, two essential stress-regulatory structures of the brain. We tested the hypothesis that allostatic load (AL), derived from a battery of peripheral biomarkers indexing the cumulative effects of stress, is associated with abnormalities in brain white matter microstructure, especially the fornix, and that higher AL may help explain the white matter abnormalities in schizophrenia.

Methods: Using 13 predefined biomarkers, we tested AL in 44 schizophrenic patients and 33 healthy controls.

Repetitive Model of Mild Traumatic Brain Injury Produces Cortical Abnormalities Detectable by Magnetic Resonance Diffusion Imaging, Histopathology, and Behavior.

Noninvasive detection of mild traumatic brain injury (mTBI) is important for evaluating acute through chronic effects of head injuries, particularly after repetitive impacts. To better detect abnormalities from mTBI, we performed longitudinal studies (baseline, 3, 6, and 42 days) using magnetic resonance diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) in adult mice after repetitive mTBI (r-mTBI; daily × 5) or sham procedure. This r-mTBI produced righting reflex delay and was first characterized in the corpus callosum to demonstrate low levels of axon damage, astrogliosis, and microglial activation, without microhemorrhages.

[F]FDG-PET Combined with MRI Elucidates the Pathophysiology of Traumatic Brain Injury in Rats.

Non-invasive measurements of brain metabolism using F-fluorodeoxyglucose (FDG) with positron emission tomography (PET) may provide important information about injury severity following traumatic brain injury (TBI). There is growing interest in the potential of combining functional PET imaging with anatomical and functional magnetic resonance imaging (MRI). This study aimed to investigate the effectiveness of combining clinically available FDG-PET with T2 and diffusion MR imaging, with a particular focus on inflammation and the influence of glial alterations after injury.

Heterochronicity of white matter development and aging explains regional patient control differences in schizophrenia.

Background: Altered brain connectivity is implicated in the development and clinical burden of schizophrenia. Relative to matched controls, schizophrenia patients show (1) a global and regional reduction in the integrity of the brain's white matter (WM), assessed using diffusion tensor imaging (DTI) fractional anisotropy (FA), and (2) accelerated age-related decline in FA values. In the largest mega-analysis to date, we tested if differences in the trajectories of WM tract development influenced patient-control differences in FA.

Tryptophan Metabolism and White Matter Integrity in Schizophrenia.

Schizophrenia is associated with abnormalities in the structure and functioning of white matter, but the underlying neuropathology is unclear. We hypothesized that increased tryptophan degradation in the kynurenine pathway could be associated with white matter microstructure and biochemistry, potentially contributing to white matter abnormalities in schizophrenia. To test this, fasting plasma samples were obtained from 37 schizophrenia patients and 38 healthy controls and levels of total tryptophan and its metabolite kynurenine were assessed.

Heritability of complex white matter diffusion traits assessed in a population isolate.

Introduction: Diffusion weighted imaging (DWI) methods can noninvasively ascertain cerebral microstructure by examining pattern and directions of water diffusion in the brain. We calculated heritability for DWI parameters in cerebral white (WM) and gray matter (GM) to study the genetic contribution to the diffusion signals across tissue boundaries.

Methods: Using Old Order Amish (OOA) population isolate with large family pedigrees and high environmental homogeneity, we compared the heritability of measures derived from three representative DWI methods targeting the corpus callosum WM and cingulate gyrus GM: diffusion tensor imaging (DTI), the permeability-diffusivity (PD) model, and the neurite orientation dispersion and density imaging (NODDI) model.

Impaired thalamocortical connectivity in autism spectrum disorder: a study of functional and anatomical connectivity.

The thalamus plays crucial roles in the development and mature functioning of numerous sensorimotor, cognitive and attentional circuits. Currently limited evidence suggests that autism spectrum disorder may be associated with thalamic abnormalities, potentially related to sociocommunicative and other impairments in this disorder. We used functional connectivity magnetic resonance imaging and diffusion tensor imaging probabilistic tractography to study the functional and anatomical integrity of thalamo-cortical connectivity in children and adolescents with autism spectrum disorder and matched typically developing children.

Temperature and intensity dependence of Yb-fiber laser light absorption in water.

Absorption of CW Yb-fiber laser light of 1.07 μm wavelength in water has been measured at different water temperatures and laser intensities. The absorption coefficient was estimated to be 0.

Underconnected, but how? A survey of functional connectivity MRI studies in autism spectrum disorders.

Growing consensus suggests that autism spectrum disorders (ASD) are associated with atypical brain networks, thus shifting the focus to the study of connectivity. Many functional connectivity studies have reported underconnectivity in ASD, but results in others have been divergent. We conducted a survey of 32 functional connectivity magnetic resonance imaging studies of ASD for numerous methodological variables to distinguish studies supporting general underconnectivity (GU) from those not consistent with this hypothesis (NGU).

Microstructural abnormalities of short-distance white matter tracts in autism spectrum disorder.

Recent functional connectivity magnetic resonance imaging and diffusion tensor imaging (DTI) studies have suggested atypical functional connectivity and reduced integrity of long-distance white matter fibers in autism spectrum disorder (ASD). However, evidence for short-distance white matter fibers is still limited, despite some speculation of potential sparing of local connectivity in ASD. Short-distance U-fibers are an important component of neural networks and are thought to play a crucial role in cognitive function.

White matter compromise of callosal and subcortical fiber tracts in children with autism spectrum disorder: a diffusion tensor imaging study.

Objective: Autism spectrum disorder (ASD) is increasingly viewed as a disorder of functional networks, highlighting the importance of investigating white matter and interregional connectivity. We used diffusion tensor imaging (DTI) to examine white matter integrity for the whole brain and for corpus callosum, internal capsule, and middle cerebellar peduncle in children with ASD and typically developing (TD) children.

Method: DTI data were obtained from 26 children with ASD and 24 matched TD children.

Tract-specific analyses of diffusion tensor imaging show widespread white matter compromise in autism spectrum disorder.

Background: Previous diffusion tensor imaging (DTI) studies have shown white matter compromise in children and adults with autism spectrum disorder (ASD), which may relate to reduced connectivity and impaired function of distributed networks. However, tract-specific evidence remains limited in ASD. We applied tract-based spatial statistics (TBSS) for an unbiased whole-brain quantitative estimation of the fractional anisotropy (FA), mean diffusion (MD) and axial and radial diffusion of the white matter tracts in children and adolescents with ASD.

Regional homogeneity of fMRI time series in autism spectrum disorders.

Functional magnetic resonance imaging (fMRI) and functional connectivity MRI (fcMRI) studies of autism spectrum disorders (ASD) have suggested atypical patterns of activation and long-distance connectivity for diverse tasks and networks in ASD. We explored the regional homogeneity (ReHo) approach in ASD, which is analogous to conventional fcMRI, but focuses on local connectivity. FMRI data of 26 children with ASD and 29 typically developing (TD) children were acquired during continuous task performance (visual search).

Effects of pioglitazone on diffusion tensor imaging indices in multiple sclerosis patients.

Pioglitazone is an FDA-approved peroxisome proliferator activated receptor gamma (PPARgamma) agonist. We tested the hypothesis that treatment with pioglitazone reduces new lesion development in patients with RRMS. Twenty-two patients were treated with pioglitazone or placebo and monitored by diffusion tensor imaging (DTI) at baseline and after 12 months.

A pilot test of pioglitazone as an add-on in patients with relapsing remitting multiple sclerosis.

The peroxisome proliferator-activated receptor gamma agonist pioglitazone is FDA-approved for treatment of type-2 diabetes due to insulin sensitizing effects. However pioglitazone has anti-inflammatory and neuroprotective effects, reduces glial and T-cell activation, and reduces signs in an animal model of multiple sclerosis (MS). We tested the effects of daily treatment with pioglitazone in a small cohort of relapsing remitting MS patients.