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Background Recent progress in neuroscience research has provided evidence that schizophrenia is a disease that involves dysconnectivity of brain networks. Widespread gray matter loss was commonly observed but how these gray matter abnormalities are characterized at the large-scale network-level in schizophrenia, especially patients with first-episode (FE-SCZ) remains unclear. Methods In this study, gray matter structural network aberrations were investigated by applying structural covariance network analysis to 193 first episode schizophrenia patients and 178 age and gender-matched healthy controls (HCs). The mean gray matter volume in seed regions relating to eight specific networks (visual, auditory, sensorimotor, speech, semantic, default-mode, executive control, and salience) were extracted, and voxel-wise analyses of covariance were conducted to compare the association between whole-brain gray matter volume and each seed region for FE-SCZ and HCs. Results The auditory network was less extended in FE-SCZ compared with HCs, with a significant decrease in the structural association between the Hesch's gyrus and the middle frontal gyrus and the superior frontal gyrus. Hyperconnectivity was observed in executive control network with a significant increase in the structural association between the dorsal lateral prefrontal cortex and the superior frontal gyrus and supplementary motor area. Conclusion Our research shows that seed based structural covariance analysis can well characterize multiple large-scale networks, the observed changes might underly the hallucinations and cognitive impairments observed in FE-SCZ. Given that these patients were experiencing their first episode of schizophrenia, our findings suggest that such structural network deficits are present at an early stage in this disorder.

Despite evidence of structural brain abnormalities in schizophrenia, the current study aimed to explore the effects of antipsychotic treatment on gray matter (GM) volume using structural magnetic resonance imaging (MRI) and investigate the relationship between brain structure and treatment response. The GM volumes of 33 patients with first-episode schizophrenia were calculated with voxel-based morphometry (VBM), with 33 matched healthy controls. Longitudinal volume changes within subjects after 4-month antipsychotic treatment were also evaluated. Correlation between volumetric changes and clinical symptoms derived from the Positive and Negative Syndrome Scale (PANSS) were further investigated. Compared with healthy controls, decreased GM volumes in the frontal gyrus were observed in schizophrenia patients. After 4-month treatment, patients showed significantly decreased GM volume primarily in the bilateral frontal, temporal and left parietal brain regions. In addition, the GM volume changes of the left postcentral gyrus was positively correlated with negative symptoms improvement, and the correlation analysis revealed the total PANSS scores changes were associated with GM volume changes in the right inferior frontal gyrus and the right superior temporal gyrus. Besides, non-responders had reduced GM volume in the bilateral middle frontal gyrus and the right superior frontal gyrus compared with responders and healthy controls. Our results suggest that the abnormality in the right frontal gyrus exists in the early stage of schizophrenia. Moreover, the relationship between antipsychotics and structural changes was identified. The GM volume might have the potential to reflect the symptom improvement in schizophrenia patients. And MRI may assist in predicting the antipsychotic treatment response in first-episode schizophrenia patients.

Objective We aimed to evaluate the functional network properties in first-episode schizophrenia (SZ) patients at baseline and after 4-months treatment with second-generation antipsychotic drugs. Methods Resting-state functional magnetic resonance imaging and graph theory approaches were utilized to evaluate the functional integration and segregation of brain networks in 36 first-episode patients (20 male/16 female) with SZ and 36 age and sex matched healthy controls (20 male/16 female). Results Compared with healthy controls, SZ at baseline showed lower clustering coefficient (Cp) and local network efficiency (Eloc), and this abnormal pattern was modulated with treatment of antipsychotic drugs at follow-up. Longitudinally, the increase of Cp was associated with the improvement of negative symptom. We found that the strength of functional connectivity between brain regions were significantly increased in three connections after treatment, mainly involving the frontal, parietal and occipital lobes. Conclusion The current study suggested that antipsychotic drugs could modulate the faulty local clustering of the functional connectome in SZ. Furthermore, Cp, the parameter that reflects local clustering of topological organization, demonstrated the potential to be a connectome-based biomarker of treatment response to second-generation antipsychotics in patients with SZ.

The goal of the study was to investigate cerebral blood flow (CBF) and its connectivity (an across-subject covariance measure) patterns of schizophrenia (SZ) patients with auditory verbal hallucinations (AVHs). A total of demographically matched 25 SZ patients with AVHs, 25 without AVHs, and 25 healthy controls (HCs) underwent resting state perfusion imaging using a pulsed arterial spin labeling sequence. CBF and its connectivity were analyzed and then CBF topological properties were calculated. AVHs patients exhibited decreased CBF in the bilateral superior and middle frontal gyri and postcentral gyri, and right supplementary motor area compared with SZ patients without AVHs. SZ patients without AVHs showed reduced CBF in the left middle frontal gyrus relative to HCs. Moreover, AVHs groups showed distinct connectivity pattern, an intermediate level between HCs and patients without AVHs in the global efficiency. Our study demonstrates aberrant CBF in the brain regions associated with inner speech monitoring and language processing in SZ patients with AVHs. The complex network measures showed by CBF-derived functional connectivity indicate dysconnectivity between different functional units within the network of AVHs in SZ. Our findings might shed light on the neural underpinnings behind AVHs in this devastating disease at the level of CBF and its connectivity.

Heterogeneous findings across studies of structural abnormality in schizophrenia (SZ) have impeded the development a unified theory of white matter pathology. As a cardinal symptom of SZ, auditory verbal hallucination (AVH) has been suspected to be associated with improper communication among several brain regions, which might indicated white matter pathology. Participants comprised 25 first-episode (FE) patients with AVH, 25 patients without AVH and 25 healthy subjects. Diffusion tensor imaging (DTI) measures were calculated using the TBSS of FSL. Voxel-based ANOVA tests were performed among the three groups and threshold-free cluster enhancement (TFCE) method correction was used for multiple comparisons. Voxel-based one-way ANOVA showed significant group effects for fractional anisotropy (FA) and radial diffusivity (RD) values. Post-hoc t-tests indicated that schizophrenia patients had lower FA and higher RD values in the internal capsule and anterior corona radiata than control subjects. Post-hoc analyses exhibited more widespread fiber disruptions in AVH patients than non-AVH patients. These results hinted on the important role of projection fiber disruption in schizophrenia patients. In addition, the current study also suggested that direct comparison between studies using patients with different symptom profiles should be interpreted with caution.

Abnormal expression of Retinoid X Receptor α (RXRα) seems to be a frequent incident in a variety of cancers. However, the expression pattern and the mechanisms in gastric carcinoma (GC) remain unclear.In GC tissues and cell lines, the expression levels of RXRα mRNA and protein were detected by Q-PCR and Western blot, respectively; the localization of RXRα was evaluated by immunohistochemistry (IHC) or immunocytochemistry (ICC). The effect of IL-1β on RXRα expression and localization was detected by Western blot and ICC. Nuclear factor-κB (NF-κB) pathway was assessed via Western blot.RXRα expression was markedly elevated at both mRNA and protein levels in GC tissues and cell lines (all P0.05). The abnormal overexpression of RXRα was predominantly visualized in cytoplasm. IL-1β significantly induced cytoplasmic expression of RXRα in a time-dependent manner. Co-incubation with IL-1β enhanced phospho-IKKα (p-IKKα) expression and this effect could be inhibited by the specific inhibitor for NF-κB (all P0.01).IL-1β upregulated RXRα through activation of NF-κB signaling and these suggested a possible clinic significance of retinoid receptor expression in the diagnosis and treatment of GC.

Porous films were fabricated from nonporous layer-by-layer multilayers composed of a blend of positively charged disulfide-containing polyamidoamine and poly(allylamine hydrochoride), and negatively charged poly(acrylic acid), followed by removal of cleavable disulfide-containing polycation after incubation in 1 mM DTT solution. The thickness of original multilayered films decreased with the increase of incubation time in DTT solution. Atomic force microscopy (AFM) measurements and electrochemical analysis demonstrated the formation of nanopores with sizes ranging from 50 to 120 nm. The formed porous films were stable in buffer solution at pHs ranging from 7.4 to 1.6, whereas they showed slight changes in pore number and pore size when incubated in PBS buffer at a pH of 10.0. This research might provide a universal method for the fabrication of noncrosslinked porous multilayered films.

A novel ditopic chromogenic receptor, N-5-(8-hydroxy)quinoline-N'-4'-nitro-phenyl thiourea (1), was synthesized. The metal complex 1-Hg(2+) showed sensitive and highly selective responses to F(-) over other anions such as CH(3)CO(2)(-), H(2)PO(4)(-), HSO(4)(-) and Cl(-). 1-Hg(2+)-F(-) complex formed, which promoted the intramolecular charge transfer and led to a dramatic spectral change. The color of 1-Hg(2+) solution changed from colorless to red upon addition of F(-). Thus, a colorimetric assay of F(-) was developed in acetonitrile by naked-eye detection. F(-) behaved linearly in the 8.0 x 10(-6) to 2.0 x 10(-5) mol L(-1) concentration range with LOD as 1.4 x 10(-6) mol L(-1).

The effect of physical aging and side group on the free volume has been studied by positron annihilation lifetime spectroscopy (PALS) and differential scanning calorimeter (DSC) for a series of epoxy resins cured separately with novolac resin and esterified novolac resins, that is, the hydroxyl group of phenol novolac resin was placed by a CH3COO-group, a CH3CH2 CH2COO- and a C6H5 CH2COO-group, which were named EP, EPA, EPB and EPP, respectively. Positron experimental results show that the side group plays an important role in determining free volume properties of epoxy resins, i.e. the stronger the cross-linking of curing agent, the smaller the free volume. This is confirmed by DSC measurement. On the other hand, the free volume relaxation properties were investigated by the Kolrausch–Williams–Watt (KWW), the single exponential and the double exponential functions in aging course for all samples, respectively. We found that ortho-positronium (o-Ps) intensity decreased with increasing aging time, which meant that the free volume diminished resulting from the formation of the local order structure due to the chain segmental rearrangement. The relaxation time constants of both τ and the parameter β have been calculated, which indicated that the order of relaxation rate of free volume characterized by τ−1 measured by PALS was the same as the enthalpy relaxation rate characterized by ∂Δ H/ ∂ ( log t) measured by DSC.

The dispersion relations for polariton modes in superlattice systems with free charges localized at the interfaces are derived and evaluated numerically for bulk and surface modes in GaAsAlAs superlattice system. The effects of free charge and retardation on polaritons are discussed.

The general dispersion relation for polariton modes of a system described by a spatially periodic local dielectric function is derived. The dispersion relation is evaluated numerically for a number of different semiconductor superlattice systems.