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Background: Patients with major depressive disorder (MDD) can frequently develop new depressive episodes after remission. However, the neural mechanisms underlying the increased risk for depressive relapse remain unclear. Herein, we aimed to explore whether the specific changes to regional and inter-regional spontaneous brain activities within DMN are associated with the course of episodes in pooled MDD patients.Methods: Resting-state functional magnetic resonance imaging was performed on patients with single-episode MDD (SEMDD, n = 30) and multiple-episode MDD (MEMDD, n = 54), and 71 age-, gender-, and educational level-matched healthy controls (HCs). We then accessed the differences in both the fractional amplitude of low-frequency fluctuations (fALFF) and functional connectivity by using the right precuneus as the seed among different groups.Results: Compared to the MEMDD and HC groups, the SEMDD group exhibited increased fALFF values in the right subgenual anterior cingulate cortex and right middle temporal gyrus. Decreased fALFF values in the right thalamus in the MEMDD group were also identified relative to the SEMDD and HC group. The peak values of fALFF in the right precuneus showed a negative correlation with the number of depressive episodes across the entire pool of MDD patients. No correlation was identified between functional connectivity using the right precuneus as the seed and the number of depressive episodes for the pooled MDD patients.Limitations: Medication, a relatively small sample size, and hypothesis driven study.Conclusions: Our neuroimaging results identified depression relapse-associated neural signatures and also indicated the role of reduced emotional appraisals in the thalamus. It is now possible to believe that the regional activity not inter-regional connectivity within the DMN may be involved in the pathology of depression relapse. [ABSTRACT FROM AUTHOR]

To investigate the altered interhemispheric functional connectivity in the resting state in patients with recurrent major depressive disorder (MDD). Voxel-mirrored homotopic connectivity (VMHC), a measure of the functional connectivity between any pair of symmetrical interhemispheric voxels, and pattern classification were examined in 41 recurrent MDD patients (22 during the depressive state and 19 during the remitted state) and 60 age, sex, and education level-matched healthy controls (HC) using resting-state functional magnetic resonance imaging (fMRI). Compared with HC, the recurrent MDD patients exhibited decreased VMHC values in the bilateral fusiform, inferior occipital gyrus, posterior insula, precentral gyrus, precuneus, superior temporal gyrus, and thalamus. A significant negative correlation between the VMHC value of the bilateral posterior insula and illness duration in recurrent MDD was identified. Support vector machine (SVM) analysis showed that VMHC in the fusiform and posterior insula could be used to distinguish recurrent MDD patients from HC with a sensitivity and accuracy >0.6. Our findings revealed a reduction in the resting-state brain activity across several neural networks in patients with recurrent MDD, including within the posterior insula. Lower VMHC values in the posterior insula were associated with longer illness duration, suggesting that impairment in interhemispheric synchronization within the salience network may be due to the accumulated pathology of depression and may contribute to future depression relapse. VMHC changes in the posterior insula may serve as a potential imaging marker to discriminate recurrent MDD patients from HC. • Several neural networks were reduced in patients with recurrent MDD. • Impairment in interhemispheric synchronization within salience network may contribute to MDD relapse. • VMHC changes in the posterior insula may serve as a imaging marker. [ABSTRACT FROM AUTHOR]

Purpose: To compare self‐reported (SR) and interviewer‐rated (IR) oral health between schizophrenia (SZ), bipolar disorder (BP), and major depressive disorder (MDD) patients. Design and Methods: 356 patients with SZ, BP, or MDD underwent assessments of psychopathology, side effects, SR, and IR oral health status. Findings: 118 patients (33.1%) reported poor oral health; the corresponding proportion was 36.4% in BP, 34.8% in SZ, and 25.5% in MD (p =.21). SR and IR oral health correlated only modestly (r = 0.17–0.36) in each group. Practice Implications: Psychiatric patients need to be assessed for both SR and IR oral health. [ABSTRACT FROM AUTHOR]

Bipolar depression (BD) is a common psychiatric illness characterized by deficits in emotional and cognitive processing. Abnormalities in the subregions of the insula are common findings in neuroanatomical studies of patients with bipolar disorder. However, the specific relationships between morphometric changes in specific insular subregions and the pathogenesis of BD are not clear. In this study, structural magnetic resonance imaging (MRI) was used to investigate gray matter volume abnormalities in the insular subregion in 27 patients with BD and in 27 age and sex-matched controls. Using DARTEL (diffeomorphic anatomical registration through exponentiated lie algebra) for voxel-based morphometry (VBM), we examined changes in regional gray matter volumes of the insula in patients with BD. As compared with healthy controls, the BD patients showed decreased gray matter volumes in the right posterior insula and left ventral anterior insula and increased gray matter volumes in the left dorsal anterior insula. Consistent with the emerging theory of insular interference as a contributor to emotional-cognitive dysregulation, the current findings suggest that the insular cortex may be involved in the neural substrates of BD. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the utilization of Pennisetum sinese as cellulose source for the preparation of cellulose nanocrystals (CNC). The cellulose was extracted from P. sinese by chemical treatment and bleaching, and obtained cellulose nanocrystals by acid hydrolysis. Transmission electron microscopy (TEM) showed that CNC were rod-like with the diameter of 20–30 nm and the length of 200–300 nm. Fourier transform infrared (FTIR) showed that chemical treatment removed most of the lignin and hemicellulose from P. sinese , and CNC had similar structure to that of native cellulose. The crystallinity indexes calculated from X-ray diffraction (XRD) for P. sinese and CNC were 40.6% and 77.3%, respectively. The zeta-potential analysis showed that CNC had higher stability than P. sinese had. The thermal stability was investigated by thermogravimetric analysis (TGA), and the result showed that P. sinese had higher thermal stability than that of prepared CNC. [ABSTRACT FROM AUTHOR]

Abstract: Cellulose nanocrystals (CNC) were prepared from microcrystalline cellulose (MCC) by hydrolysis with cation exchange resin (NKC-9) or 64% sulfuric acid. The cation exchange resin hydrolysis parameters were optimized by using the Box–Behnken design and response surface methodology. An optimum yield (50.04%) was achieved at a ratio of resin to MCC (w/w) of 10, a temperature of 48°C and a reaction time of 189min. Electron microscopy (EM) showed that the diameter of CNCs was about 10–40nm, and the length was 100–400nm. Regular short rod-like CNCs were obtained by sulfuric acid hydrolysis, while long and thin crystals of cellulose were obtained with the cation exchange resin. X-ray diffraction (XRD) showed that, compared with MCC, the crystallinity of H2SO4-CNC and resin-CNC increased from 72.25% to 77.29% and 84.26%, respectively. The research shows that cation exchange resin-catalyzed hydrolysis of cellulose could be an excellent method for manufacturing of CNC in an environmental-friendly way. [Copyright &y& Elsevier]

Accumulating evidence supports the hypothesis that white matter (WM) abnormalities are involved in the pathophysiology of bulimia nervosa (BN); however, findings from in vivo neuroimaging studies have been inconsistent. We aimed to investigate the possible brain WM alterations, including WM volume and microstructure, in patients with BN. We recruited 43 BN patients and 31 healthy controls (HCs). All participants underwent structural and diffusion tensor imaging. Differences in WM volume and microstructure were evaluated using voxel‐based morphometry, tract‐based spatial statistics, and automated fibre quantification analysis. Compared with HCs, BN patients showed significantly decreased fractional anisotropy in the middle part of the corpus callosum (nodes 31–32) and increased mean diffusivity in the right cranial nerve V (CN V) (nodes 27–33 and nodes 55–88) and vertical occipital fasciculus (VOF) (nodes 58–85). Moreover, we found decreased axial diffusivity in the right inferior fronto‐occipital fasciculus (node 67) and increased radial diffusivity in the CN V (nodes 22–34 and nodes 52–89) and left VOF (nodes 60–66 and nodes 81–85). Meanwhile, WM microstructural changes were correlated with patients' clinical manifestations. We did not find any significant differences in WM volume and the main WM fibre bundle properties between BN patients and HCs. Taken together, these findings provide that BN shows significant brain WM reorganization, but primarily in microstructure (part of WM fibre bundle), which is not sufficient to cause changes in WM volume. The automated fibre quantification analysis could be more sensitive to detect the subtle pathological changes in a point or segment of the WM fibre bundle. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the alterations of topological organization of the whole brain functional networks in hypertension patients with cognitive impairment (HTN-CI) and characterize its relationship with cognitive scores. Methods: Fifty-seven hypertension patients with cognitive impairment and 59 hypertension patients with normal cognition (HTN-NC), and 49 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging. Graph theoretical analysis was used to investigate the altered topological organization of the functional brain networks. The global topological properties and nodal metrics were compared among the three groups. Network-based statistic (NBS) analysis was used to determine the connected subnetwork. The relationships between network metrics and cognitive scores were also characterized. Results: HTN-CI patients exhibited significantly decreased global efficiency, lambda, and increased shortest path length when compared with HCs. In addition, both HTN-CI and HTN-NC groups exhibited altered nodal degree centrality and nodal efficiency in the right precentral gyrus. The disruptions of global network metrics (lambda, Lp) and the nodal metrics (degree centrality and nodal efficiency) in the right precentral gyrus were positively correlated with the MoCA scores in HTN-CI. NBS analysis demonstrated that decreased subnetwork connectivity was present both in the HTN-CI and HTN-NC groups, which were mainly involved in the default mode network, frontoparietal network, and cingulo-opercular network. Conclusion: This study demonstrated the alterations of topographical organization and subnetwork connectivity of functional brain networks in HTN-CI. In addition, the global and nodal network properties were correlated with cognitive scores, which may provide useful insights for the understanding of neuropsychological mechanisms underlying HTN-CI. [ABSTRACT FROM AUTHOR]

Poor sleep and insomnia have been recognized to be strongly correlated with the development of depression. The exploration of the basic mechanism of sleep disturbance could provide the basis for improved understanding and treatment of insomnia and prevention of depression. In this study, 31 subjects with insomnia symptoms as measured by the Hamilton Rating Scale for Depression (HAMD-17) and 71 age- and gender-matched subjects without insomnia symptoms were recruited to participate in a clinical trial. Using resting-state functional magnetic resonance imaging (rs-fMRI), we examined the alterations in spontaneous brain activity between the two groups. Correlations between the fractional amplitude of low frequency fluctuations (fALFF) and clinical measurements (e.g., insomnia severity and Hamilton Depression Rating Scale [HAMD] scores) were also tested in all subjects. Compared to healthy participants without insomnia symptoms, participants with insomnia symptoms showed a decreased fALFF in the left ventral anterior insula, bilateral posterior insula, left thalamus, and pons but an increased fALFF in the bilateral middle occipital gyrus and right precentral gyrus. More specifically, a significant, negative correlation of fALFF in the left thalamus with early morning awakening scores and HAMD scores in the overall sample was identified. These results suggest that insomnia symptoms are associated with altered spontaneous activity in the brain regions of several important functional networks, including the insular cortex of the salience and the thalamus of the hyperarousal network. The altered fALFF in the left thalamus supports the “hyperarousal theory” of insomnia symptoms, which could serve as a biomarker for insomnia. [ABSTRACT FROM AUTHOR]

Of major depression patients, 29–66% show only partial remission on a single antidepressant trial. Such patients are characterized by residual depressive symptoms such as anhedonia, psychic anxiety, sleep disturbance, and cognitive dysfunction. Despite having a tremendous impact on outcomes such as future relapse, morbidity, and mortality, the neural mechanisms of partially remitted depression remain unclear. Using the amplitude of low-frequency fluctuations (ALFF) approach, we investigated the intrinsic neural oscillation alterations during resting state in partially remitted depression. A total of 23 partially remitted depression patients and 68 healthy controls underwent magnetic resonance imaging for functional imaging. We compared ALFF differences between groups as well as correlations between clinical measurements and ALFF in the brain regions showing significant group differences. Compared with healthy controls, partially remitted depression patients showed increased ALFF in the left ventral anterior insula, bilateral posterior insula, and bilateral supramarginal gyrus, and decreased ALFF in the left calcarine gyrus. A trend positive correlation between the number of depressive episodes and ALFF values was found in the right posterior insula in the partially remitted depression group. In addition, the ALFF in the right supramarginal gyrus were negatively correlated with Hamilton Depression Rating Scale scores. Consistent with the emerging theory of the role of the salience network in sensing the changes of homeostasis that contributes to partially remitted depression, the current findings suggest that the increased intrinsic neural oscillation of the insula is related to the refractoriness to treatment and may be an imaging marker for predicting future depression recurrence. [ABSTRACT FROM AUTHOR]