Search

Post-stroke depression (PSD) is the most common and severe neuropsychiatric complication after stroke. However, the molecular mechanism of PSD is still unclear. Previous studies have identified peripheral tissues metabolites associated with PSD using metabolomics techniques. We searched and systematically summarized metabolites that may be involved in metabolic changes in peripheral tissues of patients with PSD from the Metabolite Network of Depression Database (MENDA) and other biomedical databases. MetaboAnalyst5.0 software was used for pathway analysis and enrichment analysis of differential metabolites, and subgroup analyses were performed according to tissue types and metabolomics techniques. We identified 47 metabolites that were differentially expressed between patients with and without PSD. Five differential metabolites were found in both plasma and urine, including L-glutamic acid, pyroglutamic acid, palmitic acid, L-phenylalanine, and L-tyrosine. We integrated these metabolites into metabolic pathways, and six pathways were significantly altered. These pathways could be roughly divided into three modules including amino acid metabolism, nucleotide metabolism, and glucose metabolism. Among them, the most significantly altered pathway was “phenylalanine metabolism” and the pathway containing the most associated molecules was “aminoacyl-tRNA biosynthesis”, which deserve further study to elucidate their role in the molecular mechanism of PSD. In summary, metabolic changes in peripheral tissues are associated with PSD, especially the disruption of “phenylalanine metabolism” and “aminoacyl-tRNA biosynthesis” pathways. This study provides clues to the metabolic characteristics of patients with PSD, which may help to elucidate the molecular pathogenesis of PSD.

Major depressive disorder (MDD) is a serious mental illness, characterized by high morbidity, which has increased in recent decades. However, the molecular mechanisms underlying MDD remain unclear. Previous studies have identified altered metabolic profiles in peripheral tissues associated with MDD. Using curated metabolic characterization data from a large sample of MDD patients, we meta-analyzed the results of metabolites in peripheral blood. Pathway and network analyses were then performed to elucidate the biological themes within these altered metabolites. We identified 23 differentially expressed metabolites between MDD patients and controls from 46 studies. MDD patients were characterized by higher levels of asymmetric dimethylarginine, tyramine, 2-hydroxybutyric acid, phosphatidylcholine (32:1), and taurochenodesoxycholic acid and lower levels of l-acetylcarnitine, creatinine, l-asparagine, l-glutamine, linoleic acid, pyruvic acid, palmitoleic acid, l-serine, oleic acid, myo-inositol, dodecanoic acid, l-methionine, hypoxanthine, palmitic acid, l-tryptophan, kynurenic acid, taurine, and 25-hydroxyvitamin D compared with controls. l-tryptophan and kynurenic acid were consistently downregulated in MDD patients, regardless of antidepressant exposure. Depression rating scores were negatively associated with decreased levels of l-tryptophan. Pathway and network analyses revealed altered amino acid metabolism and lipid metabolism, especially for the tryptophan–kynurenine pathway and fatty acid metabolism, in the peripheral system of MDD patients. Taken together, our integrated results revealed that metabolic changes in the peripheral blood were associated with MDD, particularly decreased l-tryptophan and kynurenic acid levels, and alterations in the tryptophan–kynurenine and fatty acid metabolism pathways. Our findings may facilitate biomarker development and the elucidation of the molecular mechanisms that underly MDD.

Objective To investigate the efficacy and acceptability of virtual reality (VR) with time-dose-matched conventional therapy (CT) in patients poststroke with upper limb dysfunction. Data Sources Cochrane, PubMed, Web of Science, Embase, and ProQuest were systematically searched up to May 24, 2021. Study Selection Randomized controlled trials comparing VR with time-dose-matched CT in patients poststroke with upper limb dysfunction were included. Data Extraction The extracted data included efficacy (mean change in structure/function, activity, and participation scores), acceptability (dropouts for all reasons), adverse events, and characteristics of the included studies. The Cochrane risk of bias assessment tool was used to assess the risk of bias. Data Synthesis Thirty-one randomized controlled trails were included. VR was superior to time-dose-matched CT in terms of the World Health Organization's International Classification of Functioning, Disability and Health structure/function, with a standardized mean difference (SMD) of 0.35, but not activity and participation. Subgroup analyses demonstrated that virtual environment was superior to CT in structure/function (SMD=0.38) and activity (SMD=0.27), whereas there were no significant differences between commercial gaming and CT in any World Health Organization International Classification of Functioning, Disability and Health domain. VR mixed with CT was more effective than time-dose-matched CT in structure/function (SMD=0.56), whereas VR only was not significantly different from CT. There were no significant differences in the incidence of adverse events and dropout rates between VR and CT. Conclusions The results suggest that VR is superior to time-dose-matched CT in terms of recovery of upper extremity motor function, especially when a virtual environment is used or VR is mixed with CT. However, VR (VR only or mixed with CT) does not improve patients’ daily activity performance and participation compared with CT. Overall, VR appears to be safe and acceptable as CT. Large-scale definitive trials are needed to verify or refute these findings.

Major depressive disorder (MDD) in children and adolescents is a recurrent and disabling condition globally but its pathophysiology remains poorly elucidated and there are limited effective treatments available. We performed metabolic profiling of plasma samples based on ultra-high-performance liquid chromatography equipped with quadrupole time-offlight mass spectrometry to explore the potential biomarkers of depression in children and adolescents with MDD. We identified several perturbed pathways, including fatty acid metabolism—particularly the polyunsaturated fatty acids metabolism, and purine metabolism—that were associated with MDD in these young patients. In addition, inosine was shown as a potential independent diagnostic biomarker for MDD, achieving an area under the ROC curve of 0.999 in discriminating drug-naive MDD patients and 0.866 in discriminating drug-treated MDD from healthy controls. Moreover, we found evidence for differences in the pathophysiology of MDD in children and adolescents to that of adult MDD, specifically with tryptophan metabolism. Through metabolomic analysis, we have identified links between a framework of metabolic perturbations and the pathophysiology and diagnostic biomarker of child and adolescent MDD.

We aimed to provide an overview of psychotherapy in young anxious children (mean age

Summary Background Depressive disorders are common in children and adolescents. Antidepressants, psychotherapies, and their combination are often used in routine clinical practice; however, available evidence on the comparative efficacy and safety of these interventions is inconclusive. Therefore, we sought to compare and rank all available treatment interventions for the acute treatment of depressive disorders in children and adolescents. Methods We did a systematic review and network meta-analysis. We searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, PsycINFO, ProQuest, CINAHL, LiLACS, international trial registries, and the websites of regulatory agencies for published and unpublished randomised controlled trials from database inception until Jan 1, 2019. We included placebo-controlled and head-to-head trials of 16 antidepressants, seven psychotherapies, and five combinations of antidepressant and psychotherapy that are used for the acute treatment of children and adolescents (≤18 years old and of both sexes) with depressive disorder diagnosed according to standard operationalised criteria. Trials recruiting participants with treatment-resistant depression, bipolar disorder, psychotic depression, treatment duration of less than 4 weeks, or an overall sample size of fewer than ten patients were excluded. We extracted data following a predefined hierarchy of outcome measures, and assessed risk of bias and certainty of evidence using validated methods. Primary outcomes were efficacy (change in depressive symptoms) and acceptability (treatment discontinuation due to any cause). We estimated summary standardised mean differences (SMDs) or odds ratios (ORs) with credible intervals (CrIs) using network meta-analysis with random effects. This study was registered with PROSPERO, number CRD42015020841. Findings From 20 366 publications, we included 71 trials (9510 participants). Depressive disorders in most studies were moderate to severe. In terms of efficacy, fluoxetine plus cognitive behavioural therapy (CBT) was more effective than CBT alone (–0·78, 95% CrI −1·55 to −0·01) and psychodynamic therapy (–1·14, −2·20 to −0·08), but not more effective than fluoxetine alone (–0·22, −0·86 to 0·42). No pharmacotherapy alone was more effective than psychotherapy alone. Only fluoxetine plus CBT and fluoxetine were significantly more effective than pill placebo or psychological controls (SMDs ranged from −1·73 to −0·51); and only interpersonal therapy was more effective than all psychological controls (–1·37 to −0·66). Nortriptyline (SMDs ranged from 1·04 to 2·22) and waiting list (SMDs ranged from 0·67 to 2·08) were less effective than most active interventions. In terms of acceptability, nefazodone and fluoxetine were associated with fewer dropouts than sertraline, imipramine, and desipramine (ORs ranged from 0·17 to 0·50); imipramine was associated with more dropouts than pill placebo, desvenlafaxine, fluoxetine plus CBT, and vilazodone (2·51 to 5·06). Most of the results were rated as “low” to “very low” in terms of confidence of evidence according to Confidence In Network Meta-Analysis. Interpretation Despite the scarcity of high-quality evidence, fluoxetine (alone or in combination with CBT) seems to be the best choice for the acute treatment of moderate-to-severe depressive disorder in children and adolescents. However, the effects of these interventions might vary between individuals, so patients, carers, and clinicians should carefully balance the risk-benefit profile of efficacy, acceptability, and suicide risk of all active interventions in young patients with depression on a case-by-case basis. Funding National Key Research and Development Program of China.

Background Major depressive disorder is one of the most common mental disorders in children and adolescents. However, whether to use pharmacological interventions in this population and which drug should be preferred are still matters of controversy. Consequently, we aimed to compare and rank antidepressants and placebo for major depressive disorder in young people. Methods We did a network meta-analysis to identify both direct and indirect evidence from relevant trials. We searched PubMed, the Cochrane Library, Web of Science, Embase, CINAHL, PsycINFO, LiLACS, regulatory agencies' websites, and international registers for published and unpublished, double-blind randomised controlled trials up to May 31, 2015, for the acute treatment of major depressive disorder in children and adolescents. We included trials of amitriptyline, citalopram, clomipramine, desipramine, duloxetine, escitalopram, fluoxetine, imipramine, mirtazapine, nefazodone, nortriptyline, paroxetine, sertraline, and venlafaxine. Trials recruiting participants with treatment-resistant depression, treatment duration of less than 4 weeks, or an overall sample size of less than ten patients were excluded. We extracted the relevant information from the published reports with a predefined data extraction sheet, and assessed the risk of bias with the Cochrane risk of bias tool. The primary outcomes were efficacy (change in depressive symptoms) and tolerability (discontinuations due to adverse events). We did pair-wise meta-analyses using the random-effects model and then did a random-effects network meta-analysis within a Bayesian framework. We assessed the quality of evidence contributing to each network estimate using the GRADE framework. This study is registered with PROSPERO, number CRD42015016023. Findings We deemed 34 trials eligible, including 5260 participants and 14 antidepressant treatments. The quality of evidence was rated as very low in most comparisons. For efficacy, only fluoxetine was statistically significantly more effective than placebo (standardised mean difference −0·51, 95% credible interval [CrI] −0·99 to −0·03). In terms of tolerability, fluoxetine was also better than duloxetine (odds ratio [OR] 0·31, 95% CrI 0·13 to 0·95) and imipramine (0·23, 0·04 to 0·78). Patients given imipramine, venlafaxine, and duloxetine had more discontinuations due to adverse events than did those given placebo (5·49, 1·96 to 20·86; 3·19, 1·01 to 18·70; and 2·80, 1·20 to 9·42, respectively). In terms of heterogeneity, the global I2 values were 33·21% for efficacy and 0% for tolerability. Interpretation When considering the risk–benefit profile of antidepressants in the acute treatment of major depressive disorder, these drugs do not seem to offer a clear advantage for children and adolescents. Fluoxetine is probably the best option to consider when a pharmacological treatment is indicated.

Women are an important part of the medical workforce, yet little is known about gender differences in psychological morbidity, burnout, job stress and job satisfaction among neurologists. This study assessed gender differences in a large national sample of Chinese neurologists. Multivariate analyses were performed to examine associations. A total of 5558 neurologists were included in the analysis. Compared with their male counterparts, female neurologists were generally younger; were less likely to be married or to have children; had higher levels of education; were in practice for a shorter period of time; were less likely to hold senior roles; and had lower incomes. Male and female neurologists worked similar hours and spent a similar number of nights on call. No gender differences were found in psychological morbidity, burnout, and high levels of job stress for female and male, respectively. Women had higher emotional exhaustion scores, while men were more likely to have low levels of job satisfaction. The multivariate analysis showed that factors independently associated with psychological morbidity, burnout, high levels of job stress and low levels of job satisfaction were generally similar for women and men. These findings increase our understanding of gender differences in psychological morbidity, burnout, job stress, and job satisfaction among neurologists. As more women join the medical profession, these differences may be useful in designing medical training and practice.

Key Points Question What is the best psychotherapeutic approach for anxiety disorders in children and adolescents in terms of efficacy and acceptability? Findings This network meta-analysis included 101 unique trials with 6625 unique participants who received 11 different psychotherapies and 4 control conditions. Only group cognitive behavioral therapy was significantly more effective in reducing anxiety symptoms than other psychotherapies and all control conditions posttreatment and at short-term follow-up. Meaning Group cognitive behavioral therapy may be the initial choice of psychotherapy for anxiety disorders in children and adolescents, after replication in future research with focus on disorder-specific psychotherapies and identification of moderators of treatment effect., This network meta-analysis compares and ranks the different types of psychotherapies and the different ways of delivering psychological treatments for anxiety disorders in children and adolescents., Importance Anxiety disorders are common in children and adolescents, and uncertainty remains regarding the optimal strategy of psychotherapies in this population. Objective To compare and rank the different types of psychotherapies and the different ways of delivering psychological treatments for anxiety disorders in children and adolescents. Data Sources PubMed, Cochrane Central Register of Controlled Trials, EMBASE, PsycINFO, Web of Science, CINAHL (Cumulative Index to Nursing and Allied Health Literature), ProQuest Dissertations, LILACS (Literatura Latino Americana em Ciências da Saúde), international trial registers, and US Food and Drug Administration reports were searched from inception to November 30, 2017. Study Selection Randomized clinical trials that compared any structured psychotherapy with another psychotherapy or a control condition for anxiety disorders in children and adolescents were selected. Data Extraction and Synthesis Four researchers independently performed data extraction and quality assessment. Pairwise meta-analyses and Bayesian network meta-analysis within the random-effects model were used to synthesize data. Main Outcomes and Measures Efficacy (change in anxiety symptoms) posttreatment and at follow-up, acceptability (all-cause discontinuation), and quality of life and functional improvement were measured. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation framework. Results A total of 101 unique trials including 6625 unique participants compared 11 different psychotherapies with 4 specific control conditions. The certainty of evidence was rated as low or very low for most comparisons. For efficacy, most psychotherapies were significantly more effective than the wait list condition posttreatment (standardized mean difference [SMD], −1.43 to −0.61) and at the longest follow-up (SMD, −1.84 to −1.64). However, only group cognitive behavioral therapy (CBT) was significantly more effective than the other psychotherapies and all control conditions posttreatment. For acceptability, bibliotherapy CBT had significantly more all-cause discontinuations than some psychotherapies and control conditions (range of odds ratios, 2.48-9.32). In terms of quality of life and functional improvement, CBT (delivered in different ways) was significantly beneficial compared with psychological placebo and the wait list condition (SMDs, 0.73 to 1.99). Conclusions and Relevance Group CBT would be the more appropriate choice of psychotherapy for anxiety disorders in children and adolescents, based on these findings. Other types of psychotherapies and different ways of delivering psychological treatment can be alternative options. Further research is needed to explore specific anxiety disorders, disorder-specific psychotherapy, and moderators of treatment effect. Trial Registration PROSPERO Identifier: CRD42015016283

In recent years, whether, when and how to use antidepressants to treat depressive disorder in children and adolescents has been hotly debated. Relevant evidence on this topic has increased rapidly. In this paper, we present the construction and content of a database of randomised controlled trials of antidepressants to treat depressive disorder in children and adolescents. This database can be freely accessed via our website and will be regularly updated. Major bibliographic databases (PubMed, the Cochrane Library, Web of Science, Embase, CINAHL, PsycINFO and LiLACS), international trial registers and regulatory agencies’ websites were systematically searched for published and unpublished studies up to April 30, 2017. We included randomised controlled trials in which the efficacy or tolerability of any oral antidepressant was compared with that of a control group or any other treatment. In total, 7377 citations from bibliographical databases and 3289 from international trial registers and regulatory agencies’ websites were identified. Of these, 53 trials were eligible for inclusion in the final database. Selected data were extracted from each study, including characteristics of the participants (the study population, setting, diagnostic criteria, type of depression, age, sex, and comorbidity), characteristics of the treatment conditions (the treatment conditions, general information, and detail of pharmacotherapy and psychotherapy) and study characteristics (the sponsor, country, number of sites, blinding method, sample size, treatment duration, depression scales, other scales, and primary outcome measure used, and side-effect monitoring method). Moreover, the risk of bias for each trial were assessed. This database provides information on nearly all randomised controlled trials of antidepressants in children and adolescents. By using this database, researchers can improve research efficiency, avoid inadvertent errors and easily focus on the targeted subgroups in which they are interested. For authors of subsequent reviews, they could only use this database to insure that they have completed a comprehensive review, rather than relied solely on the data from this database. We expect this database could help to promote research on evidence-based practice in the treatment of depressive disorder in children and adolescents. The database could be freely accessed in our website: http://xiepengteam.cn/research/evidence-based-medicine .

IntroductionPost-traumatic stress disorder (PTSD) is common among children and adolescents who are exposed to trauma, and it is often associated with significant negative impacts on their psychosocial functioning and quality of life. Many types of psychotherapies have been found to be effective for PTSD in children and adolescents. However, due to the lack of direct comparisons between different psychotherapies, the hierarchy of treatment efficacy is still unclear. Therefore, we plan to conduct a systematic review and network meta-analysis to evaluate the efficacy and acceptability of various types of psychotherapies for PTSD in children and adolescents.Methods and analysisA systematic search will be conducted among eight electronic databases, including PubMed, Cochrane, Embase, Web of Science, PsycINFO, Cumulative Index of Nursing and Allied Health, Published International Literature on Traumatic Stress (PILOTS) and ProQuest Dissertations, from inception to October 2017. Randomised controlled trials, regardless of language, publication year and publication type, comparing any psychotherapies for PTSD to any control condition or alternative treatment in children and adolescents (18 years old or less) diagnosed with full or subclinical PTSD will be included. Study duration and the number of treatment sessions will not be limited. The primary outcome will be PTSD symptom severity at post-treatment as measured by a rating scale reported by the child, parent or a clinician. The secondary outcomes will include: (1) efficacy at follow-up; (2) acceptability (all-cause discontinuation); (3) anxiety symptom severity; (4) depressive symptom severity and (5) quality of life and functional improvement. Bayesian network meta-analyses for all relative outcome measures will be performed. We will conduct subgroup and sensitivity network meta-analyses to determine whether the findings are affected by study characteristics. The quality of the evidence contributing to network estimates of the primary outcome will be evaluated by the Grading of Recommendations, Assessment, Development and Evaluations framework.Ethics and disseminationNo ethical issues are foreseen. The results will be published in a peer-reviewed journal, which will be disseminated electronically and in print. This network meta-analysis may be updated to inform and guide the clinical management of PTSD in children and adolescents.PROSPERO registration numberCRD42016051786.

Shuai Yuan,1,* Xinyu Zhou,1,2,* Yuqing Zhang,1,3,* Hanpin Zhang,1,3,* Juncai Pu,1,3 Lining Yang,1,3 Lanxiang Liu,1,3 Xiaofeng Jiang,1,3 Peng Xie1,3 1Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, 2Department of Psychiatry, 3Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China *These authors contributed equally to this work Background: Depression and anxiety are the most common mental disorders in children and adolescents. Bibliotherapy is a treatment using written materials for mental health problems. Its main advantages are ease of use, low cost, low staffing demands, and greater privacy. Yet few meta-analyses have focused on the effect of bibliotherapy on depression and anxiety disorders in children and adolescents. Methods: We included randomized controlled trials comparing bibliotherapy with control conditions for depression and anxiety in children and adolescents (aged ≤18 years). Five electronic databases (PubMed, Embase, Cochrane, Web of Science, and PsycINFO) were searched from inception to January 2017. Efficacy was defined as mean change scores in depression and anxiety symptoms. Acceptability was defined as the proportion of participants who discontinued the treatment. Random effects model was used. An intention-to-treat analysis was conducted. Results: Eight studies with 979 participants were selected. At posttreatment, bibliotherapy was significantly more effective than the control conditions in reducing the symptoms of depression or anxiety (standardized mean difference, -0.52; 95% confidence interval [CI], -0.89 to -0.15). Bibliotherapy did not have statistically significantly more all-cause discontinuations than controls (risk ratios, 1.66; 95% CI, 0.93 to 2.95). We also performed subgroup analyses for efficacy outcomes in different categories (types of disorder, mean age, control conditions, and parental involvement) of studies and found that bibliotherapy has been more effective in depressive adolescents. Limitations: Limited studies were eligible in this review and hence there was potential publication bias. Conclusion: According to the findings in this review, bibliotherapy may be more beneficial in treating depression in adolescents, but shows less robust effects for anxiety in children. Further well-defined clinical studies should be performed to confirm these outcomes. Keywords: mental disorders, bibliotherapy, young, meta-analysis, self help, psychotherapy

Social anxiety disorder (SAD) is highly prevalent and persistent in children and adolescents. However, evidence for the efficacy and acceptability of psychological interventions for SAD in children and adolescents remains unclear. Seven electronic databases (PubMed, CENTRAL, Embase, Web of Science, PsycINFO, CINAHL, and ProQuest) were searched. Randomized controlled trials (RCTs) that compared psychological interventions for SAD with control conditions in children and adolescents were included. Primary outcomes were the efficacy (mean change in anxiety symptom scores) and acceptability (dropouts for all reasons). Secondary outcomes were remission, quality of life/functional improvement, and depressive symptoms measures. Seventeen RCTs were included in this meta-analysis. Psychological interventions (including cognitive behavioral therapy and behavioral therapy) were significantly more effective than control conditions, with a standardized mean difference (SMD) of − 1.13, and remission with a risk ratio (RR) of 8.99, the number needed to treat was 3.3. There was no statistically significant difference between psychological interventions and control conditions for all-cause dropouts (RR = 1.00). Psychological interventions were superior to control conditions in improving quality of life/functioning (SMD = 0.79) and reducing depressive symptoms (SMD = − 0.39). Given considerable heterogeneity of primary efficacy outcome, a series of subgroup analyses of different variables were conducted. Psychological interventions are probably efficacious in the treatment of SAD among children and adolescents, and may markedly improve quality of life and functioning in this population. However, this finding should be interpreted with caution because of the high heterogeneity of trials and low literature quality.

IntroductionDepressive disorder is common in children and adolescents, with important consequences and serious impairments in terms of personal and social functioning. While both pharmacological and psychological interventions have been shown to be effective, there is still uncertainty about the balance between these and what treatment strategy should be preferred in clinical practice. Therefore, we aim to compare and rank in a network meta-analysis (NMA) the commonly used psychological, pharmacological and combined interventions for depressive disorder in children and adolescents.Methods and analysisWe will update the literature search of two previous NMAs for the identification of trials of antidepressant and psychotherapy alone for depressive disorder in children and adolescents. For identification of trials of combination interventions, seven databases (PubMed, EMBASE, CENTRAL (Cochrane Central Register of Controlled Trials), Web of Science, PsycINFO, CINAHL, LiLACS) will be searched from date of inception. We will also search ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform and check relevant reports on the US Food and Drug Administration website for unpublished data. Building on our previous findings in the field, we will include any commonly prescribed oral antidepressants and any manualised or structured psychotherapies, as well as their combinations. Randomised controlled trials assessing any active intervention against active comparator or pill placebo/psychological controls in acute treatment for depressive disorder in children and adolescents will be included. The primary outcomes will be efficacy (mean change in depressive symptoms), and acceptability of treatment (dropout rate due to any cause). The secondary outcomes will be remission rate, tolerability of treatment (dropouts for adverse events), as well as suicide-related outcomes (suicidal behaviour or ideation). We will perform Bayesian NMAs for all relative outcome measures. Subgroup analyses and sensitivity analyses will be conducted to assess the robustness of the findings.DisseminationThis NMA will provide the most up to date and clinically useful information about the comparative efficacy and acceptability of antidepressants, psychological intervention and their combination in the acute treatment of children and adolescents with depressive disorder. This is the newest NMA and therefore these results are very important in terms of evidence-based medicine. The results will be disseminated through peer-reviewed publication.Protocol registrationPROSPERO CRD42015020841.

Major depressive disorder is a serious mental disorder with high morbidity and mortality. The role of social stress in the development of depression remains unclear. Here, we used the social defeat stress paradigm to induce depression-like behavior in rats, then evaluated the behavior of the rats and measured metabolic changes in the prefrontal cortex using gas chromatography-mass spectrometry. Within the first week after the social defeat procedure, the sucrose preference test (SPT), open field test (OFT), elevated plus maze (EPM) and forced swim test (FST) were conducted to examine the depressive-like and anxiety-like behaviors. For our metabolite analysis, multivariate statistics were applied to observe the distribution of all samples and to differentiate the socially defeated group from the control group. Ingenuity pathway analysis was used to find the potential relationships among the differential metabolites. In the OFT and EPM, there were no significant differences between the two experimental groups. In the SPT and FST, socially defeated rats showed less sucrose intake and longer immobility time compared with control rats. Metabolic profiling identified 25 significant variables with good predictability. Ingenuity pathways analysis revealed that "Hereditary Disorder, Neurological Disease, Lipid Metabolism" was the most significantly altered network. Stress-induced alterations of low molecular weight metabolites were observed in the prefrontal cortex of rats. Particularly, lipid metabolism, amino acid metabolism, and energy metabolism were significantly perturbed. The results of this study suggest that repeated social defeat can lead to metabolic changes and depression-like behavior in rats.

Nowadays it is more difficult to continuously monitoring physiological parameters in the clinical work, thus we use photoplethysmography signal to simultaneously supervise heart rate and respiration rate parameters of human body. This paper mainly adopt wavelet analysis algorithm analyzing and processing the pulse signal, of which employ wave crests searching algorithm in the calculation of heart and apply wavelet transform combining with power spectrum method in the calculation of respiratory. The result indicates that the proposed methods can meanwhile obtain heart rate and respiration rate parameters, therefore providing an easy monitor way for clinic workers.

Purpose: Dielectric resonances have previously been advanced as a significant cause of image degradation at higher fields. In this work, a study of dielectric resonances in ultra high field MRI is presented to explore the real importance of dielectric resonances in the human brain in this setting. Method: Gradient-recalled echo images were acquired using a transverse electromagnetic resonator at 1.5, 4.7, and 8 T. Images were obtained from the human head and from phantoms filled with pure water, saline, and mineral oil. In addition, an exact theoretical analysis of dielectric resonances is presented for a spherical phantom and for a model of the human head. Results: Theoretical results demonstrate that distilled water can sustain dielectric resonances in head-sized spheres near 200 and 360 MHz, but the presence of significant conductivity suppresses these resonances. These findings are confirmed experimentally with proton images of water and saline (0.05 and 0.125 M NaCl). For lossy phantoms, coupling between the source and phantom overwhelms the dielectric resonance. Because of their low relative permittivity, mineral oil phantoms with 20 cm diameter do not exhibit dielectric resonances below -900 MHz. Significant dielectric resonances were not observed in human head images obtained at 1.5, 4.7, and 8 T. Conclusion: It appears that dielectric resonances do not have any real importance in determining image quality for MR studies of the human head. It is advanced that RF coils are much more likely to be the source of any inhomogeneity. Index Terms: Magnetic resonance imaging, artifacts-Magnetic resonance imaging, ultra high frequency-Dielectric resonance-Image quality.

The interactive and high quality rendering of very complex scenes in a virtual environment is very difficult if not impossible to achieve. This research extends our previous EGVE paper that presents a panoramic walkthrough system, allowing the user to move inside the datasets on a pre-defined track and look around interactively in both the horizontal and vertical directions. The interactivity is achieved by using Image-Based Rendering ideas to pre-compute the partial renderings for the reference viewpoints chosen on the track and store them on the server so that the client can retrieve and reconstruct novel views using the appropriate information. In this paper, we present simple and efficient methods to partition the scene into depth layers to avoid occlusion and dis-occlusion problems. We also present a novel track-dependent occlusion cullion algorithm to efficiently cull away unnecessary information. The system is tested using several scenes and provides realtime walkthroughs on even the most challenging scenes.

Purpose: The purpose of this report is to describe the design and construction of an 8 T/80 cm whole-body MRI system operating at 340 MHz. Method: The 8 T/80 cm magnet was constructed from 414 km of niobium titanium superconducting wire. The winding of this wire on four aluminum formers resulted in a total inductance of 4,155 H. Gradient subsystems included either a body gradient or a head gradient along with a removable shim insert. The magnet and gradient subsystems were interfaced to two spectrometers. These provided the control of the gradient amplifiers and the two sets of four RF power amplifiers. The latter provide in excess of 8 kW of RF power from 10 to 140 MHz and 10 kW of RF power from 245 to 345 MHz. A dedicated computer-controlled patient table was designed and assembled. The entire system is located in a clinical setting, facilitating patient-based studies. Results: The 8 T/80 cm magnet was energized without complication and achieved persistent operation using 198.9 A of current, thereby storing 81.5 MJ of magnetic energy. Exceptional performance was observed for nearly all components both in isolation and when combined within the complete system. Conclusion: An 8 T/80 cm MRI system has been assembled. The magnet subsystem is extremely stable and is characterized by good homogeneity and acceptable boil-off rates. Index Terms: Magnetic resonance imaging, apparatus and equipment-Magnetic resonance imaging, techniques-Tesla-Image quality.