139 research outputs found

    Automatic Extraction and Sign Determination of Respiratory Signal in Real-time Cardiac Magnetic Resonance imaging

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    In real-time (RT) cardiac cine imaging, a stack of 2D slices is collected sequentially under free-breathing conditions. A complete heartbeat from each slice is then used for cardiac function quantification. The inter-slice respiratory mismatch can compromise accurate quantification of cardiac function. Methods based on principal components analysis (PCA) have been proposed to extract the respiratory signal from RT cardiac cine, but these methods cannot resolve the inter-slice sign ambiguity of the respiratory signal. In this work, we propose a fully automatic sign correction procedure based on the similarity of neighboring slices and correlation to the center-of-mass curve. The proposed method is evaluated in eleven volunteers, with ten slices per volunteer. The motion in a manually selected region-of-interest (ROI) is used as a reference. The results show that the extracted respiratory signal has a high, positive correlation with the reference in all cases. The qualitative assessment of images also shows that the proposed approach can accurately identify heartbeats, one from each slice, belonging to the same respiratory phase. This approach can improve cardiac function quantification for RT cine without manual intervention.Comment: IEEE ISBI 2020, International Symposium on Biomedical Imagin

    Impact of citalopram combined with mindfulness-based stress reduction on symptoms, cognitive functions and self-confidence in patients with depression

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    Purpose: To investigate the impact of the combination of citalopram and mindfulness-based stress reduction (MBSR) on the symptoms, cognitive functions and self-confidence of patients with depression.Methods: A total of 98 patients with depression were selected as study subjects and divided into combination therapy group (CT, n = 51) and conventional group (C, n = 47. The conventional group was treated with citalopram, while the combined group was treated with a combination of citalopram and MBSR. Depressive symptoms and self-confidence were evaluated using the 17-item Hamilton Depression Rating Scale (HAMD-17) and General Self-efficacy Scale (GSES). Cognitive functions were assessed by Wisconsin Card Sorting Test (WCST) and Trail Making Test (TMT). Changes in depressive symptoms, cognitive functions, self-confidence and clinical efficacies between the two groups were compared.Results: At weeks 1, 4 and 8 after treatment, CT group had lower HAMD-17 scores but higher GSES scores when compared with the conventional group (p < 0.05). In addition, CT group was superior to the conventional group in efficacy and overall response rate (100.00 vs. 85.11 %, p < 0.05). Also, CT group showed a shorter time of perseverative and non-perseverative errors on WCST and a shorter time for TMT-A and TMT-B, compared with the conventional group (p < 0.05).Conclusion: The combination therapy of citalopram and MBSR is effective in ameliorating depressive symptoms, and enhancing cognitive functions and self-confidence in patients with depression. These findings will increase the understanding of this combination therapy, and provide a clinical reference for the treatment of depression

    Shyness and Learning Adjustment in Senior High School Students: Mediating Roles of Goal Orientation and Academic Help Seeking

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    Learning maladjustment is a common phenomenon in the context of examination-oriented education system in china, especially among high school students who experience intense pressure when preparing for the national college entrance examination. Previous literature suggests that shyness may negatively affect onesā€™ cognition, emotion, and behavioral performance and lead to academic and social maladjustment. Therefore, learning adjustment among shy high school students is a critical and practical point of inquiry. With a sample of 677 Chinese senior high school students, this study aims to assess the association between shyness and learning adjustment and related mechanisms of goal orientation (i.e., mastery-approach goals, mastery-avoid goals, performance-approach goals, and performance-avoid goals) and academic help seeking (i.e., instrumental help seeking from teacher, instrumental help seeking from classmate, executive help seeking, and avoidance of help seeking). Self-report measures were adopted to collect information on: demographic characteristics, the level of shyness, goal orientation, academic help seeking, and learning adjustment. Results indicated that shyness was negatively correlated with learning adjustment, and this association was mediated by the dimensions of goal orientation and dimensions of academic help seeking. Specifically, shyness not only predicted learning adjustment through mastery-approach goals, and instrumental help seeking (teachers) but also predicted learning adjustment through the multiple mediating effects of the dimensions of goal orientation and the dimensions of academic help seeking (i.e., mastery-approach goals and instrumental help seeking from teachers, mastery-approach goals and executive help seeking, mastery-avoid goals and instrumental help seeking from classmates, mastery-avoid goals and executive help seeking, and performance-avoid goals and executive help seeking). Identifying these mediators further enables us to work out effective measures to promote shy high school studentsā€™ learning adjustment

    Structureā€“Function Aspects of PstS in Multi-Drugā€“Resistant Pseudomonas aeruginosa

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    The increasing prevalence of multi-drugā€“resistant (MDR) strains of Pseudomonas aeruginosa among critically ill humans is of significant concern. In the current study, we show that MDR clinical isolates of P. aeruginosa representing three distinct genotypes that display high virulence against intestinal epithelial cells, form novel appendage-like structures on their cell surfaces. These appendages contain PstS, an extracellular phosphate binding protein. Using anti-PstS antibodies, we determined that the PstS-rich appendages in MDR strains are involved in adherence to and disruption of the integrity of cultured intestinal epithelial cell monolayers. The outer surfaceā€“expressed PstS protein was also identified to be present in P. aeruginosa MPAO1, although to a lesser degree, and its role in conferring an adhesive and barrier disruptive phenotype against intestinal epithelial cells was confirmed using an isogenic Ī”PstS mutant. Formation of the PstS rich appendages was induced during phosphate limitation and completely suppressed in phosphate-rich media. Injection of MDR strains directly into the intestinal tract of surgically injured mice, a known model of phosphate limitation, caused high mortality rates (60%ā€“100%). Repletion of intestinal phosphate in this model completely prevented mortality. Finally, significantly less outer surface PstS was observed in the MPAO1 mutant Ī”HxcR thus establishing a role for the alternative type II secretion system Hxc in outer surface PstS expression. Gene expression analysis performed by RT-PCR confirmed this finding and further demonstrated abundant expression of pstS analogous to pa5369, pstS analogous to pa0688/pa14ā€“55410, and hxcX in MDR strains. Taken together, these studies provide evidence that outer surface PstS expression confers a highly virulent phenotype of MDR isolates against the intestinal epithelium that alters their adhesive and barrier disrupting properties against the intestinal epithelium

    Differential Temporal Evolution Patterns in Brain Temperature in Different Ischemic Tissues in a Monkey Model of Middle Cerebral Artery Occlusion

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    Brain temperature is elevated in acute ischemic stroke, especially in the ischemic penumbra (IP). We attempted to investigate the dynamic evolution of brain temperature in different ischemic regions in a monkey model of middle cerebral artery occlusion. The brain temperature of different ischemic regions was measured with proton magnetic resonance spectroscopy (1H MRS), and the evolution processes of brain temperature were compared among different ischemic regions. We found that the normal (baseline) brain temperature of the monkey brain was 37.16Ā°C. In the artery occlusion stage, the mean brain temperature of ischemic tissue was 1.16Ā°C higher than the baseline; however, this increase was region dependent, with 1.72Ā°C in the IP, 1.08Ā°C in the infarct core, and 0.62Ā°C in the oligemic region. After recanalization, the brain temperature of the infarct core showed a pattern of an initial decrease accompanied by a subsequent increase. However, the brain temperature of the IP and oligemic region showed a monotonously and slowly decreased pattern. Our study suggests that in vivo measurement of brain temperature could help to identify whether ischemic tissue survives

    Isolation and extraction of glansreginin A from walnut meal and its effect on the proliferation of 3T3-L1 cells

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    Abstract Glansreginin A is an indicative component in walnut and is abundant in walnut meal. The aim of this study was to isolate and purify glansreginin A from the walnut meal, and to investigate the weight loss and lipid-lowering potential of glansreginin A by studying the effect of glansregin A on the proliferation of 3T3-L1 preadipocytes. Firstly, the response surface methodology was used to effectively improve the extraction yield of glansreginin A. The maximum extraction rate of glansreginin A was 0.363%, and the optimal extraction process conditions were determined. In addition, the lipid-lowering activity of glansreginin A was investigated by cell experiments. The results showed that glansreginin A could inhibit the proliferation of 3T3-L1 preadipocytes in a dose-dependent manner. And cell cycle of different groups of cells treated with glansreginin A was also measured using flow cytometry. The results showed most of the cells were blocked in G0/G1 phase and significantly decreased in S phase. These results suggest that glansreginin A could inhibit the proliferation of 3T3-L1 preadipocytes by causing cell cycle arrest. These findings provided a theoretical basis for the future research of glansreginin A and the development of slimming and fat-reducing foods
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