56 research outputs found
A Resonance Model for Spontaneous Cortical Activity
How human brain function emerges from structure has intrigued researchers for
decades and numerous models have been put forward, yet none of them yields a
close structure-function relation. Here we present a resonance model based on
neuronal spike timing dependent plasticity (STDP) principle to describe the
spontaneous cortical activity by incorporating the dynamic interactions between
neuronal populations into a wave equation, which is able to accurately predict
the resting brain functional connectivity (FC), including the resting-state
networks. Besides, the proposed model provides strong theoretical and
experimental evidences that the spontaneous dynamic coupling between brain
regions fluctuates with a low frequency. Crucially, it is able to account for
how the negative functional correlations emerge during resonance. We test the
model with a large cohort of subjects (1038) from the Human Connectome Project
(HCP) S1200 release in both time and frequency domain, which exhibits superior
performance to existing eigen-decomposition models
Neuroendoscopy surgery for hypertensive intracerebral hemorrhage with concurrent brain herniation: a retrospective study of comparison with craniotomy
BackgroundHypertensive intracerebral hemorrhage combined with cerebral hernia (HIH-CH) is a serious condition. Neuroendoscopy can effectively remove intracranial hematoma, but there is no relevant research support for its utility in patients with HIH-CH. The purpose of this study is to investigate the efficacy and safety of neuroendoscopy in patients with HIH-CH.MethodsPatients with HIH-CH who received craniotomy or neuroendoscopy treatment were included. The patients were divided into craniotomy (CHE) group and neuroendoscopy (NEHE) group. Clinical data and follow-up outcome of the two groups were collected. The primary outcome was hematoma clearance.ResultsThe hematoma clearance rate (%) of patients in NEHE group was 97.65 (92.75, 100.00), and that of patients in CHE group was 95.00 (90.00, 100.00), p > 0.05. The operation time and intraoperative bleeding volume of patients in NEHE group were significantly less than those in CHE group (p < 0.05). There was no significant difference in the volume of residual hematoma and the incidence of rebleeding between the two groups (p > 0.05). The length of stay in ICU in NEHE group was significantly shorter than that in CHE group (p < 0.05).ConclusionNeuroendoscopy can safely and effectively remove the intracranial hematoma in patients with hypertensive intracerebral hemorrhage and cerebral hernia, significantly shorten the operation time, reduce the amount of intraoperative hemorrhage, shorten the ICU stay
Vpliv in optimizacija parametrov laserskega teksturiranja površine poliformaldehida (POM)
This research aimed to investigate the influence of laser process parameters on the surface texture of Polyformaldehyde (POM) and to improve its processability and process predictability. A comparative experiment and analysis involving multiple processing parameters, including laser power, scanning speed, and pulse width, were conducted on POM. Statistical prediction models of laser processing POM were established among the laser power, scanning speed, pulse width, texture depth, surface roughness at the bottom of texture, and multi-objective optimization and experimental verification of process parameters were carried out based on the grey-Taguchi analysis method. Experimental results show that the laser power and scanning speed significantly affect the texture depth. Higher laser power and lower scanning speed are conducive to forming depth. The surface roughness at the bottom of the texture increases with the increase in scanning speed and shows a tendency to rise and then fall as the laser power increases. The surface roughness and texture depth obtained under the optimal process parameters(A5B1C1) are 1.373 ÎĽm and 466.891 ÎĽm, respectively, which were reduced by 10.08 % and increased by 3.42 % compared with the minimum surface roughness and maximum depth in the orthogonal experiments. The validation experiments of the prediction model show that it can meet the reliability requirements, and the errors of the predicted values of depth and surface roughness are 1.86 % and 7.60 %, respectively. The above research provides theoretical and experimental support for the precise control of surface texture prepared by laser processing POM
Dual-Channel Underwater Acoustic Topological Rainbow Trapping Based on Synthetic Dimension
The concept of “rainbow trapping” has generated considerable interest in wave propagation and energy harvesting, offering new possibilities for diverse and efficient acoustic wave operations. In this work, we investigate a dual-channel topological rainbow trapping device implemented within an underwater two-dimensional phononic crystal based on synthetic dimension. The topological edge states with different frequencies are separated and trapped at different spatial locations. Acoustic waves propagate simultaneously along two boundaries due to the degeneracy of the edge states. In particular, the propagation of a dual-channel topological rainbow is also realized by using a bend design. This work contributes to the advancement of multi-channel devices in synthetic space and provides a reference for the design of highly efficient underwater acoustic devices
Acoustic transport in higher-order topological insulators with Dirac hierarchy
Dirac cones (DCs) are an important band structure in topological insulators (TIs) for realizing topological phase transition, and they provide unique ways to artificially regulate wave transport. Herein, we proposed a simple method to achieve Dirac hierarchy in three-dimensional (3D) acoustic TIs with rich and controllable topological phase transitions. The split of multifold DCs in each bulk Dirac hierarchy induced boundary Dirac hierarchy, including topological surface states and topological hinge states. We successfully realized 3D higher-order topological insulators (HOTIs) that exhibited two-fold boundary Dirac hierarchy with hinge states and achieved energy transport along three independent directions based on hinge-to-hinge channels. The proposed method is not limited to single hinges, and it provides a new design idea for multidimensional sound transport, serving as the basis for controllable acoustic functional devices
Image4_Exercise improves choroid plexus epithelial cells metabolism to prevent glial cell-associated neurodegeneration.TIF
Recent studies have shown that physical activities can prevent aging-related neurodegeneration. Exercise improves the metabolic landscape of the body. However, the role of these differential metabolites in preventing neurovascular unit degeneration (NVU) is still unclear. Here, we performed single-cell analysis of brain tissue from young and old mice. Normalized mutual information (NMI) was used to measure heterogeneity between each pair of cells using the non-negative Matrix Factorization (NMF) method. Astrocytes and choroid plexus epithelial cells (CPC), two types of CNS glial cells, differed significantly in heterogeneity depending on their aging status and intercellular interactions. The MetaboAnalyst 5.0 database and the scMetabolism package were used to analyze and calculate the differential metabolic pathways associated with aging in the CPC. These mRNAs and corresponding proteins were involved in the metabolites (R)-3-Hydroxybutyric acid, 2-Hydroxyglutarate, 2-Ketobutyric acid, 3-Hydroxyanthranilic acid, Fumaric acid, L-Leucine, and Oxidized glutathione pathways in CPC. Our results showed that CPC age heterogeneity-associated proteins (ECHS1, GSTT1, HSD17B10, LDHA, and LDHB) might be directly targeted by the metabolite of oxidized glutathione (GSSG). Further molecular dynamics and free-energy simulations confirmed the insight into GSSG’s targeting function and free-energy barrier on these CPC age heterogeneity-associated proteins. By inhibiting these proteins in CPC, GSSG inhibits brain energy metabolism, whereas exercise improves the metabolic pathway activity of CPC in NVU by regulating GSSG homeostasis. In order to develop drugs targeting neurodegenerative diseases, further studies are needed to understand how physical exercise enhances NVU function and metabolism by modulating CPC-glial cell interactions.</p
Video5_Exercise improves choroid plexus epithelial cells metabolism to prevent glial cell-associated neurodegeneration.MP4
Recent studies have shown that physical activities can prevent aging-related neurodegeneration. Exercise improves the metabolic landscape of the body. However, the role of these differential metabolites in preventing neurovascular unit degeneration (NVU) is still unclear. Here, we performed single-cell analysis of brain tissue from young and old mice. Normalized mutual information (NMI) was used to measure heterogeneity between each pair of cells using the non-negative Matrix Factorization (NMF) method. Astrocytes and choroid plexus epithelial cells (CPC), two types of CNS glial cells, differed significantly in heterogeneity depending on their aging status and intercellular interactions. The MetaboAnalyst 5.0 database and the scMetabolism package were used to analyze and calculate the differential metabolic pathways associated with aging in the CPC. These mRNAs and corresponding proteins were involved in the metabolites (R)-3-Hydroxybutyric acid, 2-Hydroxyglutarate, 2-Ketobutyric acid, 3-Hydroxyanthranilic acid, Fumaric acid, L-Leucine, and Oxidized glutathione pathways in CPC. Our results showed that CPC age heterogeneity-associated proteins (ECHS1, GSTT1, HSD17B10, LDHA, and LDHB) might be directly targeted by the metabolite of oxidized glutathione (GSSG). Further molecular dynamics and free-energy simulations confirmed the insight into GSSG’s targeting function and free-energy barrier on these CPC age heterogeneity-associated proteins. By inhibiting these proteins in CPC, GSSG inhibits brain energy metabolism, whereas exercise improves the metabolic pathway activity of CPC in NVU by regulating GSSG homeostasis. In order to develop drugs targeting neurodegenerative diseases, further studies are needed to understand how physical exercise enhances NVU function and metabolism by modulating CPC-glial cell interactions.</p
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