topology properties

  • 文章类型: Journal Article
    日益频繁的城市洪水使传统的灰色基础设施紧张,压倒排水网络的能力,并在管理雨水方面带来挑战。强降水导致洪水和排水系统的损坏。因此,对有效的洪水减灾策略进行了深入研究。绿色基础设施(GI)已被证明可以有效地应对不断增加的洪水风险并减轻排水系统的压力。然而,作为雨水管理的主要基础设施,在降水事件中,城市下水道系统的动态运行特征仍然缺乏关注。为了填补这个空白,我们提出了一种新颖的方法,集成了水力特性和下水道网络系统的拓扑结构。这种方法旨在识别有影响力的节点,在降水事件期间流入的动态变化中,这有助于下水道网络的连通性。此外,我们采用了雨桶作为地理标志的典范,根据影响节点的不同等级,生成了14种GI布局方案。在性能不佳和性能良好的节点上实施GI措施可以在减轻节点泛洪方面产生明显的好处。这种方法为雨洪管理提供了新的视角,在GI和排水系统之间建立有效的协同作用。
    Increasingly frequent urban floods strain the traditional grey infrastructure, overwhelming the capacity of drainage networks and causing challenges in managing stormwater. The heavy precipitation leads to flooding and damage to drainage systems. Consequently, efficient mitigation strategies for flooding have been researched deeply. Green infrastructure (GI) has proved to be effective in responding the increasing risk of flood and alleviate pressure on drainage systems. However, as the primary infrastructure of stormwater management, there is still a lack of attention to the dynamic operation feature of urban sewer systems during precipitation events. To fill this gap, we proposed a novel approach that integrates hydraulic characteristics and the topological structure of a sewer network system. This approach aims to identify influential nodes, which contribute to the connectivity of the sewer network amidst dynamic changes in inflow during precipitation events. Furthermore, we adopted rain barrels to serve as exemplars of GI, and 14 GI layout schemes are produced based on the different ranks of influential nodes. Implementing GI measures on both poorly performing and well-performing nodes can yield distinct benefits in mitigating node flooding. This approach provides a new perspective for stormwater management, establishing effective synergy between GI and the drainage system.
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  • 文章类型: Journal Article
    背景:恐慌症(PD)是一种常见的致残疾病,其特征是反复发作的惊恐发作。情绪和行为障碍与功能连接(FC)和网络异常有关。我们用了整个大脑FC,模块化网络,和图论分析研究PD中广泛的网络概况。
    方法:纳入82个PD和97个对照的功能MRI数据。每对160个区域之间的本征FC,6个内部网络,并对15个网络间进行了分析。探索了拓扑性质。
    结果:PD患者显示右侧脑岛内的FCs改变,额叶皮质-后扣带皮质(PCC)之间,额叶皮质-小脑,和PCC-枕骨皮质(校正后的P值<0.001)。在感觉运动网络(SMN)和SMN-枕骨网络(OCN)内检测到较低的连接(P值<0.05)。在PD中发现了各种减少的全局和局部网络特征(P值<0.05)。此外,脑岛的PD症状与结节效率(Ne)之间存在显着相关性(r=-0.273,P=0.016),和岛内FC(r=-0.226,P=0.041)。
    结论:PD患者存在功能异常的脑网络,特别是脑岛内的FC和Ne减少,提示信息整合功能障碍在PD中起重要作用。
    BACKGROUND: Panic disorder (PD) is a common disabling condition characterized by recurrent panic attacks. Emotional and behavioral impairments are associated with functional connectivity (FC) and network abnormalities. We used the whole brain FC, modular networks, and graph-theory analysis to investigate extensive network profiles in PD.
    METHODS: The functional MRI data from 82 PD and 97 controls were included. Intrinsic FC between each pair of 160 regions, 6 intra-networks, and 15 inter-networks were analyzed. The topological properties were explored.
    RESULTS: PD patients showed altered FCs within the right insula, between frontal cortex-posterior cingulate cortex (PCC), frontal cortex-cerebellum, and PCC-occipital cortex (corrected P values < 0.001). Lower connections within the Sensorimotor Network (SMN) and SMN-Occipital Network (OCN) were detected (P values < 0.05). Various decreased global and local network features were found in PD (P values < 0.05). In addition, significant correlations were found between PD symptoms and nodal efficiency (Ne) in the insula (r = -0.273, P = 0.016), and the FC of the intra-insula (r = -0.226, P = 0.041).
    CONCLUSIONS: PD patients present with abnormal functional brain networks, especially the decreased FC and Ne within insula, suggesting that dysfunction of information integration plays an important role in PD.
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  • 文章类型: Journal Article
    The oncogenesis and progression of gastric cancer are closely correlated with the complex regulatory relationships among messenger RNA (mRNA), long noncoding RNA (lncRNA), and microRNA (miRNA). After constructing the gastric cancer lncRNA-miRNA-mRNA regulatory network, we analyzed the network topology properties and found that lncRNA ADAMTS9-AS2 and C20orf166-AS1 and miRNA hsa-mir-204 are key nodes. Further functional enrichment analysis and survival analysis were performed on these key nodes and the RNAs interacting with them. We found that CHRM2, ANGPT2, and COL1A1 interacting with ADAMTS9-AS2 are enriched in the PI3K-Akt signaling pathway, and low expression of the ADAMTS9-AS2 is closely related to the prognosis of patients. Abnormal expression of CACNA1H, FLNA, and FLNC interacting with lncRNA C20orf166-AS1 is associated with MAPK signaling pathway in gastric cancer. In addition, the downregulated miRNA hsa-mir-204 promotes invasion and proliferation of gastric cancer cells by regulating the abnormal expression of mRNAs (CHRDL1 and NPTX1) and lncRNAs (ADAMTS9-AS2, NKX2-1-AS1, TLR8-AS1, and VCAN-AS1). This study systematically analyzed the lncRNA-miRNA-mRNA regulatory network of gastric cancer, which not only has a new understanding of the pathogenesis of gastric cancer, but also provides new insights for the early diagnosis and treatment of gastric cancer.
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  • 文章类型: Journal Article
    臂丛神经损伤后脑功能的研究集中在局部皮质功能重组,很少有研究关注臂丛神经损伤后的大脑网络。大脑网络的变化可能有助于在全球范围内理解大脑的可塑性。我们假设单侧臂丛神经损伤后全脑静息状态功能网络的拓扑结构发生变化。因此,在这项横断面研究中,我们招募了8名单侧臂丛神经损伤的男性患者(右撇子,平均年龄27.9±5.4岁)和8名男性健康对照(右撇子,平均年龄28.6±3.2)。在采集并预处理静息状态磁共振成像数据后,将大脑分为90个区域,并计算区域之间的Pearson相关系数。然后将这些相关矩阵转换成具有0.1-0.46的附加稀疏度值的二进制矩阵。在稀疏条件下,这两个团体都满足了这个小世界的财产。聚类系数明显降低,而与健康对照组相比,患者的平均最短路径明显更高。这些发现证实,患者的大脑功能网络仍然表现出小世界特征,对大脑中的信息传输非常有效,以及正常控制。或者,不同的小世界表明臂丛神经损伤患者不同脑区的信息传递和整合能力受损。
    Research on brain function after brachial plexus injury focuses on local cortical functional reorganization, and few studies have focused on brain networks after brachial plexus injury. Changes in brain networks may help understanding of brain plasticity at the global level. We hypothesized that topology of the global cerebral resting-state functional network changes after unilateral brachial plexus injury. Thus, in this cross-sectional study, we recruited eight male patients with unilateral brachial plexus injury (right handedness, mean age of 27.9 ± 5.4 years old) and eight male healthy controls (right handedness, mean age of 28.6 ± 3.2). After acquiring and preprocessing resting-state magnetic resonance imaging data, the cerebrum was divided into 90 regions and Pearson\'s correlation coefficient calculated between regions. These correlation matrices were then converted into a binary matrix with affixed sparsity values of 0.1-0.46. Under sparsity conditions, both groups satisfied this small-world property. The clustering coefficient was markedly lower, while average shortest path remarkably higher in patients compared with healthy controls. These findings confirm that cerebral functional networks in patients still show small-world characteristics, which are highly effective in information transmission in the brain, as well as normal controls. Alternatively, varied small-worldness suggests that capacity of information transmission and integration in different brain regions in brachial plexus injury patients is damaged.
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