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Background: The default mode network (DMN) is not a single system, but rather is composed of smaller and distinct functional subsystems that interact with each other. The functional relevance of these subsystems in tobacco use disorder (TUD) and the neurobiological features associated with smoking motivation are still unclear; thus, we sought to assess causal or direct connectivity alterations within 3 subsystems of the DMN among people with TUD. Methods: We recruited male smokers and nonsmokers. We conducted resting- state functional magnetic resonance imaging (rs-fMRI) and collected ratings on smoking-related clinical scales. We applied dynamic causal modell ing (DCM) to rs-fMRI to characterize changes of effective connectivity in TUD from 3 DMN subsystems, including the midline core network (i.e., the posterior cingulate cortex and the anterior medial prefrontal cortex [PCC-aMPFC] core DMN), the medial temporal subsystem (MTL-DMN), and the dorsal medial prefrontal cortex subsystem (dMPFC-DMN). We used leave-one-out cross-validation to investigate whether the neural response could predict smoking reasons, evaluated using the Russell Reason for Smoking Questionnaire). Results: We recruited 88 smokers and 54 nonsmokers. Among people with TUD, the parahippocampal cortex (PHC) region showed enhanced selfconnection, which was associated with the severity of TUD after nighttime withdrawal. Compared with nonsmokers, people with TUD displayed significant increased effective connectivity within the dMPFC-DMN, and decreased effective connectivity from the dMPFC- DMN to the PCC-aMPFC core DMN. Moreover, decreased effective connectivity from the lateral temporal cortex to the dMPFC could predict the smoking reason related to automatic behaviour. Limitations: Although we found aberrance in causal connections in DMN subsystems among people with TUD, our cross-sectional study could not be used to investigate changes in effective connectivity over time and their relationship with clinical features. Conclusion: This study emphasized the aberrant causal connections of different functional subsystems of the DMN in TUD and revealed the neural correlates of automatic smoking behaviours. These findings suggested DMN subsystem-derived indicators could be a potential biomarker for TUD and could be used to identify the heterogeneity in motivation for smoking behaviour., Introduction Cigarette smoking is an important risk factor for chronic noncommunicable diseases and has a negative effect on economic development and physical or mental health. (1) Tobacco use disorder (TUD) [...]

[Objective] Energy trade has always been one of the important elements of the Belt and Road Initiative (BRI) economic and trade cooperation. The analysis of the change and resilience of the BRI energy trade network holds paramount significance for comprehensively understanding the BRI energy trade system and advancing energy cooperation strategies within the region. [Methods] Drawing inspiration from the complex network theory, this study employed a holistic approach to complex network analysis, extracting and scrutinizing the backbone network of energy trade among the BRI countries. By employing multidimensional identification and analysis of the topological characteristics of the backbone network, it measured the resilience response of the BRI energy trade network under different attack strategies. [Results] Structural analyses showed a clear trend of diversification in the backbone network of the BRI energy trade. The backbone structure encompasses major energy-exporting countries such as Russia, Saudi Arabia, the United Arab Emirates, Iraq, and Qatar, along with major energy-importing countries like China, India, Singapore, Poland, and Thailand. Change analyses showed that since 2000, the connectivity pattern of the BRI energy trade backbone network has undergone multilevel fluctuations, displaying a more pronounced aggregated form and continuously strengthened links among nodes. The resilience analysis showed that the resilience of the backbone network was positively correlated with the network size. Under random attacks, the resilience of the BRI energy trade backbone network gradually improves. In deliberate attacks, the largest connected subgraph demonstrates a power-law distribution, with a “sharp-slow-sharp” continuous decline trend as the number of failed nodes increases. [Conclusion] The introduction of the BRI has effectively promoted energy trade among countries along the route, and the degree of trade network connectivity has improved. However, a small number of trade nodes still have very strong control, which has a greater impact on the overall energy trade network’s ability to withstand external disturbances.