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Background: Impaired value-based decision-making is a feature of behavioral addictions and drug addictions. Both reward and loss aversion are key elements in value-based decisionmaking. Studies have consistently investigated reward in behavioral addictions and drug addictions, however, few studies explored loss aversion especially in behavioral addictions. In this study, we investigated loss aversion in the Internet gaming disorder patients. Method: In this study, Internet gaming disorder patients (PIGD) and healthy controls (Con-PIGD) performed the Iowa gambling task (IGT), under functional magnetic resonance imaging (fMRI). We investigated group differences in loss aversion, brain functional networks of node-centric functional connectivity (nFC) and the overlapping community features of edge-centric functional connectivity (eFC) in IGT. Results: PIGD performed worse with lower average net score in IGT. The computational model results showed that PIGD significantly reduced loss aversion. There was no group difference in nFC. However, there were significant group differences in the overlapping community features of eFC. Furthermore, in Con-PIGD, loss aversion was positively correlated with the edge community profile similarity of the edge between left IFG and right hippocampus at right caudate. This relationship was suppressed by response consistency in PIGD. In addition, reduced loss aversion was negatively correlated with the promoted bottom-to-up neuromodulation from the right hippocampus to the left IFG in PIGD. Conclusions: The present study consistently demonstrated that Internet gaming disorder showed loss aversion deficit, a key element in the value-based decision-making. These findings may have important implications for the definition, diagnosis, and prevention of Internet gaming disorder in the future, and we calls for future research to investigate loss aversion in other behavioral addictions. [ABSTRACT FROM AUTHOR]

Background: Internet gaming disorder and tobacco use disorder are globally common, nonsubstance-related disorders and substance-related disorders worldwide, respectively. However, whether Internet gaming disorder share common neurobiological pattern with the tobacco use disorder remains unknown. Recognizing the commonalities between Internet gaming disorder and tobacco use disorder will deepen understanding of the underlying mechanisms of addictive behavior and excessive online gaming. Method: Using node strength, 141 resting-state data were collected in this study to compute network homogeneity. The participants included participants with Internet gaming disorder (PIGD: n = 34, male = 29, age: 15-25 years), participants with tobacco use disorder (PTUD: n = 33, male = 33, age: 19-42 years), and matched healthy controls (control-for-IGD: n = 41, male = 38, age: 17-32 years; control-for-TUD: n = 33, age: 21-27 years). Results: PIGD and PTUD exhibited common enhanced node strength between the subcortical and motor networks. Additionally, a common enhanced resting-state functional connectivity (RSFC) was found between the right thalamus and right postcentral gyrus in PIGD and PTUD. Node strength and RSFC were used to distinguish PIGD and PTUD from their respective healthy controls. Interestingly, models trained on PIGD versus controls could classify PTUD versus controls and vice versa. Conclusions: The present study consistently demonstrates Internet gaming disorder share common neurobiological patterns with substance-related disorders such as tobacco use disorder. The present study discovered that the connectivity between the subcortical and motor networks is a potential biological target for developing addiction treatment in the future. [ABSTRACT FROM AUTHOR]

The process parameters of Directed Energy Deposition (DED) have been widely studied including laser power, powder flow rate, and scanning speed. These parameters affect clad dimension and melt pool temperature, which are directly related to part quality. However, laser/powder profiles and their alignment have obtained less attention due to the cumbersome characterization process, although they can be directly associated with local energy density for melt pool formation. This study examines the impact of the alignment between the laser beam and powder flow distributions in DED on clad dimension and melt pool temperature. The laser beam and powder profiles are characterized by measuring their respective 2D Gaussian profiles for a given standoff distance. Aligned and misaligned laser-powder profiles are then used to build single-clad square geometries. It was found that a 500-µm offset between the centers of the laser and powder profiles causes up to a 20% change in both the width and the height of a single clad as well as an average temperature increase of 100 K. To understand the interaction between powder flow, energy flux, and local temperature, the local specific energy density distribution was plotted in 2D. These results suggest that laser-powder misalignment may significantly alter the thermal history and shape of deposited clads, possibly preventing DED-manufactured parts from meeting design properties and causing build failures. [ABSTRACT FROM AUTHOR]

The process parameters of Directed Energy Deposition (DED) have been widely studied including laser power, powder flow rate, and scanning speed. These parameters affect clad dimension and melt pool temperature, which are directly related to part quality. However, laser/powder profiles and their alignment have obtained less attention due to the cumbersome characterization process, although they can be directly associated with local energy density for melt pool formation. This study examines the impact of the alignment between the laser beam and powder flow distributions in DED on clad dimension and melt pool temperature. The laser beam and powder profiles are characterized by measuring their respective 2D Gaussian profiles for a given standoff distance. Aligned and misaligned laser-powder profiles are then used to build single-clad square geometries. It was found that a 500-µm offset between the centers of the laser and powder profiles causes up to a 20% change in both the width and the height of a single clad as well as an average temperature increase of 100 K. To understand the interaction between powder flow, energy flux, and local temperature, the local specific energy density distribution was plotted in 2D. These results suggest that laser-powder misalignment may significantly alter the thermal history and shape of deposited clads, possibly preventing DED-manufactured parts from meeting design properties and causing build failures. [ABSTRACT FROM AUTHOR]

Background Internet gaming disorder (IGD) is a mental health issue that affects individuals worldwide. However, the lack of knowledge about the biomarkers associated with the development of IGD has restricted the diagnosis and treatment of this disorder. Aims We aimed to reveal the biomarkers associated with the development of IGD through resting-state brain network analysis and provide clues for the diagnosis and treatment of IGD. Methods Twenty-six patients with IGD, 23 excessive internet game users (EIUs) who recurrently played internet games but were not diagnosed with IGD and 29 healthy controls (HCs) performed delay discounting task (DDT) and Iowa gambling task (IGT). Resting-state functional magnetic resonance imaging (fMRI) data were also collected. Results Patients with IGD exhibited significantly lower hubness in the right medial orbital part of the superior frontal gyrus (ORBsupmed) than both the EIU and the HC groups. Additionally, the hubness of the right ORBsupmed was found to be positively correlated with the highest excessive internet gaming degree during the past year in the EIU group but not the IGD group; this might be the protective mechanism that prevents EIUs from becoming addicted to internet games. Moreover, the hubness of the right ORBsupmed was found to be related to the treatment outcome of patients with IGD, with higher hubness of this region indicating better recovery when undergoing forced abstinence. Further modelling analysis of the DDT and IGT showed that patients with IGD displayed higher impulsivity during the decision-making process, and impulsivity-related parameters were negatively correlated with the hubness of right ORBsupmed. Conclusions Our findings revealed that the impulsivity-related right ORBsupmed hubness could serve as a potential biomarker of IGD and provide clues for the diagnosis and treatment of IGD. [ABSTRACT FROM AUTHOR]

Background and aims: Impaired value-based decision-making is a feature of substance and behavioral addictions. Loss aversion is a core of value-based decision-making and its alteration plays an important role in addiction. However, few studies explored it in internet gaming disorder patients (IGD). Methods: In this study, IGD patients (PIGD) and healthy controls (Con-PIGD) performed the Iowa gambling task (IGT), under functional magnetic resonance imaging (fMRI). We investigated group differences in loss aversion, brain functional networks of node-centric functional connectivity (nFC) and the overlapping community features of edge-centric functional connectivity (eFC) in IGT. Results: PIGD performed worse with lower average net score in IGT. The computational model results showed that PIGD significantly reduced loss aversion. There was no group difference in nFC. However, there were significant group differences in the overlapping community features of eFC. Furthermore, in Con-PIGD, loss aversion was positively correlated with the edge community profile similarity of the edge between left IFG and right hippocampus at right caudate. This relationship was suppressed by response consistency in PIGD. In addition, reduced loss aversion was negatively correlated with the promoted bottom-to-up neuromodulation from the right hippocampus to the left IFG in PIGD. Discussion and conclusions: The reduced loss aversion in value-based decision making and their related edge-centric functional connectivity support that the IGD showed the same value-based decision-making deficit as the substance use and other behavioral addictive disorders. These findings may have important significance for understanding the definition and mechanism of IGD in the future. [ABSTRACT FROM AUTHOR]