Ultrathin ferroic HfO2-ZrO2 superlattice gate stack for advanced transistors.

With the scaling of lateral dimensions in advanced transistors, an increased gate capacitance is desirable both to retain the control of the gate electrode over the channel and to reduce the operating voltage1. This led to a fundamental change in the gate stack in 2008, the incorporation of high-dielectric-constant HfO2 (ref. 2), which remains the material of choice to date. Here we report HfO2-ZrO2 superlattice heterostructures as a gate stack, stabilized with mixed ferroelectric-antiferroelectric order, directly integrated onto Si transistors, and scaled down to approximately 20 ångströms, the same gate oxide thickness required for high-performance transistors. The overall equivalent oxide thickness in metal-oxide-semiconductor capacitors is equivalent to an effective SiO2 thickness of approximately 6.5 ångströms. Such a low effective oxide thickness and the resulting large capacitance cannot be achieved in conventional HfO2-based high-dielectric-constant gate stacks without scavenging the interfacial SiO2, which has adverse effects on the electron transport and gate leakage current3. Accordingly, our gate stacks, which do not require such scavenging, provide substantially lower leakage current and no mobility degradation. This work demonstrates that ultrathin ferroic HfO2-ZrO2 multilayers, stabilized with competing ferroelectric-antiferroelectric order in the two-nanometre-thickness regime, provide a path towards advanced gate oxide stacks in electronic devices beyond conventional HfO2-based high-dielectric-constant materials.

Altered core networks of brain connectivity and personality traits in internet gaming disorder.

BACKGROUND AND AIMS: Although the Internet has provided convenience and efficiency in many areas of everyday life, problems stemming from Internet use have also been identified, such as Internet gaming disorder (IGD). Internet addiction, which includes IGD, can be viewed as a behavioral addiction or impulse control disorder. This study investigated the altered functional and effective connectivity of the core brain networks in individuals with IGD compared to healthy controls (HCs). METHODS: Forty-five adults with IGD and 45 HCs were included in this study. To examine the brain networks related to personality traits that influence problematic online gaming, the left and right central executive network (CEN) and the salience network (SN) were included in the analysis. Also, to examine changes in major brain network topographies, we analyzed the default mode network (DMN). RESULTS: IGD participants showed lower functional connectivity between the dorsal lateral prefrontal cortex (DLPFC) and other regions in the CEN than HC participants during resting state. Also, IGD participants revealed reduced functional connectivity between the dorsal anterior cingulate cortex and other regions in the SN and lower functional connectivity in the medial prefrontal cortex of the anterior DMN. Notably, in IGD individuals but not HC individuals, there was a positive correlation between IGD severity and effective connectivity and a positive correlation between reward sensitivity and effective connectivity within the ventral striatum of the SN. CONCLUSIONS: Problematic online gaming was associated with neurofunctional alterations, impairing the capacity of core brain networks.

Reliability and Validity of the Korean Version of the General-Food Craving Questionnaire-Trait for Children.

OBJECTIVE: The General-Food Craving Questionnaire-Trait (G-FCQ-T) is a validated, assessment scale for food craving. The aim of this study was to measure its reliability and validity for Korean children. METHODS: A total of 172 children (94 boys and 78 girls) were selected to fill out a set of questionnaires, including the G-FCQ-T, the Children's version of the Dutch Eating Behavior Questionnaire (DEBQ-C), and the Three-Factor Eating Questionnaire (TFEQ) in the Korean language. RESULTS: The internal consistency (Cronbach's alpha=0.933) and test-retest reliability (r=0.653) were satisfactory. The G-FCQ-T showed a significantly positive correlation with the DEBQ-C (r=0.560) and the TFEQ (r=0.397). The optimum cutoff score of the G-FCQ-T set by Receiver Operating Characteristics analysis was 51, with sensitivity and specificity of 0.833 and 0.825, respectively, for children. CONCLUSION: The G-FCQ-T showed good reliability and validity for assessing food craving for children and could become a practial instrument in clinical and research settings.

Structural alterations in the prefrontal cortex mediate the relationship between Internet gaming disorder and depressed mood.

Adaptive gaming use has positive effects, whereas depression has been reported to be prevalent in Internet gaming disorder (IGD). However, the neural correlates underlying the association between depression and Internet gaming remain unclear. Moreover, the neuroanatomical profile of the striatum in IGD is relatively less clear despite its important role in addiction. We found lower gray matter (GM) density in the left dorsolateral prefrontal cortex (DLPFC) in the IGD group than in the Internet gaming control (IGC) group and non-gaming control (NGC) group, and the GM density was associated with lifetime usage of Internet gaming, depressed mood, craving, and impulsivity in the gaming users. Striatal volumetric analysis detected a significant reduction in the right nucleus accumbens (NAcc) in the IGD group and its association with lifetime usage of gaming and depression. These findings suggest that alterations in the brain structures involved in the reward system are associated with IGD-related behavioral characteristics. Furthermore, the DLPFC, involved in cognitive control, was observed to serve as a mediator in the association between prolonged gaming and depressed mood. This finding may provide insight into an intervention strategy for treating IGD with comorbid depression.

Risk Factors for Internet Gaming Disorder: Psychological Factors and Internet Gaming Characteristics.

Background: Understanding the risk factors associated with Internet gaming disorder (IGD) is important to predict and diagnose the condition. The purpose of this study is to identify risk factors that predict IGD based on psychological factors and Internet gaming characteristics; Methods: Online surveys were conducted between 26 November and 26 December 2014. There were 3568 Korean Internet game users among a total of 5003 respondents. We identified 481 IGD gamers and 3087 normal Internet gamers, based on Diagnostic and Statistical Manual for Mental Disorders (DSM-5) criteria. Logistic regression analysis was applied to identify significant risk factors for IGD; Results: The following eight risk factors were found to be significantly associated with IGD: functional and dysfunctional impulsivity (odds ratio: 1.138), belief self-control (1.034), anxiety (1.086), pursuit of desired appetitive goals (1.105), money spent on gaming (1.005), weekday game time (1.081), offline community meeting attendance (2.060), and game community membership (1.393; p < 0.05 for all eight risk factors); Conclusions: These risk factors allow for the prediction and diagnosis of IGD. In the future, these risk factors could also be used to inform clinical services for IGD diagnosis and treatment.

The influence of game genre on Internet gaming disorder.

Background and aims Although Internet gaming disorder (IGD) has been investigated in detail, minimal research has been conducted regarding the influence of different game genres on IGD. The aim of this study is to compare the characteristics of members of game genre-specific groups with IGD and to identify factors associated with IGD status in each group in a large sample of adults. Methods Internet games were categorized into four genres: real-time strategy games, massive multiplayer online role-playing games (MMORPG), sport games, and first-person shooter (FPS) games. Participants (n = 2,923) who usually played one of these games completed an anonymous online survey that collected sociodemographic, game usage pattern, and psychopathological assessment data. Results MMORPG and FPS game players more frequently met the criteria for IGD than participants in the other two groups. Differences between the IGD-suspected gamers within the genre-specific groups were observed for a few items, such as average game-playing time and the subscales of the behavioral activation system; however, the factors that contributed to the development of IGD within each game genre-specific group were found to be considerably different. Discussion and conclusions The findings of this study suggest that IGD is a stable psychiatric diagnosis encompassing users of a broad range of game genres. In addition, the development of strategies for the prevention of and early intervention on individuals at high risk for developing IGD may require consideration of the distinct characteristics identified as effective predictors of IGD in users of each game genre.

Investigating the effects of reduced size on the properties of ferroelectrics.

A series of experiments has been undertaken to understand more about the fundamental origin of the thickness-induced permittivity collapse often observed in conventional thin film ferroelectric heterostructures. The various experiments are discussed, highlighting the eventual need to examine permittivity collapse in thin film single crystal material. It has been seen that dielectric collapse is not a direct consequence of reduced size, and neither is it a consequence of unavoidable physics associated with the ferroelectric-electrode boundary. Research on three-dimensional shape-constrained ferroelectrics, emphasizing self-assembled structures based on nanoporous alumina templates and on FIB-milled single crystals, is also presented, and appears to represent an exciting area for ongoing research.

Predictors and patterns of problematic Internet game use using a decision tree model.

Background and aims Problematic Internet game use is an important social issue that increases social expenditures for both individuals and nations. This study identified predictors and patterns of problematic Internet game use. Methods Data were collected from online surveys between November 26 and December 26, 2014. We identified 3,881 Internet game users from a total of 5,003 respondents. A total of 511 participants were assigned to the problematic Internet game user group according to the Diagnostic and Statistical Manual of Mental Disorders Internet gaming disorder criteria. From the remaining 3,370 participants, we used propensity score matching to develop a normal comparison group of 511 participants. In all, 1,022 participants were analyzed using the chi-square automatic interaction detector (CHAID) algorithm. Results According to the CHAID algorithm, six important predictors were found: gaming costs (50%), average weekday gaming time (23%), offline Internet gaming community meeting attendance (13%), average weekend and holiday gaming time (7%), marital status (4%), and self-perceptions of addiction to Internet game use (3%). In addition, three patterns out of six classification rules were explored: cost-consuming, socializing, and solitary gamers. Conclusion This study provides direction for future work on the screening of problematic Internet game use in adults.

Association Between Drinking and Obesity in Pre- and Postmenopausal Women: Korea National Health and Nutrition Examination Survey 2010-2012.

BACKGROUND: Women are more vulnerable to the adverse effects of alcohol than men. The present study aimed to investigate the link between drinking and obesity in pre- and postmenopausal women in Korea. METHODS: We performed a cross-sectional study of 4374 premenopausal and 2927 postmenopausal women using a multistage probability cluster survey sample to produce nationally representative estimates. We assessed the subjects' alcohol drinking tendencies rates according to their drinking levels as well as Alcohol Use Disorders Identification Test (AUDIT); obesity was identified based on body mass index (BMI) ≥25 kg/m2, waist circumference (WC) ≥80 cm, and waist-to-height ratio (WHtR) ≥50%. We performed t-tests and chi-square tests to assess the association between drinking and obesity. RESULTS: In premenopausal subjects, obesity indices increased significantly as alcohol consumption rose. Significant correlations between drinking level and obesity factors were found in premenopausal women after adjusting for age (odds ratios [ORs] for BMI, WC, and WHtR were 1.58 [1.08-2.31], 1.94 [1.11-3.00], and 1.80 [1.24-2.61], respectively). Furthermore, an AUDIT score of 20 or higher indicated a significantly higher likelihood of obesity (ORs for BMI, WC, and WHtR were 2.02 [1.18-3.46], 2.75 [1.70-4.87], and 2.86 [1.78-4.59], respectively). There was a significant correlation between AUDIT scores and obesity factors after adjusting for age, energy intake, fat intake, exercise, smoking, education, and income in premenopausal women (ORs for BMI and WHtR were 1.71 [0.85-3.47] and 1.73 [0.97-3.06], respectively). CONCLUSION: Our results suggest that alcohol is associated with a risk factor for obesity in premenopausal women.

Personality Factors Predicting Smartphone Addiction Predisposition: Behavioral Inhibition and Activation Systems, Impulsivity, and Self-Control.

The purpose of this study was to identify personality factor-associated predictors of smartphone addiction predisposition (SAP). Participants were 2,573 men and 2,281 women (n = 4,854) aged 20-49 years (Mean ± SD: 33.47 ± 7.52); participants completed the following questionnaires: the Korean Smartphone Addiction Proneness Scale (K-SAPS) for adults, the Behavioral Inhibition System/Behavioral Activation System questionnaire (BIS/BAS), the Dickman Dysfunctional Impulsivity Instrument (DDII), and the Brief Self-Control Scale (BSCS). In addition, participants reported their demographic information and smartphone usage pattern (weekday or weekend average usage hours and main use). We analyzed the data in three steps: (1) identifying predictors with logistic regression, (2) deriving causal relationships between SAP and its predictors using a Bayesian belief network (BN), and (3) computing optimal cut-off points for the identified predictors using the Youden index. Identified predictors of SAP were as follows: gender (female), weekend average usage hours, and scores on BAS-Drive, BAS-Reward Responsiveness, DDII, and BSCS. Female gender and scores on BAS-Drive and BSCS directly increased SAP. BAS-Reward Responsiveness and DDII indirectly increased SAP. We found that SAP was defined with maximal sensitivity as follows: weekend average usage hours > 4.45, BAS-Drive > 10.0, BAS-Reward Responsiveness > 13.8, DDII > 4.5, and BSCS > 37.4. This study raises the possibility that personality factors contribute to SAP. And, we calculated cut-off points for key predictors. These findings may assist clinicians screening for SAP using cut-off points, and further the understanding of SA risk factors.

Vascular complications after living related liver transplantation: evaluation with gadolinium-enhanced three-dimensional MR angiography.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of gadolinium-enhanced three-dimensional (3D) MR angiography for detection of vascular complications in patients who have undergone living related liver transplantation. MATERIALS AND METHODS: Seventy-six patients who underwent living related liver transplantation were evaluated with gadolinium-enhanced 3D MR angiography. All MR angiograms were assessed for patency of the hepatic artery and the portal vein using a four-point scale (grades I-IV). The results were correlated with conventional angiography (n = 23) and clinical follow-up with Doppler sonography (n = 53) for more than 6 months. RESULTS: Seventy-three of 76 MR angiography procedures were technically adequate. When grades III (focal narrowing [> 50%] at the anastomotic site) and IV (abrupt cutoff at the anastomotic site with nonvisualization of the right [or left] hepatic artery distal to the anastomosis) were regarded as the diagnostic criteria for hepatic artery stenosis, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MR angiography were 100%, 74%, 29%, 100%, and 77%, respectively. In the portal vein, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MR angiography were 100%, 84%, 35%, 100%, and 85%, respectively, when grades III (narrowing [> 50%] without poststenotic dilatation) and IV (narrowing [> 50%] with poststenotic dilatation) were defined as criteria for portal vein stenosis. CONCLUSION: MR angiography was sensitive but not specific in the detection of significant vascular stenosis after living related liver transplantation. However, normal MR angiography findings reliably exclude the possibility of significant stenosis.