Effect of Home-Based Transcranial Direct Current Stimulation on Cognitive Function in Patients with Mild Cognitive Impairment: A Two-Week Intervention.

PURPOSE: Repeated transcranial direct current stimulation (tDCS) is expected to have the potential to improve cognitive function in patients with mild cognitive impairment (MCI). We aimed to evaluate the efficacy and safety of at-home tDCS for elderly patients with MCI. MATERIALS AND METHODS: Patients aged 60-80 years, who maintained normal daily living but reported objective memory impairments, were enrolled. Active or sham stimulations were applied to the dorsal frontal cortex (left: anode; right: cathode) at home for 2 weeks. Changes in cognitive function were assessed using visual recognition tasks and the Mini-Mental State Exam (MMSE), and safety and efficacy were assessed using self-reports and a remote monitoring application. RESULTS: Of the 19 participants enrolled, 12 participants were included in the efficacy analysis. Response times and MMSE scores significantly improved after active stimulation compared to the sham stimulation; however, there were no significant differences in the proportion of correct responses. The mean compliance of the efficacy group was 97.5%±4.1%. Three participants experienced burns, but no permanent sequelae remained. CONCLUSION: This preliminary result suggests that home-based tDCS may be a promising treatment option for MCI patients; however, it requires more attention and technological development to address safety concerns. CLINICAL TRIAL REGISTRATION: Clinical Research Information Service (CRIS), KCT0002721.

Clinical Features of Delirium among Patients in the Intensive Care Unit According to Motor Subtype Classification: A Retrospective Longitudinal Study.

PURPOSE: Delirium in the intensive care unit (ICU) poses a significant safety and socioeconomic burden to patients and caregivers. However, invasive interventions for managing delirium have severe drawbacks. To reduce unnecessary interventions during ICU hospitalization, we aimed to investigate the features of delirium among ICU patients according to the occurrence of hypoactive symptoms, which are not expected to require invasive intervention. MATERIALS AND METHODS: Psychiatrists assessed all patients with delirium in the ICU during hospitalization. Patients were grouped into two groups: a "non-hypoactive" group that experienced the non-hypoactive motor subtype once or more or a "hypoactive only" group that only experienced the hypoactive motor subtype. Clinical variables routinely gathered for clinical management were collected from electronic medical records. Group comparisons and logistic regression analyses were conducted. RESULTS: The non-hypoactive group had longer and more severe delirium episodes than the hypoactive only group. Although the non-hypoactive group was prescribed more antipsychotics and required restraints longer, the hypoactive only group also received both interventions. In multivariable logistic regression analysis, BUN [odds ratio (OR): 0.993, pH OR: 0.202], sodium (OR: 1.022), RASS score (OR: 1.308) and whether restraints were applied [OR: 1.579 (95% confidence interval 1.194-2.089), p<0.001] were significant predictors of hypoactive only group classification. CONCLUSION: Managing and predicting delirium patients based on whether patients experienced non-hypoactive delirium may be clinically important. Variables obtained during the initial 48 hours can be used to determine which patients are likely to require invasive interventions.

The Relationship Between the Big Five Personality Traits and the Theory of Planned Behavior in Using Mindfulness Mobile Apps: Cross-sectional Survey.

BACKGROUND: Mindfulness has emerged as a promising approach toward improving mental health. Interest in mindfulness mobile app services has also increased in recent years. Understanding the determinants of mindfulness behavior is essential to predict people's utilization of mindfulness mobile apps and beneficial for developing and implementing relevant intervention strategies. Nevertheless, little has been done to determine the predictors of mindfulness behavior. OBJECTIVE: This study investigates the association between the Big Five personality traits and the Theory of Planned Behavior (TPB) variables in the context of using mindfulness mobile apps to explore the potential indirect effects of conscientiousness and neuroticism on people's behavioral intention for mindfulness, mediated by their attitude toward mindfulness, subjective norm about mindfulness, and perceived behavior control over mindfulness. METHODS: The authors conducted an online, cross-sectional survey in December 2021. Structural equation modeling was conducted to evaluate the overall model fit and test possible linkages among conscientiousness, neuroticism, attitude toward mindfulness, subjective norm about mindfulness, perceived behavior control over mindfulness, and behavioral intention for mindfulness. Bootstrapping mediation analyses were also conducted to test the potential mediating effect in the model. RESULTS: A total of 297 Korean participants' responses (153 males and 144 females) were analyzed. The proposed model had a good fit. Conscientiousness was correlated with attitude toward mindfulness (ß=.384, P<.001), subjective norm about mindfulness (ß=.249, P<.001), and perceived behavior control over mindfulness (ß=.443, P<.001). Neuroticism was not correlated with attitude toward mindfulness (ß=-.072, P=.28), but was correlated with subjective norm about mindfulness (ß=.217, P=.003) and perceived behavior control over mindfulness (ß=-.235, P<.001). Attitude toward mindfulness (ß=.508, P<.001), subjective norm about mindfulness (ß=.132, P=.01), and perceived behavior control over mindfulness (ß=.540, P<.001) were separately correlated with behavioral intention for mindfulness. Conscientiousness was not directly correlated with behavioral intention for mindfulness (ß=-.082, P=.27), whereas neuroticism was directly correlated with behavioral intention for mindfulness (ß=.194, P=.001). Conscientiousness was indirectly linked with behavioral intention for mindfulness through attitude toward mindfulness (B=0.171, 95% CI 0.103-0.251) and perceived behavior control over mindfulness (B=0.198, 95% CI 0.132-0.273) but not through subjective norm about mindfulness (B=0.023, 95% CI -0.002 to 0.060). Neuroticism was indirectly linked with behavioral intention for mindfulness via perceived behavior control over mindfulness (B=-0.138, 95% CI -0.197 to -0.088) but not via subjective norm about mindfulness (B=0.021, 95% CI -0.002 to 0.059). CONCLUSIONS: The results show that the integration of the Big Five personality traits and TPB constructs is useful in predicting the use of mindfulness mobile apps. Focusing on conscientiousness and neuroticism in developing information dissemination and implementation strategies for enhancing mindfulness behavior using mobile apps may lead to the successful promotion of mindfulness mobile apps and adherence to mindfulness techniques.

A Chatbot for Perinatal Women's and Partners' Obstetric and Mental Health Care: Development and Usability Evaluation Study.

BACKGROUND: To motivate people to adopt medical chatbots, the establishment of a specialized medical knowledge database that fits their personal interests is of great importance in developing a chatbot for perinatal care, particularly with the help of health professionals. OBJECTIVE: The objectives of this study are to develop and evaluate a user-friendly question-and-answer (Q&A) knowledge database-based chatbot (Dr. Joy) for perinatal women's and their partners' obstetric and mental health care by applying a text-mining technique and implementing contextual usability testing (UT), respectively, thus determining whether this medical chatbot built on mobile instant messenger (KakaoTalk) can provide its male and female users with good user experience. METHODS: Two men aged 38 and 40 years and 13 women aged 27 to 43 years in pregnancy preparation or different pregnancy stages were enrolled. All participants completed the 7-day-long UT, during which they were given the daily tasks of asking Dr. Joy at least 3 questions at any time and place and then giving the chatbot either positive or negative feedback with emoji, using at least one feature of the chatbot, and finally, sending a facilitator all screenshots for the history of the day's use via KakaoTalk before midnight. One day after the UT completion, all participants were asked to fill out a questionnaire on the evaluation of usability, perceived benefits and risks, intention to seek and share health information on the chatbot, and strengths and weaknesses of its use, as well as demographic characteristics. RESULTS: Despite the relatively higher score of ease of learning (EOL), the results of the Spearman correlation indicated that EOL was not significantly associated with usefulness (ρ=0.26; P=.36), ease of use (ρ=0.19; P=.51), satisfaction (ρ=0.21; P=.46), or total usability scores (ρ=0.32; P=.24). Unlike EOL, all 3 subfactors and the total usability had significant positive associations with each other (all ρ>0.80; P<.001). Furthermore, perceived risks exhibited no significant negative associations with perceived benefits (ρ=-0.29; P=.30) or intention to seek (SEE; ρ=-0.28; P=.32) or share (SHA; ρ=-0.24; P=.40) health information on the chatbot via KakaoTalk, whereas perceived benefits exhibited significant positive associations with both SEE and SHA. Perceived benefits were more strongly associated with SEE (ρ=0.94; P<.001) than with SHA (ρ=0.70; P=.004). CONCLUSIONS: This study provides the potential for the uptake of this newly developed Q&A knowledge database-based KakaoTalk chatbot for obstetric and mental health care. As Dr. Joy had quality contents with both utilitarian and hedonic value, its male and female users could be encouraged to use medical chatbots in a convenient, easy-to-use, and enjoyable manner. To boost their continued usage intention for Dr. Joy, its Q&A sets need to be periodically updated to satisfy user intent by monitoring both male and female user utterances.

Which Visual Modality Is Important When Judging the Naturalness of the Agent (Artificial Versus Human Intelligence) Providing Recommendations in the Symbolic Consumption Context?

This study aimed to explore how the type and visual modality of a recommendation agent's identity affect male university students' (1) self-reported responses to agent-recommended symbolic brand in evaluating the naturalness of virtual agents, human, or artificial intelligence (AI) and (2) early event-related potential (ERP) responses between text- and face-specific scalp locations. Twenty-seven participants (M = 25.26, SD = 5.35) whose consumption was more motivated by symbolic needs (vs. functional) were instructed to perform a visual task to evaluate the naturalness of the target stimuli. As hypothesized, the subjective evaluation showed that they had lower attitudes and perceived higher unnaturalness when the symbolic brand was recommended by AI (vs. human). Based on this self-report, two epochs were segmented for the ERP analysis: human-natural and AI-unnatural. As revealed by P100 amplitude modulation on visual modality of two agents, their evaluation relied more on face image rather than text. Furthermore, this tendency was consistently observed in that of N170 amplitude when the agent identity was defined as human. However, when the agent identity was defined as AI, reversed N170 modulation was observed, indicating that participants referred more to textual information than graphical information to assess the naturalness of the agent.

Mobile App Use for Insomnia Self-Management in Urban Community-Dwelling Older Korean Adults: Retrospective Intervention Study.

BACKGROUND: As an evidence-based psychotherapy for treating insomnia, cognitive behavioral therapy for insomnia (CBT-I), which helps people with sleep problems to change their unhelpful sleep-related beliefs and habits, has been well-established in older adults. Recently, the utilization of mobile CBT-I apps has been getting attention from mental health professionals and researchers; however, whether mobile CBT-I apps are usable among older users has yet to be determined. OBJECTIVE: The aims of this study were to explore the relationships between subjective sleep quality and subjective memory complaints and depressive symptoms; to explore the relationship between perceived difficulty in mobile app use and usability of the mobile phone-based self-help CBT-I app, named MIND MORE, in urban community-dwelling Korean older adults; to compare changes in subjective sleep quality from pre-intervention to post-intervention, during which they used the mobile app over a 1-week intervention period; and evaluate adherence to the app. METHODS: During the 2-hour training program delivered on 1 day titled "Overcoming insomnia without medication: How to use the 'MIND MORE' mobile app for systematic self-management of insomnia" (pre-intervention), 41 attendants were asked to gain hands-on experience with the app facilitated by therapists and volunteer workers. They were then asked to complete questionnaires on sociodemographic characteristics, subjective evaluation of mental health status (ie, depression, memory loss and impairment, and sleep problems), and app usability. For the 1-week home-based self-help CBT-I using the app (post-intervention), 9 of the 41 program attendants, who had already signed up for the pre-intervention, were guided to complete the given questionnaires on subjective evaluation of sleep quality after the 1-week intervention, specifically 8 days after the training program ended. RESULTS: Due to missing data, 40 of 41 attendants were included in the data analysis. The main findings of this study were as follows. First, poor subjective sleep quality was associated with higher ratings of depressive symptoms (40/40; ρ=.60, P<.001) and memory complaints (40/40; ρ=.46, P=.003) at baseline. Second, significant improvements in subjective sleep quality from pre-intervention to post-intervention were observed in the older adults who used the MIND MORE app only for the 1-week intervention period (9/9; t8=3.74, P=.006). Third, apart from the program attendants who did not have a smartphone (2/40) or withdrew from their MIND MORE membership (3/40), those who attended the 1-day sleep education program adhered to the app from at least 2 weeks (13/35, 37%) to 8 weeks (2/35, 6%) without any further contact. CONCLUSIONS: This study provides empirical evidence that the newly developed MIND MORE app not only is usable among older users but also could improve subjective sleep quality after a 1-week self-help intervention period.

Reducing food waste in residential complexes using a pilot-scale on-site system.

A pilot-scale on-site system combining biological treatment and a drying stage was applied to achieve mass reduction of food waste (FW) at an urban residential complex. The effectiveness of biodegrading the organic portion of FW via microorganisms existing in FW improved by 38.80% by controlling rates of FW loading and air-flow. In one stage of the on-site biological treatment, the major bacterial community was identified to be mesophilic and facultative; Lactobacillus was the most dominant genus, accounting for 78.1% of bacterial community. Total mass reduction of FW approached 90.15% by increasing removal of both moisture and the organic portion of FW. In addition, the solids and liquids of the final by-products have the potential to be recycled into resources such as fertilizer, a bio-solid refuse fuel or external carbon sources for wastewater treatment plants. The proposed decentralized system offers practical and environmental approaches for FW management in residential complexes.

Medical Help-Seeking Strategies for Perinatal Women With Obstetric and Mental Health Problems and Changes in Medical Decision Making Based on Online Health Information: Path Analysis.

BACKGROUND: Previous studies have revealed that most pregnant women rarely discuss informal information found on the internet with health professionals and have frequently expressed concerns for medical experts' reactions to the online information they shared, as well as the lack of time to consult the medical experts in general. To date, little information is available on the effect of individual differences in utilizing medical help-seeking strategies on their medical decisions during the perinatal period. OBJECTIVE: The objectives of this study were (1) to determine associations among perinatal women's medical help-seeking strategies, changes in medical decision making, and online health information utilization with a focus on the mediating effect of self-efficacy in perinatal health literacy on the intent to consult health professionals, and (2) to clarify these associations in perinatal women with two different medical problems: obstetric and mental health. METHODS: A total of 164 perinatal women aged 24 to 47 years (mean 34.64, SD 3.80) repeatedly completed the Problem Solving in Medicine and Online Health Information Utilization questionnaires to examine the moderating effect of two types of medical problems on their decision-making processes. To validate the hypothesized relationships in the proposed conceptual model encompassing obstetric and mental health problem-solving models, path analyses were performed. RESULTS: This study found that some perinatal women, who use an online informal medical help-seeking (OIMH) strategy, would be more likely to change their medical decisions based only on internet-based information without consulting health professionals (P<.001), compared to other women using different medical help-seeking strategies. Particularly, this concern is significantly prevalent when encountering obstetric problems during the perinatal period (obstetric problem-solving: P<.001; mental health problem-solving: P=.02). Furthermore, perinatal women with mental health issues using the OIMH strategy showed a significant difference in intent to consult health professionals based on online health information when the medical problem they had to solve was different (obstetric problem-solving: P=.94; mental health problem-solving: P=.003). CONCLUSIONS: Despite the positive mediating effects of perinatal women's enhanced health literacy on the intent to discuss personal medical issues with health professionals based on online health information, the strategy used is of fundamental importance for understanding their help-seeking and decision-making processes during the perinatal period. Beyond a short consultation to steer patients quickly and authoritatively towards an obstetric doctor's choice of action, it is recommended in this study that obstetricians attempt to provide their patients with needed context for the information found online. To fully explain this information with an open mind, they should actively develop or support information and communications technology (ICT)-based health information services.

Response Time as an Implicit Self-Schema Indicator for Depression Among Undergraduate Students: Preliminary Findings From a Mobile App-Based Depression Assessment.

BACKGROUND: Response times to depressive symptom items in a mobile-based depression screening instrument has potential as an implicit self-schema indicator for depression but has yet to be determined; the instrument was designed to readily record depressive symptoms experienced on a daily basis. In this study, the well-validated Korean version of the Center for Epidemiologic Studies Depression Scale-Revised (K-CESD-R) was adopted. OBJECTIVE: The purpose of this study was to investigate the relationship between depression severity (ie, explicit measure: total K-CESD-R Mobile scores) and the latent trait of interest in schematic self-referent processing of depressive symptom items (ie, implicit measure: response times to items in the K-CESD-R Mobile scale). The purpose was to investigate this relationship among undergraduate students who had never been diagnosed with, but were at risk for, major depressive disorder (MDD) or comorbid MDD with other neurological or psychiatric disorders. METHODS: A total of 70 participants-36 males (51%) and 34 females (49%)-aged 19-29 years (mean 22.66, SD 2.11), were asked to complete both mobile and standard K-CESD-R assessments via their own mobile phones. The mobile K-CESD-R sessions (binary scale: yes or no) were administered on a daily basis for 2 weeks. The standard K-CESD-R assessment (5-point scale) was administered on the final day of the 2-week study period; the assessment was delivered via text message, including a link to the survey, directly to participants' mobile phones. RESULTS: A total of 5 participants were excluded from data analysis. The result of polynomial regression analysis showed that the relationship between total K-CESD-R Mobile scores and the reaction times to the depressive symptom items was better explained by a quadratic trend-F (2, 62)=21.16, P<.001, R2=.41-than by a linear trend-F (1, 63)=25.43, P<.001, R2=.29. It was further revealed that the K-CESD-R Mobile app had excellent internal consistency (Cronbach alpha=.94); at least moderate concurrent validity with other depression scales, such as the Korean version of the Quick Inventory for Depressive Symptomatology-Self Report (ρ=.38, P=.002) and the Patient Health Questionnaire-9 (ρ=.48, P<.001); a high adherence rate for all participants (65/70, 93%); and a high follow-up rate for 10 participants whose mobile or standard K-CESD-R score was 13 or greater (8/10, 80%). CONCLUSIONS: As hypothesized, based on a self-schema model for depression that represented both item and person characteristics, the inverted U-shaped relationship between the explicit and implicit self-schema measures for depression showed the potential of an organizational breakdown; this also showed the potential for a subsequent return to efficient processing of schema-consistent information along a continuum, ranging from nondepression through mild depression to severe depression. Further, it is expected that the updated K-CESD-R Mobile app can play an important role in encouraging people at risk for depression to seek professional follow-up for mental health care.

Effect of home-based transcranial direct current stimulation (tDCS) on cognitive function in patients with mild cognitive impairment: a study protocol for a randomized, double-blind, cross-over study.

BACKGROUND: The possible effect of transcranial direct current stimulation (tDCS) in improving cognitive function is clear from studies involving pre-dementia stage mild cognitive impairment (MCI). However, the application of tDCS in actual clinical practice entails repeated hospital visits almost every day for treatment. The objective of this study is to confirm the possibility of self-application of tDCS at home by elderly patients with declined cognitive function and the significant clinical effect of tDCS administered at home. METHODS/DESIGN: This study will be conducted in 20 elderly people aged 60 to 80 years with complaints of subjective memory impairment while maintaining general functions with limited activities of daily living. This study involves a cross-over design that will include 2-week active or sham stimulation of both dorsolateral prefrontal cortexes (left, anode; right, cathode) randomly with a 2-week wash-out phase. Changes in cognitive function will be evaluated using visual recognition tasks and neuropsychological tests. In this study, tDCS will be carried out by each patient at his/her home and its safety and suitability will be evaluated. DISCUSSION: In this study, patients will apply a portable tDCS, developed for home use, for more than 2 weeks. Such studies can contribute to the use of tDCS as a realistic therapy. In addition, the utility of home-based tDCS will be confirmed by application of tDCS at home by the elderly with declined cognitive function. Furthermore, confirmation of tDCS as a significant therapeutic method can facilitate treatment of Alzheimer's dementia at an early stage, including MCI. TRIAL REGISTRATION: Clinical Research Information Service (CRIS), KCT0002721 . Registered on 9 March 2018.

Discrepancies of Implicit and Explicit Self-Esteem as Predictors of Attributional Bias and Paranoia.

OBJECTIVE: The current study aimed to examine the association of implicit self-esteem, explicit self-esteem and their interaction with paranoia and attributional bias. The relationship of the size and the direction of the discrepancy between implicit and explicit self-esteem with paranoia and attributional bias was examined. METHODS: A total of 128 female college students participated. We administered the Implicit Association Test to assess implicit self-esteem, and the Rosenberg Self-Esteem Scale to measure explicit self-esteem. Paranoia Scale was used, and the attributional bias was assessed using the Ambiguous Intentions Hostility Questionnaire. RESULTS: Results showed that explicit but not implicit self-esteem was negatively associated with paranoia, blame bias and hostility perception bias in ambiguous situations. The interaction of implicit and explicit self-esteem was associated with hostility perception in ambiguous situations. As for the discrepancy, the size of the discrepancy between implicit and explicit self-esteem was positively associated with hostility perception in ambiguous situations. Moreover, the direction of the discrepancy was specifically relevant: damaged self-esteem (high implicit and low explicit self-esteem) was associated with increased levels of paranoia, blame bias and hostility perception in ambiguous situations. CONCLUSION: These findings provide new insights into the role of the implicit and explicit self-esteem in attributional bias and paranoia and point to damaged self-esteem as a possible vulnerability marker for illogical attribution of blaming others and perceiving hostility in social situations.

Involuntary Attention Restoration During Exposure to Mobile-Based 360° Virtual Nature in Healthy Adults With Different Levels of Restorative Experience: Event-Related Potential Study.

BACKGROUND: With the global trend of urbanization, there are increasing reports of a possible association between decreased exposure to nature and increased occurrence of mental disorders. New 360° virtual reality (VR) technology using smartphones and portable VR glasses can overcome spatial and temporal limitations to help people deal with mental fatigue in everyday life. OBJECTIVE: On the basis of attention restoration theory (ART), this study aimed to investigate whether the amplitude of the mismatch negativity (MMN)/P3a complex could act as an event-related potential (ERP) biomarker of involuntary attention restoration during exposure to 360° virtual nature in healthy young adults with different levels of restorative VR experience. METHODS: A total of 40 healthy adults completed prequestionnaires on demographics and simulator sickness and postquestionnaires on simulator sickness and perceived restorativeness before and after exposure to virtual nature, respectively. During the VR exposure, brain activity was measured by electroencephalography as participants were asked to conduct a 2-tone passive auditory oddball task. RESULTS: The amplitude and latency of the MMN/P3a complex were compared between individuals reporting a highly restorative experience and those reporting a less restorative experience. Although viewing a virtual nature environment, the high restorative group (N=19) exhibited significantly reduced P3a amplitudes compared with the low restorative group (N=20; t38=2.57; P=.02; d=0.59). Particularly, a moderate but significant negative correlation was found between the self-reported restorativeness scores and the P3a amplitudes at the fronto-central region (r=-.38; P=.02). However, the latency of the MMN/P3a complex did not significantly differ between the 2 groups (auditory mismatch negativity: t38=-1.47; P=.15 and P3a: t38=-0.31; P=.76). CONCLUSIONS: Considering individuals' restorative experience, the amplitude of the fronto-central MMN/P3a complex can potentially be employed as a distinct ERP component of interest in involuntary attention restoration during virtual nature experience in healthy young adults. The findings for the 360° virtual nature experience seem to be consistent with those of previous ERP studies on the effects of meditation practice. This study extends the findings of previous ART and ERP studies of real-world meditation, restoration, and mental fatigue management into the virtual world created by mobile phone-based VR glasses and 360° video content.

Development and evaluation of a mobile-optimized daily self-rating depression screening app: A preliminary study.

The aims of this study were to design a mobile app that would record daily self-reported Korean version of the Center for Epidemiologic Studies Depression Scale-Revised (K-CESD-R) ratings in a "Yes" or "No" format, develop two different algorithms for converting mobile K-CESD-R scores in a binary format into scores in a 5-point response format, and determine which algorithm would be more appropriately applied to the newly developed app. Algorithm (A) was designed to improve the scoring system of the 2-week delayed retrospective recall-based original K-CESD-R scale, and algorithm (B) was designed to further refine the scoring of the 24-hour delayed prospective recall-based mobile K-CESD-R scale applied with algorithm (A). To calculate total mobile K-CESD-R scores, each algorithm applied certain cut-off criteria for a 5-point scale with different inter-point intervals, defined by the ratio of the total number of times that users responded "Yes" to each item to the number of days that users reported daily depressive symptom ratings during the 2-week study period. Twenty participants were asked to complete a K-CESD-R Mobile assessment daily for 2 weeks and an original K-CESD-R assessment delivered to their e-mail accounts at the end of the 2-week study period. There was a significant difference between original and mobile algorithm (B) scores but not between original and mobile algorithm (A) scores. Of the 20 participants, 4 scored at or above the cut-off criterion (≥13) on either the original K-CESD-R (n = 4) or the mobile K-CESD-R converted with algorithm (A) (n = 3) or algorithm (B) (n = 1). However, all participants were assessed as being below threshold for a diagnosis of a mental disorder during a clinician-administered diagnostic interview. Therefore, the K-CESD-R Mobile app using algorithm (B) could be a more potential candidate for a depression screening tool than the K-CESD-R Mobile app using algorithm (A).

Beyond the real world: attention debates in auditory mismatch negativity.

The aim of this study was to address the potential for the auditory mismatch negativity (aMMN) to be used in applied event-related potential (ERP) studies by determining whether the aMMN would be an attention-dependent ERP component and could be differently modulated across visual tasks or virtual reality (VR) stimuli with different visual properties and visual complexity levels. A total of 80 participants, aged 19-36 years, were assigned to either a reading-task (21 men and 19 women) or a VR-task (22 men and 18 women) group. Two visual-task groups of healthy young adults were matched in age, sex, and handedness. All participants were instructed to focus only on the given visual tasks and ignore auditory change detection. While participants in the reading-task group read text slides, those in the VR-task group viewed three 360° VR videos in a random order and rated how visually complex the given virtual environment was immediately after each VR video ended. Inconsistent with the finding of a partial significant difference in perceived visual complexity in terms of brightness of virtual environments, both visual properties of distance and brightness showed no significant differences in the modulation of aMMN amplitudes. A further analysis was carried out to compare elicited aMMN amplitudes of a typical MMN task and an applied VR task. No significant difference in the aMMN amplitudes was found across the two groups who completed visual tasks with different visual-task demands. In conclusion, the aMMN is a reliable ERP marker of preattentive cognitive processing for auditory deviance detection.

Sequential Combination of Electro-Fenton and Electrochemical Chlorination Processes for the Treatment of Anaerobically-Digested Food Wastewater.

A two-stage sequential electro-Fenton (E-Fenton) oxidation followed by electrochemical chlorination (EC) was demonstrated to concomitantly treat high concentrations of organic carbon and ammonium nitrogen (NH4+-N) in real anaerobically digested food wastewater (ADFW). The anodic Fenton process caused the rapid mineralization of phenol as a model substrate through the production of hydroxyl radical as the main oxidant. The electrochemical oxidation of NH4+ by a dimensionally stable anode (DSA) resulted in temporal concentration profiles of combined and free chlorine species that were analogous to those during the conventional breakpoint chlorination of NH4+. Together with the minimal production of nitrate, this confirmed that the conversion of NH4+ to nitrogen gas was electrochemically achievable. The monitoring of treatment performance with varying key parameters (e.g., current density, H2O2 feeding rate, pH, NaCl loading, and DSA type) led to the optimization of two component systems. The comparative evaluation of two sequentially combined systems (i.e., the E-Fenton-EC system versus the EC-E-Fenton system) using the mixture of phenol and NH4+ under the predetermined optimal conditions suggested the superiority of the E-Fenton-EC system in terms of treatment efficiency and energy consumption. Finally, the sequential E-Fenton-EC process effectively mineralized organic carbon and decomposed NH4+-N in the real ADFW without external supply of NaCl.

Effect of Fe-chelating complexes on a novel M2FC performance with ferric chloride and ferricyanide catholytes.

As an effort to better utilize the microbial fuel cell (MFC) technology, we previously proposed an innovative MFC system named M2FC consisting of ferric-based MFC part and ferrous-based fuel cell (FC) part. In this reactor, ferric ion, the catholyte in the MFC part, was efficiently regenerated by the FC part with the generation of additional electricity. When both units were operated separately, the ferric-based MFC part produced approximately 1360 mW m(-2) of power density with FeCl(3) as catholyte and Fe-citrate as anolyte. The ferrous-based FC part with FeCl(3) as catholyte and Fe-EDTA as anolyte displayed the highest power density (1500 mW m(-2)), while that with ferricyanide as catholyte and Fe-noligand as anolyte had the lowest power density (380 mW m(-2)). The types of catholytes and chelating complexes as anolyte were found to play important roles in the reduction of ferric ions and oxidation of ferrous ion. Linear sweep voltammetry results supported that the cathode electrolytes were electrically active and these agreed well with the M2FC reactor performance. These results clearly showed that ligands played critical role in the efficiency and rate for recycling iron ion and thus the M2FC performance.

Development of a hybrid microbial fuel cell (MFC) and fuel cell (FC) system for improved cathodic efficiency and sustainability: the M2FC reactor.

In an effort to improve the efficiency and sustainability of microbial fuel cell (MFC) technology, a novel MFC reactor, the M2FC, was constructed by combining a ferric-based MFC with a ferrous-based fuel cell (FC). In this M2FC reactor, ferric ion, the catholyte in the MFC component, is regenerated by the FC system with the generation of additional electricity. When the MFC component was operated separately, the electricity generation was maintained for only 98 h due to the depletion of ferric ion in the catholyte. In combination with the fuel cell, however, the production of power was sustained because ferric ion was continually replenished from ferrous ion in the FC component. Moreover, the regeneration process of ferric ion by the FC produced additional energy. The M2FC reactor yielded a power density of up to 2 W m(-2) (or time-averaged value of approximately 650 mW m(-2)), density up to 20 times (or approximately six times based on time-averaged value) higher than the corresponding MFC system.

Effect of formation of biofilms and chemical scale on the cathode electrode on the performance of a continuous two-chamber microbial fuel cell.

A two-chamber MFC system was operated continuously for more than 500 days to evaluate effects of biofilm and chemical scale formation on the cathode electrode on power generation. A stable power density of 0.57 W/m(2) was attained after 200 days operation. However, the power density decreased drastically to 0.2 W/m(2) after the cathodic biofilm and chemical scale were removed. As the cathodic biofilm and chemical scale partially accumulated on the cathode, the power density gradually recovered with time. Microbial community structure of the cathodic biofilm was analyzed based on 16S rRNA clone libraries. The clones closely related to Xanthomonadaceae bacterium and Xanthomonas sp. in the Gammaproteobacteria subdivision were most frequently retrieved from the cathodic biofilm. Results of the SEM-EDX analysis revealed that the cation species (Na(+) and Ca(2+)) were main constituents of chemical scale, indicating that these cations diffused from the anode chamber through the Nafion membrane. However, an excess accumulation of the biofilm and chemical scale on the cathode exhibited adverse effects on the power generation due to a decrease in the active cathode surface area and an increase in diffusion resistance for oxygen. Thus, it is important to properly control the formation of chemical scale and biofilm on the cathode during long-term operation.

Characterization of electrochemical activity of a strain ISO2-3 phylogenetically related to Aeromonas sp. isolated from a glucose-fed microbial fuel cell.

The microbial communities associated with electrodes in closed and open circuit microbial fuel cells (MFCs) fed with glucose were analyzed by 16S rRNA approach and compared. The comparison revealed that bacteria affiliated with the Aeromonas sp. within the Gammaproteobacteria constituted the major population in the closed circuit MFC (harvesting electricity) and considered to play important roles in current generation. We, therefore, attempted to isolate the dominant bacteria from the anode biofilm, successfully isolated a Fe (III)-reducing bacterium phylogenetically related to Aeromonas sp. and designated as strain ISO2-3. The isolated strain ISO2-3 could grow and concomitantly produce current (max. 0.24 A/m(2)) via oxidation of glucose or hydrogen with an electrode serving as the sole electron acceptor. The strain could ferment glucose, but generate less electrical current. Cyclic voltammetry supported the strain ISO2-3 was electrically active and likely to transfer electrons to the electrode though membrane-associated compounds (most likely c-type cytochrome). This mechanism requires intimate contact with the anode surface. Scanning electron microscopy revealed that the strain ISO2-3 developed multiplayer biofilms on the anode surface and also produced anchor-like filamentous appendages (most likely pili) that may promote long-range electron transport across the thick biofilm.

Continuous power generation and microbial community structure of the anode biofilms in a three-stage microbial fuel cell system.

A mediator-less three-stage two-chamber microbial fuel cell (MFC) system was developed and operated continuously for more than 1.5 years to evaluate continuous power generation while treating artificial wastewater containing glucose (10 mM) concurrently. A stable power density of 28 W/m(3) was attained with an anode hydraulic retention time of 4.5 h and phosphate buffer as the cathode electrolyte. An overall dissolved organic carbon removal ratio was about 85%, and coulombic efficiency was about 46% in this MFC system. We also analyzed the microbial community structure of anode biofilms in each MFC. Since the environment in each MFC was different due to passing on the products to the next MFC in series, the microbial community structure was different accordingly. The anode biofilm in the first MFC consisted mainly of bacteria belonging to the Gammaproteobacteria, identified as Aeromonas sp., while the Firmicutes dominated the anode biofilms in the second and third MFCs that were mainly fed with acetate. Cyclic voltammetric results supported the presence of a redox compound(s) associated with the anode biofilm matrix, rather than mobile (dissolved) forms, which could be responsible for the electron transfer to the anode. Scanning electron microscopy revealed that the anode biofilms were comprised of morphologically different cells that were firmly attached on the anode surface and interconnected each other with anchor-like filamentous appendages, which might support the results of cyclic voltammetry.