Neuroanatomical and neurocognitive correlates of delusion in Alzheimer's disease and mild cognitive impairment.

BACKGROUND: Neuropsychiatric symptoms and delusions are highly prevalent among people with dementia. However, multiple roots of neurobiological bases and shared neural basis of delusion and cognitive function remain to be characterized. By utilizing a fine-grained multivariable approach, we investigated distinct neuroanatomical correlates of delusion symptoms across a large population of dementing illnesses. METHODS: In this study, 750 older adults with mild cognitive impairment and Alzheimer's disease completed brain structural imaging and neuropsychological assessment. We utilized principal component analysis followed by varimax rotation to identify the distinct multivariate correlates of cortical thinning patterns. Five of the cognitive domains were assessed whether the general cognitive abilities mediate the association between cortical thickness and delusion. RESULTS: The result showed that distributed thickness patterns of temporal and ventral insular cortex (component 2), inferior and lateral prefrontal cortex (component 1), and somatosensory-visual cortex (component 5) showed negative correlations with delusions. Subsequent mediation analysis showed that component 1 and 2, which comprises inferior frontal, anterior insula, and superior temporal regional thickness accounted for delusion largely through lower cognitive functions. Specifically, executive control function assessed with the Trail Making Test mediated the relationship between two cortical thickness patterns and delusions. DISCUSSION: Our findings suggest that multiple distinct subsets of brain regions underlie the delusions among older adults with cognitive impairment. Moreover, a neural loss may affect the occurrence of delusion in dementia largely due to impaired general cognitive abilities.

Exploring transfer effects on memory and its neural mechanisms through a computerized cognitive training in mild cognitive impairment: randomized controlled trial.

BACKGROUND: Computerized cognitive training (CCT) has been proposed as a potential therapy for cognitive decline. One of the benefits of CCT is a transfer effect, but its mechanism on the memory domain is unclear. This study aimed to investigate the transfer effect of non-memory multidomain CCT on the memory domain and its neural basis in patients with mild cognitive impairment (MCI) through a randomized controlled trial. METHODS: Patients with MCI recruited from memory clinics were randomly assigned to either the CCT or the control group. The CCT group received multidomain CCT training excluding memory training, while the control group read educational books with learning-based quizzes twice a week for 8 weeks. Participants underwent memory tests yielding a composite score, other cognitive domain tests, non-cognitive scales, and resting-state functional magnetic resonance imaging (rsfMRI), at baseline and after intervention. Within- and between-group comparisons, group × time interactions, and seed-to-voxel analyses in memory-involving brain networks were performed. RESULTS: The CCT group showed improvement over the control group in memory domain (Group × time, F = 5.87, P = 0.03, η2 = 0.31), which was related with the increased connectivity in the hippocampal-frontal and fusiform-occipital network. No other cognitive and non-cognitive symptoms differed between groups after adjusting for covariates. CONCLUSION: Eight weeks of multidomain CCT without memory training improved memory function and restored functional network in the hippocampal and medial temporal region in MCI patients. These results can provide evidence for the transferring ability of CCT on memory functioning with its neural basis.

Vasomotion in human arteries and their regulations based on ion channel regulations: 10 years study.

Vasomotion is the oscillation of vascular tone which gives rise to flow motion of blood into an organ. As is well known, spontaneous contractile organs such as heart, GI, and genitourinary tract produce rhythmic contraction. It imposes or removes pressure on their vessels alternatively for exchange of many substances. It was first described over 150 years ago, however the physiological mechanism and pathophysiological implications are not well understood. This study aimed to elucidate underlying mechanisms and physiological function of vasomotion in human arteries. Conventional contractile force measurement, immunohistochemistry, and Western blot analysis were employed to study human left gastric artery (HLGA) and uterine arteries (HUA). RESULTS: Circular muscle of HLGA and/or HUA produced sustained tonic contraction by high K+ (50 mM) which was blocked by 2 µM nifedipine. Stepwise stretch and high K+ produced nerve-independent spontaneous contraction (vasomotion) (around 45% of tested tissues). Vasomotion was also produced by application of BayK 8644, 5-HT, prostagrandins, oxytocin. It was blocked by nifedipine (2 µM) and blockers of intracellular Ca2+ stores. Inhibitors of Ca2+ -activated Cl- channels (DIDS and/or niflumic acid) and ATP-sensitive K+ (KATP ) channels inhibited vasomotion reversibly. Metabolic inhibition by sodium cyanide (NaCN) and several neuropeptides also regulated vasomotion in KATP channel-sensitive and -insensitive manner. Finally, we identified TMEM16A Ca2+ -activated Cl- channels and subunits of KATP channels (Kir 6.1/6.2 and sulfonylurea receptor 2B [SUR2B]), and c-Kit positivity by Western blot analysis. We conclude that vasomotion is sensitive to TMEM16A Ca2+ -activated Cl- channels and metabolic changes in human gastric and uterine arteries. Vasomotion might play an important role in the regulation of microcirculation dynamics even in pacemaker-related autonomic contractile organs in humans.

In Situ Opto-Hydrodynamic Characterization of Lubricant-Infused Surface Degradation.

Vapor condensation is widely used in industrial systems due to its effective heat and mass transfer when compared to single-phase thermal transport. In particular, dropwise condensation can significantly enhance heat transfer performance due to rapid droplet shedding and promotion of additional nucleation sites for vapor condensation. Recently, lubricant-infused surfaces (LISs) composed of superhydrophobic structures infused with a low surface tension lubricant have been shown to effectively promote dropwise condensation of a variety of fluids by forming chemically and topographically homogeneous low-surface-energy surfaces. However, depletion of the infused lubricant remains a critical limitation to developing durable LISs which can sustain prolonged dropwise condensation. Moreover, the observed degradation is difficult to detect especially during active condensation on the surface. Here, we introduce an optical measurement technique to quantify in situ and in operando lubricant drainage from LISs. The optical method allows for non-invasive, instantaneous, and accurate prediction of the lifespan of LISs. The method implements the analysis of sample transient transparency, with depletion leading to exposure of the structure and increased light scattering. Our work demonstrates the logarithmic relation between the amount of the lubricant remaining in the LIS and the optical transmittance of the LIS, validating our unique technique for estimating the durability of LISs.

Genome-wide association study of occupational attainment as a proxy for cognitive reserve.

Occupational attainment, which represents middle-age cognitive activities, is a known proxy marker of cognitive reserve for Alzheimer's disease. Previous genome-wide association studies have identified numerous genetic variants and revealed the genetic architecture of educational attainment, another marker of cognitive reserve. However, the genetic architecture and heritability for occupational attainment remain elusive. We performed a large-scale genome-wide association study of occupational attainment with 248 847 European individuals from the UK Biobank using the proportional odds logistic mixed model method. In this analysis, we defined occupational attainment using the classified job levels formulated in the UK Standard Occupational Classification system considering the individual professional skill and academic level. We identified 30 significant loci (P < 5 × 10-8); 12 were novel variants, not associated with other traits. Among them, four lead variants were associated with genes expressed in brain tissues by expression quantitative trait loci mapping from 10 brain regions: rs13002946, rs3741368, rs11654986 and rs1627527. The single nucleotide polymorphism-based heritability was estimated to be 8.5% (standard error of the mean = 0.004) and partitioned heritability was enriched in the CNS and brain tissues. Genetic correlation analysis showed shared genetic backgrounds between occupational attainment and multiple traits, including education, intelligence, leisure activities, life satisfaction and neuropsychiatric disorders. In two-sample Mendelian randomization analysis, we demonstrated that high occupation levels were associated with reduced risk for Alzheimer's disease [odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.65-0.92 in inverse variance weighted method; OR = 0.73, 95% CI = 0.57-0.92 in the weighted median method]. This causal relationship between occupational attainment and Alzheimer's disease was robust in additional sensitivity analysis that excluded potentially pleiotropic single nucleotide polymorphisms (OR = 0.72, 95% CI = 0.57-0.91 in the inverse variance weighted method; OR = 0.72, 95% CI = 0.53-0.97 in the weighted median method). Multivariable Mendelian randomization confirmed that occupational attainment had an independent effect on the risk for Alzheimer's disease even after taking educational attainment into account (OR = 0.72, 95% CI = 0.54-0.95 in the inverse variance weighted method; OR = 0.68, 95% CI = 0.48-0.97 in the weighted median method). Overall, our analyses provide insights into the genetic architecture of occupational attainment and demonstrate that occupational attainment is a potential causal protective factor for Alzheimer's disease as a proxy marker of cognitive reserve.

Polypropylene nanoplastic exposure leads to lung inflammation through p38-mediated NF-κB pathway due to mitochondrial damage.

BACKGROUND: Polypropylene (PP) is used in various products such as disposable containers, spoons, and automobile parts. The disposable masks used for COVID-19 prevention mainly comprise PP, and the disposal of such masks is concerning because of the potential environmental pollution. Recent reports have suggested that weathered PP microparticles can be inhaled, however, the inhalation toxicology of PP microparticles is poorly understood. RESULTS: Inflammatory cell numbers, reactive oxygen species (ROS) production, and the levels of inflammatory cytokines and chemokines in PP-instilled mice (2.5 or 5 mg/kg) increased significantly compared to with those in the control. Histopathological analysis of the lung tissue of PP-stimulated mice revealed lung injuries, including the infiltration of inflammatory cells into the perivascular/parenchymal space, alveolar epithelial hyperplasia, and foamy macrophage aggregates. The in vitro study indicated that PP stimulation causes mitochondrial dysfunction including mitochondrial depolarization and decreased adenosine triphosphate (ATP) levels. PP stimulation led to cytotoxicity, ROS production, increase of inflammatory cytokines, and cell deaths in A549 cells. The results showed that PP stimulation increased the p-p38 and p-NF-κB protein levels both in vivo and in vitro, while p-ERK and p-JNK remained unchanged. Interestingly, the cytotoxicity that was induced by PP exposure was regulated by p38 and ROS inhibition in A549 cells. CONCLUSIONS: These results suggest that PP stimulation may contribute to inflammation pathogenesis via the p38 phosphorylation-mediated NF-κB pathway as a result of mitochondrial damage.

Textural and Volumetric Changes of the Temporal Lobes in Semantic Variant Primary Progressive Aphasia and Alzheimer's Disease.

BACKGROUND: Texture analysis may capture subtle changes in the gray matter more sensitively than volumetric analysis. We aimed to investigate the patterns of neurodegeneration in semantic variant primary progressive aphasia (svPPA) and Alzheimer's disease (AD) by comparing the temporal gray matter texture and volume between cognitively normal controls and older adults with svPPA and AD. METHODS: We enrolled all participants from three university hospitals in Korea. We obtained T1-weighted magnetic resonance images and compared the gray matter texture and volume of regions of interest (ROIs) between the groups using analysis of variance with Bonferroni posthoc comparisons. We also developed models for classifying svPPA, AD and control groups using logistic regression analyses, and validated the models using receiver operator characteristics analysis. RESULTS: Compared to the AD group, the svPPA group showed lower volumes in five ROIs (bilateral temporal poles, and the left inferior, middle, and superior temporal cortices) and higher texture in these five ROIs and two additional ROIs (right inferior temporal and left entorhinal cortices). The performances of both texture- and volume-based models were good and comparable in classifying svPPA from normal cognition (mean area under the curve [AUC] = 0.914 for texture; mean AUC = 0.894 for volume). However, only the texture-based model achieved a good level of performance in classifying svPPA and AD (mean AUC = 0.775 for texture; mean AUC = 0.658 for volume). CONCLUSION: Texture may be a useful neuroimaging marker for early detection of svPPA in older adults and its differentiation from AD.

Circadian rest-activity rhythm and longitudinal brain changes underlying late-life cognitive decline.

AIM: The neurobiological substrates underlying the relationship of circadian rest-activity rhythm (RAR) alteration with accelerated late-life cognitive decline are not clearly understood. In the present study, the longitudinal relationship of objectively measured circadian RAR with in vivo Alzheimer disease (AD) pathologies and cerebrovascular injury was investigated in older adults without dementia. METHODS: The present study included 129 participants without dementia who participated in the KBASE (Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer's Disease) cohort. All participants underwent actigraphy at baseline and two consecutive [11 C] Pittsburgh compound-B positron emission tomography (PET), [18 F] fluorodeoxyglucose-PET, magnetic resonance imaging, and Mini-Mental State Examination (MMSE) at baseline and at a 2-year follow-up assessment. The associations of circadian RAR with annualized change in neuroimaging measures including global amyloid-beta retention, AD-signature region cerebral glucose metabolism (AD-CM), and white matter hyperintensity volume were examined. RESULTS: Delayed acrophase at baseline was significantly associated with greater annualized decline of AD-CM over a 2-year period, but not with that of other neuroimaging measures. In contrast, other circadian RAR parameters at baseline had no association with annualized change of any neuroimaging measures. Annualized decline of AD-CM was also significantly positively associated with the annual change in MMSE scores. Furthermore, a mediation analysis showed that greater reduction in AD-CM mediated the effect of delayed acrophase at baseline on faster decline of MMSE score. CONCLUSION: The findings indicate that delayed acrophase in late life may cause or predict hypometabolism at AD-signature brain regions, which underlies cognitive decline in the near future.

Facial Expressions Track Depressive Symptoms in Old Age.

Facial expressions play a crucial role in the diagnosis of mental illnesses characterized by mood changes. The Facial Action Coding System (FACS) is a comprehensive framework that systematically categorizes and captures even subtle changes in facial appearance, enabling the examination of emotional expressions. In this study, we investigated the association between facial expressions and depressive symptoms in a sample of 59 older adults without cognitive impairment. Utilizing the FACS and the Korean version of the Beck Depression Inventory-II, we analyzed both "posed" and "spontaneous" facial expressions across six basic emotions: happiness, sadness, fear, anger, surprise, and disgust. Through principal component analysis, we summarized 17 action units across these emotion conditions. Subsequently, multiple regression analyses were performed to identify specific facial expression features that explain depressive symptoms. Our findings revealed several distinct features of posed and spontaneous facial expressions. Specifically, among older adults with higher depressive symptoms, a posed face exhibited a downward and inward pull at the corner of the mouth, indicative of sadness. In contrast, a spontaneous face displayed raised and narrowed inner brows, which was associated with more severe depressive symptoms in older adults. These findings suggest that facial expressions can provide valuable insights into assessing depressive symptoms in older adults.

Weight loss and risk of dementia in individuals with versus without obesity.

INTRODUCTION: Using nationwide cohort data, we aimed to elucidate whether baseline obesity altered the relationship between loss in body mass index (BMI) or waist circumference (WC) and risk of dementia. METHODS: Among 9689 participants whose BMIs and WCs were repeatedly measured over 1 year, 1:1 propensity score matching was conducted between participants with and without obesity (n = 2976 per group, mean age 70.9). For each group, we explored the association between loss in BMI, or WC, and incidence of dementia during an approximately 4-year follow-up period. RESULTS: BMI loss was associated with an increased risk of all-cause dementia and Alzheimer's disease in participants without obesity; however, this association was absent in participants with obesity. WC loss was associated with decreased Alzheimer's disease risk only in participants with obesity. DISCUSSION: Only unfavorable loss (loss from non-obese state) in BMI, not WC, can be a metabolic biomarker of prodromal dementia.

Multiple Cognitive and Behavioral Factors Link Association Between Brain Structure and Functional Impairment of Daily Instrumental Activities in Older Adults.

OBJECTIVE: Functional impairment in daily activity is a cornerstone in distinguishing the clinical progression of dementia. Multiple indicators based on neuroimaging and neuropsychological instruments are used to assess the levels of impairment and disease severity; however, it remains unclear how multivariate patterns of predictors uniquely predict the functional ability and how the relative importance of various predictors differs. METHOD: In this study, 881 older adults with subjective cognitive complaints, mild cognitive impairment (MCI), and dementia with Alzheimer's type completed brain structural magnetic resonance imaging (MRI), neuropsychological assessment, and a survey of instrumental activities of daily living (IADL). We utilized the partial least square (PLS) method to identify latent components that are predictive of IADL. RESULTS: The result showed distinct brain components (gray matter density of cerebellar, medial temporal, subcortical, limbic, and default network regions) and cognitive-behavioral components (general cognitive abilities, processing speed, and executive function, episodic memory, and neuropsychiatric symptoms) were predictive of IADL. Subsequent path analysis showed that the effect of brain structural components on IADL was largely mediated by cognitive and behavioral components. When comparing hierarchical regression models, the brain structural measures minimally added the explanatory power of cognitive and behavioral measures on IADL. CONCLUSION: Our finding suggests that cerebellar structure and orbitofrontal cortex, alongside with medial temporal lobe, play an important role in the maintenance of functional status in older adults with or without dementia. Moreover, the significance of brain structural volume affects real-life functional activities via disruptions in multiple cognitive and behavioral functions.

Synergy effect of microwave annealing and high-pressure hydrogen annealing on Poly-Si thin-film transistor.

Grain boundary (GB) is a significant factor that deteriorates the transfer characteristics of poly-Si thin-film transistors (TFTs). In this study, we utilized the synergistic effect of microwave annealing (MWA) and high-pressure hydrogen annealing (HPHA) to effectively reduce grain boundary trap (GBT) density, resulting in improved field-effect mobility (µ) and subthreshold swing (SS). To investigate the synergistic effect of MWA and HPHA, the transfer characteristics of rapid thermal annealing and forming gas annealing devices were compared and analyzed as control devices. Furthermore, the mechanism of SS and mobility enhancement can be quantitatively understood by lowering the GB barrier height. In addition, Raman spectroscopy proved that poly-Si crystallinity was improved during MWA. Our results showed that MWA and HPHA play a vital role in reducing GBT density and improving poly-Si TFT characteristics.

Presence of Night Pain, Neuropathic Pain, or Depressive Disorder Does Not Adversely Affect Outcomes After Total Knee Arthroplasty: A Prospective Cohort Study.

BACKGROUND: A considerable proportion of patients warranting total knee arthroplasty (TKA) have night pain, neuropathic pain, and/or depressive disorder, which may not be resolved by TKA. This prospective, longitudinal cohort study aimed to document the prevalence of night pain, neuropathic pain, and depressive disorder in patients with advanced knee osteoarthritis undergoing TKA and to determine whether the specific coexisting pain and/or disorder at the time of TKA adversely affected postoperative outcomes. METHODS: In this study, 148 patients undergoing TKA were longitudinally evaluated. The presence of night pain, neuropathic pain (determined using Douleur Neuropathique 4 [DN4]) and depressive disorder (determined using the Patient Health Questionnaire-9 [PHQ-9]) was determined before and 6 weeks, 3 months and 1 year after TKA. In addition, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and EuroQol-5 Dimension (EQ-5D) scores were assessed before and 1 year after TKA. Potential associations of night pain, neuropathic pain, and/or depressive disorder with pre- and postoperative WOMAC and EQ-5D scores were examined in subgroup analyses. RESULTS: Preoperatively, 72% (n = 106) of patients reported night pain, and the prevalences of neuropathic pain and depressive disorder were 15% and 17%, respectively. Preoperatively, compared with patients without night pain, those with night pain had significantly poorer preoperative WOMAC scores, but no significant difference was seen between groups 1 year after TKA. Preoperatively, the WOMAC, EQ-5D, and EQ-5D health scores of patients with neuropathic pain were not significantly different from those of patients without neuropathic pain, and there was no difference in clinical outcome scores 1 year after TKA between these groups. Preoperatively, the patients with depressive disorder showed significantly poorer preoperative WOMAC, EQ-5D, and EQ-5D health scores than those without depressive disorder, but no significant differences in scores were observed 1 year after TKA between these groups. CONCLUSION: This study revealed a considerable prevalence of night pain, neuropathic pain, and depressive disorder in patients undergoing TKA and that patients with these specific conditions reported poorer functional and quality of life scores preoperatively. However, such adverse effects disappeared after TKA. Our study findings suggest that TKA can provide satisfactory outcomes for patients with these specific conditions.

Spouse bereavement and brain pathologies: A propensity score matching study.

AIM: Spouse bereavement is one of life's greatest stresses and has been suggested to trigger or accelerate cognitive decline and dementia. However, little information is available about the potential brain pathologies underlying the association between spouse bereavement and cognitive decline. We aimed to investigate that lifetime spouse bereavement is associated with in vivo human brain pathologies underlying cognitive decline. METHODS: A total of 319 ever-married older adults between the ages of 61 and 90 years underwent comprehensive clinical assessments and multimodal brain imaging including [11 C] Pittsburgh compound B-positron emission tomography (PET), AV-1451 PET, [18 F] fluorodeoxyglucose-PET, and magnetic resonance imaging. Participants were classified as experiencing no spouse bereavement or spouse bereavement, and comparisons using propensity score matching (59 cases and 59 controls) were performed. RESULTS: Spouse bereavement was significantly associated with higher cerebral white matter hyperintensity (WMH) volume compared with no spouse bereavement. Interaction and subsequent subgroup analyses showed that spouse bereavement was significantly associated with higher WMH in the older (>75 years) subgroup and among those with no- or low-skill occupations. In addition, spouse bereavement at 60 years or older affects WMH volume compared with no spouse bereavement, whereas spouse bereavement at younger than 60 years did not. No group differences were observed in other brain pathologies between spouse bereavement categories. CONCLUSIONS: The findings suggest that the spouse bereavement may contribute to dementia or cognitive decline by increasing cerebrovascular injury, particularly in older individuals and those with no- or low-skill occupations.

Research topics in intellectual disabilities in North Korea: A scoping review.

BACKGROUND: Research outcomes on intellectual development and related disabilities in North Korea are not widely known. Therefore, the current scoping review aimed to provide preliminary insight on research topics concerning intellectual disabilities in North Korea. METHOD: A six-stage framework for scoping review was adopted to examine research trends. Articles were categorised based on the era of supreme leader and research topic. RESULTS: There is a greater amount of research regarding intellectual disabilities in the recent Kim Jong-un era compared to the period of the previous leader where research outcomes on general intelligence were the focus. Significant qualitative progress was similarly found. CONCLUSIONS: The current analysis on research outcomes provides meaningful insights to aid in understanding the atmosphere in North Korea surrounding intellectual disabilities. Follow-up studies and open discussions are necessary for further progress.

Efficacy of Smart Speaker-Based Metamemory Training in Older Adults: Case-Control Cohort Study.

BACKGROUND: Metamemory training (MMT) is a useful training strategy for improving cognitive functioning in the older adult population. Despite the advantages, there are limitations imposed by location and time constraints. OBJECTIVE: This study aimed to develop a smart speaker-based MMT program and evaluate the efficacy of the program in older adults without cognitive impairment. METHODS: This study used a case-control cohort design. The smart speaker-based MMT program comprised 3 training sessions per day, 5 days a week, for 8 weeks. Each training session took approximately 15 minutes. This program was implemented using smart speakers, not human trainers. All participants completed the Mini-Mental State Examination, Subjective Memory Complaints Questionnaire, Verbal Learning Test, Digit Span Test, fluency tests, and a short-form version of the Geriatric Depression Scale before and after training. RESULTS: A total of 60 subjects (29 in the MMT group and 31 in the control group) participated in the study. The training group showed significant increases in the delayed free recall, digit span forward, digit span backward, and fluency test scores compared with the control group. CONCLUSIONS: This study confirmed the efficacy of smart speaker-based MMT in older adults. Home-based smart speaker-based MMT is not limited with respect to location or constrained by space and may help older adults with subjective cognitive decline without requiring intervention by human professionals.

Effect of Cognitive Training in Fully Immersive Virtual Reality on Visuospatial Function and Frontal-Occipital Functional Connectivity in Predementia: Randomized Controlled Trial.

BACKGROUND: Cognitive training can potentially prevent cognitive decline. However, the results of recent studies using semi-immersive virtual reality (VR)-assisted cognitive training are inconsistent. OBJECTIVE: We aimed to examine the hypothesis that cognitive training using fully immersive VR, which may facilitate visuospatial processes, could improve visuospatial functioning, comprehensive neuropsychological functioning, psychiatric symptoms, and functional connectivity in the visual brain network in predementia. METHODS: Participants over 60 years old with subjective cognitive decline or mild cognitive impairment from a memory clinic were randomly allocated to the VR (n=23) or the control (n=18) group. The VR group participants received multidomain and neuropsychologist-assisted cognitive training in a fully immersive VR environment twice a week for 1 month. The control group participants did not undergo any additional intervention except for their usual therapy such as pharmacotherapy. Participants of both groups were evaluated for cognitive function using face-to-face comprehensive neuropsychological tests, including the Rey-Osterrieth Complex Figure Test (RCFT) copy task; for psychiatric symptoms such as depression, apathy, affect, and quality of life; as well as resting-state functional magnetic resonance imaging (rsfMRI) at baseline and after training. Repeated-measures analysis of variance was used to compare the effect of cognitive training between groups. Seed-to-voxel-based analyses were used to identify the cognitive improvement-related functional connectivity in the visual network of the brain. RESULTS: After VR cognitive training, significant improvement was found in the total score (F1,39=14.69, P=.001) and basic components score of the RCFT copy task (F1,39=9.27, P=.005) compared with those of the control group. The VR group also showed improvements, albeit not significant, in naming ability (F1,39=3.55, P=.07), verbal memory delayed recall (F1,39=3.03, P=.09), and phonemic fluency (F1,39=3.08, P=.09). Improvements in psychiatric symptoms such as apathy (F1,39=7.02, P=.01), affect (F1,39=14.40, P=.001 for positive affect; F1,39=4.23, P=.047 for negative affect), and quality of life (F1,39=4.49, P=.04) were found in the VR group compared to the control group. Improvement in the RCFT copy task was associated with a frontal-occipital functional connectivity increase revealed by rsfMRI in the VR group compared to the control group. CONCLUSIONS: Fully immersive VR cognitive training had positive effects on the visuospatial function, apathy, affect, quality of life, and increased frontal-occipital functional connectivity in older people in a predementia state. Future trials using VR cognitive training with larger sample sizes and more sophisticated designs over a longer duration may reveal greater improvements in cognition, psychiatric symptoms, and brain functional connectivity. TRIAL REGISTRATION: Clinical Research Information Service KCT0005243; https://tinyurl.com/2a4kfasa.

Trends in the Prevalence of Major Depressive Disorder by Sociodemographic Factors in Korea: Results from Nationwide General Population Surveys in 2001, 2006, and 2011.

BACKGROUND: This study investigated trends in the prevalence of major depressive disorder (MDD) by sociodemographic factors in South Korea. METHODS: National samples of the general population aged 18 years or older collected from the nationwide Korean Epidemiologic Catchment Area surveys conducted in 2001 (n = 6,206), 2006 (n = 6,466), and 2011 (n = 5,986) were used. For MDD diagnosis, we conducted face-to-face interviews using the Korean version of the Composite International Diagnostic Interview. We performed logistic regression analyses stratified by gender, after adjusting for other sociodemographic variables, to calculate the 2006-to-2001 odds ratio (OR) and 2011-to-2001 OR by subgroups of sociodemographic factors to explore the association of MDD prevalence with sociodemographic factors over time. RESULTS: The prevalence of MDD in the general population of South Korea increased steadily from 2001, to 2006, and to 2011 (1.6%, 2.5%, and 3.1%, respectively). Among the men, the prevalence of MDD continued to increase significantly in 18-29 years of age group (2006: adjusted OR [AOR], 3.32; 2011: AOR, 7.42), at-risk drinking group (2006: AOR, 3.56; 2011: AOR, 4.77), and not living with a partner group (2006: AOR, 3.24; 2011: AOR, 3.25). Meanwhile, among the women, the prevalence of MDD continued to significantly increase in the below-average household income group (2006: AOR, 2.58; 2011: AOR, 2.59), at-risk drinking group (2006: AOR, 2.02; 2011: AOR, 2.47), and unemployed group (2006: AOR, 1.48; 2011: AOR, 2.04). CONCLUSION: This study may provide significant information for public policymakers to allocate sufficient health resources on MDD to vulnerable groups, particularly, men aged 18-29 years and women living in households with below-average income, and for clinicians to develop appropriate screening and treatment modalities for MDD.

Changes in Computer-Analyzed Facial Expressions with Age.

Facial expressions are well known to change with age, but the quantitative properties of facial aging remain unclear. In the present study, we investigated the differences in the intensity of facial expressions between older (n = 56) and younger adults (n = 113). In laboratory experiments, the posed facial expressions of the participants were obtained based on six basic emotions and neutral facial expression stimuli, and the intensities of their faces were analyzed using a computer vision tool, OpenFace software. Our results showed that the older adults expressed strong expressions for some negative emotions and neutral faces. Furthermore, when making facial expressions, older adults used more face muscles than younger adults across the emotions. These results may help to understand the characteristics of facial expressions in aging and can provide empirical evidence for other fields regarding facial recognition.

TiO2 Decorated Low-Molecular Chitosan a Microsized Adsorbent for a 68Ge/68Ga Generator System.

We report column material for a 68Ge/68Ga generator with acid resistance and excellent adsorption and desorption capacity of 68Ge and 68Ga, respectively. Despite being a core element of the 68Ge/68Ga generator system, research on this has been insufficient. Therefore, we synthesized a low molecular chitosan-based TiO2 (LC-TiO2) adsorbent via a physical trapping method as a durable 68Ge/68Ga generator column material. The adsorption/desorption studies exhibited a higher separation factor of 68Ge/68Ga in the concentration range of HCl examined (0.01 M to 1.0 M). The prepared LC-TiO2 adsorbent showed acid resistance capabilities with >93% of 68Ga elution yield and 1.6 × 10-4% of 68Ge breakthrough. In particular, the labeling efficiency of DOTA and NOTA, by using the generator eluted 68Ga, was quite encouraging and confirmed to be 99.65 and 99.69%, respectively. Accordingly, the resulting behavior of LC-TiO2 towards 68Ge/68Ga adsorption/desorption capacity and stability with aqueous HCl exhibited a high potential for ion-exchange solid-phase extraction for the 68Ge/68Ga generator column material.