Central odontogenic fibroma: report of 29 cases in a Korean population with tooth management.

This study presents the behavioural findings of central odontogenic fibroma (COF) in a specific ethnic group, analysing treatment methods and demonstrating how involved teeth should be managed in detail. Clinical, radiographic, and histological findings were gathered for 29 patients who visited our clinic, with all patients' data carefully examined by radiologists and reviewed microscopically. The cohort comprised 29 patients, with 16 females and 13 males, having a mean (SD) age of 33.1 (16.0) years. Among them, 19 patients were affected in the maxilla, with 15 showing anterior preference, and palatal depression was observed in six patients. Tooth resorption was evident in 15 patients, while 10 patients showed tooth displacement. Within the cohort, 13 patients underwent tooth extraction and resection, while the remaining 16 did not have teeth extracted. Notably, there was no significant difference in recurrence observed between these two groups. This study represents the largest study to date of COF within a single ethnic group and institution. A subset of cases exhibited noteworthy features of COF. However, intriguingly, despite these characteristics, the preservation of contiguous teeth did not demonstrate a significant impact on recurrence rates.

Importance of differential diagnosis of EBV mucocutaneous ulcer and EBV-positive diffuse large B-cell lymphoma: A case report.

RATIONALE: Epstein-Barr virus mucocutaneous ulcers (EBVMCUs) were officially recognized as a clinicopathologic entity in the 2017 revision of the World Health Organization classification, which often occurs in the elderly or in immunosuppressive condition presented as an isolated ulcerative lesion. EBVMCUs are defined as "shallow, sharply circumscribed, mucosal or cutaneous ulcers with underlying polymorphous infiltration." It mostly involves oral mucosa, but some appear in skin or gastrointestinal tract. Typically, patients with EBVMCUs display a slow disease progression and may even undergo spontaneous regression. PATIENT CONCERNS: This report describes the case of a 76-year-old woman who visited our outpatient clinic with the chief complaint of inflammation and ulceration on lower labial, lower right lingual gingiva seemed like acute necrotizing ulcerative gingivitis, and malignancy. DIAGNOSES: She was diagnosed with EBVMCU after tissue biopsy. INTERVENTIONS: Since most oral ulcerations usually appear in nonspecific form, it is important to check thoroughly for any underlying immunosuppressive systemic conditions and laboratory test results in case of viral infection. But she has no remarkable underlying immunosuppressive disorder. OUTCOMES: For this patient, she was initially diagnosed with EBVMCU and showed spontaneous healing, but then relapsed after 4 to 6 months. The patient was re-diagnosed as EBV-positive diffuse large B-cell lymphoma (EBV-positive DLBCLs) after re-biopsy. LESSONS: EBVMCU shows similar symptoms to malignant lesions or acute necrotizing ulcerative gingivitis but shows spontaneous healing. However, in case of EBV-positive DLBCLs, failing to detect and treat the disease in its early stages can lead to a fatal outcome. Thus, this case report highlights the differential diagnosis and appropriate treatment of EBVMCU and EBV-positive DLBCLs.

Optimal bilayer composites for temperature-tracking wireless electronics.

Modern silicone-based epidermal electronics engineered for body temperature sensing represent a pivotal development in the quest for advancing preventive medicine and enhancing post-surgical monitoring. While these compact and highly flexible electronics empower real-time monitoring in dynamic environments, a noteworthy limitation is the challenge in regulating the infiltration or obstruction of heat from the external environment into the surface layers of these electronics. The study presents a cost-effective temperature sensing solution by embedding wireless electronics in a multi-layered elastomeric composite to meet the dual needs of enhanced thermal insulation for encapsulation in contact with air and improved thermal conductivity for the substrate in contact with the skin. The encapsulating composite benefits from the inclusion of hollow silica microspheres, which reduce the thermal conductivity by 40%, while non-spherical aluminum nitride enhances the thermal conductivity of the substrate by 370%. The addition of particles to the respective composites inevitably leads to an increase in modulus. Two composite elements are engineered to coexist while maintaining a matching low modulus of 3.4 MPa and a stretchability exceeding 30%, all without compromising the optimized thermal properties. Consecutive thermal, electrical, and mechanical characterization confirms the sensor's capacity for precise body temperature monitoring during a single day's lifespan, while also assessing the influence of behavioral factors on body temperature.

Machine-learned wearable sensors for real-time hand-motion recognition: toward practical applications.

Soft electromechanical sensors have led to a new paradigm of electronic devices for novel motion-based wearable applications in our daily lives. However, the vast amount of random and unidentified signals generated by complex body motions has hindered the precise recognition and practical application of this technology. Recent advancements in artificial-intelligence technology have enabled significant strides in extracting features from massive and intricate data sets, thereby presenting a breakthrough in utilizing wearable sensors for practical applications. Beyond traditional machine-learning techniques for classifying simple gestures, advanced machine-learning algorithms have been developed to handle more complex and nuanced motion-based tasks with restricted training data sets. Machine-learning techniques have improved the ability to perceive, and thus machine-learned wearable soft sensors have enabled accurate and rapid human-gesture recognition, providing real-time feedback to users. This forms a crucial component of future wearable electronics, contributing to a robust human-machine interface. In this review, we provide a comprehensive summary covering materials, structures and machine-learning algorithms for hand-gesture recognition and possible practical applications through machine-learned wearable electromechanical sensors.

Novel criteria of sampled-data synchronization controller design for gated recurrent unit neural networks under mismatched parameters.

Synchronization between neural networks (NNs) has been intensively investigated to analyze stability, convergence properties, neuronal behaviors and response to various inputs. However, synchronization techniques of NNs with gated recurrent units (GRUs) have not been provided until now due to their complicated nonlinearity. In this paper, we address the sampled-data synchronization problems of GRUs for the first time, and propose controller design methods using discretely sampled control inputs to synchronize master and slave GRUs. The master and slave GRUs are mathematically modeled as a linear parameter varying (LPV) system in which the parameter of the slave GRUs is constructed independently of the master GRUs. This distinctive modeling feature provides flexibility to extend the existing master and slave NNs into a more general structure. Indeed, the sampled-data synchronization can be achieved by formulating the design condition in terms of linear matrix inequalities (LMIs). The novel sampled-data synchronization criteria are devised by combining the H∞ controller design with the looped-functional approach. The synthesized synchronization controllers guarantee not only asymptotic stability of the synchronization error system with aperiodic sampling, but also provides a satisfactory H∞ control performance. Moreover, the communication efficiency is improved by using the proposed method in which the sampled-data synchronization controller is combined with the event-triggered mechanism. Finally, the numerical example validates the proposed theoretical contributions via simulation results.

COVID-19 Economic and Academic Stress on Mexican American Adolescents' Psychological Distress: Parents as Essential Workers.

OBJECTIVES: In a sample of Mexican American adolescents (N = 398; 51% females; aged 13-17), we examined the associations between psychological distress, COVID-19 household economic stress, COVID-19 academic stress, and whether these associations varied by adolescents' gender and by parents/caregivers' essential worker status. METHOD: First, linear regression models assessed the main effects of household economic and academic stress on psychological distress. Second, the moderating effects of gender and parents/caregivers' essential worker status on the association between household economic and academic stress, and psychological distress were examined. Third, the three-way interaction effect of household economic stress, gender, and parents/caregivers' essential worker status on psychological distress as well as the three-way interaction effect of academic stress, gender, and parents/caregivers' essential worker status on psychological distress were calculated. RESULTS: Household economic and academic stress were associated with psychological distress. However, these associations did not vary based on adolescents' gender or parents/caregivers' essential worker status. The three-way interaction for household economic stress, parents/caregivers' essential worker status, and gender for psychological distress was significant. Specifically, the effects of household economic stress on psychological distress was worse for boys than girls whose parents/caregivers were essential workers. Furthermore, the three-way interaction among academic stress, parents/caregivers' essential worker status, and gender was significant. Particularly, the effects of academic stress when grades were worse on adolescents' psychological distress was worse for boys than girls whose parents/caregivers were essential workers. CONCLUSION: Parents/caregivers' essential worker status was salient among Mexican American adolescents' mental health outcomes during COVID-19, particularly for adolescent boys.

Real-time counting of wheezing events from lung sounds using deep learning algorithms: Implications for disease prediction and early intervention.

This pioneering study aims to revolutionize self-symptom management and telemedicine-based remote monitoring through the development of a real-time wheeze counting algorithm. Leveraging a novel approach that includes the detailed labeling of one breathing cycle into three types: break, normal, and wheeze, this study not only identifies abnormal sounds within each breath but also captures comprehensive data on their location, duration, and relationships within entire respiratory cycles, including atypical patterns. This innovative strategy is based on a combination of a one-dimensional convolutional neural network (1D-CNN) and a long short-term memory (LSTM) network model, enabling real-time analysis of respiratory sounds. Notably, it stands out for its capacity to handle continuous data, distinguishing it from conventional lung sound classification algorithms. The study utilizes a substantial dataset consisting of 535 respiration cycles from diverse sources, including the Child Sim Lung Sound Simulator, the EMTprep Open-Source Database, Clinical Patient Records, and the ICBHI 2017 Challenge Database. Achieving a classification accuracy of 90%, the exceptional result metrics encompass the identification of each breath cycle and simultaneous detection of the abnormal sound, enabling the real-time wheeze counting of all respirations. This innovative wheeze counter holds the promise of revolutionizing research on predicting lung diseases based on long-term breathing patterns and offers applicability in clinical and non-clinical settings for on-the-go detection and remote intervention of exacerbated respiratory symptoms.

Case report: Ghost cell odontogenic carcinoma in a dog: diagnostics and surgical outcome.

A 6 year-old spayed female Poodle presented with a mandibular mass. Radiographic examination revealed osteolysis from the right mandibular canine to the fourth premolar, along with horizontal bone loss and dorsal displacement of the right mandibular first and second premolars. Skull cone beam computed tomography revealed osteolysis at the level of the right mandibular canine and fourth premolar. A destructive bone lesion was observed in the apical area of the right mandibular canine, with mass invasion of the interradicular bone of the right mandibular first molar near the mandibular canal. Consequently, unilateral total mandibulectomy and skin flap surgery were performed. Histopathological examination revealed poorly demarcated and infiltrative neoplastic epithelial cells that formed small islands and trabeculae. Neoplastic cells exhibited the malignant features of cytological atypia and high mitotic activity. Furthermore, the neoplastic epithelial cells frequently showed ghost cell changes and were diagnosed as ghost cell odontogenic carcinoma (GCOC). The dog was followed up for 1 year, during which no severe complications or local recurrence was observed, except for slight mandibular drift, tongue protrusion, and drooling. This case report describes the clinical features, diagnostic imaging, and histologic features of an unreported GCOC in a dog and the favorable outcome following surgical resection.

Acceptability and Feasibility of Saliva-delivered PCR Coronavirus 2019 Tests for Young Children.

OBJECTIVES: Access to readily available, reliable, and easy-to-use coronavirus disease 2019 (COVID-19) tests remains critical, despite great vaccination progress. Universal back-to-school testing offered at early care and education ([ECE]; ie, preschool) sites to screen for positive cases may help preschoolers safely return to, and stay in, ECE. We examined the acceptability and feasibility of using a quantitative polymerase chain reaction COVID-19 saliva test for young children (n = 227, 54.0% girls: mean age = 52.3 ± 8.1 months) and their caregivers (n = 70 teachers: mean = 36.6 ± 14.7 years; n = 227 parents: mean = 35.5 ± 9.1 years) to mitigate the spread of COVID-19 and reduce days of school and work missed for households with children who test positive. METHODS: Participants were recruited at ECE sites serving low-income communities as part of the Rapid Acceleration of Diagnostic Testing-Underserved Populations Back to Early Care and Education Safely with Sustainability via Active Garden Education project (NCT05178290). RESULTS: Surveys in English or Spanish administered at testing events to children and caregivers at ECE sites showed child and adult acceptability and feasibility ratings were generally high. More favorable child and parent ratings were positively associated with child age and whether the child was able to produce a saliva sample. Language preference was not associated with any outcomes. CONCLUSIONS: Saliva sampling for COVID-19 at ECE sites is an acceptable strategy as an additional layer of protection for 4- and 5-year-olds; however, alternate testing strategies may be needed for younger children.

The impact of a meditative movement practice intervention on short- and long-term changes in physical activity among breast cancer survivors.

PURPOSE: Tai Chi Easy (TCE) is a low-impact, meditative movement practice that is feasible for breast cancer survivors, even in the face of post-treatment symptoms, and may even serve as a gateway into developing an active lifestyle and improving overall physical activity (PA). In the context of a randomized controlled trial testing effects of an 8-week TCE intervention on breast cancer survivors' symptoms, we examined the short- (8-week) and long-term (9-month) impact on total PA compared to an educational control group. METHODS: Participants were recruited from two hospital systems, local community organizations, and different media platforms. Eligible participants were predominant non-Hispanic White (82%), college educated (92%), and middle- to high-income (65%), and most commonly reported stage 1 (40%) or 2 breast cancer (38%). After baseline assessments, participants were randomized to the 8-week TCE intervention (N=51) or education control (N=53). Weekly intervention TCE classes were led by a trained instructor. Weekly educational control classes focused on a series of readings and group discussions. Total PA and steps were objectively measured via accelerometry, and the international physical activity questionnaire was used to measure self-reported total PA. RESULTS: Multilevel mixed-effects linear regression models revealed no significant short- or long-term changes in objectively measured total PA or steps in either group; however, participants in the intervention reported short- and long-term changes in self-reported total PA. CONCLUSIONS: TCE is an appropriate PA strategy for survivors that may lead to modest improvements in PA; however, more research is needed to examine the long-term impact on PA as well as other physical and psychological outcomes (i.e., flexibility, mobility, stress). IMPLICATIONS FOR CANCER SURVIVORS: Low-impact, low-intensity activities like meditative movement practices are needed to assist survivors in overcoming post-treatment physical and psychological limitations to initiate a more active lifestyle.

Scale dependence in hydrodynamic regime for jumping on water.

Momentum transfer from the water surface is strongly related to the dynamical scale and morphology of jumping animals. Here, we investigate the scale-dependent momentum transfer of various jumping organisms and engineered systems at an air-water interface. A simplified analytical model for calculating the maximum momentum transfer identifies an intermediate dynamical scale region highly disadvantageous for jumping on water. The Weber number of the systems should be designed far from 1 to achieve high jumping performance on water. We design a relatively large water-jumping robot in the drag-dominant scale range, having a high Weber number, for maximum jumping height and distance. The jumping robot, around 10 times larger than water striders, has a take-off speed of 3.6 m/s facilitated by drag-based propulsion, which is the highest value reported thus far. The scale-dependent hydrodynamics of water jumpers provides a useful framework for understanding nature and robotic system interacting with the water surface.

Pilot study of Qigong/Tai Chi Easy acute effects of meditative movement, breath focus and "flow" on blood pressure, mood and oxytocin in older adults.

BACKGROUND: Older adults are increasingly lonely and at risk for hypertension. Endogenous oxytocin levels are associated with lowering blood pressure (BP), suggesting value in increasing oxytocin. Regular practice of Tai Chi improves BP and mood; we explored a single session of Tai Chi Easy (TCE) with older adults and feasibility of measuring oxytocin as a key biomarker. METHOD: In a single-arm pre-post design pilot study, 21 older adults (age 55-80) with mild-moderate hypertension practiced a single session (50-min) TCE. BP, psychosocial measures, and saliva samples were collected pre/post to examine feasibility of acute measures of oxytocin and explore effect sizes of outcomes. Participants (N = 21; 19 % Latinx, 76.2 % female, mean age 66.76). RESULTS: BP systolic: 138.43-134.86; diastolic 78.48-78.00 (p > .05; Cohen's d -0.23; -0.08 respectively). Total Mood Disturbance (TMD) and Connection (CN) improved [TMD mean pre 41.891 (SD=19.60) to post 35.00 (SD=10.21), p = .01; Cohen's d - 0.67); CN mean 7.85 (SD=2.01) to post 9.05 (SD=1.00), p = .01; Cohen's d 0.70]. Baseline oxytocin was positively correlated with baseline loneliness (N = 14, r = .599); pre/post oxytocin changes were negatively correlated with baseline loneliness (N = 14, r = -.585). BP decrease was associated with characteristics of the intervention: "flow" (coef=.=0.58N = 17) and meditative/breath focus (coef=-1.78; N = 17). DISCUSSION/CONCLUSION: Medium to large effect sizes indicating change in mood and connection were found for this single session intervention. Knowing that Tai Chi improves BP when practiced over time, this TCE intervention shows promise for planning a fully powered, randomized controlled study of BP, mood and perceptions of connection in hypertensive older adults. Feasibility of assessing acute salivary oxytocin is less promising. Increase in oxytocin levels occurred for those less lonely, but declined for lonelier participants. With different responses based on baseline loneliness scores, no mean change in oxytocin levels was found. Seemingly unstable levels (possibly related to interaction with study staff) suggests the need for further testing in more controlled study designs. Finally, BP associations with meditative/breath focus and flow could be further explored in future study designs addressing mediation.

Migration Intentions and Alcohol Use Among Adolescents in West-Central Mexico.

This study explores the association between migration intentions and alcohol use among west-central Mexico adolescents living in high migration communities. This study used the baseline data from the Family Migration and Early Life Outcomes (FAMELO) project (N = 1286), collected in 2018. We used multiple imputations to address missingness and propensity score matching to reduce the selection bias. We also conducted subgroup analyses to compare gender difference (i.e., boys vs. girls) on the relationship between migration intention and alcohol use. The findings show that for the whole sample, youth with migration intentions had significant higher odds (OR = 1.78; p = .010) of having a lifetime drinking experience when compared to youth who reported no interest in living abroad, but this association remained significant only for boys (OR = 2.14; p = .010). This study makes an important contribution to our understanding of the etiology of migration intentions and alcohol use for adolescents living in sending migration communities. The findings have specific alcohol prevention, policy, and future research implications in Mexico and the U.S.

High-performance electrified hydrogel actuators based on wrinkled nanomembrane electrodes for untethered insect-scale soft aquabots.

Hydrogels have diverse chemical properties and can exhibit reversibly large mechanical deformations in response to external stimuli; these characteristics suggest that hydrogels are promising materials for soft robots. However, reported actuators based on hydrogels generally suffer from slow response speed and/or poor controllability due to intrinsic material limitations and electrode fabrication technologies. Here, we report a hydrogel actuator that operates at low voltages (<3 volts) with high performance (strain > 50%, energy density > 7 × 105 joules per cubic meter, and power density > 3 × 104 watts per cubic meter), surpassing existing hydrogel actuators and other types of electroactive soft actuators. The enhanced performance of our actuator is due to the formation of wrinkled nanomembrane electrodes that exhibit high conductivity and excellent mechanical deformation through capillary-assisted assembly of metal nanoparticles and deswelling-induced wrinkled structures. By applying an electric potential through the wrinkled nanomembrane electrodes that sandwich the hydrogel, we were able to trigger a reversible and substantial electroosmotic water flow inside a hydrogel film, which drove the controlled swelling of the hydrogel. The high energy efficiency and power density of our wrinkled nanomembrane electrode-induced actuator enabled the fabrication of an untethered insect-scale aquabot integrated with an on-board control unit demonstrating maneuverability with fast locomotion speed (1.02 body length per second), which occupies only 2% of the total mass of the robot.

Actuating compact wearable augmented reality devices by multifunctional artificial muscle.

An artificial muscle actuator resolves practical engineering problems in compact wearable devices, which are limited to conventional actuators such as electromagnetic actuators. Abstracting the fundamental advantages of an artificial muscle actuator provides a small-scale, high-power actuating system with a sensing capability for developing varifocal augmented reality glasses and naturally fit haptic gloves. Here, we design a shape memory alloy-based lightweight and high-power artificial muscle actuator, the so-called compliant amplified shape memory alloy actuator. Despite its light weight (0.22 g), the actuator has a high power density of 1.7 kW/kg, an actuation strain of 300% under 80 g of external payload. We show how the actuator enables image depth control and an immersive tactile response in the form of augmented reality glasses and two-way communication haptic gloves whose thin form factor and high power density can hardly be achieved by conventional actuators.

Design of a Biologically Inspired Water-Walking Robot Powered by Artificial Muscle.

The agile and power-efficient locomotion of a water strider has inspired many water-walking devices. These bioinspired water strider robots generally adopt a DC motor to create a sculling trajectory of the driving leg. These robots are, thus, inevitably heavy with many supporting legs decreasing the velocity of the robots. There have only been a few attempts to employ smart materials despite their advantages of being lightweight and having high power densities. This paper proposes an artificial muscle-based water-walking robot capable of moving forward and turning with four degrees of freedom. A compliant amplified shape memory alloy actuator (CASA) used to amplify the strain of a shape memory alloy wire enables a wide sculling motion of the actuation leg with only four supporting legs to support the entire weight of the robot. Design parameters to increase the actuation strain of the actuator and to achieve a desired swing angle (80°) are analyzed. Finally, experiments to measure the forward speed and angular velocities of the robot are carried out to compare with other robots. The robot weighs only 0.236 g and has a maximum and average speed of 1.56, 0.31 body length per second and a maximum and average angular velocity of 145.05°/s and 14.72°/s.

Restored Action Generative Adversarial Imitation Learning from observation for robot manipulator.

In this paper, a new imitation learning algorithm is proposed based on the Restored Action Generative Adversarial Imitation Learning (RAGAIL) from observation. An action policy is trained to move a robot manipulator similar to a demonstrator's behavior by using the restored action from state-only demonstration. To imitate the demonstrator, the trajectory is generated by Recurrent Generative Adversarial Networks (RGAN), and the action is restored from the output of the tracking controller constructed by the state and the generated target trajectory. The proposed imitation learning algorithm is not required to access the demonstrator's action (internal control signal such as force/torque command) and provides better learning performances. The effectiveness of the proposed method is validated through the experimental results of the robot manipulator.

Deprivation or discrimination? Comparing two explanations for the reverse income-obesity gradient in the US and South Korea.

In high-income countries, poverty is often associated with higher average body mass index (BMI). To account for this reverse gradient, deprivation theories posit that declining economic resources make it more difficult to maintain a healthy weight. By contrast, discrimination theories argue that anti-fat discrimination in hiring and marriage sorts heavier individuals into lower-income households. This study assesses competing predictions of these theories by examining how household income in representative samples from South Korea (2007-2014, N=20,823) and the US (1999-2014, N=6395) is related to BMI in two key contrasting groups: (1) currently-married and (2) never-married individuals. As expected by anti-fat discrimination in marriage, the reverse gradient is observed among currently-married women but not among never-married women in both countries. Also consistent with past studies no evidence was found for a reverse gradient among men. These findings are consistent with anti-fat discrimination in marriage as a key cause of the reverse gradient and raise serious challenges to deprivation accounts as well as explanations based on anti-fat discrimination in labour markets.

Bright Light Treatment of Combat-related PTSD: A Randomized Controlled Trial.

INTRODUCTION: Post-traumatic stress disorder (PTSD) is a prevalent consequence of combat with significant associated morbidity. Available treatments for PTSD have had limitations, suggesting a need to explore alternative or adjuvant treatments. Numerous rationales for bright light treatment of PTSD include its benefits for common PTSD comorbidities of depression, anxiety, and circadian misalignment and its relative ease of use with few side effects. The primary aims of this research were to examine the effects of bright light treatment for combat-related PTSD and associated morbidity. MATERIALS AND METHODS: A randomized controlled trial was performed in N = 69 veterans with PTSD attributable to combat in Afghanistan and/or Iraq. Following a 1-week baseline, participants were randomized to 4 weeks of daily morning bright light treatment (10,000 lux for 30 min/day) or a control treatment (inactivated negative ion generator). At baseline and at the end of treatment, participants were rated blindly on the Clinician Assessed PTSD Scale (CAPS), the Clinical Global Impressions Scale (CGI), and the Hamilton Depression Scale and rated themselves on the PTSD Checklist-Military (PCL-M). Following baseline and each treatment week, participants completed self-reported scales of state anxiety, depression, and sleep, and sleep and the circadian rhythm of wrist activity were also assessed with wrist actigraphy. RESULTS: Compared with the control treatment, bright light elicited significantly greater improvements in the CAPS and CGI-Improvement. The bright light also elicited a significantly greater rate of treatment response (reduction ≥33%) for the CAPS (44.1% vs. 8.6%) and PCL-M (33% vs. 6%), but no participant had remission from PTSD. Changes in depression, anxiety, and sleep did not differ between treatments. Improvement in CAPS was significantly correlated with a phase advance of the circadian rhythm of wrist activity. CONCLUSIONS: The most comprehensive study on the topic to date indicated significant short-term efficacy of bright light treatment on the primary variables (CAPS and CGI) with clinical relevance (i.e., treatment response) in veterans with chronic PTSD who did not report extremely high habitual light exposure. No significant effects were found for anxiety, depression, or sleep disturbance. Further research is warranted, particularly exploration of circadian phase-shifting mechanisms of bright light for PTSD.

Mechanistic Effects of Aerobic Exercise in Alzheimer's Disease: Imaging Findings From the Pilot FIT-AD Trial.

Despite strong evidence from animal models of Alzheimer's disease (AD) supporting aerobic exercise as a disease-modifying treatment for AD, human mechanistic studies are limited with mixed findings. The objective of this pilot randomized controlled trial was to examine the effects of 6-month aerobic exercise on hippocampal volume, temporal meta-regions of interest (ROI) cortical thickness, white matter hyperintensity (WMH) volume, and network failure quotient (NFQ), measured with MRI, in community-dwelling older adults with AD dementia. Additionally, the relationships between 6- and 12-month changes in MRI biomarkers and the AD Assessment Scale-Cognition (ADAS-Cog) were examined. Sixty participants were randomized, but one was excluded because baseline MRI failed quality control: 38 randomized to cycling and 21 to stretching. The intervention was moderate-intensity cycling for 20-50 mins, three times a week for 6 months. Control was low-intensity stretching. The study outcomes include hippocampal volume, temporal meta-ROI cortical thickness, WMH volume, and NFQ. Outcomes were measured at baseline, 6 months, and 12 months. The sample averaged 77.3 ± 6.3 years old with 15.6 ± 2.9 years of education and 53% men. Both groups experienced significant declines over 6 months in hippocampal volume (2.64% in cycling vs. 2.89% in stretching) and temporal meta-ROI cortical thickness (0.94 vs. 1.54%), and over 12 months in hippocampal volume (4.47 vs. 3.84%) and temporal meta-ROI cortical thickness (2.27 vs. 1.79%). These declines did not differ between groups. WMH volume increased significantly with the cycling group increasing less (10.9%) than stretching (24.5%) over 6 months (f = 4.47, p = 0.04) and over 12 months (12.1 vs. 27.6%, f = 5.88, p = 0.02). NFQ did not change significantly over time. Pairwise correlational analyses showed a significant negative correlation between 6-month changes in hippocampal volume and ADAS-Cog (r = -0.34, p < 0.05). To conclude, aerobic exercise may reduce the decline in hippocampal volume and temporal meta-ROI cortical thickness during the intervention period, but the effect sizes are likely to be very small and dose-dependent and reverse once the intervention stops. Aerobic exercise is effective on slowing down WMH progression but has no effect on NFQ. Hippocampal atrophy was associated with cognitive decline during the intervention period. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT01954550.