Sleep and Military Leaders: Examining the Values, Beliefs, and Quality of Sleep and the Impact on Occupational Performance.

INTRODUCTION: Sleep deprivation is rampant within the military population, and insufficient sleep can lead to physical and mental health problems impacting soldier's readiness and deployability. Past research has shown the importance of leadership's role in subordinates' sleep health. Understanding the values, beliefs, and quality of military leader sleep is essential to the development of effective interventions to optimize occupational performance and overall sleep health. Therefore, the purpose of this study was to examine the military leaders' values, beliefs, and sleep quality and the impact on occupational performance. The authors aimed to (1) identify military leaders' sleep quality and beliefs; (2) explore the relationship between military leaders' sleep quality, beliefs and attitudes about sleep, and impact on occupational performance; and (3) examine the value leaders place on sleep for themselves and subordinates in relation to occupational performance. MATERIALS AND METHODS: This observational, mixed-methods study design recruited a convenience sample of 109 Army active duty medical service members currently serving in a leadership role. Participants completed an electronic survey to include general demographic information and three self-report measures: the Pittsburgh Quality of Sleep Index, the Dysfunctional Beliefs about Sleep, and the Functional Outcomes of Sleep Questionnaire. Eleven participants completed the semi-structured qualitative interview focusing on sleep values and the impacts on performance. Univariate and multivariate regressions were performed for statistical analysis of the quantitative survey data, whereas thematic analysis was used to analyze the qualitative interview data. This study was approved by the U.S. Army Medical Center of Excellence Institutional Review Board. RESULTS: Multivariate regression analysis demonstrated small-to-medium effect sizes (R2 = 0.355-0.559) for relationships between sleep quality, sleep beliefs, functional performance, and demographic variables. More specifically, military grade, position, use of alcohol, time in service, and gender were all found to contribute significantly to scores on the Pittsburgh Sleep Quality Index, the Dysfunctional Beliefs About Sleep Scale-16, and the Functional Outcomes of Sleep Questionnaire-10 (P < .05). Qualitative data resulted in three primary themes: (1) Poor sleep degrades performance, (2) sleep is a top priority, and (3) leaders have a responsibility for subordinates' sleep health. CONCLUSIONS: This sample of military leaders was found to perceive themselves as poor-quality sleepers despite demonstrating more functional attitudes and beliefs about sleep and reporting normal-to-mild impairments in daily functioning as a result of daytime sleepiness. Furthermore, findings suggest that leaders' sleep quality and beliefs stand to be further improved, whereas their sleep values need to be consistently demonstrated to subordinates. With a clearer understanding of military leaders' values, beliefs, and sleep quality, future research could focus on implementing and developing holistically based and individualized sleep interventions intended to optimize performance and sleep health.

Study of Symptomatic vs. Silent Brain Infarctions on MRI in Elderly Subjects.

Brain infarctions are closely associated with future risk of stroke and dementia. Our goal was to report (i) frequency and characteristics that differentiate symptomatic vs. silent brain infarctions (SBI) on MRI and (ii) frequency and location by vascular distribution (location of stroke by major vascular territories) in a population based sample. From Mayo Clinic Study of Aging, 347 participants (≥50 years) with infarcts detected on their first MRI were included. Infarct information was identified visually on a FLAIR MRI image and a vascular territory atlas was registered to the FLAIR image data in order to identify the arterial territory of infarction. We identified the subset with a clinical history of stroke based on medical chart review and used a logistic regression to evaluate the risk factors associated with greater probability of a symptomatic stroke vs. SBI. We found that 14% of all individuals with infarctions had a history of symptomatic stroke (Silent: n = 300, symptomatic: n = 47). Factors associated with a symptomatic vs. SBI were size which had an odds ratio of 3.07 (p < 0.001), greater frequency of hypertension (odds ratio of 4.12, p = 0.025) and alcohol history (odds ratio of 4.58, p = 0.012). The frequency of infarcts was greater in right hemisphere compared to the left for SBI. This was primarily driven by middle cerebral artery (MCA) infarcts (right = 60%, left = 40%, p = 0.005). While left hemisphere strokes are more common for symptomatic carotid disease and in clinical trials, right hemispheric infarcts may be more frequent in the SBI group.

Dynamic Tuning of a Thin Film Electrocatalyst by Tensile Strain.

We report the ability to tune the catalytic activities for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) by applying mechanical stress on a highly n-type doped rutile TiO2 films. We demonstrate through operando electrochemical experiments that the low HER activity of TiO2 can reversibly approach those of the state-of-the-art non-precious metal catalysts when the TiO2 is under tensile strain. At 3% tensile strain, the HER overpotential required to generate a current density of 1 mA/cm2 shifts anodically by 260 mV to give an onset potential of 125 mV, representing a drastic reduction in the kinetic overpotential. A similar albeit smaller cathodic shift in the OER overpotential is observed when tensile strain is applied to TiO2. Results suggest that significant improvements in HER and OER activities with tensile strain are due to an increase in concentration of surface active sites and a decrease in kinetic and thermodynamics barriers along the reaction pathway(s). Our results highlight that strain applied to TiO2 by precisely controlled and incrementally increasing (i.e. dynamic) tensile stress is an effective tool for dynamically tuning the electrocatalytic properties of HER and OER electrocatalysts relative to their activities under static conditions.

Experiences of Veterans Transitioning to Postsecondary Education.

An increasing number of U.S. military veterans are entering postsecondary education with problems attributed to deployed military service. The primary objective of this research was to describe the lived experiences of student veterans transitioning from active military service to postsecondary education. Phenomenological interviews were performed with 13 student veterans who had transitioned from military deployment to postsecondary education. An overall essential meaning of "emerging in college culture" was manifested from three themes, supported by rich textural and structural descriptions of student veterans' experiences: (1) repurposing military experiences for life as a student veteran, (2) reconstructing civilian identity, and (3) navigating postsecondary context and interactions. These findings highlight implications that may facilitate occupational therapists' efforts in supporting the needs of student veterans.

Age, Sex, and APOE ε4 Effects on Memory, Brain Structure, and ß-Amyloid Across the Adult Life Span.

IMPORTANCE: Typical cognitive aging may be defined as age-associated changes in cognitive performance in individuals who remain free of dementia. Ideally, the full adult age spectrum should be included to assess brain imaging findings associated with typical aging. OBJECTIVE: To compare age, sex, and APOE ε4 effects on memory, brain structure (adjusted hippocampal volume [HVa]), and amyloid positron emission tomography (PET) in cognitively normal individuals aged 30 to 95 years old. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional observational study (March 2006 to October 2014) at an academic medical center. We studied 1246 cognitively normal individuals, including 1209 participants aged 50 to 95 years old enrolled in a population-based study of cognitive aging and 37 self-selected volunteers aged 30 to 49 years old. MAIN OUTCOMES AND MEASURES: Memory, HVa, and amyloid PET. RESULTS: Overall, memory worsened from age 30 years through the 90s. The HVa worsened gradually from age 30 years to the mid-60s and more steeply beyond that age. The median amyloid PET was low until age 70 years and increased thereafter. Memory was worse in men than in women overall (P < .001) and more specifically beyond age 40 years. The HVa was lower in men than in women overall (P < .001) and more specifically beyond age 60 years. There was no sex difference in amyloid PET at any age. Within each sex, memory performance and HVa were not different by APOE ε4 status at any age. From age 70 years onward, APOE ε4 carriers had significantly greater median amyloid PET than noncarriers. However, the ages at which 10% of the population were amyloid PET positive were 57 years for APOE ε4 carriers and 64 years for noncarriers. CONCLUSIONS AND RELEVANCE: Male sex is associated with worse memory and HVa among cognitively normal individuals, while APOE ε4 is not. In contrast, APOE ε4 is associated with greater amyloid PET (from age 70 years onward), while sex is not. Worsening memory and HVa occur at earlier ages than abnormal amyloid PET. Therefore, neuropathological processes other than ß-amyloidosis must underlie declines in brain structure and memory function in middle age. Our findings are consistent with a model of late-onset Alzheimer disease in which ß-amyloidosis arises in later life on a background of preexisting structural and cognitive decline that is associated with aging and not with ß-amyloid deposits.

Working memory and language network dysfunctions in logopenic aphasia: a task-free fMRI comparison with Alzheimer's dementia.

We aimed to determine whether network-level functional connectivity differs in 2 clinical variants of Alzheimer's disease: logopenic primary progressive aphasia (lvPPA) and dementia of the Alzheimer's type (DAT). Twenty-four lvPPA subjects with amyloid deposition on positron emission tomography and task-free functional magnetic resonance imaging were matched to 24 amyloid-positive DAT subjects and 24 amyloid-negative controls. Independent-component analysis and spatial-temporal dual regression were used to assess functional connectivity within the language network, left and right working memory networks, and ventral default mode network. lvPPA showed reduced connectivity in left temporal language network and inferior parietal and prefrontal regions of the left working memory network compared with controls and DAT. Both groups showed reduced connectivity in the parietal regions of the right working memory network compared with controls. Only DAT showed reduced ventral default mode network connectivity compared with controls. Aphasia severity correlated with connectivity in the left working memory network within lvPPA. Patterns of network dysfunction differ across these 2 clinical variants of Alzheimer's disease, with lvPPA particularly associated with disruptions in the language and left working memory networks.

Rates of ß-amyloid accumulation are independent of hippocampal neurodegeneration.

OBJECTIVE: To test the hypotheses predicted in a hypothetical model of Alzheimer disease (AD) biomarkers that rates of ß-amyloid (Aß) accumulation on PET imaging are not related to hippocampal neurodegeneration whereas rates of neurodegenerative brain atrophy depend on the presence of both amyloid and neurodegeneration in a population-based sample. METHODS: A total of 252 cognitively normal (CN) participants from the Mayo Clinic Study of Aging had 2 or more serial visits with both amyloid PET and MRI. Subjects were classified into 4 groups based on baseline positive/negative amyloid PET (A+ or A-) and baseline hippocampal volume (N+ or N-). We compared rates of amyloid accumulation and rates of brain atrophy among the 4 groups. RESULTS: At baseline, 148 (59%) were amyloid negative and neurodegeneration negative (A-N-), 29 (12%) amyloid negative and neurodegeneration positive (A-N+), 56 (22%) amyloid positive and neurodegeneration negative (A+N-), and 19 (8%) amyloid positive and neurodegeneration positive (A+N+). High rates of Aß accumulation were found in those with abnormal amyloid at baseline and were not influenced by hippocampal neurodegeneration at baseline. In contrast, rates of brain atrophy were greatest in A+N+. CONCLUSIONS: We describe a 2-feature biomarker approach to classifying elderly CN subjects that is complementary to the National Institute on Aging-Alzheimer's Association preclinical staging criteria. Our results support 2 key concepts in a model of the temporal evolution of AD biomarkers. First, the rate of Aß accumulation is not influenced by neurodegeneration and thus may be a biologically independent process. Second, Aß pathophysiology increases or catalyzes neurodegeneration.

Visible-light-assisted photoelectrochemical water oxidation by thin films of a phosphonate-functionalized perylene diimide plus CoOx cocatalyst.

A novel perylene diimide dye functionalized with phosphonate groups, N,N'-bis(phosphonomethyl)-3,4,9,10-perylenediimide (PMPDI), is synthesized and characterized. Thin films of PMPDI spin-coated onto indium tin oxide (ITO) substrates are further characterized, augmented by photoelectrochemically depositing a CoOx catalyst, and then investigated as photoanodes for water oxidation. These ITO/PMPDI/CoOx electrodes show visible-light-assisted water oxidation with photocurrents in excess of 150 µA/cm(2) at 1.0 V applied bias vs. Ag/AgCl. Water oxidation is confirmed by the direct detection of O2, with a faradaic efficiency of 80 ± 15% measured under 900 mV applied bias vs. Ag/AgCl. Analogous photoanodes prepared with another PDI derivative with alkyl groups in place of PMPDI's phosphonate groups do not function, providing evidence that PMPDI's phosphonate groups may be important for efficient coupling between the inorganic CoOx catalyst and the organic dye. Our ITO/PMPDI/CoOx anodes achieve internal quantum efficiencies for water oxidation ∼1%, and for hydroquinone oxidation of up to ∼6%. The novelty of our system is that, to the best of our knowledge, it is the first device to achieve photoelectrochemically driven water oxidation by a single-layer molecular organic semiconductor thin film coupled to a water-oxidation catalyst.

Amyloid-first and neurodegeneration-first profiles characterize incident amyloid PET positivity.

OBJECTIVE: To estimate the incidence of and to characterize cognitive and imaging findings associated with incident amyloid PET positivity. METHODS: Cognitively normal (CN) participants in the Mayo Clinic Study of Aging who had 2 or more serial imaging assessments, which included amyloid PET, FDG-PET, and MRI at each time point, were eligible for analysis (n = 207). Twelve subjects with Alzheimer disease dementia were included for comparison. RESULTS: Of the 123 CN participants who were amyloid-negative at baseline, 26 met criteria for incident amyloid PET positivity. Compared to the 69 subjects who remained stable amyloid-negative, on average these 26 did not differ on any imaging, demographic, or cognitive variables except amyloid PET (by definition) and task-free functional connectivity, which at baseline was greater in the incident amyloid-positive group. Eleven of the 26 incident amyloid-positive subjects had abnormal hippocampal volume, FDG-PET, or both at baseline. CONCLUSIONS: The incidence of amyloid PET positivity is approximately 13% per year among CN participants over age 70 sampled from a population-based cohort. In 15/26 (58%), incident amyloid positivity occurred prior to abnormalities in FDG-PET and hippocampal volume. However, 11/26 (42%) incident amyloid-positive subjects had evidence of neurodegeneration prior to incident amyloid positivity. These 11 could be subjects with combinations of preexisting non-Alzheimer pathophysiologies and tau-mediated neurodegeneration who newly entered the amyloid pathway. Our findings suggest that both "amyloid-first" and "neurodegeneration-first" biomarker profile pathways to preclinical AD exist.

Non-stationarity in the "resting brain's" modular architecture.

Task-free functional magnetic resonance imaging (TF-fMRI) has great potential for advancing the understanding and treatment of neurologic illness. However, as with all measures of neural activity, variability is a hallmark of intrinsic connectivity networks (ICNs) identified by TF-fMRI. This variability has hampered efforts to define a robust metric of connectivity suitable as a biomarker for neurologic illness. We hypothesized that some of this variability rather than representing noise in the measurement process, is related to a fundamental feature of connectivity within ICNs, which is their non-stationary nature. To test this hypothesis, we used a large (n = 892) population-based sample of older subjects to construct a well characterized atlas of 68 functional regions, which were categorized based on independent component analysis network of origin, anatomical locations, and a functional meta-analysis. These regions were then used to construct dynamic graphical representations of brain connectivity within a sliding time window for each subject. This allowed us to demonstrate the non-stationary nature of the brain's modular organization and assign each region to a "meta-modular" group. Using this grouping, we then compared dwell time in strong sub-network configurations of the default mode network (DMN) between 28 subjects with Alzheimer's dementia and 56 cognitively normal elderly subjects matched 1:2 on age, gender, and education. We found that differences in connectivity we and others have previously observed in Alzheimer's disease can be explained by differences in dwell time in DMN sub-network configurations, rather than steady state connectivity magnitude. DMN dwell time in specific modular configurations may also underlie the TF-fMRI findings that have been described in mild cognitive impairment and cognitively normal subjects who are at risk for Alzheimer's dementia.

Compensating poly(3-hexylthiophene) reveals its doping density and its strong exciton quenching by free carriers.

Adding increasing quantities of an n-type compensating dopant, cobaltocene, to poly(3-hexylthiophene) reveals an almost perfect mirror symmetry between the conductivity and the luminescence intensity. The sharp minimum/maximum shows that the uncompensated p-type doping density is 1.2 × 10(18) cm(-3) and that excitons are strongly quenched by free charge carriers, not by bound charges.

Palladium-catalyzed direct arylation of imidazolone N-oxides with aryl bromides and its application in the synthesis of GSK2137305.

The palladium-catalyzed direct arylation of imidazolone N-oxides with aryl bromides to afford the corresponding 4-aryl imidazolone N-oxides is described. This method has been successfully used for the synthesis of GSK2137305.

Cross-linked perylene diimide-based n-type interfacial layer for inverted organic photovoltaic devices.

This contribution describes the synthesis and characterization of a perylene diimide (PDI)-based n-type semiconductor and its application to organic photovoltaic (OPV) devices having inverted architecture. Films of N,N'-bis(3-trimethoxysilylpropyl)-1,6,7,12-tetrachloroperylene-3,4,9,10-tetracarboxyldiimide (Cl(4)PSi(2)) and blends of this material with various polymers are solution-deposited on tin-doped indium oxide (ITO) substrates as interfacial layers (IFLs). The organic IFL described in this work is based on the air- and light-stable PDI core, annealed at low temperatures compatible with flexible substrates, and crosslinks in air for compatibility with device fabrication. Morphological, optical, and electrochemical analysis of these IFL films demonstrate predominantly smooth surfaces and HOMO and LUMO energies of ~4.5 and 7.0 eV, respectively, which are ideal for accepting electrons and blocking holes in inverted devices. A cationic silane species is added to the Cl(4)PSi(2) at an optimum ~2-5 wt % to reduce IFL series resistance and enhance device performance. Also, a short light soaking procedure is necessary for completed devices to achieve high fill factors in current density-voltage analysis, a phenomenon previously only observed for inverted devices having an n-type inorganic IFL.

Chemically treating poly(3-hexylthiophene) defects to improve bulk heterojunction photovoltaics.

Defect engineering has been of vital importance to the development of inorganic semiconductors. Here, we report the chemical modification of electrical defects in the prototypical organic semiconductor, regioregular poly(3-hexylthiophene), P3HT. Previously, we have covalently treated defect sites with either a nucleophile or an electrophile, leaving the defects of primarily opposite polarity. Consecutively using both nucleophilic and electrophilic treatments allows us to covalently fix both positively and negatively charged defect sites in a single procedure. Here we describe the effects of treating P3HT first with lithium aluminum hydride, LAH, to decrease the overall defect density, and then with dimethylsulfate, Me(2)SO(4), to eliminate some of the remaining n-type defects (equivalent to a p-type doping process). The resulting polymer, P3HT_LAH_Me(2)SO(4), behaves differently than the polymer obtained when the order of treatments is reversed, P3HT_Me(2)SO(4)_LAH. Slightly improved structural and optical differences between these two new polymers and the starting P3HT are observed, whereas greatly improved electrical differences are found. Both treatments improve the performance of the photovoltaic cells, especially the short circuit current and the fill factor, and increase the stability against photodegradation. The significantly decreased series resistance and increased shunt resistance with a combined treatment suggest improved charge transport in the cell. The effective doping density can be increased or decreased with these treatments while the carrier mobility and the exciton diffusion length increase. It should be possible to employ these simple chemical treatments with any π-conjugated polymer to beneficially modify, or eliminate, some of its electronic defects. As a consequence, our approach provides a new method of improving the air-stability and electrical characteristics for organic photovoltaic and other electronic applications.

Homeotropic alignment and director structures in thin films of triphenylamine-based discotic liquid crystals controlled by supporting nanostructured substrates and surface confinement.

We explore the effects of nanoscale morphology of supporting solid substrates on alignment, defects, and director structures exhibited by thin films of triphenylamine-based discotic liquid crystals. Fluorescence confocal polarizing microscopy and intrinsic polarized fluorescence properties of studied molecules are used to visualize three-dimensional director fields in the liquid crystal films. We demonstrate that, by controlling surface anchoring on supporting or confining solid substrates such as those of carbon nanotube electrodes on glass plates, both uniform homeotropic and in-plane (edge-on) alignment and nonuniform structures with developable domains can be achieved for the same discotic liquid crystal material.

Design and synthesis of aryl ether and sulfone hydroxamic acids as potent histone deacetylase (HDAC) inhibitors.

A series of novel hydroxamic acid based histone deacetylases (HDAC) inhibitors with aryl ether and aryl sulfone residues at the terminus of a substituted, unsaturated 5-carbon spacer moiety have been synthesized for the first time and evaluated. Compounds with meta- and para-substitution on the aryl ring of ether hydroxamic acids 19c, 20c, 19e, 19f and 19g are potent HDAC inhibitors with activities at low nanomolar levels.

Expedient Lewis acid catalyzed synthesis of a 3-substituted 5-arylidene-1-methyl-2-thiohydantoin Library.

An efficient and rapid solution phase combinatorial synthesis of a 3-substituted 5-arylidene-1-methyl-2-thiohydantoin library was developed. The salient feature for this library production procedure is the addition of the Lewis acid catalyst, indium(III) trifluoromethanesulfonate, which serves to facilitate the direct condensation of aldehydes with 3-substituted 1-methyl-2-thiohydantoins. Use of this Lewis acid catalyst has resulted in faster reaction times, higher conversions and better purity profiles for these condensation reactions as compared to traditional uncatalyzed reactions. The resulting 315 member library of 3-substituted 5-arylidene-1-methyl-2-thiohydantoin is described.

Indium(III) trifluoromethanesulfonate as an efficient catalyst for the deprotection of acetals and ketals.

Acetals and ketals are readily deprotected under neutral conditions in the presence of acetone and catalytic amounts of indium(III) trifluoromethanesulfonate (<0.8 mol %) at room temperature or mild microwave heating conditions to give the corresponding aldehydes and ketones in good to excellent yields.