Measurement of a solid-state triple point at the metal-insulator transition in VO2.

First-order phase transitions in solids are notoriously challenging to study. The combination of change in unit cell shape, long range of elastic distortion and flow of latent heat leads to large energy barriers resulting in domain structure, hysteresis and cracking. The situation is worse near a triple point, where more than two phases are involved. The well-known metal-insulator transition in vanadium dioxide, a popular candidate for ultrafast optical and electrical switching applications, is a case in point. Even though VO2 is one of the simplest strongly correlated materials, experimental difficulties posed by the first-order nature of the metal-insulator transition as well as the involvement of at least two competing insulating phases have led to persistent controversy about its nature. Here we show that studying single-crystal VO2 nanobeams in a purpose-built nanomechanical strain apparatus allows investigation of this prototypical phase transition with unprecedented control and precision. Our results include the striking finding that the triple point of the metallic phase and two insulating phases is at the transition temperature, Ttr = Tc, which we determine to be 65.0 ± 0.1 °C. The findings have profound implications for the mechanism of the metal-insulator transition in VO2, but they also demonstrate the importance of this approach for mastering phase transitions in many other strongly correlated materials, such as manganites and iron-based superconductors.

Executive functioning in a racially diverse sample of children who are overweight and at risk for eating disorders.

Difficulties with executive functioning may underlie both overweight and loss of control (LOC) eating behavior across the age spectrum, but there is a relative paucity of research in children with both conditions. This study aimed to characterize general executive functioning among children with overweight and LOC eating as compared to their overweight and normal-weight peers. Participants were 75 racially diverse children (58.7% female; 81.3% African-American), aged 9-12y (M age = 10.5 ± 1.1), of whom 26 were overweight/obese and endorsed LOC eating (OW-LOC), 34 were overweight controls (OW-CON), and 15 were normal-weight controls (NW-CON). All children completed interview-based measures of eating pathology, and behavioral measures of executive functioning. Parents reported on behavioral facets of children's executive functioning. Groups were compared across parent-report measures and behavioral tasks using analyses of covariance (ANCOVAs) and multivariate analyses of covariance (MANCOVAs) which adjusted for general intellectual functioning. Significant group differences were revealed on a behavioral measure of planning, the Tower of London task [F (5,65) = 3.52; p = 0.007], and a behavioral measure of working memory, the List Sorting task [F (2,71) = 6.45; p = 0.003]. Post-hoc tests revealed that OW-LOC and OW-CON performed worse than NW-CON on the Tower of London, with relative decrements in accuracy rather than performance time. Further, OW-LOC performed worse than both OW-CON and NW-CON on the List Sorting task. Overweight with or without concomitant LOC eating in children may characterize a unique pattern of executive dysfunction. Interventions for eating- and weight-related problems in youth should address underlying deficits in planning and working memory.

Effect of Sleep-disordered Breathing Severity on Cognitive Performance Measures in a Large Community Cohort of Young School-aged Children.

RATIONALE: Sleep-disordered breathing (SDB) in children is associated with cognitive challenges. However, potential associations between SDB severity and neurocognitive function, as well as the presence of an SDB cutoff, have not been fully explored. OBJECTIVES: To determine whether SDB-associated adverse changes in neurocognitive functioning are severity dependent. METHODS: A total of 1,010 snoring and nonsnoring children ages 5-7 years were prospectively recruited from public schools and underwent polysomnography and neurocognitive assessments of intellectual, attention, memory, language, and executive function development. The children were subdivided into four severity groups on the basis of apnea-hypopnea index (AHI), followed by comparisons of cognitive function, with a particular focus on standardized subtests of intellectual, language, attention, memory, and executive function. MEASUREMENT AND MAIN RESULTS: Differential Ability Scales Verbal (P < 0.001) and Nonverbal (P = 0.002) performance, as well as global conceptual ability (IQ) (P < 0.001) scores, differed significantly across the groups, with individuals with higher AHI showing worse performance. Additionally, specific NEPSY (a Developmental Neuropsychological Assessment) subscores focused on attention and executive skills differed across the groups, indicating differences in levels of engagement and problem solving. Children with higher AHI (>5 per hour of total sleep time) were significantly more impaired than all three lower AHI groups, indicating a dose-response impact of SDB. CONCLUSIONS: This large community-based sample of children highlights the significant deleterious impact of SDB, particularly in children with moderate to severe obstructive sleep apnea, and also that even snoring alone affects neurocognitive function. By affecting developing capabilities, as illustrated by cognitive measures in a severity-graded manner, SDB could adversely impact children's capacity to attain academic and adaptive goals, ultimately hampering their ability to reach independence. Our findings support the need for increased awareness of SDB, with particular emphasis on children with more severe obstructive sleep apnea.

Observer variability identifying attention deficit/hyperactivity disorder in 10-year-old children born extremely preterm.

AIM: A DSM-5 diagnosis of attention deficit/hyperactive disorder (ADHD) requires that symptoms be present in two settings. We wanted to see how teachers and parents compare on their assessments. METHODS: We evaluated how well Child Symptom Inventory-4 (CSI-4) reports from 871 parents and 634 teachers of 10-year-old children born before the 28th week of gestation provided information about indicators of school dysfunction. RESULTS: Kappa values for parent and teacher agreement of any ADHD were at best fair to poor (<0.41). Nevertheless, ADHD identified by each alone provided a moderate amount of information about such indicators of school dysfunction as grade repetition. Only occasionally did agreement provide more information than provided by only one reporter. Mother's social class and intelligence level did not discriminate between parents who did and did not agree with the teacher. CONCLUSION: ADHD identified by a single observer can provide appreciable information about a range of the child's functions needed for success in school and, therefore, should not be discounted when another observer does not consider the child to have ADHD symptoms.

Antiretroviral Drug Resistance Among Children and Youth in the United States With Perinatal HIV.

Among 234 US youths with perinatal human immunodeficiency virus, 75% had antiretroviral resistance, substantially higher than that of the reference laboratory overall (36%-44%). Resistance to newer antiretrovirals and to all antiretrovirals in a class was uncommon. The only factor independently associated with future resistance was a higher peak viral load.

Prevalence and Persistence of Varicella Antibodies in Previously Immunized Children and Youth With Perinatal HIV-1 Infection.

BACKGROUND: Two doses of live-attenuated varicella-zoster vaccine are recommended for human immunodeficiency virus 1 (HIV-1)-infected children with CD4% ≥ 15%. We determined the prevalence and persistence of antibody in immunized children with perinatal HIV (PHIV) and their association with number of vaccinations, combination antiretroviral therapy (cART), and HIV status. METHODS: The Adolescent Master Protocol is an observational study of children with PHIV and perinatally HIV-exposed but uninfected (PHEU) children conducted at 15 US sites. In a cross-sectional analysis, we tested participants' most recent stored sera for varicella antibody using whole-cell and glycoprotein enzyme-linked immunosorbent assay. Seropositivity predictors were identified using multivariable logistic regression models and C statistics. RESULTS: Samples were available for 432 children with PHIV and 221 PHEU children; 82% of children with PHIV and 97% of PHEU children were seropositive (P < .001). Seropositivity after 1 vaccine dose among children with PHIV and PHEU children was 100% at <3 years (both), 73% and 100% at 3-<7 years (P < .05), and 77% and 97% at ≥ 7 years (P < .01), respectively. Seropositivity among recipients of 2 vaccine doses was >94% at all intervals. Independent predictors of seropositivity among children with PHIV were receipt of 2 vaccine doses, receipt of 1 dose while on ≥ 3 months of cART, compared with none (adjusted odds ratio [aOR]: 14.0 and 2.8, respectively; P < .001 for overall dose effect), and in those vaccinated ≥ 3 years previously, duration of cART (aOR: 1.29 per year increase, P = .02). CONCLUSIONS: Humoral immune responses to varicella vaccine are best achieved when children with PHIV receive their first dose ≥ 3 months after cART initiation and maintained by completion of the 2-dose series and long-term cART use.

Impact of sleep disordered breathing on behaviour among elementary school-aged children: a cross-sectional analysis of a large community-based sample.

Sleep disordered breathing (SDB) in children has been associated with inattention, impulsivity and hyperactivity, but the associations between SDB severity and the type and severity of behavioural disruption are unclear.1022 children aged 5-7 years old prospectively underwent sleep studies and behavioural assessments through completion of standardised instruments. Participants were subdivided into four categorical groups based on the apnoea-hypopnoea index (AHI; measured per hour of total sleep time (hTST)), i.e. Group 1: nonsnoring and AHI <1 hTST-1; Group 2: habitual snoring and AHI <1 hTST-1; Group 3: habitual snoring and AHI 1-5 hTST-1; and Group 4: habitual snoring and AHI >5 hTST-1, followed by comparisons of behavioural functioning across the groups.All 10 behavioural variables differed significantly between Group 1 and all other groups. Post hoc comparisons indicated that Group 2 was the most impaired for most behavioural measures. Furthermore, differences between Group 2 and more severe sleep pathology conditions were rarely significant.This large community-based paediatric cohort confirms earlier findings highlighting a significant impact of SDB on behavioural regulation, with the greatest impact being already apparent among habitually snoring children. Thus, a likely low asymptote exists regarding SDB behavioural impact, such that further increases in severity do not measurably increase parent-rated difficulties with behavioural regulation relative to controls. Our findings do support the need for considering early intervention, particularly among those children manifesting a behavioural impact of SDB.

Superhydrophobic materials and coatings: a review.

Over the past few years, the scientific community, as well as the world's coatings industry has seen the introduction of oxide/polymer-based superhydrophobic surfaces and coatings with exceptional water repellency. Online videos have caught the public's imagination by showing people walking through mud puddles without getting their tennis shoes wet or muddy, and water literally flying off coated surfaces. This article attempts to explain the basics of this behavior and to discuss and explain the latest superhydrophobic technological breakthroughs. Since superhydrophobic surfaces and coatings can fundamentally change how water interacts with surfaces, and the fact that earth is a water world, it can legitimately be said that this technology has the potential to literally change the world.

Optically transparent and environmentally durable superhydrophobic coating based on functionalized SiO2 nanoparticles.

Optical surfaces such as mirrors and windows that are exposed to outdoor environmental conditions are susceptible to dust buildup and water condensation. The application of transparent superhydrophobic coatings on optical surfaces can improve outdoor performance via a 'self-cleaning' effect similar to the Lotus effect. The contact angle (CA) of water droplets on a typical hydrophobic flat surface varies from 100° to 120°. Adding roughness or microtexture to a hydrophobic surface leads to an enhancement of hydrophobicity and the CA can be increased to a value in the range of 160°-175°. This result is remarkable because such behavior cannot be explained using surface chemistry alone. When surface features are on the order of 100 nm or smaller, they exhibit superhydrophobic behavior and maintain their optical transparency. In this work we discuss our results on transparent superhydrophobic coatings that can be applied across large surface areas. We have used functionalized silica nanoparticles to coat various optical elements and have measured the CA and optical transmission between 190 and 1100 nm on these elements. The functionalized silica nanoparticles were dissolved in a solution of the solvents, while the binder used was a polyurethane clearcoat. This solution was spin-coated onto a variety of test glass substrates, and following a curing period of about 30 min, these coatings exhibited superhydrophobic behavior with a static CA ≥ 160°.

Cognitive and psychosocial phenotype of young children with neurofibromatosis-1.

Children with neurofibromatosis-1 (NF1), a neurodevelopmental disorder resulting from a mutation of the NF1 gene (17q11.2), often have difficulties with learning and attention, but there is little research in the early childhood years. In this study, the cognitive and psychosocial functioning of 40 young children with NF1 (ages 3 through 6) was examined and compared both to normative data and to a contrast group comprised of unaffected siblings and community members matched for age and socio-economic status (n = 37). Children with NF1 showed significantly weaker cognitive abilities across all domains and for the vast majority of subtests. Consistent with research in older children, a variety of patterns of intra-individual strength and weakness were present for young children with NF1. Few significant group differences in psychosocial functioning were observed, but the children with NF1 showed significantly greater functional communication problems than did the unaffected group. Overall, the results indicate that in participant groups matched for age and socioeconomic status, cognitive vulnerabilities are evident for close to half of young children with NF1, with some relations to psychosocial functioning, particularly functional communication, attention problems and social skills.

Population-Level Portal-Based Anxiety and Depression Screening Perspectives in HIV Care Clinicians: Qualitative Study Using the Consolidated Framework for Implementation Research.

BACKGROUND: Depression and anxiety are common among people with HIV and are associated with inadequate viral suppression, disease progression, and increased mortality. However, depression and anxiety are underdiagnosed and undertreated in people with HIV owing to inadequate visit time and personnel availability. Conducting population-level depression and anxiety screening via the patient portal is a promising intervention that has not been studied in HIV care settings. OBJECTIVE: We aimed to explore facilitators of and barriers to implementing population-level portal-based depression and anxiety screening for people with HIV. METHODS: We conducted semistructured hour-long qualitative interviews based on the Consolidated Framework for Implementation Research with clinicians at an HIV clinic. RESULTS: A total of 10 clinicians participated in interviews. In total, 10 facilitators and 7 barriers were identified across 5 Consolidated Framework for Implementation Research domains. Facilitators included advantages of systematic screening outside clinic visits; the expectation that assessment frequency could be tailored to patient needs; evidence from the literature and previous experience in other settings; respect for patient privacy; empowering patients and facilitating communication about mental health; compatibility with clinic culture, workflows, and systems; staff beliefs about the importance of mental health screening and benefits for HIV care; engaging all clinic staff and leveraging their strengths; and clear planning and communication with staff. Barriers included difficulty in ensuring prompt response to suicidal ideation; patient access, experience, and comfort using the portal; limited availability of mental health services; variations in how providers use the electronic health record and communicate with patients; limited capacity to address mental health concerns during HIV visits; staff knowledge and self-efficacy regarding the management of mental health conditions; and the impersonal approach to a sensitive topic. CONCLUSIONS: We proposed 13 strategies for implementing population-level portal-based screening for people with HIV. Before implementation, clinics can conduct local assessments of clinicians and clinic staff; engage clinicians and clinic staff with various roles and expertise to support the implementation; highlight advantages, relevance, and evidence for population-level portal-based mental health screening; make screening frequency adaptable based on patient history and symptoms; use user-centered design methods to refine results that are displayed and communicated in the electronic health record; make screening tools available for patients to use on demand in the portal; and create protocols for positive depression and anxiety screeners, including those indicating imminent risk. During implementation, clinics should communicate with clinicians and clinic staff and provide training on protocols; provide technical support and demonstrations for patients on how to use the portal; use multiple screening methods for broad reach; use patient-centered communication in portal messages; provide clinical decision support tools, training, and mentorship to help clinicians manage mental health concerns; and implement integrated behavioral health and increase mental health referral partnerships.

Patient Perspectives on Portal-Based Anxiety and Depression Screening in HIV Care: A Qualitative Study Using the Consolidated Framework for Implementation Research.

Electronic patient portals represent a promising means of integrating mental health assessments into HIV care where anxiety and depression are highly prevalent. Patient attitudes toward portal-based mental health screening within HIV clinics have not been well described. The aim of this formative qualitative study is to characterize the patient-perceived facilitators and barriers to portal-based anxiety and depression screening within HIV care in order to inform implementation strategies for mental health screening. Twelve adult HIV clinic patients participated in semi-structured interviews that were audio recorded and transcribed. The transcripts were coded using constructs from the Consolidated Framework for Implementation Research and analyzed thematically to identify the barriers to and facilitators of portal-based anxiety and depression screening. Facilitators included an absence of alternative screening methods, an approachable design, perceived adaptability, high compatibility with HIV care, the potential for linkage to treatment, an increased self-awareness of mental health conditions, the ability to bundle screening with clinic visits, and communicating an action plan for results. The barriers included difficulty navigating the patient portal system, a lack of technical support, stigmatization from the healthcare system, care team response times, and the novelty of using patient portals for communication. The patients in the HIV clinic viewed the use of a portal-based anxiety and depression screening tool as highly compatible with routine HIV care. Technical difficulties, follow-up concerns, and a fear of stigmatization were commonly perceived as barriers to portal use. The results of this study can be used to inform implementation strategies when designing or incorporating portal-based mental health screening into other HIV care settings.

Optically transparent, mechanically durable, nanostructured superhydrophobic surfaces enabled by spinodally phase-separated glass thin films.

We describe the formation and properties of atomically bonded, optical quality, nanostructured thin glass film coatings on glass plates, utilizing phase separation by spinodal decomposition in a sodium borosilicate glass system. Following deposition via magnetron sputtering, thermal processing and differential etching, these coatings are structurally superhydrophilic (i.e., display anti-fogging functionality) and demonstrate robust mechanical properties and superior abrasion resistance. After appropriate chemical surface modification, the surfaces display a stable, non-wetting Cassie-Baxter state and exhibit exceptional superhydrophobic performance, with water droplet contact angles as large as 172°. As an added benefit, in both superhydrophobic and superhydrophilic states these nanostructured surfaces can block ultraviolet radiation and can be engineered to be anti-reflective with broadband and omnidirectional transparency. Thus, the present approach could be tailored toward distinct coatings for numerous markets, such as residential windows, windshields, specialty optics, goggles, electronic and photovoltaic cover glasses, and optical components used throughout the US military.

Metabolic abnormalities and viral replication are associated with biomarkers of vascular dysfunction in HIV-infected children.

OBJECTIVES: HIV-infected children may be at risk for premature cardiovascular disease. We compared levels of biomarkers of vascular dysfunction in HIV-infected children (with and without hyperlipidaemia) with those in HIV-exposed, uninfected (HEU) children enrolled in the Pediatric HIV/AIDS Cohort Study (PHACS), and determined factors associated with these biomarkers. METHODS: A prospective cohort study was carried out. Biomarkers of inflammation [C-reactive protein (CRP), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP1)], coagulant dysfunction (fibrinogen and P-selectin), endothelial dysfunction [soluble intracellular cell adhesion molecule-1 (sICAM), soluble vascular cell adhesion molecule-1 (sVCAM) and E-selectin], and metabolic dysfunction (adiponectin) were measured in 226 HIV-infected and 140 HEU children. Anthropometry, body composition, lipids, glucose, insulin, HIV disease severity, and antiretroviral therapy were recorded. RESULTS: The median ages of the children were 12.3 years in the HIV-infected group and 10.1 years in the HEU group. Body mass index (BMI) z-scores, waist and hip circumferences, and percentage body fat were lower in the HIV-infected children. Total and non-high-density lipoprotein (HDL) cholesterol and triglycerides were higher in HIV-infected children. HIV-infected children also had higher MCP-1, fibrinogen, sICAM and sVCAM levels. In multivariable analyses in the HIV-infected children alone, BMI z-score was associated with higher CRP and fibrinogen, but lower MCP-1 and sVCAM. Unfavourable lipid profiles were positively associated with IL-6, MCP-1, fibrinogen, and P- and E-selectin, whereas increased HIV viral load was associated with markers of inflammation (MCP-1 and CRP) and endothelial dysfunction (sICAM and sVCAM). CONCLUSIONS: HIV-infected children have higher levels of biomarkers of vascular dysfunction than do HEU children. Risk factors associated with higher biomarkers include unfavourable lipid levels and active HIV replication.

Childhood adversity and DNA methylation of genes involved in the hypothalamus-pituitary-adrenal axis and immune system: whole-genome and candidate-gene associations.

In recent years, translational research involving humans and animals has uncovered biological and physiological pathways that explain associations between early adverse circumstances and long-term mental and physical health outcomes. In this article, we summarize the human and animal literature demonstrating that epigenetic alterations in key biological systems, the hypothalamus-pituitary-adrenal axis and immune system, may underlie such disparities. We review evidence suggesting that changes in DNA methylation profiles of the genome may be responsible for the alterations in hypothalamus-pituitary-adrenal axis and immune system trajectories. Using some preliminary data, we demonstrate how explorations of genome-wide and candidate-gene DNA methylation profiles may inform hypotheses and guide future research efforts in these areas. We conclude our article by discussing the many important future directions, merging perspectives from developmental psychology, molecular genetics, neuroendocrinology, and immunology, that are essential for furthering our understanding of how early adverse circumstances may shape developmental trajectories, particularly in the areas of stress reactivity and physical or mental health.

The mental and physical health of homeless youth: a literature review.

Youth homelessness is a growing concern in the United States. Despite difficulties studying this population due to inconsistent definitions of what it means to be a youth and homeless, the current body of research indicates that abuse, family breakdown, and disruptive family relationships are common contributing factors to youth homelessness. Moreover, the experience of homelessness appears to have numerous adverse implications and to affect neurocognitive development and academics, as well as mental and physical health. Substance use, sexually transmitted infections, and psychiatric disorders are particularly prevalent in this population. Whereas some of these problems may be short-lived, the chronic stress and deprivation associated with homelessness may have long-term effects on development and functioning. Further, difficulties accessing adequate and developmentally-appropriate health care contribute to more serious health concerns. Suggestions for future research and interventions are discussed.

Cognition in pediatric SDB-Yes, no, maybe?

Numerous studies in the past 10 years have reported on the neurocognitive sequalae of pediatric sleep disordered breathing (SDB). Variations in criteria used to define SDB in conjunction with the wide variety of neuropsychological measures selected to evaluate cognitive consequences of SDB have resulted in discrepancies within the literature. This review summarizes the extent literature regarding cognitive effects of pediatric SDB across domains of global intelligence, attention, executive function, memory, language, and visuospatial ability. This review also addresses the proposed etiology underlying neurocognitive consequences of pediatric SDB. The differences in findings across the literature are highlighted and discussed throughout.

Engaging with families in child protection: lessons from practitioner research in Scotland.

This paper reports findings from practitioner-led research on engagement with families in the child protection system in Scotland. Engagement is here defined in a participative sense, to mean the involvement of family members in shaping social work processes. Key findings include the importance of workers building trusting relationships; the value of honest and clear communication, information, and explanation; and the potential for formal structures such as reports and meetings to hinder family engagement. These findings contribute to a growing critique of managerialism in social work.

Chasing language through the brain: Successive parallel networks.

OBJECTIVE: To describe the spatio-temporal dynamics and interactions during linguistic and memory tasks. METHODS: Event-related electrocorticographic (ECoG) spectral patterns obtained during cognitive tasks from 26 epilepsy patients (aged: 9-60 y) were analyzed in order to examine the spatio-temporal patterns of activation of cortical language areas. ECoGs (1024 Hz/channel) were recorded from 1567 subdural electrodes and 510 depth electrodes chronically implanted over or within the frontal, parietal, occipital and/or temporal lobes as part of their surgical work-up for intractable seizures. Six language/memory tasks were performed, which required responding verbally to auditory or visual word stimuli. Detailed analysis of electrode locations allowed combining results across patients. RESULTS: Transient increases in induced ECoG gamma power (70-100 Hz) were observed in response to hearing words (central superior temporal gyrus), reading text and naming pictures (occipital and fusiform cortex) and speaking (pre-central, post-central and sub-central cortex). CONCLUSIONS: Between these activations there was widespread spatial divergence followed by convergence of gamma activity that reliably identified cortical areas associated with task-specific processes. SIGNIFICANCE: The combined dataset supports the concept of functionally-specific locally parallel language networks that are widely distributed, partially interacting in succession to serve the cognitive and behavioral demands of the tasks.