Educational and employment outcomes associated with childhood traumatic brain injury in Scotland: A population-based record-linkage cohort study.

BACKGROUND: Traumatic brain injury (TBI) is a leading cause of death and disability among young children and adolescents and the effects can be lifelong and wide-reaching. Although there have been numerous studies to evaluate the impact of childhood head injury on educational outcomes, few large-scale studies have been conducted, and previous research has been limited by issues of attrition, methodological inconsistencies, and selection bias. We aim to compare the educational and employment outcomes of Scottish schoolchildren previously hospitalised for TBI with their peers. METHODS AND FINDINGS: A retrospective, record-linkage population cohort study was conducted using linkage of health and education administrative records. The cohort comprised all 766,244 singleton children born in Scotland and aged between 4 and 18 years who attended Scottish schools at some point between 2009 and 2013. Outcomes included special educational need (SEN), examination attainment, school absence and exclusion, and unemployment. The mean length of follow up from first head injury varied by outcome measure; 9.44 years for assessment of SEN and 9.53, 12.70, and 13.74 years for absenteeism and exclusion, attainment, and unemployment, respectively. Logistic regression models and generalised estimating equation (GEE) models were run unadjusted and then adjusted for sociodemographic and maternity confounders. Of the 766,244 children in the cohort, 4,788 (0.6%) had a history of hospitalisation for TBI. The mean age at first head injury admission was 3.73 years (median = 1.77 years). Following adjustment for potential confounders, previous TBI was associated with SEN (OR 1.28, CI 1.18 to 1.39, p < 0.001), absenteeism (IRR 1.09, CI 1.06 to 1.12, p < 0.001), exclusion (IRR 1.33, CI 1.15 to 1.55, p < 0.001), and low attainment (OR 1.30, CI 1.11 to 1.51, p < 0.001). The average age on leaving school was 17.14 (median = 17.37) years among children with a TBI and 17.19 (median = 17.43) among peers. Among children previously admitted for a TBI, 336 (12.2%) left school before age 16 years compared with 21,941 (10.2%) of those not admitted for TBI. There was no significant association with unemployment 6 months after leaving school (OR 1.03, CI 0.92 to 1.16, p = 0.61). Excluding hospitalisations coded as concussion strengthened the associations. We were not able to investigate age at injury for all outcomes. For TBI occurring before school age, it was impossible to be certain that SEN had not predated the TBI. Therefore, potential reverse causation was a limitation for this outcome. CONCLUSIONS: Childhood TBI, sufficiently severe to warrant hospitalisation, was associated with a range of adverse educational outcomes. These findings reinforce the importance of preventing TBI where possible. Where not possible, children with a history of TBI should be supported to minimise the adverse impacts on their education.

Infant feeding method and special educational need in 191,745 Scottish schoolchildren: A national, population cohort study.

BACKGROUND: While special educational needs (SEN) are increasingly recorded among schoolchildren, infant breastfeeding has been associated with reduced incidence of childhood physical and mental health problems. This study investigated relationships between infant feeding method and risk of all-cause and cause-specific SEN. METHODS AND FINDINGS: A population cohort of schoolchildren in Scotland was constructed by linking together health (maternity, birth, and health visitor records) and education (annual school pupil census) databases. Inclusion was restricted to singleton children, born in Scotland from 2004 onwards with available breastfeeding data and who attended local authority mainstream or special schools between 2009 and 2013. Generalised estimating equation models with a binomial distribution and logit link function investigated associations between infant feeding method at 6 to 8 weeks and all-cause and cause-specific SEN, adjusting for sociodemographic and maternity factors. Of 191,745 children meeting inclusion criteria, 126,907 (66.2%) were formula-fed, 48,473 (25.3%) exclusively breastfed, and 16,365 (8.5%) mixed-fed. Overall, 23,141 (12.1%) children required SEN. Compared with formula feeding, mixed feeding and exclusive breastfeeding, respectively, were associated with decreased all-cause SEN (OR 0.90, 95% CI [0.84,0.95], p < 0.001 and 0.78, [0.75,0.82], p < 0.001), and SEN attributed to learning disabilities (0.75, [0.65,0.87], p < 0.001 and 0.66, [0.59,0.74], p < 0.001), and learning difficulties (0.85, [0.77,0.94], p = 0.001 and 0.75, [0.70,0.81], p < 0.001). Compared with formula feeding, exclusively breastfed children had less communication problems (0.81, [0.74,0.88], p = 0.001), social-emotional-behavioural difficulties (0.77, [0.70,0.84], p = 0.001), sensory impairments (0.79, [0.65,0.95], p = 0.01), physical motor disabilities (0.78, [0.66,0.91], p = 0.002), and physical health conditions (0.74, [0.63,0.87], p = 0.01). There were no significant associations for mixed-fed children (communication problems (0.94, [0.83,1.06], p = 0.312), social-emotional-behavioural difficulties (0.96, [0.85,1.09], p = 0.541), sensory impairments (1.07, [0.84,1.37], p = 0.579), physical motor disabilities (0.97, [0.78,1.19], p = 0.754), and physical health conditions (0.93, [0.74,1.16], p = 0.504)). Feeding method was not significantly associated with mental health conditions (exclusive 0.58 [0.33,1.03], p = 0.061 and mixed 0.74 [0.36,1.53], p = 0.421) or autism (exclusive 0.88 [0.77,1.01], p = 0.074 and mixed 1.01 [0.84,1.22], p = 0.903). Our study was limited since only 6- to 8-week feeding method was available precluding differentiation between never-breastfed infants and those who stopped breastfeeding before 6 weeks. Additionally, we had no data on maternal and paternal factors such as education level, IQ, employment status, race/ethnicity, or mental and physical health. CONCLUSIONS: In this study, we observed that both breastfeeding and mixed feeding at 6 to 8 weeks were associated with lower risk of all-cause SEN, and SEN attributed to learning disabilities and learning difficulty. Many women struggle to exclusively breastfeed for the full 6 months recommended by WHO; however, this study provides evidence that a shorter duration of nonexclusive breastfeeding could nonetheless be beneficial with regard to the development of SEN. Our findings augment the existing evidence base concerning the advantages of breastfeeding and reinforce the importance of breastfeeding education and support.

Age within schoolyear and attention-deficit hyperactivity disorder in Scotland and Wales.

BACKGROUND: Previous studies suggest an association between age within schoolyear and attention-deficit hyperactivity disorder (ADHD). Scotland and Wales have different school entry cut-off dates (six months apart) and policies on holding back children. We aim to investigate the association between relative age and treated attention deficit hyperactivity disorder (ADHD) in two countries, accounting for held-back children. METHODS: Routine education and health records of 1,063,256 primary and secondary schoolchildren in Scotland (2009-2013) and Wales (2009-2016) were linked. Logistic regression was used to examine the relationships between age within schoolyear and treated ADHD, adjusting for child, maternity and obstetric confounders. RESULTS: Amongst children in their expected school year, 8,721 (0.87%) had treated ADHD (Scotland 0.84%; Wales 0.96%). In Wales, ADHD increased with decreasing age (youngest quartile, adjusted OR 1.32, 95% CI 1.19-1.46) but, in Scotland, it did not differ between the youngest and oldest quartiles. Including held-back children in analysis of their expected year, the overall prevalence of treated ADHD was 0.93%, and increased across age quartiles in both countries. More children were held back in Scotland (57,979; 7.66%) than Wales (2,401; 0.78%). Held-back children were more likely to have treated ADHD (Scotland OR 2.18, 95% CI 2.01-2.36; Wales OR 1.70, 95% CI 1.21-2.31) and 81.18% of held-back children would have been in the youngest quartile of their expected year. CONCLUSIONS: Children younger within schoolyear are more likely to be treated for ADHD, suggesting immaturity may influence diagnosis. However, these children are more likely to be held back in countries that permit flexibility, attenuating the relative age effect.

Educational and health outcomes of schoolchildren in local authority care in Scotland: A retrospective record linkage study.

BACKGROUND: Looked after children are defined as children who are in the care of their local authority. Previous studies have reported that looked after children have poorer mental and physical health, increased behavioural problems, and increased self-harm and mortality compared to peers. They also experience poorer educational outcomes, yet population-wide research into the latter is lacking, particularly in the United Kingdom. Education and health share a bidirectional relationship; therefore, it is important to dually investigate both outcomes. Our study aimed to compare educational and health outcomes for looked after children with peers, adjusting for sociodemographic, maternity, and comorbidity confounders. METHODS AND FINDINGS: Linkage of 9 Scotland-wide databases, covering dispensed prescriptions, hospital admissions, maternity records, death certificates, annual pupil census, examinations, school absences/exclusions, unemployment, and looked after children provided retrospective data on 715,111 children attending Scottish schools between 2009 and 2012 (13,898 [1.9%] looked after). Compared to peers, 13,898 (1.9%) looked after children were more likely to be absent (adjusted incidence rate ratio [AIRR] 1.27, 95% confidence interval [CI] 1.24 to 1.30) and excluded (AIRR 4.09, 95% CI 3.86 to 4.33) from school, have special educational need (SEN; adjusted odds ratio [AOR] 3.48, 95% CI 3.35 to 3.62) and neurodevelopmental multimorbidity (AOR 2.45, 95% CI 2.34 to 2.57), achieve the lowest level of academic attainment (AOR 5.92, 95% CI 5.17 to 6.78), and be unemployed after leaving school (AOR 2.12, 95% CI 1.96 to 2.29). They were more likely to require treatment for epilepsy (AOR 1.50, 95% CI 1.27 to 1.78), attention deficit hyperactivity disorder (ADHD; AOR 3.01, 95% CI 2.76 to 3.27), and depression (AOR 1.90, 95% CI 1.62 to 2.22), be hospitalised overall (adjusted hazard ratio [AHR] 1.23, 95% CI 1.19 to 1.28) for injury (AHR 1.80, 95% CI 1.69 to 1.91) and self-harm (AHR 5.19, 95% CI 4.66 to 5.78), and die prematurely (AHR 3.21, 95% CI 2.16 to 4.77). Compared to children looked after at home, children looked after away from home had less absenteeism (AIRR 0.35, 95% CI 0.33 to 0.36), less exclusion (AIRR 0.63, 95% CI 0.56 to 0.71), less unemployment (AOR 0.53, 95% CI 0.46 to 0.62), and better attainment (AIRR 0.31, 95% CI 0.23 to 0.40). Therefore, among those in care, being cared for away from home appeared to be a protective factor resulting in better educational outcomes. The main limitations of this study were lack of data on local authority care preschool or before 2009, total time spent in care, and age of first contact with social care. CONCLUSIONS: Looked after children had poorer health and educational outcomes than peers independent of increased neurodevelopmental conditions and SEN. Further work is required to understand whether poorer outcomes relate to reasons for entering care, including maltreatment and adverse childhood events, neurodevelopmental vulnerabilities, or characteristics of the care system.

Neurodevelopmental multimorbidity and educational outcomes of Scottish schoolchildren: A population-based record linkage cohort study.

BACKGROUND: Neurodevelopmental conditions commonly coexist in children, but compared to adults, childhood multimorbidity attracts less attention in research and clinical practice. We previously reported that children treated for attention deficit hyperactivity disorder (ADHD) and depression have more school absences and exclusions, additional support needs, poorer attainment, and increased unemployment. They are also more likely to have coexisting conditions, including autism and intellectual disability. We investigated prevalence of neurodevelopmental multimorbidity (≥2 conditions) among Scottish schoolchildren and their educational outcomes compared to peers. METHODS AND FINDINGS: We retrospectively linked 6 Scotland-wide databases to analyse 766,244 children (390,290 [50.9%] boys; 375,954 [49.1%] girls) aged 4 to 19 years (mean = 10.9) attending Scottish schools between 2009 and 2013. Children were distributed across all deprivation quintiles (most to least deprived: 22.7%, 20.1%, 19.3%, 19.5%, 18.4%). The majority (96.2%) were white ethnicity. We ascertained autism spectrum disorder (ASD) and intellectual disabilities from records of additional support needs and ADHD and depression through relevant encashed prescriptions. We identified neurodevelopmental multimorbidity (≥2 of these conditions) in 4,789 (0.6%) children, with ASD and intellectual disability the most common combination. On adjusting for sociodemographic (sex, age, ethnicity, deprivation) and maternity (maternal age, maternal smoking, sex-gestation-specific birth weight centile, gestational age, 5-minute Apgar score, mode of delivery, parity) factors, multimorbidity was associated with increased school absenteeism and exclusion, unemployment, and poorer exam attainment. Significant dose relationships were evident between number of conditions (0, 1, ≥2) and the last 3 outcomes. Compared to children with no conditions, children with 1 condition, and children with 2 or more conditions, had more absenteeism (1 condition adjusted incidence rate ratio [IRR] 1.28, 95% CI 1.27-1.30, p < 0.001 and 2 or more conditions adjusted IRR 1.23, 95% CI 1.20-1.28, p < 0.001), greater exclusion (adjusted IRR 2.37, 95% CI 2.25-2.48, p < 0.001 and adjusted IRR 3.04, 95% CI 2.74-3.38, p < 0.001), poorer attainment (adjusted odds ratio [OR] 3.92, 95% CI 3.63-4.23, p < 0.001 and adjusted OR 12.07, 95% CI 9.15-15.94, p < 0.001), and increased unemployment (adjusted OR 1.57, 95% CI 1.49-1.66, p < 0.001 and adjusted OR 2.11, 95% CI 1.83-2.45, p < 0.001). Associations remained after further adjustment for comorbid physical conditions and additional support needs. Coexisting depression was the strongest driver of absenteeism and coexisting ADHD the strongest driver of exclusion. Absence of formal primary care diagnoses was a limitation since ascertaining depression and ADHD from prescriptions omitted affected children receiving alternative or no treatment and some antidepressants can be prescribed for other indications. CONCLUSIONS: Structuring clinical practice and training around single conditions may disadvantage children with neurodevelopmental multimorbidity, who we observed had significantly poorer educational outcomes compared to children with 1 condition and no conditions.

Herbert R. Lissner: The Father of Impact Biomechanics.

Professor Herbert R. Lissner was a pioneer in impact biomechanics, having initiated research on the injury mechanisms, mechanical response, and human tolerance of the human brain to blunt impact 80 years ago-in 1939. This paper summarizes the contributions made by Professor Lissner in head injury as well as in the many areas of impact biomechanics in which he was involved. In 1977, the Bioengineering Division of ASME established the H. R. Lissner Award to recognize outstanding career achievements in the area of biomechanics. In 1987, this award was converted to a society-wide Medal, and to date it has been awarded to 44 exemplary researchers and educators. The lead author of this paper was Professor Lissner's first and only Ph.D. student, and he offers a unique insight into his research and contributions.

Educational and health outcomes of children treated for asthma: Scotland-wide record linkage study of 683 716 children.

BACKGROUND: The global prevalence of childhood asthma is increasing. The condition impacts physical and psychosocial morbidity; therefore, wide-ranging effects on health and education outcomes are plausible. METHODS: Linkage of eight Scotland-wide databases, covering dispensed prescriptions, hospital admissions, maternity records, death certificates, annual pupil census, examinations, school absences/exclusions and unemployment, provided data on 683 716 children attending Scottish schools between 2009 and 2013. We compared schoolchildren on medication for asthma with peers, adjusting for sociodemographic, maternity and comorbidity confounders, and explored effect modifiers and mediators. RESULTS: The 45 900 (6.0%) children treated for asthma had an increased risk of hospitalisation, particularly within the first year of treatment (incidence rate ratio 1.98, 95% CI 1.93-2.04), and increased mortality (HR 1.77, 95% CI 1.30-2.40). They were more likely to have special educational need for mental (OR 1.76, 95% CI 1.49-2.08) and physical (OR 2.76, 95% CI 2.57-2.95) health reasons, and performed worse in school exams (OR 1.11, 95% CI 1.06-1.16). Higher absenteeism (incidence rate ratio 1.25, 95% CI 1.24-1.26) partially explained their poorer attainment. CONCLUSIONS: Children with treated asthma have poorer education and health outcomes than their peers. Educational interventions that mitigate the adverse effects of absenteeism should be considered.

Educational and health outcomes of children and adolescents receiving antiepileptic medication: Scotland-wide record linkage study of 766 244 schoolchildren.

BACKGROUND: Childhood epilepsy can adversely affect education and employment in addition to health. Previous studies are small or highly selective producing conflicting results. This retrospective cohort study aims to compare educational and health outcomes of children receiving antiepileptic medication versus peers. METHODS: Record linkage of Scotland-wide databases covering dispensed prescriptions, acute and psychiatric hospitalisations, maternity records, deaths, annual pupil census, school absences/exclusions, special educational needs, school examinations, and (un)employment provided data on 766,244 children attending Scottish schools between 2009 and 2013. Outcomes were adjusted for sociodemographic and maternity confounders and comorbid conditions. RESULTS: Compared with peers, children on antiepileptic medication were more likely to experience school absence (Incidence Rate Ratio [IRR] 1.43, 95% CI: 1.38, 1.48), special educational needs (Odds ratio [OR] 9.60, 95% CI: 9.02, 10.23), achieve the lowest level of attainment (OR 3.43, 95% CI: 2.74, 4.29) be unemployed (OR 1.82, 95% CI: 1.60, 2.07), be admitted to hospital (Hazard Ratio [HR] 3.56, 95% CI: 3.42, 3.70), and die (HR 22.02, 95% CI: 17.00, 28.53). Absenteeism partly explained poorer attainment and higher unemployment. Girls and younger children on antiepileptic medication had higher risk of poor outcomes. CONCLUSIONS: Children on antiepileptic medication fare worse than peers across educational and health outcomes. In order to reduce school absenteeism and mitigate its effects, children with epilepsy should receive integrated care from a multidisciplinary team that spans education and healthcare.

Quantitative electroencephalography in a swine model of blast-induced brain injury.

OBJECTIVE: Electroencephalography (EEG) was used to examine brain activity abnormalities earlier after blast exposure using a swine model to develop a qEEG data analysis protocol. METHODS: Anaesthetized swine were exposed to 420-450 Kpa blast overpressure and survived for 3 days after blast. EEG recordings were performed at 15 minutes before the blast and 15 minutes, 30 minutes, 2 hours and 1, 2 and 3 days post-blast using surface recording electrodes and a Biopac 4-channel data acquisition system. Off-line quantitative EEG (qEEG) data analysis was performed to determine qEEG changes. RESULTS: Blast induced qEEG changes earlier after blast exposure, including a decrease of mean amplitude (MAMP), an increase of delta band power, a decrease of alpha band root mean square (RMS) and a decrease of 90% spectral edge frequency (SEF90). CONCLUSIONS: This study demonstrated that qEEG is sensitive for cerebral injury. The changes of qEEG earlier after the blast indicate the potential of utilization of multiple parameters of qEEG for diagnosis of blast-induced brain injury. Early detection of blast induced brain injury will allow early screening and assessment of brain abnormalities in soldiers to enable timely therapeutic intervention.

Month of Conception and Learning Disabilities: A Record-Linkage Study of 801,592 Children.

Learning disabilities have profound, long-lasting health sequelae. Affected children born over the course of 1 year in the United States of America generated an estimated lifetime cost of $51.2 billion. Results from some studies have suggested that autistic spectrum disorder may vary by season of birth, but there have been few studies in which investigators examined whether this is also true of other causes of learning disabilities. We undertook Scotland-wide record linkage of education (annual pupil census) and maternity (Scottish Morbidity Record 02) databases for 801,592 singleton children attending Scottish schools in 2006-2011. We modeled monthly rates using principal sine and cosine transformations of the month number and demonstrated cyclicity in the percentage of children with special educational needs. Rates were highest among children conceived in the first quarter of the year (January-March) and lowest among those conceived in the third (July-September) (8.9% vs 7.6%; P < 0.001). Seasonal variations were specific to autistic spectrum disorder, intellectual disabilities, and learning difficulties (e.g., dyslexia) and were absent for sensory or motor/physical impairments and mental, physical, or communication problems. Seasonality accounted for 11.4% (95% confidence interval: 9.0, 13.7) of all cases. Some biologically plausible causes of this variation, such as infection and maternal vitamin D levels, are potentially amendable to intervention.

Excited state dynamics and isomerization in ruthenium sulfoxide complexes.

Molecular photochromic compounds are those that interconvert between two isomeric forms with light. The two isomeric forms display distinct electronic and molecular structures and must not be in equilibrium with one another. These light-activated molecular switch compounds have found wide application in areas of study ranging from chemical biology to materials science, where conversion from one isomeric form to another by light prompts a response in the environment (e.g., protein or polymeric material). Certain ruthenium and osmium polypyridine sulfoxide complexes are photochromic. The mode of action is a phototriggered isomerization of the sulfoxide from S- to O-bonded. The change in ligation drastically alters both the spectroscopic and electrochemical properties of the metal complex. Our laboratory has pioneered the preparation and study of these complexes. In particular, we have applied femtosecond pump-probe spectroscopy to reveal excited state details of the isomerization mechanism. The data from numerous complexes allowed us to predict that the isomerization was nonadiabatic in nature, defined as occurring from a S-bonded triplet excited state (primarily metal-to-ligand charge transfer in character) to an O-bonded singlet ground state potential energy surface. This prediction was corroborated by high-level density functional theory calculations. An intriguing aspect of this reactivity is the coupling of nuclear motion to the electronic wave function and how this coupling affects motions productive for isomerization. In an effort to learn more about this coupling, we designed a project to examine phototriggered isomerization in bis-sulfoxide complexes. The goal of these studies was to determine whether certain complexes could be designed in which a single photon excitation event would prompt two sulfoxide isomerizations. We employed chelating sulfoxides in this study and found that both the nature of the chelate ring and the R group on the sulfoxide affect the photochemical reactivity. For example, this reactivity may be tuned such that two sulfoxide ligands isomerize sequentially following two successive excitations or that two sulfoxide ligands isomerize following a single excitation. This Account explains our understanding to date of this photochemistry.

The Effects of Helmet Weight on Hybrid III Head and Neck Responses by Comparing Unhelmeted and Helmeted Impacts.

Most studies on football helmet performance focus on lowering head acceleration-related parameters to reduce concussions. This has resulted in an increase in helmet size and mass. The objective of this paper was to study the effect of helmet mass on head and upper neck responses. Two independent test series were conducted. In test series one, 90 pendulum impact tests were conducted with four different headform and helmet conditions: unhelmeted Hybrid III headform, Hybrid III headform with a football helmet shell, Hybrid III headform with helmet shell and facemask, and Hybrid III headform with the helmet and facemask with mass added to the shell (n = 90). The Hybrid III neck was used for all the conditions. For all the configurations combined, the shell only, shell and facemask, and weighted helmet conditions resulted in 36%, 43%, and 44% lower resultant head accelerations (p < 0.0001), respectively, when compared to the unhelmeted condition. Head delta-V reductions were 1.1%, 4.5%, and 4.4%, respectively. In contrast, the helmeted conditions resulted in 26%, 41%, and 49% higher resultant neck forces (p < 0.0001), respectively. The increased neck forces were dominated by neck tension. In test series two, testing was conducted with a pneumatic linear impactor (n = 178). Fourteen different helmet makes and models illustrate the same trend. The increased neck forces provide a possible explanation as to why there has not been a corresponding reduction in concussion rates despite improvements in helmets ability to reduce head accelerations.

Development of a new biomechanical indicator for primary blast-induced brain injury.

Primary blast-induced traumatic brain injury (bTBI) has been observed at the boundary of brain tissue and cerebrospinal fluid (CSF). Such injury can hardly be explained by using the theory of compressive wave propagation, since both the solid and fuid materials have similar compressibility and thus the intracranial pressure (ICP) has a continuous distribution across the boundary. Since they have completely different shear properties, it is hypothesized the injury at the interface is caused by shear wave. In the present study, a preliminary combined numerical and theoretical analysis was conducted based on the theory of shear wave propagation/reflection. Simulation results show that higher lateral acceleration of brain tissue particles is concentrated in the boundary region. Based on this fnding, a new biomechanical vector, termed as strain gradient, was suggested for primary bTBI. The subsequent simple theoretical analysis reveals that this parameter is proportional to the value of lateral acceleration. At the boundary of lateral ventricles, high spatial strain gradient implies that the brain tissue in this area (where neuron cells may be contained) undergo significantly different strains and large velocity discontinuity, which may result in mechanical damage of the neuron cells.

One photon yields two isomerizations: large atomic displacements during electronic excited-state dynamics in ruthenium sulfoxide complexes.

Photochromic compounds efficiently transduce photonic energy to potential energy for excited-state bond-breaking and bond-forming reactions. A critical feature of this reaction is the nature of the electronic excited-state potential energy surface and how this surface facilitates large nuclear displacements and rearrangements. We have prepared two photochromic ruthenium sulfoxide complexes that feature two isomerization reactions following absorption of a single photon. We show by femtosecond transient absorption spectroscopy that this reaction is complete within a few hundred picoseconds and suggest that isomerization occurs along a conical intersection seam formed by the ground-state and excited-state potential energy surfaces.

Investigating the effects of solvent on the ultrafast dynamics of a photoreversible ruthenium sulfoxide complex.

The photochromic complex [Ru(bpy)2(pySO)](2+) [pySO is 2-(isopropylsulfinylmethyl)pyridine] undergoes wavelength specific, photoreversible S → O and O → S linkage isomerizations. Irradiation of the ground state S-bonded complex with blue light produces the O-bonded isomer, while irradiation of the O-bonded isomer with green light produces the S-bonded isomer. Furthermore, isomerization time constants are solvent-dependent. Ultrafast transient absorption spectroscopy has been employed to investigate the relaxation processes that lead to S → O isomerization in 1,2-dichloroethane, propylene carbonate, and ethylene glycol. The isomerization is most rapid in 1,2-dichloroethane and slowest in ethylene glycol. Photochemical reversion of the O-bonded isomer in propylene carbonate has further been investigated and indicates similar relaxation or isomerization kinetics, though the excited states that lead to isomerization are distinct between the S- and O-bonded isomers.

Dynamic changes of macaque cancellous bone following head-down bed rest.

INTRODUCTION: Skeletal unloading during a spaceflight could result in bone loss and osteopenia, ultimately leading to poor bone strength. The purpose of the present study was to investigate the influence of bone loss on the dynamic behavior of cancellous bone. METHODS: Microgravity-induced bone loss and osteopenia were simulated in a macaque head-down bed rest (HDBR) model, in which 20 macaques were laid on a bed tilted by -6 degrees from the horizontal. These macaques were randomly divided into control (Con) and head down bed rest (HDBR) groups. After 28 d, 5 macaques chosen at random from each group were tested for bone density and mechanical properties, and the obtained data was used to develop a density-based constitutive equation; the remaining animals were tested only for bone density in order to attain statistical power. A split Hopkinson bar was used to monitor the dynamic response of cancellous bone. Cancellous bone deformation under high strain rate conditions was recorded by high-speed videos. RESULTS: Compared with the Con group, the Young's modulus of cancellous bone from HDBR macaque lumbar vertebrae were decreased by 6.03%. Based on the static and dynamic experimental results, parameters in the Maxwell nonlinear viscoelasticity material model were estimated. DISCUSSION: This model of cancellous bone under high strain rate was useful to establish the medical tolerance and evolution criteria of impact-related trauma by finite element method calculations.

Biomechanical sex differences of crewmembers during a simulated space capsule landing.

INTRODUCTION: The objective of this study was to observe the differences in the biodynamic responses of male and female crewmembers during a simulated Soyuz spacecraft (short-duration flights) impact landing. METHODS: There were 16 volunteers (8 men and 8 women) recruited to sit in a pseudo-supine position and be exposed to several impact acceleration pulses. The acceleration peaks ranged from 7.7 to 11.8 g with a duration of around 50 ms. Acceleration responses from the drop platform and seat, and at the volunteers' head, shoulder, chest, and ilium were measured. RESULTS: Results indicated that there were significant gender-based differences in the peak acceleration measured from volunteers' shoulders and iliums. The peak decelerations measured at the head and ilium were relatively higher than those measured at other levels on the seat. DISCUSSION: It was recommended that more attention be focused on the sex differences of biodynamic responses of crews in the study of new protective designs for space capsule and personal life support equipment.

Sequential picosecond isomerizations in a photochromic ruthenium sulfoxide complex triggered by pump-repump-probe spectroscopy.

The complex [Ru(bpy)(2)(bpSO)](PF(6))(2), where bpy is 2,2'-bipydine and bpSO is 1,2-bis(phenylsulfinyl)ethane, exhibits three distinct isomers which are accessible upon metal-to-ligand charge-transfer (MLCT) irradiation. This complex and its parent, [Ru(bpy)(2)(bpte)](PF(6))(2), where bpte is 1,2-bis(phenylthio)ethane, have been synthesized and characterized by UV-visible spectroscopy, NMR, X-ray crystallography, and femtosecond transient absorption spectroscopy. A novel method of 2-color Pump-Repump-Probe spectroscopy has been employed to investigate all three isomers of the bis-sulfoxide complex. This method allows for observation of the isomerization dynamics of sequential isomerizations of each sulfoxide from MLCT irradiation of the S,S-bonded complex to ultimately form the O,O-bonded metastable complex. One-dimensional (1-D) and two-dimensional (2-D) (COSY, NOESY, and TOCSY) (1)H NMR data show the thioether and ground state S,S-bonded sulfoxide complexes to be rigorously C(2) symmetric and are consistent with the crystal structures. Transient absorption spectroscopy reveals that the S,S to S,O isomerization occurs with an observed time constant of 56.8 (±7.4) ps. The S,O to O,O isomerization time constant was found to be 59 (±4) ps by pump-repump-probe spectroscopy. The composite S,S- to O,O-isomer quantum yield is 0.42.

Educational outcomes in childhood cancer survivors: A Scotland-wide record-linkage study of 766,217 schoolchildren.

BACKGROUND: A cancer diagnosis during childhood greatly disrupts the lives of those affected, causing physical and psychological challenges. We aim to investigate educational outcomes among schoolchildren with a previous cancer diagnosis compared to their peers. METHODS: Individual records from four national education databases and three national health databases were linked to construct a cohort of all singleton schoolchildren born in Scotland attending Scottish local-authority schools between 2009-2013. Pupils previously diagnosed with any cancer, haematological cancers, and central nervous system (CNS) cancers, were compared to their unaffected peers with respect to five educational outcomes: special educational need (SEN), absenteeism, school exclusion, academic attainment, and unemployment. Analyses were adjusted for sociodemographic and maternity factors and chronic conditions. RESULTS: Of 766,217 pupils, 1,313 (0.17%) had a previous cancer diagnosis. Children with any cancer had increased odds of SEN (OR 3.26, 95% CI 2.86-3.71), absenteeism (IRR 1.82, 95% CI 1.70-1.94), and low attainment (OR 2.15, 95% CI 1.52-3.03) compared to their peers. Similar findings were observed for haematological (SEN OR 2.62, 95% CI 2.12-3.24; absenteeism IRR 2.04, 95% CI 1.85-2.25; low attainment OR 2.17, 95% CI 1.31-3.61) and CNS (SEN OR 6.44, 95% CI 4.91-8.46; absenteeism IRR 1.75, 95% CI 1.51-2.04; low attainment OR 3.33, 95% CI 1.52-7.30) cancers. Lower exclusions were observed among children with any cancer (IRR 0.51, 95% CI 0.31-0.83) and CNS cancer (IRR 0.20, 95% CI 0.06-0.61). No associations were observed with unemployment. CONCLUSIONS: This study highlights the wider impacts of childhood cancer on educational outcomes. These children need to be supported, as poor educational outcomes can further impact later health.

Adolescent Mental Health Priorities During the Covid-19 Pandemic.

Increasing evidence has shown that the Covid-19 outbreak has impacted adolescents' mental health. Utilising a mixed-method design, the current study examined a total of 518 adolescent perspectives (60% female), in Scotland, on what has and could help their mental health in the context of Covid-19. A reflexive thematic analysis revealed three themes in relation to what has helped adolescents' mental health since the Covid-19 outbreak. These related to findings about the value of: (1) engaging in recreational activities, (2) engaging with friends, and (3) the disruption to schooling. The remaining four themes related to what could have helped adolescents mental health and wellbeing since the Covid-19 outbreak. These focussed on (1) better support: in relation to mental health; school work; and communication, (2) contact with friends, and (3) more opportunities for recreational activities. Males were more likely to report recreational activities had helped and less likely to report better support could have helped. Adolescents who reached clinical threshold for depression and anxiety and those with elevated PTSD-like symptoms about Covid-19 were more likely to state more support could have helped, and adolescents who reached clinical threshold for depression were less likely to report that friends could have helped their mental health. The findings may inform mental health policy and interventions in the recovery from the Covid-19 pandemic.