Prenatal Serum Concentrations of Brominated Flame Retardants and Autism Spectrum Disorder and Intellectual Disability in the Early Markers of Autism Study: A Population-Based Case-Control Study in California.

BackgroundPrior studies suggest neurodevelopmental impacts of polybrominated diphenyl ethers (PBDEs), but few have examined diagnosed developmental disorders.ObjectivesOur aim was to determine whether prenatal exposure to brominated flame retardants (BFRs) is associated with autism spectrum disorder (ASD) or intellectual disability without autism (ID).MethodsWe conducted a population-based case-control study including children with ASD (n=545) and ID (n=181) identified from the California Department of Developmental Services and general population (GP) controls (n=418) from state birth certificates. ASD cases were matched to controls by sex, birth month, and birth year. Concentrations of 10 BFRs were measured in maternal second trimester serum samples stored from routine screening. Logistic regression was used to calculate crude and adjusted odds ratios (AOR) for associations with ASD, and separately for ID, compared with GP controls, by quartiles of analyte concentrations in primary analyses.ResultsGeometric mean concentrations of five of the six congeners with ≥55% of samples above the limit of detection were lower in mothers of children with ASD or ID than in controls. In adjusted analyses, inverse associations with several congeners were found for ASD relative to GP (e.g., quartile 4 vs. 1, BDE-153: AOR=0.56, 95% CI: 0.38, 0.84). When stratified by child sex (including 99 females with ASD, 77 with ID, and 73 with GP), estimates were consistent with overall analyses in boys, but in the opposite direction among girls, particularly for BDE-28 and -47 (AOR=2.58, 95% CI: 0.86, 7.79 and AOR=2.64, 95% CI: 0.97, 7.19, respectively). Similar patterns overall and by sex were observed for ID.ConclusionsContrary to expectation, higher PBDE concentrations were associated with decreased odds of ASD and ID, though not in girls. These findings require confirmation but suggest potential sexual dimorphism in associations with prenatal exposure to BFRs. https://doi.org/10.1289/EHP1079

1,4-Bis(iodo­meth­yl)benzene

The centrosymmetric title compound, C8H8I2, was prepared by metathesis from the dibromo analogue. In the crystal structure, weak C—H⋯I inter­actions link the mol­ecules into stacks down the b axis. The structure is further stabilized by short I⋯I contacts [3.8433 (2) Å], forming undulating sheets in the (101) plane

Precise multimodal optical control of neural ensemble activity.

Understanding brain function requires technologies that can control the activity of large populations of neurons with high fidelity in space and time. We developed a multiphoton holographic approach to activate or suppress the activity of ensembles of cortical neurons with cellular resolution and sub-millisecond precision. Since existing opsins were inadequate, we engineered new soma-targeted (ST) optogenetic tools, ST-ChroME and IRES-ST-eGtACR1, optimized for multiphoton activation and suppression. Employing a three-dimensional all-optical read-write interface, we demonstrate the ability to simultaneously photostimulate up to 50 neurons distributed in three dimensions in a 550 × 550 × 100-µm3 volume of brain tissue. This approach allows the synthesis and editing of complex neural activity patterns needed to gain insight into the principles of neural codes

6-Hy­droxy-5,7,8-trimethyl­chroman-2-one

The title compound, C12H14O3, consists of a chromanone unit with an –OH substituent at the 4-position and methyl substituents on the remaining C atoms of the aromatic ring. The fused pyran­one ring adopts a distorted envelope conformation with the methyl­ene group adjacent to the carbonyl carbon as the flap atom. The crystal structure is stabilized by classical O—H⋯O hydrogen bonds and weak C—H⋯O and C—H⋯π inter­actions, generating a three-dimensional network

Malignancy and all-cause mortality; incidence in adolescents and young adults living with perinatally acquired HIV.

Background: Adults living with HIV have an increased risk of malignancy yet there is a paucity of data for adolescents and young adults (AYA) with perinatally acquired HIV (PaHIV). Methods: Retrospective cohort analysis of all-cause mortality and malignancies in AYA with PaHIV aged 10-24 years attending a tertiary unit from 01 January 2004 to 31 December 2017, assessing cancer presentation, immunology and comparing mortality and malignancy incidence to age-matched UK general population rates. Results: A total of 290 AYA with PaHIV contributed 2644 person-years of follow up. Six (2.0%) died within the study period at a median age of 17 years (interquartile range [IQR]15-19), 3 of malignancy, 2 with end-stage HIV and 1 with cryptococcal meningitis. Overall mortality rate was 2.3/1000 person-years, with an age-matched general population rate of 0.2/1000 person-years. Eight (2.8%) were diagnosed with a malignancy; 6 with lymphoma (n=3 Hodgkin's, n=1 Burkitt's, n=2 B-cell) and one each with hepatocellular carcinoma and gastrointestinal adenocarcinoma. At cancer diagnosis the median age was 19 years (IQR 14-23), median CD4 T cell count was 453 cells/mm3 (IQR 231-645) and median length of HIV viremia was 15 years (IQR 12-17). The incidence rate of a malignancy was 3.0/1000 person-years in AYA with PaHIV, whilst that in the age-matched general population is 0.2/1000 person-years. Conclusion: AYA living with PaHIV had an increased risk of all-cause mortality and of malignancy compared to their uninfected peers, with the excess in malignancy driven by lymphomas. It is hoped that earlier access to antiretroviral therapy will mitigate some of the AIDS-defining and non-AIDS defining risks for future generations

Maternal plasma DHA levels increase prior to 29 days post-LH surge in women undergoing frozen embryo transfer: a prospective, observational study of human pregnancy

Context: Docosahexaenoic acid (DHA) is an important fatty acid required for neurological development but its importance during early fetal neurological organogenesis is unknown. Objective: To assess plasma fatty acid changes in early pregnancy in women undergoing natural cycle-frozen embryo transfer as a means of achieving accurately-timed periconceptual sampling. Design: Women undergoing frozen embryo transfer were recruited and serial fasting blood samples were taken pre-luteinising hormone (LH) surge, and at days 18, 29 and 45 post-LH surge and fatty acids were analysed using gas chromatography. Setting: Assisted Conception Unit, Glasgow Royal Infirmary, Scotland Main outcome measures: Plasma fatty acid concentrations, influence of twin pregnancies on DHA plasma concentration. Results: In pregnant women, there was a rapid, early increase in the maternal rate of change of plasma DHA concentration observed by 29 days post-LH surge (mean±SD, from 0.1±1.3 to 1.6±2.9 nmol DHA per mL plasma per day). This early pressure to increase plasma DHA concentration was further emphasised in twin pregnancies where the increase in DHA concentration over 45 days was two-fold higher than in singleton pregnancies (mean±SD increase, 74±39 nmol/mL versus 36±40 nmol/mL). An index of delta-6 desaturase activity increased 30% and positively correlated with the rate of change of DHA concentration between day 18 and 29-post LH surge (R-squared adjusted = 41%, P=0.0002). DHA was the only fatty acid with a continual accelerated increase in plasma concentration and a positive incremental area under the curve (mean±SD, 632±911 nmol/mL x day) over the first 45 days of gestation. Conclusions: An increase in maternal plasma DHA concentration is initiated in human pregnancy prior to neural tube closure which occurs at 28 days' gestation

Comprehensive Assessment of Sleep Duration, Insomnia and Brain Structure within the UK Biobank Cohort

STUDY OBJECTIVES: To assess for associations between sleeping more than or less than recommended by the National Sleep Foundation (NSF), and self-reported insomnia, with brain structure. METHODS: Data from the UK Biobank cohort were analysed (N between 9K and 32K, dependent on availability, aged 44 to 82 years). Sleep measures included self-reported adherence to NSF guidelines on sleep duration (sleeping between 7 and 9 hours per night), and self-reported difficulty falling or staying asleep (insomnia). Brain structural measures included global and regional cortical or subcortical morphometry (thickness, surface area, volume), global and tract-related white matter microstructure, brain age gap (difference between chronological age and age estimated from brain scan), and total volume of white matter lesions. RESULTS: Longer-than-recommended sleep duration was associated with lower overall grey and white matter volumes, lower global and regional cortical thickness and volume measures, higher brain age gap, higher volume of white matter lesions, higher mean diffusivity globally and in thalamic and association fibers, and lower volume of the hippocampus. Shorter-than-recommended sleep duration was related to higher global and cerebellar white matter volumes, lower global and regional cortical surface areas, and lower fractional anisotropy in projection fibers. Self-reported insomnia was associated with higher global grey and white matter volumes, and with higher volumes of the amygdala, hippocampus and putamen. CONCLUSIONS: Sleeping longer than recommended by the NSF is associated with a wide range of differences in brain structure, potentially indicative of poorer brain health. Sleeping less than recommended is distinctly associated with lower cortical surface areas. Future studies should assess the potential mechanisms of these differences and investigate long sleep duration as a putative marker of brain health

Gel actuators based on polymeric radicals

Low-voltage electrochemical actuation of radical polymer gels has been demonstrated in an organic electrolyte. Polymer gels were prepared by post-modification of active-ester precursor gels with an amine-functionalised radical. A combination of few-layer graphene and multiwall carbon nanotubes gave high conductivity and improved actuation in the gels, with 32% linear actuation. The actuator system showed good stability over at least 10 cycles, showing its promise. The cycle time was several hours due to mass-transport limited transport of ions and solvent into the device