Prefrontal cortex hemodynamic response to acute high intensity intermittent exercise during executive function processing.

We investigated prefrontal cortex (PFC) hemodynamic response, through functional near infrared spectroscopy (fNIRS) during executive function (EF) processing in response to acute high intensity intermittent exercise (HIIE) in young adults. We also assessed the associated sex differences in the cognitive scores and related PFC hemodynamic functions in response to HIIE. 49 young healthy adult participants (32 women, 17 men) were randomly assigned to either control or HIIE intervention groups. HIIE group participants performed 4 × 4 minutes of HIIE on cycle ergometer with 3 minutes of active recovery between the bouts; control group relaxed for the time equivalent to intervention. fNIRS data was collected during the performance of the EF tests including Color Word Stroop Test (CWST) and Trail Making Test (TMT) in pre and post sessions in both the groups. Results indicated a significant change in the hemodynamic response in the form of increased oxygenated and decreased deoxygenated hemoglobin in the PFC areas specific to the EF tasks, with improved CWST and TMT scores in response to HIIE intervention. PFC activation was different in men and women in response to HIIE, however similar scores of task performance were observed in men and women during the performance of executive functions in response to HIIE. The study concludes that an acute HIIE session improves executive function which is associated with an increase activation of PFC. Sex differences exist in the activation of PFC in response to HIIE during EF processing. Our study adds to the current evidence regarding exercise and cognition.

Young and Middle-aged Adults Differ in Neural Correlate of Sustained Attention: A fNIRS Study.

AIMS: The aim of the study was to assess the activation of prefrontal cortex during sustained attention task in young and middle aged adults using Functional near infrared spectroscopy system. BACKGROUND: Sustained Attention (SA) is a construct of cognition that tends to decline with age. There is a paucity of literature regarding the neural correlates of SA in middle age, a link between young and old age. OBJECTIVE: This study evaluated the differences in SA ability and its neural correlates using fNIRS between young and middle aged adults. METHODS: 38 young and 25 middle aged adults were evaluated for the changes in neural correlates (oxy and deoxy haemoglobin concentration in prefrontal cortex) during a SA task known as cognitrone. RESULTS: The results obtained showed that young adults performed significantly better than middle aged adults on the SA task with no gender difference in their performance. There was a significant difference in the prefrontal activation pattern between young and middle aged adults. We found right prefrontal dominance in young adults and left prefrontal dominance in middle aged adults. CONCLUSION: This study concludes that the ability to maintain SA diminishes with age, advancing from young to middle age. Hemodynamic findings confirmed significant differences in neural resources in the prefrontal cortical areas between young and middle age.

Gold Nanocrystal Etching as a Means of Probing the Dynamic Chemical Environment in Graphene Liquid Cell Electron Microscopy.

Graphene liquid cell electron microscopy has the necessary temporal and spatial resolution to enable the in situ observation of nanoscale dynamics in solution. However, the chemistry of the solution in the liquid cell during imaging is as yet poorly understood due to the generation of a complex mixture of radiolysis products by the electron beam. In this work, the etching trajectories of nanocrystals were used as a probe to determine the effect of the electron beam dose rate and preloaded etchant, FeCl3, on the chemistry of the liquid cell. Initially, illuminating the sample at a low electron beam dose rate generates hydrogen bubbles, providing a reservoir of sacrificial reductant. Increasing the electron beam dose rate leads to a constant etching rate that varies linearly with the electron beam dose rate. Comparing these results with the oxidation potentials of the species in solution, the electron beam likely controls the total concentration of oxidative species in solution and FeCl3 likely controls the relative ratio of oxidative species, independently determining the etching rate and chemical potential of the reaction, respectively. Correlating these liquid cell etching results with the ex situ oxidative etching of gold nanocrystals using FeCl3 provides further insight into the liquid cell chemistry while corroborating the liquid cell dynamics with ex situ synthetic behavior. This understanding of the chemistry in the liquid cell will allow researchers to better control the liquid cell electron microscopy environment, allowing new nanoscale materials science experiments to be conducted systematically in a reproducible manner.

Initial Benchmarking of the Quality of Medical Care in Childhood-Onset Systemic Lupus Erythematosus.

OBJECTIVE: To assess the quality of medical care in childhood-onset systemic lupus erythematosus (SLE) at tertiary pediatric rheumatology centers as measured by observance of SLE quality indicators (SLE-QIs). METHODS: International consensus has been achieved for childhood-onset SLE-QIs capturing medical care provision in 9 domains: diagnostic testing, education of cardiovascular (CV) risk and lifestyles, lupus nephritis (LN), medication management, bone health, ophthalmologic surveillance, transition, pregnancy, and vaccination. Using medical record information, the level of performance of these childhood-onset SLE-QIs was assessed in childhood-onset SLE populations treated at 4 tertiary pediatric rheumatology centers in the US, 2 in Brazil, and 1 center in India. RESULTS: A total of 483 childhood-onset SLE patients were assessed. Care for the 310 US patients differed markedly for childhood-onset SLE-QIs addressing LN, bone health, vaccinations, education on CV risk, and transition planning. Performance of safety blood testing for medications was high at all centers. Despite often similar performance on the childhood-onset SLE-QI, access to kidney biopsies was lower in Brazil than in the US. Irrespective of the country of practice, larger centers tended to meet the childhood-onset SLE-QIs more often than smaller centers. CONCLUSION: The childhood-onset SLE-QIs, evidence-based minimum standards of medical care, are not consistently met in the US or some other countries outside the US. This has the potential to contribute to suboptimal childhood-onset SLE outcomes.