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An investigation of electron transfer in DNA at low temperatures in an aqueous glassy medium is reported for a system in which electrons are generated by radiation and trapped on DNA. The transfer of the electron from the DNA anion radical to randomly interspaced intercalators is followed by electron spin resonance spectroscopic observation of the buildup in the intercalator electron adduct electron spin resonance (ESR) signal and the loss of the DNA anion signal with time at 77 K. The intercalators investigated, mitoxantrone, ethidium bromide, 1,10-phenanthroline, and 5-nitro-1,10-phenanthroline, test the effect of charge and electron affinity. The time frame of the experiment, minutes to weeks, allowed the use of large intercalator spacings (low loadings) at which random intercalation is most likely. The fraction of the electron captured by the intercalator was found to increase with ln(t) as expected for a single-step tunneling process. Fits of results to expressions for electron capture by intercalators based on a random distribution suggest that the random model is appropriate up to loadings of about 1 per 10−20 DNA base pairs depending on the intercalator. The distances of electron-transfer range from 4 base pairs (ethidium) to 10 base pairs (mitoxantrone) after 1 min at 77 K. The low temperatures employed allow for the observation of single-step tunneling free from competing mechanisms such as hopping. The values of the tunneling constant β found, 0.8−1.2 Å-1, do not suggest that tunneling through the DNA base stack provides a particularly facile route for transfer of excess electrons through DNA. We find that the transfer distances and rates correlate with intercalator electron affinities calculated by density functional theory.

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ObjectiveYouth with mental health problems often have difficulties engaging in education and employment. In Australia, youth mental health services have been widely established with a key aim of improving role functioning; however, there is little knowledge of those who are not engaged in employment, education or training (NEET) and the factors which may influence this. This study aimed to examine NEET status and its correlates in a sample of such youth.DesignCross-sectional data from a longitudinal cohort study.SettingBetween January 2011 and August 2012, young people presenting to one of the four primary mental health centres in Sydney or Melbourne were invited to participate.ParticipantsYoung adults (N=696) aged between 15 and 25 years (M=19.0, SD=2.8), 68% female, 58% (n=404) attended headspace in Sydney.MeasuresIndividuals ‘Not in any type of Education, Employment or Training’ in the past month were categorised as NEET. Demographic, psychological and clinical factors alongside disability and functioning were assessed using clinical interview and self-report.ResultsA total of 19% (n=130/696) were NEET. NEETs were more likely to be male, older, have a history of criminal charges, risky cannabis use, higher level of depression, poorer social functioning, greater disability and economic hardship, and a more advanced stage of mental illness than those engaged in education, training or work. Demographics such as postsecondary education, immigrant background and indigenous background, were not significantly associated with NEET status in this sample.ConclusionsOne in five young people seeking help for mental health problems were not in any form of education, employment and training. The commonly observed risk factors did not appear to influence this association, instead, behavioural factors such as criminal offending and cannabis use appeared to require targeted intervention.

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