Tuning the transport gap of functionalized graphene via electron beam irradiation

We demonstrate a novel method to tune the energy gap epsilon1 between the localized states and the mobility edge of the valence band in chemically functionalized graphene by changing the coverage of fluorine adatoms via electron-beam irradiation. From the temperature dependence of the electrical transport properties we show that epsilon1 in partially fluorinated graphene CF0.28 decreases upon electron irradiation up to a dose of 0.08 C cm−2. For low irradiation doses (0.2 C cm−2) the electrical conduction takes place via Mott variable range hopping.SR and MFC acknowledge financial support from EPSRC (grant numbers EP/G036101/1, EP/J000396/1, EP/K017160/1 and EP/K010050/1). SR acknowledges financial support from the Royal Society Research grant number 2010/R2 (grant number SH-05052)

Role of defect states in functionalized graphene photodetectors

This is the final version of the article. Available from SPIE via the DOI in this record.SPIE Optics + Photonics conference 2017, 6-10 August 2017, San Diego, California, USAThe functionalization of graphene can enhance the optoelectronic properties of graphene, allowing the creation of highly sensitive broadband photodetectors. Presently, the role played by defects, induced by the functionalization of graphene, on the performance of graphene photodetectors is not well understood. Here, we investigate the optoelectronic properties of van der Waals heterostructures comprising of graphene and a functionalized partner, formed by pristine and fluorinated graphene. We find that the electrical properties of graphene are preserved upon formation of the heterostructure. A negligible charge transfer is observed across the interface between the two materials which limits the performance of the photodetector due to the vertical separation of the two materials.J.D.M. acknowledges financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1). S.R. and M.F.C. acknowledge financial support from EPSRC (Grant No. EP/J000396/1, EP/K017160/1, EP/K010050/1, EP/G036101/1, EP/M001024/1, and EP/M002438/1) and from Royal Society International Exchanges Scheme 2016/R1

Body mass index, adiposity rebound and early feeding in a longitudinal cohort (Raine study)

Objective: This study examined the influence of type and duration of infant feeding on adiposity rebound and the tracking of body mass index (BMI) from birth to 14 years. Methods: A sample of 1330 individuals over eight follows-ups was drawn from the Western Australian Pregnancy Cohort (Raine) Study. Trajectories of BMI from birth to adolescence using linear mixed model (LMM) analysis investigated the influence of age breastfeeding stopped and age other milk introduced (binomial 4-month cut-point). A sub-sample of LMM predicted BMI was used to determine BMI and age at nadir for early infant feeding groups. Results: Chi square analysis between early feeding and weight status (normal weight, overweight and obese) groups found a significant difference between age breastfeeding stopped (p Conclusions: Early infant feeding was important in the timing and BMI at adiposity rebound. The relationship between infant feeding and BMI remained up to age 14 years. Although confounding factors cannot be excluded, these findings support the importance of exclusive breastfeeding for longer than four months as a protective behaviour against the development of adolescent obesity

Condições de vida e vocabulário receptivo em crianças de dois a cinco anos

OBJECTIVE: To assess the receptive vocabulary of children aged between two years and six months and five years and eleven months who were attending childcare centers and kindergarten schools. METHODS: An analytical cross-sectional study was carried out in the municipality of Embu, Southeastern Brazil. The Peabody Picture Vocabulary Test and analysis of factors associated with children's performance were applied. The sample consisted of 201 children of both genders, aged between two and six years. Statistical analysis was performed using multivariate analysis and logistic regression model. The dependent variable analyzed was test performance and the independent variables were child's age, mother's level of education and family socio-demographic characteristics. RESULTS: It was observed that 44.3% of the children had performances in the test that were below what would be expected for their age. The factors associated with the best performances in the test were child's age (OR=2.4; 95% CI: 1.6-3.5) and mother's education level (OR= 3.2; 95% CI: 1.3-7.4). CONCLUSIONS: Mother's education level is important for child's language development. Settings such as childcare and kindergarten schools are protective factors for child development in families of low income and education.OBJETIVO: Avaliar o vocabulário receptivo de crianças de dois anos e seis meses a cinco anos e 11 meses que freqüentam creches e pré-escolas. MÉTODOS: Estudo transversal e analítico realizado no município de Embu, Estado de São Paulo. Utilizou-se o Teste de Vocabulário por Imagem Peabody e análise de fatores associados ao desempenho. A amostra foi constituída de 201 crianças de ambos os sexos, com idade entre dois e seis anos. Foram realizados análise multivariada e modelo de regressão logística. A variável dependente analisada foi o desempenho no teste e as variáveis independentes foram a idade da criança, tempo de escolaridade e série, e características sociodemográficas de suas famílias. RESULTADOS: Observou-se que 44,3% das crianças apresentaram desempenho inferior ao esperado para a idade no teste e os fatores associados ao melhor desempenho foram a idade da criança (OR=2,4; IC 95%: 1,6-3,5) e a escolaridade materna (OR=3,2; IC 95%: 1,3-7,4). CONCLUSÕES: A escolaridade maternal é importante no desenvolvimento de linguagem da criança. As instituições como creches e pré- escolas são fatores de proteção do desenvolvimento infantil em famílias de baixa renda e com baixa escolaridade.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FonoaudiologiaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PediatriaUNIFESP, EPM, Depto. de FonoaudiologiaUNIFESP, EPM, Depto. de PediatriaSciEL

Robust automated detection of microstructural white matter degeneration in Alzheimer’s disease using machine learning classification of multicenter DTI data

Diffusion tensor imaging (DTI) based assessment of white matter fiber tract integrity can support the diagnosis of Alzheimer’s disease (AD). The use of DTI as a biomarker, however, depends on its applicability in a multicenter setting accounting for effects of different MRI scanners. We applied multivariate machine learning (ML) to a large multicenter sample from the recently created framework of the European DTI study on Dementia (EDSD). We hypothesized that ML approaches may amend effects of multicenter acquisition. We included a sample of 137 patients with clinically probable AD (MMSE 20.6±5.3) and 143 healthy elderly controls, scanned in nine different scanners. For diagnostic classification we used the DTI indices fractional anisotropy (FA) and mean diffusivity (MD) and, for comparison, gray matter and white matter density maps from anatomical MRI. Data were classified using a Support Vector Machine (SVM) and a Naïve Bayes (NB) classifier. We used two cross-validation approaches, (i) test and training samples randomly drawn from the entire data set (pooled cross-validation) and (ii) data from each scanner as test set, and the data from the remaining scanners as training set (scanner-specific cross-validation). In the pooled cross-validation, SVM achieved an accuracy of 80% for FA and 83% for MD. Accuracies for NB were significantly lower, ranging between 68% and 75%. Removing variance components arising from scanners using principal component analysis did not significantly change the classification results for both classifiers. For the scanner-specific cross-validation, the classification accuracy was reduced for both SVM and NB. After mean correction, classification accuracy reached a level comparable to the results obtained from the pooled cross-validation. Our findings support the notion that machine learning classification allows robust classification of DTI data sets arising from multiple scanners, even if a new data set comes from a scanner that was not part of the training sample

Development of a short form of Mini-Mental State Examination for the screening of dementia in older adults with a memory complaint: a case control study

<p>Abstract</p> <p>Background</p> <p>Primary care physicians need a brief and accurate screening test of dementia. The objective of this study was to determine whether a short form of Mini-Mental State Examination (SMMSE) was as accurate as the Mini-Mental State Examination (MMSE) in screening dementia.</p> <p>Methods</p> <p>Based on case control design study, SMMSE and MMSE were assessed in 184 community-dwelling older adults (mean age 81.3 ± 6.5 years, 71.7% women) with memory complaint sent by their primary care physician to a memory clinic. Included participants were separated into two groups: cognitively healthy individuals and demented individuals.</p> <p>Results</p> <p>The trade-off between sensitivity and specificity of the SMMSE for clinically diagnosed dementia was 4. Based on the cut-off value ≤ 4 for SMMSE and a cut-off value ≤ 24 for MMSE, the sensitivity of both tests was similar (89.5% for SMMSE versus 90.0% for MMSE), whereas the specificity, the positive predictive values (PPV) and the negative predictive values (NPV) were higher for SMMSE compared to MMSE (85.4 versus 75.5% for specificity; 95.5% versus 92.8% for PPV; 70.0 versus 68.9 for NPV). The positive and negative Likehood Ratio (LR) of SMMSE were higher than those of MMSE (respectively, 6.1 versus 3.7; 8.1 versus 7.7). In addition, odds ratio (OR) for dementia was higher for the SMMSE compared to the MMSE (OR = 49.8 with 95% confident interval (CI) [18.0; 137.8] versus OR = 28.6 with 95% CI [11.6; 70.3]).</p> <p>Conclusions</p> <p>SMMSE seems to be an efficient short screening test for dementia among community-dwelling older adults with a memory complaint. Further research is needed to confirm its predictive values among unselected primary care older patients.</p

DNA intercalator stimulates influenza transcription and virus replication

Influenza A virus uses its host transcription machinery to facilitate viral RNA synthesis, an event that is associated with cellular RNA polymerase II (RNAPII). In this study, various RNAPII transcription inhibitors were used to investigate the effect of RNAPII phosphorylation status on viral RNA transcription. A low concentration of DNA intercalators, such as actinomycin D (ActD), was found to stimulate viral polymerase activity and virus replication. This effect was not observed in cells treated with RNAPII kinase inhibitors. In addition, the loss of RNAPIIa in infected cells was due to the shift of nonphosphorylated RNAPII (RNAPIIa) to hyperphosphorylated RNAPII (RNAPIIo)

Are youth mentoring programs good value-for-money? An evaluation of the Big Brothers Big Sisters Melbourne Program

Background : The Big Brothers Big Sisters (BBBS) program matches vulnerable young people with a trained, supervised adult volunteer as mentor. The young people are typically seriously disadvantaged, with multiple psychosocial problems.Methods : Threshold analysis was undertaken to determine whether investment in the program was a worthwhile use of limited public funds. The potential cost savings were based on US estimates of life-time costs associated with high-risk youth who drop out-of-school and become adult criminals. The intervention was modelled for children aged 10&ndash;14 years residing in Melbourne in 2004.Results : If the program serviced 2,208 of the most vulnerable young people, it would cost AUD 39.5 M. Assuming 50% were high-risk, the associated costs of their adult criminality would be AUD 3.3 billion. To break even, the program would need to avert high-risk behaviours in only 1.3% (14/1,104) of participants.Conclusion : This indicative evaluation suggests that the BBBS program represents excellent \u27value for money\u27.<br /

Intraoperative radiotherapy electron boost in advanced and recurrent epithelial ovarian carcinoma: a retrospective study

<p>Abstract</p> <p>Background</p> <p>Relapses of epithelial ovarian carcinoma (EOC) have a poor prognosis and are almost always fatal. The aim of this study was to evaluate the clinical outcome and toxicity of intraoperative electron beam radiation therapy (IOERT) in advanced and recurrent EOC.</p> <p>Methods</p> <p>Forty-five women with EOC were treated with IOERT. Twenty-five patients had primary disease (PD) without distant metastasis at IOERT, and 20 patients had an isolated local recurrence (ILR) after surgery. All 45 patients in this series underwent optimal cytoreductive (≤ 1 cm) surgery. The whole pelvic (WP) radiotherapy was intraoperatively delivered using 12 Mev electron beam; 43 patients received 18-20 Gy and two patients received 10 Gy. Thirty-three patients received postoperateive intraperitoneal (IP) chemotherapy, while seven patients received intravenous (IV) chemotherapy. Five patients refused concurrent chemotherapy. Overall survival (OS) rates were analyzed using the Kaplan-Meier method.</p> <p>Results</p> <p>Tumor recurrence and metastasis were observed in 16 patients (35.6%). Of those, 14 patients (31.1%) relapsed and two patients (4.4%) had distant metastasis alone. Eight of 25 (32%) local failures were observed in the PD group, as compared to 6/20 (30%) in the ILR group (<it>P </it>= 0.885). Actuarial local control at five year follow-up was 31/45 (68.9%). Seventeen of the total 45 (37.8%) patients died. Nine of 25 (36%) in the PD group died, as compared to 8 of 20 (40%) in the ILR group. The 5-year OS and disease-free survival (DFS) rates were 28/45 (62.2%) and 25/45 (55.6%), respectively. In the PD group, the 5-year OS and DFS rates were 16/25 (64%) and 14/25 (56%) (<it>P </it>> 0.05, <it>vs</it>. the ILR group at 12/20 and 11/20, respectively). The OS and DFS in the IOERT plus IP group were 25/33 (75.8%) and 23/33 (69.7%), respectively, which were superior to the rates achieved with IOERT plus IV chemotherapy (<it>P </it>< 0.05, 2/7 and 1/7, respectively). The major complication of IOERT was neuropathy. Five (11.1%) patients developed peripheral neurotoxicity.</p> <p>Conclusions</p> <p>IOERT may be feasible and effective as a boosting technique for advanced and recurrent ovarian cancer. IOERT plus IP chemotherapy may achieve high locoregional disease control and survival benefit with a low risk of toxicity. Peripheral nerves in the IOERT field are dose-limiting structures requiring nerve protection policies or a dose compromise to ensure against severe neurological damage.</p