Thermal infrared emission reveals the Dirac point movement in biased graphene

Graphene is a 2-dimensional material with high carrier mobility and thermal conductivity, suitable for high-speed electronics. Conduction and valence bands touch at the Dirac point. The absorptivity of single-layer graphene is 2.3%, nearly independent of wavelength. Here we investigate the thermal radiation from biased graphene transistors. We find that the emission spectrum of single-layer graphene follows that of a grey body with constant emissivity (1.6 \pm 0.8)%. Most importantly, we can extract the temperature distribution in the ambipolar graphene channel, as confirmed by Stokes/anti-Stokes measurements. The biased graphene exhibits a temperature maximum whose location can be controlled by the gate voltage. We show that this peak in temperature reveals the spatial location of the minimum in carrier density, i.e. the Dirac point.Comment: Accepted in principle at Nature Nanotechnolog

Non-participation in population-based disease prevention programs in general practice

<p>Abstract</p> <p>Background</p> <p>The number of people with a chronic disease will strongly increase in the next decades. Therefore, prevention of disease becomes increasingly important. The aim of this systematic review was to identify factors that negatively influence participation in population-based disease prevention programs in General Practice and to establish whether the program type is related to non-participation levels.</p> <p>Methods</p> <p>We conducted a systematic review in Pubmed, EMBASE, CINAHL and PsycINFO, covering 2000 through July 6th 2012, to identify publications including information about characteristics of non-participants or reasons for non-participation in population-based disease prevention programs in General Practice.</p> <p>Results</p> <p>A total of 24 original studies met our criteria, seven of which focused on vaccination, eleven on screening aimed at early detection of disease, and six on screening aimed at identifying high risk of a disease, targeting a variety of diseases and conditions. Lack of personal relevance of the program, younger age, higher social deprivation and former non-participation were related to actual non-participation. No differences were found in non-participation levels or factors related to non-participation between the three program types. The large variation in non-participation levels within the program types may be partly due to differences in recruitment strategies, with more active, personalized strategies resulting in higher participation levels compared to an invitation letter.</p> <p>Conclusions</p> <p>There is still much to be gained by tailoring strategies to improve participation in those who are less likely to do so, namely younger individuals, those living in a deprived area and former non-participants. Participation may increase by applying more active recruitment strategies.</p

Comparação dos efeitos da estimulação elétrica nervosa transcutânea e da hidroterapia na dor, flexibilidade e qualidade de vida de pacientes com fibromialgia Comparison of transcutaneous electrical nerve stimulation and hydrotherapy effects on pain, flexibility and quality of life in patients with fibromyalgia

Este estudo visou comparar a eficácia da hidroterapia e da estimulação elétrica transcutânea do nervo (TENS) na melhora da sintomatologia de pacientes com fibromialgia Participaram do estudo 10 sujeitos com fibromialgia (48,8±9,8 anos) divididos em dois grupos: um tratado com hidroterapia e outro com TENS. Todos foram avaliados antes e após o tratamento quanto à flexibilidade (pelo índice terceiro dedo-solo), dor (por escala visual-analógica), qualidade de vida relacionada à saúde (pelos questionários SF-36 e Nottingham Health Profile - NHP) e tendência à depressão (pelo Inventário de Beck). Os dados foram tratados estatisticamente, com nível de significância fixado em p<0,05. O grupo TENS obteve melhora estatisticamente significante na intensidade da dor, na qualidade de vida medida pelo SF-36 e em alguns quesitos do NHP, enquanto a hidroterapia promoveu uma melhora na qualidade de vida medida pelo SF-36. Ambos os tratamentos foram assim eficazes ao melhorar o condicionamento físico, porém a TENS propiciou melhores resultados quanto à dor e em maior número das variáveis analisadas do que a hidroterapia, sugerindo ser mais eficaz no tratamento da fibromialgia.<br>The purpose of this study was to compare the effects of hydrotherapy and of transcutaneous electric nerve stimulation (TENS) on symptomology of patients with fibromyalgia. Ten subjects (aged 48.8±9.8 years) with fibromyalgia were divided into two groups, one treated with hydrotherapy, the other with TENS. All were evaluated before and after treatment as to flexibility (by means of the fingertip-to-floor test), pain (by visual analogue scale), health-related quality of life (by the SF-36 and the Nottingham Health Profile - NHP - questionnaires) and trend to depression (by the Beck's Depression Inventory). Data were statistically analysed, and significance level set at p<0.05. Results show that patients treated with TENS had significant pain reduction and better quality of life as measured by the SF-36 and some NHP items, while patients treated with hydrotherapy showed improvement in SF-36 scores. It may hence be said that both treatments were efficient in improving physical functioning, but TENS produced better results in relieving pain and in a greater number of variables, suggesting that it is more efficient for treating fibromyalgia